Optimizing speed breeding and seed/pod chip based genotyping techniques in pigeonpea: A way forward for high throughput line development

BACKGROUND

The challenge of pigeonpea breeding lies in its photosensitivity and seasonal specificity. This poses a problem to the breeder, as it restricts to single generation advancement in a year. Currently, the cross to cultivar gap is twelve to thirteen years resulting in a limited number of varietal releases over the past six decades. Shortening the breeding cycle was need of the hour, unlikely achieved by conventional breeding. To overcome these hindrances speed breeding was a necessary leap. An experiment was planned to optimize the speed breeding coupled with single seed descent and seed or pod chip-based genotyping to shorten the breeding cycle in pigeonpea at ICRISAT, Hyderabad. Monitored photoperiod, light wavelength, temperature and crop management regime were the indicators attributing to the success of speed breeding.

RESULT

A photoperiod of 13 h: 8 h: 13 h at vegetative: flowering and pod filling stages is ideal for shortening the breeding cycle. Broad spectrum light (5700 K LED) hastened early vegetative growth and pod formation. Whereas far-red (735 nm) light favoured early flowering. A significant difference between the photoperiods, genotypes as well as photoperiod x genotype interaction for both days to flowering and plant height was noted.

CONCLUSION

The optimized protocol serves as a road map for rapid generation advancement in pigeonpea. Deploying this protocol, it is possible to advance 2-4 generations per year. The breeding cycle can be reduced to 2-4 years which otherwise takes 7 years under conventional breeding. Single Seed Descent and seed or pod chip-based genotyping for early generation marker assisted selection, strengthened the precision of this technique aiding in high throughput line development.

Recommended Resting-State fMRI Acquisition and Preprocessing Steps for Preoperative Mapping of Language and Motor and Visual Areas in Adult and Pediatric Patients with Brain Tumors and Epilepsy

Resting-state (rs) fMRI has been shown to be useful for preoperative mapping of functional areas in patients with brain tumors and epilepsy. However, its lack of standardization limits its widespread use and hinders multicenter collaboration. The American Society of Functional Neuroradiology, American Society of Pediatric Neuroradiology, and the American Society of Neuroradiology Functional and Diffusion MR Imaging Study Group recommend specific rs-fMRI acquisition approaches and preprocessing steps that will further support rs-fMRI for future clinical use. A task force with expertise in fMRI from multiple institutions provided recommendations on the rs-fMRI steps needed for mapping of language, motor, and visual areas in adult and pediatric patients with brain tumor and epilepsy. These were based on an extensive literature review and expert consensus.Following rs-fMRI acquisition parameters are recommended: minimum 6-minute acquisition time; scan with eyes open with fixation; obtain rs-fMRI before both task-based fMRI and contrast administration; temporal resolution of ≤2 seconds; scanner field strength of 3T or higher. The following rs-fMRI preprocessing steps and parameters are recommended: motion correction (seed-based correlation analysis [SBC], independent component analysis [ICA]); despiking (SBC); volume censoring (SBC, ICA); nuisance regression of CSF and white matter signals (SBC); head motion regression (SBC, ICA); bandpass filtering (SBC, ICA); and spatial smoothing with a kernel size that is twice the effective voxel size (SBC, ICA).The consensus recommendations put forth for rs-fMRI acquisition and preprocessing steps will aid in standardization of practice and guide rs-fMRI program development across institutions. Standardized rs-fMRI protocols and processing pipelines are essential for multicenter trials and to implement rs-fMRI as part of standard clinical practice.

Comparative molecular profiling of multidrug-resistant Pseudomonas aeruginosa identifies novel mutations in regional clinical isolates from South India

Objectives

We sought to analyse the antibiotic susceptibility profiles and molecular epidemiology of MDR clinical Pseudomonas aeruginosa isolates from South India using non-MDR isolates as a reference.

Methods

We established a comprehensive clinical strain library consisting of 58 isolates collected from patients across the South Indian state of Kerala from March 2017 to July 2019. The strains were subject to antibiotic susceptibility testing, modified carbapenem inactivation method assay for carbapenemase production, PCR sequencing, comparative sequence analysis and quantitative PCR of MDR determinants associated with antibiotic efflux pump systems, fluoroquinolone resistance and carbapenem resistance. We performed in silico modelling of MDR-specific SNPs.

Results

Of our collection of South Indian P. aeruginosa clinical isolates, 74.1% were MDR and 55.8% were resistant to the entire panel of antibiotics tested. All MDR isolates were resistant to levofloxacin and 93% were resistant to meropenem. We identified seven distinct, MDR-specific mutations in nalD, three of which are novel. mexA was significantly overexpressed in strains that were resistant to the entire test antibiotic panel while gyrA and gyrB were overexpressed in MDR isolates. Mutations in fluoroquinolone determinants were significantly associated with MDR phenotype and a novel GyrA Y100C substitution was observed. Carbapenem resistance in MDR isolates was associated with loss-of-function mutations in oprD and high prevalence of NDM (blaNDM-1) within our sample.

Conclusions

This study provides insight into MDR mechanisms adopted by P. aeruginosa clinical isolates, which may guide the potential development of therapeutic regimens to improve clinical outcomes.

Efficacy of Lysostaphin functionalized silicon catheter for the prevention of Staphylococcus aureus biofilm

Staphylococcus aureus readily forms biofilms on tissue and indwelling catheter surfaces. These biofilms are resistant to antibiotics. Consequently, effective prevention and treatment strategies against staphylococcal biofilms are actively being pursued over the past two decades. One of the proposed strategies involve the incorporation of antibiotics and antiseptics into catheters, however, a persistent concern regarding the possible emergence of antimicrobial resistance is associated with these medical devices. In this study, we developed two types of silicone catheters: one with Lysostaphin (Lst) adsorbed onto the surface, and the other with Lst functionalized on the surface. To confirm the presence of Lst protein on the catheter surface, we conducted FTIR-ATR and SEM-EDS analysis. Both catheters exhibited hemocompatibility, biocompatibility, and demonstrated antimicrobial and biofilm prevention activities against both methicillin-sensitive and resistant strains of S. aureus. Furthermore, the silicone catheters that were surface-functionalized with Lst showed substantially better and more persistent anti-biofilm effects when compared to the catheters where Lst was surface-adsorbed, both under in vitro static and flow conditions, as well as in vivo in BALB/c mice. These results indicate that surface-functionalized Lst catheters have the potential to serve as a promising new medical device for preventing S. aureus biofilm infections in humans.

Identification of a Staphylococcus aureus amidase catalytic domain inhibitor to prevent biofilm formation by sequential virtual screening, molecular dynamics simulation and biological evaluation

Staphylococcus aureus (S. aureus) is one of the common causes of implant associated biofilm infections and their biofilms are resistant to antibiotics. S. aureus amidase (AM) protein, a cell wall hydrolase that cleaves the amide bond between N-acetylmuramic acid and L-alanine residue of the stem peptide, is several fold over-expressed under biofilm conditions. Previous studies demonstrated an autolysin mutant in S. aureus that lacks the AM protein, is highly impaired in biofilm development. We carried out a structure-based small molecule design using the crystal structure of AM protein catalytic domain to identify inhibitors that can block amidase activity and therefore inhibits S. aureus biofilm formation. Sequential virtual screening followed by pharmacokinetic analysis and bioassay studies filtered 25 small molecules from different databases. Two compounds from the SPECS database, SPECS-1 and SPECS-2, were selected based on the best docking score and minimum biofilm inhibitory concentration towards S. aureus biofilms. SPECS-1 and SPECS-2 were further tested for their structural/energetic stability in complex with the AM protein using molecular dynamics simulation and MM-GBSA techniques. In vitro, biofilm inhibition studies on different surfaces confirmed that treatment with SPECS-1 and SPECS-2 at a concentration of 250 μg/ml exhibited significant prevention and disruption of S. aureus biofilms. Finally, the in vitro anti-biofilm activities of these two compounds were validated against Methicillin-resistant S. aureus clinical isolates. We concluded that the discovered compounds SPECS-1 and SPECS-2 are safe and exhibit biofilm preventive and disruption activity for inhibiting the S. aureus biofilms and hence can be used to treat implant-associated biofilm infections.

Non-linear dose response of DNA double strand breaks in response to chronic low dose radiation in individuals from high level natural radiation areas of Kerala coast

BACKGROUND

The human population living in high level natural radiation areas (HLNRAs) of Kerala coast provide unique opportunities to study the biological effects of low dose and low dose rate ionizing radiation below 100 mGy. The level of radiation in this area varies from < 1.0 to 45 mGy/year. The areas with ≤ 1.50 mGy/year are considered as normal level natural radiation areas (NLNRA) and > 1.50 mGy/year, as high level natural radiation areas (HLNRA). The present study evaluated dose response relationship between DNA double strand breaks (DSBs) and background radiation dose in individuals residing in Kerala coast. Venous blood samples were collected from 200 individuals belonging to NLNRA (n = 50) and four dose groups of HLNRA; 1.51-5.0 mGy/year (n = 50), 5.01-10.0 mGy/year (n = 30), 10.01-15.0 mGy/year (n = 33), > 15.0 mGy/year (n = 37) with written informed consent. The mean dose of NLNRA and four HLNRA dose groups studied are 1.21 ± 0.21 (range: 0.57-1.49), 3.02 ± 0.95 (range: 1.57-4.93), 7.43 ± 1.48 (range: 5.01-9.75), 12.22 ± 1.47 (range: 10.21-14.99), 21.64 ± 6.28 (range: 15.26-39.88) mGy/year, respectively. DNA DSBs were quantified using γH2AX as a marker, where foci were counted per cell using fluorescence microscopy.

RESULTS

Our results revealed that the frequency of γH2AX foci per cell was 0.090 ± 0.051 and 0.096 ± 0.051, respectively in NLNRA and HLNRA individuals, which were not significantly different (t₁₉₈ = 0.33; P = 0.739). The frequency of γH2AX foci was observed to be 0.090 ± 0.051, 0.096 ± 0.051, 0.076 ± 0.036, 0.087 ± 0.042, 0.108 ± 0.046 per cell, respectively in different dose groups of ≤ 1.50, 1.51-5.0, 5.01-10.0, 10.01-15.0, > 15.0mGy/year (ANOVA, F_4,195 = 2.18, P = 0.072) and suggested non-linearity in dose response. The frequency of γH2AX foci was observed to be 0.098 ± 0.042, 0.078 ± 0.037, 0.084 ± 0.042, 0.099 ± 0.058, 0.097 ± 0.06 and 0.114 ± 0.033 per cell in the age groups of ≤ 29, 30-34, 35-39, 40-44, 45-49 and ≥ 50 years, respectively (ANOVA, F_5,194 = 2.17, P = 0.059), which suggested marginal influence of age on the baseline of DSBs. Personal habits such as smoking (No v/s Yes: 0.092 ± 0.047 v/s 0.093 ± 0.048, t₁₉₈ = 0.13; P = 0.895) and drinking alcohol (No v/s Yes: 0.096 ± 0.052 v/s 0.091 ± 0.045, t₁₉₈ = 0.62; P = 0.538) did not show any influence on DSBs in the population.

CONCLUSION

The present study did not show any increase in DSBs in different dose groups of HLNRA compared to NLNRA, however, it suggested a non-linear dose response between DNA DSBs and chronic low dose radiation.

Seasonal variability in size-resolved hygroscopicity of sub-micron aerosols over the Western Ghats, India: Closure and parameterization

Hygroscopicity of atmospheric aerosol primarily depends on the size and chemical composition of the particle and is important for estimating anthropogenic aerosol radiative forcing. There is limited information exists over the Indian region on size segregated aerosol hygroscopicity (κ) in different seasons. This study presents 'κ' as derived from a Humidified Tandem Differential Mobility Analyzer (HTDMA) over a High Altitude Cloud Physics Laboratory (HACPL) in the Western Ghats, India for more than a year (from May 2019 to May 2020). The average hygroscopicity values of aerosol particles of diameters 32, 50, 75, 110, 150, 210 and 260 nm at 90 % RH condition are 0.19, 0.18, 0.16, 0.17, 0.18, 0.20, 0.21 respectively during the entire observation period. κ was observed to decrease with an increase in size in the Aitken mode regime (32-75 nm) and an increase in the accumulation mode (110-260 nm). Seasonal variation of hygroscopicity for a wide range of particle diameters is reported which is highly demanding as there is a change in the air mass flow pattern in each of the seasons. The diurnal cycle of hygroscopicity showed a prominent peak during the midnight to early morning hours followed by a decrease in the forenoon hours and a secondary peak in the afternoon hours. κ is found to be higher in pre-monsoon compared to winter season as Chl is approximately 3 % higher in pre-monsoon and NH₄Cl is highly hygroscopic among the assumed chemical composition. Hygroscopicity derived through chemical speciation observations assuming internal and external mixing of aerosols i.e. κ_inter and κ_exter are overestimating as compared to κ_HTDMA. However, the bias between k_exter and k_HTDMA is relatively lower as external mixing type of aerosol is evident through the growth factor data sets measured by HTDMA. Utilizing the hygroscopicity measurements available for discrete diameters by HTDMA, a parameterization of hygroscopicity with the dry diameter of sub-micron particles is developed.

Enhanced inhibition of Pseudomonas aeruginosa virulence factor production and biofilm development by sublethal concentrations of eugenol and phenyllactic acid

Biofilm development in P. aeruginosa is regulated by its quorum sensing (QS) systems. It has three major QS systems: LasI/R, RhlI/R, and PQS/MvfR. Previous studies showed that phenyllactic acid (PLA) binds to RhlR and PqsR and inhibits the Rhl and PQS QS; and eugenol at sublethal concentration inhibits Las and PQS QS systems. Here, we have demonstrated that a combination of sublethal doses of eugenol and PLA enhanced the inhibition of the QS mediated production of the virulence factors and biofilm development of this pathogen. A combination of 50 μM eugenol and 0.3 mM PLA significantly inhibited the pyocyanin production, protease activity, swarming motility and cytotoxic activities of P. aeruginosa strain PAO1, whereas eugenol and PLA when added individually to PAO1 cultures were less effective in inhibiting its virulence factor expression. Biofilm formation of PAO1 was reduced by 32, 19 and 87% on glass surfaces; and 54%, 49% and 93% on catheter surfaces when treated using 50 μM eugenol or 0.3 mM PLA and their combinations, respectively. The in vitro finding in the reduction of biofilm development was further validated in vivo using a catheter associated medaka fish biofilm model. Our results indicate that a combination of QS inhibitors targeting different QS pathways should be selected while designing therapeutic molecules to achieve maximum QS mediated biofilm inhibition and clinical outcome against P. aeruginosa.

Colistimethate sodium-chitosan hydrogel for treating Gram-negative bacterial wound infections

The drug resistance is higher among Gram-negative bacteria and demands the usage of strong antibiotics which can in turn result in systemic toxicity. In the treatment of the chronic wounds harboring pathogenic Gram-negative bacteria, the demand for an antimicrobial product that can be topically administered has been on the rise. In an effort to address the above issue, we have developed Colistimethate sodium (a high-end antibiotic) loaded chitosan hydrogel and characterized. The prepared hydrogel is very stable and observed to be bio- and hemo-compatible in nature. The antibacterial activity of the prepared hydrogel was studied against both ATCC (American Type Culture Collection) strains and clinical isolates of Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae. The CMS incorporated hydrogel is also capable of inhibiting the biofilm formation. The developed hydrogel can be potentially being used for the treatment of Gram-negative bacterial infected wounds.

Minimally Invasive Discectomy and Decompression for Lumbar Spine using Tubular Retractor System: Technique, Learning Curve and Outcomes

Objective To study the indications, technical nuances, learning curve, and outcomes associated with minimally invasive tubular discectomy of spine (MITDS) and minimally invasive tubular decompression (MITD) using the tubular retractor system and compare the outcomes with open microdiscectomy and open decompression.

Materials and Methods All patients who underwent MITDS and MITD received a trial of conservative management for 6 weeks prior to surgery. Patients who had undergone open microdiscectomy and open decompression during the same period were used as controls. Operating time, intraoperative blood loss, preop and postop visual analogue scale (VAS) scores, preop and postop Oswestry disability index (ODI) scores, duration of hospital stay, complications, and need for redo surgery were analyzed.

Results Thirty-two patients who underwent MITDS and 8 patients who underwent MITD were compared with an equal number of patients who underwent open microdiscectomy and open decompression, respectively. MITDS and MITD were associated with shorter hospital stay. Short-term pain outcome was better in MITDS and MITD group, although it was not statistically significant in MITD group. Functional outcome measured in terms of ODI at 6 months was not statistically significant between minimally invasive and open procedures.

Conclusion Both MITDS and MITD have a significant learning curve and have a distinct advantage of shorter hospital stay. MITDS has the distinct advantage of better short-term pain relief compared with open procedures. For MITD, comparison of short-term pain relief requires a larger sample size. To establish long-term advantages of MITDS and MITD, larger sample size and long-term follow-up are needed.

An outcome-based composite approach for the diagnosis of intestinal tuberculosis: a pilot study from a tertiary care centre in South India

BACKGROUND

The diagnosis of intestinal TB (ITB) is challenging because of its overlapping features with Crohn's disease. This outcome-based study evaluated the combination of colonoscopy, histopathology, Xpert MTB/RIF and TB culture for best sensitivity and specificity.

METHOD

This was a four-year retrospective, observational study of 426 clinically suspected patients who underwent colonoscopy with biopsies for histopathology, Xpert MTB/RIF and TB culture. ITB was diagnosed using the composite reference standard (CRS), which comprised either histological features or culture or Xpert MTB/RIF positivity, and positive response to anti-tuberculous treatment on follow up.

RESULTS

35 (8.2%) patients were diagnosed with ITB. Histopathology had the highest sensitivity (91.4%) and negative predictive value (99.2%), MTB/RIF had the highest specificity (100%) and positive predictive value (100%). A combinatorial approach with Xpert MTB/RIF and histopathology had optimal diagnostic value (97%), approaching 100% sensitivity with culture. 40% of cases were diagnosed within 12 hours with Xpert MTB/RIF and 97% cases within three days.

CONCLUSION

This combinatorial diagnostic model provides rapid and reliable diagnosis of ITB which may be useful in endemic areas.

Antiseptic chitosan bandage for preventing topical skin infections

Infections on the wound surface are the major problem in restricting the healing process. To reduce the transmission and treat the infection, we have developed 0.05% and 0.1% octenidine dihydrochloride (Ocd) incorporated chitosan (Cs) based flexible bandages. Ocd is extensively used skin antiseptic for its mode of action over a broad spectrum of antimicrobial activity. The prepared antiseptic Cs-Ocd bandage was characterized using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM). In addition, swelling, degradation, cytocompability, antibacterial, and anti-biofilm property of the developed bandages were studied. This highly porous nature of Cs-Ocd bandage showed enhanced swelling property, slow degradation profile and controlled release of Ocd. The prepared antiseptic bandage exhibited synergistic effect showing good hemostatic potential with Cs, excellent antimicrobial and anti-biofilm activity with Ocd against Staphylococcus aureus (S. aureus) and Candida auris (C. auris). Thus, the developed Cs-Ocd bandage can be used as potential antiseptic bandage for skin infections.

Characterization of plastic debris from surface waters of the eastern Arabian Sea-Indian Ocean

The quantity of floating plastic debris (FPD) is continuously being increased in the oceans. To assess their size, structure, and composition along the eastern Arabian Sea (EAS), FPD samples were collected by using a surface plankton net. The microplastic size fraction (0.5-5 mm) was the most prevalent accounting for >50% of the total, followed by mesoplastics (5-25 mm; ~40%) and macroplastics (>25 mm; ~10%). The collected FPDs were categorized into five different types and eight colours. Attenuated Total Reflectance-Fourier Transform Infrared Spectrometry (ATR-FTIR) analysis of the plastics revealed that polypropylene, polyethylene, and nylon were the most dominant polymers, and these comprised mostly of fibre/fishing line. The abundance of FPD in the EAS (0.013 ± 0.012 no.s/m³) was found to be very low compared to elsewhere. The prevalent microplastics presence in the oceans might have occurred mainly by the degradation of larger items. It increases bioavailability, and hence, is a risk to marine ecosystems.

Therapeutic applications of lysostaphin against Staphylococcus aureus

Staphylococcus aureus, an opportunistic pathogen, causes diverse community and nosocomial-acquired human infections, including folliculitis, impetigo, sepsis, septic arthritis, endocarditis, osteomyelitis, implant-associated biofilm infections and contagious mastitis in cattle. In recent days, both methicillin-sensitive and methicillin-resistant S. aureus infections have increased. Highly effective anti-staphylococcal agents are urgently required. Lysostaphin is a 27 kDa zinc metallo antimicrobial lytic enzyme that is produced by Staphylococcus simulans biovar staphylolyticus and was first discovered in the 1960s. Lysostaphin is highly active against S. aureus strains irrespective of their drug-resistant patterns with a minimum inhibitory concentration of ranges between 0·001 and 0·064 μg ml^-1 . Lysostaphin has activity against both dividing and non-dividing S. aureus cells; and can seep through the extracellular matrix to kill the biofilm embedded S. aureus. In spite of having excellent anti-staphylococcal activity, its clinical application is hindered because of its immunogenicity and reduced bio-availability. Extensive research with lysostaphin lead to the development of several engineered lysostaphin derivatives with reduced immunogenicity and increased serum half-life. Therapeutic efficacy of both native and engineered lysostaphin derivatives was studied by several research groups. This review provides an overview of the therapeutic applications of native and engineered lysostaphin derivatives developed to eradicate S. aureus infections.

Outcome analysis of upper and lower limb motor functions after anterior cervical discectomy and fusion for degenerative cervical disc disease

Background: Anterior cervical discectomy and fusion (ACDF) is the most commonly performed surgical procedure for symptomatic cervical disc disease. In this study, we analysed the upper and lower limb motor functions after ACDF for disc prolapse in patients with degenerative cervical disc disease. Methods: One hundred consecutive adult patients who underwent ACDF for single or two-level cervical disc prolapse during the study period (October 2015 to October 2017) were included in the study. Results: Preoperative motor deficits in limbs were noted in 73% (73/100) of the patients. Enhance recovery of motor deficits was noted in 72.6% (53/73) of these patients and persisting motor deficits in the remaining patients (20/73- 27.4%). Five patients (5/27- 18.5%) without any preoperative motor deficits developed motor deficits after ACDF. Detailed pre and postoperative (at the time of discharge) motor power (graded by MRC grade) in all 4 limbs (Shoulder abduction/adduction/flexion/extension, elbow flexion/extension, wrist flexion/extension, hip abduction/adduction/flexion/extension, knee flexion/extension, ankle flexion/extension) was recorded. Statistically significant improvement in motor power (as recorded at the time of discharge) was noted in all the tested muscle groups after ACDF. Conclusion: Early improvement in preoperative motor deficits can be expected in the majority of the patients with cervical PIVD following ACDF.

Premature chromosome condensation assay to study influence of high-level natural radiation on the initial DNA double strand break repair in human G0 lymphocytes

The inherent capacity of individuals to efficiently repair ionizing radiation induced DNA double strand breaks (DSBs) may be inherited, however, it is influenced by several epigenetic and environmental factors. A pilot study tested whether chronic low dose natural radiation exposure influences the rejoining of initial DNA DSBs induced by a 2 Gy γ-irradiation in 22 individuals from high (>1.5 mGy/year) and normal (≤1.5 mGy/year) level natural radiation areas (H&NLNRA) of Kerala. Rejoining of DSBs (during 1 h at 37 °C, immediately after irradiation) was evaluated at the chromosome level in the presence and absence of wortmannin (a potent inhibitor of DSB repair in normal human cells) using a cell fusion-induced premature chromosome condensation (PCC) assay. The PCC assay quantitates DSBs in the form of excess chromosome fragments in human G₀ lymphocytes without the requirement for cell division. A quantitative difference was observed in the early rejoining of DNA DSBs between individuals from HLNRA and NLNRA, with HLNRA individuals showing a higher (P = 0.05) mean initial repair ratio. The results indicate an influence of chronic low dose natural radiation on initial DNA DSB repair in inhabitants of HLNRA of the Kerala coast.

Sterilization of N95 respirators: The time for action is upon us!

Re-processing of primary protective equipment is the need of the hour with healthcare systems all over the world strained due to the shortage precipitated by severe acute respiratory syndrome coronavirus 2. The common methods of re-sterilization do not hold well for filtering facepiece respirators (FFRs) as they affect their structure and function. We propose the validation and eventual use of gamma irradiation, an already existing method of re-sterilization, to disinfect FFRs in bulk.

Concomitant Overlapping Acute Extradural and Subdural Hematoma

Usually following traumatic brain injury, extradural hematoma (EDH) and subdural hematoma (SDH) appear in opposite locations, with EDH being a coup injury and SDH being a contrecoup injury. We present a case of 24-year-old male patient who had concomitant overlapping acute EDH and SDH requiring neurosurgical intervention and discuss the clinical relevance of these coexisting lesions. Concomitant overlapping EDH and SDH are uncommon lesions and need close observation and planned follow-up imaging.

Dynamic Contrast-Enhanced MRI in Patients with Brain Metastases Undergoing Laser Interstitial Thermal Therapy: A Pilot Study

BACKGROUND AND PURPOSE

Tumor recurrence is difficult to predict in patients receiving laser ablation for intracranial malignancy. We assessed the efficacy of the initial area under the time-to-signal intensity curve at 60 seconds (iAUC₆₀) from dynamic contrast-enhanced MR imaging in predicting progression-free survival in patients with brain metastases following laser interstitial thermal therapy.

MATERIALS AND METHODS

The study population was a consecutive series of patients undergoing laser interstitial thermal therapy for brain metastases. Patient demographics including age, sex, tumor histology, and Karnofsky Performance Scale were collected prospectively. Preoperative, postoperative, and 1-month follow-up dynamic contrast-enhanced MRIs were analyzed. Values of iAUC₆₀ were computed using a trapezoidal rule applied to the time history of contrast uptake over the first 60 seconds postenhancement. The change in iAUC₆₀ (ΔiAUC₆₀) was calculated by taking the difference between the values of iAUC₆₀ from 2 time points. Pearson correlation coefficients were calculated between progression-free survival, defined as the time from laser interstitial thermal therapy to tumor recurrence, and iAUC₆₀ or ΔiAUC₆₀ values.

RESULTS

Thirty-three cases of laser interstitial thermal therapy for 32 brain metastases in a cohort of 27 patients were prospectively analyzed. A significant relationship was observed between the values of iAUC₆₀ from postoperative dynamic contrast-enhanced MR imaging and progression-free survival with Pearson correlation (P = .03) and Cox univariate analysis (P = .01). The relationship between preoperative and 1-month follow-up dynamic contrast-enhanced MR imaging was not significantly correlated with progression-free survival. Similarly, no statistically significant relationship was observed with ΔiAUC₆₀ and progression-free survival between any time points.

CONCLUSIONS

Progression-free survival is difficult to predict in patients undergoing laser interstitial thermal therapy for brain metastases due to confounding with posttreatment change. iAUC₆₀ extracted from postoperative dynamic contrast-enhanced MR imaging shows promise for accurately prognosticating patients following this operative therapy.

Clinical presentation and outcome after anterior cervical discectomy and fusion for degenerative cervical disc disease

Background:

Anterior cervical discectomy and fusion (ACDF) is a well-described surgical approach for symptomatic degenerative cervical disc disease which does not respond to conservative management. In the present study, we assessed clinical presentation and outcomes of ACDF.

Materials and Methods:

The present study was conducted from October 1, 2015, to October 31, 2017, in the Department of Neurosurgery, Narayana Medical College and Hospital, Nellore, Andhra Pradesh, among 100 consecutive adult patients who underwent single- or two-level ACDF for degenerative cervical disc disease.

Results:

The mean age was 47.2 ± 12.8 years (range: 20–74 years). Majority of the patients were male (86/100). Presenting symptoms were neck pain (77%), limb weakness (73%), paresthesias (53%), radicular pain (49%), stiffness in limbs (16%), and bladder involvement (13%). Fusion was done with stand-alone titanium cage/bone graft or titanium cage/bone graft with anterior cervical plate. At the time of discharge, significant improvement in preoperative symptoms (neck pain [47/77-61%], radicular pain [31/49-63%], limb weakness [53/73-72.6%], paresthesias [44/53-83%], stiffness in limbs [13/16-81%], and bladder symptoms [8/13-61%]) was reported by majority of these patients. Majority of these patients also reported improvement in preoperative sensory deficits at the time of discharge. Postoperative complications were hoarseness of voice (22%), dysphagia (16%), deterioration of motor power (8%), and postoperative hematoma (7%).

Conclusions:

A significant proportion of patients with degenerative cervical disc disease show remarkable recovery after ACDF.

Implementation and Impact of an Antimicrobial Stewardship Program at a Tertiary Care Center in South India

Background

Antimicrobial resistance is a major public health threat internationally but, particularly in India. A primary contributing factor to this rise in resistance includes unregulated access to antimicrobials. Implementing antimicrobial stewardship programs (ASPs) in the acute hospital setting will help curb inappropriate antibiotic use in India. Currently, ASPs are rare in India but are gaining momentum. This study describes ASP implementation in a large, academic, private, tertiary care center in India.

Methods

An ASP was established in February 2016 consisting of an administrative champion, hospitalist, microbiologist, intensivist, and pharmacists. Antimicrobial stewardship program interventions included postprescriptive audit and establishment of institutional guidelines. The ASP tracked appropriate drug selection including loading dose, maintenance dose, frequency, route, duration of therapy, de-escalation, and compliance with ASP recommendations. Defined daily dose (DDD) of drugs and cost of antimicrobials were compared between the pre-implementation phase (February 2015–January 2016) and post-implementation phase (February 2016–January 2017).

Results

Of 48 555 patients admitted during the post-implementation phase, 1020 received 1326 prescriptions for restricted antibiotics. Antibiotic therapy was appropriate in 56% (742) of the total patient prescriptions. A total of 2776 instances of “inappropriate” antimicrobial prescriptions were intervened upon by the ASP. Duration (806, 29%) was the most common reason for inappropriate therapy. Compliance with ASP recommendations was 54% (318). For all major restricted drugs, the DDD/1000 patient days declined, and there was a significant reduction in mean monthly cost by 14.4% in the post-implementation phase.

Conclusions

Implementation of a multidisciplinary antibiotic stewardship program in this academic, large, Indian hospital demonstrated feasibility and economic benefits.

Impregnation of catheters with anacardic acid from cashew nut shell prevents Staphylococcus aureus biofilm development

AIM

The effect of anacardic acid impregnation on catheter surfaces for the prevention of Staphylococcus aureus attachments and biofilm formations were evaluated.

METHODS AND RESULTS

Silicon catheter tubes were impregnated using different concentrations of anacardic acids (0·002-0·25%). Anacardic acids are antibacterial phenolic lipids from cashew nut (Anacardium occidentale) shell oil. Anacardic acid-impregnated silicon catheters revealed no significant haemolytic activity and were cytocompatible against fibroblast cell line (L929). Sustained release of anacardic acids was observed for 4 days. Anacardic acid-impregnated silicon catheters efficiently inhibited S. aureus colonization and the biofilm formation on its surface. The in vivo antibiofilm activity of anacardic acid-impregnated catheters was tested in an intraperitoneal catheter-associated medaka fish infection model. Significant reduction in S. aureus colonization on anacardic acid-impregnated catheter tubes was observed.

CONCLUSIONS

Our data suggest that anacardic acid-impregnated silicon catheters may help in preventing catheter-related staphylococcal infections.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study opens new directions for designing antimicrobial phytochemical-coated surfaces with ideal antibiofilm properties and could be of great interest for biomedical research scientists.

Extended Daily Dialysis vs. Continuous Hemodialysis for ICU Patients with Acute Renal Failure: A Two-Year Single Center Report

Extended daily dialysis (EDD) is an easily implemented alternative to continuous renal replacement therapy (CRRT) in the intensive care unit (ICU). Since EDD offers most of the advantages of CRRT, we sought to compare the effectiveness of these two modalities. In this 2-year study, 54 ICU patients with ARF were treated with either continuous hemodialysis (CHD) or EDD. Oliguria was present in 64% of patients who received CHD vs. 73% of EDD patients (p=NS) while 93% of CHD and 81% of EDD patients required mechanical ventilation (p=NS). Patients treated with EDD were younger than those who received CHD (47.0 ± 12.6 vs. 56.7 ± 13.7, p=0.009), but there were no significant differences in gender or mean APACHE II scores at the time of randomization. Mean arterial blood pressures measured during treatment were maintained between 70 and 80 mmHg for both EDD and CHD and average daily serum electrolyte levels fell within normal ranges for EDD and CHD. Average daily fluid input and output were 5.8 ± 3.3L and 6.0 ± 3.2 L for CHD vs. 3.3 ± 2.6 and 3.0 ± 1.7 L for EDD after exclusion of data from 2 burn patients. Hourly heparin anticoagulation rates were 1080 U/hour for CHD and 643 U/hour for EDD, p=0.02. Anticoagulation-free treatments were performed during 43% of all EDD treatments vs. 21% of all CHD treatments, p<0.001. Clotting of the dialyzer or circuit occurred at least once during 51% of all CHD treatment days vs. 22% of EDD treatments (p<0.001). We conclude that EDD is a safe, effective alternative to CRRT that offers comparable hemodynamic stability and excellent small solute control.

Current Status and Future Prospects of Next-Generation Data Management and Analytical Decision Support Tools for Enhancing Genetic Gains in Crops

Agricultural disciplines are becoming data intensive and the agricultural research data generation technologies are becoming sophisticated and high throughput. On the one hand, high-throughput genotyping is generating petabytes of data; on the other hand, high-throughput phenotyping platforms are also generating data of similar magnitude. Under modern integrated crop breeding, scientists are working together by integrating genomic and phenomic data sets of huge data volumes on a routine basis. To manage such huge research data sets and use them appropriately in decision making, Data Management Analysis & Decision Support Tools (DMASTs) are a prerequisite. DMASTs are required for a range of operations including generating the correct breeding experiments, maintaining pedigrees, managing phenotypic data, storing and retrieving high-throughput genotypic data, performing analytics, including trial analysis, spatial adjustments, identifications of MTAs, predicting Genomic Breeding Values (GEBVs), and various selection indices. DMASTs are also a prerequisite for understanding trait dynamics, gene action, interactions, biology, GxE, and various other factors contributing to crop improvement programs by integrating data generated from various science streams. These tools have simplified scientists' lives and empowered them in terms of data storage, data retrieval, data analytics, data visualization, and sharing with other researchers and collaborators. This chapter focuses on availability, uses, and gaps in present-day DMASTs. Graphical Abstract.

Radio-adaptive response in peripheral blood lymphocytes of individuals residing in high-level natural radiation areas of Kerala in the southwest coast of India

The present study investigates whether the chronic low-dose radiation exposure induces an in vivo radio-adaptive response in individuals from high-level natural radiation areas (HLNRA) of the Kerala coast. Peripheral blood samples from 54 adult male individuals aged between 26 and 65 years were collected for the study with written informed consent. Each of the whole blood sample was divided into three, one was sham irradiated, second and third was exposed to challenging doses of 1.0 and 2.0 Gy gamma radiation, respectively. Cytokinesis-block micronucleus (CBMN) assay was employed to study the radio-adaptive response. Seventeen individuals were from normal-level natural radiation area (NLNRA ≤1.5 mGy/year) and 37 from HLNRA (> 1.5 mGy/year). Based on the annual dose received, individuals from HLNRA were further classified into low-dose group (LDG, 1.51-5.0 mGy/year, N = 19) and high-dose group (HDG >5.0 mGy/year, N = 18). Basal frequency of micronucleus (MN) was comparable across the three dose groups (NLNRA, LDG and HDG, P = 0.64). Age of the individuals showed a significant effect on the frequency of MN after challenging dose exposures. The mean frequency of MN was significantly lower in elder (>40 years) individuals from HDG of HLNRA as compared to the young (≤40 years) individuals after 1.0 Gy (P < 0.001) and 2.0 Gy (P = 0.002) of challenging doses. However, young and elder individuals within NLNRA and LDG of HLNRA showed similar frequency of MN after the challenging dose exposures. Thus, increased level of chronic low-dose radiation (>5.0 mGy/year) seems to act as a priming dose resulting in the induction of an in vivo radio-adaptive response in elder individuals of the Kerala coast.

Imaging Features of Malignant Lacrimal Sac and Nasolacrimal Duct Tumors

The purpose of this study was to present the imaging features of primary and secondary malignant lacrimal sac and nasolacrimal duct tumors and their pattern of tumor spread in 18 patients. The most common tumor histology in our series was squamous cell carcinoma. In 15/18 patients, tumor involved both the lacrimal sac and duct at the time of diagnosis. In 11/16 patients on CT, the nasolacrimal bony canal was smoothly expanded without erosive changes. The medial canthus region (16/18) was a frequent site of direct tumor spread. Two patients had intraconal orbital spread of tumor. Tumor spread to the sinus or nasal cavity was observed in 5/13 primary tumors. Only 1 patient presented with nodal metastasis. There was no intracranial tumor extension, perineural tumor spread along the infraorbital nerve, distant metastasis, or dacryocystocele formation in any of the patients at the time of diagnosis.

Peripheral blood lymphocyte micronucleus frequencies in men from areas of Kerala, India, with high vs normal levels of natural background ionizing radiation

We have measured the frequencies of micronuclei (MN) in adult male individuals living in areas of the Kerala coast, southwest India, with either high (HLNRA, >1.5mGy/year) or normal levels of natural ionizing radiation (NLNRA, ≤1.5mGy/year). Blood samples were obtained from 141 individuals, 94 from HLNRA and 47 from NLNRA, aged 18-72, and were subjected to the cytokinesis-block micronucleus (CBMN) assay. An average of 1835 binucleated (BN) cells per individual were scored. The overall frequency of MN (mean±SD) was 11.7±6.7 per 1000 BN cells. The frequencies of MN in the HLNRA (11.7±6.6) and NLNRA (11.6±6.7) were not statistically significantly different (P=0.59). However, a statistically significant (P<0.001) age-dependent increase in MN frequency was observed among individuals from both HLNRA and NLNRA. No natural background radiation dose-dependent increase in MN frequency was seen. MN frequency was not influenced by tobacco smoking or chewing but it was increased among individuals consuming alcohol. Chronic low-dose radiation in the Kerala coast did not have a significant effect on MN frequency among adult men.

Targeted biological therapies reach the heart: the case of serelaxin for heart failure

Acute heart failure (AHF) is one of the most important causes of mortality, morbidity and rising healthcare costs. Despite this, there has been minimal advancement in the management of AHF and the treatment continues to focus on symptomatic improvement using vasodilators, diuretics and inotropes, none of which have shown any mortality benefits. Though originally thought of as a reproductive hormone, relaxin is now recognized as a potent vasodilator that modulates systemic and renal vascular tone, resulting in pre- and after-load reduction and a decrease in cardiac workload. A single intravenous infusion of relaxin over 48 hours has been shown to provide significant dyspnea relief among AHF patients, with an ongoing study to evaluate its potential for mortality benefit. This article provides an insight into the pharmacology of this novel therapy for AHF with an eye towards future clinical applications.

Invasive mould sinusitis in patients with haematological malignancies: a 10 year single-centre study

OBJECTIVES

Invasive mould sinusitis (IMS) is a severe infection in patients with haematological malignancies. Because of a paucity of contemporaneous data about IMS, we sought to evaluate clinical aspects and outcome of IMS in these patients.

METHODS

The records of adult haematological malignancy patients with proven or probable IMS over a 10 year period were reviewed retrospectively.

RESULTS

We identified 44 patients with IMS. Mucorales were isolated in 13 (35.1%) patients and Fusarium and Aspergillus were isolated in 9 (24.3%) patients each. Patients with IMS owing to Mucorales were more likely to have a history of diabetes mellitus (P = 0.003) and high-dose corticosteroid use (P = 0.03). Thirty-five (80%) patients received antifungal combinations and 36 (82%) underwent surgical debridement. The 12 week IMS-attributable mortality was 36.4% (16 patients). A relapsed and/or refractory haematological malignancy was an independent risk factor for 6 week IMS-attributable (P = 0.038), 12 week all-cause (P = 0.005) and 12 week IMS-attributable (P = 0.0015) mortality. Neutrophil count <100/µL and lymphocyte count <200/µL were associated with increased 12 week IMS-attributable and 6 week all-cause mortality, respectively (P = 0.044 and 0.013). IMS due to Aspergillus was an independent risk factor for both 12 week all-cause (P = 0.011) and IMS-attributable (P = 0.026) mortality. Initial antifungal therapy with a triazole-containing regimen was associated with decreased 6 week all-cause (P = 0.032) and IMS-attributable (P = 0.038) mortality. Surgery was not an independent factor for improved outcome.

CONCLUSIONS

Despite combined medical and surgical therapy, IMS had high mortality. Mortality risk factors were relapsed and/or refractory malignancy, cytopenia and Aspergillus infection in this study.

Salmonella Typhimurium pneumonia in a patient with multiple myeloma

Pneumonia due to non-typhoidal Salmonella is a rarely reported entity. A fatal case of Salmonella pneumonia is reported here where Salmonella Typhimurium was isolated from the endotracheal aspirate and blood culture.

Genomewide association studies for 50 agronomic traits in peanut using the 'reference set' comprising 300 genotypes from 48 countries of the semi-arid tropics of the world

Peanut is an important and nutritious agricultural commodity and a livelihood of many small-holder farmers in the semi-arid tropics (SAT) of world which are facing serious production threats. Integration of genomics tools with on-going genetic improvement approaches is expected to facilitate accelerated development of improved cultivars. Therefore, high-resolution genotyping and multiple season phenotyping data for 50 important agronomic, disease and quality traits were generated on the ‘reference set’ of peanut. This study reports comprehensive analyses of allelic diversity, population structure, linkage disequilibrium (LD) decay and marker-trait association (MTA) in peanut. Distinctness of all the genotypes can be established by using either an unique allele detected by a single SSR or a combination of unique alleles by two or more than two SSR markers. As expected, DArT features (2.0 alleles/locus, 0.125 PIC) showed lower allele frequency and polymorphic information content (PIC) than SSRs (22.21 alleles /locus, 0.715 PIC). Both marker types clearly differentiated the genotypes of diploids from tetraploids. Multi-allelic SSRs identified three sub-groups (K = 3) while the LD simulation trend line based on squared-allele frequency correlations (r²) predicted LD decay of 15–20 cM in peanut genome. Detailed analysis identified a total of 524 highly significant MTAs (pvalue >2.1×10–6) with wide phenotypic variance (PV) range (5.81–90.09%) for 36 traits. These MTAs after validation may be deployed in improving biotic resistance, oil/ seed/ nutritional quality, drought tolerance related traits, and yield/ yield components.

Nocardia farcinica brain abscess: epidemiology, pathophysiology, and literature review

BACKGROUND

Infections caused by Nocardia farcinica are potentially lethal because of the organism's tendency to disseminate and resist antibiotics. Central nervous system involvement has been documented in 30% of infections caused N. farcinica.

METHODS

Case report and review of the literature.

RESULTS

A case of primary brain abscess caused by N. farcinica, identified by 16SrRNA sequencing, is presented, and 39 cases reported previously in the literature are reviewed. Our patient underwent a neuronavigation-guided right frontal craniotomy and was treated with trimethoprim/sulfamethoxazole and amoxicillin-clavulanic acid for 12 mo. He showed marginal improvement in his prior left hemiparesis at the last review 14 months later.

CONCLUSION

Cases of N. farcinica infections are being reported increasingly because of recent changes in taxonomy and diagnostic methodology. This change in epidemiology has implications for therapy because of the organism's pathogenicity and natural resistance to multiple antimicrobial agents, including third-generation cephalosporins. Any delay in starting appropriate antibiotic therapy can have adverse consequences.

Multidrug-resistant endemic clonal strain of Candida auris in India

Candida auris is a recently described rare agent of fungemia. It is notable for its antifungal resistance. A total of 15 C. auris isolates, originating from seven cases of fungemia, three cases of diabetic gangrenous foot, and one case of bronchopneumonia from a tertiary care hospital in south India, were investigated. All of the 15 isolates were identified by sequencing and 14 of these along with 12 C. auris isolates previously reported from two hospitals in Delhi, north India, two each from Japan and Korea were genotyped by amplified fragment length polymorphism (AFLP). In vitro antifungal susceptibility testing (AFST) was done by the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method. Candida auris isolates were misidentified as Candida haemulonii by VITEK. All were resistant to fluconazole [geometric mean minimum inhibitory concentration (MIC) 64 μg/ml] and 11 isolates were resistant to voriconazole (MIC ≥1 μg/ml). Forty-seven percent of the C. auris isolates were resistant to flucytosine (MIC ≥64 μg/ml) and 40% had high MIC (≥1 μg/ml) of caspofungin. Breakthrough fungemia developed in 28.6% of patients and therapeutic failure in 4 (66.7%) patients. Interestingly, the 26 Indian C. auris isolates from north and south India were clonal and phenotypically and genotypically distinct from Korean and Japanese isolates. The present study demonstrates that C. auris is a potential emerging pathogen that can cause a wide spectrum of human mycotic infections. The prevalence of a C. auris endemic clonal strain resistant to azoles and other antifungals in Indian hospitals with high rates of therapeutic failure in cases of fungemia is worrisome.

Tricuspid valve mycetoma in an infant successfully treated by excision and complex tricuspid valve repair followed by fluconazole therapy

BACKGROUND

Fungal valve endocarditis in children is an uncommon and lethal disease. The risk increases with use of central venous catheters (CVC), total parenteral nutrition (TPN), and use of broad-spectrum antibiotics during the neonatal period. Due to high mortality, a combination of surgery and antifungal therapy is usually recommended for treatment.

METHODS

Case report and review of the literature.

RESULTS

We present a case of an asymptomatic infant with multiple Candida tricuspid valve mycetomas. Complete cure was achieved by combined tricuspid valve repair and fluconazole therapy. We also review 26 cases of tricuspid valve Candida endocarditis in children published in the literature.

CONCLUSION

From being uniformly fatal five decades ago to a current survival rate of 64% to 100%, the prognosis of Candida endocarditis has changed dramatically with the use of antifungal therapy alone or in combination with surgery. Our case re-emphasizes the role of valve-sparing debridement with repair of the native valve using autologous pericardium in combination with long-term antifungal therapy as a feasible option in managing tricuspid valve Candida endocarditis.

Clinical Profile of Patients Admitted with Swine-Origin Influenza A (H1N1) Virus Infection: An Experience from A Tertiary Care Hospital

BACKGROUND

Pandemic influenza A (H1N1) 2009 has posed a serious public health challenge world-wide. H1N1 critical illness mostly affects young patients and is often fatal.

OBJECTIVE

Primary objective was to study clinical profile of the patients admitted with confirmed H1N1 swine flu infection. Secondary objective was to observe the risk factors associated with complications like need of mechanical ventilation and or death among H1N1 infected patients.

MATERIAL AND METHODS

A prospective observational study was conducted in a tertiary care teaching hospital from June 2009, to December, 2011. H1N1 infection was confirmed by reverse transcriptase PCR. Statistical analysis was done by SPSS, version 11. Binary logistic regression was used to find out independent risk factors for morbidity.

RESULTS

Total 495 patients were tested for H1N1 infection. Among them, 115 (23%) were positive and 88(76%) required admission. Median age of cohort was 29 years and 87% of the patients were below 54 years of age. Most common presenting symptoms were fever (98%), followed by cough (86%) and sore throat (54%). Out of 88 patients, 14 (16%) required mechanical ventilation and 6(6.8%) died. Lymphopaenia (Lymphocytes <10%) and presence of patchy infiltrates on chest X-ray (CXR) the time of presentation were independent risk factors associated with need of mechanical ventilation or death in H1N1 infected patients by multivariate analysis.

CONCLUSION

Present study showed that H1N1 swine flu mainly affected people who were < 54 years of age. Majority of patients improved with antiviral treatment. Lymphopaenia and CXR which showed bilateral pneumonia at time of presentation were found to be independent risk factors associated with requirement of mechanical ventilation and/or death in H1N1 infection. Pregnant females with flu constituted 33% of total mortality. High priority should be given to such patients. Further community based studies are required to analyze the actual impact of H1N1 infection in the community.