Porphyrins as early biomarkers for arsenic exposure in animals and humans

We studied the effect of arsenic exposure on the haem biosynthetic pathway in the rat and humans. Significant increases in protoporphyrin IX, coproporphyrin III, coproporphyrin I were observed in the blood, liver and kidney, and in the urine of rats after a single dose of arsenic. The level of increase was dependent on the arsenic species present. Most of porphyrin concentrations in the tissues increased within 24 hr and urinary excretion elevated within 48 hr. In the human study, we collected urine samples from 113 people who live in Xing Ren of Guizhou Province, a coal-borne arsenicosis endemic area in southwest of PR China and from 30 people who live in Xing Yi (about 80 km southwest of Xing Ren) where arsenicosis is not prevalent. We analyzed the urinary porphyrins using HPLC. Results indicate that all urinary porphyrins were higher in the arsenic exposed group than those in the control group. Women, children and older age people spend much of their time indoors, they had greater increases of urinary arsenic and porphyrins. They were the higher risk groups among the study subjects. A positive correlation between the urinary arsenic levels and porphyrin concentrations demonstrated the effect of arsenic on haem biosynthesis. Significant alteration in the porphyrin excretion profiles of the younger age (

Distribution of two splice variants of the glutamate transporter GLT1 in the retinas of humans, monkeys, rabbits, rats, cats, and chickens

Antibodies have been generated against two carboxyl-terminal splice variants of the glutamate transporter GLT1, namely, the originally described version of GLT1 and GLT1-B, and labelling has been examined in multiple species, including chickens and humans. Although strong specific labelling was observed in each species, divergent patterns of expression were noted. Moreover, each antibody was sensitive to the phosphorylation state of the appropriate protein, because chemical removal of phosphates using alkaline phosphatase revealed a broader range of labelled elements in most cases. In general, GLT1-B was present in cone photoreceptors and in rod and cone bipolar cells in the retinas of rabbits, rats, and cats. In the cone-dominated retinas of chickens and in marmosets, GLT1-B was associated only with cone photoreceptors, whereas, in macaque and human retinas, GLT1-B was associated with bipolar cells and terminals of photoreceptors. In some species, such as cats, GLT-B was also present in horizontal cells. By contrast, GLT1 distribution varied. GLT1 was associated with amacrine cells in chickens, rats, cats, and rabbits and with bipolar cells in marmosets and macaques. In the rat retina, rod photoreceptor terminals also contained GLT1, but this was evident only in enzymatically dephosphorylated tissues. We conclude that the two variants of GLT1 are present in all species examined but are differentially distributed in a species-specific manner. Moreover, each cell type generally expresses only one splice variant of GLT1. J. Comp. Neurol. 445:1-12, 2002. (C) 2002 Wiley-Liss, Inc.

The Australian paralysis may be the missing link tick in the transmission of Hendra virus from bats to horses to humans

Hendra virus is a new virus of the family Paramyxoviridae. This virus was first detected in Queensland, Australia, in 1994; although, it seems that the virus has infected fruit-eating bats (flying-foxes) for a very long time. At least 2 humans and 15 horses have been killed by this virus since it first emerged as a virus that may infect mammals other than flying-foxes. Hendra virus is thought to have moved from flying-foxes to horses, and then from horses to people. There is a reasonably strong hypothesis for horse-to-human transmission: transmission of virus via nasal discharge, saliva and/or urine. In contrast, there is no strong hypothesis for flying-fox-to-human transmission. I present evidence that the Australian paralysis tick, Ixodes holocyclus, which has apparently only recently become a parasite of flying-foxes, may transmit Hendra virus and perhaps related viruses from flying-foxes to horses and other mammals. (C) 2003 Elsevier Science Ltd. All rights reserved.

Decreased coumarin 7-hydroxylase activities and CYP2A6 expression levels in humans caused by genetic polymorphism in CYP2A6 promoter region (CYP2A6*9)

One of seven poor metabolizers of coumarin found in Thai subjects was previously genotyped as heterozygote for the CYP2A6*4 (whole deletion) and CYP2A6*9. Thus, we aimed to investigate the relationship between the genetic polymorphism in the TATA box of the CYP2A6 gene (CYP2A6*9), expression levels of CYP2A6 mRNA and coumarin 7-hydroxylase activities in human livers. Levels of CYP2A6 mRNA were quantified by real-time quantitative reverse transcriptase-polymerase chain reaction. The mean expression levels of CYP2A6 mRNA in individuals with CYP2A6*1/*4, CYP2A6*1/*9 and CYP2A6*4/*9 were 58%, 71% and 21% of the individuals genotyped as CYP2A6*1/*1, respectively. The mean in-vitro coumarin 7-hydroxylase activities in subjects carrying CYP2A6*1/*4, CYP2A6*1/*9 and CYP2A6*4/*9 were 41%, 71% and 12%, respectively, compared to those of the subjects judged as wild-type. Vmax values for coumarin 7-hydroxylation in the liver microsomes from human subjects with genotypes of CYP2A6*1/*1, CYP2A6*1/*4, CYP2A6*1/*9 and CYP2A6*4/*9 were 0.58, 0.26, 0.44 and 0.13 nmol/min/nmol total P450, respectively. CYP2A6 protein levels in human liver microsomes with the CYP2A6*4 and the CYP2A6*9 alleles were markedly decreased. These results suggest that the genetic polymorphism in the promoter region of the CYP2A6 gene (CYP2A6*9) reduced the expression levels of CYP2A6 mRNA and protein in human livers, resulting in the decrease of coumarin 7-hydroxylase activities. Individuals judged as CYP2A6*4/*9 were expected to be poor metabolizers, having extremely low activity of CYP2A6.

O lugar do género, dos homens e das mulheres na sociologia portuguesa: uma análise a partir da Associação Portuguesa de Sociologia e seus congressos

O e-working paper que se apresenta insere-se no campo analítico da sociologia da ciência, e tem como objectivos, por um lado, compreender como o género se constitui, ou não, como um elemento estruturante na distribuição dos actores pelo campo disciplinar e, por outro lado, explorar as configurações que a sociologia do género tem assumido na produção científica nacional. Os Congressos Portugueses de Sociologia (1988 a 2008), e a Associação Portuguesa de Sociologia constituíram o material empírico que possibilitou o exercício. This e-working paper integrates the realm of sociology of science, and aimed, on one hand, to understand how gender is a structural element in the distribution of actors within the disciplinary field and, on the other hand, to explore the configurations of sociology of gender in the scientific production. Therefore, the analysis is produced from two privileged empirical objects: the Portuguese Congress of Sociology (1988 to 2008) and the Portuguese Association of Sociology.

Fiscalização da empreitada do "Centro de Congressos, Feiras e Exposições de Oeiras": estrutura metálica da cobertura

O presente relatório é referente ao trabalho realizado na empresa Prospectiva, S.A. , e procurou descrever os trabalhos realizados para a execução da estrutura metálica da cobertura do Centro de Congressos de Oeiras. Foi feita uma pequena apresentação da empresa assim como uma descrição global mas pouco detalhada da obra em causa. Foram descritas as principais fases da execução de estruturas metálicas como, o fabrico e a montagem dos elementos, assim como o seu enquadramento com as principais disposições regulamentares impostas a este tipo de estrutura. Na fase de fabrico foram descritos todos os processos envolvidos desde a recepção da matéria-prima até ao produto final das peças, fazendo sempre um acompanhamento com o Plano de Inspecção e Ensaio da fase de fabrico. No caso da montagem da estrutura foi feita a descrição do processo de transporte e o acompanhamento das principais fases da montagem, como o seu planeamento e faseamento, até a sua importância no próprio planeamento global da obra. Foram também apresentados os equipamentos utilizados, estruturas de apoio à montagem e os tipos de ligações executadas.

Epidemiological role of humans, dogs and cats in the transmission of Trypanosoma cruzi in a central area of Argentina

Trypanosoma cruzi prevalence rates of human, dog and cat populations from 47 households of 3 rural localities of the phytogeographical Chaqueña area of Argentina were determined both by serological and xenodiagnostic procedures. Human prevalence rates were uniform and ranged from 49.6 to 58.7%. Overall prevalence rate in dogs (75.0%) was significantly higher than in humans (51.0%). The overall proportion of parasitemic individuals assessed by xenodiagnosis was significantly higher in either dog (64.2%) or cat (63.6%) populations than among humans (12.5%). Although both the average number of resident as well as infected individuals per household was higher for people than for dogs (6.5 vs. 3.3, and 3.4 vs. 2.4, respectively), the reverse was recorded when parasitemic individuals were considered (1.0 vs. 2.1). Results are discussed in relation to dog between dogs and people, and dogs and bugs. In the light of present data, dogs must be considered as the major donors of parasites to vector bugs and thus, principal contributors to transmission in this region of Argentina.

Antigenic typing of brazilian rabies virus samples isolated from animals and humans, 1989-2000

Animal and human rabies samples isolated between 1989 and 2000 were typified by means of a monoclonal antibody panel against the viral nucleoprotein. The panel had been previously established to study the molecular epidemiology of rabies virus in the Americas. Samples were isolated in the Diagnostic Laboratory of the Pasteur Institute and in other rabies diagnostic centers in Brazil. In addition to the fixed virus samples CVS-31/96-IP, preserved in mouse brain, and PV-BHK/97, preserved in cell culture, a total of 330 rabies virus samples were isolated from dogs, cats, cattle, horses, bats, sheep, goat, swine, foxes, marmosets, coati and humans. Six antigenic variants that were compatible with the pre-established monoclonal antibodies panel were defined: numbers 2 (dog), 3 (Desmodus rotundus), 4 (Tadarida brasiliensis), 5 (vampire bat from Venezuela), 6 (Lasiurus cinereus) and Lab (reacted to all used antibodies). Six unknown profiles, not compatible with the panel, were also found. Samples isolated from insectivore bats showed the greatest variability and the most commonly isolated variant was variant-3 (Desmodus rotundus). These findings may be related to the existence of multiple independent transmission cycles, involving different bat species.

Clinical-epidemiological study of leptospirosis in humans and reservoirs in Yucatán, México

A leptospirosis clinical-epidemiological study was made in humans and reservoirs in the state of Yucatán, México. Interviews and serological analyses were made on 400 persons from an open population, 439 probable cases of leptospirosis and 1060 animal reservoirs (cows, pigs, dogs, rats and opossums). IgM Leptospira DipstickTM and Microscopic Agglutination Test (MAT) was used to detect human antibodies to leptospiras and serovar respectively. Leptospirosis incidence in humans was 2.2/100,000 inhab. in 1998, 0.7/100,000 in 1999 and 0.9/100,000 in 2000. Overall seroprevalence was 14.2%, relatively unchanged from seroprevalences observed 20 years ago. Highest seropositivity was found in people over 56 years of age, predominating males over females. Predominant serovars in the open population were tarassovi, hardjo, pomona and panama. Leptospirosis cases were most frequent in rural areas, and the anicteric course predominated over the icteric. The panama, icterohaemorrhagiae and pomona serovars predominated in both anicteric and icteric courses. Dogs, pigs and rodents had the highest seropositivity among the reservoirs. Contact with rodents and natural water sources were significant factors (p £ 0.05). Human cases (74%) occurred during the rainy season. It is concluded that leptospirosis is still a serious illness with important clinical and epidemiological implications in the state of Yucatán, Mexico.

Plasmid profile in oral Fusobacterium nucleatum from humans and Cebus apella monkeys

Fusobacterium nucleatum is a strict anaerobe and is indigenous of the human oral cavity. This organism is commonly recovered from different monomicrobial and mixed infections in humans and animals. In this study, the plasmid profile, the plasmid stability and the penicillin-resistance association in oral F. nucleatum isolated from periodontal patients, healthy subjects and Cebus apella monkeys were evaluated. Forty-five F. nucleatum strains from patients, 38 from healthy subjects and seven from C. apella were identified and analyzed. Plasmid extraction was performed in all the isolated strains. These elements were found in 26.7% strains from patients and one strain from C. apella. Strains from healthy subjects did not show any plasmid. Most of strains showed two plasmid bands ranging from 4 to 16 Kb, but digestions with endonucleases showed that they belonged to a single plasmid. The plasmid profile was similar and stable in human and monkey strains. Also, plasmids were classified into three groups according to size. Two strains were positive to beta-lactamase production and no plasmid DNA-hybridization with a beta-lactamase gene probe was observed, suggesting a chromosomal resistance.

Seroprevalence of antibodies to Venezuelan equine encephalitis complex (subtypes IAB and VI) in humans from General Belgrano Island, Formosa, Argentina

This work presents the results of the detection of antibodies (immunoglobulin G) for subtypes I and VI of VEE viruses complex (Togaviridae family) in people from the General Belgrano island, Formosa province (Argentina). The prevalence of neutralizing (NT) antibodies for subtype VI was from 30% to 70% and the prevalence of antibodies inhibitory of hemagglutination (HI) was of 0% in the first and second inquiry respectively. For the subtype IAB the prevalence of NT antibodies was from 13% to 3.6%, similar to the prevalence total for both subtypes. HI antibodies were not detected in any inquiries for any subtype. It was observed that both subtypes circulate simultaneously, while subtype VI remains constant with some peaks, subtype I was found in low level.

Salmonella serovars isolated from humans in São Paulo State, Brazil, 1996-2003

Salmonellosis remains an important cause of diarrheal illness in humans in São Paulo State, Brazil. In this study were identified 3554 Salmonella isolates from human infections, during the period 1996-2003. Among 68 different serovars determined, S. Enteritidis was the most frequent one in gastrointestinal and extra-intestinal infections accounting for 67.4% of all isolates. S. Typhimurium and S. enterica subsp. enterica (4,5,12:i:-) were most frequently isolated from children aged < 1-4 year-old, in contrast, people with S. Enteritidis infections were most likely to be 20-50 year-old. In our geographic area the continued laboratorial surveillance of salmonellosis, including serotyping, has showed the trends in Salmonella serovars causing infections in humans throughout the time.