Overnight storage of whole blood: cooling and transporting blood at room temperature under extreme temperature conditions.

BACKGROUND AND OBJECTIVES: Many countries allow the overnight storage of whole blood (WB) at ambient temperature. Some countries, such as Canada, also require a rapid cooling of WB with an active cooling system. Given the significant operational constraints associated with current cooling systems, an alternative method for cooling and transporting WB at 20-24°C was evaluated. MATERIALS AND METHODS: Phase 22 cooling packs (TCP Reliable Inc., USA) were used in combination with vacuum-insulated panel (VIP) boxes. Temperature profiles of simulated WB units were studied in extreme temperatures (-35 and 40°C). The quality of blood components prepared using Phase 22 packs and CompoCool-WB (Fresenius HemoCare, Germany) was studied. RESULTS: Phase 22 packs reduced the temperature of simulated WB bags from 37 to 24°C in 1·7 ± 0·2 h. Used in combination with VIP boxes, Phase 22 packs maintain the temperature of bags between 20 and 24°C for 15 and 24 h, compared to 2 and 11 h with CompoCool-WB, when exposed at -35 and 40°C, respectively. The quality of platelet concentrates and plasma was comparable, regardless of the cooling system used. For red blood cell units, per cent haemolysis on day 42 was slightly higher in products prepared after cooling with Phase 22 packs compared to CompoCool-WB (0·33 ± 0·15% vs. 0·21 ± 0·06%; P < 0·05). CONCLUSIONS: Phase 22 packs combined with VIP boxes are an acceptable alternative to butane-1,4-diol cooling systems. This system allows blood manufacturers to transport WB to processing facilities in a broad range of environmental conditions.

Improved leucoreduction of red blood cell units prepared after a 24-h hold with the platelet-rich plasma method using newly developed filters.

BACKGROUND AND OBJECTIVES: A previous study indicated that the extension of whole blood (WB) storage from 8 to 24 h at 20-24 degrees C before the processing of platelet-rich plasma (PRP)-depleted red blood cell (RBC) units had a negative effect on the efficacy of leucoreduction filters. In this study, we further characterized the phenomenon and tested the leucoreduction capacity of two newly developed filters. MATERIALS AND METHODS: Whole blood was stored at 20-24 degrees C and processed at 4-h intervals between 8 and 24 h postcollection. Components were leucoreduced before storage. Efficacy of novel filters to leucoreduce 24-h-hold PRP-depleted RBC units was also evaluated. RESULTS: Using a conventional filter, the mean residual white blood cell (WBC) counts in leucoreduced PRP-depleted RBCs were comparable in units prepared within 12 h from collection but gradually increased upon extended preprocessing storage from 0.36 +/- 0.03 at 12 h to 0.46 +/- 0.21, 0.76 +/- 0.54 and 1.72 +/- 1.76 x 10(6) per unit at 16, 20 and 24 h, respectively. However, the mean residual WBC content in 24-h-hold RBCs was reduced to 0.60 +/- 0.39 x 10(6) and 0.46 +/- 0.13 x 10(6) per units using RC2D and the prototypes B-1582 rev B filters, respectively. CONCLUSION: For PRP-depleted RBC units, the extension of the WB room temperature storage from 8 to 24 h before processing is likely to require the introduction of newly developed filters having an increased leucoreduction capacity in order to meet the maximal residual WBC guideline in the RBCs.

Placental oxidative stress in a rat model of preeclampsia.

The onset of preeclampsia is associated with increased maternal insult that could affect placental function. By increasing sodium intake (0.9% or 1.8% NaCl in drinking water) during the last week of gestation in the rat, we developed an animal model that shows many characteristics of preeclampsia such as increased blood pressure, decreased circulatory volume and diminished activity of the renin-angiotensin-aldosterone system. The aim of the present study was to determine in this model whether maternal perturbations in pregnancy lead to placental oxidative stress. Sprague-Dawley pregnant rats receiving salted-water were compared to not-supplemented pregnant rats. Markers of oxidative stress, ensuing cell death, and changes in the production of vasoactive substances (prostanoids: thromboxane, TxB(2); and prostacyclin, PGF(1alpha)) and the pro-inflammatory cytokine tumour necrosis factor-alpha (TNF-alpha) were measured in the placenta. In tissue from pregnant rats on 1.8% NaCl supplement, 8-iso-PGF(2alpha) levels, TxB(2)/6-keto-PGF(1alpha) ratios, total TNF-alpha RNA expression, as well as the apoptotic index (Bax/Bcl-2 ratio) and endothelial nitric oxide synthase protein expression increase while total glutathione content decreases. These findings demonstrate that maternal insult during gestation induced an imbalance in the oxidative environment in the placenta favouring oxidation. This was accompanied by an increased synthesis of vasoconstrictive substances and TNF-alpha by the placenta as well as the increased rate of placental cell apoptosis.

Proteolytic activation of the interleukin-1beta precursor by Candida albicans.

Chronic inflammation rather than invasion is characteristic of some forms of superficial candidiasis such as denture stomatitis. We hypothesized that Candida albicans may play a critical role in the pathogenesis of inflammatory lesions observed in chronic candidiasis by activating the proinflammatory cytokine interleukin-1beta (IL-1beta) from epithelial stores of the precursor. The aim of this study was therefore to demonstrate the proteolytic cleavage and activation of the inactive precursor of IL-1beta (pro-IL-1beta) by C. albicans. After incubation of either blastospores or hyphae with the inactive precursor, proteolytic cleavage was monitored by sodium dodecyl sulfate-polyacrylamide gel electrophoresis Western immunoblotting analysis, and the biological activity of the cleavage products was tested in a bioassay. We report here that late-stationary-growth-phase blastospores as well as hyphae of C. albicans, but not exponentially growing cells, can efficiently cleave pro-IL-1beta to yield fragments of molecular masses compatible with mature biologically active IL-1beta (17 to 19 kDa). Assays conducted in the presence of selected proteinase inhibitors suggest that the cleavage of pro-IL-1beta involves the participation of one or more aspartyl proteinases. Cleavage products showed a dose-dependent IL-1beta-like activity in a thymocyte proliferation bioassay, which was inhibited by anti-IL-1beta neutralizing antibodies. The present data thus suggest a role for C. albicans proteinases in the activation and maintenance of the inflammatory response at epithelial surfaces.

Activation of the interleukin-1beta precursor by Treponema denticola: a potential role in chronic inflammatory periodontal diseases.

There are several indications suggesting that interleukin-1beta (IL-1beta) may play an important role in inflammatory periodontal diseases. We hypothesized that periodontal sites would represent a unique combination of both cellular sources of IL-1beta precursor (pro-IL-1beta) and microbial proteases and proposed that Treponema denticola, a suspected periodontal pathogen, would play a critical role in the inflammatory nature of adult chronic periodontitis by activating pro-IL-1beta. The aim of this study was thus to demonstrate the proteolytic cleavage and activation of the inactive precursor pro-IL-1beta by T. denticola. After incubation of bacterial cells with recombinant pro-IL-1beta, proteolytic cleavage was monitored by Western immunoblotting, and the biological activity of the digestion products was tested in a bioassay. We report here that T. denticola can cleave pro-IL-1beta to yield two fragments with molecular masses of 18 and 19 kDa. Cleavage products showed a dose-dependent biological activity in the thymocyte proliferation bioassay, and this activity was inhibited by anti-IL-1beta neutralizing antibodies. These results suggest that T. denticola may have a proinflammatory role in periodontal diseases.