Effects of gemfibrozil (Lopid) on hyperlipidemia in acitretin-treated patients. Results of a double-blind cross-over study

Retrospectively 78 patients with uni- or bilateral acute acoustic trauma (AAT) were evaluated to assess the therapeutic effect of hyperbaric oxygenation (HBO). All subjects received saline or dextran (Rheomacodrex) infusions with Ginkgo extracts (Tebonin) and prednisone. Thirty six patients underwent additional hyperbaric oxygenation at a pressure of 2 atmospheres absolute for 60 minutes once daily. Both treatment groups were comparable as far as age, gender, initial hearing loss and prednisone dose are concerned. The delay of therapy onset was 15 hours in both groups and treatment was started within 72 hours in all cases. Control audiometry was performed after 6.5 days, when the HBO group had had 5 exposures to hyperbaric oxygenation. The average hearing gain in the group without HBO was 74.3 dB and in the group treated additionally with HBO 121.3 dB (P < 0.004). It is concluded, that hyperbaric oxygenation significantly improves hearing recovery after AAT. Therefore acute acoustic trauma with significant hearing threshold depression remains an otological emergency. Minimal therapy involving waiting for spontaneous recovery, which is mostly incomplete leaving a residual C5 or C6 and handicapping tinnitus, is not the treatment of choice. Randomized prospective clinical trials with a larger patient series are needed and further experimental studies are required to understand the physiological mechanisms of HBO responsible for the clinical success in AAT.     

Non-quasi-static models including all injection levels and DC, AC,and transient emitter crowding in bipolar transistors

Two-dimensional equivalent-circuit models for bipolar junction transistors are systematically derived by solving the continuity equations for DC, AC, and transient excitations. These models take into account carrier propagation delay, all injection levels, as well as exponential doping profiles. They include analytically DC, AC, and transient emitter crowding in a more detailed and accurate manner than previously available. Extensions of the models to accommodate arbitrarily doped and heavily doped quasi-neutral layers and to include energy-gap narrowing due to the electron-hole plasma present at high current density are described. The analysis leads to compact large- and small-signal equivalent-circuit lumped models, suitable for use in circuit simulators such as SPICE. The analytical solutions obtained reveal the two-dimensional distribution of the current and carrier densities in the intrinsic base layer and the onset of emitter crowding. They also provide information for the extraction of the intrinsic base resistance. Several assumptions made in the derivations are assessed by the computer program PISCES. The methods presented apply to both homojunction and heterojunction bipolar transistors     

Platelet-Rich Plasma Promotes the Proliferation of Human Keratinocytes via a Progression of the Cell Cycle. A Role of Prolidase

Although the role of platelet-rich plasma (PRP) in tissue regeneration has been confirmed in many studies, the mechanism of this process is still not fully understood. Human keratinocytes (HaCaT) cells were used as an experimental model for studies on the effects of PRP on cell proliferation, migration, collagen biosynthesis, prolidase activity, and its expression and anabolic signaling. The activation of epidermal growth factor receptor (EGFR), β₁-integrin, and insulin-like growth factor-1 receptor (IGF-1R) by PRP were investigated by western blot and immunocytochemistry. It has been found that PRP induced keratinocytes migration and proliferation through activation of cell cycle progression and EGFR downstream signaling. Similar biological effects were achieved by an addition to the culture medium of prolidase (PEPD), a ligand of EGFR (PRP is a rich source of PEPD–2 ng/mL). PRP-dependent stimulation of collagen biosynthesis was accompanied by an increase in the expression of NF-κβ, IGF-1R-downstream signaling proteins, and PEPD activity. The data suggest that PRP activates a complex of growth factors and adhesion receptors that stimulate cell proliferation, migration, and collagen biosynthesis. PRP induces PEPD-dependent human keratinocyte proliferation through activation of the EGFR receptor. Our study provides a novel mechanism of PRP-dependent wound healing.     

Lipofilling in Breast Oncological Surgery: A Safe Opportunity or Risk for Cancer Recurrence?

Lipofilling (LF) is a largely employed technique in reconstructive and esthetic breast surgery. Over the years, it has demonstrated to be extremely useful for treatment of soft tissue defects after demolitive or conservative breast cancer surgery and different procedures have been developed to improve the survival of transplanted fat graft. The regenerative potential of LF is attributed to the multipotent stem cells found in large quantity in adipose tissue. However, a growing body of pre-clinical evidence shows that adipocytes and adipose-derived stromal cells may have pro-tumorigenic potential. Despite no clear indication from clinical studies has demonstrated an increased risk of cancer recurrence upon LF, these observations challenge the oncologic safety of the procedure. This review aims to provide an updated overview of both the clinical and the pre-clinical indications to the suitability and safety of LF in breast oncological surgery. Cellular and molecular players in the crosstalk between adipose tissue and cancer are described, and heterogeneous contradictory results are discussed, highlighting that important issues still remain to be solved to get a clear understanding of LF safety in breast cancer patients.     

Psychological work characteristics,psychological workload and associated psychological and cognitive requirements of train drivers

This study aimed to assess the psychological work characteristics and psychological workload of train drivers and to define the psychological and cognitive requirements of their work. A systematic literature search was performed, and expert interviews were conducted. The following work demands were specific to train drivers: high emotional and mental demands, small amount of autonomy and skill discretion. No evidence of a high emotional workload, a high mental workload or short-term stress reactivity was found. In general, the drivers' fatigue complaints and recovery needs after work were comparable to that of other workers. However, severe sleepiness and high need for recovery did affect a substantial proportion of train drivers. The ability to stay aware, to anticipate, to remain attentive and to cope with fatigue are psychological and cognitive skills that are required to adequately and safely perform the train drivers' job. Including these requirements in periodic assessments of train drivers is recommended.     

Chrysin,Apigenin and Acacetin Inhibit Tumor Necrosis Factor-Related Apoptosis—Inducing Ligand Receptor-1 (TRAIL-R1) on Activated RAW264.7 Macrophages

Expression level of Tumor Necrosis Factor—related apoptosis—inducing ligand (TRAIL) receptors is one of the most important factors of TRAIL-mediated apoptosis in cancer cells. We here report for the first time data concerning TRAIL-R1 and TRAIL-R2 receptor expression on RAW264.7 macrophages. Three substances belonging to flavones: chrysin, apigenin and acacetin which differ from their substituents at the 4'' position in the phenyl ring were used in assays because of the variety of biological activities (e.g., anticancer activity) of the polyphenol compounds. The expression of TRAIL-R1 and TRAIL-R2 death receptors on non-stimulated and LPS (lipopolysaccharide)-stimulated macrophages was determined using flow cytometry. We demonstrate that RAW264.7 macrophages exhibit TRAIL-R1 surface expression and that the tested compounds: chrysin, apigenin and acacetin can inhibit TRAIL-R1 death receptor expression level on macrophages.     

A case study on software risk analysis and planning in medical device development

Software failures in medical devices can lead to catastrophic situations. Therefore, it is crucial to handle software-related risks when developing medical devices, and there is a need for further analysis of how this type of risk management should be conducted. The objective of this paper is to collect and summarise experiences from conducting risk management with an organisation developing medical devices. Specific focus is put on the first steps of the risk management process, i.e. risk identification, risk analysis, and risk planning. The research is conducted as action research, with the aim of analysing and giving input to the organisation’s introduction of a software risk management process. First, the method was defined based on already available methods and then used. The defined method focuses on user risks, based on scenarios describing the expected use of the medical device in its target environment. During the use of the method, different stakeholders, including intended users, were involved. Results from the case study show that there are challenging problems in the risk management process with respect to definition of the system boundary and system context, the use of scenarios as input to the risk identification, estimation of detectability during risk analysis, and action proposals during risk planning. It can be concluded that the risk management method has potential to be used in the development organisation, although future research is needed with respect to, for example, context limitation and how to allow for flexible updates of the product.     

Crystallinity and accessibility of fibrous carboxymethylcellulose by pad-roll technology

Statistically designed experiments have been made on partially carboxymethylated cotton fabric. The effect of the reaction parameters (concentration of sodium hydroxide and mono-chioroacetic acid and period of time) on the crystallinity (measured by x-ray diffraction), on the iodine sorption and on the disorder of amorphous fraction (calculated from iodine sorption capacity) are presented by polynomial models. © 1996 John Wiley & Sons, Inc.