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S Mathew

Publications and source records attributed to S Mathew.

At least 73 records · Page 4Linked to original sources
PubMed1993

Interphase cytogenetics of gastric and esophageal adenocarcinomas.

Numerical changes affecting chromosomes 1, 2, 3, 4, 6, 7, 8, 10, 11, 12, 16, 17, 18, and the X and Y chromosomes have been analyzed using chromosome-specific centromeric alpha-satellite repeat DNA probes in a panel of biopsies of six gastric and three esophageal adenocarcinoma and one epidermoid carcinoma of esophagus obtained at surgery. For each case, with each probe, the number of hybridization signals were determined in 200 nuclei. Hybridization of each probe to phytohemagglutinin-stimulated normal peripheral blood lymphocytes served as controls. Monosomy was defined by loss of one signal in 15% or more cells and trisomy or tetrasomy was defined by the presence of 3 or 4 signals in 7% or more cells, respectively. The Y chromosome was lost in 6 of 8 cases and monosomy 10 was seen in 5 of 10 cases. Trisomy for chromosomes 17, 8, 7, 12, 11, and 1 was seen in 4 of 10, 4 of 10, 4 of 10, 2 of 10, 2 of 8, and 2 of 10 cases, respectively, and tetrasomy for chromosome 7 was seen in 1 of 10 cases. These data show that the Y chromosome and chromosomes 10, 8, 7, 17, and 12 are most frequently involved in nondisjunctional changes in these tumors. They also document the feasibility and utility of interphase cytogenetics of gastric adenocarcinomas.

Adenocarcinoma↗
PubMed1993

Chromosomal localization and nucleoside diphosphate kinase activity of human metastasis-suppressor genes NM23-1 and NM23-2.

Human metastasis-suppressor genes nm23-1 (NME1) and nm23-2 (NME2) are implicated in control of the metastatic potential of malignant cells. Using somatic cell hybrid analysis and fluorescence in situ hybridization we co-localized both genes to 17q21.3. The 17q21 region carries the locus responsible for early-onset familial breast-ovarian cancer and several other genes that are involved in tumorigenesis and differentiation and undergo frequent rearrangements during neoplastic development. Thus, our mapping places the NME genes in a region that may be subjected to multiple selection pressures. NME1 and NME2 genes were expressed as soluble proteins in a T7 bacterial expression system. Both proteins are independently active nucleotide diphosphate kinases and readily form intra- and intermolecular disulfide bonds. The biochemical properties of these proteins may explain the diversity of mature eucaryotic nucleoside diphosphate kinases.

Animals↗
PubMed1993

Chromosomal localization of genes encoding the transcription factors, c-rel, NF-kappa Bp50, NF-kappa Bp65, and lyt-10 by fluorescence in situ hybridization.

We have used fluorescence in situ hybridization (FISH) to perform precise chromosomal mapping of the genes encoding the transcription factors c-rel, NF-kappa Bp50, NF-kappa Bp65, and lyt-10. The previously published assignments of c-rel and NF-kappa Bp50 have been refined to specific bands. The map position of lyt-10, inferred from its isolation from a t(10;14)(q24;q32) translocation, has been confirmed. NF-kappa Bp65 has now been mapped to 11q13, a site of frequent involvement in aberration in multiple tumor types.

Chromosome Mapping↗
PubMed1992

Cytogenetic analysis of 124 prospectively ascertained male germ cell tumors.

We report the cytogenetic analysis of 124 adult male germ cell tumors ascertained consecutively at the Memorial Sloan-Kettering Cancer Center between 1988 and 1990. Biopsies from testicular and extragonadal primary and metastatic lesions studied included all histological subtypes of germ cell tumors and cases of malignant transformation. Nonrandom numerical and structural chromosomal abnormalities including i(12p), the previously described characteristic marker of these tumors, were determined, and their frequency was compared between histological subtypes, between gonadal and extragonadal lesions, and between primary and transformed lesions. The frequency and copy number of i(12p) were found to be higher in nonseminomas compared with seminomas. Nonrandom sites of chromosome rearrangements associated with specific histologies comprised 1p32-36 and 7q11.2 in teratomas and 1p22 in yolk sac tumors. Some tumors that underwent malignant differentiation exhibited chromosome changes previously described to be nonrandomly associated with de novo tumors with the same histological characteristics. Cytological evidence of gene amplification in the form of homogeneously staining regions and/or double minutes was detected in 24% of extragonadal lesions, mainly metastatic tumors, suggesting amplification of a gene(s) associated with metastatic progression of these tumors. While a number of previous small cytogenetic series or individual case reports of germ cell tumors identified several of the features of these tumors reported here, this series comprises analysis of the largest group of tumors ascertained consecutively at a single institution, defines the incidence of nonrandom abnormalities in tumor subsets, and addresses their biological significance.

Cell Transformation, Neoplastic↗
PubMed1992

Analysis of chromosome 12 aneuploidy in interphase cells from human male germ cell tumors by fluorescence in situ hybridization.

The i(12p) marker chromosome has been found to be a highly nonrandom chromosome abnormality associated with germ cell tumors (GCTs). We have previously shown that a chromosome 12 centromere specific alpha-satellite DNA probe detects the i(12p) by virtue of differences in the size of the signal originating from the i(12p) and normal chromosome 12 centromeres after fluorescence in situ hybridization (FISH) in metaphase and interphase cells of cultured GCT cell lines. We have now extended this analysis to 72 fresh GCT tumor biopsy specimens. Banded cytogenetic analysis was attempted on each of these tumors, 45 of which were found to be clonally abnormal. Data on i(12p) and chromosome 12 copy number obtained by FISH agreed well with those obtained by cytogenetic analysis. In addition, the FISH method made possible the detection and determination of i(12p) and the chromosome 12 copy number in cases in which conventional cytogenetic analysis was unsuccessful. We found the incidence of i(12p) in seminomas to be low (7%) compared to that in nonseminomas (75%) when tumor biopsy specimens were studied by FISH. Our results show that the FISH technique can be used reliably for detection of the diagnostically and prognostically useful i(12p) marker in GCT tumor biopsy specimens.

Aneuploidy↗
PubMed1992

Assignment of the human TYRP (brown) locus to chromosome region 9p23 by nonradioactive in situ hybridization.

The TYRP (brown) locus determines pigmentation and coat color in the mouse. The human homolog of the TYRP locus has been recently identified and shown to encode a 75-kDa transmembrane melanosomal glycoprotein called gp75. The gp75 glycoprotein is homologous to tyrosinase, an enzyme involved in the synthesis of melanin, forming a family of tyrosinase-related proteins. A genomic clone of human gp75 was used to map the human TYRP locus to chromosome 9, region 9p23, by nonradioactive fluorescent in situ hybridization. Specificity of hybridization was tested with a genomic fragment of human tyrosinase that mapped to a distinct site on 11q21. The 9p region has been reported to be nonrandomly altered in human melanoma, suggesting a role for the region near the TYRP locus in melanocyte transformation.

Chromosomes, Human, Pair 9↗
PubMed1992

Subregional mapping of 13 single-copy genes on the long arm of chromosome 12 by fluorescence in situ hybridization.

Subregional localization of 13 single-copy DNA sequences previously assigned to the long arm of chromosome 12 has been performed using the fluorescence in situ hybridization (FISH) technique. The following order is suggested for the 13 mapped genes: cen-->COL2A1-->(VDR-D12S15)-->(D12S17-D12S4++ +-D12S14-D12S6)-->D12S8-->(IAPP-MGF- D12S7-D12S12)-->IGF1-->qter. Eight of the mapped genes clustered at two regions, one at 12q13 (D12S17-D12S4-D12S14-D12S6) and the other at 12q22 (IAPP-MGF-D12S7-D12S12). Our results show that single-copy DNA sequences as small as 500 bp can be successfully mapped by FISH.

Chromosome Mapping↗
PubMed1992

The teaching of behavioural sciences.

Medical science over the last few decades has undergone vast changes. Technologically it has advanced at a rapid pace. There has been a realization as well that the behaviour of individuals and communities also influences the occurrence of disease. Medical schools around the globe have realized the need for incorporating behavioural sciences as an integral part of the basic sciences taught to medical students. This paper presents the experience of Christian Medical College, Vellore in teaching behavioural sciences. Students are taught sociology, psychology and medical anthropology through a community-based, problem-oriented teaching programme. The students have first-hand experience of living in a community and learn by observation and interaction. Pre- and post-assessment has shown a significant improvement of their knowledge and attitude. Feedback from students also indicates that they find this programme relevant and interesting.

Behavioral Sciences↗
PubMed1991

Cytogenetic studies in Down syndrome.

Cytogenetic studies were carried out in 645 patients with Down syndrome. Free trisomy of chromosome 21 was present in 600 cases (93%). Translocation karyotypes were observed in 26 cases (4%). Seventeen patients (2.6%) had mosaicism. Two (0.3%) patients had additional karyotypic abnormalities along with trisomy 21.

Chromosome Aberrations↗
PubMed1991

How long after being collected can blood still be cultured for chromosomal studies in the tropics.

To examine how long after their collection samples of peripheral blood could be successfully cultured for cytogenetic analysis in tropical countries, we determined the mitotic index in cultures of blood stored for up to 7 days in summer and winter. The results indicate that chromosomal analysis is successful if blood is stored for up to 2 days in summer or for up to 4 days in winter before initiating culture. Storing the blood in tissue culture medium rather than in heparin solution did not significantly improve the mitotic index.

Adult↗
PubMed1990

Pyloric obstruction due to gastric tuberculosis--an endoscopic diagnosis.

A 22 year old male presented with symptoms of gastric outlet obstruction. Endoscopy showed a hypertrophic nodular lesion around the pyloric opening with pyloric stenosis. The endoscopic biopsy and histopathological examination revealed tuberculosis involving the stomach, an extremely rare lesion.

Adult↗
PubMed1990

Waldenstrom's macroglobulinaemia.

Waldenstrom's macroglobulinaemia is a rare form of monoclonal plasma cell dyscrasia in which there is excess production of immunoglobulin M. Clinically the patient has features of hyperviscosity syndrome and the effects of bone marrow replacement by lympho-plasmacytoid cells. We report here two such cases seen within a period of two months.

Female↗
PubMed1990

Factors which affect growth of amniotic fluid cells.

In a study on various factors which are known to influence the growth of amniotic fluid cells for successful cytogenetic analysis in 89 samples, amniotic fluid volume greater than 10 ml enhanced the chance of success (P = 0.0003). The presence of red blood cells reduced the success rate although this was not statistically significant. Among the techniques which proved successful were the use of closed culture method (plastic flasks in which 5% CO2 is blown), and the addition of Ultroser G, which enhances the adhesion and growth of amniotic fluid cells.

Amniotic Fluid↗
PubMed1990

Prenatal diagnosis of chromosomal disorders in Delhi.

Prenatal diagnosis of chromosomal disorders was carried out in 144 samples of amniotic fluid during 1986-1989. The commonest indication was pregnancy in women having a previous child with Down syndrome. Cultures were successful in 104 (72.2%) of 144 cases. Three (2.9%) abnormal karyotypes were detected. Of 53 women who had a previous child with Down syndrome, recurrence of trisomy 21 occur d in one (1.9%); while considering all abnormal karyotypes, there were three recurrences (2.9%).

Adult↗
PubMed1987

Resolution of genetic and uterine environmental effects in a family study of new dermatoglyphic measure: sole pattern ridge counts.

The heritability of sole pattern ridge counts was examined in two family studies of endogamous castes from peninsular India. The phenotypes included ridge counts for each of the eight configurational areas separately, all areas combined, and only distal areas combined. Differences in heritability estimates were found between populations as well as among the individual configurational areas. Although some ridge counts do not show familial resemblance, others appear to be moderately heritable. Estimates of h2 range from 0.36 to 0.63 in one family series and from 0.22 to 0.51 in the other. In addition, significant uterine environmental effects were detected in one family series but not in the other.

Dermatoglyphics↗
PubMed1987

A family study of dermatoglyphic traits in India: segregation analysis of accessory palmar triradii and the atd angle.

Accessory triradii and the atd angle were examined via complex segregation analysis in order to evaluate possible genetic effects on these dermatoglyphic traits, measured in an endogamous Brahmin caste of peninsular India. The phenotypes considered included: presence of accessory palmar triradii a' and d', associated with the interdigital areas II and IV, respectively; presence of an accessory axial triradius tt' associated with the proximal margin of the palm; and an arctanh-transformation of the atd angle measurement. For all accessory triradii considered in the present investigation familial resemblance was evident. The most parsimonious model which could account for the observed resemblance was a multifactorial model that includes polygenic effects as well as transmissible environmental effects that are inherited in the same pattern as polygenes. Evidence of familial resemblance was also found for the arctanh-transformed atd angle, which could be attributed, initially, to both a major effect and a multifactorial component. Tests of transmission of a putative major gene were performed which yielded results consistent with Mendelian transmission, although an alternative test of no transmission of the major effect also fit the data. In light of these contrasting results we are precluded from accepting with confidence the notion of a major gene influence on the atd angle. We have concluded that the accessory triradii a', d', and tt', and the atd angle are influenced by multifactorial effects, including additive polygenes and possible environmental factors, such as intrauterine effects.

Dermatoglyphics↗
PubMed1987

Fetal liver infusion in aplastic anaemia.

Forty patients with severe aplastic anaemia received an intravenous infusion of 0.004 to 11.1 x 10(8) (median: 8 x 10(8) hematopoietic cells prepared from the fetal livers of 8-32 week old abortuses. Five patients, who died within 15 days of fetal liver infusion, are excluded from analysis. Twenty-two of the 35 evaluable patients (62%) responded favourably. Six of the 7 patients with good response were alive after 9 to 44 months (median: m = 20); one died 106 months after fetal liver infusion due to renal lithiasis. Four of the 7 with moderate response were alive after 9 to 31 months; 3 died within 16 months. Of 8 patients with minimal response, one was lost to follow-up and the others died in 3.4 to 10 months (m = 6). Median survival of responders was 15.7 months. Bone marrow cellularity became normal in 12 patients following fetal liver infusion. In seven patients, there was a relapse; 6 regained a normal bone marrow cellularity after a second or third fetal liver infusion. These data strongly suggest a role of fetal liver infusion in inducing bone marrow recovery. Of 13 non-responders, 4 were lost to follow-up and 9 died within 20 days-4.3 months (m = 1.6). Fetal liver infusion appears to be an effective therapy in patients with severe aplastic anaemia.

Anemia, Aplastic↗