Osteoblasts arise from partially differentiated osteogenic progenitor cells (OPCs) which in turn arise from undifferentiated marrow stromal mesenchymal stem cells (MSCs). It has been postulated that age-related defects in osteoblast number and function may be due to quantitative and qualitative stem cell defects. To examine this possibility, we compared osteogenic stem cell number and in vitro function in marrow cells from 4-month-old and 24-month-old male BALB/c mice. Histologic studies demonstrated that these mice undergo age-related bone loss resembling that seen in humans. In primary MSC cultures grown in media supplemented with 10 nM dexamethasone, cultures from older animals yielded an average of 41% fewer OPC colonies per given number of marrow cells plated (p < 0.001). This implies that for a given number of marrow cells there are fewer stem cells with osteogenic potential in older animals than there are in younger animals. The basal proliferative rate in cultures from older animals, as measured by 3H-thymidine uptake, was more than three times that observed in cultures from young animals (p < 0.005). However, the increase in proliferative response to serum stimulation was 10-fold in the younger cultures (p <0.001) and insignificant (p <0.4) in the older cultures. Colonies in both age groups became alkaline phosphatase positive at the same rate, and virtually all colonies were positive after 12 days of culture. Cultures from both age groups produced abundant type I collagen. These studies suggest that defects in the number and proliferative potential of MSCs may underlie age-related defects in osteoblast number and function.

Run-on transcription experiments were used to demonstrate that transcription of T cell receptor beta chain V genes is activated by DNA rearrangement, in a manner similar to immunoglobulin genes. A transcriptional enhancer likely to be involved in this activation has been identified. A 25-kilobase region from J beta 1 to V beta 14 was tested for enhancer activity by transient transfections, and an enhancer was found 7.5 kilobases 3' of C beta 2. The beta enhancer has low activity relative to the simian virus 40 viral enhancer, does not display a preference for V beta promoters, has a T cell-specific activity, and binds two purified immunoglobulin heavy chain enhancer factors.

BackgroundCollaborative-care management is an evidence-based practice for improving depression outcomes in primary care. The Department of Veterans Affairs (VA) has mandated the implementation of collaborative-care management in its satellite clinics, known as Community Based Outpatient Clinics (CBOCs). However, the organizational characteristics of CBOCs present added challenges to implementation. The objective of this study was to evaluate the effectiveness of evidence-based quality improvement (EBQI) as a strategy to facilitate the adoption of collaborative-care management in CBOCs.MethodsThis nonrandomized, small-scale, multisite evaluation of EBQI was conducted at three VA Medical Centers and 11 of their affiliated CBOCs. The Plan phase of the EBQI process involved the localized tailoring of the collaborative-care management program to each CBOC. Researchers ensured that the adaptations were evidence based. Clinical and administrative staff were responsible for adapting the collaborative-care management program for local needs, priorities, preferences and resources. Plan-Do-Study-Act cycles were used to refine the program over time. The evaluation was based on the RE-AIM (Reach, Effectiveness, Adoption, Implementation, Maintenance) Framework and used data from multiple sources: administrative records, web-based decision-support systems, surveys, and key-informant interviews.ResultsAdoption: 69.0% (58/84) of primary care providers referred patients to the program. Reach: 9.0% (298/3,296) of primary care patients diagnosed with depression who were not already receiving specialty care were enrolled in the program. Fidelity: During baseline care manager encounters, education/activation was provided to 100% (298/298) of patients, barriers were assessed and addressed for 100% (298/298) of patients, and depression severity was monitored for 100% (298/298) of patients. Less than half (42.5%, 681/1603) of follow-up encounters during the acute stage were completed within the timeframe specified. During the acute phase of treatment for all trials, the Patient Health Questionnaire (PHQ9) symptom-monitoring tool was used at 100% (681/681) of completed follow-up encounters, and self-management goals were discussed during 15.3% (104/681) of completed follow-up encounters. During the acute phase of treatment for pharmacotherapy and combination trials, medication adherence was assessed at 99.1% (575/580) of completed follow-up encounters, and side effects were assessed at 92.4% (536/580) of completed follow-up encounters. During the acute phase of treatment for psychotherapy and combination trials, counseling session adherence was assessed at 83.3% (239/287) of completed follow-up encounters. Effectiveness: 18.8% (56/298) of enrolled patients remitted (symptom free) and another 22.1% (66/298) responded to treatment (50% reduction in symptom severity). Maintenance: 91.9% (10/11) of the CBOCs chose to sustain the program after research funds were withdrawn.ConclusionsProvider adoption was good, although reach into the target p...

PGs play an important role in regulating articular chondrocyte function in both normal and pathological states. However, the mechanisms of the effects of PG on chondrocyte function remain undefined. We, therefore, examined the effects of PGE1, PGE2, and PGE2 alpha on second messenger generation in relation to DNA and aggrecan synthesis in the nontransformed rat RCJ 3.1C5.18 (RCJ) chondrocyte cell line. RCJ cells were grown under minimal attachment conditions on a composite collagen-agarose (0.15%/0.8%) gel to maintain a differentiated phenotype. PGE1 and PGE2 (0.001-100 microM) produced a similar dose-related increase in cAMP accumulation, with a maximal 8-fold increase over basal values, whereas PGF2 alpha produced a minimal 1.3-fold increase in cAMP levels only at 100 microM. On the other hand, both PGE2 and PGE2 alpha raised the intracellular free calcium ([Ca2+]i) concentration, derived primarily from extracellular sources, whereas PGE1 was without effect on [Ca2+]i. These three PGs also had divergent effects on DNA synthesis, as measured by [3H]thymidine ([3H]TdR) incorporation. PGF2 alpha (0.001-5 microM) produced a dose-related increase in [3H]TdR incorporation, with a maximal 1.6-fold increase over baseline values at 5 microM and a slight decline to below maximal levels at 10 microM. PGE2 exhibited a contrasting inverse biphasic response, with an initial small suppressive effect that was maximal at 0.1 microM and a secondary stimulatory phase producing a small increase over control values at 5 microM. PGE1 had a uniformly suppressive effect, producing a 30% decrease at 10 microM. Despite the divergent effects of PGE1, PGE2, and PGE2 alpha on second messenger generation and DNA synthesis, all three PGs produced a dose-related stimulation of aggrecan synthesis. PGF2 alpha was the most potent, producing significant stimulation at 0.001 microM and a maximal 104% increase at 5 microM. PGE1 and PGE2 were approximately equipotent and approximately 60% as effective as PGF2 alpha in stimulating aggrecan synthesis. Northern analysis demonstrated that the effects of PG on aggrecan synthesis were not accompanied by changes in aggrecan core protein steady state messenger RNA levels. Thus, the effects of PG on aggrecan production in RCJ cells appear to be regulated at the posttranscriptional level. Forskolin and (Bu)2cAMP mimicked the suppressive effects of PGE1 on [3H]TdR incorporation, as well as the stimulatory effect of PGE1 on aggrecan synthesis. In addition, the phorbol ester 12-O-tetradecanoyl phorbol acetate mimicked PGF2 alpha stimulation of [3H]TdR incorporation and aggrecan synthesis, and the effects of PGE2 alpha on these processes were blocked by protein kinase C inhibitors. Therefore, it appears that in mammalian chondrocytes, PGE1 primarily activates the cAMP-protein kinase A second messenger system, PGE2 alpha affects primarily the Ca2(+)-protein kinase C system, and PGE2 activates both pathways. Moreover, PG posttranscriptional regulation of aggrecan synthesis in chondrocytes involves both the cAMP-pro...

Large plasmids were detected in two aerobactin-producing enteric bacterial species (Aerobacter aerogenes 62-I, Salmonella arizona SA1, and S. arizona SL5301) and designated pSMNI, pSMN2, and pSMN3, respectively. Other Salmonella spp., namely, S. arizona SL5302, S. arizona SLS, Salmonella austin, and 300