The membrane binding and deformation property of vaccinia virus K1 ankyrin repeat domain protein

Membrane lipids are essential participants in cellular events, but only a small number of lipid‐interacting proteins have been characterized. Taking advantage of the small genome (~270 genes) of the vaccinia virus, we screened for soluble lipid‐binding proteins and found 27 proteins to be soluble after expression in Escherichia coli. Among them, 4 proteins were found to strongly bind to the total bovine brain lipid extract (Folch I fraction) that contained large amounts of phosphatidylserine in vitro. Out of the 4 proteins, 3 were unique proteins to viruses. Another protein, K1, solely contained an ankyrin repeat domain (ARD). ARD is conserved in large numbers of proteins in bacteria, archaea, eukaryotes and viruses, suggesting the possibilities of the membrane binding of ARDs in varieties of proteins. Furthermore, K1 deformed the lipid membrane dependently on the charged lipids. The tubulation and membrane binding was enhanced with increased negative membrane charge from phosphatidylinositol 4,5‐bisphosphate (PI(4,5)P₂). The basic amino acid residues in the ARD were essential for membrane deformation, suggesting electrostatic interactions between K1 and the membrane for membrane deformation.     

Cephalometric abnormalities in non-obese and obese patients with obstructive sleep apnoea.

The aim of this work was to comprehensively evaluate the cephalometric features in Japanese patients with obstructive sleep apnoea (OSA) and to elucidate the relationship between cephalometric variables and severity of apnoea. Forty-eight cephalometric variables were measured in 37 healthy males and 114 male OSA patients, who were classed into 54 non-obese (body mass index (BMI) <27 kg x m(-2), apnoea-hypopnoea index (AHI)=25.3+/-16.1 events x h(-1)) and 60 obese (BMI > or = 27 kg x m(-2), AHI=45.6+/-28.0 events h(-1)) groups. Diagnostic polysomnography was carried out in all of the OSA patients and in 19 of the normal controls. The non-obese OSA patients showed several cephalometric defects compared with their BMI-matched normal controls: 1) decreased facial A-P distance at cranial base, maxilla and mandible levels and decreased bony pharynx width; 2) enlarged tongue and inferior shift of the tongue volume; 3) enlarged soft palate; 4) inferiorly positioned hyoid bone; and 5) decreased upper airway width at four different levels. More extensive and severe soft tissue abnormalities with a few defects in craniofacial bony structures were found in the obese OSA group. For the non-obese OSA group, the stepwise regression model on AHI was significant with two bony structure variables as determinants: anterior cranial base length (S-N) and mandibular length (Me-Go). Although the regression model retained only linear distance between anterior vertebra and hyoid bone (H-VL) as an explainable determinant for AHI in the obese OSA group, H-VL was significantly correlated with soft tissue measurements such as overall tongue area (Ton), inferior tongue area (Ton2) and pharyngeal airway length (PNS-V). In conclusion, Japanese obstructive sleep apnoea patients have a series of cephalometric abnormalities similar to those described in Caucasian patients, and that the aetiology of obstructive sleep apnoea in obese patients may be different from that in non-obese patients. In obese patients, upper airway soft tissue enlargement may play a more important role in the development of obstructive sleep apnoea, whereas in non-obese patients, bony structure discrepancies may be the dominant contributing factors for obstructive sleep apnoea.     

Pharmacological analysis of protein kinases responsible for chemotaxis of rat peritoneal neutrophils

Several types of kinase inhibitors were used to investigate the possible signaling pathways leading to the chemotaxis of rat peritoneal neutrophils toward macrophage inflammatory protein-2, cytokine-induced neutrophil chemoattractant-1, and platelet-activating factor. The chemotaxis and shape changes induced by each of these chemoattractants were strongly inhibited by a tyrosine kinase inhibitor (herbimycin A) and protein kinase C inhibitors (H-7 (1-(5-isoquinolinesulphonyl)-2-methylpiperazine dihydrochloride) and calphostin C). The formation of phosphatidyl 3,4,5-triphosphate in chemoattractant-stimulated neutrophils was completely inhibited by 100 nM of wortmannin, an inhibitor of phosphatidylinositol 3-kinase, whereas the chemotaxis toward each of these chemoattractants was partially inhibited (50% inhibition). The mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK-1) inhibitor PD 98059 did not inhibit the neutrophil chemotaxis. These findings suggest that the activation of tyrosine kinase and protein kinase C strongly participates in neutrophil chemotaxis and that the activation of phosphatidylinositol 3-kinase is partially involved, but that the activation of mitogen-activated protein kinase is not involved in neutrophil chemotaxis. The cross-linking of the signaling pathways for chemotaxis toward each chemoattractant was also examined.     

Left ventricular isovolumic relaxation time estimated by the aortic root echocardiogram

Dual echocardiogram was recorded simultaneously with phonocardiogram (PCG) to analyze the isovolumic relaxation time (IRT) of the left ventricle (LV) in 85 patients with various heart diseases and in 23 normal subjects. The measurements used were time intervals from the onset of the aortic component of the second heart sound (IIA) to the onset of the posterior deflection of the posterior aortic wall in the aortic root echocardiogram (X) (IIA-X interval), and to the onset of the most rapid opening motion of the anterior mitral leaflet (D') (IIA-D' interval) during early diastole. 1. The IIA-X interval was directly proportional to the IIA-D' interval in the entire study population. 2. The IIA-X interval was prolonged with advancing age in normal subjects. 3. The IIA-X interval was significantly increased in patients with hypertensive heart disease, old myocardial infarction, hypertrophic cardiomyopathy, and dilated cardiomyopathy, but significantly decreased in patients with mitral stenosis. Thus, the IIA-X interval, which was measured easily and noninvasively from the aortic root echocardiogram is a reliable indicator of the isovolumic relaxation time of the left ventricle, as well as of the IIA-D' interval.     

Allergic individuals to Japanese cedar or orchard grass consist of two subgroups based on the sensitization to Dermatophagoides pteronyssinus

One hundred and twenty-six allergic subjects were divided into three groups based on the RAST results for Dermatophagoides pteronyssinus (D.p) and Japanese cedar (J.C.). We compared sex, age of examination for RAST, serum IgE, family history of allergic diseases, prevalence rate of bronchial asthma (BA) and allergic rhinitis (AR), and onset of AR among three groups. No significant difference in the other variables except serum IgE and prevalence rate of BA was found between the group with D.p-positive and J.C.-positive RAST and the group with D.p-positive and J.C.-negative RAST. The group with positive RAST for D.p and J.C. showed lower age of the examination, higher serum IgE, higher incidence of allergic family history, higher prevalence rate of BA, and lower onset age of AR than the group with negative RAST for D.p and positive RAST for J.C. We suggested that in J.C. RAST-positive group there might be two different subgroups distinguished by RAST result for D.p Similar results were obtained from the assessment of RAST for Orchard grass instead of J.C.     

The relationship between inclination of the occlusal plane and jaw closing path

The occlusal plane is determined according to morphologic guides such as Camper's plane and the position of the retromolar pad. However, there is no information available about the functional orientation of the occlusal plane. The purpose of this study was to investigate the relationship between the inclination of the occlusal plane and jaw closing movement path in the sagittal plane. Data from 38 young dentate subjects were obtained with a system that measures jaw movements. It was found that the occlusal plane and the masticatory closing path were consistent in maintaining an almost perpendicular relationship regardless of the variation in the inclination of the occlusal plane. This finding appears to be based on the functional formation of the occlusal plane according to the growth and change of masticatory muscles. The correlation between the inclination of the occlusal plane and masticatory closing movement could serve as the background for the functional significance of the occlusal plane.     

Nonalcoholic fatty liver disease is a novel predictor of cardiovascular disease

AIM:To clarify whether nonalcoholic fatty liver disease(NAFLD)increases the risk of cardiovascular disease.METHODS:We carried out a prospective observational study with a total of 1637 apparently healthy Japanese men and women who were recruited from a health check-up program.NAFLD was diagnosed by abdominal ultrasonography.The metabolic syndrome(MS)was defined according to the modified National Cholesterol Education Program(NCEP)ATP Ⅲ criteria.Five years after the baseline evaluations,the incidence of cardiovascular disease was assessed by a self-administered questionnaire.RESULTS:Among 1221 participants available for outcome analyses,the incidence of cardiovascular disease was higher in 231 subjects with NAFLD at baseline(5 coronary heart disease,6 ischemic stroke,and 1 cerebral hemorrhage)than 990 subjects without NAFLD(3 coronary heart disease,6 ischemic stroke,and 1 cerebral hemorrhage).Multivariate analyses indicated that NAFLD was a predictor of cardiovascular disease independent of conventional risk factors(odds ratio 4.12,95% CI,1.58 to 10.75,P = 0.004).MS was alsoindependently associated with cardiovascular events.But simultaneous inclusion of NAFLD and MS in a multivariate model revealed that NAFLD but not MS retained a statistically significant correlation with cardiovascular disease.CONCLUSION:Although both of them were predictors of cardiovascular disease,NAFLD but not MS retained a statistically significant correlation with cardiovascular disease in a multivariate model.NAFLD is a strong predictor of cardiovascular disease and may play a central role in the cardiovascular risk of MS.