Relative growth of organs and parts of a marine teleost,the porgy,Pagrus major,with special reference to metabolism-size relationships

Organ-body mass relationships were examined for 36 different organs and parts in porgies,Pagrus major, ranging in body mass from 0.0033 to 1200 g. Organs with high metabolic activity, e.g. brain, intestine, pyloric caeca and heart showed negative allometry except during very early stages in the life history. On the other hand, the trunk, which comprised mainly musculature with low metabolic activity, showed positive allometry. These results support our idea that the decline in mass-specific metabolic rate in animals with increasing body mass can be explained, partly at least, by tissues with low metabolic rates becoming heavier in proportion to the whole body with growth.     

Heme peptide as a model substance for halogenomethane activation and heme modification.

Octa-heme peptide (CHP) obtained from Candida krusei cytochrome c was tested for suicidal activation of halogenomethanes. Under anaerobic conditions, CHP was kept in the reduced state in the presence of NADPH and NADPH-cytochrome P-450 reductase. Addition of CBrCl3 to the reduced CHP caused spectral changes such as rapid disappearance of alpha and beta bands and gradual decrease in the gamma-peak height, accompanied by oxidation of NADPH. Heme content of the reaction mixture, determined as pyridine hemochrome, also decreased NADPH dependently. CCl4 was less effective than CBrCl3, while CHCl3 had almost no effect. N-tert-butyl-alpha-phenylnitrone (PBN) suppressed the CBrCl3-induced heme damage, and resulted in the formation of radical adduct .PBN-CCl3 as evidenced by ESR spectroscopy. Radical formation was also observed with CCl4. The CHP damage induced by CBrCl3 was also accompanied by the release of Br- about 11-12-times molar excess of CHP, whereas the release of CHCl3 was about 20% that of Br-.FD-MS assay of the product of CHP reaction suggested that 10 trichloromethyl radicals bonded with CHP. Thus, CBrCl3 undergoes single-electron reduction in the presence of reduced CHP to trichloromethyl radicals, which covalently bind to CHP molecules. Heme peptide may be a useful tool in the study of mechanisms involved in the destruction of cytochrome P-450 by halogenomethanes.     

Simulation of forest carbon dynamics based on a dry-matter production model

A microcomputer model for forest carbon dynamics with five functional comparments (atmosphere, foliage, woody-parts, roots and dead biomass in the soil) is constructed which incorporates dry-matter production processes of trees such as photosynthesis, respiration and allocation of photosynthate. The effect of photosynthesis rate at saturated light and dark respiration rate of a single leaf upon surplus production (P _s) is three-dimensionally illustrated as a function of cumulative leaf area index (LAI) and extinction coefficient of light. Probable values of the physiological parameters in this model are determined by repeated simulation experiments. The successional pattern during a period of 100 years is simulated, demonstrating stable and perpetual occurrence of a tropical rainforest ecosystem composed of three strata. The model is also analyzed in terms of response of relative initial density of trees, thereby displaying the law of constant final yield in a forest ecosystem. The model outputs of carbon fluxes and phytomasses at the steady state agree quite well with field data already obtained from a tropical rainforest at Pasoh.     

Soil properties and sediment accretion modulate methane fluxes from restored wetlands

Wetlands are the largest source of methane (CH₄) globally, yet our understanding of how process‐level controls scale to ecosystem fluxes remains limited. It is particularly uncertain how variable soil properties influence ecosystem CH₄ emissions on annual time scales. We measured ecosystem carbon dioxide (CO₂) and CH₄ fluxes by eddy covariance from two wetlands recently restored on peat and alluvium soils within the Sacramento–San Joaquin Delta of California. Annual CH₄ fluxes from the alluvium wetland were significantly lower than the peat site for multiple years following restoration, but these differences were not explained by variation in dominant climate drivers or productivity across wetlands. Soil iron (Fe) concentrations were significantly higher in alluvium soils, and alluvium CH₄ fluxes were decoupled from plant processes compared with the peat site, as expected when Fe reduction inhibits CH₄ production in the rhizosphere. Soil carbon content and CO₂ uptake rates did not vary across wetlands and, thus, could also be ruled out as drivers of initial CH₄ flux differences. Differences in wetland CH₄ fluxes across soil types were transient; alluvium wetland fluxes were similar to peat wetland fluxes 3 years after restoration. Changing alluvium CH₄ emissions with time could not be explained by an empirical model based on dominant CH₄ flux biophysical drivers, suggesting that other factors, not measured by our eddy covariance towers, were responsible for these changes. Recently accreted alluvium soils were less acidic and contained more reduced Fe compared with the pre‐restoration parent soils, suggesting that CH₄ emissions increased as conditions became more favorable to methanogenesis within wetland sediments. This study suggests that alluvium soil properties, likely Fe content, are capable of inhibiting ecosystem‐scale wetland CH₄ flux, but these effects appear to be transient without continued input of alluvium to wetland sediments.     

Adventitious shoot regeneration from leaf, stem and root explants of commercial cultivars of Gentiana

Several culture conditions were examined for promoting efficient plant regeneration from explants of Gentiana. Adventitious shoot regeneration from leaf explants of cv. WSP-3 was very superior on MS medium, compared to B5 medium, supplemented with four cytokinins (TDZ, 4PU-30, BA and zeatin). An auxin / cytokinin combination was required for regeneration. TDZ was the most effective cytokinin, while NAA was more effective than IAA or 2,4-D. Optimum conditions for regeneration from explants (leaf, stem and root) of cv. WSP-3, evaluated in terms of regeneration frequency and number of regenerated shoots per explant, were TDZ and NAA in combination, 5–10 mg/l and 0.1 mg/l for leaf and stem explants, and 10 mg/l and 1 mg/l for root explants, respectively. Application of these conditions to eight other commercial cultivars resulted in 30–100% regeneration from leaf explants. The number of chromosomes in each of ten regenerated plants of each cultivar was diploid, 2n=26. Shoots regenerated in vitro were rooted in phytohormone-free medium and transferred to soil.Abbreviations MS medium Murashige and Skoog's medium (Murashige and Skoog 1962) - B5 medium Gamborg B5 medium (Gamborg et al. 1968) - BA 6-benzylaminopurine - TDZ N-phenyl-N'-1,2,3-thiadiazol-5-yl urea - 4PU-30 N-(2-chloro-4-pyridyl)-N'-phenylurea - 2,4-D 2,4-dichlorophenoxyacetic acid - IAA indole-3-acetic acid - NAA 1-naphthaleneacetic acid     

Molecular cloning and enzymological characterization of pyridoxal 5′-phosphate independent aspartate racemase from hyperthermophilic archaeon <Emphasis Type="Italic">Thermococcus</Emphasis><Emphasis Type="Italic">litoralis</Emphasis> DSM 5473

We succeeded in expressing the aspartate racemase homolog gene from Thermococcus litoralis DSM 5473 in Escherichia coli Rosetta (DE3) and found that the gene encodes aspartate racemase. The aspartate racemase gene consisted of 687 bp and encoded 228 amino acid residues. The purified enzyme showed aspartate racemase activity with a specific activity of 1590 U/mg. The enzyme was a homodimer with a molecular mass of 56 kDa and did not require pyridoxal 5′-phosphate as a coenzyme. The enzyme showed aspartate racemase activity even at 95 °C, and the activation energy of the enzyme was calculated to be 51.8 kJ/mol. The enzyme was highly thermostable, and approximately 50 % of its initial activity remained even after incubation at 90 °C for 11 h. The enzyme showed a maximum activity at a pH of 7.5 and was stable between pH 6.0 and 7.0. The enzyme acted on l-cysteic acid and l-cysteine sulfinic acid in addition to d- and l-aspartic acids, and was strongly inhibited by iodoacetic acid. The site-directed mutagenesis of the enzyme showed that the essential cysteine residues were conserved as Cys83 and Cys194. d-Forms of aspartic acid, serine, alanine, and valine were contained in T. litoralis DSM 5473 cells.     

Factors relating to the mental health of women who were pregnant at the time of the Great East Japan earthquake: analysis from month 10 to month 48 after the earthquake

Background

The Great East Japan Earthquake occurred at 2:46 p.m. on March 11, 2011. The epicenter was off the coast of Miyagi prefecture, and the magnitude of the earthquake was 9.0 with a maximum seismic intensity of 7.0. Although it has already been four years, victims continue to have complex problems. In the stricken areas of Miyagi prefecture, almost ten percent of the residents continue to live in temporary housing. Life altering events that force relocation and a change of living environment are known to adversely affect mental health. The purpose of this study was to examine the mental health of mothers of infants who experienced this disaster in Miyagi prefecture.

Methods

We conducted a survey using The Edinburgh Postnatal Depression Scale (10 months) and The General Health Questionnaire-28, an efficient screening tool for psychiatric distress. Eight hundred eighty-six mothers of children born from February to October, 2011 in Miyagi prefecture were surveyed 10, 16, 24, 36 and 48 months after the disaster. Data were analyzed with the use of SPSS 21.0 J for Windows. The study was approval by the review board of ethics at Tohoku University.

Results

The questionnaire was answered by the following number of mothers at the specified months after the disaster: 677 at 10 months, 384 at 16 months, 351 at 24 months, 250 at 36 months and 193 at 48 months. Results at all time periods indicated a high prevalence of psychiatric distress among the mothers surveyed. The percentage of Japanese adults with high-risk GHQ-28 scores is 14 %, thus psychological distress among the subjects in the present study is considerably more widespread. General Health Questionnaire-28 scores were significantly higher for those mothers experiencing dissatisfaction in their marital relationships. We found that mothers have experienced severe mental distress since the disaster, which we think is a possible cause of depression that is leading to poor mental health.

Conclusion

The results indicate that the upheaval caused by the tsunami affected the mental health of the mothers. Psychological distress continued to be prevalent up to four years after the disaster. Different factors were found to be associated with their distress. The most common issues were economic problems, dissatisfaction in the marital relationship, and no support with childcare.

     

Molecular characterization of a gene encoding a photolyase from Streptomyces griseus.

By using a synthetic DNA probe derived from an amino acid sequence in the most conserved region of three known photolyases (Escherichia coli, Anacystis nidulans and Saccharomyces cerevisiae), we isolated a DNA fragment containing two long open reading frames (ORFs) from a genomic DNA library of Streptomyces griseus. One ORF encodes a polypeptide of 455 amino acids (Mr 50594), which exhibits substantial similarities with the other three photolyases. Photoreactivation-repair deficient E. coli cells could be converted into photoreactivatable ones by introduction of plasmids harboring this ORF, indicating that this is the photolyase gene of S. griseus. The deduced aa sequence of Streptomyces photolyase was most similar to that of E. coli. The putative DNA binding site as well as cofactor binding regions were proposed.     

Glycation and inactivation of human Cu-Zn-superoxide dismutase. Identification of the in vitro glycated sites

The nonenzymatic glycosylation (glycation) of Cu-Zn-superoxide dismutase led to gradual inactivation of the enzyme (Arai, K. Iizuka, S., Tada, Y., Oikawa, K., and Taniguchi, N. (1987) Biochim. Biophys. Acta 924, 292-296). The purified superoxide dismutase from human erythrocytes comprises both glycated and nonglycated forms. The nonglycated Cu-Zn-superoxide dismutase was isolated by boronate affinity chromatography. Incubation of the nonglycated superoxide dismutase with D-[6-3H]glucose in vitro resulted in the gradual accumulation of radioactivity in the enzyme protein, and Schiff base adducts were trapped by NaBH4. The sites of glycation of the superoxide dismutase were identified by amino acid analysis after reverse-phase high performance liquid chromatography of the trypsin-treated peptides. Lysine residues, i.e. Lys3, Lys9, Lys30, Lys36, Lys122, and Lys128, were found to be glycated. Three of the glycated sites lie in Lys-Gly, two in Lys-Ala, and one in Lys-Val. The inactivation of the superoxide dismutase on the glycation is due mainly to the glycation of Lys122 and Lys128, which are supposed to be located in an active site liganding loop. The remaining five sites, such as Lys-Glu, Lys-Asp, Lys-His, and Lys-Thr are relatively inactive as to the formation of either a Schiff base or an Amadori adduct.     

Comparative calcium binding and conformational studies of turkey and rabbit skeletal troponin C

Troponin C from turkey skeletal muscle has been compared with its chicken counterpart in terms of amino acid composition and fragmentation patterns and with rabbit TN-C by Ca2+ binding and conformational response to Ca2+ as monitored by CD and fluorescence. Cyanogen bromide and tryptic digestion mixtures of chicken and turkey TN-C have been separated by reversed-phase HPLC. The similarity of the elution profiles, along with the almost identical amino acid compositional data, suggest that the sequences are essentially equivalent. Both turkey and rabbit TN-C bound 2 mol Ca2+/mol protein at pH 5.3, while at pH 6.8, this figure was raised to 4 mol/mol protein. Circular dichroism and fluorescence measurements indicated that the conformations of the two proteins responded in a very similar manner to the presence of Ca2+.