The effect of two lipophilic gamma-aminobutyric acid uptake blockers in CA1 of the rat hippocampal slice.

1. Drugs that increase inhibitory synaptic transmission in the central nervous system may be valuable tools in the treatment of seizures. Theoretically, substances that block the uptake of inhibitory transmitters such as gamma-aminobutyric acid (GABA) into intracellular compartments should also increase inhibition and therefore have potential value as antiepileptic drugs. However, most of these substances penetrate the blood-brain barrier poorly and have therefore until now had limited value. NO-05-0328 and NO-05-0329 are two new lipophilic GABA uptake inhibitors that readily enter the CNS from the blood. 2. We have investigated the effect of these two uptake inhibitors on the responses to exogenous GABA and on GABA-mediated inhibitory synaptic potentials in pyramidal neurones of the CA1 region in the rat hippocampal slice. 3. We found that both drugs increased the amplitude and duration of responses to exogenous GABA. Furthermore, the inhibitory synaptic potentials increased in amplitude. This increase was seen in both early and late phases of the synaptic potentials. We conclude that NO-05-0328 and NO-05-0329, at least in vitro, are more effective than older GABA uptake inhibitors such as nipecotic acid and they therefore deserve consideration for clinical use.     

Desensitization of FSH-responsive adenylyl cyclase in cultured immature Sertoli cells by homologous hormone

Sertoli cell monolayers were prepared from 19-day-old rat testes. On day 7 of culture cells were incubated for 24 hr in the presence or absence of ovine follicle stimulating hormone (oFSH). Cells were harvested, and adenylyl cyclase responses of the membrane particles to FSH, human chorionic gonadotropin (hCG), isoproterenol, and fluoride (F-) were examined in the presence of either GTP or the nonhydrolyzable guanylyl nucleotide GMP-P(NH)P. Culturing the cells in presence of FSH caused a hormone specific desensitization of FSH-responsive adenylyl cyclase, whereas responses to isoproterenol and fluoride were unaffected. Activation of Sertoli cell adenylyl cyclase by GTP and GMP-P(NH)P showed no difference between cells preincubated with or without FSH, indicating that FSH did not change the activity of the G/F (or N) component or its interaction with the catalytic subunit of the adenylyl cyclase. FSH-responsive adenylyl cyclase in cultured Sertoli cells has been shown to be selectively desensitized by homologous hormone. The mechanism may involve alteration or loss of the FSH receptor or changes in the "coupling" of the FSH receptors to the G/F component of the adenylyl cyclase, since there was no alteration in the guanylyl nucleotide and fluoride activation.     

Pain and pain management in newborn infants: a survey of physicians and nurses

BACKGROUND: Despite an increased awareness among clinicians regarding pain and pain management for infants undergoing surgery, pain associated with procedures performed outside the operating room may not be adequately managed. PURPOSE: To examine the beliefs and self-described behavior of physicians and nurses regarding the management of procedural pain in newborn infants. METHODS: A survey was distributed to 467 clinicians (nurses and physicians) working in 11 level II and 4 level III nurseries in a large metropolitan area. Respondents were asked to rate the painfulness of 12 common bedside nursery procedures and how often pharmacologic and nonpharmacologic (comfort) measures are currently used and should be used for those procedures. Demographic data were also collected. RESULTS: Surveys were completed by 374 clinicians (80% response rate). Physicians and nurses believe infants feel as much pain as adults and that 9 of the 12 listed procedures are moderately to very painful. Neither pharmacologic nor comfort measures are believed to be used frequently, even for the most painful procedures. Physicians and nurses believe both pharmacologic and comfort measures should be used more frequently, but nurses believe comfort measures should be used more frequently than do physicians. Beliefs about infant pain and procedural pain were related to pain management preferences. Physicians' but not nurses' ratings were associated with significant personal pain. CONCLUSIONS: Despite their beliefs that infants experience significant procedure-related pain, clinicians believe pain management for infants remains below optimal levels. Barriers to more consistent and effective pain management need to be identified and surmounted.     

Bacterial and mammalian DNA alkyltransferases sensitize Escherichia coli to the lethal and mutagenic effects of dibromoalkanes

Here we confirm and extend our previous studies demonstrating that the mutagenic potency of 1,2-dibromoethane (DBE) and dibromomethane (DBM) is markedly enhanced (not prevented) in bacteria expressing the O6- alkylguanine-DNA alkyltransferase (ATase) encoded by the Escherichia coli ogt gene. We demonstrate that, in close parallel with mutagenesis, the Ogt ATase sensitizes the bacteria to the lethal effects of these carcinogens, suggesting that one or more of the potentially mutagenic lesions induced by DBE and DBM in the presence of Ogt has additional lethal capacity. We further demonstrate that the sensitization to both lethality and mutagenesis by DBE and DBM is a property shared by other DNA alkyltransferases. This objective was accomplished by quantifying the induction of mutations and lethal events in ogt- ada- E. coli expressing an exogenous bacterial or mammalian ATase from a multicopy plasmid. Mammalian recombinant ATases enhanced the lethal and mutagenic actions of DBE and suppressed the lack of sensitivity of the vector- transformed bacteria to DBM. In most cases the order of effectiveness of the ATases ranked: murine > human > Ogt > rat. Further comparisons included the full-length Ada ATase from E. coli and a truncated Ada version (T-ada) that retains the O6-methylguanine binding domain of the protein. The full-length Ada ATase was effective in enhancing the lethality but not the mutagenicity induced by DBE and DBM. The T-ada ATase provided less sensitization than Ada to lethality by DBE, but of the three bacterial ATases T-ada yielded the highest sensitization to mutagenesis by this compound. T-ada and Ada ATases were in general less effective than the mammalian versions, with the exception of the rat recombinant ATase. The effectiveness of the different mammalian and bacterial ATases in promoting the deleterious actions of dibromoalkanes was compared with the effectiveness of these proteins in suppressing the lethal and mutagenic effects induced by N-nitroso-N-methylurea. The ability to sensitize E. coli to the lethal and mutagenic effects of DBE and DBM seems restricted to DNA alkyltransferase, since overexpression of thioredoxin (Trx) or glutaredoxin (Grx1) in ogt- ada- cells showed no effect, in spite of the reported potential of bioactive dihaloethane- derived species to alkylate Trx.      

‘It’s important that we learn too’: Empowering parents to facilitate participation in physical activity for children and youth with disabilities

Aim: The actions and behaviors of parents have been identified as key factors that influence a child’s participation in physical activity. However, there is limited knowledge of how parents can be supported to embody facilitative roles. This study aimed to explore how an ecological intervention encourages parents of children with disabilities to develop as facilitators, to enable ongoing physical activity participation in a child’s local environment.

Methods: A qualitative design using grounded theory was employed. Forty four parents (26 mothers, 18 fathers) of 31 children with a range of disabilities (mean age 12y 6m (SD 2y 2m); 18 males) partaking in the Local Environment Model intervention at Beitostolen Healthsports Centre in Norway participated in the study. Data were derived from the triangulation of semi-structured interviews and participant observation. Data analysis was an iterative approach of constant comparison, where data collection, memo writing, open, axial and selective coding analysis, were undertaken simultaneously. Findings were consolidated into a model describing the central phenomenon and its relationship to other categories.

Results: Thematic concepts uncovered in this study describe a social process of parent learning and empowerment, comprising three primary components; (i) active ingredients of the intervention that enabled learning and empowerment to transpire, (ii) parent learning and empowerment as a process, and (iii) related outcomes.

Conclusion: A family-centered approach, encompassing family-to-family support, may enhance physical activity participation outcomes for children and youth with disabilities.     

Effects of fibroblast growth factor-4 (k-FGF) on long-term cultures of human bone marrow cells

Fibroblast growth factor-4 (FGF-4), a highly mitogenic protein encoded by the k-fgf/hst oncogene, stimulates the growth of a variety of cells of mesenchymal and neuroectodermal origin. Addition of FGF-4 to human long-term bone marrow cultures increased both the cell density of the stromal layer and the number of hematopoietic colony forming cells in the cultures in a dose-dependent manner. Hematopoiesis in the stromal layer persisted for up to 8 months. Erythropoiesis was maintained for up to 4 weeks, but granulocytes were the predominant nonadherent cell type. Cultures treated with FGF had increased numbers of monocytes compared with control cultures and some CD14+, CD45+ monocytes could still be detected after 8 months of continuous culture. The addition of the growth factor increased the rate of growth of the stromal layer and appeared to delay its senescence. Subcultures made in the presence of FGF-4 had up to 10-fold increases in plating efficiency and grew as relatively uniform monolayers. These subcultures retained the capacity to support hematopoiesis for several months, while untreated subcultures, made without FGF-4, grew erratically and generally lost the capacity to support hematopoiesis within 4 to 6 weeks. The improved growth after subculture greatly enhanced the reliability of limit- dilution assays of multipotential hematopoietic stem cells that use stromal cell monolayers. The primary effect of FGF-4 appeared to be on the stromal cells of the long-term bone marrow cultures, but a direct effect on hematopoietic progenitors could not be ruled out.     

Bone mineral density in patients with inflammatory bowel disease: a population-based prospective two-year follow-up study

BACKGROUND: Bone loss and osteoporosis are commonly reported in inflammatory bowel disease (IBD), especially Crohn disease (CD). The aims of the present study were to evaluate changes in bone mineral density (BMD) in IBD patients during a 2-year follow-up period, and to investigate the role played by possible contributing factors in bone loss. METHODS: Sixty patients with CD and 60 with ulcerative colitis (UC) were studied initially. Fifty-five CD and 43 UC patients were re-examined after 1 year, and 50 CD and 44 UC patients after 2 years. Lumbar spine, femoral neck and total body BMD were measured by dual X-ray absorptiometry (DXA), and Z scores were obtained by comparison with age-matched and sex-matched healthy subjects. Biochemical variables were assessed at inclusion and at the 1-year follow-up visit. RESULTS: Mean BMD values were unchanged in both CD and UC patients. In patients with repeated measurements, significant differences in Z scores (delta Z score) were found for femoral neck and total body in CD and for total body in UC. Significant bone loss occurred in 11 CD (22%) and 12 UC (27%) patients. A significant increase in BMD was found in 21 CD (42%) and 20 UC (46%) patients. In CD patients the initial BMD values for lumbar spine and femoral neck were inversely correlated to BMD changes at the same sites and the change in body mass index (BMI) was positively correlated to change in the total body BMD. C-reactive protein was significantly higher in CD patients with bone loss. Biochemical markers of bone metabolism could not be used to predict BMD changes. Although it was not significant, there was a relationship between corticosteroid therapy and bone loss in CD. CONCLUSIONS: Only minor changes in BMD were observed in both CD and UC patients during a 2-year period. The multifactorial pathogenesis of bone loss in IBD makes it difficult to assess the importance of each single contributing factor. However, our results indicate that disease activity and corticosteriod therapy are involved in bone loss in CD patients.     

Fibromyalgia and chronic widespread pain in patients with inflammatory bowel disease: a cross sectional population survey

OBJECTIVE: To assess the prevalence of fibromyalgia (FM) and chronic widespread pain (CWP) in a population based cohort of patients with inflammatory bowel disease (IBD). METHODS: Patients in a prospective survey on newly diagnosed IBD were, 5 years after study entry, invited to a clinical examination including the investigation of musculoskeletal manifestations. A total of 521 patients were examined, corresponding to 80% of surviving cases with definite diagnoses of ulcerative colitis (UC) and Crohn's disease (CD). The diagnoses of FM and CWP strictly followed the American College of Rheumatology classification criteria of 1990. RESULTS: At clinical examination, FM was diagnosed in 18 patients (3.5%), 3.7% with UC and 3.0% with CD. The prevalence was 6.4% in females and 0.4% in males. Thirty-eight patients (7.3%) had CWP (8.5% with UC; 4.8% with CD). The female:male ratio was 27:3 in the UC group and 8:0 in CD. In 19 patients (50%), CWP occurred after onset of IBD. No correlation with the extent of intestinal inflammation and the occurrence of FM and CWP was found. CONCLUSION: The prevalences of FM and CWP in patients with IBD were similar to those of the general population. There were no differences in prevalence of FM and CWP between UC and CD. Chronic idiopathic inflammation of the intestine does not appear to predispose to chronic widespread pain.