Pars intercerebralis promotes oviposition in the bean bug,Riptortus pedestris (Heteroptera: Alydidae)

Effects of the pars intercerebralis (PI) on the rate of oviposition were examined in adult females of Riptortus pedestris (F.) under long-day conditions that promote reproduction. When the neurosecretory cells in the PI were surgically removed from the females, they laid significantly fewer eggs than control females. When the PI from reproductive females was transplanted to PI-removed females, the number of eggs was significantly greater than that in PI-removed females without transplantation. Therefore, we suggest that the PI neurons promote fecundity or oviposition in R. pedestris.     

Plasma heat shock protein 72 as a biomarker of sarcopenia in elderly people

Sarcopenia is a geriatric syndrome in which there is a decrease of muscle mass and strength with aging. In age-related loss of muscle strength, there are numerous observations supporting the assertion that neural factors mediate muscle strength. A possible contributing cause may be that aging changes systemic extracellular heat shock protein (eHsp)72 activity. The present study was designed to assess the plasma levels of eHsp72 in elderly people and to investigate its potential interaction with components of sarcopenia. A total of 665 men and women participated in an official medical health examination and an integrated health examination, including psychological and physical fitness tests. Blood samples were assayed for levels of plasma Hsp72, serum C-reactive protein, interleukin 6, tumor necrosis factor α, and regular biomedical parameters. We found that higher Hsp72 in plasma is associated with lower muscle mass, weaker grip strength, and slower walking speed, and may be a potential biomarker of sarcopenia in elderly people. This finding was supported by other results in the present study: (1) older age and shrinking body and lower hemoglobin levels, all of which characterize sarcopenia, were related to higher eHsp72 tertiles and (2) the ORs of the highest tertile of eHsp72 for the lowest tertiles of muscle mass, grip strength, and walking speed were 2.7, 2.6, and 1.8, respectively. These ORs were independent of age, sex, and the incidence of related diseases. Our results would reveal that eHsp72 in plasma is linked to sarcopenia factors and is a potential biomarker or predictor of sarcopenia.     

Genetic relationships of Nuphar in central to western Japan as revealed by allozyme analysis

The genetic relationships of Nuphar japonica, N. oguraensis, N. subintegerrima and two morphologically intermediate plant groups (J-O and J-S) found in central to western Japan were investigated. Allozyme analyses (analysis of allele frequencies and principal coordinate analysis, based on shared allele distance among the 162 multi-locus genotypes) showed the three Nuphar species to be distinguished, and indicated that the intermediate plant groups were genetically intermediate either between two or among three of these species. Natural hybridization and introgression were found to have occurred among these three species in central to western Japan, producing genetically varied intermediate plant groups. Many of the intermediate plants (74.4% of the total numbers of genotypes of the intermediate plants) did not show additive combinations of parental allozymes, which were expected in F₁ hybrids. The absence of characteristic parental bands suggested that sexual reproduction had continued among the hybrids beyond the F₁.     

Effect of different dextrose equivalents of maltodextrin on oxidation stability in encapsulated fish oil by spray drying

Encapsulating fish oil by spray drying with an adequate wall material was investigated to determine if stable powders containing emulsified fish-oil-droplets can be formed. In particular, the dextrose equivalent (DE) of maltodextrin (MD) affects the powder structure, surface-oil ratio, and oxidative stability of fish oil. The carrier solution was prepared using MD with different DEs (DE = 11, 19, and 25) and sodium caseinate as the wall material and the emulsifier, respectively. The percentage of microcapsules having a vacuole was 73, 39, and 38% for MD with DE = 11, 19, and 25, respectively. Peroxide values (PVs) were measured for the microcapsules incubated at 60 °C. The microcapsules prepared with MD of DE = 25 and 19 had lower PVs than those prepared with MD of DE = 11. The difference in PV can be ascribed to the difference in the surface-oil ratio of the spray-dried microcapsules.     

Immunohistochemistry of Atrial Natriuretic Peptide in Brain Infarction

Atrial natriuretic peptide (ANP) was originally isolated from cardiac atria, and has potent natriuretic, diuretic, and vasorelaxant properties. It has been localized in neurons and astrocytes in the cerebral cortex and the white matter. We hypothesize that glial ANP may contribute to the regulation of cerebral blood flow in brain infarction. In order to elucidate this possible role, the immunohistochemistry of ANP was studied in cases of brain infarction and in other cases of brain trauma for comparison. A statistically significant increase in the number of ANP-immunoreactive glial cells (mainly astrocytes) was observed in the white matter surrounding the brain infarction compared with the intact area. No statistically significant increase in ANP-immunoreactive glial cell number was observed in the cerebral white matter from brain haemorrhage, contusion and control cases. Our results indicate that glial ANP may increase in number in brain infarction, and that it may be involved in the regulation of the cerebral blood flow in the infarcted area.     

Prostaglandin production in cultured gastric mucosal cells: Role of cAMP on its modulation

The effect of cAMP on prostaglandin production may depend on cell types. To clarify the relationship between PG and cAMP, we examined arachidonate's effects on PG synthesis and intracellular cAMP accumulation in monolayers of rat gastric mucosal cells. These cells produced PGE₂, PGI₂ and thromboxaneA₂ (TXA₂) in amounts of 316±18, 100±7 and 30±5 pg per 10⁵ cells in 10 min, respectively, in response to 10μM arachidonic acid (AA). The production of these PG, however, leveled off subsequently. Cells initially exposed to AA responded poorly to a subsequent stimulation by AA. AA simultaneously stimulated intracellular cAMP accumulation; this stimulatory effect on cAMP production was abolished by the pretreatment with indomethacin. Nevertheless, the pretreatments with dibutyryl cAMP (0.1–5mM) did not alter the amount of subsequent AA-induced PGE₂ production. Furthermore, the preincubation with 1mM isobutyl methyl xanthine also failed to affect PGE₂ synthesis, while it increased intracellular cAMP accumulation. Our studies suggest (1) AA stimulates intracellular cAMP formation in cultured gastric mucosal cells, linked with conversion of AA to cyclooxygenase metabolites, (2) AA-induced PG production is limited in these cells, and (3) it seems, however, unlikely that intracellular cAMP modulates AA metabolism to PG.     

Alteration of rheological properties of human erythrocytes by crosslinking of membrane proteins

The crosslinking of membrane proteins of human erythrocytes by diamide (diazene dicarboxylic acid bis(N,N-dimethylamide) ) was quantified by 4% polyacrylamide gel electrophoresis in 1% sodium dodecyl sulfate. The relation between the crosslinking of membrane proteins and erythrocyte functions (rheological and oxygen transporting) was quantitatively examined. (i) The crosslinking of membrane protein was induced by diamide, without changing the shape and the contents of intracellular organic phosphates (adenylates and 2,3-diphosphoglycerate). The intensity of spectrin 2 in SDS-polyacrylamide gel electrophoresis decreased proportionally to diamide concentration. The percentage decrease in spectrin 2 (using band 3 as an internal standard) was the most appropriate indicator for crosslinking ("% crosslinking'). (ii) The suspension viscosity of erythrocytes increased in proportion to the percentage of crosslinking, in the range of applied shear rates of 3.76-752 s-1. (iii) Erythrocyte deformability (measured by a high-shear rheoscope) was reduced by the crosslinking. The change was detectable even at 5% crosslinking. (iv) Rouleaux formation (measured by a television image analyzer combined with a low-shear rheoscope) was inhibited by the crosslinking. The inhibition was also sensitively detected at more than 5% crosslinking. (v) Hemoglobin in erythrocytes was chemically modified by higher dose of diamide (probably by the binding of diamide with sulfhydryl groups). Also the oxygen affinity of hemoglobin increased and the heme-heme interaction decreased. (vi) The reduction of the crosslinking of membrane proteins by dithiothreitol apparently reversed the intensity of spectrin bands in SDS-polyacrylamide gel electrophoresis and the erythrocyte functions (the suspension viscosity and the deformability), though not completely.     

Resonance Raman on the purple intermediates of the flavoenzyme D-amino acid oxidase

Resonance Raman (RR) spectra excited at 632.8 nm within a charge transfer absorption band were obtained for a catalytic intermediate, the purple complex of D-amino acid oxidase with D-proline or D-alanine as a substrate. The resonance enhanced Raman lines around 1605 and 1360 cm^?1 in either of the complexes were suggested to be derived from vibrational modes of reduced flavin molecule. Since the highest energy band at 1692 cm^?1 in the RR spectrum with D-alanine was shifted to 1675 cm^?1 upon [¹⁵N] substitution of alanine and ammonium, this Raman line in the spectrum with D-alanine or the line at 1658 cm^?1 with D-proline is assigned to the CN stretching mode of an imino acid corresponding to each amino acid. These results confirm the concept that the purple intermediate of D-amino acid oxidase consists of reduced flavin and an imino acid.