A patient-centred approach to drug regulation.
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Arthritis↗
Biomedical subjects
D J Walker
Publications and source records attributed to D J Walker.
Duloxetine in the treatment of major depressive disorder: a placebo- and paroxetine-controlled trial.
OBJECTIVE: Duloxetine doses of 80 and 120 mg/day were assessed for efficacy and safety in the treatment of major depressive disorder (MDD). METHODS: In this randomized, double-blind trial, patients age > or =18 meeting DSM-IV criteria for MDD were randomized to placebo (N=99), duloxetine 80 mg/day (N=93), duloxetine 120 mg/day (N=103), or paroxetine 20 mg/day (N=97). The primary outcome measure was mean change from baseline in the 17-item Hamilton rating scale for depression (HAMD(17)) total score after 8 weeks of treatment; a number of secondary efficacy measures also were assessed. Safety and tolerability were assessed via collection and analysis of treatment-emergent adverse events (TEAEs), vital signs, and weight. The Arizona sexual experiences scale was used to assess sexual functioning. Patients who had a > or =30% reduction from baseline in the HAMD(17) total score at the end of the acute phase entered a 6-month continuation phase where they remained on the same treatment as they had taken during the acute phase; efficacy and safety/tolerability outcomes were assessed during continuation treatment. RESULTS: More than 87% of patients completed the acute phase in each treatment group. Duloxetine-treated patients (both doses) showed significantly greater improvement (P<0.05) in the HAMD(17) total score at week 8 compared with placebo. Paroxetine was not significantly different from placebo (P=0.089) on mean change on the HAMD(17). Duloxetine 120 mg/day also showed significant improvement on most secondary efficacy measures (six of nine) compared with placebo while duloxetine 80 mg/day (three of nine) and paroxetine (three of nine) were significantly superior to placebo on fewer secondary measures. HAMD(17) mean change data from this study and an identical sister study were pooled as defined a priori for the purposes of performing a non-inferiority test versus paroxetine. Both duloxetine doses met statistical criteria for non-inferiority to paroxetine. TEAE reporting rates were low in all treatment groups and no deaths occurred in the acute or continuation phases. CONCLUSIONS: The efficacy of duloxetine at doses of 80 and 120 mg/day in the treatment of MDD was demonstrated. Tolerability, as measured by TEAEs, and safety were similar to paroxetine 20 mg/day and consistent with previous published data on duloxetine in the treatment of MDD.
Adult↗
Duloxetine 60 mg once daily in the treatment of milder major depressive disorder.
There is ongoing debate regarding the effectiveness of antidepressants in patients with milder major depressive disorder (MDD). This post-hoc analysis evaluated the efficacy and tolerability of duloxetine in the subset of 159 (75 duloxetine and 84 placebo) patients with milder MDD (baseline HAMD17 total score > or = 15 and < or = 18) who were treated once daily with duloxetine 60 mg or placebo in two identical, 9-week, randomised, double-blind trials. At endpoint, change from baseline on HAMD17 was greater in the duloxetine group (-7.0) than in the placebo group (-4.1) (p = 0.005). Response and remission rates, and improvement on the Clinical Global Impressions-Severity (CGI-S) scale, the Patient Global Impressions-Improvement (PGI-I) scale, and measures of painful symptoms were also significantly better in the duloxetine group (p < 0.05). Tolerability was consistent with that seen in previous studies of duloxetine in patients with more severe depression. In conclusion, duloxetine 60 mg/day is effective and well tolerated in milder MDD.
Adolescent↗
Vitrification of in vitro-produced bovine embryos by addition of ethylene glycol in one-step.
The objective of this study was to simplify two-step addition of cryoprotectant for vitrification of bovine embryos by developing a one-step procedure. Survival was calculated as a percentage of non-vitrified controls developed from the same batch of oocytes. In experiment 1, bovine blastocysts were vitrified following one- or two-step addition of cryoprotectant. Exposure of embryos to cryoprotectant in one-step resulted in survival rates not significantly lower (p > 0.1) than those obtained by two-step addition (85% vs 98%, respectively). Based on these results, experiments 2-4 were designed to test one-step addition of cryoprotectant more rigorously. Experiment 2 exposed day 7 blastocysts to 6, 7 or 8 M ethylene glycol for 2.5 or 3.5 min. At 24 h post-vitrification, survival of embryos was similar, irrespective of ethylene glycol concentration or exposure time (6 M 38%, 7 M 51%, 8 M 59%; 2.5 min 54%, 3.5 min 45%). In experiment 3, blastocysts were exposed to 7 M ethylene glycol for shorter times (30 or 60 s); 30 s exposure resulted in decreased survival (8% vs 31%, p < 0.05). Experiment 4 concerned one-step addition of cryoprotectant to day 6 bovine morulae, exposed to 7 M ethylene glycol for 1 or 1.5 min. There was no difference in survival between exposure times of 1 or 1.5 min (28% vs 45%, respectively; p > 0.1). It is unclear why many embryos survive vitrification with one-step addition of cryoprotectant, but others do not. Although, one-step addition of cryoprotectant simplifies the vitrification procedure, survival rates were inadequate for routine cryopreservation of in vitro-produced bovine embryos.
Animals↗
In vitro assessment of a direct transfer vitrification procedure for bovine embryos.
We developed a simple vitrification technique for bovine embryos that could permit direct transfer. Embryos were produced in-vitro by standard procedures. The base medium for cryopreservation was a chemically defined medium similar to SOF + 25 mM Hepes and 0.25% fatty acid free bovine serum albumin (FAF-BSA) (HCDM2). In experiment 1, embryos were first exposed to 3.5M ethylene glycol (V1) for 1, 2 or 3 min at room temperature (20-24 degrees C), and then moved to 7 M ethylene glycol (V2) at 4 or 20-24 degrees C and loaded in 0.25-mL straws. After 45 s in 7 M ethylene glycol, straws were placed in liquid nitrogen. Embryos that were loaded at 20-24 degrees C had higher survival rates than those loaded at 4 degrees C (P<0.05). Exposure for 1 min was best for morulae, while 3 min was best for blastocysts. In experiment 2, blastocysts were handled at 24 degrees C and exposed to two concentrations of ethylene glycol in V1 (3.5 or 5 M) followed by V2 as in experiment 1, two warming temperatures (20 or 37 degrees C) and two post-warming holding times until culture (5 or 15 min). Exposure to 5 M ethylene glycol and warming at 37 degrees C was the optimal combination of procedures, and embryos survived well after 15 min in straws if warmed at 37 degrees C. In experiment 3, ethylene glycol concentration (3, 4 or 5 M) and exposure time (0.5 or 1 min) during two-step addition of cryoprotectant were studied for bovine morulae. In experiment 4, morulae were exposed to V2 for 30 or 45 s in HCDM2 or Vigro holding medium and then held in 22-24 degrees C air or 37 degrees C water post-warming. Experiment 5 was like experiment 4 except blastocysts were used. Overall survival rates of blastocysts in experiment 5 averaged 80% of non-vitrified controls after 48 h culture. The survival rates with in vitro-produced morulae in experiments 1, 3 and 4 were unacceptable. Vitrification solutions based on Vigro tended to result in higher survival than HCDM2 for blastocysts, but not morulae. In experiment 6, the survival rate in vitro of in vivo-produced morulae and blastocysts after two-step vitrification was nearly 100%. Our vitrification technique was very effective for in vitro produced blastocysts, but not for in vitro-produced morulae.
Animals↗
Recurrence risk for psoriasis and psoriatic arthritis within sibships.
OBJECTIVE: To quantify the frequency of siblings of patients with psoriatic arthritis (PsA) having psoriasis and/or inflammatory arthritis. To describe the similarity or otherwise of patterns of arthritis in siblings. METHODS: Available and consenting index cases with PsA and one or more siblings living locally were assessed. Mean sibling concordance rates and Weinberg's segregation analysis were calculated. Heritability was also estimated. To assess whether the same type of arthritis occurred within the same sibship, the dually affected sibships were then classified for type of arthritis according to methods suggested by Moll, Helliwell, Veale and McGonagle. RESULTS: Eighty index cases and 112 siblings were assessed. The median age of index cases was 49 yr (range 24-80 yr) and for siblings 46 yr (range 18-79 yr). The concordance rate for all types of PsA was 14% (9% if enthesitis is excluded) and for psoriasis 21%. There was no difference in the two methods used to calculate concordance rates. Sixteen dually affected sib pairs were found. Four of the 16 sibships (25%) had the same pattern of joint involvement (Moll and Wright classification). The most frequent pattern seen was joint involvement identical to rheumatoid arthritis (3/5). The most common symptom in affected siblings was enthesitis (approximately 5%). When the dually affected sibships were analysed using the other classifications, the simpler the classification the greater the concordance for joint pattern. CONCLUSION: The concordance for psoriasis is greater than for PsA, but the concordance rate for PsA was similar to that in HLA identical siblings with rheumatoid arthritis. There was discordance in pattern of arthritis for most sib pairs. There is no support for the use of more complex classifications of PsA.
Adolescent↗
Teaching medical students musculoskeletal examination skills: identifying barriers to learning and ways of overcoming them.
OBJECTIVES: To elicit the barriers to the effective teaching of musculoskeletal examination skills amongst medical students. METHODS: This was a qualitative study including six focus groups with specialities most often involved in delivering musculoskeletal clinical teaching: rheumatology, orthopaedics, general practice, and geriatrics. RESULTS: The main barriers to the delivery of effective clinical teaching included the lack of agreement on what to teach, lack of confidence in teaching amongst non-musculoskeletal specialities, and poor communication between specialities. CONCLUSIONS: There is a need to overcome the identified barriers if musculoskeletal clinical teaching to medical students is to be improved. In particular, there is a need to agree which examination skills medical students should learn.
Adult↗
The efficacy and safety of tadalafil: an update.
OBJECTIVE: To provide an update on the efficacy and safety of tadalafil, a phosphodiesterase-5 inhibitor, in the treatment of erectile dysfunction (ED). PATIENTS AND METHODS: In all, 2102 men (mean age 56 years) with mild-to-severe ED of various causes were randomized to placebo or tadalafil, taken as needed with no food restrictions, at fixed 'on-demand' doses of 10 or 20 mg in 11 randomized, double-blind, placebo-controlled trials lasting 12 weeks. The three co-primary outcomes were changes from baseline in the erectile function domain of the International Index of Erectile Function (IIEF) and the proportion of 'yes' responses to questions 2 and 3 of the Sexual Encounter Profile (SEP). Additional efficacy instruments included a Global Assessment Question (GAQ). RESULTS: Compared with placebo, tadalafil gave significantly better outcomes. Patients receiving either dose of tadalafil had a significant mean improvement of 6.5 and 8.6, respectively, in the IIEF erectile function domain score from baseline (P < 0.001 vs placebo). At both doses the mean success rate for intercourse attempts (SEP-Q3) was 58% and 68%, respectively, compared with 31% in the placebo group (P < 0.001), and 71% and 84% reported improved erections at the endpoint (GAQ), vs 33% on placebo (P < 0.001). Tadalafil was effective up to 36 h after dosing and was effective regardless of disease severity and causes, and in patients of all ages. The most frequent adverse events were headache, dyspepsia, back pain and myalgia. CONCLUSION: Tadalafil was an effective and well-tolerated treatment for ED.
Adult↗
Is this the end of clinical research?
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Biomedical Research↗
Serum MMP-1 and TIMP-1 levels are increased in patients with psoriatic arthritis and their siblings.
OBJECTIVE: To determine matrix metalloproteinase-1 (MMP-1) and tissue-inhibitor metalloproteinase-1 (TIMP-1) serum levels in patients with psoriatic arthritis (PsA) and to compare this with their siblings and local blood donor controls. PsA is an interesting condition in which to study metalloproteinases because there are variations in the level of destructiveness, including a significant proportion of cases without destructive change. This is unlike rheumatoid arthritis (RA) which is more uniformly destructive and where MMP-1/TIMP-1 levels are known to be elevated. METHODS: MMP-1 and TIMP-1 serum levels were determined by enzyme-linked immunosorbent assay (ELISA) in (a) index cases with PsA (subtype: RA n = 43, distal interphalangeal disease n = 2, oligoarticular n = 15, spondyloarthropathy n = 9, enthesitis n = 1), (b) siblings with PsA, (c) siblings with psoriasis (Ps), (d) unaffected siblings and (e) local controls. Patients with Ps were divided according to the onset of disease: type I disease, onset before age 40 yr and type II, onset after age 40 yr. RESULTS: MMP-1 and TIMP-1 levels were significantly increased in both the index cases and the group including all siblings compared with the controls (P < 0.0001). There was no statistical difference in MMP-1 or TIMP-1 levels between index cases and their siblings. There was no difference in serum MMP-1 level between the different subtypes (Moll and Wright) of PsA, but there was an increased level of serum TIMP-1 in patients with rheumatoid pattern (P = 0.05). In the index cases there were increased levels of TIMP-1 in type II onset psoriasis (P = 0.03) but no difference in MMP-1 levels. CONCLUSION: MMP-1 and TIMP-1 serum levels are elevated in PsA. This is greatest in RA pattern PsA. These levels were also elevated in unaffected siblings suggesting that genetic factors may be important. TIMP-1 levels were elevated in psoriasis alone, more so in late onset psoriasis, suggesting that the pathological processes of early and late onset psoriasis may be different.
Adult↗
Musculoskeletal examination for medical students: the need to agree what we teach.
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Adult↗
Measured ambulation and self-reported health status following total joint replacement for the osteoarthritic knee.
OBJECTIVE: To quantify the increase in ambulation produced by total knee replacement for osteoarthritis (OA) of the knee and to compare this with questionnaire-derived data. METHODS: We compared the measured ambulatory activity and self-reported Nottingham Health Profile (NHP) data of 19 subjects with OA of the knee before and after total knee replacement (TKR). RESULTS: Subjects were considerably restricted in their measured activity before operation compared with subjects with less severe disease. At 6 months the activity had increased by an average of 79% (P=0.02). The pain scale of the NHP had significantly improved at 3 months, as had the mobility scale. Between 3 and 6 months, however, at the same time the measured activity was increasing, self-reported mobility declined. CONCLUSIONS: Replacement of a knee for OA is an effective way of improving ambulation. At 6 months the average increase amounted to 79%. Self-reported mobility did not correlate with mobility measured objectively.
Aged↗
Within- and between-subject variability in the reinforcing and subjective effects of nitrous oxide in healthy volunteers.
Within- and between-subject variability in the reinforcing and subjective effects of nitrous oxide (N(2)O) was studied across five sessions. Twelve volunteers with no history of drug dependence sampled 30% N(2)O and 100% oxygen for 10 min each, then chose nine times, once every 5 min, among N(2)O (e.g. "Agent A"), oxygen (e.g. "Agent B"), or "drug-free air." Choice varied across subjects but was stable within subjects. Quantitative differences in subjective effects occurred within and across subjects. Some subjective effects were correlated with choice and/or differed between subjects who were consistent choosers of N(2)O versus those who were not. However, drug liking and euphoria, two face-valid measures of abuse liability, were unrelated to choice. Thus, the present study found individual differences (i.e. between-subject variability) in subjective and reinforcing effects of N(2)O and, in terms of within-subject variability, suggested that subjective effects fluctuate across sessions to a relatively greater extent than do reinforcing effects. The varying degrees of correlation between N(2)O choice and its subjective effects emphasize the need for obtaining multiple measures when characterizing abuse liability of this drug.
Adult↗
Modelling sedimentation processes in a constructed stormwater wetland.
The design and operation of constructed wetlands for the treatment of stormwater relies heavily on promoting sedimentation, and being able to predict accurately the expected effectiveness of the pond in removing material from the inflows. A study of sediment behaviour has been carried out in a stormwater wetland in Adelaide, Australia where computer predictions, based on solving the hydrodynamic equations and the transport equation, have been compared to deposition patterns observed in the field. The long-term residence time distribution has been shown to be useful in predicting overall sediment removal rates. Comparisons between the model and field observations indicate generally good agreement. Sources of potential error identified include the variable nature of the runoff concentrations entering the pond and the sediment size distribution. The importance of the transient nature of the flow events was highlighted by the spread of sediment throughout the whole pond.
Conservation of Natural Resources↗
Subjective, psychomotor, and physiological effects of cumulative doses of mixed-action opioids in healthy volunteers.
RATIONALE: Conducting complete dose-response evaluations of multiple drugs in a single within-subjects experiment is very time-consuming when a complete session is required for evaluation of each dose. OBJECTIVE: To evaluate a within-session cumulative-dosing procedure as a potentially efficient method for conducting dose-response evaluations of mixed-action opioids. METHODS: Fifteen healthy volunteers received intravenous injections of saline, butorphanol, nalbuphine, pentazocine, or morphine in a randomized, double-blind, crossover design. Subjects received one injection per hour for the first 4 h, and a 3-h recovery period followed. Saline was injected first, then saline or increasing doses of each drug (except pentazocine, see below) were administered every hour for the next 3 h. The absolute doses per injection were morphine and nalbuphine 2.5, 5, and 10 mg/70 kg, butorphanol 0.5, 1, and 2 mg/70 kg, and pentazocine 7.5, 15, and 0 mg/70 kg. (The highest dose of pentazocine was omitted because of the risk of dysphoria and psychotomimesis). These injections resulted in cumulative doses of morphine or nalbuphine 2.5, 7.5, and 17.5 mg/70 kg, butorphanol 0.5, 1.5, and 3.5 mg/70 kg, and pentazocine 7.5 and 22.5 mg/70 kg. Mood, psychomotor performance, and vital signs were assessed. RESULTS: Effects of all opioids were similar, with some exceptions. Butorphanol had the strongest effects on psychomotor performance and some subjective effects. Morphine was associated with delayed or prolonged side effects. CONCLUSIONS: Orderly dose-response functions and replication of results of single-dosing studies confirmed that the cumulative-dosing procedure is an efficient way of determining dose-response functions for multiple opioids within the same subjects.
Adult↗
Lack of effects of ethanol pretreatment on the abuse liability of nitrous oxide in light and moderate drinkers.
AIMS: To determine effects of ethanol-use history and ethanol pretreatment on abuse liability of nitrous oxide (N(2)O). DESIGN: Placebo-controlled, double-blind, cross-over design evaluating effects of N(2)O, 0% (100% O(2), placebo) and 30% (in O(2)), in the presence of three doses of ethanol: 0 g/kg (placebo), 0.35 g/kg and 0.7 g/kg. SETTING: Subjects sat in a reclining chair in a hospital laboratory. PARTICIPANTS: Eight healthy light drinkers (one drink or less/week) and eight healthy moderate drinkers (seven or more drinks/week) with no history of drug dependence completed the study. INTERVENTION: On three sessions (1, 3, 5) subjects drank a beverage that contained one of the three ethanol doses, then sampled for 10 minute each 0% and 30% N(2)O. During choice sessions (2, 4, 6), subjects received the same ethanol dose as in the previous session, then chose six times, once every 5 min, between 0% and 30% N(2)O. MEASUREMENTS: Subjective (self-reported) drug effects, reinforcing effects of N(2)O as assessed by choice, and psychomotor effects were measured. FINDINGS: Choice of N(2)O did not differ between light (mean = 3.4 choices) and moderate (mean = 3.2 choices) drinkers and was not influenced by ethanol dose (0 g/kg: 3.3 choices, 0.35 g/kg: 3.5 choices, 0.7 g/kg: 3.1 choices). Subjective effects of N(2)O also did not depend on ethanol-use history or ethanol dose. N(2)O liking and desire to inhale the drug again were positively correlated with N(2)O choice. CONCLUSIONS: Ethanol pretreatment and ethanol-use history had no effect on the abuse liability of N(2)O as assessed in the present study.
Adult↗
Extraction and validation of a lower limb HAQ by comparison with objective measurement of ambulatory activity.
OBJECTIVES: Both the Health Assessment Questionnaire (HAQ) and the measurement of spontaneous ambulatory activity are measures that can be used to evaluate disability in RA. METHODS: A cross sectional survey was conducted of 105 RA patients where the HAQ was compared with ambulatory activity from the Numact monitor. Rank correlation was used to evaluate the relationships between activity and the complete and individual sections of the HAQ. RESULTS: Correlation of activity with total HAQ produced significant results (r= -0.29 to -0.48). Correlation with individual sections showed the strongest association with "Hygiene", followed by "Activities", and "Walking". A lower limb HAQ was devised using these and the dressing and rising items. CONCLUSIONS: HAQ and recorded activity measure different but related aspects of disability. Activity should be used if the ability to quantify the result outweighs the extra effort involved in the study.
Activities of Daily Living↗
Weight change and atypical antipsychotic treatment in patients with schizophrenia.
Schizophrenic patients who have been prescribed atypical antipsychotics have a potential risk of gaining weight. The implications of weight gain for clinical care may differ depending on whether a patient is underweight or overweight at baseline. The exact mechanism for weight gain is not known, but several factors have been identified that can help predict which patients are at risk for gaining weight. These factors include better clinical outcome, increased appetite, and low baseline body mass index. In patients treated with olanzapine for up to 3 years, weight gain trended toward a plateau at approximately 36 weeks. Weight gain interventions, including behavioral modifications, show promise in controlling or reducing weight in patients treated with antipsychotics.
Antipsychotic Agents↗