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Biomedical subjects

N Singh

Publications and source records attributed to N Singh.

At least 163 records · Page 9Linked to original sources
PubMed2000

Comparative evaluation of a field-based dot-ELISA kit with three other serological tests for the detection of Brucella antibodies in goats.

A dot-ELISA (d-ELISA) test was evaluated and compared with the serum agglutination test (SAT), micro-complement fixation test (CFT) and a plate-ELISA (p-ELISA) for field use in screening herds of goats against brucellosis. During the standardization of the dot-ELISA kit on 1732 caprine serum samples, 1571 samples out of 1666 were found to be negative in d-ELISA, SAT and micro-CFT, while 59 were positive in different combinations. Of a further 66 serum samples, 34 were negative and 31 were positive in different combinations in d-ELISA, SAT, micro-CFT and p-ELISA. A total of 1584 goats belonging to different herds were then screened for brucellosis. Of the 694 serum samples screened in the first batch using d-ELISA, a positive reaction was observed in 26 cases. Further screening of these cases revealed 13 and 21 goats as positive reactors in SAT and CFT, respectively. In a second batch of 890 goats there were 109 positive reactors in d-ELISA. Among these 109 goats, 34, 40 and 80 goats were positive reactors in SAT, CFT and p-ELISA, respectively. The results of d-ELISA correlated well with those of p-ELISA. Dot-ELISA was found to be a more suitable and rapid test for screening large numbers of goats in the field.

Agglutination Tests↗
PubMed2000

Molecular cloning and expression analysis of a mouse UDP-GlcNAc:Gal(beta1-4)Glc(NAc)-R beta1,3-N-acetylglucosaminyltransferase homologous to Drosophila melanogaster Brainiac and the beta1,3-galactosyltransferase family.

We have isolated a murine cDNA coding for a beta1,3-N-acetylglucosaminyltransferase enzyme ( beta3GnT). This enzyme is similar in sequence to Drosophila melanogaster Brainiac and to the murine and human beta1,3-galactosyltransferase family of proteins. The mouse beta 3GnT protein is 397 amino acids in length and contains 7 cysteine residues that are conserved in the human orthologue. beta 3GnT is a type II membrane protein localized to the Golgi apparatus. Enzyme assays with recombinant mouse beta 3GnT reveal that it has a preference for acceptors with Gal(beta1-4)Glc(NAc) at the non-reducing termini. Proton NMR analysis of product showed incorporation of GlcNAc in beta1,3 linkage to the terminal Gal of Gal(beta1-4)Glc(beta1-O-benzyl). Northern blot analysis revealed the presence of a single 3.0[emsp4 ]kb transcript in all adult mouse and human organs tested, with highest levels in the kidney, liver, heart and placenta. The beta 3GnT gene is also expressed in a number of tumor cell lines. The human orthologue of beta 3GnT is located on chromosome 2pl5.

Amino Acid Sequence↗
PubMed2000

Quality of life in long-term survivors after liver transplantation: impact of recurrent viral hepatitis C virus hepatitis.

Post liver transplant recurrence of infection with hepatitis C virus (HCV) occurs in approximately 50% of patients transplanted because of HCV-related liver disease. The aim of this study was to assess long-term quality of life, psychologic distress, and coping in patients with recurrent HCV after liver transplantation in comparison to patients transplanted for other etiologies of underlying liver disease. All liver transplant recipients transplanted at a University affiliated Veterans Affairs Medical Center who had greater than 6 months follow-up were sent a questionnaire investigating quality of life (assessed by Medical Outcomes study health survey SF-36), depression (assessed by Beck Depression Inventory), total mood disturbance (assessed by Profile of Mood States scale), coping (assessed by Billing and Moos Inventory of coping with illnesses), and employment status. Lower Beck Depression Inventory score (p = 0.001), lower mood disturbance score (p = 0.0001), overall satisfaction with present work (p = 0.0001), and lesser use of avoidant coping (p = 0.06) were predictors of better quality of life in long-term survivors of liver transplantation. At a mean follow-up of 4 yr after liver transplantation, patients with histopathologically diagnosed recurrent viral HCV hepatitis had significantly lower global quality of life score (mean score of 76.4 versus 86.2, p = 0.011) and physical functioning score (mean score 20 versus 25, p = 0.015), as compared to all other patients. In summary, quality of life and physical functioning were significantly impaired in liver transplant recipients with histopathologically diagnosed recurrent HCV hepatitis, as compared to those whose HCV hepatitis had not recurred or those transplanted for other reasons.

Adaptation, Psychological↗
PubMed2000

Infections of the central nervous system in transplant recipients.

Central nervous system (CNS) infections, accounting for 4-29% of CNS lesions in transplant recipients, are a significant post-transplant complication. Focal CNS infectious lesions or brain abscesses have been documented in 0.36-1% of the transplant recipients. Mycelial fungi, particularly Aspergillus, are by far the most frequent etiologies of post-transplant brain abscesses. Bacteria, with the exception of Nocardia, are rarely associated with brain abscesses in transplant recipients. Time of onset and concurrent extraneural lesions have implications relevant towards invasive diagnostic procedures in transplant recipients with brain abscesses. Meningoencephalitis in transplant recipients is predominantly due to viruses, e.g., herpesviruses, and less frequently due to Listeria monocytogenes, Toxoplasma gondii, and Cryptococcus. Despite a wide, and at times perplexing array of opportunistic pathogens that can cause CNS infections, the temporal association of the infection with the time elapsed since transplantation, risk factors, clinical manifestations, and neuroimaging characteristics of the lesion can allow a reasoned and rational approach towards the recognition, diagnosis, and appropriate management of CNS infections in transplant recipients.

Brain Abscess↗
PubMed2000

Fus deficiency in mice results in defective B-lymphocyte development and activation, high levels of chromosomal instability and perinatal death.

The gene FUS (also known as TLS (for translocated in liposarcoma) and hnRNP P2) is translocated with the gene encoding the transcription factor ERG-1 in human myeloid leukaemias. Although the functions of wild-type FUS are unknown, the protein contains an RNA-recognition motif and is a component of nuclear riboprotein complexes. FUS resembles a transcription factor in that it binds DNA, contributes a transcriptional activation domain to the FUS-ERG oncoprotein and interacts with several transcription factors in vitro. To better understand FUS function in vivo, we examined the consequences of disrupting Fus in mice. Our results indicate that Fus is essential for viability of neonatal animals, influences lymphocyte development in a non-cell-intrinsic manner, has an intrinsic role in the proliferative responses of B cells to specific mitogenic stimuli and is required for the maintenance of genomic stability. The involvement of a nuclear riboprotein in these processes in vivo indicates that Fus is important in genome maintenance.

Animals↗
PubMed2000

Field evaluation of the ICT malaria P.f/P.v immunochromatographic test for diagnosis of Plasmodium falciparum and P.vivax infection in forest villages of Chhindwara, central India.

A rapid new immunochromatographic test (ICT malaria P.f/P.v) for diagnosis of Plasmodium falciparum and P.vivax was evaluated against thick blood smears in forest villages of Chhindwara, Madhya Pradesh, where both Plasmodium falciparum and P.vivax are prevalent. 344 symptomatic patients (Gond ethnic tribe) in five villages were screened by field staff of the Malaria Research Centre in October 1999. For P.falciparum, the ICT was 97.5% sensitive and 88% specific, with a positive predictive value (PPV) of 87.6% and a negative predictive value (NPV) of 97.6%. For P.vivax the sensitivity was only 72%, the specificity 99%, with a PPV of 92% and an NPV of 96%. Although a negative test result was inadequate to exclude parasitaemia < or = 300/microl for P.falciparum and < or = 1500/microl for P.vivax, the test is potentially useful in remote areas.

Adolescent↗
PubMed2000

Human herpesviruses-6, -7 and -8 in organ transplant recipients.

The newer herpesviruses are being increasingly recognized as significant opportunistic pathogens in organ transplant recipients. Published data support the role of human herpesvirus-6 as a potential cause of encephalitis and bone marrow suppression in transplant setting. An association of human herpesvirus-6 with fungal infections and cytomegalovirus infection has also been documented. Human herpesvirus-7 also appears to be an immunomodulatory agent and may facilitate the pathogenicity of cytomegalovirus. Unlike human herpesviruses -6 and -7, human herpesvirus -8 is not ubiquitous; its seroprevalence exhibits wide geographic variation. Human herpesvirus-8 has been causally associated with post-transplant Kaposi's sarcoma. The complete spectrum of pathogenicity and ultimately the effective prophylaxis and management of these viruses has yet to be fully elucidated.

Cytomegalovirus Infections↗
PubMed2000

RAG2-/-, I kappa B-alpha-/- chimeras display a psoriasiform skin disease.

Nuclear factor-kappa B, a ubiquitous transcription factor involved in inflammatory and immune responses, is inappropriately activated in several immuno-related diseases, such as allograft rejection, or bronchial asthma. As nuclear factor-kappa B activity is regulated by inhibitor of kappa B (I kappa B), the gene encoding I kappa B-alpha was disrupted in mice to observe the in vivo effects of hyperactivation of nuclear factor-kappa B. I kappa B-alpha-/- mice have constitutive nuclear factor-kappa B activity, severe skin disease, and neonatal lethality. To determine the role of I kappa B-alpha deficient immunocytes in the pathogenesis of the skin disease in adult mice, we utilized the RAG2-deficient blastocyst complementation system to generate RAG2-/-, I kappa B-alpha-/- chimeras. These animals display a psoriasiform dermatitis characterized by hyperplastic epidermal keratinocytes and dermal infiltration of immunocytes, including lymphocytes. Skin grafts transferred from diseased chimeras to recipient nude mice produce hyperproliferative psoriasiform epidermal keratinocytes in response to stimulation. Furthermore, adoptive transfer of lymph node cells from diseased chimeras to RAG2-/- recipient mice recapitulates the disease. Taken together, these characterizations provide evidence to suggest that constitutive activation of nuclear factor-kappa B, due to deficiency in I kappa B-alpha, can invoke severe psoriasiform dermatitis in adult mice. J Invest Dermatol 115:1124-1133 2000

Animals↗
PubMed2000

Seasonality of Plasmodium vivax and P. falciparum in tribal villages in central India (1987-1995).

Microscopical examination of blood films produced from samples collected, over a 9-year period (1987-1995), from the inhabitants of four tribal villages of Mandla district, Madhya Pradesh (central India) revealed that malaria was highly endemic and probably transmitted perennially. Both Plasmodium vivax and P. falciparum were prevalent in all age-groups but their prevalence was highly seasonal: longitudinal studies showed an autumn (October-November) peak for P. falciparum and a summer (April-May) peak for P. vivax. However, both the incidence and prevalence of infection with each Plasmodium species showed inter-village variations. Analysis of the malariometric parameters investigated revealed that there had been no improvement in the malaria situation over the study period, and that, since 1992, there had been a shift in the predominant parasite, from P. vivax to P. falciparum, in each village.

Adolescent↗
PubMed2000

Evaluation of a rapid diagnostic test, 'Determine malaria pf', in epidemic-prone, forest villages of central India (Madhya Pradesh).

A rapid, immunochromatographic test for malaria diagnosis, 'Determine malaria pf', was evaluated by a field team in the epidemic-affected, forest setting of Chhindwara district, in Madhya Pradesh, central India. In all, 526 fever cases were screened for Plasmodium falciparum in October or November, 1999. Those found to be infected were treated with sulfadoxine-pyrimethamine and primaquine. Using microscopy as the gold standard, the new test had a sensitivity of 98% and a specificity of 87%. The positive and negative predictive values were 88% and 98%, respectively. Although follow-up of 64 subjects on day 7 post-treatment revealed that 20% of those who then appeared smear-negative were still antigenaemic, 34% of the subjects were still smear-positive, for asexual parasites, at that time. The Determine test was found to be very easy to perform and the results could be read reliably by field workers, without any supervision. The ease of use of the test indicates that it could be useful in the management of malaria, particularly in remote and inaccessible areas, provided that its accuracy can be assured and that it can be made affordable.

Adolescent↗
PubMed2000

Persistence of hexaconazole, a triazole fungicide in soils.

Persistence of hexaconazole (2-(2,4-dichlorophenyl)- 1-(1H-1,2,5-triazol-1-yl) hexan-2-ol) was studied in alluvial, red and black soils under flooded and nonflooded conditions. This fungicide was more persistent in all soils under flooded conditions than under nonflooded conditions and at 27 degrees C than at 35 degrees C. Degradation of hexaconazole in sterilized and nonsterilized soils proceeded at identical rates indicating a minor role of micro-organisms in its degradation. The soil persistence of hexaconazole was not affected by the addition of wheat straw both under flooded and nonflooded conditions.

Chromatography, Gas↗
PubMed2000

Methicillin-resistant Staphylococcus aureus: the other emerging resistant gram-positive coccus among liver transplant recipients.

We undertook a study of the characteristics and clinical impact of infections due to methicillin-resistant Staphylococcus aureus (MRSA) after liver transplantation. Of 165 patients who received liver transplants at our institution from 1990 through 1998, 38 (23%) developed MRSA infections. The predominant sources of infection were vascular catheters (39%; n=15), wound (18%; n=7), abdomen (18%; n=7), and lung (13%; n=5). A significant increase in MRSA infections (as a percentage of transplant patients infected per year) occurred over time (P=.0001). This increase was greater among intensive care unit patients (P=.001) than among nonintensive care unit hospital patients (P=.17). Cytomegalovirus seronegativity (P=.01) and primary cytomegalovirus infection were significantly associated with MRSA infections (P=.005). Thirty-day mortality among patients with MRSA infections was 21% (8/38). Mortality was 86% in patients with bacteremic MRSA pneumonia or abdominal infection and 6% in those with catheter-related bacteremia (P=.004). Thus the incidence of MRSA infection has increased exponentially among our liver transplant recipients since 1990. These infections have unique risk factors, time of onset, and a significant difference in site-specific mortality; deep-seated bacteremic infections, in particular, portend a grave outcome.

Adult↗
PubMed2000

Short-course empiric antibiotic therapy for patients with pulmonary infiltrates in the intensive care unit. A proposed solution for indiscriminate antibiotic prescription.

Inappropriate antibiotic use for pulmonary infiltrates is common in the intensive care unit (ICU). We sought to devise an approach that would minimize unnecessary antibiotic use, recognizing that a gold standard for the diagnosis of nosocomial pneumonia does not exist. In a randomized trial, clinical pulmonary infection score (CPIS) (Pugin, J., R. Auckenthaler, N. Mili, J. P. Janssens, R. D. Lew, and P. M. Suter. Diagnosis of ventilator-associated pneumonia by bacteriologic analysis of bronchoscopic and nonbronchoscopic "blind" bronchoalveolar lavage fluid. Am. Rev. Respir. Dis. 1991;143: 1121-1129) was used as operational criteria for decision-making regarding antibiotic therapy. Patients with CPIS </= 6 (implying low likelihood of pneumonia) were randomized to receive either standard therapy (choice and duration of antibiotics at the discretion of physicians) or ciprofloxacin monotherapy with reevaluation at 3 d; ciprofloxacin was discontinued if CPIS remained </= 6 at 3 d. Antibiotics were continued beyond 3 d in 90% (38 of 42) of the patients in the standard as therapy compared with 28% (11 of 39) in the experimental therapy group (p = 0.0001). In patients in whom CPIS remained </= 6 at the 3 d evaluation point, antibiotics were still continued in 96% (24 of 25) in the standard therapy group but in 0% (0 of 25) of the patients in the experimental therapy group (p = 0.0001). Mortality and length of ICU stay did not differ despite a shorter duration (p = 0.0001) and lower cost (p = 0.003) of antimicrobial therapy in the experimental as compared with the standard therapy arm. Antimicrobial resistance, or superinfections, or both, developed in 15% (5 of 37) of the patients in the experimental versus 35% (14 of 37) of the patients in the standard therapy group (p = 0.017). Thus, overtreatment with antibiotics is widely prevalent, but unnecessary in most patients with pulmonary infiltrates in the ICU. The operational criteria used, regardless of the precise definition of pneumonia, accurately identified patients with pulmonary infiltrates for whom monotherapy with a short course of antibiotics was appropriate. Such an approach led to significantly lower antimicrobial therapy costs, antimicrobial resistance, and superinfections without adversely affecting the length of stay or mortality.

Aged↗
PubMed2000

Toxicity of ingested formalin and its management.

Formaldehyde is a physiological intermediary metabolite taking part in many biological process in the body. It is a constituent of many items of daily use, including foods. It is also used in medicine for treatment of some conditions. A 40% solution of formaldehyde in water is known as formalin. Formalin is irritating, corrosive and toxic and absorbed from all surfaces of the body. Ingestion is rare because of alarming odour and irritant effect but documented in accidental, homicidal or suicidal attempts. Ingestion can lead to immediate deleterious effects on almost all systems of the body including gastrointestinal tract, central nervous system, cardiovascular system and hepato-renal system, causing gastrointestinal hemorrhage, cardiovascular collapse, unconsciousness or convulsions, severe metabolic acidosis and acute respiratory distress syndrome. No specific antidote is available. Treatment of toxicity is supportive care of the various organ systems. Multidisciplinary approach is required for proper management.

Administration, Oral↗
PubMed2000

Topical amiloride solution accelerates healing of mechanical skin ulcers in albino rats.

The present investigation was undertaken to explore the ulcer healing properties of three dosage schedules of various concentrations of topically administered amiloride solution in mechanically produced skin ulcers in albino rats. Four skin ulcers (two on either side of the midline) were made 2.5 cm apart on the preshaved back of each anesthetized rat with a round body skin biopsy punch (7 mm diameter) through the dermis to the depth of subcutaneous tissue. The animals were randomly divided into groups of 5 rats each. Ulcers on one side of the midline were treated with normal saline and served as control, whereas those on the other side were treated with amiloride solutions. Each ulcer was observed for its size, slough formation and any sign of irritation on alternate days until healing was complete. Healing of ulcers was significantly accelerated with all the strengths of amiloride (0.01, 0.02 and 0.04%) in all the dosage schedules (o.d., b.i.d. and q.i.d.) in terms of days required for complete healing, ulcer size and area under the size-time curve. This acceleration was dose-dependent with maximum effect at b.i.d. administration of 0.04% solution. No irritation or suppression of immunity was noticeable. Thus topical amiloride may prove to be an inexpensive and better ulcer healing agent with no apparent side effects. Inhibition of u-PA by amiloride seems to be responsible for this effect.

Administration, Topical↗