Biomedical subjects

R Rajendran

Publications and source records attributed to R Rajendran.

75 records · Page 5Linked to original sources

PubMedDate not supplied

Cell death does not herald epithelial involution ("atrophy") in oral sub mucous fibrosis: a TEM study.

The disease progression in oral submucous fibrosis (OSF) seems to be in a biphasic manner, along both fibroblastic and keratinocytic lineages. The epithelial malignancy is considered to be a sequel of connective tissue changes. "Atrophy" of epithelium makes it amenable to the effect of oral carcinogens. This concept looks rather simplistic in the light of the current understanding of epithelial cell biology. So the concept of epithelial "atrophy" needs redressal against the backdrop of recent investigations. 12 cases of clinically and histologically advanced OSF cases (M:F = 4:8) who were habitual areca-quid chewers comprise the study group. 5 (M:F=1:4) non-OSF, non-areca-nut chewing healthy volunteers, constituted the control group. Biopsy was done and the sections were processed for light and electron microscopy. Cell countings were made based on established criteria for apoptosis and necrosis under the high resolution of a TEM and electron micrographs were taken. The Apoptotic Index (A1) calculated for the diseased mucosa was 3.0 +/- 1.3 and for the control was 2.1 +/- 1.5 (X2 = 1.21, df= 1, p>0.05). The necrotic indices (NI) were respectively, 2.5 +/- 0.6 and 2.0 +/- 1.3 (X2 = 0.24, df = 1, p>0.05). The Absolute Cell death Index (ACI), which is the cumulative figure of apoptosis and necrosis indices, was 5.5 and 4.2 respectively for diseased and normal samples (X2 = 1.8, df = 1, p>0.05). The inability to compute an increased ACI in OSF epithelium, when compared to normal, goes against the concept of epithelial "atrophy". Atrophy envisages an increased apoptotic cell death of keratinocytes, induced by the same signals that caused atrophy and this may contribute to loss of cell of an entire organ. This basic concept in pathology seems to be unfounded with disease. This prompted us for an alternative concept in favour of a reduced proliferation index of the adult stem cell compartment of the oral epithelium. So this study favours the concept of epithelial hypoplasia, rather than atrophy, which causes thinning of surface epithelium in advanced OSF.

Adult↗

PubMedDate not supplied

Familial occurrence of oral submucous fibrosis: report of eight families from northern Kerala, south India.

BACKGROUND: Oral submucous fibrosis (OSF) is an archetype of pathological fibrosis due to possibly its presence for centuries amongst people of Indian ethnic extraction. The WHO criteria for a precancerous condition accords well with this disease. The fact that the disease has been reported in at least few subjects who do not practice the habit of areca nut chewing and the inability to prove a dose-effect relationship in almost all cases, the question arose whether there is a predisposition for the disease. METHODS: A house- to-house survey was carried out in northern Kerala, South India, for the detection of early and advanced OSF from June 2003 through May 2004. An analysis of the family pedigrees of all patients with a positive history of fibrosis has been carried out. RESULTS: Preliminary analysis of the family survey revealed that OSF tends to aggregate in families. The pedigrees of eight (8) such families presented here and the concept of OSF having a genetic predisposition to its occurrence revisited. CONCLUSION: The view that OSF having a family predilection, at least in a proportion of cases, and its tendency for familial linkage seems to be apparent by this study. This rather denovo observation of a trend relationship between OSF risk and the number of putative high-risk genotypes should be separately evaluated for the collagen metabolizing and cross-linking pathways. Establishing familial linkage of the disease seems to be an initial step in deciphering further the molecular pathways involved in its causation and biologic progression.

Adult↗

PubMedDate not supplied

Characterisation and quantification of mucosal vasculature in oral submucous fibrosis.

AIM: Quantitative assessment of the mucosal vascularity in oral sub mucous fibrosis (OSF) by image analysis using OPTIMAS ver 6.0 software. The vascularity was assessed by estimating (a) the mean vascular density, (b) the mean vascular area percentage, and (c) the mean vascular luminal diameter. SUBJECT AND METHODS: Twenty (20) OSF and ten (10) age and sex matched healthy volunteers comprised the study group. The 5 microm thick H and E stained mucosal sections were examined and quantified in an image analyzer for number, size, density of vessels, and percentage of vascular area using an area morphometry tool. ANOVA is used to test equality of several means without affecting Type 1 error. RESULT: The mean vascular density is found to be more or less same in the test and control samples (F = 0.82, P>0.05). The mean vascular percentage area shows an increasing trend as the disease progresses (F = 8.63, p<0.01). The mean vascular luminal diameter also shows an increasing trend as the disease progresses (F = 34.1, p<0.001). CONCLUSION: The usual tissue reaction resultant to ischaemia / hypoxia does not seem to operate in this disease, which is preconditioned by significant stromal changes as part of the disease process. The mean vascular dilatation noted is assumed to be an adaptive response to compensate tissue ischaemia/hypoxia.

Biopsy↗