Red cell life span in sickle cell-hemoglobin C disease with a note about sickle cell-hemoglobin O ARAB

Red cell survival was measured in ten subjects with S-C disease and one with S-O Arab (alpha 2 beta 2-121 glu yields lys) disease using both DF32p and 51Cr as tags. Red cell volume was slightly reduced in most patients (87% plus or minus 20% of predicted normal). In nine SC patients, mean red cell life (DF32p) was 28.9 plus or minus 4.0 days. For one SC subject it was significantly longer (47.9 days), as it was for the one with S-O Arab. The S-O Arab subject had irreversibly sickled cells in the peripheral blood, shereas those with SC had few (less than 1/1000 red cells) or none. The S-O Arab hemolysate gelled at a hemmoglobin concentration (16.2 g/100ml) near that for sickle cell anemia hemolysates (15.9 plus or minus 1.0 g/100 ml; n equals 8) but significantly lower than that for SC hemolysates (21.6 plus or minus 1.9 g/100 ml; n equals 5). It seems likely that properties of S-C red cells other than their relative ease of sickling contribute significantly to their rate of hemolysis.     

Lymphocyte subsets and cytokines in adenoviral infection in children

To determine the distribution of major blood lymphocyte subsets we evaluated blood lymphocytes by flow cytometry in adenovirus-infected infants aged 30–730 d. In addition, interleukin-1-receptor antagonist, interleukin-10 and transforming growth factor-β1 were measured in serum by enzyme-linked immunosorbent assay. According to clinical parameters, mechanical ventilation and outcome, infections were classified as moderate ( n = 15), severe ( n = 11) and fatal ( n = 12). Controls were 13 healthy children. In severe and fatal infection, T cells (CD5⁺/CD19^-), NK effectors (CD16⁺), CD4⁺ T subset and B1 subset of B lymphocytes (CD5⁺/CD19⁺) were all significantly decreased. CD8⁺ cells were decreased in severe but not fatal cases. There was no difference in serum values of interleukin-10; however, fatal cases had high interleukin 1-receptor antagonist values. Interestingly, patients with moderate infection showed significantly increased values of transforming growth factor-β1. These results demonstrate that life-threatening adenoviral infection is associated with marked abnormalities in blood lymphocyte and cytokine profile.     

Expression and function of the human granulocyte-macrophage colony- stimulating factor receptor alpha subunit

To determine the expression and function of the granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor alpha chain (GMR alpha) during hematopoiesis and on leukemic cells, monoclonal antibodies were raised by immunizing mice with cells expressing high levels of human GMR alpha. A pool of five antibodies isolated from three different mice was used to characterize GMR alpha. This antibody pool (anti-GMR alpha) immunoprecipitated a protein with the expected molecular weight of GMR alpha from COS cells transiently transfected with the GMR alpha gene. In factor-dependent cells, GMR alpha existed as a phosphoprotein. However, its phosphorylation was not stimulated by the presence of GM- CSF. Anti-GMR alpha inhibited the GM-CSF-dependent growth of cell lines and normal bone marrow cells and inhibited the binding of iodinated GM- CSF to its receptor. Cell surface expression of GMR alpha was examined using anti-GMR alpha and flow cytometry. GMR alpha was readily detectable on both blood monocytes and neutrophils. In adherence- depleted normal bone marrow, two separate populations expressed GMR alpha. The most positive cells were predominantly macrophages, whereas the cells that expressed less GMR alpha were largely myelocytes and metamyelocytes. A small population of lin-CD34+ or CD34+CD38- cells also expressed GMR alpha, but they were not capable of significant growth in colony-forming assays. In contrast, the majority of lin-CD34+ and CD34+CD38- cells were GMR alpha-, yet they produced large numbers of myeloid and erythroid colonies in the same assay. Malignant cells from patients with leukemia were also tested for GMR alpha expression. All of the myeloid leukemias and only rare lymphoid leukemias surveyed tested positive for GMR alpha. These results show that anti-GMR alpha is useful for the functional characterization of the GMR alpha and for the detection of myeloid leukemia and that GMR alpha is expressed on certain lineages throughout hematopoietic development; however, progenitors that express the receptor may have a reduced capacity to proliferate in response to hematopoietic growth factors.     

Interferon treatment for hepatitis C virus infection in patients on haemodialysis

BACKGROUND: This study examined the efficacy and tolerability of interferon alpha-2b (IFN) in the treatment of chronic hepatitis C virus (HCV) infection in patients on maintenance haemodialysis. METHODS: A 24- month prospective cohort study was performed in 11 HCV RNA-positive haemodialysis patients, who were treated with IFN at 3 MU thrice weekly for 6 months. Serial biochemical and virological monitors included serum alanine aminotransferase levels, and HCV RNA by both qualitative PCR assay and quantitative bDNA assay. HCV genotypes were determined by PCR and nucleotide sequencing. Ten patients had baseline liver biopsy. RESULTS: HCV genotypes 1b and 2b were identified in 10 and one patients respectively. Six (55%) patients had biochemical and/or histological features of chronic active hepatitis before treatment. All 11 patients became HCV RNA-negative by PCR, with normalization of deranged aminotransferase levels, within 2-8 weeks of IFN therapy. HCV RNA reappeared in eight (73%) patients 2-8 weeks after the cessation of IFN, while biochemical relapse occurred in six (55%) patients. Sustained eradication of HCV was achieved in three (27%) patients. Sustained responders were characterized by pretreatment HCV RNA level < 3.5 x 10(5) Eq/ml as determined by the bDNA assay, and less severe histological abnormalities ('Total score' 1.7 +/- 1.2 compared to 5.4 +/- 2.2 in relapsers, P < 0.05). HCV RNA levels were similar before and after IFN treatment in non-responders and relapsers. Persistent malaise and poor appetite were noted in eight (73%) patients during IFN therapy. Other side-effects of IFN included the exacerbation of anaemia, induction of resistance to erythropoietin, weight loss, and reduced serum albumin level. CONCLUSIONS: Eradication of chronic HCV infection with IFN can be achieved in 27% of haemodialysis patients. Predictors of sustained response include low baseline HCV RNA level and mild liver pathology. Virological relapse can occur despite normal liver biochemistry. Exacerbation of anaemia, erythropoietin resistance, and malnutrition constitute the side-effects of IFN that deserve special attention in uraemic subjects.      

新生大鼠腰交感神经节凋亡细胞的电镜观察

目的 :观察出生后早期大鼠腰交感神经节细胞凋亡超微结构变化特点。方法 :大鼠按出生后 1d、1w、2w和3w分组 ,取L3、L4交感神经节常规超薄切片 ,铅轴染色 ,透射电镜观察。结果 :1d 2w组腰交感神经节内可见到明显的神经节神经细胞胞体凋亡和突起的退变 ,同时可观察到包绕上述突起的雪旺细胞也发生凋亡。早期凋亡细胞的超微结构特点为核染色质在核膜下的凝集。结论 :出生后早期部分腰交感神经节神经细胞因未能与其靶区建立联系而凋亡 ,随后包绕凋亡神经细胞突起的雪旺细胞也发生凋亡。     

Human bone marrow microvascular endothelial cells support long-term proliferation and differentiation of myeloid and megakaryocytic progenitors

Endothelial cells are a major component of the bone marrow (BM) microenvironment that regulate the trafficking and homing of hematopoietic progenitor and stem cells. In this paper, we provide evidence that BM endothelial cells (BMECs) also support multilineage hematopoiesis by elaboration of soluble cytokines. Hematopoietic progenitor cells incubated in direct contact with BMEC monolayers, or physically separated by microporous membrane, expanded five-fold to sevenfold at 7 days, in the absence of exogenous cytokines. Flow cytometric analysis of proliferating progenitor cells grown in the presence of BMEC monolayers showed that by day 14 of coculture, 70% to 80% of hematopoietic cells were myeloid, expressing CD15 or CD14, and 14% to 19% were megakaryocytic, expressing GPIIb/IIIa or GPIb. CD34+ cells derived from umbilical cord blood, cultured in the upper chamber of transwell culture plates, as well as the cells grown in direct contact with BMEC monolayers, generated progenitors for up to 70 days. Unstimulated BMEC monolayers constitutively produce interleukin-6, Kit- ligand, granulocyte colony-stimulating factor, and granulocyte macrophage colony-stimulating factor. These data suggest that BMEC regulate proliferation of hematopoietic progenitor cells and long-term culture initiating cells by elaboration of lineage-specific cytokines.