Clinical effectiveness of platelets in additive solution treated with two commercial pathogen-reduction technologies.

BACKGROUND: Two noninferiority, randomized, controlled trials were conducted in parallel comparing the safety and efficacy of platelets treated with Intercept or Mirasol pathogen-reduction technologies versus standard platelets. STUDY DESIGN AND METHODS: The primary endpoint was the percentage of hematology patients who developed World Health Organization Grade 2 or greater bleeding. A noninferiority margin of 11% was chosen based on expected Grade 2 or greater bleeding in 20% of controls. The study was closed for financial restrictions before reaching the planned sample size of 828 patients, and an intention-to-treat analysis was conducted on 424 evaluable patients. RESULTS: In the Intercept trial (113 treated vs. 115 control patients), the absolute risk difference in Grade 2 or greater bleeding was 6.1%, with an upper one-sided 97.5% confidence limit of 19.2%. The absolute risk difference in the Mirasol trial (99 treated vs. 97 control patients) was 4.1%, and the upper one-sided 97.5% confidence limit was 18.4%. Neither absolute risk difference was statistically significant. In both trials, posttransfusion platelet count increments were significantly lower in treated versus control patients. Mean blood component use in treated patients versus controls was 54% higher (95% confidence interval, 36%-74%; Intercept) and 34% higher (95% confidence interval, 16%-54%; Mirasol) for platelets and 23% higher (95% confidence interval, 8%-39%; Intercept) and 32% higher (95% confidence interval, 10%-57%; Mirasol) for red blood cells. Unexpected reactions and adverse events were not reported. Mortality did not differ significantly between treated and control patients. CONCLUSION: Although conclusions on noninferiority could not be drawn due to low statistical power, the study provides additional information on the safety and efficacy of pathogen-reduced platelets treated with two commercial pathogen-reduction technologies.

Adaptive modifications in the calpain/calpastatin system in brain cells after persistent alteration in Ca2+ homeostasis.

Persistent dysregulation in Ca(2+) homeostasis is a pervasive pathogenic mechanism in most neurodegenerative diseases, and accordingly, calpain activation has been implicated in neuronal cells dysfunction and death. In this study we examined the intracellular functional state of the calpain-calpastatin system in -G93A(+) SOD1 transgenic mice to establish if and how uncontrolled activation of calpain can be prevented in vivo during the course of prolonged [Ca(2+)](i) elevation. The presented data indicate that 1) calpain activation is more extensive in motor cortex, in lumbar, and sacral spinal cord segments compared with the lower or almost undetectable activation of the protease in other brain areas, 2) direct measurements of the variations of Ca(2+) levels established that the degree of the protease activation is correlated to the extent of elevation of [Ca(2+)](i), 3) intracellular activation of calpain is always associated with diffusion of calpastatin from perinuclear aggregated forms into the cytosol and the formation of a calpain-calpastatin complex, and 4) a conservative fragmentation of calpastatin is accompanied by its increased expression and inhibitory capacity in conditions of prolonged increase in [Ca(2+)](i). Thus, calpastatin diffusion and formation of the calpain-calpastatin complex together with an increased synthesis of the inhibitor protein represent a cellular defense response to conditions of prolonged dysregulation in intracellular Ca(2+) homeostasis. Altogether these findings provide a new understanding of the in vivo molecular mechanisms governing calpain activation that can be extended to many neurodegenerative diseases, potentially useful for the development of new therapeutic approaches.

Calpain-mediated activation of NO synthase in human neuroblastoma SK-N-BE cells.

In resting human neuronal cells, nitric oxide synthase (nNOS) is present in its native 160 kDa form in a quiescent state predominantly co-localized on the plasma membrane, via its PDZ (Psd-95/Discs-large/Zona Occludens) domain, with NMDA receptor (NMDA-R) and in tight association with heat shock protein 90 (HSP90). Following exposure of the cells to Ca(2+)-ionophore or to NMDA, nNOS undergoes proteolytic removal of the PDZ domain being converted into a fully active 130 kDa form. The newly generated nNO synthase form dissociates from NMDA-R and extensively diffuses into the cytosol in direct correlation with NO production. Intracellular redistribution and activation of nNOS are completely prevented in cells preloaded with calpain inhibitor-1, indicating that these processes are triggered by a concomitant activation of calpain. The role of calpain has been confirmed by immunoprecipitation experiments revealing that also mu-calpain is specifically recruited into the NMDA-R-nNOS-HSP90 complex following calcium loading. Thus, the formation of clusters containing HSP90, mu-calpain, nNOS and NMDA-R represents the limiting step for the operation of the mechanism that links an efficient synthesis of NO to a local increase in Ca(2+) influx.

Short-term nonhormonal and nonsteroid treatment in West syndrome.

PURPOSE: West syndrome (WS) is considered an age-dependent epileptic encephalopathy and also a particular type of electrical epileptic status. Short-term hormonal or steroid treatment of WS with good efficacy is reported in the literature. The aim of this retrospective multiinstitutional study was to evaluate the early discontinuation of nonhormonal and nonsteroid treatment for WS. METHODS: Twenty-two WS cases in which treatment was discontinued after a maximum of 6 months, were collected. Inclusion criteria were the presence of typical EEG hypsarrhythmia (HY) and video-EEG recorded epileptic spasms. Exclusion criteria were the presence of partial seizures or other seizure types before spasm onset. The patients were treated with vigabatrin (VGB) in 19 cases and nitrazepam (NTZ) in three. The dose range was 70-130 mg/kg/day for VGB and 0.7-1.5 mg/kg/day for NTZ. The drug was discontinued if spasms stopped and HY disappeared after a mean treatment period of 5.1 months (range, 3-6 months). All patients underwent repeated and prolonged awake and sleep video-EEG, both before and after drug discontinuation. RESULTS: Cryptogenic (15) and symptomatic (seven) WS patients were included. All the symptomatic cases had neonatal hypoxic-ischemic encephalopathy. The mean age at spasm onset was 5.5 months (range, 3-7 months; median, 6). The interval between spasm onset and drug administration ranged from 7 to 90 days (mean, 23 days; median, 20). The interval between drug administration and spasm disappearance ranged from 2 to 11 days (mean, 6 days; median, 6 days). The interval between drug administration and HY disappearance ranged from 3 to 30 days (mean, 9 days; median, 10 days). Drugs were stopped progressively over a 30- to 60-day period. Follow-up ranged from 13 to 50 months (mean, 26 months; median, 22 months). None of our cases showed spasm recurrence. CONCLUSIONS: Our data show that successful nonhormonal and nonsteroid treatment can be shortened to a few months without spasm recurrence in patients with cryptogenic or postanoxic WS.