Virginiamycin and sodium monensin supplementation for beef cattle on pasture / Suplementação com virginiamicina e monensina sódica para bovinos de corte a pasto

The aim of this paper was to evaluate the effects of including virginiamycin (VM), sodium monensin (MON) or the association (VM+MON) in the energetic mineral supplement, on the intake and performance of beef cattle on pasture. Forty Nellore heifers with 24 months of age and initial body weight (BW) of 251.5±16.6kg, were distributed in four treatments in a randomized block design. Treatments consisted of adding VM, MON or VM+MON to the supplement (CONT). Additive concentrations were defined to reach a dose of 40 to 45mg/100kg BW. The herbage allowance was not a limiting factor for the animals' intake. Supplement intake was lower than expected, with 33.0, 18.8 and 26.3mg per 100kg BW for VM, MON and VM+MON, respectively. Dry matter intake (DMI, mean=2.65% BW) and animal performance were not affected by the inclusion of additives. The average daily gain (ADG) was 0.561kg/animal day-1. The inclusion of additives in energetic mineral supplement does not affect the DMI and the ADG of grazing animals. The variability in supplement intake and daily dose intake of additives may have influenced the performance of the animals. Monensin inclusion presented the less expensive supplementation cost, due to reduction in supplement intake without changing weight gain.(AU)

Objetivou-se avaliar o efeito da inclusão dos aditivos virginiamicina (VM), monensina sódica (MON) e associação (VM+MON) no suplemento energético-mineral sobre o consumo e desempenho de bovinos manejados em pastagem de Urochloa Brizantha cv. Marandu. Foram utilizadas 40 novilhas Nelore com 24 meses de idade e peso corporal (PC) inicial médio de 251,5+16,6kg distribuídas em delineamento em blocos ao acaso com quatro tratamentos. Os tratamentos consistiam de suplemento energético-mineral (CONT) acrescido de VM, MON ou VM+MON. A oferta de forragem não limitou o consumo dos animais. O consumo dos aditivos foi de 0; 33,0; 18,8 e 26,3mg por 100kg de PC para CONT, VM, MON e VM+MON, respectivamente. O consumo de matéria seca e o desempenho dos animais não foram afetados pela inclusão dos aditivos. O ganho médio diário dos animais foi de 0,561kg dia -1 , sem diferença entre os tratamentos. A inclusão de aditivos no suplemento energético-mineral não alterou o CMS e o desempenho dos animais em pastejo. A variabilidade no consumo de suplemento e na dose ingerida dos aditivos pode ter influenciado o desempenho dos animais.(AU)

Dose-response effect of crude extracts produced by actinobacteria on in vitro rumen fermentation / Padrão dose-resposta de extratos brutos produzidos por actinobactérias sobre a fermentação ruminal in vitro

Actinobacteria have been researched as a source that produces crude extracts, which contain bioactive compounds able to act as antimicrobial agents. The present investigation evaluated the dose-response effect of two crude extracts, obtained at Caatinga rhizosphere (Caat) and Rhizophora mangle (AMC), on in vitro ruminal fermentation by:cumulative gas production, digestibility of dry (IVDMD) and organic matter (IVOMD), and short-chain fatty acids concentration (SCFA). Three multiparous Holstein dairy cows with ruminal fistula were used as the inoculum donors and fed a basal diet consisting of corn silage, soybean meal, urea, ground corn and mineral supplement. Ruminal fluid samples were incubated in glass bottles with 1 g of the dried and milled diet, a buffer solution, and the crude extracts evaluated in four doses (0.3, 0.6, 0.9 and 1.20 mg/10 mL inoculum) in a randomized block design, and the donators were considered as blocks with random effects. Additionally, negative controls were used. The results were expressed as average values based on triplicate analyses. Decreased cumulative gas production was observed according to linear dose response at 24, 48 and 72 h of incubation with the addition of Caat extract. The IVOMD showed a linear decrease at 72 h of incubation with dose Caat inclusion. Furthermore, the inclusion of Caat extract linearly reduced butyric and isovaleric acid concentrations, as well as acetate:propionate ratio. Finally, the Caat inclusion increased the propionic acid concentration in comparison to AMC extract. However, the inclusion of AMC extract did not affect any of the analyzed variables at the used doses. The Caat extract could be used as a modulator of in vitro ruminal fermentation, since it reduced acetate:propionate ratio and cumulative gas production.(AU)

As actinobactérias têm sido pesquisadas como fonte produtoras de extratos brutos que contêm compostos bioativos capazes de atuar como agentes antimicrobianos. O presente trabalho investigou o efeito dose-resposta de dois extratos brutos, AMC e Caat, na fermentação ruminal in vitro por: produção cumulativa de gás, digestibilidade in vitro da matéria seca (IVDMD) e matéria orgânica (IVOMD) e concentração de ácidos graxos de cadeia curta (SCFA). Três vacas leiteiras da raça Holandesa, multíparas e portadoras de fístula ruminal foram utilizadas como doadoras de inóculo ruminal e foram alimentadas com uma dieta basal composta por silagem de milho, farelo de soja, ureia, milho moído e suplemento mineral. As amostras de inóculo ruminal foram incubadas em garrafas de vidro com 1 g da dieta seca e moída, solução tampão e os extratos brutos avaliados em quatro doses (0,3, 0,6, 0,9 e 1,20 mg/10 mL de inóculo) em delineamento em blocos casualizados, sendo as doadoras consideradas os blocos como efeito aleatório. Além disso, foram utilizados controles negativos para a correção da produção de gás. Os resultados foram expressos como valores médios com base em análises triplicadas. A diminuição da produção cumulativa de gás foi observada de acordo com a dose em resposta linear às 24, 48 e 72 h de incubação com a adição de extrato de Caat. A IVOMD mostrou uma diminuição linear com 72 h de incubação com inclusão de Caat. Além disso, a inclusão do Caat reduziu linearmente as concentrações de ácido butírico e isovalérico, bem como a proporção de acetato/propionato. Diferentemente, a inclusão do extrato de AMC não afetou nenhuma das variáveis analisadas nas doses utilizadas. O extrato de Caat pode ser usado como um modulador da fermentação ruminal in vitro, uma vez que reduziu a proporção de acetato/propionato e a produção de gás acumulada. (AU)

Functional oils affect blood and bacteriological parameters in sheep / Los aceites funcionales afectan parámetros sanguíneos y bacteriológicos en ovinos / Óleos funcionais afetam parâmetros sanguíneos e bacteriológicos em ovinos

Abstract Background: Feeding ionophores to sheep is intended for improving feed efficiency. Functional oils (FO) are an alternative to the use of ionophores. Objective: To evaluate the effect of feeding FO to sheep on blood parameters and fecal bacteria. Methods: Five sheep were used in a Latin square design with five treatments: 190, 285, 380, 570, and 675 g/t FO in the diet. White cell count and levels of blood glucose, total protein, urea nitrogen, and fecal bacteria presence in feces were determined. Results: The FO levels did not affect serum parameters. Salmonella spp was found only in feces of sheep fed 190 mg/t FO. Conclusion: Functional oils can be added to sheep diets to reduce the presence of Salmonella spp in the feces.

Resumen Antecedentes: Los ionóforos se suministran a los ovinos para mejorar la eficiencia alimenticia. Una alternativa al uso de ionóforos son los aceites funcionales (FO). Objetivo: Evaluar los efectos del suministro de FO en el alimento sobre los parámetros sanguíneos y bacterias fecales de ovinos. Métodos: Cinco ovejos fueron usados en un diseño de cuadrado latino con cinco tratamientos: 190, 285, 380, 570 y 675 g/t FO en la dieta. Se realizó conteo de leucocitos y niveles de glucosa, proteína total y nitrógeno ureico, y se determinó la presencia de bacterias fecales. Resultados: La inclusión dietaria de FO no afectó los parametros séricos. Se encontró Salmonella spp únicamente en heces de los ovinos que habían consumido 190 mg/t FO. Conclusión: Se puede agregar FO a la dieta de ovinos para reducir la presencia de Salmonella spp en heces.

Resumo Antecedentes: Na produção animal, ionóforos são ingeridos por ovinos para melhorar a eficiência alimentar. Alternativa ao uso de ionóforos são os óleos funcionais (FO). Objetivos: Avaliar os efeitos de FO em ovinos por meio da alimentação sobre os parâmetros sanguíneos e bacteriológicos. Métodos: Cinco ovinos foram usados em Quadrado Latino com cinco tratamentos: 190, 285, 380, 570 e 675 g/t FO nas dietas. Contagem de leucócitos e níveis de glicose, proteína total, nitrogênio ureico e presença de bactérias nas fezes foram determinados. Resultados: Os níveis de FO não afetaram os níveis séricos dos fatores mencionados. Salmonella spp foi encontrada somente em fezes de ovinos que haviam ingerido dietas com 190 mg/t FO. Conclusão: Óleos funcionais podem ser adicionados em dietas para ovinos para reduzir a presença de Salmonella spp nas fezes.

Osteogenesis capacity of constructing pELNS-BMPs and pELNS-Wnt3a co-expression in osteoblasts / 中华骨科杂志

Objective To construct the third-generation self-inactivating lentiviral vectors including BMP-2,BMP-4,BMP-6,BMP-7,BMP-9 and Wnt3a,then integrate them into the genome of mouse embryonic osteoblast cell,MC3T3-E1,and to explore the capability of osteogenic differentiation of individual bone morphogenetic control factor and the effective approaches to further improve the capability of osteogenic differentiation.Methods The plasmid vectors of gene expression including BMP-2,BMP-4,BMP-6,BMP-7,BMP-9 and Wnt3a were constructed,which were identified through enzyme cutting and further confirmed through sequencing.After packing pELNS-BMP-2,BMP-4,BMP-6,BMP-7,BMP-9 and Wnt3a,mouse embryonic osteoblast cell,MC3T3-E 1 was transfected,and the transfection efficiency was confirmed by GFP fluorescence imaging.The expression level of Runx2 mRNA and the transfection efficiency of individual bone morphogenetic control factor was detected by Real time PCR.Eight groups of MC3T3-E1 were dual-gene co-transfected,and the transfection efficiency was verified by GFP fluorescence imaging.ELISA was adopted to detect the expression level of BGP and ALP in MC3T3-E1culture supernatants;Real time PCR was adopted to detect the expression level of Runx2 mRNA;Western blot was adopted to detect the expression level of protein of BMP-2,BMP-4,BMP-6,BMP-7,BMP-9 and Wnt3a.Thus,the effectiveness of osteogenic differentiation of dual-gene co-transfection were evaluated.Results The recombination of lentiviruses,pELNS-BMP-2,pELNS-BMP-4,pELNS-BMP-6,pELNS-BMP-7,pELNS-BMP-9 and pELNS-Wnt3a were successfully constructed.MC3T3-E1 was successfully transfected.The expression levels of Runx2 mRNA were:BMP-2 ＞ BMP-4 ＞ BMP-9 ＞ BMP-7 ＞ Wnt3a ＞ BMP-6.Successful transfection of the dual-gene co-transfection of eight groups of MC3T3-E1 were verified by GFP fluorescence imaging.The expression level of Runx2 mRNA,the expression of BGP and ALP showed BMP-2 and BMP-7 co-transfection group was the most efficient in osteogenesis transfection.Western blot revealed thatthe protein expression of BMP-2,BMP-4,BMP-6,BMP-7,BMP-9 and Wnt3a increased after cotransfection of MC3T3-E1 by BMP-2 and BMP-7.Conclusion The third-generation lentiviral vector,pELNS can lead BMP-2,BMP-4,BMP-6,BMP-7,BMP-9 and Wnt3a into MC3T3-E1,mouse embryonic osteoblast cell,and stabilize its expression.Individual bone morphogenetic control factors can promote MC3T3-E1's differentiation to osteoblasts.The dual-gene co-transfection of BMP-2 and BMP-7 can effectively promote osteoblast conversion,which provides significant theoretical basis and technical support for remodeling of tissue engineering bone.

Advances in cell proliferation and apoptosis signal pathway and therapies of polycystic kidney disease / 解放军医学杂志

Polycystic kidney disease (PKD) is one of the monogenic inherited diseases. In PKD, excessive cell proliferation and fluid secretion, and disruption of the mechanisms controlling tubular diameter may all lead to cyst formation. Current evidence has demonstrated that intracellular calcium ion and cAMP imbalance drive both abnormal cell proliferation and apoptosis signal pathway. The present paper summarized the evidence implicating calcium ion and cAMP as central players in the signaling pathway of cell proliferation and apoptosis in PKD, and considered the potential therapeutic approaches targeted to slow cyst growth in PKD.

Peripheral and central sensitization / Sensibilização periférica e central

ABSTRACT BACKGROUND AND OBJECTIVES: Central sensitization is an important phenomenon for pain chronicity and is present in neuropathic pain. This study aimed at addressing some pathophysiological aspects of this phenomenon. CONTENTS: Some extra and intracellular aspects responsible for central sensitization genesis, especially phenotypic changes in plasticity of neurons involved in the process are described. CONCLUSION: Pain chronicity may result from changes in central nervous system neurons properties by the central sensitization phenomenon with constant changes in membrane excitability, inhibitory transmission reduction and increase in synaptic efficacy mediated by several convergent and divergent molecular mechanisms over a background of phenotypic and structural changes. Neuroplasticity deeply alters painful sensation, contributing for many clinical painful syndromes and may represent a major target for therapeutic intervention.

RESUMO JUSTIFICATIVA E OBJETIVOS: A sensibilização central é um fenômeno importante na cronificação da dor e presente na dor neuropática. O objetivo deste estudo foi abordar alguns aspectos fisiopatológicos deste fenômeno. CONTEÚDO: São descritos alguns aspectos extra e intracelular responsável pela gênese da sensibilização central, principalmente aspectos de alterações fenotípicas que ocorrem na plasticidade dos neurônios envolvidos no processo. CONCLUSÃO: A cronificação da dor pode surgir como resultado de alterações nas propriedades dos neurônios no sistema nervoso central pelo fenômeno da sensibilização central com constantes mudanças e alterações na excitabilidade da membrana, reduções na transmissão inibitória e aumento da eficácia sináptica, mediada por muitos convergentes e divergentes mecanismos moleculares sobre um fundo de modificações fenotípicas e alterações estruturais. A neuroplasticidade altera profundamente a sensação dolorosa, contribuindo para muitas síndromes clínicas da dor e pode representar um importante alvo para intervenção terapêutica.

Crescimento ponderal de bezerras suplementadas com monensina sódica / Weight gain of heifers supplemented with monensin

O estudo teve como objetivo avaliar o efeito da inclusão de monensina sódica no concentrado inicial de bezerras lactantes, sobre o ganho de peso, perímetro torácico, altura de cernelha, altura de garupa e comprimento corporal. Foram utilizadas 12 bezerras divididas em dois grupos experimentais de acordo com a data de nascimento. Foram avaliados os tratamentos controle (sem suplementação com monensina) e suplementação diária com 0,4 mg de monensina/kg de peso corporal, a dosagem de monensina iniciou em 0,2 mg/kg peso vivo, para adaptação dos animais, sendo os animais acompanhados a partir dos 30 dias até os 86 dias de idade. Os parâmetros avaliados semanalmente foram peso corporal, perímetro torácico, altura de cernelha, altura da garupa e comprimento corporal. Tais parâmetros não apresentaram variação em função da suplementação com monensina, o menor rendimento observado para o grupo suplementado pode ter sido decorrente da diminuição do consumo. A suplementação de monensina não apresentou efeito sobre desempenho ponderal de bezerras leiteiras em sistema de desaleitamento precoce.

The objective of the present study was to evaluate the effects of the inclusion of sodium monensin on the starter concentrate of lactating heifers on weight gain, chest girth, withers height, hip height and body length. Twelve heifers were divided into two experimental groups according to date of birth: a control group without supplementation and a daily supplemented group with 0.4 mg of sodium monensin per kg of body weight. The animals were observed from thirty days of age until 86 days of age. Production parameters as body weight, chest girth, withers height, hip height and body length were weekly evaluated. These parameters did not show variation depending on supplementation with monensin, the lowest yield observed in the supplemented group may have been due to lower consumption. The supplementation of monensin had no effect on weight gain of dairy calves in early weaning system.

Comparative Study of Calix-6-arene, 2-Hydroxy Propyl Beta Cyclodextrin and 18-Crown-6 as Ionophores in Potentiometric Ion-Selective Electrodes for Determination of Trigonelline in Trigonella foenum-graecum Seeds Extract and Plasma.

The present work evaluates the influence of Calix-6-arene, 2-hydroxy propyl β-cyclodextrin and 18-crown-6 as ionophores on the fabrication of trigonelline selective electrodes 1, 2 and 3, respectively. The three proposed sensors showed Nernstian slopes of 59, 60 and 55.75 mV/concentration decades over pH range 4-9 for sensors 1, 2 and 3, respectively. Both sensors 1 and 2 covered the concentration range 10-3 – 10-5 M, while sensor 3 showed linear response over the range 10-2 – 10-4 M. The proposed sensors offer the advantages of fast response and moderate stability time. The selectivity coefficients of the developed sensors indicated excellent selectivity for trigonelline. The proposed electrodes were successfully applied for direct determination of trigonelline in pure form, Trigonella foenum-graecum seeds extract and plasma without prior separation or pretreatment steps. The proposed sensors can be used in quality control labs and in clinical trails for routine analysis of trigonelline in Trigonella foenum-graecum seeds extract and plasma.

Comparative Study of Calix-6-arene, 2-Hydroxy Propyl Beta Cyclodextrin and 18-Crown-6 as Ionophores in Potentiometric Ion-Selective Electrodes for Determination of Trigonelline in Trigonella foenum-graecum Seeds Extract and Plasma.

The present work evaluates the influence of Calix-6-arene, 2-hydroxy propyl β-cyclodextrin and 18-crown-6 as ionophores on the fabrication of trigonelline selective electrodes 1, 2 and 3, respectively. The three proposed sensors showed Nernstian slopes of 59, 60 and 55.75 mV/concentration decades over pH range 4-9 for sensors 1, 2 and 3, respectively. Both sensors 1 and 2 covered the concentration range 10-3 – 10-5 M, while sensor 3 showed linear response over the range 10-2 – 10-4 M. The proposed sensors offer the advantages of fast response and moderate stability time. The selectivity coefficients of the developed sensors indicated excellent selectivity for trigonelline. The proposed electrodes were successfully applied for direct determination of trigonelline in pure form, Trigonella foenum-graecum seeds extract and plasma without prior separation or pretreatment steps. The proposed sensors can be used in quality control labs and in clinical trails for routine analysis of trigonelline in Trigonella foenum-graecum seeds extract and plasma.

The use of sodic monensin and probiotics for controlling subacute ruminal acidosis in sheep / O uso de monensina sódica e probióticos para o controle de acidose ruminal subaguda em ovinos

It was to validated a protocol for induction of subacute ruminal acidosis (SARA) (Experiment 1) and test the efficiency of probiotic Saccharomyces cerevisiae or monensin to avoid pH ruminal drops in sheep (Experiment 2). In Experiment 1, six ewes were fasted for two days and then fed most with concentrate during four days. Ewes in this protocol had ruminal fluid pH below 6.0 and kept it for 75 consecutive hours. In Experiment 2, 18 sheep were distributed into three groups: Control (CG, n = 6), monensin (MG, n = 6) and probiotic group (PG, n = 6). SARA was induced according Experiment 1. PG had lower pH (5.7 ± 0.1) than CG (6.0 ± 0.1) (P = 0.05), while MG (5.7 ± 0.1) was similar to both during SARA induction. SARA induction reduced ruminal protozoa population (P < 0.05) and increased chloride concentrations in ruminal fluid (P < 0.01). In serum, SARA increased concentrations of phosphorus (P < 0.01), AST (P < 0.01) and GGT (P < 0.01), but reduced LDH (P < 0.01). In conclusion, the protocol used for SARA induction was able to maintain ruminal pH between 5.5-6.0 for more than 48 hours. However, monensin and probiotics supplementation was not effective in preventing changes in ruminal and serum parameters during SARA.

Foi validado um protocolo para a indução de acidose ruminal subaguda (SARA) (Experimento 1) e testar a eficácia do probiótico Saccharomyces cerevisiae ou monensina na prevenção da queda do pH do fluido ruminal em ovinos (Experimento 2). No Experimento 1, seis ovelhas foram mantidas em jejum por dois dias e, em seguida, alimentadas basicamente com concentrado durante quatro dias. Nesse protocolo as ovelhas mantiveram o pH do fluido ruminal abaixo de 6,0 por 75 horas consecutivas. No Experimento 2, 18 ovelhas foram distribuídas em três grupos: controle (GC, n = 6), monensina (GM, n = 6) e o grupo probiótico (GP, n = 6). A SARA foi induzida de acordo com o Experimento 1. GP apresentaram valores de pH mais baixos (5,7 ± 0,1) do que o GC (6,0 ± 0,1) (P = 0,05), enquanto GM (5,7 ± 0,1) foi semelhante durante a indução de SARA. A indução SARA reduziu a população de protozoários no rúmen (P < 0,05) e aumentou a concentração de cloreto no líquido ruminal (P < 0,01). Durante a SARA observou-se aumento das concentrações séricas de fósforo (P < 0,01), AST (P < 0,01) e GGT (P < 0,01), mas reduziu a de LDH (P < 0,01). Em conclusão, o protocolo utilizado para a indução de SARA foi capaz de manter o pH do rúmen entre 5,5-6,0 por períodos superiores a 48 horas. No entanto, a suplementação com monensina e probióticos não foi eficaz na prevenção das alterações nos parâmetros ruminais e séricos durante SARA.

Benefícios do uso da monensina sódica na nutrição de cordeiros semi-confinados / Benefits of using sodium monensin in nutrition of semi-confined lambs

O objetivo deste estudo foi analisar o efeito da monensina sódica no controle de coccídeos do gênero Eimeria, no ganho de peso, no consumo de matéria seca e no crescimento de cordeiros semi-confinados. Dezenove cordeiros, sendo oito machos (15,4 kg) e onze fêmeas (15,7 kg), ½ Dorper x ½ Santa Inês, foram distribuídos aleatoriamente em um grupo tratado e outro controle. Os cordeiros foram pesados no início do experimento e quinzenalmente até atingirem 25 kg de peso vivo. Coletas de fezes, para a contagem de oocistos por grama de fezes, foram realizadas semanalmente e biometrias, quinzenalmente. Para estimativa do consumo de matéria seca, foram feitos registros diários, por baia, da oferta e das sobras da dieta. A utilização da monensina sódica, na dose de 45 ppm, se mostrou eficaz na redução de oocistos de Eimeria spp. presentes nas fezes, controlando, assim, a incidência da coccidiose. O uso de monensina na dieta promoveu redução de consumo absoluto de matéria seca na dieta total dos cordeiros, entretanto não interferiu no ganho de peso, na maioria das variáveis indicativas de crescimento e no consumo de matéria seca em relação ao peso vivo.

The aim of this paper was to analyze the monensin sodium effect in controling coccidia of the genus Eimeria, weight gain, dry matter intake and growth of semi-confined lambs. Nineteen lambs, eight males (15.4 kg) and eleven females (15.7 kg), ½ Dorper x ½ Santa Ines were randomly allocated in two groups: one who received monensin and a control group. Sheep were weighted at the beginning of the experiment and fortnightly until they reach 25 kg of liveweight. Fecal samples for counting oocysts per gram of feces were collected weekly and biometric measurements were performed fortnightly. For dry matter intake estimating, notes of supply and leftovers from the diet, per stall, were made daily. The use of monensin sodium, at a dosage of 45 ppm, was effective in reducing Eimeria spp. oocysts present in the feces, controlling, this way, the incidence of coccidiosis. The use of monensin in feed promoted reduction in absolute dry matter intake in the full diet of lambs, however had no effect on weight gain, most of indicatives variables of growth and in dry matter intake as a percentage of body weight.

Anticorpos policlonais em dietas com alta inclusão de concentrado para bovinos confinados / Polyclonal antibodies for feedlot cattle fed high-concentrate diets

Dentre as alternativas para substituir o uso de ionóforos classificados como antibiótico por alguns comitês, a utilização de anticorpos policlonais classificados como promotores de crescimento naturais tem se mostrado alternativa interessante e economicamente eficiente. Recentes estudos demonstraram pontos positivos na utilização desse aditivo em dietas com alta inclusão de ingredientes concentrados para bovinos confinados, traduzido por melhora de desempenho e saúde ruminal, em alguns casos, semelhantes à monensina sódica. No entanto, alguns pontos dessa nova tecnologia ainda devem ser elucidados, entre eles, a possível perda de atividade da forma sólida de apresentação do preparado e a diminuição do rendimento de carcaça encontrado em alguns estudos. Contudo, a presente revisão destaca a possibilidade de substituição da monensina sódica por anticorpos policlonais sem resultar em diminuição de desempenho e de rentabilidade para a bovinocultura de corte brasileira.

Among alternatives to replace ionophores, which are classified as antibiotics by some committees, the feeding of polyclonal antibodies have shown an interesting and economically efficient alternative. Recent studies have demonstrated some advantages of adding polyclonal antibodies into high-concentrate diets for feedlot cattle, showed by increased performance and ruminal health, in some cases similar to sodium monensin. However, there are blind spots of this innovated technology that still need to be elucidated, as example, if the dry form of the preparation is inactivated and decreased carcass-dressing percentage. All in all, this review demonstrates the possibility of replacing sodium monensin by this feed additive without negatively impacting animal performance and profit of cattle feeders in Brazil.

Aspectos clínicos e a bioquímica ruminal de caprinos submetidos à acidose láctica experimental e suplementados ou não com monensina sódica / Clinical aspects and ruminal chemistry in goats with lactic acidosis and sodic monensin supplementation

Objetivou-se com este trabalho estudar o comportamento clínico e laboratorial de caprinos submetidos à incorporação da monensina sódica na alimentação e avaliar os seus efeitos na prevenção da acidose láctica ruminal induzida experimentalmente. Foram avaliados os aspectos clínicos como atitude, comportamento, apetite, coloração das mucosas externas, frequência cardíaca e respiratória, motilidade retículo-ruminal, temperatura retal e o aspecto das fezes, e as características físico-químicas e microbiológicas do fluido ruminal. Foram utilizados 20 caprinos, machos, castrados, cruzados Anglo Nubiana x Saanen, com peso médio de 30kg, clinicamente sadios e submetidos a implantação de cânulas ruminais permanentes. Foram formados dois grupos de 10 animais, um grupo controle (GC) e outro que recebeu a monensina sódica (GM) através da cânula, na dose diária de 33mg/kg da dieta, por animal, no decorrer de 40 dias. A acidose láctica ruminal foi induzida fornecendo 10g de sacarose/kg de peso corpóreo, antes da alimentação matinal. As observações clínicas e a colheita das amostras de fluido ruminal foram efetuadas em intervalos de 4h, 8h, 12h, 24h, 32h, 48h e 72h pós-indução (PI). A partir das 4 horas PI, evidenciou-se sinais como apatia, apetite caprichoso ou anorexia, taquicardia, taquipnéia, atonia ruminal, distensão abdominal e diarréia de intensidade variável. O refluxo de fluido ruminal pelas narinas, sinais de cólica intestinal e secreção nasal serosa bilateral foi observado em alguns animais do GC, e laminite no GM. Ocorreu perda média de peso corpóreo de 900g no GC (P>0,05) e de 1,3kg no GM (P<0,05). Houve uma diminuição significativa (P<0,05) do pH ruminal para valores abaixo de seis; do tempo de atividade de sedimentação e flotação; da viabilidade, densidade e motilidade dos protozoários, a partir das quatro horas da indução no GC e de quatro a 24 horas no GM; no número de infusórios, às 4h PI, tanto no GC como no GM, que se manteve até o final das 72h...

The aim of the present study was to analyze clinical and laboratory findings regarding goats submitted to the incorporation of monensin in their feed and assess its effects on the prevention of experimentally induced ruminal lactic acid. Clinical aspects as well as physiochemical and microbiological characteristics of the ruminal fluid were assessed. Twenty clinically healthy, castrated, male, mixed-breed goats with a mean weight of 30kg were used, in which permanent ruminal cannulae were implanted. Two groups of ten animals were formed: A control group (CG) and a group that received 33mg/kg of monensin (GM) per animal in the diet for 40 days. Ruminal acidosis was induced by administering 10g of sucrose/ kg of live weight, prior to the morning meal. Clinical observations and the collection of ruminal fluid were carried out at 4, 8, 12, 24, 32, 48 and 72h post-induction (PI). At 4 hours PI, there were signs of apathy, capricious appetite or anorexia, tachycardia, tachypnea, rumen stasis, abdominal distention and diarrhea of varying severity. The reflux of rumen fluid through the nostrils, signs of colic intestinal and serous bilateral nasal discharge was observed in some animals of the CG, and laminitis in GM. There was an average loss of body weight of 900g in CG (P>0.05) and 1.3kg in GM (P<0.05). There was a significant decrease (P<0.05) rumen pH falls below six; uptime sedimentation and flotation, viability, motility and density of protozoan, as of four hours of induction in GC and four to 24 hours in GM, the number of infusers, at 4 PI, both in CG and GM, which remained until the end of 72 hours, and the values of acetic, propionic and butyric acids in GM. The values of butyric acid in the GC reduced there is not significant difference (P>0.05)...

Experimental study on inducing differentiation of K562 cells into dendritic cells by A23187 / 国际肿瘤学杂志

Objective To explore the method for differentiation induction of leukemia cells into dendritic cells(DC) by A23187 in vitro. Methods Chronic myeloid leukemia K562 cells were cultured with A23187 or cytokine to induce differentiation and form DC. The morphologic features of cells were observed under inverted microscope, the changes of DC surface marks were determined by flow cytometry and RT-PCR, the ability to stimulate lymphocyte proliferation was tested by MTT colorimetry. Results Under the condition of the does (385 ng/ml) of A23187 for four days, some of K562 cells were found in typical dendritic appearance.The expression of DC markers CD1a,CD83 ,HLA-DR,CD86 and CD80 was 6.65 ±2.70,7.37 ±2.40,6.24 ±4.29, 21.60 ± 3.84, 18.52 ± 4.48 repectively, and increased obviously compared with the negative control group(2.80 ±0.52,1.85 ±0.56,2.25 ±0.47,6.69 ±0.83,9.96 ±3.53). The differences had statistical significance (P < 0.05). K562 cells derived from DC acquired the ability to stimulate lymphocyte proliferation.Conclusion A23187 can induce the leukemia cells differenntiation into activated DC-like cells rapidly.

Intoxicação espontânea por antibióticos ionóforos em ovinos no Rio Grande do Sul / Spontaneous poisoning by ionophores in sheep in Rio Grande do Sul, Brazil

Um surto de intoxicação espontânea por antibióticos ionóforos em ovinos da região Central do Rio Grande do Sul é descrito. Os 16 ovinos afetados estavam em campo nativo e ingeriram acidentalmente um aditivo alimentar para frangos contendo 250g/kg de narasina. Os sinais clínicos consistiam de fraqueza, incoordenação, dispnéia, secreção nasal, decúbito e morte em poucas horas. Um ovino apresentou urina escura. Macroscopicamente havia ascite, hidrotórax, edema pulmonar e palidez hepática. Discreto grau de degeneração muscular na musculatura esquelética dos membros pélvicos e torácicos foi observado histologicamente. O diagnóstico de intoxicação por narasina foi realizado com base no histórico (ingestão de aditivo alimentar contendo narasina) e nos achados clinico-patológicos.

An outbreak of spontaneous ionophore toxicity in sheep grazing in native pasture in Rio Grande do Sul state, Brazil is described. Sixteen sheep which had accidental access to a chicken feed additive containing 250g/kg of narasin were affected. Clinical signs consisted of weakness, incoordination, dyspnea, nasal discharge, recumbency, and death in a few hours. One sheep showed dark red urine. Grossly there were ascites, hydrothorax, pulmonary edema, and hepatic paleness. Discrete skeletal muscle degeneration was observed histologically in the muscles of the pelvic and thoracic limbs. The diagnostic of narasin toxicosis was based on history (ingestion of feed additive containing narasin), clinical, and pathological findings.

Carcass quality of feedlot finished steers fed yeast, monensin, and the association of both additives / Qualidade de carcaça de novilhos terminados com dietas contendo levedura, monensina e associação de ambos aditivos

To evaluate the effects of the supplementation of feed additives on carcass quality in beef cattle, 72 Nellore steers (339.5kg, 20-month old) were feedlot finished and fed for 91 days one of the following diets: 1) control with no additives; or added of 2) live yeast culture; 3) monensin; or 4) the association of both additives. After slaughter, renal, pelvic, and inguinal fat and hot carcass weights were recorded and carcass was split into muscle, bone, and trimmable fat. Carcass Longissimus muscle area and subcutaneous fat thickness at the 12th rib were measured and steaks of Longisimus muscle were taken to determine meat color, shear force, drip, and cooking losses. Yeast increased carcass dressing percentage but there were no effects on hot carcass weight, Longissimus area, subcutaneous fat thickness, percentage and weight of retail cut yield and trimmings. Feed additives had no effect on carcass pH, meat color, fat content, shear force, and drip losses. Supplementation of yeast, monensin or the association of both additives had no important effects on carcass traits and on meat quality of feedlot finished steers.

Avaliaram-se os efeitos da suplementação de aditivos alimentares sobre a qualidade de carcaça em bovinos de corte. Usaram-se 72 novilhos Nelore com média de peso de 339,5kg e 20 meses de idade, terminados em confinamento e alimentados por 91 dias com uma das quatro dietas: 1) dieta controle sem aditivos, ou com a adição de 2) leveduras vivas, 3) monensina ou 4) associação entre ambos aditivos. Após o abate, os pesos da gordura renal, pélvica e inguinal e da carcaça foram medidos e a carcaça dividida em músculos, ossos e aparas. Foram mensurados a área de olho de lombo e a espessura de gordura subcutânea sobre o músculo Longissimus na região da 12ª costela e foram obtidos bifes para a determinação da cor, força de cisalhamento e perdas por cocção e cozimento da carne. A levedura aumentou o rendimento de carcaça, mas não houve efeito dos tratamentos sobre o peso de carcaça, porção comestível e aparas. Os aditivos não influenciaram o pH da carcaça, a cor, a gordura intramuscular, a força de cisalhamento e as perdas por exsudação da carne. A suplementação, com levedura e com monensina em associação ou separadamente, não teve efeito importante sobre a qualidade da carcaça em novilhos terminados em confinamento.

Erythrocyte stability under imposed fields.

Lysis of erythrocytes offers an unique opportunity to probe the fine structure of the bilayer as a function of its state of energization. Critical monitoring of the volumes, ion fluxes and related measures in erythrocytes exposed to a variety of milieu and treatments showed that one can critically distinguish the nature of the prelytic perturbations and the proximate forces actually responsible for the disruption of the membranes among surface charge density, elastic energy etc.

Mechanisms of transmembrane cation transport studied by nuclear magnetic resonance spectroscopy.

Several molecules like ionophores, vitamins, ion-binding cyclic peptides, acidic phospholipids, surfactants are known to expose the inner side of vesicles, to the externally added cations. Whereas ionophores and certain other systems bring about these changes by a selective transport (influx) of the cation by specialized mechanisms known as the carrier and channel mechanism, other systems cause lysis and vesicle fusion. These systems have been successfully studied using 1H,31 P and 13C nuclear magnetic resonance spectroscopy after the demonstration, fifteen years ago, of the ability of paramagnetic lanthanide ions to distinguish the inside of the vesicle from the outside. The results of these ‘nuclear magnetic resonance kinetics’ experiments are reviewed.

Receptor-mediated endocytosis: An overview of a dynamic process.

The decade of the 70’s was remarkable for the insights that rapidly accumulated to provide us with an understanding of one of the fundamental processes of animal cell metabolism, namely, how mammalian cells ingest a host of extracellular substances to satisfy their various metabolic needs. It has long been appreciated that the surfaces of mammalian cells are in a continual state of flux. Surface membranes often fold inward and pinch of in a vesicular form trapping some of the contents of the extracellular material which are thus transported into the cell. This process is called endocytosis (reviewed in Silverstein et al., 1977). When extracellular fluids are taken up in this manner, the process is called fluid-phase endocytosis or pinocytosis. When solids are ingested, the process is called phagocytosis. Although quantitatively important over the long run, these modes of uptake are slow, nonspecific and dependent on the concentration of the substance in the extracellular medium. In recent years it has been recognized that animal cells have developed a specialized form of this vesicular transport system to selectively retrieve and assimilate macromolecules from the extracellular milieu with high efficiency. This process is called receptor-mediated endocytosis. In this review an attempt is made to collate and correlate the evidence establishing receptormediated endocytosis as a dynamic process that routes cell surface receptors and ligands through multiple intracellular compartments to their ultimate destination.

Conformational characterisation of valinomycin complexation with barium salts—A nuclear magnetic resonance spectroscopic study.

Conformations of valinomycin and its complexes with Perchlorate and thiocyanate salts of barium, in a medium polar solvent acetonitrile, were studied using nuclear magnetic resonance spectroscopic techniques. Valinomycin was shown to have a bracelet conformation in acetonitrile. With the doubly charged barium ion, the molecule, at lower concentrations, predominantly formed a 1:1 complex. At higher concentrations, however, apart from the 1:1, peptide as well as ion sandwich complexes were formed in addition to a ‘final complex’. Unlike the standard 1:1 potassium complex, where the ion was centrally located in a bracelet conformation, the 1:1 barium complex contained the barium ion at the periphery. The ‘final complex’ appeared to be an open conformation with no internal hydrogen bonds and has two bound barium ions. This complex was probably made of average of many closely related conformations that were exchanging very fast (on nuclear magnetic resonance time scale) among them. The conformation of the ‘final complex’ resembled the conformation obtained in the solid state. Unlike the Perchlorate anion, the thiocyanate anion seemed to have a definite role in stabilising the various complexes. While the conformation of the 1:1 complex indicated a mechanism of ion capture at the membrane interface, the sandwich complexes might explain the transport process by a relay mechanism.