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61.
BACKGROUND: Since screening for antibody to hepatitis C virus (HCV) was introduced in 1990, posttransfusion hepatitis has been reduced to nearly background levels. This has led to reconsideration of the value of testing donated blood for elevated alanine aminotransferase (ALT). The contribution of ALT testing in detecting seronegative infection was evaluated by the performance of polymerase chain reaction (PCR) for hepatitis B virus (HBV) or HCV in plasma from ALT-elevated blood units. STUDY DESIGN AND METHODS: Testing was performed on 375 units of plasma, derived from an equivalent of 47,500 blood donations, with a highly sensitive hemi-nested PCR procedure. Using a triplet of primers directed at the conserved regions of HBV DNA and 5'-noncoding regions of HCV RNA, the hemi-nested PCR assay can reliably amplify 10 viral molecules to levels detectable in ethidium bromide-stained agarose gels. Pools of plasma from groups of four donors were screened with hemi-nested PCR. For any reactive pools, the plasma from individual donors was retested twice on different aliquots. RESULTS: Two of 375 units, both with midrange ALT elevation, were repeatedly reactive in hemi-nested PCR (one each for HBV DNA and HCV RNA). However, samples from the two suspect donors tested 9 and 5 months later revealed no seroconversion, elevated ALT, or viral genomes in hemi-nested PCR. CONCLUSION: The lack of confirmed HBV or HCV infection in this study representing an estimated 47,500 voluntary blood donations suggests that routine ALT testing for further prevention of posttransfusion hepatitis after exclusion of HBV- and/or HCV-seropositive blood may be superfluous.  相似文献   
62.

Background  

To gain insight into factors that might affect results of future case-control studies, we performed an analysis of children with sepsis and purpura admitted to the paediatric intensive care unit (PICU) of Erasmus MC-Sophia Children's Hospital (Rotterdam, The Netherlands).  相似文献   
63.
Reddington  M; Novak  EK; Hurley  E; Medda  C; McGarry  MP; Swank  RT 《Blood》1987,69(5):1300-1306
Mepacrine uptake into platelets and bone marrow megakaryocytes was analyzed to further characterize the dense granule defects in a group of seven mouse pigment mutants that have characteristics of platelet storage pool disease (SPD). In contrast to our previous studies using electron microscopy, this method revealed that all mutants had normal numbers of dense granules. However, total mepacrine uptake in all mutant platelets was significantly diminished to less than 50% of normal uptake. Also, the flashing phenomenon observed when normal dense granules are irradiated with ultraviolet light was either greatly diminished or absent when platelets of individual mutants were similarly irradiated. Therefore the principal defect in the mutant platelets is an inability to accumulate dense granule contents rather than an absence of the granules. Mepacrine uptake into megakaryocytes was indistinguishable in normal and mutant mice. This indicates the mutant dense granule defects appear either very late in megakaryocyte development or early in platelet formation in correlation with development of the mature dense granule. By standard transmission electron microscopy we have not been able to detect gross structural or subcellular abnormalities in either platelets or megakaryocytes of mutant mice. It appears all seven mutants produce immature or functionally abnormal dense granules.  相似文献   
64.
Hayes  MP; Wang  J; Norcross  MA 《Blood》1995,86(2):646-650
Interleukin-12 (IL-12) is a monocyte/macrophage-derived cytokine that is critical for T lymphocyte and natural killer cell activities and functions. In this study, we examined the regulation of IL-12 expression by human monocytes in response to bacterial lipopolysaccharide (LPS). Several novel aspects of IL-12 induction from monocytes were shown. Optimal expression of IL-12 mRNA and bioactivity required specific priming of monocytes by interferon-gamma (IFN-gamma) before LPS stimulation. Granulocyte-macrophage colony-stimulating factor (GM-CSF) provided an equivalent priming stimulus for LPS-induced tumor necrosis factor (TNF) and IL-12 p40 mRNA, but primed poorly for LPS-inducible p35 message and secreted IL-12 activity. Macrophage colony-stimulating factor (M-CSF), although a potent survival factor for monocytes, showed no priming activity for IL-12 production. Time course experiments demonstrated independent regulation of p40 and p35 by IFN-gamma and LPS. LPS inducibility of p40 expression required only a brief exposure to IFN-gamma (2 hours), while prolonged exposure (+/- 24 hours) to IFN-gamma resulted in diminishing levels of p40 mRNA. p35 inducibility (by LPS) required a longer exposure to IFN-gamma (8 to 16 hours), and continued to be inducible up to 40 hours following IFN- gamma priming. Both mRNAs were rapidly induced (1 to 2 hours) in IFN- gamma-primed monocytes; p35 message reached a plateau by 2 hours, while p40 continued to accumulate. Finally, both p40 and p35 were directly induced by LPS in the presence of cycloheximide. These results indicated that both p40 and p35 are LPS-inducible in monocytes following IFN-gamma pretreatment, and that the regulated expression of p35 controls the level of active IL-12 protein in purified human monocytes. The selectivity of priming by IFN-gamma is in accord with a putative role for IL-12 in the initiation and amplification of TH1-type responses.  相似文献   
65.
Davey  MP; Starkebaum  G; Loughran  TP Jr 《Blood》1995,85(1):146-150
CD3+ large granular lymphocyte (LGL) leukemia is a disease of unknown etiology characterized by clonal proliferation of T cells that usually express T-cell receptor (TCR) alpha beta heterodimers. The purpose of this study was to identify the variable (V), joining (J), and diversity (D) region TCR beta-chain genes expressed by CD3+ LGL leukemic cells in an attempt to gain insights into the etiology of this disorder. Twelve patients with LGL leukemia were studied, including seven with both LGL leukemia and rheumatoid arthritis (RA). RA is also a disease of unknown etiology that occurs frequently in patients with LGL leukemia. Clonally expanded T cells that express specific TCR V beta genes have been identified in fluid and tissue specimens from the joints of patients with RA. In this study, V beta expression was determined by PCR using a panel of 22 unique V beta primers to amplify cDNA prepared from peripheral blood mononuclear cells (PBMC). A dominant V beta gene product was readily apparent in all patients. To confirm that the dominant V beta gene originated from a clonal expansion, DNA fragments corresponding to the dominant V beta genes were subcloned into plasmids and independently isolated recombinants were sequenced. V-D-J region sequences that occurred repeatedly indicated clonality. The V beta and J beta genes expressed by the leukemic cells showed a pattern of distribution that followed the frequency with which these genes are represented in the peripheral blood. The residues corresponding to the third complementarity-determining region of the TCR beta chain were different in all cases. A specific pattern of VDJ usage was not identified for those patients with both LGL leukemia and RA; however, utilization of V beta-6 by LGL clones (N = 3) was observed only in the setting of RA. These data suggest that leukemic CD3+ LGL cells have been clonally transformed in a random fashion with respect to the TCR beta chain.  相似文献   
66.

Objective

Two open‐label, randomized, cross‐over trials in healthy volunteers were conducted to investigate the pharmacokinetic interaction between etravirine and tenofovir disoproxil fumarate.

Methods

Etravirine was administered as either 800 mg twice a day (bid) (phase II formulation in Study 1) or 200 mg bid (phase III formulation in Study 2) for 8 days followed by a 12 h pharmacokinetic evaluation. After a minimum of 14 days washout, tenofovir disoproxil fumarate 300 mg once a day was administered for 16 days. Volunteers were randomized to receive co‐administration of etravirine with tenofovir disoproxil fumarate on either days 1–8 or days 9–16 followed by a 12 h pharmacokinetic evaluation for etravirine on day 8 or 16, respectively. Plasma and urine tenofovir concentrations were determined on days 8 and 16 over 24 h.

Results

The least square mean (LSM) ratio [90% confidence interval (CI)] for the area under the plasma concentration–time curve from 0 to 12 h (AUC12 h) for etravirine co‐administered with tenofovir disoproxil fumarate vs. etravirine alone was 0.69 (0.61–0.79) and 0.81 (0.75–0.88) in Studies 1 and 2, respectively. The LSM ratio (90% CI) for the effect of etravirine on tenofovir AUC24 h was 1.16 (1.09–1.23) in Study 1 and 1.15 (1.09–1.21) in Study 2.

Conclusions

These alterations are not considered clinically relevant for either drug and no dose adjustment is necessary when etravirine and tenofovir disoproxil fumarate are co‐administered.  相似文献   
67.
BACKGROUND: Unstable angina is an active thrombotic process that involves thrombus formation and platelets. It requires a rapid and intensive treatment with anticoagulants and antiplatelets. HYPOTHESIS: The aim of the present study was to compare the efficacy of a very low molecular weight heparin, OP 2000, with standard heparin in the treatment of unstable angina. Tolerance and safety were also assessed. METHODS: The study population included 120 consecutive hospitalized patients with unstable angina randomized for treatment with very low molecular weight heparin or with standard heparin. The dosage of the study drug was 200 mg intramuscular (i.m.) the first day followed by 150 mg IM/day. The control drug was standard heparin starting at a dosage of 5,000 UI/ml intravenously (i.v.) and followed by continuous infusion at an activated partial thromboplastin time-adjusted dosage. The primary end points were death, acute myocardial infarction, urgent revascularization, and recurrence of angina. Tolerability was assessed using bleeding parameters, thrombocytopenia, and allergic reactions. RESULTS: Fourteen clinical events were reported in the study group compared with 25 events in the control group (p < 0.05). No adverse events were reported in either group. CONCLUSION: During the acute phase of unstable angina, treatment with a very low molecular weight heparin plus aspirin was more effective than treatment with standard heparin plus aspirin.  相似文献   
68.
NTRODUCTIONPolygonumcuspidatumSieb.etZucc.(Polygonaceae)isatraditionalChineseherbaldrug,withbitertasteandcoldnature.Itmainly...  相似文献   
69.
Alteration of the TAL1 locus is the most common nonrandom genetic defect in childhood T-cell acute lymphoblastic leukemia (T-ALL). To determine if rearrangements of the TAL1 proto-oncogene confer a distinct leukemic phenotype, we studied leukemic peripheral blood or bone marrow samples from 182 children with newly diagnosed T-ALL enrolled on Pediatric Oncology Group treatment protocols. Forty-eight (26%) of the samples had a local rearrangement of the TAL1 locus. Demographic and clinical features were compared for patient subgroups with and without TAL1 rearrangements. The only clinical correlates that were significantly associated with TAL1 gene rearrangements were higher white blood cell count (P = .017) and higher hemoglobin (P = .007) at diagnosis. Immunophenotypically, samples with altered TAL1 were more likely to be CD2+ (P = .001) and lack CD10 (cALLa) expression (P = .007) than those without the rearrangement. There was a trend toward improved event-free survival (EFS) in patients with TAL1 rearrangements (4-year EFS was 44% +/- 7% for patients without the rearrangements v 59% +/- 11% for those with rearrangements), but the difference was not significant (P = .34). The role of TAL1 in leukemogenesis has yet to be clearly defined, and the prognostic significance of TAL1 gene rearrangements in T-ALL deserves further study.  相似文献   
70.
Heparin oligosaccharides bind L- and P-selectin and inhibit acute inflammation   总被引:34,自引:4,他引:34  
Initial attachment of leukocytes to the vessel wall at sites of inflammation is supported by a family of carbohydrate-binding adhesion molecules called the selectins. Selectin ligands include sialyl-Lewis x (sLex, Neu5Ac alpha 2-3Gal beta 1-4[Fuc alpha 1-3]GlcNAc--) and related structures. We report here that defined heparin oligosaccharides interact with the selectins. Heparin chains containing four or more monosaccharide residues inhibited the function of L- and P-selectin, but not E-selectin, in vitro. In a competition enzyme-linked immunosorbent assay measuring inhibition of solution-phase selectin-Ig fusion proteins (selectin-Ig) binding to immobilized bovine serum albumin-sLex neoglycoprotein, a heparin-derived tetrasaccharide mixture inhibited 50% of L- and P-selectin-Ig binding (IC50) at 200 +/- 40 mumol/L and 850 +/- 110 mumol/L, respectively. A single hexasulfated tetrasaccharide (delta UA2S alpha 1-4GlcNS6S alpha 1-4IdoA2S alpha 1- 4GlcNS6S) was particularly active against L- and P-selectin-Ig (IC50 = 46 +/- 5 mumol/L and 341 +/- 24 mumol/L). By comparison, the tetrasaccharide sLex was not inhibitory at concentrations up to 1 mmol/L. In cell adhesion assays, heparin tetrasaccharides reduced binding of neutrophils to COS cells expressing P-selectin but not to COS cells expressing E-selectin. They also blocked colon cancer cell adhesion to L- and P-selectin but not E-selectin. In a model of acute inflammation, intravenously administered heparin tetrasaccharides diminished influx of neutrophils into the peritoneal cavities of thioglycollate-treated mice. We conclude that heparin oligosaccharides, including non-anticoagulant tetrasaccharides, are effective L- and P- selectin inhibitors in vitro and have anti-inflammatory activity in vivo.  相似文献   
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