班布特罗对豚鼠实验性哮喘的作用及其机理研究

目的 研究班布特罗对豚鼠实验性哮喘的作用、药效学及药动学特点及作用机制。方法 组胺和卵清蛋白诱发在体豚鼠实验性哮喘模型, 使用豚鼠离体气管片和肺条进行研究。结果 班布特罗剂量依赖性抑制组胺和卵清蛋白诱发的豚鼠哮喘, 班布特罗对豚鼠气管片无松弛作用, 而灌服其后的松弛气管片和肺条血浆呈剂量依赖性, 且对肺条的松弛作用强于气管片。其峰效应出现于给药后4 h 前后, 作用持续24 h 以上。结论 班布特罗作为特布他林的前药对豚鼠实验性哮喘的作用缓和而持久。     

Epidural Stimulation Combined with Triple Gene Therapy for Spinal Cord Injury Treatment

The translation of new therapies for spinal cord injury to clinical trials can be facilitated with large animal models close in morpho-physiological scale to humans. Here, we report functional restoration and morphological reorganization after spinal contusion in pigs, following a combined treatment of locomotor training facilitated with epidural electrical stimulation (EES) and cell-mediated triple gene therapy with umbilical cord blood mononuclear cells overexpressing recombinant vascular endothelial growth factor, glial-derived neurotrophic factor, and neural cell adhesion molecule. Preliminary results obtained on a small sample of pigs 2 months after spinal contusion revealed the difference in post-traumatic spinal cord outcomes in control and treated animals. In treated pigs, motor performance was enabled by EES and the corresponding morpho-functional changes in hind limb skeletal muscles were accompanied by the reorganization of the glial cell, the reaction of stress cell, and synaptic proteins. Our data demonstrate effects of combined EES-facilitated motor training and cell-mediated triple gene therapy after spinal contusion in large animals, informing a background for further animal studies and clinical translation.     

Effect of estradiol and progesterone on thyroid gland in pigs: a histochemical, stereological, and ultrastructural study

The cellular and subcellular organization of thyroid follicular cells in peripubertal (6-month-old) male pigs treated with estradiol-dipropionate (Oe) plus progesterone (Pr) in combination on the first postnatal day was studied. A stereological method was used for morphometric determinations of the relative volume densities of the follicular epithelium, colloid and interstitium, and for establishing the epithelial height and index of activation rate. Statistically significant differences of the examined parameters between the control and Oe+Pr -treated groups were determined by Student's t-test. The subcellular organization of thyroid follicular cells was studied using transmission electron microscopy (TEM). When compared with the control group, in the Oe+Pr -treated pigs, thyroid follicles possessed a noticeably higher follicular epithelium when compared with the control animals. The observed changes were quantified and comparison between the experimental groups showed that the height, volume density of follicular epithelium, and index of activation rate were significantly (P < 0.05) increased, whereas the relative volume density of the colloid was significantly (P < 0.05) decreased. At the subcellular level the thyroid follicular cells of Oe+Pr -treated pigs were characterized by increased number of polysomes and dense bodies and extensive endoplasmatic reticulum. It was concluded that a single neonatal treatment with female gonadal steroids exerted a prolonged effect on the pig's thyroid, characterized by increased biosynthesis and reabsorption of the colloid by the follicular cells.     

Performance and carcass characteristics of growing pigs and broilers fed diets containing micronised barley,ground barley,wheat and maize

Two swine starter/grower/finisher trials utilising 216 24‐day‐old pigs and one 40‐day broiler growth trial utilising 1920 1‐day‐old chicks were conducted to determine the influence of dietary micronised dehulled barley (MDB) as a replacement for hulled barley (HB), wheat (W) and maize (M) on live performance, carcass and meat measurements, organ weights (swine), plasma urea nitrogen (PUN) level (swine) and intestinal digesta viscosity (broilers). Dehulling and micronising the barley reduced crude protein by 20%, neutral detergent fibre by 17% and amino acids by varying amounts. Replacing M or W with MDB in swine diets had no effect (P > 0.05) on any measured parameter, with the exception of decreased PUN (P = 0.03) when MDB replaced 100% of W. Broilers fed W, M or HB generally had similar live performance, carcass traits and digesta viscosity, with the exception of reduced (P < 0.05) average daily gain and average daily feed intake for HB during the first 20 days of the trial. However, broilers fed MDB had slightly reduced (P = 0.05) live performance during each phase of the trial and greatly increased (P = 0.01) digesta viscosity. Addition of a commercial enzyme product to the diets reversed the reduced performance and increased the digesta viscosity of the MDB diet, but generally had no influence in the W, M and HB diets. These results suggest that MDB can be utilised in swine diets without affecting performance, but that reduced performance may result from its use in broiler diets. © 2001 Society of Chemical Industry     

甘孜藏猪与合作猪SLA-DQA基因的群体遗传研究

对甘孜藏猪和合作猪SLA-DQA基因的第1和第2内含子部分序列以及完整的第2外显子进行了PCR-RFLP分析,结果表明:经EcoRⅠ酶切后,BB基因型频率(0.5537)分别高于AB型(0.3719)和AA型(0.0744); B为优势等位基因(0.7397).经AluⅠ酶切后,MM基因型频率(0.4380)分别高于MN型(0.3637)和NN型(0.1983);M为优势等位基因(0.6198).2品种中Alu I酶切基因型在合作猪中未达到Hardy-Weinberg平衡,且群体间M、N的基因频率和NN基因型频率差异分别达极显著(P＜0.01)和显著水平(P＜0.05).共鉴别了9种组合基因型,甘孜藏猪和合作猪分别为6和8种组合基因型, BBMM、BBNN组合基因型频率在两群体间差异显著(P＜0.05).两酶切位点均表现为中度多态,AluⅠ位点多态信息含量均高于EcoRⅠ位点,合作猪杂合性高于甘孜藏猪,两群体间的遗传距离为0.0389.     

用于人工血管的功能聚氨酯的迟发型超敏反应研究

聚氨酯原料如二异氰酸酯的皮肤致敏性已有大量报道,而聚氨酯材料本身的致敏研究的报道却很少。采用豚鼠最大剂量实验(ISO 10993-10)研究了3种用于人工血管的聚氨酯材料的迟发型超敏反应。PCUL2为赖氨酸扩链的聚碳酸酯聚氨酯,PCUL2-PO和PCUL2-PN分别为接枝聚乙二醇二缩水甘油醚以及接枝聚乙二醇二胺的梳形聚氨酯。3种材料均为多孔材料,且含有可反应的官能团,便于进一步接枝生物分子以提高血管的原位内皮化。测试组为(70±2)℃浸提(24±2)h的生理盐水浸提液(0.1 g/mL),生理盐水为阴性对照组,二硝基氯苯为阳性对照组。结果显示,3种受试材料致敏率很低(PCUL2-PO∶2/12;其余1/12)。3种聚氨酯的迟发型超敏反应的结果均为阴性,值得进一步进行体内研究。     

Comparison of calpain and cathepsin (B,L and D) activities during dry-cured ham processing from heavy and light large white pigs

Calpain and cathepsin (B, L and D) levels in the Semimembranosus and the Biceps femoris muscles were determined during dry-curing of hams from heavy and light Large White pigs, to evaluate the use of heavy pigs in the production of high quality dry-cured hams. Calpains were detected only in green hams and after the salting step, while cathepsins were observed throughout the curing. Hams from heavy pigs showed lower enzyme levels than hams from light pigs, particularly in green hams. The lower levels could be attributed to the slower protein turnover of heavy pigs. Commercial improvement by means of slow curing processes on heavy White hams is suggested.     

Effect of feeding different diets on the exocrine pancreatic secretion of nitrogen,amino acids and enzymes in growing pigs

Five barrows were fitted with permanent pancreatic re-entrant cannulas to determine the influence of diet on exocrine pancreatic secretions in the weight range from 40 to 65 kg. The pigs were fed four diets. Diets 1 and 2 were based on corn starch and contained 18.6 and 16.9 % crude protein (dry matter basis) from soybean meal and canola meal, respectively. Diets 3 and 4 contained 93.9 % wheat and barley, respectively. In the same order, the crude protein contents (dry matter basis) of these diets were 14.4 and 11.2%, respectively. The experiment was carried out according to 4 × 4 Latin square design. Each experimental period comprised 12 days. Following an adaptation period of 8 days, pancreatic juice was collected from 08:00 on day 9 to 08:00 h on day 10 and from 08:00 on day 11 to 08:00 h on day 12. The pigs were fed twice daily, at 08:00 and 20:00 h, 800 g each meal. Despite large differences, up to 23%, between the overall mean values of the parameters that were measured there was no effect (P > 0.05) of diet on the volume of secretion of pancreatic juice, the pH and the secretion of total and TCA-precipitable nitrogen. Due to the high level of within-study variation there was also no effect (P > 0.05) of diet on the secretion of amino acids and the total activity of trypsin, chymotrypsin, α-amylase and lipase in pancreatic juice.     

Quinoxaline-2-carboxylic acid in pigs: criteria to distinguish between the illegal use of carbadox and environmental contamination

Carbadox cannot be used in food-producing animals within the European Union following the adoption of Commission Regulation EC 2788/98/EC. Monitoring of the longest remaining residue—quinoxaline-2-carboxylic acid (QCA)—is the most effective way of enforcing the prohibition on its use. The study was under taken to determine if QCA could be passed from pig to pig following the exposure of unmedicated animals to housing that had previously contained medicated animals. Drug-withdrawal studies were also carried out on medicated animals. Distinction between treated animals and those exposed to QCA might be required by competent national authorities to determine whether a positive result for QCA in tissue is truly 'violative'. Comparison of the ratio concentrations of QCA in tissues and body fluids was made to determine if they could be used as criteria for discrimination between illegally treated animals and environmental contamination.