Characterization and phenotypic analysis of differentiating CD34+human bone marrow cells in liquid culture

Abstract: Our current understanding of human haematopoietic stem cell biology is based in part on the characterization of human CD34⁺ bone marrow cell differentiation in vitro. CD34 is highly expressed on early stem cells and haematopoietic progenitor cells with clonogenic potential and is gradually lost during differentiation and commitment. However, CD71 (transferrin receptor) is expressed at low levels on early stem cells and generally increases during haematopoietic progenitor cell proliferation. We reasoned that the combination of these surface markers would provide a useful framework for the simultaneous analysis of multiple lineage differentiation of CD34⁺ haematopoietic progenitor cells in liquid culture. In this report, we identify the phenotype of distinct subpopulations of myeloid, erythroid and lymphoid cells in liquid suspension culture using differential expression of CD34 vs. CD71 in combination with specific lineage markers. Freshly isolated human CD34⁺ bone marrow cells were introduced into suspension culture and monitored over a 6-d period using 3-colour flow cytometry. This is the first demonstration that differential expression of CD34 vs. CD71 can be used to simultaneously monitor differentiation of multiple haematopoietic cell lineages in liquid suspension culture, facilitating the study of cytokine-, drug- or chemical-induced alterations in haematopoietic progenitor cell differentiation in vitro.     

The effects of problem-solving training on two problem-solving tasks

The present study assessed the effects of problem-solving (D'Zurilla & Goldfried, 1971) training on two problem-solving tasks. Sixty-one subjects were assigned randomly to and trained in one of the following groups: general orientation (GO)-problem definition (PD)-generation of alternatives (GA)-decision making (DM), GO-PD-GA, GO-PD-DM, GO-GA-DM, GO, and a control group. The six groups did not differ significantly at pretesting on the measures of selecting the best alternative solution and describing problem-solving behaviors used to solve problems. Training was significantly effective on selecting the best alternative solution for all groups compared with the control group at the time of posttesting. The GO-PD-GA-DM and GO-PD-DM groups described significantly more problem-solving behaviors than the GO-PD-GA, GO-GA-DM, and GO groups. All five treatment groups performed significantly better than the control group at the time of post-testing. At follow-up 1 month after posttesting, groups trained with the PD component selected significantly better alternatives than the groups without PD training. Groups trained with the DM component described significantly more problem-solving behaviors at follow-up than the groups trained without the DM component.     

Prevalence and predictors of symptoms of Perinatal Mood and anxiety Disorders among a sample of Urban Black Women in the South

Maternal and Child Health Journal - Data are scarce regarding the prevalence and predictors of perinatal mood and anxiety disorders (PMADs) among Black women. The purpose of this study was to...     

Physical Activity in Children and Adolescents

After obesity rates in youth reached alarming rates, public health officials recognized the need for specific physical activity guidelines for children and adolescents. Numerous health care groups and sports and fitness organizations collaborated on the development of the Physical Activity Guidelines for Americans in 2008, which have been widely endorsed and include recommendations for the pediatric population. Children and adolescents should participate in moderate-to-vigorous physical activity 1 or more hours per day and muscle and bone-strengthening activities 3 or more times per week. Physical activities should be age appropriate, enjoyable, and varied and occur beyond what is required for typical activities of daily living. Adequate exercise in youth improves strength, cardiorespiratory fitness, and body composition and therefore decreases cardiovascular risk factors. An improved cardiovascular profile provides a continued benefit in adulthood. Exercise also improves bone health, psychological well-being, cognition, and school performance and may decrease the risk of sports injury. Exercise habits established in childhood often continue into adulthood.     

Cryopreservation of stem cells using trehalose: evaluation of the method using a human hematopoietic cell line

While stem cell cryopreservation methods have been optimized using dimethylsulfoxide (DMSO), the established techniques are not optimal when applied to unfertilized human embryonic cells. In addition, important questions remain regarding the toxicity and characteristics of DMSO for treatment of stem cells for clinical use. The objective of this study was to establish an optimal method for cryopreservation of stem cells using low concentrations (0.2 M) of trehalose, a nontoxic disaccharide of glucose, which possesses excellent protective characteristics, in place of current methods utilizing high concentrations (1-2 M) of DMSO. A human hematopoietic cell line was used in this investigation as a surrogate for human stem cells. Trehalose was loaded into cells using a genetically engineered mutant of the pore-forming protein alpha-hemolysin from Staphylococcus aureus. This method results in a nonselective pore equipped with a metal-actuated switch that is sensitive to extracellular zinc concentrations, thus permitting controlled loading of trehalose. Preliminary experiments characterized the effects of poration on TF-1 cells and established optimal conditions for trehalose loading and cell survival. TF-1 cells were frozen at 1 degrees C/min to -80 degrees C with and without intra- and extracellular trehalose. Following storage at -80 degrees C for 1 week, cells were thawed and evaluated for viability, differentiation capacity, and clonogenic activity in comparison to cells frozen with DMSO. Predictably, cells frozen without any protective agent did not survive freezing. Colony-forming units (CFU) generated from cells frozen with intra- and extracellular trehalose, however, were comparable in size, morphology, and number to those generated by cells frozen in DMSO. There was no observable alteration in phenotypic markers of differentiation in either trehalose- or DMSO-treated cells. These data demonstrate that low concentrations of trehalose can protect hematopoietic progenitors from freezing injury and support the concept that trehalose may be useful for freezing embryonic stem cells and other primitive stem cells for therapeutic and investigational use.     

Are Gatekeeper Requirements Associated with Cancer Screening Utilization?

OBJECTIVE: There is widespread debate over whether health plans should require enrollees to use "gatekeepers," which are primary care providers that coordinate care and control access to specialists. However, little is known about whether health plan gatekeeper requirements improve or reduce quality-of-care. Our objective was to examine whether gatekeeper requirements are associated with the utilization of cancer screening for breast, cervical, and prostate cancer. DATA SOURCES: Three linked sources (N = 13,534): (1) 1996 Medical Expenditure Panel Survey (MEPS) Household Survey, a nationally representative, ongoing survey sponsored by the Agency for Healthcare Research and Quality; (2) 1996 MEPS Health Insurance Plan Abstraction, which codes data from health plan booklets obtained from privately insured respondents, and (3) 1995 National Health Interview Survey. STUDY DESIGN/DATA COLLECTION: Cross-sectional, multivariate logistic regression analysis using secondary data. PRINCIPAL FINDINGS: We found in multivariate analyses that women in gatekeeper plans were significantly more likely to obtain mammography screening (Odds Ratio [OR] = 1.22, 95 percent Confidence Interval [CI] 1.07-1.40), clinical breast examinations (OR = 1.39, 95 percent CI 1.23-1.57), and Pap smears (OR = 1.33, 95 percent CI 1.16-1.52) than women not in gatekeeper plans. In contrast, gatekeeper requirements were not associated with prostate cancer screening (OR = 1.11, 95 percent CI 0.93-1.33). We found no association between screening utilization and aggregate plan types (HMO, POS, PPO, FFS). CONCLUSIONS: Gatekeeper requirements are associated with higher utilization of widely recommended cancer screening procedures, but not with utilization of a less uniformly recommended cancer screening procedure. Researchers should consider the analysis of specific plan characteristics rather than aggregate plan types in conducting future research, and insurers and policymakers should consider the potential benefits of gatekeepers with respect to preventive care when designing health plans and legislation.     

Effect of rofecoxib on prednisolone and prednisone pharmacokinetics in healthy subjects

Patients receiving nonsteroidal anti-inflammatory drug therapy may also require administration of corticosteroids, particularly patients with rheumatoid arthritis. To investigate the effect of rofecoxib on the single-dose pharmacokinetics of oral prednisone and intravenous prednisolone, the authors conducted a randomized, double-blind, placebo-controlled crossover study in 12 healthy subjects. Oral rofecoxib (250.0 mg/day for 14 days) failed to influence prednisone or prednisolone pharmacokinetics after intravenous prednisolone or oral prednisone administration. The geometric mean ratio (GMR) (90% confidence interval) of prednisolone AUC infinity (rofecoxib/placebo) following intravenous and oral corticosteroid was 0.97 (0.94, 1.01) and 0.99 (0.91, 1.08), respectively. Similarly, the prednisone AUC infinity GMRs (rofecoxib/placebo) after intravenous and oral corticosteroid were 1.03 (0.95, 1.11) and 1.08 (0.92, 1.28), respectively. The absence of an effect of rofecoxib on the pharmacokinetics of oral prednisone or intravenous prednisolone indicates that no adjustment in dose of this corticosteroid is necessary when administered concurrently with rofecoxib.     

Headaches and oral contraceptives: impact of eliminating the standard 7-day placebo interval

OBJECTIVE: The aim was to assess the timing and severity of self-reported headaches in patients utilizing a standard 28-day oral contraceptive (OC) cycle consisting of 21 hormone (estrogen + progestin)-containing pills and 7 placebo pills (ie, 21/7-day cycle) converted to a placebo-free extended OC regimen. METHODS: An open label single-center prospective analysis of headaches recorded daily on a severity scale of 0 to 10, along with the headache item of the Penn Daily Symptom Rating (DSR17) and a weekly modified Migraine Disability Assessment (MIDAS) headache questionnaire, during standard 21/7-day cycles followed by a 168-day extended placebo-free regimen of an OC containing 3 mg of drosperinone and 30 mcg of ethinyl estradiol (DRSP/EE). RESULTS: Of the 114 patients who began the trial, 111 completed the 21/7-day cycle portion of the study. Based on the headaches scales, there were significant differences in headache severity among the 28 days of the standard 21/7 cycles (P < .001). Greater headache severity occurred on days 25 through 28 during the 7-day placebo interval of the 21/7 cycles (P < .05). Of the 111 patients who completed the 21/7 phase of the study, 102 (92%) completed the 168-day extended placebo-free OC regimen. During the first 28 days of the extended placebo-free regimen, daily headache scores decreased (P < .0001) compared to those of the previous 21 active/7 placebo day cycle. The difference on a daily basis was first detected on extended cycle days 25 through 28 (P < .0001) and persisted throughout the remainder of the 168-day regimen. Subjects were divided into 2 groups (severe and mild) based on the median of the total headache score during the 21/7 OC cycle. The group with higher total headache scores demonstrated a significant (P < .0001) reduction in daily headaches beginning in the first 28-day interval of the extended placebo-free regimen, persisting throughout the entire 168-day extended regimen. In contrast, the group with the lower total headache score remained unchanged (P= .79) throughout the extended regimen. Impact of headaches on work, family, and social functions also improved on the extended placebo-free regimen in 6 of 8 measures (P < .05) assessed by weekly headache questionnaires. CONCLUSION: Compared to a 21/7-day OC regimen, a 168-day extended placebo-free regimen of DRSP/EE led to a decrease in headache severity along with improvement in work productivity and involvement in activities. This is a preliminary study and results may not be widely generalizable.     

The effect of antiretroviral therapy on liver disease among adults with HIV and hepatitis C coinfection

In the era of antiretroviral therapy (ART), liver disease has emerged as an important cause of death among persons with human immunodeficiency virus (HIV)/hepatitis C virus (HCV) coinfection. The objective of this study was to estimate the burden of liver disease and evaluate determinants of liver fibrosis and necroinflammatory activity among HIV/HCV coinfected patients receiving ART. We studied 112 randomly selected and 98 referred HCV-infected patients undergoing care in the Johns Hopkins University HIV clinic. Liver disease was characterized clinically and histologically. Of the 210 individuals studied--64% of whom had received ART within 2 years of liver disease assessment--33% had no fibrosis (F0), and 26% had bridging fibrosis or cirrhosis (> or =F3). The median necroinflammatory activity score was 3 (range, 0-9 of 18). ART was not associated with fibrosis; however, significantly less hepatic necroinflammatory activity was observed among persons who had received highly active antiretroviral therapy longer (P = .02) and more effectively (defined by HIV RNA suppression; P < .01). Twelve percent of individuals had previous ART-associated liver enzyme elevations (grades 3-4), but liver fibrosis was not more severe if the liver enzyme elevation resolved. On the other hand, liver fibrosis was more severe in persons with persistent liver enzyme elevations (grades 1-4). In conclusion, despite widespread exposure to ART and documented instances of ART-related hepatitis, we found no evidence that ART caused serious histological liver disease. Recognition of bridging fibrosis and cirrhosis in some but not most patients underscores the importance of identifying and treating liver disease in HIV/HCV coinfected persons.