Paraoxonase gene Gln192Arg (Q192R) polymorphism is associated with coronary artery spasm

We recently reported that oxidative stress is involved in the pathogenesis of coronary spasm. We hypothesized that oxidative-stress-related genetic factors and certain polymorphisms in the paraoxonase gene (PON1) and platelet-activating factor acetylhydrolase (PAF-AH) might influence the pathogenesis of coronary spasm. We therefore examined the possible association between the PON1 Q192R or PAF-AH V279F polymorphisms and coronary spasm in 214 patients with coronary spasm and 212 control subjects. Genotypes were determined by polymerase chain reaction/restriction fragment length polymorphism analysis. The incidence of the PON1-192R allele was significantly higher in the coronary spasm group than in the control group (65% vs 53%; P=0.0005). The PAF-AH-279F allele was not associated with coronary spasm (15% vs. 16%; P=0.8781). Multiple logistic regression analysis with forward stepwise selection involving the PON1-192R allele and the environmental risk factors revealed that the most predictive independent risk factor for coronary spasm was the PON1-192R allele (significance=0.0016, OR=2.52), followed by cigarette smoking (significance=0.0007, OR=2.01). We also measured plasma levels of TBARS (thiobarbituric acid-reactive substances) as a marker of oxidative stress. TBARS levels were higher in R/R types than in Q/Q types (2.115+/-0.086 nmol/ml [ n=25] vs 1.676+/-0.102 nmol/ml [ n=11], P<0.01). Thus, there is a significant association between the PON1-192R allele and coronary spasm; the PON1-192R allele may play an important role in the genesis of coronary spasm, probably by attenuating the suppression of oxidative stress.     

The Amount of Metabolizable Glycine

Two roosters of Single Comb White Leghorn breed were fed on a formula feed containing 2-¹⁴C glycine for 16~17 days. The animals were killed and the specific activities of glycine in the tissue proteins and the purine ring of the excreted uric acid were measured. The amount of synthesized glycine in the rooster was calculated by the dilution method based on the specific activities of glycine in the liver protein and the absorbed one. The rooster absorbed about 1 g of glycine and synthesized about 10 g of glycine per day. Quantitative aspect of glycine metabolism in the rooster was discussed.     

Autotomy-induced life history plasticity in band-legged ground cricket Dianemobius nigrofasciatus

Crickets can autotomize their limbs when attacked by predators. This enables them to escape death, but imposes a short-term cost on their escape speed and a long-term cost on their future mating ability. Therefore, adaptive response compensated for the cost of autotomy might be advantageous for autotomized individuals. In the present study, we examined whether autotomy induced life history plasticities compensating for the future cost in the band-legged ground cricket Dianemobius nigrofasciatus . Life history traits of D. nigrofasciatus were compared between autotomized and intact individuals. The developmental time and head width of the individuals that were autotomized as fourth instar nymphs were significantly shorter and smaller, respectively, than those of intact individuals. However, the adult longevity, number of eggs laid and oviposition schedule did not vary between autotomized and intact individuals. In addition, there was no difference between individuals autotomized at the fourth instar and adult stages in these three traits. Early maturation in the autotomized individuals might be advantageous through reducing the risk of predation owing to the shorter period in nymphal stages. The cost of small body size in the autotomized females might not be so great because of no significant difference in fecundity between autotomized and intact individuals. However, the cost of small body size was unclear in the autotomized males because in general larger males were preferred by females. These results indicated autotomy-induced life history that might reduce the cost of autotomy.     

Protein Metabolism in the Domestic Fowl

The metabolic half lives of glycine in the tissue-proteins of the rooster were determined by single oral dose of 2-C¹⁴ glycine before measuring the amount of synthesized glycine in the rooster by ?constant pool? method. The specific activity of glycine originated from the purine ring of uric acid showed the highest value for 5 hrs. after administration, following rapid decrease until 7 days, thereafter slower one.

Although the specific activity of glycine in the tissue protein (serum and liver) decreased exponentially, its trend was not distinct in the pectoral muscle, and in the early period its decrease seemed to be considerably fast (t_1/2 about 6 days).

The specific activities of glycine in the serum protein were always higher than those in the liver protein. The metabolic half livers obtained were as follows. Liver: Faster 2 days, slower 11 days. Serum: faster 2 days, slower 11 days. Pectoral muscle: faster 6 days, slower 30 days. Recovery of C¹⁴ into 4-C and 5-C in the purine ring of excreted uric acid during 24 hours after the administration of isotope was about 24%.     

Endothelin Evokes Efflux of Glutamate in Cultures of Rat Astrocytes

Abstract: Excessive release of glutamate, from glial cells as well as neurons, is thought to be a major cause of neuronal death in ischemia. To investigate glutamate release from glial cells, we measured glutamate efflux from cultures of rat astrocytes preloaded with l -[³H]-glutamate. Glutamate efflux was induced by either 60 m M KCl or Na⁺-free medium, suggesting that the efflux is due to the reversed operation of a Na⁺- and K⁺-coupled glutamate uptake machinery. While investigating various neuropeptides and neurotransmitters, we found that endothelin (ET) specifically induced efflux of glutamate. Northern blot analysis and binding study showed that the ET type B receptor (ET_B-R) subtype was expressed two to three times more densely than the ET type A receptor (ET_A-R) in astrocytes. The ET_B-R antagonist IRL 2500 partially inhibited efflux of glutamate induced by 1 n M ET-1 in a concentration-dependent manner, causing a maximal inhibition of 60% at 1 µ M . However, the ET_A-R antagonist BQ-123 did not cause significant inhibition even at 10 µ M . Combination of both antagonists completely inhibited the ET-1-induced efflux. These results indicate that both receptor subtypes are involved in efflux of glutamate with a major contribution from the ET_B-R. Our findings suggest that ET, which is known to be released in ischemia, may exacerbate neurodegeneration by stimulating efflux of glutamate.     

Genetic variations and phylogeography of the swallowtail butterfly Papilio machaon on the Japanese Islands

The swallowtail butterfly Papilio machaon Linnaeus, 1758 is widely distributed in the Holarctic region, including all of the main islands of Japan, as well as Sakhalin, and on other smaller islands south to Yakushima Island. The Japanese population is situated at the margin of the Eurasian distribution range of this species. It is morphologically different from other populations and has been classified as the subspecies hippocrates C. & R. Felder, 1864. The population of the Japanese Islands is considered to be genetically distinct from the continental populations in relation to the geographical history of the Japanese Islands. Therefore, we examined a part of the ND5 gene sequence of the mitochondrial DNA for P. machaon individuals of various localities in Japan and some nearby countries, and found 68 haplotypes in 400 individuals from the Japanese Islands and Sakhalin. A DNA polymorphism analysis revealed that the genetic structure of the Hokkaido population was significantly different from that of the southern populations on the main Japanese islands. These results imply that P. machaon expanded its range from the Amur region of Russia southward through Sakhalin to the Japanese Islands, and that the Tsugaru Strait between Hokkaido and Honshu may have subsequently limited their gene flow as a geographical barrier.     

Quinacrine fluorescence patterns in somatic chromosomes of a t(15q15q) carrier

Summary A sporadic translocation between two homologues of chromosome 15 was identified, by means of the quinacrine mustard fluorescence technique, in a phenotypically normal female infant with ventricular septal defect. Familial studies revealed certain individual variations regarding the intensely fluorescent centromeric regions in chromosomes 3 and 13, which appeared to be transmitted from the parents to offspring.

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Zusammenfassung Eine sporadische Translokation zwischen zwei homologen Chromosomen Nr. 15 wurde mit Hilfe der Quinacrine-Mustard-Fluorescenztechnik bei einem weiblichen Säugling mit Ventrikelseptumdefekt festgestellt, der sonst phänotypisch normal war. Familienuntersuchungen ergaben gewisse individuelle Varianten der Zentromerregion in den Chromosomen 3 und 13, und es wurde eine Vererbung von den Eltern auf ihre Kinder festgestellt.Familienberatungen ergaben gewisse individuelle Variationen der intensiv fluorescierenden Zentromerregion.

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Contributions from the Chromosome Research Unit, Faculty of Science, Hokkaido University, Sapporo, Japan. Supported by grants, No. 584099, and No. 92035, from the Scientific Research Fund of the Ministry of Education.     

Genomic sequence and virulence evaluation of MN184A‐like porcine reproductive and respiratory syndrome virus in Japan

In this study, a porcine reproductive and respiratory syndrome virus (PRRSV) that was isolated from a 9‐week‐old diseased pig on a farm in Japan with a high mortality rate during 2007–2008 was characterized. This unique isolate, designated as Jpn5‐37, did not have a high nucleotide identity in open reading frame 5 against any Japanese isolates. Among all available type 2 PRRSV complete genome sequences, Jpn5‐37 shared the highest nucleotide identity (93.6%) with virulent strain MN184A. The genomic characteristics of Jpn5‐37 were highly conserved with respect to the virulent MN184A, including a continuous eight amino acid deletion in the nonstructural protein 2 region. Moreover, virus distribution, viremia and the gross and microscopic characteristics of lesions were investigated in pigs 10 days post‐inoculation to elucidate the pathogenicity of the isolate. Intranasal inoculation was found to rapidly result in viremia and dissemination of the Jpn5‐37 isolate to several tissues in a similar manner to EDRD1; however, the amounts of Jpn5‐37 RNA in serum were significantly greater. Similarly, the quantities of Jpn5‐37 viral RNA in all organs tested tended to be higher than with EDRD1 infection. Mean rectal temperatures were significantly higher in the Jpn5‐37‐inoculated than in the control group at 4 and 6 days post infection (dpi) and in the EDRD1‐inoculated group at 6 and 8 dpi. These results suggest that the Jpn5‐37 strain replicates and is more efficiently distributed to the organs than is EDRD1 under the same conditions.     

Drebrin attenuates the interaction between actin and myosin-V

Drebrin-A is an actin-binding protein localized in the dendritic spines of mature neurons, and has been suggested to affect spine morphology [K. Hayashi, T. Shirao, Change in the shape of dendritic spines caused by overexpression of drebrin in cultured cortical neurons, J. Neurosci. 19 (1999) 3918-3925]. However, no biochemical analysis of drebrin-A has yet been reported. In this study, we purified drebrin-A using a bacterial expression system, and characterized it in vitro. Drebrin-A bound to actin filaments with a stoichiometry of one drebrin molecule to 5-6 actin molecules. Furthermore, drebrin-A decreased the Mg-ATPase activity of myosin V. In vitro motility assay revealed that the attachment of F-actin to glass surface coated with myosin-V was decreased by drebrin-A, but once F-actin attached to the surface, the sliding speed of F-actin was unaffected by the presence of drebrin A. These findings suggest that drebrin-A may affect spine dynamics, vesicle transport, and other myosin-V-driven motility in neurons through attenuating the interaction between actin and myosin-V.