人乳铁蛋白对宫颈癌Hela细胞凋亡的影响

为了研究人乳铁蛋白对宫颈癌Hela细胞的生长抑制作用及其对细胞凋亡、p53蛋白表达和Caspase-3活性的影响,试验采用MTT方法检测细胞的生长抑制率、DNA片段化试验检测细胞凋亡、流式细胞术测定细胞周期、Western-blot检测p53蛋白表达、Caspase-3活性检测试剂盒检测Caspase-3的活性.结果表明:人乳铁蛋白对宫颈癌Hela细胞的抑制呈现时间和剂量依赖性,有73%的Hela细胞停滞在G0～G1期;Western-blot检测结果显示人乳铁蛋白可以上调p53蛋白的表达; 人乳铁蛋白作用48 h后Caspase-3的活性是0小时时的5.5倍,二者差异极显著(P<0.01).结果说明人乳铁蛋白能显著抑制宫颈癌Hela细胞生长,其抗肿瘤机制与诱导细胞凋亡、调控细胞周期、上调p53表达、活化Caspase-3有关.     

华蟾毒精对胃腺癌细胞MGC-803作用的研究

研究华蟾毒精（cinobufagin,CBG）体外对人胃腺癌细胞MGC-803的抑制作用,并初步探讨其抗肿瘤的作用机制。MTT法测定CBG对胃腺癌MGC-803细胞的生长抑制情况;采用光镜观察CBG对人胃腺癌细胞MGC-803形态的影响;流式细胞术检测CBG对MGC-803细胞的抑制作用、细胞周期及细胞早期凋亡的影响。一定浓度范围内CBG对MGC-803细胞的增殖有剂量、时间依赖性抑制作用;光镜下可见细胞形态明显发生变化,细胞变圆,分泌颗粒增多,细胞折光性下降,大部分细胞脱壁;流式细胞仪检测MGC-803细胞,G1期细胞减少,大量细胞停滞在G2/M期,凋亡细胞增多。CBG对MGC-803细胞的抑制作用与诱导其细胞阻滞及凋亡密切相关。     

去甲斑蝥素抑制肺癌细胞增殖的体外研究

为分析去甲基斑蝥素二钠盐对人和小鼠肺癌细胞增殖的抑制作用,体外培养人非小细胞肺癌A549细胞和小鼠肺癌Lewis细胞,用WST-1还原法检测不同浓度去甲斑蝥素(norcantharidin,NCTD)对肿瘤细胞增殖的抑制作用,并用流式细胞术分析细胞周期;免疫印迹技术分析MAPK激酶表达。NCTD抑制A549和Lewis增殖的IC50值分别为13.5和9.5μmol/L;0、6.25、12.50和25.00μmol/L NCTD处理24h,诱导A549细胞G2/M期阻滞率分别为26.30%、29.44%、49.83%和81.35%。结果表明,抑制肿瘤细胞增殖可能是去甲基斑蝥素抗肿瘤作用的分子机制之一。     

成骨生长肽对体外培养奶牛成骨细胞碱性磷酸酶和骨钙素的影响初探

体外培养奶牛成骨细胞,用10^-12mol／L、10^-11mol／L、10^-10mol／L、10^-9mol／L和10^-8mol／L成骨生长肽（OGP）干预5d后．紫外分光光度法检测细胞上清液中碱性磷酸酶（ALP）活性,以放射免疫法检测细胞上清液中骨钙素（OC）含量。结果显示：成骨生长肽对细胞上清液中ALP活性起抑制作用,其中在10^-10mol／L时抑制作用最为显著（P〈0．01）;对细胞上清液中OC亦起抑制作用,且该抑制呈现剂量双向性．在10^-10mol／L时抑制作用显著。结论：成骨生长肽对体外培养奶牛成骨细胞碱性磷酸酶和骨钙素起轻微抑制作用而且呈双向性。     

柞蚕蛹虫草水提物对人乳腺癌细胞MCF-7增殖和凋亡的影响

研究柞蚕蛹虫草水提物（Aqueous extract from cordycep militaris of antheraea pemyi,AEoAPC）对人乳腺癌细胞MCF-7生长抑制与凋亡的作用.将不同浓度的AEoAPC分别作用于人乳腺癌细胞MCF-7 24、48、72 h后,应用倒置相差显微镜观察人乳腺癌细胞MCF-7的形态变化,噻唑蓝比色法测定细胞生长抑制效应,流式细胞术检测细胞周期变化及凋亡率.结果表明：AEoAPC能显著抑制人乳腺癌细胞MCF-7的增殖,且在一定的浓度范围内呈时间和浓度的依赖性;形态学观察发现,细胞形状不规则、变暗、皱缩;FCM检测结果显示,作用72 h后G0-G1期（DNA合成前期）的细胞分布有所增加,使细胞阻滞于G2期（DNA合成后期）和S期（DNA合成期）;0.8g/L AE0-APC在24、48、72 h凋亡率分别为8.65％、14.20％、26.30％,其凋亡程度与时间呈正相关.说明AEoAPC能明显抑制人乳腺癌细胞MCF-7的生长,诱导其细胞凋亡.     

17-β-雌二醇对小鼠胸腺上皮细胞增殖的影响

为探讨17-β-雌二醇对小鼠胸腺上皮细胞增殖的影响及其分子机制,将小鼠胸腺上皮细胞系(MTEC1)经不同浓度和不同时间的17-β-雌二醇处理后,采用CCK-8法、Edu掺入法检测细胞增殖活性的变化;流式细胞术检测细胞周期的变化;DAPI染色法检测细胞核形态的变化;Western blot技术检测细胞周期相关基因CDK1及CyclinB1蛋白表达的变化。结果显示,雌激素显著抑制MTEC1细胞的生长,并呈时间和剂量依赖性;雌激素处理组G2/M期细胞显著增多,出现G2/M期阻滞;细胞形态变化明显,出现形状变大、多核、核染色质凝聚等现象;CDK1及CyclinB1的蛋白表达水平显著下调。结果表明,17-β雌二醇可以抑制MTEC1细胞的增殖,其机制可能是通过下调细胞周期正调节因子CDK1及CyclinB1的表达,使细胞阻滞于G2/M期。     

桑黄水提物诱导黑色素瘤细胞系B16-F10 G0/G1期阻滞的研究

通过噻唑蓝(MTT)比色法、流式细胞分析、转录组测序和蛋白印迹等手段,探究桑黄水提物(SH)对黑色素瘤细胞系B16-F10的抑制作用及分子作用机制。MTT实验结果显示,SH能够抑制B16-F10细胞系增殖,且呈剂量依赖性。流式细胞分析发现,SH能够诱导细胞G₀/G₁期阻滞,但对细胞凋亡无明显影响。RNA-seq、qRT-PCR和Western blot分析发现,SH主要通过上调p53信号通路中p21的表达,进而抑制细胞周期通路中CyclinD3、CDK2和CDK6的表达来影响细胞周期阻滞。研究结果证明SH对黑色素瘤细胞增殖具有显著的抑制作用,p21-CyclinD3-CDKs信号通路介导的G₀/G₁期阻滞是其作用机制之一。     

花椒精油对HaCaT细胞增殖和凋亡的影响

为探究花椒精油抗人永生化表皮细胞(HaCaT)增殖活力和诱导凋亡的潜在机制,通过采用磺酰罗丹明B(sulforhodamine B,SRB)法对花椒精油的抗增殖活力进行了检测,用流式细胞仪和Western blot检测了细胞周期和细胞凋亡影响情况。研究发现,花椒精油能显著抑制HaCaT细胞增殖,作用48h花椒精油半抑制浓度(IC50)值为199.2μg/mL,其抑制作用呈时间、剂量依赖性。流式细胞仪检测结果显示,精油能使HaCaT细胞周期停滞在S期,并诱导细胞凋亡。Western blot结果显示,花椒精油处理的HaCaT细胞中剪切的Caspase-8/9/3、PARP、Bax表达量增加,同时Bcl-2表达量减少。说明花椒精油能够显著抑制HaCaT细胞增殖,并能通过内源和外源两种途径诱导细胞发生凋亡。     

家兔胚胎细胞周期的调控

本实验用化学药物对家兔胚胎细胞周期进行调控,以建立细胞周期同期化的方法.实验结果表明(1)用1.00μg/ml噻氨酯哒唑(nocodazole)处理家兔16-细胞胚胎12h,可使胚胎细胞完全同期化于M期;(2)细胞周期同期化于M期的家兔胚胎细胞用0.20μg/ml阿菲迪霉素(aphidicolin)处理8h,可完全抑制DNA的合成,使胚胎细胞同期化于G1期;(3)细胞周期同期化于M期的家兔胚胎细胞在体外培养8h后,然后用1.00μg/ml环己酰胺(cycloheximide)处理8h,可使胚胎细胞同期化于G2期.本研究的结果还表明细胞周期同期化处理不影响胚胎的体外发育,但胚胎移植后的产仔率明显低于对照组(P＜0.05).     

17β-雌二醇对仔猪支持细胞周期的影响

为了研究17β-雌二醇对仔猪睾丸支持细胞周期的影响,实验采用流式细胞术测定了细胞周期中DNA含量,分析了细胞周期细胞增殖指数(PI)和S期细胞指数(SPF)的变化。结果表明:低浓度的17β-雌二醇(10-10～10-7mol/L)能够促进支持细胞周期的转化,其中17β-雌二醇浓度为10-9mol/L时的作用最强;而高浓度的17β-雌二醇(10-6mol/L)则抑制支持细胞周期的转化。17β-雌二醇(10-9mol/L)能以时间依赖性促进支持细胞周期转化,其中24h的作用最明显。ERK1/2抑制剂U0126能减少17β-雌二醇诱导的细胞周期的转化。cAMP的激动剂8-Br-cAMP促进了细胞周期的转化,而抑制剂Rp-cAMP阻止了17β-雌二醇诱导的细胞周期的转化。表明17β-雌二醇对细胞周期的调节呈现一定的时间-剂量依赖性,cAMP和ERK1/2级联参与了这一过程。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein