长效驱避剂的初步筛选研究

目的　研究一种对人有效保护时间 >8h ,且安全经济的长效驱避剂配方。方法　采用实验室 (GB T173 2 2 .10 -1998)和现场的药效测试方法对所配制的驱避剂配方进行效果测试。结果　实验室试验表明 ,以 2 0 %IR3 5 3 5配制 10、12、13、14号驱避剂配方在实验室内对白纹伊蚊的有效防护时间可达 8h以上 ;现场试验表明 ,10、12、13、14号驱避剂配方对人有效防止丘陵地区伊蚊的叮咬时间达 9h ,有效防止稻田地区中华按蚊的叮咬时间达 8h。结论以 2 0 %IR3 5 3 5与纤维素配制的驱避剂对人的有效保护时间可达 8h。纤维素对IR3 5 3 5有一定延长有效保护时间的缓释作用。实验所用配方对人的皮肤无不良反应 ,可作为户外活动人群防止蚊虫刺叮的驱避剂。     

Quantitation of T2′ anisotropic effects on magnetic resonance bone mineral density measurement

In this paper, the authors quantitate the anisotropy of susceptibility effects in an uniaxial trabecular bone model and show its relevance to clinical MR bone mineral density measurements. A physical model is described that quantitates the anisotropic MR behavior of uniaxial trabecular bone. To test the model, a phantom of parallel polyethylene filaments was scanned every 15° between 0° and 90° with respect to the system's main magnetic field (B₀). The distal radial metaphysis of a healthy female volunteer was scanned in orthogonal projections. The signal from each phantom image and each radial image was separated in a pixel-wise fashion into R₂ and R₂′ maps. As predicted, R₂′ relaxation showed anisotropic behavior and changed according to sin² (?), confirming that columnar structures parallel with B₀ will cause no MR susceptibility effects. Scans of the distal radius showed that R₂′ relaxation was twice as great with the forearm perpendicular to B₀ as when it was parallel to it, demonstrating different contributions from struts and columns. For both phantom and radial bone scans, R₂ relaxation was isotropic and did not change with object orientation.     

汉防己甲素对硫唑嘌呤致大鼠肝损伤的保护作用

研究汉防己甲素(Tet)对硫唑嘌呤(Aza)致大鼠肝损伤的保护作用。方法大鼠分为三组 :①对照组 ;②Aza组 ;③Aza Tet组。给药量分别为Aza25mg/kg·d。Tet30mg/kg·d,测定用药1wk和2wk时大鼠血清谷丙转氨酶(ALT)、碱性磷酸酶(AKP)、总蛋白(TP)和白蛋白(Alb)等肝功能指标以及血清中丙二醛(MDA)、超氧化物歧化酶(SOD)和全血谷胱甘肽含量(GSH) ,并作病理观察。结果用药1wk及2wk后 ,Aza组大鼠血清ALT、AKP、MDA含量均显著升高 ,TP、Alb、SOD、GSH含量均显著降低 ;合用Tet组则上述变化不明显 ,与对照组比较无显著性差异。病理学检查发现合用Tet组病理改变较轻微。结论Tet对Aza致大鼠肝损伤有保护作用 ,推测此作用与其抗脂质过氧化物、增加内源性解毒物质有关。     

Controlling for occasion-specific effects when assessing the test–retest reliability of self-report health questionnaires

OBJECTIVE: This study proposes a method for self-report health questionnaires to adjust test-retest reliability for changes during the test-retest interval based on an external measure, and to distinguish such changes from random response errors. METHODS: In our application, eighty participants completed the Symptoms of Illness Checklist (SIC) on two occasions, two weeks apart, immediately before interviews given on each occasion by one of two physicians in a crossover design. The physician interview scores served as external measures, and structural equation modeling was used to estimate the parameters of a model that corrected for the occasion-specific effect of participants' responses using information from the interviews. RESULTS: Correcting for changes in symptoms during the test-retest interval increased SIC test-retest reliability from .744 to .804 and significantly improved model fit (chi2(diff)(1) = 30.78, p < .001). CONCLUSIONS: The results suggest methods that can improve the evaluation of self-report health questionnaire test-retest reliability by identifying changes using an external measure, and distinguishing these from random response errors; these increased the estimated SIC test-retest reliability and indicated that the SIC was indeed able to measure changes over the studied time interval. This method can be applied across a broad range of questionnaires.     

Effect of concomitant food intake on absorption kinetics of fenoldopam (SK&F 82526) in healthy volunteers

Summary Eight healthy volunteers participated in an open crossover study to assess the effect of a standardised meal on the systemic availability of a single oral dose of fenoldopam mesylate 100 mg. Subjects were studied on four separate occasions, twice fasting and twice fed in randomised, balanced order. Plasma and urine samples were obtained before and at regular intervals up to 25 h post dose. Measurement of fenoldopam (SK&F 82526) and its 8-sulphate metabolite (SK&F 87782) were by means of HPLC-EC analysis. Area under the plasma concentration time curve (AUC) and maximum detected plasma concentration (C_max) for fenoldopam and SK&F 87782 were significantly reduced whereas time to maximum concentration was significantly increased with food. Using AUC's for fenoldopam and SK&F 87782, mean relative bioavailabilities were 35% and 81% respectively under fed compared with fasting conditions. Twenty-four hour excretion of fenoldopam was significantly reduced with food, but excretion of SK&F 87782 was apparently unchanged. Mean relative bioavailabilities calculated from these data were 83% and 86% respectively. Relatively large inter-subject variability in AUC and C_max were seen, but intra-subject variability was not marked. Mild symptoms associated with vasodilation were reported on all study days.     

微波与X线联合辐射对人体血液系统的影响

本文调查了微波与X线同时接触工人49名(联合组)、单微波接触工人48名(微波组)以及两者均不接触的工人46名(对照组)。联合组和微波组工人的微波辐射剂量每日平均约300μw/cm~2,联合组工人接触的X线剂量,每年小于5rem。结果显示:联合组中性粒细胞ACP、AKP活性以及中性粒细胞核棘突出现率均较微波组和对照组明显增高(P<0.01),糖原含量则较其它两组明显下降(P<0.01)。调查表明,低强度微波与低剂量X线联合辐射比单独微波辐射对人体的潜在危害更大。因此,对雷达等发射设备周围的工作人员,除必要的微波防护外。同时需要对X线进行防护。     

防晒制剂皮肤安全性的实验研究

目的 :探讨同一系列不同SPF(sunprotectionfactor)防晒制剂对皮肤的安全性 ,筛选安全有效的防晒制剂配方。方法 :选用白化豚鼠背部去毛 ,分别涂抹SPF值为 15、2 8、30 +三种防晒制剂 ,以UV光源照射 ,波长为 32 0～4 0 0nm ,强度为 ( 16 8± 2 )mW/cm2 。结果 :三种不同SPF防晒制品对实验动物皮肤各时相点反应积分为 ,SPF15组为0 ;SPF2 8组为 1;SPF30 +组为 3。结论 :三种不同SPF值产品对皮肤的光毒性有一定差异 ,提示SPF值在 2 8以内的防晒制剂皮肤安全性较好 ,SPF30 +的防晒制剂对皮肤有一定光毒刺激反应。     

Comparative observation of protective effects of earplug and barrel on auditory organs of guinea pigs exposed to experimental blast underpressure

Objective: To explore the protective effects of earplug and barrel on auditory organs of guinea pigs exposed to experimental blast underpressure (BUP). Methods : The hearing thresholds of the guinea pigs were assessed with auditory brainstem responses ( ABR). The traumatic levels of tympanic membrane and ossicular chain were observed under stereo-microscope. The rate of outer hair cells (OHCs) loss was analyzed using a light microscope. The changes of guinea pigs protected with barrel and earplug were compared with those of the control group without any protection. Results: An important ABR threshold shift of the guinea pigs without any protection was detected from 8h to 14d after being exposed to BUP with a peak ranging from -64.5 kPa to -69.3 kPa (P<0.01). The rate of perforation of tympanic membrane reached 87.5 % and that of total OHCs loss was 19.46%±5.38% at 14d after exposure. The guinea pigs protected with barrel and earplug had lower ABR threshold and total OHCs loss rate compared with the animals without any protection (P<0.01). All of the tympanic membrane and ossicular chain of the protected animals maintained their integrities. Meanwhile, the guinea pigs protected with the barrel had lower ABR threshold and total OHCs loss rate than those with earplug (P<0.01). Conclusions: The earplug and barrel have protective effects against BUP-induced trauma on auditory organs of the guinea pigs and the protective effects of barrel are better than those of earplug.     

The Effect of Antiepileptic Drugs on Cognition: Patient Perceived Cognitive Problems of Topiramate versus Levetiracetam in Clinical Practice

Summary:  Introduction: Neurocognitive complaints may interfere with long-term antiepileptic drug (AED) treatment and are an important issue in clinical practice. Most data about drug-induced cognitive problems are derived from highly controlled short-term clinical trials. We analyzed such cognitive complaints for the two most commonly used AEDs in a clinical setting using patient perceived problems as primary outcome measure.
Method: All patients of the epilepsy center Kempenhaeghe that received topiramate (TPM) or levetiracetam (LEV) from the introduction to mid 2004 were analyzed using a medical information system, an automated medical file. Patients were analyzed after 6, 12, and 18 months of treatment.
Results: Four hundred and two patients used either TPM (n = 260) or LEV (n = 142); 18 months retention showed a statistically significant difference, revealing 15% more patients that continued LEV compared to TPM: 18 months retention 46% for TPM and 61% for LEV [F (1.400) = 3.313, p = 0.043]. Neurocognitive complaints accounted for a significant number of drug discontinuations and especially the high frequency of neurocognitive complaints in the first period of TPM treatment appeared to be significant different from LEV [F(2,547) = 3.192, p = 0.042]. In the remaining patients, the difference in neurocognitive complaints was not statistically significant.
Conclusion: cognitive complaints are common in TPM treatment and frequently lead to drug withdrawal. The impact of LEV on cognitive function is only mild. This leads to a much higher (15%) drug discontinuation rate for TPM compared to LEV.     

LEEP刀治疗与护理相结合治疗宫颈疾病的作用

目的探讨LEEP刀治疗与护理相结合在治疗宫颈疾病中的作用。方法选择应用LEEP刀治疗与红外光治疗两组患者各60例。比较其疗效和护理作用。结果LEEP刀治疗比红外光治疗宫颈疾病效果要好。结论LEEP刀治疗与护理相结合对宫颈疾病的治疗值得推广应用。