Effect of pituitary adenylate cyclase-activating polypeptide 38 (PACAP38) on tissue oxygen content--treatment in central nervous system of mice

It has been reported that pituitary adenylate cyclase-activating polypeptide (PACAP) plays an important role in preventing neuronal cell death and is also a potent vasodilator. Cerebral hypotension and hypoperfusion during cerebral ischemia and neurodegenerative diseases are well known as some of the negative factors which aggravate neuronal cell death. Nevertheless, the effect of PACAP on the cerebral circulation was not understood well. Therefore, in the present study, we determined the mean arterial blood pressure (MBP), regional cerebral blood flow (rCBF) and cerebral oxygen content (pO2) in mice, and estimated the therapeutically useful doses of PACAP. Under barbiturate anesthesia, polyethylene tubes were inserted into mice to monitor MBP and to administer PACAP (5 x 10(-13)-5 x 10(-8) mol/kg) or vasoactive intestinal peptide (VIP; 5 x 10(-12) and 5 x 10(-9) mol/kg). Then, MBP, rCBF and cerebral pO2 were simultaneously measured in the mice. PACAP (5 x 10(-10)-5 x 10(-9) mol/kg) injections transiently decreased MBP, and cerebral pO2. PACAP (5 x 10(-8) mol/kg) injections produced a long-lasting potent decline of MBP, rCBF and cerebral pO2. Therefore, PACAP should be applied at low doses which do not influence the MBP and cerebral circulation to determine the therapeutically useful doses of PACAP for neuroprotection.     

Carbohydrate carriers affect adhesion of H. pylori to immobilized Leb-oligosaccharide

The present study involved comparison of adhesion of Helicobacter pylori KH202 to immobilized Le(b)-oligosaccharide carried on different carriers, i.e. Leb-oligosaccharide conjugated with polyacrylamide, bovine serum albumin, and dipalmitoylphosphatidylethanolamine (Le(b)-PAA, Le(b)-BSA, and Le(b)-DPPE). All of the Le(b)-oligosaccharide-carrying neoglycoconjugates served as ligands for H. pylori. However, H. pylori required 10-fold and 100-fold quantities of Le(b)-antigen to adhere to Le(b)-PAA and to Le(b)-DPPE in comparison to the quantity of Le(b)-antigen needed to adhere to Le(b)-BSA, respectively. H. pylori adhesion to Le(b)-PAA and Le(b)-DPPE was clearly inhibited by Le(b)-oligosaccharide, but adhesion to Le(b)-BSA was hardly inhibited by the oligosaccharide. Therefore, the carbohydrate carrier affects the affinity of H. pylori KH202 toward Le(b)-antigen, although the bacteria recognize Le(b)-antigen regardless of the carbohydrate carrier.     

Embryonic Development and Postnatal Changes in Free d-Aspartate and d-Serine in the Human Prefrontal Cortex

Abstract: We have analyzed free chiral amino acids (aspartate and serine) in the human frontal cortex at different ontogenic stages (from 14 weeks of gestation to 101 years of age) by HPLC with fluorometric detection after derivatization with N-tert -butyl-oxycarbonyl- l -cysteine and o -phthaldialdehyde. Exceptionally high levels of free d -aspartate and d -serine were demonstrated in the fetal cortex at gestational week 14. The ratios of d -aspartate and of d -serine to the total corresponding amino acids were also high, at 0.63 and 0.27, respectively. The concentration of d -aspartate dramatically decreased to a trace level by gestational week 41 and then remained very low during all postnatal stages. In contrast, the frontal tip contained persistently high levels of d -serine throughout embryonic and postnatal life, whereas the d -amino acid content in adolescents and aged individuals was about half of that in the fetuses. Because d -aspartate and d -serine are known to have selective actions at the NMDA-type excitatory amino acid receptor, the present data suggest that these d -amino acids might play a pivotal role in cerebral development and functions that are related to the NMDA receptor.     

Suppressing effect of gamma-irradiated weevils on progeny production in the West Indian sweetpotato weevil Euscepes postfasciatus (Coleoptera: Curculionidae)

The West Indian sweet potato weevil Euscepes postfasciatus (Fairmaire) (Coleoptera: Curculionidae) is a major pest of sweet potato Ipomoea batatas (L.) in the tropical and subtropical regions. The sterile insect technique (SIT) could be used as one of the most effective methods for suppression or eradication of the weevil. The effectiveness of SIT depends on the ability of the released sterile males to mate with and inseminate wild females. However, the effect of sterile weevils on the fitness of E. postfasciatus has not been evaluated on natural density. Here, we investigated the effect of gamma-irradiated weevil density on the number of weevil progeny. When irradiated weevils were released in numbers equal to those of non-irradiated weevils, the number of progeny was reduced by half of that in the control treatment, and it remained at this state for 2?weeks. Our results show that irradiated weevils ensure adequate and efficient suppression of wild weevils. We conclude that the SIT programs will be employed as effective eradication method for E. postfasciatus.     

Similarities and Varieties: A Brief Sketch on the Reception of Darwinism and Sociobiology in Japan

This paper discusses the reception of Darwinian evolutionary theory and sociobiology in Japan. Darwinism was introduced into Japan in the late 19th century and Japanese people readily accepted the concept of evolution because, lacking Christianity, there was no religious opposition. However, the theory of evolution was treated as a kind of social scientific tool, i.e., social Spencerism and eugenics. Although evolutionary biology was developed during the late 19th and the early 20th century, orthodox Darwinian theory was neglected for a long time. In the mid 1980s, sociobiology was introduced but it was ignored and criticized by a large part of the ecologist-evolutionist community in Japan. This hostile attitude was due to the absence of Darwinism among these scientists. Compared with the reception of sociobiology in English-speaking countries, there were both similarities and differences in Japan.     

Actin-independent behavior and membrane deformation exhibited by the four-transmembrane protein M6a

M6a is a four-transmembrane protein that is abundantly expressed in the nervous system. Previous studies have shown that over-expression of this protein induces various cellular protrusions, such as neurites, filopodia, and dendritic spines. In this detailed characterization of M6a-induced structures, we found their varied and peculiar characteristics. Notably, the M6a-induced protrusions were mostly devoid of actin filaments or microtubules and exhibited free random vibrating motion. Moreover, when an antibody bound to M6a, the membrane-wrapped protrusions were suddenly disrupted, leading to perturbation of the surrounding membrane dynamics involving phosphoinositide signaling. During single-molecule analysis, M6a exhibited cytoskeleton-independent movement and became selectively entrapped along the cell perimeter in an actin-independent manner. These observations highlight the unusual characteristics of M6a, which may have a significant yet unappreciated role in biological systems.     

Development of the eggs and larvae of the pike eel,Muraenesox cinereus

Embryonic and larval development of the pike eel,Muraenesox cinereus, are described following natural fertilization in the laboratory. Eggs are pelagic and spherical with diameters from 1.8 to 2.1 mm and have a colorless, transparent chorion and numerous oil globules. Hatching occurs 36 hours after spawning at a water temperature of 25°C. Newly-hatched larvae are 5.8 mm in mean TL, and the number of myomeres averages 86. Absorption of the yolk is completed 8 days after hatching, at 9–10 mm TL. Larvae survive for 10 days without food supply. At this time they are 11.2 mm in mean TL and have 97 + 55=152 myomeres, which is a diagnostic character of this species. They have large eyes and well-developed jaws with sharp teeth.     

The finding and partial purification and characterization of thymone C

A fraction, isolated from bovine thymus by sequences of $\text{ca.}$ ten steps of extractions, gel filtrations, ion exchange chromatography, etc., stimulated the synthesis of both cAMP and cGMP at a level of 100 μg/ml. Thymone A stimulated cAMP, but is chromatographically remote from the fraction. Essentially pure thymone B, which stimulates cGMP, did not stimulate cAMP even at a high level of 100 μg/ml. The presence of thymone B in this fraction is supported by TLC data. This fraction also stimulated the mixed lymphocyte reaction. The cAMP-stimulating entity is designated thymone C until it is characterized and related to or differentiated from products of other investigators.     

Two human genes isolated by a novel method encode DNA-binding proteins containing a common region of homology

Two cDNAs encoding new DNA-binding proteins (Dbps) have been cloned using a human placenta lambda gt11 recombinant cDNA library and DNA fragments as probes. Hybrid proteins expressed by the lambda gt11 cDNA library were blotted onto nitrocellulose filters, and incubated with three different radio-labeled DNA probes containing the human epidermal growth factor (EGF) receptor enhancer or the human c-erbB-2 promoter. Two kinds of clones, named dbpA and dbpB, showed high affinities for the DNA probes. The comparison of the nucleotide and the deduced amino acid (aa) sequences between these two cDNAs indicated that 100 of 109 aa located in the central region of these two Dbps were identical. The dbpA and dbpB-coded proteins also had an affinity for other cDNA probes such as the human c-ski gene, but not for poly(dI-dC).poly(dI-dC), suggesting that the sequence(s) recognized by the dbpA and dbpB-coded proteins may occur frequently, or that these proteins bind to DNA non-specifically in a different manner from that of histones. A simple method, described in this paper, can be used to isolate cDNA clones encoding Dbps. Strategies used for the detection of sequence-specific and non-specific Dbps are discussed.