激活素Activin A对猪卵母细胞胞质成熟的影响

[目的]探讨体外成熟过程中在培养液中添加激活素Activin A对猪卵母细胞胞质成熟的影响。[方法]在TCM-199中添加不同剂量Activin A的培养猪卵母细胞40 h,以激光共聚焦显微镜观察到的着色的线粒体排布形态类型来判断卵母细胞胞质是否成熟。[结果]当Activin A剂量为100 ng/ml时,胞质中线粒体呈弥散型分布形态的卵母细胞数目极显著增加(P0.01),同时线粒体呈圆周型排布与半周型排布的卵母细胞数目显著下降(P0.05)。[结论]猪卵母细胞体外成熟过程中在成熟培养液中添加激活素Activin A,能促进卵母细胞胞质的成熟。     

Activin-binding protein from rat ovary is follistatin

Activin, a member of the transforming growth factor beta protein family, was originally isolated from gonadal fluids and stimulates the release of pituitary follicle-stimulating hormone (FSH). Activin has numerous functions in both normal and neoplastic cells. Various cells synthesize activin and have a specific binding site for this peptide. However, the molecular basis for its actions is unknown. A binding protein for activin was purified from rat ovary and was identical to follistatin, a specific inhibitor of FSH release. It is likely that the binding protein participates in the diverse regulatory actions of activin.     

欧洲油菜花粉cDNA文库的构建

从欧洲油菜（Ｂｒａｓｓｉｃａｎａｐｕｓ）成熟花粉中提纯出ｍＲＮＡ．ｐｏｌｙ（Ａ）＋ｍＲＮＡ在ｏｌｉｇｏ（ｄＴ）引导下，用反转录酶合成ｃＤ－ＮＡ第一链，用大肠杆菌ＲＮＡ酶Ｈ和大肠杆菌ＤＮＡ聚合酶Ｉ置换合成ＣＤＮＡ第二链．加上ＥｃｏＲＩ／ＮｏｔＩ接头。最后将双链ＤＮＡ克隆子λｇｔｌｌ载体中。用Ｂｃｐｌ作探针，杂交筛选构建的ｃＤＮＡ文库。     

Mediation of wound-related Rous sarcoma virus tumorigenesis by TGF-beta

In Rous sarcoma virus (RSV)-infected chickens, wounding leads to tumor formation with nearly 100% frequency in tissues that would otherwise remain tumor-free. Identifying molecular mediators of this phenomenon should yield important clues to the mechanisms involved in RSV tumorigenesis. Immunohistochemical staining showed that TGF-beta is present locally shortly after wounding, but not unwounded controls. In addition, subcutaneous administration of recombinant transforming growth factor-beta 1 (TGF-beta 1) could substitute completely for wounding in tumor induction. A treatment protocol of four doses of 800 nanograms of TGF-beta resulted in v-src-expressing tumors with 100% frequency; four doses of only 10 nanograms still led to tumor formation in 80% of the animals. This effect was specific, as other growth factors with suggested roles in wound healing did not elicit the same response. Epidermal growth factor (EGF) or TGF-alpha had no effect, and platelet-derived growth factor (PDGF) or insulin-like growth factor-1 (IGF-1) yielded only occasional tumors after longer latency. TGF-beta release during the wound-healing response may thus be a critical event that creates a conducive environment for RSV tumorigenesis and may act as a cofactor for transformation in this system.     

Synthesis of RNA-polyadenylic acid by isolated brain nuclei

Nuclei, isolated from mouse brain tissue at various stages of postnatal development and incubated under cell-free conditions, synthesized RNA molecules that were associated with polyadenylic acid [poly(A)]. The RNA synthesized by these nuclei was similar to the poly(A)-associated products described for intact eukaryotic cells. The brain nuclei synthesized a similar proportion of RNA-poly(A) in the presence either of Mg(2+) or of Mn(2+) with (NH(4))(2)So(4). The RNA from neonatal brain nuclei appeared to have a greater proportion of poly(A)-containing RNA than nuclear products obtained from more mature neural tissue.     

Endothelial adhesiveness for blood neutrophils is inhibited by transforming growth factor-beta

Adhesion of blood cells to endothelial cells is an essential component of all inflammatory responses. The capacity of the endothelium to support adhesion of neutrophils is increased by cytokines such as tumor necrosis factor-alpha, interleukin-1, and endotoxin. Another cytokine, transforming growth factor-beta (TGF-beta), was a strong inhibitor of basalneutrophil adhesion and also decreased the adhesive response of endothelial cells to tumor necrosis factor-alpha (TNF-alpha). The ability of cells to respond to TGF-beta was related to the duration of culture of endothelial cells after explantation from umbilical veins. TGF-beta is likely to serve an anti-inflammatory role at sites of blood vessel injury undergoing active endothelial regeneration.     

Inhibition of endothelial regeneration by type-beta transforming growth factor from platelets

Damage to the vessel wall is a signal for endothelial migration and replication and for platelet release at the site of injury. Addition of transforming growth factor-beta (TGF-beta) purified from platelets to growing aortic endothelial cells inhibited [3H]thymidine incorporation in a concentration-dependent manner. A transient inhibition of DNA synthesis was also observed in response to wounding; cell migration and replication are inhibited during the first 24 hours after wounding. By 48 hours after wounding both TGF-beta-treated and -untreated cultures showed similar responses. Flow microfluorimetric analysis of cell cycle distribution indicated that after 24 hours of exposure to TGF-beta the cells were blocked from entering S phase, and the fraction of cells in G1 was increased. The inhibition of the initiation of regeneration by TGF-beta could allow time for recruitment of smooth muscle cells into the site of injury by other platelet components.     

小麦叶片内1,5-二磷酸核酮糖羧化酶/加氧酶大亚基由53 000到50 000裂解反应的定位研究

研究了小麦叶片内1，5-二磷酸核酮糖羧化酶／加氧酶（Rubisco，EC 4．1．1．39）大亚基（LSU）由53000裂解为50000的反应。结果显示，成熟叶片的粗提液在pH5．5的条件下反应后能检测到50000的裂解产物，而暗诱导衰老叶片的粗提液在pH7．5的条件下也能发现LSU的这一降解。分别从成熟叶片和衰老叶片中提取叶绿体，以其裂解液为反应体系研究LSU由53000裂解为50000这步反应的细胞器定位。结果显示，衰老叶片中的叶绿体裂解液在pH7．5时反应1h后能检测到50000降解产物，而成熟叶片叶绿体裂解液在pH5．5和pH7．5的条件下反应后均未检测到LSU的50000裂解产物。上述结果表明：衰老叶片中ISU由53000部分裂解为50000的反应定位于叶绿体内，而成熟叶片中LSU由53000裂解为50000的反应可能定位于叶绿体外。     

Accelerated healing of incisional wounds in rats induced by transforming growth factor-beta

The role of polypeptide growth factors in the processes of inflammation and repair was investigated by analyzing the influence of transforming growth factor-beta (TGF-beta), applied directly to linear incisions made through rat dorsal skin. A dose-dependent, direct stimulatory effect of a single application of TGF-beta on the breaking strength of healing incisional wounds was demonstrated. An increase in maximum wound strength of 220 percent of control was observed at 5 days; the healing rate was accelerated by approximately 3 days for at least 14 days after production of the wound and application of TGF-beta. These increases in wound strength were accompanied by an increased influx of mononuclear cells and fibroblasts and by marked increases in collagen deposition at the site of application of TGF-beta. TGF-beta is thus a potent pharmacologic agent that can accelerate wound healing in rats.     

Reversible inhibition of mammary gland growth by transforming growth factor-beta

Transforming growth factor-beta (TGF-beta) can stimulate or inhibit growth of cells in vitro, as well as induce the transformed phenotype. Although widely distributed in animal tissue, the effects of TGF-beta in vivo are largely unknown, and a physiological role for the peptide hormone has not been demonstrated. The effect of TGF-beta on developing epithelial tissue in situ was studied by using slow-release plastic pellets containing TGF-beta to treat developing mouse mammary gland. Powerful inhibition of mammary growth and morphogenesis was observed. This growth-inhibited mammary tissue was histologically normal, and the inhibitory effect was fully reversible. Under the conditions of these experiments, TGF-beta displayed many of the characteristics expected of a physiologically active growth-regulatory molecule.     

民猪与长白猪主要组织器官生长规律研究

选择民猪和长白猪为研究对象,利用异速生长式分析两个品种1～8月龄组织器官的早熟顺序。结果表明,民猪脂肪沉积较早,在2.5～6月龄间沉积大量的脂肪,生长发育全期腹内脂肪的沉积能力突出,而长白猪在6月龄后沉积脂肪速度加快;两个品种各脂肪组织占胴体比率在6～8月龄维持不变。民猪肉、脂、骨、皮早熟性顺序为:骨骼>肌肉>皮肤>脂肪,而长白猪为:骨骼>皮肤>肌肉>脂肪;两品种猪脂肪组织早熟性顺序均为:肠系膜脂肪>皮下脂肪>肾周脂肪>大网膜脂肪。民猪内脏器官早熟性顺序为:小肠>肾>胰>肝>脾>肺>心>胃>大肠;长白猪内脏器官早熟性顺序为:小肠>肾>肝>胰>心>脾>胃>肺>大肠。     

鸡γ干扰素基因的分子克隆及其在大肠杆菌中的表达

根据GenBank已发表的鸡γ干扰素cDNA基因序列设计一对引物,以血淋巴细胞提取的总RNA为模板,通过RT-PCR的方法克隆出鸡γ干扰素基因,把它与融合表达载体pET32a相重组。通过对阳性宿主菌的不同时间的诱导摸索出最佳表达时间。     

岭南黄鸡肌生长抑制素基因成熟肽的克隆及酵母表达质粒的构建

根据Genebank上登录的鸡的myostatin基因cDNA全长序列以及成熟肽序列设计一对引物,并分别在两引物前设计两个酶切位点EcoRⅠ和KpnⅠ,克隆岭南黄鸡肌肉生长抑制激素的成熟肽蛋白编码基因,然后将特异性片段连接到pMD18-T载体,经酶切、PCR鉴定后,构建了岭南黄鸡真核单纯表达载体pPICZαA-MSTN-m,经测序鉴定,结果表明所克隆的myosta-tin成熟肽基因与Genebank上发表的鸡（AF019621）、猪（AY208121）和家鹅（AF440862）的MSTN-m核酸序列同源性分别可达到99%、92%、86%,但翻译后的成熟蛋白氨基酸序列与鸡、猪和家鹅的同源性可以分别达到100%、99.1%及99.1%。     

Losartan, an AT1 antagonist, prevents aortic aneurysm in a mouse model of Marfan syndrome

Aortic aneurysm and dissection are manifestations of Marfan syndrome (MFS), a disorder caused by mutations in the gene that encodes fibrillin-1. Selected manifestations of MFS reflect excessive signaling by the transforming growth factor-beta (TGF-beta) family of cytokines. We show that aortic aneurysm in a mouse model of MFS is associated with increased TGF-beta signaling and can be prevented by TGF-beta antagonists such as TGF-beta-neutralizing antibody or the angiotensin II type 1 receptor (AT1) blocker, losartan. AT1 antagonism also partially reversed noncardiovascular manifestations of MFS, including impaired alveolar septation. These data suggest that losartan, a drug already in clinical use for hypertension, merits investigation as a therapeutic strategy for patients with MFS and has the potential to prevent the major life-threatening manifestation of this disorder.     

TGF-beta signaling in fibroblasts modulates the oncogenic potential of adjacent epithelia

Stromal cells can have a significant impact on the carcinogenic process in adjacent epithelia. The role of transforming growth factor-beta (TGF-beta) signaling in such epithelial-mesenchymal interactions was determined by conditional inactivation of the TGF-beta type II receptor gene in mouse fibroblasts (Tgfbr2fspKO). The loss of TGF-beta responsiveness in fibroblasts resulted in intraepithelial neoplasia in prostate and invasive squamous cell carcinoma of the forestomach, both associated with an increased abundance of stromal cells. Activation of paracrine hepatocyte growth factor (HGF) signaling was identified as one possible mechanism for stimulation of epithelial proliferation. Thus, TGF-beta signaling in fibroblasts modulates the growth and oncogenic potential of adjacent epithelia in selected tissues.     

小鼠动情周期中卵巢内卵泡和黄体的动态组织学观察

本实验通过对17只昆明白小鼠动情周期中卵泡和黄体等组织学观察，结果表明：0d，初级卵泡数达其最高值，中小型有腔卵泡数处于一个峰值；1d，大型有腔卵泡数达其最高值，有成熟卵泡出现；2d，中小型有腔卵泡处在又一个波峰，成熟卵泡达其最高值；3d，大量黄体和间质腺出现；4d，萎缩卵泡和间质腺达其最高值．