Reproducible volar partial lacerations in flexor tendons: a new device for biomechanical studies

A device was designed to create clinically relevant, precise partial flexor digitorum profundus tendon lacerations for in vitro studies but can be adapted for in vivo studies. This caliper-based system utilizes a direct measurement of the tendon height and assumes an elliptical cross section to select the depth of the cut. The accuracy was tested on 60 cuts on 12 human tendons lacerated to an expected 50% or 75% of their cross-sectional area, based on the assumption that the cross-section was elliptical in shape. The cuts were made in portions of the tendon that varied in cross-sectional shape and size. The cut surface of the laceration was colored with Methylene blue and then the laceration was completed. The tendon cross-section was digitally imaged and the respective areas of the stained and unstained regions were evaluated using image-processing software. The mean lacerated areas were 52% (SD 5%) and 73% (SD 6%) for targeted lacerations of 50% and 75%, respectively. The device thus appears to be accurate within an acceptable 5% margin of error from the expected area, and adaptable to intra- and inter-tendinous size variations.     

Evaluation of a community-based automated blood pressure measuring device

Background

Automated devices are widely available in the community for people to measure their blood pressure. We assessed the accuracy and reproducibility of a brand of community-based automated device against the standard mercury sphygmomanometer.

Methods

Same-arm pairs of blood pressure readings were obtained with the Vita-Stat 90550 automated device, a sphygmomanometer and the Omron HEM-705CP automated device in random order on volunteers in 3 community pharmacies using a modified protocol for evaluating blood pressure devices. Comparison of readings between the Omron device and the sphygmomanometer served as a positive control of how well a laboratory-validated automated device could perform in the community. Both the Association for the Advancement of Medical Instrumentation (AAMI) and British Hypertension Society (BHS) criteria were used to assess the accuracy and reproducibility of readings.

Results

The mean blood pressure reading and standard error (SE) of the mean for the 108 volunteers (66 women and 42 men) was 133/77 (SE 2/1) mm Hg with the Vita-Stat device, 131/77 (SE 2/1) mm Hg with the Omron device and 129/76 (SE 2/1) mm Hg with the sphygmomanometer. The mean difference in readings was 4.4/1.0 (standard deviation [SD] 9.4/6.2) mm Hg between the Vita-Stat device and the sphygmomanometer and 1.6/0.6 (SD 9.3/6.4) mm Hg between the Omron device and the sphygmomanometer. Neither automated device met the AAMI accuracy criteria for the systolic readings. The BHS grades were C/A (systolic unacceptable/diastolic acceptable) for each automated device. According to the BHS analytical criterion, all devices achieved acceptable reproducibility grades.

Interpretation

Neither automated device met the AAMI or BHS criteria for accuracy while in use in the community, and neither performed as well in the community as in the laboratory.Measurement of blood pressure outside the office setting, using ambulatory monitors, home recorders or community-based devices has become popular among both physicians and patients. These devices may help to improve patients'' involvement in their care¹ and they may allay physicians'' concerns about a possible “white-coat syndrome.” However, incorrect readings could lead to a false sense of security or incorrect clinical decisions.The British Hypertension Society (BHS)² and the Association for the Advancement of Medical Instrumentation (AAMI)³ have developed laboratory protocols to evaluate automated blood pressure measuring devices. Many devices have failed to meet minimum standards for accuracy and reproducibility.⁴One community-based device, the Vita-Stat, has been available in various models since 1976, although none has performed uniformly well in community evaluations.^5,6,7,8,9 The newest model, the Vita-Stat 90550, available in about 3000 Canadian communities since 1990, provides 40 million readings yearly (Fred Sarkis, Spacelabs Medical: personal communication, 2000). Hence, we decided to evaluate the Vita-Stat 90550 against the mercury sphygmomanometer for accuracy and reproducibility in the community. To assess how well a laboratory-validated device could perform in the community, we compared the Omron HEM-705CP, which has met both the BHS and the AAMI criteria,¹⁰ against the mercury sphygmomanometer.     

Gene therapy for ocular neovascularization: a cure in sight

Recent advances in the field of ocular gene transfer have led researchers pursuing treatment for age-related macular degeneration and diabetic retinopathy to turn to gene therapy for the answer. Viral vector-mediated delivery of both anti-angiogenic proteins and molecules that inhibit the eye's endogenous pro-angiogenic factors has successfully diminished the pathology of ocular diseases in rodent models. A gene-therapy solution to the debilitating blindness caused by ocular neovascularization may be on the horizon.     

B群脑膜炎单抗原疫苗能否出现

<正>脑膜炎仍旧是一种健康问题,因为还没有抗B群脑膜炎球菌的疫苗,B群脑膜炎球菌是引起脑膜炎疾病最常见的细菌。感染了脑膜炎的个体常常遭受到脑损伤、弱智、听力丧失、肢残,甚至死亡。脑膜炎病是全球的重大公共卫生问题,特别是对于婴幼     

Evaluation of a consumer fitness-tracking device to assess sleep in adults

Wearable fitness-tracker devices are becoming increasingly available. We evaluated the agreement between Jawbone UP and polysomnography (PSG) in assessing sleep in a sample of 28 midlife women. As shown previously, for standard actigraphy, Jawbone UP had high sensitivity in detecting sleep (0.97) and low specificity in detecting wake (0.37). However, it showed good overall agreement with PSG with a maximum of two women falling outside Bland–Altman plot agreement limits. Jawbone UP overestimated PSG total sleep time (26.6?±?35.3?min) and sleep onset latency (5.2?±?9.6?min), and underestimated wake after sleep onset (31.2?±?32.3?min) (p’s?<?0.05), with greater discrepancies in nights with more disrupted sleep. The low-cost and wide-availability of these fitness-tracker devices may make them an attractive alternative to standard actigraphy in monitoring daily sleep–wake rhythms over several days.     

Evaluation of mitochondrial membrane potential using a computerized device with a tetraphenylphosphonium-selective electrode

Mitochondrial membrane potential (Deltapsi(m)) plays important roles in the normal function of cells and in pathobiochemical situations. The application of ion-selective electrodes for the measurement of Deltapsi(m) is important for studying normal biological reactions and pathways and mitochondrial diseases. We constructed and optimized a computerized device for real-time monitoring of the Deltapsi(m), which included modification of tetraphenylphosphonium (TPP(+))-selective membrane that improved reproducibility of the TPP(+)-selective electrode. Application of MATLAB software increased the sensitivity of the system. We tested our improved device for membrane potential measurements of isolated mitochondria (in absolute scale of millivolts). In addition, we assessed relative changes of Deltapsi(m) (as changes in TPP(+) concentration) of digitonin-permeabilized cells (hepatocytes, control transmitochondrial cybrids, HeLa G and BSC-40) after addition of substrates, inhibitors, and uncoupler of respiratory chain. Our system can be successfully used for studies of many aspects of the regulation of mitochondrial bioenergetics and as a diagnostic tool for mitochondrial oxidative phosphorylation disorders.     

Evaluation of brushes for removal of fouling from fouling-release surfaces, using a hydraulic cleaning device

A portable hydraulic device has been developed for use in optimizing the design of brushes and cleaning units that may be employed to maintain fouling-release coatings. Laboratory tests showed that characteristics of experimental cleaning brushes, including bristle stiffness, density, and angle, significantly affected the shear and normal forces imparted to the surface and thus, to any encrusting organisms. The standoff distance between the cleaning unit and the surface also influenced the forces generated. The rate of rotation of the brush, however, had little effect on force. The hydraulic device, with its experimental brushes, can also be used to evaluate the cleanability of fouling-release surfaces in situ, or to assess wear of the coating system due to cleaning.     

Vision: a brake on the speed of sight

We move our eyes more often than our heart beats. Our brain seems to cope effortlessly with the consequences of these rapid visual alterations, but a new study shows that similar scene changes in the absence of eye movements delay the speed of information processing. So are there costs in constantly shifting our focus of gaze?     

我国部分小麦种质资源主要品质性状鉴定评价

"九五"期间,测定了来自10省(市、自治区)的1589份小麦种质资源的主要品质性状,了解了其籽粒的硬度、沉降值和蛋白质含量状况.筛选出一批高蛋白质、高硬度、高沉降值的优质资源,为小麦生产和品质育种提供种质基础.     

Evaluation of a portable light device for phase advancing the circadian rhythm in the home environment

This study evaluated the effectiveness of a head-mounted portable light device, Re-Timer, for phase advancing the circadian rhythm of healthy sleepers in the home environment. The Re-Timer was designed to address the limitations of traditional bright light boxes, making it more practical and efficient for administering light therapy. Eighteen healthy participants underwent a crossover design treatment protocol, consisting of seven consecutive mornings of using Re-Timer compared with the same procedure but not using Re-Timer. Circadian phase was measured using salivary dim light melatonin onset (DLMO) and subjective sleepiness was also assessed for other phase-change effects. After using the Re-Timer for seven mornings, a significant phase advance in DLMO of 41 min compared to a 10-min delay in the no-light control condition was observed. However, subjective sleepiness did not differ significantly between the two conditions. A few minor and transient side effects were experienced by participants, but no treatment was required. The Re-Timer is an effective and safe device for advancing the circadian rhythm of healthy sleepers at home. Future research on its clinical utility could make Re-Timer a practical and affordable way to self-administer bright light therapy for sleep disorders.