Can microcystins affect zooplankton structure community in tropical eutrophic reservoirs? / Microcistinas podem afetar a estrutura da comunidade zooplanctônica em reservatórios eutróficos tropicais?

Abstract The aim of our study was to assess whether cyanotoxins (microcystins) can affect the composition of the zooplankton community, leading to domination of microzooplankton forms (protozoans and rotifers). Temporal variations in concentrations of microcystins and zooplankton biomass were analyzed in three eutrophic reservoirs in the semi-arid northeast region of Brazil. The concentration of microcystins in water proved to be correlated with the cyanobacterial biovolume, indicating the contributions from colonial forms such as Microcystis in the production of cyanotoxins. At the community level, the total biomass of zooplankton was not correlated with the concentration of microcystin (r2 = 0.00; P > 0.001), but in a population-level analysis, the biomass of rotifers and cladocerans showed a weak positive correlation. Cyclopoid copepods, which are considered to be relatively inefficient in ingesting cyanobacteria, were negatively correlated (r2 = – 0.01; P > 0.01) with the concentration of cyanotoxins. Surprisingly, the biomass of calanoid copepods was positively correlated with the microcystin concentration (r2 = 0.44; P > 0.001). The results indicate that allelopathic control mechanisms (negative effects of microcystin on zooplankton biomass) do not seem to substantially affect the composition of mesozooplankton, which showed a constant and high biomass compared to the microzooplankton (rotifers). These results may be important to better understand the trophic interactions between zooplankton and cyanobacteria and the potential effects of allelopathic compounds on zooplankton.

Resumo Com o objetivo de avaliar se as cianotoxinas (microcistinas) podem afetar a composição da comunidade zooplanctônica, levando à dominância de formas microzooplanctônicas (protozoários e rotiferos), as variações nas concentrações de microcistina e a biomassa do zooplâncton foram analisadas em três reservatórios eutróficos na região semi-árida do nordeste brasileiro. A concentração de microcistinas na água esteve correlacionada com o biovolume de cianobactérias, indicando a contribuição de formas coloniais como Microcystis na produção de cianotoxinas. A nível de comunidade, a biomassa total do zooplâncton não apresentou correlacão com a concentração de microcistina (r2 = 0.00; P > 0.001), mas em uma análise a nível de populações, a biomassa de rotíferos e cladóceros apresentou uma fraca correlação positiva. Copépodos Cyclopoida, os quais são considerados relativamente ineficientes na ingestão de cianobactérias, estiveram negativamente correlacionados com a concentração de microcistinas (r2 = - 0.01; P > 0.01). Surpreendentemente, a biomassa de copépodos Calanoida foi positivamente correlacionada com a concentração de cianotoxinas (r2 = 0.44; P > 0.001). Os resultados indicam que mecanismos de controle alelopáticos (efeitos negativos da microcistina sobre o zooplâncton) parecem não afetar substancialmente a composição do mesozooplâncton, que apresentou uma alta e constante biomassa, quando comparada à biomassa do microzooplâncton (rotíferos). Esses resultados podem ser importantes para um melhor entendimento das interações tróficas entre o zooplâncton e cianobactérias, e do efeito potencial de compostos alelopáticos sobre o zooplâncton.

Can microcystins affect zooplankton structure community in tropical eutrophic reservoirs?

The aim of our study was to assess whether cyanotoxins (microcystins) can affect the composition of the zooplankton community, leading to domination of microzooplankton forms (protozoans and rotifers). Temporal variations in concentrations of microcystins and zooplankton biomass were analyzed in three eutrophic reservoirs in the semi-arid northeast region of Brazil. The concentration of microcystins in water proved to be correlated with the cyanobacterial biovolume, indicating the contributions from colonial forms such as Microcystis in the production of cyanotoxins. At the community level, the total biomass of zooplankton was not correlated with the concentration of microcystin (r2 = 0.00; P > 0.001), but in a population-level analysis, the biomass of rotifers and cladocerans showed a weak positive correlation. Cyclopoid copepods, which are considered to be relatively inefficient in ingesting cyanobacteria, were negatively correlated (r2 = - 0.01; P > 0.01) with the concentration of cyanotoxins. Surprisingly, the biomass of calanoid copepods was positively correlated with the microcystin concentration (r2 = 0.44; P > 0.001). The results indicate that allelopathic control mechanisms (negative effects of microcystin on zooplankton biomass) do not seem to substantially affect the composition of mesozooplankton, which showed a constant and high biomass compared to the microzooplankton (rotifers). These results may be important to better understand the trophic interactions between zooplankton and cyanobacteria and the potential effects of allelopathic compounds on zooplankton.

Dermatosparaxis in two White Doper lambs in Brazil: case report / Dermatosparaxis em dois cordeiros White Dorper no Brasil: relato de caso

Dermatosparaxis is a genetic disease that affects collagen maturation. This disease is characterized by marked impairment of the resistance of collagen fibers that leads to skin fragility, and it may affect several species. This is the first report of dermatosparaxis in sheep in Brazil. Clinically, two White Dorper lambs had multiple skin lacerations in the neck, dorsum and limbs. Transmission microscopy demonstrated irregular collagen fibers arranged in hieroglyphic shape and scanning electron microscopy demonstrated thin collagen fibrils that were not arranged in bundles as observed in the normal dermis. These findings are consistent with the diagnosis of dermatosparaxis.

A dermatosparaxis é uma doença genética que afeta a maturação do colágeno. Essa doença é caracterizada por redução acentuada da resistência das fibras colágenas que leva à fragilidade da pele. Esse é o primeiro relato de dermatosparaxis em ovinos no Brasil. Clinicamente, dois cordeiros da raça White Dorper tiveram múltiplas lacerações na pele do pescoço, dorso e membros. A microscopia de transmissão demonstrou fibras de colágeno irregularares arranjadas em formato de hieroflifo, e a microscopia de varredura demonstrou fibras finas de colágeno não arranjadas em bandas como na derme do animal normal. Esses achados são consistentes com o diagnóstico de dermatosparaxis.

Indirect ELISA for diagnosis of Brucella ovis infection in rams / ELISA indireto para diagnóstico da infecção por Brucella ovis em carneiros

Brucella ovis is a major cause of epididymitis in sexually mature rams, resulting in subfertility, infertility, and economic losses for the sheep industry worldwide. The aim of this study was to develop an indirect ELISA (iELISA) using recombinant proteins, namely rBoP59 and rBP26, as antigens for serological diagnosis of B. ovis infection. The BoP59 and BP26 recombinant proteins were expressed in E. coli and purified by affinity chromatography. Antigenicity was tested by Western blot and iELISA. Standardization of iELISA was performed with 500ng and 1µg BoP59 and rBP26 per well, testing serum from uninfected and experimentally infected rams. rBP26 was effective in distinguishing positive from negative rams. The rBP26 iELISA developed in this study is the first to use a completely purified rBP26 as antigen resulting in high sensitivity (100%) and specificity (90.2%), and an overall accuracy equal to 1.0...

Brucella ovis é uma das principais causas de epididimite em carneiros sexualmente maduros, resultando em subfertilidade e infertilidade e consequentes perdas econômicas para a ovinocultura em todo o mundo. O objetivo deste estudo foi desenvolver ELISA indireto (ELISAi), utilizando como antígeno proteínas recombinantes BoP59r e BP26r para diagnóstico da infecção por B. ovis. BoP59r e BP26r foram expressas em E. coli e purificadas por cromatografia de afinidade e a antigenicidade testada por Western blot e ELISAi. A padronização do ELISAi foi realizada testando 500 ng e 1 µg de BoP59r e BP26r por poço e soros de carneiros infectados e não infectados. A BP26r foi eficiente em diferenciar ovinos negativos de positivos. O ELISAi com BP26 desenvolvido neste estudo foi o primeiro a utilizar BP26 completamente purificada como antígeno, resultando em elevada sensibilidade (100%) e sensibilidade (90,2%), com acurácia igual a 1,0...

Monocyte-derived macrophages from Zebu (Bos taurus indicus) are more efficient to control Brucella abortus intracellular survival than macrophages from European cattle (Bos taurus taurus).

Brucellosis is one of the most important zoonotic diseases in the world. Considering its strict zoonotic nature, understanding of the pathogenesis and immunity of Brucella spp. in natural animal hosts is essential to prevent human infections. Natural resistance against brucellosis has been demonstrated in cattle, and it is associated with the ability of macrophages to prevent intracellular replication of Brucella abortus. Identification of breeds that are resistant to B. abortus may contribute for controlling and eradicating brucellosis in cattle. This study aimed to compare macrophages from Nelore (Bos taurus indicus) or Holstein (Bos taurus taurus) regarding their resistance to B. abortus infection. Macrophages from Nelore were significantly more efficient in controlling intracellular growth of B. abortus when compared to Holstein macrophages even under intralysosomal iron restricting conditions. Furthermore, Nelore macrophages had higher transcription levels of inducible nitric oxide synthase (iNOS) and TNF-α at 12h post-infection (hpi) and higher levels of IL-12 at 24 hpi when compared to Holstein macrophages. Conversely, Holstein macrophages had higher levels of IL-10 transcripts at 24 hpi. Macrohages from Nelore also generated more nitric oxide (NO) in response to B. abortus infection when compared to Holstein macrophages. In conclusion, cultured Nelore macrophages are more effective in controlling intracellular replication of B. abortus, suggesting that Nelore cattle is likely to have a higher degree of natural resistance to brucellosis than Holstein.

Chronic intestinal pseudo-obstruction in a dog: case report / Pseudo-obstrução intestinal crônica em um cão: relato de caso

Intestinal pseudo-obstruction is a rare disorder that affects gastrointestinal propulsion. It may be secondary to several pathological conditions or it may develop without a known cause. A 1.2 year-old intact Pug bitch had a history of vomiting and constipation, which were followed by diarrhea and distended abdomen. Hypomotility and dilation of the small intestine, which was filled with gas, were observed during laparotomy. Histologically, full thickness biopsy specimens demonstrated a severe loss and degeneration of leiomyocytes in the inner and outer muscular layers of the intestinal wall, whereas there was a marked hypertrophy and hyperplasia of smooth muscle cells in the lamina propria, and extremely thickened muscularis mucosae arranged in bundles oriented in different directions with marked hypertrophy and hyperplasia of leiomyocytes. Distribution of leiomyocytes was further characterized by immunohistochemistry. These findings support the diagnosis of intestinal pseudo-obstruction in a Pug, associated with degeneration and loss of leiomyocytes in the muscular layer.

A pseudo-obstrução intestinal é um distúrbio raro que afeta a propulsão gastrointestinal. Pode ser secundária a diversas condições patológicas ou pode ser idiopática. Uma cadela Pug de um ano e dois meses de idade apresentou histórico de vômitos e constipação, que foram seguidos por diarreia e distensão abdominal. Hipomotilidade e dilatação do intestino delgado, que estava cheio de gás, foram observados durante a laparotomia. Ao exame histológico, observou-se grande perda e degeneração de leiomiócitos das camadas musculares interiores e exteriores da parede intestinal, com acentuada hipertrofia e hiperplasia das células do músculo liso da lâmina própria e espessamento acentuado da muscularis mucosae com feixes orientados em direções diferentes e acentuada hipertrofia e hiperplasia dos leiomiócitos. A distribuição de leiomiócitos foi caracterizada por imunoistoquímica. Estes resultados suportam o diagnóstico de pseudo-obstrução intestinal em um Pug, associado à degeneração e perda de leiomiócitos da camada muscular.

Solid state evaluation of some thalidomide raw materials.

Thalidomide presents polymorphism and is a problematic drug due to its poor solubility and difficult tablet processability, which is the dosage form available in Brazil. In most cases, the pharmacopoeias specify do not address solid state characterization of drugs precisely. In this work, different thalidomide commercial samples were characterized by infrared spectroscopy, particle size analysis, scanning electron microscopy, and X-ray diffraction. In addition, the polymorphic forms were quantified for Rietveld analysis and their intrinsic dissolution rates were evaluated. The results demonstrated the market availability of different raw materials which lack of homogeneity due to differences related to crystalline constitution, crystal habit and intrinsic dissolution rate.

Opinion of hepatic transplant waiting list patients regarding split liver transplantation.

BACKGROUND: Split liver transplantation (SLT) increases organ supply for hepatic transplantation. Long-term patient survival and complication rates seem to be equivalent between orthotopic liver transplantation (OLT) and SLT. There are controversies among transplant physicians due to an ethical dilemma between benefiting individual needs or those of society. Barshes and Goss (Am J Transplant 5:2047, 2005) demonstrated that the majority of adult liver transplant candidates are favorable to SLT. The aim of our study was to evaluate the opinions of patients at a Brazilian university hospital regarding SLT. MATERIALS AND METHODS: A questionnaire with 14 questions was applied to 50 patients included in a hepatic transplant waiting list regarding SLT. RESULTS: The overall attitudes of 66% of the participants were classified as utilitarian, 31% were classified as self-preserving, and 3% were undecided. Ninety-one percent of patients would be willing to share even if their expected survival after SLT was shorter than that with OLT. For 77% of patients, children must have priority over adults. However, 83% were unaware of the donors for pediatric transplantations. CONCLUSIONS: SLT is a consistent solution for organ demand despite controversies among transplant physicians. The present study demonstrated that most patients were favorable to SLT. In conclusion, attitudes toward graft sharing are not barriers to SLT.