Detraining from total body exercise ergometry in individuals with spinal cord injury

Fibroblast-mediated cytokine gene therapy has proven to be a promising strategy for restoring hematopoiesis following repeated chemotherapy. Interleukin 3 (IL-3) and interleukin 6 (IL-6) can synergistically promote the recovery of hematopoiesis following chemotherapy. In this investigation, combined use of fibroblast-mediated IL-3 and IL-6 gene therapy was tested for hematopoietic effects on mice with or without 5-fluorouracil administration. The results demonstrated that combined therapy with IL-3 gene-modified NIH3T3 cell (NIH3T3-IL-3) and IL-6 gene-modified fibroblast NIH3T3 cell (NIH3T3-IL-6) implantation achieves obvious stimulation of hematopoiesis in normal mice and accelerates recovery of hematopoiesis. In normal mice the quantities of platelets, neutrophils, and total white blood cells in peripheral blood increased significantly after the combined implantation of NIH3T3-IL-3 and NIH3T3-IL-6 cells. The numbers of colony-forming unit (CFU) granulocyte/macrophage (CFU-GM) and CFU megakaryocyte (CFU-MK) formed by stem cells in bone marrow was significantly higher after the combined implantation of NIH3T3-IL-3 and NIH3T3-IL-6 cells than after the implantation of NIH3T3-IL-3 alone, NIH3T3-IL-6 alone, or neomycin gene-modified NIH3T3 cells. In hematopoiesis-depressed mice induced by preinjection with 5-fluorouracil at the dose of 150 mg/kg before cell implantation, the platelets, neutrophils, and white blood cells showed accelerated recovery, and the numbers of CFU-GM and CFU-MK formed by bone marrow cells were also markedly higher after the combined implantation of NIH3T3-IL-3 and NIH3T3-IL-6 cells than in control groups. Our data show that combined use of fibroblast-mediated IL-3 and IL-6 gene therapy may be of clinical relevance for the recovery of hematopoietic depression for patients after chemotherapy.     

Protein kinase A stimulates binding of multiple proteins to a U-rich domain in the 3'-untranslated region of lactate dehydrogenase A mRNA that is required for the regulation of mRNA stability

We have explored the molecular basis of the cAMP-induced stabilization of lactate dehydrogenase A (LDH-A) mRNA and identified four cytoplasmic proteins of 96, 67, 52, and 50 kDa that specifically bind to a 30-nucleotide uridine-rich sequence in the LDH 3'-untranslated region with a predicted stem-loop structure. Mutational analysis revealed that specific protein binding is dependent upon an intact primary nucleotide sequence in the loop as well as integrity of the adjoining double-stranded stem structure, thus indicating a high degree of primary and secondary structure specificity. The critical stem-loop region is located between nucleotides 1473 and 1502 relative to the mRNA cap site and contains a previously identified cAMP-stabilizing region (CSR) required for LDH-A mRNA stability regulation by the protein kinase A pathway. The 3'-untranslated region binding activity of the proteins is up-regulated after protein kinase A activation, whereas protein dephosphorylation is associated with a loss of binding activity. These results imply a cause and effect relationship between LDH-A mRNA stabilization and CSR-phosphoprotein binding activity. We propose that the U-rich CSR is a recognition signal for CSR-binding proteins and for an mRNA processing pathway that specifically stabilizes LDH mRNA in response to activation of the protein kinase A signal transduction pathway.     

Outcome measures for low back pain research. A proposal for standardized use

STUDY DESIGN: An international group of back pain researchers considered recommendations for standardized measures in clinical outcomes research in patients with back pain. OBJECTIVES: To promote more standardization of outcome measurement in clinical trials and other types of outcomes research, including meta-analyses, cost-effectiveness analyses, and multicenter studies. SUMMARY OF BACKGROUND DATA: Better standardization of outcome measurement would facilitate comparison of results among studies, and more complete reporting of relevant outcomes. Because back pain is rarely fatal or completely cured, outcome assessment is complex and involves multiple dimensions. These include symptoms, function, general well-being, work disability, and satisfaction with care. METHODS: The panel considered several factors in recommending a standard battery of outcome measures. These included reliability, validity, responsiveness, and practicality of the measures. In addition, compatibility with widely used and promoted batteries such, as the American Academy of Orthopaedic Surgeons Lumbar Cluster were considered to minimize the need for changes when these instruments are used. RESULTS: First, a six-item set was proposed, which is sufficiently brief that it could be used in routine care settings for quality improvement and for research purposes. An expanded outcome set, which would provide more precise measurement for research purposes, includes measures of severity and frequency of symptoms, either the Roland or the Oswestry Disability Scale, either the SF-12 or the EuroQol measure of general health status, a question about satisfaction with symptoms, three types of "disability days," and an optional single item on overall satisfaction with medical care. CONCLUSION: Standardized measurement of outcomes would facilitate scientific advances in clinical care. A short, 6-item questionnaire and a somewhat expanded, more precise battery of questionnaires can be recommended. Although many considerations support such recommendations, more data on responsiveness and the minimally important change in scores are needed for most of the instruments.     

Prostaglandin E2 and dexamethasone inhibit IL-12 receptor expression and IL-12 responsiveness

Regulation of the factors governing IL-12R expression and IL-12 responsiveness has been shown to be important in the generation and stability of Th1- and Th2-type responses. In this regard, cytokines have been shown to have a prominent role in regulating IL-12R expression. In this study, the role that PGE2 and dexamethasone (DXM) have in regulating IL-12R expression was evaluated. Addition of PGE2 or DXM to human PBMCs stimulated with immobilized anti-CD3 plus IL-12 inhibited the production of IFN-gamma in a dose-responsive manner. Moreover, PBMCs stimulated with immobilized anti-CD3 in the presence of PGE2 or DXM for 3 days, washed extensively, and restimulated in the presence of IL-12 still did not produce IFN-gamma. This lack of IL-12 responsiveness from cells cultured in either PGE2 or DXM was correlated with diminished surface expression of IL-12Rbeta1, IL-12Rbeta2 mRNA expression, and IL-12 binding. Finally, the PGE2- and DXM-mediated inhibition of IL-12R expression was not affected significantly by addition of neutralizing Abs against either IL-4, IL-10, or TGF-beta. By contrast, addition of dibutyryl cAMP, 8-bromoadenosine 3:5 cAMP (8-Br-cAMP), or cholera toxin substantially reduced IL-12R expression, suggesting that PGE2 may be mediating its effects through enhancement of cAMP.     

Mapping the prion protein using recombinant antibodies

The fundamental event in prion disease is thought to be the posttranslational conversion of the cellular prion protein (PrPC) into a pathogenic isoform (PrPSc). The occurrence of PrPC on the cell surface and PrPSc in amyloid plaques in situ or in aggregates following purification complicates the study of the molecular events that underlie the disease process. Monoclonal antibodies are highly sensitive probes of protein conformation which can be used under these conditions. Here, we report the rescue of a diverse panel of 19 PrP-specific recombinant monoclonal antibodies from phage display libraries prepared from PrP deficient (Prnp0/0) mice immunized with infectious prions either in the form of rods or PrP 27-30 dispersed into liposomes. The antibodies recognize a number of distinct linear and discontinuous epitopes that are presented to a varying degree on different PrP preparations. The epitope reactivity of the recombinant PrP(90-231) molecule was almost indistinguishable from that of PrPC on the cell surface, validating the importance of detailed structural studies on the recombinant molecule. Only one epitope region at the C terminus of PrP was well presented on both PrPC and PrPSc, while epitopes associated with most of the antibodies in the panel were present on PrPC but absent from PrPSc.     

Europa's differentiated internal structure: inferences from four Galileo encounters

Radio Doppler data from four encounters of the Galileo spacecraft with the jovian moon Europa have been used to refine models of Europa's interior. Europa is most likely differentiated into a metallic core surrounded by a rock mantle and a water ice-liquid outer shell, but the data cannot eliminate the possibility of a uniform mixture of dense silicate and metal beneath the water ice-liquid shell. The size of a metallic core is uncertain because of its unknown composition, but it could be as large as about 50 percent of Europa's radius. The thickness of Europa's outer shell of water ice-liquid must lie in the range of about 80 to 170 kilometers.     

Dual origins of Finns revealed by Y chromosome haplotype variation

The objective of this study was to determine effects of photoperiod and age on the circulating concentrations of LH, testosterone (T), thyroxine (T4), and semen production in male turkeys. Male turkeys from 10 or 12 wk of age were maintained under either a long-day (LD) photoperiod of 16L:8D up to 35 wk (LL), or a short-day (SD) photoperiod of 6L:18D to 29 wk and then an LD photoperiod of 16L:8D up to 35 wk of age (SL). Plasma concentrations of both LH and T increased by 17 or 18 wk of age under both photoperiods, but higher levels were attained in the LL group prior to 29 wk of age. Both LH and T levels increased significantly within days in the SL group after the group was switched to LD at 29 wk of age. Higher levels of T4 were present in the LL group prior to sexual maturation. No differences were observed in T4 concentration between lighting treatments after sexual maturation. The LL group first produced semen at 20-22 wk of age, which was about 1 wk earlier than first semen production in the SL group. A significantly larger volume of semen was produced in the LL group at most ages. No further increase in semen production was observed in the first 6 wk after the SL group was switched to the LD photoperiod at 29 wk of age. Pulsatile patterns of LH and T were characterized by serial blood sampling at 13, 23, and 35 wk of age under both the LL and SL photoperiods. The baseline levels of both LH and T in male turkeys were influenced by age and photoperiod. However, pulse characteristics (numbers, duration, and amplitude) of LH did not change with age or lighting treatment, while pulse characteristics of T did change with age. We conclude that exposing male turkeys to an LD photoperiod from 10 or 12 wk of age advanced the age of sexual maturation and induced earlier increased concentrations of LH and T.     

Characterization of a high capacity calcium transport system in mitochondria of the yeast Endomyces magnusii

The Ca2+ transport system of Endomyces magnusii mitochondria has been shown previously to be activated by spermine. Here we report it to be regulated also by low, physiological ADP concentrations, by the intramitochondrial NADH/NAD+ ratio, and by Ca2+ ions. The combination of all these physiological modulators induced high initial rates of Ca2+ uptake and high Ca2+-buffering capacity of yeast mitochondria, enabling them to lower the medium [Ca2+] to approximately 0.2 microM. The mechanisms of stimulation by these agents are discussed.