桑1-脱氧野尻霉素降血糖作用的研究进展

1-脱氧野尻霉素是桑树中的一种生物碱,是哺乳动物α-葡萄糖苷酶的有效抑制剂,具有降糖、降脂、抗病毒、抗肿瘤等药理作用。本文针对已报道的1-脱氧野尻霉素功能,综述了近年来1-脱氧野尻霉素降糖作用研究的最新进展,为更好利用和开发桑叶1-脱氧野尻霉素提供参考。     

Comparative Analysis of mRNA Expression of Surface Antigens between Histiocytic and Nonhistiocytic Sarcoma in Dogs

Background

Definitive diagnosis of histiocytic sarcoma (HS) in dogs is relatively difficult by conventional histopathological examination because objective features of HS are not well defined.

Hypothesis

Quantitative analysis of mRNA expression of selected cellular surface antigens (SAs) specific to HS in dogs can facilitate objective and rapid diagnosis.

Animals

Dogs with HS (n = 30) and dogs without HS (n = 36), including those with other forms of lymphoma (n = 4), inflammatory diseases (n = 6), and other malignant neoplasias (n = 26).

Methods

Retrospective clinical observational study. Specimens were collected by excisional biopsy, needle core biopsy, or fine needle aspiration. To determine HS detection efficacy, mRNA expression levels of selected SAs specific to HS in dogs, including MHC class IIα, CD11b, CD11c, and CD86, were quantitatively analyzed using real‐time quantitative polymerase chain reaction.

Results

Each SA mRNA expression level was significantly higher in HS dogs than in non‐HS dogs (P = .0082). Cutoff values for discriminating between HS and non‐HS dogs based on these expression levels were calculated on the basis of receiver‐operating characteristic analysis. Accuracy of the cutoff values, including MHC class IIα, CD11b, CD11c, and CD86, was 87.9, 86.4, 86.4, and 84.8%, respectively.

Conclusions and Clinical Importance

Our results suggest that quantitative analysis of mRNA expression of the selected SAs could be an adjunctive diagnostic technique with high diagnostic accuracy for HS in dogs. Substantial investigation is required for exclusion of diseases with similar cell types of origin to lymphoma.     

Effects of pre‐partum milking of dairy cows on calcium metabolism at start of milking and at calving

This experiment studied the effect of pre‐partal milk removal on calcium metabolism at start of milking and at calving. Nine cows of the Swedish Red breed were milked for 1–7 days pre‐partum. The average milk yield at the first milking was 4.8 l, and the average yield the last day prior to calving was 13.4 l. Five cows were used as control cows and were only milked post‐partum. Samples of plasma and urine were taken to determine the effect of pre‐partum milking and calving on levels of calcium, magnesium, parathyroid hormone and plasma C‐terminal crosslinked telopeptide of type 1‐collagen (CTx), used as a marker of bone resorption. Pre‐partum milking resulted in a decrease in plasma calcium that was evident 2 days after the first milking. Parathyroid hormone increased at the same time, and CTx started to increase from 24 h after the first milking. There were no effects on plasma magnesium or urinary output of calcium or magnesium. The first week after calving, there were no differences between pre‐partum milked cows and control cows in plasma or urine variables, or in milk yield. In conclusion, pre‐partum milking activated the calcium‐restoring mechanisms but did not improve calcium status at calving.     

Relationship of Progesterone,Bovine Pregnancy-Associated Glycoprotein-1 and Nitric Oxide with Late Embryonic and Early Fetal Mortalities in Dairy Cows

The aim of the present study was to determine the relationship of progesterone (P4), bovine pregnancy-associated glycoprotein-1 (bPAG-1) and nitric oxide (NO) levels with late embryonic (LEM; day 28 to day 42) and early fetal mortalities (EFM; > day 42 to day 56) in dairy cows. Transrectal ultrasonography (6–8 MHz) was performed in 100 Holstein-Friesian cows at days 28, 42 and 56 after artificial insemination (AI; day 0) to diagnose pregnancy and to monitor the fate of the embryo. After ultrasound scanning of each cow, a milk sample was collected for assessment of P4 by an ELISA test and a blood sample was collected for assessment of bPAG-1, by using a double-antibody radioimmunoassay, and serum NO metabolites (nitrate + nitrite). Based on ultrasonographic examinations and bPAG-1-RIA, 41 of 100 inseminated cows were confirmed pregnant at day 28 after AI. Nine cows suffered of LEM, and 6 cows suffered of EFM and the overall pregnancy loss rate was 36.6% (15/41) between days 28 and 56 of pregnancy. By logistic regression analysis, there were no significant relationships between the level of P4 and bPAG-1 at day 28 after AI and the occurrence of LEM and EFM. Also, there were no significant relationships between the levels of P4 and bPAG-1 at day 42 and the occurrence of EFM. On the other hand, a significant relationship (P<0.05) was found between NO level at day 28 and the occurrence of LEM. In conclusion, measurement of the serum NO concentration at day 28 of pregnancy might help to predict the outcome of pregnancy by day 42 in dairy cows but further studies are needed to confirm this.     

Genetic variation in the ovine uncoupling protein 1 gene: association with carcass traits in New Zealand (NZ) Romney sheep,but no association with growth traits in either NZ Romney or NZ Suffolk sheep

The uncoupling protein 1 (UCP1) plays an important role in the regulation of lipolysis and thermogenesis in adipose tissues. Genetic variation within three regions (the promoter, intron 2 and exon 5) of the ovine UCP1 gene (UCP1) was investigated using polymerase chain reaction‐single‐strand conformational polymorphism (PCR‐SSCP) analyses. These revealed three promoter variants (designated A, B and C) and two intron 2 variants (a and b). The association of this genetic variation with variation in lamb carcass traits and postweaning growth was investigated in New Zealand (NZ) Romney and Suffolk sheep. The presence of B in a lamb's genotype was associated with decreased subcutaneous carcass fat depth (V‐GR) (p = 0.004) and proportion of total lean meat yield of loin meat (p = 0.005), and an increased proportion of total lean meat yield of hind‐leg meat (p = 0.018). In contrast, having two copies of C was associated with increased V‐GR (p < 0.001) and proportion of total lean meat yield of shoulder meat (p = 0.009), and a decreased hind‐leg yield (p = 0.032). No associations were found with postweaning growth. These results suggest that ovine UCP1 is a potential gene marker for carcass traits.     

Volatile fatty acid profile for grass hay or alfalfa hay fed to alpacas (Vicugna pacos)

The purpose of this study was to determine the diurnal composition and concentration of volatile fatty acids (VFA) and to determine VFA composition and concentration differences between stomach compartment 1 (C1) and caecum of alpacas fed grass and alfalfa hay. The study was divided into two experiments. In Experiment 1 (EXP 1), 10 male alpacas (3+ years old, 65 kg BW) were divided into two groups, housed in drylot pens, provided ad libitum water and fed alfalfa (AH) or grass hay (GH) for 30 days. The alpacas were slaughtered and the digestive tract collected, divided into sub‐tract sections, weighed and digesta sampled for pH, dry matter (DM) and NDF. Volatile fatty acid composition and concentration were determined on C1 and caecal material. Four adult male (3+ years old, 60 kg BW), C1 fistulated alpacas were housed in metabolism crates and divided into two forage groups for Experiment 2 (EXP 2). Alpacas were fed the forages as in EXP 1. Diurnal C1 VFA samples were drawn at 1, 3, 6, 9, 12, 18 and 24 h post‐feeding. There were no differences between forages for tract weight, C1 and caecum digesta DM or NDF. Differences were noted (p < 0.05) for pH between forages and sub‐tract site. Volatile fatty acids concentrations were different (p < 0.05) for forage and site, and total VFA was higher for AH than GH (110.6 and 79.1 mm ) and C1 than caecum (40.7 and 27.6 mm ). Proportion of VFA was significant (p < 0.05) for forage and site, C1 acetate highest for GH (84.8 vs. 74.0 mm ) and caecum acetate 83.7 and 76.2 mm for GH and AH respectively. These data demonstrate the level of VFA produced in C1 and the caecum of alpacas and the diurnal VFA patterns. Composition of VFA is similar to other ruminant species.     

布鲁菌感染小鼠RAW264．7细胞对IRGl基因的表达调控作用

针对小鼠RAW264．7细胞IRGl基N设计4个RNA干扰靶位,筛选出最佳干扰序列构建shRNA慢病毒载体质粒并包装获得慢病毒颗粒,进而经嘌呤霉素筛选获得稳转细胞系,实现IRGl基因在RAW264．7细胞基因表达的沉默。并通过布鲁菌l6M株及M5株感染基因沉默细胞对IRGl基因在布鲁菌感染中的作用进行研究。结果表明,慢病毒介导的shRNA高效、稳定地沉默了IRGl基因的表达,布鲁菌侵染RAW264．7细胞后IRGl基因表达上调。未试验为1RG1基因及相美调控基因抗布鲁菌病作用研究奠定了基础。     

产蛋循环过程中TRPV6、CaBP-D_（28K）和PMCA 1b在蛋壳腺的动态表达

将40羽220日龄ISA蛋鸡分为5组,于产蛋后0、2、4.5、8、16h断头处死,采集蛋壳腺组织,运用Real-time PCR和Western-blot方法检测产蛋循环过程中瞬时性受体单位香草精受体6（Transient receptor potential vanilloid receptor 6,TRPV6）、钙结合蛋白（calbindin D28K,CaBP-D28K）、质膜钙离子ATP酶1b（plasma membrane Ca2＋-ATPase 1b,PMCA 1b）mRNA和蛋白浓度的动态变化。结果显示,卵子未进入蛋壳腺前（产蛋后0~4.5h）,蛋壳腺内TRPV6、CaBP-D28K和PMCA 1bmRNA表达水平较低,随后表达量逐渐升高,在蛋壳钙化过程中达到最大值（产蛋后16h）,与0h相比,TRPV6和CaBP-D28KmRNA表达差异均极显著（P〈0.01）;另外,产蛋循环过程中,TRPV6、CaBP-D28K和PMCA 1b蛋白浓度变化与mRNA变化一致,产蛋后16h到达最大值,其中CaBP-D28K蛋白浓度与0h相比,差异显著（P〈0.05）。结果表明,产蛋循环可调控蛋壳腺内TRPV6、CaBP-D28K和PMCA 1b的表达,并提示钙离子跨细胞转运途径在钙离子进入蛋壳腺形成蛋壳过程中发挥重要作用。     

美国褐牛杂交改良新疆褐牛效果的研究

[目的]旨在为研究美国褐牛对新疆褐牛杂交改良的效果。[方法]选取伊犁新褐种牛场纯种新疆褐牛母牛30头作为对照组、美新 F1代母牛30头作为试验组,跟踪测定两组0~36月生长发育性能指标,进行体重、体尺对比分析,计算体尺指数,构建体重、体尺生长曲线,分析体重、体尺相对增长曲线。[结果]表明：美新 F1代母牛在18~36月龄体高、体长、胸围和体重等指标极显著高于新疆褐牛母牛（P 〈0.01）;新疆褐牛、美新 F1代母牛6~36月龄体重体尺整体呈现快速增长趋势,且美新 F1代母牛各项指标总体上均高于新疆褐牛母牛;新疆褐牛、美新 F1代母牛在12月龄之前体重、体尺增加速度均较快,12月龄之后增加速度均减慢。[结论]表明两组牛早期生长强度明显高于后期,体重的增加速度和强度一直高于体尺,且美新 F1代母牛6~24月龄体尺指标相对增长值要高于新疆褐牛母牛。