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Biomedical subjects

S Ahuja

Publications and source records attributed to S Ahuja.

At least 73 records · Page 4Linked to original sources
PubMed1987

Chemotherapy of thyroid carcinoma.

On the basis of 8 patients of our own and a survey of the literature, the present state of chemotherapy of thyroid carcinoma is discussed. Chemotherapy is only indicated in cases of progressing disease after exhaustion of all conventional therapies. Only in cases of undifferentiated giant- or spindle-cell thyroid carcinomas can chemotherapy following conventional treatment be approved right from the beginning. The three most widely applied cytostatics are adriamycin, bleomycin and cis-platinum, and it seems that adriamycin monotherapy, is superior to all other therapies, even combinations, except probably for the undifferentiated thyroid carcinoma. In addition to the patient's general condition, a sufficiently high single dose of adriamycin, which should be increased in case of nonresponse, appears to be essential for the therapeutical effect. Due to its low toxicity, especially cardiotoxicity, 4'-epi-adriamycin, which, while being almost as effective, can be applied at higher doses and over longer periods, seems to be promising. Approximately 1/3 of thyroid carcinomas respond to adriamycin monotherapy, the response rate probably being highest for medullary types and lowest for undifferentiated thyroid carcinomas. The highest response is observed in the case of pulmonary metastases, followed by bone metastases and local tumor growth. If thyroid carcinomas respond to chemotherapy--even by no-change behavior only--a prolongation of median survival rates from 3-5 months (nonresponders) to 15-20 months (responders) can be achieved.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

The effects of different inactivating agents on the potency, toxicity and stability of pertussis vaccine.

The effect of heat (56 degrees C for 10 min), formaldehyde (0.1% at 37 degrees for 24h), glutaraldehyde (0.05% at room temperature for 10 min), thimerosal (0.02% at 37 degrees C for 24h), acetone-I (three treatments at room temperature) and acetone-II (three treatments at room temperature and fourth treatment at 37 degrees C), when used as inactivating agents in the preparation of pertussis suspension, was studied with regard to potency, toxicity and stability. Five batches each of Bordetella pertussis strains 134 and 509 were used for the study. The thimerosal inactivated pertussis (TIP) preparation was 1.5-2 times more potent than the heat inactivated pertussis (HIP) preparation. The potency values of the formaldehyde inactivated pertussis (TIP) and glutaraldehyde inactivated pertussis (GIP) preparations were similar to those of the HIP preparation, while the potencies of the acetone-I treated pertussis (A(I)TP) and acetone-II treated pertussis (A(II)TP) preparations were about half those of the HIP preparation. The FIP preparation was the least toxic showing maximum weight gain in the mouse weight-gain test (MGWT), while the TIP preparation did not pass the MWGT. The weight gains shown the GIP, A(I)TP and A(II)TP preparations were greater than those shown by the HIP preparation. The potency of pertussis component in the adsorbed diphtheria-pertussis-tetanus (DPT) vaccine was stable at 4-8 degrees C and 25 degrees C for three months for all types of pertussis vaccine. There was about 54-65% loss in the potency of the samples after three months at 35 degrees C. The inactivating agents used in the manufacture of pertussis preparations had no effect on the stability of the vaccine.

Acetone↗
PubMed1987

Glutaraldehyde inactivated pertussis vaccine: a less histamine sensitizing vaccine.

The effects of different inactivating agents on the biological activity of the histamine sensitization factor of Bordetella pertussis toxin were examined. The agents were used for inactivation in the preparation of whole cell pertussis suspension. The histamine sensitizing activity was reduced to 36.9-13.3% by treatment with glutaraldehyde, to about 50% by treatment with formaldehyde and by the acetone-II treatment, relative to the reduction by heat treatment. Treatment with thimerosal and the acetone-I treatment did not reduce the histamine sensitizing activity as the 50% histamine sensitizing doses of the heat inactivated pertussis preparation, the thimerosal inactivated pertussis preparation and the acetone-I treated pertussis preparation were very similar. Glutaraldehyde has thus been found to be a better inactivating agent for the preparation of a safe pertussis suspension as it considerably reduced the histamine sensitizing activity of pertussis toxin.

Acetone↗
PubMed1987

Glutaraldehyde inactivated pertussis vaccine: a safe vaccine in the innocuity test.

The adsorbed diphtheria-pertussis-tetanus (DPT) vaccine containing glutaraldehyde inactivated pertussis vaccine passed the innocuity test only after one month's storage of the preparation at 4-8 degrees C when the adsorbed DPT vaccine containing pertussis vaccine inactivated by heat, formaldehyde, thimerosal or acetone did not pass the test. The adsorbed DPT vaccine became innocuous when it was stored at 4-8 degrees C. The innocuity test was passed more easily in guinea pigs than in mice.

Animals↗
PubMed1987

Further observations on the stability of cholera vaccine at different temperatures.

The stability of cholera vaccine samples held at 4-8 and 20-25 degrees C for 2 1/2 years was studied with regard to the number of organisms, total nitrogen content and relative antigenicity. After this length of time, the percentage loss in the number of organisms averaged 10.7 at 4-8 degrees C and 22.7 at 20-25 degrees C. The maximum loss in number of organisms took place during the first six months and in the next two years there was very little loss in the number of organisms. The total nitrogen content after 2 1/2 years remained almost unaltered at these temperatures. All the ten samples had acceptable relative antigenicity for both the Inaba and Ogawa serotypes after exposure at 4-8 degrees C for 2 1/2 years, while at 20-25 degrees C only two samples for the Inaba serotype and one sample for the Ogawa serotype retained antigenicity within acceptable limits after the same time. The loss of antigenicity after 2 1/2 years at 20-25 degrees C in comparison with antigenicity at 4-8 degrees C ranged from 41.5 to 83.1% (mean 61.9%) for the Inaba serotype and from 47.3 to 80.3% (mean 65.1%) for the Ogawa serotype. From this study on the cholera vaccine manufactured at the Central Research Institute, Kasauli, it is concluded that the shelf life of cholera vaccine may be increased from 18 months to at least 24 months, when the vaccine is stored under refrigeration.

Animals↗
PubMed1987

A comparison of the indirect haemagglutination test with the toxin neutralization test for the estimation of diphtheria antitoxin in mouse sera.

Serum samples from 42 groups of mice immunized for different immunization periods with various doses of Adsorbed Diphtheria-Tetanus Vaccine, Adsorbed Diphtheria-Tetanus and Pertussis Vaccine and a standard diphtheria toxoid were assayed for their diphtheria antitoxin content by indirect haemagglutination (IHA) and by toxin neutralization (TN) tests. A very good correlation of 0.91 was obtained between the results of the two methods. There was no statistically significant difference between the IHA and the TN titres obtained. Adsorption with sheep red cells and treatment of the sera with 2-mercaptoethanol had no effect on the IHA titres. The minimum level of antitoxin detectable by the IHA test was 0.00039 IU ml-1. IHA proved to be a sensitive, specific and reproducible method which can be used reliably for the assay of diphtheria antitoxin in mouse sera.

Animals↗
PubMed1987

Evaluation of repeated immunoassays (mouse intracerebral potency tests) of the second International Standard of Pertussis Vaccine.

During one year 27 potency assays of second International Standard of Pertussis Vaccine were performed, when the Indian Standard of pertussis vaccine was being standardized. In all the 27 assays, the 50% immunizing dose (ImD50) was calculated both by Wilson-Worcester method and by probit analysis. The ImD50 of the International Standard varied from 0.022 I.U. to 0.076 I.U. (Mean 0.041 I.U.) when it was calculated by Wilson-Worcester method and from 0.0226 I.U. to 0.0704 I.U. (Mean 0.0402 I.U.) when it was calculated by probit analysis. There were no statistically significant differences between ImD50 values calculated by Wilson-Worcester method and by probit analysis. The challenge dose of Bordetella pertussis in terms of LD50 units had no effect on the ImD50 values. The average slope (b) of the assays was 1.92 when calculated by probit analysis and the average homogeneity factor (alpha) in these assays calculated by Wilson-Worcester method was 1.73.

Animals↗
PubMed1986

Tuberous sclerosis with angiomyolipoma and metastasized hypernephroma.

This is a case report of a patient with angiomyolipomas in both kidneys which was confirmed in one kidney by open biopsy and histologic examination. Two years after diagnosis of the angiomyolipomatosis, the patient died of metastatic hypernephromas of both kidneys. The tumors had affected the kidneys almost totally; only in the right kidney were remnants of the angiomyolipoma still recognizable. A review of the literature shows how rare is the simultaneous occurrence of angiomyolipomas and hypernephroma.

Adult↗
PubMed1986

Effects of elevated temperatures on the opacity and toxicity of pertussis vaccines manufactured with different inactivating agents.

Plain pertussis vaccine manufactured with different inactivating agents was evaluated for its stability at 4-8, 25 and 35 degrees C with regard to the opacity and the toxicity [mouse weight gain test (MWGT) and histamine sensitizing (HS) activity]. Two pools each of heat inactivated pertussis vaccine (HIPV), formaldehyde inactivated pertussis vaccine (FIPV), glutaraldehyde inactivated pertussis vaccine (GIPV), thimerosal inactivated pertussis vaccine (TIPV) and acetone (I) treated pertussis vaccine [A(I)TPV] were taken for the study. The test for determination of opacity and MWGT were performed at monthly intervals for three months and the test for HS activity was performed after three months exposure of the samples at various temperatures. There was almost no loss in the opacity of GIPV and TIPV at all the selected storage temperatures and of HIPV and FIPV at 4-8 degrees C, while A(I)TPV lost about 16% opacity in three months at 4-8 degrees C. At 25 degrees C after three months, the percentage loss in opacity of HIPV averaged about 12, of FIPV 17 and of A(I)TPV 33. At 35 degrees C after three months, the average percentage loss in opacity of HIPV was 16, of FIPV was 25 and of A(I)TPV was 33. Regarding the effect of elevated temperatures on the toxicity of the vaccine, it was observed that the samples held at 35 degrees C for three months were the least toxic followed by those held at 25 and 4-8 degrees C as detected by MWGT and the test for HS activity.

Acetone↗
PubMed1986

Occurrence of calcitonin, somatostatin-like immunoreactivity, and carcinoembryonic antigen in two sisters suffering from familial thyroid medullary carcinoma.

The presence of calcitonin, somatostatin-like immunoreactivity and carcinoembryonic antigen in tumor tissues (surgically obtained) and identified by the peroxidase-antiperoxidase technique, is reported in two sisters suffering from familial thyroid medullary carcinoma. C-cell hyperplasia occurred in both individuals. Preoperatively, both patients had elevated calcitonin serum levels (290 pM, 991.8 ng/l), and carcinoembryonic antigen (60 micrograms/l). No ACTH or thyroglobulin immunoreactivity could be found in the tumor tissue. After thyroidectomy, 131I-treatment and percutaneous radiation, somatostatin-like immunoreactivity and carcinoembryonic antigen plasma levels were in the normal range, whereas calcitonin was still elevated. It is proposed that calcitonin, somatostatin, and carcinoembryonic antigen are produced by the thyroid medullary carcinoma.

Adult↗
PubMed1984

Gentamicin resistance among salmonellae. A ten-year study, 1973-1982.

A total of 8579 Salmonella strains received during 1973-1982 were tested for their antibiogram patterns against nine routinely used antibiotics including gentamicin. Of these, 380 strains (4.4%) showed resistance to gentamicin at levels of 10 micrograms/ml and above. A high degree of resistance to gentamicin was recorded in 1979 (18.7%) and 1980 (9.4%). M.I.C. levels of strains received during 1982 were determined and it was found that some strains had levels as high as 160 micrograms/ml. The comparative results of gentamicin resistance from 1973 to 1982 are presented and the public health significance of the alarming increase in two years (1979-1980) is discussed.

Animals↗
PubMed1984

Effect of storage temperatures on opacity and total nitrogen content of cholera vaccine.

Fluid cholera vaccine was examined for its stability at 4-8 degrees C, 20-25 degrees C and 37 degrees C with regard to the number of organisms present and the total nitrogen content. Ten batches of fluid cholera vaccine manufactured at the Central Research Institute, Kasauli, India were taken for the study. The number of organisms was determined at weekly intervals for the first month and at monthly intervals for the next 11 months. The percentage loss in the number of organisms after one year averaged 6.5 at 4-8 degrees C, 20.6 at 20-25 degrees C and 21.5 at 37 degrees C. The maximum loss in number of organisms took place during the first six months at these temperatures, in the following six months the number of organisms remained almost constant even at 37 degrees C. The total nitrogen content of the vaccine remained virtually unaltered during the same period. From this study it was concluded that the number of organisms and the total nitrogen content does not reflect the antigenicity nor potency of the vaccine.

Cholera Vaccines↗