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Biomedical subjects

M N Mehta

Publications and source records attributed to M N Mehta.

At least 19 recordsLinked to original sources
PubMed1993

Measurement of serum thyrotropin levels using sensitive immunoradiometricassays in patients with chronic renal failure: alterations suggesting an intact pituitary thyroid axis.

Serum thyroid stimulating hormone (TSH) levels were measured in 127 patients with varying grade of chronic renal failure (CRF). Sensitive immunoradiometricassays (IRMA) were used so that small changes in TSH levels if any, could be appreciated, and to see if such alterations exhibit some relationship with those in thyroid hormone levels. Mean serum TSH levels in the patient group of 2.33 microU/ml (0.07-7.3) was significantly higher in comparison to 1.73 microU/ml (0.25-4.6) in normal subjects (p < 0.001). However, they were not significantly different when measured by radioimmunoassay (RIA) as compared to normals. Serum triiodothyronine (T3), thyroxine (T4) and free triiodothyronine (FT3) levels of 72 +/- 32 ng/dl, 7.4 +/- 2.6 micrograms/dl and 2.9 +/- 0.9 pg/ml were significantly lower than in normal subjects, whereas serum free thyroxine (FT4) showed a slight though not significant elevation. When patients were divided in three subgroups according to the degree of renal insufficiency, TSH levels showed a gradual rise with corresponding depression in their T3, FT3 and T4 levels. In 19 patients who were on hemodialysis (HD) and subsequently received successful renal transplantation, most of the thyroid function parameters returned towards the normals with TSH undergoing significant depression from their pretransplant levels as well as from normal levels. The results indicated that a slight but significant elevation in TSH levels could be revealed by sensitive IRMA in patients with CRF. Rising TSH levels with increasing renal insufficiency and its inverse relationship with T3 and T4 levels suggest maintenance of pituitary thyroid axis.(ABSTRACT TRUNCATED AT 250 WORDS)

Combined Modality Therapy↗
PubMed1991

Insulin reverses haemodynamic changes and pulmonary oedema in children stung by the Indian red scorpion Mesobuthus tamulus concanesis, Pocock.

The efficacy of insulin administration in reversing haemodynamic changes in pulmonary oedema in victims of poisonous scorpion sting is assessed by a study based on animal experiments in which insulin administration reversed metabolic and electrocardiographic changes induced by scorpion envenomation. Six previously healthy children aged 18 months to 11 years were admitted to hospital five to 17 hours after scorpion sting. Frusemide for raised central venous pressure and pulmonary oedema, crystalloid infusion for reduced central venous pressure, and hydrocortisone and dopamine for hypotension were used as standard therapy. Insulin (0.3 units g-1 of glucose) was administered when the standard therapy failed to produce an improvement, and at the earliest sign of haemodynamic instability. Reversal of pulmonary oedema and haemodynamic changes, and attainment or normal respiratory rate, blood pressure and central venous pressure, were observed. It is concluded that insulin administration may be useful in reversing haemodynamic changes and pulmonary oedema in victims of scorpion stings.

Animals↗
PubMed1991

Total and free thyroid hormone levels in chronic renal failure.

The levels of serum total thyroxine (TT4), triiodothyronine (TT3), free T3, (FT3) free T4 (FT4) and thyrotropin (TSH) were measured in 127 clinically euthyroid patients with varying grades of chronic renal failure (CRF); and 97 healthy individuals. They were grouped as: Group I containing 93 patients on conservative management; Group II containing 34 patients on regular dialysis therapy; and Group III (normals). Group I patients showed significant decrease in TT3, TT4 and FT3 levels (p less than 0.001) as compared to Group III, whereas FT4 and TSH values in group I were not significantly altered. TT3, TT4 and FT3 levels reduced as the severity of renal damage increased. Variations in TT3, TT4, FT3, FT4 and TSH levels in Group II patients were similar to those in Group I, except for a decrease in TSH levels (p less than 0.05) as compared to normals. Several thyroid function tests are abnormal in CRF patients, however, finding of normal FT4 and TSH levels would indicate functional euthyroid status.

Humans↗
PubMed1991

Detection of autoantibodies against 3,5,3'-triiodothyronine in a hyperthyroid patient (a case report).

A 35-year-old female patient was evaluated for thyroid function and was found to be hyperthyroid clinically and by laboratory tests. During the course of treatment with neomercazole, she developed a bizarre picture with consistently low T3 levels irrespective of her clinical thyroid status and other laboratory tests like serum T4 and TSH levels. The serum of the patient when analysed for the presence of autoantibodies was positive for those against T3. The presence of T3 autoantibodies was confirmed by other laboratory techniques like assessment of blank values in radioimmunoassay, binding of T3-125I to isolated gamma globulin and starch gel electrophoresis. Autoantibodies were found to be present only against T3 and not against. T4 The affinity constant of T3 antibodies was 4 x 10(9) lit. mol-1 as determined by Scatchard plot analysis while total binding capacity was 23 x 10(-11) mol/L.

Adult↗
PubMed1989

Simultaneous production of antibodies against T3 and T4 in a single animal; their characteristics and usefulness in radioimmunoassay.

Simultaneous production of antibodies against triiodothyronine and thyroxine was attempted in a single rabbit by immunizing the animal with T3-albumin conjugate and T4-albumin conjugate at the same time. This resulted in the production of antibodies against both T3 and T4. The characteristics of each antibody were studied and the antiserum was used for determination of serum T3 and T4 concentrations by radioimmunoassay. The results were compared with those obtained with antibodies against T3 and T4 which were produced individually in different rabbits and were found to be more or less similar. From the results of the experiments, it appears that it is possible to make antibodies against T3 and T4 simultaneously in a single rabbit.

Animals↗
PubMed1988

Measurement of specific activity of radiolabelled antigens by a simple radioimmunoassay technique.

A simple radioimmunoassay (RIA) technique for measurement of specific activity of radiolabelled antigen is described. The technique involves setting up of a conventional RIA using multiple amounts of radiolabelled antigen as the unknown substance together with several RIA tubes containing the same amount of radiolabelled antigen with various known amounts of stable carrier. The known and unknown substances are equated at identical B/F ratio which would give the amounts of radiolabelled antigen. Counting the radioactivity in a counter with known efficiency gives its radioactive strength.

Radioimmunoassay↗
PubMed1987

Thyroid function and thyrotropin levels in rabbits immunized to produce antibodies against thyroid hormones.

Various parameters of thyroid function were studied in 27 rabbits, out of which 10 were immunized to produce antibodies against triiodothyronine (T3), 9 against thyroxine (T4) and 8 were normals. Estimations of T3, T4, Free T4 (FT4) and thyrotropin (TSH) in blood, qualitative and quantitative analysis of iodoamino acids in serum, protein bound iodine-131 (PB131I), butanol extractable iodine-125 (BE125I) and measurement of the disappearance rates of 125I-labelled T3 and T4 from plasma were done. In addition, glandular changes were also studied by measurement of 131I uptake, thyroid scanning and chromatographic analysis of hydrolysate of soluble iodoproteins. In T3 immunized animals, levels of T3 in serum increased by 38 to 125 times, levels of TSH also showed a significant rise (7.4 +/- 1.2 vs 28 +/- 9 ng/mL). Chromatographic analysis of iodoamino acids in serum as well as in the hydrolysate of the thyroid gland demonstrated a selective increase in synthesis of T3. Rate of disappearance of T3 from blood showed a significant decline. Thyroid glands in the immunized rabbits showed signs of hypertrophy and hyperplasia. Identical studies done in rabbits immunized to produce antibodies against T4 showed a similar pattern though of variable degree. Our studies indicate that the thyroid glands of the immunized rabbits undergo marked alterations resulting in selective increase in the synthesis and secretion of the particular thyroid hormone against which they were immunized. They do so under the influence of increased levels of TSH.

Amino Acids↗
PubMed1987

Increased sensitivity of triiodothyronine antibodies for radioimmunoassay after removal of endogenous antigen by simple laboratory procedures.

Conventionally produced antibodies against triiodothyronine (T3) are known to possess high amounts of endogenously produced T3 associated with them. We felt that such antibodies would work better for T3 radioimmunoassay (RIA) after prior removal of the antigen. With this in view, we attempted dissociation and subsequent removal of T3 from antisera by two different methods, viz. dialysis and alcohol extraction. It was possible to remove T3 to an extent of 77% by alcohol extraction and 60% by dialysis. Resultant antisera fail to demonstrate any increase in the titre. However, when standard curves were generated using these antisera, the assays became more sensitive and it was possible to detect T3 in concentrations as low as 6.25 pg. The affinity constants of these antisera calculated from the respective Scatchard plots were found to have increased after both dialysis treatment was well as alcohol extraction. This was thought to be due to rendering some of the high affinity binding sites on the antibodies free of antigen after treatment. Serum T3 levels were measured in 68 patients with various thyroid status using both treated as well as untreated antiserum. The difference between the average values of serum T3 concentration estimated using various antisera before and after the treatment was not statistically significant. Our results suggested that a simple procedure like stripping of antigen from antibodies could be of help for acquiring high affinity and high sensitivity antibodies for this purpose.

Antibodies↗
PubMed1986

Comparison of rice water, rice electrolyte solution, and glucose electrolyte solution in the management of infantile diarrhoea.

150 infants aged under 6 months and admitted to hospital with acute gastroenteritis were treated with rice water (RW), rice-based electrolyte solution (RES), and the glucose electrolyte solution (GES) recommended by the World Health Organisation. Two-thirds of the patients were moderately dehydrated and only 8% had positive stool culture. Vomiting, present in 11%, did not interfere with successful oral rehydration. Before treatment serum electrolytes and other biochemical variables were similar in the three groups. After 48 h of treatment the blood urea nitrogen and serum creatinine were lower (p less than 0.05) in the RW and RES group than in the GES group. Serum potassium was also lower in the RW than in the RES group. RW and RES were superior to GES in reducing the frequency and volume of stool output and in producing weight gain.

Acute Disease↗
PubMed1985

Child labor in Bombay.

Of the world's largest child labor force in India, Bombay has over 30,000 working children, most of them migrants. In a prospective study of 73 working children from a part of Dharavi, the biggest slum in Asia, 68% were working as hotel boys; 22% had started working before their 10th birthday, a large number doing so to increase the family income, but earning less than Rs. 100 ($11) per month. Forty percent worked more than 12 hours a day and only 16% continued schooling. Two-thirds depended entirely on their employers for food which was adequate and no child in the study was malnourished. Overall incidence of anemia and vitamin deficiency was 10% each. Only 7% had ailments related to their occupation. Because this was a cross-sectional study no conclusions can be drawn regarding long term and residual effects. Preventing children from working is likely to make worse their own as well as their families' problems unless substitute sources of income or welfare are available. Legal protection and other services near their working places are essential for those who have to work.

Adolescent↗
PubMed1983

Adoptions: follow-up from an orphanage in Bombay.

The practice of adoption, though long accepted as a social phenomenon, is only recently gaining popularity in India. Due to the paucity of adequate follow-ups, evaluation of these adopted children is incomplete. For the purpose of studying the well-being of these children after adoption, they were followed-up at the various places, i.e., orphanages, institutions, juvenile courts and adoption agencies, responsible for their care. One hundred sixty children, 63 boys and 97 girls, adopted from an orphanage in the vicinity of our hospital over a period of 13 years are included in this study. There were 104 local and 56 foreign adoptions. Due to sociocultural background in Indian adoptions, males were preferred; whereas the international adoptions mostly depended on human considerations without any specific preference for the sex of the child. On follow-up, all children except three were reported to be physically healthy and well-adjusted emotionally in the new family, and well accepted by the society. Although adoption is not the only solution for an abandoned child, it may open some avenues for the betterment of socially deserted and deprived children.

Adoption↗