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K Ramanujam

Publications and source records attributed to K Ramanujam.

At least 19 recordsLinked to original sources
PubMed1998

Interleukin-10 gene transfer inhibits murine mammary tumors and elevates nitric oxide.

Transfection of cDNA for IL-10 into line 66.1 murine mammary tumor cells results in marked suppression of tumor growth and metastasis. Others have reported that nitric oxide has potent antitumor activity and IL-10 is known to regulate the inducible isoform of nitric oxide synthase (iNOS) expressed in macrophages. We identified nitric oxide production in mammary tumors as indicated by electron paramagnetic resonance detection of nitric oxide-hemoglobin (NO-Hb). IL-10 expression resulted in elevated levels of NO-Hb in mammary tumors. Immunohistochemical examination of mammary tumors for iNOS protein revealed few positively staining cells in parental or control neo-transfected tumors but strong iNOS staining in all IL-10 transfected tumors, consistent with the NO-Hb data. To determine if mammary epithelial tumor cells themselves, express nitric oxide synthase activity, cultured tumor cells were treated with pro-inflammatory cytokines and nitrite accumulation was assessed in the conditioned medium. All IL-10 producing cell lines accumulated uM concentrations of nitrite in response to short term (24 hr) cytokine stimulation. Cells not expressing IL-10 (parental and neo-transfectants) accumulated no nitrite under similar culture conditions. After longer stimulation (48 hr), parental and 66-neo cells accumulated lower amounts of nitrite. IL-10 gene transfer is associated with increased iNOS protein expression and enzymatic activity detected both in vitro and in vivo. Our findings suggest that the antimetastatic and antitumor activity of IL-10 is related to enhanced production of nitric oxide.

Adenocarcinoma↗
PubMed1982

Tuberculoid leprosy or sarcoidosis? A diagnostic dilemma.

During an intensive survey in a leprosy endemic area in South India, a young male adult was detected with infiltrated skin lesions and diagnosed as a case of major tuberculoid leprosy. The presence of leprosy in the individual could not be clinically established, despite a histological diagnosis of tuberculoid leprosy made on his skin biopsy. In a eighteen year follow up during which he was examined on six occasions, the skin patches continued very much the same in appearance with a progressive increase in size; he was re-biopsied from the same lesion thrice and was declared tuberculoid or borderline tuberculoid leprosy. At no time did the clinical findings warrant a diagnosis of leprosy but suggested that it could be sarcoidosis or lupus vulgaris. The biopsy done for the fifth time from the same skin lesion during the seventh examination and from the site of Kveim test confirmed the condition to be sarcoidosis.

Adult↗
PubMed1981

Histology of the Fernandez reaction. An appraisal.

The early lepromin reaction was studied clinically and histologically in 38 leprosy patients. There was a quantitative and a qualitative difference in the character of the early inflammatory response to lepromin in the different groups of leprosy patients. In tuberculoid patients, the extent and degree of inflammation and the density of lymphocytic infiltration were maximal. In the polar lepromatous group, the inflammatory reaction was far less intense, and lymphocytes were scarce or absent. An intermediate histology was noted in the borderline and indeterminate groups of patients. In 11 patients with negative clinical reactions, the histology showed moderately dense lymphocytic infiltrations. The paucity of the clinical reaction could be due to the injection and localization of the antigen in the mid- and deep dermis. The correlation between early and late lepromin reactivity, both clinically and histologically, in the polar tuberculoid group and the polar lepromatous group was good. In the borderline and indeterminate groups, only the correlation between the early and late histological reactions to lepromin was good. The relationships between the early and late clinical reactions to lepromin showed marked variation. It is suggested that the early reaction is as good an indicator of lepromin reactivity as the late reaction in all forms of leprosy but only if it is assessed histologically.

Adolescent↗
PubMed1979

Histocompatibility antigens in patients with leprosy from Azarbaijan, Iran.

The distribution of 24 histocompatibility antigens in 88 Azerbaijani patients with leprosy was determined and compared with those of 125 normal, ethnically matched individuals. HLA-BW35 was increased in frequency among the Kurdish patients as compared to the controls; HLA-A1, however, displayed decreased frequency in patients with the lepromatous form of the disease. Among the Turks, diminished frequency of HLA-BW15 was noted in the total patient population. None of these comparisons, however, reached statistical significance when corrected for the number of antigens tested. Across the two ethnic groups, differences in the frequencies of HLA antigens between the patients and the controls were only marginal.

HLA Antigens↗