The Effects of Copper Sulfate on Liver Histology and Biochemical Parameters of Term Ross Broiler Chicks

Copper is an essential trace element that is extremely toxic to organisms and organs at high doses. We have investigated the histological and biochemical effects of a toxic dose of copper sulfate on the liver of term Ross broiler chicks. Fertilized eggs were divided into three groups: experimental, injected with 50 mcg/0.1 ml copper sulfate in the air chambers on day 1; sham, injected with 0.1 ml saline; and control, no injection. Term chicks were killed and their livers investigated histologically, with hematoxylin–eosin-stained sections examined under light microscopy, and biochemically, for malondialdehyde and glutathione levels. Histological examinations showed copper-treated samples with granular degeneration and necrosis of hepatocytes and impairment to the cell lining of the remark cords. The samples had a congestive appearance, with blood in the vena centralis and sinusoids, slight connective tissue increase, and lymphocyte infiltration. Control and sham group sections had normal appearances. As oxidative damage parameters, in the copper-treated group, malondialdehyde levels were increased and glutathione levels decreased. In the sham and control groups, there were no significant differences. At this toxic dose, copper sulfate shows oxidative damage according to the histology of term chick liver that are confirmed biochemically by the changes in malondialdehyde and glutathione levels.     

Fish skin bacteria: Colonial and cellular hydrophobicity

Dental plaque is a complex community of bacteria coexisting in an environment frequently limited by carbon and energy sources. UnlikeStreptococcus mutans, other oral streptococci such asS. milleri andS. sanguis have an absolute requirement for and actually consume all available arginine when grown glucose limited in a chemically defined medium. The conditions, particularly in terms of arginine concentration, under which the dental plaque bacteriaS. mutans andS. milleri would coexist under glucose-limiting conditions were investigated. The minimum level of arginine supporting optimal growth ofS. milleri was found to be ca. 50M, and above this level these strains outcompetedS. mutans. However, coexistence withS. mutans could be achieved at arginine levels of 14–40M, depending upon theS. milleri andS. mutans strains used. Under such dual limitation,S. milleri was unable to respond to glucose pulses but did respond to pulses of arginine and arginine plus glucose. One of the twoS. milleri strains did not tolerate low pH. In contrast,S. mutans did not tolerate high pH whereasS. milleri was unaffected. This is relevant to dental plaque where arginine catabolism produces a pH rise. Additionally, arginine is an important nutrient since it can be used as an energy source by some oral streptococci.     

Early increases in the frequency of DNA initiations and of phospholipid synthesis discontinuities after nutritional shift-up in Escherichia coli

Cultures of Escherichia coli (strains ML30 and K12 AB1157), synchronized by repeated phosphate starvation, were submitted to nutritional shifts-up at various cell ages. The progression of the replication forks was assessed by DNA-DNA hybridization of pulse-labelled chromosomal DNA with plasmid DNA probes containing specific chromosomal sequences. The rate of phospholipid synthesis and its cyclic discontinuities were measured by continuous and pulse labelling with palmitate. The DNA-DNA hybridization experiments showed that a shift-up induces a burst of initiation from the oriC region. These hybridization results, taken together with older data from the literature, suggest that most DNA initiations belonging to this burst are not followed by complete replication. Following a shift-up, the rate of phospholipid synthesis is maintained for 13-20 min, depending on cell age at shift-up, then doubles. The new steady-state rate of phospholipid synthesis is reached through a series of three doublings, while the cell mass doubles approximately twice. This discrepancy brings the rate of phospholipid synthesis per mass unit to its steady-state postshift value.     

Interspecific variation in arrangement and morphology of micrasters of Tethya species (Porifera,Demospongiae)

Summary A new distinctive feature between the two Mediterranean species of Tethya, T. aurantium and T. citrina has been found in the body arrangement of different types of micrasters. Contrary to the previous assumptions, T. aurantium has two clearly distinct categories of micrasters: the chiaster-tylaster in the cortex and the larger, slender oxyaster in the choanosome. T. citrina has only slightly differentiated micraster sets in the cortex and choanosome; in the latter the shape of micrasters is close to that of oxyasters. SEM analysis shows that differences in micraster shape depend on the cylindrical or conical form of rays and on the distribution, density and strength of the microspines along their axis. The relationship between the degree of micraster differentiation and the development of the cortex in the two species is discussed.     

Contribution to the ecology ofMarsilea quadrifolia L.

Data are presented on the aboveground and underground biomass of the speciesMarsilea quadrifolia and on the water regime and soil conditions in a habitat of this species in Central Europe (Czechoslovakia).     

Differential distribution of3H dihydrotestosterone and3H estradiol nuclear binding sites in mouse male accessory sex organs

Summary The distribution of specific nuclear binding sites for androgens and estrogens in the male accessory sex organs of the mouse was assessed by autoradiography with³H dihydrotestosterone (³H DHT) and³H estradiol (³H E₂). With³H DHT nuclear labeling differed among the epithelia of the organs. It was high in seminal vesicle and ampullary gland, moderate in ventral prostate, urethral gland, prostatic excretory ducts and the ampulla ductus deferentis, low in dorsal prostate and low or absent in coagulation gland. With³H E₂, in contrast, epithelial nuclear labeling was high only in coagulation gland, moderate or low in seminal vesicle, low or absent in ventral and dorsal prostate and absent in ampullary gland and ampulla ductus deferentis. In the lamina propria of all organs nuclear labeling with³H DHT was generally moderate and existed only in some cells, with the highest number in the ampulla ductus deferentis. With³H E₂, nuclear labeling in the lamina propria showed a high intensity in all organs, except in ventral and dorsal prostate which remained unlabeled. Many labeled cells were found in the deferent duct and its ampulla, while in the other organs only a few cells showed nuclear labeling with³H E₂. In the smooth muscle sheath of all organs, some muscle cells were moderately labeled with³H DHT, but not with³H E₂. The results indicate the presence of nuclear receptors in male accessory sex organs for both dihydrotestosterone and estradiol. The differential patterns of³H DHT and³H E₂ nuclear uptake suggest differential sensitivities of the individual organs and their tissue compartments for androgens and estrogens. Supported by PHS grant NSO9914 to W.E.S. and Deutsche Forschungsgemeinschaft Dr94/4 to U.D. The work of Dr. Schleicher and his stay in Chapel Hill were additionally sponsored by Studienstiftung des Deutschen Volkes and Boehringer-Ingelheim Fonds     

Autoradiographic studies with 3H dihydrotestosterone in the brain of sex reversed mice,heterozygous for androgen insensitive testicular feminization (Tfm)

Summary Specific binding sites for ³H dihydrotestosterone are demonstrated by autoradiography in brain nuclei of sex reversed mice heterozygous for testicular feminization (Tfm) which are phenotypically intersexes with testes and accessory sex glands that consist of a mosaic of androgen insensitive Tfm cells which lack specific dihydrotestosterone binding and androgen sensitive normal cells. The nuclear group evaluated include: nucleus (n.) septi lateralis, n. interstitialis striae terminalis, n. medialis amygdalae, the hypothalamic n. arcuatus, n. ventromedialis lateralis, n. premammillaris ventrialis, n. preopticus medialis, and nuclei of the cranial nerves VII, X, and XII. In the sex reversed males and the female, used as controls, the frequency of neurons with specific DHT binding show a distinct male-female difference in the caudal part of the arcuate nucleus. In the sex reversed Tfm heterozygotes, in all brain nuclei studied, the frequency of labeled neurons is reduced. The extent of reduction of androgen binding in the different brain nuclei varies among as well as within individual sex reversed Tfm heterozygotes, suggesting variations of the ratio of normal to Tfm neurons in sex reversed Tfm heterozygotes. The differentially reduced androgen binding of different brain systems corresponds to a differentially reduced androgen dependent behaviour reported in the literature.Supported by US PHS grant NSO9914 to W.E.S. and Deutsche Forschungsgemeinschaft Dr94/4 to U.D.. The work of Dr. Schleicher and his stay in Chapel Hill were sponsored by Studienstiftung des Deutschen Volkes and Boehringer-Ingelheim Fonds