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Biomedical subjects

F Bernardi

Publications and source records attributed to F Bernardi.

At least 163 records · Page 9Linked to original sources
PubMed1993

The parental origin of hydatidiform moles and blighted ova: molecular probing with hypervariable DNA polymorphisms.

The androgenetic origin of hydatidiform moles, due to a monospermic or dispermic mechanism, has been reported, and a possible pathogenetic relation with blighted ova suggested. To evaluate the origin of hydatidiform moles and their genetic relationship with blighted ova we investigated a series of samples, utilizing several hypervariable DNA polymorphisms by Southern blotting or PCR. Seven complete or partial hydatidiform mole and 49 blighted ovum cases were investigated. The results confirm the androgenetic origin of complete hydatidiform moles, which were always due in our sample to a monospermic mechanism. Our data exclude a relationship between hydatidiform moles and blighted ova, as in the latter a mixed paternal and maternal DNA contribution was always shown. A high incidence of chromosomal abnormalities in blighted ova was also found.

Blotting, Southern↗
PubMed1993

Molecular analysis of factor VII deficiency in Italy: a frequent mutation (FVII Lazio) in a repeated intronic region.

Molecular defects and polymorphic haplotypes of coagulation factor VII gene were studied in eight unrelated Italian subjects with factor VII deficiency, seven having the factor VII- variant, one the factor VIIR variant. An intron 7 mutation, which alters the consensus donor splice site sequence, was found in six subjects. The presence of the founder effect is suggested by their common geographical origin (a mountain area in the Lazio region) and by the identical polymorphic haplotype underlying the mutation. A different mutation, also located in the 5' monomer of the repeated intron 7 sequence, was found in the heterozygous condition in a subject from Northern Italy. New polymorphic alleles were detected in the repeated intron 7 region in subjects from Eastern Africa. Two missense mutations in codon 97 (Gly-->Cys, Gly-->Ser), the first found in the compound heterozygous condition with the frequent intron 7 mutation, suggest the presence of a hot spot mutation site in the second epidermal growth factor domain. Two neutral dimorphisms at codon 333Ser and 115His were detected, the last in linkage disequilibrium with the 353Arg/Gln polymorphism, and showing differences in frequency in the FVII deficient and control subjects.

Base Sequence↗
PubMed1993

D8S7 is consistently deleted in inverted duplications of the short arm of chromosome 8 (inv dup 8p).

Ten patients with inverted duplication of 8p (inv dup 8p) were studied with cytogenetic, biochemical and molecular techniques. The duplication for the region 8p12-p22 was always associated with a deletion of the locus D8S7 (mapped in 8p23.1) as demonstrated with the probe pSW50 by both in situ hybridization and Southern blot. Restriction fragment length polymorphisms detected by probes pSW50 (1 case) and by pG2LPL35 (locus LPL) (two cases) were informative as to a maternal origin of the anomaly. The activity of glutathione reductase, whose gene maps in the duplicated region at 8p21.1, was increased in all patients. The recognizable phenotype of inv dup 8p includes neonatal hypotonia, prominent forehead, large mouth with everted lower lip, abnormally shaped large ears, brain malformations and severe mental retardation. Our findings indicate that the chromosome rearrangement is homogeneous at least for the presence of the deletion and support the hypothesis of a common mechanism of origin.

Abnormalities, Multiple↗
PubMed1993

In-frame deletion of von Willebrand factor A domains in a dominant type of von Willebrand disease.

von Willebrand disease (vWD), the most common inherited bleeding disorder in humans, is very heterogeneous and has been classified into several subtypes. Missense mutations have been found to be responsible for the dominant type II vWD, characterized by qualitative abnormalities affecting von Willebrand factor (vWF) function. The breakpoints of a heterozygous vWF gene deletion (31 Kb), occurring 'de novo' in a patient with a variant of type II vWD, were localized to introns 25 and 34 and sequenced. An Alu repeat in intron 25 was interrupted between the transcriptional boxes A and B. The new junction present in the abnormal von Willebrand factor mRNA was sequenced after reverse transcription of platelet RNA. The codon 1104 (Cys) is followed in frame by the mutated codon 1926 (Cys to Arg), thus removing the complete A domains, found in a wide variety of genes and characterized by independent assembly 'in vitro'. We propose that the abnormal vWF, which carries intact protein domains responsible for vWF dimer and multimer formation, makes ineffective interactions with the normal molecules in the biosynthetic process, causing the dominant type II phenotype through a novel mechanism.

Base Sequence↗
PubMed1993

Symptomatic type II protein C deficiency caused by a missense mutation (Gly 381-->Ser) in the substrate-binding pocket.

A patient with recurrent deep vein thrombosis and heterozygous type II deficiency, characterized by reduced protein C activity in both amidolytic and clotting functional assays, was investigated by direct sequencing of PCR fragments derived from the coding portion of the protein C gene. AG (8856) to A transition was noted in the patient which was not present in healthy controls. This mutation is predicted to cause the substitution of Ser for Gly 381, an evolutionari'y conserved residue in the substrate binding pocket of serine-proteases (Gly 216, chymotrypsin numbering). A computer model of the structure of the serine-protease domain indicates that the properties of the altered protein C molecule can be explained on the basis of steric hindrance between the substituted serine and the substrate arginine side chains.

Adult↗
PubMed1993

Study of a protein S gene polymorphism at DNA and mRNA level in a family with symptomatic protein S deficiency.

A protein S gene polymorphism, detectable by restriction analysis of amplified exonic sequences, was investigated in a family with members affected by protein S deficiency, deep vein thrombosis and ictus. The clinical laboratory findings as well as RFLP analysis were consistent with the presence of a type WP III protein S deficiency clearly marked by a polymorphic allele, thus enabling us to determine the carrier status in several subjects. The RFLP analysis, extended to platelet mRNA after reverse transcription and amplification, demonstrated that the mRNA produced by the putative defective gene was present in a subject affected by thrombosis.

Adult↗
PubMed1993

Characterization of a deleted Y chromosome in a male with Turner stigmata.

A 46,X,+mar karyotype was detected in an 11-year-old male with a clinical picture characterized by obesity, short stature, bilateral cryptorchidism and coarctation of the aorta. The presence of ZFY and SRY genes was demonstrated by PCR amplification, and the origin of the marker chromosome from a deleted Y chromosome was analyzed by in situ hybridization. The proximal limits of a deletion in Yq were defined by the absence of Southern blot hybridization signals upon probing with Yq11 markers. Cytogenetics and molecular methods taken together indicate a deletion in q11.21. In addition, the loss of Yp subtelomeric sequences was suggested by the analysis of Southern blots hybridized with a 29A24 (DXYS14) probe and by the presence of coarctation of the aorta tentatively localized in Yp. The karyotype of the patient was suggested to be: 46,X,del (Y) (p11.3-q11.21).

Base Sequence↗
PubMed1993

A double-blind study of L-sulpiride versus amitriptyline in lithium-maintained bipolar depressives.

A double-blind group comparison study of L-sulpiride and amitriptyline was carried out in 30 bipolar outpatients on maintenance treatment with lithium suffering from a major depressive recurrence. L-sulpiride showed equivalent antidepressant activity to amitriptyline at 4 weeks using the Hamilton Rating Scale for Depression. However, the onset of action was faster in the L-sulpiride group, showing a significant improvement at 1 week in both anxiety-somatization and specific depression items, including depressed mood, feelings of guilt, work & activities and retardation. The incidence of anticholinergic side effects was significantly higher in the amitriptyline treatment group.

Ambulatory Care↗
PubMed1993

Types, stability, and phenotypic consequences of chromosome rearrangements leading to interstitial telomeric sequences.

Using in situ hybridisation, we identified interstitial telomeric sequences in seven chromosomal translocations present in normal and in syndromic subjects. Telomeric sequences were also found at the centromeric ends of a 4p and a 4q caused by centric fission of one chromosome 4. We found that rearrangements leading to interstitial telomeric sequences were of three types: (1) termino-terminal rearrangements with fusion of the telomeres of two chromosomes, of which we report one case; (2) rearrangements in which an acentric fragment of one chromosome fuses to the telomere of another chromosome. We describe four cases of Prader-Willi syndrome with the 15q1-qter transposed to the telomeric repeats of different recipient chromosomes; (3) telomere-centromere rearrangements in which telomeric sequences of one chromosome fuse with the centromere of another chromosome. We describe two examples of these rearrangements in which not only telomeric sequences but also remnants of alphoid sequences were found at the fusion point. Instability at the fusion point of the derivative chromosome was found in the Prader-Willi translocations but we were unable to correlate this instability with culture conditions. The two subjects with the termino-terminal rearrangement and the centric fission respectively have normal phenotypes. The two patients with telomere-centromere fusions were unbalanced for the short arm of an acrocentric chromosome and had failure to thrive; one of them also had dysmorphic facies. We postulate that these phenotypes could be the result of uniparental disomy.

Chromosome Aberrations↗
PubMed1993

[Diagnosis of gastro-esophageal reflux in children. Ultrasonography versus pH monitoring].

The reliability of ultrasonography (US) was investigated in the diagnosis of gastroesophageal reflux in the pediatric patient. Therefore, specificity and sensitivity of US were compared with those of a 24-hour pH monitoring. A hundred and twenty-nine patients were examined; their age ranged 38 days to 14 years (56 were under and 73 over 2 years old). Since these patients presented with gastroesophageal symptoms, they underwent both pH monitoring and US. The results of the two methods were in agreement in 79.8% of the cases. Notably, in the age group ranging 0 to 2 years, US exhibited greater sensitivity (87% vs. 78.8%) and slightly lower specificity (76.5% vs. 81.1%) than in the age group ranging 2 to 14 years. The greater sensitivity in the 0-2 age group can be explained by physiological factors (which are typical of the first months of life) as well as by technical factors. Therefore, in infants, US should be combined with pH monitoring to identify the cases which are unquestionably pathological. The high specificity in the children over 2 years of age could justify the use of US alone in this group of patients for both diagnosis and follow-up, while pH monitoring might be used only in the most severe and/or complicated cases. The results suggest that, in the two age groups considered, abdominal US can be used not only as the diagnostic method of choice in the study of gastroesophageal reflux, but also as an extremely useful tool during follow-up when therapeutic monitoring is also needed.

Adolescent↗
PubMed1992

Species specific protein--DNA interactions may determine the chromatin units of genes in S.cerevisiae and in S.pombe.

Yeast genes, such as URA3, are chromatin units characterized by positioned nucleosomes and flanking nuclease sensitive regions (NSRs). To investigate the structural determinants at the chromatin level in vivo, the URA3 gene was dissected into three parts (U5', Umid and U3'), and the chromatin structures of the individual parts were analysed after insertion into minichromosomes and after chromatin assembly in vivo in Saccharomyces cerevisiae. While nucleosome positions were altered on Umid, the 5'-end and the 3'-end of URA3 maintained their native structures (a positioned nucleosome and a NSR each) independent of the site or orientation of insertion. This suggests that the chromatin unit of the native URA3 gene is dominated by strong protein boundaries at the 5'- and 3'-ends. In an alternative approach, we investigated whether nucleosome positions or NSRs were maintained when the whole URA3 gene was placed on a shuttle vector and assembled into chromatin by Schizosaccharomyces pombe providing different proteins, but the same nucleosomal spacing. In a complementary exchange experiment, the ade6 gene of S.pombe was shuttled to S.cerevisiae. In spite of a general conservation of histone proteins and nucleosome core structures, neither nucleosome positions nor NSRs were maintained in the heterologous background. The results demonstrate that chromatin structures are species specific and that the structural boundaries of yeast genes may be dominated by strong species specific protein-DNA interactions.

Chromatin↗
PubMed1992

Detection of two missense mutations and characterization of a repeat polymorphism in the factor VII gene (F7).

The 3' portion of the coagulation factor VII gene, containing the activation and serine protease domains, was investigated in four subjects with factor VII deficiency by temperature gradient gel electrophoresis and sequencing of polymerase chain reaction (PCR) products. Molecules displaying an altered melting behaviour were detected in three subjects, and direct sequencing showed two mutations. A G-to-T transversion causing a missense mutation, Cys-310 to Phe, suppresses a disulphide bond conserved in the catalytic domain of all serine proteases. This mutation, which in the homozygous form causes a severe reduction in protease activity (4%), was found in two patients from different Italian regions. A G-to-A transition, which gives rise to a missense mutation, Arg-304 to Gln, and is associated with the factor VII padua variant, was found in the heterozygous form in a subject also affected by von Willebrand disease. Two polymorphic alleles, which differ in one repeat monomer element, were precisely mapped in a region spanning the exon-intron 7 border of the factor VII gene and studied in families with factor VII or X deficiency.

Base Sequence↗
PubMed1992

Characterization and mapping of the 5' portion of von Willebrand factor pseudogene.

A genomic fragment containing the 5' boundary of the von Willebrand factor pseudogene was cloned, partially sequenced and used for in situ hybridization experiments on metaphase spreads from a Philadelphia chromosome (Ph1)-positive chronic myelogenous leukemia patient. Data obtained indicate that the von Willebrand factor pseudogenic region is centromeric to the breakpoint cluster region on 22q11.2. This probe could be used for the study of deletions in the DiGeorge syndrome.

Chromosomes, Human, Pair 22↗
PubMed1992

Rapid detection of a protein C gene mutation present in the asymptomatic and not in the thrombosis-prone lineage.

The presence of mutations in the serine protease domain of protein C was investigated by temperature gradient gel electrophoresis of PCR products in five patients with protein C deficiency and thrombosis. Molecules with an altered melting behaviour were detected in one subject with a history of venous and arterial thrombosis. Direct sequencing showed that a G deletion, present in the heterozygous state, caused a reading frame shift at Trp 300 and subsequently a premature termination at the codon 335. The resulting suppression of the protein C catalytic function explains the reduction of protease activity to half. In addition the mutation caused a reduction of the antigen level in plasma. Temperature gradient gel electrophoresis enabled the rapid detection of the gene alteration in the family of the propositus. Several members of the paternal lineage had had severe thrombotic episodes. Unexpectedly the mutation was found to be inherited from the clinically asymptomatic maternal lineage, thus suggesting that an additional unknown defect from the paternal lineage is present in the thrombosis-prone propositus.

Adult↗