Biomedical subjects

K K Talwar

Publications and source records attributed to K K Talwar.

165 records · Page 10Linked to original sources

PubMedDate not supplied

Pathology of cardiac transplantation--the initial experience.

BACKGROUND: Cardiac transplantation has recently been started in India at the All India Institute of Medical Sciences, New Delhi. All transplants are monitored by right ventricular endomyocardial biopsies. This study describes our initial experience with the histopathological assessment of post-transplant endomyocardial biopsies. METHODS: Fifty-four endomyocardial biopsies from 8 transplanted hearts were reviewed. At least 3 haematoxylin-eosin and Masson trichrome stained sections were available on each biopsy. Special stains and immunohistochemistry were done as required. Biopsies were graded for rejection using the grading system of the International Society for Heart and Lung Transplantation. Infection, 'Quilty' effect, biopsy site, ischaemia and reperfusion injury were also assessed. RESULTS: There was no evidence of rejection in 34 biopsies. Eleven biopsies showed mild rejection. Only 9/54 biopsies from 4 of the transplant recipients had clinically significant grades of rejection. Biopsy sites were present in 13/54 biopsies. Ischaemia was present in the first biopsy after transplantation in 4 recipients. There was no evidence of viral or parasitic infection. 'Quilty' lesions were seen in 14/54 biopsies from 5 transplant recipients. Four of these 5 recipients had 'Quilty' lesions on more than 1 biopsy. CONCLUSIONS: The low rejection rate at our centre is consistent with reports from around the world. Endomyocardial biopsy has been a safe, convenient and useful method for diagnosing rejection and monitoring the postoperative course of cardiac transplants at our centre.

Adult↗

PubMedDate not supplied

Effect of endothelial cells on the lymphoproliferative response in Takayasu's arteritis.

Takayasu's arteritis, also known as 'non-specific aortoarteritis' is an inflammatory disease of the aorta and its major branches. It also involves the pulmonary artery. The aetiology of the disease is not known so far. Abnormalities of the endothelial cells in terms of their structure and function are seen in the pathology of a number of diseases affecting the blood vessel wall. However, involvement of the endothelial cells in non-specific aortoarteritis is not known. In an effort to identify the role of endothelial cells in the pathogenesis of Takayasu's arteritis, peripheral blood lymphocytes isolated from the blood of patients suffering from Takayasu's arteritis were cultured in the presence of endothelial cells alone and in the presence of mitogens concanavalin-A and phytohaemagglutinin-P. The peripheral blood lymphocytes of patients with Takayasu's arteritis showed a significantly decreased blastogenic response to the mitogen concanavalin-A when cultured in the presence of endothelial cells. Our result thus suggests that endothelial cells may probably induce an inhibitory effect on the lymphocytes in patients with Takayasu's arteritis.

Adolescent↗

PubMedDate not supplied

Enzyme-linked immunosorbent assay and immunoblot study in Takayasu's arteritis patients.

Takayasu's arteritis or non-specific aortoarteritis is an inflammatory and stenotic disease of the aorta of questionable aetiology. Immunopathogenic mechanism, the precise nature of which is uncertain, is often suspected to be one of the basic causes of this disease. The present study was designed to estimate the antiaorta antibody titre in Takayasu's arteritis patients and to further locate the antigen in the vessel wall. Thirty clinically and angiographically proven cases of Takayasu's arteritis patients with appropriate controls were studied. Antiaorta antibody titres were estimated using Enzyme-Linked Immunosorbent Assay method. The controls included patients of vascular diseases other than Takayasu's arteritis, autoimmune diseases like rheumatoid arthritis and systemic lupus erythematosis and normal healthy individuals. Absorbance value at 492 nm at a dilution of 1:500 of the patients' sera was expressed as the antiaorta, antibody titre. There was significant difference (p < 0.005) between the mean value of the antibody titre in patients (0.471 +/- 0.073) and patients of other vascular diseases (0.209 +/- .056); autoimmune diseases (0.143 +/- .024); and, controls (0.108 +/- 0.012). Collagenase treatment of the aorta resulted in the fall of the antibody titre of aortitis patients (0.162 +/- 0.036) suggesting that the collagen might be one of the components responsible for autoantigenecity of aorta resulting in aortitis. The aortic extract was further subjected to 10 percent sodium dodecyle sulphate-polyacrylamide gel electrophoresis and immunoblot was done with Takayasu's arteritis patients' sera as well as controls' sera. The sera in 80 percent of Takayasu's arteritis patients immunoprecipitated a protein of molecular weight 45,000 (45 kilodalton) whereas only 15 percent patients of autoimmune disease group showed precipitation band though of lower molecular weight. Normal human sera gave no immunoprecipitation band. The precise nature of the antigen still needs to be identified.

Autoimmune Diseases↗