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Biomedical subjects

S A Pai

Publications and source records attributed to S A Pai.

At least 19 recordsLinked to original sources
PubMed2001

Apoptosis index is a predictor of metastatic phenotype in patients with early stage squamous carcinoma of the tongue: a hypothesis to support this paradoxical association.

BACKGROUND: Patients with squamous carcinoma of the oral tongue in clinical stages TIN0M0 and T2N0M0 with a tumor thickness < or = 3 mm usually do not have lymph node (LN) metastasis. However, factors that are useful in predicting LN metastasis in thicker tumors (> 3 mm thick) need to be identified. The authors investigated the clinical relevance of the apoptotic index (AI), the proliferation index, and tumor grade in relation to LN metastasis in patients with early stage squamous carcinoma of the oral tongue. METHODS: Twenty-three patients with squamous carcinoma of the anterior two-thirds of the tongue measuring < 2 cm in height and > 3 mm in thickness were evaluated for tumor grade, AI (by using the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling technique), and proliferation index (by proliferating cell nuclear antigen [PCNA] expression). RESULTS: The mean AI value was significantly higher in LN positive patients compared with LN negative patients (P = 0.012). The LN positive and LN negative subgroups did not differ in the mean PCNA index, and there was no significant difference in the distributions of tumor grade between LN positive and LN negative subsets. Four of 12 tumors with an AI < or = 5% and 10 of 11 tumors with an AI > 5% had LN metastasis (P = 0.009; risk ratio, 20). The AI maintained its significance with respect to LN metastasis in the multivariate analysis (P = 0.003). The 4-year recurrence free survival was significantly better in patients with tumors that had an AI value < or = 5% compared with patients with tumors that had an AI > 5% (92% vs. 32%) (P = 0.033). However, the AI lost its impact on recurrence free survival within a Cox proportional hazards model (P = 0.068). CONCLUSIONS: A higher AI value is a predictor of LN metastasis and may serve as a prognostic factor in patients with early stage squamous carcinoma of the oral tongue. The authors present a hypothesis to explain this rather surprising finding.

Apoptosis↗
PubMed2001

Induction of lymphomas on implantation of human oral squamous cell carcinomas in nude mice.

Cancer cells from five oral cancer patients and pleomorphic adenoma cells from one individual were inoculated as single cell suspension into subcutis of 30 Swiss nude mice and tail vein of additional 30 mice. Further, tumor tissue pieces from three oral cancer patients were xenografted s.c. in 18 nude mice, and 10 mice were kept as controls. In animals implanted with tumor pieces, 7/18 (39%) mice, developed squamous cell carcinoma at the site of inoculation within 8-15 days, while tumors were not observed in mice inoculated with single cell suspension, up to 60/90 days. In 8/68 (12%) mice, white foci were observed in several tissues, with hepatomegaly and splenomegaly noted in 27/68 (39%) mice. Histopathological examination of various tissues revealed presence of large cell lymphoma in several organs in 14/68 (21%) mice. No regional or distant metastasis of the implanted oral tumor cells was detected. Mice injected with cells from pleomorphic adenoma, also demonstrated large cell lymphoma in 2/10 (20%) mice, whereas none of the 10 control animals showed any gross abnormalities or microscopic abnormalities in several organs. 2/16 (12%) lymphomas exhibited positive reaction with mouse B cell antibodies illustrating the murine origin of the lymphomas, and these were immunophenotyed as B cell lymphomas. The lymphomas were also examined with mouse T cell antibodies and none reacted positively with the mouse T cell antibodies. The lymphomas also failed to react with human T cell, B cell and human Leucocyte common antigen (LCA) antibodies, indicating that the induced lymphomas were not of human origin. The tumor specimens from seven of eight oral cancer patients and the pleomorphic adenoma patient induced lymphomas in nude mice. Thus it appears that xenografting oral tumor cells into nude mice may cause induction of the murine lymphomas, and this needs further investigation.

Adolescent↗
PubMed2000

Osler's pathology.

Sir William Osler, one of the giants of clinical medicine, had his initial training as a pathologist. He was one of the physicians responsible for the impact that autopsies have had on medicine. He also contributed to the development of laboratory medicine. Osler made significant discoveries in anatomic pathology and hematology. His expertise was restricted not just to human pathology, but also to veterinary pathology. His mentors played a fundamental role in his achievements in academics.

Autopsy↗
PubMed1999

Can genetic instability be studied at the single chromosome level in cancer cells? Evidence from human melanoma cells.

We evaluated whether genetic instability, which is the hallmark of cancer cells, can be investigated at the single chromosomal level. We established in culture and examined a human malignant melanoma cell line and its 11 distinct clones as well as peripheral blood cultures from the original patient by G-banding, C-banding, and silver-staining (AgNOR) techniques. There were six marker chromosomes common to most of the 11 clones and eight or nine additional marker chromosomes found in only one or in very few clones. Chromosome 1 had a pericentric inversion in the C-banded region in both the tumor and the lymphocyte metaphase spreads. This same homologue was also involved in the formation of one of the shared marker chromosomes; this marker, in turn, was rearranged to form two unique markers in one clone. Our findings suggest that genetic instability can be studied at the single chromosome level. Moreover, this study further supports our earlier contention that peripheral blood lymphocyte cultures can show chromosomal lesions that are stable markers in cancer cells.

Abdominal Neoplasms↗
PubMed1998

Reduced DNA repair capacity in breast cancer patients and unaffected individuals from breast cancer families.

It has been suggested that increased fragile site expression in lymphocyte cultures can be used as a marker for genetic predisposition to cancer. We wished to determine whether aphidicolin (APC), an inhibitor of the DNA repair enzyme DNA polymerase alpha, could be used as a reliable biomarker in identification of DNA repair capacity in unaffected individuals at high risk from breast cancer families. PHA-stimulated lymphocyte cultures, with and without APC, were set up in 65 individuals, of whom 14 were breast cancer patients, 26 were unaffected individuals from breast cancer families, and 25 were controls. A significant proportion of breast cancer patients and unaffected individuals from familial breast cancer (FBC) families exhibited premature separation of centromeres (PSC) and aneuploidy in the untreated cultures. In the APC treated cultures, almost all such individuals exhibited a marked depression of mitotic index and increased aneuploidy, as compared to controls. Our results indicate that these individuals have defective DNA repair capacity. Such individuals could thus have a much higher risk of cancer as compared to persons exhibiting PSC and aneuploidy or DNA repair defects alone. We propose that APC may be a valuable biomarker in identifying individuals with genetic predisposition to cancer from FBC families.

Adult↗
PubMed1998

Teratocarcinosarcoma of the paranasal sinuses: a clinicopathologic and immunohistochemical study.

We report four cases of sinonasal teratocarcinosarcoma (SNTCS), a rare malignant tumor that displays combined features of an immature or malignant teratoma and a carcinosarcoma. The patients, three men and one woman, were all adults ranging in age from 21 to 69 years who presented with nasal obstruction and epistaxis. The tumors were typically composed of round cells and short spindle cells with neuroectodermal/rosette-like structures. Also seen were foci of fetal-like squamous epithelium, glandular epithelium, immature mesenchyme, immature cartilage, and neuronal differentiation. Immunohistochemistry performed in three cases showed expression of vimentin, CD99 (MIC2), and neuron-specific enolase in most cells, and focal expression of cytokeratin, epithelial membrane antigen, alpha fetoprotein, glial fibrillary acidic protein, chromogranin, and synaptophysin. The tumors were consistently negative for beta human chorionic gonadotrophin, neurofilament protein, and leukocyte common antigen. The entities considered in the differential diagnosis were poorly differentiated carcinomas, sarcomas, and olfactory neuroblastoma. We suggest that these neoplasms arise from a primitive cell capable of organized divergent differentiation.

12E7 Antigen↗
PubMed1998

Uteruslike masses of the ovary associated with breast cancer and raised serum CA 125.

We describe three cases of a uteruslike mass of the ovary, a condition in which the ovary is replaced by a mass that grossly and microscopically resembles the uterus. The patients were 38, 43, and 39 years of age, and only the first was nulliparous. Two of them also had breast carcinomas. Two patients also had elevated CA 125 levels that gave rise to a clinical suspicion of ovarian malignancy. There were no anatomic abnormalities in any of the patients. The presence of residual ovarian stroma in two of the patients (both of whom had breast cancer) suggests that metaplasia rather than a congenital anomaly is the cause. Elevated CA 125 levels are consistent with the endomyometriosis nature of the lesion.

Adult↗
PubMed1998

Pseudolymphomatous phase of Kikuchi-Fujimoto disease.

Kikuchi-Fujimoto lymphadenitis is a distinctive entity which is easily recognised in its classical histology. However, cases which are biopsied in the early stage of the disease, before entering the necrotic phase may be misdiagnosed as non-Hodgkin's lymphoma. Ten cases of Kikuchi-Fujimoto disease which mimicked non-Hodgkin's lymphoma and in which less than 10% of the lymph node was occupied by necrosis were chosen for this study. The patients included 4 males and 6 females with an age range of 15-40 years. Eight patients presented with cervical lymphadenopathy. The pathologic areas ranged from 70% to 95% of the total nodal area. The features that helped distinguish this lesion from non-Hodgkin's lymphoma were: 1) a sprinkling of karyorrhectic debris throughout the node 2) plasmacytoid monocytes as well as "histiocytes" in the company of transformed lymphocytes (immunoblasts) 3) enlarged mottled T-zone areas, and 4) presence of residual lymphoid follicles. Follow up on six patients revealed no evidence of disease.

Adolescent↗