Mast cell growth factor modulates CD36 antigen expression on erythroid progenitors from human bone marrow and peripheral blood associated with ongoing differentiation

To study the differentiation process of erythroid progenitors from normal human bone marrow and peripheral blood, CD34/CD36 sorted cells were cultured in the presence of Erythropoietin (Epo) and Epo plus mast cell growth factor (MGF). The CD34+/CD36- cell fraction from bone marrow supported 74 +/- 33 erythroid burst forming units (BFU-E)/10(4) cells (mean +/- SD, n = 4) in the presence of Epo, which increased 2.1- fold by coculturing with MGF. However, erythroid colony-forming units (CFU-E) were not cultured from the CD34+/CD36- cell fraction. In contrast, the CD34-/CD36+ cell fraction supported CFU-Es in the presence of Epo (152 +/- 115/10(5)) or Epo plus MGF (180 +/- 112/10(5)), whereas BFU-Es were hardly noticed. However, the transition of the BFu-E to CFU-E was observed by incubating CD34+/CD36- cells (10(4)/100 microL) in suspension with Epo plus MGF for 7 days followed by Epo in the colony assay. This was reflected by the appearance of CD34-/CD36+/Glycophorin A+/CD14- cells. In addition high numbers of CFU- Es (1,000 +/- 150, n = 4) were cultured from this cell fraction. In contrast to bone marrow erythroid progenitors, no peripheral blood CFU- Es were cultured from either the CD36+ or CD36- fraction, whereas BFU- Es were predominantly present in the CD36+ fraction. However, the CD34+ progenitor cell from peripheral blood did have intrinsic capacity to differentiate to CFU-Es because CD34+/CD36- cells incubated with Epo plus MGF for 7 days and followed by Epo in the colony assay, supported high numbers of CFU-Es (1,200 +/- 400, n = 3). To study whether additional growth factors have similar effects on erythroid progenitors, experiments were performed with interleukin 1 (IL-1), IL- 3, and IL-6. IL-1 and IL-6 did not modulate the Epo supported proliferation and differentiation. In contrast, IL-3 in the presence of Epo did support CFU-Es, from CD34+/CD36- cells after 7 days in suspension culture. However, flow cytometry analysis showed that Epo plus IL-3 not only supported CD34-/CD36+/Glycophorin A+ cells but also CD36+/CD14+ cells, indicating the differentiation along different cell lineages. In summary, the data show a phenotypic distinction between bone marrow and peripheral blood erythroid progenitors with regard to CD36 expression. In addition, the results suggest that Epo plus MGF or IL-3 and preincubation in suspension culture are prerequisites for the transition of the BFU-E to the CFU-E.     

急性肺损伤患者肺复张手法的应用评价

背景和目的:对于急性肺损伤(ALI)患者应用肺复张手法的安全性和有效性尚存争议,本研究旨在对成人ALI患者接受肺复张手法出现的生理学效应和不良事件进行系统评价.方法:对Au病例的系列、观察性研究和随机临床试验的结果进行分类综述.结果:40项研究的1185例符合选择标准.31项研究的636例应用肺复张手法后氧合显著增     

口服芬戈莫德治疗复发缓解型多发性硬化的安慰剂对照试验

背景:芬戈莫德是1-磷酸鞘氨醇受体调节剂,可以阻止淋巴细胞移行出淋巴结.在Ⅱ期和Ⅲ期临床试验中已经证实,芬戈莫德与安慰剂或肌肉注射β干扰素相比均能显著减少多发性硬化(MS)患者的复发率,并且改善MRI预后指标.方法:本研究为期24个月,采用双盲随机设计,纳入18～55岁,扩展的神经功能障碍量表(EDSS)评分在0～5.5分,且入选前1年内复发至少1次或2年内复发至少2次的复发缓解型MS(RRMS)患者.     

Spatial dynamics of alcohol availability, neighborhood structure and violent crime.

OBJECTIVE: This study examined the relationship between neighborhood social structure, alcohol outlet densities and violent crime in Camden, New Jersey. METHOD: Data pertaining to neighborhood social structure, violent crime and alcohol density were collected for 98 block groups, and analyzed using bivariate, multivariate and spatial analyses. RESULTS: Each type of analysis showed that those areas with high alcohol outlet densities experienced more violent crime than low-density areas, after controlling for neighborhood social structure. In the multivariate regression analysis, alcohol outlet densities explained close to one fifth of the variability in violent crime rates across block groups--more than any one of the neighborhood structural variables included in the analysis. These findings were replicated in the spatial analysis, which also showed that alcohol outlet densities contributed significantly to violent crime within target block groups but not in adjacent block groups. CONCLUSIONS: High alcohol outlet density is associated with high rates of violent crime in this urban community. Spatial analysis suggests that alcohol outlets elevate the rate of violent crime within the immediate neighborhood context, not in surrounding neighborhoods.     

Does the conformation of adsorbed fibrinogen dictate platelet interactions with artificial surfaces?

Platelet activation by polymer surfaces is thought to require preliminary adsorption of fibrinogen and perhaps changes in fibrinogen conformation. We measured fibrinogen adsorption by a series of polymers by two methods, using either 125I-labeled fibrinogen or 125I-labeled antifibrinogen antibodies, and correlated the results with platelet reactivity (retention and secretion) in columns of beads coated with the polymers. For polyalkyl methacrylates with 1 to 4 carbon side chains, platelet reactivity varied directly with increasing length of the alkyl side chain and with the quantity of bound fibrinogen recognizable by antifibrinogen antibody but not with the total quantity of fibrinogen adsorbed. The same pattern of results was seen with five antibody preparations, including affinity-purified Fab fragments against the D or E domain of fibrinogen. Tests of platelet retention and fibrinogen binding to four polyalkyl acrylates and to three unrelated polymers (polystyrene, polymethyl methacrylate, and a polyether polyurethane) indicated that platelet retention correlated positively with both total fibrinogen binding and with the amount of antibody-recognizable fibrinogen bound. Drugs that block platelet aggregation, but not adhesion, did not alter the hierarchy of platelet retention to the polyalkyl methacrylates. These data suggest that, contrary to previous views, platelet adhesion to artificial surfaces increases with increasing surface coverage of adsorbed fibrinogen if the bound fibrinogen maintains a conformation such that its functional domains remain recognizable by antibody probes.     

The Compliance of Healthcare Workers with Universal Precautions in the Emergency Room at the University Hospital of the West Indies

Objectives:

The study assessed compliance among health workers in the Emergency Room at the University Hospital of the West Indies with universal precautions. This was done by determining the knowledge, practices and perceptions of staff of universal precautions and by assessing compliance. Reported adherence with universal precautions was compared with observed practice.

Methods:

This was a cross-sectional study conducted over a one-year period. It was approved by the University Hospital of the West Indies/University of the West Indies/Faculty of Medical Sciences Ethics Committee. Data were analysed using Stata version 11.1.

Results:

During the study period, 67 persons gave consent for the study; data were obtained for 62 of these participants and 52 of the respondents were observed. All of the participants were aware that universal precautions related to blood. Eighty-six per cent erroneously thought that universal precautions applied to urine. Seventy-nine per cent of the participants reported always washing their hands after performing a procedure and 43.5% reported always washing their hands before a procedure.Just over half of the participants reported always wearing gloves while doing procedures (56.5%). Only 9% reported always using a gown with a trauma patient. However, 31% and 43.3% reported wearing a gown when placing a chest tube and when anticipating splashes, respectively. Of those participants who reported washing their hands often after a procedure, over 30% did not perform hand-washing when observed. Fifty per cent of persons that reported never recapping needles were observed to recap needles by hand.

Conclusion:

The study revealed that compliance among staff in the Emergency Room with universal precautions was unsatisfactory. The need for education in this area was recognized.     

Differences and Similarities in Explanatory Models of Hypertension in the United States of America,Tanzania and Jamaica

Background:

Misperceptions detract from effective disease management in a number of conditions but the nature of underlying illness beliefs and their relative consistency in patients with chronic hypertension (cHTN) who present to the Emergency Department (ED) with poor blood pressure control is not known.

Objectives:

1) To explore disease knowledge in ED patients with cHTN using explanatory modelling; and 2) to compare gaps in cHTN knowledge across racially similar but geographically divergent ED patients.

Methods:

Emergency department patients of African origin with cHTN were recruited from three sites: Detroit Receiving Hospital (DRH - Detroit, MI, USA), the Tanzanian Training Center for International Health (TTCIH – Ifakara, TZ) and the University Hospital of the West Indies (UHWI – Kingston, JA). Demographic and baseline data were collected along with open-ended responses to a series of questions related to cHTN. Qualitative responses were coded into predefined, disease-relevant quantitative domains by two separate, blinded reviewers and multilevel comparisons were performed using Kruskal-Wallis or analysis of variance (ANOVA) tests, where appropriate.

Results:

One hundred and ninety-seven patients were enrolled; mean age (50.5 years vs 51.6 years vs 50.8 years; p = 0.86) and gender distribution (% male: 49.5 vs 44 vs 40; p = 0.53) were similar across sites but patients at DRH (vs TTCIH vs UHWI) were more hypertensive at presentation (mean systolic BP in mmHg: 166.8 vs 153 vs 152.7; p = 0.003), had a longer mean duration of cHTN (12.1 years vs 4.6 years vs 9.1; p < 0.0001), and were less likely to be on antihypertensive therapy (84.5% vs 92% vs 100%, p = 0.001). Explanatory models revealed limited recognition of cHTN as a "disease" (19.6% vs 28% vs 16%; p = 0.31) and consistency in the belief that cHTN was curable (44.3% vs 36% vs 42%; p = 0.62). Stress (48.4% vs 60% vs 50%; p = 0.31) and, especially at DRH, diet (62.2% vs 22% vs 36%; p < 0.0001) were identified most frequently as causes of cHTN and an association with symptoms was common (83.5% vs 98% vs 78%; p = 0.15). Clear differences existed for perceived benefits of treatment and consequences of poor control by site, but in general, both were under-appreciated.

Conclusions:

Misperceptions related to cHTN are common in ED patients. While specific areas of disconnect exist by geographic region, failure to recognize cHTN as a dire and fixed disease state is consistent, suggesting that a uniform educational intervention may be of benefit in this setting.