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Selected AbstractsMethadone doses of 100 mg or greater are more effective than lower doses at suppressing heroin self-administration in opioid-dependent volunteersADDICTION, Issue 10 2005Eric C. Donny ABSTRACT Aims Methadone maintenance has been an effective pharmacotherapy for the treatment of heroin dependence for nearly four decades. Recent clinical research suggests that methadone doses larger than those used in most clinics are more effective at suppressing illicit heroin use. This greater efficacy may result from greater cross-tolerance to the reinforcing effects of heroin. Design The purpose of this double-blind, within-subject study was to examine the relationship between methadone maintenance dose and the reinforcing effects of heroin. Setting Participants were stabilized on 50, 100 and 150 mg methadone (ascending order) during separate outpatient periods before being admitted to an inpatient research unit for testing at each maintenance dose. Participants Five opiate-dependent volunteers completed the study. Measurements During each 4-week inpatient testing period, participants sampled three doses of heroin (0, 10, or 20 mg; random order; one dose per week) and were subsequently allowed seven opportunities to choose between another injection of that week's heroin dose and varying amounts of money ($2,38). Findings The number of heroin injections chosen decreased as methadone dose was increased. Larger alternative monetary reinforcers were required to suppress heroin self-administration during maintenance on 50 compared to 100 or 150 mg methadone. Larger methadone doses also completely blocked the subjective effects of heroin and produced greater withdrawal suppression during the outpatient periods. Conclusions These results support other clinical and laboratory-based research indicating that persistent heroin use may be reduced by providing larger methadone maintenance doses that produce more effective cross-tolerance to heroin. [source] Tribological Studies of a Zr-Based Glass-Forming Alloy with Different States,ADVANCED ENGINEERING MATERIALS, Issue 11 2009Feng Jiang Abstract The tribological characteristics of a glass-forming alloy, Zr52.5Cu17.9Ni14.6Al10.0Ti5.0, in atomic percent (at.%, Vit 105), with different microstructural states have been investigated. Friction and wear studies were conducted using a ball-on-flat reciprocating sliding apparatus against an AISI E52100 bearing steel under dry condition. The observed wear resistance in an ascending order is: the deformed, creep-tested, and as-cast states. Wear analyses suggested that the wear processes of glass-forming alloys involved abrasion, adhesion, and oxidation. The differences in hardness, free volume, and brittleness in different states significantly affected the friction and wear behaviors of the glass-forming alloys. [source] Effect of 8-Month Vertical Whole Body Vibration on Bone, Muscle Performance, and Body Balance: A Randomized Controlled Study,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 5 2003Saila Torvinen MD Abstract Recent animal studies have given evidence that vibration loading may be an efficient and safe way to improve mass and mechanical competence of bone, thus providing great potential for preventing and treating osteoporosis. Randomized controlled trials on the safety and efficacy of the vibration on human skeleton are, however, lacking. This randomized controlled intervention trial was designed to assess the effects of an 8-month whole body vibration intervention on bone, muscular performance, and body balance in young and healthy adults. Fifty-six volunteers (21 men and 35 women; age, 19-38 years) were randomly assigned to the vibration group or control group. The vibration intervention consisted of an 8-month whole body vibration (4 min/day, 3-5 times per week). During the 4-minute vibration program, the platform oscillated in an ascending order from 25 to 45 Hz, corresponding to estimated maximum vertical accelerations from 2g to 8g. Mass, structure, and estimated strength of bone at the distal tibia and tibial shaft were assessed by peripheral quantitative computed tomography (pQCT) at baseline and at 8 months. Bone mineral content was measured at the lumbar spine, femoral neck, trochanter, calcaneus, and distal radius using DXA at baseline and after the 8-month intervention. Serum markers of bone turnover were determined at baseline and 3, 6, and 8 months. Five performance tests (vertical jump, isometric extension strength of the lower extremities, grip strength, shuttle run, and postural sway) were performed at baseline and after the 8-month intervention. The 8-month vibration intervention succeeded well and was safe to perform but had no effect on mass, structure, or estimated strength of bone at any skeletal site. Serum markers of bone turnover did not change during the vibration intervention. However, at 8 months, a 7.8% net benefit in the vertical jump height was observed in the vibration group (95% CI, 2.8-13.1%; p = 0.003). On the other performance and balance tests, the vibration intervention had no effect. In conclusion, the studied whole body vibration program had no effect on bones of young, healthy adults, but instead, increased vertical jump height. Future human studies are needed before clinical recommendations for vibration exercise. [source] Provision of radical pelvic urological surgery in England, and compliance with improving outcomes guidanceBJU INTERNATIONAL, Issue 10 2009Erik K. Mayer OBJECTIVE To investigate compliance with Improving Outcomes Guidance (IOG) for radical pelvic surgery in England, and explore the pattern of service provision for radical cystectomy (RC) and radical prostatectomy (RP) before and after the introduction of IOG. METHODS For the period 2000/01,2006/07, all admissions for RC and RP were extracted from Hospital Episode Statistics (HES). At the institutional level, the numbers of RC and RP cases were combined to assess adherence to IOG. The IOG catchment populations for each institution were calculated by linking HES data to census ward population data. The pattern of service provision for RC and RP was independently assessed by assigning institutions into low-, medium- and high-volume groups of roughly equal volumes a priori, based on the ascending order of annual RC or RP rate, respectively. For RC it was also possible to explore the between-institution referral activity for RC by identifying the ,final endoscopic bladder procedure' that occurred immediately before the RC for each patient. This gave an indication of where the diagnosis and decision for RC had been made. RESULTS The percentage of institutions achieving the recommended IOG minimal case volume of 50 per year increased significantly between 2000/01 and 2006/07 (36% in odds per year, P < 0.001; odds ratio 1.36, 95% confidence interval 1.24,1.50), although absolute numbers remained relatively low (34% in 2006/07). Only one institution had a catchment population greater than the recommended 1 million. The total number of institutions performing RC decreased significantly over the years (P = 0.03), whereas for RP the decrease was not significant (P = 0.6). The decrease reflected a decline in the number of low-volume institutions, both for RC and RP, although this decline was not more than expected by chance. There had been a significant increase in the percentage of patients referred to another provider for their RC, from 5.5% in 2000/01 to 19.6% in 2006/07 (28% rise in odds per year, P < 0.001: odds ratio 1.28, 95% confidence interval 1.23,1.33). CONCLUSION There was evidence of centralization of radical pelvic urological surgery, although it is only relatively recently that this seems to have taken place with any certainty. The absolute numbers of providers achieving the IOG minimum caseload standard was relatively low. What impact this has had, if any, on the quality of patient care is yet to be fully determined. [source] | ||||||||||