Clinical evaluation of the GlucoWatch® biographer: a continual, non-invasive glucose monitor for patients with diabetes

A device providing frequent, automatic, and non-invasive glucose measurements for persons with diabetes has been developed: the GlucoWatch^® biographer. This device extracts glucose through intact skin via reverse iontophoresis where it is detected by an amperometric biosensor. The biographer can provide glucose readings every 20 min for 12 h. The performance of this device was evaluated in two large clinical studies in a controlled clinical environment (n=231), and the home environment (n=124). Accuracy of the biographer was evaluated by comparing the automatic biographer readings to serial finger-stick blood glucose (BG) measurements. Biographer performance was comparable in both environments. Mean difference between biographer and finger-stick measurements was −0.01 and 0.26 mmol l⁻¹ for the clinical and home environments, respectively. The mean absolute value of the relative difference was 1.06 and 1.18 mmol l⁻¹ for the same studies. Correlation coefficient (r) between biographer and finger-stick measurements was 0.85 and 0.80 for the two studies. In both studies, over 94% of the biographer readings were in the clinically acceptable A+B region of the Clarke Error Grid. A slight positive bias is observed for the biographer readings at low BG levels. Biographer accuracy is relatively constant over all rates of BG changes, except when BG decreases more than 10 mmol l⁻¹ h⁻¹, which occurred for only 0.2% of points in the home environment study. Biographer precision, as measured by CV%, is approx. 10%. Skin irritation, characterized by erythema and edema, was either non-existent or mild in >90% of subjects and resolved in virtually all subjects without treatment in several days.     

Behaviour of late-instar gypsy moth larvae in high and low density populations

ABSTRACT. 1. Using scaffolding and night-vision equipment, we observed fifth and sixth instars of the gypsy moth, Lymantria dispar (L.), on Quercus velutina Lam. in the field.
2. In low-density populations, larvae fed at night and spent the day resting in sheltered sites away from the canopy. In high-density populations, larvae remained in the canopy throughout the day and night, and the amount of feeding during daylight hours increased with population density.
3. Larvae at all population densities used a similar sequence of behaviours and sampled a number of leaves when selecting feeding sites, but larvae in high-density populations switched feeding sites more frequently and fed continuously for shorter periods.
4. Larvae seldom interfered with each other's feeding in any of the populations.
5. When fifth instars were collected from the field and held for 24 h in an electronic feeding monitor, they maintained feeding rhythms that were characteristic of their source populations. Larvae spent more time crawling and less time feeding when offered foliage from high-density rather than low-density populations.     

Automatic recording of flea activity

An Insect Activity Monitor was created to measure the behavioural responses of fleas (Siphonaptera). The apparatus allows for a range of visual, chemo- and mechanoreceptor cues to be presented. The jumping response is detected by counting amplified pulses produced as the fleas land on a stretched membrane held over a microphone. Horizontal movements are detected using a system of infra-red beams and phototransistors which, when broken, are counted as a measure of activity. The apparatus was tested using Ceratophyllus hirundinis (Curtis), Ceratophyllus farreni (Rothschild) and Ceratophyllus rusticus (Wagner), co-inhabiting species from the nests of the house martin (Delichon u.urbica L.). No unaided emigration or immigration has been demonstrated in these species (Clark, 1988) and much of their time is spent confined to the darkness of the nest. In addition to species contrasts, females were more active than males and fleas were more active at 25 degrees C than at 18 degrees C. The more active bird flea Ceratophyllus garei (Rothschild) from the nest of pheasant (Phasianus colchicus L), was tested for responses to light of varying intensity. Activity was stimulated by white light, but not proportional to light intensity.     

电容法在线测定发酵过程中毕赤酵母浓度的研究

活细胞量是与细胞生长、代谢、生产力相关的重要生理参数。在线活细胞测定仪能够利用电容的原理检测发酵液中的活细胞量。本文详细介绍了国产在线活细胞测定仪的检测原理,并说明了其在毕赤酵母发酵过程中的应用情况。结果表明,我们设计的在线活细胞测定仪能够直接、实时、在线获得发酵过程中可靠的活细胞量,且有效避免采样操作的干扰。这一技术符合过程分析技术(PAT)的要求,并可以与其他参数相结合进行分析,作为发酵过程开发、控制和优化的有利工具。     

Real-time monitoring of nitric oxide and blood flow during ischemia-reperfusion in the rat testis

In the present study, we attempted to clarify the role of nitric oxide (NO) and its release during the ischemia-reperfusion rat testis. Eight-week-old male Sprague-Dawley rats were divided into seven groups: age-matched control rats, ischemia (30 minutes)-reperfusion (30 minutes) rats without N^G-nitro-L-arginine methyl ester (L-NAME) and L-arginine (L-Arg) treatment, ischemia (30 minutes)-reperfusion (30 minutes) rats treated with L-NAME (10, 30, and 100 mg/kg), ischemia-reperfusion rats treated with L-Arg (10 and 30 mg/kg). Sixty minutes prior to induction of ischemia, L-NAME or L-Arg was administrated intraperitoneally. Real-time monitoring of blood flow and NO release were measured simultaneously with a laser Doppler flowmeter and an NO-selective electrode, respectively. NO₂-NO₃ and malonaldehyde (MDA) concentrations were measured in the experimental testes. Furthermore, we investigated possible morphological changes in the testis. Clamping of the testicular artery decreased blood flow to 5–20% of the basal level measured before clamping. Immediately following clipping of the artery, NO release rapidly increased. After removing the clip, NO release gradually returned to the basal level. This phenomenon was enhanced by treatment with L-Arg and inhibited by treatment with L-NAME. NO₂-NO₃ concentrations were increased by treatment with L-Arg and decreased by treatment with L-NAME, while MDA concentrations were increased by treatment with L-NAME and were decreased by treatment with L-Arg. In histological studies, the ischemia-reperfusion caused infiltration of leukocytes and a rupture of microvessels in the testis. Our data suggest that NO has cytoprotective effects on ischemia-reperfusion injury in the rat testis.     

实时定量PCR技术及应用

实时定量PCR(Real-tim e Quantitative Polym erase Chain Reaction,RQ-PCR),是20世纪90年代中期发展起来的基于PCR技术的利用不同的荧光检测来给核酸定量的技术。克服了传统PCR的许多不足,能准确敏感地检测模板浓度,DNA拷贝数和检测基因变异。综述了RQ-PCR技术的原理,RQ-PCR实时定量检测系统及应用。     

氟磺酰胺复配毒饵对红火蚁的田间防治效果

在深圳市龙岗区和宝安区对氟磺酰胺复配毒饵进行药效评价,试验结果表明,施药后3～15d,龙岗实验区蚁巢周围均有死亡工蚁陆续出现。第7d时,0.75%氟磺酰胺复配毒饵防治效果为16.99%,第28d时防治效果达47.43%,在试验结束的第140d时防治效果达97.93%;对照药剂0.5%氟磺酰胺毒饵对红火蚁Solenopsis invicta Buren的防除效果迅速,在第7d防治效果达50%以上。在宝安实验区,蚁巢的防治效果也随施药后时间的延长而增加,第28d的防治效果为51.65%,试验结束时防治效果达到94.72%;对照药剂0.5%氟磺酰胺毒饵42d防治效果达最大值为92.88%。上述结果显示,0.75%氟磺酰胺复配毒饵具有较快压低红火蚁种群密度,持效控制实验区红火蚁种群的特点。     

一种利用分泌型荧光素酶基因表达变化监测活细胞中miRNA活性的新方法

建立了一种以分泌型的荧光素酶Gluc为报告基因的miRNA传感器质粒(命名为Gsensor)监测活细胞中miRNA(microRNA)活性的方法。首先构建了pAAV2neo-Gluc-MCS-polyA质粒作为Gsensor的空载体,同时其中的MCS位点可供插入miRNA的靶序列。以miR142-3p为检测对象,将1个和3个拷贝的与miR142-3p完全互补靶序列分别插入pAAV2neo-Gluc-MCS-polyA中,构建成miR142-3p Gsensor和miR142-3p Gsensor-3。将它们分别转染至U937细胞中,检测培养上清中Gluc的表达水平。结果显示二者均可有效反映U937细胞中miR142-3p的抑制活性(分别与Gsensor空载体相比),提示Gsensor中采用一个拷贝的miRNA靶序列即可满足检测要求。并且miR142-3p Gsensor也能有效地反映出Anti-miR142对miR142-3p活性的抑制作用。随后,分析了时间、转染剂量对Gsensor检测结果的影响。结果表明,在U937细胞中miR142-3p Gsensor表现的miR142-3p活性在48h后趋于稳定;Gsensor转染剂量在0.001~0.05pg/cell范围内不影响其功能。最后,利用miR142-3p Gsensor检测了HEK293、U937、K562、SP2/0和P815细胞内miR142-3p活性,结果发现miR142-3p活性在U937、K562、SP2/0和P815细胞中均较高,而在HEK293中几乎没有活性。用QRT-PCR方法检测miR142-3p的相对拷贝数。结果表明,在HEK293、U937和K562细胞中,miR142-3p活性与其相对拷贝数呈正相关。本研究表明Gsensor可作为一种有效的miRNA活性检测工具,为体外实时动态监测miRNA活性提供了一种新方法。     

我国药用植物资源调查方法及资源监控机制研究进展

药用植物是中药资源的重要组成部分,设计调查方法是资源调查的前提,合理的调查方法需充分结合调查对象的特点及调查预期目标。本文通过概述我国野生与栽培药用植物的特点及开发利用中的问题,分析传统药用植物调查方法的适用性及高光谱遥感与“5S”集成技术在药用植物资源调查中的应用价值。实现药用植物资源从掌握资源总量向监控资源整体的跨越式转变对我国中药事业现代化及可持续发展具有重要意义,建立资源监控机制要求调查方法的高效率与高准确性,并可长期运作,建立卫星遥感动态监测平台与中药现代化产业统计报表制度作为我国药用植物资源整体监控机制具有较大应用前景。