Thrombocytopenia Induced by Polysulfone Dialysis Membranes.

BACKGROUND Biocompatible hemodialysis membranes have greatly advanced the treatment of renal failure. Synthetic polysulfone dialysis membranes are considered to be very biocompatible because of their low propensity to activate complement. However, these membranes can reduce platelet count through platelet activation, although the mechanism of this activation is unknown. CASE REPORT We report the case of an 82-year-old man with a history of chronic kidney disease with recurrent gastrointestinal bleeding and worsening renal function who was initiated on renal replacement therapy with polysulfone dialysis membranes. On admission, the patient's platelet count was normal at 233×10³/µL. A significant fall in platelet count was observed following most dialysis treatments, reaching a nadir of 37×10³/µL. With occasional dialysis treatments, his platelet count did not change. This dialysis-induced thrombocytopenia resolved following substitution with Cellentia-H cellulose triacetate single-use, hollow-fiber, high-flux hemodialyzer membrane. CONCLUSIONS Polysulfone membranes are capable of activating platelets, which can result in severe thrombocytopenia. However, the magnitude of dialysis-induced thrombocytopenia varies from treatment to treatment. As such, it may not be evident when the pre- and postdialysis platelet counts are measured for a single treatment. Because the etiology of this platelet activation is unknown, substitution with cellulose triacetate membranes should be considered. These membranes have an unrelated chemical composition and a very low propensity to activate platelets.

Pharmacological interaction between NSAIDS with clomipramine and risperidone in mice visceral pain.

Nonsteroidal anti-inflammatory drugs (NSAIDs) possess as primary action mechanism the inhibition of cyclooxygenases (COX-1, COX-2, and COX-3), thus producing a decreasing prostaglandin synthesis. This study was designed to evaluate whether the antinociception induced by NSAIDs could be modulated by clomipramine or risperidone using a chemical model of inflammatory acute visceral pain, the abdominal acetic acid induced a writhing test in mice. Dose-response curves, intraperitoneal, or intrathecal for the antinociceptive activity displayed by ketoprofen, piroxicam, nimesulide, parecoxib, and paracetamol were analyzed in order to obtain the ED50 of each drug. Pretreatment of mice with either clomipramine or risperidone, increased antinociceptive potency of ketoprofen, piroxicam, nimesulide, parecoxib, and paracetamol, expressed by a decrease in the values of antinociceptive ED50. The results that were obtained are in line with those where the inhibition of COXs provides a justification for most of the pharmacological actions. Nevertheless, several findings suggest other molecular mechanisms, among which may be mentioned, L-selecting shedding; inhibition of i-NOS; inhibition of NF-Kappa B; suppression metaloproteinasas; inhibition of ß2 integrin activation; activation of α2 -adrenoceptor; increase of IL-1ß; upregulation IL-6. In conclusion, the data generated in this study demonstrated that risperidone and clomipramine, separately, increase antinociceptive potency of NSAIDs in a chemical model of inflammatory acute visceral tonic pain.

Improvement of Apolipoprotein B in Argentine Indigenous School Children after Vitamin D Supplementation.

OBJECTIVE: To determine whether vitamin D supplementation improves non-traditional cardiovascular risk factors such as Apo B levels among indigenous children. METHODS: A prospective two-year study evaluated a treated cohort of 190 children (104 males) aged 9.4+ 2.2 years. Children were divided into group A (n=104; 54.7%) and group B (n=86; 45.3%). Both groups received vitamin D supplementation with 100,000 u/year; group B was treated in 2013 and group A in 2014. All subjects were evaluated at the end of each treatment and anthropometric measures, lipids and vitamin D levels between the two groups were compared. RESULTS: Changes in vitamin D levels were significantly higher in Group A, which was supplied in 2014, than in group B, which was not supplied in 2014 (6.8 vs 0.96 ng/dL; respectively). Levels of LDL-C and Apo B were improved in group A versus B: LDL-C (-5.7 vs 6.9 mg/dL respectively) and Apo B (-0.9 vs 11. mg/dL respectively). Several multiple regression linear analyses showed that changes in vitamin D were significantly associated with lower LDL-C levels (Beta- 0.41, p<0.01; R2 0.07); and with lower Apo B levels (Beta-0.37, p<0.01; R2 0.17). CONCLUSION: Vitamin D supplementation among indigenous children could improve Apo B levels.

High temperature optical fiber sensor based on compact fattened long-period fiber gratings.

A compact high temperature fiber sensor where the sensor head consists of a short fattened long period fiber grating (F-LPFG) of at least 2 mm in length and background loss of -5 dBm is reported. On purpose two different F-LPFGs were used to measure temperature variations, taking advantage of their broad spectrum and the slope characteristics of the erbium light source. This approach affected the spectrum gain as the linear band shifting took place. The measured sensitivity of the long period fiber gratings were about 72 pm/°C in a range from 25 to 500 °C. Here, the temperature rate of the experiment was 0.17 °C/s and the temperature response time was within 3 s. Moreover, temperature changes were detected with an InGaAs photodetector, where a sensitivity of 0.05 mV/°C was achieved.

Domain wall dynamics under nonlocal spin-transfer torque.

We study spin-diffusion effects within a continuously variable magnetization distribution, integrating with micromagnetics the diffusive model of Zhang and Li [Phys. Rev. Lett. 93, 127204 (2004)]. Current-driven wall motion is, in the steady velocity regime, shown to be adequately described by an effective nonlocal nonadiabatic parameter. This parameter is found to be 20% larger than its local counterpart for a vortex wall in a NiFe nanostrip and hardly modified for a transverse wall. This may account for the yet unexplained experimental evidence that vortex walls move more easily under current when compared with transverse walls. It is shown that this effective parameter can be derived from the domain wall structure at rest.