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Biomedical subjects

P Gangadharan

Publications and source records attributed to P Gangadharan.

At least 19 recordsLinked to original sources
PubMed1984

Management of Hodgkin's disease in western India.

The authors report a retrospective analysis of 441 patients with Hodgkin's disease seen at the Tata Memorial Hospital, Bombay, over a 4-year period from 1975 to 1978. Clinicopathologic features seem to vary from those reported in the western literature, but are similar to the patterns observed in Africa and South America. Thirty-three percent of all malignant lymphomas were Hodgkin's disease. Histologically, the mixed cell (MC) type (40%) and the lymphocytic predominant (LP) type (24%) were the most common, with 52% of patients presenting in Stages III and IV. The nodular sclerosis (NS) variant occurred in only 11% of the cases. Systemic symptoms were present in 24% of clinical Stage I patients, and increased steadily to 85% in Stage IV patients. Bone marrow biopsies in 242 patients were found to be of little value in Stages I and II. Thirty of 34 patients with positive bone marrow biopsy were in clinical Stages III B and IV, whereas 24 of 34 patients showed MC and LD patterns. Lymphangiography in 104 patients altered the clinical staging of Stages I and II in 27% of the cases with accuracy of 80%. Staging laparotomy performed in 93 patients altered the stage in 45% of clinical Stage I and 62% of Stage II patients. Splenic involvement was common in the presence of systemic symptoms (67%) and MC/LD histology (82%). The incidence of liver involvement was 16% in 15 patients with all, but one, associated with splenic pathology. The clinical stage and histopathologic variants of the disease bear an excellent correlation with a significant impact on treatment responses and total survival. The survival rates for Stage I were 81%, Stage II 76%, Stage IIIA 71%, and Stage IIIB and IV 46% at 48 months. The LP type had the best prognosis with 85% survival at 48 months, whereas the survival in the depleted variety was only 56%. Surprisingly, the MC type did better with a 64% survival, while the nodular sclerosis group had 59% surviving at 48 months.

Adolescent↗
PubMed1982

Hodgkin's disease in Western India: review of 1082 cases.

Hodgkin's disease (HD) had a low overall incidence rate in Bombay when compared to western countries. However, the incidence rate in childhood was quite high. Review of 1082 cases of Hodgkin's disease recorded at the Tata Memorial Hospital, Bombay. India during a period of 35 years showed that mixed cellularity, with 54% of the total, was the most frequent histologic subtype and this, together with lymphocyte depleted type formed 68% of all HD. The nodular sclerosis type formed only 9%. A bimodal character of the age pattern with a young age peak in the second decade of life, a male preponderance, a high incidence in childhood, and the predominance of low survival types, are the major features of the disease in India. The current data, which are the largest series reported from Bombay and other parts of India, indicate that the type-I pattern as described by Correa and O'Connor may be the characteristic feature of the Hodgkin's disease in India.

Adolescent↗
PubMed1981

Metabolic studies on the possible mode of action of isoniazid tumorigenicity.

Data on tumorigenicity and mutagenicity of INH show that INH is tumorigenic in mice but not in rats. The metabolic studies on the two species denote that rats are rapid inactivators whereas mice are slow inactivators of INH. Rats are also resistant to the immediate inhibitory effect of INH on DNA biosynthesis. Using Ames test it was observed that INH is mutagenic to salmonella typhimurium strains TA 100 and 1535 and this effect is abolished in presence off 59 mixture. In vivo and in vitro studies on INH interaction with macromolecules reveal that there is a greater interaction with RNA than with DNA and the site of interaction is the cytidine and deoxycytidine, respectively. A preliminary study is undertaken to see if healed TB cases have a higher risk for cancer. It is found that cancer incidence in this group is higher as compared to noncancer patients.

Animals↗
PubMed1981

Portable transfer digital dosemeter for beam output measurements with X and gamma rays, electrons and neutrons.

This instrument was developed in response to a requirement for an accurate, stable and portable transfer dosemeter for calibration, at therapy dose levels, of equipment used for generating X and gamma rays, electrons and neutrons. The detector is a 0.5 cm3 ionization chamber capable of fitting various wall materials reproducibly at the end of the chamber stem. The measuring system uniquely combines the features of a MOSFET electrometer and an automatic Townsend balance. When used for X, gamma and neutron radiations, the instrument measures the tissue kerma in free air on two ranges: 0.001 - 1.999 Gy (0.1 - 199.9 rad) and 0.01 - 19.99 Gy (1 - 1999 rad) or their exposure equivalents, with autoranging feature when the first range is exceeded. The polarizing voltage (180 V) can be reversed for electron and neutron dosimetry. The dosemeter has a measuring accuracy of +/- 0.2% FS +/- 1 digit and operates on four 1.5 V torchlight cells or on AC mains (200-250 V, 50 - 60 Hz). It utilizes solid state devices, CMOS integrated circuits and displays, and is not affected by RF fields. The instrument is enclosed in a brief-case for portability and is easy to operate and maintain in a hospital.

Electronics↗
PubMed1980

A portable versatile x- and gamma-ray dosemeter with ditigal display for medical use.

A multipurpose dosemeter based on analogue-to-digita (A-d) conversion has been developed using solid state devices, micropower integrated circuits and displays. The A-D converter combines the features of a MOSFET electrometer, a voltage-to-frequency converter, the automatic Townsend balance, LED(LCD) display for exposure, analogue output and has a voltage-measuring accuracy of +/- 0.1% FS +/- 1 digit. The dosemeter, which is designed to measure a wide range of x- and gamma-ray exposure rates (1 mR h-1 to 1000 R min-1) and exposures (1 mR to 1000 R) with a variety of air-equivalent ionisation chambers, is compact, rugged and battery or AC mains powered. It is designed to provide trouble-free performance, easy operation and maintenance and to be independent of climatic conditions. Combining the features of a survey meter, dosemeter and a radioisotope calibrator, it can be fabricated using the facilities locally available in hospitals or universities.

Calibration↗
PubMed1977

Cancer of the Colon: 32 years of experience in Bombay, India.

Incidence rate of colon cancer is low in India compared to the Western countries. The dietary habits may be the protective factor in our population. During a 32 year period (1941-1972), 555 cases of colonic cancer were recorded at the Tata Memorial Hospital, Bombay. Among the social groups utilizing this hospital, the Parsis (Zoroastrians) have the highest incidence of colonic cancer. The frequency of cancer of the caecum and sigmoid are almost equal. Cancer of splenic and hepatic flexures are predominantly seen in men. Of the resected cases 50% survived for 5 years and 40% for 10 years. When cancer was localised, the 5 year survival rate was 64%. The 5 year survival rat among transverse colon cancer patients was 70%. The skin was the commonest site of a second cancer among colon cancer patients; the possible etiological association of these two cancers appears very intriguing.

Adolescent↗
PubMed1977

Prognostic significance of blood vessel invasion in carcinoma of the breast in women.

Prognostic significance of blood vessel invasion in carcinoma of the female breast has been evaluated by study of 242 cases of radical mastectomy done at the Tata Memorial Hospital. The significance of axillary node involvement with the disease has been simultaneously evaluated. In the absence of blood vessel invasion and lymph node metastasis the 5 year survival rate was 98%. Compared with this, 5 year survival rate was reduced to 59% when the blood vessel invasion was present but no lymph node metastasis. Only 12% survived for 5 years when both blood vessels and lymph nodes were involved with the disease. The study indicated that blood vessel invasion in the primary breast carcinoma is more significant than lymph node metastasis.

Adult↗
PubMed1976

Feasibility of undertaking cancer incidence studies in rural areas of India.

In the rural areas of developing countries, modern medical facilities are well below optimum levels and death registration is not mandatory. In India, as a result of such a situation, very few studies have been undertaken on the incidence of cancer in the rural population, though 80% of the people live in villages. The paper presents cancer incidence rates observed in a rural area of India by means of a method involving the use of paramedical personnel for initial screening, to minimize the cost. A statistical evaluation of the results shows that the method can be used for registering common sites of cancer in an area where conventional cancer registration methods are not applicable.

Humans↗