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Biomedical subjects

B Dallapiccola

Publications and source records attributed to B Dallapiccola.

At least 343 records · Page 19Linked to original sources

Transformation of human choroid cells in vitro by SV40. Ultrastructural and cytogenetic analysis of cloned cell lines.

Several clones were isolated from a Simian Virus 40-transformed human choroid cell line (HC/SV40) by the soft agar plating technique. Five of them which showed different morphology, growth capacity and cell density, were plated in monolayer and subjected to ultrastructural, immunological and cytogenetic analyses. The morphological features at both TEM and SEM were distinct for every examined clone but uniform in the cells of the same clone. In particular clone 3 (HC/SV40-C13) showed a greater increase of intracytoplasmic granules, a marker of all cells of choroid origin, while clone 2 (HC/SV40-C12) was totally devoid of them. No virus production was observed at the electron microscope. Immunofluorescence experiments revealed 100% positivity for nuclear T-antigen in all the clones, thus demonstrating the persistence of SV40 genome in these cells. Cytogenetic analysis showed a hyperdiploid number of chromosomes in clones 1 and 3, while clones 2 and 4 were clearly hypodiploid. All clones showed a general tendency to cytogenetic stabilization as compared to the karyotypes found in HC/SV40 parental cell line.

Cell Division↗

Prenatal prediction of duplication 10q24 leads to qter by gene dosage of GOT1 on uncultured amniotic cells.

Glutamic-oxaloacetic transaminase (GOT1) gene dosage studies were performed on uncultured amniotic cells from a fetus at risk for duplication/deficiency of 10q24 leads to qter, due to maternal translocation t(9;10)(p24;q24). Previous investigations in the same pedigree had shown triplex dosage effect of GOT1 on red blood cells of a 10q24 leads to qter trisomic fetus monitored by midtrimester amniocentesis. In the present pregnancy, the GOT1 activity of amniotic cells exhibited a triplex gene dosage, suggesting duplication of region 10q24 leads to qter in the fetus. The biochemical prediction was confirmed two weeks later by cytogenetic analysis.

Adult↗

Mating between two balanced translocation carriers in two unrelated families.

Partial trisomy 9p and a 13/14 translocation occurred in the daughter of a t(5;9)(p15;p12) mother and a t(13;14)(p11;q11) father. Two additional offspring displayed a normal karyotype and a translocation trisomy 13 respectively. Two first cousins, selected for chromosome analysis because of a spontaneous abortion, were found to have an identical translocation t(14;21)(p11;q11). Their second pregnancy was monitored by midtrimester amniocentesis and disclosed a balanced fetus. The different zygotic chromosome constitutions and the counselling problems in the marriages between two balanced translocation carriers are discussed.

Adult↗

Failure of diepoxybutane to enhance sister chromatid exchange levels in Fanconi's anemia patients and heterozygotes.

Peripheral lymphocytes of three Fanconi's anemia (FA) patients and of five heterozygotes have been tested for their susceptibility to chromosomal breakage and sister chromatid exchange (SCE) induction by diepoxybutane (DEB). As previously shown, DEB dramatically increases the chromosomal breakage level in both homozygotes and heterozygotes. Slightly, but significantly, reduced spontaneous levels of SCE were found in cultures from FA patients and FA gene carriers as compared with controls. SCE rates were not enhanced in lymphocytes grown in the presence of DEB, irrespective of the time at which it had been added to the culture, and were comparable in cells of FA patients and FA heterozygotes. This was in contrast with SCE rates in control cells, which showed increases positively related to the length of DEB treatment.

Adolescent↗

Linkage relationships between Retinoschisis, Xg, and a cloned DNA sequence from the distal short arm of the X chromosome.

A cloned DNA sequence, RC8, from the short arm of the X chromosome which is linked to the Duchenne muscular dystrophy (DMD) gene has been employed to study linkage relationships with the Xg-linked retinoschisis (RS) locus. Results of three point linkage analyses in two families suggest that the gene order on Xp is Xg-RS-RC8. Moreover, it can be inferred from these date that the genetic distance between Xg and DMD is approximately 55 cM.

Alleles↗

Ultrastructural and biological characterization of human choroid cell cultures transformed by Simian Virus 40.

A human diploid cell line of choroid origin was isolated from the retrouveal portion of an enucleated eye and designated HC. After 10 passages, when the proliferative capacity of HC cells decreased, they were infected and transformed by Simian Virus 40 (SV40). A proliferating long-term cultured cell line designated HC/SV40 was established and it has been maintained as monolayer for more than 100 passages so far. The two cell lines, HC and HC/SV40, were compared for growth characteristics, capacity to form colonies in soft agar, presence of nuclear T-antigen, and ultrastructure. Cytogenetic analysis was also performed to determine the presence of chromosomal aberrations due to the permanent viral transformation of the cell line. The results indicate that HC/SV40 should be considered the transformed counterparts of HC cells because they are morphologically similar to the latter but can grow in soft agar, possess T-antigen, and show a pattern of karyotypic changes similar to that induced by SV40 in human fibroblasts. The choroid origin of HC and HC/SV40 cell lines was confirmed by the presence, in their cytoplasm, of typical electron dense granules. Their neural origin will make these cell lines very useful for neuropharmacological and differentiation studies.

Antigens, Viral↗

Red blood cell glucose metabolism in trisomy 10p: possible role of hexokinase in the erythrocyte.

Red blood cell glucose metabolism was investigated in a male patient with de novo trisomy 10p. According to previous evidence, when assigning hexokinase gene locus in the 10p11 leads to pter region, a triplex dosage effect of hexokinase activity (HK) was found, while all the other erythrocyte glycolytic enzymes were in the normal values range. Red blood cell glucose utilization was 2.87 mumole/hr/ml RBC as compared to 1.43 in normal controls; the rate of glucose metabolized through the hexose monophosphate shunt (HMPS) was unchanged. Glucose-6-phosphate, fructose-6-phosphate, fructose-1,6-diphosphate, and dihydroxyacetone phosphate increased with respect to normal controls, while normal levels of 3-phosphoglycerate, 2-phosphoglycerate, phosphoenolpyruvate, and ATP were found. The HK activity increased in all the red blood cell fractions obtained by density gradient ultracentrifugation. However, a small difference in the distribution of cells through the gradient was evident. The experiments reported in this article show that in the red blood cells of patients with trisomy 10p, an increased level of HK leads to higher concentrations of glucose-6-phosphate and to a faster glucose utilization in the Embden-Meyerhof pathway, while the HMPS rate is unchanged.

Blood Glucose↗

Cytogenetic findings in 4952 prenatal diagnoses. An Italian collaborative study.

The development of prenatal diagnosis in Italy was made difficult by the restrictions of the old abortion law and only in recent years has a consistent number of cases been investigated. We report the experience on prenatal chromosome diagnosis of ten Italian centers participating in a collaborative study on 4952 diagnoses performed from 1972 to 1980. The main indication groups were: advanced maternal age (2882 cases), previous child with chromosome anomaly from parents with normal karyotype (847 cases), and chromosome anomaly in one parent (97 cases). The other indications for amniocentesis, including cases without a cytogenetic risk, have been assembled into a "miscellaneous" group (1126 cases). We found 125 abnormal fetal karyotypes (2.5%) of which 89 were unbalanced (1.8%). The frequencies and types of chromosome anomalies are reported in detail for each indication group and are compared with the corresponding one from the European Munich Conference. The great majority of these Italian data were not included in the Munich report.

Chromosome Aberrations↗

Chromosomal, morphological and clinical correlations in blastic crisis of chronic myeloid leukaemia: a study of 69 cases.

The karyotypic pattern in 69 patients with Ph1-positive chronic myeloid leukaemia (CML) was investigated during the blastic phase (BC) and correlated with survival and certain parameters of potential prognostic significance, including blast morphology, basophilia and thrombocytopenia. There was no difference in median survival in BC between patients with and without aberrations in addition to the Ph1. Nor were there any differences in this respect among patients with the specific aberrations +Ph1, +8, iso(17q), or other abnormalities. There was no correlation between the incidence of thrombocytopenia and any particular karyotypic change. However, the incidence of basophilia was a characteristic feature for patients with an iso(17q). The survival time in BC was considerably longer in patients with a lymphoid morphology of the blastic cells compared to the myeloid varieties, and within the myeloid varieties the survival in BC was longer in patients with granular differentiated blasts than in those with granular atypical blast cells. No obvious correlation was apparent between blast morphology and karyotypic pattern. However, a pattern was discernible regarding survival and certain chromosomal changes within some morphologic groups: in patients with granular differentiated and lymphoid morphology, the median survival in BC was considerably longer when the bone marrow cells had a Ph1 as the sle abnormality compared to patients who had additional aberrations.

Acute Disease↗

Fetal liver transplantation in 2 patients with acute leukaemia after total body irradiation.

2 patients with acute leukaemia in relapse were transplanted with fetal liver cells following a conditioning regimen of cyclophosphamide (120 mg/kg) and total body irradiation (1000 r). Each patient achieved a remission with haematopoietic recovery that was rapid in one case and delayed in the other. In one case there was evidence of chimerism as demonstrated by the presence of the XYY karyotype of the donor fetus in 20% of marrow metaphases, by the presence of double Y bodies in the peripheral blood, by the appearance of new HLA-antigens, and by red cell isoenzyme phenotypes of donor origin. In the second case there was prompt haematopoietic recovery and the appearance of red cell isoenzyme phenotype of donor origin. Survival was 153 and 30 d, respectively, and both patients died of interstitial pneumonia without evidence of graft versus host disease.

Acute Disease↗

t(21q21q)/r[t(21q21q)] mosaic in two unrelated patients with mild stigmata of Down's syndrome.

Two cases of t(21q21q)/r[t(21q21q)] mosaic in unrelated infants, 17 and 14 months old respectively are reported. The proportion of cells with the ring chromosome was 45% in the former, 80% in the latter. Both cases had mild manifestations of the Down's syndrome. The origin of this unusual mosaicism as well as the significance of the difference in the proportions of the ring chromosome in the two have been discussed.

Chromosome Banding↗