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Notes: We deposited polymer-like a-C:H films using the plasma-enhanced chemical vapor deposition technique and characterized film microstructure by variable-energy positron lifetime spectroscopy, photoluminescence (PL), and UV-visible absorption spectroscopy. It was confirmed that PL occurs from a chromophore in a sp2 cluster as a result of fast recombination of a photoexcited electron-hole pair. Positron annihilation lifetime spectroscopy showed that positronium (Ps) formation takes place via electron-positron recombination in the sp3 matrix. The lifetime of ortho-positronium (o-Ps) in our a-C:H films was similar to that in polyethylene, indicating their polymer-like nature. The relative PL efficiency increased by about an order of magnitude with increasing film band gap from 1.3 to 3.4 eV, which can be related to the decreasing concentration of nonradiative centers. On the other hand, Ps formation was much less influenced by the band gap and nonradiative centers. Comparison of this result with that for polyethylene mixed with carbon-black nanoparticles, where a considerable reduction in Ps formation was observed, showed that nonradiative centers were of a different nature from the defects on the carbon nanoparticle surface. This work demonstrated the usefulness of positron lifetime spectroscopy combined with optical measurements to study the nanostructure of a-C:H. © 2001 American Institute of Physics.

Notes: Positronium annihilation was applied to characterize the nanoporous structure of thin silicon oxide films sputter-deposited at different argon pressures ranging from 0.1 to 2.0 Pa. At higher argon pressures, the 3γ decay probability of ortho-positronium (o-Ps) was substantially enhanced. A comparison of this result with that obtained for capped samples indicated that: (a) 3γ annihilation is due to the intrinsic decay of o-Ps diffusing out from the film into vacuum and (b) films deposited at high argon pressures contain highly connected, open pores. Positron lifetime spectroscopy measurements on the capped films showed that the characteristic size of the pores can be as large as 2.6 nm, depending on the argon pressure. © 2002 American Institute of Physics.

Notes: : Chemical analysis showed soft snow crab muscle to have a higher water content and a lower protein content than hard crab muscle. Histological observations revealed frequent occurrences of disintegrated regions in muscle fibers and pericellular connective tissue of soft snow crab muscle tissue. Salinity of the free body fluid recovered from the meropodites of the soft snow crab was significantly higher than that of the hard snow crab. Sensory evaluation revealed differences in texture and taste between soft and hard crabs, which corresponded well to their compositional and histological differences.

Notes: Background T helper-type 2 cytokines, such as interleukin-4 (IL-4) and IL-13, may play a central role in allergic diseases. The protein known as ‘signal transducers and activators of transcription 6’ (STAT-6) is a key transcription factor involved in both IL-4- and IL-13-mediated biological responses.Objective The objective of this study was to evaluate the possible role of the STAT-6 gene in modulating atopy in the Japanese population.Methods We screened all 23 exons of the STAT-6 gene from 10 subjects for mutations by direct polymerase chain reaction (PCR) sequencing. The STAT-6 gene polymorphisms were genotyped by PCR fragment length polymorphism analysis and PCR-SSCP analysis. The IL-4 receptor Q576R polymorphism was also examined by PCR-SSCP analysis.Results We found a novel dinucleotide repeat polymorphism in the first exon of the STAT-6 gene. The genotypes were classified into four groups according to the number of GT repeats present, from 13 to 16. The frequency of the A1 allele (326 bp, containing 13 repeats of GT) was higher in children with allergic diseases (bronchial asthma, atopic dermatitis and/or food-related anaphylaxis) than controls, although this was not statistically significant (P = 0.0158). In addition, a strong association between the A1 and A3 allele (containing 15 repeats of GT) heterozygote and allergic diseases was identified (P = 0.0002). However, the levels of IgE were not related to the GT repeat polymorphism in the allergic subjects. The GT repeat polymorphism was not associated with the polymorphism in the IL-4 receptorachain gene (Q576R) and there was no association between the G2964A variant and allergic diseases.Conclusion This suggests that genetic variation in the STAT-6 gene may be associated with predisposition to allergic diseases.

Notes: Background: The pathogenesis of atopic dermatitis (AD) is still unknown. A recent study has shown that inducible nitric oxide synthase (iNOS) is expressed in the atopic skin lesion, suggesting the involvement of nitric oxide in the skin inflammation of AD. The purpose of the study was to examine serum nitrate (NO3) levels in relation to the disease severity in children with AD. Methods: Serum nitrate levels were assessed in relation to the skin scores in 88 patients with atopic dermatitis (AD) (aged 0.4–8 years: mean±SD, 2.2±1.9, 41 boys and 47 girls) and 12 nonatopic children (aged 0.8–4 years: mean±SD, 1.8±0.9, seven boys and five girls). Results: Serum nitrate levels of patients with AD were significantly increased as compared to nonatopic controls and were also correlated with the disease severity. The skin scores were significantly correlated with serum nitrate levels as well as peripheral eosinophil counts. Conclusions: Our results indicate that nitric oxide may be involved in the pathogenesis of vasodilation and erythema in AD skin.

Notes: This study was undertaken to clarify prognostic indices of a long-term clinical course in IgA nephropathy in large series.〈section xml:id="abs1-1"〉〈title type="main"〉PATIENTSFrom 1972 to 1990, a total of 603 patients were diagnosed to have primary IgA nephropathy in our renal unit. Of these patients 366 patients were continuously followed up for 10 years or more. These patients were the subjects of this study.〈section xml:id="abs1-2"〉〈title type="main"〉METHODSAs predictive factors, several parameters were evaluated as follows: initial proteinuria; initial creatinine clearance (Ccr) values; initial hypertension; histological severity (eight parameters and total score); % duration of massive proteinuria (%DP); % duration of hypertension (%DH). %DP was defined as [(duration of proteinuria of 1.0g/day or more ÷ total duration of follow-up observation) × 100]. %DH was defined as [duration of hypertension ÷ total duration of follow-up observation] × 100].As histological severity, eight parameters were evaluated according to the semiquantitative method of Pirani et al. Each of these lesions was graded from 0 to 3. A total score was defined as a total of all eight scores, graded from 0 to 24.During the 10-year follow-up observation, corticosteroid treatment was conducted in 112 patients. Most of the patients received antiplatelet drugs. Hypertensive patients were treated with antihypertensive therapy.Final outcome at 10 years since the initial renal biopsy was divided into three clinical courses as follows: a stable course was defined as no decrease of renal function for 10 years; a progressive course was defined as a decrease of 15% or more of initial Ccr values without going into HD; and haemodialysis (HD).Univariate analysis for these predictive factors was performed by using one-factor ANOVA corrected by Bonferroni/Dunn or Kruskal-Wallis test to determine the final outcome. A multivariate analysis was done by using a logistic model.〈section xml:id="abs1-3"〉〈title type="main"〉RESULTSThe age of the 366 patients was 33 ± 10 (range: 13–61); gender (M/F) 181/185; initial proteinuria 1.0 ± 1.0g/day (range: 0–6.6); initial Ccr values 85 ± 21 mL/min (range: 25–139); initial hypertension 63 cases (17%); total score as histological severity 7.7 ± 4.6.The final proteinuria was 0.9 ± 1.0 g/day (range: 0–5.7); final Ccr values 58 ± 38 mL/min (0–128); final hypertension 94 cases (25%); %DP 33 ± 39; %DH 18 ± 30. Numbers of patients having a stable course, a progressive course and haemodialysis were 192 (52%), 89 (25%) and 85 (23%), respectively.Clinical prognostic indices showed significant differences in age, initial proteinuria, initial Ccr, initial hypertension, %DO and %DH, respectively (P 〈 0.0001). Treatment with corticosteroids was significantly frequent in progressive and haemodialysis groups than a stable group (P 〈 0.0003).Histological prognostic indices showed significant differences in hypercellularity, active crescent, tuft adhesion, mesangial sclerosis, global sclerosis, tubular atrophy, interstitial fibrosis, vascular sclerosis and total score (P 〈 0.005).Multivariate analysis of clinical prognostic indices showed the highest relevance in %DP (relative risk 32.9, P 〈 0.0001), followed by %DH (relative risk 14.2, P 〈 0.0001).Multivariate analysis of histological prognostic indices showed the highest relevance in tubular atrophy (relative risk 9.2, P 〈 0.002), followed by interstitial fibrosis (relative risk 3.0, P 〈 0.05).Multivariate analysis of clinicohistological indices showed the highest relevance in %DP (relative risk 38.0, P 〈 0.0001), followed by %DH (relative risk 18.7, P 〈 0.0001).Patients with 30% or less in %DP underwent a favourable clinical course, while patients with 40% or more had a poor prognosis.%DH was one of the most reliable prognostic indices. However, there was no evidence of a turning point determining a long-term prognosis.〈section xml:id="abs1-4"〉〈title type="main"〉COMMENTThirty-three years have passed since IgA nephropathy was first reported in 1968. Many investigations have documented a long-term prognosis of the disease and predictive factors for a long-term clinical course. It is generally accepted that the renal survival rate of the disease is recognized to be 70–80% 10 to 20 years after clinical onset. Clinically, initial proteinuria and initial renal function are well related with a long-term prognosis. Histologically, interstitial fibrosis is a most reliable predictive factor for a poor prognosis as well. However, there are few reports evaluated by a large series with a long-term follow-up observation.In this study, all 366 patients have been continuously followed up for 10 years since the first renal biopsy. About 50% of the patients underwent a progressive course, with 25% of the total patients entering into chronic haemodialysis. Multivariate analyses of clinical and histological predictors at the time of the first renal biopsy indicated that not only initial proteinuria and initial renal function but also tubular atrophy and interstitial fibrosis are very important factors, as reported previously.However, in practical clinical observation, it is difficult to predict a long-term prognosis merely at the time of renal biopsy. Therefore, careful follow-up observation is needed to evaluate the disease activity.In the present study, the continuous examination of daily urinary protein excretion and blood pressure was performed during a follow-up period of 10 years. As the result, %DP of 1.0 g/day or more is clarified to be the most reliable independent predictor for a long-term prognosis, followed by %DH. Moreover, 40% or more of %DP is found to be well related with a poor prognosis.In conclusion, the most reliable, independent factor determining a long-term prognosis in IgA nephropathy is persistent massive proteinuria of 1.0 g/day or more.