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Biomedical subjects

S K Ghosh

Publications and source records attributed to S K Ghosh.

At least 181 records · Page 10Linked to original sources
PubMed1984

Monoclonal antibodies specific for two different histological types of human lung carcinoma.

Hybridomas secreting monoclonal antibodies specific for human lung cancer were produced by fusing immunized mouse spleen cells with mouse myeloma line X63-Ag8.653. Prior to fusion, BALB/c mice were immunized with two different histological types of human lung cancer (Squamous cell carcinoma and adenocarcinoma) obtained from surgery. An immunocytoadherence test was used to select hybridomas secreting antibodies that bound the patient's lung tumor, but did not bind to a B-lymphoblastoid cell line derived from the same patient. Five stable antibody-producing hybrids have been established and cloned. The antibodies produced by these clones have been characterized according to their light and heavy chain isotypes and for their specificity. In addition to binding to the tumor used for immunization, the antibodies bound to other lung tumors of the same histological type (i.e., squamous cell or adenocarcinoma). This reactivity was observed with both established lung tumor cell lines and with fresh tumors obtained from biopsy of patients in our clinic. Some significant reactivity was also observed with large cell carcinoma but the antibodies did not react with small cell carcinomas of the lung, bronchiolo-alveolar cell carcinoma, cancer of the esophagus and stomach, melanomas, several types of leukemias, normal human lung tissue, fibroblasts, or erythrocytes of type A, B, or O. Two of the five antibodies, 5C7 and 5E8 cross-reacted with one breast cancer obtained from surgery, and 5C7 also cross-reacted with one melanoma biopsy specimen. These results suggest that we have generated monoclonal antibodies that recognize a set of antigenic determinants that are commonly expressed on a portion of human lung tumors that are not detectable on a variety of other human tumors or normal human tissue.

Adenocarcinoma↗
PubMed1984

Presence of a specific immune complex in the cell-free ascites of a spontaneously metastasizing rat mammary adenocarcinoma, TMT-081.

We have previously reported that a mammary tissue-specific antigen (MTA) occurs in the circulation of rats bearing the metastatic mammary tumor, TMT-081. In this communication we present immunochemical evidence that MTA also exists in the form of a soluble immune complex in the sera and ascites of TMT-081-bearing rats. This immune complex, however, has no effect on the growth of TMT-081 in rats. Neither the MTA nor the immune complex could be detected in the circulation of lactating rats or rats bearing the nonmetastatic mammary tumor, MT-100. Thus, it appears that the spontaneously metastasizing tumor, TMT-100, considered previously to be nonimmunogenic or weakly immunogenic by conventional tests, does in fact elicit an apparently ineffective humoral response as manifested by the formation of an immune complex containing MTA.

Adenocarcinoma↗
PubMed1984

Generation of heavy chain-loss mutants in a B cell hybrid mediated by syngeneic idiotype-specific spleen cells.

Idiotype-specific spleen cells from appropriately primed BALB/c mice cause a marked and irreversible suppression of the membrane and secreted forms of idiotype-positive immunoglobulin (Ig) of an antigen-specific B cell hybrid clone (2C3E1). The suppression of this BALB/c B cell line has been observed in vitro and in vivo, and appears to require intimate contact between effector spleen cells and target 2C3E1 cells. The observed suppression in the 2C3E1 cell line is due to an induced mutation or a selection of pre-existing mutants within the 2C3E1 cell population, because the resultant light and heavy chain-loss variants are phenotypically stable in vitro and in vivo in the absence of any further active suppression. Biochemical analysis of the 2C3E1 cells after this suppression indicates that all of the variants are negative for the production of idiotype-positive Ig. Heavy chain synthesis by the variants is almost totally eliminated, and light chain synthesis is decreased by 10 to 90%. Spleen cells from identically primed nude mice do not induce any alteration in the 2C3E1 cell line, suggesting that induction or selection of the heavy and light chain-loss mutants requires the presence of mature T lymphocytes. The generation of idiotype-negative 2C3E1 variants during the period of tumor growth in the spleen (but not elsewhere) may represent one mechanism by which this tumor escapes the host's immune recognition.

Animals↗
PubMed1984

Quantitation and the elimination of errors in bile reflux tests using a gamma camera.

Entero-gastric reflux may be assessed quantitatively using 99mTc HIDA and a gamma camera. We have devised a computer program which applies corrections for several sources of error. The technique was validated using naso-gastric aspiration and phantom experiments. In 23 patient studies, 13 patients considered not to show reflux by visual assessment had a mean percentage injected dose (PID) in the stomach of 1.9% before correction and less than 1% after correction. The 10 patients with reflux showed a fall of PID from 5.8% to 1.7% as a result of the correction. In 14 patients the mean PID in the stomach after computer correction (3%) was not significantly different from that (3.5%) measured by aspiration. Computer correction of bile reflux data is essential when attempting to quantify the amount of entero-gastric reflux using a gamma camera.

Bile Reflux↗
PubMed1983

Fractionation of the mycobacillin-synthesizing enzyme system.

The mycobacillin-synthesizing enzyme system was highly purified by fractionation at 30-55% (NH4)2SO4 saturation. The enzyme concentrate on Sephadex G-200 gel chromatography was resolved into three distinct fragments. Each of the fragments on further purification by DEAE-cellulose ion-exchange chromatography behaved as a single-component system, as clearly indicated by the sharpness of the peaks in the elution diagram. None of the fragments alone nor any two of them in all possible combinations possessed mycobacillin-synthesizing activity, which was restored only when the three fragments were used together in the test system.

Antifungal Agents↗
PubMed1983

Establishment of two nonmetastasizing and one metastasizing rat mammary carcinoma cell lines.

Two continuous rat mammary tumor cell lines have been established in culture from the lymphogenously metastasizing rat mammary carcinoma TMT-081 and one from the nonmetastasizing MT-100 and some of their in vitro and in vivo characteristics studied. Cell line TMT-081-MS was established as a free-floating cell suspension from the metastasis-free spleen of a rat bearing TMT-081 in the ascites form and is characterized by a high level of mammary tissue specific antigen (MTA), an antigen present on lactating or hormonally stimulated rat mammary tissues but not detected on normal mammary tissue. This line metastasizes in the syngeneic host but is rejected by the nude mouse without metastases. Cell line TMT-081-NM is a line derived from the ascites of a rat also bearing TMT-081 ascites. Cell line MT-100-TC is a line derived from the ascites of a rat bearing the ascites form of MT-100. Neither TMT-081-NM nor MT-100-TC has ever shown metastases in the syngeneic host but they are lethal; in the nude mice they grow rapidly, are lethal, and sometimes show hematogenous metastases. Both grow in small clusters and show a low level of MTA. These cell lines have been in continuous culture for a year and have proliferated and maintained their individual in vitro and in vivo growth characteristics during more than 100 consecutive subcultivations.

Animals↗
PubMed1983

A close-range photogrammetric system for 3-D measurements and perspective diagramming in biomechanics.

Criteria considered in developing a close-range photogrammetric three-dimensional mapping system and its overall performance are discussed. The system consists of a stereophotographic capability of two cameras with synchronized shutters, a stereoplotting instrument with three-dimensional digitizing capability and a Calcomp plotter. Mapping of human knee-bones (femur and tibia) and perspective diagramming for various attitudes of one bone head with regard to the other are illustrated. The system works off-line with respect to the three principal components. The system is fully operational and is considered very efficient with regard to the current needs. Various possibilities are discussed.

Biomechanical Phenomena↗
PubMed1979

Studies on saprozoonosis. I. A survey on Aspergillus species with special reference to occupational habits.

A comprehensive survey of Aspergillus species has been carried out among different cattle and donkey handlers. A total of 300 pharyngeal swabs of different subjects including 100 control and 100 each from cattle and donkey handlers was investigated. All the subjects were found healthy. Among the species of Aspergillus, the number of A. flavus appeared higher followed by A. fumigatus, still lower number was encountered with other species like A. nidulans and A. glaucus. In order to establish the saprozoonotic relationship, soil and air samples of various animal sheds were also analyzed. It was found that the total number of isolates of Aspergillus species from animal sheds were always higher compared to the control samples. None of the A. flavus strains obtained from air samples produced aflatoxin. Histopathological changes in Swiss mice caused by intratail vein administration of spores of Aspergillus species have been investigated.

Air Microbiology↗