Functional analysis of ldlr genetic variants identified in hypercholesterolemic patients in brazil, USING CRISPR/CAS9

BACKGROUND AND AIMS: Introduction: The familial hypercholesterolemia (FH) is one of the main causes of cardiovascular diseases, and it is mainly caused by genetic variants at the low-density lipoprotein receptor (LDLR). Although ultrasequencing technology has allowed the identification of several genetic variants, few of them was functional analyzed. The CRISPR/ Cas9 tool promotes precise genetic editing and allows the creation of experimental models, therefore contributing to the functional validation process. Aim: To use the CRISPR/Cas9 tool to perform in vitro functional analysis of LDLR variants identified in FH patients. METHODS: Two missense LDLR variants were selected within a group of variants identified in FH patients, based on in silico data, the affected protein domain and MAF. Three sgRNAs were designed for each of the variants c.551G>A and c.1118G>A, to analyze the accuracy of the sgRNAs. The sgRNAs were inserted on PX458 plasmid, cloned, purified in E. coli DH5a, and then co-transfected with the DNA template at HepG2 cells. The DNAs templates were designed to contain the selected variants. RESULTS: HepG2 cells co-transfected with PX458 constructs and DNA templates showed considerably transfection rate, being possible to visualize it at fluorescence microscopy. However, it was noted that single transfection of sgRNAs showed a higher transfection efficiency than cotransfection. CONCLUSIONS: We designed sgRNA for c.551G>A and c.1118G>A variants, being able to analyze the transfection efficiency. In further steps, we will select new sgRNAs for LDLR variants that have not been described yet, and functional analysis will be performed to determine the clinical relevance of these variants.

Genetic susceptibility in pharmacodynamic and pharmacokinetic pathways underlying drug-induced arrhythmia and sudden unexplained deaths

ABSTRACT: Drug-induced arrhythmia is an adverse drug reaction that can be potentially fatal since it is mostly related to drug-induced QT prolongation, a known risk factor for Torsade de Pointes and sudden cardiac death (SCD). Several risk factors have been described in association to these drug-induced events, such as preexistent cardiac disease and genetic variation. Our objective was to study the genetic susceptibility in pharmacodynamic and pharmacokinetic pathways underlying suspected drug-induced arrhythmias and sudden unexplained deaths in 32 patients. The genetic component in the pharmacodynamic pathway was studied by analysing 96 genes associated with higher risk of SCD through massive parallel sequencing. Pharmacokinetic-mediated genetic susceptibility was investigated by studying the genes encoding cytochrome P450 enzymes using mediumthroughput genotyping. Pharmacodynamic analysis showed three probably pathogenic variants and 45 variants of uncertain significance in 28 patients, several of them previously described in relation to mild or late onset cardiomyopathies. These results suggest that genetic variants in cardiomyopathy genes, in addition to those related with channelopathies, could be relevant to drug-induced cardiotoxicity and contribute to the arrhythmogenic phenotype. Pharmacokinetic analysis showed three patients that could have an altered metabolism of the drugs they received involving CYP2C19 and/or CYP2D6, probably contributing to the arrhythmogenic phenotype. The study of genetic variants in both pharmacodynamic and pharmacokinetic pathways may be a useful strategy to understand the multifactorial mechanism of drug-induced events in both clinical practice and forensic field. However, it is necessary to comprehensively study and evaluate the contribution of the genetic susceptibility to drug-induced cardiotoxicity. (AU)

Genetic susceptibility in pharmacodynamic and pharmacokinetic pathways underlying drug-induced arrhythmia and sudden unexplained deaths.

Drug-induced arrhythmia is an adverse drug reaction that can be potentially fatal since it is mostly related to drug-induced QT prolongation, a known risk factor for Torsade de Pointes and sudden cardiac death (SCD). Several risk factors have been described in association to these drug-induced events, such as preexistent cardiac disease and genetic variation. Our objective was to study the genetic susceptibility in pharmacodynamic and pharmacokinetic pathways underlying suspected drug-induced arrhythmias and sudden unexplained deaths in 32 patients. The genetic component in the pharmacodynamic pathway was studied by analysing 96 genes associated with higher risk of SCD through massive parallel sequencing. Pharmacokinetic-mediated genetic susceptibility was investigated by studying the genes encoding cytochrome P450 enzymes using medium-throughput genotyping. Pharmacodynamic analysis showed three probably pathogenic variants and 45 variants of uncertain significance in 28 patients, several of them previously described in relation to mild or late onset cardiomyopathies. These results suggest that genetic variants in cardiomyopathy genes, in addition to those related with channelopathies, could be relevant to drug-induced cardiotoxicity and contribute to the arrhythmogenic phenotype. Pharmacokinetic analysis showed three patients that could have an altered metabolism of the drugs they received involving CYP2C19 and/or CYP2D6, probably contributing to the arrhythmogenic phenotype. The study of genetic variants in both pharmacodynamic and pharmacokinetic pathways may be a useful strategy to understand the multifactorial mechanism of drug-induced events in both clinical practice and forensic field. However, it is necessary to comprehensively study and evaluate the contribution of the genetic susceptibility to drug-induced cardiotoxicity.

Análise funcional in silico das variantes no gene da APOB em pacientes com hipercolesterolemia familial / In silico functional analysis of variants in the APOB gene in patients with familial hypercholesterolemia

INTRODUÇÃO: O diagnóstico molecular da hipercolesterolemia familial (HF) é atribuído principalmente as variantes nos genes LDLR, LDLRAP1, APOB e PCSK9. O objetivo deste estudo foi realizar análise in silico para investigar o impacto de variantes sem descrição na literatura no gene APOB observado em pacientes com HF. MÉTODOS: Foram selecionados 141 indivíduos com diagnóstico clínico de HF. As variantes no gene da APOB foram selecionadas após sequenciamento dos éxons de 61 genes utilizando a plataforma MiSeq (Illumina). Os dados foram analisados nos programas Real Time Analysis, MiSeq Reporter, BaseSpace Sequence Hub e VariantStudio. Para a análise in silico, as sequências molde das moléculas da apoB-100 e o LDLr foram selecionadas por modelagem comparativa considerando o maior grau de identidade. As sequências proteicas foram alinhadas e os modelos 3D foram construídos utilizando os programas SEAVIEW e MODELLER v9.21. O gráfico de Ramachandran do modelo de menor energia apresenta 0,5% de outliers e análise de regiões de desordem, como principal validação. Os resultados das conformações de ancoragem foram analisados no software PyMol 2.1. Os estudos de docking molecular foram realizados para identificar o melhor complexo de conformação usando o servidor web clusPRO. RESULTADOS: Após a análise molecular dos 141 pacientes foram identificadas 7 variantes missenses sem descrição na literatura no gene APOB (c.433C>T, c.2630C>T, c.2950G>A, c.5743G>A, c.7367C>A, c.9880T>C e c.10780T>C). Os estudos de docking das variantes demonstraram uma maior afinidade entre o LDLr e a apoB-100 (c.2630C> T; Pro877Leu) em comparação com a proteína não mutada. A troca dos resíduos permaneceu como propriedade físico-química, e comparando as distâncias de ligação das proteínas não-mutadas (5Å) e mutadas (3,5Å), sugere-se uma maior afinidade do complexo (LDLr-apoB-100) para a leucina, tal fato é afirmado pela análise da região de desordens da apoB-100, onde a posição 877 está em uma região desorganizada e flexível. Esta maior afinidade poderia levar a uma menor dissociação intracelular deste complexo, resultando em uma alta taxa de degradação do LDLr pelas enzimas lisossômicas, levando ao aumento da concentração plasmática de LDLc. Para as outras variantes não houve alterações significativas. CONCLUSÃO: Os resultados sugerem que estudos in silico baseados na ferramenta de docking molecular podem melhorar o conhecimento da contribuição genética no desenvolvimento da doença HF. Além disso, a variante APOB c.2630C> T deve ser avaliada in vitropara validação do mecanismo proposto. (AU)

Associação entre o polimorfismo VKORC1: C. 174-136G>A (rs9934438) e a dose semanal de varfarina em pacientes idosos ­ estudo piloto / Association between VKORC1: C.174-136G> A (rs9934438) polymorphism and weekly warfarin dose in elderly patients - pilot study

A varfarina é um anticoagulante utilizado na prevenção e no tratamento de doenças tromboembólicas, com janela terapêutica estreita e, elevado risco de hemorragias. Nos idosos, a principal indicação para tratamento anticoagulante oral é fibrilação atrial, cuja prevalência aumenta com a idade, atingindo 8% após os 80 anos. O exame utilizado para controle da anticoagulação oral é o tempo de protrombina, através do cálculo da razão normalizada internacional (RNI), visando o ajuste de dose e manutenção da faixa terapêutica (RNI= 2 a 3). Os idosos requerem um monitoramento efetivo devido a fatores inerentes da idade. Embora seja conhecido que os fatores genéticos influenciam na resposta terapêutica à varfarina, na rotina da maioria dos hospitais a farmacogenética ainda não é considerada no ajuste de dose. Visando estabelecer uma conduta terapêutica personalizada, o presente estudo tem como objetivo avaliar a associação entre o polimorfismo rs9934438 do gene VKORC1, que codifica a enzima vitamina K epóxido redutase, e a dose semanal de varfarina necessária para atingir o RNI adequado. Até o momento, foram incluídos 52 pacientes com idade superior a 70 anos, de ambos os sexos e em uso de varfarina. A análise do polimorfismofoi realizada através da PCR em tempo real utilizando os reagentes TaqMan™ Sample-to-SNP™ e o sistema de detecção TaqMan® SNP Genotyping Assay. As análises estatísticas foram realizadas utilizando o pacote SPSS v. 16.0 e nível de significância adotado foi de 5%. Dos 52 pacientes incluídos até o momento, 37 (71%) permaneceram na faixa terapêutica (Time in Therapeutic Range, TTR) em pelo menos 50% do tempo de anticoagulação e, para eles a dose semanal de varfarina variou de 15mg a 62,5mg. Apesar de ser um estudo piloto, a distribuição dos genótipos está em equilíbrio gênico, segundo Hardy-Weinberg (AA=19,2%, AG=34,6%, GG= 46,2%, χ2= 3,34 e p=0,067). Para os idosos com TTR ≥50%, a frequência do alelo A foi significantemente maior entre os pacientes que utilizaram doses menores de varfarina (Exato de Fisher, p=0,005). Adicionalmente, os portadores do genótipo AA necessitaram, em média, de aproximadamente metade da dose para atingir a faixa terapêutica quando comparados aos portadores do genótipo GG, 20,5 versus 36,5 mg/semana, respectivamente (ANOVA, p=0,006/ Pós-teste Bonferroni, p=0,039). Os resultados permitem concluir que portadores de alelo A são mais responsivos ao tratamento com varfarina, sugerindo que o perfil genotípico pode ser de grande valor para o direcionamento da dose terapêutica em idosos. (AU)

The association between the HLA-G 14-bp insertion/deletion polymorphism and type 1 diabetes.

Type 1 diabetes (T1D) is a multifactorial disease that has a strong genetic component. The HLA-G is a nonclassical HLA class I locus that is associated with immunomodulatory functions, including downregulation of innate and adaptive immune responses and induction of immune tolerance. However, there is currently limited information about the involvement of HLA-G in T1D susceptibility. This case-control study aims to investigate the T1D susceptibility association of alleles and genotypes of a widely investigated 14-bp insertion/deletion polymorphism in the HLA-G and to provide further evidence of the frequency distribution of class II HLA-DR-DQ-risk genotypes in T1D children and adolescents in the Brazilian population. The deletion allele and the homozygous deletion genotype are associated with susceptibility to T1D and the insertion allele and the heterozygous deletion/insertion genotype are associated with protection from T1D. We also confirm that genetic susceptibility to T1D is associated with the DRB1*03:01-DQA1*05:01-DQB1*02:01 and DRB1*04-DQA1*03:01-DQB1*03:02 haplotypes in Brazilian northeast region. The DR3-DQ2/DR4-DQ8 genotype conferred the highest detected risk for T1D. Our results identify a novel association of the 14-bp deletion allele and the homozygous deletion genotype with T1D development and provide additional evidence of the importance of HLA class II heterozygous DR3-DQ2/DR4-DQ8 genotype in T1D susceptibility.

Genetic and non-genetic factors that increase the risk of non-syndromic cleft lip and/or palate development.

OBJECTIVES: We investigated the relationship between non-syndromic cleft lip/palate (NSCLP) and polymorphisms in methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTR), methionine synthase reductase (MTRR), and RFC1, as well as the corresponding interactions with environmental factors. SUBJECTS AND METHODS: One hundred and forty NSCLP patients and their mothers, as well as 175 control individuals and their mothers, were recruited. Information regarding smoking and alcohol consumption was recorded. Blood samples were obtained in order to measure serum folate and cobalamin, as well as, plasma total homocysteine concentrations and to extract DNA. Polymorphisms in MTHFR(677C>T and 1298A>C), MTR(2756A>G), MTR(66A>G), and RFC1(80A>G) were analyzed by PCR-restriction fragment length polymorphism. RESULTS: Among the patients, 59.5% had cleft lip and palate, 22.0% had cleft palate, and 18.5% had cleft lip only. Maternal alcohol consumption and reduced folic acid concentrations in both children and mothers (P < 0.001 and P = 0.003, respectively) were risk factors for NSCLP. Patients and their mothers carrying the MTHFR 667T allele showed lower serum folate than CC (P = 0.011 and P = 0.030, respectively). Mothers who carried the MTHFR 1298C allele exhibited increased risk of having a child with NSCLP, after adjusting for alcohol consumption (OR: 1.75, 95% CI: 1.03-2.99, P = 0.038). CONCLUSIONS: Reduced folic acid levels, alcohol consumption, and the MTHFR 677T and 1298C alleles may have contributed to NSCLP development in this sample population from Rio Grande do Norte.

Multiplex-PCR for differentiation of Mycobacterium bovis from Mycobacterium tuberculosis complex.

We evaluated a multiplex-PCR to differentiate Mycobacterium bovis from M. tuberculosis Complex (MTC) by one step amplification based on simultaneous detection of pncA 169 C > G change in M. bovis and the IS6110 present in MTC species. Our findings showed the proposed multiplex-PCR is a very useful tool for complementation in differentiating M. bovis from other cultured MTC species.

Chlamydophila pneumonia and increased TLR4 gene expression in leukocytes are associated with acute myocardial infarction.

We investigated the relationship of the positivity for Chlamydophila pneumoniae (Cpn) and Mycoplasma pneumonia (Mpn), inflammatory and metabolic markers, and mRNA expression and polymorphisms of the TLR2, TLR4, IL-6 and TNFA genes with acute myocardial infarction (AMI). Two hundred and eighteen individuals (98 AMI and 120 non-AMI) were selected at two Clinical Centers. Blood samples were drawn to extract DNA and RNA and to measure laboratory variables including anti-Cpn IgM and IgG. Cpn and Mpn genomic DNA as well as TLR2, TLR4, IL-6 and TNFA mRNA expression were evaluated by quantitative real-time PCR (qPCR). Gene polymorphisms were detected by PCR-HRM. AMI patients had higher positivity for Cpn-DNA (17.3%) than non-AMI group (6.7%, p=0.018). In addition, Cpn-DNA positivity was an independent predictor of risk for AMI (OR: 2.56, CI: 1.08 - 6.04, p=0.031). Positivity for anti-Cpn IgG and Mpn-DNA was similar between AMI and non-AMI (> 0.05). TLR4 mRNA expression was higher in AMI than non-AMI individuals (p=0.005). CD14 -260C> T, TNFA -308A> G, TLR2 c.2258G> A, TLR4 c.896A> G and TLR4 c.1196> T variants were not associated with increased risk for AMI (p> 0.05). In the AMI group, individuals carrying CD14 -260CC genotype had higher hsCRP levels than CT/TT carriers (p=0.041). These results are suggestive that Cpn-DNA positivity and increased TLR4 mRNA expression in blood leukocytes may be associated with AMI and could be useful markers to evaluate the severity and progression of the atherosclerotic disease in AMI patients.

Multiplex-PCR for differentiation of Mycobacterium bovis from Mycobacterium tuberculosis complex

We evaluated a multiplex-PCR to differentiate Mycobacterium bovis from M. tuberculosis Complex (MTC) by one step amplification based on simultaneous detection of pncA 169C > G change in M. bovis and the IS6110 present in MTC species. Our findings showed the proposed multiplex-PCR is a very useful tool for complementation in differentiating M. bovis from other cultured MTC species.

Genetic variants in genes related to lipid metabolism and atherosclerosis, dyslipidemia and atorvastatin response.

OBJECTIVE: Using candidate gene approach, we have investigated the effect of single nucleotide polymorphism (SNP) in genes related to lipid metabolism and atherosclerosis on dyslipidemia and atorvastatin response. METHODS: The study included 157 patients treated with atorvastatin and 145 controls. Genomic DNA was isolated and genotyped using SNPlex technology. RESULTS: Allele and genotype disease association test revealed that APOB rs693 (OR: 2.2 [1.5-3.2], p=0.0001) and CD36 rs1984112 (OR: 3.7 [1.9-7.0], p=0.0002) SNPs were independent risk factors for hypercholesterolemia. Only APOB rs693 T variant allele was associated with increased LDL cholesterol levels (>160mg/dL). After atorvastatin treatment (10mg/day/4weeks), LIPC -514T allele was positively associated with LDL cholesterol reduction. CONCLUSION: The current study reinforces the current knowledge that carrying APOB rs693 is an independent risk factor for dyslipidemia and higher LDL levels. Furthermore, we found that a variant of CD36 was associated with dyslipidemia as a risk (rs1984112) factor. Finally, atorvastatin response could be predicted by LIPC -514C>T SNP and physical activity. In conclusion, our data evidences the contribution of genetic markers and their interaction with environmental factor in the variability of statin response.

MSX1 gene polymorphisms in non-syndromic cleft lip and/or palate.

OBJECTIVE: The aim of this study was to investigate the contribution of 6 polymorphic variants of the MSX1 gene in non-syndromic cleft lip and/or palate (NSCL/P). METHODS: Three hundred and fifty-eight individuals (158 NSCL/P cases and 200 controls) were genotyped by TaqMan allelic discrimination using predesigned SNP assays. Statistical analyses were conducted using the software spss 15.0 and the r statistical suite. Haplotype block structure and haplotype frequencies were determined using the Haploview. A P-value of 0.05 and confidence interval of 95% were used for all of statistical tests. RESULTS: The patients with non-syndromic cleft lip and/or palate were characterized by similar distribution of MSX1 genotypes and allele in comparison to subjects without oral clefts (P > 0.05). Two haplotype blocks were constructed with polymorphisms of MSX1 gene and haplotypes formed showed a similar frequency in patients with and without oral clefts. CONCLUSIONS: The present study provides no evidence that MSX1 polymorphisms (rs3775261, rs1042484, rs12532, rs6446693, rs4464513 and rs1907998) play a major role in NSCL/P.

Use of the polymerase chain reaction to detect Mycobacterium leprae in urine

Leprosy is an infectious disease caused by Mycobacterium leprae. The polymerase chain reaction (PCR) has been applied to detect M. leprae in different clinical samples and urine seems to be attractive for this purpose. PCR was used to improve the sensitivity for diagnosing leprosy by amplifying a 151-bp PCR fragment of the M. leprae pra gene (PCR-Pra) in urine samples. Seventy-three leprosy patients (39 males and 34 females, 14 to 78 years old) were selected for leprosy diagnosis at a reference laboratory in Maringá, PR, Brazil. Of these, 36 were under anti-leprosy multidrug therapy with dapsone and rifampicin for tuberculoid (TT) and dapsone, rifampicin and clofazimine for borderline (BB) and lepromatous (LL) forms. The control group contained 50 healthy individuals without any clinical history of leprosy. DNA isolated from leprosy patients’ urine samples was successfully amplified by PCR-Pra in 46.6 percent (34/73) of the cases. The positivity of PCR-Pra for patients with the TT form was 75 percent for both patients under treatment and non-treated patients (P = 0.1306). In patients with the LL form, PCR-Pra positivity was 52 and 30 percent for patients under treatment and non-treated patients, respectively (P = 0.2386). PCR-Pra showed a statistically significant difference in detecting M. leprae between the TT and LL forms of leprosy in patients under treatment (P = 0.0033). Although the current study showed that the proposed PCR-Pra has some limitations in the detection of M. leprae, this method has the potential to be a useful tool for leprosy diagnosis mainly in TT leprosy where the AFB slit-skin smear is always negative.

Use of the polymerase chain reaction to detect Mycobacterium leprae in urine.

Leprosy is an infectious disease caused by Mycobacterium leprae. The polymerase chain reaction (PCR) has been applied to detect M. leprae in different clinical samples and urine seems to be attractive for this purpose. PCR was used to improve the sensitivity for diagnosing leprosy by amplifying a 151-bp PCR fragment of the M. leprae pra gene (PCR-Pra) in urine samples. Seventy-three leprosy patients (39 males and 34 females, 14 to 78 years old) were selected for leprosy diagnosis at a reference laboratory in Maringá, PR, Brazil. Of these, 36 were under anti-leprosy multidrug therapy with dapsone and rifampicin for tuberculoid (TT) and dapsone, rifampicin and clofazimine for borderline (BB) and lepromatous (LL) forms. The control group contained 50 healthy individuals without any clinical history of leprosy. DNA isolated from leprosy patients' urine samples was successfully amplified by PCR-Pra in 46.6% (34/73) of the cases. The positivity of PCR-Pra for patients with the TT form was 75% for both patients under treatment and non-treated patients (P = 0.1306). In patients with the LL form, PCR-Pra positivity was 52 and 30% for patients under treatment and non-treated patients, respectively (P = 0.2386). PCR-Pra showed a statistically significant difference in detecting M. leprae between the TT and LL forms of leprosy in patients under treatment (P = 0.0033). Although the current study showed that the proposed PCR-Pra has some limitations in the detection of M. leprae, this method has the potential to be a useful tool for leprosy diagnosis mainly in TT leprosy where the AFB slit-skin smear is always negative.

HFE gene mutations and iron status of Brazilian blood donors

Mutations of the HFE and TFR2 genes have been associated with iron overload. HFE and TFR2 mutations were assessed in blood donors, and the relationship with iron status was evaluated. Subjects (N = 542) were recruited at the Hemocentro da Santa Casa de São Paulo, São Paulo, Brazil. Iron status was not influenced by HFE mutations in women and was independent of blood donation frequency. In contrast, men carrying the HFE 282CY genotype had lower total iron-binding capacity (TIBC) than HFE 282CC genotype carriers. Men who donated blood for the first time and were carriers of the HFE 282CY genotype had higher transferrin saturation values and lower TIBC concentrations than those with the homozygous wild genotype for the HFE C282Y mutation. Moreover, in this group of blood donors, carriers of HFE 63DD plus 63HD genotypes had higher serum ferritin values than those with the homozygous wild genotype for HFE H63D mutation. Multiple linear regression analysis showed that HFE 282CY leads to a 17.21 percent increase (P = 0.018) and a 83.65 percent decrease (P = 0.007) in transferrin saturation and TIBC, respectively. In addition, serum ferritin is influenced by age (3.91 percent, P = 0.001) and the HFE 63HD plus DD genotype (55.84 percent, P = 0.021). In conclusion, the HFE 282Y and 65C alleles were rare, while the HFE 63D allele was frequent in Brazilian blood donors. The HFE C282Y and H63D mutations were associated with alterations in iron status in blood donors in a gender-dependent manner.

HFE gene mutations and iron status of Brazilian blood donors.

Mutations of the HFE and TFR2 genes have been associated with iron overload. HFE and TFR2 mutations were assessed in blood donors, and the relationship with iron status was evaluated. Subjects (N = 542) were recruited at the Hemocentro da Santa Casa de São Paulo, São Paulo, Brazil. Iron status was not influenced by HFE mutations in women and was independent of blood donation frequency. In contrast, men carrying the HFE 282CY genotype had lower total iron-binding capacity (TIBC) than HFE 282CC genotype carriers. Men who donated blood for the first time and were carriers of the HFE 282CY genotype had higher transferrin saturation values and lower TIBC concentrations than those with the homozygous wild genotype for the HFE C282Y mutation. Moreover, in this group of blood donors, carriers of HFE 63DD plus 63HD genotypes had higher serum ferritin values than those with the homozygous wild genotype for HFE H63D mutation. Multiple linear regression analysis showed that HFE 282CY leads to a 17.21% increase (P = 0.018) and a 83.65% decrease (P = 0.007) in transferrin saturation and TIBC, respectively. In addition, serum ferritin is influenced by age (3.91%, P = 0.001) and the HFE 63HD plus DD genotype (55.84%, P = 0.021). In conclusion, the HFE 282Y and 65C alleles were rare, while the HFE 63D allele was frequent in Brazilian blood donors. The HFE C282Y and H63D mutations were associated with alterations in iron status in blood donors in a gender-dependent manner.

Direct detection of Mycobacterium bovis in bovine lymph nodes by PCR.

Thirty-five lymph node samples were taken from animals with macroscopic lesions consistent with Mycobacterium bovis infection. The animals were identified by postmortem examination in an abattoir in the northwestern region of state of Paraná, Brazil. Twenty-two of the animals had previously been found to be tuberculin skin test positive. Tissue samples were decontaminated by Petroff's method and processed for acid-fast bacilli staining, culture in Stonebrink and Lowenstein-Jensen media and DNA extraction. Lymph node DNA samples were amplified by PCR in the absence and presence (inhibitor controls) of DNA extracted from M. bovis culture. Mycobacterium bovis was identified in 14 (42.4%) lymph node samples by both PCR and by culture. The frequency of PCR-positive results (54.5%) was similar to that of culture-positive results (51.5%, P > 0.05). The percentage of PCR-positive lymph nodes increased from 39.4% (13/33) to 54.5% (18/33) when samples that were initially PCR-negative were reanalysed using 2.5 microl DNA (two samples) and 1 : 2 diluted DNA (three samples). PCR sensitivity was affected by inhibitors and by the amount of DNA in the clinical samples. Our results indicate that direct detection of M. bovis in lymph nodes by PCR may be a fast and useful tool for bovine tuberculosis epidemic management in the region.

Polimorfismos no receptor Scavenger classe B tipo I e sua relação com perfil lipídico sérico e resposta a atorvastatina em indivíduos brasileiros / Scavenger receptor class B type I polymorphisms and its relation with serum lipids profile and response to atorvastatin in Braszilian individuals

O receptor scavenger BI (SR-BI) é um componente chave do transporte reverso do colesterol. Polimosfismos no gene SCARB1 foram associados com variações no perfil lipídico e outros de risco cardiovascular. Os polimosfismos de nucleotídeo único In5C>T e Ex8C>T no SCARB1 e medidas de lípides e apolipoproteínas foram avaliadas em 79 hipercolesterolêmicos (HC) e 173 normolipidêmicos (NL) provenientes do Brasil. Pacientes HC foram tratados com atorvastatina (10mg/dia/4semanas). Os polimosfismos foram identificados por PCR-RFLP. Os indivíduos HC portadores dos genótipos In5CC+TT mostraram concentrações mais elevadas de LDL-C, apoB, e menores da relação apoAI/apoB. No grupo NL, os genótipos In5CC+TT foram associados com concentrações maiores de LDL-C. Os indivíduos HC portadores de genótipo Ex8CC tiveram uma variação menor da razão apoAI/apoB em resposta à atorvastatina (p<0,05). Nos Hc portadores do haplótipo Ex8CC+CT/In5CT+TT tiveram valores basais elevados de LDL-C e relação apoAI/apoB diminuída. Após o tratamento com atorvastatina, os indivíduos Hc portadores do haplótipo Ex8CC/In5CC tiveram uma variação menor na relação apoAI/apoB. Os genótipos In5CT+TT no SCANB1 conferem um perfil lipídico mais aterogênico. O genótipo Ex8CC e o haplótipo Ex8CC estão associados com uma resposta à atorvastatina menor da razão apoAI/apoB na nossa população.

Genetic population data of 12 STR loci of the PowerPlex Y system in the state of São Paulo population (Southeast of Brazil).

Allele frequency distributions and population data for 12 Y-chromosomal short tandem repeats (STRs) included in the PowerPlex Y Systems (Promega) were obtained for a sample of 200 healthy unrelated males living in São Paulo State (Southeast of Brazil). A total of 192 haplotypes were identified, of which 184 were unique and 8 were found in 2 individuals. The average gene diversity of the 12 Y-STR was 0.6746 and the haplotype diversity was 0.9996. Pairwise analysis confirmed that our population is more similar with the Italy, North Portugal and Spain, being more distant of the Japan.

Association between decreased vitamin levels and MTHFR, MTR and MTRR gene polymorphisms as determinants for elevated total homocysteine concentrations in pregnant women.

OBJECTIVES: To examine the association between methylenetetrahydrofolate reductase (MTHFR) (C677T and A1298C), methionine synthase (MTR) A2756G and methionine synthase reductase (MTRR) A66G gene polymorphisms and total homocysteine (tHcy), methylmalonic acid (MMA) and S-adenosylmethionine/S-adenosylhomocysteine (SAM/SAH) levels; and to evaluate the potential interactions with folate or cobalamin (Cbl) status. SUBJECTS/METHODS: Two hundred seventy-five healthy women at labor who delivered full-term normal babies. Cbl, folate, tHcy, MMA, SAM and SAH were measured in serum specimens. The genotypes for polymorphisms were determined by PCR-restriction fragment length polymorphism (RFLP). RESULTS: Serum folate, MTHFR 677T allele and MTR 2756AA genotypes were the predictors of tHcy levels in pregnant women. Serum Cbl and creatinine were the predictors of SAM/SAH ratio and MMA levels, respectively. The gene polymorphisms were not determinants for MMA levels and SAM/SAH ratios. Low levels of serum folate were associated with elevated tHcy in pregnant women, independently of the gene polymorphisms. In pregnant women carrying MTHFR 677T allele, or MTHFR 1298AA or MTRR 66AA genotypes, lower Cbl levels were associated with higher levels of tHcy. Lower SAM/SAH ratio was found in MTHFR 677CC or MTRR A2756AA genotypes carriers when Cbl levels were lower than 142 pmol/l. CONCLUSIONS: Serum folate and MTHFR C677T and MTR A2576G gene polymorphisms were the determinants for tHcy levels. The interaction between low levels of serum Cbl and MTHFR (C677T or A1298C) or MTRR A66G gene polymorphisms was associated with increased tHcy.