Time-budgeting and foraging strategy of the stoplight parrotfish Sparisoma viride Bonnaterre,in Jamaica

Quantitative data on the ways in which the different phases of the stoplight parrotfish (Sparisomaviride Bonnaterre) distribute their time among various activities in different habitats are presented. Individuals spent from 84–97% of their diurnal time swimming, feeding, and hovering. Additionally, large adults spent a significant amount of time sheltering among crevices. Phase-related differences in these activities are statistically significant, as are differences in duration and rates of change of the activities. Large individuals spent more time swimming, while small individuals spent more time hovering. In addition, large individuals performed longer bouts of activity and switched activities less frequently than small individuals. Adult males and females spent approximately equal proportions of time in each of the activity states. Stochastic analyses of behavioural sequences show second order Markov chain dependencies, suggesting that preceding activity states affect subsequent behaviour. Possible relationships between behavioural sequencing and the species foraging strategy are discussed, and it is suggested that the sequence of behavioural activities can provide an estimation of the distribution of food resources in the environment.     

Dolichol and Dolichyl Phosphate Levels in Brain Tissue from English Setters with Ceroid Lipofuscinosis

Human ceroid lipofuscinosis (CL) is an inherited disease marked by cerebromacular degeneration and early death. We have utilized the canine model to investigate the possible role of dolichol and dolichyl phosphate in the developmental pathology of CL. We found that while brain levels of dolichol increase with age in both affected and unaffected dogs, the amount in the diseased animal was similar to that in controls. Brain levels of dolichyl phosphate ranged from 20 to 35 micrograms/g in control dogs at all ages examined, but increased substantially during development in the affected dogs, a value of 113 +/- 24 micrograms/g (mean +/- SD) being obtained in the end-stage animals. In addition to the results obtained in the canine model, dolichyl phosphate levels in human brain tissues from a 5-year-old with late infantile CL and from a 19-year-old with juvenile CL were found to be 153 and 382 micrograms/g, respectively, compared with a control that assayed 26 micrograms/g. The preliminary findings with human tissues provide further evidence for an association of elevated brain dolichyl phosphate levels with CL. Whether the increase is primary or secondary remains to be determined.     

Immune reactivity in cattle with ocular squamous cell carcinoma after intralesional BCG immunotherapy

Summary Lymphocyte stimulation with Con A and specific immune reactivity to BCG (antibody formation to BCG and DTH reaction to PPD) were determined in BCG-treated, surgically treated and untreated cows with ocular squamous cell carcinoma. In tumor-bearing cows the Con A-induced proliferation of lymphocytes was reduced when compared to healthy controls. This suppression consisted of a reduced blastogenic response to Con A of lymphocytes from tumor-bearing cows, and the presence of a factor in the sera of these animals, as these sera suppressed the blastogenic response of lymphocytes from healthy cows. BCG had only a minor influence on the suppressive activity. Antibodies to BCG were demonstrated in 50% of the BCG-treated animals. The formation of antibodies was not influenced by intradermal injection of PPD of Mycobacterium bovis. Absorption of a BCG antibody containing serum with BOSCC tumor extracts did not reveal the existence of cross reacting antigens between BCG and BOSCC. Pretherapeutic and posttherapeutic Con A reactivity could not be correlated with clinical response. Of the 30 BCG treated cows 29 developed a positive DTH reaction to PPD. Correlation between clinical response and immune reactivity was seen only with regard to the DTH reaction to PPD: this reaction remained positive for a longer period after treatment in animals with a favorable clinical outcome than in nonresponding animals.Animals were maintained under the guidelines laid down by the Faculty of Veterinary Medicine, State University, Utrecht, The NetherlandsGrant recipient of the Koningin Wilhelmina Fonds (Netherlands Cancer Foundation) Abbreviations used: BCG, Bacillus Calmette-Guerin; BOSCC, bovine ocular squamous cell carcinoma PBL peripheral blood leukocytes; PPD, purified protein derivative of Mycobacteria; DTH, delayed type hypersensitivity Con A, concanavalin A; PHA, phytohemagglutinin; PWM, pokeweed mitogen     

Modification of susceptibility to Klebsiella pneumoniae during murine cytomegalovirus infection

The effect of murine cytomegalovirus (MCMV) infection on susceptibility to bacterial infection was studied in mice by a combination of intraperitoneal (ip) inoculation of a sublethal dose of MCMV with subsequent ip challenge of 2 X 10(3) cfu of a strain of Klebsiella pneumoniae (KP). When given alone, KP produced a mortality of 30-40%. Mortality was increased when KP was given 1 to 7 days after MCMV injection with the peak increase at the 4th to 5th day when 100% mortality occurred. Virus levels in various organs of mice infected with MCMV alone, or superinfected with KP did not differ. Bacterial counts on the other hand, showed that increased mortality in mixed MCMV and KP infected mice was due to an uncontrolled growth of bacteria at the site of primary lodgment, i.e., the peritoneum, and severe systemic infection. Neutrophil response to growth of KP during the first 3 days of bacterial infection was defective in MCMV infected mice. While the initial clearance of KP from the blood was more efficient in MCMV infected mice, probably due to activated reticuloendothelial function, it did not protect the mice against KP infection. Using the in vivo model, it was shown that poor neutrophil response and possibly other defective neutrophil functions were responsible for increased mortality to KP infection in MCMV infected mice.     

Inhibition of microbial growth by interference with siderophore biosynthesis. Oxidation of primary amino groups in aerobactin synthesis by Escherichia coli

Abstract The first step of aerobactin biosynthesis, oxidation of an aliphatic primary amino group to an N -hydroxy-amino compound seems to be involved in the biosynthesis of most of the hydroxamatetype siderophores which are widely distributed among bacteria and fungi. Therefore, the first step of aerobactin biosynthesis, oxidation of lysine to N ⁶-hydroxylysine was studied as a model reaction using a strain of Escherichia coli that contains the first gene aerA of aerobactin synthesis on a multi-copy plasmid and which is lacking the gene for the subsequent step in the pathway. In addition, culture conditions are described which lead to the secretion of N ⁶-hydroxylysine into the medium in amounts that can easily be quantitatively determined by a simple, reliable chemical assay. This assay can be used for screening inhibitors of the oxidation of α-amino groups, which should interfere with the biosynthesis of siderophore hydroxamates and thus should create bacteriostatic conditions.     

Isolation of virus causing hemorrhagic fever with renal syndrome (HFRS) through a cell culture system

Twenty-three rat lung specimens collected in outbreaks of hemorrhagic fever with renal syndrome (HFRS) in three medical institutions were inoculated onto the VERO-E6 cell monolayers. After several blind passages, an agent growing serially in the cell cultures and reacting specifically with known HFRS-positive sera was isolated from two of these specimens. The two isolates were antigenically identical each other. The agent, named strain SR-11, was identified as the causative virus of HFRS by its antigenic identity with E6 cell-adapted HFRS virus, Hantaan 76-118 strain, and the specific reactions with sera from various HFRS cases.     

Calcium-stimulated, ATP-magnesium-dependent inactivation of pig liver glycogen synthase

Ca2+-stimulated inactivation of liver glycogen synthase was observed when a partially purified liver phosphorylase kinase fraction containing glycogen synthase was incubated with ATP-Mg2+. The Ca2+-stimulated portion of this inactivation was partially counteracted by trifluoperazine and slightly stimulated by exogenously added calmodulin. These results suggest that Ca2+-calmodulin may be involved as one of the factors causing this glycogen synthase inactivation. Although the exact mechanism mediated by Ca2+ has not been clearly determined, the possibility of the participation of some Ca2+-dependent protein kinase is discussed.     

Purification and properties of carnitine octanoyltransferase and carnitine palmitoyltransferase from rat liver

The activities of carnitine octanoyltransferase (COT) and carnitine palmitoyltransferase (CPT) in rat liver were markedly increased by administration of di(2-ethyl-hexyl)phthalate. COT and CPT were purified from the enzyme-induced rat liver. COT was a 66,000-dalton polypeptide. The molecular weight of native CPT was 280,000--320,000 daltons, and the enzyme consisted of 69,200-dalton polypeptides. CAT, COT, and CPT were immunologically different. COT exhibited activity with all of the substrates tested (acyl-CoA's and acylcarnitines of saturated fatty acids having carbon chain lengths of C2--C20), though maximum activity was observed with hexanoyl derivatives. CPT exhibited catalytic activity with medium- and long-chain acyl derivatives. 2-Bromo-palmitoyl-CoA inactivated COT but not CPT. Malonyl-CoA inhibited CPT but not COT. CPT was confined to mitochondria, whereas COT was found in peroxisomes and the soluble compartment but not in mitochondria.