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Biomedical subjects

G Guanti

Publications and source records attributed to G Guanti.

At least 55 records · Page 3Linked to original sources
PubMed1996

Cytogenetic studies in coke oven workers.

Chromosome aberrations, micronuclei, and sister chromatid exchanges (SCE) were evaluated in cultured lymphocytes of coke oven workers of an Italian steel industry plant, occupationally exposed to polycyclic aromatic hydrocarbons, and in a group of unexposed controls from a non-oven plant in the same area. No differences were found between exposed and controls for rates of total abnormal metaphases (including and excluding gaps), chromatid-type and chromosome-type aberrations, cells with 2 or more breaks, and for micronuclei. On the contrary, SCE were significantly increased in the exposed versus the controls, but, when smoking habits were considered, the increase was significant only for smokers.

Adult↗
PubMed1996

Clinical findings in a family with familial adenomatous polyposis and a missense mutation of the adenomatous polyposis coli gene.

BACKGROUND: More than 100 different mutations in the adenomatous polyposis coli (APC) gene have been identified; virtually all lead to the production of a truncated protein. Clinical details of patients with missense mutations undoubtedly cosegregating with the disease have not been reported and may be relevant in understanding the APC protein function. METHODS: In one family with familial adenomatous polyposis (FAP) the APC gene was analyzed by SSCP and sequencing of the aberrant SSCP band. RESULTS: A missense mutation in exon 15 at nucleotide 4921 segregating with the disease was observed. This predicts a tryptophan instead of an arginine at amino acid 1641 of the APC protein. No such mutation was present in 100 control subjects. CONCLUSIONS: In this family the colonic manifestations are as expected for classical FAP. However, the occurrence of congenital hypertrophy of the retinal pigment epithelium is unusual, owing to the inconsistency of this manifestation between family members and because congenital hypertrophy of the retinal pigment epithelium is generally absent when mutations are after codon 1387.

Adenomatous Polyposis Coli↗
PubMed1995

Recurrent simple tandem repeat mutations during human Y-chromosome radiation in Caucasian subpopulations.

The haplotypes at four polymorphic loci of the Y chromosome were determined in 245 Caucasian males from 12 subpopulations. The data show that haplotype radiation occurred among Caucasians. Haplotype radiation was accompanied by recurrent mutations at STR loci that caused partial randomization of haplotype structure. The present distribution of alleles at short tandem repeats (STRs) can be explained by a mutation pattern similar to those described for autosomal STRs. The degree of variation among groups of subpopulations was assayed by using the Analysis of Molecular Variance. The results confirm a faster divergence of the Y chromosome as compared to the rest of the genome.

Haplotypes↗
PubMed1995

[Holt-Oram syndrome: cardiological, radiological and genetic evaluation].

A case of a 63-year-old woman with Holt-Oram syndrome is presented. The patient, operated at 38 years for correction of an interatrial defect of the ostium secundum type presented with upper extremity skeletal abnormalities, in particular on the left, and a severe mitral insufficiency with ruptured chordae tendinae of the posterior leaflet. Mitral valve reconstruction was followed by an unusual severe hemolytic anemia and acute secondary renal insufficiency. Valve replacement was therefore necessary. At present, the patient, whose karyotype is normal, is in NYHA functional class I.

Abnormalities, Multiple↗
PubMed1993

Infertility in carriers of two bisatellited marker chromosomes.

Two unrelated sterile patients, a male and a female, with karyotypes characterized by the presence of two supernumerary bisatellited marker chromosomes, were studied with the aid of fluorescence in situ hybridization (FISH). Using alphoid centromeric specific probes, the markers were identified as an idic (15) (pter-q11) and a mar (14). In both cases a single accessory bisatellited marker was present in the karyotype of one of the parents. A possible correlation between the excess of constitutive heterochromatin and meiotic disturbances in the two patients is discussed.

Adult↗
PubMed1993

Genetic contribution to idiopathic adult-onset blepharospasm and cranial-cervical dystonia.

A family study in 29 patients with idiopathic adult-onset blepharospasm (n = 16) and cranial-cervical dystonia (n = 13) was undertaken by examining 189 first-degree relatives. Six relatives with dystonia were identified in 6 families. A further 3 affected relatives, now deceased, were from 2 other families. All the secondary cases were parents or siblings. There was a tendency for affected relatives to have the same type of dystonia of index patients. To assess the significance of secondary cases we compare the incidence of affected siblings between probands and their spouses. Dystonia was found in 5 out of 120 proband siblings whereas none of the 142 spouse siblings was affected (p < 0.05). Segregation analysis suggested an autosomal-dominant transmission and reduced penetrance or, alternatively, polygenic inheritance.

Adult↗
PubMed1993

Exclusion of the APC gene as the cause of a variant form of familial adenomatous polyposis (FAP)

Familial adenomatous polyposis (FAP) is a premalignant disease inherited as an autosomal dominant trait, characterized by hundreds to thousands of polyps in the colorectal tract. Recently, the syndrome has been shown to be caused by mutations in the APC (adenomatous polyposis coli) gene located on chromosome 5q21. We studied two families that both presented a phenotype different than that of the classical form of FAP. The most important findings observed in these two kindreds are (a) low and variable number of colonic polyps (from 5 to 100) and (b) a slower evolution of the disease, with colon cancer occurring at a more advanced age than in FAP in spite of the early onset of intestinal manifestations. To determine whether mutations of the APC gene are also responsible for this variant syndrome, linkage studies were performed by using a series of markers both intragenic and tightly linked to the APC gene. The results provide evidence for exclusion of the APC gene as the cause of the variant form of polyposis present in the two families described.

Adenomatous Polyposis Coli↗
PubMed1992

Familial adenomatous polyposis: identification of a new frameshift mutation of the APC gene in an Italian family.

Familial Adenomatous Polyposis (FAP) is a premalignant disease of the gastrointestinal tract inherited as an autosomal dominant trait assigned to chromosome 5q21. The 15 exons of the APC gene responsible for the defect were amplified from the DNA of one FAP patient. SSCP analysis of the amplified DNA revealed a variant conformer of exon 10. The sequencing of the cloned PCR product showed a 1 base insertion at position 1370, creating a stop codon four nucleotides downstream. SSCP analysis of 20 family members and nucleotide sequencing of exon 10 in three affected members confirmed the Mendelian inheritance of the mutant allele.

Adenomatous Polyposis Coli↗
PubMed1990

Robinow's syndrome: prenatal diagnosis.

The prenatal diagnosis of Robinow's syndrome was accomplished in our case by measuring the length of the long bones and the ulna/humerus ratio. Although the prenatal sonographic appearance did not show the typical 8-week fetal face, pathological findings confirmed this particular feature. In view of the strongly suggestive family history, the authors consider the possible mechanisms of genetic inheritance.

Adult↗
PubMed1990

Cancer family syndrome: cytogenetic investigations, in vitro tetraploidy, and biomarker studies in a large family.

Fifty-five members of a family with the cancer family syndrome (CFS) were investigated for the following potential biomarkers for cancer proneness: (1) cytogenetics of peripheral blood lymphocytes and skin fibroblasts; (2) in vitro tetraploidy of dermal fibroblast monolayer cultures; (3) quantitative serum immunoglobulin determinations; (4) study of genetic linkage with respect to eight blood group markers including Kidd. Biological specimens were obtained from 14 patients affected with cancer, 21 subjects at risk, and 20 healthy subjects. None of the markers tested in this family, in order to identify a biomarker for the status of CFS gene carrier, was found to be useful. Our search for linkage to other biological markers (DNA RFLPs and NK cells) is in progress.

Adult↗
PubMed1989

Depressed level of natural killer cells in cancer family syndrome.

Individuals from kindred with cancer family syndrome (CFS) have an increased genetic risk for the development of adenocarcinoma of the colon as well as of several other organs. Previous studies have suggested that this high occurrence of adenocarcinoma in this as in other hereditary neoplastic syndromes may be correlated to an underlying abnormality in immunological tumor surveillance. In attempt to define a marker that might identify individuals within CFS kindred at risk of developing cancer, we determined natural killer (NK) cell number and NK cell function in affected and healthy members of a CFS family. We studied 13 cancer-affected patients, 20 unaffected but "at-risk" subjects, 20 healthy subjects and 26 normal individuals matched to the patients with colon cancer on the basis of sex and age. We determined the number of NK cells and their function concurrently, using a monoclonal antibody and a 51Cr-release assay with K562 as target cells. We found that the number of NK cells was significantly (P = 0.00004) reduced in cancer patients as compared with healthy subjects and normal controls. Of the 20 at-risk individuals 9 had levels lower than the norm, while 11 showed normal-values. Consequently, the mean percentage of NK cells of this group does not differ either from that of normal subjects or from that of cancer patients. Mean NK cell function was lower in cancer patients than in healthy members of the CFS family but the differences were not statistically significant. Therefore, the mean NK cell function per single cell, expressed as a ratio between cytotoxicity (LU) and the number of NK1-positive cells, resulted paradoxically in an increase when compared with that of normal subjects. The possible mechanisms for this dichotomy were examined.

Adolescent↗
PubMed1987

New phenotypic aspects in a family with Lynch syndrome II.

Increasing attention has been given to hereditary nonpolyposis colorectal cancer (HNPCC). This report provides medical genetic/pathologic findings on an HNPCC kindred from southern Italy that shows criteria consistent with Lynch syndrome II. An international collaborative effort led to extension of this kindred with disclosure of a potentially new spectrum of phenotypic findings: an excess of gastric carcinoma; complete intestinal metaplasia and chronic atrophic gastritis restricted to the antrum; an apparent excess of colonic mucosal macrophagia, which by special stain appeared to be positive for mucin, with a constant content of both sialo and sulfomucin, a lack of iron, and an inconstant positivity for lysozyme obtained by immunoperoxidase technique; and findings of crypt atrophy of the colonic mucosa. During the relatively short period of investigation of this family, an intensive educational and surveillance program has been mounted in the interest of improving cancer control through direct application of knowledge of natural history and the risk factor evidence through pedigree assessment.

Adult↗
PubMed1986

Adherence of Lyme disease spirochetes to rat lymphocytes.

In the present work, the capacity of Lyme disease (LD) Spirochetes to spontaneously adhere to rat lymphocytes has been evaluated. Borrelia organisms adhere to thymus, spleen, Payer's patches and peripheral blood lymphocytes in a higher frequency than that observed with Salmonella minnesota R345 (Rb) used as reference strain. Employing enriched splenic T and B cell populations, Spirochete binding to B lymphocytes is more elevated than that obtained with Salmonella, while similar percentage of T cells forms rosettes with both microorganisms. Taken together, these findings provide evidence for a novel mode of interaction between LD Spirochetes and host immune system.

Animals↗
PubMed1983

Rat liver mitochondrial aspartate aminotransferase mRNA: isolation of mRNA by polyacrylamide gel electrophoresis.

In order to obtain an enriched fraction of mRNA for mAAT we applied the following method: preparation of cytoplasmic polysomes; isolation of total RNA; isolation of mRNA by chromatography on oligo(dT)-cellulose column; polyacrylamide gel electrophoresis; extraction of mRNA from the gel. The procedure seems to allow isolation of mRNA enriched fraction for mAAT. An enriched fraction of mRNAs can be useful for the preparation of corresponding cDNAs.

Animals↗
PubMed1983

Free H-Y antigen induces in vitro testicular differentiation of human XX embryonic indifferent gonads.

In accordance with the anchorage site hypothesis, Daudi beta 2-microglobulin (-) HLA (-) human male Burkitt lymphoma cells are incapable of stably maintaining H-Y antigen on their plasma membrane; instead, they excrete it into the culture medium. The proposed testis-organizing function of Daudi H-Y antigen in solution, previously demonstrated in bovine ovarian embryonic cells, has been tested for the first time in human undifferentiated gonads. Cultured in the presence of Daudi excreted H-Y antigen, gonads obtained from early human embryos of 46, XX chromosomal constitution underwent precocious and complete testicular differentiation.

Cell Differentiation↗
PubMed1983

alpha-Thalassaemia in Apulia: biosynthetic studies.

Analysis of haemoglobin chain synthesis was performed in 15 Apulian patients with Hb H disease and in their patients and offspring. The Apulian carriers of Hb H disease show a marked imbalance of alpha and beta chain synthesis (0.39 +/- 0.1) with variable clinical and haematological manifestations. However, we are dealing with an intermediate form similar to that described in Italians from other regions. A significant difference was found between the mean alpha/beta ratio values (0.81 +/- 0.13) of parents and offspring of Hb H patients and those of the normal controls (1.05 +/- 0.09); however, extensive overlapping between these two groups exists. These results have led us to the conclusion that the forms of alpha-thalassaemia found in Apulia are similar to the alpha defects observed in Sicily; in both cases, in fact, haemoglobin chain synthesis was an unreliable test for discriminating between alpha-thalassaemia-1 trait and alpha-thalassaemia-2 trait.

Hemoglobin H↗