[Utility of chromosome banding with ALU I enzyme for identifying methylated areas in breast cancer].

Cancer is a group of disorders characterized by uncontrolled cell growth which is produced by two successive events: increased cell proliferation (tumor or neoplasia) and the invasive capacity of these cells (metastasis). DNA methylation is an epigenetic process which has been involved as an important pathogenic factor of cancer. DNA methylation participates in the regulation of gene expression, directly, by preventing the union of transcription factors, and indirectly, by promoting the "closed" structure of the chromatine.

Trisomy 19 and t(9;22) in a patient with acute basophilic leukemia.

We report a case of acute basophilic leukemia with two coexisting clonal abnormalities, t(9;22) and trisomy 19. The blast showed positive reaction with myeloperoxidase but negative reaction with chloroacetate esterase and acid phosphatase. Metachromatic features of the blast were observed with toluidine blue stain.

[G138A polymorphism of the RNASEL gene and its association with the development of prostate cancer. Preliminary study].

Prostate Cancer (CAP), is a complex disease with a multifactorial origin. It is characterized by heterogenous patterns of growth of neoplasic tissue, varying widely in its progression, age of beginning and therapy response. It is considered as the second most common cause of death by cancer in men and, it has been estimated, that one of five, suffers of CAP through the course of his life.

[Frequency and clinicopathological associations of K-ras mutations in Venezuelan patients with colo-rectal cancer].

Mutations in the K-ras oncogene are common in colo-rectal cancer, which affect the biological behaviour and may influence the susceptibility to therapy in these tumors. The objective of this work was to identify the types of K-ras mutations observed in referred patients with colo-rectal cancer and to relate them to their degree of histological differentiation and clinical stage. Histopathological and clinical data were obtained from medical records.

[Relationship of oncogene C-erbB-2 amplification in breast cancer with pathological parameters and disease free survival].

Background: Proto-oncogene c-erbB-2 is located in chromosome 17 region q21 and codifies a 185 Kd protein, with tyrosine kinase activity. The amplification of this gene is associated with relapse and lower survival in breast cancer. Overexpression of this gene can be detected by immunohistochemistry (IHC).

[Chromosome anomalies in Venezuelan patients with multiple myeloma].

The cytogenetic study is an important prognostic factor in Multiple Myeloma (MM). The chromosomal analysis has demonstrated to be essential for the genetic advise in relation to the diagnosis, prognosis and might suggest precociously, the most appropriate treatment for the majority of hematological malignancies. The objective of this investigation was to identify the chromosomal abnormalities in samples of bone marrow (BM) from patients with diagnosis of MM.

[Diminished zinc plasma concentrations and alterations in the number of lymphocyte subpopulations in Down's syndrome patients].

Alterations of plasma levels of zinc and in the immune system in Down's syndrome (DS) have been reported. These alterations have been associated with a high rate of infectious diseases, which represent the main cause of mortality in affected individuals. The objectives of this study were to determine plasma zinc levels and to evaluate the immune system in DS patients.

[Clonal chromosomal anomalies in colorectal tumors].

Colorectal tumors constitute a reason of frequent consultation in gastroenterology services in the world. They constitute the second cause of mortality in the world and the fourth cause of mortality for cancer in Venezuela. It usually begins as a polyp that becomes malignant due to a mutation at the level of the genetic code that controls the growth and the repair of cells.

[Carrier detection of Duchenne/Becker muscular dystrophy by analysis of STRs loci linked to the gene of dystrophin in Venezuelan families].

The Duchenne/Becker Muscular Dystrophy (DMD/BMD) is an X linked recessive lethal disease. The female carrier will transmit the disease gene to half of her sons and half of her daughters; half of the daughters will be carriers, while half will be normal. Half of the sons will be normal and, on average, half will have the disease.

Del(1)(q23) in a patient with Hutchinson-Gilford progeria.

A 9-year-old patient with the classical clinical picture of Hutchinson-Gilford progeria (HGP) is described. The karyotype shows a 46,XY,del(1)(q23) constitution. Our findings suggest that the interval 1q23 may play a roll in the etiology of HGP.

[Cytogenetic findings in ductal carcinoma of the breast].

Breast cancer in women is an important medical problem with public health and social implications. In spite of its great clinical importance, little is known about the cytogenetic features of breast carcinomas. Chromosomal abnormalities in some malignant tumors have been used for diagnosis and prognosis or for localizing genes involved in the pathology malignancies.

[Prenatal diagnosis. I: Prenatal diagnosis program at the Medical Genetics Unit of the Universidad de Zulia, Maracaibo, Venezuela].

The Prenatal Diagnosis Program of the Medical Genetic Unit of University of Zulia has the following objectives: Identification of Genetic Risk Factors (GRF) in those couples who attend to the Prenatal Genetic Clinic, application of different prenatal diagnostic procedures (PDP), and providing adequate genetic counseling. The goal of this paper is to show preliminary results obtained between January 1993 and December 1996. Three hundred and twenty one pregnant women were analyzed by determining the GRF and taking into account the genetic clinical history.

[Clonal chromosome abnormalities in malignant hematological diseases using fluorescence in situ hybridization].

Fluorescent in situ hybridization (FISH) is a rapid, sensitive and reliable method for the identification of complete chromosomes, or segments of them, during metaphase or nuclear interphase. The present study shows the results of the analysis of 32 bone marrow aspirates from patients with malignant hematological diseases (11 AML, 7 ALL, 12 CML and 2 CLL), referred to the Medical Genetics Unit of the Faculty of Medicine, Zulia University, Maracaibo, Venezuela between 1994 and 1996. All samples were studied by conventional and molecular techniques (FISH), using probes of total chromosomes, alpha-satellites and locus specific.

[Chronic myeloid leukemia. Karyotype changes].

Chronic Myeloid Leukemia (CML) is a clonal disease of bone marrow, citogenetically characterized by the presence of the Philadelphia chromosome (Ph). Additional anomalies in the Ph cromosome have been found during the evolution of CML. This paper will show evidence of cytogenetic abnormalities during the evolution of CML in this region, and its correlation with clinical evolution.

[Hereditary diseases and congenital malformations at the Unit of Medical Genetics of the University of Zulia. Years: 1983-1992].

The Medical Genetics Unit at Universidad del Zulia (UGM-LUZ) gives counsel to patients with partial and total genetic diseases. Counseling is available for patients of both sexes and all ages, from public and private health centers and several medical specialities. In the present study an analysis of 4617 clinical records from families referred for genetic counseling to the UGM-LUZ is given.

Clinical experience with balanced reciprocal translocations.

Clinical experience with balanced reciprocal translocations: In order to evaluate past experience with respect to the occurrence of balanced reciprocal translocations (BRT) in patients with malformation syndromes and/or mental retardation (MS/MR) and in couples with reproductive failure, 4,335 karyotypes from the Genetics Unit of the Universidad del Zulia from January 1971 to December 1994 were reviewed, resulting in the identification of 15 cases of BRT (0.34%). All BRT were classic (CT) according to the number of breakpoints.

[Application of the high resolution chromosomic technic in patients in high risk of cytogenetic anomalies].

Since the beginning of cytogenetics, there has been a constant improvement of chromosomal culture and banding techniques. In 1976, Yunis described a high chromosomal resolution technique (HRC), that permits the detection of subtle chromosomal abnormalities. The present work, reports the results obtained when HRC was applied to the study of chromosomal abnormalities in patients with high risk of such.

[Significance of chromosome changes in chronic myeloid leukemia].

Chronic myelocytic leukemia is a particular subtype of leukemia characterized by increased myeloid precursor cells. It has been associated with the presence of the Philadelphia chromosome, described by Nowel and Hungerford in 1960, as a deletion of part of the long arm of a G group chromosome, the 22 chromosome. The present work reports the chromosomal abnormalities observed in 39 patients with chronic myelocytic leukemia, studied at the Genetic Unit, in the Faculty of Medicine of Zulia University, during the period from 1987 to 1991.