Prestorage white cell reduction in saline-adenine-glucose-mannitol red cells by use of an integral filter: evaluation of storage values and invivo recovery

BACKGROUND : Prestorage white cell (WBC) reduction in blood components may decrease the incidence of adverse reactions and improve component quality. A bottom-and-top system with an integral third-generation WBC- reduction filter has been studied. STUDY DESIGN AND METHODS : Whole blood was collected from 30 healthy donors: from 20 by using a blood container system with an integral filter and from 10 controls by using a standard blood container system. Ten test units were buffy coat- depleted, stored for 72 hours at 4 degrees C, and then filtered, while an additional 10 test units were buffy coat-depleted and filtered at room temperature within 8 hours of collection. All units were stored at 4 degrees C for 42 days and sampled weekly. RESULTS : The mean WBC content of the 72-hour, 4 degrees C units was 0.33 × 10(6), that of the room-temperature units was 2.6 × 10(6), and that of the buffy coat- depleted controls was 460 × 10(6) (p < 0.0005). No significant differences were found among lactate, glucose, sodium, potassium, and plasma hemoglobin levels in the three groups. ATP and 2,3 DPG levels were significantly better preserved in control units than in 72-hour, 4 degrees C units (p = 0.016 and p = 0.032, respectively), but not better than in the room-temperature units. Significant differences were observed between pH values in filtered units and both groups of test units (p = 0.016). In biologic terms however, these differences were small. Red cells from an additional eight healthy volunteer donors were processed by an 8-hour room-temperature method and stored for 35 days. Studies in vivo 24-hour recovery of autologous red cells were performed by transfusing a radiolabeled (51Cr plus 131I-albumin) aliquot after 35 days' storage. Good recovery (mean > 80%) was found by both the single- and double-isotope-label methods. Recovery was significantly greater when calculated by the single-isotope method (p = 0.02). CONCLUSION : The combination of buffy coat removal and filtration in the blood container system with an integral filter achieved effective WBC reduction (> or = 3 log10 reduction from whole blood) without biologically significant detriment to in vitro or in vivo storage values.     

Gender Differences in service connection for PTSD

BACKGROUND: Mentally ill female veterans obtain a smaller proportion of their care from Department of Veterans Affairs (VA) facilities than mentally ill male veterans do, possibly because women are less likely than men to be service connected for psychiatric disabilities. "Service connected" veterans have documented, compensative conditions related to or aggravated by military service, and they receive priority for enrollment into the VA healthcare system. OBJECTIVES: To see if there are gender discrepancies in rates of service connection for posttraumatic stress disorder (PTSD) and, if so, to see if these discrepancies could be attributed to appropriate subject characteristics (eg, differences in symptom severity or impairment). RESEARCH DESIGN: Mailed survey linked to administrative data. Claims audits were conducted on 11% of the sample. SUBJECTS: Randomly selected veterans seeking VA disability benefits for PTSD. Women were oversampled to achieve a gender ratio of 1:1. RESULTS: A total of 3337 veterans returned usable surveys (effective response rate, 68%). Men's unadjusted rate of service connection for PTSD was 71%; women's, 52% (P < 0.0001). Adjustment for veterans' PTSD symptom severity or functional impairment did not appreciably reduce this discrepancy, but adjustment for dissimilar rates of combat exposure did. Estimated rates of service connection were 53% for men and 56% for women after adjusting for combat exposure. This combat preference could not be explained by more severe PTSD symptoms or greater functional impairment. CONCLUSIONS: Instead of a gender bias in awards for PTSD service connection, we found evidence of a combat advantage that disproportionately favored men. The appropriateness of this apparent advantage is unclear and needs further investigation.     

Ability of flt3 ligand to stimulate the in vitro growth of primitive murine hematopoietic progenitors is potently and directly inhibited by transforming growth factor-beta and tumor necrosis factor-alpha

The recently cloned flt3 ligand (FL) stimulates the growth of primitive hematopoietic progenitor cells through synergistic interactions with multiple other cytokines. The present study is the first demonstrating cytokines capable of inhibiting FL-stimulated hematopoietic cell growth. Tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta 1 (TGF-beta l) potently inhibited the clonal growth of murine Lin-Sca-l+ bone marrow progenitors stimulated by FL alone or in combination with granulocyte colony-stimulating factor (G-CSF), stem cell factor (SCF), interleukin (IL)-3, IL-6, IL-11, or IL-12. TGF-beta 1 inhibited more than 96% of the myeloid colony formation in response to these cytokine combinations, whereas TNF-alpha reduced the number of colonies by 58% to 96% depending on the cytokine by which FL was combined. In addition, both TNF-alpha and TGF-beta 1 inhibited more than 90% of B220+ cell production from B220- bone marrow cells stimulated by FL + IL-7. The effects of TNF-alpha and TGF-beta 1 appeared to be due to a direct effect and on the early progenitors because the inhibition was observed at the single cell level, and because delayed addition of the two inhibitors for only 48 hours dramatically reduced their inhibitory effects. A neutralizing anti-TGF- beta antibody showed the presence of endogenous TGF-beta in the cultures and potently enhanced the ability of FL to stimulate progenitor cell growth in the absence of other cytokines. Agonistic antibodies specifically activating the p75 TNF receptors were more efficient than wild type murine TNF-alpha in signaling growth inhibition of Lin-Sca-l+ progenitor cells, whereas the p55 agonist had less effect than murine TNF-alpha. Finally, TGF-beta increased the number of FL + IL-11-stimulated Lin-Sca-1+ cells in the G1 phase of the cell cycle with 76%, whereas TNF-alpha only had a marginal effect on cell cycle distribution. Thus, TGF-beta, TNF-alpha, and p75 TNF receptor agonists are potent direct inhibitors of FL-stimulated progenitor cell growth in vitro.     

The use of monoclonal antibodies and flow cytometry in the diagnosis of paroxysmal nocturnal hemoglobinuria

We have characterized the erythrocytes, granulocytes, and platelets of 54 patients with paroxysmal nocturnal hemoglobinuria (PNH) with antibodies to glycosylphosphatidylinositol-anchored proteins (anti- CD55, anti-CD59, and anti-CD16) and flow cytometry to establish the usefulness of this technique in the diagnosis of this disorder. All patients demonstrated either completely (PNH III) or partially (PNH II) deficient red cells and granulocytes. Anti-CD59 best demonstrated PNH II red cells, which were present in 50% of the patients. The proportion of abnormal granulocytes was usually greater than the proportion of abnormal red cells; 37% of the patients had >80% abnormal granulocytes. Anti-CD55 did not delineate the erythrocyte populations as well as did anti-CD59. Either anti-CD55 or anti-CD59 could be used equally well to analyze granulocytes; anti-CD16 did not demonstrate cells of partial deficiency. Platelets could not be used for detailed analysis as the normal and abnormal populations were not well distinguished. Flow cytometry of erythrocytes using anti-CD59 or of granulocytes using either anti-CD55 or anti-CD59 provides the most accurate technique for the diagnosis of paroxysmal nocturnal hemoglobinuria; it is clearly more specific, more quantitative, and more sensitive than the tests for PNH that depend upon hemolysis by complement (the acidified serum lysis [Ham] test, the sucrose lysis test, and the complement lysis sensitivity [CLS] test).     

K562 cells produce and respond to human erythroid-potentiating activity

Human erythroid-potentiating activity (EPA) is a 28,000 mol wt glycoprotein that stimulates the growth of erythroid progenitors in vitro and enhances colony formation by the K562 human erythroleukemia cell line. EPA has potent protease inhibitory activity, and is also referred to as tissue inhibitor of metalloproteinases (TIMP). We observed that colony formation by K562 cells in semi-solid medium containing reduced fetal calf serum (FCS) is not directly proportional to the number of cells plated, suggesting production of autostimulatory factors by K562 cells. Using radioimmunoprecipitation and a bioassay for EPA, medium conditioned by K562 cells was found to contain high levels of biologically active EPA; Northern hybridization analysis confirmed the expression of EPA mRNA. Radiolabeled EPA was used to identify cell surface receptors on K562 cells. Together, these results suggest that EPA may act as an autocrine growth factor for K562 cells.     

Effects of recombinant erythropoietin on the concentration and cycling status of human marrow hematopoietic progenitor cells in vivo

The concentration of human marrow progenitors CFU-E, BFU-E, CFU-GM, and CFU-Mk and the percentage of these progenitor cells in DNA synthesis were studied in nine patients with transfusion-dependent anemia of end- stage renal failure before and 2 weeks after treatment with human recombinant erythropoietin (Epo) at a dose of 150 to 300 U/kg intravenously three times per week. The concentration of CFU-E in the posttreatment marrow increased by a mean of 4.15-fold, BFU-E by 3.37- fold, CFU-GM by 1.86-fold, and CFU-Mk by 1.96-fold as compared with their respective concentrations in the pretreatment marrows. This increase in the concentrations of marrow progenitors was accompanied by almost a doubling of the percentage of these cells in DNA synthesis as assessed by the 3H-thymidine suicide technique. These observations demonstrate that at the progenitor cell level the human marrow responds to therapeutic doses of Epo as an organ rather than by a selective expansion of the erythroid cell line.     

超声造影检测心肌梗死患者受损左室壁的价值

目的探讨超声造影在检测心肌梗死患者左室壁受损范围中的价值。方法对75名发生心肌梗死的患者进行实时心肌造影,分别于超声造影前后观察心内膜边界显示情况,评价和比较节段室壁运动情况。结果超声造影后左室心内膜边界的显示较造影前明显清晰,受损节段与未受损节段的对比增强。以冠状动脉造影结果为标准,造影检测的灵敏度、特异度和准确度均高于造影前（p〈0．05）。结论实时超声造影能有效增强左室心内膜边界显示和受损心肌边界显影,提高对左室壁受损范围检测的准确性。