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Biomedical subjects

M Pinotti

Publications and source records attributed to M Pinotti.

At least 19 recordsLinked to original sources
PubMed2006

Molecular bases of type II protein S deficiency: the I203-D204 deletion in the EGF4 domain alters GLA domain function.

OBJECTIVE: To characterize the first type II protein S (PS) deficiency affecting the epidermal growth factor (EGF)4 domain, a calcium-binding module with a poorly defined functional role. PATIENTS: The proband suffered from recurrent deep vein thrombosis and showed reduced PS anticoagulant activity (31%), and total, free PS antigen and C4bBP levels in the normal range. RESULTS: Reverse transcription-polymerase chain reaction analysis showed the presence of the IVSg-2A/T splicing mutation that, by activating a cryptic splice site, causes the deletion of codons Ile203 and Asp204. Free PS, immunopurified from proband's plasma, showed an altered electrophoretic pattern in native condition or in the presence of Ca2+. The recombinant PS (rPS) mutant showed reduced anticoagulant (<10%) and activated protein C-independent activities (24-38%) when compared with wild-type rPS (rPSwt). Binding of the rPS variant to phospholipid vesicles (Kd 235.7 +/- 30.8 nM, rPSwt; Kd 15.2 +/- 0.9 nM) as well as to Ca2+-dependent conformation-specific monoclonal antibodies for GLA domain was significantly reduced. CONCLUSIONS: These data aid in the characterization of the functional role of the EGF4 domain in the anticoagulant activities of PS and in defining the thrombophilic nature of type II PS deficiency.

Adult↗
PubMed2006

Intracellular readthrough of nonsense mutations by aminoglycosides in coagulation factor VII.

BACKGROUND: Nonsense mutations in coagulation factor (F) VII potentially cause a lethal hemorrhagic diathesis. Readthrough of nonsense mutations by aminoglycosides has been studied in a few human disease models with variable results. OBJECTIVES: We investigated the K316X and W364X FVII mutations, associated with intracranial hemorrhage, and their correction by aminoglycosides. The rare nonsense mutations in FVII represent favorite models to test this strategy, because even tiny increases in the amount of functional full-length protein in patients could ameliorate hemorrhagic phenotypes. RESULTS: A FVII-green fluorescent protein (GFP) chimaera provided us with a fluorescent model of FVII expression in living cells. Appreciable fluorescence in cells transfected with nonsense FVII-GFP mutants was detected upon geneticin treatment, thus demonstrating suppression of premature translation termination. To investigate the rescue of FVII function, nonsense variants of the native FVII without GFP (p316X-FVII and p364X-FVII) were transfected and found to secrete low amounts of FVII (approximately 1% of Wt-FVII activity), thus suggesting a spontaneous stop codon readthrough. Geneticin treatment of cells resulted in a significant and dose-dependent increase of secreted FVII molecules (p316X-FVII, 24 +/- 12 ng mL(-1), 3.6 +/- 0.8% of Wt-FVII activity; p364X-FVII, 26 +/- 10 ng mL(-1), 3.7+/-0.6%) characterized by reduced specific activity, thus indicating the synthesis of dysfunctional proteins. Similar results were observed with gentamicin, a commonly used aminoglycoside of potential interest for patient treatment. CONCLUSIONS: Our approach, extendable to other coagulation factors, represents an effective tool for a systematic study of the effects of aminoglycosides and neighboring sequences on nonsense codon readthrough. These results provide the rationale for a mutation-specific therapeutic approach in FVII deficiency.

Adolescent↗
PubMed2005

The factor V Glu1608Lys mutation is recurrent in familial thrombophilia.

BACKGROUND: Co-inheritance of heterozygous factor V deficiency with FV Leiden enhances the activated protein C resistance (APCR) associated with this mutation, resulting in pseudo-homozygous APCR. The role of FV deficiency in modulating thrombotic risk in this rare condition is poorly understood. METHODS AND RESULTS: We have identified in thrombophilic patients with FV deficiency a novel FV gene mutation (c. 4996G>A), predicting the Glu1608Lys substitution in the A3 domain. The heterozygous mutation was detected in three unrelated patients, two carriers of the FV Leiden mutation, and one of the FVHR2 haplotype. The Glu1608Lys change was also present in two subjects with mild FV deficiency, and absent in 200 controls. The FV1608Lys carriers showed reduced mean FV activity (42% +/- 12%) and antigen (53% +/- 18%) levels and, in Western blot analysis, reduced amounts of intact platelet FV. The restriction fragment length polymorphism (RFLP) study identified two haplotypes underlying the mutation, which suggests that it is recurrent. In heterozygous subjects the amount of FV1608Lys mRNA in white blood cells was similar to that produced by the counterpart alleles (FVWt or FVHR2). Recombinant FV1608Lys (rFV1608Lys), detected by Western blot in the conditioned medium, was indistinguishable from rFVWt and FV antigen and activity were found to be respectively 44% +/- 20% and 13% +/- 4% of rFVWt. CONCLUSIONS: Our data indicate that FVGlu1608Lys predicts a CRM (plasma)/CRMred (cell culture) FV deficiency, and may contribute to thrombophilia in carriers of FV Leiden and FVHR2 haplotype via a pseudo-homozygosity mechanism. Our findings help to define the molecular bases of FV deficiency and thrombophilia.

Case-Control Studies↗
PubMed2003

Breast cancer metastatic to uterine leiomyosarcoma. A case report and review of the literature.

An unusual case of breast cancer metastatic to leiomyosarcoma of the uterus is reported. The patient had multiple metastases from the breast carcinoma and presented a pelvic mass in its evolution. A laparotomy with total hysterectomy and bilateral oophorectomy was performed to give pain relief. A review of the world literature about these uncommon sites of breast metastases is presented.

Biopsy, Needle↗
PubMed2002

Reduced activation of the Gla19Ala FX variant via the extrinsic coagulation pathway results in symptomatic CRMred FX deficiency.

We characterized a symptomatic CRMred factor X (FX) deficiency produced by the Glu19Ala mutation in the gamma-carboxyglutamic-rich domain. FX activity levels in plasma were markedly reduced in prothrombin time assays (< 1-5%), whereas in activated partial thromboplastin assays (16%) and in RVV assays (17%) the reduction in activity mirrored that in antigen levels (17%). Activation of recombinant 19Ala-FX by factor IXa/factor VIIIa or RVV, and the activity in thrombin generation assays, were comparable to those of wild-type FX. Differently, complete activation of recombinant 19Ala-FX required a factor VIIa/TF concentration 30-fold higher than that of wild-type FX. The recombinant FVIIa significantly reduced PT values in 19Ala-FX reconstituted plasma, thus suggesting an alternative approach for treatment of FX deficiencies characterized by defective FX activation. The study of this FX deficiency provides an "in vivo" and "in vitro" model for the investigation of Gla domain interactions.

Blood Coagulation↗
PubMed2001

Comprehensive health care for women in a public hospital in São Paulo, Brazil.

This paper describes a model of integrated reproductive health care services for women at the primary health care level, put into practice at the Pérola Byington Hospital, São Paulo, Brazil, from 1991 to 1998. Some 2,000 women from poor social strata, whose health condition was poor, were being seen every day in the last two years of the programme, including new consultations and women with a previous attendance returning. Women were attended first by nurse-assistants, who had been trained to screen for the most frequent gynaecological problems, and then a physician. Because doctors spent less time with each patient, four times as many women could be seen. Programmes were set up for the diagnosis and treatment of gynaecological cancers, STDs, HIV/AIDS, hypertension and other degenerative disorders such as diabetes. Screening and treatment programmes for cervical and breast cancer achieved significant improvements in the stage at which a diagnosis was made, allowing more lives to be saved. This model also succeeded in decreasing the costs for these health services per woman seen.

Adult↗
PubMed2000

Polymorphisms in the factor VII gene and the risk of myocardial infarction in patients with coronary artery disease.

BACKGROUND: High plasma levels of coagulation factor VII have been suggested to be predictors of death due to coronary artery disease. Since polymorphisms in the factor VII gene contribute to variations in factor VII levels, such polymorphisms may be associated with the risk of myocardial infarction, which is precipitated by thrombosis. METHODS: We studied a total of 444 patients, 311 of whom had severe, angiographically documented coronary atherosclerosis. Of these 311 patients, 175 had documentation of a previous myocardial infarction. As a control group, 133 patients with normal coronary arteriograms were also included. We measured the levels of activated factor VII and assessed three polymorphisms in the factor VII gene, one involving the promoter (A1 and A2 alleles), one involving the catalytic region (R353Q), and one involving intron 7. RESULTS: Each of the polymorphisms influenced factor VII levels. Patients with the A2A2 and QQ genotypes had the lowest levels of activated factor VII (66 percent and 72 percent lower, respectively, than the levels in patients with the wild-type genotypes). The frequencies of the various genotypes in the patients free of coronary artery disease were similar to those in the entire population of patients with coronary artery disease. In the latter group, there were significantly more heterozygotes and homozygotes for the A2 and Q alleles among those who had not had a myocardial infarction than among those who had had an infarction (P=0.008 for the presence of the promoter polymorphism and P=0.01 for the presence of the R353Q polymorphism by chi-square analysis). The adjusted odds ratio for myocardial infarction among the patients with the A1A2 or RQ genotype was 0.47 (95 percent confidence interval, 0.27 to 0.81). CONCLUSIONS: Our findings suggest that certain factor VII genotypes have a role in protection against myocardial infarction. This may explain why some patients do not have myocardial infarction despite the presence of severe coronary atherosclerosis.

Case-Control Studies↗
PubMed2000

Modulation of factor VII levels by intron 7 polymorphisms: population and in vitro studies.

Previous studies have established that factor VII gene (F7) polymorphisms (5'F7 and R353Q) contribute about one-third of factor VII (FVII) level variation in plasma. However, F7 genotyping in patients with cardiovascular disease has produced conflicting results. Population and expression studies were used to investigate the role of intron 7 (IVS7 ) polymorphisms, including repeat and sequence variations, in controlling activated FVII (FVIIa) and antigen (FVIIag) levels. Genotype-phenotype studies performed in 438 Italian subjects suggested a positive relation between the IVS7 repeat number and FVII levels. The lowest values were associated with the IVS7 + 7G allele. The screening of 52 patients with mild FVII deficiency showed an 8-fold increase in frequency (8%) of this allele, and among heterozygotes for identical mutations, lower FVII levels were observed in the IVS7 + 7G carriers. This frequent genetic component participates in the phenotypic heterogeneity of FVII deficiency. The evaluation of the individual contribution of polymorphisms was assisted by the expression of each IVS7 variant, as a minigene, in eukaryotic cells. The novel quantitative analysis revealed that higher numbers of repeats were associated with higher mRNA expression levels and that the IVS7 + 7G allele, previously defined as a functionally silent polymorphism, was responsible for the lowest relative mRNA expression. Taken together, these findings indicate that the IVS7 polymorphisms contribute to the plasmatic variance of FVII levels via differential efficiency of mRNA splicing. These studies provide further elements to understand the control of FVII levels, which could be of importance to ensure the hemostatic balance under pathologic conditions.

Amino Acid Substitution↗
PubMed2000

Integrated approach to women's health.

The objective of this study was to demonstrate the importance of the practical application of the concept of reproductive health in São Paulo, Brazil, from 1991 to 1998 at the Pérola Byington Hospital with a new model of Primary Health Care (PHC) in which 2000 women/day, separated into two groups and over 45 years, was attended by nurses trained to detect the most frequently occurring gynecological problems supervised by doctors, who finalized the visit of each patient. The results demonstrated the advantages and viability of this strategy and also the bad health conditions of the women. Based on the high incidence of different kind of diseases detected, programs were set up for the diagnosis and treatment of gynecological cancer, STD, AIDS, hypertension, diabetes, etc. The results of two of these control programs, cervical cancer and breast cancer, demonstrated a significant increase in the diagnosis of early lesions. An economic study demonstrated an obvious and significant impact of this model not only in saving lives, but also in decreasing financial expenses in health.

Adolescent↗
PubMed1998

Molecular mechanisms of FVII deficiency: expression of mutations clustered in the IVS7 donor splice site of factor VII gene.

In three Italian patients, two point mutations and a short deletion were found in the intron 7 of factor VII gene, clustered in the donor splice site and located in the first of several repeats. The mutation 9726+5G-->A, the most frequent cause of symptomatic factor VII deficiency in Italy, as well as the deletion (9729del4) gave rise in expression studies to abnormally spliced transcripts, which were exclusively produced from the cryptic site in the second repeat. The insertion in the mature mRNA of the first intronic repeat caused (9726+5G-->A) a reading frameshift, abolishing most of the factor VII catalytic domain, or produced (9729del4), an altered factor with 11 additional residues, the activity of which was not detectable in the cell medium after mutagenesis and expression studies. Studies of factor VII ectopic mRNA from leukocytes and expression studies indicated that the deleted gene produced 30% of normally spliced transcript. Differently, the 9726+5G-->A mutation permitted a very low level (0.2% to 1%) of correct splicing to occur, which could be of great importance to prevent the onset, in the homozygous patients, of most of the life-threatening bleeding symptoms. The 9726+7A-->G mutation was found to be a rare and functionally silent polymorphism. These findings, which provide further evidence of the interplay of sequence and position in the 5' splice site selection, throw light on the heterogeneous molecular bases and clinical phenotypes of FVII deficiency.

Animals↗
PubMed1998

Molecular and clinical aspects of factor VII deficiency.

Factor VII (FVII) plays an important role in the initiation of blood coagulation, forming a complex with tissue factor (TF) which activates FIX and FX and FVII zymogen. FVII deficiency displays considerable phenotypic and molecular heterogeneity and there are inconsistencies between the clinical picture observed and the underlying clotting and molecular defects. We have reviewed the data available in the literature on FVII-deficient patients. Clinically, cases range from asymptomatic to patients with severe haemorrhagic tendencies. Asymptomatic patients typically have FVII activity levels of >20% and are heterozygotes, double heterozygotes or homozygotes. Mild FVII-deficient patients, with FVII activity levels >2%, may be double heterozygotes or homozygotes for FVII gene missense mutations. Undetectable FVII levels in severely affected patients are often due to severe gene defects such as frameshifts or mutations affecting the splice sites. The analysis of structure-function relationships in FVII deficiency is difficult due to the complexity of the interactions involving FVII. Also, assays using different reagents may give different results with a given plasma sample, and are not very accurate at low levels of FVII which, although relatively low, may be clinically significant, adding complexity to the analysis of FVII deficiency. The sensitivity of our methods for phenotypic evaluation of FVII deficiency remains inadequate.

Factor VII Deficiency↗
PubMed1997

Contribution of factor VII genotype to activated FVII levels. Differences in genotype frequencies between northern and southern European populations.

The relationship between coagulation factor VII (FVII) levels in plasma and FVII genotypes, determined by three polymorphisms (5'F7, IVS7, and 353R/Q), were studied in 500 control subjects enrolled in European multicenter study. The selection of particular FVII genotypes and the analysis of variance clearly indicated the independent contribution of a single 5'F7 insertion (A2) or 353Q (M2) allele to lowering plasma levels of activated FVII (FVIIa) (by a mean 25%). The M2 allele alone was found to make a major contribution to the genetically determined component of the FVIIa levels. Genotypes associated with low FVII levels were significantly rarer in the northern part of Europe (Oslo) than in the southern part (Rome, Murcia). The contribution made by the FVII genotype to the total variance of FVIIa levels was higher (30%) than that made to either FVII activity (25%) or FVII antigen (12%). Subjects with different FVII genotypes showed up to fivefold differences in mean FVIIa values, thus allowing attribution of a substantial part of the considerable interindividual variation to genetic variation, which may be of assistance in the interpretation of FVIIa levels on an individual basis. When FVII levels were adjusted by age and by triglyceride levels, the contribution of FVII genotypes to the FVII phenotypic variance was virtually unchanged. Taken together, these data indicate that in healthy control subjects the FVII genotype is a major predictor of plasma FVIIa levels and would support further study on the role of FVII genetic components in the development of cardiovascular disease.

Adult↗
PubMed1996

Mutation pattern in clinically asymptomatic coagulation factor VII deficiency.

A total of 122 subjects, referred after presurgery screening or checkup for prolonged prothrombin time, were characterized for the presence of coagulation factor VII deficiency. Fourteen subjects carried a partial and asymptomatic deficiency, and in half of them dysfunctional molecules were detected in plasma. In nine subjects we found five missense mutations differing from those previously found in factor VII deficient patients. The others were homozygous for a common polymorphism (R353Q) that affects factor VII levels. A new codon dimorphism (A330) was also found in exon 8. Four mutations (R223W, M298I, R304Q, and R353Q) located at FVII-specific residues point out protein regions that are important for coagulation factor evolution, and two mutations (G342E and E265K) affect generic or partially generic residues. The newly reported mutations were combined with those we previously found, totalling 17 independent mutations responsible for FVII deficiency in 27 Italian pedigrees. We observed several similarities with the mutation pattern determined in factor IX, which include a high percentage of transitions at CpG doublets, the presence of hot spot sites affected by multiple substitutions, and of several topologically equivalent mutations.

Factor VII Deficiency↗
PubMed1996

Factor VII gene polymorphisms contribute about one third of the factor VII level variation in plasma.

To assess the role of genetic variation in determining factor VII (FVII) activity and antigen levels we studied a polymorphism located in the 5' region of the gene (5'F7), an intronic mutation (IVS7), and the 353Arg-Gln polymorphism. All the polymorphisms, which showed strong allelic association, analyzed separately or in combination by the one-way analysis of variance, were associated with significantly different FVII levels. The 5'F7 and 353Arg-Gln polymorphic systems, which have very similar allele frequencies, contributed to a similar extent to the total phenotypic variance, whereas the contribution of the IVS7 polymorphism was lower. Genetic variation at the FVII locus, evaluated on combined genotypes, accounted for up to 40% of the phenotype FVII variance. As also shown by the two-way analysis of variance, the use of two out of three markers is advisable, and since the 5'F7 polymorphism can be screened by a simple immunoassay, it should be preferred for population-based studies. No substantial differences between FVII activity and FVII antigen levels were found, thus suggesting that the variation was due to biosynthesis- or stability-mediated mechanisms. The genetic control of FVII levels described in this study plays an important role in determining plasma FVII level variability, which may influence the hemostatic balance.

Adolescent↗
PubMed1996

Detection of new polymorphic markers in the factor V gene: association with factor V levels in plasma.

Three novel polymorphisms were found in the repeated region of the large exon 13 of factor V gene, one giving rise to a codon dimorphism (Ser1240) and two causing aminoacid substitutions (His1299Arg, Leu1257Ile). An increasing frequency of the Arg1299 (R2 allele) correlated with a decreasing mean plasma factor V activity in the groups of subjects under study, which included 26 unrelated subjects with partial factor V deficiency. Family studies supported the co-inheritance both of low factor V activity and of R2 allele. The reduction of factor V activity associated with the R2 allele was not clinically symptomatic even in the homozygous condition and was characterized by a parallel reduction of antigen in plasma, in which abnormal molecules were not detected. Data suggest that the R2 allele represents a marker in linkage with an unknown defect rather than a functional polymorphism. These studies provide the first evidence of a genetic component in determining factor V levels in plasma and of a genetic linkage between the factor V gene and factor V deficiency. They also define specific haplotypes which are associated with factor V deficiency or with APC resistance (Arg506Gln) and are valuable tools for the study of factor V defects.

Base Sequence↗