The present work was undertaken in a cattle ranch of the north of Puebla state, Mexico. The aim was to incorporate Guazuma leaves （Guazuma ulmifolia） in the diet of growing calves and evaluate its effect on weight g...The present work was undertaken in a cattle ranch of the north of Puebla state, Mexico. The aim was to incorporate Guazuma leaves （Guazuma ulmifolia） in the diet of growing calves and evaluate its effect on weight gain. Twenty-four Cebu × Swiss calves （approximately live weight 250 kg） were used during all the experimental period （64 d）. They were assigned to a completely randomized design under two treatments （n = 12 for each treatment）： control （T1） consisted of commercial feed based on 15% crude protein （CP） ＋ cut Taiwan grass and the treatment （T2） consisted of a formulated diet containing 14.7% CP including Guazuma. The composition of the formulated diet consisted of： Guazuma （60%）, rolled corn （12%）, ground sorghum （9%）, oats in grain （7%）, wheat bran （9%） and vitamins and minerals. The feed was offered twice a day at a rate of 3% of live weight for 64 d. The mean daily gain for T1 and T2 was 1.15 g/animal and 1.52 g/animal, respectively （p 〈 0.05）. Results indicate that Guazuma-based supplements resulted in greater productive yield in growing calves.展开更多
AIM: To assess the effects of ulcerogenic agents on actin cytoskeleton and cell motility and the contribution of oxidative stress.METHODS: Rat gastric mucosal cell monolayers were cultured on coverslips. The cells wer...AIM: To assess the effects of ulcerogenic agents on actin cytoskeleton and cell motility and the contribution of oxidative stress.METHODS: Rat gastric mucosal cell monolayers were cultured on coverslips. The cells were exposed, with or without allopurinol (2 mmol/L), for 15 min to ethanol (10-150 mL/L), ASA (1-20 mmol/L) or taurocholate (1-20 mmol/L), then the cells were processed for actin and vinculin staining. Cell migration after wounding was also measured.RESULTS: Exposure to 10 mL/L ethanol caused divergence of zonula adherens-associated actin bundles of adjacent cells and decreased rate of migration. These actions were opposed by xanthine oxidase inhibitor allopurinol. Exposure to 50 mL/L ethanol induced degradation and divergence of zonula adherens-associated vinculin from adjacent cells,which was, again, partially reverted by allopurinol. With 1 mmol/L ASA actin filaments became shorter and thicker.However, higher concentrations (10, 20 mmol/L) of ASA returned microfilaments thinner and longer, and decreased rate of migration. Zonula adherens-associated actin bundles were moderately distorted with 10 mmol/L ASA and with 10 mmol/L taurocholate. Exposure to taurocholate provoked changes resembling those of ASA. Taurocholate 5-20 mmol/L decreased the rate of migration dose dependently. The effects of ASA and taurocholate were not prevented by allopurinol.CONCLUSION: All ulcerogenic agents decreased the rate of migration dose dependently and induced divergence of zonula adherens-associated actin bundles of adjacent cells.In addition, ethanol and ASA caused degradation of actin cytoskeleton. Oxidative stress seems to underlie ethanol,but not ASA or taurocholate, induced cytoskeletal damage.展开更多
Stable sub 500 nm bovine serum albumin (BSA) microsphere suspensions were produced by controlled addition of acetone and ethanol to an aqueous solution of BSA, followed by stabilization process of the formed microsphe...Stable sub 500 nm bovine serum albumin (BSA) microsphere suspensions were produced by controlled addition of acetone and ethanol to an aqueous solution of BSA, followed by stabilization process of the formed microspheres at an elevated temperature. Microspheres produced by this acetone ethanol heat denaturation method were stabilized at relatively low temperatures (70～75℃) over a short period of time (20 min). The acetone ethanol heat denaturation method, in comparison with the traditional oil/ water technique for preparation of albumin microspheres, which requires high temperature (over 100℃) and longer heating time (more than 30 min) for stabilization, offers a number of advantages. This report describes the influence of process conditions, such as ratios of acetone to ethanol to BSA aqueous solution, heating time and heating temperature, on microsphere formation and their stability. A loading efficiency of 40% rose bengal was achieved. Rose bengal release rates from these microspheres in phosphate buffered saline medium at 37 ℃ were dependent on microsphere stabilities and 25% to 60% of initial loading drug were released in 15 days.展开更多
In this work, the biocompatibility of a biomimetic, fully biodegradable ionomer phosphorylcholine (PC)-functionalized poly(butylene succinate) (PBS-PC) was investigated by means of hemolysis, platelet adhesion, protei...In this work, the biocompatibility of a biomimetic, fully biodegradable ionomer phosphorylcholine (PC)-functionalized poly(butylene succinate) (PBS-PC) was investigated by means of hemolysis, platelet adhesion, protein adsorption and cytotox- icity experiments. The reference materials were poly(butylene succinate) (PBS) and chloroethylphosphoryl functionalized poly(butylene succinate) (PBS-Cl). The hemolysis rates (HR) of the leaching solutions of PBS, PBS-Cl and PBS-PC were all lower than the safe value, and the rate of PBS-PC was reduced to 1.07%. Scanning electron microscopy (SEM) measurements showed that platelet adhesion and aggregation were significant on both PBS and PBS-Cl surface. In contrast, very few platelets were observed on PBS-PC surface. Bicinchoninic acid (BCA) measurements revealed that the adsorption amounts of bovine serum albumin (BSA) and bovine plasma fibrinogen (BPF) on PBS-PC surface were 52% and 72% reduction respectively compared with those on PBS surface. Moreover, non-cytotoxicity of both PBS-PC particles and its leaching solution was sug- gested by MTT assay using mouse L929 fibroblast cells. All the results demonstrated that the biocompatibility of PBS could be greatly improved by PC end-capping strategy. This PC functionalized polyester may have potential applications in biological environments as a novel carrier for controlled drug release and scaffold for tissue engineering.展开更多
文摘The present work was undertaken in a cattle ranch of the north of Puebla state, Mexico. The aim was to incorporate Guazuma leaves （Guazuma ulmifolia） in the diet of growing calves and evaluate its effect on weight gain. Twenty-four Cebu × Swiss calves （approximately live weight 250 kg） were used during all the experimental period （64 d）. They were assigned to a completely randomized design under two treatments （n = 12 for each treatment）： control （T1） consisted of commercial feed based on 15% crude protein （CP） ＋ cut Taiwan grass and the treatment （T2） consisted of a formulated diet containing 14.7% CP including Guazuma. The composition of the formulated diet consisted of： Guazuma （60%）, rolled corn （12%）, ground sorghum （9%）, oats in grain （7%）, wheat bran （9%） and vitamins and minerals. The feed was offered twice a day at a rate of 3% of live weight for 64 d. The mean daily gain for T1 and T2 was 1.15 g/animal and 1.52 g/animal, respectively （p 〈 0.05）. Results indicate that Guazuma-based supplements resulted in greater productive yield in growing calves.
基金Supported by the Grants from Antti and Jenny Wihuri Foundation and Research Foundation of Helsinki University Central Hospital, TYH4228
文摘AIM: To assess the effects of ulcerogenic agents on actin cytoskeleton and cell motility and the contribution of oxidative stress.METHODS: Rat gastric mucosal cell monolayers were cultured on coverslips. The cells were exposed, with or without allopurinol (2 mmol/L), for 15 min to ethanol (10-150 mL/L), ASA (1-20 mmol/L) or taurocholate (1-20 mmol/L), then the cells were processed for actin and vinculin staining. Cell migration after wounding was also measured.RESULTS: Exposure to 10 mL/L ethanol caused divergence of zonula adherens-associated actin bundles of adjacent cells and decreased rate of migration. These actions were opposed by xanthine oxidase inhibitor allopurinol. Exposure to 50 mL/L ethanol induced degradation and divergence of zonula adherens-associated vinculin from adjacent cells,which was, again, partially reverted by allopurinol. With 1 mmol/L ASA actin filaments became shorter and thicker.However, higher concentrations (10, 20 mmol/L) of ASA returned microfilaments thinner and longer, and decreased rate of migration. Zonula adherens-associated actin bundles were moderately distorted with 10 mmol/L ASA and with 10 mmol/L taurocholate. Exposure to taurocholate provoked changes resembling those of ASA. Taurocholate 5-20 mmol/L decreased the rate of migration dose dependently. The effects of ASA and taurocholate were not prevented by allopurinol.CONCLUSION: All ulcerogenic agents decreased the rate of migration dose dependently and induced divergence of zonula adherens-associated actin bundles of adjacent cells.In addition, ethanol and ASA caused degradation of actin cytoskeleton. Oxidative stress seems to underlie ethanol,but not ASA or taurocholate, induced cytoskeletal damage.
文摘Stable sub 500 nm bovine serum albumin (BSA) microsphere suspensions were produced by controlled addition of acetone and ethanol to an aqueous solution of BSA, followed by stabilization process of the formed microspheres at an elevated temperature. Microspheres produced by this acetone ethanol heat denaturation method were stabilized at relatively low temperatures (70～75℃) over a short period of time (20 min). The acetone ethanol heat denaturation method, in comparison with the traditional oil/ water technique for preparation of albumin microspheres, which requires high temperature (over 100℃) and longer heating time (more than 30 min) for stabilization, offers a number of advantages. This report describes the influence of process conditions, such as ratios of acetone to ethanol to BSA aqueous solution, heating time and heating temperature, on microsphere formation and their stability. A loading efficiency of 40% rose bengal was achieved. Rose bengal release rates from these microspheres in phosphate buffered saline medium at 37 ℃ were dependent on microsphere stabilities and 25% to 60% of initial loading drug were released in 15 days.
基金financially supported by the National Natural Science Foundation of China (21004048, 20974087)the Natural Science Foundation of Shaanxi Educational Committe (2010JK886)the Science Foundation of Northwest University (NF0912)
文摘In this work, the biocompatibility of a biomimetic, fully biodegradable ionomer phosphorylcholine (PC)-functionalized poly(butylene succinate) (PBS-PC) was investigated by means of hemolysis, platelet adhesion, protein adsorption and cytotox- icity experiments. The reference materials were poly(butylene succinate) (PBS) and chloroethylphosphoryl functionalized poly(butylene succinate) (PBS-Cl). The hemolysis rates (HR) of the leaching solutions of PBS, PBS-Cl and PBS-PC were all lower than the safe value, and the rate of PBS-PC was reduced to 1.07%. Scanning electron microscopy (SEM) measurements showed that platelet adhesion and aggregation were significant on both PBS and PBS-Cl surface. In contrast, very few platelets were observed on PBS-PC surface. Bicinchoninic acid (BCA) measurements revealed that the adsorption amounts of bovine serum albumin (BSA) and bovine plasma fibrinogen (BPF) on PBS-PC surface were 52% and 72% reduction respectively compared with those on PBS surface. Moreover, non-cytotoxicity of both PBS-PC particles and its leaching solution was sug- gested by MTT assay using mouse L929 fibroblast cells. All the results demonstrated that the biocompatibility of PBS could be greatly improved by PC end-capping strategy. This PC functionalized polyester may have potential applications in biological environments as a novel carrier for controlled drug release and scaffold for tissue engineering.
