北京油鸡与AA肉鸡脂肪组织差异表达基因的研究

运用mRNA差异显示技术对AA肉鸡和北京油鸡脂肪组织基因的差异表达进行研究,从分子遗传学角度分析导致两品种脂肪组织差异表达的原因,对了解性状形成的遗传基础和调控机理是十分必要的。通过反Northern杂交验证共筛选出脂肪组织差异表达基因10条,经与GenBank数据库进行相似性比对,XF1 与已知基因有较高同源性,该基因是人类cDNA全长开放阅读框（ORF）的一段; XF2、YF1、YF2及YF4经与nr数据库进行同源性比对,均可找到同源性较高的基因,但功能未知;XF4 与克隆人类胎盘CL0BA010ZF08基因的一段cDNA序列同源性为83%;YF3与预测原鸡MLL5 (LOC417712)基因有一定的同源性,目前尚无功能报道;XF5和YF5 与原鸡高迁移率族蛋白（HMGN3）有较高同源性;XF3 在nr库中未找到同源序列,确定为新发现的EST,提交数据库获得GenBank登录号(Accession number: EU594549)。为进一步研究北京油鸡与AA肉鸡脂肪组织差异基因的功能与脂肪发育的关系奠定基础。     

Enzyme-linked lectin assay (ELLA). II. Detection of carbohydrate groups on the surface of unfixed cells

An enzyme-linked lectin assay (ELLA) has been developed to detect specific carbohydrate units on the surface of unfixed cells. The assay may be read in standard ELISA plate readers, since the cell-bound enzyme-lectin conjugate is specifically eluted from the cells prior to development of the conjugate. ELLA, when read in an enzyme-linked immunosorbent assay (ELISA) plate reader, allows better detection and relative quantitation of specific surface carbohydrate units than is possible by standard immunofluorescence with fluorescein-conjugated lectins.     

Enhancement and suppression of immunoglobulin G-producing B cells in the presence of immune T cells.

Mice were immunized one to three times with sheep red blood cells. Four to seven days after the last immunization, the spleens were removed and the cells were cultured in vitro in the absence of antigen. Removal of most T cells by anti-θ serum treatment prior to culture could increase the number of IgG-producing B cells without affecting the number of specific or nonspecific IgM-producing B cells detected after 2 days of culture. Addition of graded numbers of immune cells to pure immune B cells enhanced the number of IgG-producing B cells, whereas addition or higher number of immune cells caused suppression. Since removal of T cells could also enhance the proliferation of IgG-producing B cells induced by lipopolysaccharide (LPS), a polyclonal B-cell activator, it is suggested that the suppressive effects of high numbers of immune T cells are exerted directly on the B cells.     

The inhibitive effects of steroid analogues in the binding of tritiated 5alpha-dihydrotestosterone to receptor proteins from rat prostate tissue.

The relationship between molecular structure and the binding potential of steroids to receptor proteins was investigated. Twenty-four selected steroids were studied in minced incubations of rat prostate tissue. Measurements of the inhibitory effects of the steroids on the binding of tritiated 5alpha-dihydrotestosterone to the receptor proteins were obtained in the 100,000 times g dialysed supernatant and the purified nuclear component of the prostate cells. The steroids that achieved the highest degree of inhibition were those compounds that exhibited a generally planar geometric shape and were known to possess potent androgenic activity. Several of the compounds were shown to possess a higher degree of inhibition than that of testosterone or 5alpha-dihydrotestosterone. The data is further supportive of the two step theory that necessitates the complexing of the free steroids to the receptor proteins in the cytosol before transport to the nuclei. Evidence is also suggestive of the presence of 17-esterase activity. The inhibitory effect of the steroids apparently involves the binding to the intracellular receptors and is not related to the uptake of 5alpha-dihydrotestosterone into the cell.     

Red cell ouabain binding sites, Na+K+-ATPase, and intracellular Na+ as individual characteristics

Healthy male volunteers were infused for three hours with either a dopamine hydrochloride solution at a rate of 4 ug/kg/min or with normal saline. Plasma amine oxidase and platelet MAO activity towards benzylamine both increased in response to intravenous dopamine. There was no increase in enzyme activity when dopamine was added to the platelet and plasma enzymes in vitro. This heretofore unreported increase in the oxidative deaminating capacity of the human organism may represent an adaptive physiologic response to the high circulating levels of dopamine and provides further evidence for a possible functional significance of these enzymes in man.     

Androgen receptor protein binding properties and tissue distribution of 2-selena-a-nor-5α-androstan-17β-ol in the rat

2-selena-A-nor-5α-androstan-17β-ol was studied $\text{in vitro}$ and $\text{in vivo}$ in the rat prostate gland. The data demonstrates the ability of this compound to selectively complex with the specific receptors of 5α-dihydrotestosfcerone (5α-DHT) in the cytosol and to be retained in the nuclei in an unaltered form. Studies with selenium-75 labeled material suggests that the uptake and localization is similar to endogenous 5α-dihydrotestosterone.     

Rapid and efficient preparation of free amino acids from strong acid salts on columns of crosslinked poly-4-vinylpyridine

Acidic and neutral amino acids were recovered from their strong acid salts or from large excesses of strong acids by passage through columns of crosslinked poly-4-vinylpyridine. Basic amino acids eluted as the monoacid salts. High recoveries were possible with submicromolar samples.     

24-nor-5β-chol-22-enes derived from the major bile acids by oxidative decarboxylation

The preparation of 24-nor-5β-chol-22-enes from formyloxy-5β-cholanic acids by oxidative decarboxylation with lead tetraacetate is described. NMR data is presented with other physical constants for the norcholenes derived from cholic, chenodeoxycholic, ursodeoxycholic, hyodeoxycholic, and deoxycholic acids. The facile synthesis of these norcholenes demonstrates the applicability of the formyloxy protecting group to oxidative decarboxylations in the bile acid series.     

Potential tumor or organ-imaging agents, 24. Radioiodinated pregnenolone esters

A series of radioiodinated pregnenolone esters was prepared in an effort to find an agent that would be rapidly and selectively taken up by adrenal cortical tissue. Achievement of such a goal would provide the basis for the development of an adrenal imaging agent having several advantages over those agents currently available for clinical use. The radioiodinated esters for this study were readily prepared by treating pregnenolone with the appropriate iodobenzoic acid in the presence of dicyclohexylcarbodiimide (DCC) and 4-dimethylamino-pyridine (DMAP). The resulting esters were readily labeled with radioiodine by isotope exchange with sodium iodide-125 in pivalic acid. Subsequent tissue distribution studies in rats revealed that those esters displaying the most stability towards hydrolysis achieved the highest concentration in adrenal cortical tissue. For example, the 2,3,5-triiodobenzoate (6) showed an adrenal uptake of 23% of administered dose per gram of tissue at 0.5 hours. The achievement of high levels of radioactivity in the adrenal with this agent at early time periods warrants further evaluation of this agent in other animals.