封闭负压引流联合局部给氧治疗兔耳缺血性创面的实验研究

目的：观察封闭负压引流联合局部给氧促进兔耳缺血性创面愈合的效果。方法：28只大耳白兔,双耳背各造成直径2．5cm全层皮肤缺损,结扎中央血管神经束及后边缘动静脉,形成缺血创面。56个创面随机分为七组：A组（-50mmHg负压同时给氧,浓度为40％±5％,每日4小时）、B组（持续-50mmHg负压4小时继之局部给氧l小时）、c组（负压治疗4min,停止1min,每日4小时,之后给氧1小时）,D组（．50mrnHg负压治疗每日4小时）、E组（-125rnmHg负压治疗每日4小时）、F组（单纯给40％±5％氧l小时）和G组（空白对照）。在创面形成第0、1、3、5、7、10、14、18天拍照,测量创面面积,计算创面愈合率及创面愈合时间;在各时相点切取创面标本,组织学观察创面肉芽、上皮生长、水肿和炎细胞,Ki67免疫组化标记增殖细胞并计算增殖指数,TUNEL法计算凋亡指数。结果：负压给氧组在相同时相点创面愈合率高于单纯负压、氧疗或空白组（P〈0．05）,创面肉芽生长快,水肿和炎症轻,细胞增殖指数高于对照组（P〈0．05）,而细胞凋亡指数显著低于对照组（P〈0．05）。结论：负压联合局部给氧能显著促进兔耳缺血创面的愈合。     

VAC 技术治疗兔耳缺血性创面的实验研究

目的:观察间歇和持续负压下缺血创面不同处理与愈合的关系。方法:实验前1天,用脱毛剂(Nair,美国)对兔耳背脱毛。动物用1%戊巴比妥钠耳缘静脉注射麻醉(30 mg/kg体重),固定于手术台。75%乙醇消毒双侧耳背皮肤。距耳根3-3.5cm处分离、结扎兔耳中央神经血管束。在耳背中部形成直径2.5cm全层皮肤缺损创面(保留软骨膜)[1]。止血后置动物于特制木盒内。42只大白兔共84个创面,随机分为-50mmHg-75mmHg和-100mmHg 3大组,分别施以间歇负压(运行2分钟,停1分钟)和持续负压组。实验分别运用-50mmHg,-75mmHg,-100mmHg三个不同负压值进行连续、间歇治疗兔耳缺血性创面,观察伤后1,3,7,10,14,20d创面愈合情况,取伤后7d组织标本进行Western blot、HE染色,观察VEGF(vascular endothelial growth factor)的表达及创面上皮的再生和肉芽组织生长情况[1]。以及各时间点细胞凋亡的检测。结果:-50mmHg(纱布+海绵)间歇负压引流技术治疗兔耳缺血性创面的愈合最快,-75mmHg治疗组次之,-100mmHg治疗组创面愈合最慢。在同一时间点上,-50mmHg治疗组与-75mmHg,-100mmHg治疗组和空白对照组之间相比,能够更快地促进创面VEGF的表达和肉芽组织的再生,毛细血管增多。封闭负压治疗能够降低创面组织细胞的凋亡的发生。结论:(1)封闭负压治疗能够促进缺血创面的肉芽组织再生及VEGF的表达,减少创面组织细胞的凋亡的发生;(2)-50mmHg间歇封闭负压治疗效果最好。     

封闭负压引流对兔糖尿病溃疡创面组织愈合影响的观察

目的:探讨封闭负压引流(VAC)对兔糖尿病溃疡创面组织愈合的影响及其可能机制。方法:采用四氧嘧啶法建立兔糖尿病溃疡模型,设空白对照组和实验组(对照组创面采用常规包扎治疗处理,实验组创面则采用VAC处理),观察和比较两组动物的创面肉眼观、愈合时间,在致伤前、致伤后3 d、7 d、14 d取创面软组织,检测和比较两组动物的创面组织含水量、血流量以及血浆ET-1和NO含量。结果:与对照组比较,实验组动物的创面肿胀及分泌物得到明显控制,创面坏死组织的清除与肉芽组织的生长明显加快,平均愈合时间明显缩短(P0.05);致伤后3 d、7 d和14 d,创面组织含水量与血浆ET-1含量明显下降(P0.05),创面组织血流量与血浆NO含量明显增加(P0.05)。结论:VAC对兔糖尿病溃疡创面组织的愈合可起到积极的促进作用,这可能与其增加血浆NO含量及降低ET-1的含量有关,其具体机制尚有待于进一步的研究。     

负压封闭引流对兔颅骨外露创面愈合效果的实验研究

目的:探讨负压封闭引流技术(VSD)对兔颅骨外露缺损创面愈合的治疗效果。方法:选取成年新西兰大白兔76只,平均分为四组并建立兔颅骨外露实验模型。其中,A组(19只):于兔颅骨上方制作直径为2.0cm的圆形创面,保留骨膜,采用-120mmHg负压引流和常规换药治疗;B组(19只):实验动物处理同A组,仅采用常规换药治疗;C组(19只):在兔颅骨上制作直径2.0cm的圆形创面,剔除骨膜,治疗方法同A组;D组(19只):实验动物处理同C组,治疗方法同B组。每组各抽取10只,观察创面愈合率和创面愈合时间;其余9只分别在第7天、10天、20天、30天进行取材检测,分析疗效机制。结果:A组创面愈合时间为19.40±1.65天,B组为24.00±2.31天;C组为25.40±4.43天,D组为30.00±5.50天。运用VSD治疗和常规治疗创面愈合时间比较有统计学意义(P0.05)。结论:VSD治疗兔骨外露缺损创面能有效缩短创面愈合时间,促进血管再生,胶原蛋白合成。     

负压创面治疗肝源性糖尿病并发糖尿病足的研究

目的:讨论创面负压治疗促进肝硬化合并糖尿病并发糖尿病足的临床疗效。方法:将30例慢性肝硬化合并糖尿病并发糖尿病足患者随机分为创面负压治疗组和敷料包扎组,观察两组创面细菌负荷及创面微循环血流量变化。结果:清创即刻,负压创面治疗组和敷料包扎组细菌负荷与创面微循环血流量无显著差异(P>0.01);创后3天、6天和9天时,负压创面组创面细菌负荷低于敷料包扎组(P<0.01),创面微循环血流量高于敷料包扎组(P<0.01)。负压创面组创面愈合时间少于敷料包扎组(P<0.01)。结论:负压创面治疗有助于慢性肝硬化并发糖尿病合并糖尿病足的创面愈合。     

负压封闭引流术治疗犬胸壁全层缺损的实验研究

目的:探讨不同负压大小下的封闭负压引流术(vacuum sealing drainage,VSD)在治疗犬胸壁全层缺损创面愈合的效果。方法:25只健康成年犬的右胸壁制作3cm×4cm大小的全层缺损,随机分为5组,所有胸壁缺损处安装一次性封闭式负压吸引器,手动抽吸负压排出胸膜腔气体产生负压,致伤24小时后复查CT观察气胸情况;然后按照压力表显示调节负压至60kpa,40kpa,20kpa,10kpa,0kpa吸引胸壁,比较五组1d,3d,5d的伤口液体引流量,胸膜闭合时间;5d时伤口取材做HE染色及CD34免疫组化染色观察伤口愈合情况。结果:在60kpa和40kpa负压吸引下,1天引流液体量最多,分别为77.6±6.62 ml,77.8±4.97 ml;胸膜闭合最快,分别为3.2±1.30天,3.6±0.55天,但是60kpa组有一只犬血气分析显示为Ⅰ型呼吸衰竭;HE染色和CD34免疫组化染色显示各组均有肉芽组织增生及血管新生,且40kpa和60kpa负压组肉芽组织和血管密度明显多于其他组,二者之间无明显差异。结论:封闭负压吸引器对胸壁全层缺损创面有明显治疗作用,并且在40kpa负压下治疗效果最好而且安全。     

解毒活血汤促进肛周脓肿术后创面愈合的效果分析

目的:研究解毒活血汤治疗肛周脓肿术后患者创面愈合的临床效果及可能机制。方法:选择2017年1月～2019年1月我院肛肠科三病区收治的300例肛周脓肿患者,根据其就诊的顺序,随机数字表法均分为两组,各150例,两组均采取一期肛周脓肿根治术治疗,对照组于术后采用高锰酸钾溶液坐浴疗法,观察组于术后联合服用解毒活血汤治疗。均治疗4 w后,比较两组创面愈合的有效率,肛周脓肿患者创面的愈合时间和视觉模拟评分(visual analogue scale,VAS)评分,治疗前后肉芽组织中的血红蛋白含量、羟脯氨酸含量、血管内皮生长因子水平以及组织微血管计数。结果:治疗后,观察组创面愈合的总有效率明显高于对照组(90.67 vs. 71.33%,P0.05);观察组肛周脓肿患者创面愈合的时间明显短于对照组(P0.05)。对照组治疗前后的肉芽组织中的血红蛋白含量、羟脯氨酸含量、血管内皮生长因子水平以及组织微血管计数无明显的差异(P0.05),观察组治疗后的肉芽组织中的血红蛋白含量、羟脯氨酸含量、血管内皮生长因子水平以及组织微血管计数明显高于治疗前和对照组(P0.05)。观察组术后3 d、1 w和2 w的VAS评分均明显低于对照组(P0.05)。结论:解毒活血汤可能通过提升肉芽组织中的血红蛋白含量、羟脯氨酸含量、血管内皮生长因子水平以及组织微血管计数有效促进肛周脓肿术后的创面愈合,减轻术后疼痛。     

全蝎软膏对大鼠糖尿病皮肤溃疡创面愈合的效果评价

目的:探讨全蝎软膏治疗糖尿病皮肤创面愈合的作用及其机制。方法:采用SPF级SD大鼠构建糖尿病皮肤溃疡模型,将其随机平均分为对照组、模型组、全蝎软膏组和湿润烧伤膏组。造模后,分别在创面处涂抹全蝎软膏或湿润烧伤膏处理,空白组和模型组用PBS处理,观察和比较各组创面的愈合情况,并收集用药后3 d、7 d、10 d和14 d的创面肉芽组织进行HE染色,通过ELISA及荧光定量PCR检测肉芽组织内碱性成纤维细胞生长因子(bFGF)、血管性假血友病因子(v WF)、肿瘤坏死因子α(TNF-α)与Smad 4基因的表达。结果:成功构建大鼠糖尿病皮肤溃疡模型,成模率为96.15%。创伤后第3 d、7 d、10 d和14 d,各治疗组创面愈合率均显著高于模型组(P0.05),给药14 d时,全蝎软膏组创面愈合率已接近对照组水平。HE染色结果显示与模型组相比,全蝎软膏组中肉芽组织生长较快、毛细血管数量增多且组织纤维化程度较低。ELISA和荧光定量PCR检测结果显示与模型组和湿润烧伤膏组相比,全蝎软膏组肉芽组织内bFGF、v WF含量上调更显著(P0.05),而TNF-α含量与Smad 4 m RNA显著降低(P0.05)。结论:全蝎软膏可促进糖尿病皮肤溃疡创面肉芽组织的生长,可能与其抑制炎症反应并改善血管功能有关。     

游离植皮联合负压封闭引流治疗骨科创面的临床研究

目的:观察游离植皮联合负压封闭引流(vacuumsealingdrainage,后文简称VSD)对骨科创面的疗效,并与植皮后传统加压包扎相比较,为临床实践提供更好的治疗方法。方法:对广州中医药大学第一附属医院创伤骨科2008年3月至2010年2月收治的65例感染创面病例采取手术清创后予VSD引流,合理应用抗生素,创面感染得到控制后,创面干净,肉芽生成良好,外露的肌腱、骨膜表面有新鲜的肉芽组织覆盖,达到植皮的要求后,随机分成两组,其中30例(实验组)采用游离植皮联合VSD法闭合创面,35例(对照组)采用游离植皮加压包扎植皮区,对两组术后的平均换药次数、创面平均愈合时间、植皮成活率情况、平均住院时间(植皮后)、平均抗生素应用次数(植皮后)进行统计学分析,采用t检验和卡方检验,对此两种方法进行评价。结果:植皮联合VSD组与植皮加压包扎组,在平均换药次数、创面平均愈合时间、植皮成活率、平均住院时间(植皮后)、平均抗生素应用次数(植皮后)的对比,有显著性差异(P<0.05)。结论:创面达到游离植皮条件后,游离植皮联合VSD负压引流可以促使皮片黏附,保持创面洁净,避免皮下渗液积聚,有利于皮片的存活,与植皮加压包扎组相比,减少了平均换药次数,缩短创面平均愈合时间及平均住院时间(植皮后),减少抗生素平均应用次数,提高了植皮成活率,说明游离植皮联合VSD组优于游离植皮加压包扎组,游离植皮联合VSD法治疗骨科创面有显著疗效。该手术方法操作简单,术后护理方便,是一种较理想的植皮后的固定方法,有利于创面的愈合,值得临床推广应用。     

大血藤醇提物抗炎镇痛和止血活性研究初探

为观察大血藤醇提物抗炎、镇痛、止血活性,该文采用75%乙醇提取制备大血藤醇提物(AESC),利用HPLC法测定其绿原酸含量; KM鼠(或新西兰兔)在测定抗炎、镇痛、止血活性时随机分为空白对照组、阳性对照组(云南白药酊组)、AESC组,依次测定其抑制二甲苯致小鼠耳肿胀度作用、痛阈值和兔肝脏局部创面损伤出血的记分分值,分别考察其抗炎、镇痛、止血作用。结果表明:AESC中绿原酸含量为(0.294±0.013 5)%;与空白组比较,剂量为0.700 g·kg~(-1)的AESC组能显著减轻二甲苯所致的小鼠耳肿胀度(P0.01),抑制率达26.3%;与空白组及给药前比较,剂量为1.40 g·kg~(-1)的AESC组均能显著提高小鼠痛阈值(P0.01);与空白组相比,剂量为1.40 g·kg~(-1)的AESC组能显著提高兔肝脏局部创面损伤出血的记分分值(P0.001)。大血藤醇提取物具有显著的抗炎、镇痛、止血作用,有望将其开发为抗炎、镇痛、止血制剂。该结果也为大血藤的临床应用提供理论依据。     

Conception rates in dairy cows after timed-insemination and simultaneous treatment with gonadotrophin releasing hormone and/or prostaglandin F2 alpha

This study was designed to determine conception rates in dairy cows after timed-insemination and simultaneous treatment with gonadotrophin releasing hormone (GnRH) and/or prostaglandin F2 alpha (PGF2alpha). A total of 2352 cows was randomly assigned to six groups. Cows in Groups 1 to 5 were palpated per rectum to determine the presence of a corpus luteum (CL) on the ovary, and blood samples were obtained for the determination of plasma progesterone (P4) concentrations. Cows with a CL and P4 concentrations >1 ng/ml were treated (Day 0) with PGF2alpha (25 mg, i.m.) and were observed for estrus. Cows in estrus prior to 72 hours after treatment (Group 5, n = 106) were bred, but were not treated. Cows not observed in estrus by 72 hours were divided into four remaining groups, were bred between 72 and 80 hours and were assigned as follows: Cows in Group 1 (n = 203) were not treated; Cows in Group 2 (n = 200) were treated with GnRH (100 ug, i.m.); Cows in Group 3 (n = 201) were treated with PGF2alpha (25 mg, i.m.); and cows in Group 4 (n = 202) were treated with both GnRH and PGF2alpha. Cows in Group 6 (n = 1440) were not treated with PGF2alpha on Day 0 and were estrual cows that were bred on days when cows in Groups 1 to 5 were time-inseminated. The percentage of cows in all groups pregnant at 45 to 50 days after one insemination was compared using analysis of variance (P<0.05). The conception rate of cows in Group 2 was significantly higher than that of cows in Groups 1 to 4. There was a significant group-by-season interaction. Cows treated with GnRH during the spring had a higher conception rate than at other times of the year. Conception rates of cows in Groups 1 to 4 that were inseminated during the summer were low and not significantly different from each other. Conception rates of cows in Groups 5 and 6 inseminated during the summer were not significantly different from each other, but were significantly higher than that of cows in Groups 1 to 4 that were inseminated during the summer.     

The use of FSH and GnRH as alternative compounds to PMSG for springtime breeding of ewes

During early springtime, ewes were treated with a single injection of PMSG (500 IU) administered at the time of progesterone sponge withdrawal (Group I) or four, twice daily injections of FSH (2 mg each) administered from twelve hours before, to 24 hours after sponge withdrawal (Group II). One hundred mug of GnRH was administered 36 hours after sponge withdrawal in Group II. The two groups were compared with respect to estrous display, conception rate and other reproductive parameters. There were no significant differences (p>.05) between the two treatment group in any of the reproductive parameters measured. The occurrence of estrus during the first 96 hours after synchronization was low (X = 45% of all treated ewes). Conception of all treated ewes during this estrous period was also low (X = 32% of all treated ewes). The potential use of FSH and GnRH in estrous synchronization regimes was discussed. Possible reasons for the poor estrous and conception rates in present experiment were also considered.     

百草枯中毒大鼠TNF-α、IL-10 的表达及大黄保护作用的研究

目的:观察大黄对急性百草枯中毒大鼠TNF-α、IL-10的干预作用,探讨其可能的作用机制。方法:90只SD大鼠随机分为生理盐水对照组(A组)、PQ(60 mg/kg)灌胃染毒组(B组)、生大黄(300mg/kg.d)干预组(C组),每组30只。中毒后6h、24h、72h分批处死存活的大鼠,并且检测大鼠血浆TNF-α、IL-10水平。结果:B组、C组TNF-α、IL-10水平在染毒后6h开始升高,72h达到高峰,与A组相比,差异有统计学意义(P<0.05、P<0.01),在相同时间点C组TNF-α和IL-10的表达低于B组,差异均有统计学意义(P<0.01)。B组、C组血浆TNF-α、IL-10水平与中毒时间呈显著正性相关关系(r=0.849,P<0.01;r=0.790,P<0.01;r=0.0.943,P<0.01;r=0.892,P<0.01)。结论:大黄能够通过降低百草枯中毒大鼠体内的TNF-α、IL-10水平,减轻百草枯对大鼠的损伤作用。     

Agrobacterium-mediated transformation of germinating seeds of Arabidopsis thaliana: A non-tissue culture approach

Summary Germinating seeds of Arabidopsis thaliana were cocultivated with an Agrobacterium tumefaciens strain (C58Clrif) carrying the pGV3850:pAK1003 Ti plasmid. This Ti plasmid contains the neomycin phosphotransferase II gene (NPT II) which confers resistance to kanamycin and G418. Seeds (T1 generation) imbibed for 12 h before a 24 h exposure to Agrobacterium gave rise to the highest number of transformed progeny (T2 generation). Over 200 kanamycin-resistant T2 seedlings were isolated. Some of the T2 seedlings and T3 families were characterized for genetic segregation of functional NPT II gene(s), NPT II activity, and the presence of T-DNA inserts (Southern analysis). Ninety percent of the T2 individuals transmitted the resistance factor to the T3 families in a Mendelian fashion. Of the T3 families segregating in a Mendelian fashion (n=111), 62% segregated for one functional insert, 29% for two unlinked or linked functional inserts, 5% for three unlinked inserts, 1% for four unlinked inserts, whereas 3% appeared to be homozygous for the insert(s). The 13 families that did not exhibit Mendelian segregation ratios fell into 2 classes, both of which had a deficiency of kanamycin-resistant seedlings. In the Group I T3 families (n=6) only 0%–2% of the seedlings were resistant to kanamycin (100 mg/l), whereas in the Group II families (n=7) 8%–63% of the seedlings were resistant. All of the kanamycin-resistant plants that were tested were found to possess NPT II activity. Southern analysis revealed that all of the resistant plants contained at least one copy of the T-DNA and that the majority of the plants had multiple inserts. Explants from kanamycin-resistant plants survived and formed callus when cultured on callus-inducing medium containg G418.     

连续肾脏替代疗法治疗重症急性胰腺炎时机的探讨

目的:探讨连续肾脏替代疗法(CRRT)治疗重症急性胰腺炎的最佳时机。方法:选取我院收治的30例重症急性胰腺炎(SAP)患者为研究对象,按发病后行CRRT的时间分将患者随机为A、B两组,A组发病后72小时内治疗,B组发病后72小时后治疗,分析和比较两组治疗后的临床转归及生命体征变化、APACHEⅡ评分变化急性生理与慢性健康状况、住院费用、平均住院时间。结果:经CRRT治疗后,A组死亡率(14.3%)低于B组(43.7%),差异有统计学意义(P0.05);A、B两组治疗后体温、心率、呼吸、平均动脉压平稳,A组优于B组,差异有统计学意义(P0.05);A组的平均住院时间(15.7±8.9)d、住院费用(107000±65000)万元均明显优于B组,差异有统计学意义(P0.05);两组患者治疗后APACHEⅡ评分均明显优于治疗前,治疗后A组APACHEⅡ评分明显优于B组,差异显著有统计学意义(P0.05)。结论:早期行CRRT能明显改善重症急性胰腺炎患者的疗效和预后,最佳治疗时机可能为发病后72小时内。     

HSV-tk/GCV自杀基因系统与重组TNF联合杀伤肿瘤细胞的光学成像检测

目的:应用光学成像方法检测HSV-tk/GCV自杀基因系统与重组改造的人肿瘤坏死因子(recombinanthuman tumor necrosis factor,rmhTNF)的联合使用,对人涎腺腺样囊性癌细胞(adenoid cystic carcinoma,ACC-M)的杀伤效率。方法:实验分为四组,细胞模型对照组、单纯HSV-tk/GCV自杀基因系统治疗组、rmhTNF处理组、自杀基因联合rmhTNF治疗组。将稳定表达胸苷激酶-绿色荧光蛋白(thymidine kinase-green fluorescen protenin,tk-GFP)的ACC-M细胞(ACC-M-tk-GFP)按5 000个/孔接种到96孔板中,24 h后给药治疗;分别于加药前、给药后6 h、给药后24 h进行荧光成像。检测绿色荧光蛋白(green fluorescent protein,GFP)的荧光用于准确显示胸苷激酶(tk)基因表达的肿瘤细胞,检测碘化丙啶(propidium iodide,PI)的荧光用于显示死亡的肿瘤细胞。通过细胞的透射图及其PI和GFP荧光图像,分别计算tk 细胞和tk-细胞的死亡率。结果:HSV-tk/GCV自杀基因系统与rmhTNF联合治疗组的细胞在加药后6 h就已经出现细胞死亡迹象,而单纯HSV-tk/GCV自杀基因系统治疗组的细胞在加更昔洛韦(ganciclovir,GCV)后24 h才出现细胞死亡,单纯rmhTNF治疗组在加药后24 h还没有细胞死亡发生。对于给药后24 h的tk 细胞死亡率,联合治疗组(85.88%)明显高于GCV(38.13%)和rmhTNF单独治疗组(2.97%),并且联合治疗组给药24 h后会引发部分tk-细胞死亡(9.83%)。结论:HSV-tk/GCV自杀基因系统与rmhTNF联合治疗具有显著的协同抗肿瘤效应,能够明显提高对肿瘤细胞的杀伤率;结合光学成像方法,能为更直观方便地检测各组药物分别对tk 细胞和tk-细胞的杀伤率,可为深入研究"旁观者效应"提供参考。     

5-Azacytidine increases the activity of neomycin phosphotransferase II in transgenic Nicotiana tabacum: A posttranslational mechanism may play a role

In previous studies, tobacco protoplasts were transformed with the bacterial gene encoding neomycin phosphotransferase II (NPT II). Transformed calluses lost neomycin phosphotransferase II activity after several subcultures. Treatment of calluses with 5-azacytidine, a demethylating agent, restored enzyme activity, suggesting that methylation of npt II sequences might be responsible for loss of NPT II activity. Studies presented here were designed to test that hypothesis. Results indicated that the effect of 5-azacytidine could not be blocked by the DNA replication inhibitor, hydroxyurea, nor by the 5-azacytidine analogue, cytidine as would be expected with a DNA demethylation mechanism. The level of NPT II mRNA was not increased by 5-azacytidine. Treatment with cycloheximide, a protein synthesis inhibitor, had no effect on 5-azacytidine-increased NPT II activity. There was no increase of NPT II protein caused by 5-azacytidine, whereas 5-azacytidine increased activity of NPT II. In contrast, the auxin 2,4-D increased both the NPT II protein and activity. Assays for malate dehydrogenase demonstrated that the effect of 5-azacytidine and hydroxyurea on NPT II was not due to an overall effect on callus metabolism. In vitro studies involving standard bacterial NPT II enzyme and crude extracts from untreated and 5-azacytidine- or hydroxyurea-treated calluses showed that the activity of NPT II added to the untreated extracts was lower than the activity of NPT II added to the extracts from calluses treated with 5-azacytidine or hydroxyurea, indicating that there was an unknown factor (or factors) in callus extracts which affected the activity of NPT II and itself was affected by 5-azacytidine and hydroxyurea treatment. These results suggested that one effect of 5-azacytidine in increasing NPT II activity was posttranslational.Abbreviations ELISA enzyme-linked immunosorbent assay - NOS nopalene synthase - nos DNA segment encoding NOS - NPT II neomycin phosphotransferase - npt II DNA segment encoding NPT II - PAGE polyacrylamide gel electrophoresis     

The use of dimenhydrinate in conjunction with dexamethasone for induction of parturition in beef cattle

Forty-eight crossbred Chianina cows (3 to 5 years of age), with an expected gestation length of 288 days, were randomly divided into four treatment groups to evaluate the use of dimenhydrinate (an antihistamine agent) in conjunction with dexamethasone (DEX) for inducing parturition in beef cattle. Group (A) received a 20 mg dose of DEX (im) on day 282 of gestation and a carrier vehicle (iv) 24 hours later (day 283); Group (B) was given a carrier vehicle (im) on day 282 and 500 mg of dimenhy-drinate (DMH) diluted in 200 ml of 2.5% dextrose-0.9% saline solution given (iv) on day 283 and Group (C) received 20 mg of DEX (im) on day 282 and 500 mg of DMH in solution (iv) on day 283 of gestation. The remaining 12 cows assigned to Group (D) were not handled and were allowed to calve under natural conditions. The number of cows calving and percent calving within 60 hours after the first injection were: 10(91%), none(0%) and 12(100%) for the DEX, DMH and DEX plus DMH groups, respectively. The mean gestation length of the control cows in Group (D) was 288.6 days. Frequency of dystocia was: 18.2, 8.3, 0 and 0% and retained placentae (>/=24 hours) was: 72.8, 16.6, 33.3 and 0% for DEX, DMH, DEX plus DMH and control groups, respectively. In this study, a 20 mg dose of DEX (im) followed 24 hours later with 500 mg of DMH (iv) was more successful for calving induction than when DEX or DMH was used alone. The combination DEX and DMH treatment induced calving in a shorter interval from treatment (P<.05) and decreased the incidence of retained placentae (P<.01) when compared with those induced following DEX treatment.