Weak antioxidant defenses make the heart a target for damage in copper-deficient rats

Copper deficiency causes more salient pathologic changes in the heart than in the liver of rats. Although oxidative stress has been implicated in copper deficiency-induced pathogenesis, little is known about the selective toxicity to the heart. Therefore, we examined the relationship between the severity of copper deficiency-induced oxidative damage and the capacity of antioxidant defense in heart and liver to investigate a possible mechanism for the selective cardiotoxicity. Weanling rats were fed a purified diet deficient in copper (0.4 μg/g diet) or one containing adequate copper (6.0 μg/g diet) for 4 weeks. Copper deficiency induced a 2-fold increase in lipid peroxidation in the heart (thiobarbituric assay) but did not alter peroxidation in the liver. The antioxidant enzymatic activities of superoxide dismutase, catalase, and glutathione peroxidase were, respectively, 3-, 50- and 1.5-fold lower in the heart than in the liver, although these enzymatic activities were depressed in both organs by copper deficiency. In addition, the activity of glutathione reductase was 4 times lower in the heart than in the liver. The data suggest that a weak antioxidant defense system in the heart is responsible for the relatively high degree of oxidative damage in copper-deficient hearts.     

Complex duplications in maize lines

Rp1 is a disease resistance complex and is the terminal morphological marker on the short arm of maize chromosome 10. Several restriction fragment length polymorphisms (RFLPs), which map within 5 map units of Rp1, were examined to determine if they are also complex in structure. Two RFLP loci, which mapped distally to Rp1, BNL3.04 and PIO200075, existed in a single copy in all maize lines examined. These two loci cosegregated perfectly in 130 test cross progeny. Two RFLP loci that map proximally to Rp1 had unusual structures, which have not yet been reported for maize RFLPs; the loci were complex, with variable numbers of copies in different maize lines. One of the loci, NPI285, occasionally recombined in meiosis to yield changes in the number of copies of sequences homologous to the probe. The other proximal locus, detected by the probes NPI422, KSU3, and KSU4, was relatively stable in meiosis and no changes in the number of restriction fragments were observed. The similarity in map position between Rp1 and the complex RFLP loci indicate there may be genomic areas where variable numbers of repeated sequences are common. The structure of these complex loci may provide insight into the structure and evolution of Rp1.     

Sophorose lipid production from lipidic precursors: Predictive evaluation of industrial substrates

Summary Sophorose lipids stand out as biosurfactants with a wide potential for industrial application and which can be produced in good yield from glucose and a lipidic cosubstrate.Candida bombicola CBS 6009 (ATCC 22214) was used in the present study. The influence of the lipidic cosubstrate on various aspects of production performance of these glycolipids (final concentration, yield) and on product composition (in particular, the structure of the hydroxy fatty acid vegetable and animal oils, markedly influenced product composition. In terms of production performance, the best substrates were oils or esters rich in C18:0 and C18:1 fatty acids. Optimal overall performance was obtained with esters (340 g L^–1 sophorose lipids with rapeseed esters). Conclusions drawn from the results allow predictive evaluation of lipidic industrial substrates.     

肝癌组织中GD3合成酶的纯化

ＧＤ３合成酶是膜嵌合蛋白,定位于高尔基体,经过制作微粒体,Ｔｒｉｔｏｎ增溶、ＡＨ－Ｓｅｐｈａｒｏｓｅ及ＧＭ３－Ｇｌａｓｓｂｅａｄｓｅ及ＧＭ３－Ｇｌａｓｓｂｅａｄｓ亲和层析等步骤,二乙基亚硝胺诱发大鼠肝癌组织中的ＳＴ２被纯化了３１５９７倍,得率为０．３５％。ＳＤＳ－聚丙烯酰胺凝胶电泳后银染色呈１条蛋白着色带,分子量为５５ｋｄ。     

发酵活性豆渣饲料的研究

活性豆渣饲料是新鲜豆渣经微生物发酵而得到的。本文介绍了发酵菌株的筛选过程,并对发酵的最适条件进行了研究。分析结果表明,这种饲料含有蛋白酶等多种酶类,蛋白质、氨基酸的含量均比未发酵的豆渣有所增加,而且克服了豆渣含水量大、易腐败的缺点,有利于畜禽更充分地消化吸收。经动物喂养实验证明．活性豆渣饲料可代替５０％以上的鱼粉,是一种非常理想的蛋白饲料。     

Identification and characterization of glucocorticoid receptors in liver of nude mice

Glucocorticoids regulate the expression of many liver-specific genes via glucocorticoid receptors. The presence of glucocorticoid receptors in liver has been reported in many mammalian species but not in nude mice. In the present study, we demonstrate the presence of specific glucocorticoid receptors in nude mouse liver. The binding of ligands to these receptors could be completely inhibited by RU486, and partially blocked by hydrocortisone and progesterone, whereas estrogen and testosterone had no effect. Hydrocortisone down-regulated the level of glucocorticoid receptors in livers of nude mice and correspondingly enhanced the activities of tyrosine aminotransferase and -glutamyltransferase. Our results indicate that glucocorticoid receptors in nude mouse liver are specific, fully functional, and present at levels 28.5-fold higher than in the liver of normal inbred mice. We suggest that the nude mouse is a valuable model for studies of hepatic glucocorticoid action and may provide a clue to a putative hepatic-thymic interaction.     

Development of IVM-IVF produced 8-cell bovine embryos in simple,serum-free media after conditioning or Co-culture with buffalo rat liver cells

Development of 8-cell bovine embryos derived from in vitro matured/in vitro fertilized (IVM/IVF) oocytes was evaluated in two simple, serum-free media (CZB and SOM) with buffalo rat liver cells co-culture (BRLC) or after conditioning compared to a commonly used, serum-supplemented complex medium TCM-199. In a 3 x 4 factorial design, 578 eight-cell embryos were randomly assigned to 12 treatment groups. The factors were: first, type of culture medium (M199/FBS, CZBg and SOM), and second, the use of BRLC (as co-culture or to condition media for 24 hr and 48 hr) and unconditioned media. Development to morula was not affected by the type of medium, but co-culture and 48 hr conditioning within media type resulted in better development when compared to the 24-hr conditioned or unconditioned groups. Blastocyst development in SOM (38.9%) was different (P < 0.05) than in CZBg (46.6%) and M199/FBS (48.7%) and was lowest in the unconditioned group (27.8%) followed by 24 hr conditioned (33.3%), 48 hr (56.3%), and co-culture (59.6%). No blastocyst expansion was observed with unconditioned media and 24 hr conditioned SOM. Significant differences (P < 0.05) were found among all treatment groups except the co-culture and 48-hr conditioned groups. Hatching occurred only with co-culture and 48-hr conditioned groups of M199/FBS and CZBg media. These data show that CZB with glucose conditioned by BRLC monolayers for 48 hr can support the development of IVM/IVF produced bovine embryos to blastocyst compared to culture in TCM-199 with serum. © 1994 Wiley-Liss, Inc.     

The periodicities in and biometeorological relationships with bed occupancy of an acute psychiatric ward in Antwerp,Belgium

Recently, some investigators have established a seasonal pattern in normal human psychology, physiology and behaviour, and in the incidence of psychiatric psychopathology. In an attempt to elucidate the chronopsy and meteotropism in the latter, we have examined the chronograms of, and the biometeorological relationships to bed occupancy of the psychiatric ward of the Antwerp University Hospital during three consecutive calendar years (1987–1989). Weather data for the vicinity were provided by a local meteorological station and comprise mean atmospheric pressure, air temperature, relative humidity, wind speed and minutes of sunlight and precipitation/day. The number of psychiatric beds occupied during the study period exhibited a significant seasonal variation. Peaks in bed occupancy were observed in March and November, with lows in August. An important part of the variability in the number of beds occupied could be explained by the composite effects of weather variables of the preceding weeks. Our results suggest that short-term fluctuations in atmospheric activity may dictate some of the periodicities in psychiatric psychopathology.     

Accumulation of scopoletin is associated with the high disease resistance of the hybrid Nicotiana glutinosa x Nicotiana debneyi

The high disease resistance of the amphidiploid hybrid of Nicotiana glutinosa x Nicotiana debneyi is associated with high constitutive levels of two phenolic compounds as analysed by high-performance liquid chromatography. The structures of these two compounds were elucidated by means of gas chromatography-tandem mass spectrometry, fluorescence- and light-spectrophotometry to be those of scopolin and scopoletin. They reached levels of 4 nmol·(g FW)^?1 and 35 nmol·(g FW)^?1, respectively, in leaf tissues of the hybrid, about 10–50 times the amount found in the parental species. Scopoletin showed a direct antimicrobial activity against Cercospora nicotianae, Phytophthora parasitica var. nicotianae, Pseudomonas syringae pvs. tabaci and syringae and tobacco mosaic virus when added to synthetic growth media, mixed with the inoculum or sprayed onto tobacco plants prior to inoculation. We postulate that the high amount of toxic phenolics in the leaves of the hybrid N. glutinosa x N. debneyi contributes to its high disease resistance.     

Influence of A1 cytoplasmic substitution on the downy-mildew incidence of pearl millet

Large-scale cultivation of pearl millet [Pennisetum glaucum (L.) R. Br. F₁ hybrids in India has led to increased incidence of downy-mildew (Sclerospora graminicola). There is concern that the A₁ male-sterile cytoplasm used in all the hybrids released so far is responsible for this increase. The influence of A₁ malesterile cytoplasm on downy-mildew incidence in pearl millet was studied by comparing the disease reaction of 40 pairs of F₁ hybrids, each pair carrying respectively a₁ male-sterile and normal B cytoplasm. Mean downy-mildew incidence was similar in the hybrids carrying either A₁ male-sterile or B cytoplasm. The general combining ability of lines with and without A₁ cytoplasm was found to be similar for downy-mildew incidence. These results indicated that in pearl millet A₁ cytoplasm is not associated with increased downymildew incidence. The possible danger of using only one source of cytoplasm has been briefly discussed.