Peripheral white blood cell counts throughout pregnancy in non-aborting Neospora caninum-seronegative and seropositive high-producing dairy cows in a Holstein Friesian herd

Pregnancy is characterized by transient changes in the maternal immune system, also evident at peripheral level. The present study analyzes the kinetics and possible factors affecting peripheral white blood cell populations throughout pregnancy in a herd of high-producing dairy cows chronically infected or not with Neospora caninum. We examined 54 pregnant parous cows: 29 Neospora-seronegative and 25 Neospora-seropositive cows. Blood samples were collected on Days 90, 120, 150, 180 and 210 of gestation. General Linear Model (GLM) repeated measures analysis of variance showed that the interaction Neospora-seropositivity × parity significantly affected total leukocyte, neutrophil and monocyte counts with lower levels of total leukocytes, lower neutrophil and higher monocyte counts recorded in primiparous Neospora-seropositive cows. In addition, N. caninum-seropositive cows had significantly increased monocyte counts on Day 180 of gestation compared to seronegative ones. Other factors significantly associated with changes in total and/or differential leukocyte profiles were period of pregnancy, season, twin pregnancy and milk production. In conclusion, a parity-associated effect of chronic N. caninum infection was observed on peripheral blood cell profiles in dairy cattle during gestation.     

应用电镜技术快速检测培养细胞中的支原体污染

应用电镜技术可快速准确地检测培养细胞中的支原体污染。通过高速离心浓缩样品,负染色后电镜观察,可在30min内做出判定,方法快速、简便、准确。     

凋亡素基因真核表达载体的构建及在人肿瘤细胞中的表达

为探讨凋亡素对肿瘤的基因治疗效果,构建了凋亡素基因的真核表达载体。将凋亡素基因重组入 ｐｃ Ｄ Ｎ Ａ３ 载体,并通过脂质体介导凋亡素在人喉癌、人肺癌细胞系中表达;通过 Ｒ Ｔ Ｐ Ｃ Ｒ 在转染细胞中检测到了凋亡素的 ｍ Ｒ Ｎ Ａ,这为应用凋亡素进行肿瘤的基因治疗奠定了基础。     

Effects of Photoperiod on Stem Cells Activation in Cashmere Goat Hair Follicles

In order to extend the anagen of cashmere goat hair follicles and increase the production of cashmere,this study was performed with artificially shorten the daylight time among Arbas White cashmere goats. Skin tissue sections from cashmere goats were collected to compare the morphologic changes between artificial daylight and natural daylight,and immunohistochemical method was used to study the hair follicle cell proliferation and important protein expression in related signaling pathways. The results showed that strong cell proliferation occurred in cashmere goat hair follicle cells during artificial daylight,plenty of cytokeratin 15 (K15) positive signals were distributed in the outer root sheath,β-catenin protein was actively expressed in hair matrix and root sheath, indicating that the hair follicles were in the anagen growth phase;Meanwhile,cashmere goat hair follicles under natural daylight were in telogen with weak signals. Above all prove that short photoperiod played an important role in promoting hair follicle growth,the artificial short photoperiod could change hair follicle growth cycle and make hair follicles earlier enter to the anagen growth phase,causing a variety of typical gene expressions during hair follicle growth.     

性成熟前小鼠生精细胞的发育过程

用光镜、电镜观察了生后 1～ 1 8d昆明白小鼠的生精上皮。结果显示 ,生后 1～ 3 d,曲细精管内只有生殖母细胞和支持细胞 2类形态结构截然不同的细胞 ,前者位于管中部 ;生后 4～ 5d,少数生殖母细胞已附着在基膜上 ;生后 6～ 7d,原始 A型精原细胞大量出现并附着在基膜上 ;生后 8d,A型精原干细胞大量出现 ,B型精原细胞开始出现 ;生后 1 0 d,B型精原细胞大量出现 ;生后 1 2～ 1 3 d,前初级精母细胞出现 ,少数曲细精管的管腔开始出现 ;生后 1 4～ 1 5d,多数曲细精管管腔基本形成 ,前初级精母细胞大量出现。本试验的结果表明 ,7～ 8d小鼠的睾丸最适于分离精原干细胞     

Follicular wave dynamics and Growth factors gene expression in Braford heifers

The objectives of the present study were (experiment 1) to characterized development and dynamics of the dominant follicles (DF) and the corpus luteum (CL) to determine patterns of two (W2) and three (W3) follicular waves in beef heifers, and (experiment 2) to determine gene expression of growth factors gene expression in follicular cells of W2 and W3 heifer. Twenty-eight Braford heifers were used. Dominant follicular and CL were monitored daily by ultrasonography to identify the development W2 and W3 in heifers. Pre-ovulatory DF were aspirated on day 19 in W2 and on day 22 in W3 heifers. In W2 and W3, follicular cells (FC) of gene expression of growth differentiation factor 9, bone morphogenetic protein 15 (BMP15), fibroblast growth factor basic, transforming growth factor beta receptor 1, bone morphogenetic protein receptor type IB and fibroblast growth factor receptor 2 were evaluated. The regression of the DF of the first follicular wave and the emergency of the DF of the second follicular wave began later in the heifers W2 than in W3 (p = .02 and p < .01). The regression of the CL began earlier in the W2 than in W3 group (p < .01). Gene expression of growth factors and receptors was similar between groups. However, higher relative levels of BMP15 was observed in W2 group (p = .07). Results propose that wave patterns were regulated by the development time of the DF in the first wave and the life of the CL. Furthermore, higher levels of BMP15 could produce shorter life of CL. The present work suggest that ultrasonography associated with molecular assays could be used as an easy and effective tool to characterize follicular wave patterns.     

High‐level exogenous trans10, cis12 conjugated linoleic acid plays an anti‐lipogenesis role in bovine mammary epithelial cells

Primary bovine mammary epithelial cells (BMECs) were treated by 0, 37.5, 75, 112.5, 150 μmol/L trans10, cis12 conjugated linoleic acid (CLA) to evaluate the effects of different level trans10, cis12 CLA on lipogenesis in BMEC. Addition of 75–150 μmol/L trans10, cis12 CLA reduced significantly the triacylglycerol (TAG) content (P < 0.05), but did not have inhibiting action on cell proliferation (P > 0.05). Treatment with 150 μmol/L trans10, cis12 CLA for 48 h resulted in a 17.1% reduction (P < 0.0001) of medium chain fatty acids (MCFA, C14 < C < C16), a 26.5% reduction (P < 0.0001) of unsaturated fatty acids (UFA) and a corresponding reduction of the mRNA abundance of acetyl coenzyme A (acetylCoA) carboxylase (ACC) (P = 0.046), fatty acid synthase (FAS) (P = 0.017) and stearoylCoA desaturase1 (SCD1) (P = 0.002). Another finding was that trans10, cis12 CLA elevated expression of diacylglycerol acyltransferase2 (DGAT2) (P = 0.020) and long chain acylCoA synthetases (ACSL) (P = 0.032). In conclusion, higher trans10, cis12 CLA, not low trans10, cis12 CLA, inhibited milk fat synthesis and changed fatty acid composition by regulating the expression of FAS, ACC, SCD1, DGAT2 and ACSL.     

Radiosensitivity of canine osteosarcoma cells transfected with wild‐type p53 in vitro*

The p53 gene is one of the important tumour suppressor genes that are involved with the cell survival signal pathway. One of the major functions of the p53 protein is to organize cell cycle regulation and induction of apoptosis for cellular genetic stability. It has been documented that more than 50% of all human cancers include a p53 mutation. We evaluated the difference in radiosensitivity between upregulating the expression of canine wild‐type p53 (cp53) in cultured osteosarcoma (D17) cells and naive D17 cells in vitro. We found that upregulating transfected cp53 D17 cells increased their radiation sensitivity in vitro, and there was a significant decrease (P < 0.009) in survival between cp53‐transfected D17 cells and naive D17 cells. In this experiment, a p53 enhancement ratio (p53ER) reached approximately 3.0 at high doses. The transfected cp53 D17 cells were significantly more radiosensitive at all doses evaluated than naive D17 cells, except at 1 Gy where too few data points were available. The p53ER increased rapidly at doses less than 4 Gy, achieving a maximum of about 3.0 for doses of 4 Gy and above. This study shows the enhanced radiosensitivity of the transfected p53 at clinically relevant doses.