The effects of a settled industrial–domestic sewage works effluent from percolating filters on the survival and growth of various stages of rainbow trout, Salmo gairdneri (Richardson)

Comparisons were made of the mortality, growth and condition factor over a 50-day period of eleutheroembryos, alevins, 2-month fry, 4-month fry and 1 + rainbow trout, Salmo gairdneri , in water of three qualities–Birmingham tap-water, 50% and 100% settled effluent from percolating filters (Minworth Effluent Treatment Works) when dissolved oxygen levels were maintained near 100% ASV.
There was no significant mortality among life stages in control tap-water but the LT50 values of life stages in both 50% effluent and 100% effluent revealed significant differences. Inter-treatment comparisons showed similar mortalities of eleutheroembryos, of 2-month fry and of 1 + fish in the three treatments but LT50 values of 4-month fry showed significant differences. Growth rates of 2-month and 4-month fry were suppressed in both effluents after 7 days and there was a significant deterioration in the K factor of these life stages after 14 days. Predicted toxicities (the sum of the proportions of the 48-h LC50 of the individual poisons to rainbow trout) were compared with the observed toxicity in 50% and 100% effluent. The relevance of in vivo testing in comparison to predictive techniques is compared.     

Epitope mapping of the human surface suppressor/cytotoxic T cell molecule Tp32

The complexity of the suppressor/cytotoxic subset marker of human T lymphocytes was demonstrated by biochemical analysis, cross-blocking experiments, phylogenetic comparisons, and functional studies. At the biochemical level, the antigen was shown to be a heteromultimer of at least three polypeptide chains covalently associated into four different higher m.w. species. Sixteen different murine monoclonal antibodies were used to map epitopes of this heteromultimeric complex. Cross-blocking experiments undertaken with six directly labeled reference antibodies identified at least seven spacially distinct epitopes. Flow microfluorometric analysis of peripheral blood lymphocytes showed two distinct subpopulations of bright and dull-stained cells that differed approximately 10-fold in antigen density. The distribution of epitopes on bright and dull cells was not uniform because in several combinations, blocking was observed on bright cells only. Studies with nonhuman primate T cells demonstrated a high degree of phylogenetic heterogeneity in the antigen. The combined cross-blocking and primate data divided the 17 antibodies into 15 groups. Each of the antibodies was capable of blocking lysis by alloreactive cytotoxic T lymphocytes, indicating that the mechanism of inhibition may not necessarily involve hindrance of an active site.     

Hyperbaric hyperoxia reversibly inhibits erythrocyte phospholipid fatty acid turnover

The present study is one component of a comprehensive investigation of oxygen tolerance of tissues and organs in normal human subjects. The focus of this study was the acylation of membrane phospholipid in situ by erythrocytes. Activation of exogenous [9,10-3H]oleic acid to acyl thioester and transesterification of the acyl thioester into phospholipid by intact human erythrocytes incubated in vitro decreased 30% after exposure of 10 human subjects to hyperbaric hyperoxia (100% O2, 3 ATA, 3.5 h). Partial recovery of activity could be detected when additional cells were obtained from these subjects and assayed in vitro 24 h after cessation of exposure. No significant change in membrane phospholipid fatty acid composition was detected under these conditions. The reduced glutathione content of intact erythrocytes increased by 15% after hyperbaric hyperoxia and remained elevated 24 h after exposure. In isolated membranes prepared from the same cells activation of [9,10-3H]oleic acid to acyl thioester and its transesterification into phospholipid did not change after hyperoxia. Since the ability of intact cells to replace oxidized fatty acids in membrane phospholipids via deacylation and reacylation in situ may be necessary for the maintenance of membrane integrity during exposure to oxidative stress, the decrease in [9,10-3H]oleic acid incorporation by human erythrocytes detected in vitro after hyperbaric hyperoxia in vivo may reflect an early event in the pathogenesis of oxygen-induced cellular injury and may be a useful index for assessment of the tolerance of tissues to hyperoxia.     

Age-related augmentation of phosphorylase b kinase in hepatic tissue from the glycogen-storage-disease (gsd/gsd) rat.

The effects of food deprivation on body weight, liver weight, hepatic glycogen content, glycogenolytic enzymes and blood metabolites were compared in young and old phosphorylase b kinase-deficient (gsd/gsd) rats. Although the concentration of glycogen in liver from 9-week-old female gsd/gsd rats (730 mumol of glucose equivalents/g wet wt.) was increased by 7-8% during starvation, total hepatic glycogen was decreased by 12% after 24 h without food. In 12-month-old male gsd/gsd rats the concentration of liver glycogen (585 mumol of glucose equiv./g wet wt.) was decreased by 16% and total hepatic glycogen by nearly 40% after food deprivation for 24 h. Phosphorylase b kinase and phosphorylase a were present at approx. 10% of the control activities in 9-week-old gsd/gsd rats, but both enzyme activities were increased more than 3-fold in 12-month-old affected rodents. It is concluded that the age-related ability to mobilize hepatic glycogen appears to result from the augmentation of phosphorylase b kinase during maturation of the gsd/gsd rat.     

Construction of fifteen human chromosome-specific DNA libraries from flow-purified chromosomes

We report the construction of 15 human chromosome-specific DNA libraries. Metaphase chromosomes were purified by flow sorting and the DNA was extracted and cleaved with HindIII before cloning into the lambda vector Charon 21A. A sensitive miniblot hybridization method was used to monitor the physical and biochemical steps in the cloning procedure. Using this method, we have developed a highly efficient protocol for producing large numbers of recombinant phage from 0.2-1.0 X 10(6) sorted chromosomes. DNA from the following chromosomes was cloned: #4, 6, 8, 9, 11, 13, 14 + 15, 16, 17, 18, 19, 20, 21, 22 and Y. These libraries are available to the scientific research community and will be valuable in the genetic analysis of the human genome.     

Olfactory responses of aquatic and terrestrial tiger salamanders to airborne and waterborne stimuli

Summary Electro-olfactograms (EOGs) were used to assess olfactory responding by aquatic larval and terrestrial adult tiger salamanders (Ambystoma tigrinum) to airborne volatile compounds, and volatile and non-volatile compounds in aqueous solution. Both forms of salamander showed saturation effects to presentations of airborne stimuli (Fig. 2). Saturation was not observed, however, to stimulus presentations in aqueous solution (Figs. 2, 3). When threshold values and concentration-response curve parameters were compared, non-volatile amino acids in solution were more potent stimuli for larvae while airborne volatiles were more potent stimuli for adults (Tables 1, 2). We infer that metamorphosis in the tiger salamander is accompanied by changes in olfactory response characteristics, due possibly to changes in receptor population, changes in perireceptor properties (e.g. mucus) or to changes in stimulus access.Abbreviations EOG electro-olfactogram - PPM (ppm) parts per million     

Androgen metabolism and actions in rat ventral prostate epithelial and stromal cell cultures

The rat ventral prostate requires androgens for normal development, growth, and function. To investigate the relationship between androgen metabolism and its effects in the prostate and to examine differences between the epithelial and stromal cells, we have established a system of primary cell cultures of immature rat ventral prostate cells. Cultures of both cell types after reaching confluency (6-7 days) actively metabolized 3H-labelled testosterone (T), 5 alpha-dihydrotestosterone (5 alpha-DHT), 5 alpha-androstane-3 alpha,17 beta-diol, and 5 alpha-androstane-3 beta,17 beta-diol. The epithelial cells actively reduced T to 5 alpha-DHT and formed significant amounts of 5 alpha-androstane-3,17-dione from T, 5 alpha-DHT, and 5 alpha-androstane-3 alpha,17 beta-diol. All substrates were converted to significant amounts of C19O3 metabolites. The stromal cells also metabolized all substrates, but very little 5 alpha-androstane-3,17-dione was formed. The metabolism studies indicate that both cell types have delta 4-5 alpha-reductase, 3 alpha- and 3 beta-hydroxysteroid oxidoreductase and hydroxylase activities. The epithelial cells have significant 17 beta-hydroxysteroid oxidoreductase activity. The epithelial cells cultures grown in the presence of T have higher acid phosphatase (AP) contents (demonstrated histochemically and by biochemical assay). Tartrate inhibition studies indicate that the epithelial cells grown in the presence of T are making secretory AP. Stromal cell AP is not influenced by T. The results indicate that the cultured cells maintain differentiated prostatic functions: ability to metabolize androgens and, in the case of the epithelial cells, synthesize secretory AP.     

Development of the cytosolic defence system against microsomal lipid peroxidation in rat liver

Ascorbate-induced lipid peroxidation in rat liver microsomes reaches the adult level in 2-3 days. NADPH-induced peroxidation develops more gradually, in parallel with the activity of NADPH-cytochrome P-450 reductase, attaining adult levels by 10-12 days. The glutathione-dependent cytosolic enzyme activity which inhibits peroxidation is inhibited by bromosulphophthalein. The development of this system lags behind the development of microsomal lipid peroxidation between the ages of 2 and 20 days, allowing peroxidation to proceed.     

The diabetic Zucker fatty rat

A noninsulin-dependent diabetes appeared in fatty rats in our Zucker rat colony. A breeding program yielded a genetic pattern of diabetes consistent with a dominant gene not closely linked to the fatty gene. Fatty males were more frequently affected than fatty females. Since no markers could be identified for heterozygous carriers and since affected fatty rats were 6 months old when diabetes appeared, the diabetic trait could not be sustained in our small colony. Glucose tolerance tests showed that the diabetic fatty rats had little increase in plasma insulin concentration after a glucose load was administered. Plasma insulin concentrations were unchanged relative to control fatty rats. Percentage body fat and plasma triglyceride values were decreased in fatty diabetic rats relative to control fatty rats, however, consistent with insulin resistance in fat and liver. The content of pancreatic insulin was markedly decreased in the diabetic fatty rat relative to either the ad libitum or diet-restricted fatty rats. The occurrence of a genetically based diabetes in a normally outbred colony underscores the importance of genetic traits that interact with obesity in determining diabetes in rodent models.