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Biomedical subjects

N Singh

Publications and source records attributed to N Singh.

At least 523 records · Page 29Linked to original sources
PubMed1989

Persistent malaria transmission in Kundam block, district Jabalpur (M.P.).

Malaria survey was undertaken in 7 villages of Kundam PHC from August 1987 to July 1988. Epidemiological findings revealed high spleen (20-70), child parasite (40-85) and infant parasite rates (20-75) in the area. P. falciparum was the predominant species and unchecked malaria transmission continued almost throughout the year. The study of monthwise distribution of positive cases and the period during which intensive intervention measures were undertaken revealed that despite an extra round of HCH and intensive chemotherapeutic measures, there was no marked decrease in the prevalence of malaria.

Animals↗
PubMed1988

Proton/product time course ratios: a new approach to transient-state kinetic analysis.

The usefulness of the indicator dye method for the detection of transient enzyme-product intermediates has been very limited due to the near impossibility of resolving the apparent single exponential time courses resulting from sequences of steps linked by rather similar rate constants. We propose here a novel approach, the proton-product time course method, a procedure which can extract a great deal of the mechanistic information which remains buried in conventional proton release-time course measurements. The method involves nothing more than measuring the ratio, r, of the moles of H+ released to the moles of product formed as a function of time. We derive the theory relating this r function to mechanisms of varying complexity, explore the theoretical behavior of the function in various possible mechanistic situations, and employ the new approach in an experimental system. We demonstrate the fact that the proton/product time course ratio method can provide evidence of the existence of hidden steps in transient state kinetic studies, that it can determine accurate thermodynamic pK values of the intermediate complexes involved in those steps, and that it can produce time courses of individual intermediates which are obscure to conventional kinetic methods.

Coloring Agents↗
PubMed1988

Infections with cytomegalovirus and other herpesviruses in 121 liver transplant recipients: transmission by donated organ and the effect of OKT3 antibodies.

One hundred twenty-one adult liver transplant recipients were studied for the incidence, risk factors, and morbidity associated with herpesviruses infections after transplantation. The overall incidence of infection was 59% for cytomegalovirus (CMV), 35% for herpes simplex virus (HSV), 25% for Epstein-Barr virus (EBV), and 7% for varicella-zoster virus (VZV). Primary CMV infection occurred in 46% and reactivation CMV infection in 67% of the susceptible recipients. Symptomatic and disseminated CMV diseases were more common when patients developed primary infection (P less than .01, for both comparisons). The donor organ appeared to be the only important source of CMV infection in seronegative recipients. The use of OKT3 antibodies was associated with disseminated CMV disease in patients with primary infection (P = .04) but not with reactivation infection (P greater than .10). Although most HSV infections were oral or genital reactivations, three cases of HSV hepatitis occurred--one was a primary infection. Symptomatic reactivations of HSV were observed in 53% of HSV-seropositive recipients who received OKT3, versus 31% of seropositive recipients who did not receive OKT3 (P = .05).

Antibodies, Monoclonal↗
PubMed1988

Infections after liver transplantation. An analysis of 101 consecutive cases.

We studied infections in 101 consecutive patients who underwent liver transplantation between July 1984 and September 1985. The mean length of follow-up was 394 days. Eighty-three percent of population had 1 or more episodes of infection and 67% of the population had severe infections. The overall mortality was 26/101 (26%) and 23 of 26 deaths (88%) were associated with infection. Seventy percent of severe infections occurred in the first 2 months after transplantation. The most frequent severe infections were abdominal abscess, bacterial pneumonia, invasive candidiasis, Pneumocystis pneumonia, and symptomatic cytomegalovirus infection. Patients with more than 12 hours of cumulative surgical time had a higher rate of severe infections (P less than 0.001), particularly fungal (P less than 0.001) and bacterial (P less than 0.01) infections. Also, the use of choledocho-jejunostomy was associated with a higher rate of infection in patients who had more than 1 transplant operation (P less than 0.02). No increase in infection was found in patients who received azathioprine, or more than the median number of steroid boluses or "recycles"; but patients who received OKT3 therapy had a higher rate of protozoal infections (P less than 0.05). A result similar to that of our previous studies was a strong relation between the number of severe fungal infections and prolonged courses of antibiotics after transplant operation (P less than 0.001). Pretransplant manifestations of severe liver disease such as ascites, encephalopathy, and gastrointestinal bleeding were not associated with higher rates of infection after transplantation, but high serum levels of ALT were. Patients with lower ratios of T-helper to T-suppressor lymphocytes had more severe viral (P less than 0.02) and fungal (P less than 0.01) infections after transplantation.

Adult↗
PubMed1987

Binding of linker histones to the core nucleosome.

Binding of chicken erythrocyte linker histones H1/H5 to the core nucleosome has been studied. Histones H1/H5 bind very efficiently to the isolated core nucleosome in vitro. The binding of linker histones to the core nucleosome is associated with aggregation of the particles. Approximately one molecule of linker histone binds per core nucleosome in the aggregates, irrespective of the concentration of the linker histones and the salt used. Histone H5 shows greater binding affinity to the core nucleosome as compared to H1. The carboxyl-terminal fragment of the linker histones binds strongly to the core nucleosome while the binding of the central globular domain is weak. Each core nucleosome is capable of binding two molecules of carboxyl-terminal fragment of linker histone. The core nucleosome containing one molecule of carboxyl-terminal fragment of linker histone requires higher salt concentration for aggregation while the core nucleosome containing two molecules of carboxyl-terminal fragment of linker histone can self-associate even at lower salt concentrations. On the basis of these results we are proposing a novel mechanism for the condensation of chromatin by linker histones and other related phenomena.

Animals↗
PubMed1987

A perspective on therapeutic work with in-patient adolescents.

It is generally difficult to explain the complex practice of psychotherapeutic work with in-patient adolescents. This is because the adolescent workers' relatively "relaxed" enterprise of promoting the process of self-understanding within the adolescents is overshadowed by the concurrent high profile activity of their managing these troubled young people. This paper attempts to address what is indeed a perennial difficulty by way of a close study or phenomenology of the workers' on-going therapeutic relationships with in-patient adolescents. For the purposes of the investigation the author utilizes the idea of "working closely" as technical concept and guiding principle in the residential treatment and care of troubled adolescents.

Adjustment Disorders↗
PubMed1987

The influence of permethrin-impregnated bednets and mass drug administration on the incidence of Plasmodium falciparum malaria in children in Sabah, Malaysia.

A small-scale trial was carried out in the Upper Kinabatangan district of Sabah, Malaysia, to determine the effect of using permethrin-impregnated bednets on malaria transmission. A total of 306 nylon bednets with cotton borders, impregnated at a dose estimated to have been 0.062 g permethrin/m2 of nylon netting, were distributed to 139 households in five villages. At the time of distributing bednets, mass drug administration with Fansidar plus primaquine was also administered to the human population to clear all parasitaemias due to Plasmodium falciparum Welch. In another village, for comparison, mass drug administration was the only intervention. After intervention measures in December 1984 and January 1985, the parasite rates in children declined in all villages during the first month, significantly more in the villages with impregnated bednets than in the control, thus proving that the nets had an impact on malaria. However, after about 2 months, parasite rates started to increase again. After 4-6 months, parasite rates in the villages with bednets approached the rate in the control village without nets. The increase in parasite rates was paralleled by a significant deterioration in the quality, physical condition and the degree of non-utilization of bednets. Entomological evaluation proved the efficacy of permethrin-impregnated nets for controlling Anopheles balabacensis Baisas and other anophelines. Bioassays (1 h exposure) of permethrin-impregnated bednets gave 100% mortality initially and 44-61% mortality after 85-106 days. Mosquito collections in treated bednets were significantly reduced for at least 217 days. The project failed to achieve prolonged suppression of malaria transmission for a combination of entomological, sociological and practical reasons which are discussed in relation to the objectives and implementation of future bednet studies.

Animals↗
PubMed1987

Acute renal failure amongst children in a tropical environment.

The pathogenetic factors leading to acute renal failure (ARF) in 223 children between the ages of 20 days and 14 years were studied. Diarrhoeal diseases were responsible for ARF in 49.8%, acute glomerulonephritis in 34.1%, drug induced intravascular hemolysis in glucose -6-phosphate dehydrogenase deficiency in 4.5%, snake bite in 4%, hemolytic uremic syndrome in 2.2%, and miscellaneous causes in 5.4%. Dialysis was instituted in 178 children and the others were treated conservatively. Renal histology in 39 out of 76 children who presented with an acute nephritic illness revealed acute endocapillary proliferative glomerulonephritis in 27 and crescentic glomerulonephritis in 12. The histology in 79 out of 147 remaining patients showed acute tubular necrosis in 64, acute cortical necrosis in 13, and acute interstitial nephritis in 2. Overall mortality was 27.4%. This high incidence of ARF due to infective diarrhoeas and dysentery reflects poor socio-economic and hygienic conditions, inadequate facilities in rural areas, delays in seeking medical advice, and lack of knowledge about fluid and electrolyte therapy amongst the staff.

Acute Disease↗
PubMed1987

Progression to end stage renal disease in post-streptococcal glomerulonephritis (PSGN)---Chandigarh Study.

193 patients (142 adults and 51 children) with acute PSGN were followed long term. Sixty percent had elevated serum creatinine and 14% had nephrotic range proteinuria at the onset. By two years 28 patients (14%) had died from uremia, and 19 were lost to follow up. Amongst the remainder, 8 patients (4%) had developed mild to moderate renal insufficiency, 12% were hypertensive, and 22% had urinary abnormalities. Of the 146 patients alive at 2 years, 107 were followed up to 10 years (mean 4.8 years). In addition to the 8 patients with renal insufficiency at 2 years, another 7 developed renal failure subsequently. Four out of these 15 patients progressed to uremia within 4 to 10 years after the onset of disease. Hypertension and persistent urinary abnormalities were present in 15% and 24% respectively. Progression to uremia occurred in 6% of children and 20% of adults. Nephrotic range proteinuria, renal insufficiency at the onset, and crescents in more than one third of glomeruli indicated a poor prognosis.

Adolescent↗
PubMed1986

Oliva vidua fulminans, a marine mollusc, responsible for five fatal cases of neurotoxic food poisoning in Sabah, Malaysia.

This is the first report in which a marine mollusc, Oliva vidua fulminans (olives), generally not known to be poisonous, was responsible for death in five children after consuming boiled olives with tamarind. The onset of symptoms was rapid 10 to 20 min after consumption of the olives. Signs and symptoms included nausea, vomiting, abdominal pain, tingling sensation around the lips, numbness around the mouth, drowsiness, lethargy and generalized weakness with paraesthesia in the limbs. The five deaths occurred within 3 to 4 hours after eating the poisoned olives and resulted from respiratory failure. Left-over olives from the affected household and freshly collected live olives had a toxicity of 14,200 mouse units (M.U.) and 15,000 M.U. per 100 g meat respectively. No other common chemical poison and organophosphorus insecticides were detected. The neurotoxic agent was acid and heat stable and was toxic at pH less than 4. Its action was similar to that of paralytic shellfish poisoning which was caused by toxins from certain dinoflagellates.

Adolescent↗
PubMed1986

A comparison of current smokers and self-cured quitters on Rosenbaum's Self Control Schedule.

This study compared the responses of current and former smokers on Rosenbaum's (1982) Self Control Schedule (SCS). Among the current smokers, all of them had tried to quit smoking before but failed. Likewise, ex-smokers were all "self-cured" and all of them had been cigarette-free for at least 6 months. Results were consistent with predictions and showed that ex-smokers scored significantly higher on the SCS. This suggests that some cigarette smokers who want to quit may be better prepared to do so because of individual differences in self-control skills. Other implications of the results are briefly discussed.

Adaptation, Psychological↗