Social Behaviours under Anaerobic Conditions in Pseudomonas aeruginosa

Pseudomonas aeruginosa is well adapted to grow in anaerobic environments in the presence of nitrogen oxides by generating energy through denitrification. Environmental cues, such as oxygen and nitrogen oxide concentrations, are important in regulating the gene expression involved in this process. Recent data indicate that P. aeruginosa also employs cell-to-cell communication signals to control the denitrifying activity. The regulation of denitrification by these signalling molecules may control nitric oxide production. Nitric oxide, in turn, functions as a signalling molecule by activating certain regulatory proteins. Moreover, under denitrifying conditions, drastic changes in cell physiology and cell morphology are induced that significantly impact group behaviours, such as biofilm formation

Dechlorination of Chloral Hydrate by Pseudomonas putida LF54 which Possesses Biofilm Adhesin Protein LapA

Because of the lack of enzymes in critical steps of catabolic pathways, low-molecular-weight halogenated compounds are often recalcitrant to biodegradation. In our previous study, we isolated Pseudomonas sp. LF54 (LF54), the first bacterium that has been shown to use chloral hydrate (CH) as sole carbon source by an assimilation pathway in which dechlorination is the critical step. In this study, we identified a transposon (Tn) mutant that can render LF54 defective in CH dechlorination. The molecular characterization of Tn mutants revealed that the transposon insertion sites map to lapA. Sequence analyses verified the existence of lapA in LF54. Additionally, induced expression of lapA in the conditional lapA mutant of LF54 further verified that defective lapA expression renders LF54 defective in dechlorination. Recent studies have revealed that the largest cell-surface-associated protein LapA, a biofilm adhesin, is able to initiate biofilm formation. This function was also verified in the induced conditional lapA mutant and in LF54. Furthermore, we also found out that the defective lapA mutant rendered the variation of bacterial motility. LapA, the largest biofilm adhesin protein of P. putida, which influences CH dechlorination and flagella motility, is a novel discovery not previously reported

A Prospective Comparison of EUS-Guided FNA Using 25-Gauge and 22-Gauge Needles

Background and Aims. There are limited data on the differences in diagnostic yield between 25-gauge and 22-gauge EUS-FNA needles. This prospective study compared the difference in diagnostic yield between a 22-gauge and a 25-gauge needle when performing EUS-FNA. Methods. Forty-three patients with intraluminal or extraluminal mass lesions and/or lymphadenopathy were enrolled prospectively. EUS-FNA was performed for each mass lesion using both 25- and 22-gauge needles. The differences in accuracy rate, scoring of needle visibility, ease of puncture and quantity of obtained specimen were evaluated. Results. The overall accuracy of 22- and 25-gauge needle was similar at 81% and 76% respectively (N.S). Likewise the visibility scores of both needles were also similar. Overall the quantity of specimen obtained higher with the 22-gauge needle (score: 1.64 vs. P < .001). However the 25-gauge needle was significantly superior to the 22-gauge needle in terms of ease of puncture (score: 1.9 vs. 1.29, P < .001) and in the quantity of specimen in the context of pancreatic mass EUS-FNA (score: 1.8 vs. 1.58, P < .05). Conclusion. The 22-gauge and 25-gauge needles have similar overall diagnostic yield. The 25-gauge needle appeared superior in the subset of patients with hard lesions and pancreatic masses

松本歯科大学病院における小児全身麻酔下集中歯科治療の検討 : 過去11年間の環境要因の変遷について

We investigated the actual child-rearing environment, considering factors such as hygiene training, among 177 children (102 boys, 75 girls) ranging from 1 year and 9 months to 7 years and 2 months in age who underwent intensive dental treatment under general anesthesia in the Department of Pediatric Dentistry, Matsumoto Dental University Hospital between January 1990 and December 2000. The following results were obtained. 1) The annual number of patients slightly increased between 1992 and 1994. Thereafter, the annual number of patients decreased slightly each year. 2) The mean age attreatmentwas 3 years and 7 months (44.5±12.9 months). 3) Concerning the regional distribution, more than 50% of the children came from Nagano Prefecture areas other than Shiojiri City, where our university is located. 4) With respect to feeding methods during infancy, most children were breast fed or mixed breast and bottle fed. Furthermore, any feeding irregularity was noted. 5) The mean interval from birth until the start of weaning was 7.5±4.1 months. The mean interval until completion of weaning was 16.0±6.3 months. 6) 95.5% of the children habitually brushed their teeth. The frequency of tooth brushing was "once a day" or "sometimes" in 69.5% of the children. 7) Overall, 46.9% of the children had received fluoride application

中国上海市小児における乳歯列形態の検討 : 正常咬合児72例の模型から

To obtain the dimensional data of the dental casts of growing and developing Chinese children, and to compare the data to the Japanese, we have performed dental examinations on children in the kindergarten attached to Shanghai Teachers\u27 University in Shanghai since 1996. As study materials, dental casts obtained between 1996 and 1999 from 72 Chinese children aged 3 to 6 years with normal primary occlusion were used to evaluate the mesio-distal crown diameters of the primary teeth, the sizes of the primary dental arch, and the standard values and frequency distributions of primary occlusion. 1. Males showed higher values in mesio-distal crown diameters in deciduous teeth, and the size of dental arch than females. 2. In regard to the interdental spaces both in the maxilla and mandible, primate and developmental spaces together were most frequently observed. 3. In regard to the occlusal relationship, the incidence of terminal planes was higher in the order of Vertical type > Mesial step type > Distal step type, and the incidence of primary canine occlusal relationship was higher in the order of type I>type III>type II. 4. The items that were thought to be characteristic of Chinese children were the frequency of only primate spaces, and the incidence of the Mesial step type of terminal plane and type III primary canine occlusal relationship

中国人小児の歯科疾患実態調査 : 天津(市内・郊外)および日本との比較

Dental health checkups of children were conducted in Tianjin, China (central and suburban areas of the city). The prevalence of dental disease in Tianjin was compared with that in Japan as reported in a 1999 survey report. The following results were obtained. 1. There was no marked difference in the prevalence of dental disease between central and suburban areas of Tianjin. 2. The caries incidence ratio and the average number of decayed teeth per child were significantly higher in Tianjin than in Japan, but the treated teeth rate was significantly lower in Tianjin than in Japan. This indicates that the treatment of dental caries is not sufficient in China. 3. Dental caries tended to be more severe among Japanese than Chinese children. As the economy develops and living conditions change in China, dental caries may become more prevalent there, coming to resemble Japan\u27s present condition. Follow-up sur-veys are needed