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Biomedical subjects

D M Vasudevan

Publications and source records attributed to D M Vasudevan.

At least 37 records · Page 2Linked to original sources

Jack fruit lectin binding pattern in carcinoma of the uterine cervix.

A lectin was isolated and purified from the seeds of Jack Fruit (Artocarpus integrifolia) using a column of immobilized N-acetyl D-Galactosamine. The Jack Fruit lectin (JFL) was conjugated to horse radish peroxidase (HRP). The purified conjugate was used to study the binding properties of tissues from carcinomas of the uterine cervix. The binding to cancer tissues was compared with that of normal controls. The carcinomatous cells showed varying degrees of binding towards JFL in contrast to normal controls which generally had uniform binding. The nature and intensity of binding of the lectin with the cancer tissues suggest that this lectin may be used as a diagnostic marker in carcinoma of uterine cervix.

Carcinoma, Papillary↗

Chromosome abnormalities in squamous cell carcinoma of the human oral cavity.

Cytogenetic studies carried out in tissues of 75 patients with squamous cell carcinoma of the oral cavity gave satisfactory results in 12 cases. Remarkable variation characterized the modal chromosome numbers of these tumors, ranging from marked hypodiploidy to tetraploidy. Chromosomes which were lost belonged to group A whereas chromosomes which were gained belonged to groups C, D, E, F and G. Marker chromosomes were present in three cases. There was no correlation between the chromosome abnormalities observed and the clinical stages of the disease. The pattern of chromosome abnormalities ranging from marked hypodiploidy to tetraploidy observed in oral cancer tissues suggests an association of DNA oncogenic virus possibly Herpes simplex virus Type I (HSV-1) with oral cancer.

Adult↗

Serum levels of iron and proteins in oral submucous fibrosis (OSMF).

Serum proteins, serum iron and total iron binding capacity were estimated in 50 patients with oral submucous fibrosis and 50 patients with oral leukoplakia. The values were compared with that of 50 age- and sex-matched controls. A significant depression in hemoglobin and serum iron was observed in both groups of patients, whereas total iron binding capacity showed significant change only in the oral submucous fibrosis patients. Serum protein values were significantly lower in all the patients. The role of iron deficiency anemia in the causation of this premalignant lesion is discussed.

Adult↗

Total hemolytic complement (CH50) and its fractions (C3 and C4) in the sera of patients with premalignant and malignant lesions of the oral cavity.

Total hemolytic complement (CH50) and its fractions (C3 and C4) were estimated in the sera of 50 patients with oral leukoplakia, 50 patients with oral submucous fibrosis and 50 oral cancer patients. The values were compared with that of 50 normal controls. No significant alterations in the values of CH50, C3 or C4 were observed in the sera of patients with either leukoplakia or oral submucous fibrosis whereas the values were found to be altered significantly in oral cancer (P less than 0.001). In the case of oral submucous fibrosis the mean complement levels were slightly lower than those of normal controls and leukoplakia. Age and sex had no influence either on the total complement activity or its fractions (C3 and C4). The serum complement levels may be useful as a biological marker for the early detection of tissue dysplasia.

Adult↗

Presence of a receptor for the active component of Iscador in ascites fluid of tumour bearing mice.

Tumour bearing mice exhibit a specific "receptor" in the ascites fluid which binds with the active component isolated from Iscador. This "receptor" was found to be a protein which inhibited the cytotoxicity of Iscador and its isolated active component at low concentration. The receptor protein was also found in the sonicates of tumour cells which are susceptible to the action of Iscador but not in lymphocytes which were not susceptible to Iscador or its isolated active component. The receptor was separated on a Sephadex G-50 column. Activity was lost upon heat denaturation and dialysis.

Animals↗

An alternative pathogenetic pathway for oral submucous fibrosis (OSMF).

Oral submucous fibrosis is a potent pre-cancerous condition which occurs almost exclusively in Indians but cases have been reported from several countries. The definite aetiology of OSMF is still unknown and there is no known treatment for it. Chilles, tobacco use, vitamin deficiencies and betel quid chewing have been implicated. Ramanathan is of the view that OSMF seems to be the Asian version of sideropenic dysphagia. He suggests that OSMF appears to be an altered oral mucosa following prolonged period of chronic deficiency of iron and/or vitamin "B" complex especially folic acid. This changed state of the oral mucosa subsequently appears to develop more easily a hypersensitivity to oral irritants such as spices especially chillies and to the betel quid. We hold that the hypersensitivity caused by local irritants and the resultant persistent juxta epithelial inflammatory response noted in OSMF (in a host system already primed by an intrinsic genetic defect) act as the initiating factor leading to a defective inflammatory--reparative response, culminating in fibrotic healing. The role of iron and "B"complex together with others may be contributory (promotor) to this pre-existing pathologic response of the lamina propria.

Anemia↗

Ackerman's tumour (Verrucous carcinoma) of the oral cavity: a histopathologic study of 426 cases.

Salient histopathological features of four hundred and twenty six (426) cases of verrucous carcinoma of the oral cavity reported jointly by the Department of Oral Pathology, Dental College and Department of Pathology, Medical College, Trivandrum, during the period from January 1975 to December 1984 were evaluated. They constituted 5.27% of 7,988 primary malignant neoplasms of the oral cavity detected during the period. Locally aggressive behaviour with bone, muscle and salivary gland invasion occurred in 53% of cases. Examination of the neighbouring areas of the lesion, which showed some light on the natural evolution of the disease, is described. The gradual transformation of a hyperplastic verrucous lesion into carcinoma is appraised. Evidence suggestive of a distant metastatic spread of the tumour could not be detected.

Carcinoma, Papillary↗

Assessment of immunological parameters during tumour development in a murine model.

Natural Killer activity assessed by 51Cr release assay from K-562 cells showed detectable activity from 5th day after tumour transplantation, reaching a peak on 12th day and thereafter showing a gradual decline in the activity. Antibody dependent cell mediated cytotoxicity estimated by 51Cr labelled sheep red blood cells anti SRBC system demonstrated a peak activity on 5th day. Cytotoxic T lymphocyte activity detected by 51Cr release of Dalton's lymphoma ascites target cells showed a peak on 10th day. Antibody complement mediated cytotoxicity revealed a similar pattern as natural killer cell activity.

Animals↗

Isolation and identification of a tumour reducing component from mistletoe extract (Iscador).

Using a combination of gel filtration and paper chromatography, a tumour reducing component from mistletoe extract (Iscador) was isolated and identified to be a peptide of approximate molecular weight 5000. The isolated peptide reduced the solid tumour induced by Dalton's lymphoma ascites tumour cells (DLA cells) in mice. The isolated component was very cytotoxic to the DLA cells but was not cytotoxic to normal lymphocytes, indicating a cell dependent specificity.

Animals↗

Role of levamisole immunotherapy as an adjuvant to radiotherapy in oral cancer--immune responses.

Investigations were carried out to assess the effect of levamisole immunotherapy as an adjuvant to radiotherapy on the immune response of patients with squamous cell carcinoma of the oral cavity. Parameters assessed were leukocyte migration inhibition, response to PPD and oral cancer extract (OCA), lymphocyte transformation to PHA, circulating antibodies to OCA and circulating immune complexes (CIC). Comparisons were made between groups receiving levamisole (L), those receiving placebo (P) and normal controls. The results of a thirty-month follow-up are presented. Radiotherapy resulted in a depression of cell-mediated functions, reduction in antibody titer also showed a gradual increase with time of follow-up. Levamisole, however, appeared to reduce the levels of CIC.

Antibodies, Neoplasm↗

Role of levamisole immunotherapy as an adjuvant to radiotherapy in oral cancer. II. Lymphocyte subpopulations.

The effect of radiotherapy and adjuvant levamisole immunotherapy on the lymphocyte subpopulations was investigated. Comparisons were made between the groups receiving levamisole, those receiving placebo and normal healthy controls. Results of a thirty-month follow-up are reported. Radiotherapy caused leukopenia and lymphopenia affecting all the subsets (T, B, TG, and TM), T lymphocytes were affected to a greater extent. This study demonstrates that levamisole does hasten the restoration of T lymphocytes, with the TM lymphocytes showing a faster repopulation in comparison to the TG lymphocytes.

B-Lymphocytes↗

Demonstration of HSV-I antigen in patients with oral cancer by immunofluorescence and immunoperoxidase techniques.

Biopsies from one hundred and seventy five patients suffering from carcinoma of the oral cavity were examined for the presence of Herpes simplex virus Type 1 (HSV-1) antigen, using Immunofluorescence (Direct and indirect) and immunoperoxidase techniques. Seventy-seven percent of the biopsies showed significant fluorescence, while 71% showed positivity with immunoperoxidase staining. There was no correlation either in the degree of fluorescence or in the intensity of peroxidase staining with clinical stage of the disease. Normal oral biopsies showed 30% and 20% positivity in immunofluorescence and immunoperoxidase respectively. In the case of oral cancer cells, the fluorescence was very much diminished when HSV-1 antiserum was absorbed with specific homologous virus-infected Vero cells.

Animals↗

Tissue binding patterns of lectins in premalignant and malignant lesions of the oral cavity.

Lectins from the seeds of Jackfruit (Artocarpus integrifolia) and winged bean (Psophocarpus tetragonolobus) were isolated using an immobilized N-acetyl D-galactosamine column and conjugated to type VI horse radish peroxidase. The purified conjugate was used for the study of tissue specificities using diaminobenzidine as the substrate on dewaxed tissue sections of normal, oral leukoplakia, oral submucous fibrosis, verucous carcinoma and squamous cell carcinoma of the oral cavity. In spite of having a common inhibitory sugar, winged bean lectin did not bind to any lectins whereas Jackfruit lectin showed varying degrees of binding towards the above tissues. The difference in the nature and intensity of binding of the Jackfruit lectin suggest the utilizing this lectin in the differential diagnosis of the premalignant and malignant lesions of the oral cavity.

Carcinoma, Papillary↗

Role of levamisole immunotherapy as an adjuvant to radiotherapy in oral cancer. I. A three-year clinical follow up.

Eighty-two patients with squamous cells carcinoma of the oral cavity belonging to stages T1N0M0 and T2N0M0 were randomized to receive either levamisole or placebo therapy following conventional radiotherapy. Oral levamisole, at 150 mg daily doses for three consecutive days, was given once every two weeks. The patients were followed-up for three years and the results reported. Levamisole appears to have some beneficial effect in prolonging the disease-free interval of these patients (44% in the levamisole group compared to 32% in the placebo group after 30 months of therapy). This, however, did not have any effect of the metastatic potential of the tumors. The effects of levamisole on peripheral blood leukocytes and lymphocytes were more promising. The restoration of leukopenia and lymphopenia observed after radiotherapy was faster in the levamisole group when compared to the placebo group.

Adjuvants, Immunologic↗

Serum immunoglobulins in patients with carcinoma of the oral cavity, uterine cervix and breast.

Serum immunoglobulin levels (IgG, IgA, IgM, IgD and IgE) were estimated in 196 patients with carcinoma of the oral cavity, 172 patients with cervical cancer and 166 patients with breast cancer. The values were compared with those of 50 patients with benign lesions of the breast and cervix and 100 healthy adult controls. Only the serum IgE levels were found to be elevated in the benign group. Serum IgA, IgD and IgE levels were found to be elevated in all the three types of cancers and the levels were found to increase with clinical stage. In carcinoma of uterine cervix IgG levels were also found to be elevated. Immunoglobulins A and D returned to normal after clinical cure whereas IgE remained slightly elevated. IgD and IgE remained high in patients who had residual cancer.

Adult↗

High affinity rosette forming cells in carcinoma of the oral cavity, uterine cervix and breast.

Total rosette forming cells (TRFC) and high affinity rosette forming cells (HARFC) were enumerated in 534 patients with carcinoma of oral cavity, uterine cervix or breast, and the results were compared with adult controls. The HARFC levels were found to be significantly decreased in cancer patients, and this decrease was more pronounced in advanced clinical stages. The HARFC levels returned to normal in patients who had a clinical cure but remained low in patients having residual disease. Enumeration of HARFC may therefore be useful in assessing the cell mediated immunity in cancer patients.

Adult↗