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Biomedical subjects

F Nuzzo

Publications and source records attributed to F Nuzzo.

At least 37 records · Page 2Linked to original sources
PubMed1989

Chromosome instability in lymphocytes from a patient with Werner's syndrome is not associated with DNA repair defects.

Different cellular parameters used to detect genetic instability were analyzed in lymphocytes from a patient affected by Werner's syndrome (WS). Cytogenetic studies indicated the presence of structural and numerical chromosomal abnormalities and the occurrence of variegated translocation mosaicism. The baseline mutation frequency was similar to that observed in normal donor samples. DNA repair investigations showing a normal capability to perform UV-induced DNA repair synthesis and a normal sensitivity to various mutagens (UVC light, mono- and bi-functional alkylating agents) indicate that different DNA repair mechanisms act normally in WS. In this feature, WS appears to differ from the other genetically determined syndromes in which chromosomal instability is associated with a marked hypersensitivity to specific DNA-damaging agents.

Cells, Cultured↗
PubMed1989

Cellular and genetic characterization of UV sensitive Chinese hamster mutants.

Results of cellular and genetic characterization of UV sensitive clones (UVs) isolated from CHO-K1 cell line are reported. The cross-sensitivity to agents inducing a variety of DNA lesions, the induction of chromosome aberrations and of 6-thioguanine and ouabain resistant mutants, the occurrence of methotrexate resistant cells were analyzed in clones showing different degrees of UV sensitivity. Genetic analysis was performed by complementation analysis of hybrids obtained by fusion of our mutants with UVs cells belonging to the six complementation groups (c.g.) so far identified. Three clones were assigned to c.g. 2, one clone to c.g. 5. Two clones (CHO7PV and CHO4PV), were able to complement each other and showed complementation after fusion with any of the six c.g.; these clones were considered carriers of two new mutations in genes presumably involved in DNA repair.

Animals↗
PubMed1989

Monitoring of genetic instability in subjects with increased risk of cancer.

Results of investigations performed to obtain data on genomic instability in subjects with increased risk of cancer are reported. People at risk for environmental or genetic factors included in this study were: 1) individuals from the Seveso population exposed to dioxin; 2) psoriatic patients exposed to photochemotherapy; 3) members of a family with a high incidence of colonic cancer; 4) patients affected by nevoid basal cell carcinoma syndrome; 5) patients with photosensitivity. The following cellular parameters were analyzed in peripheral blood lymphocytes: (i) frequency of chromosome aberrations and of sister chromatid exchanges; ii) sensitivity to different DNA damaging agents; iii) efficiency of DNA repair after UV irradiation and iv) frequency of spontaneous mutations.

Chromosome Aberrations↗
PubMed1988

Human papillomavirus (HPV) cervical lesions: results from 300 Italian women studied with DNA hybridization techniques and morphology.

Human papillomavirus cervical infection was investigated in a series of 300 unselected women by comparing morphological diagnoses (cytology and histology) with results of DNA hybridization techniques (filter in situ hybridization of DNA from exfoliated cervical cells and Southern blot analysis of HPV-DNA in cervical biopsy specimens). The prevalence of HPV cervical infection diagnosed by PAP smears was 11.6%. Despite disadvantages, filter in situ hybridization was confirmed to be particularly useful for screening purposes to detect HPV in cervical scrapings. In 3 cases it was the only applicable method for diagnosing "high-risk" HPV infection. Southern blot hybridization of tissue DNA with HPV 16-DNA revealed the presence of this virus in 8 cases, and HPV 31-DNA and HPV 42-DNA in 1 case each.

Cervix Uteri↗
PubMed1988

Chromosome and blood marker studies in families of patients affected by xeroderma pigmentosum and trichothiodystrophy.

Chromosome and blood marker studies were performed in the families of 4 patients in which the association of 2 rare recessive Mendelian disorders, xeroderma pigmentosum (XP-D) and trichothiodystrophy (TTD), was present. Blood genotypes did not indicate any linkage with the pathologic condition, nor any segregation anomaly. Cytogenetic analysis using high-resolution banding techniques showed a normal karyotype both in the heterozygous and in the homozygous individuals. These findings lead us to exclude a cytologically detectable chromosome rearrangement, such as a microdeletion, as a possible cause of the association of XP-D and TTD in our patients.

Blood Group Antigens↗
PubMed1988

Normal sensitivity to mutagens, spontaneous chromosome breakage, and mutation frequency in nevoid basal cell carcinoma syndrome.

Genetic instability in nevoid basal cell carcinoma syndrome (NBCCS) was investigated by measuring in lymphocytes obtained from four patients the level of UV-induced DNA repair synthesis, the DNA replication rate after treatment with different mutagens (UV light, mono- and bifunctional alkylating agents), the baseline mutation frequency, and the spontaneous chromosome breakage. All the parameters analyzed showed normal values; only the response to mitogens in NBCCS lymphocytes was delayed in comparison to that in normal donors. Our findings indicate that chromosomal instability and cellular UV hypersensitivity described in some NBCCS patients are not distinctive and constant features of NBCCS.

Adolescent↗
PubMed1987

Chromosomal aberrations induced in human cultured cells by liposome-encapsulated deoxyribonuclease I.

Experiments of incorporation of a nucleolytic enzyme into human cells cultured in vitro have been carried out with the aim of inducing structural chromosome variations. Human heteroploid cells, either as asynchronous populations or enriched in mitoses, and PHA-stimulated lymphocytes were used as recipients. We found that all these cells when exposed to pancreatic DNAase I encapsulated in liposomes, either of multilamellar (MLV) or of small unilamellar (SUV) type, show an incidence of chromosome damage higher than that induced by the enzyme free in the incubation buffer. Our results indicate that liposomes are suitable vehicles for the transfer of an exogenous nuclease into human cultured cells. The enzyme remains functionally active and interacts with nuclear DNA, giving rise to chromosome lesions.

Aneuploidy↗
PubMed1987

Complementation studies in cells from patients affected by trichothiodystrophy with normal or enhanced UV photosensitivity.

A normal level of UV-induced DNA-repair synthesis (UDS) was observed in fibroblasts from a patient affected by trichothiodystrophy (TTD) without photosensitivity. This finding indicates that the hypersensitivity to UV light and the reduced UDS due to the presence of xeroderma pigmentosum complementation group D mutation (XP-D), described in photosensitive TTD patients, are not constantly associated with TTD. Complementation analysis in heterokaryons, obtained by fusion of repair-proficient with repair-deficient TTD cells, demonstrates that cells from the patient showing normal photosensitivity are able to restore UDS in UV-hypersensitive TTD cells.

Cell Fusion↗
PubMed1986

Xeroderma pigmentosum (complementation group D) mutation is present in patients affected by trichothiodystrophy with photosensitivity.

We studied the response to UV irradiation in cells from four patients, from three apparently unrelated families, affected by trichothiodystrophy (TTD). They showed all the symptoms of this rare autosomal recessive disorder (brittle hair with reduced sulfur content, mental and physical retardation, ichthyosis, peculiar face) together with photosensitivity. We found a decreased rate of duplicative DNA synthesis in stimulated lymphocytes, reduced survival in fibroblasts, and very low levels of unscheduled DNA synthesis (UDS) in Go lymphocytes and fibroblasts after UV irradiation. Complementation studies showed that normal values of UDS are restored in heterokaryons obtained by fusion of TTD cells with normal and xeroderma pigmentosum (XP)-complementation group A-cells. In contrast the defect is not complemented by fusion with XP-complementation group D-fibroblasts.

Cells, Cultured↗
PubMed1986

Altered cellular response to UV irradiation in a patient affected by premature ageing.

An abnormal response to UV-irradiation was found in a patient affected by precocious senescence. A decreased level of unscheduled DNA synthesis (UDS) was present in 60% of Go lymphocytes and in fibroblasts after the fifth culture passage. Hypersensitivity of lymphocytes to UV-light was indicated also by a decreased rate of DNA synthesis after mitogen stimulation. The results of this study indicate that the defect which determines the premature ageing influences the capacity to repair UV-induced DNA damage.

Adult↗
PubMed1986

Sensitivity to DNA-damaging agents and mutation induction by UV light in UV-sensitive CHO cells.

Three UV-sensitive (UVs) mutants isolated from a CHO cell line were analyzed for survival after exposure to H2O2, EMS, MMC, CCNU, X-rays and for mutation induction after UV-irradiation. The UVs mutants showed normal sensitivities to EMS and H2O2, whereas they were hypersensitive to the bifunctional alkylating agents MMC and CCNU and to hypoxic X-irradiation. Compared to parental cells, one of the UV-sensitive clones showed approximately 3- and 7-fold enhancement in the mutagenic response per unit UV dose for 6-thioguanine and ouabain resistance, respectively.

Animals↗
PubMed1986

The use of absorbable suture: morphological findings in a newborn three months after coarctation repair.

The macroscopic and histological findings in a case of surgical repair of aortic coarctation in a newborn, performed using polydioxanone, a monofilament absorbable suture material, are reported. The persistence of suture material three months after surgery, the lack of severe inflammatory changes, calcification and elastic disruption of the arterial wall, confirm previous experimental data. For these characteristics, the use of polydioxanone in the repair of aortic coarctation in newborns is suggested, in order to avoid recoarctation, the most frequent complication of this surgical therapy.

Absorption↗
PubMed1985

Liposomes induce chromosome aberrations in human cultured cells.

The genotoxic effect of multilamellar lipid vesicles (MLV) was analysed on cultured heteroploid and diploid human cells. Dose-dependent reduction of cell survival and mitotic rate as well as induction of chromosome aberrations were observed. Chromatid and chromosome breaks and chromatid exchanges were found in 24-h culture after liposome treatment, whereas chromosome rearrangements were prevalent at 48 h. Neutral (PC/Chol) and positive (PC/SA) MLV showed a greater damage than negative (PS/PC; PS) MLV. Fibroblasts were the most sensitive cell type. In the case of PC/Chol MLV vesicles, control experiments with PC and Chol of controlled purity ruled out the possibility that the observed chromosome aberrations were caused by toxic oxidation products present in commercial preparations.

Cell Line↗
PubMed1984

Chromosomal effects of methotrexate on cultured human lymphocytes.

The effect of MTX on chromosome morphology was analyzed in cultured lymphocytes, and a high percentage of aberrant mitoses was found. Chromosome anomalies, such as gaps and breaks, are observed on all the chromosomes, but are preferentially located on chromosome n.3 at band p14. When the cells were continuously exposed to the drug, the chromosome damage appeared to be particularly severe.

Cells, Cultured↗
PubMed1980

Differences in the levels of UV repair and in clinical symptoms in two sibs affected by xeroderma pigmentosum.

UV-repair activity was studied in two sibs affected by XP showing different clinical symptoms. Complementation studies indicated that both patients fit into complementation group A. The levels of UV-induced 3H-thymidine incorporation, in fibroblasts and in lymphocytes, are different in the two patients: residual level of repair DNA synthesis in the sister is higher than in the brother. In one of the cell samples analyzed UDS analysis showed that in the sister a low proportion of cells with normal repair synthesis is present.

Adolescent↗
PubMed1980

Frequencies of sister-chromatid exchanges in relation to cell kinetics in lymphocyte cultures.

The frequency of sister-chromatid exchanges (SCE) was determined on second-division metaphases of lymphocytes stimulated by phytohaemagglutinin (PHA) during 9 days of culture. By using either a continuous or a pulsed bromodeoxyuridine (BUdR) treatment, cells were selected that had divided only twice, or at least twice, after different culture periods. No significant differences were observed in the SCE frequencies among the various samples. The incidence of SCE appears to be independent of the proliferation properties of cultured lymphocytes, such as length of cell cycle, fast or delayed response to PHA and number of divisions performed in vitro.

Adult↗