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Ramachandran G, Pottakkat B. Probiotics-A Promising Novel Therapeutic Approach in the Management of Chronic Liver Diseases. J Med Food 2024. [PMID: 38574254 DOI: 10.1089/jmf.2023.k.0129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024] Open
Abstract
An increased incidence of liver diseases has been observed in recent years and is associated with gut dysbiosis, which causes bacterial infection, intestinal permeability, and further leads to disease-related complications. Probiotics, active microbial strains, are gaining more clinical importance due to their beneficial effect in the management of many diseases, including liver diseases. Clinical scenarios show strong evidence that probiotics have efficacy in treating liver diseases due to their ability to improve epithelial barrier function, prevent bacterial translocation, and boost the immune system. Moreover, probiotics survive both bile and gastric acid to reach the gut and exert their health benefit. Evidence shows that probiotics are a promising approach to prevent several complications in clinical practice. Herein, we discuss the recent evidence, challenges, and appropriate use of probiotics in managing advanced liver diseases, which may have an impact on future therapeutic strategies. Furthermore, the superior effect of strain-specific probiotics and their efficacy and safety in managing liver diseases are discussed.
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Affiliation(s)
- Gokulapriya Ramachandran
- Department of Surgical Gastroenterology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India
| | - Biju Pottakkat
- Department of Surgical Gastroenterology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India
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Ramachandran G, Pottakkat B, Mohan P, Basu S. Effectiveness of different tools for malnutrition in the assessment of patients with cirrhosis. Am J Med Sci 2024:S0002-9629(24)01121-2. [PMID: 38492774 DOI: 10.1016/j.amjms.2024.03.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 03/08/2024] [Accepted: 03/13/2024] [Indexed: 03/18/2024]
Abstract
BACKGROUND We aimed to evaluate the prevalence of malnutrition using traditional measures of nutritional assessments like body mass index (BMI), mid-arm circumference (MAC), triceps skin fold thickness (TSF), mid-arm muscle circumference (MAMC), hand grip strength (HGS) and subjective global assessments (SGA) among cirrhotic patients referred for liver transplantation (LT). METHODS The study was conducted among 215 cirrhotic patients referred for LT at a tertiary care hospital. Patients were enrolled between July 2021 and October 2022 to assess the prevalence of malnutrition. Patient's demographic details, clinical history, BMI using dry weight, MAMC, HGS, SGA score and disease severity were assessed. RESULTS Chronic alcoholism was the main causative factor for cirrhosis, followed by viral infection. 58% of cirrhotic patients were moderately to severely malnourished based on SGA, 12% were undernourished based on BMI, 91% had low MAC, and 94% had low HGS/muscle strength indicating malnutrition. Low MAC (p = 0.048) and SGA (p = 0.000) were associated with CTP - B and C class, and low MAC (p = 0.046), low TSF (p = 0.005), and SGA (p = 0.000), were associated with MELD Na score >15. Low MAC (p = 0.011) and SGA (P = 0.000) were associated with mortality, although 78% of patients had MAC within the normal range. A strong association exists between malnutrition and complications, liver disease severity, and death. CONCLUSION In patients with chronic liver diseases, SGA performed well as a good predictor of malnutrition, this might be because SGA analyses various domains which can be affected in chronic liver disease. Assessing malnutrition early may help in initiating appropriate medical nutritional therapy.
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Affiliation(s)
- Gokulapriya Ramachandran
- Department of Surgical Gastroenterology, Jawaharlal Institute of Postgraduate Medical Education and Research, Dhanvantri Nagar, Puducherry 605006, India
| | - Biju Pottakkat
- Department of Surgical Gastroenterology, Jawaharlal Institute of Postgraduate Medical Education and Research, Dhanvantri Nagar, Puducherry 605006, India.
| | - Pazhanivel Mohan
- Department of Medical Gastroenterology, Jawaharlal Institute of Postgraduate Medical Education and Research, Dhanvantri Nagar, Puducherry 605006, India
| | - Sharbari Basu
- Department of Biochemistry, Jawaharlal Institute of Postgraduate Medical Education and Research, Dhanvantari Nagar, Puducherry 605006, India
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Ramachandran G, Pottakkat B, Basu S, Mohan P. Effect of probiotics on nutritional status, biochemical parameters, and disease severity in cirrhotic patients referred for liver transplantation-A randomised double blind, placebo-controlled trial. Clin Nutr ESPEN 2023; 57:703-710. [PMID: 37739726 DOI: 10.1016/j.clnesp.2023.08.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 08/12/2023] [Accepted: 08/19/2023] [Indexed: 09/24/2023]
Abstract
INTRODUCTION Probiotics have been shown to be effective in many diseases. However, their effects on the nutritional status in patients with cirrhosis is uncertain. AIM We aimed to study the effect of probiotics on nutritional status, biochemical parameters, and liver disease severity in patients with cirrhosis referred for liver transplantation. METHODS A randomised, double-blind, placebo-controlled study was conducted from July 2021-October 2022. A total of 215 patients with cirrhosis referred for liver transplantation were enrolled and randomised to two groups to receive either probiotics (VSL#3, Sun Pharma, India, 112.5 billion colony-forming units (cfu) containing eight strains of bacteria) or placebo (corn starch filled capsules), two capsules/day for six weeks. Nutritional assessment was done, and biochemical parameters were measured before and after the intervention. RESULTS Nutritional assessment parameters like body mass index (p = 0.001), triceps skin fold thickness (p = 0.011), muscle strength (p = 0.007) and subjective global assessment scores (p < 0.000) showed a positive trend in the probiotic group. Probiotic intake also significantly downregulated direct bilirubin levels (p = 0.043) and increased albumin levels compared to baseline, but other biochemical parameters remained unchanged. Child Turcotte Pugh score also decreased significantly compared to pre therapy (p = 0.0001). These changes were not observed in the placebo group. Moreover, probiotic VSL#3 supplementation was safe and well-tolerable without any adverse events in patients with cirrhosis. CONCLUSION Probiotic VSL#3 supplementation improved the nutritional status, reduced the severity of liver disease and was safe and tolerable in patients with cirrhosis. TRIAL REGISTRATION www.ctri.nic.in (CTRI/2021/07/034917).
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Affiliation(s)
- Gokulapriya Ramachandran
- Department of Surgical Gastroenterology, Jawaharlal Institute of Postgraduate Medical Education and Research, Dhanvantri Nagar, Puducherry, 605006, India.
| | - Biju Pottakkat
- Department of Surgical Gastroenterology, Jawaharlal Institute of Postgraduate Medical Education and Research, Dhanvantri Nagar, Puducherry, 605006, India.
| | - Sharbari Basu
- Department of Biochemistry, Jawaharlal Institute of Postgraduate Medical Education and Research, Dhanvantri Nagar, Puducherry, 605006, India
| | - Pazhanivel Mohan
- Department of Medical Gastroenterology, Jawaharlal Institute of Postgraduate Medical Education and Research, Dhanvantari Nagar, Puducherry, 605006, India
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Shivakumar SVBY, Padmapriyadarsini C, Chavan A, Paradkar M, Shrinivasa BM, Gupte A, Dhanasekaran K, Thomas B, Suryavanshi N, Dolla CK, Selvaraju S, Kinikar A, Gaikwad S, Kohli R, Sivaramakrishnan GN, Pradhan N, Hanna LE, Kulkarni V, DeLuca A, Cox SR, Murali L, Thiruvengadam K, Raskar S, Ramachandran G, Golub JE, Gupte N, Mave V, Swaminathan S, Gupta A, Bollinger RC. Concomitant pulmonary disease is common among patients with extrapulmonary TB. Int J Tuberc Lung Dis 2022; 26:341-347. [PMID: 35351239 PMCID: PMC8982647 DOI: 10.5588/ijtld.21.0501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND : Microbiologic screening of extrapulmonary TB (EPTB) patients could inform recommendations for aerosol precautions and close contact prophylaxis. However, this is currently not routinely recommended in India. Therefore, we estimated the proportion of Indian patients with EPTB with microbiologic evidence of pulmonary TB (PTB). METHODS : We characterized baseline clinical, radiological and sputum microbiologic data of 885 adult and pediatric TB patients in Chennai and Pune, India, between March 2014 and November 2018. RESULTS : Of 277 patients with EPTB, enhanced screening led to the identification of 124 (45%) with concomitant PTB, including 53 (19%) who reported a cough >2 weeks; 158 (63%) had an abnormal CXR and 51 (19%) had a positive sputum for TB. Of 70 participants with a normal CXR and without any cough, 14 (20%) had a positive sputum for TB. Overall, the incremental yield of enhanced screening of patients with EPTB to identify concomitant PTB disease was 14% (95% CI 12–16). CONCLUSIONS : A high proportion of patients classified as EPTB in India have concomitant PTB. Our results support the need for improved symptom and CXR screening, and recommends routine sputum TB microbiology screening of all Indian patients with EPTB.
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Affiliation(s)
| | - C Padmapriyadarsini
- Indian Council of Medical Research-National Institute for Research in Tuberculosis, Chennai, India
| | - A Chavan
- Johns Hopkins India, Pune, India, Byramjee Jeejeebhoy Government Medical College-Johns Hopkins University Clinical Research Site, Pune, India
| | - M Paradkar
- Johns Hopkins India, Pune, India, Byramjee Jeejeebhoy Government Medical College-Johns Hopkins University Clinical Research Site, Pune, India
| | - B M Shrinivasa
- Indian Council of Medical Research-National Institute for Research in Tuberculosis, Chennai, India
| | - A Gupte
- Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - K Dhanasekaran
- Indian Council of Medical Research-National Institute for Research in Tuberculosis, Chennai, India
| | - B Thomas
- Indian Council of Medical Research-National Institute for Research in Tuberculosis, Chennai, India
| | - N Suryavanshi
- Johns Hopkins India, Pune, India, Byramjee Jeejeebhoy Government Medical College-Johns Hopkins University Clinical Research Site, Pune, India, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - C K Dolla
- Indian Council of Medical Research-National Institute for Research in Tuberculosis, Chennai, India
| | - S Selvaraju
- Indian Council of Medical Research-National Institute for Research in Tuberculosis, Chennai, India
| | - A Kinikar
- Byramjee Jeejeebhoy Government Medical College, Pune, India
| | - S Gaikwad
- Byramjee Jeejeebhoy Government Medical College, Pune, India
| | - R Kohli
- Johns Hopkins India, Pune, India, Byramjee Jeejeebhoy Government Medical College-Johns Hopkins University Clinical Research Site, Pune, India
| | - G N Sivaramakrishnan
- Indian Council of Medical Research-National Institute for Research in Tuberculosis, Chennai, India
| | - N Pradhan
- Johns Hopkins India, Pune, India, Byramjee Jeejeebhoy Government Medical College-Johns Hopkins University Clinical Research Site, Pune, India
| | - L E Hanna
- Indian Council of Medical Research-National Institute for Research in Tuberculosis, Chennai, India
| | - V Kulkarni
- Johns Hopkins India, Pune, India, Byramjee Jeejeebhoy Government Medical College-Johns Hopkins University Clinical Research Site, Pune, India
| | - A DeLuca
- Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - S R Cox
- Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - L Murali
- District Tuberculosis Office, Thiruvallur, India
| | - K Thiruvengadam
- Indian Council of Medical Research-National Institute for Research in Tuberculosis, Chennai, India
| | - S Raskar
- Johns Hopkins India, Pune, India, Byramjee Jeejeebhoy Government Medical College-Johns Hopkins University Clinical Research Site, Pune, India
| | - G Ramachandran
- Indian Council of Medical Research-National Institute for Research in Tuberculosis, Chennai, India
| | - J E Golub
- Johns Hopkins School of Medicine, Baltimore, MD, USA, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - N Gupte
- Johns Hopkins India, Pune, India, Byramjee Jeejeebhoy Government Medical College-Johns Hopkins University Clinical Research Site, Pune, India, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - V Mave
- Johns Hopkins India, Pune, India, Byramjee Jeejeebhoy Government Medical College-Johns Hopkins University Clinical Research Site, Pune, India, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | | | - A Gupta
- Johns Hopkins School of Medicine, Baltimore, MD, USA, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - R C Bollinger
- Johns Hopkins School of Medicine, Baltimore, MD, USA, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
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Sahmel J, Arnold S, Ramachandran G. Influence of repeated contacts on the transfer of elemental metallic lead between compartments in an integrated conceptual model for dermal exposure assessment. J Toxicol Environ Health A 2022; 85:89-109. [PMID: 34569450 DOI: 10.1080/15287394.2021.1979435] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Transfer of contaminants to and from the skin surface has been postulated to occur through a number of different pathways and compartments including: object(s)-to-skin, skin-to-skin, skin-to-clothing, skin-to-gloves, air-to-skin, skin-to-lips, and skin-to-saliva. However, many identified transfer pathways have been only minimally examined to determine the potential for measurable transfer. The purpose of this study was to quantitatively evaluate repeated transfer between different compartments using elemental metallic lead (Pb) in the solid form using a series of systematic measurements in human subjects. The results demonstrated that some transfer pathways and compartments are significantly more important than others. Transfer of Pb could not be measured from skin to cotton clothing or skin to laminate countertop surfaces. However, transfer was consistently measured for skin-to-skin and between the skin and the surface of nitrile gloves, suggesting the potential for significant transfer to or from these compartments in real-world exposure scenarios, and the importance of these pathways. With repeated contacts, transfer increased non-linearly between 1 and 5 contacts, but appeared to approach a steady state distribution among the compartments within 10 contacts. Consistent with other studies, relative to 100% transfer for a single contact, the quantitative transfer efficiency decreased with repeated contacts to 29% after 5 contacts and 11-12% after 10 contacts; for skin-to-skin transfer measurements, transfer efficiency after either 5 or 10 contacts was approximately 50% of the single contact transfer. These data are likely to be useful for refining current approaches to modeling of repeated contacts for dermal exposure and risk assessment.
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Affiliation(s)
- J Sahmel
- Insight Exposure and Risk Sciences, Boulder, Colorado, USA
- Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, Minnesota, USA
| | - S Arnold
- Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, Minnesota, USA
| | - G Ramachandran
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
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Khaled JM, Alyahya SA, Chenthis Kanisha C, Alharbi NS, Kadaikunnan S, Ramachandran G, Alanzi KF, Rajivgandhi G, Vimala R, Manoharan N. Anti-biofilm activity of LC-MS based Solanum nigrum essential oils against multi drug resistant biofilm forming P. mirabilis. Saudi J Biol Sci 2021; 28:302-309. [PMID: 33424310 PMCID: PMC7785425 DOI: 10.1016/j.sjbs.2020.10.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 09/30/2020] [Accepted: 10/04/2020] [Indexed: 10/24/2022] Open
Abstract
Urinary tract infections are second most important diseases worldwide due to the increased amount of antibiotic resistant microbes. Among the Gram negative bacteria, P. mirabilis is the dominant biofilm producer in urinary tract infections next to E. coli. Biofilm is a process that produced self-matrix of more virulence pathogens on colloidal surfaces. Based on the above fact, this study was concentrated to inhibit the P. mirabilis biofilm formation by various in-vitro experiments. In the current study, the anti-biofilm effect of essential oils was recovered from the medicinal plant of Solanum nigrum, and confirmed the available essential oils by liquid chromatography-mass spectroscopy analysis. The excellent anti-microbial activity and minimum biofilm inhibition concentration of the essential oils against P. mirabilis was indicated at 200 µg/mL. The absence of viability and altered exopolysaccharide structure of treated cells were showed by biofilm metabolic assay and phenol-sulphuric acid method. The fluorescence differentiation of P. mirabilis treated cells was showed with more damages by confocal laser scanning electron microscope. Further, more morphological changes of essential oils treated cells were differentiated from normal cells by scanning electron microscope. Altogether, the results were reported that the S. nigrum essential oils have anti-biofilm ability.
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Affiliation(s)
- Jamal M Khaled
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Sami A Alyahya
- National Center for Biotechnology, King Abdulaziz City for Science and Technology, Riyadh 11442, Saudi Arabia
| | - C Chenthis Kanisha
- Noorul Islam Centre for Higher Education, Thuckalay, Kumaracoil, Tamil Nadu 629180, India
| | - Naiyf S Alharbi
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Shine Kadaikunnan
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - G Ramachandran
- Marine Pharmacology & Toxicology Laboratory, Department of Marine Science, Bharathidasan University, Tiruchirappalli, Tamil Nadu 620024, India
| | - Khalid F Alanzi
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - G Rajivgandhi
- Marine Pharmacology & Toxicology Laboratory, Department of Marine Science, Bharathidasan University, Tiruchirappalli, Tamil Nadu 620024, India
| | - Rtv Vimala
- Department of Biotechnology, Bharathidasan University, Tiruchirappalli, Tamil Nadu 620024, India
| | - N Manoharan
- Marine Pharmacology & Toxicology Laboratory, Department of Marine Science, Bharathidasan University, Tiruchirappalli, Tamil Nadu 620024, India
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Abstract
Recent advancement in technologies such as Cloud, Internet of Things etc., leads to the increase usage of mobile computing. Present day mobile computing are too sophisticated and advancement are reaching great heights. Moreover, the present day mobile network suffers due to external and internal intrusions within and outside networks. The existing security systems to protect the mobile networks are incapable to detect the recent attacks. Further, the existing security system completely depends on the traditional signature and rule based approaches. Recent attacks have the property of not fluctuating its behaviour during attack. Hence, a robust Intrusion Detection System (IDS) is desirable. In order to address the above mentioned issue, this paper proposed a robust IDS using Machine Learning Techniques (MLT). The key of using MLT is to utilize the power of ensembles. The ensembles of classifier used in this paper are Random Forest (RF), KNN, Naïve Bayes (NB), etc. The proposed IDS is experimentally tested and validated using a secure test bed. The experimental results also confirms that the proposed IDS is robust enough to withstand and detect any form of intrusions and it is also noted that the proposed IDS outperforms the state of the art IDS with more than 95% accuracy.
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Affiliation(s)
- N. Ravi
- Department of Computer and Information Sciences, Annamalai University Annamalainagar, Tamil Nadu, India
| | - G. Ramachandran
- Department of Computer Science and Engineering, Annamalai University Annamalainagar, Tamil Nadu, India
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Zhang F, Ramachandran G, Mothana RA, Noman OM, Alobaid WA, Rajivgandhi G, Manoharan N. Anti-bacterial activity of chitosan loaded plant essential oil against multi drug resistant K. pneumoniae. Saudi J Biol Sci 2020; 27:3449-3455. [PMID: 33304155 PMCID: PMC7715482 DOI: 10.1016/j.sjbs.2020.09.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/10/2020] [Accepted: 09/10/2020] [Indexed: 12/20/2022] Open
Abstract
The development of antibiotic resistant in K. pneumoniae is an emerging thread worldwide due to the poor antimicrobial drugs. To overcome this issue, researchers are focused on plant material and their essential oils to fight against multi drug resistant bacteria. In this context, the current study was concentrated in medicinal plant of guva leaves and their essential oils to combat multi drug resistant bacterial infections. The essential oils were successfully screened and confirmed by HRLC-MS analysis. The anti-bacterial ability of the compounds were loaded into the chitosan nanoparticles and proved by FT-IR analysis. In addition, the chitosan loaded essential oils morphology was compared with chitosan alone in SEM analysis and suggested that the material was loaded successfully. Further, the anti-bacterial ability of the chitosan loaded essential oils were primarily confirmed by agar well diffusion method. At the 100 µg/mL of lowest concentration of chitosan loaded essential oils, the multi-drug resistant K. pneumoniae was inhibited with 96% and confirmed by minimum inhibition concentration experiment. Hence, all the experiments were proved that the essential oils were successfully loaded into the chitosan nanoparticles, and it has more anti-bacterial activity against multi-drug resistant K. pneumoniae.
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Affiliation(s)
- Feng Zhang
- Chest Endoscopy Minimally Invasive Area, Shandong Provincial Chest Hospital, Shandong Province 250013, China
| | - G Ramachandran
- Department of Marine Science, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India
| | - Ramzi A Mothana
- Department of Pharmacognosy, College of Pharmacy, King Saud University, P.O. BOX 2457, Riyadh 11451, Saudi Arabia
| | - Omar M Noman
- Department of Pharmacognosy, College of Pharmacy, King Saud University, P.O. BOX 2457, Riyadh 11451, Saudi Arabia
| | - Waleed A Alobaid
- Department of Pharmacognosy, College of Pharmacy, King Saud University, P.O. BOX 2457, Riyadh 11451, Saudi Arabia
| | - G Rajivgandhi
- Department of Marine Science, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India
| | - N Manoharan
- Department of Marine Science, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India
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Perumal R, Naidoo K, Naidoo A, Ramachandran G, Requena-Mendez A, Sekaggya-Wiltshire C, Mpagama SG, Matteelli A, Fehr J, Heysell SK, Padayatchi N. A systematic review and meta-analysis of first-line tuberculosis drug concentrations and treatment outcomes. Int J Tuberc Lung Dis 2020; 24:48-64. [PMID: 32005307 PMCID: PMC10622255 DOI: 10.5588/ijtld.19.0025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Low serum concentrations of first-line tuberculosis (TB) drugs have been widely reported. However, the impact of low serum concentrations on treatment outcome is less well studied. A systematic search of MEDLINE/Pubmed and the Cochrane Central Register of Controlled Trials up to 31 March 2018 was conducted for articles describing drug concentrations of first-line TB drugs and treatment outcome in adult patients with drug-susceptible TB. The search identified 3073 unique publication abstracts, which were reviewed for suitability: 21 articles were acceptable for inclusion in the qualitative analysis comprising 13 prospective observational cohorts, 4 retrospective observational cohorts, 1 case-control study and 3 randomised controlled trials. Data for meta-analysis were available for 15 studies, 13 studies of rifampicin (RMP), 10 of isoniazid (INH), 8 of pyrazinamide (PZA) and 4 of ethambutol (EMB). This meta-analysis revealed that low PZA concentration appears to increase the risk of poor outcomes (8 studies, n = 2727; RR 1.73, 95%CI 1.10-2.72), low RMP concentrations may slightly increase the risk of poor outcomes (13 studies, n = 2753; RR 1.40, 95%CI 0.91-2.16), whereas low concentrations of INH (10 studies, n = 2640; RR 1.32, 95%CI 0.66-2.63) and EMB (4 studies, n = 551; RR 1.12, 95%CI 0.41-3.05) appear to make no difference to treatment outcome. There was no significant publication bias or between-study heterogeneity in any of the analyses. The potential clinical impact of low concentrations of PZA and RMP warrants further evaluation. Also, comprehensive assessments of the complex pharmacokinetic-pharmacodynamic relationships in the treatment of TB are urgently needed.
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Affiliation(s)
- R Perumal
- Centre for the AIDS Programme of Research in South Africa, Nelson R Mandela School of Medicine, College of Health Sciences, Medical Research Council-CAPRISA HIV-TB Pathogenesis and Treatment Research Unit, Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, Department of Pulmonology and Critical Care, Groote Schuur Hospital, University of Cape Town, South Africa
| | - K Naidoo
- Centre for the AIDS Programme of Research in South Africa, Nelson R Mandela School of Medicine, College of Health Sciences, Department of Pulmonology and Critical Care, Groote Schuur Hospital, University of Cape Town, South Africa
| | - A Naidoo
- Centre for the AIDS Programme of Research in South Africa, Nelson R Mandela School of Medicine, College of Health Sciences
| | - G Ramachandran
- Department of Biochemistry and Clinical Pharmacology, National Institute for Research in Tuberculosis, Chennai, India
| | - A Requena-Mendez
- Infectious Diseases Institute, College of Health Sciences, Makerere University, Uganda
| | | | | | - A Matteelli
- Kibong'oto Infectious Diseases Hospital, Siha, Kilimanjaro, Tanzania
| | - J Fehr
- Department of Infectious and Tropical Diseases, WHO Collaborating Centre for TB/HIV and TB Elimination, University of Brescia, Brescia, Italy
| | - S K Heysell
- Department of Public Health, Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Switzerland
| | - N Padayatchi
- Centre for the AIDS Programme of Research in South Africa, Nelson R Mandela School of Medicine, College of Health Sciences, Department of Pulmonology and Critical Care, Groote Schuur Hospital, University of Cape Town, South Africa
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Stott KE, Pertinez H, Sturkenboom MGG, Boeree MJ, Aarnoutse R, Ramachandran G, Requena-Méndez A, Peloquin C, Koegelenberg CFN, Alffenaar JWC, Ruslami R, Tostmann A, Swaminathan S, McIlleron H, Davies G. Pharmacokinetics of rifampicin in adult TB patients and healthy volunteers: a systematic review and meta-analysis. J Antimicrob Chemother 2019; 73:2305-2313. [PMID: 29701775 PMCID: PMC6105874 DOI: 10.1093/jac/dky152] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 03/31/2018] [Indexed: 12/29/2022] Open
Abstract
Objectives The objectives of this study were to explore inter-study heterogeneity in the pharmacokinetics (PK) of orally administered rifampicin, to derive summary estimates of rifampicin PK parameters at standard dosages and to compare these with summary estimates for higher dosages. Methods A systematic search was performed for studies of rifampicin PK published in the English language up to May 2017. Data describing the Cmax and AUC were extracted. Meta-analysis provided summary estimates for PK parameter estimates at standard rifampicin dosages. Heterogeneity was assessed by estimation of the I2 statistic and visual inspection of forest plots. Summary AUC estimates at standard and higher dosages were compared graphically and contextualized using preclinical pharmacodynamic (PD) data. Results Substantial heterogeneity in PK parameters was evident and upheld in meta-regression. Treatment duration had a significant impact on the summary estimates for rifampicin PK parameters, with Cmax 8.98 mg/L (SEM 2.19) after a single dose and 5.79 mg/L (SEM 2.14) at steady-state dosing, and AUC 72.56 mg·h/L (SEM 2.60) and 38.73 mg·h/L (SEM 4.33) after single and steady-state dosing, respectively. Rifampicin dosages of at least 25 mg/kg are required to achieve plasma PK/PD targets defined in preclinical studies. Conclusions Vast inter-study heterogeneity exists in rifampicin PK parameter estimates. This is not explained by the available modifying variables. The recommended dosage of rifampicin should be increased to improve efficacy. This study provides an important point of reference for understanding rifampicin PK at standard dosages as efforts to explore higher dosing strategies continue in this field.
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Affiliation(s)
- K E Stott
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - H Pertinez
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - M G G Sturkenboom
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - M J Boeree
- Radboud University Medical Center, Nijmegen, The Netherlands
| | - R Aarnoutse
- Radboud University Medical Center, Nijmegen, The Netherlands
| | - G Ramachandran
- Department of Biochemistry and Clinical Pharmacology, National Institute for Research in Tuberculosis, Chennai, India
| | - A Requena-Méndez
- CRESIB, Barcelona Institute for Global Health, University of Barcelona, Barcelona, Spain
| | - C Peloquin
- College of Pharmacy and Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | - C F N Koegelenberg
- Department of Pulmonology, Stellenbosch University & Tygerberg Academic Hospital, Cape Town, South Africa
| | - J W C Alffenaar
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - R Ruslami
- Department of Pharmacology and Therapy, Universitas Padjadjaran, Bandung, Indonesia
| | - A Tostmann
- Department of Primary and Community Care, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - S Swaminathan
- Indian Council of Medical Research, New Delhi, India
| | - H McIlleron
- Division of Clinical Pharmacology, University of Cape Town, Cape Town, South Africa
| | - G Davies
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK.,Institute of Global Health, University of Liverpool, Liverpool, UK
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11
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Shivakumar SVBY, Chandrasekaran P, Kumar AMV, Paradkar M, Dhanasekaran K, Suryavarshini N, Thomas B, Kohli R, Thiruvengadam K, Kulkarni V, Hannah LE, Sivaramakrishnan GN, Pradhan N, Dolla C, Gupte A, Ramachandran G, DeLuca A, Meshram S, Bhardawaj R, Bollinger RC, Golub J, Selvaraj K, Gupte N, Swaminathan S, Mave V, Gupta A. Diabetes and pre-diabetes among household contacts of tuberculosis patients in India: is it time to screen them all? Int J Tuberc Lung Dis 2019; 22:686-694. [PMID: 29862955 DOI: 10.5588/ijtld.17.0598] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING Pre-diabetes mellitus (pre-DM) and DM increase the risk of developing tuberculosis (TB). Screening contacts of TB patients for pre-DM/DM and linking them to care may mitigate the risk of developing TB and improve DM management. OBJECTIVE To measure the prevalence of pre-DM/DM and associated factors among the adult household contacts (HHCs) of pulmonary TB patients. METHODS Between August 2014 and May 2017, adult HHCs of newly diagnosed adult PTB patients in Pune and Chennai, India, had single blood samples tested for glycosylated haemoglobin (HbA1c) at enrolment. DM was defined as previously diagnosed, self-reported DM or HbA1c 6.5%, and pre-DM as HbA1c between 5.7% and 6.4%. Latent tuberculous infection (LTBI) was defined as a positive tuberculin skin test (5 mm induration) or QuantiFERON® Gold In-Tube (0.35 international units/ml). RESULTS Of 652 adult HHCs, 175 (27%) had pre-DM and 64 (10%) had DM. Forty (64%) HHCs were newly diagnosed with DM and 48 (75%) had poor glycaemic control (HbA1c 7.0%). Sixty-eight (22%) pre-DM cases were aged 18-34 years. Age 35 years, body mass index 25 kg/m2, chronic disease and current tobacco smoking were significantly associated with DM among HHCs. CONCLUSIONS Adult HHCs of TB patients in India have a high prevalence of undiagnosed DM, pre-DM and LTBI, putting them at high risk for developing TB. Routine DM screening should be considered among all adult HHCs of TB.
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Affiliation(s)
| | - P Chandrasekaran
- National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India
| | - A M V Kumar
- International Union Against Tuberculosis and Lung Disease, Paris, France
| | - M Paradkar
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research site, Pune, Maharashtra, India
| | - K Dhanasekaran
- National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India
| | - N Suryavarshini
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research site, Pune, Maharashtra, India
| | - B Thomas
- National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India
| | - R Kohli
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research site, Pune, Maharashtra, India
| | - K Thiruvengadam
- National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India
| | - V Kulkarni
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research site, Pune, Maharashtra, India
| | - L E Hannah
- National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India
| | | | - N Pradhan
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research site, Pune, Maharashtra, India
| | - C Dolla
- National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India
| | - A Gupte
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - G Ramachandran
- National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India
| | - A DeLuca
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - S Meshram
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research site, Pune, Maharashtra, India, Byramjee Jeejeebhoy Government Medical College, Pune, India
| | - R Bhardawaj
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research site, Pune, Maharashtra, India, Byramjee Jeejeebhoy Government Medical College, Pune, India
| | - R C Bollinger
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - J Golub
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - K Selvaraj
- Pondicherry Institute of Medical Sciences (PIMS), Puducherry
| | - N Gupte
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research site, Pune, Maharashtra, India, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - S Swaminathan
- Indian Council of Medical Research, New Delhi, India
| | - V Mave
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research site, Pune, Maharashtra, India, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - A Gupta
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
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12
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Ramachandran G, Rajivgandhi G, Maruthupandy M, Manoharan N. Extraction and partial purification of secondary metabolites from endophytic actinomycetes of marine green algae Caulerpa racemosa against multi drug resistant uropathogens. Biocatalysis and Agricultural Biotechnology 2019. [DOI: 10.1016/j.bcab.2019.01.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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13
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Hegerle N, Bose J, Ramachandran G, Galen JE, Levine MM, Simon R, Tennant SM. Overexpression of O-polysaccharide chain length regulators in Gram-negative bacteria using the Wzx-/Wzy-dependent pathway enhances production of defined modal length O-polysaccharide polymers for use as haptens in glycoconjugate vaccines. J Appl Microbiol 2018; 125:575-585. [PMID: 29603538 PMCID: PMC6726474 DOI: 10.1111/jam.13772] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 10/20/2017] [Accepted: 03/26/2018] [Indexed: 11/30/2022]
Abstract
Aims O‐polysaccharide (OPS) molecules are protective antigens for several bacterial pathogens, and have broad utility as components of glycoconjugate vaccines. Variability in the OPS chain length is one obstacle towards further development of these vaccines. Introduction of sizing steps during purification of OPS molecules of suboptimal or of mixed lengths introduces additional costs and complexity while decreasing the final yield. The overall goal of this study was to demonstrate the utility of engineering Gram‐negative bacteria to produce homogenous O‐polysaccharide populations that can be used as the basis of carbohydrate vaccines by overexpressing O‐polysaccharide chain length regulators of the Wzx‐/Wzy‐dependent pathway. Method and Results The O‐polysaccharide chain length regulators wzzB and fepE from Salmonella Typhimurium I77 and wzz2 from Pseudomonas aeruginosa PAO1 were cloned and expressed in the homologous organism or in other Gram‐negative bacteria. Overexpression of these Wzz proteins in the homologous organism significantly increased the proportion of long or very long chain O‐polysaccharides. The same observation was made when wzzB was overexpressed in Salmonella Paratyphi A and Shigella flexneri, and wzz2 was overexpressed in two other strains of P. aeruginosa. Conclusions Overexpression of Wzz proteins in Gram‐negative bacteria using the Wzx/Wzy‐dependant pathway for lipopolysaccharide synthesis provides a genetic method to increase the production of an O‐polysaccharide population of a defined size. Significance and Impact of the Study The methods presented herein represent a cost‐effective and improved strategy for isolating preferred OPS vaccine haptens, and could facilitate the further use of O‐polysaccharides in glycoconjugate vaccine development.
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Affiliation(s)
- N Hegerle
- Center for Vaccine Development and Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - J Bose
- Center for Vaccine Development and Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - G Ramachandran
- Center for Vaccine Development and Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - J E Galen
- Center for Vaccine Development and Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - M M Levine
- Center for Vaccine Development and Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, USA
| | - R Simon
- Center for Vaccine Development and Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - S M Tennant
- Center for Vaccine Development and Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
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14
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Hemanth Kumar AK, Kannan T, Chandrasekaran V, Sudha V, Vijayakumar A, Ramesh K, Lavanya J, Swaminathan S, Ramachandran G. Pharmacokinetics of thrice-weekly rifampicin, isoniazid and pyrazinamide in adult tuberculosis patients in India. Int J Tuberc Lung Dis 2018; 20:1236-41. [PMID: 27510252 DOI: 10.5588/ijtld.16.0048] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE To study the pharmacokinetics of rifampicin (RMP), isoniazid (INH) and pyrazinamide (PZA) in adult tuberculosis (TB) patients and examine factors that influence drug pharmacokinetics. METHODS Adult TB patients (n = 101) receiving thrice-weekly anti-tuberculosis treatment in the Revised National TB Control Programme (RNTCP) were studied. The study was conducted at steady state after directly observed drug administration. RMP, INH and PZA concentrations were estimated using high-performance liquid chromatography and NAT2 genotyping by real-time polymerase chain reaction. RESULTS RMP peak concentration (Cmax) was sub-therapeutic (<8 μg/ml) in 88% of the patients. The Cmax of RMP, INH and PZA at 2 h was observed in respectively 83.2%, 97.0% and 92.1% of the patients. The Cmax and area under the curve from 0 to 8 h (AUC0-8) of PZA was lower in TB patients with diabetes mellitus than in non-diabetics. Significant associations were observed between the Cmax and the AUC0-8 of RMP, INH and PZA with drug doses; RMP with category of treatment; INH with smoking, body mass index and N-acetyl transferase 2 genotype; and PZA with sex and smoking. CONCLUSIONS Several risk factors for drug concentration variations were identified. Two-hour post-dosing drug concentrations mimicked Cmax. A high proportion of TB patients had RMP Cmax below the expected range, which is a matter of concern.
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Affiliation(s)
| | - T Kannan
- National Institute for Research in Tuberculosis, Chennai, India
| | | | - V Sudha
- National Institute for Research in Tuberculosis, Chennai, India
| | - A Vijayakumar
- National Institute for Research in Tuberculosis, Chennai, India
| | - K Ramesh
- National Institute for Research in Tuberculosis, Chennai
| | | | - S Swaminathan
- National Institute for Research in Tuberculosis, Chennai, India
| | - G Ramachandran
- National Institute for Research in Tuberculosis, Chennai, India
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15
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Mave V, Chandanwale A, Kinikar A, Khadse S, Kagal A, Gupte N, Suryavanshi N, Nimkar S, Koli H, Khwaja S, Bharadwaj R, Joshi S, Horng H, Benet LZ, Ramachandran G, Dooley KE, Gupta A, Gandhi M. Isoniazid hair concentrations in children with tuberculosis: a proof of concept study. Int J Tuberc Lung Dis 2018; 20:844-7. [PMID: 27155191 PMCID: PMC4889729 DOI: 10.5588/ijtld.15.0882] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Assessing treatment adherence and quantifying exposure to anti-tuberculosis drugs among children is challenging. We undertook a 'proof of concept' study to assess the drug concentrations of isoniazid (INH) in hair as a therapeutic drug monitoring tool. Children aged <12 years initiated on a thrice-weekly treatment regimen including INH (10 mg/kg) for newly diagnosed tuberculosis were enrolled. INH concentrations in hair were measured using liquid chromatography-tandem mass spectrometry at 1, 2, 4 and 6 months after initiating anti-tuberculosis treatment. We found that INH hair concentrations in all children on thrice-weekly INH were detectable and displayed variability across a dynamic range.
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Affiliation(s)
- V Mave
- Byramjee-Jeejeebhoy Medical College Clinical Trials Unit, Pune, India; Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - A Chandanwale
- Byramjee-Jeejeebhoy Medical College Clinical Trials Unit, Pune, India
| | - A Kinikar
- Byramjee-Jeejeebhoy Medical College Clinical Trials Unit, Pune, India
| | - S Khadse
- Byramjee-Jeejeebhoy Medical College Clinical Trials Unit, Pune, India
| | - A Kagal
- Byramjee-Jeejeebhoy Medical College Clinical Trials Unit, Pune, India
| | - N Gupte
- Byramjee-Jeejeebhoy Medical College Clinical Trials Unit, Pune, India; Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - N Suryavanshi
- Byramjee-Jeejeebhoy Medical College Clinical Trials Unit, Pune, India
| | - S Nimkar
- Byramjee-Jeejeebhoy Medical College Clinical Trials Unit, Pune, India
| | - H Koli
- Byramjee-Jeejeebhoy Medical College Clinical Trials Unit, Pune, India
| | - S Khwaja
- Byramjee-Jeejeebhoy Medical College Clinical Trials Unit, Pune, India
| | - R Bharadwaj
- Byramjee-Jeejeebhoy Medical College Clinical Trials Unit, Pune, India
| | - S Joshi
- Byramjee-Jeejeebhoy Medical College Clinical Trials Unit, Pune, India
| | - H Horng
- University of California, San Francisco, California, USA
| | - L Z Benet
- University of California, San Francisco, California, USA
| | - G Ramachandran
- National Institute of Research in Tuberculosis, Chennai, India
| | - K E Dooley
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - A Gupta
- Byramjee-Jeejeebhoy Medical College Clinical Trials Unit, Pune, India; Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - M Gandhi
- University of California, San Francisco, California, USA
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16
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Ramesh K, Hemanth Kumar AK, Kannan T, Vijayalakshmi R, Sudha V, Manohar Nesakumar S, Bharathiraja T, Lavanya J, Swaminathan S, Ramachandran G. SLCO1B1 gene polymorphisms do not influence plasma rifampicin concentrations in a South Indian population. Int J Tuberc Lung Dis 2016; 20:1231-5. [DOI: 10.5588/ijtld.15.1007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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17
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Hemanth Kumar AK, Narendran G, Kumar RS, Ramachandran G, Sekar L, Raja K, Swaminathan S. RMP exposure is lower in HIV-infected TB patients receiving intermittent than daily anti-tuberculosis treatment. Int J Tuberc Lung Dis 2016; 19:805-7. [PMID: 26056105 DOI: 10.5588/ijtld.14.0702] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
We compared the pharmacokinetics of rifampicin (RMP) during daily and intermittent (thrice weekly) anti-tuberculosis treatment in human immunodeficiency virus infected tuberculosis patients. Patients treated with a thrice-weekly regimen had significantly lower plasma peak concentration, area under the time concentration curve from 0 to 24 h and higher oral clearance of RMP than those treated with the daily regimen. The median values were respectively 3.7 and 6.4 μg/ml (P < 0.001), 20.7 and 29.4 μg/ml.h (P = 0.03) and 21.7 and 15.3 ml/min (P = 0.03).
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Affiliation(s)
| | - G Narendran
- National Institute for Research in Tuberculosis, Chennai, India
| | - R S Kumar
- National Institute for Research in Tuberculosis, Chennai, India
| | - G Ramachandran
- National Institute for Research in Tuberculosis, Chennai, India
| | - L Sekar
- National Institute for Research in Tuberculosis, Chennai, India
| | - K Raja
- Government Hospital of Thoracic Medicine, Chennai, India
| | - S Swaminathan
- National Institute for Research in Tuberculosis, Chennai, India
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18
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Savic RM, Ruslami R, Hibma JE, Hesseling A, Ramachandran G, Ganiem AR, Swaminathan S, McIlleron H, Gupta A, Thakur K, van Crevel R, Aarnoutse R, Dooley KE. Pediatric tuberculous meningitis: Model-based approach to determining optimal doses of the anti-tuberculosis drugs rifampin and levofloxacin for children. Clin Pharmacol Ther 2015; 98:622-9. [PMID: 26260983 DOI: 10.1002/cpt.202] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 07/15/2015] [Accepted: 08/01/2015] [Indexed: 01/15/2023]
Abstract
Pediatric tuberculous meningitis (TBM) is a highly morbid, often fatal disease. Standard treatment includes isoniazid, rifampin, pyrazinamide, and ethambutol. Current rifampin dosing achieves low cerebrospinal fluid (CSF) concentrations, and CSF penetration of ethambutol is poor. In adult trials, higher-dose rifampin and/or a fluoroquinolone reduced mortality and disability. To estimate optimal dosing of rifampin and levofloxacin for children, we compiled plasma and CSF pharmacokinetic (PK) and outcomes data from adult TBM trials plus plasma PK data from children. A population PK/pharmacodynamic (PD) model using adult data defined rifampin target exposures (plasma area under the curve (AUC)0-24 = 92 mg*h/L). Levofloxacin targets and rifampin pediatric drug disposition information were literature-derived. To attain target rifampin exposures, children require daily doses of at least 30 mg/kg orally or 15 mg/kg intravenously (i.v.). From our pediatric population PK model, oral levofloxacin doses needed to attain exposure targets were 19-33 mg/kg. Our results provide data-driven guidance to maximize pediatric TBM treatment while we await definitive trial results.
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Affiliation(s)
- R M Savic
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California, USA
| | - R Ruslami
- Universitas Padjadjaran/Hasan Sadikin Hospital, Bandung, Indonesia
| | - J E Hibma
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California, USA
| | - A Hesseling
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Stellenbosch University, Tygerberg, South Africa
| | - G Ramachandran
- National Institute for Research in Tuberculosis, Chetpet, Chennai, India
| | - A R Ganiem
- Universitas Padjadjaran/Hasan Sadikin Hospital, Bandung, Indonesia
| | - S Swaminathan
- National Institute for Research in Tuberculosis, Chetpet, Chennai, India
| | - H McIlleron
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - A Gupta
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - K Thakur
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - R van Crevel
- Radboud University Medical Center, Nijmegen, The Netherlands
| | - R Aarnoutse
- Radboud University Medical Center, Nijmegen, The Netherlands
| | - K E Dooley
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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19
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Affiliation(s)
- S. Swaminathan
- National Institute for Research in Tuberculosis; Chennai India
| | - G. Ramachandran
- National Institute for Research in Tuberculosis; Chennai India
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20
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Muthu S, Ramachandran G, Isac Paulraj E, Swaminathan T. Quantum mechanical study of the structure and spectroscopic (FTIR, FT-Raman), first-order hyperpolarizability and NBO analysis of 1,2-benzoxazol-3-ylmenthane sulfonamide. Spectrochim Acta A Mol Biomol Spectrosc 2014; 128:603-613. [PMID: 24691375 DOI: 10.1016/j.saa.2014.02.183] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Revised: 02/22/2014] [Accepted: 02/25/2014] [Indexed: 06/03/2023]
Abstract
Fourier transform infrared (FTIR) and FT-Raman spectra of 1,2-benzoxazol-3-ylmenthane sulfonamide in the solid phase were recorded and analyzed. The molecular geometry, vibrational frequencies, infrared intensities, Raman activities and atomic charges were calculated using HF and density functional theory calculation (B3LYP) with standard 6-31G(d, p) basis set. Complete vibrational assignment and analysis of the fundamental modes of the compound were carried out using the observed FTIR and FT-Raman spectra. The thermodynamic functions of the title compound were also performed. Stability of the molecule arising from hyper-conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The dipole moment (μ), polarizability (α) and the hyperpolarizability (β) values of the molecule has been computed. Potential Energy Distribution (PED) were computed for the assignment of unambiguous vibrational fundamental modes. UV-vis spectrum of the compound was also recorded. The theoretical electronic absorption spectra have been calculated by TD-DFT/B3LYP using 6-31G(d,p) basis set. The HOMO and LUMO energy gap reveals that the chemical activity of the molecule. The molecular orbital contributions were studied by density of energy states (DOSs). Thermodynamic properties (heat capacity, entropy and enthalpy) of the title compound at different temperatures were calculated. Finally, simulated FTIR and FT-Raman spectra of 1,2-benzoxazol-3-ylmenthane sulfonamide showed good agreement with the observed spectra.
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Affiliation(s)
- S Muthu
- Department of Physics, Sri Venkateswara College of Engineering, Sriperumbudur 602 105, Tamil Nadu, India.
| | - G Ramachandran
- Research Scholar Research and Development Centre, Bharathiyar University, Coimbatore, Tamil Nadu, India
| | - E Isac Paulraj
- Department of Applied Physics, Pallavan College of Engineering, Kancheepuram 631 502, Tamil Nadu, India
| | - T Swaminathan
- Department of Chemical Engineering, Sri Venkateswara College of Engineering, Sriperumbudur 602 105, Tamil Nadu, India
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21
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Ramachandran G, Bhavani PK, Hemanth Kumar AK, Srinivasan R, Raja K, Sudha V, Venkatesh S, Chandrasekaran C, Swaminathan S. Pharmacokinetics of rifabutin during atazanavir/ritonavir co-administration in HIV-infected TB patients in India. Int J Tuberc Lung Dis 2014; 17:1564-8. [PMID: 24200269 DOI: 10.5588/ijtld.13.0390] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING Rifabutin (RBT) is reported to be as effective as and to have less inducing effect on cytochrome P450 enzymes than rifampicin against tuberculosis (TB). The optimal dose of RBT during ritonavir (RTV) co-administration remains a matter of debate. OBJECTIVE To study the pharmacokinetics of 150 mg RBT thrice weekly during concomitant atazanavir/RTV administration in human immunodeficiency virus (HIV) infected TB patients. METHODS This observational study was conducted in 16 adult HIV-infected TB patients being treated for TB with an RBT-containing regimen and an antiretroviral therapy regimen with RTV; the dose of RBT was 150 mg thrice weekly. Serial blood draws were performed at pre-dosing and at 1, 2, 4, 6, 8, 12 and 24 h after the drug was administered. Plasma RBT was estimated using high-performance liquid chromatography. RESULTS AND CONCLUSIONS Peak RBT concentration was below the lower therapeutic limit (<0.3 μg/ml) in seven patients, while 10 patients had trough concentrations below the minimal inhibitory concentration against Mycobacterium tuberculosis (0.06 μg/ml), suggesting that the RBT dosage may be inadequate. Prospective studies in different settings are required to arrive at the proper therapeutic dose for RBT to be used during co-administration with RTV.
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Affiliation(s)
- G Ramachandran
- National Institute for Research in Tuberculosis, Chetpet, Chennai, India
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22
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23
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Ramachandran G, Raman A, Easwaramoorthi S, Rathore RS, Sathiyanarayanan K. Four component domino reaction for the synthesis of highly functionalized dimeric tetracyclic dilactam fluorophores: H-bond aided self-assembly. RSC Adv 2014. [DOI: 10.1039/c4ra03622k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A series of new dimeric tetracyclic dilactam fluorophores (DTDF) consisting of diazabicyclooctane-dione (DBOD) fused to tetrahydronaphthalene (THP) was designed and synthesized from a simple precursor.
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Affiliation(s)
- G. Ramachandran
- Chemistry Division
- School of Advanced Sciences
- VIT University
- Vellore, India
- Department of Chemical Sciences
| | - A. Raman
- Chemical Laboratory
- CSIR-Central Leather Research Institute
- Chennai – 600020, India
- Academy of Scientific and Innovative Research (AcSIR)
- , India
| | - S. Easwaramoorthi
- Chemical Laboratory
- CSIR-Central Leather Research Institute
- Chennai – 600020, India
- Academy of Scientific and Innovative Research (AcSIR)
- , India
| | - R. S. Rathore
- Bioinformatics Infrastructure Facility
- School of life sciences
- University of Hyderabad
- Hyderabad – 500046, India
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Ramachandran G, Hemanth Kumar AK, Bhavani PK, Poorana Gangadevi N, Sekar L, Vijayasekaran D, Banu Rekha VV, Ramesh Kumar S, Ravichandran N, Mathevan G, Swaminathan S. Age, nutritional status and INH acetylator status affect pharmacokinetics of anti-tuberculosis drugs in children. Int J Tuberc Lung Dis 2013; 17:800-6. [PMID: 23676165 DOI: 10.5588/ijtld.12.0628] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING The currently recommended dosages of rifampicin (RMP), isoniazid (INH), pyrazinamide (PZA) and ethambutol in children are extrapolated from adult pharmacokinetic studies, and have not been adequately evaluated in children. OBJECTIVE To describe the pharmacokinetics of RMP, INH and PZA given thrice weekly in children with tuberculosis (TB), and to relate pharmacokinetics to treatment outcomes. METHODS Eighty-four human immunodeficiency virus negative children with TB aged 1-12 years in Chennai and Madurai, India, were recruited. Phenotypic INH acetylator status was determined. Nutritional status was assessed using Z scores. During the intensive phase of anti-tuberculosis treatment, a complete pharmacokinetic study was performed after directly observed administration of drugs. At 2 and 6 months, drug levels were measured 2 h post-dose. Drug concentrations were measured using high performance liquid chromatography and pharmacokinetic variables were calculated. Multivariable regression analysis was performed to explore factors impacting drug levels and treatment outcomes. RESULTS AND CONCLUSIONS Children aged <3 years had significantly lower RMP, INH and PZA concentrations than older children, and 90% of all children had sub-therapeutic RMP Cmax (<8 μg/ml). Age, nutritional status and INH acetylator status influenced drug levels. Peak RMP and INH concentrations were important determinants of treatment outcome. Recommendations for anti-tuberculosis treatment in children should take these factors into consideration.
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Affiliation(s)
- G Ramachandran
- National Institute for Research in Tuberculosis, Indian Council of Medical Research, Chetpet, Chennai, India
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Muthu S, Ramachandran G. Spectroscopic studies (FTIR, FT-Raman and UV-Visible), normal coordinate analysis, NBO analysis, first order hyper polarizability, HOMO and LUMO analysis of (1R)-N-(Prop-2-yn-1-yl)-2,3-dihydro-1H-inden-1-amine molecule by ab initio HF and density functional methods. Spectrochim Acta A Mol Biomol Spectrosc 2013; 121:394-403. [PMID: 24280302 DOI: 10.1016/j.saa.2013.10.093] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 10/14/2013] [Accepted: 10/17/2013] [Indexed: 06/02/2023]
Abstract
The Fourier transform infrared (FT-IR) and FT-Raman of (1R)-N-(Prop-2-yn-1-yl)-2,3-dihydro-1H-inden-1-amine (1RNPDA) were recorded in the regions 4000-400 cm(-1) and 4000-100 cm(-1) respectively. A complete assignment and analysis of the fundamental vibrational modes of the molecule were carried out. The observed fundamental modes have been compared with the harmonic vibrational frequencies computed using HF method by employing 6-31G(d,p) basis set and DFT(B3LYP) method by employing 6-31G(d,p) basis set. The vibrational studies were interpreted in terms of Potential Energy Distribution (PED). The complete vibrational frequency assignments were made by Normal Co-ordinate Analysis (NCA) following the scaled quantum mechanical force field methodology (SQMFF). The first order hyper polarizability (β0) of this molecular system and related properties (α, μ, and Δα) are calculated using B3LYP/6-31G(d,p) method based on the finite-field approach. The thermodynamic functions of the title compound were also performed at the above methods and basis set. A detailed interpretation of the infrared and Raman spectra of 1RNPDA is reported. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated using the GIAO method confirms with the experimental values. Stability of the molecule arising from hyper-conjugative interactions and charge delocalization has been analyzed using Natural Bond Orbital (NBO) analysis. UV-vis spectrum of the compound was recorded and electronic properties such as excitation energies, oscillator strength and wavelength were performed by TD-DFT/B3LYP using 6-31G(d,p) basis set. The HOMO and LUMO energy gap reveals that the energy gap reflects the chemical activity of the molecule. The observed and calculated wave numbers are formed to be in good agreement. The experimental spectra also coincide satisfactorily with those of theoretically constructed spectra.
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Affiliation(s)
- S Muthu
- Department of Physics, Sri Venkateswara College of Engg., Sriperumbudur 602 105, India.
| | - G Ramachandran
- Research Scholar, Research and Development Centre, Bharathiar University, Coimbatore 641046, India
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26
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Ramachandran G, Muthu S, Renuga S. Quantum mechanical study of the structure and spectroscopic (FT-IR, FT-Raman), first-order hyperpolarizability, NBO and HOMO-LUMO analysis of S-S-2 methylamino-1-phenyl propan-1-ol. Spectrochim Acta A Mol Biomol Spectrosc 2013; 107:386-398. [PMID: 23485937 DOI: 10.1016/j.saa.2013.01.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 12/27/2012] [Accepted: 01/10/2013] [Indexed: 06/01/2023]
Abstract
The experimental and theoretical vibrational spectra of S-S-2 methylamino-1-phenyl propan-1-ol (SSMPL). Fourier transform infrared (FTIR) and FT Raman spectra of SSMPL in the solid phase were recorded and analyzed. The molecular geometry, vibrational frequencies, infrared intensities, Raman activities and atomic charges were calculated using density functional theory calculation (B3LYP) with standard 6-31G(d,p) and high level 6-311++G(d,p) basis sets. Complete vibrational assignment and analysis of the fundamental modes of the compound were carried out using the observed FTIR and FT Raman data. The thermodynamic functions of the title compound were also performed by B3LYP with two basis sets 6-31G(d,p) and 6-311++G(d,p). Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. Using the method B3LYP, the dipole moment (μ), polarizability (α) and the hyperpolarizability (β) values of the investigated molecule has been computed. Total energy distribution (TED) was used for the assignment of Unambiguous vibrational fundamental modes. Finally, Simulated FTIR and FT Raman spectra of SSMPL showed good agreement with the observed spectra.
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27
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Hemanth AKK, Sudha V, Ramachandran G. Simple and rapid liquid chromatography method for simultaneous determination of isoniazid and pyrazinamide in plasma. ACTA ACUST UNITED AC 2012. [DOI: 10.3126/saarctb.v9i1.6960] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Introduction: Treatment of tuberculosis (TB) requires a combination of drugs. Isoniazid (INH) and pyrazinamide (PZA) are key components of the fi rst-line regimen used in the treatment of TB and monitoring these drug levels in plasma would help in better patient care. The objective of the study is to develop and validate a simple and rapid high performance liquid chromatographic method for simultaneous determination of INH and PZA in human plasma. Methodology: The method involved deproteinisation of plasma with para hydroxy benzaldehyde and trifl uoroacetic acid and analysis using a reversed-phase C8 column and UV detection at 267nm. The fl ow rate was set at 1.5 ml/min at ambient temperature. The accuracy, linearity, precision, specifi city, stability and recovery of the method were evaluated. The method was applied to estimate plasma INH and PZA collected from six children with TB. Results: Well resolved peaks of PZA and INH at retention times of 3.2 and 6.1 minutes respectively were obtained. The assay was linear from 0.25 - 10.0 ìg/ml for INH and 1.25 – 50.0 ìg/ml for PZA. The within-day and between-day relative standard deviation for standards were below 10%. The average recoveries of INH and PZA from plasma were 104 and 102% respectively. Conclusions: A rapid and accurate method for simultaneous determination of INH and PZA in plasma was validated. The assay spans the concentration range of clinical interest. The easy sample preparation and small sample size makes this assay highly suitable for pharmacokinetic studies of INH and PZA in TB patients. SAARC Journal of Tuberculosis, Lung Diseases & HIV/AIDS 2012; IX (1) 13-18 DOI: http://dx.doi.org/10.3126/saarctb.v9i1.6960
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Muthu S, Ramachandran G, Uma Maheswari J. Vibrational spectroscopic investigation on the structure of 2-ethylpyridine-4-carbothioamide. Spectrochim Acta A Mol Biomol Spectrosc 2012; 93:214-222. [PMID: 22481178 DOI: 10.1016/j.saa.2012.02.107] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2011] [Revised: 02/21/2012] [Accepted: 02/23/2012] [Indexed: 05/31/2023]
Abstract
Fourier transform Raman and Fourier transform infrared spectra of 2-ethylpyridine-4-carbothioamide were recorded in the regions 3600-100 cm(-1) and 4000-450 cm(-1), respectively in the solid phase. 2-Ethylpyridine-4-carbothioamide is used as anti-tubercular agent that inhibits mycolic acid synthesis. The equilibrium geometry harmonic vibrational frequencies, infrared intensities and Raman scattering activities were calculated by Hartee Fock and density functional B3LYP methods with 6-31 G (d,p) basis set, using Gaussian 03 W program package on a Pentium IV/1.6 GHz personal computer(.) A detailed interpretation of the vibrational spectra of this compound has been made on the basis of the calculated potential energy distribution (PED). The thermodynamic functions of the title compound were also performed at the above methods and basis set. A detailed interpretation of the infrared and Raman spectra of 2-ethylpyridine-4-carbothioamide is reported. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecules were calculated using the GIAO method confirms with the experimental values. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The linear polarizability (α) and the first order hyperpolarizability (β) values of the investigated molecule have been computed using DFT quantum mechanical calculations. The HOMO and LUMO energy gap reveals that the energy gap reflects the chemical activity of the molecule. The observed and calculated wave numbers are found to be in good agreement. The experimental spectra also coincide satisfactorily with those of theoretically constructed spectra.
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Affiliation(s)
- S Muthu
- Department of physics, Sri Venkateswara College of Engg, Sriperumbudur 602105, Tamil Nadu, India.
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29
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Li HQ, Ramachandran G, Satheesh V, Sathiyanarayanan K, Rathore RS. 1,1'-[(2-Bromo-phen-yl)-methyl-ene]-dipyrrolidin-2-one. Acta Crystallogr Sect E Struct Rep Online 2012; 68:o768. [PMID: 22412642 PMCID: PMC3295531 DOI: 10.1107/s1600536812006277] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2012] [Accepted: 02/13/2012] [Indexed: 11/11/2022]
Abstract
In the title compound, C(15)H(17)BrN(2)O(2), both pyrrolidinone rings adopt envelope conformations. The crystal packing is characterized by short C-Br⋯O=C inter-actions [Br⋯O = 3.1730 (13) Å], leading to supra-molecular dimers. Inter-molecular C-H⋯O and C-H⋯π inter-actions are also observed.
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Li H, Ramachandran G, Sathishkumar M, Sathiyanarayanan K, Rathore RS. 1-Meth-oxy-4-({[(4-meth-oxy-phen-yl)-sulfan-yl](phen-yl)meth-yl}sulfan-yl)benzene. Acta Crystallogr Sect E Struct Rep Online 2012; 68:o782. [PMID: 22412655 PMCID: PMC3297852 DOI: 10.1107/s1600536812006320] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2012] [Accepted: 02/13/2012] [Indexed: 11/10/2022]
Abstract
The title compound, C(21)H(20)O(2)S(2), forms a propeller-shaped structure with the tetra-hedral C atom as the central hub and meth-oxy-benzene and phenyl residues as radiating blades. Short C-H⋯π contacts are observed.
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31
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Karthikeyan NS, Ramachandran G, Sathiyanarayanan K, Raghavaiah P, Rathore RS. 3-(7,8,13,14-Tetra-hydrodi-benzo-[a,i]phen-an-thridin-5-yl)benzene-1,2-diol. Acta Crystallogr Sect E Struct Rep Online 2010; 66:o1753. [PMID: 21587969 PMCID: PMC3007033 DOI: 10.1107/s1600536810023688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2010] [Accepted: 06/18/2010] [Indexed: 05/30/2023]
Abstract
In the title compound, C(27)H(21)NO(2), the half-chair conformation of the alicyclic rings gives rise to a slightly folded structure of the central tricyclic tetra-hydrophenanthridine unit. Tandem intra-molecular O-H⋯N and O-H⋯O hydrogen bonds give rise to adjacent S(6) and S(5) rings, respectively, which dictate the conformation of the 5-aryl substituent. In the crystal structure, an inter-molecular C-H⋯O contact generates chains parallel to [101]. Short O-H⋯π and C-H⋯π contacts are also observed.
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Affiliation(s)
- N. S. Karthikeyan
- Chemistry Division, School of Advanced Sciences, VIT University, Vellore 632014, India
| | - G. Ramachandran
- Chemistry Division, School of Advanced Sciences, VIT University, Vellore 632014, India
| | - K. Sathiyanarayanan
- Chemistry Division, School of Advanced Sciences, VIT University, Vellore 632014, India
| | - P. Raghavaiah
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India
| | - R. S. Rathore
- Bioinformatics Infrastructure Facility, Department of Biotechnology, School of Life Science, University of Hyderabad, Hyderabad 500046, India
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Ramachandran G, Suresh R, Sreedevi S, Kanakam CC, Ramkumar V. 6-Formyl-2-methoxy-3-nitrophenyl 4-toluenesulfonate. Acta Crystallogr Sect E Struct Rep Online 2008; 64:o2046. [PMID: 21201238 PMCID: PMC2959389 DOI: 10.1107/s1600536808029711] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2008] [Accepted: 09/16/2008] [Indexed: 11/15/2022]
Abstract
In the title compound, C15H13NO7S, the interplanar angle between the two aromatic rings is 26.04 (3)°. The crystal structure is stabilized by C—H⋯O interactions.
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Ramachandran G, Kanakam CC, Gunasekaran B, Manivannan V. 2-Methoxy-4-methylphenyl 4-toluenesulfonate. Acta Crystallogr Sect E Struct Rep Online 2008; 64:o1760. [PMID: 21201742 PMCID: PMC2960684 DOI: 10.1107/s1600536808025749] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Accepted: 08/10/2008] [Indexed: 11/12/2022]
Abstract
In the title molecule, C15H16O4S, the interplanar angle between the two aromatic rings is 45.07 (7)°. The crystal packing is stabilized by weak intermolecular C—H⋯O interactions.
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Ramachandran G, Suresh R, Chakkaravarthi G, Kanakam CC, Manivannan V. 2-(5,7-Dimeth-oxy-4-oxo-4H-chromen-2-yl)phenyl 4-toluene-sulfonate. Acta Crystallogr Sect E Struct Rep Online 2008; 64:o1576. [PMID: 21203275 PMCID: PMC2962194 DOI: 10.1107/s1600536808022654] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Accepted: 07/18/2008] [Indexed: 11/27/2022]
Abstract
In the crystal structure of the title compound, C(24)H(20)O(7)S, the chromone system makes a dihedral angle of 37.32 (7)° with the adjacent benzene ring. The chromone ring system and the tolyl ring are almost parallel, with a dihedral angle of 4.56 (9)°. The tolyl ring is twisted at an angle of 41.75 (6)° with respect to the benzene ring. Weak intra- and inter-molecular C-H⋯O inter-actions are observed.
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Affiliation(s)
- G. Ramachandran
- Department of Chemistry, Valliammai Engineering College, SRM Nagar, Chennai 603 203, India
| | - R. Suresh
- Department of Chemistry, Presidency College, Chennai 600 005, India
| | - G. Chakkaravarthi
- Department of Physics, CPCL Polytechnic College, Chennai 600 068, India
| | | | - V. Manivannan
- Department of Physics, Presidency College, Chennai 600 005, India
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Ramachandran G, Kanakam CC, Manivannan V. 2,4-Dinitro-1-naphthyl 4-toluene-sulfonate. Acta Crystallogr Sect E Struct Rep Online 2008; 64:o873. [PMID: 21202359 PMCID: PMC2961114 DOI: 10.1107/s1600536808010052] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2008] [Accepted: 04/12/2008] [Indexed: 11/29/2022]
Abstract
In the title compound, C17H12N2O7S, the dihedral angle between the benzene ring and the naphthyl plane is 26.34 (6)°. The nitro groups make dihedral angles of 40.09 (4) and 37.05 (3)° with the naphthyl plane. In the crystal structure, weak intra- and intermolecular C—H⋯O interactions are observed.
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Raynor PC, Kim BG, Ramachandran G, Strommen MR, Horns JH, Streifel AJ. Collection of biological and non-biological particles by new and used filters made from glass and electrostatically charged synthetic fibers. Indoor Air 2008; 18:51-62. [PMID: 18093124 DOI: 10.1111/j.1600-0668.2007.00504.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
UNLABELLED Synthetic filters made from fibers carrying electrostatic charges and fiberglass filters that do not carry electrostatic charges are both utilized commonly in heating, ventilating, and air-conditioning (HVAC) systems. The pressure drop and efficiency of a bank of fiberglass filters and a bank of electrostatically charged synthetic filters were measured repeatedly for 13 weeks in operating HVAC systems at a hospital. Additionally, the efficiency with which new and used fiberglass and synthetic filters collected culturable biological particles was measured in a test apparatus. Pressure drop measurements adjusted to equivalent flows indicated that the synthetic filters operated with a pressure drop less than half that of the fiberglass filters throughout the test. When measured using total ambient particles, synthetic filter efficiency decreased during the test period for all particle diameters. For particles 0.7-1.0 mum in diameter, efficiency decreased from 92% to 44%. It is hypothesized that this reduction in collection efficiency may be due to charge shielding. Efficiency did not change significantly for the fiberglass filters during the test period. However, when measured using culturable biological particles in the ambient air, efficiency was essentially the same for new filters and filters used for 13 weeks in the hospital for both the synthetic and fiberglass filters. It is hypothesized that the lack of efficiency reduction for culturable particles may be due to their having higher charge than non-biological particles, allowing them to overcome the effects of charge shielding. The type of particles requiring capture may be an important consideration when comparing the relative performance of electrostatically charged synthetic and fiberglass filters. PRACTICAL IMPLICATIONS Electrostatically charged synthetic filters with high initial efficiency can frequently replace traditional fiberglass filters with lower efficiency in HVAC systems because properly designed synthetic filters offer less resistance to air flow. Although the efficiency of charged synthetic filters at collecting non-biological particles declined substantially with use, the efficiency of these filters at collecting biological particles remained steady. These findings suggest that the merits of electrostatically charged synthetic HVAC filters relative to fiberglass filters may be more pronounced if collection of biological particles is of primary concern.
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Affiliation(s)
- P C Raynor
- Division of Environmental Health Sciences, University of Minnesota, Minneapolis, MN 55455, USA.
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Jonnavithula N, Durga P, Kulkarni DK, Ramachandran G. Bilateral intra-oral, infra-orbital nerve block for postoperative analgesia following cleft lip repair in paediatric patients: comparison of bupivacaine vs bupivacaine-pethidine combination. Anaesthesia 2007; 62:581-5. [PMID: 17506736 DOI: 10.1111/j.1365-2044.2007.05028.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This prospective, randomised, double blind study compared the efficacy of pethidine as an adjuvant to bupivacaine with the efficacy of bupivacaine alone for infra-orbital nerve block in alleviating postoperative pain in children undergoing cleft lip repair. Forty paediatric patients aged between 5 and 60 months undergoing cleft lip repair were randomly allocated to two groups of 20. After tracheal intubation, group B received bilateral intra-oral, infra-orbital nerve block with 1 ml of 0.25% bupivacaine on each side and group P received 1 ml of 0.25% bupivacaine along with 0.25 mg.kg(-1) body weight pethidine. Sedation after recovery from anaesthesia was assessed using the University of Michigan Sedation Scale (UMSS) and pain was assessed postoperatively up to 36 h using the FLACC scale (Face, Legs, Activity, Cry, Consolability). The median (IQR) duration of analgesia from the time of administration of block in group B was 18 h (14.2-20) compared to 29.1 h (24-36) in group P (p = 0.001). Addition of pethidine as an adjunct to local anaesthetic significantly prolonged the duration of postoperative analgesia without any adverse effects.
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Affiliation(s)
- N Jonnavithula
- Nizam's Institute of Medical Sciences, Hyderabad-500082, India.
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Alexander BH, Ramachandran G, Hoftbeck RW, Rice C. Silicosis and Lung Burden From Respirable Silica and Non-Silica Exposure. Am J Epidemiol 2006. [DOI: 10.1093/aje/163.suppl_11.s157-d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Mönkkönen P, Pai P, Maynard A, Lehtinen KEJ, Hämeri K, Rechkemmer P, Ramachandran G, Prasad B, Kulmala M. Fine particle number and mass concentration measurements in urban Indian households. Sci Total Environ 2005; 347:131-47. [PMID: 16084974 DOI: 10.1016/j.scitotenv.2004.12.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2004] [Accepted: 12/17/2004] [Indexed: 05/03/2023]
Abstract
Fine particle number concentration (D(p)>10 nm, cm(-3)), mass concentrations (approximation of PM(2.5), microg m(-3)) and indoor/outdoor number concentration ratio (I/O) measurements have been conducted for the first time in 11 urban households in India, 2002. The results indicate remarkable high indoor number and mass concentrations and I/O number concentration ratios caused by cooking. Besides cooking stoves that used liquefied petroleum gas (LPG) or kerosene as the main fuel, high indoor concentrations can be explained by poor ventilation systems. Particle number concentrations of more than 300,000 cm(-3) and mass concentrations of more than 1000 microg m(-3) were detected in some cases. When the number and mass concentrations during cooking times were statistically compared, a correlation coefficient r>0.50 was observed in 63% of the households. Some households used other fuels like wood and dung cakes along with the main fuel, but also other living activities influenced the concentrations. In some areas, outdoor combustion processes had a negative impact on indoor air quality. The maximum concentrations observed in most cases were due to indoor combustion sources. Reduction of exposure risk and health effects caused by poor indoor air in urban Indian households is possible by improving indoor ventilation and reducing penetration of outdoor particles.
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Affiliation(s)
- P Mönkkönen
- University of Helsinki, Department of Physical Sciences, P.O. Box 64, 00014 Helsinki, Finland.
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Ramachandran G, Santha T, Garg R, Baskaran D, Iliayas SA, Venkatesan P, Fathima R, Narayanan PR. Vitamin A levels in sputum-positive pulmonary tuberculosis patients in comparison with household contacts and healthy 'normals'. Int J Tuberc Lung Dis 2004; 8:1130-3. [PMID: 15455600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023] Open
Abstract
OBJECTIVE To estimate serum vitamin A in pulmonary tuberculosis (PTB) patients at the start and end of anti-tuberculosis treatment. DESIGN Serum vitamin A was estimated in 47 PTB patients (pre and post treatment), 46 healthy household contacts and 30 healthy 'normals'. RESULTS Mean serum vitamin A in patients at the start of treatment was 21.2 microg/dl, which was significantly lower than in household contacts (42.2 microg/dl) and healthy 'normals' (48.1 microg/dl). The vitamin A levels in patients increased following treatment. CONCLUSION The low vitamin A levels observed in patients returned to normal at the end of anti-tuberculosis treatment without vitamin A supplementation.
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Vincent JH, Ramachandran G, Kerr SM. Particle size and chemical species 'fingerprinting' of aerosols in primary nickel production industry workplaces. J Environ Monit 2001; 3:565-74. [PMID: 11785627 DOI: 10.1039/b105848g] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A field study was conducted at a range of worksites at a number of plants, for two companies, in the primary nickel production industry. The aim of the field study was to provide direct measurements of the distributions of both particle size and relevant nickel species groups (soluble, sulfidic, metallic and oxidic). and to use the data to characterize health-relevant aerosol exposures of workers at the worksites in question. Since there was no commercially-available sampler that could provide samples of sufficient quantity to enable chemical speciation for the species fractions of interest, as well as particle size distribution information, new instrumentation was developed, based on a modified version of the Andersen cascade impactor, incorporating a porous foam media top stage that produced particle classification over the upper end of the inhalable range (Kerr, Vincent and Ramachandran, Annals of Occupational Hygiene, 2001, in the press). This modified-Andersen sampler was used in extensive field studies, along with other sampling instruments, including, in particular, the IOM personal inhalable aerosol sampler. The results of the field study provided results that could be represented succinctly in terms of the distributions of the four nickel species groups and the three health-related particle-size fractions: inhalable, thoracic and respirable. They showed that, for practical purposes, the distributions of the four nickel species groups were consistently uniform across the full range of particle-size distribution. For the purpose of characterizing the distribution of nickel species for each worksite, this finding enabled incorporation of additional data taken at those same sites using the IOM personal inhalable aerosol sampler. This yielded a data set sufficient to permit the development of exposure 'fingerprints' for each worksite. Such 'fingerprints' make it possible for the occupational hygienists at the plants in question to estimate workers' exposure to individual nickel species fractions based on measurement only of overall inhalable nickel. In addition, by reference to the differing threshold limit values (TLV) for the various nickel species, the 'fingerprints' also allow the individual worksites to be characterized by hazard indices (in the form of 'equivalent sulfidic fractions', or ESFs) that reflect the weightings of the risks experienced by workers at each worksite.
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Affiliation(s)
- J H Vincent
- Department of Environmental Health Sciences, School of Public Health University of Michigan, Ann Arbor 48109-2029, USA
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Ramachandran G. Retrospective exposure assessment using Bayesian methods. Ann Occup Hyg 2001; 45:651-67. [PMID: 11718661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
This paper presents the application of a Bayesian framework for retrospective exposure assessment of workers in a nickel smelter. Using only sparsely available historical measurements will result in exposure estimates with large uncertainties. However, additional information, in the form of expert judgments informed by knowledge of historical plant conditions, can be brought to bear on this process. The experts are provided with an information packet that contains historical process information, process throughput levels for each year, the dimensions of the workplace, ventilation records, and task descriptions for each job category. Based on this information, the experts provide subjective prior probability distributions for input parameters to a general ventilation model that predicts building concentrations. These priors can be synthesized with the historical measurements using Bayes theorem. The prior distributions of exposures are updated using the average measured exposures (historical measurements) and their associated variances to obtain the posterior probability distributions for building concentrations as well as concentrations at specific locations in the building. Expert input was also obtained from a plant industrial hygienist, in the form of probability distributions, regarding the amounts of time spent by each job category in different locations in the building. Monte Carlo sampling, from the posterior probability distributions of concentrations in different micro-environments and the probability distributions of time spent by each job category in those micro-environments, was used to obtain worker exposures using a time-weighted averaging model.
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Affiliation(s)
- G Ramachandran
- Division of Environmental and Occupational Health, School of Public Health, University of Minnesota, Mayo Mail Code 807, 420 Delaware Street SE, Minneapolis, MN 55455, USA.
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Kerr SM, Vincent JH, Ramachandran G. A new approach to sampling for particle size and chemical species "fingerprinting" of workplace aerosols. Ann Occup Hyg 2001; 45:555-68. [PMID: 11583657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
A commercially-available, high-volume (28.3 Lpm) Andersen-type cascade impactor was modified in order to extend its operational range further into the range of large inhalable particles for purposes of use in an exposure assessment study in the primary nickel production industry. The modification involved incorporating a 10-ppi (pores per inch) porous plastic foam top stage that has a wide penetration curve with a (50)d(ae)-value of approximately 27 microm. This enabled the upper end of the range of the instrument to be extended from about 10 to greater than 70 microm. The inlet of the original instrument was also modified to incorporate the new top stage and provide "representative" aspiration of total airborne particulate with an efficiency of close to 100% over the range of aerodynamic particle sizes of interest. A mathematical inversion algorithm developed in earlier research was modified so that it could be applied to this new instrument. This enabled raw data on particulate material recovered from all stages of the instrument (including the new porous foam top stage) to be used for the determination of continuous particle size distributions, as well as chemical speciation, over the inhalable range. The new instrument was deployed in a pilot field study in the nickel primary production industry by which to demonstrate the potential of the new instrument for generating useful information pertaining to health-relevant aerosol size tractions (e.g., inhalable, thoracic, and respirable), and for soluble, sulphidic, metallic, oxidic and total nickel chemical species groups.
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Affiliation(s)
- S M Kerr
- Division of Environmental and Occupational Health, School of Public Health, University of Minnesota, Minneapolis, MN 55455, USA
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Cross DP, Ramachandran G, Wattenberg EV. Mixtures of nickel and cobalt chlorides induce synergistic cytotoxic effects: implications for inhalation exposure modeling. Ann Occup Hyg 2001; 45:409-18. [PMID: 11418091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Workers are often simultaneously exposed to two or more chemicals, yet little is known about the toxicity of most chemical mixtures. The traditional assumption, in the absence of further information, has been that the chemical components of a mixture have mutually independent effects, and the toxic response to multiple chemicals is additive. The data presented here show that mixtures of NiCl(2) and CoCl(2) induce a synergistic (that is, greater than additive) toxic response in cell culture. Immortalized alveolar epithelial type II cells were incubated for 4 h with various concentrations of either NiCl(2), CoCl(2), or NiCl(2) and CoCl(2) together, and cell viability assessed 24 h later. The LD(50) for NiCl(2) was 5.7 mM. CoCl(2), with an LD(50) of 1.1 mM, was about five times more potent than NiCl(2). Mixtures of NiCl(2) and CoCl(2) decreased cell viability synergistically. For example, a mixture of 750 microM NiCl(2) and 750 microM CoCl(2) reduced cell viability by more than three times the value predicted by the additive approach. We used concentration-response data from these studies in a mathematical model; this model describes the equivalent inhalation exposure to an aerosol composed of a mixture of chemicals with different toxicities and also accounts for synergistic responses to these chemicals. Our results along with previous studies using an animal model suggest that these synergisms should be taken into account when conducting future exposure assessments.
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Affiliation(s)
- D P Cross
- Division of Environmental and Occupational Health, School of Public Health, University of Minnesota, Mayo Mail Code 807, 420 Delaware Street SE, 55455, Minneapolis, MN, USA
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Sexton K, Greaves IA, Church TR, Adgate JL, Ramachandran G, Tweedie RL, Fredrickson A, Geisser M, Sikorski M, Fischer G, Jones D, Ellringer P. A school-based strategy to assess children's environmental exposures and related health effects in economically disadvantaged urban neighborhoods. J Expo Anal Environ Epidemiol 2000; 10:682-94. [PMID: 11138660 DOI: 10.1038/sj.jea.7500132] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/15/2023]
Abstract
The School Health Initiative: Environment, Learning, Disease (SHIELD) study is a novel school-based investigation of children's environmental health in economically disadvantaged urban neighborhoods of Minneapolis. This article describes the study design and summarizes lessons learned about recruiting and monitoring this historically understudied population. The SHIELD study focused on measuring children's exposures to multiple environmental stressors [volatile organic chemicals (VOCs), environmental tobacco smoke, allergens, bioaerosols, metals, pesticides, polychlorinated biphenyls (PCB), phthalates] and exploring related effects on respiratory health (e.g., lung function) and learning outcomes (e.g., standardized test scores, academic achievement). It involved intensive exposure monitoring, including environmental measurements inside and outside the children's schools and inside their homes, personal measurements with passive dosimeters worn by the children, and biological marker measurements in blood and urine. The SHIELD participants comprised a stratified random sample of 153 "index" children and 51 of their siblings enrolled in grades 2-5 at two adjacent elementary schools. The Minneapolis Public Schools (MPS) assisted with identifying, contacting, recruiting, and monitoring this population, which traditionally is difficult to study because families/children are highly mobile, speak a diversity of languages, frequently do not have a telephone, endure economic hardships, often do not trust researchers, and have a spectrum of unconventional lifestyles and living arrangements. Using a school-based approach, the overall SHIELD enrollment (response) rate was 56.7%, with a wide disparity between English-speaking (41.7%) and non-English-speaking (71.0%) families/children. Most children remained involved in the study through both monitoring sessions and exhibited an acceptable degree of compliance with study protocols, including providing blood and urine samples. Results indicate that it is both practical and affordable to conduct probability-based exposure studies in this population, but that it is also important to improve our understanding of factors (e.g., cultural, economic, psychological, social) affecting the willingness of families/children to participate in such studies, with special emphasis on developing cost-effective recruitment methods.
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Affiliation(s)
- K Sexton
- School of Public Health, University of Minnesota, Minneapolis 55455, USA.
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Ramachandran G, Adgate JL, Hill N, Sexton K, Pratt GC, Bock D. Comparison of short-term variations (15-minute averages) in outdoor and indoor PM2.5 concentrations. J Air Waste Manag Assoc 2000; 50:1157-66. [PMID: 10939209 DOI: 10.1080/10473289.2000.10464160] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Measurements of 15-min average PM2.5 concentrations were made with a real-time light-scattering instrument at both outdoor (central monitoring sites in three communities) and indoor (residential) locations over two seasons in the Minneapolis-St. Paul metropolitan area. These data are used to examine within-day variability of PM2.5 concentrations indoors and outdoors, as well as matched indoor-to-outdoor (I/O) ratios. Concurrent gravimetric measurements of 24-hr average PM2.5 concentrations were also obtained as a way to compare real-time measures with this more traditional metric. Results indicate that (1) within-day variability for both indoor and outdoor 15-min average PM2.5 concentrations was substantial and comparable in magnitude to day-to-day variability for 24-hr average concentrations; (2) some residences exhibited substantial variability in indoor aerosol characteristics from one day to the next; (3) peak values for indoor short-term (15-min) average PM2.5 concentrations routinely exceeded 24-hr average outdoor values by factors of 3-4; and (4) relatively strong correlations existed between indoor and outdoor PM2.5 concentrations for both 24-hr and 15-min averages.
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Affiliation(s)
- G Ramachandran
- Division of Environmental and Occupational Health, School of Public Health, University of Minnesota, Minneapolis, USA
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Kandaswamy D, Ramachandran G, Maheshwari S, Mohan B. Bone regeneration using hydroxyapatite crystals for periapical lesions. Endodontology 2000. [DOI: 10.4103/0970-7212.351781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Sreenath A, Vincent JH, Ramachandran G. New experimental studies of the basic performance characteristics of aerosol samplers. Appl Occup Environ Hyg 1999; 14:624-31. [PMID: 10510525 DOI: 10.1080/104732299302431] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The study of the basic physical performance characteristics of aerosol samplers, like those used in the occupational hygiene setting, will provide insights to enable the improved development of new instruments and cost-effective testing procedures. These will be required as the new particle size-selective sampling criteria become the basis of new occupational exposure standards. A new body of work is being conducted, in which the factors influencing sampler performance are being investigated using idealized samplers of spherical shape in small wind tunnels. By the experimental methods described, a large amount of performance data can be acquired in a very short time. The results for wide ranges of particle size, wind speed, sampling flow rate, and sampler orientation conditions show that there are strong trends as functions of these variables. Those trends are very complicated. But it is encouraging that they are broadly consistent with recent semi-empirical models, suggesting that extensions of that type of modelling approach--supported by the large amount of new experimental data now being generated by such experiments--might provide new models of aerosol sampler performance accessible to researchers and occupational hygienists.
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Affiliation(s)
- A Sreenath
- Division of Environmental and Occupational Health, School of Public Health, University of Minnesota, Minneapolis, USA
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