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ABSTRACT: Uniparental disomy can be caused by different genetic mechanisms such as gamete complementation, chromosome duplication in monosomic zygote, or post-zygotic aneuploidy correction. This last mechanism is well documented in human reproduction and is related to placental mosaicism. In the case of a trisomic zygote which has originated by paternal or maternal non-disjunction at the first or second meiotic cell division, mosaicism will result from chromosome loss and restoration of a 'normalized' diploid fetal karyotype. In order to enrich the literature with new observations on this subject, we studied by DNA polymorphism analysis ten cases of confined placental mosaicism (CPM). The finding in placental DNA of three different alleles at polymorphic loci of chromosomes 13, 16, and 20 demonstrated the trisomic status of the zygote in three cases. On the basis of these results, we believe that systematic DNA polymorphism analysis could give useful additional information to improve knowledge on aneuploidy correction in human reproduction.
Prenatal Diagnosis 04/1998; 18(3):201-6. · 2.11 Impact Factor
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ABSTRACT: A diagnostic test for feline infectious peritonitis virus (FIPV) infection based on a nested PCR (nPCR) assay was developed and tested with FIPV, feline enteric coronavirus (FECV), canine coronavirus (CCV), and transmissible gastroenteritis virus (TGEV) and clinical fluid samples from cats with effusive feline infectious peritonitis (FIP). The target sequence for the assay is in the S1 region of the peplomer protein E2 gene. A vaccine strain of FIPV and two wild-type FIPV strains tested positive, but FECV, TGEV, and CCV tested negative. Preliminary tests with 12 cats with clinical evidence of effusive FIP and 11 cats with an illness associated with effusions, but attributed to other causes, were performed. Eleven of the 12 cats with effusive FIP tested positive, while 1 was negative. Ten of the 11 cats ill from other causes tested negative, while 1 was positive. On the basis of clinical laboratory and histopathologic criteria, the preliminary sensitivity and specificity of the assay were 91.6 and 94%, respectively.
Journal of Clinical Microbiology 04/1997; 35(3):673-5. · 4.15 Impact Factor
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ABSTRACT: The study of the placental HIV infection in cases of seropositive pregnant women after exclusion of maternal contamination of chorionic villi samples by variable number of tandem repeats (VNTR) analysis.
We studied 30 HIV-positive women: 17 terminated their pregnancy (11 in the first trimester and six in the second) and 13 delivered at term (one was a twin gestation). We selected chorionic villi and ruled out maternal contamination by VNTR analysis. DNA from chorionic villi and cord and maternal blood were tested for HIV by PCR. All infants underwent a paediatric follow-up.
All maternal blood samples tested positive for HIV-1 by polymerase chain reaction. No maternal contamination was revealed and HIV was found in six out of 11 first trimester placentas, in all second trimester samples, and in 10 out of 14 at term. Cord blood tested positive in all second trimester cases and in seven out of 14 liveborns. In no case was HIV found in cord blood without infection of the corresponding placenta; conversely, three placentas tested positive but cord blood was negative. Two infants were HIV-positive, 11 were uninfected (one case was lost to follow-up).
Our study indicates that HIV-1 can infect the placenta from first trimester onwards. HIV was found in two-thirds of our cord blood samples but it is possible that some viral DNA in cord blood may have come from infected placental cells. Additional studies are needed to assess the source of HIV in cord blood and the possible contribution of placental or maternal cells infected with HIV to vertical transmission of the virus.
AIDS 07/1996; 10(7):711-5. · 6.24 Impact Factor
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ABSTRACT: Microsatellites have recently been used for linkage analysis of genetic diseases and for DNA fingerprinting in forensic medicine. In the present study the heterozygosity, PIC values and allele distributions of four microsatellites, D8S85, D8S88, D5S346 and D7S460, in an Italian population have been investigated. After amplification with primers specific for each locus, alleles were separated and detected by denaturing gel electrophoresis and ethidium bromide staining. High heterozygosity and PIC values were observed for all microsatellites in accordance with data in other Caucasian populations. However, different allele distributions for D8S85, D8S88 and D5S346, due to the presence of additional bands or to different frequencies, were found. D7S460, which has never been fully characterized before, appeared to have five alleles in the range 172 to 188 bp. When used for paternity testing, all microsatellites gave results which were consistent with those obtained with established markers, including apo B 3'HVR, D1S80 and COL2A1. This indicates that D8S85, D8S88, D5S346 and D7S460 may be useful as additional informative markers or for solving discrepancies in selected cases.
Molecular and Cellular Probes 05/1996; 10(2):155-8. · 2.08 Impact Factor
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ABSTRACT: To assess the risk of developing familial adenomatous polyposis (FAP) in presymptomatic individuals using APC gene flanking and intragenic polymorphic markers.
Twenty families enrolled in the Italian Registry of Polyposis comprising a total of 217 individuals, including 53 (24%) presymptomatic subjects with a 50% a priori risk of FAP, were analysed. Direct analysis techniques had previously failed to identify the FAP mutation in these families.
DNA isolated from peripheral mononuclear blood cells and tissue sections was analysed by the polymerase chain reaction and a panel of seven highly polymorphic markers--YN5.64, CB83, CB26, LNS, APC1458.5, MBC, 37AB. Amplification products were separated by a modified denaturing gel electrophoresis method.
The haplotype associated with the disease was identified in 18 families (90%). The segregation of the FAP haplotype in these kindreds showed that 10 presymptomatic individuals had inherited the FAP mutation and carried a high risk of developing the disease. The remaining two families were not informative because of the lack of a sufficient number of probands or biological specimens.
These data indicate that indirect analysis with linked DNA markers has a high rate of success in defining the risk of FAP of presymptomatic subjects, provided that a sufficient number of probands or samples is available. Uninformative families accounted for 10% of the total, indicating that linkage analysis may still have higher sensitivity than direct mutation analysis techniques. The combined use of both approaches should be implemented, however, to enhance further the application of molecular genetics to the screening of families with FAP.
Journal of Medical Screening 02/1996; 3(4):195-9. · 1.69 Impact Factor
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ABSTRACT: Maternal contamination of fetal DNA represents a major problem when highly sensitive molecular techniques are used in the prenatal diagnosis of genetic diseases. For this reason, we have studied the possibility of using DNA isolated from syncytiotrophoblast vesicles as a target of gene amplification (PCR). Three PCR systems were selected which included a repetitive 149 bp fragment of the Y chromosome, the VNTR locus D1S80, and a portion of the beta-globin gene. The results of these experiments indicate that DNA isolated from syncytiotrophoblast vesicles is free of maternal contamination and is suitable for gene amplification and DNA analysis.
Prenatal Diagnosis 06/1993; 13(5):335-40. · 2.11 Impact Factor
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Fertility and Sterility 11/1992; 58(4):821-2. · 3.56 Impact Factor
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ABSTRACT: Prenatal paternity testing was evaluated by DNA analysis in chorionic villus biopsies obtained during the 7th-22nd weeks of gestation. Using highly polymorphic variable number of tandem repeats (VNTR) probes, we analysed four cases consisting of mother/child/alleged father trios. In all cases, we were able to detect maternal and paternal alleles and could establish or exclude paternity. The application of DNA analysis represents a new important diagnostic aid for all cases that require a prenatal identification of paternity.
Prenatal Diagnosis 06/1991; 11(5):343-6. · 2.11 Impact Factor
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ABSTRACT: In our Centre for Prenatal Diagnosis, we undertook a punctuation of the umbilical cord on a pregnant woman infected with varicella, complicated by viral encephalitis, to diagnose a foetal viraemia. In cooperation with the Toma Laboratory and Clonit Ltd., who have long been working on the development of specific viral genome probes, we succeeded in proving, that the foetus had contracted varicella.
Geburtshilfe und Frauenheilkunde 02/1991; 51(1):63-4. · 0.82 Impact Factor
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ABSTRACT: The presence of hepatitis B virus (HBV) genome, transcripts, and antigens (HBsAg, HBcAg, HBeAg) was examined in peripheral blood lymphocytes (PBL) from 12 patients with HBsAg-positive (B) chronic active hepatitis (CAH) and 8 normal donors by Southern and Northern blot techniques and enzyme-linked immunoassays (ELISA). HBV DNA was detected in 5 patients with B-CAH as extrachromosomal, full-length monomers of 3.2 kb. In 3 of these patients Northern blot analysis revealed the presence of the 3.6-3.8 kb RNA species, which were accompanied in one case by the HBsAg-specific 2.4 kb transcript. An ELISA performed on cell lysate obtained from this patient showed low but detectable amounts of HBsAg as compared to control PBL incubated with up to 50 micrograms/ml of the viral antigen. Serum HBV DNA was found in 3 patients with B-CAH, whereas all individuals positive for cellular HBV DNA had circulating HBeAg. These data indicate that lymphocytes from some patients with hepatitis B can harbor a transcriptionally and translationally active HBV genome.
Journal of Medical Virology 08/1990; 31(3):190-4. · 2.82 Impact Factor
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ABSTRACT: A 22 weeks pregnant women was affected by a life-threatening pneumonia and a paresis of the proximal muscles with cerebrospinal fluid pleocytosis. Her past medical history had been unremarkable except for recurrent episodes of paraumbilical herpes zoster. The clinical findings suggested a dissemination of varicella-zoster virus without skin lesions. Acyclovir was added to the therapy, and the clinical picture began to improve. Varicella-zoster virus DNA was detected in placental tissue by DNA-hybridisation analysis.
Infection 22(3):216-8. · 2.66 Impact Factor
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ABSTRACT: HBeAg/anti-HBe seroconversion is associated, in some patients affected by type B chronic active hepatitis (CAH), with the occurrence of HBV pre-core mutants characterized by a common G-A change at codon 83. Since this mutation has important clinical correlations, we tried to develop a fast and reliable PCR test based on the amplification refractory mutation system (ARMS) technique, which has been successfully used to identify point mutations associated with genetic diseases. Following this approached, we analysed HBV particles isolated from 7 patients with anti-HBe CAH and previously characterized by DNA sequencing. Sera containing only wild type or mutant HBV DNA or a combination of both showed a discrete amplification product only in the presence of the specific wild type or mutant upstream primer. These results confirm the efficacy of the ARMS technique in detecting in a rapid and specific fashion the most common and clinically relevant HBV pre-core mutation.
Research in Virology 144(4):307-9.
