Biomedical subjects
Publications and source records attributed to M Rocchi.
A No. 15 chromosome with a short arm longer than usual is observed in two phenotypically normal brothers. This chromosome appears to have no visible satellite, shows no N-band staining, and is never involved in satellite association. These results have led us to the conclusion that this chromosome lacks the nucleolus organizer region.
143 patients were examined for SNRT and thus divided: 1st group: 39 patients with indisputable clinical signs of MNS (bradycardia-tachycardia, synocopes); 2nd group: 18 patients with constant sinusal bradycardia, but without arrhythmias; 3rd group: 86 patients without any clinical signs of sisusal automatism deficit. The average SNRT results were: 2346 plus or minus 1404 msec in the 1st group; 1337 plus or minus 181 msec in the 2nd group and 1021 plus or minus 216 msec in the 3rd. Corrected SNRT gave an average result of 1315 plus or minus 1300 msec in the 1st group; 329 plus or minus 229 msec in the 2nd and 234 plus or minus 133msec in the 3rd group. The values between the average and standard deviation...
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A prenatal diagnosis of the fragile-X syndrome in monozygotic male twins is reported. The expression of the fragile site was discordant in amniotic cells. Fetal blood and, after therapeutic abortion, skin fibroblasts were positive in both fetuses. Our data suggest that great care should be taken when using amniocytes for prenatal diagnosis of the fragile-X syndrome.
Duane syndrome (MIM126800) is an autosomal dominant disease responsible for 1% of all strabismus cases and has been related to a 8q12-13 contiguous gene syndrome. We report on an insertion of chromosome region 8q13-q21.2 on to band 6q25 in a patient presenting with Duane syndrome, mental retardation, and other dysmorphisms. FISH analysis using chromosome 8 radiation hybrid LIA2L indicated a concurrent deletion within the 8q rearranged region. These results were corroborated by STR-PCR analysis and FISH using YAC contig WC8.8 disclosed a deletion in 8q13. Comparison of the two known patients with Duane syndrome associated with deletion of 8q identifies a small region of overlap (SRO) of < 3 cM extending from D8S533 and D8S1767 in which a Duane syndrome locus is assigned. In addition YAC analysis in our patient showed that 8q rearrangement was rather complex since 8q deletion and insertion occurred in two distinct segments separated by a region which maintained its location on 8q.
An unexpected finding of the human genome was the large fraction of the genome organized as blocks of interspersed duplicated sequence. We provide a comparative and phylogenetic analysis of a highly duplicated region of 16p12.2, which is composed of at least four different segmental duplications spanning in excess of 160 kb. We contrast the dispersal of two different segmental duplications (LCR16a and LCR16u). LCR16a, a 20 kb low-copy repeat sequence A from chromosome 16, was shown previously to contain a rapidly evolving novel hominoid gene family (morpheus) that had expanded within the last 10 million years of great ape/human evolution. We compare the dispersal of this genomic segment with a second adjacent duplication called LCR16u. The duplication contains a second putative gene family (KIAA0220/SMG1) that is represented approximately eight times within the human genome. A high degree of sequence identity (approximately 98%) was observed among the various copies of LCR16u. Comparative analyses with Old World monkey species show that LCR16a and LCR16u originated from two distinct ancestral loci. Within the human genome, at least 70% of the LCR16u copies were duplicated in concert with the LCR16a duplication. In contrast, only 30% of the chimpanzee loci show an association between LCR16a and LCR16u duplications. The data suggest that the two copies of genomic sequence were brought together during the chimpanzee/human divergence and were subsequently duplicated as a larger cassette specifically within the human lineage. The evolutionary history of these two chromosome-specific duplications supports a model of rapid expansion and evolutionary turnover among the genomes of man and the great apes.
The chromosomal localisation of the human gene coding for peroxisomal 3-oxoacyl-CoA thiolase (ACAA) was determined by human-hamster somatic cell hybrids and fluorescence in situ hybridisation, using cDNA and genomic probes, respectively. The results allowed an exclusion of the previously suggested presence of a second site for ACAA on chromosome 11 and an assignment of the gene to a single chromosome band (3p22).
BACKGROUND: The technique of Fluorescence In-Situ Hybridization (FISH), a hybrid of cytogenetics and molecular biology has increased the resolution and application of cytogenetics in various neoplastic processes. In various types of leukemias, primary investigation by conventional cytogenetic [CC] technique followed by FISH has increased our understanding of the abnormal clonal formation involving different gene region. AIMS: Present study is aimed to use different kinds of in-house FISH probes in various hematological malignancies and its correlation with conventional cytogenetic finding. MATERIAL AND METHODS: Cytogenetic study was carried out in 360 patients either from peripheral blood or from bone marrow cells suspected for various types of leukemias. Four of 360 cases were further selected for FISH study by using different types of in-house probes, such as BAC [Bacterial Artificial Chromosome], PAC [Phague Artificial Chromosome], alphoid, PCP [Partial Chromosome Paint] and WCP [Whole Chromosome paint]. RESULTS: The results confirmed breakpoints of inversion 16 and del 16 in case 2 and 3 respectively. Whereas, case 1 did not confirm the cytogenetic findings of t(15;17) by PML/RARa fusion signals as multiple cell lines were involved in the patients. PCP and WCP were helpful in the identification of the marker chromosome in case 1. Telomeric and centromeric probes confirmed the cytogenetic findings of t(5;7) in case 4. CONCLUSION: We observe from this study that, in addition to the conventional cytogenetic study, FISH study provide further confirmation of chromosomal rearrangements. This facilitates our understanding of the neoplastic process more precisely for the better prognostication of the patient.
Between April 1, 1999 and June 30, 2000, 144 isolates of enterococci (one per patient) from cultures of several anatomic sites were collected. One hundred and nineteen (82.6%) E. faecalis, 11 (7.6%) E. faecium and 14 (9.7%) of other species (5 E. raffinosus, 4 E. avium, 3 E. casseliflavus, 1 E. pseudoavium, and 1 E. dispar) were associated with clinical infections. The most common sites of isolation were: the urinary tract 54.9%, abdominal cavity 12.5%, surgical wounds 12.5%, abscesses 6.9% and diabetic foot 6.2%. High-level resistance to gentamicin or streptomycin or both was detected in 48.6% of the isolates. E. faecium and E. raffinosus were significantly more resistant than E. faecalis to ampicilin and imipenem. None of the strains exhibited beta-lactamase activity. One strain of E. faecium (0.7%) was resistant to vancomicin and teicoplanin (Van A phenotype) and two strains of E. casseliflavus (1.4%) showed low level of resistance to vancomicin (Van C phenotype). Because of these diverse antimicrobial resistance mechanisms, successful treatment and control of enterococcal infections with current antimicrobial agents are becoming increasingly difficult.
Defensins are a family of host defence peptides that play an important role in the innate immunity of mammalian and avian species. In humans, four beta-defensins have been isolated so far, corresponding to the products of the genes DEFB1 (h-BD1, GenBank accession number NM_005218); DEFB4 (h-Bd2, NM_004942.2), DEFB103 (h-BD3, NM_018661); and DEFB104 (hBD4, NM_080389) mapping on chromosome 8p23.22. We have localized beta-defensin genes on metaphasic chromosomes of great apes and several non-human primate species to determine their physical mapping. Using fluorescent in situ hybridization and BAC probes containing the four beta-defensin genes, we have mapped the homologous regions to the beta-defensin genes on chromosome 8p23-p.22 in non-human primates, while no signals were detected on prosimians chromosomes.
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We have purified and characterized Pseudorabies virus (PRV) DNA polymerase from infected TK- mouse cells. PRV DNA polymerase has a 3'- > 5' exonuclease activity; it is stimulated by ionic strength, requires magnesium for optimal activity and it is more sensitive to aphidicolin than eukaryotic and HSV-1 replicative DNA polymerases. Aphidicolin inhibits in vitro PRV DNA polymerase competitively with respect to dCTP with a Ki of 0.06 microM and completely blocks viral growth in vivo at 4.4 microM. The high sensitivity to aphidicolin of animal herpesvirus DNA polymerases might allow a topical use of this drug in the treatment of animal herpesvirus keratitis and stomatitis.
Fluorescent in situ hybridization (FISH) can be used to determine chromosome changes in human neoplasia. In our study, we have tested the feasibility of FISH to interphase cells of renal carcinoma to evaluate chromosome aneuploidies. We carried out in parallel in situ hybridization and flow cytometric studies in order to evaluate the possible correlation between numerical chromosome abnormalities and ploidies detected by flow cytometry (FCM). The ploidy of chromosomes 7, 11, 17 and 18 was investigated in three cases of this tumour utilizing specific probes. We found evaluable and comparable results in every case of renal carcinoma analyzed for both FISH and DNA FCM analyses and our results indicate that fluorescent in situ hybridization with chromosome-specific repetitive DNA probes can serve as a cytogenetic tool for the detection of numerical specific chromosome abnormalities of interphase nuclei of renal carcinoma.