Background Erythrocyte cell membranes undergo morphologic changes during storage, but it is unclear whether these changes are reversible. We assessed erythrocyte cell membrane deformability in patients before and after transfusion to determine the effects of storage duration and whether changes in deformability are reversible after transfusion. Methods Sixteen patients undergoing posterior spinal fusion surgery were studied. Erythrocyte deformability was compared between those who required moderate transfusion (≥5 units erythrocytes) and those who received minimal transfusion (0–4 units erythrocytes). Deformability was measured in samples drawn directly from the blood storage bags before transfusion, and in samples drawn from patients before and after transfusion (over 3 postoperative days). In samples taken from the blood storage bags, we compared deformability of erythrocytes stored for a long duration (≥21 days), those stored for a shorter duration (<21 days), and cell-salvaged erythrocytes. Deformability was assessed quantitatively using the elongation index (EI) measured by ektacytometry, a method which determines the ability for the cell to elongate when exposed to shear stress. Results Erythrocyte deformability was significantly decreased from the preoperative baseline in patients after moderate transfusion (EI decreased by 12±4 to 20±6 %) (P = 0.03) but not after minimal transfusion (EI decreased by 3±1 to 4±1 %) (P = 0.68). These changes did not reverse over 3 postoperative days. Deformability was significantly less in erythrocytes stored for ≥21 days (EI = 0.28±0.02) than in those stored for <21 days (EI = 0.33±0.02) (P = 0.001) or those drawn from patients preoperatively (EI = 0.33±0.02) (P = 0.001). Cell-salvaged erythrocytes had intermediate deformability (EI = 0.30±0.03) that was greater than that of erythrocytes stored ≥21 days (P = 0.047), but less than that of erythrocytes stored <21 days (P = 0.03). Conclusions The findings demonstrate that increased duration of erythrocyte storage is associated with decreased cell membrane deformability and that these changes are not readily reversible after transfusion.

There is no ideal bowel cleansing regimen and, thus, various protocols are in use. We propose several evidence-based protocols to optimize bowel cleansing in children prior to colonoscopy and minimize adverse events.

Cans of ground cooked beef, inoculated with 106 or 108 spores per can of Clostridium botulinum 33A, were irradiated with 60Co gamma rays at a series of 14 temperatures ranging from −196 to 95C. The higher inoculum level required higher sterilizing doses. The D values, computed on the basis of recoverable C. botulinum, were independent of the inoculum level, and showed that spore resistance progressively decreased with increasing temperature. A statistical analysis of these data disclosed that the change in D values from −196 to 65C followed equally well a quadratic, exponential, or linear best-fit plot; above 65C radiation death was much more rapid. An equation was derived from the linear plot to predict D values for any desired temperature between −196 and 65C. Calculations of Ea and Q10 values, based on the linear curve, indicated a very small thermodynamic effect on radiation kill. An Arrhenius analysis of the temperature effect suggested that there was no simple physicochemical mechanism occurring in the inoculated beef pack which might explain the change in spore kill as a function of temperature. Theoretical commercial radiation processes for beef, based on the 12D concept and strain 33A spores, are presented for several easily controlled irradiation temperatures.

Ten lots of diced cured ham, packed in cans, were inoculated with approximately 106 Clostridium botulinum spores per can. Each lot was seeded with a different strain (five type A and five type B strains). All cans were irradiated to various dose levels with Co60. Evidence provided by swelling, toxicity, and recoverable C. botulinum with 6,350 cans demonstrated that: (i) 4.5 Mrad was more than adequate as a sterilization dose; (ii) the minimal experimental sterilizing dose (ESD) based on nonswollen nontoxic endpoints was 2.0 < ESD < 2.5 Mrad, and based on nonspoiled sterile cans was 3.0 < ESD < 3.5 Mrad (the latter was supported by the computed theoretical 12D dose); (iii) D values calculated from botulinal survival data indicated that, as a group, the type A strains were more radioresistant than type B strains; strains 12885A and 41B, with respective D values of 0.242 and 0.175, represented the most resistant of each type; (iv) swollen cans did not always contain toxin, nor were toxic cans always swollen; (v) viable C. botulinum can exist for 6 months at 30 C without producing visible or toxic spoilage at doses of 3.0 Mrad and lower, including, in some instances, 0.0 Mrad; and (vi) a phenomenon similar to heat activation of spores occurred at sublethal radiation doses. MATERIALS AND MErHODS Test organisms. Ten strains of C. botulinum were used: 33A, 36A, 62A, 77A, 12885A, 9B, 40B, 41B, 51B, 53B. These strains represent the highest, lowest, and intermediate radioresistances of 102 strains screened in a model system (4). The sources of these organisms, their serotypes, maintenance, and spore preparations were previously described (4). The only modifications employed were the substitution of distilled water for buffer as the spore diluent, and the use of pork-pea-agar (2) in conjunction with screw-cap 166

An oxygen scavenging system enclosed in a pouch with baked, meal, ready-to-eat bread prevented growth of a mixed mold inoculum on the surface of the bread for 13 months. In the absence of the oxygen scavenger, growth of Aspergillus and Penicillium was visible on the bread within 14 d. Growth of molds on pouched culture media, with and without sorbate, was also prevented by oxygen scavenging packets.