负压状态下压力变化导致鲫鱼身体组织的损伤

通过试验研究负压状态下压力变化过程对鲫（Carassius auratus auratus)的损伤,试验采用真空泵和空气压缩机在试验容器内形成不同的压力变化过程,统计不同体长的鲫经历压力变化过程后的损伤情况,并对部分受损伤的鲫进行解剖和组织观察。研究发现负压状态下压力时变导数较大的变化过程会对鲫的生存构成直接威胁,主要损伤是鱼鳔部分或全部受损,在肝胰脏、肾脏等处有明显出血点。综合分析不同试验条件对鲫损伤的情况,得到了对鲫尽可能安全的压力时变导数极限值,从而为新型环保水力设施的设计提供参考依据,起到保护渔业资源的作用。     

重组乙肝疫苗纯度高效液相层析(HPLC)测定方法的改进

为建立重组汉逊酵母乙肝疫苗HPLC检定方法,应用TSK－G5000PW检测系统测定汉逊酵母重组乙肝疫苗表面抗原的纯度,对不同样品处理液的配比浓度和处理时间分别进行了探讨,作者选用DTT／Tween-80作为样品处理效果优于DTT＋Tween-20,1:50Tween-80与0.1mol/L等量混合为样品处理液的适宜浓度。样品处理液与等量样品混匀时间介于35s-2min时,HPLC分离效果好,结果稳定。该处理液及处理时间对CHO细胞及Merck酿酒酵母重组乙肝疫苗表面抗原的HPLC纯度测定无影响。结果表明：现有的HPLC检测系统用0.1mol/L DTT与1：50 Tween-80等量混合处理后能有效地检测不同类型重组乙肝疫苗表面抗原的纯度。     

Novel instrumented probe for measuring 3D pressure distribution along the vaginal canal

We developed an intravaginal instrumented probe (covered with a 10 × 10 matrix of capacitive sensors) for assessing the three-dimensional (3D) spatiotemporal pressure profile of the vaginal canal. The pressure profile was compared to the pelvic floor (PF) digital assessment, and the reliability of the instrument and repeatability of the protocol was tested. We also tested its ability to characterize and differentiate two tasks: PF maximum contraction and Valsalva maneuver (maximum intra-abdominal effort with downward movement of the PF). Peak pressures were calculated for the total matrix, for three major sub-regions, and for 5 planes and 10 rings throughout the vaginal canal. Intraclass correlation coefficients indicated excellent inter- and intra-rater reliability and intra-trial repeatability for the total and medial areas, with moderate reliability for the cranial and caudal areas. There was a moderate correlation between peak pressure and PF digital palpation [Spearman’s coefficient r = 0.55 (p < 0.001)]. Spatiotemporal profiles were completely different between tasks (2-way ANOVAs for repeated measures) with notably higher pressures (above 30 kPa) for the maximum contraction task compared to Valsalva (below 15 kPa). At maximum contraction, higher pressures occurred in the mid-antero-posterior zone, with earlier peak pressure onsets and more variable along the vaginal depth (from rings 3 to 10-caudal). During Valsalva, the highest pressures were observed in rings 4–6, with peak pressure onsets more synchronized between rings. With this protocol and novel instrument, we obtained a high-resolution and highly reliable innovative 3D pressure distribution map of the PF capable of distinguishing vaginal sub-regions, planes, rings and tasks.     

Effect of biceps-to-triceps transfer on rotator cuff stress during upper limb weight-bearing lift in tetraplegia: A modeling and simulation analysis

Rotator cuff stress during upper limb weight-bearing lifts presumably contribute to rotator cuff disease, which is the most common cause of shoulder pain in individuals with tetraplegia. Elbow extension strength appears to be a key determinant of rotator cuff stress during upper limb weight-bearing lifts since individuals with paraplegia who generate greater elbow extensor moments experience lower rotator cuff stress relative to individuals with tetraplegia. Biceps-to-triceps transfer surgery can increase elbow extension strength in individuals with tetraplegia. The purpose of this study was to determine whether active elbow extension via biceps transfer decreases rotator cuff stress during weight-bearing lifts in individuals with tetraplegia. A forward dynamics computational framework was used to estimate muscle stress during the lift; stress was computed as muscle force divided by the peak isometric muscle force. We hypothesized that rotator cuff stresses would be lower in simulated lifting with biceps transfer relative to simulated lifting without biceps transfer. We found that limited elbow extension strength in individuals with tetraplegia, regardless of whether elbow strength is enabled via biceps transfer or is residual after spinal cord injury, results in muscle stresses exceeding 85% of the peak isometric muscle stress in the supraspinatus, infraspinatus, and teres minor. The rotator cuff stresses we estimated suggest that performance of weight-bearing activities should be minimized or assisted in order to reduce the risk for shoulder pain. Our results also indicate that biceps transfer is unlikely to decrease rotator cuff stress during weight-bearing lifts in individuals with tetraplegia.     

Pressure effects on the apparent viscosity of artificial dipalmitoylphosphatidylcholine and dimyristoylphosphatidylcholine membranes using intramolecular excimer probe

Emission spectroscopy of intramolecular excimer probes allows the determination of ‘equivalent viscosity’ of membranes. While increasing the pressure on artificial membrane suspensions, variations in viscosity — essentially related to an increase in the order parameter in the membranes — are observed. In the case of mixed phospholipids, the effect of pressure is amplified, probably due to the existence of holes on the molecular scale between the two lipidic layers.     

Pressure effects on lipid-protein interactions in (Na+ + K+)-ATPase

The (Na⁺ + K⁺)-stimulated ATPase activity decreases with increasing pressure and a plot of the logarithm of the activity versus pressure shows a change in slope at a defined breakpoint pressure (P_b). The value of P_b increases linearly with increasing temperature. A $\text{d}\text{T}\text{d}\text{P}$ value of 27.7 ± 0.4 (S.D.) K/1000 atm is obtained. This is in very good agreement with the pressure shift for the melting transitions in phospholipids and aliphatic chains. This strongly indicates that an aliphatic chain melting process is involved in the breakpoint in the Arrhenius plot and pressure dependence of (Na⁺ + K⁺)-ATPase. The p-nitrophenyl phosphatase activity of this enzyme also decreases with pressure. In this case the plot of the logarithm of the activity versus pressure is linear without a break-point. The temperature dependence for (Na⁺ + K⁺)-ATPase was also studied in the presence of fluidizing drugs: desipramine and benzylalcohol. The presence of these drugs had no effect on the inflection point in the Arrhenius plot.     

Evolución clínica y funcional de los pacientes que ingresan en residencias tras una fractura de cadera. Implementación de un programa de intervención multinivel

Background and objectiveThe aim of this study was to determine the clinical and functional outcomes of patients discharged to nursing homes after a hip fracture.MethodsThe study included all patients admitted to a group of nursing homes after a hip fracture in 2016. A geriatric assessment protocol was applied, and patients were treated with a specific protocol for 90 days. They were assessed for nutritional status (Mini-Nutritional Assessment and Body Mass Index), pain (Visual Analogue Scale, and the PAINAD Scale), the presence of pressure ulcers, blood test (D vitamin, haemoglobin, proteins), and functional status (Barthel index and Functional Assessment Categories).ResultsOut of a total of 175 patients, 116 (75%) met the inclusion criteria. The mean age was 84.9 years old (±6.7 SD), and 91 (78.4%) were women. At admission, 73.8% of 65 residents had anaemia, 76.7% hypovitaminosis D, 88% malnutrition or «at risk of malnutrition», and 15.3% had pressure ulcers. After 90 days, the moderate-severe functional status (Barthel index < 60) was reduced from 90.4 to 39.6%, dependence due to gait from 97.3 to 36.1%, and moderate-severe pain from 88.9 to 14.4%. Most of the pressure ulcers healed (94.4%).ConclusionsPatients admitted to nursing homes after a hip fracture had poor clinical and functional status. This study shows that after 90 days from admission these patients had positive outcomes in terms of functionality, gait, pain control, and pressure ulcers healing.     

Suppression of LRRC19 promotes cutaneous wound healing in pressure ulcers in mice

The ischemia-reperfusion (I/R) induced skin lesion has been identified as primary cause of pressure ulcer. Better understanding of the mechanism is required for new therapy development. Leucine rich repeat containing protein 19 (LRRC19) is a recently discovered transmembrane protein containing leucine-rich repeats and plays a role in immune response. To investigate the role of LRRC19 in pressure ulcers, mouse ulcer model was established with two cycles of I/R. The expression of LRRC19 was assessed during injury. siRNA mediated LRRC19 downregulation was applied to investigate the disease severity, immune cell infiltration and pro-inflammatory cytokines production. The primary skin fibroblasts were stimulated with IL-1β to dissect the molecular mechanism. LRRC19 was readily induced in I/R induced lesion site in a pattern mimicking the disease progress as measured by wound area. Knockdown of LRRC19 by siRNA significantly alleviated the disease severity and attenuated immune cell infiltration and pro-inflammatory cytokines production. In primary skin fibroblast model, siRNA knockdown of LRRC19 suppressed IL-1β mediated NFκB activation and its downstream cytokines production. LRRC19 was a novel factor for I/R-induced tissue damage by promoting NFκB dependent pro-inflammatory response. Our results supported that LRRC19 could be a potential therapeutic target for pressure ulcers.     

The molecular biology of barophilic bacteria

Many microorganisms from the deep-sea display high-pressure-adapted — also described as barophilic or piezophilic — growth characteristics. Phylogenetic studies have revealed that a large proportion of the barophilic bacteria currently in culture collections belong to a distinct subgroup of the genus Shewanella, referred to as the “barophile branch.“ Many of the basic properties of barophiles that enable their survival at extremes of pressure remain to be elucidated. However, several genes whose expression is regulated by pressure, or which appear to be critical to baroadaptation, have been uncovered. One such operon, whose presence appears to be restricted to the “barophile branch,” has been identifed in DNA samples obtained from sediments recovered in the deepest ocean trench. In the case of another set of pressure-regulated genes, regulatory elements required for pressure signaling have been uncovered. The nature and regulation of these genes is discussed. Received: February 19, 1997 / Accepted: March 3, 1997     

加压对茶叶加工中酶活力影响的研究

本试验验采用调控大气压力的物理方法,研究了在红茶制作过程中加压与多酚氧化酶、α—淀粉酶、转化酶、蛋白水解酶活力强弱的关系。结果发现：加压能提高这四种酶活力,且在一定范围内随压力增加和加压时间延长,其活力均提高。同时,又研究了压力对多酚氧化酶（ＰＰＯ）同工酶活力的影响。结果发现：ＰＰＯ１、ＰＰＯ２的活力有较小幅度的提高,ＰＰＯ３基本没有变化,ＰＰＯ４、ＰＰＯ５、ＰＰＯ６随加压时间延长,活力呈大幅度提高。