基于光电传感器的多段脉搏波传播速度检测系统的研制

采用了一种以反射式和透射式红外光光电传感器和单片机为基础,用同步检测心电信号、桡动脉脉搏波、手指脉搏波信号来测定桡动脉和外周动脉脉搏波传播速度的方法,研制一种无创的多段脉搏波传播速度检测系统。在软件编程中脉搏波周期信号的识别是以心电R波峰值为基准,同时再根据它们之间的时延关系进一步确定脉搏波的波峰与波谷的范围,提高检测准确性及精度。该系统通过检测心电、桡动脉脉搏波和手指脉搏波信号可获得多段脉搏波传播速度参数,具有较高的检测精度和良好的应用前景。     

Large particle hyaluronic acid for the treatment of facial lipoatrophy in HIV‐positive patients: 3‐year follow‐up study

Objectives

Facial lipoatrophy can be a stigmatizing side effect of antiretroviral (AVR) treatment for HIV‐infected patients. We sought to evaluate the long‐term efficacy and safety of a new formulation of hyaluronic acid that can be injected in larger amounts and into deeper skin layers during 3 years of follow‐up.

Methods

Twenty patients received injections of Restylane SubQ^™. Refill treatment was offered at 12 and 24 months. Treatment effects were evaluated using ultrasound, the Global Aesthetic Improvement Scale, visual analogue scale (VAS) and the Rosenberg self‐esteem scale.

Results

Seventeen patients remained at 36 months. Mean (± standard deviation) total cutaneous thickness increased from 6 ± 1 mm at baseline to 12 ± 1 mm (P<0.001) at 36 months. Response rate (total cutaneous thickness >10 mm) was 70%. Fifteen patients classified their facial appearance as very much or moderately improved. VAS increased from 39 ± 25 to 70 ± 20 (P<0.05) and higher self‐esteem scores were reported. Local swelling and tenderness after treatment was common. Persistent papules found in several patients after treatment were removed effectively with hyaluronidase injections. Three patients, treated only at baseline, still had higher total cutaneous thickness scores at 36 months.

Conclusions

Our results indicate that a large particle hyaluronic acid formulation is a durable and well‐tolerated dermal filler for treating HIV‐positive patients with facial lipoatrophy.

     

p.R254Q mutation in the aquaporin‐2 water channel causing dominant nephrogenic diabetes insipidus is due to a lack of arginine vasopressin‐induced phosphorylation

Vasopressin regulates human water homeostasis by re‐distributing homotetrameric aquaporin‐2 (AQP2) water channels from intracellular vesicles to the apical membrane of renal principal cells, a process in which phosphorylation of AQP2 at S256 by cAMP‐dependent protein kinase A (PKA) is thought to be essential. Dominant nephrogenic diabetes insipidus (NDI), a disease in which the kidney is unable to concentrate urine in response to vasopressin, is caused by AQP2 gene mutations. Here, we investigated a reported patient case of dominant NDI caused by a novel p.R254Q mutation. Expressed in oocytes, AQP2‐p.R254Q appeared to be a functional water channel, but was impaired in its transport to the cell surface to the same degree as AQP2‐p.S256A, which mimics non‐phosphorylated AQP2. In polarized MDCK cells, AQP2‐p.R254Q was retained and was distributed similarly to that of unstimulated wt‐AQP2 or AQP2‐p.S256A. Upon co‐expression, AQP2‐p.R254Q interacted with, and retained wt‐AQP2 in intracellular vesicles. In contrast to wild‐type AQP2, forskolin did not increase AQP2‐p.R254Q phosphorylation at S256 or its translocation to the apical membrane. Mimicking constitutive phosphorylation in AQP2‐p.R254Q with the p.S256D mutation, however, rescued its apical membrane expression. These date indicate that a lack of S256 phosphorylation is the sole cause of dominant NDI here, and thereby, p.R254Q is a loss of function instead of a gain of function mutation in dominant NDI. © 2009 Wiley‐Liss, Inc.     

Bone marrow mesenchymal stem cells undergo nemosis and induce keratinocyte wound healing utilizing the HGF/c-Met/PI3K pathway

We previously showed cell–cell contacts of human dermal fibroblasts to induce expression of the hepatocyte growth factor/scatter factor (HGF) in a process designated as nemosis. Now we report on nemosis initiation in bone marrow mesenchymal stem cells (BMSCs). Because BMSCs are being used increasingly in cell transplantation therapy we aimed to demonstrate a functional effect and benefit of BMSC nemosis for wound healing. Nemotic and monolayer cells were used to stimulate HaCaT keratinocyte migration in a scratch-wound healing assay. Both indicators of nemosis, HGF production and cyclooxygenase-2 expression, were induced in BMSC spheroids. When compared with a similar amount of cells as monolayer, nemotic cells induced keratinocyte in vitro scratch-wound healing in a concentration-dependent manner. The HGF receptor, c-Met, was rapidly phosphorylated in the nemosis-stimulated keratinocytes. Nemosis-induced in vitro scratch-wound healing was inhibited by an HGF-neutralizing antibody as well as the small molecule c-Met inhibitor, SU11274. HGF-induced in vitro scratch-wound healing was inhibited by PI3K inhibitors, wortmannin and LY294002, while LY303511, an inactive structural analogue of LY294002, had no effect. Inhibitors of the mitogen-activated protein kinases MEK/ERK1/2 (PD98059 and U0126), and p38 (SB203580) attenuated HGF-induced keratinocyte in vitro scratch-wound healing. We conclude that nemosis of BMSCs can induce keratinocyte in vitro scratch-wound healing, and that in this effect signaling via HGF/c-Met is involved.     

Trends in ethical and legal frameworks for the use of human biobanks.

Numerous studies of genetic epidemiology and post-genomics in respiratory diseases rely on the use of biobanks, defined as organised biological sample collections with associated personal and clinical data. The use of biobanks is increasing and raises several ethical issues. What are the ethical trends and legal frameworks in the post-genomic era? Are there new issues in relation to the developments of techniques and new study designs? How does this affect the clinician's attitudes and relationship with the patients? The main ethical issues encountered are: informed consent; confidentiality; secondary use of samples and data over time; return of results; and data sharing. Different levels and modalities of dealing with such issues are identified and vary from legally binding measures to "soft" regulations, such as ethical recommendations by various committees or professional organisations. A further level of complexity appears with the increasing international dimension of such activities in a context in which national positions vary on those topics. There is a tension between a necessary level of diversity in ethical positions and an indispensable common pedestal of principles and procedures to manage these issues in order to foster research. Current legal and ethical trends favour the facilitation of secondary use of samples, more biobank openness, balanced with a growing attention to dialogue and public/stakeholder consultation, an increased role for research ethics committees and more sophisticated data protection and governance structures.