用混合粘合剂碳糊电极测定丁螺环酮

用混合粘合剂碳糊电极测定丁螺环酮张正奇，曾鸽鸣，刘传桂，黎艳飞（湖南大学化学化工系，长沙４１００８２）碳糊电极无毒，制作方便，表面更新容易，应用电位范围广，在药物分析中已有应用［１～５］。我们在液体石腊中加入添加剂，组成混合粘合剂，可显著改善电极的检...     

Viral infections in the mouth

Oral hairy leukoplakia (OHL) and Kaposi's sarcoma (KS) are commonly encountered in the HIV-infected patient. A unique feature of OHL is non-cytolytic high level of replication of Epstein–Barr virus (EBV) in the glossal epithelium. The expression of viral-encoded anti-apoptotic proteins concomitant to replicative proteins probably underlies this phenomenon. The question of whether OHL arises from activation of EBV latent in the tongue, or from superinfection by endogenous EBV shed via non-glossal sites or by exogenous EBV remains unresolved. Human herpesvirus 8 (HHV8) is now seen as necessary but not sufficient cause of KS. Expression of HHV8-encoded oncogenic proteins in endothelial cells probably explains the aberrant proliferation of these cells in KS lesions. Studies into why KS is so commonly observed at the palate in HIV-infected patients may provide important clues to its pathogenesis.     

Effects of 2 ankle fatigue models on the duration of postural stability dysfunction

Context: Muscle fatigue is generally categorized in 2 ways: that caused by peripheral weakness (peripheral fatigue) and that caused by a progressive failure of voluntary neural drive (central fatigue). Numerous variables have been studied in conjunction with fatigue protocols, including postural stability, maximum voluntary contraction force, and reaction time. When torque recordings fall below 50% of a maximum voluntary contraction, the muscle is described as fatigued, but whether this value is a good indicator of fatigue has not been studied.Objective: To compare the effects of 2 ankle musculature fatigue protocols (30% and 50%) on the duration of postural stability dysfunction.Design: To assess differences between the 30% and 50% fatigue protocols, we calculated a 1 between-groups factor (subjects) and 2 within-groups factors (fatigue, test) analysis of variance.Setting: E.J. Nutter Athletic Training Facility.Patients or Other Participants: Twenty subjects (10 men, 10 women; age = 21.15 ± 2.23 years; height = 172.97 ± 9.86 cm; mass = 70.62 ± 14.60 kg) volunteered for this study. Subjects had no history of lower extremity injury, vestibular or balance disorders, functional ankle instability, or head injury in the past 6 months.Intervention(s): On separate days, subjects performed isokinetic fatiguing contractions of the plantar flexors and dorsiflexors in a 30% protocol (70% decrease in strength) and a 50% protocol (50% decrease in strength).Main Outcome Measure(s): Baseline and postfatigue postural stability scores were determined before and after the isokinetic fatiguing contractions. Plantar-flexion peak-torque measurements were obtained for the 2 fatiguing protocols. Three prefatigue and 12 postfatigue postural stability trials were recorded. Velocities for testing were 60°/s for plantar flexion and 120°/s for dorsiflexion.Results: Sway velocity was significantly greater when the ankle was fatigued to 30% (1.56°/s) than in the 50% condition (1.36°/s). For the 30% protocol, sway was significantly impaired when the pretest condition (1.19°/s) was compared with posttest trial 1 (2.34°/s), trial 2 (2.37°/s), and trial 3 (1.71°/s). For the 50% protocol, sway was significantly impaired when the pretest condition (1.27°/s) was compared with posttest trial 1 (2.02°/s).Conclusions: The 30% fatigue protocol resulted in significantly longer impairment of postural stability than the 50% protocol. Because the 30% protocol resulted in a greater effect but was relatively short-lived (approximately 75 to 90 s), it is more useful for research purposes.     

Intertester reliability of assessing postural sway using the chattecx balance system

In this study, we examined intertester reliability of dynamic and static balance using the Chattecx Dynamic Balance System. Ten female and two male subjects were randomly assigned to two testers and completed ten, 10-second preprogrammed double- and single-leg test conditions. Balance was measured as postural sway in centimeters by the Chattecx Dynamic Balance System. Static balance consisted of the platform remaining stable, whereas dynamic balance consisted of the platform tilting in an anterior and posterior direction during testing. The protocols and average postural sway values were:1. Double-Leg Static Eyes Open ([unk] = .28 cm)2. Double-Leg Static Eyes Closed ([unk] = .37 cm)3. Double-Leg Dynamic Eyes Open ([unk] = .86 cm)4. Double-Leg Dynamic Eyes Closed ([unk] = 1.72 cm)5. Single-Leg Static Dominant Eyes Open ([unk] = .99 cm)6. Single-Leg Static Dominant Eyes Closed ([unk] = 1.70 cm)7. Single-Leg Static Nondominant Eyes Open ([unk] = .65 cm)8. Single-Leg Static Nondominant Eyes Closed ([unk] = 1.48 cm)9. Single-Leg Dynamic Dominant Eyes Open ([unk] = .99cm)10. Single-Leg Dynamic Nondominant Eyes Open ([unk] = .91 cm).The mean values of postural sway ranged from .28 cm to 1.72 cm for double-leg stance measures and from .65 cm to 1.70 cm for the single-leg stance measures. The intraclass correlations (ICCs)(2,1) ranged from poor to excellent (ICCs = .06 to .90) and the standard error of measurement (SEM) ranged from .06 to .34 for the 10 trials. We feel that variability exists between subjects and/or testers between trials. The wide range of reliability values suggests that further research should determine both intratester and intertester reliability using a variety of protocols for assessment of static and dynamic balance.     

Effect of a semi-rigid ankle stabilizer on performance in persons with functional ankle instability

STUDY DESIGN: Within-group repeated measures. OBJECTIVES: To determine the effect of a semi-rigid prophylactic ankle stabilizer (PAS) on performance of subjects with post-acute, unilateral ankle sprains who have mechanically stable ankles, but are functionally impaired. BACKGROUND: Most studies on PAS performance to date are limited to subjects with noninjured, nonimpaired ankles. No research has been reported to determine the effect PASs have on performance in subjects who have a mechanically stable, nonacute ankle sprain with functional impairment. METHODS AND MEASURES: Twenty-five subjects (8 men and 17 women; average height = 168.91 +/- 33.02 cm, average weight = 61.10 +/- 29.5 kg, and average age = 16.2 +/- 6 years) met the qualification criteria of the study. Subjects had unilateral grade I or II lateral ankle sprains of 3 to 4 weeks duration and were cleared medically to return to activities of daily living. Each subject's injured ankle was mechanically stable as determined by physical exam but was functionally impaired as determined by instability during the modified Rhomberg test. Separate 2 x 2 ANOVAs with repeated measures on brace condition (Aircast SportStirrup and nonbraced control) and test session (test session 1 and test session 2) were completed to assess the effect of ankle stabilization on 2 dependent variables (36.58-m shuttle-run and vertical-jump). RESULTS: Shuttle-run time was significantly faster for the braced condition (mean = 9.43 +/- .72 seconds) than for the nonbraced control (mean = 9.57 +/- .75 seconds), regardless of test session. Shuttle-run time was significantly faster for test session 2 (mean = 9.43 +/- .79 seconds) than for test session 1 (mean = 9.57 +/- .68 seconds), regardless of brace condition. No significant main or interaction effects occurred for vertical-jump. CONCLUSIONS: Use of a semi-rigid PAS significantly increased shuttle-run but not vertical-jump performance. This effect was immediate and did not require PAS acclimation.     

Inhibition of cigarette smoke-related lipophilic DNA adducts in rat tissues by dietary oltipraz

The present study investigated the effects of dietary oltipraz on cigarette smoke-related lipophilic DNA adduct formation. Female Sprague- Dawley rats were exposed daily to sidestream cigarette smoke in a whole- body exposure chamber 6 h/day for 4 consecutive weeks. One group of rats was maintained on control diet while another group received the same diet supplemented with either a low (167 p.p.m.) or high (500 p.p.m.) dose of oltipraz, starting 1 week prior to initiation of smoke exposure until the end of the experiment. Analysis of lipophilic DNA adducts by the nuclease P1-mediated 32P-post-labeling showed up to five smoke-related adducts. Adduct no. 5 predominated in both the lung and the heart while adduct nos 3 and 2 predominated in the trachea and bladder, respectively. Quantitative analysis revealed that the total adduct level was the highest in lungs (270+/-68 adducts/10(10) nucleotides), followed by trachea (196+/-48 adducts/10(10) nucleotides), heart (141+/-22 adducts/10(10) nucleotides) and bladder (85+/-16 adducts/10(10) nucleotides). High dose oltipraz treatment reduced the adduct levels in lungs and bladder by >60%, while the reduction in lungs in the low-dose group was approximately 35%. In trachea, the effect of low and high dietary oltipraz on smoke DNA adduction was equivocal, while smoke-related DNA adducts in the heart were minimally inhibited by high-dose oltipraz. In a repeat experiment that employed a 3-fold lower dose of cigarette smoke, oltipraz (500 p.p.m.) was found to inhibit the formation of DNA adducts in rat lungs and trachea by 80 and 65%, respectively. These data clearly demonstrate a high efficacy of oltipraz in inhibiting the formation of cigarette smoke-induced DNA adducts in the target tissues.