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Biomedical subjects

R Rajendran

Publications and source records attributed to R Rajendran.

At least 73 records · Page 4Linked to original sources
PubMed1989

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↗
PubMed1988

Circulating immune complexes as an immunological marker in premalignant and malignant lesions of the oral cavity.

Circulating immune complexes and their immunoglobulin contents 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. The circulating immune complexes and their immunoglobulin contents were found to be elevated significantly both in oral submucous fibrosis and oral cancer. This study seems to be of help in monitoring the malignant transformation of oral submucous fibrosis to oral cancer.

Adult↗
PubMed1988

A rare human model for oncogenesis.

A rare female human model of oral carcinoma (OC) who refrained from any type of tobacco and/or betel nut habits, belonged to an younger age group, had no pre-existing precancerous lesions in the oral cavity and who was exposed chronically to cashew nut oil, is presented. The role of genetic inherited influences, occupational and endocrine disturbances with racial factors in the causation of oral carcinoma is discussed. The significance of further studies at the genetic level, to rule out protooncogenic activation in the causation of oral cancer is summed up. The literature on the concept of oncogenesis is reviewed briefly.

Adolescent↗
PubMed1987

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↗
PubMed1986

Cell mediated and humoral immune responses in oral submucous fibrosis.

Cell-mediated and humoral immune responses were assessed in 50 patients with oral submucous fibrosis (OSMF) and the results were compared with those of 50 patients with oral-leukoplakia, 50 oral cancer patients, and 50 normal healthy adult controls. The number of high-affinity rosette-forming cells (HARFC) was found to be significantly decreased in OSMF and oral cancer, whereas the number of total rosette-forming cells (TRFC) remained unaltered. Levels of serum IgA, IgD, and IgE were found to be elevated both in OSMF and oral cancer. Immunologic derangements were found to be more pronounced in oral cancer than in OSMF. The enumeration of HARFC along with the estimation of serum levels of IgA, IgD, and IgE indicates that OSMF can be an intermediary stage in the malignant transformation of a normal cell, and that these parameters may serve as markers for the early detection of oral cancer.

Adult↗
PubMedDate not supplied

Surveillance for Japanese encephalitis in villages near Madurai, Tamil Nadu, India.

A simple dusk index was developed to monitor the density of recognized vectors of Japanese encephalitis virus (JEV) based on hand catches around cattlesheds at dusk and parous rates. When used routinely in combination with sentinel animal studies for surveillance in villages with a high prevalence (46.2%) of neutralizing antibodies against JEV in children under 16 years, there was a peak in vector density and virus activity during the north-east monsoon period, October-December. The reasons for an unusual outbreak of cases of encephalitis during the summer months of 1984 are discussed.

Animals↗
PubMedDate not supplied

Immunochromatographic test (ICT) for estimation of true prevalence of bancroftian filariasis in an endemic area in southern India.

Percentage prevalences of microfilaraemia (PPMF) and antigenaemia (PPCFA) were examined in 1999 in 3505 subjects from 3 villages in India. All microfilaraemics were positive for antigenaemia, and PPCFA was always higher than PPMF. Amicrofilaraemia among antigenaemic persons decreased steadily from 92% in the age-group 2-5 years to 40% in the age-group 21-30 years.

Adolescent↗
PubMedDate not supplied

Sustainability of soil-transmitted helminth control following a single-dose co-administration of albendazole and diethylcarbamazine.

We evaluated the long-term impact of single-dose diethylcarbamazine plus albendazole combination therapy with that of diethylcarbamazine alone on the control of soil-transmitted helminths (STH) in 2 blocks (revenue units) of Villupuram district, south India, as part of an ongoing mass drug administration (MDA) campaign for the elimination of lymphatic filariasis in 2001. The prevalence and intensities of STHs were studied in 287 children, aged 9 and 10 years (136 in the combination therapy cohort and 151 in the diethylcarbamazine alone cohort), using the Kato-Katz technique to examine stool samples at 4 time-points (baseline, and 3 weeks, 6 months and 11 months after MDA). The combination therapy showed long-term efficacy against STHs and the magnitude of control remained at a moderate and significant level for 11 months after MDA compared with the moderate gains of diethylcarbamazine alone. Single-dose MDA with albendazole and diethylcarbamazine combination therapy may prove to be a good strategy in treating multiple parasitic infections in endemic communities.

Albendazole↗
PubMedDate not supplied

Pentoxifylline therapy: a new adjunct in the treatment of oral submucous fibrosis.

OBJECTIVE: This study was designed to determine the effect of pentoxifylline (Trental) on the clinical and pathologic course of oral submucous fibrosis. This drug is a methylxanthine derivative that has vasodilating properties and was envisaged to increase mucosal vascularity. STUDY DESIGN: This investigation was conducted as a randomized clinical trial incorporating a control group (Standard drug group SDG, multivitamin, and local heat therapy) in comparison to pentoxifylline test cases (Experimental drug group EDG, 400mg 3 times daily, as coated, sustained release tablets). The stipulated treatment period was 7 months and a total of 29 cases of advanced fibrosis (14 test subjects and 15 age and sex matched diseased controls) were included in this study and 100% compliance was reported at the end ofthe test period. RESULTS: Mild gastric irritation that could be managed by diet protocols was the only untoward symptom reported during this trial. Review of the patients and controls was done at an interval of 30 days and subjective and objective measurements were recorded. The follow up data at each visit with respect to each other and to base-line values was calibrated using a nonparametric test of Mann-Whitney (Kruskal-Wallis test). Significant comparisons with regard to improvement were recorded as objective criteria of mouth opening (t=11.285, p= 0.000), tongue protrusion (t= 3.898, p = 0.002), and relief from perioral fibrotic bands (p = 0.0001554). Subjective symptoms of intolerance to spices (p = 0.0063218), burning sensation of mouth (p = 0.0005797), tinnitus (p=0.000042), difficulty in swallowing (p=0.0000714). and difficulty in speech (p=0.0000020) were also recorded significant improvement at the end of the trial period. CONCLUSION: This pilot investigation points to the effectiveness of pentoxifylline as an adjunct therapy in the routine management of oral submucous fibrosis.

Adult↗
PubMedDate not supplied

Expression of matrix metalloproteinases (MMP-1, MMP-2 and MMP-9) and their inhibitors (TIMP-1 and TIMP-2) in oral submucous fibrosis.

Immunohistochemical staining of formalin fixed, paraffin embedded tissue sections of OSF for MMPs-1,2,9 and their tissue inhibitors TIMP-1and 2 was performed using monospecific antibodies coupled with gelatin zymography (MMP-2 and 9) for measuring enzymatic activity quantitatively and for distinguishing the active from the inactive variants of enzymes. The present study, contrary to earlier reports, recorded statistically significant increase in the levels of stromal expression of MMP-1, MMP-2 and MMP-9 and TIMP-1 and TIMP-2 using monospecific antibodies reacting against tissue antigens. The simultaneous increase in reactivity of MMPs and TIMPs poise difficulty in interpretingthe results of this study. The possible reasons for this result, against the backdrop of existing knowledge, were attempted in this study.

Adult↗
PubMedDate not supplied

Further on the causation of oral submucous fibrosis.

Oral submucous fibrosis is perhaps a disease of multifactorial aetiology, of which areca nut usage is definitely a causative factor. We disagree with the previous reports in that the action of areca quid on the oral mucosa is not that simplistic and is not dictated solely by the duration of exposure to it or by simple process of passive diffusion. We noted that the role of copper cannot be segregated from that of zinc, the biochemical relatedness of these two elements is well elucidated. The transport of copper in to the oral epithelium may be dictated more by the composition of the quid rather than the time of exposure. Zinc is implicated in the modulation of mucosal metallothionein, thereby interfering with copper absorption. The bioavailability of zinc in its turn depends on elements like calcium and iron present in oral fluid. The usage of slaked lime(calcium hydroxide) as as ingredient of betel quid, thereby causing an interference with zinc bioavailability is a matter of concern. Of practical importance is the processing of raw areca nut and the various proprietary forms (sachets) available in the market, the toxic effects of which varies depending on its contents. Studies on the role of geochemical factors in modulating the chemical composition of the various nut forms, thereby altering its toxic effects will be an interesting pursuit.

Absorption↗
PubMedDate not supplied

Liver ultrasound and faecal copper estimation in oral submucous fibrosis.

There is no evidence of an increased quantity of ingestion of copper in areca nut chewers by way of habitually swallowing the 'quid juice' allegedly contain 'appreciable quantity' of soluble copper. Our experimental findings are favour of assuming that the amount of copper ingested, if at all, is well within the threshold limit of tolerance and therefore of no clinical significance. In conjunction with our earlier observation this study again proved the absence of visible and clinically/diagnostically detectable fibrosis in visceral organs, that includes liver, in patients suffering from advanced oral submucous fibrosis.

Adult↗
PubMedDate not supplied

Morphohistometric analysis of advancing tumor fronts in malignancies associated with oral submucous fibrosis.

The objective of this study was to address retrospectively the invasive tumor fronts of epithelial neoplasms associated with OSF and non-associated tumors. Review of a data base of 25 OSF patients who have had concurrent oral squamous cell carcinoma served as the test sample. The controls constituted an equal number of age standardized (roughly) squamous cell carcinomas, non-associated with OSF. The diagnsis and grading were performed based on established criteria. Altogether a total of 8 histopathological variables were evaluated related to the advancing tumor fronts. After selection of cut-off levels, single parameter analysis by means of univariate test revealed significant result in none. A Total Malignancy Score (TMS) of 14.98 and 15.13(mean) were recorded for test and control respectively. Multivariate analysis showed that degree of nuclear plemorphism (p=0.015) and the pattern of invasion (p=0.003) were the only two variables which significantly affected the TMS. OSF associated tumors did not show features unique to it and therefore its response to therapy need not vary significantly from conventional cases.

Areca↗