"活体生物反应器"研究新进展

本刊曾介绍了生物反应器研究的新进展(2005,21(5):808),这里再作几点补充。1.克隆猪及克隆羊表达有关人体有益基因:日本农业生物资源研究所与名古屋大学合作,用克隆技术和基因操作技术成功克隆出含有人体基因的猪和羊,再用这种含人体基因的猪器官移植到人体内,不会发生排异反应     

拒绝"猪头猪脑"的非洲红河猪

正如果知道猪也有长相贵气的品种,也许很多人再也不会骂人"猪头猪脑"了。分布于非洲撒哈拉沙漠以南大部分地区和马达加斯加岛的红河猪,一改猪类痴傻呆憨的形象,浑身焕发着一种漂亮偶蹄目动物的模样,堪称是猪族中的贵族。红河猪也被称为非洲野猪或丛林猪,它们很少远离雨林,并且通常靠近河流或沼泽地区居住。     

重组猪生长激素表达研究进展

猪生长激素作为猪生长发育过程中起主导作用的蛋白质激素,能增加肌肉组织蛋白含量、降低脂肪含量、促进骨骼发育、刺激乳汁分泌等,是畜牧养殖业中值得开发利用的激素之一。利用基因工程技术生产重组猪生长激素使猪生长激素在生产上应用成为可能。本文简要介绍了猪生长激素,总结了重组猪生长激素表达的研究进展,并展望了重组猪生长激素的应用与发展前景。     

我国小型猪品系资源状况初浅分析

小型猪正逐渐成为生命科学研究中的重要实验动物。我国具有独特和丰富的小型猪资源,我国小型猪品系或资源涉及资源品系、封闭群、近交培育品系等。本文就我国的小型猪品系资源状况进行了介绍和初步分析。     

国内外小型猪资源概况

猪和人在解剖学、生理学上有极大的相似性,而小型猪还具有品系繁多、遗传性能稳定等诸多优点,因此,作为实验动物已经被广泛应用于生物医学研究的多个方面。本文主要介绍了从40年代末美国开始培育小型猪以来,国内外小型猪的主要品系、培育、开发研究的发展情况以及国内培育小型猪的优势。     

猪环曲病毒病原特点和流行病学

猪环曲病毒在世界范围内广泛分布,猪群感染率高,在腹泻病例中检出率高,被认为是一种可能的猪腹泻病原。凸隆病毒的型间重组和抗原交叉反应,意味着猪环曲病毒存在人兽共患的风险。基于近年在我国部分地区因为仔猪腹泻导致了较大损失,本文介绍了猪环曲病毒发展历史,综述了该病毒基因组和蛋白特点、流行病学、实验室诊断等,以期为相关研究提供参考。     

猪体细胞核移植技术研究进展

猪体细胞核移植技术已发展十年多,技术日趋完善,许多实验室已可获得克隆猪和基因修饰猪。近年来新兴了多种基因高效靶向修饰和调控技术,为基因修饰猪研究奠定了技术基础,推进了基因修饰猪的研究从基础研究转向应用研究。介绍了猪体细胞核移植技术的发展历程,主要技术环节的优化,并对猪体细胞核移植的技术优势,在农业、生物医药上的应用及意义,存在问题与前景等进行了概述。     

巴马小型猪在医学研究中的应用进展简

广西巴马小型猪作为国内小型猪主要品种之一,具有遗传性稳定、多产、体重较小、体表多覆白毛等特征,组织器官及生化指标与人类相似,已越来越广泛地应用于医学研究领域：猪的心脏解剖与生理特点与人类高度相似,已被广泛应用于心血管系统研究中,在我国,巴马小型猪被用来构建心肌缺血、卵圆孔未闭等心血管疾病模型;猪具有杂食性及与人相似的脂质代谢,可用于研究内分泌疾病,巴马小型猪已用于糖尿病动物模型建立及其遗传易感性、并发症的防治研究等;巴马小型猪的消化系统与人类相似,利用此特点已建立阻塞性慢性胰腺炎、结肠穿孔、胆肠吻合等消化系统疾病模型;巴马小型猪除头、尾外,体表覆以白毛,这一特点使其成为研究皮肤创伤、烧伤修复等的理想动物;小型猪的牙齿解剖结构与人类相似,口裂大,可作为口腔医学研究中的理想动物,巴马小型猪已用来建立牙髓坏死模型及对上颌扩弓方式的研究;类似人的解剖、生理、病理使其成为较为适合的异种移植供体.在中医药研究方面,已用巴马小型猪分别建立了肝脏、脾脏、股动、静脉出血及头颈恶性肿瘤放疗后的腮腺损伤动物模型以研究中药制剂的疗效及机制.     

潮安县凤凰镇"猪-沼-茶"生态农业模式的结构与效益研究

对潮安县“猪-沼-茶”生态农业模式的结构及其功能效益进行了案例调查与研究分析。“猪-沼-茶”生态农业模式是以种茶为中心,以沼气和沼渣为纽带,综合发展种植业和养殖业的一种生态模式。这种模式可提高茶叶品质,节约生产成本;改善茶园生态环境和提高土壤肥力,具有较好的经济效益、生态效益和社会效益。这种模式适合于我国南方丘陵山区推广应用。     

一组特异存在于猪乳中的高分子量蛋白质

猪乳中含有多种蛋白质,介绍了猪乳中新发现的一组高分子量蛋白质的研究现状,对其生化性质和功能作了综述,并探讨对其进一步研究和开发的重要意义。     

Prenatal development of "synaptic" ribbons in the guinea pig pineal gland

Pineal "synaptic" ribbons are a heterogeneous population of organelles. "Synaptic" ribbons (SR) sensu stricto, "synaptic" spherules (SS), and intermediate forms (IMF) are present. Their function and origin are unknown, and a knowledge of their prenatal development is lacking. Thus the pineal glands of prenatal, neonatal, and adult guinea pigs were prepared for electron microscopy. "Synaptic" ribbons were studied morphologically and quantitatively. The three categories of "synaptic" ribbons reported in adult pineal glands were also present in prenatal pineal glands. Their structural features, distribution, grouping, and composition patterns are similar to those in adults. "Synaptic" ribbons were first detected in pinealocytes of the distal region of a 42-day postcoitus (PC) pineal gland and were comparable with those in adults. They increased in number with age and reached a peak at 63 days PC, followed by a steep decline at 66 and 67 days PC. By day 69 PC, the numbers increased again and showed a dramatic increase after birth. Several true ribbon synapses were seen at day 63 PC between pinealocyte cell processes or between pinealocyte cell process and pinealocyte cell body. Since true ribbon synapses have not been found in adult guinea pig pinealocytes, their synaptic nature could have been lost during development. No precursors for the "synaptic" ribbons were found. The endoplasmic reticulum cisternae may be the origin for the ribbon vesicles because of their close association with the "synaptic" ribbons.     

Postnatal development of "synaptic" ribbons and spherules in the guinea pig pineal gland

Previous studies have shown that the functionally enigmatic pineal "synaptic" ribbons are structurally a heterogeneous group of organelles consisting of rodlike ribbons sensu stricto, spherules, and intermediate forms. As ribbons and spherules react differently under various experimental conditions, these organelles were studied qualitatively and quantitatively during the postnatal period in guinea pigs. It was found that the pinealocytes were highly differentiated at birth and contained all three forms of "synaptic" structures. Ribbons and intermediate forms were more abundant than spherules and exhibited a striking increase in number on postnatal days 1 and 2; this increase was followed by a distinct trough and by a second peak at days 12 and 13, after which their numbers declined to reach adult levels by day 20. The spherules were small in number at birth and did not show the large immediate postnatal increase observed for the ribbons and intermediate forms. Instead there was a steady numerical increase up to day 12 (absolute number) or day 15 (relative numbers), followed by a decrease to adult level by day 20. Whereas during the early postnatal period (days 1 to 3) the majority of pinealocytes were characterized by ribbons and intermediate forms, with increasing age spherule-bearing pinealocytes increased in number. As ribbons and spherules were usually not found in the same pinealocyte, the present findings are interpreted to mean that ribbons and spherules characterize different types of pinealocytes showing an inverse numerical development postnatally. Developmentally intermediate forms behave like ribbons.     

Histochemical studies of several "K"-cell enzymes in guinea pig thyroid glands]

The thyroid gland of guinea pigs were studied morphologically. Histochemical methods were used for detection of lactate dehydrogenase, succinic dehydrogenase, cholinesterase, alkaline phosphatase and acid phosphatase. The distribution of "C"-cells in normal thyroid glands was proved to be uneven. In the center of the gland they were more numerous. For statistical investigations the method of silver impregnation of "C"-cells is more practicable, since they can not be obviously distinguished from acinar cells on the basis of glycerophosphate dehydrogenase only. The activity of cholinestarase in "C"-cells and in some other cells of folliculi epithelium is very high. A supposition is made that there exist two kinds of the follicular lining thyrocytes, having different histochemical properties and histogenesis as well.     

Antibodies to guinea pig lymphokines. II. Suppression of delayed hypersensitivity reactions by a "second generation" goat antibody against guinea pig lymphokines.

A "second generation" antibody to a highly purified lymphocyte product was raised in a goat against material eluted from a rabbit anti-guinea pig lymphokine immunoadsorbent column. This anti-lymphokine serum, in constrast to anti-lymphocyte serum (ALS) did not appear to contain cytotoxic antibodies directed against membrane antigens on guinea pig lymph node lymphocytes. Furthermore, the anti-lymphokine serum did not inhibit the formation of spontaneous T rosettes nor significantly depress lymphocyte response to mitogens. The anti-lymphokine serum totally suppressed the delayed skin reactivity to PPD and contact sensitivity to DNCB when injected intradermally around the site of antigen challenge. By contrast, intradermally injected ALS did not appear to suppress the PPD response in sensitized guinea pigs. Intravenously and i.p. administered anti-lymphokine serum was somewhat less effective in suppressing the delayed skin response to PPD. The intradermal injection of the antiserum had no effect on nonspecific inflammation evoked by turpentine-olive oil or on the extravasation of circulating Evans blue evoked by intradermally injected histamine. Histologic examination of 24-hr DNCB-induced skin lesions from sensitized guinea pigs treated with intradermally injected anti-lymphokine serum showed marked reduction of mononuclear infiltration of the dermis and of epidermal lesions, as compared with skin sites taken from sensitized animals pretreated with normal goat serum. The anti-lymphokine serum injected i.v. also markedly reduced the perivascular infiltration of the dermis and subcutis in skin reaction sites from sensitized animals challenged with PPD. Intravenous treatment with ALS for 3 consecutive days caused extensive depletion of the paracortical areas of peripheral lymph nodes whereas treatment with normal serum and anti-lymphokine serum caused no such depletion. It is proposed that the anti-lymphokine serum is directed against activated lymphocyte products, one of them being MIF. These products are involved in the mediation of delayed hypersensitivity reactions. This is in marked contrast to ALS, the suppressive action of which appears to be central rather than peripheral.     

The in vivo regulation of the progesterone "receptor" in guinea pig uterus: dependence on estrogen and progesterone

An assay for quantifying the high affinity progesterone binding protein in guinea pig uterine cytosol was developed using Florisil to separate bound and free steroid. The activity of the progesterone binding protein increased between 4–12 hours following estrogen administration and by 4 days of treatment was 10-fold higher than castrate controls. When estrogen administration was discontinued the progesterone binding activity declined slowly with a half-life of 3 days. By contrast, progesterone treatment caused a rapid decline of binding activity within 3 hours. These studies suggest that the antagonistic actions of estrogen and progesterone determine the quantity of available progesterone binding sites in guinea pig uterine cytosol.