PubMed Health⌕ Search

Biomedical subjects

G Rechavi

Publications and source records attributed to G Rechavi.

At least 55 records · Page 3Linked to original sources
PubMed2000

A locus for an autosomal dominant form of progressive renal failure and hypertension at chromosome 1q21.

Linkage studies were performed in a large family with an autosomal dominant phenotype characterized by nephropathy and hypertension. In this family of Iraqi Jewish origin, the nephropathy develops into progressive renal failure. By performing a genomewide linkage search, we localized the disease gene to chromosome 1q21; the highest LOD score was obtained for the marker at locus D1S305, which yielded a maximum LOD score of 4.71 at a recombination fraction of 0. Recombination mapping defined an interval of approximately 11.6 cM, between the markers at loci D1S2696 and D1S2635, that contains the disease gene. Localization of the disease-causing gene in this family represents a necessary step toward isolation of the defective gene and toward a deeper understanding of the mechanisms of hypertension and progressive renal failure.

Adult↗
PubMed2000

The risk for cancer among children of women who underwent in vitro fertilization.

BACKGROUND: The possible association between ovarian carcinoma and ovulation-inducing drugs has led to renewed interest in the potential carcinogenic risks of these drugs. In vitro fertilization (IVF) has been linked to multiple pregnancies and possibly congenital malformations. However, to the authors' knowledge the association between IVF and pediatric cancer has been described only in sporadic case reports. The aim of this study was to assess the incidence rate of pediatric cancer among a cohort of children born after IVF. METHODS: A historic prospective study based on a cohort of 332 children from 1254 women who underwent IVF treatment between 1981-1994 was performed. Medical files were reviewed and names were linked to the National Population and Cancer Registries. Pediatric cancer incidence rates were compared with the expected age-adjusted rates of the general population during the respective time period. RESULTS: No cancer cases were observed among the study cohort with respect to 1.7 cases that were expected. CONCLUSIONS: Because the small cohort analysis in the current study lacked the necessary power to reach definite conclusions, larger prospective studies are needed to assess the potential carcinogenic effect on children born after ovulation induction and IVF.

Adult↗
PubMed2000

Profile of gene expression regulated by induced p53: connection to the TGF-beta family.

The transcription regulatory function of p53 was analyzed by using two inducible p53 systems in the human lung cancer cell line H1299. cDNA probes derived from RNA harvested 12 h after p53 induction were used to probe filters containing cDNA arrays. Over 20 genes were found to be significantly induced or suppressed by p53. The induced genes can be classified mainly as cell cycle inhibitors like p21waf, GADD45, apoptosis-related genes like Fas/APO1 and PIG3 or DNA repair genes like DDB2, DNA ligase and G/T mismatch DNA glycosylase. The suppressed genes include mainly cell cycle regulators like cyclin B1, cyclin H and kinases like c-abl, CLK1 and others. The most notable induced gene was MIC-1, encoding a TGF-beta-related secretory protein, suggesting a potential paracrine component for p53 growth suppression.

Cell Cycle Proteins↗
PubMed2000

Effective preventive central nervous system therapy with extended triple intrathecal therapy and the modified ALL-BFM 86 chemotherapy program in an enlarged non-high risk group of children and adolescents with non-B-cell acute lymphoblastic leukemia: the Israel National Study report.

BACKGROUND: Preventive cranial radiotherapy (CRT) in childhood acute lymphoblastic leukemia (ALL), although effective, may be associated with neurologic sequelae and second malignancies. Attempts to replace CRT with intensified intrathecal therapy (IT) have shown promise in lower risk subgroups. In the Israel National Study (INS) 89 trial, the efficacy of extended triple IT (TIT) alone for cranial prophylaxis in an enlarged non-high risk group (Non-HRG) was assessed in the context of a modified ALL-Berlin-Frankfurt-Munster (BFM) systemic chemotherapy program. METHODS: Non-HRG patients included the standard-risk group (SRG) and the risk group (RG), as defined in ALL-BFM 86. In the INS 89 protocol, all Non-HRG patients were treated with extended TIT x 18 times and systemic therapy based on the BFM 86 protocol, with the addition of etoposide x 4 times. The HRG patients, classified according to BFM 86 criteria, were treated with the BFM 90 HRG protocol including CRT. RESULTS: A total of 250 patients were enrolled. At a median follow-up of 58 months (range, 2-8.5 years), the overall 5-year event free survival (EFS) was 73.5% +/- 3% (standard error ¿SE), and the cumulative central nervous system (CNS) recurrence rate was 4.3% +/- 1.4% (SE) (isolated, 2.3%; combined, 2%). Of the 220 eligible children, 189 (86%) were in the Non-HRG group, and their 5-year EFS was 77.8% +/- 3% (SE). The cumulative CNS recurrence rate for patients without CNS disease at presentation was 3.1% +/- 1% (SE) (isolated, 1.7%; combined, 1.4%). Within the risk subsets defined by the BFM 86 of the Non-HRG, the 5-year EFS rates of the RG (148 patients) and the SRG (41 patients) were 74.8% +/- 4% (SE) and 89.5% +/- 5% (SE), respectively, and the rates of CNS recurrence (isolated and combined) were 4% and 0%, respectively. For the HRG (31 patients), the 5-year EFS and CNS recurrence rates were 47.9% +/- 9% (SE) and 8. 5% +/- 6% (SE), respectively. CONCLUSIONS: Early extended TIT therapy in the context of modified BFM 86 systemic chemotherapy was found to provide adequate CNS protection and systemic leukemia control in patients with non-high risk ALL. However, no benefit for etoposide could be proven in this study.

Antimetabolites, Antineoplastic↗
PubMed2000

Mutation analysis of the MEN1 gene in Israeli patients with MEN1 and familial isolated hyperprolactinemia.

Multiple endocrine neoplasia type 1 (MEN-1) is characterized by hyperfunction and tumor formation of the parathyroids, anterior pituitary and endocrine pancreas. We carried out exon-specific, PCR-based DNA sequencing of the coding exons of the MEN1 gene in 8 Israeli MEN1 patients: 4 familial and 4 sporadic. We similarly analyzed Israeli families with a unique phenotype of isolated hyperprolactinemia (HPRL). Four mutations were detected in 4 MEN1 patients: C to T alteration at nucleotide 2608 resulting in R108X, and three intronic insertions/deletions (a 13 basepair (bp) deletion and a 1 bp insertion both in intron 1, and a 2 bp insertion in intron 3) leading to exonic frame shifts as they encompass the splice junctions. An additional patient exhibited a compound mutation: a G to T change at position 7614 resulting in E463X, and insertion/deletion of 9 bp at position 7622-7630 resulting in EAE466-468X. Haplotype analysis showed no segregation of phenotype with 11q13 markers in 4 familial HPRL, and no men 1 germline mutations were detected in three representative individuals, from 3 families. Our results confirm that men 1 gene germline mutations occur in the majority of patients with clinically diagnosed MEN1, and that familial HPRL is a genetically distinct disorder.

Adolescent↗
PubMed2000

Standardization criteria for the detection of BCR/ABL fusion in interphase nuclei of chronic myelogenous leukemia patients by fluorescence in situ hybridization.

Fluorescence in situ hybridization (FISH), as a new clinical test, is not presently standardized. For practical reasons, each laboratory must build its own criteria. In this work, we present our standardization criteria for clinical practice, which include not only the methods for cell fixation, specimen preparation, and hybridization conditions, but mainly the definition of false-positive range and the scoring criteria of microscopic analysis. These include signal assessment, difference between individual microscopists, evaluation of specimen homogeneity, and the minimum number of scored nuclei required for a clinically reliable result. For this purpose, we analyzed by FISH 24 healthy volunteer donors, 31 patients affected by non-chronic myelogenous leukemia (CML) hematological malignancies, 47 CML patients at diagnosis, and 82 CML patients during treatment for the BCR/ABL fusion. In this article, we present several quality control and assurance methods that can be useful in providing standardization of the FISH technique.

Cell Nucleus↗
PubMed2000

Successful treatment of invasive aspergillosis in chronic granulomatous disease by granulocyte transfusions followed by peripheral blood stem cell transplantation.

Chronic granulomatous disease (CGD) is a primary immunodeficiency disorder characterized by impaired microbial killing and susceptibility to bacterial and fungal infections. Cure of the disease can be achieved by stem cell transplantation when performed early in its course, and before severe infections have developed. Invasive aspergillosis constitutes a very high risk for transplantation. We report a 4-year-old boy with X-linked CGD who underwent successful HLA-identical peripheral blood stem cell (PBSC) transplantation during invasive pulmonary aspergillosis and osteomyelitis of the left fourth rib, which was unresponsive to antifungal treatment. During the 2 months prior to the transplant he received G-CSF-mobilized granulocyte transfusions (GTX) from unrelated donors three times a week in addition to the antifungal treatment. This resulted in clinical improvement in his respiratory status. He also received GTX during the aplastic period after the conditioning regimen, until he had engrafted. Post-transplant superoxide generation test revealed that neutrophil function was within normal range. One year post transplant the CT scan showed almost complete clearance of the pulmonary infiltrates and a marked improvement in the osteomyelitic process. Based on other reports and our own experience, GTX can serve as important treatment in patients with CGD who have failed conventional anti-fungal treatment and for whom stem cell transplantation is the only chance for cure.

Amphotericin B↗
PubMed2000

Spontaneous regression of congenital leukaemia with an 8;16 translocation.

Congenital leukaemia (CL) is a rare disorder that presents with extramedullary infiltrates and a myeloid phenotype. CL can progress rapidly without adequate treatment, but, paradoxically, may also remit spontaneously. Because of the significant toxicity involved in delivering chemotherapy to newborns, it is important to identify those newborns who may not require treatment. We describe an infant who presented at 1 week of age with congenital myeloid leukaemia. Cytogenetic analysis revealed a t(8;16)(q11;p13) translocation. The infant's leukaemia underwent a spontaneous regression. This case further confirms the possibility of spontaneous remission in congenital leukaemia. Moreover, it suggests that the presence of a clonal cytogenetic aberration does not preclude the possibility of a spontaneous regression in CL.

Chromosomes, Human, Pair 16↗
PubMed2000

Three-dimensional spectral precision distance microscopy of chromatin nanostructures after triple-colour DNA labelling: a study of the BCR region on chromosome 22 and the Philadelphia chromosome.

Topological analysis of the three-dimensional (3D) chromatin nanostructure and its function in intact cell nuclei implies the use of high resolution far field light microscopy, e.g. confocal laser scanning microscopy (CLSM). However, experimental evidence indicates that, in practice, under biologically relevant conditions, the spatial resolution of CLSM is limited to about 300 nm in the lateral direction and about 700 nm in the axial direction. To overcome this shortcoming, the use of a recently developed light microscopical approach, spectral precision distance microscopy (SPDM) is established. This approach is based on the precise localization of small labelling sites of a given target in spectrally differential images. By means of quantitative image analysis, the bary centres (intensity weighted centroid analogous to the centre of mass) of these independently registered labelling sites can be used as point markers for distance and angle measurements after appropriate calibration of optical aberrations (here, polychromatic shifts). In combination with specific labelling of very small chromatin target sites with dyes of different spectral signatures by fluorescence in situ hybridization (FISH), SPDM presently allows us to analyse the nuclear topology in three-dimensionally conserved nuclei with a 'resolution equivalent', many times smaller than the conventional optical resolution. Chronic myelogeneous leukaemia (CML) is genetically characterized by the fusion of parts of the BCR and ABL genes on chromosomes 22 and 9, respectively. In most cases, the fusion leads to a translocation t(9; 22) producing the Philadelphia chromosome. SPDM was applied to analyse the 3D chromatin structure of the BCR region on the intact chromosome 22 and the BCR-ABL fusion gene on the Philadelphia chromosome (Ph) by using a new triple-colour FISH protocol: two different DNA probes were used to detect the BCR region and the third DNA probe was used to identify the location of the ABL gene. Consistent 3D distance measurements down to values considerably smaller than 100 nm were performed. The angle distributions between the three labelled sites on the Philadelphia chromosome territory were compared to two state-of-the-art computer models of nuclear chromatin structure. Significant differences between measured and simulated angle distributions were obtained, indicating a complex and non-random angle distribution.

Bone Marrow Cells↗
PubMed2000

Factor V Leiden and antiphospholipid antibodies are significant risk factors for ischemic stroke in children.

BACKGROUND AND PURPOSE: The association between ischemic childhood stroke and thrombophilia has been debated. We studied the prevalence of thrombophilia risk factors in 65 unrelated children with ischemic stroke compared with 145 control subjects. METHODS: Patients and control subjects were tested for antithrombin protein C and protein S deficiencies, the presence of antiphospholipid antibodies (APLA), factor V Leiden (FVL), G20210A polymorphism of factor II gene (FII G20210A), and C677T polymorphism of 5,10-methylenetetrahydrofolate reductase gene (C677T MTHFR). RESULTS: Of 65 children, 7 had a stroke in the neonatal/perinatal period and therefore were analyzed separately. Thirty-one of the remaining 58 patients with pediatric stroke (53.4%) were found to have at least 1 thrombophilia marker compared with only 25.5% of control subjects. None of the patients or control subjects had protein S or antithrombin III deficiency. The prevalence of protein C deficiency was higher among pediatric stroke patients than among control subjects, but the difference was not statistically significant (OR=7, 95% CI 0.75 to 65.1). Heterozygous FII G20210A and homozygous MTHFR 677T were not associated with an increased risk for stroke (OR=1.29, 95% CI 0.2 to 8.2; and OR=1.06, 95% CI 0.4 to 2.7, respectively). In contrast, the presence of APLA was associated with a >6-fold risk of stroke (OR=6. 08, 95% CI 1.5 to 24.3), and the heterozygosity for FVL increased the risk of stroke by almost 5-fold (OR=4.82, 95% CI 1.4 to 16.5). Five patients with pediatric stroke had a combination of > or =2 thrombophilia markers, whereas none of the control subjects had a combination of the markers. Most of the patients with neonatal/perinatal stroke were found to have at least 1 thrombophilia marker. CONCLUSIONS: These data suggest that the prevalence of thrombophilia markers is increased in children with stroke compared with control subjects and, specifically, that FVL and APLA contribute significantly to stroke occurrence.

3' Untranslated Regions↗
PubMed1999

Coexistence of several unbalanced translocations in a case of neuroblastoma: the contribution of multicolor spectral karyotyping.

Spectral karyotyping (SKY) is based on the simultaneous hybridization of a set of 24 chromosome-specific DNA painting probes, each labeled with a different fluor combination. Automatic classification, based on the measurement of the spectrum for each chromosome, was applied to metaphases obtained from the affected bone marrow of a neuroblastoma case. Spectral karyotyping allowed the identification of chromosomal aberrations that could not be identified by the use of the G-banding technique, and revealed a number of gains and unbalanced translocations.

Child, Preschool↗
PubMed1999

Successful human umbilical cord blood stem cell transplantation without conditioning in severe combined immune deficiency.

A 2-month-old girl with severe combined immunodeficiency (SCID), presented with mild staphylococcal skin infection, lymphopenia, low T cell number, absence of B cells, high number of NK cells, and a negligible response to mitogens. Since her older brother died as a result of SCID 2 years earlier, cord blood was harvested from a sister born 2 1/2 years earlier, who was normal and fully matched both by serology and molecular typing. In view of her clinical condition and in spite of a high number of NK cells with normal activity, HUCBT without preparative conditioning was performed. No G-CSF was administered. Engraftment with mixed chimerism was evident 3 weeks post transplantation. There were no peritransplantation complications. Eighteen months post transplantation, the girl is in excellent condition, blood counts are normal, T cell engraftment is complete, B cell engraftment is proceeding gradually, and the mitogen stimulation tests are normal. Due to the unique nature of HUCB hematopoietic cells, engraftment without conditioning may be possible in patients with SCID with fully matched donors. This is the first HUCBT performed without conditioning.

Female↗
PubMed1999

Genetic linkage of autosomal-dominant Alport syndrome with leukocyte inclusions and macrothrombocytopenia (Fechtner syndrome) to chromosome 22q11-13.

Fechtner syndrome is an autosomal-dominant variant of Alport syndrome, manifested by nephritis, sensorineural hearing loss, cataract formation, macrothrombocytopenia, and polymorphonuclear inclusion bodies. As opposed to autosomal-recessive and X-linked Alport syndromes, which have been genetically well studied, the genetic basis of Fechtner syndrome remains elusive. We have mapped the disease-causing gene to the long arm of chromosome 22 in an extended Israeli family with Fechtner syndrome plus impaired liver functions and hypercholesterolemia in some individuals. Six markers from chromosome 22q yielded a LOD score >3.00. A maximum two-point LOD score of 7.02 was obtained with the marker D22S283 at a recombination fraction of 0. Recombination analysis placed the disease-causing gene in a 5.5-Mb interval between the markers D22S284 and D22S1167. No collagen genes or genes comprising the basement membrane have been mapped to this region.

Alleles↗
PubMed1998

Instability of dinucleotide repeats in Hodgkin's disease.

Tumorigenesis has been shown to proceed through a series of genetic alterations involving protooncogenes and tumor suppressor genes. However, the investigation of genomic instability of microsatellites has disclosed a new mechanism for human carcinogenesis, which is involved not only in hereditary nonpolyposis colon cancer (HNPCC) but in a number of other malignancies as well. To determine whether microsatellite instability is involved in Hodgkin's disease, we screened 16 such tumors using 7 microsatellite marker loci on 6 chromosome arms 4, 5, 9p, 9q, 11, 14, and 17. Using the polymerase chain reaction method, DNA samples from the tumors and from normal peripheral blood leukocytes from each patient were compared for the allelic pattern produced at each locus. Five cases of genomic instability were identified, suggesting that this mechanism is relevant to the pathogenesis of HD.

Chromosomes, Human↗
PubMed1998

Early fulminant leukaemia post autologous bone marrow transplantation in non-Hodgkin's lymphoma patients.

Although autologous bone marrow transplantation (ABMT) is a curative option for about 50% of the patients with progressive or relapsing lymphomas, considerable concern has been raised recently over the emerging rates of secondary malignancies following ABMT. A 15% cumulative incidence of myelodysplasia 5 years after BMT is of major concern. We hereby describe a unique form of leukaemia occurring 4-6 weeks post ABMT for non-Hodgkin's lymphoma patients. The possible etiology for this phenomenon as well as its relation to the classical MDS post ABMT is discussed.

Acute Disease↗