蛭弧菌与微生物污染的相互关系探讨

本文在实验室条件下动态观察了蛭弧菌含量与微生物污染的相互关系。结果表明：蛭弧菌含量的增加滞后于水体污染，而污染过后蛭弧菌则可在较长时间内维持较高水平，这一特性在水污染指示中的可能作用值得进一步探讨。     

Evaluation of the debonding characteristics of 2 ceramic brackets: an in vitro study.

The objectives of this study were to evaluate and compare the shear bond strengths and bond failure locations of 2 currently available orthodontic ceramic brackets. Forty polycrystalline ceramic brackets (Clarity, 3M Unitek, Monrovia, Calif) and 40 monocrystalline ceramic brackets (Inspire, Ormco, Orange, Calif) were bonded to 80 extracted premolars with the same bonding system. All bonded specimens were placed in distilled water for 42 hours at 37 degrees C followed by thermal cycling for 700 complete cycles. Forty ceramic brackets, 20 of each type, were tested on a universal testing machine to determine the shear force levels required to debond them. Forty ceramic brackets were removed with the debonding pliers recommended by the manufacturers. All teeth were examined under an optical microscope, and the adhesive remnant index was used to assess the bond failure locations. The mean shear bond strength of the Clarity brackets was 21.67 +/- 5.19 MPa, and the mean shear bond strength of the Inspire brackets was 20.32 +/- 8 MPa. The mean shear bond strengths of both brackets were higher than those considered clinically optimal. Most of the brackets (85% of Clarity and 75% of Inspire) tested on the machine failed at the bracket-adhesive interface. One premolar bonded with an Inspire bracket had enamel fracture upon debonding. Most of the brackets (90% of Clarity and 95% of Inspire) debonded with pliers failed at the bracket-adhesive interface. No enamel damage was evident in any specimen when the brackets were removed with the appropriate pliers. The results indicate that the safest way to remove ceramic brackets with respect to reducing the chance of enamel damage is to use the debonding technique specifically designed for each.     

Distribution of the exfoliative toxin D gene in clinical Staphylococcus aureus isolates in France

Exfoliative toxin D (ETD) was identified recently as a new exfoliative toxin serotype. Like other exfoliative toxins, ETD induces intra-epidermal cleavage through the granular layer of the epidermis of neonatal mice. The distribution of ETD production was investigated in Staphylococcus aureus isolates from infected and colonised patients in France. The etd gene was found in 55 (10.5%) of 522 isolates tested. Isolates responsible for bullous impetigo and generalised staphylococcal scalded skin syndrome did not harbour etd, but etd was significantly more frequent in isolates causing cutaneous abscesses and furuncles. Most etd- and Panton-Valentine leukocidin-positive strains belonged to the clone of community-acquired methicillin-resistant S. aureus spreading currently throughout France.     

Characterization of adenosine receptors involved in adenosine-induced bronchoconstriction in allergic rabbits.

1. Recent work has suggested that adenosine may be involved in asthma via the activation of A1 receptors. However, the role of the recently cloned A3 receptor in airways is largely unknown. In the present study, we have investigated the role of the A3 receptor in adenosine-induced bronchoconstriction in allergic rabbits. 2. Aerosol challenge of antigen (Ag) immunized rabbits with the adenosine precursor, adenosine 5'-monophosphate (AMP), resulted in a dose-dependent fall in dynamic compliance (Cdyn). The maximum fall in Cdyn in these rabbits was significantly greater than that in litter matched, sham immunized animals (P < 0.05). However, there was no significant difference in the maximum increase in airways resistance (Rt) between Ag and sham immunized rabbits (P > 0.05). 3. Aerosol challenge of Ag immunized rabbits with cyclopentyl-adenosine (CPA) (A1-receptor agonist) elicited a dose-dependent fall in Cdyn in Ag immunized rabbits and the maximum fall in Cdyn in these rabbits was significantly greater than that observed in sham immunized rabbits (P < 0.05). Similarly, CPA induced dose-dependent increases in R1 in Ag immunized rabbits whereas sham immunized rabbits failed to respond to CPA within the same dose range. The maximum increase in RL in Ag immunized rabbits was significantly greater than that of sham immunized rabbits (P < 0.05). 4. Aerosol challenge of either Ag or sham immunized rabbits with the A3 agonist aminophenylethyladenosine (APNEA) did not elicit dose-dependent changes in either RL or Cdyn. Moreover, there was no significant difference in the maximum response, measured by either parameter, between the two animal groups (P > 0.05). 5. These data provide further evidence for a role of the A1 receptor in the airways, but do not support a role for the A3 receptor in adenosine-induced bronchoconstriction in the allergic rabbit.     

Effect of isoelectric point on biodistribution and inflammation imaging with indium-111-labelled IgG

Electrostatic effects play an important role in protein interactions and may alter the biodistribution of antibodies. To study the effect of molecular charge on the biodistribution and infection imaging properties of human polyclonal immunoglobulin G (IgG), its iso electric point was varied by changing the level of diethylene triamine penta-acetic acid (DTPA) substitution: 0.8, 0.9, 3.7, 5.1 and 5.9 DTPA/IgG. Biodistributions of the different IgG preparations were determined at 10 min, 1, 6, 24, and 48 h post injection in normal rats, and infection imaging properties were determined in rats withEscherichia coli thigh infections. The biodistribution was significantly affected by pl. The immunoglobulin preparations with 0.9 and 3.7 DTPA/IgG showed faster clearance from the circulation and generally lower accumulation in most organs. The images had a target-to-background ratio of approximately 1.3–2.3:1. These results suggest that even though targeting is not affected by the level of DTPA substitutions, preparations with 0.9 and 3.7 DTPA/IgG may be superior imaging agents because of reduced accumulation by background organs.     

Negative perceptions about self-control and identification with gender-role stereotypes related to binge eating, problem drinking, and to co-morbidity among adolescents.

PURPOSE: To examine the role of both positive and negative styles of self-control, and gender-role stereotypes in binge eating and problem drinking. METHOD: Participants were 428 adolescent boys and 555 girls from predominantly Anglo-Australian backgrounds who attended regional state schools in New South Wales, Australia. Students completed standardized questionnaires that assessed problem drinking, binge eating, self-control styles, and identification with gender-role stereotypes. ANOVA and post hoc Tukey tests were conducted to examine differences among adolescents who reported problems in binge eating, drinking, and both domains. RESULTS: Adolescents who reported eating and drinking problems also reported a high negative and a low positive sense of self-control coupled with self-identification with the traits that typically describe negative dimensions of gender-role stereotypes. Regardless of gender, problem drinking was mainly related to traits of negative masculinity (bossy, noisy aggressive, etc.) whereas binge eating was mainly related to negative femininity (shy, needs approval from others, etc.). Participants who reported eating and drinking symptoms recorded low scores on positive control, high scores on negative control, and also high scores on the negative dimensions of masculinity and femininity. SUMMARY: A negative and passive style of self-control coupled with an identification with negative dimensions of gender summarizes the type of self-regulation that is implicated in both binge eating and problem drinking, and co-morbid symptoms. There is a need for interventions working toward a more balanced gender self-concept and a positive sense of self-control.