Brain glucose hypometabolism and hippocampal inflammation in Goto-Kakizaki rats

Brain glucose hypometabolism and neuroinflammation are early pathogenic manifestations in neurological disorders. Neuroinflammation may also disrupt leptin signaling, an adipokine that centrally regulates appetite and energy balance by acting on the hypothalamus and exerting neuroprotection in the hippocampus. The Goto-Kakizaki (GK) rat is a non-obese type 2 diabetes mellitus (T2DM) animal model used to investigate diabetes-associated molecular mechanisms without obesity jeopardizing effects. Wistar and GK rats received the maintenance adult rodent diet. Also, an additional control group of Wistar rats received a high-fat and high-sugar diet (HFHS) provided by free consumption of condensed milk. All diets and water were provided ad libitum for eight weeks. Brain glucose uptake was evaluated by 2-deoxy-2-[fluorine-18] fluoro-D-glucose under basal (saline administration) or stimulated (CL316,243, a selective β3-AR agonist) conditions. The animals were fasted for 10-12 h, anesthetized, and euthanized. The brain was quickly dissected, and the hippocampal area was sectioned and stored at -80°C in different tubes for protein and RNA analyses on the same animal. GK rats exhibited attenuated brain glucose uptake compared to Wistar animals and the HFHS group under basal conditions. Also, the hippocampus of GK rats displayed upregulated leptin receptor, IL-1β, and IL-6 gene expression and IL-1β and the subunit of the transcription factor NF-κB (p-p65) protein expression. No significant alterations were detected in the hippocampus of HFHS rats. Our data indicated that a genetic predisposition to T2DM has significant brain deteriorating features, including brain glucose hypometabolism, neuroinflammation, and leptin signaling disruption in the hippocampal area.

Microbial source tracking and antimicrobial resistance in one river system of a rural community in Bahia, Brazil / Rastreamento de fontes microbianas e resistência antimicrobiana em um sistema fluvial de uma comunidade rural da Bahia, Brasil

Use of antibiotics inevitably leads to antimicrobial resistance. Selection for resistance occurs primarily within the gut of humans and animals as well as in the environment through natural resistance and residual antibiotics in streams and soil. We evaluated antimicrobial resistance in Gram negative bacteria from a river system in a rural community in Bahia, Brazil. Water was collected from the Jiquiriçá and Brejões rivers and the piped water supply. Additionally, stools were collected from a random sample of residents, cows, pigs and horses near the river. The samples were screened for bacteria resistant to ciprofloxacin, cefotaxime, and meropenem and identified biochemically at the genus and species levels. Microbial source tracking demonstrated that ruminant and human fecal contamination increased as the rivers neared the village center and decreased after the last residence. Antibiotic bacteria were identified from all samples (n = 32). No bacteria were resistant to carbapenems, but the majority of the enterobacteria were resistant to ciprofloxacin, even though this class of antibiotics is not commonly used in food animals in this region. Considering these facts, together with the pattern of human fecal contamination, a human source was considered most likely for these resistant isolates.

O uso de antibióticos inevitavelmente leva à resistência antimicrobiana. A seleção para resistência antimicrobiana ocorre principalmente no intestino de seres humanos e animais, bem como no meio ambiente, através da resistência natural e resíduos de antibióticos nos esgotos e no solo. Avaliamos a resistência antimicrobiana em bactérias Gram-negativas de um sistema fluvial em uma comunidade rural da Bahia, Brasil. A água foi coletada nos rios Jiquiriçá e Brejões e no abastecimento de água encanada. Além disso, foram coletadas amostras randomizadas de fezes de moradores, vacas, porcos e cavalos próximos ao rio. As amostras foram triadas para bactérias resistentes à ciprofloxacina, cefotaxima e meropenem e identificadas bioquimicamente nos níveis de gênero e espécie. O rastreamento de fontes microbianas demonstrou que a contaminação fecal de ruminantes e humanos aumentou à medida que os rios se aproximavam do centro da vila e diminuía após a última residência. Bactérias resistentes a antibióticos foram identificadas em todas as amostras (n = 32). Nenhuma bactéria demonstrou ser resistente aos carbapenêmicos testados, contudo, foi encontrado enterobactérias resistentes à ciprofloxacina, ainda que essa classe de antibióticos não seja comumente usada na medicina veterinária dos animais dessa região. Considerando esses fatos, juntamente com o padrão de contaminação fecal avaliado, a fonte de contaminação humana foi considerada a mais provável na interação desses isolados resistentes.

Root deformation affects mineral nutrition but not leaf gas exchange and growth of Genipa americana seedlings during the recovery phase after soil flooding / A deformação de raízes afeta a nutrição mineral mas não as trocas gasosas foliares e o crescimento de mudas de Genipa americana durante a fase de recuperação após o alagamento do solo

Root deformation (RD) caused by errors in the pricking out process are irreversible and very difficult to detect in container-grown seedlings at the time of planting in the field. The objective of this study was to evaluate the effects of RD on leaf gas exchange, growth, biomass allocation and mineral nutrition of G. americana seedlings during the recovery phase after soil flooding. Four-months-old seedlings, with and without RD, were flooded for 42 days and their recovery was evaluated 28 days after soil drainage. There were no significant interactions between RD and soil flooding for all leaf gas exchange, growth and mineral nutrition after soil drainage, with the exception of leaf P concentrations. In plants with no RD, the P concentration in leaves of non-flooded plants was significantly higher than that of plants with RD. Soil flooding and RD did not influence leaf or root N concentrations or whole-plant N content. RD increased the K concentration in the roots, but not in the leaves. Changes in the nutrient concentrations in leaves and roots indicate that RD may affect physiological performance of seedlings after planting in the field.

A deformação da raiz (RD) causada por erros no processo de repicagem é irreversível e difícil de detectar em mudas produzidas em embalagens no momento do plantio no campo. O objetivo deste estudo foi avaliar os efeitos do RD nas trocas gasosas foliares, crescimento, alocação de biomassa e nutrição mineral de mudas de G. americana na fase de recuperação após o alagamento do solo. Mudas com quatro meses de idade, com e sem RD, foram alagadas por 42 dias e a sua recuperação foi avaliada 28 dias após a drenagem do solo. Não houve interação significativa entre RD e alagamento do solo nas trocas gasosas foliares, crescimento e nutrição mineral após a drenagem, com exceção das concentrações de P foliar. Em plantas sem RD, a concentração de P nas folhas de plantas não alagadas foi significativamente maior que a das plantas com RD. O alagamento do solo e a RD não influenciaram as concentrações de N nas folhas e raízes, e no conteúdo de N na planta inteira. A RD aumentou a concentração de K nas raízes, mas não nas folhas. Alterações nas concentrações de nutrientes nas folhas e raízes indicam que a RD pode afetar o desempenho fisiológico das mudas após o plantio no campo.

Microbial source tracking and antimicrobial resistance in one river system of a rural community in Bahia, Brazil

Abstract Use of antibiotics inevitably leads to antimicrobial resistance. Selection for resistance occurs primarily within the gut of humans and animals as well as in the environment through natural resistance and residual antibiotics in streams and soil. We evaluated antimicrobial resistance in Gram negative bacteria from a river system in a rural community in Bahia, Brazil. Water was collected from the Jiquiriçá and Brejões rivers and the piped water supply. Additionally, stools were collected from a random sample of residents, cows, pigs and horses near the river. The samples were screened for bacteria resistant to ciprofloxacin, cefotaxime, and meropenem and identified biochemically at the genus and species levels. Microbial source tracking demonstrated that ruminant and human fecal contamination increased as the rivers neared the village center and decreased after the last residence. Antibiotic bacteria were identified from all samples (n = 32). No bacteria were resistant to carbapenems, but the majority of the enterobacteria were resistant to ciprofloxacin, even though this class of antibiotics is not commonly used in food animals in this region. Considering these facts, together with the pattern of human fecal contamination, a human source was considered most likely for these resistant isolates.

Resumo O uso de antibióticos inevitavelmente leva à resistência antimicrobiana. A seleção para resistência antimicrobiana ocorre principalmente no intestino de seres humanos e animais, bem como no meio ambiente, através da resistência natural e resíduos de antibióticos nos esgotos e no solo. Avaliamos a resistência antimicrobiana em bactérias Gram-negativas de um sistema fluvial em uma comunidade rural da Bahia, Brasil. A água foi coletada nos rios Jiquiriçá e Brejões e no abastecimento de água encanada. Além disso, foram coletadas amostras randomizadas de fezes de moradores, vacas, porcos e cavalos próximos ao rio. As amostras foram triadas para bactérias resistentes à ciprofloxacina, cefotaxima e meropenem e identificadas bioquimicamente nos níveis de gênero e espécie. O rastreamento de fontes microbianas demonstrou que a contaminação fecal de ruminantes e humanos aumentou à medida que os rios se aproximavam do centro da vila e diminuía após a última residência. Bactérias resistentes a antibióticos foram identificadas em todas as amostras (n = 32). Nenhuma bactéria demonstrou ser resistente aos carbapenêmicos testados, contudo, foi encontrado enterobactérias resistentes à ciprofloxacina, ainda que essa classe de antibióticos não seja comumente usada na medicina veterinária dos animais dessa região. Considerando esses fatos, juntamente com o padrão de contaminação fecal avaliado, a fonte de contaminação humana foi considerada a mais provável na interação desses isolados resistentes.

Root deformation affects mineral nutrition but not leaf gas exchange and growth of Genipa americana seedlings during the recovery phase after soil flooding

Abstract Root deformation (RD) caused by errors in the pricking out process are irreversible and very difficult to detect in container-grown seedlings at the time of planting in the field. The objective of this study was to evaluate the effects of RD on leaf gas exchange, growth, biomass allocation and mineral nutrition of G. americana seedlings during the recovery phase after soil flooding. Four-months-old seedlings, with and without RD, were flooded for 42 days and their recovery was evaluated 28 days after soil drainage. There were no significant interactions between RD and soil flooding for all leaf gas exchange, growth and mineral nutrition after soil drainage, with the exception of leaf P concentrations. In plants with no RD, the P concentration in leaves of non-flooded plants was significantly higher than that of plants with RD. Soil flooding and RD did not influence leaf or root N concentrations or whole-plant N content. RD increased the K concentration in the roots, but not in the leaves. Changes in the nutrient concentrations in leaves and roots indicate that RD may affect physiological performance of seedlings after planting in the field.

Resumo A deformação da raiz (RD) causada por erros no processo de repicagem é irreversível e difícil de detectar em mudas produzidas em embalagens no momento do plantio no campo. O objetivo deste estudo foi avaliar os efeitos do RD nas trocas gasosas foliares, crescimento, alocação de biomassa e nutrição mineral de mudas de G. americana na fase de recuperação após o alagamento do solo. Mudas com quatro meses de idade, com e sem RD, foram alagadas por 42 dias e a sua recuperação foi avaliada 28 dias após a drenagem do solo. Não houve interação significativa entre RD e alagamento do solo nas trocas gasosas foliares, crescimento e nutrição mineral após a drenagem, com exceção das concentrações de P foliar. Em plantas sem RD, a concentração de P nas folhas de plantas não alagadas foi significativamente maior que a das plantas com RD. O alagamento do solo e a RD não influenciaram as concentrações de N nas folhas e raízes, e no conteúdo de N na planta inteira. A RD aumentou a concentração de K nas raízes, mas não nas folhas. Alterações nas concentrações de nutrientes nas folhas e raízes indicam que a RD pode afetar o desempenho fisiológico das mudas após o plantio no campo.

Root deformation affects mineral nutrition but not leaf gas exchange and growth of Genipa americana seedlings during the recovery phase after soil flooding / A deformação de raízes afeta a nutrição mineral mas não as trocas gasosas foliares e o crescimento de mudas de Genipa americana durante a fase de recuperação após o alagamento do solo

Root deformation (RD) caused by errors in the pricking out process are irreversible and very difficult to detect in container-grown seedlings at the time of planting in the field. The objective of this study was to evaluate the effects of RD on leaf gas exchange, growth, biomass allocation and mineral nutrition of G. americana seedlings during the recovery phase after soil flooding. Four-months-old seedlings, with and without RD, were flooded for 42 days and their recovery was evaluated 28 days after soil drainage. There were no significant interactions between RD and soil flooding for all leaf gas exchange, growth and mineral nutrition after soil drainage, with the exception of leaf P concentrations. In plants with no RD, the P concentration in leaves of non-flooded plants was significantly higher than that of plants with RD. Soil flooding and RD did not influence leaf or root N concentrations or whole-plant N content. RD increased the K concentration in the roots, but not in the leaves. Changes in the nutrient concentrations in leaves and roots indicate that RD may affect physiological performance of seedlings after planting in the field.

A deformação da raiz (RD) causada por erros no processo de repicagem é irreversível e difícil de detectar em mudas produzidas em embalagens no momento do plantio no campo. O objetivo deste estudo foi avaliar os efeitos do RD nas trocas gasosas foliares, crescimento, alocação de biomassa e nutrição mineral de mudas de G. americana na fase de recuperação após o alagamento do solo. Mudas com quatro meses de idade, com e sem RD, foram alagadas por 42 dias e a sua recuperação foi avaliada 28 dias após a drenagem do solo. Não houve interação significativa entre RD e alagamento do solo nas trocas gasosas foliares, crescimento e nutrição mineral após a drenagem, com exceção das concentrações de P foliar. Em plantas sem RD, a concentração de P nas folhas de plantas não alagadas foi significativamente maior que a das plantas com RD. O alagamento do solo e a RD não influenciaram as concentrações de N nas folhas e raízes, e no conteúdo de N na planta inteira. A RD aumentou a concentração de K nas raízes, mas não nas folhas. Alterações nas concentrações de nutrientes nas folhas e raízes indicam que a RD pode afetar o desempenho fisiológico das mudas após o plantio no campo.

Expression and purification of the immunogenically active fragment B of the Park Williams 8 Corynebacterium diphtheriae strain toxin

The construction of a hexahistidine-tagged version of the B fragment of diphtheria toxin (DTB) represents an important step in the study of the biological properties of DTB because it will permit the production of pure recombinant DTB (rDTB) in less time and with higher yields than currently available. In the present study, the genomic DNA of the Corynebacterium diphtheriae Park Williams 8 (PW8) vaccine strain was used as a template for PCR amplification of the dtb gene. After amplification, the dtb gene was cloned and expressed in competent Escherichia coli M15™ cells using the expression vector pQE-30™. The lysate obtained from transformed E. coli cells containing the rDTB PW8 was clarified by centrifugation and purified by affinity chromatography. The homogeneity of the purified rDTB PW8 was confirmed by immunoblotting using mouse polyclonal anti-diphtheria toxoid antibodies and the immune response induced in animals with rDTB PW8 was evaluated by ELISA and dermonecrotic neutralization assays. The main result of the present study was an alternative and accessible method for the expression and purification of immunogenically reactive rDTB PW8 using commercially available systems. Data also provided preliminary evidence that rabbits immunized with rDTB PW8 are able to mount a neutralizing response against the challenge with toxigenic C. diphtheriae.

First detection of Corynebacterium ulcerans producing a diphtheria-like toxin in a case of human with pulmonary infection in the Rio de Janeiro metropolitan area, Brazil

The frequency and severity of human infections associated with Corynebacterium ulcerans appear to be increasing in different countries. Here, we describe the first C. ulcerans strain producing a diphtheria-like toxin isolated from an elderly woman with a fatal pulmonary infection and a history of leg skin ulcers in the Rio de Janeiro metropolitan area.

Inquerito parasitologico pelo exame de fezes em criancas pertencentes a creches no Rio de Janeiro. / Parasitological survey by stool examination in institutionalized children in Rio de Janeiro

Os autores apresentam os resultados de 117 exames parasitologicos de fezes realizados pelos metodos de Faust e Hoffman, Pons e Janner, em criancas de 0 a quatro anos de idade que frequentavam creches no Rio de Janeiro. Foram encontrados 41 (35,04%) casos positivos e 76 (64,96%) casos negativos. Os parasitos mais frequentemente diagnosticados foram Giardia lamblia (23, 93%), Entamoeba coli (11,97%),Ascaris lumbricoides (9,40%) e Trichuris trichiura (8,54%). Foram observados 14 (11,97%) casos positivos em creches particulares e 27 (23,08%) casos positivos em creches que atendiam criancas de nivel socio-economico mais baixo. Dentre os casos positivos 18 (43,09%) eram de monoparasitismo e os restantes 23 (56,10%) eram de poliparasitismo As associacoes mais frequentemente diagnosticadas foram Entamoeba coli e Giardia lamblia (quatro casos), Giardia lamblia e Trichuris trichiura (tres casos) e Ascaris lumbricoides e Trichuris trichiura (dois casos). Os presentes resultados sao comparados com os de outros inqueritos coproscopicos, inclusive quando realizados em criancas de faixa etaria mais elevada