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Biomedical subjects

M B Donati

Publications and source records attributed to M B Donati.

At least 37 records · Page 2Linked to original sources

Polymorphisms in the thrombopoietin gene are associated with risk of myocardial infarction at a young age.

Five polymorphisms in the thrombopoietin (TPO) gene were identified, one in the 5' untranslated region (UTR) (C1796T), two within intron 5 (C4830A and A4877C), and two in the 3' UTR (A5713G and A6160T). The allele frequencies were determined in a group of 450 healthy middle aged men from the UK and found to be 0.46 for 1796T, 0.38 for 4830A, 0.004 for 4877C, 0.47 for 5713G and 0.07 for 6160T. Genotypes for the three common polymorphisms were determined in a group of 176 young male Swedish survivors of a myocardial infarction (MI) and 186 age-matched controls and a group of 156 young Italian survivors of an MI and 147 age and sex matched controls. In both the Swedish and the Italian studies polymorphisms were found to be associated with increased risk of MI. In the Swedish sample the frequency of 4830A was significantly higher in controls (0.40) compared with patients (0.29) (P=0.003), with an odds ratio for AA homozygotes of 0.48 (0.25-0.92; P=0.03) compared with CC homozygotes. In the Italian sample the frequency of 5713G was significantly lower in controls (0.31) compared with cases (0.40) (P=0.03), with an odds ratio for GG homozygotes of 2.29 (1.08-4.89; P=0.03) compared with AA homozygotes. These risk associations are consistent since 4830A and 5713A show strong allelic association. After adjusting for other measured risk factors the effect on risk was still significant in the Italian sample 2.39 (1.02-5.58), but not in the Swedish sample 0.46 (0.16-1.32). The observation of frequency differences between cases and controls in two independent samples strongly suggests that the TPO gene is involved as a risk factor for developing MI at a young age, but the identified polymorphisms are probably acting as markers for an unidentified functional mutation elsewhere in the gene locus.

Adult↗

Pathogenesis of thrombosis in patients with malignancy.

Cancer cells can contribute to activation of the clotting system by their capacity to produce and release procoagulant/fibrinolytic substances and inflammatory cytokines, and by their interaction with host cells (endothelial, monocytes, platelets, and neutrophils). Moreover, anticancer drugs (chemotherapy/hormone therapy) may greatly affect the risk of thromboembolic complications in cancer patients by similar mechanisms, eg, through the release of procoagulants by tumor cells, through endothelial damage, or stimulation of tissue factor production by host cells. The interactions between cancer/metastatic processes and thrombosis have been reviewed here from the pathogenetic viewpoint. We hope that better knowledge of these pathogenetic pathways will lead to the development of more targeted strategies to prevent thromboembolism in cancer patients.

Blood Coagulation Factors↗

Pathogenetic mechanisms of thrombosis in malignancy.

The interactions between components of the hemostatic system and cancer cells are multifaceted. Strong clinical evidence is accumulating on the prothrombotic tendency of cancer patients, which is enhanced by anticancer therapy, such as surgery and chemotherapy. The mechanisms of thrombus promotion in malignancy include some general responses of the host to the tumor (acute phase, inflammation, angiogenesis) and specific interactions of tumor cells with the clotting/fibrinolysis systems and with blood (leukocytes, platelets) or vascular cells. It is at present difficult to rank the relative weight of these multiple interactions on the basis of the well-recognized clinical evidence of enhanced thrombotic episodes in tumor patients. In any case, the mechanisms explored so far offer a sound experimental basis for prevention/treatment of thrombosis in tumor patients and leave open the possibility that some antithrombotic strategies may also affect the processes of tumor growth and dissemination.

Biomarkers↗

In vivo anti-inflammatory effect of statins is mediated by nonsterol mevalonate products.

This study set out to clarify whether the inhibition of sterol or nonsterol derivatives arising from mevalonate biotransformation plays a major role in the in vivo anti-inflammatory action of statins. Hepatic synthesis of all these derivatives was inhibited in mice by administered statins, whereas squalestatin inhibited only sterol derivatives. Using a short-term treatment schedule, we found that statins reduced the hepatic activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase without affecting blood cholesterol. This treatment inhibited lipopolysaccharide- and carrageenan-induced pouch leukocyte recruitment and the exudate production of interleukin-6, monocyte chemotactic protein-1, and RANTES. Coadministration of mevalonate reversed the effect of statin on leukocyte recruitment. The inhibition of sterol synthesis by squalestatin did not have any anti-inflammatory effect, indicating that the biosynthesis of nonsterol compounds arising from mevalonate is crucial for the in vivo regulation of cytokine and chemokine production by statins. Their inhibition by statins may account for the reported anti-inflammatory effects of these drugs and may provide a biochemical basis for the recently reported effects of statins in the prevention of cardiovascular disease and mortality.

Animals↗

Platelet glycoprotein receptor IIIa polymorphism PLA1/PLA2 and coronary risk: a meta-analysis.

Membrane glycoprotein IIb/IIIa plays a major role in platelet function. The gene encoding the glycoprotein IIIa shows a common polymorphism PLA1/PLA2 that was variably associated with vascular disease. To clarify the role of PLA1/PLA2 polymorphism in coronary risk, a meta-analysis of published data was conducted. Studies were identified both by MEDLINE searches, and hand searching of journals and abstract books. A total of 34 studies for coronary artery disease (CAD), and 6 for restenosis after revascularization were identified, for a total of 9,095 cases and 12,508 controls. In CAD, the overall odds ratio for carriers of the PLA2 allele was 1.10 (95% CI: 1.03 to 1.18), and it was 1.21 (95% CI: 1.05 to 1.38) in subjects younger than 60. Overall odds ratio was 1.31 (95% CI: 1.10 to 1.56) after revascularization procedures. The association of PLA2 status with overall cardiovascular disease in the general population is significant but weak; higher risk has been identified in less heterogeneous subgroups as in the younger cohorts and in the restenosis subset with stents.

Adult↗

Experimental arterial thrombosis in genetically or diet induced hyperlipidemia in rats--role of vitamin K-dependent clotting factors and prevention by low-intensity oral anticoagulation.

To investigate the relationship among lipids, coagulation and thrombosis in the absence of atherosclerosis, spontaneous or dietary-induced hyperlipidemic (FHL) rats were studied. FHL showed higher levels of coagulation factors VII, IX, X, VIII and XII and a shortening of the occlusion time (OT) of an artificial arterial prosthesis as compared with normolipidemic (FNL) animals. Damage of abdominal aorta of FHL was followed by increased fibrin deposition in the vascular intima as compared to FNL. After 5 months of cholesterol-rich diet FNL showed increased cholesterol, triglycerides and factor II, VII, IX, X, XII levels. A significant shortening of the OT and increased fibrin deposition was also observed. Two-month diet withdrawal restored the initial condition. Warfarin treatment, at a dose decreasing vitamin K-dependent factor to levels found in FNL, prolonged the OT and reduced fibrin deposition, without modifying F XII or changing lipid profile. An increase in the activated form of F VII was observed. In contrast, no difference was found in F VII clearance. High lipid levels favour the process of thrombus formation by increasing the activation of vitamin K-dependent coagulation factors. Low-dose warfarin treatment reverts the prothrombotic effect of hyperlipidemia.

Administration, Oral↗

Dietary habit profile in European communities with different risk of myocardial infarction: the impact of migration as a model of gene-environment interaction. The IMMIDIET Study.

The risk of myocardial infarction (MI) is lower in southern than in northern European countries. The lower rate of MI in the Mediterranean regions of Europe suggested a potential role of the traditional Mediterranean diet in the prevention of MI. Unfortunately, in the last 20 years, a tendency to adopt Westernised food habits even in southern regions of Europe is reflected by an increase in the prevalence of obesity. Therefore the impact of diet on MI risk profile among European populations needs to be reconsidered. Genetic risk factors have also been implicated in the development of MI. Genes, indeed, continuously interact with environmental factors in determining the pathogenesis of MI. The aims of the IMMIDIET study are to evaluate: 1. The present dietary habits and the risk profile of three European communities at different risk of MI; 2. The impact of migration on risk factors for MI. Dietary habits and genetic polymorphisms will be evaluated in an Italian, Belgian and British population sample. The historical Italian migration to Belgium and the integration through mixed marriage will be considered as a model of gene-environment interaction. As an index of MI risk profile, factors that are most likely under the combined influence of both dietary and genetic determinants will be investigated.

Belgium↗

The decanucleotide insertion/deletion polymorphism in the promoter region of the coagulation factor VII gene and the risk of familial myocardial infarction.

Recently, an association has been found between factor VII polymorphisms and the risk of familial myocardial infarction. To obtain a thorough evaluation of the influence of factor VII gene on the risk of myocardial infarction, we extended our analysis to the role of a decanucleotide insertion/deletion functional polymorphism (-323 0/10-bp) in the promoter region of factor VII and to possible interactions with the HVR4 intron polymorphism. We performed a case-control study of 176 patients with myocardial infarction, over 45 years, who had a familial history of arterial thrombosis and 227 control subjects without a personal or family history of cardiovascular disease. The frequency of the rare allele of 10 bp was lower in cases (0.14 95% CI, 0.10-0.17) than in controls (0.19 95% CI, 0.16-0.23; chi(2)=4.7, p=0.03). Allowing for Hardy-Weinberg equilibrium in controls and testing for association under restricted maximisation, there was a significant difference in genotype frequency between cases and controls (p=0.02). Carriers of the 10-bp allele had an odds ratio for myocardial infarction of 0.65 (95% CI, 0.37-1.12), in multivariate logistic regression analysis. Combination analysis of -323 0/10-bp and HVR4 polymorphisms shows half reduction in the risk of myocardial infarction in comparison with the reference group for all the other groups, suggesting that there was no additivity between the effect of the 10-bp and the H7 alleles. Our findings suggest that the promoter polymorphism of factor VII gene may influence the risk of familial myocardial infarction.

Aged↗

IDN5109, a taxane with oral bioavailability and potent antitumor activity.

IDN5109 is a new taxane, derived from 14beta-hydroxy-10-deacetylbaccatin III, selected for its lack of cross-resistance in tumor cell lines expressing the multidrug resistant phenotype. Because, unlike paclitaxel, IDN5109 is a poor substrate for P-glycoprotein, we hypothesized that IDN5109 given p.o. could improve bioavailability compared with paclitaxel. Here, we studied the p.o. and i.v. pharmacokinetics of IDN5109 together with its antitumor activity. Using a high-performance liquid chromatography method, the bioavailability of IDN5109 was determined to be 48% after oral delivery. IDN5109 given p.o. was highly active against the two human ovarian carcinoma xenografts 1A9 and HOC18 (90-100% tumor regressions) and showed significant activity on the paclitaxel-resistant MNB-PTX1 xenograft (10% tumor regressions). The p.o. administration was as active as the i.v. route at doses reflecting the pharmacokinetic data. IDN5109 is the first taxane with good oral bioavailability and potent antitumor activity and represents a potential candidate for clinical investigation.

Administration, Oral↗

Genes, coagulation and cardiovascular risk.

Coronary artery disease (CAD) is a multifactorial disease influenced by both genetic and environmental determinants. Coagulation activation plays a key role in thrombus formation and variation in its factors has been associated with the risk of CAD. The levels of these factors are genetically determined and polymorphisms in their genes can also be responsible for disease development. Three polymorphic alleles of coagulation factor VII (FVII) gene have been associated with a protective effect on the risk of familial myocardial infarction. Their distribution in Europe covaries across populations with the rate of myocardial infarction mortality, being higher in countries (like Italy, Spain, Greece) at low risk. These polymorphisms are major determinants of FVII variability in humans. They can also determine the response of FVII to environmental stimuli. Indeed, they modulate the association between triglycerides or smoking and FVII, while a gender-dependent regulation of FVII, probably related to sexual hormones, has also been described. Interestingly, lowering the plasma levels of FVII with low dose warfarin to the same low normal range as that associated with the 'protective' genotypes, results in protection against ischaemic heart disease, reducing mortality in high risk men. Journal of Human Hypertension (2000) 14, 369-372

Cardiovascular Diseases↗

Pharmacogenetics: a molecular sophistication or a new clinical tool for cardiologists?

The study of genetic risk factors for multifactorial diseases is attracting increasing interest. In particular interest has been focused on the interaction between genetic polymorphisms and environmental factors in determining the risk of disease. Among environmental factors therapeutic approaches should be considered. Therapeutic responses to a given drug, failure of drug efficacy, interindividual variability in side effects and toxicity of drugs could be at least partially accounted for by genetic polymorphisms. This paper summarizes the presently available applications of genetic concepts to some drugs commonly used in patients with cardiovascular disease. Statins and probucol fail to lower cholesterol levels in carriers of specific polymorphisms. The progression of cardiovascular disease is decreased by pravastatin only when certain polymorphisms are present. Induction problems and bleeding complications of warfarin occur in subgroups of populations carrying specific genetic variants of key enzymes in the drug metabolism. A new interpretation of the results of a thrombosis prevention trial will be given in the light of a genetic approach to pharmacology; indeed, prevention and treatment of thrombotic disease could be better focused on the basis of this knowledge. Future clinical trials and cost-effectiveness evaluation of drugs should be conducted taking these gene-drug interactions into account.

Administration, Oral↗