不同因素对抑制素基因免疫肉牛反应性的影响

为探讨佐剂、质粒纯度和免疫次数3种因素对抗抑制素抗体效价的影响,以分析抑制素基因免疫是否使肉牛产生免疫应答,利用已构建的抑制素真核融合表达质粒pCISI对肉牛进行了免疫试验.结果表明,抑制素pCISI基因免疫肉牛后佐剂处理组比无佐剂组免疫效果明显.对抗体P/N(待测血样的吸光值P与阴性血样吸光值N的比值)来说,普鲁卡因佐剂显著优于脂质体,但就抗体阳性率来说,普鲁卡因和脂质体差异不显著.无论是抗体P/N值还是抗体阳性率,高纯度组的效果略高于低纯度组,但差异不明显.随着免疫次数的增加抗体P/N值和抗体阳性率均升高,两者差异显著,说明了抑制素基因免疫肉牛可诱导产生抗抑制素抗体,纯度对抗体的产生和抗体阳性牛比例没有影响,但免疫佐剂与免疫次数有影响.

日本肉牛胴体品质分级标准及其制定与修订背(景续)

本文简单介绍了日本和牛的改良进程,详细介绍了日本“胴体分级标准”及其制定和修订背景,借以对我国的肉牛胴体品质分级研究有所启发。

加快改良步伐 促进肉牛产业化开发

国家肉牛发展的总体战略布局安排是在农区建成三大肉牛带，其中陕西、山东、河南、河北、山西、皖北、苏北等地同属于中原肉牛带。陕西省把肉牛产业化已列为“九五”期农业主导产业之一，而牛的存栏数和这些兄弟省区相比相对较低，所以，笔者认为我省要在全国肉牛业发展中...

提高玉米酒糟蛋白水平对肉牛利用温和性粗饲料的影响

在家畜粗饲料补充料的研究已经有几十年的历史，然而，如何使副产品作为补充料发挥效用就需要确定其最佳的饲喂比例，以提高补充料的作用效率。试验选择5头作十二指肠瘘管处理的肉牛（体重446±42kg），采用5×5拉丁方设计，评定提高补充料玉米酒糟蛋白（DDGS含CP25-4％，脂肪9．8％；干物质基础）水平时的趋向指标：

Isolation, Cuture and Biological Characteristic Analysis of Stromal and Glandular Epithelial Cells of Buffalo (Bubalus bubalis) Endometrium

[Objective] The experiment aimed to set up a method for isolating and culturing endometrial stromal cells (BESC) and endometrial glandular epithelial cells(BEGEC) of buffalo as well as laid foundation for studying biological mechanism of embryo implantation and uterine diseases. [Method] The enzymatic digestion method, scraping method, serial filtration and differential velocity adherent technique were used to isolate BESC and BEGEC, then immunocytochemical method and TRYPAN-Blue assay were used to determine the purity and survival rate of isolated cells. [Result] The BESC and BEGEC were successfully isolated and cultured while immunocytochemical method and cell count method demonstrated that the purity was over 90%. The result of TRYPAN-Blue assay shown that survival rate of BESC and BEGEC was 91% and 78% respectively. [Conclusion] The enzymatic digestion method, scraping method, serial filtration and differential velocity adherent technique could isolate BESC and BEGEC with high purity.

Preliminary Study on Transgenesis by Injecting Exogenous DNA into Zygote Cytoplasm of Buffalo

[Objective] This study aimed to investigate the feasibility of transgenesis by injecting exogenous DNA into zygote cytoplasm of Buffalo. [Method] Buffalo oocytes were randomly divided into two groups 20-22 h after in vitro maturation. One group of oocytes was introduced with about 7.5 pl of 50 μg/ml DNA solution containing linear EGFP fragment by cytoplasmic injection 7-10 h or 18-20 h after in vitro fertilization （IVF）; the other group of oocytes was introduced with mixture of a single buffalo sperm and about 7.5 pl of 50 μg/ml DNA solution containing linear EGFP fragment by cytoplasmic injection （generally called ICSI-Mediated Gene Transfer, ICSI-Tr）. Expression of exogenous DNA was observed and recorded during the process of embryonic development. [Result] Early embryonic gene expression efficiency and blastocyst gene expression efficiency in IVF injection group showed no significant difference compared with that in ICSI-Tr group （P0.05）. In addition, the cleavage rate and early embryonic gene expression efficiency in IVF injection group were significantly higher with injection at 7-10 h post IVF than that at 18-20 h post IVF （P0.05）. [Conclusion] These results indicate that transgenic buffalo embryos can be generated by injecting exogenous DNA into cytoplasm of IVF oocytes, and the optimal injection time is 7-10 h post IVF.

An Improved Enucleation Method of Bovine Somatic Cell Nuclear Transfer

The aim of this work was to improve the rate of conventionally blind enucleation for bovine somatic cell nuclear transfer. The cross section of a 0.5 ml Eppendorf tube was attached with a sheet of 400 mesh/inch2-cell screen after the bottom of the Eppendorf tube had been cut, and put into a 1 mL Eppendorf tube. In experiment 1, the oocytes in the metaphase Ⅱ stage were placed on the membrane in the Eppendorf tube, and centrifuged at 1,000, 2,000, or 3,000 r/min for 10 min, respectively. The oocytes were stained with Hoechst 33342 and then the relative position of the first polar body to the chromosomes, and the efficiency of enucleation were evaluated. In experiment 2, enucleated oocytes were fused with granulosa cells, following centrifugation and enucleation, and the potential development of the reconstituted embryos was estimated. The results indicated that the rate of enucleation in oocytes after centrifugation at 2,000 r/min for 10 min was 86.6% with an angle less then 20° between the first polar body and chromosomes. The rate of enucleation in cells spun at 2,000 r/min was higher than that of controls （87.4% vs. 64.4%, P 〈 0.05）. Fur- thermore; centrifugation of recipient oocytes did not have a detrimental effect on the development of reconstituted embryos following nuclear transfer. In conclusion, centrifugation assisted enucleation may significantly improve the rate of bovine oocyte enucleation.

与四海宾朋携手奔未来

驻马店地区畜禽食品进出口总公司始建于1965年,在几十年的经营活动中,本着“以诚待客,以信取人”的宗旨,广交国内外客商,树立了良好的企业形象,曾先后被省政府命名为“

Forward modeling and inversion of tensor CSAMT in 3D anisotropic media

Tensor controlled-source audio-frequency magnetotellurics （CSAMT） can yield information about electric and magnetic fields owing to its multi-transmitter configuration compared with the common scalar CSAMT. The most current theories, numerical simulations, and inversion of tensor CSAMT are based on far-field measurements and the assumption that underground media have isotropic resistivity. We adopt a three-dimensional （3D） staggered-grid finite difference numerical simulation method to analyze the resistivity in axial anisotropic and isotropic media. We further adopt the limited-memory Broyden- Fletcher-Goldfarb-Shanno （LBFGS） method to perform 3D tensor CSAMT axial anisotropic inversion. The inversion results suggest that when the underground structure is anisotropic, the isotropic inversion will introduce errors to the interpretation.

Energy Value and Amino Acid Bioavailability of Faba Bean Seeds in Broilers Diets

The aim of this study was to determine the apparent （AME） and true metabolizable energy （TMEn） as well as the crude protein （CP） and amino acid （AA） total tract （by excreta collection） digestibility （bioavailability） of faba bean seeds （FBS） of the Greek cultivar ＂Polikarpi＂. Forty eight broilers were placed in individual cages and randomly allocated into 4 dietary treatments. Birds consumed 80 g d1 of either a typical commercial diet or the same diet in which 100, 200 or 300 g kg^-1 had been substituted by ground FBS. The experiment lasted 15 d. Apparent and true CP bioavailability of FBS were significantly decreased （P 〈 0.05） only at the inclusion rate of 300 g kg-1. AA bioavailability remained at high levels （-0.80） with the exception of cystine and was similar to CP mean. The mean AME and TMEn values of FBS were estimated equal to 11.1 and 11.4 MJ ME kg^-1, respectively.

An intracellular study of pretectal influence on the optic tectum of the frog, Rana catesbeiana

Objective A few investigations have been reported about pretectal suppressive influences on the optic tectum of frog, but characteristics of tectal activity to pretectal input are left unknown. We made intracellular recordings to demonstrate the unexpected complexity in synaptic mechanisms involved in the suppressive influences of pretecal stimulation on the tectal cells. Methods In the present study, we investigated the neuronal activity evoked by pretectal （Lpd/P） nuclei stimulation using intracellular recording technique. Results The pretectal stimulation mainly elicited two types of responses in the ipsilateral tectum： an excitatory postsynaptic potential （EPSP） followed by an inhibitory postsynaptic potential （IPSP） and a pure IPSP. The latter predominated in the tectal cells responding to pretectal stimulation. In a few cells, biphasic hyperpolarization appeared under stronger stimulus intensities. The spikes of tecto-pretectal projecting cells elicited by antidromical stimulation were recorded in the ipsilateral tectum, which revealed reciprocal connections between the tectum and particular pretectal nuclei. The synaptic natures underlying pretecto-tectal information transformation have also been demonstrated. EPSPs with short latencies were concluded to be monosynaptic. Most IPSPs were generated through polysynaptic paths, but monosynaptic IPSPs were also recorded in the tectum. Nearly 98% of impaled tectal cells （except for antidromically projecting cells） showed inhibitory responses to pretectal stimulation. Conclusion The results provide strong evidence that pretectal cells broadly inhibit tectal neurons as that has suggested by behavioral and extracellular recording studies.

Anatomical and Histological Study of the Foot of Iraqi Endogenous Buffaloes （Bubalus bubalis）

The anatomical and histological study were conducted on 72 specimens of buffaloes foot, regardless of the age and species The foot structures were described which included first phalanx, second phalanx, third phalanx, digital cushion, joint, ligaments and tendons, as well as the foot＇s sole, blood and nerve supply. The main source of blood supply is the median artery, the radial artery, dorsal metacarpal artery. On the other hand, the metacarpophalangeal joint, proximal interphalangeal joint and joint＇s capsules were shown by radiographic pictures. The median nerve is the main source of the nerve supply of foot, as well as ulnar and radial nerve. However, the digital tendons on the dorsal surface and palmer surface were represented by common, proper flexor digital tendons and deep superficial digital extensor tendons respectively, the histological picture of coronary region revealed that it consistd of horn tubules and intertubular horn. While the lamellae region showed that it consisted of primary epidermal lamellae, containing the epidermis and dermis regions, also, noticed that the epidermal lamellae was interfered with faced dermis lamellar. The histological structure of the hoof revealed that it consisted of keratinocytes which connected with each other by desmosal adhesion. Digital cushion contained of elastic and collagen fibers with presence of adipose cells masses greater than that at foot sole.

利用PCR-DGGE技术分析肉牛阴道菌群结构

利用PCR-DGGE技术明确肉牛阴道菌群结构并比较黄体期和卵泡期肉牛阴道菌群结构差异。选择7头肉牛,分别采集黄体期和卵泡期阴道分泌物,提取细菌总DNA,采用巢式PCR分别对细菌16SrDNA的V3区进行扩增,将PCR产物进行变性梯度凝胶电泳(denatured gradient gel electrophoresis,DGGE)。对DNA指纹图谱特异性条带切胶回收并进行克隆测序,通过BLAST与已知序列对比,鉴定细菌菌种,分析比较黄体期和卵泡期肉牛阴道菌群结构。结果显示:健康肉牛阴道内存在阴道气球菌(Aerococcus vaginalis str.)、绿色气球菌(Aerococcusviridans str.)、睡眠嗜血杆菌(Haemophilussomnus str.)、多动物链球菌(Streptococcus pluranimalium str.)、嗜冷杆菌(Psychrobactermarincolastr.)、大肠杆菌(Escherichia coli O157:H7str.)和鞘氨醇单胞菌(Sphingomonasroseiflavastr.)等。

Introduction to the Turbulent Flows Theory--An Axially-Symmetric Non-peaceful Flows

In fluid mechanics, there is lack of turbulent flows theory. The theory of laminar flows is also not completed. Therefore, the aim of this paper is to fill in the gaps in the theory of laminar flow. First time in the history of fluid mechanics, it shows that the value of the boundary Reynolds number, dividing the flows of Newtonian fluids into laminar and turbulent, can be calculated theoretically. The very existence of this boundary has been known to researchers over a century ago, but all knowledge in this area so far comes only from experimental physics. This paper marks a turning point, as it not only explains the theory of the said phenomenon, but also presents the methodology of its analytical description. It should be noted that the said description refers to the type of flow which is best understood by scientists, i.e., steady axially-symmetric laminar flow through a straight-axis duct of a circular cross-section of the radius R under the action of constant natural gravitational forces. This paper comes second in a series of papers aimed at eliminating chaos from fluid mechanics and replacing it with harmony and mathematical order.

Chemical Composition of Meat in Castrated Male Brahman Cattle in Venezuela

Chemical composition of Brahman cattle was studied and determined in this study. Fifty males had been castrated at birth, farmed semi-intensively on the Venezuelan plain and then slaughtered at the age of 31 months with an approximate weight of 500 kilograms. The average pH value of beef was 5,84 after obtained for 24 hours after staughtering, which matches the ~atue found in similar studies made on the same breed in Venezuela （5.8）. The moisture, crude protein and ash contents correspond to the expected values of cattle, while the intramuscular fat values are slightly higher than those of the different breeds ofBos indicus. The total collagen values found in this study are either similar or lower than those found by other researches from the different breeds ofBos indicus and their crossbreeds, while the collagen solubility value （39%） was higher than the one found in other studies on the Brahman breed.

EXPRESSION OF HUMAN α-GALACTOSIDASE AND α1,2-FUCOSYL-TRANSFERASE GENES MODIFIES THE CELL SURFACE GALα1,3GAL ANTIGEN AND CONFERS RESISTANCETO HUMAN SERUM-MEDIATED CYTOLYSIS

Objective To explore the strategies which reduce the amount of xenoantigen Galα1, 3 Gal. Methods Human α-galactosidase gene and α1,2-fucosyltransferase gene were transferred into cul-tured porcine vascular endothelial cells PEDSV.15 and human α-galactosidase transgenic mice were produced. The Galα1,3Gal on the cell surface and susceptibility of cells to human antibody-mediated lysis were analyzed. Results Human α-galactosidase gene alone reduced 78% of Galα1,3Gal on PEDSV.15 cell surface while human α-galactosidase combined with α1,2-fucosyltransferase genes removed Galα1,3Gal completely. Decrease of Galα1,3Gal could reduce susceptibility of cells to human antibody-mediated lysis, especially during co-expression of α-galactosidase gene and α1,2-fucosyltransferase gene. RT-PCR indicated positive human α-galactosidase gene expression in all organs of positive human α-galacto-sidase transgenic F1 mice including heart, liver, kidney, lung, and spleen, the amount of Galα1,3Gal antigens on which was reduced largely. 58% of spleen cells from F1 mice were destroyed by comp-lement-mediated lysis compared with 24% of those from normal mice. Conclusions Human α-galactosidase gene and α1,2-fucosyltransferase gene effectively reduce the expression of Galα1,3Gal antigens on endothelial cell surface and confers resistance to human serum-mediated cytolysis. The expression of human α-galactosidase in mice can also eliminate the Galα1,3Gal antigens in most tissues and decrease the susceptibility of spleen cells to human serum-mediated cytolysis.

HYPOXIA CONCOMITANT WITH SERUM DEPRIVATION INDUCES ENDOTHELIAL PROGENITOR CELL DEATH

Objective To evaluate the effects endothelial progenitor cells （EPCs） survival in vitro of serum deprivation （SD） and hypoxia on the bone marrow Methods Rat bone marrow EPCs were exposed for 48 h to 02 deprivation, serum deprivation （ SD ） , and prolonged （ 120 h） hypoxia concomitant with serum deprivation. Cell death was assessed by Live/Dead staining and image analysis. Reaulta The EPCs death rate seemed not affected by 48 h hypoxia （ P 〉 0. 05 ）, but affected by SD （ P 〈 0. 01 ）. Prolonged hypoxia concomitant with SD resulted in the death of nearly all EPCs from 72 h, but this rate was remarkably reduced when with 20% fetal bovine serum（ P 〈 0. 01 ）. Conclusion Our findings indicate that EPCs are sensitive to hypoxia/SD stimuli, while serum may be the more important factor for EPCs survival.

Punicalagin protects bovine endometrial epithelial cells against lipopolysaccharide-induced inflammatory injury

Objective：Bovine endometritis is one of the most common reproductive disorders in cattle.The aim of this study was to investigate the anti-inflammation potential of punicalagin in lipopolysaccharide（LPS）-induced bovine endometrial epithelial cells（bE ECs）and to uncover the underlying mechanisms.Methods：bE ECs were stimulated with different concentrations（1,10,30,50,and 100μg/ml）of LPS for 3,6,9,12,and 18 h.MTT assay was used to assess cell viability and to identify the conditions for inflammatory injury and effective concentrations of punicalagin.Quantitative real-time polymerase chain reaction（q RT-PCR）was used to assess gene expression of pro-inflammatory cytokines.Western blotting was used to assess levels of inflammation-related proteins.Results：Treatment of b EECs with 30μg/ml LPS for 12 h induced cell injury and reduced cell viability.Punicalagin（5,10,or 20μg/ml）pretreatment significantly decreased LPS-induced productions of interleukin（IL）-1β,IL-6,IL-8,and tumor necrosis factor-α（TNF-α）in bE ECs.Molecular research showed that punicalagin inhibited the activation of the upstream mediator nuclear factor-κB（NF-κB）by suppressing the production of inhibitorκBα（IκBα）and phosphorylation of p65.Results also indicated that punicalagin can suppress the phosphorylation of mitogen-activated protein kinases（MAPKs）including p38,c-Jun N-terminal kinase（JNK）,and extracellular signal-regulated kinase（ERK）.Conclusions：Punicalagin may attenuate LPS-induced inflammatory injury and provide a potential option for the treatment of dairy cows with Escherichia coli endometritis.