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Biomedical subjects

G Marchetti

Publications and source records attributed to G Marchetti.

At least 91 records · Page 5Linked to original sources
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

Puerperal psychoses: a clinical case study with follow-up.

Thirty cases of post-partum psychotic disorders occurred between 1973 and 1987 and hospitalized at the Psychiatric Ward of Florence University were studied and followed up. A structured diagnostic interview was used, which explored DSM Ill-R diagnosis both for mood disorders and for psychotic features. The psychotic symptoms had started within 8 weeks of parturition in all cases. Only 36.7% of the patients showed no subsequent pathology after the puerperal symptoms. The diagnoses, both at the index episode and at the follow-up, revealed a great predominance of mood disorders and the absence of schizophrenia. The follow-up survey showed a greater proportion of bipolar disorders than it appeared at the puerperal onset of the disease. A high frequency of puerperal psychotic relapses has also occurred after subsequent deliveries during the follow-up period.

Adult↗
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↗
PubMed1992

Localization of cloned human DNA sequences and analysis of chromosomal alterations by in situ hybridization.

The in situ hybridization technique was used for the localization on human chromosomes of single-copy and repeated sequences and, in addition, for the characterization of altered human chromosomes. Two anonymous clones, single or low-copy, obtained from a human X chromosome library were localized on the distal part of the long arm and in the paracentromeric region of X chromosome, respectively. A genomic fragment of the single-copy thyroglobulin (TG) gene was used to confirm the localization on the distal part of the long arm of chromosome 8. The localization and distribution on human chromosomes of the glyceraldehyde-3-phosphate dehydrogenase (GAPD) multigene family obtained by in situ hybridization and by somatic cell hybrids were compared. A phosphoglycerate kinase (PGK) c-DNA clone, which detects genic and pseudogenic sequences on the X chromosome, was used for the characterization of three small ring markers present in unrelated female patients.

Chromosome Aberrations↗
PubMed1991

Time course of pressure and flow in ascending aorta during ejection.

To analyze aortic flow and pressure relationships, 10 closed-chest anaesthetised dogs were instrumented with electromagnetic aortic flow probes and micromanometers in the left ventricle and ascending aorta. Left ventricular ejection time was divided into: time to peak flow (T1) (both pressure and flow rising), peak flow to peak pressure time (T2) (pressure rising, flow decreasing), and peak pressure to dicrotic notch time (T3) (pressure and flow both decreasing). These time intervals were expressed as percent of total ejection time. Load-active interventions rose markedly T2 (from 4.2 +/- 5.5 to 19.4 +/- 3.5 after phenylephrine (p less than 0.02); from 4.2 +/- 6.5 to 21.2 +/- 5.3 after dextran (p less than 0.02)). Conversely, dobutamine reduced T2 from 4.4 +/- 5.9 to -2.5 +/- 6.5 (p less than 0.05). Thus, during load-active interventions aortic pressure increases for a longer T2 time although forward flow is decreasing, as a result of higher aortic elastic recoil during ejection. Conversely, beta 1-adrenergic stimulation significantly shortens T2. Dynamic pressure-flow relationship is thus continuously changing during ejection. T2 seems to be inversely related to the efficiency of left ventricular ejection dynamics.

Animals↗
PubMed1991

Characterization of the pseudogenic and genic homologous regions of von Willebrand factor.

The homologous pseudogenic and genic regions of von Willebrand factor (vWF) were studied in DNA from a patient with homozygous deletion of vWF genes and compared with a normal control. This analysis indicates informative restriction patterns for the investigation of restriction fragment length polymorphisms (RFLPs) and gene lesions, and for molecular cloning. A useful new genic XbaI RFLP was found and characterized. A large BgIII fragment of the pseudogenic region was cloned and mapped, and single sequences (9 kb) were used as probes. Corresponding genic and pseudogenic fragments, which contain exons 23-28, and specific restriction patterns were identified, including a new polymorphic TaqI site that was mapped in the gene. A cloned fragment contains the 5' boundary of the pseudogene and recognizes an additional and unknown homologous sequence in the genome. The chromosomal localization of the vWF pseudogene and of the breakpoint cluster region (BCR) gene were compared by 'in situ' hybridization: overlapping patterns were detected. The cloning, characterization and mapping of the pseudogenic region improves the analysis of this portion of chromosome 22 affected by several somatic and constitutional alterations, and also of the corresponding genic region on chromosome 12.

Base Sequence↗
PubMed1990

A de novo and heterozygous gene deletion causing a variant of von Willebrand disease.

An abnormal von Willebrand factor (vWF) gene restriction pattern has been found in a patient with von Willebrand disease. Because this gene alteration is not present in his parents or in 50 normal and 25 affected subjects, and the restriction fragment length polymorphism haplotypes are inherited normally in the patient's family, we suggest that a de novo mutation is present. Bands with reduced intensity and additional fragments, observed in several restriction digests, hybridize with noncontiguous copy DNA (cDNA) portions, thus indicating the presence of a heterozygous gene deletion. The deletion removes a genomic region containing at least codons 1147 through 1854 and corresponding to the D3-A3 homologous protein domains. The extent of the vWF pseudogene on chromosome 22 is roughly similar to that of the deleted area. However, the pseudogenic nature of the deletion is excluded by the mapping of bands with reduced intensity in the patient to the true vWF gene. The vWF antigen levels are one fourth of normal and ristocetin cofactor activity is severely impaired. The reduction of high molecular weight multimers in plasma and platelets and the altered triplet morphology are compatible with the presence of a dominant variant of type II von Willebrand disease.

Bleeding Time↗
PubMed1990

Characterization of polymorphic markers in the von Willebrand factor gene and pseudogene.

Three TaqI restriction fragment length polymorphisms (RFLP) detected by the central portion of von Willebrand factor cDNA, which recognizes the true gene and in addition pseudogenic sequences, were characterized and mapped. Small cDNA fragments which hybridized with DNA from families with von Willebrand disease were used. Two of the RFLP, recognized by 1.7 and 0.45 kb cDNA fragments, are not in linkage either with von Willebrand disease or with RFLP located in the von Willebrand factor (vWF) gene, which indicates their pseudogenic location. These markers located in 22q11, near to the bcr gene, provide new tools for the study of several somatic and constitutional alterations affecting this chromosomal region. The third RFLP is recognized by a cDNA fragment corresponding to the N-terminal portion of mature vWF and is localized in the true gene. Since significant linkage disequilibrium with other informative RFLP is not present, this marker contributes to the definition of family haplotypes associated with von Willebrand disease.

Blotting, Southern↗
PubMed1990

Bronchoalveolar lavage and morphology of the airways after cessation of exposure in asthmatic subjects sensitized to toluene diisocyanate.

To evaluate the morphologic basis of the different outcomes of toluene diisocyanate (TDI) asthma after quitting occupational exposure, we examined ten patients with TDI asthma who showed, at diagnosis, a positive TDI challenge test and nonspecific bronchial hyperresponsiveness (NSBH) to methacholine. After diagnosis, all patients ceased work and a 4- to 40-month follow-up was obtained with three to eight determinations of the cumulative dose producing a 15 percent fall in FEV1 (PD15FEV1) methacholine in each patient. Bronchoalveolar lavage (BAL) and biopsy of bronchial muscosa were performed 3 to 39 months after cessation of work, in the absence of acute exacerbations of the disease. Total cell count in BAL fluid was moderately increased in four of ten patients, eosinophils were increased in five of ten patients, and neutrophils were increased in eight of ten patients. Mucosal biopsy specimens of main or lobar bronchi were available in eight of ten patients; epithelial damage and thickening of basement membrane was observed in almost all patients, as well as a mild-to-moderate inflammatory reaction in the submucosa, mainly represented by lymphocytes, eosinophils, and neutrophils. No relationship was observed between the cellularity of BAL and the degree of NSBH at the time of BAL; mean values of total cells and differential count were not different between patients with presence or absence of the different histologic findings. Mucosal biopsy and BAL were performed also in four subjects exposed to dusts without respiratory symptoms or NSBH; similar findings were obtained except for the absence of eosinophils in BAL and a lesser degree of basement membrane thickening and inflammatory reaction in the submucosa. The study of the changes in NSBH after quitting exposure showed that five of ten patients had a significant improvement in NSBH to methacholine, as evaluated by a positive significant linear regression between months of work cessation and PD15FEV1 methacholine; only one of these five patients had an increased number of eosinophils in BAL fluid. By contrast, four of the five patients with persistent NSBH after quitting exposure had an increased number of eosinophils in BAL. We suggest that persistent NSBH in TDI asthma after cessation of work may be related to an inflammatory reaction in which eosinophil infiltration seems to be a major determinant.

Adult↗
PubMed1990

Cough test to assess cardiovascular autonomic reflexes in diabetes.

Coughing induces cardioacceleratory responses under cholinergic control. The Cough Test (CT), a standardized test that uses a series of coughs with electrocardiographic monitoring, was used to assess the functional integrity of cardiovascular autonomic nerves. In 224 control subjects and 235 diabetic patients, heart-rate (HR) responses were compared with four established tests: lying to standing (LS), standing to lying (SL), deep breathing (DB), and Valsalva maneuver (VM). In control subjects, HR responses declined significantly with age in a curvilinear pattern. Log-transformed indices were used to estimate percentiles. The CT-HR responses were reproducible and significantly associated with other HR-response tests. Sixty-nine (29%) diabetic patients had an abnormal value less than or equal to 1st percentile, whereas only 2 control subjects had such an abnormality. Among diabetic patients, age and duration of diabetes exerted a significant negative influence. With the use of the criteria of two abnormal or one abnormal and two borderline tests (among CT, LS, SL, DB, or VM) as a minimal criteria for cardiovascular autonomic neuropathy, CT and LS had the least overlap between the control and diabetic populations and were significantly better than SL or VM (P less than 0.005 for CT, P less than 0.01 for LS). They were not different from DB. We found the CT to be simple to perform, reproducible, and useful for the assessment of cardiovascular autonomic reflexes.

Adult↗
PubMed1990

Direct detection of a missense mutation causing severe hemophilia A by PCR amplification and fluorescence scanning.

The amplification of Factor VIII gene-specific sequences, obtained by polymerase chain reaction, was used for hemophilia A carrier detection. Exon 24 sequences were employed in the carrier status determination of a missense mutation causing severe hemophilia A in two unrelated patients. After agarose gel electrophoresis, the digested DNA was subjected to quantitative determination of fluorescence. This technique significantly improves the digest analysis.

Base Sequence↗
PubMed1989

Acute haemodynamic effects of ibopamine and dopamine on isovolumic relaxation.

The effects of intraduodenal ibopamine (a new orally active inotropic agent claimed to have haemodynamic effects similar to dopamine) on isovolumic relaxation were monitored for 90 min in eight closed-chest anaesthetized dogs. Dopamine and epinine (ibopamine active metabolite) were also infused at graded doses. After 15 min, ibopamine (12 mg/kg) shortened the time constant of isovolumic relaxation, and increased stroke volume and mean aortic pressure. Peak positive dP/dt increased significantly only 10 min later. Heart rate did not change. Dopamine (10 micrograms/kg per min) similarly reduced the time constant, and increased stroke volume, mean aortic pressure, peak positive dP/dt and heart rate. Epinine (10 micrograms/kg per min) caused similar changes in peak positive dP/dt, stroke volume, mean aortic pressure, and accelerated time constant without raising the heart rate. Ibopamine and epinine therefore significantly improved the isovolumic relaxation phase, like dopamine, without however affecting the heart rate.

Animals↗
PubMed1989

Clinical and hemodynamic effects of long-term administration of gallopamil in patients with coronary artery disease and normal or impaired left ventricular function.

The hemodynamic and clinical profiles of gallopamil, a new calcium antagonist, were evaluated in 20 patients with severe coronary artery disease in a placebo-controlled, single-blind study. The patients were divided into 2 groups depending on baseline ejection fraction (greater than 45 or less than or equal to 45%) and underwent nuclear ventriculography, both at rest and during bicycle exercise under electrocardiographic monitoring, after 3 weeks of therapy (50 mg 3 times daily) and the 1-week run in and washout placebo periods. The mean anginal weekly frequency per patient was significantly reduced, from 3.4 to 0.5 (p less than 0.001). The left ventricular ejection fraction, cardiac volumes, ejection and filling indexes at rest and for the same workload were not altered in the population as a whole or in each of the 2 groups. The rate pressure product during exercise was reduced for the same workload from 18.0 +/- 5.0 X 10(3) to 16.8 +/- 4.7 X 10(3), while the regional ejection fraction in ischemic regions was not significantly changed. Individual variations of ventriculographic parameters in both groups were not related to basal values. Gallopamil increased the total duration of exercise from 432 +/- 201 to 537 +/- 188 s (p less than 0.001). Six patients did not complain of angina and their exercise was interrupted because of muscular weakness. The hemodynamic and clinical responses did not differ when the results in the population as a whole and in each of the 2 groups were compared. Gallopamil was effective and well tolerated, even in patients with very depressed cardiac function.

Aged↗
PubMed1989

Sublocalization of von Willebrand factor pseudogene to 22q11.22-q11.23 by in situ hybridization in a 46,X,t(X;22)(pter;q11.21) translocation.

The von Willebrand factor pseudogene, previously mapped to chromosome 22, was sublocalized by in situ hybridization using as probe a von Willebrand factor cDNA fragment completely contained in the pseudogenic region. Chromosome spreads were from a patient carrying a unique balanced de novo translocation 46,X,t(X;22)(pter;q11.21). Silver grain analysis indicated that the human von Willebrand factor pseudogene is located on 22q,11,22-q11,23, a region relevant for several somatic and constitutional chromosomal alterations.

Child, Preschool↗
PubMed1989

A recurrent missense mutation (Arg----Gln) and a partial deletion in factor VIII gene causing severe haemophilia A.

The presence of gene lesions in coagulation factor VIII (FVIII) gene was investigated in 70 Italian patients severely affected by haemophilia A. cDNA probes specific for exons 14-26 of the FVIII gene were used. In two related patients a gene deletion removes exon 26, a gene lesion similar to that described previously in a British haemophiliac. In exon 24 a C to T transition in the reverse complement strand causes a missense mutation in the coding strand (CGA----CAA, 2209 Arg----Gln). The mutation is located in a very conserved FVIII homology region and severely reduces FVIII activity. By restriction analysis and hybridizations with oligonucleotide probes this gene alteration was found in two unrelated haemophiliacs and in their relatives.

Chromosome Deletion↗