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Biomedical subjects

U N Rao

Publications and source records attributed to U N Rao.

At least 19 recordsLinked to original sources
PubMed2001

Comparative genomic hybridization of hepatocellular carcinoma: correlation with fluorescence in situ hybridization in paraffin-embedded tissue.

BACKGROUND: Proto-oncogene MYC, mapped to chromosomal band 8q24 and the genes for hepatocyte growth factor (HGF at 7q21) and its receptor, MET, at chromosomal band 7q31, have an important role in the biology and growth of normal and neoplastic liver. Comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH) studies have reported frequent abnormalities of chromosomes 1 and 8 in hepatocellular carcinomas (HCCs) of various clinical and pathological stages. Chromosome 7 involvement is reported to be less frequent. MATERIALS AND METHODS: Frozen tissue from 17 HCCs was used for CGH analysis and sections of corresponding formalin-fixed, paraffin-embedded HCC tissue were used for dual-color FISH with locus-specific (LSI-cMYC for chromosome 8q24 and LSI D7S486 for chromosome 7q31) and centromeric probes, CEP8 (8p11.1-q11.2) and CEP7 (7p11.1-q11.2) (Vysis, Inc, Downers Grove, IL). This study intended to determine the pattern of chromosomal aberrations in early-stage (incidental) HCC and large surgically resected HCC, and also compared the efficiency and usefulness of the two cytogenetic methods. RESULTS: CGH showed abnormalities on chromosomes 1q, 5q, 7q, 8q, 9, 10, 13q, 15, 16, 17p, 18q, 19, 20, 21, 22, and X. Gains of 8q were noted in 50% of the HCCs, including five cases of incidental HCCs by CGH. Increase in copy numbers of MYC detected by FISH was noted in 25% of tumors that had shown 8q gains by CGH and in five cases with no chromosome abnormalities noted by CGH. Three cases with 7q31 copy number abnormalities were found by FISH in addition to those detected by CGH. CONCLUSION: Combined use of CGH and FISH may provide important information about early and/or primary genetic changes in the development of HCC.

Adolescent↗
PubMed1999

Max interacting protein 1: loss of heterozygosity is frequent in desmoplastic melanoma.

Max interacting protein 1 (MXI1), a negative regulator of myc oncoprotein with tumor suppressor properties, has been mapped to chromosome 10q24-25. MXI1 gene loss, demonstrated by loss of heterozygosity (LOH) analysis (allelic imbalance), is a frequent event in astrocytomas and other forms of glial neoplasia. Development and progression of malignant melanoma likely involves several cooperative oncogene/tumor suppressor gene alterations, many of which remain to be elucidated. We sought to discover whether desmoplastic melanoma (DM) exhibited MXI1 LOH. Archival fixative treated tissue was used for genotyping; this necessitated a microdissection-based molecular approach uniquely designed for minute tissue samples. Nineteen formalin-fixed tissue samples from 11 patients representing primary, locally recurrent, and metastatic DM were available for study. In each case, normal and neoplastic tissue was microdissected under stereomicroscopic observation as a basis for genetic analysis. We identified MXI1 LOH in neoplastic tissue by observing allelic imbalance for a microsatellite repeat polymorphism in the 3' nontranslated region of the MXI1 gene in subjects shown to be informative. Colorectal adenocarcinoma (n = 21) and astrocytomas (n = 19) were similarly analyzed, serving as negative and positive controls, respectively, for MXI1 LOH. Five of 11 DMs in subjects informative for the MXI1 microsatellite manifested MXI1 allelic imbalance consistent with tumor suppressor LOH. Genotype fidelity with respect to MXI1 status was present in two patients from whom primary and recurrent tumor was available for comparative analysis. We found that MXI1 LOH was independent of tumor stage and survival. MXI1 LOH seems to be a relatively frequent and early event in DM development and progression, consistent with neuroectodermal histogenesis of the neoplasm.

Adult↗
PubMed1999

Comparative immunohistochemical and molecular analysis of uterine and extrauterine leiomyosarcomas.

Histologic criteria defining malignancy in smooth muscle tumors are currently site specific. This study was undertaken to determine whether, in leiomyosarcomas (LMS) occurring in different anatomic locations, there were differences in patterns of expression of molecules that have been demonstrated to be associated with biologically aggressive behavior in malignant neoplasms, and also to determine their diagnostic utility. Formalin-fixed paraffin-embedded tissue blocks were selected from 16 extrauterine leiomyosarcomas (EULMS), 14 cases of uterine leiomyosarcomas (ULMS) and from five cases each of uterine and extrauterine leiomyomas (LM). Utilizing immunohistochemical (ABC) techniques with antigen retrieval, we assessed serial sections of each tumor for immunoreactivity with Glut1, CD44s, bcl2, cyclin D1, and estrogen receptor. Molecular genotyping for detecting k-ras-2 point mutation, p53 gene loss, and mdm2 gene amplification was performed on microdissected tumor samples from the same histologic sections. All of the uterine and extrauterine LM were diffusely positive for CD44s, bcl2, and cyclin D1, and uniformly negative for Glut1. In contrast, 50% of the ULMS and 25% of EULMS were Glutl positive. Moreover, Glut1 positivity closely correlated with aggressive biologic behavior reflected by distant metastatic spread. Eighty-percent of LM and 70% of the ULMS were estrogen receptor positive, whereas only one retroperitoneal tumor had focal weak positivity. Over 80% of the extrauterine and 50% of the uterine sarcomas showed absence of CD44s immunoreactivity. Percentage of cyclin D1 immunoreactivity was independent of tumor grade and inversely proportional to the percent of bcl2 positivity. An LMS of the male breast contained k-ras-2 exon 1 point mutation (codon 12 aspartate substitution of glycine). P53 allelic imbalance was present in 29% of ULMS and 57% EULMS. Mdm2 amplification was present in three of six EULMS but not in ULMS. In addition to clinical staging, Glut1 positivity together with patterns of immunoreactivity of CD44 and bcl2 may be helpful in identifying aggressive smooth muscle tumors of the uterus and some EULMS. The presence of estrogen receptor staining may be helpful in identifying uterine versus nonuterine LMS. Although sample numbers are too small for definite conclusions, this study suggests that there are differences in glucose transport, expression of adhesion molecules, and estrogen receptors in ULMS and EULMS, which in part may be due to the estrogen dependency of the ULMS. P53 mutations and mdm2 amplifications appear to be more frequent in EULMS.

Adult↗
PubMed1998

Distant skin and soft tissue metastases from sarcomas.

BACKGROUND AND OBJECTIVES: This small series documents the clinical and pathological features and the rarity of distant skin and soft tissue metastases from sarcomas. MATERIALS AND METHODS: Five cases of sarcomas from different anatomical locations that had metastasized to skin and subcutaneous soft tissue were identified in three women and two men. The age range was 41-77 years. The primary tumors had wide excisions, followed by either radiation or chemotherapy, or both. The histological types were epithelioid sarcoma, malignant fibrous histiocytoma, malignant peripheral nerve sheath tumor, and leiomyosarcoma. Metastases occurred to the skin and soft tissue of the chest wall, leg, breast, and abdominal wall. The diagnosis was established by excision biopsies for three cases and by needle biopsy and fine-needle aspiration for two cases. RESULTS: Three patients died within 7 months of the diagnosis of soft tissue metastases that were always histologically high grade and never solitary. One patient is alive with lung metastasis discovered 17 months after excision of primary. Lung metastases occurred either simultaneously or within a short period after soft tissue metastases. CONCLUSION: Distant skin and soft tissue metastases from sarcomas are very rare and often occur as a terminal event.

Adult↗
PubMed1997

Hepatocyte growth factor and c-MET in benign and malignant peripheral nerve sheath tumors.

Hepatocyte growth factor (HGF), secreted by mesenchymal cells, has pleiotropic biological activities on several cell types. HGF and its receptor, the c-met proto-oncogene product (c-MET) have been implicated in the genesis and progression of several carcinomas and sarcomas. It has been suggested that MET/HGF autocrine signaling may contribute to tumorigenesis in sarcomas. HGF has been recently found to be a mitogen for rat Schwann cells and to be present in neurofibromas in NF1 patients. In this investigation, we assessed the immunoreactive patterns of HGF and MET in benign and malignant peripheral nerve sheath tumors (PNST) using archival formalin-fixed tissue. The standard avidin-biotin-peroxidase method was used. All benign tumors were negative with HGF. Eight cases of MPNST were positive with both HGF and MET. In some malignant PNST, positivity with both ligand and the receptor may be indicative of an autocrine mediated signal transduction and may implicate HGF/MET in tumor progression. Immunoreactivity with MET was strikingly greater in MPNST in contrast to benign PNST; this finding may prove to be helpful in distinguishing some histologically low-grade MPNST from cellular and atypical benign PNST.

Adult↗
PubMed1996

Cytogenetic and histologic correlation of peripheral nerve sheath tumors of soft tissue.

Cytogenetic analysis was performed on 11 peripheral nerve sheath tumors of soft tissue from 10 patients. They include 6 benign and 5 malignant schwannomas. Five cases which include two benign, one cellular and two malignant schwannomas had a known association with a nerve, but only one patient with malignant schwannoma has clinically documented neurofibromatosis type I. All the patients had a normal diploid constitutional karyotype. Two cases of cellular schwannoma were analyzed by routine cytogenetic analysis and fluorescence in situ hybridization (FISH). One tumor was karyotyped as 45, XX,-13,-22 +mar; and the other case had a 45,X,-Y,t(1;17) (p12;q11.2) karyotype. In the latter, the breakpoint in 17q occurred below the centromere and is at or in the region of the Neurofibromatosis Type 1 (NF1) gene. Four benign tumors had a normal diploid karyotype. One hypodiploid malignant schwannoma with myxoid features demonstrated monosomy of chromosomes 17 and 22 by FISH analysis. The rest of the malignant schwannomas showed a wide range of numerical and structural aberrations, with frequent loss of 22q and gains of chromosomes 2 and 7. Loss of a sex chromosome was observed in cellular as well as malignant schwannomas. Regional karyotypic evolution was noted in one malignant schwannoma. Cytogenetic analysis may prove to be useful in identifying tumors, such as cellular schwannomas, which, because of their histologic features may be inadvertently categorized as malignant. Simultaneous involvement of NF1 and NF2 genes, which are located on chromosomes 17q and 22q, respectively, should be investigated at a molecular level in both benign and malignant tumors of peripheral nerves.

Adolescent↗
PubMed1994

Studies on the effect of ethanol on dominant lethal mutations in Swiss, C57BL6 and CBA mice.

Swiss, C57BL6 and CBA males were given 0.1 ml of 40% ethanol per mouse per day for three consecutive days, intraperitoneally. These males were mated with untreated virgin Swiss females employing a 4-day mating schedule and three consecutive matings were carried out. In another study, C57BL6 males were given an ascending gradient of 5% to 40% ethanol in drinking water for a total period of 11 weeks. These males were mated with C57BL6 females for 2 weeks. Females were dissected at mid-term pregnancy for the examination of uterine contents including total, live and dead implants. All the investigations comprised at least two or three independent experiments which were evaluated independently as well as after pooling the data. Swiss, C57BL6 and CBA males given 0.1 ml of 40% ethanol, intraperitoneally, gave no evidence of any significant increase in post-implantation lethality in the postmeiotic phase of spermatogenesis attributable to ethanol treatment. A moderate but significant reduction in mean total implants indicating pre-implantation losses was seen in Swiss but not in CBA mice. Prolonged feeding of ethanol up to 40% in drinking water failed to provide any evidence of dominant lethal mutations in C57BL6 males at the pre-implantation level and the post-implantation lethals were also not significantly higher than in controls. In Swiss mice, however, the mutagenic index based on both pre- and post-implantation lethality was consistently positive.

Animals↗
PubMed1993

Malignant pleural mesothelioma: a clinicopathological study.

In this paper the results of a retrospective review of 58 patients with malignant pleural mesothelioma treated at our Institute are reported. There were 50 males and 8 females; the mean age was 56.3 years (range: 13-77). History of asbestos exposure was ascertained in 25 patients (43%). The most common finding in chest X-ray was pleural effusion which was seen in 47/58 patients on presentation. The cytological examination of pleural effusion was most of the time nondiagnostic. Pleural biopsy was needed for the correct diagnosis. Pathologically, 26 patients (44.8%) had epithelial type, 24 patients (41.4%) had mixed type, and 8 patients (13.8%) had fibrous or sarcomatous type of pleural mesothelioma. Most of the patients on presentation had Stage I disease by Butchart's classification. The overall survival time ranged from 1 month to as long as 17 years with a median of 12.5 months. The mean survival of patients who received nonsurgical therapies was 7-13.4 months. Thirteen patients were treated surgically: three patients survived over 5 years, but the median survival was 15 months. Six patients received no treatment, and the median survival was seven months.

Adolescent↗
PubMed1992

Cytogenetic findings in a malignant fibrous histiocytoma of the gallbladder.

We report the cytogenetic findings in a rare tumor, a malignant fibrous histiocytoma of the gallbladder. Four related clones, two near-diploid and two near-tetraploid, which appeared to have been formed by a doubling of the near-diploid clones, were present. Numerous structural and numerical abnormalities characterized the tumor. Structural rearrangements included reciprocal translocations, translocations of unidentified material onto chromosomes, and deletions. Chromosomes involved in the rearrangements included 1, 3, 10, 12, 14, 16, and 19. Numerical changes included trisomy of chromosomes 2, 8, 10, and 20. Double minute chromatin bodies ranging in number from 5 to several were present in over a third of the cells.

Adult↗
PubMed1992

Complex karyotypic aberrations, including i(12p), in malignant mixed mullerian tumor of uterus.

We report the cytogenetic findings in a malignant mixed mullerian tumor of the uterus in a 59-year-old woman. Karyotypic analysis of short-term cultures revealed two abnormal clones of cells characterized by extensive structural and numerical rearrangements. An i(12p) maker chromosome was present in addition to other changes in both clones. This marker, characteristically associated with testicular germ cell tumors in males, has recently been reported in ovarian germ cell tumors, a mediastinal germ cell tumor and in a mixed mullerian tumor of the ovary.

Chromosome Aberrations↗
PubMed1991

Clonal chromosomal abnormalities in hemangiopericytoma.

We report the cytogenetic findings in nine hemangiopericytomas studied after short-term culture. Clonal chromosome abnormalities were present in four cases. One case had a simple translocation (12;19)(q13;q13.3) as the sole abnormality whereas complex and multiple chromosomal abnormalities involving almost all chromosomes in the complement characterized tumors from the three other cases.

Chromosome Aberrations↗
PubMed1991

Adjuvant, specific, active immunotherapy for resectable squamous cell lung carcinoma: a 5-year survival analysis.

In 1976 Stewart et al. (Annals of the New York Academy of Sciences 277:436-466) reported the effectiveness of adjuvant specific active immunotherapy of lung carcinoma in improving the postoperative survival of stage I lung carcinoma patients in a phase II study using lung carcinoma-associated antigen (TAA) and complete Freund's adjuvant (CFA). A phase III study was then designed by the authors to see the effects of specific active immunotherapy compared to the conventional management (no treatment) and to nonspecific immunotherapy. From 1976 to 1981, 85 patients with resectable (stages I and II) squamous cell lung carcinoma were entered into a randomized study: 1) control group; 2) specific immunotherapy group--three monthly doses of 500 micrograms of TAA emulsified with CFA; 3) nonspecific immunotherapy group--three monthly doses of CFA emulsified in saline. All the patients in the study received skin tests with 100 micrograms of the same TAA used for the immunotherapy. Recently, a 5-year follow-up of all the patients became available: The life table 5-year survival of group 1 was 34%, of group 2 was 75%, and of group 3 was 53%. The median survivals for the three groups were group 1, 38 months; group 2, 106 months; and group 3, 71 months. The difference was significant at P = .007 (Cox-Mantel test).

Adult↗
PubMed1989

Pathologic analysis of advanced adult soft tissue sarcomas, bone sarcomas, and mesotheliomas. The Eastern Cooperative Oncology Group (ECOG) experience.

A total of 488 tumors entered in the Eastern Cooperative Oncology Group (ECOG) Study EST 3377 were evaluated histologically by a panel of pathologists from member institutions for quality control purposes. The overall agreement rate between the eligible submitting diagnosis and the pathology review panel's diagnosis was 74% (312/424). In 10% (44/424), the case was excluded because it was deemed to be nonsarcoma. In the other 16%, the disagreement concerned the type of sarcoma. The histologic type with the lowest agreement rate was rhabdomyosarcoma (17%), followed by sarcoma not otherwise specified (NOS) (27%), angiosarcoma (33%), and fibrosarcoma (48%). These figures reflect the significant degree of difficulty in the diagnosis of these tumor types. The treatment response rate of soft tissue sarcomas in the randomized study of Adriamycin (Adria Laboratories, Columbus, OH) regimens was slightly higher for those with lower grade sarcomas, i.e., 25% (four of 16) response rate for Grade 1 lesions; 22% (17/77) for Grade 2, and 21% (35/170) for Grade 3. When adjusted for type of sarcoma, there was no noticeable difference between Grade 1-2 versus 3 in response rate. A statistically significant difference in the percentage of complete responders was noted between Group A tumors (synovial sarcoma, hemangiopericytoma, sarcoma NOS, and Ewing's; 12.2%) versus Group B tumors (all other types--mostly spindle cell sarcomas; 3.5%) (P = 0.02).

Adolescent↗
PubMed1988

The rabbit as an experimental animal for tracheal surgery.

The circumferential resection of the trachea with end-to-end anastomosis is a well-established clinical procedure. Still, some problems remain to be solved, such as the choice of optimal suture material. Dogs are primarily used for experimental work in this field, but are difficult to obtain. This operation was performed on nine rabbits, eight of whom survived to the preplanned date of sacrifice. Two of the survivors were found to have severe stricture at the anastomosis. This study indicates that the rabbit is a suitable experimental animal for circumferential resection and anastomosis of the trachea.

Animals↗
PubMed1986

Chemotherapy followed by lung resection in inoperable non-small cell lung carcinomas due to locally far-advanced disease.

From 1977, 29 patients with inoperable non-small cell lung carcinoma due to locally far-advanced disease underwent lung resection after receiving two to eight courses of chemotherapy. After the surgery was performed, three additional courses of chemotherapy were given. The overall median survival from onset of the chemotherapy was 30.5 months; postoperatively, it was 24.5 months (five patients survived greater than 5 years). Postoperative mortality was 10.3%. The overall survival results compare favorably with those obtained with radiation therapy.

Adult↗
PubMed1986

An experimental comparison of suture materials for tracheal and bronchial anastomoses.

Tracheal anastomosis, after circumferential resection, and bronchial anastomosis, after sleeve resection, have become widely accepted procedures. Nevertheless, there appears to be no agreement as to the optimal suture material for these anastomoses. Fifty-two rabbits were operated on, and 10 cervical tracheal rings were resected in each animal. End-to-end anastomosis was performed using 5/0 silk, chronic catgut, Teflon-coated polyester, coated polyglactin 910, polypropylene, or polydioxanone sutures. Twelve rabbits died. Rabbits which survived the intended length of time were evaluated with respect to acute and chronic inflammation and stricture formation. The results suggest that polypropylene is the best suture material, whereas silk is the worst material. Monofilament sutures should be used with caution for bronchial anastomosis, as their bristly knots can perforate adjacent blood vessels.

Animals↗