Correlating clinical breakpoint concentration of moxifloxacin with gyrA mutations using the GenoType MTBDRsl assay Version 2.0

INTRODUCTION

Widespread use of Fluoroquinolones (FQs) has led to the development of its resistance in clinical isolates of Mycobacterium tuberculosis. However, in Mycobacterium tuberculosis, phenotypic resistance to FQs has been shown to be heterogeneous, ranging from low-level resistance to high-level resistance. This stratification in resistance has important implications for the inclusion of moxifloxacin (Mfx) in the treatment regimen. The World Health Organization recommends the use of GenoType MTBDRsl assay as the initial test for detecting resistance conferring mutations (both high and low) to FQs in patients with confirmed MDR-RR TB. The present study was conducted to explore the relationship of MTBDRsl Version 2.0 detected mutations in gyrA gene and genotypic DST of Mfx at WHO defined Clinical Breakpoint (CB).

MATERIALS AND METHODS

A total of 200 sputum samples from Confirmed MDR/RR TB patients were included in this study. All of these samples had mutations conferring resistance to FQ confirmed by GenoType MTBDRsl assay. These samples were further subjected to Phenotypic DST against moxifloxacin using the Bactec MGIT-960 system.

RESULTS

All of the 200 representative FQ resistant isolates had mutations in gyrA gene only with no detectable mutation in gyrB gene. 109 (54.5%) of the isolates had mutations associated with high-level increase in MIC while 91 (45.5%) isolates had mutations associated with low-level increase in MIC. Phenotypic DST of these 200 isolates against Mfx at CB (1.0μg/ml) revealed that of the 109 isolates with mutations associated with high-level increase in MIC and expected to be resistant at CB, only 34 (31.2%) were resistant and the remaining 75 (68.8%) were sensitive.

CONCLUSION

Moxifloxacin is an important drug in the regimen for treating Drug-resistant TB and the decision to exclude this drug from the regimen should not be taken merely on the basis of mutational patterns. It should rather be taken after considering the combined results of mutational analysis and phenotypic DST.

Effectiveness of Xpert MTB/RIF for the diagnosis of extrapulmonary tuberculosis at various stand-alone laboratories in Delhi

BACKGROUND

Globally, EPTB accounts for 15% of the notified incident TB cases. Laboratory confirmation of EPTB is challenging and majority of the cases remain undetected for a longer time. A major breakthrough in the diagnosis of EPTB was the introduction of nucleic acid amplification tests (NAAT). One such test-the Xpert MTB/RIF assay also known as Cartridge based nucleic acid amplification test (CBNAAT) was endorsed by the Scientific and Technical Advisory Board of the WHO for the diagnosis of Tuberculosis. The present study was conduct to evaluate the outcome of various extrapulmonary samples tested in the year 2019 at different standalone NAAT laboratories in Delhi.

MATERIALS AND METHODS

A total of 20,238 samples consisting mainly of Pus (21.77%), Cerebrospinal fluid (CSF) (14.96%), Biopsies (13.87%), Pleural fluid (10.49%), Lymph node aspirations (FNAC aspirates) (6.75%), synovial fluid (0.54%) and gastric aspirates (26.4%) tested at 22 standalone NAAT laboratories were included in this study.

RESULTS

Mycobacterium tuberculosis was detected in 3496 samples and resistance to rifampicin was detected in 329 of the samples. The overall yield of all the specimens combined was 17.2%. Highest yield was seen in Lymph nodes aspirates (FNAC) (36.0%), followed by pus (35.4%), tissues (15.7%), synovial fluid (13.5%), Endometrial tissues (10.7%), Pleural fluid (9.5%), Gastric aspirates (9.4%) and CSF (6.5%). The lowest yield was seen in Cavitary fluids (6.2%).

CONCLUSION

The results of this study highlight the usefulness of Xpert MTB/RIF assay in the diagnosis of EPTB. In particular, this assay proved to be of great utility while testing pus samples, tissue samples and lymph node FNACs.

Benefits and limitations of serological assays in COVID-19 infection

Accurate and rapid diagnostic tests are critical for achieving control of coronavirus disease 2019 (covid-19), a pandemic illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Diagnostic tests for covid-19 fall into two main categories: molecular tests that detect viral RNA, and serological tests that detect anti-SARS-CoV-2 immunoglobulins. Reverse transcriptase polymerase chain reaction (RT-PCR), a molecular test, has become the gold standard for diagnosis of covid-19; however, this test has many limitations that include potential false negative results, changes in diagnostic accuracy over the disease course, and precarious availability of test materials. Serological tests have generated substantial interest as an alternative or complement to RT-PCR and other Nucleic acid tests in the diagnosis of acute infection, as some might be cheaper and easier to implement at the point of care. A clear advantage of these tests over RT-PCR is that they can identify individuals previously infected by SARS-CoV-2, even if they never underwent testing while acutely ill. Many serological tests for covid-19 have become available in a short period, including some marketed for use as rapid, point-of-care tests. The pace of development has, however, exceeded that of rigorous evaluation, and important uncertainty about test accuracy remains.

Laboratory diagnosis of novel corona virus (2019-nCoV)-present and the future

Background

In December 2019 a novel coronavirus SARS-CoV-2 emerged in the Hunan seafood market in Wuhan, China, and soon became a global health problem. Since its outbreak, SARS-CoV-2 has had a major impact on clinical diagnostic laboratories. The scientific community has quickly risen to the occasion and reports of new developments have arrived at an unprecedented scale. At present, there is a growing list of over 400 SARC-CoV-2 diagnostic tests either in development or approved for clinical use. This presentation reviews the current laboratory methods available for testing COVID- 19 in microbiology laboratories and also provides an insight into the future diagnostics approaches.

Methods

Proper respiratory specimen collected at the appropriate time and from the right anatomical site is critical in the accurate and timely diagnosis of SARSCoV2. While oropharyngeal and nasopharyngeal swabs are recommended for the detection of early infection, other lower respiratory tract specimens like the sputum and bronchoalveolar lavage are used for late detection and monitoring of patients with severe COVID-19 pneumonia.

Results and Conclusion

Real-time RT-PCR based molecular assay remains the test of choice for the etiological diagnosis of SARS-CoV-2 while serological tests are being introduced as supplementary tools. Finally, there is an urgent need for scaling up the diagnostic capacity by the introduction of reliable and accurate point-of-care tests which will assist in effective control of this outbreak. These assays can be used in the local hospitals and clinics bearing the burden of identifying and treating patients.

•

At present, there is a growing list of over 400 SARC-CoV-2 diagnostic tests either in development or approved for clinical use.

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Real-time RT-PCR based molecular assay remains the test of choice for the etiological diagnosis of SARS-CoV-2.

•

Oropharyngeal and nasopharyngeal swabs are recommended for the detection of early infection.

•

Lower respiratory tract specimens can be used for late detection and monitoring of patients with severe COVID-19 pneumonia.

•

There is an urgent need for scaling up the diagnostic capacity by the introduction of reliable POC tests.

Upfront Xpert MTB/RIF for diagnosis of pediatric TB-Does it work? Experience from India

Background

Diagnosis of TB in pediatric population poses several challenges. A novel initiative was implemented in several major cities of India aimed at providing upfront access to free-of-cost Xpert MTB/RIF to presumptive pediatric TB cases. This paper aims to describe the experience of implementing this large initiative and assess feasibility of the intervention in high TB burden settings.

Methods

Data were drawn from the pediatric TB project implemented in 10 major cities of India between April 2014 and March 2018. In each city, providers, both public and private, were engaged and linked with a high throughput Xpert MTB/RIF lab (established in that city) through rapid specimen transportation and electronic reporting system. Rates and proportions were estimated to describe the characteristics of this cohort.

Results

Of the total 94,415 presumptive pediatric TB cases tested in the project, 6,270 were diagnosed positive for MTB (6.6%) on Xpert MTB/RIF (vs 2% on smear microscopy). Among MTB positives, 545 cases were rifampicin resistant (8.7%). The median duration between collection of specimens and reporting of results was 0 days (same day) and >89% cases were initiated on treatment. Approximately 50% of the specimens tested were non-sputum. The number of providers/facilities engaged under the project increased >10-fold (from 124 in Q2’14 to 1416 in Q1’18).

Conclusion

This project, which was one of the largest initiatives globally among pediatric population, demonstrated the feasibility of sustaining rapid and upfront access to free-of-cost Xpert MTB/RIF testing. The project underscores the efficiency of this rapid diagnostic assay in tackling several challenges in pediatric TB diagnosis, identifies opportunities for further interventions as well as brings to light scope for effective engagement with healthcare providers. The findings have facilitated a policy decision by National TB Programme mandating the use of Xpert MTB/RIF as a primary diagnostic tool for TB diagnosis in children, which is being scaled-up.

Variable characteristics of viscosity and thermal conductivity in peristalsis of magneto-Carreau nanoliquid with heat transfer irreversibilities

BACKGROUND

Peristaltic is a basic way of fluid transportation in physiology, engineering and nuclear industry. Importance of peristalsis is due to its contraction and compulsion property of symmetric and asymmetric type channel walls. Another beauty of this mechanism is that the channel walls propagates and push the material along the tube/conduit channel walls. This mechanism shows its presence in physiology while food particles are transferred through esophagus and stomach, urine through intestines, spermatoza transportation in reproductive tract. In industry it is found in roller and finger pumps, drug delivery and various nuclear materials e.g. toxic, corrosive, noxious etc. Magnetic field in peristalsis is found helpful in treatment of various treatments using magnets. Actually earth and human body as a whole comprises of magnetic and electric fields. The medical specialists found that unbalances of electromagnetic field in human body is the reason for emotional and physical disturbance. In addition it has significant and potential utilizations in modification of medical, industrial and chemical, procedures for example MRI, evaporation, convection, thermoregulation, MHD throttles, and in various types of tumor treatments. Entropy production work out irreversibility in complex systems which are frequently encountered in industrial mechanisms. In view of that, this methodology is effectually implemented in distinct technological applications covering porous media, propulsion ducts, electronic cooling, turbo-machinery and combustion.

METHOD

Modelled flow mechanism is nonlinear and coupled due to considered assumptions (i.e. nanofluid, nonlinear porous channel, mixed convection, variable viscosity and thermal conductivity, activation energy and chemical reaction). Such nonlinear and coupled system is difficult to tackle analytically. Thus to obtain the solution we employed RK algorithm for numerical simulations.

RESULTS

Stronger magnetic parameter shows resistive characteristics to the flow field. Nonlinear Darcy medium assists the fluid motion at channel center and resits at walls vicinity. Variable characteristics of thermal conductivity moderate the soak or disperse up heat ability which corresponds to temperature reduction. Thermal slip quantity increase the temperature whereas concentration slip deduct the concentration of Carreau nanomaterial. Entropy and Bejan number shows maximum response for higher dissipation estimations. Brownian and thermopherotic motions aspects has reverse impact on nanomaterial concentration.

CONCLUSION

Entropy and Bejan number deduces for higher variable thermal conductivity values. Carreau material variable enhance the entropy of the system as a whole.

Inelastic scattering of photoelectrons from He nanodroplets

We present a detailed study of inelastic energy-loss collisions of photoelectrons emitted from He nanodroplets by tunable extreme ultraviolet (XUV) radiation. Using coincidence imaging detection of electrons and ions, we probe the lowest He droplet excited states up to the electron impact ionization threshold. We find significant signal contributions from photoelectrons emitted from free He atoms accompanying the He nanodroplet beam. Furthermore, signal contributions from photoionization and electron impact excitation/ionization occurring in pairs of nearest-neighbor atoms in the He droplets are detected. This work highlights the importance of inelastic electron scattering in the interaction of nanoparticles with XUV radiation.

Upfront Xpert MTB/RIF testing on various specimen types for presumptive infant TB cases for early and appropriate treatment initiation

Background

Diagnosis of tuberculosis (TB) in infants is challenging due to non-specific clinical presentations of the disease in this age-group and low sensitivity of widely available TB diagnostic tools, which in turn delays prompt access to TB treatment. Upfront access to Xpert/MTB RIF (Xpert) testing, a highly sensitive and specific rapid diagnostic tool, could potentially address some of these challenges. Under the current project, we assessed the utility and feasibility of applying upfront Xpert for diagnosis of tuberculosis in infants, including for testing of non-sputum specimens.

Methods

A high throughput lab was established in each of the four project cities, and linked to various health care providers across the city, through rapid specimen transportation and electronic reporting linkages. Free Xpert testing was offered to all infant (<2 years of age) presumptive TB cases (both pulmonary and extra-pulmonary) seeking care at public and private health facilities.

Results

A total of 7,994 presumptive infant TB cases were enrolled in the project from April 2014 to October 2016, detecting 465 (5.8%, CI: 5.3–6.4) TB cases. The majority (93.9%; CI: 93.4–94.4) of patient specimens were non-sputum and TB positivity was higher amongst non-sputum specimens. Further, a high proportion (5.6% CI 3.8–8.1) of infant TB cases were found to be rifampicin resistant. Covering large cities with a single lab per city over more than two years, the project demonstrated the feasibility of same-day diagnosis with upfront Xpert testing. This in turn led to prompt treatment initiation, with a two-day median turnaround time to treatment initiation. Case mortality observed in the project cohort of diagnosed TB cases was 11.0% (CI 8.4–14.1), the majority of which was pre- or early treatment mortality, in spite of prompt access to treatment for most diagnosed cases.

Conclusion

The current project demonstrated the feasibility of applying rapid and upfront Xpert testing for presumptive infant TB cases. Rapid TB diagnosis in turn facilitates prompt and appropriate treatment initiation. Further, levels of rifampicin resistance observed in infants TB cases highlight the additional benefit of upfront resistance testing. However, high rates of early case mortality, in spite of prompt diagnosis and treatment initiation, highlight the need for further research in infant patient pathways for overall improvement in TB care for infant populations.

A rare case of haemorrhagic shock secondary to spontaneous rupture of a branch of the left colic artery and the right gastric artery

Spontaneous splanchnic artery rupture is associated with up to 70% mortality. Affected vessels are often aneurysmal, secondary to atherosclerosis. We report, to our knowledge, the only case of spontaneous rupture of a branch of the left colic artery and the right gastric artery, possibly secondary to vasculitis.

Catalysing progressive uptake of newer diagnostics by health care providers through outreach and education in four major cities of India

BACKGROUND

Unlike in adults, diagnosis of TB can be challenging in children, as signs and symptoms of paediatric TB can be very non-specific and similar to other common childhood chest infections, which may lead to under or delayed diagnosis of TB disease. In spite of the increasing availability of rapid high-sensitivity diagnostics in public and private sectors, majority of paediatric TB cases are empirically diagnosed, without laboratory confirmation. To address these diagnostic challenges, World Health Organization (WHO) has recommended upfront Xpert MTB/RIF (Xpert) testing for the diagnosis of TB in paediatric presumptive pulmonary and extra-pulmonary TB (EPTB) cases. However, in spite of the increasing availability of rapid high-sensitivity diagnostics, a significant gap exists in its application with Xpert being rarely used as an upfront diagnostic among patients presumed to have TB. Under an ongoing paediatric project since April 2014, which provided free-of-cost upfront Xpert testing, several low-cost outreach and education interventions were undertaken to increase the diagnostic uptake by different providers catering to the paediatric population, thereby increasing adherence to global guidance.

METHODS

Providers catering to paediatric population in the project cities were systematically mapped and contacted using different outreach strategies. The focus of outreach efforts was to increase provider literacy and increase their awareness of the availability of free rapid diagnostic services with the goal of changing their diagnostic approaches.

RESULTS

From April 2014 to June 2016, more than 5,700 providers/facilities were mapped and 3,670 of them were approached. The number of providers/facilities engaged under the project increased more than 10-fold (43 in April, 2014 to 466 in June, 2016), with significant increase in project uptake, both from public and private sector. Overall 42,238 paediatric presumptive TB cases were enrolled in the project, across the four cities. Over the project period, quarterly diagnostic uptake and paediatric TB cases detection rates increased more than two-fold. TB detection rates were similar in patients from public and private sectors.

CONCLUSIONS

Ongoing efforts in scaling up new rapid diagnostics involves significant investments. These efforts need to be complemented with proactive provider engagement to ensure provider-literacy and awareness, for maximizing impact of this scale-up. The current project demonstrated the usefulness of outreach and education interventions for the effective uptake of newer diagnostics.

Laparoscopic cholecystectomy: a prospective cohort study assessing the impact of grade of operating surgeon on operative time and 30-day morbidity

Introduction There is an increasing trend towards day case surgery for uncomplicated gallstone disease. The challenges of maximising training opportunities are well recognised by surgical trainees and the need to demonstrate timely progression of competencies is essential. Laparoscopic cholecystectomy provides the potential for excellent trainee learning opportunities. Our study builds upon previous work by assessing whether measures of outcome are still affected when cases are stratified based on procedural difficulty. Material and methods A prospective cohort study of all laparoscopic cholecystectomies conducted at a district general hospital between 2009 and 2014, performed under the care of a single consultant. The operative difficulty was determined using the Cuschieri classification. The primary endpoint was duration of operation. Secondary endpoints included length of hospital stay, delayed discharge rate and 30-day morbidity. Results A total of 266 laparoscopic cholecystectomies were performed during the study period. Mean operative time for all consultant-led cases was 52.5 minutes compared with 51.4 minutes for trainees (P = 0.67 unpaired t-test). When cases were stratified for difficulty, consultant-led cases were on average 5 minutes faster. Median duration of hospital stay was equivalent in both groups and there was no statistical difference in re-attendance (12.9% vs. 15.3% P = 0.59) or re-admission rates (3.2% vs. 8.1% P = 0.10) at 30 days. Conclusions Our study provides evidence that laparoscopic cholecystectomy provides a good training opportunity for surgical trainees without being detrimental to patient outcome. We recommend that, in selected patients, under consultant supervision, laparoscopic cholecystectomy can be performed primarily by the surgical trainee without impacting on patient outcome or theatre scheduling.

Accelerating access to quality TB care for pediatric TB cases through better diagnostic strategy in four major cities of India

Background

Diagnosis of TB in children is challenging, and is largely based on positive history of contact with a TB case, clinical and radiological findings, often without microbiological confirmation. Diagnostic efforts are also undermined by challenges in specimen collection and the limited availability of high sensitivity, rapid diagnostic tests that can be applied with a quick turnaround time. The current project was undertaken in four major cities of India to address TB diagnostic challenges in pediatric population, by offering free of cost Xpert testing to pediatric presumptive TB cases, thereby paving the way for better TB care.

Methods

A high throughput lab was established in each of the four project cities, and linked to various health care providers across the city through rapid specimen transportation and electronic reporting linkages. Free Xpert testing was offered to all pediatric (0–14 years) presumptive TB cases (both pulmonary and extra-pulmonary) seeking care at public and private health facilities.

Results

The current project enrolled 42,238 pediatric presumptive TB cases from April, 2014 to June, 2016. A total of 3,340 (7.91%, CI 7.65–8.17) bacteriologically confirmed TB cases were detected, of which 295 (8.83%, CI 7.9–9.86) were rifampicin-resistant. The level of rifampicin resistance in the project cohort was high. Overall Xpert yielded a high proportion of valid results and TB detection rates were more than three-fold higher than smear microscopy. The project provided same-day testing and early availability of results led to rapid treatment initiation and success rates and very low rates of treatment failure and loss to follow-up.

Conclusion

The current project demonstrated the feasibility of rolling out rapid and upfront Xpert testing for pediatric presumptive TB cases through a single Xpert lab per city in an efficient manner. Rapid turnaround testing time facilitated prompt and appropriate treatment initiation. These results suggest that the upfront Xpert assay is a promising solution to address TB diagnosis in children. The high levels of rifampicin resistance detected in presumptive pediatric TB patients tested under the project are a major cause of concern from a public health perspective which underscores the need to further prioritize upfront Xpert access to this vulnerable population.

Band pattern analysis of mutations in rifampicin resistance strain of Mycobacterium tuberculosis by Line Probe assay in patients from Delhi, India

BACKGROUND

The GenoType MTBDRplus, a commercial Line Probe Assay (LPA) kit from Hain Lifescience, Germany, is endorsed by India's RNTCP Program for diagnosis of DRTB cases among smear-positive sputum samples. Although the LPA has been studied in several laboratories, there is a wide variation in existing M. tuberculosis strains across the globe, and false results can occur due to the presence of unique genetic mutations in different settings.

AIM AND OBJECTIVE

An attempt was made to carry out band pattern analysis using LPA and also to observe uncommon mutations in MDR strains.

MATERIALS AND METHODS

Sputum samples were collected from MDR suspects and transported to intermediate reference laboratory (IRL) at New Delhi Tuberculosis Centre in Delhi. Sputum decontamination, DNA extraction, amplification, hybridization, and band pattern analysis of Line Probe assay strips was performed as per manufacturer's instructions.

RESULTS

Among the 3000 samples with interpretable LPA strips, rifampicin drug resistance with or without isoniazid was observed in 600 samples. The most common mutation detected by LPA in the rpoB gene was Ser516Leu (29.0%). Novel mutations reported in this study include mutation from CAG (Gin) to CAT (His) at codon 517, AGC (Ser)-AGG (Arg) at codon 512, ACA (Thr) to GCA (Ala) at codon 526, TTG (Leu)-CTG (Leu)^s at codon 524.

CONCLUSION

High frequencies of uncommon mutations in rpoB gene by LPA were observed, highlighting possibility of those in-silico detected mutations that may not impart phenotypic resistance further.

Role of pRIFLE Criteria in Early Diagnosis of Severity Staging of Neonatal AKI and its Impact on Management

Mortality is high among sick neonates who have concomitant acute kidney injury (AKI). This observational study was done at Special Care Baby Unit (SCABU) of Dhaka Medical College Hospital (DMCH), Bangladesh from October 2013 to March 2014 to find out the role of pRIFLE criteria in prediction of severity stages of AKI in neonate and early intervention to see the immediate outcome. A total of 44 neonates with AKI were included, all were treated conservatively and with intermittent peritoneal dialysis (IPD) as needed. The neonate of ≤7 days old comprised the main bulk (n=28) and M: F = 21: 23. The diagnosis was based on eCCL criteria of pRIFLE showed that 40.9% neonates were at risk of AKI, 20.5% have had already injured. Higher proportions of neonates were classified as failure (38.6%). The distribution of biochemical parameters among three stages of AKI showed serum potassium was significantly higher in failure group (p<0.001). The serum creatinine both at baseline and at next evaluations were significantly raised in the failure group (p<0.001). However, failure group had a significantly longer hospital stay compared to risk and injury group (p<0.001). Multiorgan failure was found to be lower in the risk group compared to other two groups (p=0.026). Majority of the failure group needed dialysis as compared to the risk and injury group (p<0.001). The mortality was progressively higher from risk to failure groups (p=0.106). Overall 27% of the neonates diagnosed AKI by pRIFLE were died of the disease. The study concluded that pRIFLE staging in AKI is useful and sensitive in the diagnosis and management of AKI in neonates.

Health Related Quality of Life in Children with Nephrotic Syndrome in Bangladesh

Outcome of children with nephrotic syndrome has continued to improve over time. However minimal data exist to describe health-related quality of life in children with nephrotic syndrome. This cross sectional study was conducted over a period of six months to assess the health related quality of life in children with nephrotic syndrome in the Department of Pediatric Nephrology, Dhaka Medical College Hospital, Bangladesh. Fifty children (age ranged 2-12 years) with nephrotic syndrome who had three or more relapses diagnosed at least one year back receiving treatment and on follow up were included in this study. Quality of Life scores were collected using Bengali translated instruments- the Pediatric Quality of Life Inventory™ (PedsQL™) version 4.0 Generic Scale and the Pediatric Quality of Life Questionnaire for Nephrotic Syndrome proxy-report from parents. Medical data and Demographic data were collected from medical records, and from parents in outpatient department or hospital ward. Interviews of eligible guardians were performed individually to collect quality of life (QoL) scores. Among 50 children, mean±SD age of the children was 7±2.92 years. Most children were male (58%). Female parents respondent during interview were 62%, most parents (48%) were very poor in socioeconomic condition. Most children had frequent relapses (60%). Median time since diagnosis was 2 years. Regarding PedsQL scores, child age with physical summary score (p value <0.001), child age with social summary score (p value 0.003), frequent relapse with kidney disease summary score (p value 0.04) and time since diagnosis (p value <0.001) were statistically significant. In conclusion physical and social summary score were worst. Frequent relapse found to be an important factor in impaired QoL. Prolonged duration of the disease activity was associated with significant impairment of QoL.

Experience of Percutaneous Versus Surgically Placed Catheter for Continuous Ambulatory Peritoneal Dialysis in Children with Chronic Kidney Disease Stage-V

The lifespan and outcome of end stage renal disease (ESRD) children have dramatically improved since the development of continuous ambulatory peritoneal dialysis (CAPD), it offers several advantages over hemodialysis. Percutaneous placement of CAPD catheters in children is minimally invasive, reliable, safe and cost-effective method. Percutaneous method of CAPD catheter insertion can be used in children to avoid the complications of general anesthesia and surgery. This study was done to evaluate the efficacy of CAPD in children, to find out the complication profile of CAPD & to compare the advantages of surgical versus percutaneously placed CAPD catheters in children. This prospective longitudinal comparative study was carried out in the department of Pediatric Nephrology, Dhaka Medical College Hospital (DMCH), Bangladesh from July 2011 to June 2014. A total of 8 children with ESRD were included (Age 5-14 year, M: F=1: 1). All underwent CAPD, Group I = surgically placed CAPD catheter (N=5), Group II = percutaneously placed CAPD catheter (N=3). Average duration of CAPD in Group I and Group II were 31.6 vs. 9 (months) with a total of 158 vs. 27 patient months of CAPD respectively. The rate of complications of the 2 groups and their outcome were compared. Common complications being observed were peritonitis 1 episode per 12.1 vs. 1.8 patient months (p<0.001), catheter obstruction by omental capture 1 vs. 3 in Group I and Group II respectively. Catheter tip dislocation was commonly found in all Group II children (p<0.01) and all needed laparotomy and omentectomy. Three out of 5 in Group I is still on CAPD, 1 transferred to HD and another 1 expired due to uncontrolled hypertension with congestive heart failure. Among 3 of Group II, 2 died of repeated peritonitis and hypertensive complications and rest 1 is transferred to HD after 1year due to exit site fluid leaking. Satisfactory level of improvement of mean weight, mean serum albumin and declining of serum creatinine in both groups has been found after CAPD. Although CAPD is an effective modality of renal replacement therapy for children, but percutaneous method of catheter insertion is associated with higher rate of complications. Placement of catheter by surgical method with elective omentectomy will reduce catheter related complications. Early detection of peritonitis and prompt therapy is essential for a favourable outcome.

Random blinded rechecking of AFB smears in a pilot project at an intermediate reference laboratory

BACKGROUND

In most developing countries, sputum smear microscopy for acid-fast bacilli remains the front line and often the only diagnostic tool for the diagnosis of tuberculosis (TB), making quality assurance of smear microscopy an important activity.

OBJECTIVE

To evaluate the results of a pilot study, where the random blinded rechecking for the entire state of Delhi was conducted at a reference laboratory.

METHODOLOGY

Slides from 25 Revised National Tuberculosis Control Programme designated districts (200 peripheral microscopy centres) in Delhi were re-read after proper coding by all the Senior Tuberculosis Laboratory Supervisors (STLS) at an intermediate reference laboratory under proper supervision.

RESULTS

Of 12,162 re-read slides, 204 discrepant results were found. Of these, 150 (73.5%) errors were attributed to the peripheral microscopy centres and 54 (26.5%) to STLS. High false-positive errors were observed at a frequency of 12/150 (8%), and high false-negative errors at a frequency of 38/150 (25%). Minor errors, i.e., low false-negative, low false-positive and quantification errors, were observed at frequencies of respectively 68/150 (45.3%), 17/150 (11.3%) and 15/150 (10.0%).

CONCLUSION

Greater stringency in the supervision of random blinded rechecking at the district level is essential to make smear rechecking more efficient and effective.

FROM Qutn TO Bt COTTON: DEVELOPMENT, ADOPTION AND PROSPECTS. A REVIEW

Cotton has unique history of domestication, diversification, and utilization. Globally it is an important cash crop that provides raw material for textile industry. The story of cotton started from human civilization and the climax arrived with the efforts of developing transgenic cotton for various traits. Though conventional breeding brought steady improvement in developing resistance against biotic stresses but recent success story of gene transferfrom Bacillus thuringiensis into cotton showed game changing effects on cotton cultivation. Amongst various families of insecticidal proteins Bt Cry-toxins received more attention because of specificity against receptors on the cell membranes of insect midgut epithelial cells. Rapid Bt cotton adoption by farmers due to its economic and environmental benefits has changed the landscape of cotton cultivation in many countries. But the variable expression of Bt transgene in the newly developed Bt cotton genotypes in tropical environment is questionable. Variability of toxin level in different plant parts at various life stage of plant is an outcome of genotypic interaction with environmental factors. Temporal gene expression of Cry1Ac is also blamed for the epigenetic background in which transgene has been inserted. The presence of genotypes with sub-lethal level of Bt toxin might create resistance in Lepidopteron insects, limiting the use of Bt cotton in future, with the opportunityfor other resistance development strategies to get more attention like gene stacking. Until the farmers get access to more recent technology, best option is to delay the development of resistance by applying Insect Resistance Management (IRM) strategies.

Development and in-vitro Evaluation of Once Daily Tablet Dosage Form of Loxoprofen Sodium

Purpose: To formulate and characterize once daily controlled release tablet of loxoprofen sodium.Methods: Eudragit RS-100, hydroxylpropyl methylcellulose (HPMC) and pectin were used as release retarding polymers. All the formulations were prepared by direct compression method. Various precompression studies were carried out to determine Hausner’s ratio, Carr’s index, angle of repose, bulk density and tapped density Differential scanning calorimetry (DSC) studies and also post-compression studies to evaluate hardness, friability, weight variation, drug content, in-vitro drug release were conducted on the tablets. The drug release data were subjected to kinetic models, including zero order, first order, Hixon Crowell, Higuchi and Korsmeyer-Peppas.Results: Compressibility index (7.6 ± 1.32 - 12.5 ± 1.43%), Hausner’s ratio (1.08 ± 0.04 - 1.14 ± 0.03), angle of repose (27.78 ± 0.47 - 30.49 ± 0.46°), hardness (6.25 ± 0.27 - 7.21±0.21 kg/cm2), friability (0.14 ± 0.06 - 0.28 ± 0.0 %), weight variation (249.5 ± 2.09 - 251.35 ± 2.41 mg) and drug content  (97.30 ± 0.28 - 103.70 ± 0.31 %) were within generally accepted limits for the pre-and post-compression formulations, respectively. The tablets having the maximum amount of among the three polymers tested as matrix materials, HPMC, represented by F3 tablets, exerted better sustained release properties after 12 h. Release pattern was more of Fickian diffusion followed by Higuchi mechanism.Conclusion: The release of the loxoprofen sodium was optimized up to 12 h.Keywords: Loxoprofen, Sustained release, hydroxypropyl methylcelluose, Pectin, Eudragit, Matrix tablets

Prediction of Risk Factors of Frequent Relapse Idiopathic Nephrotic Syndrome

This case control study was aimed to identify the predictive risk factors for frequent relapse idiopathic nephrotic syndrome (INS) and conducted in Sir Salimullah Medical College & Mitford Hospital, Dhaka and at Renal and Dialysis Unit of Dhaka Shishu Hospital and Bangladesh Institute of Child Health (BICH), Dhaka, from January 2006 to December 2006. We examined retrospectively the clinical course of fifty cases of frequent relapse nephrotic syndrome (FRNS) as cases and fifty cases of infrequent relapse nephrotic syndrome (IRNS) as control who met the predefined enrollment criteria, followed for at least one year after initial onset of disease. After enrollment following parameters were studied as predictors of frequent relapse: i) Socio-demographic variables: age, sex, socio-economic condition, number of living room ii) Disease related variables i.e. age of onset, duration of illness, frequency of relapse within the 1st year, regimen of initial steroid therapy, total cumulative dose of steroid for remission, day of remission after starting steroid, association with atopy and infection, concomitant upper respiratory illness iii) Biochemical and pathological variables (at the time of initial attack) i.e. Serum albumin, serum cholesterol, blood urea, 24 hours urinary protein, serum creatinine, complete blood count, urine RBC, urine pus cell, urine culture. The test statistics used to analyses the data were descriptive statistics, Chi-square probability test, Student's t-test and Binary logistic regression analysis for Odds ratio. Both univariate and multivariate logistic regression analysis revealed that age of onset (P<0.001, OR=0.9, 95% CI=0.85-0.95), poor socioeconomic status (P<0.034, OR=0.5.8, 95% CI=1.14-29.5) and low serum albumin level at the time of initial presentation (P<0.022, OR=0.8, 95% CI=0.65-0.97) were independent predictors of frequent relapse nephrotic syndrome. In conclusion, we demonstrated that age at onset, poor socioeconomic condition and low serum albumin level at the time of initial attack is independent risk factors for frequent relapse idiopathic nephrotic children. This information can be used as a predictor of FRNS.

Fluoroscopically guided balloon dilatation for the treatment of achalasia: long-term outcomes

To report the immediate and long-term outcomes following the fluoroscopically guided balloon dilatations performed in our department for the treatment of achalasia. We reviewed retrospectively all patients that underwent a fluoroscopically guided balloon dilatation because of achalasia in our department between April 2007 and September 2010. The follow-up was performed by interviews and/or investigation of the patient's medical and imaging records. The primary endpoints of the study were technical success, clinical success, major complication rates, and repeat dilatation rates because of recurrence of clinical symptomatology. Secondary endpoints were the rate of minor complications and the dilatation-free interval. Various parameters that could affect the clinical outcome were also analyzed. Thirty-nine consecutive patients (20 female) with a mean age 44 ± 17 years underwent 69 dilatations, while 10/39 (25.6%) patients had a history of a previous laparoscopic myotomy. The most common symptom was dysphagia (64/69, 92.7%), while regurgitation and/or retrosternal pain were present in 12/39 (30.7%) and 9/39 (23%) of the cases, respectively. Technical success was achieved in 98.5% (68/69). There were no procedure-related major complications. The mean balloon diameter used was 30 ± 3.9 mm, and the mean period of follow-up was 27.7 ± 16.0 months. Excellent or good initial responses were noted in 54/66 cases (81.8%). A repeated dilatation to deal with recurrence of symptoms was performed in 69.4% of the cases (25/36). In the majority of the cases, two dilatations were needed in order to achieve long-term relief from symptoms. A dilatation-free interval of 4 years was observed in 26.4%. Clinical success was achieved in 30/36 patients (83.3%). Subgroup analysis did not detect significantly different recurrence rates in patients with and without previous laparoscopic myotomy (50% vs. 69% respectively), those of young age (75% < 21 years vs. 68.8% > 21 years), and male gender (71.4% male vs. 55.0% females). The high redilatation rate was attributed to the utilization of smaller balloons by less experienced operators. Fluoroscopically guided balloon dilatation is a safe and effective method for the treatment of achalasia. Young age and prior Heller's laparoscopic myotomy were not associated with increased rates of recurrence rate or clinical failure.

Introgression of cotton leaf curl virus-resistant genes from Asiatic cotton (Gossypium arboreum) into upland cotton (G. hirsutum)

Cotton is under the constant threat of leaf curl virus, which is a major constraint for successful production of cotton in the Pakistan. A total of 3338 cotton genotypes belonging to different research stations were screened, but none were found to be resistant against the Burewala strain of cotton leaf curl virus (CLCuV). We explored the possibility of transferring virus-resistant genes from Gossypium arboreum (2n = 26) into G. hirsutum (2n = 52) through conventional breeding techniques. Hybridization was done manually between an artificial autotetraploid of G. arboreum and an allotetraploid G. hirsutum, under field conditions. Boll shedding was controlled by application of exogenous hormones, 50 mg/L gibberellic acid and 100 mg/L naphthalene acetic acid. Percentage pollen viability in F(1) hybrids was 1.90% in 2(G. arboreum) x G. hirsutum and 2.38% in G. hirsutum x G. arboreum. Cytological studies of young buds taken from the F(1) hybrids confirmed that they all were sterile. Resistance against CLCuV in the F(1) hybrids was assessed through grafting, using the hybrid plant as the scion; the stock was a virus susceptible cotton plant, tested under field and greenhouse conditions. All F(1) cotton hybrids showed resistance against CLCuV, indicating that it is possible to transfer resistant genes from the autotetraploid of the diploid donor specie G. arboreum into allotetraploid G. hirsutum through conventional breeding, and durable resistance against CLCuV can then be deployed in the field.

Relationship between serum IgE and frequent relapse idiopathic nephrotic syndrome

This prospective case control study was carried out in Renal and Dialysis Unit of Dhaka Shishu Hospital, Bangladesh from January 2004 to December 2004 to determine serum IgE level in frequent relapse Idiopathic nephrotic syndrome and to evaluate any role of IgE in the rate of relapse. Thirty cases of frequent relapse (FR) Idiopathic nephrotic syndrome (INS) were considered as cases and thirty cases of infrequent relapse nephrotic syndrome (IRNS) were considered as control. Serum IgE level was measured in all patients at the time of relapse and again four weeks after steroid treatment when patient was in remission. The test statistics used to analyses the data were descriptive statistics, Chi-square probability test, Student's "t"-Test, Mann Whitney test and Wilcoxon Signed Rank test. Majority of the patients' age in both the groups was between 2-6 years. The male female ratio in FR group was 2:1, while that in IR group was 3:2. Forty percent of the frequent relapsers and 30% of infrequent relapsers were found to possess the history of atopy. However, the difference between the two groups was not statistically significant (p>0.05). The mean serum albumin in FR was observed to be significantly lower (13.73±0.59 gm/L) than that in IR (15.73±0.67 gm/L) (p<0.05). Mean serum IgE at the time of relapse in FR (1791±95 IU/mL) was found to be more than 3 times higher than that in IR (560±50 IU/mL) (p<0.001). Serum IgE level at the time of remission has decreased to almost normal in IR group (204±21 IU/mL) but it was still found 5 times higher in FR group (1086±79 IU/mL) (p<0.001). Serum IgE level is high in both FR and IR groups of nephrotic syndrome at the time of relapse. It reverts back to normal in IRNS but persistently and significantly high in FR group in both relapse and remission. Level of the serum IgE can be used as a predictor of FRNS.

Evaluation of a new quality assessment strategy for blinded rechecking of random sputum smears for TB in Delhi, India

This study was conducted at the New Delhi Tuberculosis Center, Delhi, India, from 1 January 2006 to 31 December 2007 to assess the feasibility of implementing random blinded rechecking (RBRC), a quality assurance strategy, and its impact on the performance of tuberculosis smear microscopy in Delhi, RBRC activities are carried out monthly at District Tuberculosis Centers (DTCs). Forty thousand five hundred and six slides were rechecked during the study period. RBRC, as a method of quality assurance was found to be feasible for a large application. The quality of sputum microscopy improved, with a significant reduction in the number of false positive and false negative errors in 2007 compared to 2006. The number of microscopy centers reporting high false errors decreased significantly in 2007.

Prevalence of multidrug-resistant tuberculosis among category II pulmonary tuberculosis patients

BACKGROUND & OBJECTIVES

Multidrug-resistant tuberculosis (MDR-TB) has emerged as a significant global health concern. The most important risk factor for the development of MDR-TB is previous anti-tuberculosis therapy. Category II pulmonary TB includes those patients who had failed previous TB treatment, relapsed after treatment, or defaulted during previous treatment. We carried out this study to ascertain the prevalence of MDR-TB among category II pulmonary TB patients.

METHODS

This was a cross-sectional, descriptive study involving category II pulmonary TB patients diagnosed between 2005 and 2008. All sputum-positive category II TB cases were subjected to mycobacterial culture and drug-susceptibility testing (DST). MDR-TB was defined as TB caused by bacilli showing resistance to at least isoniazid and rifampicin.

RESULTS

A total of 196 cases of sputum-positive category II pulmonary tuberculosis patients were included. Of these, 40 patients (20.4%) had MDR-TB. The mean age of MDR-TB patients was 33.25 ± 12.04 yr; 9 patients (22.5%) were female. Thirty six patients showed resistance to rifampicin and isoniazid; while 4 patients showed resistance to rifampicin, isoniazid and streptomycin. The prevalence of MDR-TB among category-II pulmonary tuberculosis patients was 20.4 per cent.

INTERPRETATION & CONCLUSIONS

The prevalence of MDR-TB in category II TB patients was significant. However, nation-wide and State-wide representative data on prevalence of MDR-TB are lacking. We stress the importance of continuous monitoring of drug resistance trends, in order to assess the efficacy of current interventions and their impact on the TB epidemic.

Emergence of high-level fluoroquinolone-resistant Escherichia coli in Bangladesh

Fifteen fluoroquinolone-resistant strains of Escherichia coli were isolated from different clinical specimens of paediatric patients, 2 years after introduction of the drugs into Bangladesh. However, none of these patients had any definite history of treatment with fluoroquinolones. MICs of these strains to different antibiotics were determined by the broth microdilution method recommended by the Working Party of BSAC. Strains were highly resistant to all drugs except ceftriaxone. Study indicates a high frequency of fluoroquinolone-resistant E. coli strains among the clinical isolates which is possibly related to fluoroquinolone introduction.

Study of different methods of susceptibility testing of M. tuberculosis

This communication is on a multi-centre collaborative study carried out by New Delhi Tuberculosis (NDTB) Centre, Delhi, to compare the different methods of drug susceptibility testing (DST) of Mycobacterium tuberculosis for Streptomycin, Rifampicin, Isoniazid and Ethambutol in various accredited laboratories 40 samples (selected by simple random sampling technique) from sputum positive out-patients presenting between December 2004 and January 2005 were collected at New Delhi Tuberculosis Centre from 24 males and 16 females (age ranging from 18 to 55 years) were taken up for culture and susceptibility testing. The proportion method of DST done at NDTB Centre was taken as standard for comparing the other methods after it was found to have a good agreement with the proportion method performed at Tuberculosis Research Centre, Chennai (Kappa coefficient 0.75 to 1). All 40 sub-cultures were processed for DST by the resistance ratio and proportion methods at NDTB Centre. Also, the 40 sub-cultures were sent to Central JALMA Institute for Leprosy (JALMA), Agra that used the resistance ratio method and 25 sub-cultures were transported to National Institute of Communicable Diseases (NICD), Delhi for performing the Bactec 460TB method. The resistance ratio and proportion methods were compared both intra-laboratory (NDTB Centre) and inter-laboratory (NDTB Centre and JALMA). The sensitivity and specificity of the resistance ratio method compared to the proportion method both inter and intra-laboratory, were very high for all the drugs (except Ethambutol inter-laboratory). This was corroborated by the good agreement between the resistance ratio performed at the two centres. Bactec 460TB method, on the other hand, did not have acceptable measures of validity (sensitivity and specificity) compared to the proportion method for Streptomycin and Ethambutol. Both resistance ratio method & proportion method are comparable and either can be used for making clinical decisions. But Bactec 460 method, despite yielding early results loses out on validity.

Efficacy of repeat sputum examination in RNTCP

BACKGROUND

The guidelines of repeat sputum smear examination in initial smear negative patients (ISN), who also fail the antibiotic trial of three samples have been incorporated in the RNTCP diagnostic algorithm in India in 2005. This study was conducted to assess the utility of repeat sputum smear examination in symptomatic initial smear negative patients to detect new smear positives in the state of Delhi.

MATERIAL AND METHODS

The monthly records of the laboratory abstracts for the six quarters for all the 24 districts of Delhi were analysed w.e.f. first of January 2006 to 30th June 2007.

RESULTS

A total of 243,244 TB suspects were examined for diagnosis during the six quarters w.e.f. January 2006. Of these, 37,666 were found positive on sputum smear microscopy giving a positivity rate of 15.4%. During the same period, a total of 2,195 (1% of ISN ) TB suspects underwent repeat sputum examination, of which 272 were found positive giving a mean positivity of 12.3%.

CONCLUSION

A significant number of apparently smear negative TB cases may in fact be smear positive due to various reasons and can be detected by a simple repeat sputum examination. Yield of sputum positive cases in sputum reexamination is almost the same as in initial sputum examination i.e. 10-15%. Therefore, the policy of repeat sputum examination in symptomatic initial sputum negative cases failing the antibiotic trial should be meticulously followed as advocated in the RNTCP diagnostic algorithm.

Acquired drug resistance pattern in tuberculosis cases at the State Tuberculosis Centre, Delhi, India

SETTING

State TB Demonstration Centre, Delhi, India.

OBJECTIVE

To obtain a baseline estimate of the prevalence of multidrug-resistant tuberculosis (MDR-TB) among previously treated tuberculosis (TB) cases at the State Tuberculosis Centre in 2006.

DESIGN

A retrospective study. Drug susceptibility data of 5252 previously treated patients tested at this centre were analysed.

RESULTS

Of 2880 Mycobacterium tuberculosis isolates from previously treated cases, 1498 (52%) were resistant to one or more anti-tuberculosis drugs, of which 47.1% were MDR. Resistance to isoniazid was observed in all resistant isolates, followed by resistance to rifampicin in 1357 (47.1%), streptomycin in 403 (14.2%) and ethambutol in 107 (3.72%). A significantly higher rate of resistance, including MDR, was observed among treatment failures compared to relapses and defaulters.

CONCLUSION

A very high proportion of drug-resistant cases had MDR besides resistance to two or more drugs. This proportion was significantly higher among treatment failures compared to relapses and treatment after default cases, underlining the need for early identification of treatment failure by early referral for culture and drug susceptibility testing, and initiation of appropriate treatment.

Outcome of multi-drug resistant tuberculosis cases treated by individualized regimens at a tertiary level clinic

AIM

To determine the clinical, radiological and drug resistance profile as well as the factors associated with treatment outcome of Multi-Drug Resistant Tuberculosis (MDR-TB).

MATERIAL AND METHODS

All newly diagnosed patients with pulmonary MDR-TB from August 2002 to December 2004 enrolled at New Delhi Tuberculosis Centre, were included in the study. They were followed up clinically, radiologically and bacteriologically by sputum smear, culture and Drug Susceptibility Testing (DST) at regular intervals. According to their DST pattern and previous history of Anti-Tubercular Treatment (ATT), individualized treatment regimens were tailored for each patient.

RESULTS

Out of total 27 bacteriologically proven cases of MDR-TB included in this study, 19 were males (mean age and weight 38.5 years and 52.6 kgs, respectively) and eight females (mean age and weight 34.3 years and 40.7 kgs, respectively). A majority (18) were residents of Delhi and the rest hailed from different parts of North India. All of them had a history of previous treatment ranging from six to 34 months. Cavity on chest X-rays was seen in 81%, while 44% showed extensive involvement. The patients received at least four "second line drugs" during their treatment with a mean of 6.2 anti-tubercular drugs during their intensive phase. Of the 27 patients, 13 were cured, 10 defaulted, one died, one is still on treatment and two were referred for surgery. Radiological improvement was observed in two third of cases and chest X-ray of two patients showed a complete resolution. Six predictors were identified for successful outcome of MDR-TB. They include weight gain at six months, culture conversion, radiological improvement during treatment, disease with M. tuberculosis strains exhibiting resistance to less than or up to three anti-tubercular drugs, use of less than or up to three second line drugs in treatment and no change of regimen during treatment.

CONCLUSION

Default from treatment was observed to be a major challenge in the treatment of MDR-TB due to long duration and expense of ATT.

Molecular typing of Mycobacterium tuberculosis isolates from different parts of India based on IS6110 element polymorphism using RFLP analysis

BACKGROUND & OBJECTIVE

IS 6110 based typing remains the internationally accepted standard and continues to provide new insights into the epidemiology of Mycobacterium tuberculosis. The aim of the study was to characterize M. tuberculosis isolates obtained from different parts of India based on IS6110 element polymorphism using restriction fragment length polymorphism (RFLP) analysis.

METHODS

RFLP was analyzed among 308 isolates of M. tuberculosis deposited in the Mycobacterial Repository Centre, Agra, from different parts of India. DNAs isolated from these strains were restricted with Pvu II, transferred on to nylon membrane and hybridized with a PCR amplified DIG-labeled 245 bp IS6110 probe.

RESULTS

Based on the copy number, M. tuberculosis isolates were classified into four groups, (i) lacking IS6110 element; (ii) low copy number (1-2); (iii) intermediate copy number (3-5); and (iv) high copy number (6-19). Copy number higher than 19 however was not observed in any of the isolates studied. At the national level, 56 per cent of the isolates showed high copy number of IS6110, 13 per cent showed intermediate copy number, 20 per cent showed low copy number, whereas 11 per cent isolates lacked IS6110 element. At the regional level, there was not much difference in the RFLP profiles of isolates (IS6110 copy numbers/patterns) from different parts of the country.

INTERPRETATION & CONCLUSION

IS6110 DNA based fingerprinting could be a potentially useful tool for investigating the epidemiology of tuberculosis in India.