Prevalence of Methicillin-Resistant Staphylococci on a Farm: Staff can Harbour MRS When Animals do Not

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Larvicidal activity of the water extract of Moringa oleifera seeds against Aedes aegypti and its toxicity upon laboratory animals

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avanços metodológicos na seleção do sexo de espermatozóides bovinos para utilização no melhoramento genético e na produção animal

O mercado demanda, desde final da década de 20, uma tecnologia para a sexagem de espermatozóides que possa ser inserida na indústria de produção de sêmen congelado e que tenha as seguintes características: a) não altere a viabilidade espermática; b) seja compatível com a congelação do espermatozóide sexado; c) permita a sexagem de espermatozóides previamente congelados e descongelados; d) permita a produção de várias doses de sêmen sexado congelado por dia, com custo compatível ao mercado. A importância dessa tecnologia para maximizar a produção animal a um custo baixo tem sido um desafio da pesquisa a vários anos. A possibilidade de produzir, em escala comercial, doses de sêmen enriquecidas com espermatozóides X ou Y aumentará os benefícios do uso da inseminação artificial no seu papel de maximizar o progresso genético entre gerações de acordo com os requerimentos de cada programa de melhoramento animal. Diferentes rotas tecnológicas são percorridas na tentativa de selecionar-se o sexo em mamíferos, tanto nas espécies de interesse zootécnico quanto em espécies ameaçadas de extinção, animais de companhia. Neste sentido, existem duas alternativas: a separação de espermatozóides portadores do cromossomo X, daqueles portadores do cromossomo Y; ou a sexagem de embriões pré-implantados. A viabilidade da sexagem de espermatozóides em bovinos é esperada por muitos anos e os desenvolvimentos recentes tornaram essa tecnologia de aplicação commercial. Entretanto, muitas limitações ainda existem, principalmente, referente à taxa de gestação em condições de campo. Isso restringe a utilização dessa tecnologia no melhoramento genético e produção animal. Nessa palestra abordaremos os potenciais sistemas de criação e produção que poderão beneficiar-se com a sexagem de espermatozóides, quando essas limitações forem solucionadas.

Ovarian remnant syndrome in small animals

The ovarian remnant syndrome (ORS) is an iatrogenic disorder in bitches and queens, which is characterized by recurrence of estrus following surgical spay, due to the presence of a piece of ovarian tissue within the abdominal cavity. In most cases, the remnant ovary is found in the right ovarian pedicle, due to its topographic position, deeper and more cranial than the left ovary. The main clinical signs of ORS in small animals are the heat behavior and the presence of vaginal swelling/secretion, especially in canines. The diagnosis should be performed by means of vaginal cytology when attraction of males is detected, serum estrogen and progesterone levels and/or by challenging test with GnRH or hCG administration. However, vaginal citology is the most suitable and less expensive diagnostic tool. Nowadays the treatment of choice is a new laparotomy or laparoscopy, followed by removal of the remnant ovarian tissue. The surgical treatment has more chances of success if it is performed in the diestrus (i.e., between 15 and 60 days after the detection of attraction of males). Furthermore, a careful and accurate surgical procedure aided by advanced visualization techniques during ovariohysterectomy or ovariectomy is the best way to prevent ORS in companion animals.

Comparative study of the sedative and antinociceptive effects of levomepromazine, azaperone and midazolam in laboratory animals

Os efeitos sedativos e antinociceptivos da levomepromazina, azaperone e midazolam foram avaliados utilizando-se três testes de comportamento em ratos e camundongos. No teste da atividade locomotora espontânea em campo aberto observou-se que tanto o comportamento exploratório como a atividade locomotora espontânea foram significativamente diminuídos quando se utilizou levomepromazina e azaperone. O efeito causado pelo azaperone foi menos prolongado quando comparado ao da levomepromazina. O midazolam causou diminuição do comportamento exploratório sem alterar a atividade locomotora espontânea. Quando se avaliou o efeito antinociceptivo por meio da latência para o reflexo da retirada da cauda em ratos após estímulo doloroso, as drogas não apresentaram nenhum efeito antinociceptivo observável. No teste das contorções em camundongos, os fármacos foram capazes de abolir as contorções quando comparados ao efeito do grupo-controle. Levomepromazina, azaperone e midazolam nas doses utilizadas foram capazes de inibir o comportamento exploratório de ratos, comprovando seus efeitos sedativos. Com relação aos efeitos antinociceptivos para dor visceral, eles foram capazes de inibir as contorções.

Molecular and serological detection of Leishmania spp. in captive wild animals from Ilha Solteira, SP, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tenoplastia experimental do calcâneo em cães com peritônio bovino conservado em glicerina

No presente estudo, avaliou-se a eficácia do emprego do peritônio bovino, conservado em glicerina a 98%, no reparo de lesões induzidas no tendão calcâneo (TC) de cães, quando um fragmento de aproximadamente 1cm do TC foi excisado e o espaço resultante preenchido por um fragmento de peritônio. Foram utilizados 21 cães, pesando entre 10 e 15kg, divididos em 7 grupos de 3, sacrificados aos 02, 07, 15, 30, 60, 90 e 120 dias de pós-operatório. Analisaram-se os aspectos clínico-cirúrgicos referentes à recuperação funcional motora, bem como, a integração do peritônio com o tecido tendíneo mediante avaliação macroscópica, por microscopia óptica e por microscopia eletrônica de varredura. Clinicamente, verificou-se que, por volta do 55º dia de pós-operatório, os animais já apresentavam deambulação normal e que o neotendão apresentou resistência suficiente para suportar o estresse normalmente aplicado ao TC. Microscopicamente, o peritônio implantado esteve presente em todos os períodos de observação. Proliferação fibroblástica e neoformação vascular foram observadas de forma incipiente no segundo dia; entretanto, no sétimo dia de pós-operatório, esta condição foi exacerbada. Com a evolução, as fibras de peritônio tendiam a se dissociar, entrando em estreita associação com fibras conjuntivas, fibroblastos e colágeno. Aos 30, 60, 90 e 120 dias de pós-operatório, notava-se maior presença de colágeno que se tornava cada vez mais organizado. Concluiu-se que o peritônio estimulou uma rápida deposição de tecido conjuntivo com mínima reação inflamatória, sendo incorporado ao tecido cicatricial e servindo como alicerce para o desenvolvimento de um novo tecido, restabelecendo assim a estrutura do tendão.

Venous tone and cardiac function in the South American rattlesnake Crotalus durissus: mean circulatory filling pressure during adrenergic stimulation in anaesthetised and fully recovered animals

The effects of adrenergic stimulation on mean circulatory filling pressure (MCFP), central venous pressure (P-CV) and stroke volume (Vs), as well as the effects of altered MCFP through changes of blood volume were investigated in rattlesnakes (Crotalus durissus). MCFP is an estimate of the upstream pressure driving blood towards the heart and is determined by blood volume and the activity of the smooth muscle cells in the veins (venous tone). MCFP can be determined as the plateau in P-CV during a total occlusion of blood flow from the heart.Vs decreased significantly when MCFP was lowered by reducing blood volume in anaesthetised snakes, whereas increased MCFP through infusion of blood (up to 3 ml kg(-1)) only led to a small rise in Vs. Thus, it seems that end-diastolic volume is not affected by an elevated MCFP in rattlesnakes. To investigate adrenergic regulation on venous tone, adrenaline as well as phenylephrine and isoproterenol (alpha- and beta-adrenergic agonists, respectively) were infused as bolus injections (2 and 10 mu g kg(-1)). Adrenaline and phenylephrine caused large increases in MCFP and P-CV, whereas isoproterenol decreased both parameters. This was also the case in fully recovered snakes. Therefore, adrenaline affects venous tone through both alpha- and beta-adrenergic receptors, but the alpha-adrenergic receptor dominates at the dosages used in the present study. Injection of the nitric oxide donor SNP caused a significant decrease in P-CV and MCFP. Thus, nitric oxide seems to affect venous tone.

Genetic variability among the wild boars (Sus scrofa scrofa), crossbred animals and pigs using microsatellite markers (STRs)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Immunological response in mice bearing LM3 breast tumor undergoing Pulchellin treatment

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Anxiolytic-like effect of way-100635 microinfusions into the median (but not dorsal) raphe nucleus in mice exposed to the plus-maze: influence of prior test experience

Studies in several laboratories have confirmed the anxiolytic potential of a wide range of 5-HT1A receptor antagonists in rats and mice, with recent evidence pointing to a postsynaptic site of action in the ventral hippocampus. It would, therefore, be predicted that blockade of 5-HT1A somatodendritic autoreceptors in the midbrain raphe nuclei should produce anxiogenic-like effects. To test this hypothesis, we investigated the effects of WAY-100635 microinfusions (0, 1.0 or 3.0 mug in 0.1 mul) into the dorsal (DRN) or median (MRN) raphe nuclei on behaviours displayed by male Swiss-Webster mice in the elevated plus-maze. As this test is sensitive to prior experience. The effects of intra-raphe infusions were examined both in maze-naive and maze-experienced subjects. Sessions, were videotaped and subsequently scored for conventional indices of anxiety (open arm avoidance) and locomotor activity (closed arm entries), as well as a range of ethological measures (e.g. risk assessment). In maze-naive mice, intra-MRN (but not intra-DRN) infusions of WAY-100635 (3.0 mug) increased open arm exploration and reduced risk assessment. Importantly, these effects could not be attributed to a general reduction in locomotor activity. A similar, though somewhat weaker, pattern of behavioural change was observed in maze-experienced animals. This unexpected anxiolytic effect of 5-HT1A autoreceptor blockade in the MRN cannot be accounted fur by a disinhibition of 5-HT release in forebrain targets (e.g. hippocampus and amygdala), where stimulation of postsynaptic 5-HT1A receptors enhances anxiety-like responses. However, as the MRN also projects to the periaqueductal gray matter (PAG), an area known to be sensitive to the anti-aversive effects or 5-HT, it is argued that present results may reflect increased 5-HT release at this crucial midbrain locus within the neural circuitry of defense. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Experimental kinetics of infection induced by Yersinia pseudotuberculosis isolated from stock animals

The course of in vivo infection of five isolates of Yersinia pseudotuberculosis was followed for three weeks in Swiss mice. The strains were isolated from diarrheic and normal feces and mesenteric lymph nodes of healthy and sick stock animals. Four strains of serogroup O:3 and one of serogroup O:1a, with and without the virulence plasmid, were inoculated intragastrically and intravenously in the mice. Groups of five animals were sacrificed at 6 h and 3, 6, 10, 15, and 21 days after inoculation, and organs and tissues were checked for possible macroscopic alterations. Development of infection was monitored at these times by performing viable bacterial counts in homogenates of selected tissues. The animals were cheked daily for clinical alterations. The results of the study showed that strains with the virulence plasmid infected organs and tissues at various times and at varying intensity by both routes of infection, the strain of type O:1a being the most invasive. Moreover, clinical and pathological alterations occurred only in animals inoculated with bacteria carrying the virulence plasmid, regardless of the route of infection.

Ribotyping and virulence markers of Yersinia pseudotuberculosis strains isolated from animals in Brazil

Ribotyping and virulence markers has been used to investigate 68 Yersinia pseudotuberculosis strains of serogroups O:1a and O:3. The strains were isolated from clinical material obtained from healthy and sick animals in the Southern region of Brazil. Ribotypes were identified by double digestion of extracted DNA with the restriction endonucleases SmaI and PstI, separation by electrophoresis and hybridization with a digoxigenin-labeled cDNA probe. The presence of the chromosomal virulence marker genes inv, irp1, irp2, psn, ybtE, ybtP-ybtQ, and ybtX-ybtS, of the IS100 insertion sequence, and of the plasmid gene lcrF was detected by polymerase chain reaction. The strains were grouped into four distinct ribotypes, all of them comprising several strains. Ribotypes 1 and 4 presented distinct profiles, with 57.3% genetic similarity, ribotypes 2 and 3 presented 52.5% genetic similarity, and genetic similarity was 45% between these two groups (1/4 and 2/3). All strains possessed the inv, irp1, and irp2 genes. Additionally, strains of serogroup O:1a carried psn, ybtE, ybtP-ybtQ, ybtX-ybtS, and IS100. As expected lcrF was only detected in strains harboring the virulence plasmid. These data demonstrate the presence of Y. pseudotuberculosis strains harboring genotypic virulence markers in the livestock from Southern Brazil and that the dissemination of these bacteria may occur between herds.

A lethal effect associated with polymorphism of the NOR-bearing chromosomes in rainbow trout (Oncorhynchus mykiss)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)