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Biomedical subjects

D K Jain

Publications and source records attributed to D K Jain.

At least 19 recordsLinked to original sources
PubMed1991

Estimation of ED50 or LD50 using a programmable pocket calculator.

A program is developed for estimation of median effective dose (ED50 or LD50), using the hand-held programmable pocket calculator HP41CV. The well-known Finney's algorithm of probit analysis is used. Input of data is simple, but is restricted to a maximum of 15 groups. The program structure makes use of the technique of indirect addressing for storage, and statistical register manipulation for weighted regression. The ability of the calculator to give sufficiently precise results can be exploited in other similar situations.

Algorithms↗
PubMed1988

Mechanisms of vasoactive intestinal peptide release in short-term culture of vasoactive intestinal peptide-producing tumor.

Vasoactive intestinal peptide-producing tumor tissue fragments obtained at surgery were maintained in short-term culture. Functional cellular integrity of vasoactive intestinal peptide-producing tumor tissue was reflected by progressive protein synthesis and the ability of tumor tissue to release vasoactive intestinal peptide when stimulated by the intracellular second messengers cyclic adenosine monophosphate and calcium. Studies with verapamil and ethyleneglycol-bis (beta-aminoethylether)-N,N'-tetraacetic acid suggest that cyclic nucleotide- and ionophore A23187-mediated vasoactive intestinal peptide release are dependent, at least in part, upon the availability and transmembrane transport of extracellular calcium.

1-Methyl-3-isobutylxanthine↗
PubMed1985

Functional and anatomical relationships between antral gastrin cells and gastrin-releasing peptide neurons.

The present studies were directed to examine the effect of gastrin-releasing peptide (GRP) on beta-adrenergic stimulated gastrin release by cultured rat antral mucosa and to assess the anatomical relationship between gastrin cells and GRP nerves in rat and human antrum. Peptide-containing cells were identified by application of an avidin-biotin-peroxidase immunocytochemical double staining method utilizing antibodies to GRP and gastrin prepared in rabbits. Rat antral mucosa was cultured for 60 min and gastrin released into the culture medium was measured by radioimmunoassay. Inclusion of antibodies to GRP in culture medium did not affect carbachol-stimulated gastrin release, whereas isoproterenol-stimulated gastrin release into the medium was inhibited significantly by addition of GRP antiserum to the culture medium. GRP-containing neurons and axonal fibers were stained immunocytochemically with diaminobenzidine (reddish-brown specific staining) and were located in the lamina propria adjacent to and surrounding the main lobules of antral glands. After double staining utilizing 4-Cl-1-Naphthol as substrate, blue stained gastrin-containing cells were identified in the middle and deeper regions of antral glands in close proximity to GRP neuronal elements. These studies suggest that beta-adrenergic, but not cholinergic, stimulation of gastrin release is mediated, at least in part, through GRP. They also demonstrate intimate anatomical, as well as functional, relationships between gastrin cells and GRP-containing neurons.

Animals↗
PubMed1985

Zollinger-Ellison syndrome associated with persistently normal fasting serum gastrin concentrations.

A 63-year-old man with a 2-year history of upper gastrointestinal ulcers was found to have the Zollinger-Ellison syndrome. Despite histologic verification of gastrinoma, several fasting serum gastrin concentrations were normal. However, in response to intravenous secretin infusion, a paradoxical increase in serum gastrin levels indicative of gastrinoma was seen. Although serum gastrin concentrations in patients with suspected gastrinoma may be persistently normal, provocative testing may be necessary to establish the diagnosis of the Zollinger-Ellison syndrome.

Fasting↗
PubMed1984

Effects of carbachol on gastrin and somatostatin release in rat antral tissue culture.

Recent studies have demonstrated that somatostatin-containing cells are in close anatomic proximity to gastrin-producing cells in antral mucosa, suggesting a potential local regulatory role for somatostatin. The purpose of this study was to examine further the relationships between gastrin and somatostatin and the effects of the cholinergic agonist carbachol on content and release of gastrin and somatostatin using rat antral mucosa in tissue culture. Antral mucosa was cultured at 37 degrees C in Krebs-Henseleit buffer, pH 7.4, gassed with 95% O2-5% CO2. After 1 h, the culture medium was decanted and the tissue was boiled to extract mucosal gastrin and somatostatin. Inclusion of carbachol 2.5 X 10(-6) M in the culture medium decreased medium somatostatin from 1.91 +/- 0.28 (SEM) ng/mg tissue protein to 0.62 +/- 0.12 ng/mg (p less than 0.01), extracted mucosal somatostatin from 2.60 +/- 0.30 to 1.52 +/- 0.16 ng/mg (p less than 0.001), and percentage of somatostatin released from 42% +/- 2.6% to 27% +/- 2.2% (p less than 0.01). Carbachol also increased culture media gastrin from 14 +/- 2.5 to 27 +/- 3.0 ng/mg protein (p less than 0.01). Tissue content and release of gastrin and somatostatin were also examined during culture of rat antral mucosa in culture media containing antibodies to somatostatin in the presence and in the absence of carbachol. Incubation with somatostatin antisera, both with and without carbachol, markedly increased culture media concentrations of somatostatin, all of which was effectively bound by antibodies present in the media. Antibody binding of somatostatin was accompanied by significant increases in culture media gastrin concentrations, both in the presence and in the absence of carbachol. Results of these studies support the hypothesis that antral somatostatin exerts a local regulatory effect on gastrin release and that cholinergic stimulation of gastrin release is mediated, at least in part, through inhibition of somatostatin synthesis and release.

Animals↗
PubMed1979

Lung cancer in Greater Bombay: correlations with religion and smoking habits.

The resident population of Greater Bombay was analysed for the incidence of lung cancer and other variables of possible significance to lung cancer incidence. During a 10-year period from 1964-73, 2177 lung cancer cases (1861 males, 316 females) were registered, from a population pool consisting of 5.24 million persons (3.07 million males, 2.17 million females). The average annual incidence of lung cancer was 13.6 per 10(5) males but only 3.3 per 10(5) females, age-adjusted to the Standard World Population. The incidence in non-Parsi males (14.0) was almost double the figure in Parsi males (6.8). There was however no significant difference in incidence between non-Parsi (3.8) and Parsi females (3.3). Time-trend analyses did not reveal statistically significant differences in the incidence of lung cancer in any particular (male or female) age group. The data from death certificates for the same 10-year period 1964-73, showed that the age-adjusted rates (standardized to the world population) were 11.0 and 3.3 per 10(5), for males and females, in the total population. In a retrospective study, 792 males with lung cancer (42.6% of 1861 male cancer patients) for whom detailed smoking history is available, were matched for age and community with randomly selected controls, obtained from the voters list of the Greater Bombay Corporation, and significant statistical association was found between tobacco smoking and lung cancer. All smokers appear to be at high risk (16.8) compared with non-smokers. The relative risk in bidi smokers was however 19.3, even higher than in cigarette smokers (896). Hindu, Muslim and Christian smokers are apparently at identical risks. A dose-reponse relationship was found in bidi and cigarette smokers.

Adolescent↗
PubMed1977

Breast cancer and religion in greater Bombay women: an epidemiological study of 2130 women over a 9-year period.

The resident female population of Greater Bombay consists of women professing different religious faiths, between which the frequency of breast cancer varies to a great extent. During the 9-year period 1964 to 1972 inclusive, a total of 2130 women with breast cancer were seen, with break-down by religion as follows: Hindus (1259), Muslims (306), Christians (264), Parsi (Zoroastrians) (226), Jains (25), Buddhists (26) and others (24). The average annual age-adjusted (world population) incidence rates, however, were found to be 48.5 and 18.2 per 100,000 in the Parsis and non-Parsis respectively, with an average of 19.9 per 100,000 for the total population. For reasons not yet clear, in every age group the incidence rate in Parsis was 2 to 3 times higher than in the non-Parsis. Time-trend analyses of our data do not reveal any statistically significant increase or decrease in the incidence of breast cancer in any particular age group. Data from death certificates for the same 9-year period show that the age-adjusted mortality rate (world population) is 9.2 per 100,000/year.

Adolescent↗
PubMed1976

Histomorphology and proteolytic activity in the gastric apparatus of frugivorous, carnivorous and omnivorous species of birds.

The histomorphology of the gastric apparatus, the pepsin level and the optimum pH for pepsin were investigated in Psittacula krameri (frugivore), Lanius schach (carnivore) and Acridotheres tristis (omnivore) species of birds. The proventricular glands were found to be made up of oxynticopeptic cells. The lobules of the oxynticopeptic cells are polyhedral; they are the largest in P. krameri, and the smallest in A. tristis. However, their greater number in A. tristis enables a higher secretion of hydrochloric acid and pepsin. The villi are more developed in A. tristis than in L. schach and P. krameri. The gizzard is larger in A. tristis than in P. krameri and A. tritis than in the carnivore L. schach. Koilin lining is beset with horny cones, which were well developed in A. tristis, moderately developed in P. krameri and absent in L. schach. The pepsin activity is higher in the proventriculus of the carnivorous L. schach and the omnivorous A. tristis than in the frugivorous P. krameri. Slight pepsin activity was also observed in gizzard tissue extracts in all the three species. The optimum pH for pepsin was found to be 1.5 for P. krameri and 1.8 for both L. schach and A. tristis.

Animals↗
PubMed1975

Isolation and characterization of viruses from natural outbreaks of reticuloendotheliosis in turkeys.

We have described the in vitro isolation of type-C RNA viruses from two outbreaks of a fatal neoplastic disease in turkeys we diagnosed as reticuloendotheliosis. The virus had a density of 1.16 g/ml in sucrose gradients, had a DNA polymerase capable of using both endogenous and exogenous (synthetic) templates, and was infectious in vitro for turkey and chick cells. The culture-propagated virus was oncogenic for turkeys. The virus isolates were unrelated to avian leukosis virus and antigenically identical to reticuloendotheliosis virus (REV) strain T. Thus our studies suggested that REV is a causative agent of naturally occurring, fatal leukosis in turkeys.

Animals↗
PubMed1971

Cancer in Chiang Mai, North Thailand. A relative frequency study.

The relative frequency of histologically diagnosed cancer at the Chiang Mai Medical School in North Thailand in 1964-67 inclusive is examined.Most of the 1877 cancers seen are in Thais (males, 927; females, 908), the remainder arising in Chinese (males, 21; females, 12), Hill People (males, 6; females, 1) and others (females, 2). The cancers in Thais are presented by site, sex and 10-year age-group together with the relative frequency (crude and corrected for age).In Thais, the outstanding finding is the extraordinarily high frequency of cancer of the hypopharyngeal-laryngeal region in both sexes (males, 18.4 per cent; females, 3.4 per cent). This may be associated with the smoking of a local variety of the cigar called "keeyo" This cigar, smoked in the usual manner, contains approximately equal quantities of home-grown, sun-dried, Thai tobacco and the chopped bark of the "koi" tree (Streblus asper). In women, who also smoke "keeyo", the frequency of hypopharyngeal-laryngeal cancer is unusually high by occidental standards. There is no sex difference in the frequency of bronchial cancer (4 per cent).In males cancer of the penis, in second rank (6.6 per cent) is much more frequent than cancer of the prostate and testis combined. Stomach and skin cancers (ICD 191) are in third place (each 5.7 per cent).In females the most frequent cancers are cervix uteri (19.8 per cent), breast (8.8 per cent) and skin (ICD 191) (6.1 per cent). Cancers of the lip and skin of the head and neck are more frequent in females than in males. Choriocarcinoma is common (1.9 per cent) and there is a large number of vulvar cancers in young women (2.6 per cent).The geography, economy and medical facilities of Chiang Mai Province are described. It is considered that, although there is likely to be considerable under-reporting of internal cancers, the high frequency of hypopharyngeallaryngeal cancer is not due to selective bias.

Adolescent↗
PubMed1971

Geographical variation of carcinoma of the penis in Uganda.

A series of 458 cases of carcinoma of the penis occurring in Ugandan Africans is analysed. These were derived from the records of a country-wide biopsy service over the 5-year period 1964-68.Where circumcision is practised the incidence of this tumour is very low.However, the geographical variation also showed marked differences in the uncircumcised, regardless of tribal antecedents and sometimes over quite small distances.It is suggested, therefore, that in Uganda other aetiological factors apart from circumcision are operative and that these factors vary with geographical location rather than with tribal affiliation.

Adolescent↗