Eccentric, but not concentric muscle contraction induce inflammation and impairs fibrinolysis in healthy young men.

Different types of muscle contraction can cause different damage to the musculature and differences in inflammatory responses. Acute increases in circulatory inflammation markers can influence the crosstalk between coagulation and fibrinolysis processes, increasing the risk of thrombus formation and detrimental cardiovascular events. The aim of this study was to analyze the effects of concentric and eccentric exercise on hemostasis markers, C-reactive protein (CRP), and the relationship between these variables. Eleven healthy subjects with a mean age of 25.4 ± 2.8, non-smokers, with no history of cardiovascular disease and blood type O, randomly performed an isokinetic exercise protocol consisting of 75 concentric (CP) or eccentric (EP) contractions of knee extension, divided into five sets of 15 repetitions combined with 30-s rest. Blood samples for analysis of FVIII, von Willebrand factor, tissue plasminogen activator (t-PA), plasminogen activator inhibitor type-1 (PAI-1), and CRP were collected pre, post, 24 h, and 48 h after each protocol. Increased levels of CRP at 48 h in EP versus CP (p = 0.002), increased PAI-1 activity 48 h in EP versus CP (p = 0.044), and a reduction in t-PA at 48 h when compared with post-protocol in both protocols (p = 0.001). A correlation was found between CRP and PAI-1 at 48 h of PE (r2 = 0.69; p = 0.02). This study showed that both EP and CP increase the clotting process, albeit only the exercise performed eccentrically induces inhibition of fibrinolysis. This is possibly due to the increase in PAI-1 48 h after the protocol, which correlates with the increase in inflammation as demonstrated by the CRP levels.

Unveiling the influence of factor VIII physicochemical properties on hemophilia A phenotype through an in silico methodology.

BACKGROUND AND OBJECTIVES: Hemophilia A (HA) is an X-linked blood disorder. It is caused by pathogenic F8 gene variants, among which missense mutations are the most prevalent. The resulting amino acid substitutions may have different impacts on physicochemical properties and, consequently, on protein functionality. Regular prediction tools do not include structural elements and their physiological significance, which hampers our ability to functionally link variants to disease phenotype, opening an ample field for investigation. The present study aims to elucidate how physicochemical changes generated by substitutions in different protein domains relate to HA, and which of these features are more consequential to protein function and its impact on HA phenotype. METHODS: An in silico evaluation of 71 F8 variants found in patients with different HA phenotypes (mild, moderate, severe) was performed to understand protein modifications and functional impact. Homology modeling was used for the structural analysis of physicochemical changes including electrostatic potential, hydrophobicity, solvent-accessible/excluded surface areas, disulfide disruptions, and substitutions indexes. These variants and properties were analyzed by hierarchical clustering analysis (HCA) and principal component analysis (PCA), independently and in combination, to investigate their relative contribution. RESULTS: About 69% of variants show electrostatic changes, and almost all show hydrophobicity and surface area modifications. HCA combining all physicochemical properties analyzed was better in reflecting the impact of different variants in disease severity, more so than the single feature analysis. On the other hand, PCA led to the identification of prominent properties involved in the clustering results for variants of different domains. CONCLUSIONS: The methodology developed here enables the assessment of structural features not available in other prediction tools (e.g., surface distribution of electrostatic potential), evaluating what kind of physicochemical changes are involved in FVIII functional disruption. HCA results allow distinguishing substitutions according to their properties, and yielded clusters which were more homogeneous in phenotype. All evaluated properties are involved in determining disease severity. The nature, as well as the position of the variants in the protein, were shown to be relevant for physicochemical changes, demonstrating that all these aspects must be collectively considered to fine-tune an approach to predict HA severity.

Variants p.Pro2063Ser and p.Arg324* co-segregate in type 3 von Willebrand disease patients from Southern Brazil.

INTRODUCTION: von Willebrand factor (VWF) is a multimeric plasma glycoprotein that plays an important role in haemostasis. von Willebrand disease (VWD) is an inherited heterogeneous bleeding disorder caused by either a quantitative or qualitative defect of VWF. Type 3 VWD, the most severe form of the disease, leads to complete quantitative VWF deficiency. AIM: The present study aims to investigate the molecular pathogenesis of type 3 VWD patients from Southern Brazil. METHODS: The VWF gene was sequenced in 26 cases clinically diagnosed with type 3 VWD by next-generation sequencing using Ion Torrent PGM. RESULTS: In 25 patients, we were able to identify both disease-causing variants. We identified 72 different variants: 31 intronic and 41 exonic. Five novel variants were found: c.6976+5G>T; c.6885_6886insC; c.3378C>T (p.Cys1126); c.3346_3347insCCA; and c.2503G>T (p.Glu835*). Variants p.Pro2063Ser and p.Arg324* co-segregated in 17 patients, 15 of them in homozygosity. CONCLUSION: Our results may contribute to the discussion on whether the variant p.Pro2063Ser is pathogenic or not. Finally, the presence of a common haplotype in patients bearing these two variants suggests a founder effect for this variant in our region.

Aerobic exercise improves postprandial inflammatory and hemostatic markers after a high-fat meal: a randomized crossover study.

Exercise intensity modulates postprandial lipemia. However, its effect on hemostatic and pro- and anti-inflammatory markers in the postprandial state is still unknown. Eleven young males performed a 2-day trial on different conditions: (i) REST: rest for 45 min; (ii) MIE: moderate-intensity exercise; and (iii) HIE: heavy-intensity exercise. Experimental conditions were performed in the evening. On the following morning, blood samples were taken in the fasted state (0 h) and at 1, 3, and 5 h after the consumption of a high-fat meal (HFM). Interleukin-10 (IL-10) levels were higher in the HIE vs. MIE trial at 0 and 1 h (p < 0.033) and IL-10 incremental area under the curve (iAUC) was greater in the MIE (p = 0.027) and HIE (p = 0.045) trials vs. REST. Lower levels of anti-coagulation factor VII (FVII) were observed at 1 h in the MIE condition vs. REST (p = 0.043). In comparison with REST, MIE improved hemostatic (FVII) and anti-inflammatory markers (IL-10 iAUC) whereas HIE enhanced IL-10 in the postprandial state. Regardless of the exercise intensity, aerobic exercise mitigates the deleterious consequences of an HFM. Novelty: Prior aerobic exercise at moderate-intensity attenuates next day's postprandial FVII and IL-10 levels whereas exercise performed at heavy-intensity increases IL-10 levels. Moderate-intensity exercise may be more beneficial to improve hemostatic (FVII) and anti-inflammatory (IL-10) responses while heavy-intensity exercise may improve anti-inflammatory (IL-10) levels only.

Identification of environmental and genetic factors that influence warfarin time in therapeutic range.

Warfarin is an oral anticoagulant prescribed to prevent and treat thromboembolic disorders. It has a narrow therapeutic window and must have its effect controlled. Prothrombin test, expressed in INR value, is used for dose management. Time in therapeutic range (TTR) is an important outcome of quality control of anticoagulation therapy and is influenced by several factors. The aim of this study was to identify genetic, demographic, and clinical factors that can potentially influence TTR. In total,422 patients using warfarin were investigated. Glibenclamide co-medication and presence of CYP2C9*2 and/or *3 alleles were associated with higher TTR, while amiodarone, acetaminophen and verapamil co-medication were associated with lower TTR. Our data suggest that TTR is influenced by co-medication and genetic factors. Thus, individuals in use of glibenclamide may need a more careful monitoring and genetic testing (CYP2C9*2 and/or *3 alleles) may improve the anticoagulation management. In addition, in order to reach and maintain the INR in the target for a longer period, it is better to discuss dose adjustment in office instead of by telephone assessment. Other studies are needed to confirm these results and to find more variables that could contribute to this important parameter.

Prevalence of inversions in introns 1 and 22 of the factor VIII gene and inhibitors in patients from southern Brazil / Prevalência das inversões nos íntrons 1 e 22 do gene do fator VIII e inibidores em pacientes do sul do Brasil

ABSTRACT Objectives: The development of antibodies (inhibitors) against exogenous factors is the main complication in the treatment of hemophilia. Both genetic and non-genetic factors are related to inhibitor development. Among the genetic factors, the type of mutation that caused the disease is one of the most important. The objectives of the present study were to establish the prevalence of inversions in introns 1 and 22 of the factor VIII gene in patients with severe hemophilia A, correlating these with inhibitor development, and to compare the results with data from the literature. Method: Unrelated severe hemophilia A patients were analyzed for the presence of inversions in intron 1 (n = 77) and intron 22 (n = 39) by polymerase chain reaction (PCR). Detection of the inhibitor was performed by the mixing test and its quantification was performed by the Bethesda method. Results: The prevalence of inversions in introns 1 and 22 was 2.6% and 41%, respectively. No patient with inversions in intron 1 had inhibitors, whereas 26.3% of patients with inversions in intron 22 developed inhibitors. Conclusion: Due to the small number of patients with inversions in intron 1, it was not possible to perform a statistical test for the correlation with risk of inhibitor development. Inversions in intron 22 of the factor VIII gene were not associated with an increased risk of inhibitor development in the analyzed samples (p = 1).

RESUMEN Introducción: El desarrollo de anticuerpos (inhibidores) contra elfactor exógeno es la principal complicación del tratamiento de hemofilias. Tanto factores genéticos como no genéticos están relacionados con la aparición de los inhibidores. Entre los factores genéticos, el tipo de mutación que originó la enfermedad es uno de los más importantes. El objetivo de este estudio fue establecer laprevalencia de las inversiones en los intrones 1 y 22 del gen del factor VIII en pacientes con hemofilia A severa, relacionándola con el desarrollo de inhibidores, así como comparar los resultados encontrados con datos de la literatura en el mundo. Método: Pacientes con hemofilia A severa no emparentados fueron analizados cuanto a la presencia de inversión en el intrón 1 (n = 77) y de la inversión en el intrón 22 (n = 39), usando la técnica de reacción en cadena de lapolimerasa. La detección del inhibidor fue realizada por el estudio de mezclas; su cuantificación, por el método Bethesda. Resultados: La prevalencia de las inversiones en los intrones 1 y 22 fueron 2,6% y 41%, respectivamente. Ningúnpaciente con la inversión en el intrón 1 presentó inhibidores, mientras 26,3% de los pacientes con la inversión en el intrón 22 desarrollaron anticuerpos. Conclusión: El pequeno número de pacientes con inversión en el intrón 1 no permitió la aplicación de la prueba estadística para correlación con el riesgo de desarrollo de inhibidores. La inversión en el intrón 22 del gen del factor VIII no se asoció a un mayor riesgo de desarrollo de inhibidores en la muestra analizada (p = 1).

RESUMO Introdução: O desenvolvimento de anticorpos (inibidores) contra o fator exógeno é a principal complicação do tratamento de hemofilias. Tanto fatores genéticos quanto não genéticos estão relacionados com o surgimento dos inibidores. Entre os fatores genéticos, o tipo de mutação que originou a doença é um dos mais importantes. Os objetivos do presente estudo foram estabelecer a prevalência das inversões nos íntrons 1 e 22 do gene do fator VIII em pacientes com hemofilia A grave, correlacionando-a com o desenvolvimento de inibidores, bem como comparar os resultados encontrados com dados da literatura mundial. Método: Foram analisados pacientes hemofílicos A graves não aparentados quanto à presença da inversão no íntron 1 (n = 77) e da inversão no íntron 22 (n = 39), utilizando a técnica de reação em cadeia dapolimerase (PCR). A detecção do inibidor foi realizada pelo teste de mistura; a sua quantificação, pelo método de Bethesda. Resultados: As prevalências das inversões nos íntrons 1 e 22 foram de 2,6% e 41%, respectivamente. Nenhum paciente com a inversão no íntron 1 apresentou inibidores, enquanto 26,3% dos pacientes com a inversão no íntron 22 desenvolveram os anticorpos. Conclusão: O número reduzido de pacientes com a inversão no íntron 1 não permitiu a aplicação de teste estatístico para a correlação com o risco de desenvolvimento de inibidores. A inversão no íntron 22 do gene do fator VIII não se associou ao maior risco de desenvolvimento de inibidores na amostra analisada (p = 1).

A new in silico approach to investigate molecular aspects of factor IX missense causative mutations and their impact on the hemophilia B severity.

Factor IX (encoded by F9) is a protein in the coagulation process, where its lack or deficiency leads to hemophilia B. This condition has been much less studied than hemophilia A, especially in Latin America. We analyzed the structural and functional impact of 54 missense mutations (18 reported by us previously, and 36 other mutations from the Factor IX database) through molecular modeling approaches. To accomplish this task, we examine the electrostatic patterns, hydrophobicity/hydrophilicity, disulfide, and H-bond differences of the Factor IX structures harboring the missense mutations found, correlating them with their clinical effects. The 54 mutated sequences were modeled and their physicochemical features were determined and used as input in clusterization tools. The electrostatic pattern seems to influence in disease severity, especially for mutations investigated in epidermal growth factors 1 and 2 (EGF1/2) domains. The combined use of all physicochemical information improved the clustering of structures associated to similar phenotypes, especially for mutations from GLA and EGF1-2 domains. The effect of mutations in the disease phenotype severity seems to be a complex interplay of molecular features, each one contributing to different impacts. This highlights that previous studies and tools analyzing individually single features for single mutations are missing elements that fulfill the whole picture.

Influence of vitamin intake and MTHFR polymorphism on the levels of DNA damage in tobacco farmers.

BACKGROUND: Genetic damage may occur spontaneously under normal metabolic circumstances, inadequate intake of nutrients, and excessive exposure to environmental mutagens. OBJECTIVES: To evaluate the influence of the intake of micronutrients vitamin B12, vitamin B6, and folate and of the polymorphism methylenetetrahydrofolate reductase (MTHFR) C677T on the induction of DNA damage in tobacco farmers. METHODS: The study involved 66 men and 44 women engaged in tobacco cultivation in the region of Venâncio Aires (Rio Grande do Sul state, Brazil). Peripheral blood samples were collected to analyze DNA damage using the Comet assay, the micronucleus (MN) test and MTHFR C677T polymorphism. Dietary intake was evaluated based on the mean values obtained from three 24-h diet recall questionnaires, and nutrient intake data were computerized and estimated in the Food Processor SQL 10.9 program. The statistical tests used to generate the stated results were Kruskal-Wallis test, Exact Fisher's test, and multivariate linear regression analysis. RESULTS: DNA damage was significantly higher in individuals who had an inadequate intake of folate, vitamin B12, and vitamin B6 (P < 0.01) assessed by Comet assay. In relation to MN test results, buccal cells showed MN frequency higher in individuals with inadequate intake of vitamin B6 (P < 0.01). No difference was observed in MN lymphocytes frequency. No significant association was detected between MTHFR C677T polymorphism and DNA damage in tobacco farmers. CONCLUSION: Our results suggest that folate, vitamin B12, and vitamin B6 deficiency may be associated with genotoxic effect in individuals exposed to pesticides.

PPARA gene and phenprocoumon: a new predictor of response variability.

Phenprocoumon is an anticoagulant used for thromboembolic disorder prophylaxis metabolized mainly by CYP3A4. However, polymorphisms in this gene did not explain the observed variability. PPARA (peroxisome proliferator-activated receptor-α) is a nuclear receptor that, among others, influences CYP3A4 gene expression. The aim of this study was to determine whether PPARA gene polymorphisms and the CYP3A4*22 allele are associated with phenprocoumon dose variability. A total of 198 patients on a stable dose of phenprocoumon were included in the study. Genotyping was performed by allele discrimination using standardized TaqMan assays. Differences between the average phenprocoumon dose and genotypes/haplotypes were assessed by analysis of variance and multiple linear regression analyses. Patients with the PPARA rs4253728A allele needed higher phenprocoumon doses. However, the effect size (3%) of this association was small. The CYP3A4*22 allele was not associated with the dose of phenprocoumon. As this is the first report of an association between PPARA gene polymorphisms and phenprocoumon dose, future studies are warranted to confirm these results.

A new algorithm for weekly phenprocoumon dose variation in a southern Brazilian population: role for CYP2C9, CYP3A4/5 and VKORC1 genes polymorphisms.

Phenprocoumon is widely used in prophylaxis and treatment of thromboembolic disorders. However, its pharmacokinetics and pharmacodynamics vary according to several genetic and non-genetic factors. Phenprocoumon metabolism is mediated by CYP2C9 and CYP3A enzymes. Moreover, VKORC1 is phenprocoumon target of action. Therefore, the aim of this study was to evaluate the association of single nucleotide polymorphisms (SNPs) in VKORC1, CYP2C9, CYP3A4 and CYP3A5 genes with the variance of weekly phenprocoumon dose as well as to develop an algorithm for dose prediction based on genetic and environmental factors. A total of 198 patients with stable phenprocoumon dose, 81% of European ancestry, were investigated. Genotypes were determined by allelic discrimination with TaqMan assays. Polymorphisms -1639G>A and 1173C>T in VKORC1 and the presence of CYP2C9*2 and/or CYP2C9*3 are associated with lower doses. On the other hand, 3730G>A in VKORC1 gene is associated with higher doses. No association was found between CYP3A4*1B, CYP3A5*3 and CYP3A5*6 polymorphisms. Among non-genetic factors, gender, height, age and use of captopril, omeprazole, simvastatin and ß-blockers are associated with dose. Two algorithms were derived: one for the whole sample explained 42% of dose variation and one for patients of European ancestry only which explained 46% of phenprocoumon dose. The mean absolute difference between observed and predicted dose was low in both models (3.92 mg/week and 3.54 mg/week, for models 1 and 2, respectively). However, more studies with other genes and environmental factors are needed to test and to improve the algorithm.

Factor VIII mutations and inhibitor formation in a southern Brazilian population.

A total of 110 patients with severe (n = 43), moderate (n = 15) or mild (n = 52) haemophilia A were studied in relation to their F8 gene mutation and inhibitor status. Nineteen percentage of them had anti-factor VIII antibodies. Significant heterogeneity in inhibitor prevalence considering the location of the patients' mutation was found, with higher frequencies in carriers of mutations in the C1 and B domains. Twelve specific mutations showed associations with inhibitor formation, seven deletions, two nonsense, two insertions and one missense changes. Bioinformatic analysis of the missense mutation confirmed the formation of a B-cell epitope in the protein. This information is important for comparative purposes with series of other ethnic constitutions, as well as for individual prevention of this serious clinical problem in the patient population.

Influence of VKORC1 gene polymorphisms on the effect of oral vitamin K supplementation in over-anticoagulated patients.

Significant inter-individual variability on the effect of vitamin K to reverse overanticoagulation has been identified. Genetic polymorphisms of the vitamin K epoxide reductase complex subunit 1 (VKORC1) gene might explain in part this variability. The objective of this study was to evaluate the influence of VKORC1 -1639G>A and 3730G>A polymorphisms on the effect of oral vitamin K supplementation in overanticoagulated patients. We performed an interventional trial of oral vitamin K supplementation in over-anticoagulated outpatients (international normalized ratio [INR] ≥ 4). Subjects received vitamin K (2.5-5.0 mg) according to baseline INR and were genotyped by real time polymerase chain reaction (PCR). INR values were determined at 3, 6, 24 and 72 h after supplementation. We evaluated 33 outpatients, 61 % were males, with a mean age of 62 ± 12 years old. There was a significant decrease in INR values over time for both polymorphisms after oral vitamin K. At 3 h after supplementation, patients carrying the G allele for the -1639G>A polymorphism had a greater decrease in INR values compared to AA patients (p < 0.05 for difference among groups; p < 0.001 for time variation; p = 0.001 for time × group interaction), with differences of -1.01 for GG versus AA (p = 0.003) and -0.84 for GA versus AA (p = 0.024). Mean INR value at 24 h was 1.9 ± 0.6 and at 72 h was 2.1 ± 0.7, with no differences among genotypes. No significant interaction was identified between the 3730G>A polymorphism and vitamin K supplementation. Our study indicated that the VKORC1 -1639G>A polymorphism plays a role in the response to acute vitamin K supplementation in over-anticoagulated patients, with faster decrease of INR value in patients carrying the G allele.

Genetic changes in severe haemophilia A: new contribution to the aetiology of a complex disease.

Haemophilia A is an X-linked bleeding disorder caused by reduced or absent clotting factor VIII (FVIII) activity, determined by heterogeneous mutations in the F8 gene. Identification of these pathogenic mutations is important for genetic counseling and the assessment of clinical manifestations. Although more than 700 mutations of the F8 gene have been reported as responsible for severe haemophilia (FVIII: C<1%), the corresponding data is currently insufficient for southern Brazilian populations, and world reviews concerning these changes are scarce. Thirty-six unrelated severe haemophilia A patients who showed negative results for introns 22 and 1 inversions were studied for gross exon deletions and mutations there and in adjacent regions. Missense mutations were examined using molecular structural methods. The presence of FVIII inhibitors was also investigated. The results were compared with the information available from respectively 2878 and 1952 patients from all over the world. Twenty-nine different genetic changes were found, 16 of them novel. Seventeen of the carriers developed FVIII inhibitors, and molecular analysis suggested that Asp542Gly and Ser109Pro may interfere with calcium binding, whereas Leu2297Arg clearly affects the molecule's electrostatic surface. The main aetiological factor in the severe form of haemophilia seems to be missense mutations. Of all genetic changes occurring in these patients, large deletions are the most important in inhibitors formation.

Susceptibility to DNA damage in workers occupationally exposed to pesticides, to tannery chemicals and to coal dust during mining.

Our mutagenesis group has been studying with important economic drivers of our state, such as agriculture, the foot-wear and leather industry and open-cast coal mining. Working conditions in these sectors have potentially harmful to humans. The aim of these studies is to determine the health risk of workers by biomonitoring subjects exposed to genotoxic agents. The main results of our studies with vineyard farmers we observed a high rate of MN and DNA damage in individuals exposed to pesticides (p < 0.001). In addition, some effects of genetic polymorphisms in the modulation of MN results were observed in this group. Tobacco farmers were also evaluated at different crop times. The results showed a significant increase in the Damage index and frequency in tobacco farmers compared to the non-exposed group, for all crop times. The results for footwear and tannery workers showed a significant increase in the mean ID for the solvent-based adhesive (p < 0.001) group in comparison to the water-based adhesive group and control (p < 0.05). For open-cast coal mine workers, the EBCyt indicated a significant increase in nuclear bud frequency and cytokinetic defects in the exposed group compared to the non-exposed group (p < 0.0001). We were able to associate specific genetic susceptibility with each type of exposure and with the non-use or improper use of personal protection equipment and diet adequacy. These results show how important the continuous education of exposed workers is to minimizing the effect of the occupational exposure and the risk of disease associated with the work.

Influence of genetic, biological and pharmacological factors on warfarin dose in a Southern Brazilian population of European ancestry.

AIMS: To investigate the influence of polymorphisms in CYP2C9, VKORC1, CYP4F2 and F2 genes on warfarin dose-response and develop a model including genetic and non-genetic factors for warfarin dose prediction needed for each patient. METHODS: A total of 279 patients of European ancestry on warfarin medication were investigated. Genotypes for -1639G>A, 1173C>T, and 3730G>A SNPs in the VKORC1 gene, CYP2C9*2 and CYP2C9*3, 1347C>T in the CYP4F2 gene and 494C>T in the F2 gene were determined by allelic discrimination with Taqman 5'-nuclease assays. RESULTS: The CYP2C9*2 and CYP2C9*3 polymorphisms in the CYP2C9 gene, -1639G>A and 1173C>T in the VKORC1 gene and 494C>T in the F2 gene are responsible for lower anticoagulant doses. In contrast, 1347C>T in the CYP4F2 gene and 3730G>A in the VKORC1 gene are responsible for higher doses of warfarin. An algorithm including genetic, biological and pharmacological factors that explains 63.3% of warfarin dose variation was developed. CONCLUSION: The model suggested has one of the highest coefficients of determination among those described in the literature.

Maternal gene polymorphisms involved in folate metabolism as risk factors for Down syndrome offspring in Southern Brazil.

This study aimed to investigate the role of maternal polymorphisms, as well as their risk genotypes combinations of MTR A2756G, MTRR A66G, CBS 844ins68, and RFC A80G, involved in folate/homocysteine metabolism, as possible risk factors for Down syndrome (DS) in Southern Brazil. A case-control study was conducted with 239~mothers of DS children and 197~control mothers. The investigation of polymorphisms was performed by PCR and PCR-RFLP. The distribution of genotypic variants was similar in both groups when they were analyzed separately. An investigation of combined risk genotypes showed that the risk of having a DS child for one, two or three risk genotypes was 6.23, 6.96 and 5.84 (95%CI 1.48-26.26; 1.69-28.66; 1.37-24.86), respectively. The combined MTRR 66G and MTHFR 677T alleles were significantly more common among mothers of children with DS than among control mothers (OR 1.55; IC 95% 1.03-2.35). The results show that individual polymorphisms studied in this work are not associated with DS; however, the effects of the combined risk genotypes among MTR, MTRR, CBS and RFC genes are considered maternal risk factors for DS offspring in our population.

Association between mannose-binding lectin gene polymorphisms and pre-eclampsia in Brazilian women.

PROBLEM: Mannose-binding lectin (MBL) is involved in the maintenance of an inflammatory environment in uterus. High MBL levels have been associated with successful pregnancies whereas low levels are involved in pre-eclampsia (PE) development. Here, we evaluated MBL2 gene polymorphisms in the structural and promoter regions addressing their association with PE. METHOD OF STUDY: DNA samples from 162 control pregnant women and 157 pregnant PE women were genotyped and data compared with demographic and clinical characteristics. RESULTS: High frequency of C and D alleles (related to low MBL levels) was observed in PE women when compared to controls (C: 0.08 versus 0.03, P = 0.006; D: 0.10 versus 0.05, P = 0.009). Grouping the MBL genotypes according to phenotype, a higher frequency of OO genotype was observed in PE women when compared to control women (0.15 versus 0.04, P = 0.007). CONCLUSION: Our data suggest that women with genotypes associated with low MBL levels could be potential PE developers.

Evaluation of C677T and A1298C polymorphisms of the MTHFR gene as maternal risk factors for Down syndrome and congenital heart defects.

Abnormal folate/homocysteine metabolism due to polymorphisms in genes involved in this pathway has been implicated as an etiologic factor in Down syndrome (DS). This case-control study aimed to evaluate the effect of maternal C677T and A1298C polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) as risk factors for the development of DS and congenital heart defects (CHD). The distribution of these genotypic variants was similar between mothers of children with DS (n = 239) and control mothers of normal children (n = 197), but the combined genotypes 677CT or TT and 1298AA increased the risk of having offspring with DS (OR = 1.99; 95% CI 1.11-3.55). The presence of the 677T allele in case mothers resulted in a 2.07-fold higher odds of CHD in the offspring (P < 0.01). Among the 57 mothers of CHD-affected children with DS who carried the MTHFR 677CT or TT genotypes and did not have periconceptional folic acid intake, we observed a 2.26-fold increased odds (95% CI 1.25-4.09) of having any CHD-affected child with DS. Our results show that MTHFR genetic polymorphisms may be involved in the etiology of DS in our population when controlling for age. We noted a borderline significant association for the C677T polymorphism (P = 0.05). Maternal 677T allele may be associated with an increased occurrence of CHD in children with DS and we anticipate that women who carry this polymorphism would benefit from periconceptional folic acid supplementation. (c) 2009 Wiley-Liss, Inc.

The effect of ABO blood group on von Willebrand response to exercise.

Individuals of O blood group have significantly lower plasma levels of either Factor VIII (FVIII) or the von Willebrand factor (vWF). Conversely, there is accumulating evidence that elevated FVIII-vWF levels may represent an important risk factor for ischemic heart and venous thromboembolic disease. In this study, individuals exercised for 20 minutes at 10% below the first ventilatory threshold (aerobic threshold), which corresponds to 48% of maximum oxygen uptake. People with non-O blood group show higher resting and postexercise vWF levels compared with those of O blood group, as evidenced by a lower maximal heart rate. The groups were compared using the ANOVA one-way test, and a P < 0.05 was considered statistically significant. These results could change the way in which exercise training is designed for both healthy and sick individuals because O group individuals could have a more thrombogenic response to exercise.

Portal vein thrombosis in children and adolescents: the low prevalence of hereditary thrombophilic disorders.

PURPOSE: The aim of this study was to determine the frequency of thrombophilic disorders in children and adolescents with portal vein thrombosis (PVT) as well as assessing the hereditary character of this disorder. METHODS: A 2-year prospective study was carried out in pediatric PVT patients (n = 14), their parents (n = 25), and an age-matched control group free of liver disease (n = 28). The presence of PVT was assessed by means of Doppler ultrasound scan or angiography. None of the PVT patients presented biochemical or histologic signs of liver disease. RESULTS: The frequency in PVT patients of protein C (PC), protein S (PS) and antithrombin (AT) deficiency was 42.9% (P <.05 v controls), 21.4% (P >.05) and 7.1% (P >.05), respectively. None of the controls or parents of PVT patients presented hereditary PC, PS, or AT deficiency. One PVT patient and one control (P =.999) presented prothrombin G20210A mutation. Homozygous methylenetetrahydrofolate reductase C677T genotype was observed in 3 of 14 (21.4%) PVT patients and in 5 of 28 (17.9%; P =.356) controls. None of these patients presented factor V G1691A mutation. CONCLUSIONS: PC deficiency was frequent in pediatric PVT patients and does not seem to be an inherited condition. The hereditary prothrombotic disorders do not seem to play a vital role in thrombosis in children and adolescents with PVT.