Evaluation of cardiac biomarkers in children with acute severe bronchial Asthma-A prospective study from tertiary care center in northern India

OBJECTIVES

During the attacks of acute severe bronchial asthma there are marked cardiopulmonary changes leading to hypoxia. The study aims to find the incidence of myocardial dysfunction in patients of acute severe bronchial asthma based on cardiac enzyme levels at admission and see whether the myocardial damage is transient or persistent even after stabilization of the patient based on enzyme levels at discharge.

MATERIALS AND METHODS

This prospective, case control study was done at Department of Pediatrics, Institute of Medical Sciences, Banaras Hindu University between October 2016 to May 2018. Sixty pediatric patients of acute severe bronchial asthma were taken as cases and 15 age and sex matched children served as controls. Blood samples were collected in Ethylene diamine tetra acetic acid vials before the start of treatment, for measurement of cardiac biomarkers Troponin I (TnI), Brain natriuretic peptide (BNP) and Creatine Kinase-muscle/brain (CK-MB) and repeat samples were taken before discharge.

RESULTS

Fifty percent of the cases had abnormal TnI levels, 15% had abnormal CK-MB levels and 8.3% had abnormal BNP levels at admission. At discharge, only 1 (1.7%) case had abnormal levels of CK-MB, whereas the levels of TnI and BNP normalized in all. The level of cardiac biomarkers were significantly raised at admission when compared to discharge values (p value < 0.001).

CONCLUSIONS

The raised cardiac biomarkers suggest myocardial stress during acute exacerbation of bronchial asthma. Though, the present study showed that the changes are of transient nature, larger follow up studies are required to document any permanent damage to myocardium.

Higher Frequency of HIV-1 Drug Resistance and Increased Nucleoside Reverse Transcriptase Inhibitor Mutations among the HIV-1 Positive Antiretroviral Therapy-Naïve patients Coinfected With Mycobacterium tuberculosis Compared With Only HIV Infection in India

Background:

Emergence of human immunodeficiency virus (HIV) drug resistance mutations prior to highly active antiretroviral therapy is a serious problem in clinical management of HIV/AIDS. Risk factors for appearance of drug resistance mutations are not known. We hypothesize that Mycobacterium tuberculosis infection may contribute to rapid emergence of such mutations in antiretroviral therapy–naïve patients.

Methods:

A total of 115 patients were recruited in this study of which 75 were HIV+TB+ coinfected (group 1) and 40 were HIV+TB− (group 2). Blood samples from all the patients were collected and CD4+ cell counts; HIV-1 plasma viral load and sequencing of protease and two-third region of reverse transcriptase of HIV-1 was performed and analyzed for drug resistance pattern.

Results:

For patients with HIV+TB+, 10.6% (8/75) had mutations to non-nucleoside reverse transcriptase inhibitors (NNRTIs), 4% (3/75) to nucleoside reverse transcriptase inhibitors, and only 2.6% (2/75) patients had mutations to protease inhibitors. Interestingly, for group 2 (HIV+TB−), there were only NNRTI mutations found among these patients, and only 3 patients (7.5%) had these drug-resistant mutations. Clade typing and phylogenetic tree analysis showed HIV-1 subtype C predominance in these patients.

Conclusions:

Our study showed that higher percentage of HIV drug resistance mutations was found among HIV+TB+ individuals compared with tuberculosis-uninfected patients. Tuberculosis coinfection may be a risk factor for emergence of high frequency of drug resistance mutations. Studies with a larger sample size will help to confirm these findings from the Indian population.

Hemostatic Parameters in Newborn - II. Sequential Study During the First Four Weeks of Life

A sequential study of kaolin cephalin clotting time (KCCT), prothrombin time (PT), thrombin time (TT), plasma fibrinogen and serum FDP was conducted during the first four weeks of life on term and preterm babies. A “physiological dip” of PT and TT was noted inappropriate for gestational age (AGA) babies both term and preterm; in case of KCCT, the dip was significant in term AGA babies only. At the end of four weeks, PT and TT had moderately improved in term babies but showed little improvement in preterm ones; KCCT reached almost an adult value in all babies except in preterm AGA and term LGA (large for gestational age) ones. Plasma fibrinogen showed no “physiological dip” and reached adult level in two to four weeks. Serum FDP levels were appreciably raised in preterm AGA babies only at birth and there too normalised by 72 h.

Hemostatic Parameters in Newborn - I. Effect of Gestation and Rate of Intrauterine Growth

The present study comprises of 208 term, 159 preterm and 18 post-term neonates born to mothers with no history of drug intake or any disease likely to effect coagulation of the newborn. PT, TT and KCCT were relatively prolonged and plasma fibrinogen reduced to varying degree in newborns (as compared to adults). There was further prolongation of TT and reduction in plasma fibrinogen levels amongst preterm newborns as compared to term babies; TT was more prolonged amongst post-term babies also. PT was significantly more prolonged till 30 weeks of gestation, after which a near plateau was formed. KCCT showed significant improvement after 33 weeks and a further trend to normalisation after 38 weeks of gestation. Serum FDP values showed too much of variation for any meaningful statistical analysis but generally FDPs were higher in preterm babies. Intrauterine growth rate had no significant effect on these parameters amongst preterms -similar values for SGA (small for gestational age), AGA (appropriate for gestational age) and LGA (large for gestational age). On the other hand, amongst term babies SGA neonates had significantly prolonged PT and low plasma fibrinogen as compared to AGA; LGA babies also showed more prolongation of TT as compared to AGA.

Impact of HIV infection and highly active antiretroviral therapy (HAART) on B cell subpopulations in children

B-cells play an important role in defending children against various infections. In view of scare data, we undertook this prospective cohort study to describe B cell compartment in HIV infected children (<5 years of age) and the effect of HAART on B cell subpopulations. HIV infected children (<5 years) from Pediatric HIV services of the Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, were recruited (April 2012-December 2015). The enrolled HIV-1 infected children (n = 59) were followed up regularly for 12 months; healthy controls (n = 51) included HIV uninfected children with no major illness. Flow cytometry was performed on fresh EDTA-treated blood samples to characterize B cell subpopulations. In HIV-infected children, marked depletion of naive (P = 0.003), non-switched memory (P = 0.02), mature (P = 0.0005), resting memory (P < 0.0001) B cells, and expansion of double negative memory (P < 0.0001), activated memory (P < 0.0001) and tissue like memory (P < 0.0001) B cells were observed as compared to healthy controls. In children started on HAART, at the end of 12 months of therapy, frequencies of non-switched memory (P = 0.04), switched memory (P = 0.01), and resting memory (P = 0.003) B cells were lower; activated memory (P = 0.04), and tissue-like memory (P = 0.0001) B cells were still higher than healthy controls. HIV infection resulted in reduced memory B cells in HIV infected children. Following HAART, there was normalization of some B cell subpopulations. The study emphasizes the need of re-vaccination in HIV infected children to maintain the memory B cell pool and adequate humoral immune response against infections.

Vibrational spectroscopic and computational studies on diisopropylammonium bromide

Diisopropylammonium bromide (DIPAB) can be crystallized either in an orthorhombic (P2₁2₁2₁) or in a monoclinic (P2₁) structure at room temperature depending on synthesis conditions. The non-polar orthorhombic structure exhibits a subtle, irreversible transformation into the ferroelectric monoclinic-II (m-II) phase above ~421K. At a slightly higher temperature of 426K this m-II (P2₁) phase reversibly transforms into a disordered, paraelectric monoclinic-I (P2₁/m) structure. We synthesized DIPAB in the orthorhombic structure, heated it to obtain the m-II phase and carried out a systematic study of their Raman and IR spectra. We obtained the phonon irreducible representations from factor group analysis of the orthorhombic and m-II structures based on the reported structural information. DIPAB is an organic molecular crystal, and the vibrational spectra in the intramolecular region (200-3500cm^-1) of the two different phases are identical to each other, indicating weak inter-molecular interactions in both crystalline structures. In the low wavenumber region (10-150cm^-1) the Raman spectra of the two phases are different due to their sensitivity to molecular environment. We also carried out first principles calculations using Gaussian 09 and CASTEP codes to analyze the vibrational frequencies. Mode assignments were facilitated by isolated molecule calculations that are also in good agreement with intramolecular vibrations, whereas CASTEP (solid state) results could explain the external modes.

Evolution of cross-neutralizing antibodies and mapping epitope specificity in plasma of chronic HIV-1-infected antiretroviral therapy-naïve children from India

Delineating the factors leading to the development of broadly neutralizing antibodies (bnAbs) during natural HIV-1 infection and dissecting their epitope specificities generates useful information for vaccine design. This is the first longitudinal study to assess the plasma-neutralizing antibody response and neutralizing determinants in HIV-1-infected children from India. We enrolled 26 and followed up 20 antiretroviral therapy (ART)-naïve, asymptomatic, chronic HIV-1-infected children. Five (19.2 %) baseline and 10 (50 %) follow-up plasma samples neutralized ≥50 % of subtypes A, B and C tier 2 viruses at an ID50 titre ≥150. A modest improvement in neutralization breadth and potency was observed with time. At baseline, subtype C-specific neutralization predominated (P=0.026); interestingly, follow-up samples exhibited cross-neutralizing activity. Epitope mapping revealed V3C reactive antibodies with significantly increased Max50 binding titres in follow-up samples from five infected children; patient #4's plasma antibodies exhibited V3-directed neutralization. A salient observation was the presence of CD4 binding site (CD4bs)-specific NAbs in patient #18 that improved with time (1.76-fold). The RSC3 wild-type (RSC3WT) protein-depleted plasma eluate of patient #18 demonstrated a more than 50% ID50 decrease in neutralization capacity against five HIV-1 pseudoviruses. Further, the presence of CD4bs-neutralizing determinants in patient #18's plasma was confirmed by the neutralizing activity demonstrated by the CD4bs-directed IgG fraction purified from this plasma, and competition with sCD4 against JRFLgp120, identifying this paediatric donor as a potential candidate for the isolation of CD4bs-directed bnAbs. Overall, we observed a relative increase in plasma-neutralizing activity with time in HIV-1-infected children, which suggests that the bnAbs evolve.

Coagulase-negative staphylococci causing blood stream infection at an Indian tertiary care hospital: Prevalence, antimicrobial resistance and molecular characterisation

INTRODUCTION

Recent years have seen a rise of coagulase-negative staphylococci (CoNS) from common contaminants to agents of nosocomial blood stream infections (BSI's). Molecular typing and establishing a correlation with antibiotic resistance is essential particularly in countries like India where genotyping studies for drug-resistant CoNS are sparse.

METHODS

A prospective study was done over 18 months, wherein 42,693 blood samples were received, and 59 patients with BSI due to CoNS were evaluated. The isolates recovered were identified by a biochemical test panel and matrix-assisted laser desorption ionization - time of flight mass spectrometry followed by antimicrobial susceptibility testing by Kirby-Baur disc diffusion method and E-test strips. Staphylococcal chromosomal cassette mec (SCCmec) element was characterised by multiplex polymerase chain reaction for all methicillin-resistant (MR) isolates.

RESULTS

The majority of CoNS isolated were constituted by Staphylococcus haemolyticus (47.5%) followed by Staphylococcus epidermidis (33.9%), Staphylococcus hominis (11.86%), Staphylococcus cohnii (5.08%) and Staphylococcus warneri (1.69%). Among all isolates 57.6% were MR with statistically significant higher resistance versus methicillin sensitive-CoNS. This difference was significant for erythromycin (76% vs. 44%, P = 0.011), rifampicin (50% vs. 12%,P= 0.002) and amikacin (26.5% vs. 4%, P = 0.023), ciprofloxacin (64.7% vs. 20%, P = 0.001) and cotrimoxazole (55.9% vs. 20%, P = 0.006). SCCmec type I was predominant (61.8%, P = 0.028) and exhibited multidrug resistance (76.2%). Coexistence of SCCmec type I and III was seen in 8.82% MR isolates.

CONCLUSION

CoNS exhibit high antimicrobial resistance thereby limiting treatment options. The presence of new variants of SCCmec type in hospital-acquired CoNS may predict the antibiotic resistance pattern. This is the first evaluation of the molecular epidemiology of CoNS causing BSI from India and can serve as a guide in the formulation of hospital infection control and treatment guidelines.

Molecular characterisation of antimicrobial resistance in Pseudomonas aeruginosa and Acinetobacter baumannii during 2014 and 2015 collected across India

BACKGROUND

Surveillance of antimicrobial resistance (AMR) is of great importance. Pseudomonas aeruginosa and Acinetobacter baumannii are important pathogens and emergence of resistance in these have increased the morbidity and mortality rates. This surveillance study was initiated by the Government of India - Indian Council of Medical Research. The aim of this study is to determine the antimicrobial susceptibility profile and to characterise the enzyme mediated antimicrobial resistance such as extended spectrum beta-lactamases (ESBLs) and carbapenemases among multidrug-resistant (MDR) P. aeruginosa and A. baumannii.

MATERIALS AND METHODS

A multi-centric study was conducted from January 2014 to December 2015 with a total number of 240 MDR P. aeruginosa and 312 MDR A. baumannii isolated from blood, cerebrospinal fluid, respiratory, pus, urine and intra-abdominal infections. Kirby-Bauer disc diffusion was done to determine the antimicrobial susceptibility profile. Further, MDR isolates were characterised by multiplex polymerase chain reaction to determine the resistance genes for ESBLs and carbapenemases.

RESULTS

Among the ESBLs, blaVEB (23%), blaTEM (5%) and blaSHV (0.4%) in P. aeruginosa and blaPER (54%), blaTEM (16%) and blaSHV (1%) in A. baumannii were the most prevalent. Likewise, blaVIM (37%), blaNDM (14%), blaGES (8%) and blaIMP (2%) in P. aeruginosa and blaOXA-23like (98%), blaOXA-58like (2%), blaNDM (22%) and blaVIM (3%) in A. baumannii were found to be the most prevalent carbapenemases. blaOXA-51like gene, intrinsic to A. baumannii was present in all the isolates tested.

CONCLUSION

The data shown highlight the wide difference in the molecular mechanisms of AMR profile between P. aeruginosa and A. baumannii. In P. aeruginosa, plasmid-mediated mechanisms are much lesser than the chromosomal mediated mechanisms. In A. baumannii, class D oxacillinases are more common than other mechanisms. Continuous surveillance to monitor the trends in AMR among MDR pathogens is important for implementation of infection control and to guide appropriate empirical antimicrobial therapy.

What puts them at risk? A cross-sectional case-control survey of demographic profile and sexual behavior of patients with sexually transmitted infections at a tertiary care center in North India

BACKGROUND

Sexually transmitted infections (STIs) are a major public health problem in developing nations. Identification of risk factors can help in formulating effective strategies against them. The present study was conducted in a tertiary care hospital in North India over 1 year to identify the risk factors associated with STIs.

MATERIALS AND METHODS

A questionnaire-based cross-sectional case-control survey was conducted where participants answered questions on demographic details, sexual behavior, and awareness of STIs. Cases were patients with STIs whereas controls were randomly selected from healthy individuals accompanying patients with nonvenereal complaints attending our hospital.

RESULTS

There were 106 cases and 64 controls. STI patients had sexual debut 2 years before controls. A higher proportion of STI cases had lower education, multiple sexual partners, lived separately from their partner, had nonregular partners, had protected sex in the last month, had sex under influence of alcohol/illicit drugs, sex in unstructured settings, and engaged in transactional sex, in comparison to controls (P < 0.05). More cases were aware of the symptoms/preventive measures of STIs (P < 0.001). On multivariate analysis, multiple sexual partners, sex under influence of alcohol/illicit drugs with nonregular partner, protected sex in the last month, and knowledge of preventive measures were found to be statistically associated with STIs (P < 0.05).

CONCLUSIONS

Our study identifies risk-behavior patterns in patients with STIs, which should be modified to reduce the burden of these diseases. Increasing the knowledge about STIs in these patients can translate into more common condom usage that lends support for strengthening sexual health programs at grass-root levels.

LIMITATIONS

The small size of the study population could have led to decreased power of the study to detect differences between cases and controls. The external validity of our results needs to be tested in different population groups involving larger sample sizes.

What puts them at risk? A cross-sectional case-control survey of demographic profile and sexual behavior of patients with sexually transmitted infections at a tertiary care center in North India

BACKGROUND

Sexually transmitted infections (STIs) are a major public health problem in developing nations. Identification of risk factors can help in formulating effective strategies against them. The present study was conducted in a tertiary care hospital in North India over 1 year to identify the risk factors associated with STIs.

MATERIALS AND METHODS

A questionnaire-based cross-sectional case-control survey was conducted where participants answered questions on demographic details, sexual behavior, and awareness of STIs. Cases were patients with STIs whereas controls were randomly selected from healthy individuals accompanying patients with nonvenereal complaints attending our hospital.

RESULTS

There were 106 cases and 64 controls. STI patients had sexual debut 2 years before controls. A higher proportion of STI cases had lower education, multiple sexual partners, lived separately from their partner, had nonregular partners, had protected sex in the last month, had sex under influence of alcohol/illicit drugs, sex in unstructured settings, and engaged in transactional sex, in comparison to controls (P < 0.05). More cases were aware of the symptoms/preventive measures of STIs (P < 0.001). On multivariate analysis, multiple sexual partners, sex under influence of alcohol/illicit drugs with nonregular partner, protected sex in the last month, and knowledge of preventive measures were found to be statistically associated with STIs (P < 0.05).

CONCLUSIONS

Our study identifies risk-behavior patterns in patients with STIs, which should be modified to reduce the burden of these diseases. Increasing the knowledge about STIs in these patients can translate into more common condom usage that lends support for strengthening sexual health programs at grass-root levels.

LIMITATIONS

The small size of the study population could have led to decreased power of the study to detect differences between cases and controls. The external validity of our results needs to be tested in different population groups involving larger sample sizes.

Diminished IL-17A levels may protect filarial-infected individuals from development of rheumatoid arthritis and systemic lupus erythematosus

Nematode infections have been observed to inversely correlate with autoimmune disorders. Recently, we have shown the absence of filarial infection in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) who live in filarial-endemic areas. The mechanism(s) by which filarial-infected individuals are protected against the development of RA or SLE are unknown. In mice CIA, an experimental model for RA, ES-62, an execratory product of rodent filarial nematode , has been shown to improve arthritis through suppression of the IL-17 pathway. A total of 160 individuals, 40 each of endemic normal, filarial-infected cases, SLE and RA patients, from filarial-endemic areas, were enrolled in the study. Plasma levels of IL17-A, IFN-α and TNF-α were quantified by enzyme-linked immunosorbent assay (ELISA). RA and SLE patients displayed significantly higher plasma IL-17A, IFN-α and TNF-α levels compared to endemic normal and infected individuals. Furthermore, IL-17A levels were significantly low in participants with filarial infection compared to endemic controls ( p < 0.05). Interestingly, plasma IL-17A levels correlated inversely with circulating filarial antigen (CFA) ( p = 0.004, Spearman r = −0.51). Filarial infection was associated with low plasma IL-17A levels, a mechanism by which it possibly protects individuals in filarial-endemic areas from the development of autoimmune disorders like RA and SLE.

Seasonality and Antimicrobial Resistance Pattern of Vibrio Cholerae in a Tertiary Care Hospital of North India

We retrospectively analysed the seasonal distribution of cholera and the antimicrobial resistance pattern of Vibrio cholerae isolates over a 5-year period from January 1998 to December 2002. Of 3213 stool specimens processed from 3213 patients with acute watery diarrhoea during this period, 431 samples (13.4%) were found positive for V. cholerae. There were 423 V. cholerae Ol biotype E1Tor, 2 V. cholerae 0139 and six isolates of non-01 non-0139. The highest number of cholera cases occurred in May-June followed by July-August. Cases started appearing in April for all years except in the year 2002 when three cases occurred in the first week of March. A large number (90.25% strains) were resistant to at least one antibiotic.

Declining trends of Syphilis seroprevalance among antenatal clinic cases and STD clinic cases in a tertiary care centre: from January 2002 to December 2012

Syphilis affects nearly 1.36 million pregnant women, majority of these cases being concentrated in the developing countries. We aimed at analysing the 11 years' trends in syphilis seroprevalence in antenatal clinics (ANC) and STD clinic cases. Laboratory data of syphilis cases from 2002-2012 were retrospectively analysed. Out of the total 73,642 cases, 393 (0.53%) tested positive for Syphilis. A statistically significant decline in syphilis prevalence was found in both ANC and STD clinic cases. The efforts of various interventional programs should continue to make the screening and treatment facilities readily accessible to continue the decline in syphilis seropositivity.

Urine Nested Polymerase Chain Reaction in Neonatal Septicemia

This cross-sectional study was done to evaluate diagnostic efficacy of urine nested polymerase chain reaction (PCR) using broad-range 16SrDNA PCR-based amplification, followed by restriction analysis and sequencing in neonatal septicemia. The study included 50 babies; 48% had vaginal delivery, 46% were preterm, 20% had a history of prolonged rupture of membranes and 56% were low birth weight (≤2500 g). Clinical presentations were lethargy (96%), respiratory distress (80%) and bleeding diathesis (16%). Absolute neutrophil count <1800/mm(3) was observed in 60%, and positive C-reactive protein in 46%. Thirty neonates had positive blood culture, and Klebsiella pneumoniae (22%) was the predominant organism. Nested urine PCR was positive in 38 (76%) and detected bacterial DNA in 8 neonates with negative blood cultures. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of nested PCR were 100, 60, 78.9, 100 and 84%, respectively, compared with blood culture. Nested PCR can detect most bacteria in single assay and identify unusual and unexpected causal agents.

Study of the role of efflux pump in ciprofloxacin resistance in Salmonella enterica serotype Typhi

PURPOSE

There are increasing reports on failure of clinical response to ciprofloxacin in typhoid fever despite the strain being sensitive to drug in in-vitro using standard guidelines and showing mutations in DNA gyrase. But this increased MIC and clinical failures with ciprofloxacin are not always co-related with mutations presently identified in gyrA and parC genes. This shows that there may be other mechanisms such as an active drug efflux pump responsible as has been shown in other Enterobacteriaceae. This study was carried out to determine the role of efflux pump in Salmonella Typhi isolates.

MATERIALS AND METHODS

Total 25 already characterized nalidixic acid sensitive and nalidixic acid resistant S. Typhi strains with different range of ciprofloxacin MIC were included to study the role of efflux pump in the presence of CCCP (efflux pump inhibitor). For genotypic characterization, the entire acrR gene was sequenced to confirm the presence of any mutation in the gene.

RESULTS

The MIC of ciprofloxacin remained same in the presence and absence of CCCP in the studied strains and no significant mutations were found in the acrR gene in any of the isolates studied.

CONCLUSIONS

No role of efflux pump in ciprofloxacin resistance was found in strains studied. There is a need to explore further mechanism of ciprofloxacin resistance in Salmonella Typhi.

Antibiotics in third molar extraction; are they really necessary: A non-inferiority randomized controlled trial

INTRODUCTION

Antibiotic resistance is now a serious problem, although it was not so only a few years ago. The need of the hour is to give clear evidence of the efficacy of antibiotic use, or lack thereof, to the surgeon for a procedure as common as mandibular third molar surgery.

AIM

This study aimed to evaluate whether postoperative combined amoxicillin and clavulanic acid in mandibular third molar extraction is effective in preventing inflammatory complications.

STUDY AND DESIGN

The study was structured as a prospective randomized double-blind placebo-controlled clinical trial.

MATERIALS AND METHODS

A study was designed wherein the 96 units (two bilaterally similar impacted mandibular third molars per head in 48 patients) were randomly assigned to two treatment groups (Group I and Group II). Each patient served as his/her own control. Each patient received 625 mg of combined amoxicillin and clavulanic acid 1 h before surgery. In the case of third molars belonging to Group I, 625 mg of combined amoxicillin and clavulanic acid TDS was continued for 3 days; in Group II, placebo in similar-looking packs was continued for 3 days. The patients were evaluated on the third and seventh postoperative days for signs of clinical infection and for microbial load evaluation.

STATISTICAL ANALYSIS

The data between the two groups were statistically analyzed by the two-tailed Fisher's exact test, with a 95% confidence interval.

RESULTS

The difference was not statistically significant between the test group and the control group with regard to erythema, dehiscence, swelling, pain, trismus, and infection based on microbial load. The data were statistically significant for alveolar osteitis, with the occurrence of alveolar osteitis (14.58%) in the placebo group.

CONCLUSION

Postoperative antibiotics are recommended only for patients undergoing contaminated, long-duration surgery.

Semi-analytical model of arrayed waveguide grating in SOI using Gaussian beam approximation

The arrayed waveguide grating structure can be used as an important component in high-speed CMOS optical interconnects in silicon-on-insulator (SOI) platform. However, the performance of such device is found to be extremely sensitive to the fabrication-related errors in defining the critical features. In the absence of an appropriate analytical model, one needs to rely on numerical computation to analyze the device characteristics and fabrication tolerances. Because compact design of such a device structure has foot-print ∼mm² and the smallest features can be as small as ∼500  nm×220  nm (waveguide cross section), it demands a huge computational budget to optimize the design parameters. A semi-analytical model using Gaussian beam approximation of guided mode profiles has been developed to analyze the output spectrum of arrayed waveguide grating and to estimate the phase errors due to waveguide inhomogeneities. This model has been validated with existing numerical methods and published experimental results. It has been observed that a probabilistic waveguide width variations of ΔW∼5  nm can cause a cross-talk degradation of about 40 dB (25 dB) for a device (operating at λ∼1550  nm) fabricated on SOI substrate with 220 nm (2 μm) device layer thickness.

Serum ferritin level correlates with SLEDAI scores and renal involvement in SLE

Introduction

Ferritin is an acute-phase reactant that is elevated in various autoimmune disorders. Serum ferritin levels have been positively correlated with disease activity scores of rheumatoid arthritis and systemic lupus erythematosus (SLE). Further, enhanced levels of ferritin have also been reported in lupus nephritis. However, there are no reports from the Indian subcontinent.

Methods

Seventy-six female SLE patients, diagnosed on the basis of revised ACR criteria, and 50 healthy females, age matched from similar geographical areas, were enrolled in the present study. Serum levels of ferritin, IFN-α and IL-6 were quantified by enzyme-linked immunosorbent assay (ELISA). Clinical, biochemical, serological and other markers of disease activity (C3, C4 and anti-dsDNA) were measured by standard laboratory procedure.

Results

Serum ferritin levels were significantly higher in SLE patients compared to healthy controls ( p < 0.0001). Ferritin levels positively correlated with SLE Disease Activity Index (SLEDAI) ( p = 0.001, r = 0.35), anti-dsDNA ( p = 0.001, r = 0.35), IFN-α ( p < 0.0001, r = 0.51) and IL-6 (p < 0.0001, r = 0.65) and negatively correlated with C3 ( p = 0.0006, r = −0.38) and C4 ( p = 0.01, r = −0.28). Interestingly, serum levels of ferritin were positively associated with proteinuria ( p = 0.001, r = 0.36), serum urea ( p = 0.0004, r = 0.39) and serum creatinine ( p = 0.0006, r = 0.38).

Conclusion

Serum ferritin is an excellent marker of disease activity and renal dysfunction in SLE.