Effect of differential gastric evacuation and multispecies prey items on estimates of daily energy intake in juvenile chinook salmon

Synopsis The caloric density of stomach contents in juvenile chinook salmon,Oncorhynchus tshawytscha, was not affected by gastric evacuation, suggesting a constant caloric density of stomach contents during evacuation. Differences in the caloric density of prey consumed did affect caloric density of stomach contents over a 24-h period. Consumption of the amphipodCorophium sp. was associated with reduced caloric densities of stomach contents. During periods whenCorophium contributed more than 4% of the stomach contents, average caloric density declined from 5.56 to 5.33 kcal g^–1. Despite this difference, estimates of daily energy intake of juvenile chinook salmon were only 3%, greater when developed from the mean caloric density of stomach contents excludingCorophium.     

Factors associated with involuntary admission to psychiatric facilities in Newfoundland.

To assess what factors determine the involuntary status of psychiatric patients, we reviewed the case records of 5729 patients consecutively admitted to one of four inpatient psychiatric facilities, including a mental hospital, in St. John''s between October 1975 and October 1978. Of the 5729 patients 5005 (87.4%) were voluntary and 724 (12.6%) involuntary. Involuntary patients were more likely than voluntary patients to be male, single and unemployed and to have been referred by police or transferred from another facility to the mental hospital, where most of the involuntary admissions occurred. They had higher rates of previous admissions to a psychiatric facility and of suicidal and violent behaviour, were more likely to have a diagnosis of schizophrenia or mania and were less likely to be suffering from depression or a neurotic disorder. In correspondence with differences in diagnosis, involuntary patients stayed in hospital more than twice as long as voluntary patients, were less likely to receive electroconvulsive therapy, minor tranquillizers and antidepressants, and were more likely to receive neuroleptics and lithium carbonate. Stepwise logistic regression analysis revealed that only the source of referral and a diagnosis of neurotic disorder had an independent effect on admission status. The findings are discussed in the context of the controversy over the parens patriae approach v. the legal approach to involuntary admission of psychiatric patients.     

Cricket Paralysis Virus, a Potential Control Agent for the Olive Fruit Fly, Dacus oleae Gmel

Representatives of several families of insect viruses were tested for growth and pathogenicity in the olive fruit fly, Dacus oleae Gmel. The viruses included nuclear polyhedrosis viruses, an iridovirus, two picornaviruses, and Trichoplusia ni small RNA virus (a member of the Nudaurelia β family), in addition to two naturally occurring viruses of the olive fruit fly. Two viruses, one of the two picornaviruses (cricket paralysis virus [CrPV] and the iridovirus (type 21 from Heliothis armigera), were found to replicate in adult flies. Flies which were fed on a solution containing CrPV for 1 day demonstrated a high mortality with 50% dying within 5 days and nearly 80% dying within 12 days of being fed. The virus was transmissible from infected to noninfected flies by fecal contamination. The CrPV which replicated in the infected flies was demonstrated to be the same as input virus by infection of Drosophila melanogaster cells and examination of the expressed viral proteins, immunoprecipitation of the virus purified from flies, and electrophoretic analysis of the structural proteins.     

Current utilization and further development of the palmyra palm (Borassus flabellifer L., Arecaceae) in Tamil Nadu state,India

The palmyra palm Borassus flabellifer,), a multipurpose tree of great utility, occurs extensively in Tamil Nadu state, India. Figuring in history, literature, and folklore of the state, it is exploited for food from the fruit and tuberous seedlings; beverage and sugar from the sap; fiber from the leaf and leafbase for brushes, cordage, weaving, and plaiting; trunk wood for construction and fuel; and numerous minor products. Increasing exploitation of the palmyra threatens the future supply of palm raw materials so important to rural populations. Integrated development of palmyra products for local and export markets, as well as management/conservation measures, are needed both to maximize the economic value of the products and to assure sustained yield from native stands.     

Linkage analysis of the myosin heavy chain gene in Dictyostelium discoideum using a mutation generated by homologous recombination

Summary A mutation (mhcA1 in strain HMM) created by insertional gene inactivation was used to map the Dictyostelium discoideum myosin heavy chain gene (mhcA) to linkage group IV. Three phenotypic traits associated with this mutation (slow colony growth, inability of the mutant to develop past aggregation, and the presence of five to ten integrated vector copies) cosegregated as expected for the consequences of a single insertional event. This linkage was confirmed using a restriction fragment length polymorphism. The mhcA1 mutation was recessive to wild type and was nonallelic with mutations at the following loci on linkage group IV: aggJ, aggL, couH, minA, phgB and tsgB. This work demonstrates the ability to apply standard techniques developed for D. discoideum parasexual genetic analyses to mutants generated by transformation, which is of particular relevance to analysis of genes for which no classical mutations or restriction fragment length polymorphisms are available.     

Purification of two glycoproteins expressing beta 1-6 branched Asn-linked oligosaccharides from metastatic tumour cells.

Increased branching at the trimannosyl core of 'complex-type' Asn-linked oligosaccharides has been observed in both human and murine tumour cells, and appears to be associated with enhanced metastatic potential in several murine tumour models [Dennis, Laferte, Waghorne, Breitman & Kerbel (1987), Science 236, 582-585]. The lectin leucoagglutinin (L-PHA) requires the-GlcNAc beta 1-6Man alpha 1-6Man-linked lactosamine antenna in complex-type oligosaccharides for high-affinity binding and can be used to detect these structures in glycoproteins separated on SDS/polyacrylamide-gel electrophoresis. The major L-PHA-binding glycoproteins in the highly metastatic lymphoid tumour cell line called MDAY-D2 were purified and resolved into two major species, termed P2A (110 kDa) and P2B (130 kDa). P2A had L-PHA-reactive Asn-linked oligosaccharides with polylactosamine sequences as well as a large component of sialylated O-linked carbohydrates. The glycoprotein showed structural characteristics similar to those of leukosialin (i.e. CD43), a glycoprotein previously identified on the surface of leukocytes. Based on monosaccharide compositional analysis and glycosidase digestions, P2B was found to be 50-60% Asn-linked oligosaccharide containing polylactosamine sequences and sialic acid. The N-terminal peptide sequence of P2B was determined to be very similar to that of murine lysosomal membrane glycoprotein (LAMP-1), a ubiquitous glycoprotein found largely in the lysosomal membranes but also in the plasma membrane of several murine and human tumour cell lines.     

Structure and evolution of the L11, L1, L10, and L12 equivalent ribosomal proteins in eubacteria, archaebacteria, and eucaryotes

The genes corresponding to the L11, L1, L10, and L12 equivalent ribosomal proteins (L11e, L1e, L10e, and L12e) of Escherichia coli have been cloned and sequenced from two widely divergent species of archaebacteria, Halobacterium cutirubrum and Sulfolobus solfataricus, and the L10 and four different L12 genes have been cloned and sequenced from the eucaryote Saccharomyces cerevisiae. Alignments between the deduced amino acid sequences of these proteins and to other available homologous proteins of eubacteria and eucaryotes have been made. The data suggest that the archaebacteria are a distinct coherent phylogenetic group. Alignment of the proline-rich L11e proteins reveals that the N-terminal region, believed to be responsible for interaction with release factor 1, is the most highly conserved region and that there is specific conservation of most of the proline residues, which may be important in maintaining the highly elongated structure of the molecule. Although L11 is the most highly methylated protein in the E. coli ribosome, the sites of methylation are not conserved in the archaebacterial L11e proteins. The L1e proteins of eubacteria and archaebacteria show two regions of very high similarity near the center and the carboxy termini of the proteins. The L10e proteins of all kingdoms are colinear and contain approximately three fourths of an L12e protein fused to their carboxy terminus, although much of this fusion has been lost in the truncated eubacterial protein. The archaebacterial and eucaryotic L12e proteins are colinear, whereas the eubacterial protein has suffered a rearrangement through what appear to be gene fusion events. Within the L12e derived region of the L10e proteins there exists a repeated module of 26 amino acids, present in two copies in eucaryotes, three in archaebacteria, and one in eubacteria. This modular sequence is apparently also present in the L12e proteins of all kingdoms and may play a role in L12e dimerization, L10e-L12e complex formation, and the function of the L10e-L12e complex in translation.     

Molecular orbital studies of oxygen activation and mechanisms of cytochromes P-450-mediated oxidative metabolism of xenobiotics

Molecular dimensions and molecular orbital calculations of the electronic structures of 56 substrates, inhibitors and inducers of the cytochromes P-448 and other families of the cytochromes P-450 are reported. Substrates of the cytochromes P-448 are shown to be planar molecules with relatively large values of area/depth², and to have electronic structures with relatively low values for ΔE, the difference in energy between the frontier orbitals (E(LEMO) − E(HOMO)). Substrates of other families of the cytochromes P-450 are globular molecules, with relatively low values of area/depth² and relatively high values of ΔE. Molecular orbital calculations of the active oxygen species, singlet oxygen and superoxy anion, have also been made. Singlet oxygen is a poor electron donor (low values of E(HOMO)) but a good electron acceptor (low values of E(LEMO)), whereas superoxy anion is a good electron donor and a poor electron acceptor. Cytochrome P-448 substrates, which are good electron donors, would preferentially accept singlet oxygen, a good electron acceptor; substrates of the other families of cytochrome P-450, which are less effective electron donors, would preferentially accept superoxy anion, a good electron donor, although substrates of both cytochromes P-448 and other P-450s may accept both species of active oxygen. Together with recent published evidence, these data provide a greater understanding of the mode of activation of oxygen by the various families of the cytochromes P-450, and to the insertion of active oxygen into the substrates. Mechanisms are proposed for the oxygenation of substrates, namely, epoxidation involving singlet oxygen and hydroxylation by superoxy anion. Finally, a detailed explanation of the cytochrome P-450 cycle is discussed, and mechanisms of the different types of oxidative metabolism are presented.     

Conformational transitions in cytidine bulge-containing deoxytridecanucleotide duplexes: extra cytidine equilibrates between looped out (low temperature) and stacked (elevated temperature) conformations in solution

High-resolution homonuclear and heteronuclear two-dimensional NMR studies have been carried out on the self-complementary d(C-C-G-C-G-A-A-T-T-C-C-G-G) duplex (designated GCG 13-mer) in aqueous solution. This sequence contains an extra cytidine located between residues G3 and G4 on each strand of the duplex. The exchangeable and nonexchangeable proton resonances have been assigned from an analysis of two-dimensional nuclear Overhauser enhancement (NOESY) and correlated (COSY and relay COSY) spectra for the GCG 13-mer duplex in H2O and D2O solution. The extra cytidine at the bulge site (designated CX) results in more pronounced changes in the NOE distance connectivities for the G3-CX-G4 segment centered about the CX residue compared to the C9-C10 segment on the partner strand opposite the CX residue for the GCG 13-mer duplex at 25 degrees C. The cross-peak intensities in the short mixing time NOESY spectrum also establish that all glycosidic torsion angles including that of CX are anti in the GCG 13-mer duplex at 25 degrees C. The observed chemical shift changes for the CX base protons and the G3pCX phosphorus resonance with temperature between 0 and 40 degrees C demonstrate a temperature-dependent conformational equilibrium in the premelting transition region. The NOE and chemical shift parameters establish that the predominant conformation at low temperature (0 degree C) has the extra cytidine looped out of the helix with the flanking G3.C10 and G4.C9 base pairs stacked on each other. These results support conclusions based on earlier one-dimensional NMR studies of extra cytidine containing complementary duplexes in aqueous solution [Morden, K. M., Chu, Y. G., Martin, F. H., & Tinoco, I., Jr. (1983) Biochemistry 22, 5557-5563. Woodson, S. A., & Crothers, D. M. (1987) Biochemistry 26, 904-912]. By contrast, the chemical shift and NOE parameters demonstrate that the conformational equilibrium shifts toward a structure with a stacked extra cytidine on raising the temperature to 40 degrees C prior to the helix-coil melting transition. The most downfield shifted phosphorus resonance in the GCG 13-mer duplex has been assigned to the phosphate in the C2-G3 step, and this observation demonstrates that the perturbation in the phosphodiester backbone extends to regions removed from the (G3-CX-G4).(C9-C10) bulge site.