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Biomedical subjects

N P Singh

Publications and source records attributed to N P Singh.

At least 19 recordsLinked to original sources

DNA damage in human sperm is related to urinary levels of phthalate monoester and oxidative metabolites.

BACKGROUND: The ubiquitous use of phthalate esters in plastics, personal care products and food packaging materials results in widespread general population exposure. In this report, we extend our preliminary study on the relationship between urinary concentrations of phthalate metabolites and sperm DNA damage among a larger sample of men and include measurements of mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), two oxidative metabolites of di-(2-ethylhexyl) phthalate (DEHP). METHODS: Among 379 men from an infertility clinic, urinary concentrations of phthalate metabolites were measured using isotope-dilution high-performance liquid chromatography-tandem mass spectrometry. Sperm DNA damage measurements, assessed with the neutral comet assay, included comet extent (CE), percentage of DNA in tail (Tail%) and tail distributed moment (TDM). RESULTS: Monoethyl phthalate (MEP), a metabolite of diethyl phthalate, was associated with increased DNA damage, confirming our previous findings. Mono-(2-ethylhexyl) phthalate (MEHP), a metabolite of DEHP, was associated with DNA damage after adjustment for the oxidative DEHP metabolites. After adjustment for MEHHP, for an interquartile range increase in urinary MEHP, CE increased 17.3% [95% confidence interval (CI) = 8.7-25.7%], TDM increased 14.3% (95% CI = 6.8-21.7%) and Tail% increased 17.5% (95% CI = 3.5-31.5%). CONCLUSIONS: Sperm DNA damage was associated with MEP and with MEHP after adjusting for DEHP oxidative metabolites, which may serve as phenotypic markers of DEHP metabolism to 'less toxic' metabolites. The urinary levels of phthalate metabolites among these men were similar to those reported for the US general population, suggesting that exposure to some phthalates may affect the population distribution of sperm DNA damage.

Adult↗

Force field calculations for 2-amino-5-chloro- and 2-amino-5-bromo-benzotrifluorides.

Force field calculations have been carried out for 2-amino-5-chloro- and 2-amino-5-bromo-benzotrifluorides using the earlier (Ref. of this article) reported IR and Raman spectra. As the frequencies of the corresponding modes for the C-Br and the C-Cl groups do not differ widely the two molecules are assumed to be isotopomers for the purpose of the force field calculations. The calculated and the observed frequencies match nicely for both the molecules. Consistent assignments have been proposed for the ring modes and the internal modes of the CF3 and the NH2 groups based on the potential energy distributions (PEDs), the IR and the Raman intensities and the depolarisation ratios of the Raman lines.

Fluorobenzenes↗

Ataxia and deafness in a young male: an unusual aetiology.

We report here a case of 18 year old male with tremors of hands, deafness, tendency to fall while walking, drowsiness and double vision of total duration 1(1/2) years. He had internuclear ophthalmoplegia, broken saccades, hypertonia and hyperreflexia of all four limbs, intention tremors, signs of gait and limb ataxia. Pupillary reactions and fundus examination were normal and signs of meningeal irritation or sensory neurological deficit were absent. MRI head and cervical spine with gadolinium enhancement revealed demyelination as evident from multiple oblong foci isointense on T1-weighted images and hyperintense on T2-weighted and fluid attenuated inversion recovery sequences in corpus callosum, sub-cortical white matter, right thalamus, pons and periaqueductal region of midbrain. Ill-defined linear hyperintense signals were observed in cervical spinal cord. No skeletal abnormality was noted in the skull or cervical spine. Oligoclonal bands were present in the cerebrospinal fluid. Brainstem auditory evoked potentials were abnormal, although visual evoked potentials were in normal range. A diagnosis of primary progressive multiple sclerosis (PPMS) was made fulfilling the revised criteria as laid down. In view of its presentation, it is a unique case of PPMS from India.

Adolescent↗

Liver abscess caused by Edwardsiella tarda biogroup 1 and identification of its epidemiological triad by ribotyping.

Two clinical isolates and an environmental isolate of Edwardsiella tarda biogroup 1 (ETB1), recovered from liver pus, the stool specimen and from the pond water of the village of the patient, diagnosed to have liver abscess, were found to be identical by protein fingerprinting and ribotyping. It can be construed that the pond water served as the source of infection. The epidemiological triad of the agent (ETB1), host (the patient) and environment (pond water) was thus established. This is the first report in which the triad for extraintestinal Edwardsiellosis caused by ETB1 has been identified. This also constitutes the first report of typing of ETB1 strains by SDS-PAGE and ribotyping.

Adult↗

Multiple cranial nerve palsies associated with type 2 diabetes mellitus.

Although isolated cranial nerve palsies are common in patients with diabetes mellitus, multiple simultaneous cranial neuropathies are rare. We report a 48-year-old man, a known case of diabetes mellitus, who presented with facial palsy, foot drop and painful ophthalmoplegia of the left eye. The initial differential diagnosis included diabetic polyneuropathy, septic cavernous sinus thrombosis, mucormycosis and the Tolosa Hunt syndrome. Magnetic resonance (MR) imaging findings were consistent with those of the Tolosa Hunt syndrome. The patient had a remarkable complete resolution of his ophthalmoplegia after four weeks of steroid treatment, with repeat MR imaging showing resolution of the initial changes.

Comorbidity↗

Molecular epidemiology of clinical isolates of ampc producing Klebsiella pneumoniae.

PURPOSE: AmpC producing K. pneumoniae have been increasingly reported from India but epidemiological studies are lacking. In the present study, molecular epidemiology of extended-spectrum AmpC beta-lactamases (ESACs) producing clinical isolates of K. pneumoniae prevalent in our hospital was studied. METHODS: Fifty-one non-repeat, consecutive, clinical isolates of K. pneumoniae producing AmpC enzymes, were subjected to whole cell protein profile analysis (SDS-PAGE) and ribotyping. The antimicrobial susceptibility was determined using standard disk diffusion technique. The isolates showing decreased susceptibility to cefoxitin (< 18 mm) or cefotetan (< 16 mm) were subjected to modified three- dimensional test for detection of AmpC enzyme. RESULTS: Six different types of protein profiles were observed. Ribotyping could further discriminate between the strains that were clustered by protein fingerprinting. Twelve different ribo-patterns were identified. Ribotyping was found to have a better Discriminatory Index (0.98) than that of SDS-PAGE (0.78). Of the 26 isolates that showed decreased susceptibility to cefoxitin and/or cefotetan 13 isolates were found to harbour AmpC enzyme. CONCLUSIONS: The study demonstrated the usefulness of SDS-PAGE whole cell protein profile analysis and ribotyping to identify the clonality of the ESACs isolates, the latter having a higher discriminatory power. The presence of ESACs isolates in the community as well as in hospital settings emphasizes the need for regular monitoring of antimicrobial resistance.

Adolescent↗

Simple and economical method for speciation and resistotyping of clinically significant coagulase negative staphylococci.

An attempt was made to speciate 102 clinically significant isolates of coagulase negative staphylococci (CoNS) by a practical scheme adapted from various references. This scheme utilizes slide and tube coagulase test, urease test ornithine decarboxylase, novobiocin susceptibility and aerobic acid from mannose for assigning species group. Inclusion of one or two additional tests in a species group could identify the isolates to species level. Ninety eight (97%) isolates were conveniently identified as S. epidermidis (41%), S. saprophyticus (16.6%), S. haemolyticus (14.7%), S. hominis (14.7%), S. lugdunensis (4.9%), S. schleiferi (1.9%) and S. capitis (1.9%). Only four isolates were not identified to the species level, two of which were probably S. capitis subspecies ureolyticus / S. warneri / S. simulans . Antibiotic susceptibility testing showed maximum resistance to ampicillin (89%) followed by cefotaxime (59%) with no resistance to vancomycin. The increasing recognition of pathogenic potential of CoNS and emergence of drug resistance amongst them denotes the need to adopt simple laboratory procedures to identify and understand the diversity of staphylococci isolated from clinical material.

Bacteriological Techniques↗

Oral versus high dose parenteral iron supplementation in pregnancy.

OBJECTIVE: To compare the effect of daily oral iron supplementation with two injections of high dose parenteral iron. METHOD: A total of 220 pregnant women with a singleton pregnancy and hemoglobin between 8 to 11 g% at 16-24 weeks gestation were identified and randomly divided into two groups. Group A was started on daily oral iron therapy of 100 mg of elemental iron. Group B was given 250 mg of iron sorbitol intramuscularly and repeated at an interval of 4-6 weeks. Blood indices were evaluated at the beginning of study and at 36 weeks to see the effect after iron supplementation in the two groups. The data were analyzed using SPSS software, version 10.1. RESULTS: Definitive and comparable improvement in hemoglobin and all the blood indices (hematocrit, MCH, MCHC, MCV, Serum iron and TIBC) was observed. The absolute change in hemoglobin and hematocrit was 1.18+/-0.68 g% and 4.02+/-2.59% in oral group, 1.34+/-0.77 g% and 4.93+/-3.65% in parenteral group, respectively. Serum ferritin showed statistically significant absolute rise (10.43+/-7.92 microg/dl) after parenteral iron supplementation as compared to oral iron supplementation (9.76+/-4.78 microg/dl). Obstetric outcome was comparable in two groups. CONCLUSION: Two treatment regimens are biologically equivalent in terms of hematological response. Two high doses of intramuscular iron can be a good substitute to meet iron requirement in pregnancy.

Administration, Oral↗

Septic arthritis due to Arcanobacterium haemolyticum.

Diphtheroids or "coryneform" bacilli are usually considered to be nonpathogenic "normal flora" of human skin and mucous membranes. Because bacterial cultures are frequently contaminated with these organisms the correct diagnosis and treatment may be delayed by the failure to recognize serious infections caused by them. Few confirmed cases of orthopaedic infections due to Arcanobacterium haemolyticum infection have been reported, partly because of inadequate identification of this bacterium. We report a case of septic arthritis due to A. haemolyticum.

Actinomycetaceae↗

Psoriatic nephropathy--does an entity exist?

Psoriasis is an immune-mediated chronic inflammatory disorder of the skin. Association with kidney disease has been debated for a long time. Secondary renal amyloidosis in psoriatic arthropathy and drug-induced renal lesions secondary to methotrexate or cyclosporine are accepted accompaniments of psoriasis. IgA nephropathy is also known to occur in psoriatics. We report three interesting cases of renal involvement in long-standing established psoriasis on topical therapy alone. The patients presented with hypertension, significant proteinuria, hypoalbuminemia, and dyslipidemia. Kidney biopsies revealed "mesangioproliferative glomerulonephritis with IgA nephropathy," "focal proliferative glomerulonephritis," and "membranous glomerulonephropathy." The former two had marked active urinary sediment. Patients improved on prednisolone and angiotensin-converting enzyme inhibitors. Contrary to the belief that renal involvement in psoriasis is coincidental, we propose that kidney disease may be a common accompaniment of psoriasis, which may be labeled as "psoriatic nephropathy" or "psoriatic kidney disease." The exact mechanism of this entity is yet to be elucidated.

Adult↗

Continuous ambulatory peritoneal dialysis (CRPD)--an initial Indian experience.

Continuous ambulatory peritoneal dialysis (CAPD) is a widely accepted mode of renal replacement therapy. CAPD is largely underutilised in India. Twenty patients of chronic renal failure (CRF) were started on CAPD-10 on the standard straight set, 10 on the Y-set. The efficacy of CAPD was evaluated by assessment of laboratory parameters at the onset and after three months of CAPD. Significant improvements in blood, urea, serum creatinine, serum bicarbonate, serum calcium, serum phosphorous, haemoglobin level and blood pressure were observed. There was a significant deterioration in the serum lipid and protein levels on CAPD. Peritonitis was a major complication observed. On the standard set the incidence of peritonitis was one episode per 5.92 patient months compared to one episode per 19.33 patient months with the Y-set (P value = 0.05). Peritonitis occurred more frequently in the summer months. At the end of one year, 70% patients continued on CAPD, with 3 deaths, one each due to malnutrition, myocardial infarction and tunnel infection. Three patients switched over to other replacement therapies. To conclude, CAPD can emerge as a safe, viable mode of renal replacement in developing countries like India.

Adult↗

Candidemia--an under-recognized nosocomial infection in Indian hospitals.

OBJECTIVE: To study the occurrence of candidemia as a nosocomial infection in a large Indian teaching hospital and to evaluate the predisposing factors for development of such infections. METHODS: One hundred and one hospitalized patients that developed signs and symptoms of nosocomial bloodstream infections were screened for candidemia and were analyzed for the various predisposing factors like the age of the patient, the duration of hospitalization before the development of fever, neutropenia, use of chemotherapeutic agents, central venous catheters, broad spectrum antibiotics, infection with HIV, diabetes mellitus, use of corticosteroids, administration of total parenteral nutrition, haemodialysis, use of mechanical ventilation, hematological or other malignancies, underlying disease, and any surgical procedure performed on the patient. Candidemic patients were followed up for outcome and the effect of nosocomial candidemia on mortality was assessed and analyzed statistically. RESULTS: Out of the 101 patients, seven patients had candidemia, an incidence in study population of 6.9%. Three (42.8%) were infected with albicans and the rest with non-albicans candidemia. All the patients with candidemia were admitted in the Intensive Care Units. Amongst the risk factors, the length of hospitalization (p = 0.018), broad-spectrum antibiotics (p = 0.045), central venous catheters (p = 0.005), mechanical ventilation (p = 0.0139) and total parenteral nutrition (p = 0.001) were found to be significantly related to acquisition of nosocomial candidemia. Mortality in the candidemic patients was influenced only by the age of the patients (p = 0.001). Although the mortality amongst the candidemic patients was twice as much as that of the patients not having this infection, still the difference did not reach significance (p = 0.117). CONCLUSION: Candidemia is an important problem in Indian hospitals. Diagnostic delays could be shortened by more active screening for candidemia especially in the intensive care settings. The rising incidence of non-albicans candidemia in the United States probably is true here as well. There should be a concerted effort to control known risk factors especially in intensive care units.

Adolescent↗

Phenotypic characteristics of clinical isolates of Klebsiella pneumoniae & evaluation of available phenotypic techniques for detection of extended spectrum beta-lactamases.

BACKGROUND & OBJECTIVES: Identifying organisms that harbour extended spectrum beta lactamases (ESBLs) is a major challenge for a diagnostic clinical microbiology laboratory. Wide variety of ESBLs produced and lack of a sensitive phenotypic method for their detection make the detection of ESBLs difficult and is responsible for under-recognition. The present study was undertaken to evaluate phenotypic characteristics, initial screening tests and established confirmatory phenotypic methods for detection of ESBLs Klebsiella pneumoniae isolates prevalent in a hospital in north India. METHODS: One hundred, non-repeat clinical isolates of K. pneumoniae collected over a period of six months were included in the study. Susceptibilities of the isolates to 20 different antimicrobial agents were determined. Agar dilution and broth dilution methods were used to determine minimum inhibitory concentrations (MICs) of ceftazidime (CAZ) and cefotaxime (CTX). CAZ and CTX were used with and without clavulanic acid to detect ESBL harbouring isolates. Using agar dilution and broth dilution, MIC reduction of two and three doubling dilutions were evaluated as a criterion for ESBL harbouring isolates. Standard double disk synergy test (DDST) with disks placed at 30 mm and modified DDST with disks placed at 16 mm center-to-center distance, using at least two different third generation cephalosporins and combined disk method were also performed to detect ESBL harbouring isolates. RESULTS: Multi-drug resistance (resistance to three or more antimicrobials of different classes) was found among 94 per cent of the isolates. Pooling the results of all the three confirmatory techniques MIC reduction of >3 doubling dilutions using broth dilution method (using CTX and CAZ), combined disk method [(using CTX, ceftriaxone [(CRO), CAZ and aztreonam)] and standard DDST (using CTX, CRO, CAZ and aztreonam), revealed as many as 87 per cent of the isolates as ESBL producers. CTX had greater sensitivity in identifying isolates that harboured ESBLs. Modified DDST using CTX was as sensitive method as broth dilution method and combined disk method in detecting ESBL harbouring isolates. MIC reduction technique using agar dilution method and standard DDST had lowest overall sensitivity in detecting ESBLs. INTERPRETATION & CONCLUSION: Modified DDST using at least two different third generation cephalosporins was considered to be the best technique for detection of ESBL producing K. pneumoniae at our hospital. MIC reduction test with >2 doubling dilution reduction in MICs was found to be a better criterion than the presently recommended >3 doubling dilution reduction. For screening of potential ESBL producers, MIC determination using agar dilution was as good as that using broth dilution method. However, while performing MIC reduction test agar dilution method was found highly unreliable for detection of ESBL harbouring isolates.

Humans↗

The 2003 outbreak of Dengue fever in Delhi, India.

Dengue fever (DF) and Dengue hemorrhagic fever (DHF) are widespread in Southeast Asia. An outbreak of DF/DHF in Delhi in 2003 started during September, reached its peak in October-November, and lasted until early December. This study describes the clinical and laboratory data of the 185 cases of DF/DHF admitted to Lok Nayak Hospital, New Delhi. The mean age of the patients was 26 +/- 10 years. Fever was present in all the cases with an average duration of fever being 4.5 +/- 1.2 days with headache (61.6%), backache, (57.8%), vomiting (50.8%) and abdominal pain (21%) being the other presenting complaints. Hemorrhagic manifestations in the form of a positive tourniquet test (21%), gum bleeding and epistaxis (40%), hematemesis (22%), skin rashes (20%) and melena (14%) were also observed. Hepatomegaly and splenomegaly were observed in 10% and 5% of cases, respectively. Laboratory investigations revealed thrombocytopenia (with a platelet count of < 100,000/microl) in about 61.39% of cases, Leukopenia (WBC <3,000/mm2) and hemoconcentration (Hct >20% of expected for age and sex) were found in 68% and 52% of the cases, respectively. The mortality rate was 2.7%. Despite widespread measures taken to control outbreaks of DF, it caused major outbreaks. More stringent measures in the form of vector control, improved sanitation and health education are needed to decrease morbidity, mortality and health care costs caused by a preventable disease.

Adolescent↗

Diagnosis of neurocysticercosis by enzyme-linked immunosorbent assay.

Neurocysticercosis, a disease caused by larvae of T solium produces variable and non-specific symptoms. Computerised tomography, magnetic resonance imaging, immunological tests in the serum and cerebrospinal fluid are available options to diagnose the condition. Two hundred serum samples collected and stored frozen at -20 degrees C and were tested for cysticercosis by commercial Melotest cysticercosis kit. Diagnosis was confirmed by other investigations. After the confirmative diagnosis results of ELISA for cysticercosis were compared and the values of sensitivity, specificity, prevalence and precision were obtained along with positive and negative predictive values. Overall prevalence was found to be 10% in this study. Only 26.5% serologically positive cases had neurocysticercosis positively. The positive predictive value of the serological test was only 26.4% suggesting that the diagnosis of neurocysticercosis by ELISA is not reliable in an endemic area.

Enzyme-Linked Immunosorbent Assay↗

Successful pregnancy in untreated limited Wegener's granulomatosis.

A thirty four year old female presented with upper and lower respiratory symptoms in the third trimester of pregnancy. After the delivery of a healthy baby, the symptoms progressed to involve multiple organ systems and eventually a diagnosis of limited Wegener's Granulomatosis (Carrington-Liebow syndrome) was made. The extremely rare combination of WG and pregnancy, especially the onset of disease in late pregnancy is discussed. The successful outcome of pregnancy even without treatment of WG is the highlight of the case.

Adult↗

A clinical trial of the efficacy and safety of montelukast as monotherapy in patients with chronic stable bronchial asthma.

This study is aimed to evaluate the efficacy and safety of montelukast, as monotherapy, in the treatment of chronic stable bronchial asthma in adults. This was a multicentre, open label, non-comparative, prospective, 4-week study. Eligible patients discontinued all anti-inflammatory medication (steroids, chromoglycate sodium) 2 weeks prior to starting therapy with montelukast (10 mg daily). The primary efficacy criteria were improvements in forced expiratory volume in one second (FEV1), peak exploratory flow rate (PEFR) after 4 weeks of therapy. Secondary efficacy criteria were improvement in the patients' symptoms (assessed on an ordinal scale), decrease in discomfort levels (scored on a scale of 0-100), change in peripheral eosinophil counts, decrease in total daily dose of inhaled beta2 agonist (salbutamol). A total of 148 patients, mean age (+/- SD) 40.21 +/- 13.70 years, were enrolled into the study. At the end of the study there were significant improvements in FEV1 and PEFR (29% and 28% increase respectively from baseline values, p<0.000001). The mean total daily dose of inhaled salbutamol decreased significantly from prestudy values of 461 +/- 332 microg/day to 161 +/- 207 microg/day (p<0.000001). The mean eosinophil counts fell from 5.80 +/- 4.90% (+/- SD) to 4.84 +/- 4.42% (+/- SD) (p=0.02). Symptom scores improved significantly as did subjective assessment of discomfort. A total of 29 (19.6%) adverse events were reported, all of which were of mild to moderate intensity. Monotherapy with montelukast significantly improved parameters of asthma control. It was well tolerated with no reports of serious or severe adverse events.

Acetates↗