Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
1.
J Endocrinol Invest ; 40(12): 1279-1288, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28612285

RESUMO

PURPOSE: Non-alcoholic fatty liver disease (NAFLD) is an insidious pathologic condition that can manifest from simple steatosis to steatohepatitis (NASH) with potential progression to cirrhosis. Like the polycystic ovary syndrome (PCOS), NAFLD is associated with obesity, diabetes mellitus, insulin resistance and metabolic syndrome. PCOS women have an increased risk of NAFLD, but it is debatable which features of PCOS, either specific (androgen excess) or unspecific (metabolic derangements) affect the NAFLD risk. METHODS: We performed a systematic review and meta-analysis of studies that addressed the association of PCOS and NAFLD. We selected 17 studies published between 2007 and 2017 that included 2734 PCOS patients and 2561 controls of similar age and body mass index (BMI). RESULTS: PCOS patients have increased prevalence of NAFLD (odds ratio 2.54, 95% confidence interval 2.19-2.95). PCOS women with hyperandrogenism (classic phenotype) have a higher prevalence of NAFLD compared to women with PCOS without hyperandrogenism, even after correction for confounding variables. Among women with PCOS, those with NAFLD have higher serum total testosterone (mean difference 0.40 nmol/L, 95% CI 0.29-0.50 nmol/L) and free androgen index (mean difference 4.46, 95% CI 3.53-5.39) than those without NAFLD. The studies that used multivariate analysis controlling for age, BMI, triglycerides, and insulin resistance index confirmed that serum androgens are independent predictors of NAFLD in women with PCOS. CONCLUSION: The prevalence of NAFLD is increased in women with PCOS and the presence of NAFLD is associated with high serum androgen levels, in addition to obesity and insulin resistance.


Assuntos
Hepatopatia Gordurosa não Alcoólica/etiologia , Síndrome do Ovário Policístico/complicações , Feminino , Humanos , Fatores de Risco
2.
Genet Mol Res ; 15(4)2016 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-27886332

RESUMO

Bacterial wilt of common bean caused by Curtobacterium flaccumfaciens pv. flaccumfaciens is an important disease in terms of economic importance. It reduces grain yield by colonizing xylem vessels, subsequently impeding the translocation of water and nutrients to the superior plant parts. The existence of physiological races in C. flaccumfaciens pv. flaccumfaciens has not so far been reported. The objective of the present investigation was to identify physiological races, evaluate differential interaction, and select resistant genotypes of common bean. Initially, 30 genotypes of common bean were inoculated with eight isolates exhibiting different levels of aggressiveness, under controlled greenhouse conditions. Disease was assessed 15 days after inoculation. The existence of differential interactions between C. flaccumfaciens pv. flaccumfaciens isolates and common bean genotypes were identified by utilizing partial diallel analysis. The most aggressive isolates were BRM 14939 and BRM 14942 and the least aggressive isolates were BRM 14941 and BRM 14946. The genotypes IPA 9, Ouro Branco, and Michelite were selected as more resistant among the test isolates. The genotypes IAC Carioca Akytã, BRS Notável, Pérola, IAC Carioca Aruã, and Coquinho contributed more to the isolate x genotype interaction according to the ecovalence method of estimation, and were, therefore, indicated as differentials. Based on these results, it was possible to conclude that physiological races of the pathogen exist, to select resistant genotypes, and to propose a set of differentials.


Assuntos
Actinomycetales/patogenicidade , Resistência à Doença , Phaseolus/genética , Doenças das Plantas/microbiologia , Actinomycetales/genética , Genes de Plantas , Genótipo , Interações Hospedeiro-Patógeno , Phaseolus/microbiologia , Fatores de Virulência/genética
3.
Genet Mol Res ; 15(4)2016 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-27813612

RESUMO

The aim of this study was to evaluate the phenotypic stability and specific and broad adaptability of common black bean genotypes for the Central and Center-South regions of Brazil by using the Annicchiarico and AMMI (weighted average of absolute scores: WAAS, and weighted average of absolute scores and productivity: WAASP) methodologies. We carried out 69 trials, with 43 and 26 trials in the Central and Center-South regions, respectively. Thirteen genotypes were evaluated in a randomized block design with three replications, during the rainy, dry, and winter seasons in 2 years. To obtain estimates of specific adaptation, we analyzed the parameters for each method obtained in the two geographic regions separately. To estimate broad adaptation, we used the average of the parameters obtained from each region. The lines identified with high specific adaptation in each region were not the same based on the Annicchiarico and AMMI (WAAS) methodologies. It was not possible to identify the same genotypes with specific or broad stability by using these methods. By contrast, the Annicchiarico and AMMI (WAASP) methods presented very similar estimates of broad and specific adaptation. Based on these methods, the lines with more specific adaptation were CNFP 8000 and CNFP 7994, in the Central and Center-South regions, respectively, of which the CNFP 8000 line was more widely adapted.


Assuntos
Adaptação Fisiológica/genética , Interação Gene-Ambiente , Modelos Genéticos , Phaseolus/genética , Brasil , Variação Genética , Genótipo , Phaseolus/crescimento & desenvolvimento , Fenótipo , Estações do Ano
4.
Genet Mol Res ; 15(2)2016 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-27323172

RESUMO

One of the current focus of common bean breeding programs in Brazil is to increase iron (FeC) and zinc content (ZnC) in grains. The objectives of this study were to estimate genetic parameters for FeC and ZnC in common bean, verify the need for conducting multi-site evaluation tests, identify elite lines that combine high FeC and ZnC with good adaptability, stability, and agronomic potential, and examine the genetic association between FeC and ZnC. Elite lines (140) were evaluated for important agronomic traits in multiple environments. In one trial, FeC and ZnC were evaluated and genetic parameters were estimated. Based on the high heritability estimates and significant selection gains obtained, the conditions for a successful selection was favorable. Of the 140 evaluated lines, 17 had higher FeC and ZnC, and were included in the validation test (2013, five environments), specifically for the evaluation of FeC and ZnC. The line by environment interaction for FeC and ZnC was detected, but it was predominantly simple. The environmental effect strongly influenced FeC and ZnC . The environment Brasília/rainy season was selected as the best evaluation site for preliminary tests for FeC and ZnC, because it resulted in similar conclusions as the mean of the five environments. The lines CNFP 15701 and CNFC 15865 had higher FeC and ZnC and were highly adaptable and stable, and are recommended for utilization in breeding programs. The lines CNFC 15833, CNFC 15703, and CNFP 15676 showed excellent combined agronomic and nutritional traits, and were selected for the development of biofortified cultivars. Additionally, the genetic association between FeC and ZnC was detected.


Assuntos
Ferro/química , Phaseolus/genética , Característica Quantitativa Herdável , Zinco/química , Brasil , Cruzamento , Grão Comestível/química , Grão Comestível/genética , Meio Ambiente , Phaseolus/crescimento & desenvolvimento , Phaseolus/metabolismo , Fenótipo , Sementes/química , Sementes/genética
5.
Braz. j. med. biol. res ; 47(11): 990-994, 11/2014. tab, graf
Artigo em Inglês | LILACS | ID: lil-723905

RESUMO

Estimates of occult hepatitis B virus (HBV) infection prevalence varies among different studies depending on the prevalence of HBV infection in the study population and on the sensitivity of the assay used to detect HBV DNA. We investigated the prevalence of occult HBV infection in cirrhotic patients undergoing liver transplantation in a Brazilian referral center. Frozen liver samples from 68 adults were analyzed using a nested polymerase chain reaction assay for HBV DNA. The specificity of the amplified HBV sequences was confirmed by direct sequencing of the amplicons. The patient population comprised 49 (72.1%) males and 19 (27.9%) females with a median age of 53 years (range=18-67 years). Occult HBV infection was diagnosed in three (4.4%) patients. The etiologies of the underlying chronic liver disease in these cases were alcohol abuse, HBV infection, and cryptogenic cirrhosis. Two of the patients with cryptic HBV infection also presented hepatocellular carcinoma. Markers of previous HBV infection were available in two patients with occult HBV infection and were negative in both. In conclusion, using a sensitive nested polymerase chain reaction assay to detect HBV DNA in frozen liver tissue, we found a low prevalence of occult HBV infection in cirrhotic patients undergoing liver transplant, probably due to the low prevalence of HBV infection in our population.


Assuntos
Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , DNA Viral/isolamento & purificação , Vírus da Hepatite B/isolamento & purificação , Hepatite B Crônica/epidemiologia , Transplante de Fígado , Cirrose Hepática/virologia , Infecções Assintomáticas/epidemiologia , Biomarcadores , Brasil/epidemiologia , Carcinoma Hepatocelular/complicações , Vírus da Hepatite B/genética , Hepatite B Crônica/complicações , Hepatite Crônica/complicações , Hepatite Crônica/epidemiologia , Neoplasias Hepáticas/complicações , Reação em Cadeia da Polimerase , Prevalência , Centros de Atenção Terciária
6.
Braz J Med Biol Res ; 47(11): 990-4, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25296362

RESUMO

Estimates of occult hepatitis B virus (HBV) infection prevalence varies among different studies depending on the prevalence of HBV infection in the study population and on the sensitivity of the assay used to detect HBV DNA. We investigated the prevalence of occult HBV infection in cirrhotic patients undergoing liver transplantation in a Brazilian referral center. Frozen liver samples from 68 adults were analyzed using a nested polymerase chain reaction assay for HBV DNA. The specificity of the amplified HBV sequences was confirmed by direct sequencing of the amplicons. The patient population comprised 49 (72.1%) males and 19 (27.9%) females with a median age of 53 years (range=18-67 years). Occult HBV infection was diagnosed in three (4.4%) patients. The etiologies of the underlying chronic liver disease in these cases were alcohol abuse, HBV infection, and cryptogenic cirrhosis. Two of the patients with cryptic HBV infection also presented hepatocellular carcinoma. Markers of previous HBV infection were available in two patients with occult HBV infection and were negative in both. In conclusion, using a sensitive nested polymerase chain reaction assay to detect HBV DNA in frozen liver tissue, we found a low prevalence of occult HBV infection in cirrhotic patients undergoing liver transplant, probably due to the low prevalence of HBV infection in our population.


Assuntos
DNA Viral/isolamento & purificação , Vírus da Hepatite B/isolamento & purificação , Hepatite B Crônica/epidemiologia , Cirrose Hepática/virologia , Transplante de Fígado , Adolescente , Adulto , Idoso , Infecções Assintomáticas/epidemiologia , Biomarcadores , Brasil/epidemiologia , Carcinoma Hepatocelular/complicações , Feminino , Vírus da Hepatite B/genética , Hepatite B Crônica/complicações , Hepatite Crônica/complicações , Hepatite Crônica/epidemiologia , Humanos , Neoplasias Hepáticas/complicações , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Prevalência , Centros de Atenção Terciária , Adulto Jovem
7.
Genet Mol Res ; 13(3): 6773-85, 2014 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-25177957

RESUMO

The common bean is an important source of iron and zinc in humans. Increases in the contents of these minerals can combat mineral deficiencies, but these contents are influenced by environmental conditions. Thus, the objectives of this study were to investigate the interaction between common bean lines and water availability on iron and zinc contents (CFe and CZn, respectively), identify superior lines with stable CFe and CZn, and test for a genetic relationship between CFe and CZn. Six crop trials were performed using a randomized block design with three replications. The trials were performed during the winter sowing period for three different combinations of year and site in Brazil. For each combination, 53 lines were evaluated across two parallel trials; one trial was irrigated according to the crop requirements, and the other trial operated under a water deficit. Interaction was detected between lines and environments, and between lines and water availability for CFe and CZn. However, some lines exhibited high CFe and CZn in both conditions. Lines G 6492 and G 6490 exhibited high mean values, stability, and adaptability for both minerals. Other lines exhibited high CFe (Xamego) or CZn (Bambuí and Iapar 65). A moderate genetic correlation (0.62) between CFe and CZn was detected. Water availability during the common bean cycle had an effect on CFe and CZn; however, lines with high CFe and CZn in different conditions of water availability and environment were detected.


Assuntos
Variação Genética , Ferro/metabolismo , Phaseolus/genética , Phaseolus/metabolismo , Água/metabolismo , Zinco/metabolismo , Adaptação Fisiológica/genética , Algoritmos , Interação Gene-Ambiente , Genótipo , Humanos , Modelos Genéticos
8.
J Theor Biol ; 358: 208-31, 2014 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-24928152

RESUMO

One of the great challenges of the scientific community on theories of genetic information, genetic communication and genetic coding is to determine a mathematical structure related to DNA sequences. In this paper we propose a model of an intra-cellular transmission system of genetic information similar to a model of a power and bandwidth efficient digital communication system in order to identify a mathematical structure in DNA sequences where such sequences are biologically relevant. The model of a transmission system of genetic information is concerned with the identification, reproduction and mathematical classification of the nucleotide sequence of single stranded DNA by the genetic encoder. Hence, a genetic encoder is devised where labelings and cyclic codes are established. The establishment of the algebraic structure of the corresponding codes alphabets, mappings, labelings, primitive polynomials (p(x)) and code generator polynomials (g(x)) are quite important in characterizing error-correcting codes subclasses of G-linear codes. These latter codes are useful for the identification, reproduction and mathematical classification of DNA sequences. The characterization of this model may contribute to the development of a methodology that can be applied in mutational analysis and polymorphisms, production of new drugs and genetic improvement, among other things, resulting in the reduction of time and laboratory costs.


Assuntos
Modelos Genéticos , Análise de Sequência de DNA , Algoritmos
9.
Am J Transplant ; 14(1): 96-101, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24369026

RESUMO

Visceral leishmaniasis is an uncommon disease in transplant recipients; however, if left untreated, the mortality can be high. If an organ donor or recipient is known to be an asymptomatic Leishmania spp. carrier,monitoring is advised. This study proposes to assess the prevalence of asymptomatic Leishmania spp.infection in liver transplant donors and recipients from an endemic area. A total of 50 liver recipients and 17 liver donors were evaluated by direct parasite search, indirect fluorescent antibody test (IFAT), anti-Leishmania rK39 rapid test and Leishmania spp.DNA detection by polymerase chain reaction (PCR).Leishmania spp. amastigotes were not observed in liver or spleen tissues. Of the 67 serum samples, IFAT was reactive in 1.5% and indeterminate for 17.9%, and the anti-Leishmania rK39 rapid test was negative for all samples. The PCR test was positive for 7.5%, 8.9%, and 5.9% of blood, liver and spleen samples, respectively(accounting for 23.5% of the donors and 8% of the recipients). Leishmania infantum-specific PCR confirmed all positive samples. In conclusion, a high prevalence of asymptomatic L. infantum was observed in donors and recipients from an endemic area, and PCR was the most sensitive method for screening these individuals.


Assuntos
Leishmaniose Visceral/epidemiologia , Transplante de Fígado/efeitos adversos , Adolescente , Adulto , Idoso , Brasil/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , DNA de Protozoário/análise , Feminino , Imunofluorescência , Humanos , Leishmania/genética , Leishmania infantum/imunologia , Leishmaniose Visceral/diagnóstico , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Prevalência , Estudos Prospectivos , Doadores de Tecidos
10.
Transplant Proc ; 45(1): 297-300, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23375318

RESUMO

The Model for End-Stage Liver Disease (MELD), which predicts mortality on the waiting list before liver transplantation, has changed organ allocation criteria to prioritize severely ill patients. The aim of this study was to investigate the impact of the new criteria on the incidence of Healthcare Associated Infections (HAI) and patient survival after liver transplantation. This retrospective cohort included liver transplant recipients from 2005 to 2007. Infection notification followed the recommended criteria of the National Healthcare Safety Network (NHSN). Statistical analysis was performed using the Statistical Package for the Social Sciences. Of 142 patients, 67 (47.2%) underwent transplantation before June 2006. There were no differences between the 2 periods considering patient gender, diagnosis, age, length of hospitalization, and mean time to first infection occurrence. However, the length of intensive care unit (ICU) hospitalization (P = .006) and central venous catheter (CVC) use (P = .025) were higher in the first period of the study. Comparison of time until first systemic infection before and after changes in allocation criteria showed no significant difference (log-rank = 0.06; P = .81). There was a trend toward greater lethality during the second period of the study (P = .09). There was no difference in time to death between the 2 periods (log-rank = 0.9; P = .76). However, when comparing time to death of all patients with systemic infection versus those without this event, patients without infection showed a higher mortality rate (log-rank = 15.7; P < .001).


Assuntos
Doença Hepática Terminal/patologia , Doença Hepática Terminal/terapia , Falência Hepática/cirurgia , Transplante de Fígado/métodos , Obtenção de Tecidos e Órgãos/métodos , Listas de Espera , Adolescente , Adulto , Idoso , Algoritmos , Brasil , Estudos de Coortes , Doenças Transmissíveis/complicações , Doenças Transmissíveis/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
11.
Braz J Infect Dis ; 14(1): 54-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20428655

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) infections frequently complicate the post-operative course of transplant recipients, and despite nasal carriage and endemic colonization, MRSA outbreaks are not commonly described. This study reports a case of MRSA outbreak and discusses infection control measures and recommendations for this situation.


Assuntos
Infecção Hospitalar/epidemiologia , Surtos de Doenças , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/epidemiologia , Transplante , Transplante de Medula Óssea/estatística & dados numéricos , Infecção Hospitalar/microbiologia , Genótipo , Humanos , Transplante de Rim/estatística & dados numéricos , Transplante de Fígado/estatística & dados numéricos , Fenótipo , Estudos Prospectivos , Fatores de Risco , Infecções Estafilocócicas/microbiologia , Transplante/estatística & dados numéricos
12.
Neurology ; 73(17): 1413-7, 2009 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-19858464

RESUMO

BACKGROUND: Dengue infection is caused by a flavivirus, with 4 virus serotypes (types 1 to 4). The serotypes 2 and 3 represent the principal agents related to nervous system involvement. Neurologic involvement occurs in 4%-5% of dengue infection cases. The major mechanisms of the disease may be related to direct viral infection or postinfectious autoimmune process. The detection of intrathecal synthesis of specific antibodies has been used to support neurologic diagnosis as a proof of local reaction. It may be quantitatively calculated by the specific antibody index. OBJECTIVES: To determine if patients with neurologic manifestations associated with dengue produce specific antibodies in the CNS and to determine the antibodies' clinical and pathophysiologic relevance. METHODS: CSF and serum were evaluated for dengue immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies by ELISA and for intrathecal synthesis of IgG antibodies to the dengue virus. Subjects included 10 patients IgM seropositive for dengue virus diagnosed with myelitis, encephalitis, optic neuromyelitis, or Guillain-Barré syndrome. RESULTS: All patients had IgG and IgM antibodies to dengue virus in their sera; 7 were IgM positive and 9 were IgG positive for dengue virus in CSF. Only the 3 patients with myelitis had intrathecal synthesis of specific IgG antibodies. CONCLUSIONS: Intrathecal synthesis of antibodies to dengue virus occurs in the CNS. It may be used as a marker of myelitis associated with dengue, and it seems to be related to the pathogenesis of spinal cord disease due to direct viral invasion.


Assuntos
Anticorpos Antivirais/líquido cefalorraquidiano , Vírus da Dengue/imunologia , Dengue/imunologia , Encefalite Viral/imunologia , Síndrome de Guillain-Barré/imunologia , Mielite/imunologia , Neurite Óptica/imunologia , Adulto , Idoso , Anticorpos Antivirais/sangue , Dengue/sangue , Dengue/líquido cefalorraquidiano , Encefalite Viral/sangue , Encefalite Viral/líquido cefalorraquidiano , Ensaio de Imunoadsorção Enzimática , Feminino , Síndrome de Guillain-Barré/sangue , Síndrome de Guillain-Barré/líquido cefalorraquidiano , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/líquido cefalorraquidiano , Imunoglobulina M/sangue , Imunoglobulina M/líquido cefalorraquidiano , Masculino , Pessoa de Meia-Idade , Mielite/sangue , Mielite/líquido cefalorraquidiano , Neurite Óptica/sangue , Neurite Óptica/líquido cefalorraquidiano , Estudos Retrospectivos , Adulto Jovem
13.
Br J Radiol ; 82(979): e145-7, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19541943

RESUMO

A case of acute toxaemic schistosomiasis is presented. Abdominal ultrasound examination revealed hepatosplenomegaly, lymphadenomegaly, heterogeneous hepatic parenchyma and heterogeneous focal lesions in the pancreas. CT confirmed lymph node enlargement and hepatosplenomegaly, and showed multiple small focal nodular lesions in the liver and focal lesions in the pancreas. To our knowledge, this is the first description of pancreatic lesions associated with acute Schistosoma mansoni infection.


Assuntos
Hepatopatias Parasitárias , Pancreatopatias , Esquistossomose mansoni , Doença Aguda , Hepatomegalia/diagnóstico , Hepatomegalia/parasitologia , Humanos , Hepatopatias Parasitárias/diagnóstico por imagem , Doenças Linfáticas/diagnóstico , Doenças Linfáticas/parasitologia , Masculino , Pancreatopatias/diagnóstico por imagem , Esquistossomose mansoni/diagnóstico por imagem , Esplenomegalia/diagnóstico , Esplenomegalia/parasitologia , Tomografia Computadorizada por Raios X , Toxemia/parasitologia , Ultrassonografia , Adulto Jovem
14.
J Neurol Sci ; 249(1): 19-24, 2006 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-16870213

RESUMO

Neurological manifestation is considered a rare complication of dengue infection. Neurological and cerebrospinal fluid (CSF) findings of 13 patients with dengue infection were studied. Seven patients had encephalitis, two had myelitis and four showed Guillain-Barré syndrome (GBS). No alteration in CSF was found from 57% of those with encephalitis. Patients with GBS and myelitis showed a CSF-blood barrier dysfunction. The differences in the CSF may be related to the location of the lesion and multiple mechanisms of the disease in the nervous system.


Assuntos
Proteínas do Líquido Cefalorraquidiano/imunologia , Vírus da Dengue/imunologia , Dengue/complicações , Encefalite Viral/diagnóstico , Síndrome de Guillain-Barré/diagnóstico , Mielite/diagnóstico , Adulto , Idoso , Proteínas do Líquido Cefalorraquidiano/análise , Criança , Encefalite Viral/líquido cefalorraquidiano , Encefalite Viral/virologia , Feminino , Síndrome de Guillain-Barré/líquido cefalorraquidiano , Síndrome de Guillain-Barré/virologia , Humanos , Imunoglobulina M/líquido cefalorraquidiano , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Mielite/líquido cefalorraquidiano , Mielite/virologia , Valor Preditivo dos Testes , Sorotipagem , Medula Espinal/patologia , Medula Espinal/fisiopatologia , Medula Espinal/virologia
15.
Neuroscience ; 125(4): 965-71, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15120856

RESUMO

Succinate is a dicarboxylic acid that accumulates due to succinate dehydrogenase inhibition by malonate and methylmalonate exposure. These neurotoxins cause increased excitability and excitotoxic damage, which can be prevented by administering high amounts of succinate. In the present study we investigated whether succinate alters hippocampal field excitatory post-synaptic potentials. Bath application of succinate at intermediate concentrations (0.3-1 mM) increased the slope of field excitatory post-synaptic potentials in hippocampal slices, and at high concentrations (above 1 mM) did not alter or decrease field excitatory post-synaptic potentials slope. Succinate-induced enhancement of field excitatory post-synaptic potentials slope was abolished by the addition of d-2-amino-5-phosphonovaleric acid (50 microM) to the perfusate, supporting the involvement of N-methyl-d-aspartate receptors in the excitatory effect of this organic acid. Accordingly, succinate (0.8-7.5 micromol) i.c.v. administration caused dose-dependent convulsive behavior in mice. The i.c.v. co-administration of MK-801 (7 nmol) fully prevented succinate-induced convulsions, further suggesting the involvement of N-methyl-d-aspartate receptors in the convulsant action of succinate. Our data indicate that accumulation of moderate amounts of succinate may contribute to the excitotoxicity induced by succinate dehydrogenase inhibitors, through the activation of N-methyl-d-aspartate receptors.


Assuntos
Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/administração & dosagem , Receptores de N-Metil-D-Aspartato/metabolismo , Convulsões/etiologia , Ácido Succínico/administração & dosagem , Animais , Maleato de Dizocilpina/farmacologia , Relação Dose-Resposta a Droga , Antagonistas de Aminoácidos Excitatórios/farmacologia , Potenciais Pós-Sinápticos Excitadores/fisiologia , Hipocampo/efeitos dos fármacos , Hipocampo/fisiologia , Injeções Intraventriculares , Masculino , Camundongos , Neurônios/fisiologia , Ratos
16.
Rev Inst Med Trop Sao Paulo ; 43(1): 45-50, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11246283

RESUMO

Whipple's disease (WD) is a rare systemic disease of infectious etiology which involves the small intestine but can virtually affect any organ. We present here five cases (four males and one female) ranging in age from 20 to 59 years. All patients had intestinal involvement associated or not with clinical manifestations linked to this organ. Vegetation in the tricuspid valve was observed in one patient, suggesting endocarditis caused by Tropheryma whippelii, with disappearance of the echocardiographic alterations after treatment. In one of the male patients the initial clinical manifestation was serologically negative spondylitis, with no diarrhea occurring at any time during follow-up. Ocular involvement associated with intestinal malabsorption and significant weight loss were observed in one case. In the other two cases, diarrhea was the major clinical manifestation. All patients were diagnosed by histological examination of the jejunal mucosa and, when indicated, of extraintestinal tissues by light and electron microscopy. After antibiotic treatment, full remission of symptoms occurred in all cases. A control examination of the intestinal mucosa performed after twelve months of treatment with sulfamethoxazole-trimethoprim revealed the disappearance of T. whippelii in four patients. The remaining patient was lost to follow-up.


Assuntos
Doença de Whipple/patologia , Adulto , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Whipple/terapia
17.
J Automat Chem ; 14(3): 97-100, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-18924939

RESUMO

A monosegmented continuous-flow system (MCFS) has been evaluated for determination of creatinine in urine using the Jaffé reaction. The analyser is compact and allows 130 determinations to be performed per hour, with a relative standard deviation of the peak height better than 1.5% (N =10). The results for real samples agree with those obtained by. the standard manual Jaffé procedure and with the kinetic automatic method.

18.
Analyst ; 116(4): 357-60, 1991 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1872483

RESUMO

A flow injection method was developed, aimed at the determination of urea in human serum. The system makes use of the naturally immobilized urease present in Canavalia ensiformis DC (jack bean). A column is filled with small pieces of this bean, and the sample (50 microliters) containing urea passes through it carried by a 1% NaCl solution. On leaving the column the stream is merged with an alkaline reagent (0.5 mol dm-3 NaOH; 0.5% disodium dihydrogen ethylenediaminetetraacetate). The ammonium ions, arising from the enzymatic reaction that occurs inside the column, are changed into the molecular form, which permeates a polytetrafluoroethylene membrane and is received in a de-ionized water acceptor stream. The ammonia ionizes causing an increase in the conductance, which is proportional to the urea content of the sample. About 40 samples can be processed in 1 h with negligible carry-over and with a relative standard deviation of 1% or less. The results are in agreement with those obtained by a standard spectrophotometric method.


Assuntos
Condutometria/métodos , Enzimas Imobilizadas , Ureia/sangue , Urease , Condutometria/estatística & dados numéricos , Humanos , Concentração de Íons de Hidrogênio , Urease/antagonistas & inibidores
19.
J Automat Chem ; 13(4): 143-6, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-18924899

RESUMO

A flow injection analyser has been constructed to allow an operator-free determination of up to 40 samples. Besides the usual FIA apparatus, the analyser includes a home-made sample introduction device made with three electromechanical three-way valves and an auto-sampler from Technicon which has been adapted to be commanded by an external digital signal. The analyser is controlled by a single board SDK-8085 microcomputer. The necessary interface to couple the analyser components to the microcomputer is also described. The analyser was evaluated for a Cr(VI)-FIA determination showing a very good performance with a relative standard deviation for 15 signals from the injection of 100 mul of a 1.0 mg.ml(-1) standard Cr(VI) solution being equal to 0.5%.

20.
J Automat Chem ; 10(4): 188-91, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-18925214

RESUMO

Minor modifications to a Coleman MAS-50A Mercury Analyser System allowed the determination of mercury by flow injection analysis. Using sample volumes of 600 mul it was possible to analyse up to 120 samples per hour, with a detection limit of 0.2 mug. l(-1) (120 pg) of mercury. The authors also report on a simple digestion procedure which replaces the time- and reagent-consuming EPA procedure, when the sample content permits.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...