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Biomedical subjects

A Sinha

Publications and source records attributed to A Sinha.

At least 109 records · Page 6Linked to original sources
PubMed1996

An unusual foreign body migrating from pharynx to mediastinum.

A case of a swallowed foreign body migrating from the pharynx into the soft tissues of the neck is presented, whose management was complicated by its undetected migration to the superior mediastinum occurring between radiological localization in the neck three days prior to exploration and its attempted removal. A median sternotomy was then required to retrieve the object. Radiological guidance with regard to the localization of a foreign body in the neck can only be relied on when performed immediately prior to surgical removal.

Foreign-Body Migration↗
PubMed1996

Zinc supplementation reduces the incidence of persistent diarrhea and dysentery among low socioeconomic children in India.

Persistent diarrhea (PD) and dysentery (DD) account for most diarrhea-associated deaths among children in developing countries. Zinc deficiency can cause stunting and impaired immune function, both of which are risk factors for these diarrheal illnesses. We investigated the effect of zinc supplementation on the incidence of PD and DD in a community-based, double-blind randomized trial in children 6-35 mo of age. Increase over baseline in plasma zinc concentrations in the supplemented group compared with a control group (3.61 vs. 0.009 mumol.L-1), indicated successful supplementation. The overall reductions in the zinc supplemented group of 21% in the incidence of PD (95% CI -6 to 42%) and 14% in the incidence of dysentery (95% CI -15 to 36%) were not significant. There was a significant interaction of treatment effect with baseline plasma zinc concentration and age for PD and with gender for DD. In the zinc-supplemented group compared with the control group, the incidence of PD was reduced by 73% (P < 0.05; 95% CI 34 to 91%) in children with a baseline zinc < 7.65 mumol.L-1 and by 49% (P < 0.05; 95%CI 24 to 66%) in children > 11 mo of age. Zinc supplementation resulted in a 38% (P < 0.05 95%CI 8 to 59%) reduction in the incidence of DD in boys. There was no effect on PD among children 6-11 mo old or on DD in girls. In conclusion, zinc supplementation had a significant impact on the incidence of persistent diarrhea in children > 1 y old and in children with low plasma zinc, as well as on dysentery in boys. These findings may have important implications for reducing diarrhea-related morbidity and mortality.

Child, Preschool↗
PubMed1996

Neural-network-based classification of Space Acceleration Measurement Systems (SAMS) data via supervised learning.

This paper illustrates the applicability of neural networks in classifying events using Space Acceleration Measurement System (SAMS) data. Computer programs have been written in the MATLAB environment for the following purposes: automatic retrieval of SAMS data from NASA CDROM disks, computation of power spectral densities for SAMS data and construction of input patterns for the training of a multi-layer neural network (MNN). The MNN has been trained using the backpropagation learning algorithm and the SAMS data collected on the STS-50 Space Shuttle mission for three crew exercise events. It is found that the trained MNN is highly successful in classifying events. In addition, the performance of MNN is found to be better than that of the nearest neighbor classifier.

Acceleration↗
PubMed1996

Isoflurane hepatotoxicity: a case report and review of the literature.

Isoflurane, hailed as the anesthetic of the 1980s, is less hepatotoxic than its predecessors, halothane and enflurane. Since its release by the Food and Drug Administration in 1979, controversy has existed about the extent to which isoflurane is capable of producing hepatotoxic effects. In this report, we provide direct evidence that isoflurane can induce liver injury and should therefore be considered as a potential cause of serum transaminase elevations in any patient who is exposed to this anesthetic.

Aged↗
PubMed1995

Zinc supplementation in young children with acute diarrhea in India.

BACKGROUND: In developing countries the duration and severity of diarrheal illnesses are greatest among infants and young children with malnutrition and impaired immune status, both factors that may be associated with zinc deficiency. In children with severe zinc deficiency, diarrhea is common and responds quickly to zinc supplementation. METHODS: To evaluate the effects of daily supplementation with 20 mg of elemental zinc on the duration and severity of acute diarrhea, we conducted a double-blind, randomized, controlled trial involving 937 children, 6 to 35 months of age, in New Delhi, India. All the children also received oral rehydration therapy and vitamin supplements. RESULTS: Among the children who received zinc supplementation, there was a 23 percent reduction (95 percent confidence interval, 12 percent to 32 percent) in the risk of continued diarrhea. Estimates of the likelihood of recovery according to the day of zinc supplementation revealed a reduction of 7 percent (95 percent confidence interval, -9 percent to +22 percent) in the risk of continued diarrhea during days 1 through 3 and a reduction of 38 percent (95 percent confidence interval, 27 percent to 48 percent) after day 3. When zinc supplementation was initiated within three days of the onset of diarrhea, there was a 39 percent reduction (95 percent confidence interval, 7 percent to 61 percent) in the proportion of episodes lasting more than seven days. In the zinc-supplementation group there was a decrease of 39 percent (95 percent confidence interval, 6 percent to 70 percent) in the mean number of watery stools per day (P = 0.02) and a decrease of 21 percent (95 percent confidence interval, 10 percent to 31 percent) in the number of days with watery diarrhea. The reductions in the duration and severity of diarrhea were greater in children with stunted growth than in those with normal growth. CONCLUSION: For infants and young children with acute diarrhea, zinc supplementation results in clinically important reductions in the duration and severity of diarrhea.

Acute Disease↗
PubMed1995

A study on estimation of age from pubic symphysis.

The present study has been carried on 82 pairs of pubic symphysis collected from fresh male cadavers. Various features were noted on the symphyseal surface--ridges and furrows, dorsal margin, ventral bevelling, lower extremity, ossific nodule, upper extremity, ventral rampart, dorsal plateau and symphyseal rim. Varying combination of these features were used as criteria for age estimation of the subjects.

Adolescent↗
PubMed1995

Purification, characterization and antitumor activity of L-asparaginase isolated from Pseudomonas stutzeri MB-405.

An L-asparaginase produced by Pseudomonas stutzeri MB-405 was isolated and characterized. After initial ammonium sulfate fractionation, the enzyme was purified by consecutive column chromatography on Sephadex G-100, Ca-hydroxylapatite, and DEAE-Sephadex A-50. The 665.5-fold purified enzyme thus obtained has the specific activity of 732.3 units mg protein-1 with an overall recovery of 27.2%. The apparent M(r) of the enzyme under nondenaturing and denaturing conditions was 34 kDa and 33 kDa respectively, and the isoelectric point was 6.38 +/- 0.02. It displayed optimum activity at pH 9.0 and 37 degrees C. The enzyme was very specific for L-asparagine and did not hydrolyze L-glutaminate. The Km of the L-asparaginase was found to be 1.45 x 10(-4) M towards L-asparagine and was competitively inhibited by 5-diazo-4-oxo-L- norvaline (DONV) with a Ki of 0.03 mM. Metal ions such as Mn2+, Zn2+, Hg2+, Fe3+, Ni2+, and Cd2+ potentially inhibited the enzyme activity. The activity was enhanced in the presence of thiol-protecting reagents such as DTT, 2-ME, and glutathione (reduced), but inhibited by PCMB and iodoacetamide. The tumor inhibition study with Dalton's lymphoma tumor cells in vivo indicated that this enzyme possesses antitumor properties.

Amino Acids↗
PubMed1995

Dopamine D3-preferring ligands act at synthesis modulating autoreceptors.

Several compounds exist that demonstrate a binding preference for cloned dopamine D3 receptors vs. D2 receptors, including (+/-)7-OH DPAT, (+)-UH232 and (+)-AJ76. Inasmuch as recent evidence suggests that the dopamine D3 receptor may function as a dopamine autoreceptor, we have investigated the ability of these D3-preferring ligands to act at synthesis modulating dopamine autoreceptors using the gamma-butyro-lactone model in vivo to isolate the presynaptic effects of (+/-)7-OH DPAT, (+)-UH232 and (+)-AJ76. Further, given the discrete anatomical distribution of the D3 receptor, the striatum, n. Accumbens, and olfactory tubercles were examined for comparative analyses. (+/-)7-OH DPAT displayed agonist characteristics at synthesis modulating dopamine autoreceptors with a greater potency in the olfactory tubercle vs. either the striatum or the nucleus accumbens (ED-50 values were 31.8, 38.1 and 10.2 micrograms/kg for the striatum, nucleus accumbens and olfactory tubercles, respectively). Further, (+)-UH232 and (+)-AJ76 attenuated the effects of (+/-)7-OH DPAT (60 micrograms/kg s.c.) in all three regions examined. However, the effects of (+/-)7-OH DPAT were antagonized to a lesser extent in the olfactory tubercles than in either the striatum or the nucleus accumbens. Given the relative abundance of D3 receptors in the olfactory tubercles, the data are consistent with the notion that (+/-)7-OH DPAT may exert its autoreceptor effects preferentially through dopamine D3 receptors.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1994

Significance of spina bifida occulta in children with diurnal enuresis.

We reviewed retrospectively 456 patients with diurnal enuresis to determine the relationship between spina bifida occulta and attainment of continence. Of these patients 127 had undergone x-rays of the spine and 48 children (48%) had spina bifida occulta. The clinical course of these patients was compared to 79 enuretic children with normal spine films. All patients were initially treated with a timed voiding program and 28 with persistent enuresis were given anticholinergic medication. Findings on urodynamic studies were similar for both groups. Uninhibited bladder contractions were found in the majority of patients and 2 children in each group had hypertonic filling curves. Of 10 children with spina bifida occulta magnetic resonance imaging or ultrasound of the spine revealed lipoma and tethering of the cord in 1. Mean followup for both groups was 3 years. The outcome for enuretic children with spina bifida occulta was comparable to those with normal spine x-rays. The majority of patients had resolution of the enuresis with conservative management. Spinal ultrasound or magnetic resonance imaging may be warranted in those children with abnormal neurological findings on examination or hypertonic filling curves, or those who fail to respond to medical treatment. However, neurosurgical intervention to achieve continence appears necessary in only a small percentage of enuretic children with spina bifida occulta.

Child↗
PubMed1994

Congenital fistula of the penile urethra.

Congenital fistula of the penile urethra is rare. We report a case associated with glandular hypospadias without chordee, and discuss the possible etiology and management of this unusual anomaly.

Humans↗
PubMed1994

Osteomyelitis.

Osteomyelitis can be difficult to treat. Current trends emphasize early diagnosis and aggressive treatment. Imaging has improved with nuclear scans and magnetic resonance imaging, and recent modifications in technique have enhanced the specificity. Treatment depends on debridement of necrotic bone and tissue, obtaining accurate cultures, and administration of culture- and sensitivity-directed antibiotics. Antibiotic delivery has expanded to include effective oral agents and local agents mixed with polymethylmethacrylate or a biodegradable substance. Success rates in treating this disease have improved with a systematic approach, making outcome more predictable.

Chronic Disease↗
PubMed1994

Complementary effects of pravastatin and nicotinic acid in the treatment of combined hyperlipidaemia in diabetic and non-diabetic patients.

BACKGROUND: Given that treatment with a single drug is frequently unsuccessful in patients with combined hyperlipidaemia, there is a rationale for the study of regimens using drugs that have complementary therapeutic profiles. We therefore set out to compare the efficacy of a combined pravastatin and nicotinic acid regimen with higher dose monotherapy using either drug in patients with non-insulin-dependent diabetes and in non-diabetic patients with combined hyperlipidaemia. METHODS: Forty-four patients with total-cholesterol levels of 6.5 mmol/l or higher and triglyceride levels of 2.5 mmol/l or above were randomly assigned to receive either pravastatin alone (40mg/day) or nicotinic acid alone (1500mg/day) for 12 weeks. At the end of this period, the participants received a combination of pravastatin (20mg/day) and nicotinic acid (1000mg/day) for a further 12 weeks. The lipid parameters measured included levels of total cholesterol, triglycerides, low-density-lipoprotein (LDL) cholesterol and high-density-lipoprotein (HDL) cholesterol. RESULTS: Thirty-three patients (22 without and 11 with diabetes) completed the protocol. Monotherapy with pravastatin was more effective than that with nicotinic acid in reducing levels of total cholesterol (-24.9 versus -9.8%, P<0.001) and LDL cholesterol (-32.1 versus -16.9%, P < 0.01), similar in reducing levels of triglyceride (-28.0 versus -31.8%, NS) and tended to be less effective in elevating levels of HDL cholesterol (+16.4 versus +30.8%, P = 0.06). Combination therapy was more effective than pravastatin monotherapy in reducing levels of triglyceride (-39.3 versus -28.0%, P < 0.05) and elevating those of HDL cholesterol (+35.6 versus +16.4%, P < 0.001) and was equally effective in reducing total-cholesterol (-22.3 versus -24.9%, NS) and LDL-cholesterol (-27.1 versus -32.1%, NS) levels. Combination therapy was more effective than nicotinic acid monotherapy in reducing levels of total cholesterol (-23.8 versus -9.8%, P < 0.001), triglyceride (-39.4 versus -31.8%, P < 0.05) and LDL cholesterol (-35.7 versus -16.9%, P < 0.05) and equally effective in elevating HDL-cholesterol levels (+33.6 versus +30.8%, NS). Diabetic and non-diabetic participants responded similarly to combination therapy. Eleven patients (25%) were withdrawn from the study: nine as a result of nicotinic acid intolerance (flushing and nausea) and one through pravastatin intolerance (nausea); one patient died of a myocardial infarction. Combination therapy elevated glycosylated haemoglobin A1c levels in non-diabetic patients (5.5 to 5.8%, P < 0.001); in diabetic patients, however, the observed rise (7.4 to 7.9%) was not statistically significant. Fasting plasma glucose levels, liver function tests and levels of creatine kinase or uric acid were unaffected by either monotherapy or by combination therapy, with the exception of an elevation of the glucose level in diabetic patients receiving nicotinic acid monotherapy. CONCLUSION: Pravastatin and nicotinic acid in lower-dose combination are more effective than pravastatin alone in reducing levels of triglyceride and elevating those of HDL cholesterol and are more effective than nicotinic acid alone in reducing total-cholesterol triglyceride and LDL-cholesterol levels. Combination therapy is equally effective in type-II diabetic and non-diabetic people. The complementary effects of the combination therapy on lipid levels suggest that this regimen should be considered as a therapeutic option in patients with combined hyperlipidaemia who tolerate the side effects of nicotinic acid.

Adult↗
PubMed1994

Progressive decline in renal function in diabetic patients with and without albuminuria.

This study describes patterns of progression of albuminuria and renal function in a subgroup of 40 patients from a total cohort of 211 diabetic patients (118 type I, 93 type II) followed over a period of 8-14 years. Forty patients (18 with type I diabetes, 22 with type II diabetes) showed progressive increases in albumin excretion rate (AER) and/or decreases in creatinine clearance (CC) during the study period. Of these, AER alone increased in 15 patients, AER increased and CC decreased in 13 patients, and CC alone decreased in 12 patients, with a similar distribution of type I and type II diabetic patients in each group. Of the 28 patients who showed an increase in albuminuria, AER increased at an annual rate of 30-40%, resulting in a 4- to 8-fold increase in AER to > 20 micrograms/min during the study. Of the 25 patients who showed a decrease in renal function, CC decreased at an annual rate of 4-5 ml/min, resulting in an approximate halving of CC to < 90 ml/min during the study. The rate of fall in CC was not related to the presence or absence of concomitant increases in albuminuria. However, a significant preponderance of women in the group showed a decline in CC alone. The decline in CC was associated with an increase in plasma creatinine as well as a progressive decrease in urinary creatinine excretion, but the underlying mechanisms remain unexplained. These data support the concept that a subgroup of diabetic patients may show a decline in renal function in the absence of significant increases in AER.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Cryptococcal meningitis (C. neoformans var. gattii) leading to blindness in previously healthy Melanesian adults in Papua New Guinea.

Cryptococcal meningitis is a common cause of chronic meningitis in Papua New Guinea, affecting apparently immunocompetent people. The majority of infections are believed to be due to Cryptococcus neoformans var. gattii. We have reviewed the records of 49 Melanesian adults who presented with proven cryptococcal meningitis to the University teaching hospital in Port Moresby, and compare our findings with other published studies of cryptococcal meningitis in the tropics and sub-tropics. None of the patients had an obvious cause of immunosuppression. Visual disturbances and fundoscopic changes of papilloedema or papillitis were particularly common. The in-hospital case fatality rate for patients treated with amphotericin B and flucytosine was 22.4%. Of the fully treated patients, 31% became completely blind before being discharged from hospital. Therapy directly aimed at reducing intracranial pressure may improve outcome.

Adolescent↗
PubMed1993

Relationship of progressively increasing albuminuria to apoprotein(a) and blood pressure in type 2 (non-insulin-dependent) and type 1 (insulin-dependent) diabetic patients.

This study has explored the temporal relationship between apoprotein(a), blood pressure and albuminuria over a mean interval of 11 years in a cohort of 107 diabetic patients of whom 26 (14 Type 2 (non-insulin-dependent), 12 Type 1 (insulin-dependent) had progressively increasing albuminuria ('progressors'). In Type 2 diabetic patients, no significant differences were noted for HbA1, blood pressure, creatinine clearance or serum lipids between progressors and non-progressors. In Type 1 diabetic patients, final systolic and diastolic blood pressures were higher in progressors compared with non-progressors and progressors showed impairment of renal function in association with a rise in blood pressure at the macroalbuminuric stage. Initial apoprotein(a) levels were similar in progressors and non-progressors of either diabetes type. Apoprotein(a) levels increased exponentially with time in 12 of 14 Type 2 progressors but only in 5 of 12 Type 1 progressors (p < 0.01). In Type 2 diabetic patients, the annual increase in apoprotein(a) levels was 9.1 +/- 2.4%, which was significantly greater than in non-progressors, 2.0 +/- 1.2% (p < 0.01) and also exceeded the rates of increase of apoprotein(a) in progressors with Type 1 diabetes, 4.0 +/- 1.4%, (p < 0.05). Apoprotein(a) levels correlated significantly with albuminuria in 8 of 14 Type 2 progressors but only in 3 of 12 Type 1 progressors (p < 0.05). The rate of increase of apoprotein(a) levels was not related to mean HbA1, creatinine or creatinine clearance levels, or to albuminuria.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

A field trial of Billings' ovulation method for spacing and limitation of birth.

In spite of constant efforts by health and social workers, existing family planning measures are not used by a vast majority of eligible couples. This is because of the fear that the method may affect their health and happiness. Billings' ovulation method is based on the scientific observation that by noting the changes in cervical mucus, which is clear, slippery and copious in periovulatory period, it is possible to prevent pregnancy by avoiding intercourse during this period. As this method does not require the use of drugs or devices it was decided to promote this method in the urban areas and slums of Patna, Bihar where couples were not using other methods. This is not a comparative study of the cost-effectiveness of Billings' ovulation method versus other contraceptive measures at all. An analysis of 501 cases (267 in urban and 234 in slums) over a period of 2 1/2 years has been presented and it is gratifying to note that the couples from all religions and strata of the society (nearly 47% were slum dwellers) agreed to continue this method.

Adult↗