Ozone-Sensitive Arabidopsis Mutants with Deficiencies in Photorespiratory Enzymes.

An ozone-sensitive mutant was isolated from T-DNA-tagged lines of Arabidopsis thaliana. The T-DNA was inserted at a locus on chromosome 3, where two genes encoding glycolate oxidases, GOX1 and GOX2, peroxisomal enzymes involved in photorespiration, reside contiguously. The amounts of the mutant's foliar transcripts for these genes were reduced, and glycolate oxidase activity was approximately 60% of that of the wild-type plants. No difference in growth and appearance was observed between the mutant and the wild-type plants under normal conditions with ambient air under a light intensity of 100 µmol photons m-2 s-1. However, signs of severe damage, such as chlorosis and ion leakage from the tissue, rapidly appeared in mutant leaves in response to ozone treatment at a concentration of 0.2 µl l-1 under a higher light intensity of 350 µmol photons m-2 s-1 that caused no such symptoms in the wild-type plant. The mutant also exhibited sensitivity to sulfur dioxide and long-term high-intensity light. Arabidopsis mutants with deficiencies in other photorespiratory enzymes such as glutamate:glyoxylate aminotransferase and hydroxypyruvate reductase also exhibited ozone sensitivities. Therefore, photorespiration appears to be involved in protection against photooxidative stress caused by ozone and other abiotic factors under high-intensity light.

Relationship between periodontitis and hepatic abnormalities in young adults.

OBJECTIVE: Obesity has been implicated as a risk factor for periodontitis and non-alcoholic fatty liver disease (NAFLD). In NAFLD, elevated alanine aminotransferase (ALT) is associated with obesity. Although a possible interrelationship between liver function and periodontitis has been reported among the middle-aged population, the correlation in young adults is little known. This study was designed to investigate the relationship between ALT and the presence of periodontitis in university students in Japan. MATERIAL AND METHODS: Medical and oral health data were collected in a cross-sectional examination conducted by the Health Service Center of Okayama University. Systemically healthy, non-smoking students aged 18 and 19 years old (n = 2225) were included. The protocol of the United States National Health and Nutrition Examination Survey was applied. Subjects with probing pocket depth >or= 4 mm were defined as having periodontitis. Logistic regression analysis was used to estimate the association between ALT, body mass index and periodontitis. RESULTS: The number of subjects with periodontitis was 104 (4.7%). In males, having periodontitis was significantly associated with an increased level of ALT (>or= 41 IU/l) in logistic regression analysis (adjusted odds ratio 2.3; 95% confidence interval 1.0-5.2; p < 0.05). However, there was no significant association between periodontitis and ALT in female students. CONCLUSIONS: Elevated ALT could be a potential risk indicator for periodontitis among young males. Monitoring hepatic abnormalities to prevent periodontitis must be better understood, even in the young adult population.

Risks of chest X-ray examination for students.

Chest X-ray (CXR) examination is considered essential for health checkups of students;thus, it is important to objectively assess the CXR for a better understanding of the appropriate X-ray exposure dose, and the risks such an examination entails. Accordingly, we performed a multi-institutional study regarding students' CXR exposure, during a 6year-period from 2002 (partially including 2001) to 2007, with the collaboration of national, municipal, and private universities and colleges in Japan. A glass badge was worn by the students at the time of CXR screening examination. These glass badges were collected, and their X-ray exposure doses were measured. The results indicated a tendency of decreasing exposure dose over the 6 years, though the difference was not significant. In a comparison of the chest X-ray systems within institutions (own X-ray equipmentinside systems) with those outside the institution (mobile X-ray equipmentoutside systems), the average exposure dose with the outside systems exceeded that of the inside systems. Both inside and outside systems included a few X-ray machines with which the exposure was more than 1mSv. Based on these facts, individuals in charge of student health checkups should be aware of the exposure dose of each chest fluorographic system at their institution.

Whole blood interferon-gamma assay for baseline tuberculosis screening among Japanese healthcare students.

BACKGROUND: The whole blood interferon-gamma assay (QuantiFERON-TB-2G; QFT) has not been fully evaluated as a baseline tuberculosis screening test in Japanese healthcare students commencing clinical contact. The aim of this study was to compare the results from the QFT with those from the tuberculin skin test (TST) in a population deemed to be at a low risk for infection with Mycobacterium tuberculosis. METHODOLOGY/PRINCIPAL FINDINGS: Healthcare students recruited at Okayama University received both the TST and the QFT to assess the level of agreement between these two tests. The interleukin-10 levels before and after exposure to M tuberculosis-specific antigens (early-secreted antigenic target 6-kDa protein [ESAT-6] and culture filtrate protein 10 [CFP-10]) were also measured. Of the 536 healthcare students, most of whom had been vaccinated with bacillus-Calmette-Guérin (BCG), 207 (56%) were enrolled in this study. The agreement between the QFT and the TST results was poor, with positive result rates of 1.4% vs. 27.5%, respectively. A multivariate analysis also revealed that the induration diameter of the TST was not affected by the interferon-gamma concentration after exposure to either of the antigens but was influenced by the number of BCG needle scars (p = 0.046). The whole blood interleukin-10 assay revealed that after antigen exposure, the median increases in interleukin-10 concentration was higher in the subgroup with the small increase in interferon-gamma concentration than in the subgroup with the large increase in interferon-gamma concentration (0.3 vs. 0 pg/mL; p = 0.004). CONCLUSIONS/SIGNIFICANCE: As a baseline screening test for low-risk Japanese healthcare students at their course entry, QFT yielded quite discordant results, compared with the TST, probably because of the low specificity of the TST results in the BCG-vaccinated population. We also found, for the first time, that the change in the interleukin-10 level after exposure to specific antigens was inversely associated with that in the interferon-gamma level in a low-risk population.

Development of an automatic Doppler flow signal detection system: variability of pulmonary and aortic peak flow velocity.

PURPOSE: Automatic Doppler flow signal detection systems can provide beat-to-beat information for large blood vessels. We have developed new equipment for automatic measurement of Doppler flow signals. The reliability of the system was examined, and the variability of aortic and pulmonary peak flow velocity was determined. METHODS: We measured peak flow velocity using a newly developed system in healthy volunteers and patients with atrial fibrillation. Analysis of variability of peak flow velocity was performed with maximal entropy methods. RESULTS: In Bland-Altman plots, the mean and standard deviation (SD) of differences in aortic peak flow velocities between the automatic and manual measurements were 0.22 ± 0.75 cm/s and 0.85 ± 0.38 cm/s, respectively, in five normal volunteers. Moreover, less than 5% of the plotted points were beyond ± 2 SD of the differences. Furthermore, good reproducibility was demonstrated using Bland-Altman plots and Pearson's correlation analysis. Identical reliability was obtained in patients with atrial fibrillation. The same results were obtained for pulmonary peak flow velocity. In five healthy subjects, aortic and pulmonary peak flow showed standard deviations of 7.2 ± 2.4 and 3.8 ± 0.6 cm/s, respectively, and coefficients of variation of 6.1% ± 1.0% and 5.1% ± 1.1%, respectively, in time-domain variability. Similarly, frequency-domain variability was obtained for both peak flow velocities. CONCLUSION: The present study demonstrated the reliability of a newly developed automatic Doppler flow signal detection system. Using this system, the present study demonstrated for the first time aortic and pulmonary peak flow velocity variability. The present analytical methods may have considerable potential for studying aortic and/or pulmonary flow variability in connection with cardiac performance and prognosis of cardiac disease.

Seed germination and seedling emergence of three annuals growing on desert sand dunes in China.

BACKGROUND AND AIMS: Information on the initial growth characteristics of annuals found in Chinese deserts is very limited. The aim of this study was to investigate seed germination and interactive effects of irrigation and seed burial depth in sand on seedling emergence and seedling survival in three annuals (Agriophyllum squarrosum, Bassia dasyphylla and Aristida adscensionis) commonly growing on sand dunes in these regions. METHODS: Effects of temperature, light and polyethylene glycol-6000 on seed germination were examined by irrigating seeds sown on filter paper in Petri dishes. Seedling emergence was examined for seeds sown on the surface of, or at different depths (5, 10, 20, 30, 40 and 50 mm) in, sand-filled pots, which were irrigated under different regimes. For seeds buried at a depth of 50 mm, seed viability was examined after irrigation of the pots. KEY RESULTS: Seeds of three species germinated at most temperatures recorded between spring and autumn in their native habitats. No seed dormancy was found in any species. For all three species, seedling emergence was most favoured when seeds were buried at a depth of 10 mm. When seeds sown on the sand surface were irrigated, seed germination was considerably suppressed due to water deficiency, but many seeds remained viable. For A. squarrosum and B. dasyphylla, many seeds that were deeply buried and irrigated remained ungerminated but viable, while for A. adscensionis deeply buried seeds germinated, but the seedlings did not emerge due to unfavourable seedling growth in deep sand. CONCLUSIONS: Precipitation is the most crucial factor in determining the seasonal emergence of seedlings of the three tested species in the field. The vertical distribution of seeds in sand determines the proportion of seeds that germinate after precipitation and acts to maintain seed banks over multiple years.

Recent trends of hyperuricemia and obesity in Japanese male adolescents, 1991 through 2002.

The aim of the present study was to determine the change of serum uric acid (UA) levels in male adolescents and to characterize the relationship between UA levels and obesity or its related factors. This study was conducted in 17,155 students at enrollment in Okayama University from 1991 through 2002, in which the mean serum UA level as a whole was 5.64 +/- 0.009 mg/dL (mean +/- SEM) and the incidence of hyperuricemia (>/=7.6 mg/dL) was 4.13%. Serum UA levels were correlated with obesity-related indicators, including body mass index (BMI; r = 0.282, P <.0001) and skin-fold thickness (r = 0.286, P <.0001). The incidence of hyperuricemia was increased in parallel with BMI. In the last 4 years (1999 through 2002) of the study period, serum UA levels (5.76 mg/dL) and the incidence of hyperuricemia (4.5%) were significantly increased compared with those in the earlier period (1991 through 1994: 5.50 mg/dL and 3.5%, respectively). However, BMI has been rather gradually decreased throughout 12-year observation in all the subjects. Hyperuricemia was related to the presence of other risk factors, including hypercholesterolemia, liver function abnormality, and hypertension. The frequencies of such abnormalities were higher than euuricemic subjects and this trend was notable in the most recent students enrolled from 1999 through 2002. Hyperuricemia was even found in the group of non-obese male adolescents. Taking into consideration that hyperuricemia is associated with a high prevalence of lifestyle-related diseases in adults, it is of great importance to prevent hyperuricemia at the early stage in Japanese adolescents.

Relationship between adrenomedullin and vasopressin-aquaporin system under general anesthesia.

AIM: The roles of adrenomedullin (AM) in body fluid balance under general anesthesia were investigated. METHODS: Time course changes in plasma osmolality, AM, arginine vasopressin (AVP), and urinary aquaporin 2 (AQP2) in 17 patients undergoing abdominal surgery under general anesthesia were examined. RESULTS: Increases in plasma AM levels were observed in parallel with increases in the levels of urinary AQP2/creatinine (Cr) before induction and 90 and 180 min after initiation of anesthesia. Significant correlations between plasma AM and urinary AQP2/Cr (r = 0.62, p < 0.0001) as well as urinary AVP/Cr and AQP2/Cr (r = 0.60, p < 0.0001) were uncovered. Multivariate stepwise analysis identified plasma AM as the critical independent factor affecting urinary AQP2/Cr level. CONCLUSION: A novel correlation of AM and AQP2 which overlays an AVP-AQP2 system may play a key role in fluid homeostasis during general anesthesia.

An exocellular thermolysin-like metalloprotease produced by Vibrio fluvialis: purification, characterization, and gene cloning.

An exocellular metalloprotease produced by Vibrio fluvialis, an enteropathogenic vibrio, was purified and characterized. The metalloprotease (V. fluvialis protease [VFP]) was found to have very similar characteristics to V. vulnificus protease, including a molecular mass of 45kDa, sensitivity to chelating agents or competitive inhibitors for thermolysin-like metalloproteases, and the substrate specificity. The structural gene for VFP was also cloned, and its nucleotide sequence was determined. The deduced amino acid sequence confirmed that VFP was a member of the thermolysin family. VFP, like V. vulnificus protease, showed the haemagglutinating, permeability-enhancing and haemorrhagic activities in addition to the proteolytic activity toward oligopeptide, casein or elastin.

Effect of change in body mass index on morbidity in non-obese university graduates.

To establish the actual serial changes in body weight in Japanese people and to elucidate the influence of changes in BMI on morbidity, we conducted a historical cohort study of university graduates from 1955 to 1990 using questionnaires and BMI data. The subjects of this study were 3,675 university graduates aged 26-62 years in whom BMI was determined at the time of enrollment in the university (Pre-BMI), 5 to 40 years earlier. Morbidity (one or more system diseases or obesity-related system diseases) was analyzed according to current age, sex, current BMI, deltaBMI (difference between current BMI and pre-BMI), and various lifestyle variables. The proportion of overweight subjects at enrollment to university was higher in recent male students compared to old students, but not in female graduates, and the BMI in both genders increased progressively after graduation, especially in recent male graduates. Pre-BMI correlated negatively and significantly with deltaBMI. The percentages of obese (BMI > or = 30 kg/m2) males and females were 1.6% and 0.5%, respectively, and high morbidity was observed in 56.1% and 42.2% of males and females, respectively. Stepwise regression analysis showed that in subjects with normal BMI at enrollment, prospective morbidity was dependent on ABMI in addition to age. Our results indicate that in subjects with normal body weight, prospective morbidity is determined by increment of ABMI, and suggest that maintenance of BMI at the late adolescence level is an important factor in preventing future disease.