Development of a new wound dressing with antimicrobial delivery capability

A bilaminar wound dressing composed of an outer membrane and an inner three-dimensional matrix of a fabric or a sponge may be considered to constitute an ideal structure that promotes wound healing: the outer membrane prevents body fluid loss, controls water evaporation, and protects the wound surface from bacterial invasion, and the inner matrix encourages adherence by tissue growth into the matrix. Using this concept, we developed a biosynthetic wound dressing with a drug delivery capability. This medicated wound dressing is composed of a spongy sheet of a chitosane derivative and collagen mixture that is laminated to an antimicrobial-impregnated polyurethane membrane. In this study, a gentamycin sulfate-impregnated wound dressing was prepared and evaluated. The antimicrobial efficacy of this wound dressing was examined on an agar plate seeded with Pseudomonas aeruginosa. Also, the cytotoxicity of an antimicrobial released from this wound dressing was examined in an in vitro system with cultured skin substitutes. Both in vitro tests have shown that this wound dressing is capable of suppressing bacterial growth and minimizing cellular damage. In addition, in the treatment of wounds inflicted on rats and rabbits, this wound dressing was shown to be efficacious in covering full-thickness and split-thickness skin defects. Finally, the efficacy of this wound dressing was evaluated in a nonrandomized open-label study of 31 clinical cases. In 31 cases treated with this wound dressing, good or excellent wound healing was achieved.     

Heart rate variability and apnea during sleep in Down's syndrome

Autonomic system dysfunction has been reported to occur frequently in patients with Down's syndrome (DS) and is constituted mainly by an imbalance between the sympathetic and vagal systems. The analysis of heart rate variability (HRV) during sleep is a quantitative reliable method for studying such a mechanism, but it has not yet been extensively and adequately applied in DS. In this study, HRV during sleep was evaluated in seven DS patients and in six normal controls, by also controlling for the presence of sleep apnea or arousal. The main results were an increased sympathetic function (low-frequency component of HRV) and a decreased vagal activity (high-frequency component of HRV) in DS with respect to normal controls, during apnea-free periods. Moreover, the presence of apnea, in DS, induced a further significant increase in low-frequency and very low-frequency components of HRV during sleep Stage 2. This study provides additional evidence of a brainstem dysfunctioning in DS, responsible for the abnormal imbalance between the sympathetic and vagal systems and confirms the brainstem involvement already suggested in the literature in order to explain brainstem-auditory evoked potential abnormalities and central sleep apnea in these patients.     

207例预激综合征的心律失常

对207例预激综合征行电生理检查.检出心律失常171例.占82.6%。房室折返性心动过速占所有心律失常的80.4%,心房颤动13.1%,其他6.5%.房室折返性心动过速占我院同期室上速的56.5%.远较房室结折返性心动过速(24.4%)多见。隐性旁路在室上速中占29%,居首位。上述情况反映我国人室上速的构成比可能与西方国家不同。     

Airway eosinophilia and expression of interleukin-5 protein in asthma and in exacerbations of chronic bronchitis

Background An increased nutnber of eosinophils in the bronchial mucosa has been demonstrated both in asthma and in exacerbations of chronic bronchitis. Oiyective To investigate whether the airway eosinophilia present in asthma and in chronic bronchitis during exacerbations is associated with interleukin (IL)-5 protein expression in the bronchial mucosa. Methods We obtained bronchial biopsies in 18 subjects with asthma (four intrinsic, seven extrinsic and seven occupational) and in II subjects with chronic bronchitis examined during an exacerbation. The findings were compared wilh those of bronchial biopsies from 10 subjects with chronic bronchitis examined under baseline conditions and from seven normal subjects, taken as controls. By immunohistochemistry, we assessed the expression of IL-5 protein and the number of eosinophils (EG2), mast cells ftryptase), and T-lymphocytes (CD3) in the submucosa. Results As compared with controls, the number of eosinophils was increased to a similar degree in both asthma (P < 0.001) and in exacerbations of ehronic bronchitis (P < 0.001). whereas the number of I L-5 immunopositive cells was increased significantly only in asthma (P < 0.01). No diflerences were observed in the number of tnast cells and T-lymphocytes between the four groups of subjects examined. Conciusions This study shows that the degree of airway eosinophilia is similar in asthma and in exacerbations of ehronic bronchitis, but only in asthma is it associated with an increased expression of I L-5 protein in the bronchial tnucosa.     

胸苷酸合成酶基因3’-UTR多态性与晚期胃癌化疗敏感性关系的研究

目的：研究胸苷酸合成酶（TS）基因3’-UTR多态性与胃癌对5-Fu化疗敏感性的关系。方法：收集经病理学确诊的晚期胃癌106例，所有病例化疗前抽静脉血，提取白细胞DNA，用PCR-RFLP技术检测TS3’-UTR基因型。所有患者均经5-FU为基础的化疗方案治疗。以WHO实体瘤疗效评定标准和毒性评定标准评价疗效和毒性。结果：（1）106例胃癌患者中TS＋6／＋6bp、＋6／-6bp、-6／-6bp基因型频度分别为7．6％、44．3％和48．1％，化疗的总有效率为35．9％。（2）TS＋6／＋6bp、＋6／-6bp、-6／-6bp基因型组化疗的有效率分别为0％（0／8）、40．4％（19／47）和37．3％（19／51）。TS-6／-6bp基因型组和＋6／-6bp组化疗的有效率均显著高于＋6／＋6bp组（Fisher双侧精确检验，P值分别为0．0452和0．0404）。TS-6／-6bp基因型组Ⅱ度以上毒副反应的发生率高于＋6bp／＋6bp基因型组，但其差异无统计学意义。结论：TS基因3’-UTR多态性与晚期胃癌对5-FU为基础的化疗敏感性相关，TS基因型检测有助于指导晚期胃癌的化疗。     

应城市食品从业人员肺结核患病情况监测分析

食品从业人员健康状况直接关系到食品安全,根据《食品卫生法》的相关规定,应城市疾病预防控制中心对本地区食品从业人员进行一年一次的预防性健康体检,现将近年对该行业患活动性肺结核者监测结果分析如下。     

纳米羟基磷灰石/硫酸钙复合人工骨顺铂缓释系统注射液的制备与研究

目的研制可注射α-CSH-nano-HA/PHBV-PEG顺铂释药系统,为骨转移瘤提供新型的局部药物缓释系统。方法α-CSH-nano-HA/PHBV-PEG载顺铂制成可注射用α-CSH-nano-HA/PHBV-PEG cis-platinum缓释微球,研究其结构、释药特性、可注射性以及力学性能。结果(1)第1、3、5、7天缓释微球的释药浓度分别为97.5、90.7、83.2、68.5μg/mL,第7天后趋于稳定。(2)可注射α-CSH-nano-HA/PHBV-PEG顺铂释药系统在液固比为0.7时可注射性强,与此同时缓释药系统随着液固比的增大凝固时间延长。结论α-CSH-nano-HA/PHBVPEG顺铂释药系统具有良好的注射性能和缓释作用。     

Patterns of Atrioventricular Conduction During Postexercise Recovery in Patients with Atrial Fibrillation and Wolff-Parkinson-White Syndrome

The effects of the postexercise recovery phase on the functional anterograde conduction properties of the accessory pathway (AP) were evaluated. Twenty-nine patients with Wolff-Parkinson-White (WPW) syndrome were submitted to supine maximal bicycle exercise testing. In seven patients (group I), in whom sustained atrial fibrillation (AF) could be induced by transesophageal pacing (TP), mean ventricular rate (MVR), the shortest R-R interval (SRR) between preexcited beats, and the observed percentage of preexcited beats were evaluated at rest, after each step of exercise and 2 minutes after the end of exercise. In 22 patients (group II), in whom sustained AF could not be induced, decremental TP was performed to evaluate the shortest atrial cycle length (SCL) with 1:1 conduction over AP at rest, after each step of exercise, and 2 minutes after the end of exercise. In four patients in group I, the protocol was repealed with atropine injected during the last minute of exercise. In 12 patients (three from group I and nine from group II), catecholamine plasma levels were measured at rest, at peak exercise, and during recovery. MVR was 144 ± 20 beats/min at rest, 186 ± 21 beats/min at peak exercise (P < 0.001 vs rest), and 179 ± 21 beats/min during recovery (P < 0,001 vs rest; P < 0.05 vs peak exercise). SRR was 289 ± 73 msec at rest, 223 ± 25 msec at peak exercise (P < 0.05 vs rest), and 227 ± 29 msec during recovery. Preexcited beat percentage was 95.4 ± 12 at rest, 35.2 ± 24.2 at peak exercise (P < 0.001 vs rest), and 85.1 ± 22.5 during recovery fP < 0.01 vs peak exercise and n.s. vs rest). In patients in whom atropine was injected MVR was 139 ± 17 beafs/min at rest, 184 ± 19 beats/min at peak exercise (P < 0.05 vs rest), and 172 ± 16 beats/min during recovery (P < 0.05 vs peak exercise, P < 0.05 vs rest); SRR was 320 ± 71 msec at rest, 225 ± 25 msec at peak exercise, and 232 ± 3 inset; during recovery; preexcited beat percentage was 99 ± 1 at rest, 26 ± 18 at peak exercise (P < 0.01 vs rest), and 28 ± 20 during recovery (NS vs peak exercise, P < 0.01 vsrest). In group II. mean sinus rate was 84 ± 12 beats/min at rest, 151 ± 15 beats/min at peak exercise, and 117 ± 21 beats/min 2 minutes after the end of exercise; mean SCL was 328 ± 75 msec at rest, 273 ± 76 msec at peak exercise (P < 0.0001 vs rest), and 280 ± 79 msec during recovery (P < 0.0001 vs rest and NS vs peak exercise). Mean epinephrineand norepinephrine plasma levels (12 patients from groups I and II) were; 4 7.9 ± 76.6 and 355.5 ± 185.1 pg/mL at rest; 193.0 ± 88.0 and 823.9 ± 390.3 pg/mL at peak exercise (P < 0.0001 vsrest); 148.5 ± 94.5 and 672.7 ± 272.3 during recovery (P < 0.001 vs rest; P < 0.01 vs peak exercise). Thus, during early recovery versus peak exercise: SCL and SRR are still lower and confirm the persistence of increased AP conductivity; in patients with atrial fibrillation preexcited beat percentage is markedly enhanced while the duration of preexcited complexes is increased and MVR is still high. The poslexercise recovery phase in patients with WPWand atrial fibrillation determines a higher ventricular response rate with major preexcitation than does rest and peak exercise. The fact that atropine prevents increases in preexcited beats percentage demonstrates that the underlying electrophysiological basis is a discordance of autonomic effects on the conduction properties of the two afrioventricular pathways.