Resposta em parâmetros sanguíneos e urinários de vacas leiteiras ao aumento no balanço cátion-aniônico da dieta / Response in blood and urinary parameters of dairy cows to the increase in dietary cation-anion balance

Estudou-se efeito de quatro níveis de dietas catiônicas sobre os parâmetros ácido-base do sangue e o pH urinário de vacas em lactação. Para a manipulação dos níveis do balanço cátion-amônico da dieta (BCAD), foram adicionadas diferentes concentrações de bicarbonato de sódio às dietas, obtendo-se os seguintes tratamentos: +150, +250, +400 e +500mEq/kg de matéria seca. O experimento foi realizado durante o verão, por um período total de 72 dias, utilizando-se oito vacas da raça Holandesa após o pico de lactação, distribuídas em quadrado latino (4x4), replicado, em que cada período teve duração de 18 dias. O pH urinário e o bicarbonato, o pH, o CO2 total e a pCO2 do sangue aumentaram linearmente (P<0,01) com o aumento do BCAD. As concentrações de sódio e potássio do sangue não foram modificadas (P>0,05) pelo BCAD. A concentração de cloro no sangue diminuiu linearmente (P<0,01) com o aumento do BCAD. O aumento do BCAD afetou o equilíbrio ácido-base das vacas, promovendo efeito alcalinogênico, o que poderia levar a diferenças significativas no desempenho do animal.

The effect of four levels of cationic diets on acid-basic parameters of blood and the urinary pH were studied in dairy cattle. In order tomanage the dietary cation-anion balance (DCAB) different concentrations of sodium bicarbonate were added to diets, obtaining the following treatments: +150, +250, +400, and +500mEq/kg dry matter. The experiment was performed during the summer, totalizing 72 days, using eight Holstein cows after the lactating peak, distributed in 4 x 4 replicated latin square, with 18 days in each period. The urinary pH and the blood parameters (bicarbonate, pH, total CO2, and pCO2) linearly increased (P<0.01) with the DCAB increase. The sodium and potassium concentrations in blood were not modified (P>0.05) by DCAB. The chloride concentration in blood linearly decreased (P<0.01) with the DCAB increase. The DCAB increase affected the acid-base status of cows, promoting an alkalinogenic effect, what could lead to significant differences on animal performance.

Concentration of cations in different parts of male reproductive system and their influence on in vitro sperm motility in lizard, Mabuya carinata Schneider.

Concentrations of mono- and divalent cations in the testis, three different regions of the epididymis and the vas deferens of lizard, M. carinata were determined. The concentrations of Na+, K+ and Ca2+ increased gradually from testis to vas deferens. However, no significant variation in the levels of Mg2+ was observed between testis and anterior epididymis, and between posterior epididymis and vas deferens. Further, in an in vitro sperm motility study, wherein different concentrations of the cations were tested, the maximum forward progressive motility of posterior epididymal spermatozoa was observed following treatment with 140 mMNaCl, 25 mM KCl, and 50 mM CaCl2 whereas, treatment with magnesium brought about a decrease in sperm motility. The results indicate that Na+, K+, and Ca2+ have stimulatory effect at an optimum dose, whereas Mg2+ has an inhibitory effect even at very low concentration, on sperm motility in the lizard M carinata.

Influência do balanco cátion-aniônico da dieta no rúmen e no desempenho de ovinos / Influence of dietary cation-anion balance on rumen and performance variables in sheep

Estudou-se o efeito do balanco cátion-aniônico da dieta (BCAD) no desempenho animal e na fermentacão ruminal, utilizando-se 25 carneiros machos, da raca Santa Inês, durante 75 dias. O delineamento experimental foi em blocos ao acaso, com cinco tratamentos. Para a manipulacão do BCAD, foram adicionados sulfato de amônio e bicarbonato de sódio, obtendo-se os seguintes tratamentos: -160, -40, 140, 250 e 500 mEq/kg de matéria seca. O aumento do BCAD resultou em aumentos da ingestão de matéria seca, do ganho diário, da eficiência alimentar e do pH ruminal (P<0,05). O perfil de ácidos graxos ruminais não foi afetado pelo BCAD.

Cationic liposome-mediated bcl-xl gene transfection into human keratocytes / 华中科技大学学报（医学）（英德文版）

The efficiency and safe range of Lipofectamine2000 (LF2000)/bcl-xl applied in human keratocytes, the optimal ratio of LF2000/bcl-xl and the bcl-xl gene expression in human keratocytes were investiaged. By using trypan-blue staining, the effects of LF2000 and bcl-xl on the survival rate of the cultured human keratocytes were measured respectively. By using semi-quantitative RT-PCR, the efficiency and the expression of LF2000-mediated bcl-xl transfection into keratocytes were examined. The results showed that the survival rate of human keratocytes had no signficant change in the presence of LF2000 (20 microg/ml) or bcl-xl (10 microg/ml) for 24 h. LF2000 could effectively mediate the transfection of exogenous gene bcl-xl into human keratocytes. The best transfection efficiency could be obtained when the ratio of bcl-xl/LF2000 was 1:8. One day after transfection, the positive cells for bcl-xl could be detectable, and the positive rate reached the peak-on the posttransfection day 3 (48.3%), then gradually decreased. Fifteen days after transfection, there were few positive cells. It was suggested that LF2000 could effectively transfer the exogenous gene bcl-xl into human keratocytes without obvious toxicity during a concentration range. LF2000/bcl-xl may be likely to play an important role in gene therapy of human keratocytes.

Gene Delivery to the Rat Liver Using Cationic Lipid Emulsion/DNA Complex: Comparison between Intra-arterial, Intraportal and Intravenous Administration

OBJECTIVE: To compare the efficiency of intra-arterial, intraportal, and intravenous administration of cationic lipid emulsion/DNA complex, as used for gene transfer to rat liver. MATERIALS AND METHODS: DNA-carrier complex for the in-vivo experiment was prepared by mixing DNA and a cationic lipid emulsion. According to the administration route used (intra-arterial, intraportal, or intravenous), the animals were assigned to one of three groups. The heart, lung, liver, spleen and kidneys were removed and assayed for total protein and luciferase concentration. RESULTS: The cationic lipid emulsion/DNA complex used successfully transfected the various organs via the different administration routes employed. Luciferase activity in each organ of untreated animals was negligible. Liver luciferase values were significantly higher in the groups in which intra-arterial or intraportal administration was used. CONCLUSION: The intra-arterial or intraportal administration of cationic lipid emulsion/DNA complex is superior to intravenous administration and allows selective gene transfer to the liver.