Vitamin K-dependent coagulation factors and fibrinogen levels in FFP remain stable upon repeated freezing and thawing

BACKGROUND: FFP is considered adequate for transfusion up to 24 hours after thawing and is currently used most often to replace deficient clotting factors, such as in warfarin overdose. We set to examine the levels of vitamin K-dependent factors (i.e., prothrombin, FVII, F IX, FX), as well as fibrinogen, upon twice freezing and thawing of FFP. If factor levels in refrozen FFP remain within normal limits, this component can possibly be transfused, thus avoiding wastage of precious blood components. STUDY DESIGN AND METHODS: Twenty units of FFP, five units of each blood group A, B, AB, and O, were thawed, and aliquots were taken for measurement of coagulation factors. The plasma units were then kept for 24 hours at 4 degrees C, at which point a second aliquot was taken, The remaining FFP units were refrozen and kept at -80 degrees C for 1 week. The above procedure was then repeated. Coagulation-factor activity and fibrinogen level were measured by the coagulation analyzer. RESULTS: The mean levels of prothrombin, FVII, F IX, FX, and fibrinogen of each blood group (A, B, AB, and O) were calculated for each of four time points and found not statistically different (p > 0.05). Therefore, the rest of the analysis was done for all 20 FFP units as one group. The mean +/- SD levels of each coagulation factor at each time point demonstrated that all levels were within normal limits of all factors measured and that for none of the factors was there a significant decay of activity. CONCLUSIONS: The levels of prothrombin, FVII, F IX, FX, and fibrinogen remain stable and adequate for transfusion in twice-thawed-and-refrozen FFP. This component can be safely used for transfusion as a source of vitamin K-dependent clotting factors and fibrinogen.     

Evidence that DNA damage triggers interleukin 10 cytokine production in UV-irradiated murine keratinocytes.

UV irradiation interferes with the induction of T cell-mediated immune responses, in part by causing cells in the skin to produce immunoregulatory cytokines. Recent evidence implicates UV-induced DNA damage as a trigger for the cascade of events leading to systemic immune suppression in vivo. However, to date, there has been no direct evidence linking DNA damage and cytokine production in UV-irradiated cells. Here we provide such evidence by showing that treatment of UV-irradiated murine keratinocytes in vitro with liposomal T4 endonuclease V, which accelerates the repair of cyclobutylpyrimidine dimers in these cells, inhibits their production of immunosuppressive cytokines, including interleukin 10. Application of these liposomes to murine skin in vivo also reduced the induction of interleukin 10 by UV irradiation, whereas liposomes containing heat-inactivated T4 endonuclease V were ineffective. These results support our hypothesis that unrepaired DNA damage in the skin activates the production of cytokines that down-regulate immune responses initiated at distant sites.     

NAD(P)H oxidase 4 mediates transforming growth factor-beta1-induced differentiation of cardiac fibroblasts into myofibroblasts

Human cardiac fibroblasts are the main source of cardiac fibrosis associated with cardiac hypertrophy and heart failure. Transforming growth factor-beta1 (TGF-beta1) irreversibly converts fibroblasts into pathological myofibroblasts, which express smooth muscle alpha-actin (SM alpha-actin) de novo and produce extracellular matrix. We hypothesized that TGF-beta1-stimulated conversion of fibroblasts to myofibroblasts requires reactive oxygen species derived from NAD(P)H oxidases (Nox). We found that TGF-beta1 potently upregulates the contractile marker SM alpha-actin mRNA (7.5+/-0.8-fold versus control). To determine whether Nox enzymes are involved, we first performed quantitative real time polymerase chain reaction and found that Nox5 and Nox4 are abundantly expressed in cardiac fibroblasts, whereas Nox1 and Nox2 are barely detectable. On stimulation with TGF-beta1, Nox4 mRNA is dramatically upregulated by 16.2+/-0.8-fold (n=3, P<0.005), whereas Nox5 is downregulated. Small interference RNA against Nox4 downregulates Nox4 mRNA by 80+/-5%, inhibits NADPH-driven superoxide production in response to TGF-beta1 by 65+/-7%, and reduces TGF-beta1-induced expression of SM alpha-actin by 95+/-2% (n=6, P<0.05). Because activation of small mothers against decapentaplegic (Smads) 2/3 is critical for myofibroblast conversion in response to TGF-beta1, we also determined whether Nox4 affects Smad 2/3 phosphorylation. Depletion of Nox4 but not Nox5 inhibits baseline and TGF-beta1 stimulation of Smad 2/3 phosphorylation by 75+/-5% and 68+/-3%, respectively (n=7, P<0.0001). We conclude that Nox 4 mediates TGF-beta1-induced conversion of fibroblasts to myofibroblasts by regulating Smad 2/3 activation. Thus, Nox4 may play a critical role in the pathological activation of cardiac fibroblasts in cardiac fibrosis associated with human heart failure.     

The composition of surrogate alcohols consumed in Russia

BACKGROUND: In the course of a case-control study examining determinants of premature death among working age men, it became clear that a significant percentage of the population (7.3%) were drinking a variety of surrogate alcohol products (products not legally sold for consumption). In this population, where there is a high death rate from alcohol-related causes, including acute alcohol poisoning, it was important to know what these products contained. METHODS: The identity of products being consumed was identified from the survey of controls. Representative samples were obtained and subjected to analysis using gas chromatography and mass spectrometry to determine their composition. RESULTS: Three broad groups of product were identified: samogon (home-produced spirits); medicinal compounds; and other spirits (mainly sold as aftershaves). Commercially produced vodkas were used for comparison. Samogon contained lower quantities of ethanol than vodka [mean, 39 vs. 44 volumetric percentage (v/v%), respectively] but in addition contained certain toxic long-chain alcohols. Medicinal compounds contained only ethanol, at a higher concentration that vodka (mean, 66 v/v%), while the other spirits, which were also essentially pure ethanol, contained a mean of 94 v/v%. CONCLUSIONS: A significant number of Russian men are drinking products that have either very high concentrations of ethanol or contaminants known to be toxic. These products are untaxed and thus much less expensive than vodka. There is an urgent need for policy responses that target their production and consumption.     

Early mortality rates in older kidney recipients with comorbid risk factors

BACKGROUND: There are over 60,000 candidates on the deceased donor kidney wait-list and the percentage of candidates over age 50 years continues to grow each year. National data have not previously been used to evaluate the association of comorbidities with mortality in older patients. METHODS: A multivariate analysis of 30,262 deceased donor primary kidney recipients aged 18-59 years and 8,895 aged >or=60 years evaluated the association of six recipient comorbidities on 90- and 365-day patient mortality rates. The additional effects of expanded criteria donors (ECD) and development of delayed graft function (DGF) were also evaluated. RESULTS: The 365-day mortality rate for recipients aged >or=60 years (10.5%) was more than twice that of recipients aged 18-59 years (4.4%) and comorbidities significantly increased mortality rates even higher (10.6-21.4%). The 365-day mortality rate for recipients aged >or=60 years who received an ECD kidney was 14.4% and who developed DGF was 15.9% while recipients with comorbidities but no DGF and no ECD ranged from 16.0 to 42.3%. The 365-day transplant mortality rate of recipients aged >or=60 years with comorbidities is higher than the 365-day wait-list mortality for patients with the same comorbidities, suggesting a lack of survival benefit from transplantation. CONCLUSIONS: Mortality rates for patients aged >or=60 years with comorbidities are higher than for those without comorbidities, significantly higher than for younger patients, and higher than for wait-listed patients. Thus, utility may be poorly served by allocating kidneys to older patients with comorbidities, and perhaps discussion of exclusionary listing criteria is warranted.     

A deficit of brain dystrophin 71 impairs hypothalamic osmostat

Patients with Duchenne muscular dystrophy (DMD) and mdx mice, devoid of dystrophin proteins, show altered ionic homeostasis. To clarify dystrophin's involvement in the central control of osmotic stimuli, we investigated the effect of the disruption of Dp71, the major form of dystrophin in the brain, on the hypothalamoneurohypophysis system (HNHS) osmoregulatory response. Dp71 and Dp140 are the principal DMD gene products in the supraoptic nucleus (SON) and neurohypophysis (NH). They are present in astrocyte and pituicyte end‐feet, suggesting involvement in both intrinsic osmosensitivity of the SON and vasopressin (AVP) release from the NH. In Dp71‐null mice, the cellular distribution of Dp140 was modified, this protein being detected on the membrane of magnocellular soma. The plasma osmolality of Dp71‐null mice was lower than that of wild‐type mice under normal conditions, and this difference was maintained after salt loading, indicating a change in the set point for osmoregulation in the absence of Dp71. The increase in AVP levels detected in the SON and NH of the wild‐type was not observed in Dp71‐null mice following salt loading, and the increase in AVP mRNA levels in the SON was smaller in Dp71‐null than in wild‐type mice. This suggests that Dp71 may be involved in the functional activity of the HNHS. Its astrocyte end‐feet localization emphasizes the importance of neuronal–vascular–glial interactions for the central detection of osmolality. In the SON, Dp71 may be involved in osmosensitivity and definition of the “osmostat,” whereas, in the neurohypopohysis, it may be involved in fine‐tuning AVP release. © 2009 Wiley‐Liss, Inc.