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Biomedical subjects

R MacDonald

Publications and source records attributed to R MacDonald.

At least 19 recordsLinked to original sources

Laser prostatectomy for benign prostatic obstruction.

BACKGROUND: Symptomatic benign prostatic obstruction is a common problem for older men. The gold standard treatment, transurethral resection of the prostate (TURP), significantly improves urinary symptoms and urinary flow. However, TURP has up to a 20% morbidity. Currently, there are a number of minimally invasive procedures that may be safe, effective alternatives to TURP. One promising surgical technique is laser prostatectomy. OBJECTIVES: To assess the therapeutic efficacy and safety of laser prostatectomy techniques for treating men with symptomatic benign prostatic obstruction. SEARCH STRATEGY: Randomized controlled trials were identified from the Cochrane Collaboration Library, MEDLINE, EMBASE, bibliographies of retrieved articles and reviews, and contacting expert relevant trialists and laser manufacturers. SELECTION CRITERIA: All randomized controlled trials evaluating laser prostatectomy treatment for men with symptomatic BPH. Trials were eligible if they (1) were randomized comparisons of a laser technique with TURP, (2) included at least 10 men with BPO in each treatment arm, (3) provided at least 6-months follow-up, and (4) included clinical outcomes such as urologic symptom scales or urodynamic measurements. DATA COLLECTION AND ANALYSIS: Data extraction and assessment of methodologic quality was performed independently by two reviewers. Information on study design, subject and treatment characteristics, adverse events, urinary symptoms, and urinary flow were extracted using a standard form. MAIN RESULTS: 20 studies involving 1898 subjects were evaluated, including studies 4 with multiple comparisons. We found 8 comparisons of TURP with contact lasers, 8 with non-contact lasers, 4 with hybrid techniques, and one with interstitial laser coagulation (ILC). Two studies compared transurethral electrovaporization (TUVP) with contact lasers, one study compared interstitial laser coagulation with transurethral microwave thermotherapy (TUMT), and one study compared holmium contact lasers (HoLRP) with open prostatectomy. Among the studies comparing laser prostatectomy with TURP, follow-up duration ranged from 6 to 36 months. Mean age (67.2 yrs), mean baseline symptom score (20.2), and mean baseline peak urinary flow (9.2 ml/s) did not differ by treatment group. The pooled percentage improvements for mean urinary symptoms ranged from 59% to 68% with lasers and 63% to 77% with TURP. The improvements for mean peak urinary flow ranged from 56% to 119% with lasers and 96% to 127% with TURP. Overall, laser subjects were less likely to receive transfusions or develop strictures and their hospitalizations were shorter. Non-contact laser subjects were more likely to have dysuria, urinary tract infection, and retention. Re-operation occurred more often following laser procedures. REVIEWER'S CONCLUSIONS: Laser techniques are a useful alternative to TURP for treating BPO. Small sample sizes and differences in study design limit any definitive conclusions regarding the preferred type of laser technique. Data were insufficient to compare laser techniques with other minimally invasive procedures.

Aged↗

Trazodone for erectile dysfunction: a systematic review and meta-analysis.

OBJECTIVE: To determine the efficacy and safety of trazodone in the treatment of erectile dysfunction (ED) in a meta-analysis. METHODS: The data sources used were Medline and the Cochrane Library databases (January 1966 to May 2002), bibliographies of retrieved articles and review articles, and conference proceedings and abstracts. Trials were eligible for inclusion in the review if they included men with ED, compared trazodone with a control, were randomized, of > or = 7 days' duration and assessed clinically relevant outcomes. Two reviewers independently evaluated study quality and extracted data in a standardized fashion. RESULTS: Six trials (comprising 396 men) met the inclusion criteria; they consisted of heterogeneous populations, were small, brief and in some cases methodologically weak. Three of the six trials showed an apparently clinically meaningful benefit of trazodone for ED compared with placebo, the differences being statistically significant in two. In pooled results, trazodone monotherapy appeared more likely than placebo to lead to a 'positive treatment response', although this difference was not statistically significant (37% vs 20%; relative benefit increase, 1.6; 95% confidence interval, CI, 0.8-3.3). Subgroup analyses suggested that men with psychogenic ED might be more likely to benefit from trazodone than those with mixed or physiological ED. The efficacy of trazodone also appeared greater at higher doses (150-200 vs 50 mg/day). Men randomized to trazodone were not significantly more likely than those receiving placebo to withdraw for any reason or for an adverse event, or to have specific adverse events, but wide CIs could not exclude a greater risk of these adverse outcomes with trazodone. Specific adverse events with trazodone included dry mouth (19%), sedation (16%), dizziness (16%) and fatigue (15%). CONCLUSION: Trazodone may be helpful in men with ED, possibly more so at higher doses, and in men with psychogenic ED. Future high-quality trials should compare trazodone with placebo and other therapies in men with depression and psychogenic ED.

Adult↗

Early versus deferred androgen suppression in the treatment of advanced prostatic cancer.

BACKGROUND: Prostate cancer is a leading cause of cancer death in men. Treatment goals for men with advanced prostate cancer include prolonging survival, preventing or delaying symptoms due to disease progression, improving and maintaining quality of life, reducing treatment related morbidity. Androgen suppression therapy is considered a mainstay of treatment for men with advanced prostate cancer. However it is not clear whether early androgen suppression for men with locally advanced disease or asymptomatic metastases improves length and quality of life compared to androgen suppression deferred until signs and symptoms of clinical progression. OBJECTIVES: This systematic review assessed the efficacy and adverse effects of primary therapy with early versus deferred androgen suppression therapy in men with advanced prostate cancer. SEARCH STRATEGY: Randomized controlled trials were searched in general and specialized databases (MEDLINE, EMBASE, CancerLIT, Cochrane Library, VA Cochrane Prostate Disease register) and by reviewing bibliographies including those of the Blue Cross and Blue Shield Association Technology Evaluation Center/Evidence-based Practice Center of the Agency for Healthcare Research and Quality (BCBS/TEC-AHRQ) report No.4. SELECTION CRITERIA: All published randomized trials were eligible for inclusion provided they: randomized men with advanced prostate cancer to early versus deferred androgen suppression; reported overall, progression-free, and cancer-specific survival, and/or adverse events; did not utilize androgen suppression as adjuvant therapy to radiation treatment. DATA COLLECTION AND ANALYSIS: An independent reviewer using a standardized form extracted information on trial characteristics, interventions, and outcomes. Results were reviewed for accuracy and discrepancies resolved by discussion. The main outcome measure for comparing effectiveness was the overall survival at 1, 2, 5 and 10 years. Progression-free survival, cancer-specific survival, complications due to disease progression and the incidence of adverse effects of treatment were also measured. MAIN RESULTS: Four trials involving 2,167 patients were included in this review. All of the trials were conducted prior to use of prostate specific antigen (PSA) testing. There was variability between studies regarding the treatments used and the requirements for initiation of treatments. The percent overall survival at 1, 2, 5, and 10 years for the early treatment group was 88%, 73%, 44%, and 18%. For the deferred therapy group the percent overall survival was 86%, 71%, 37%, and 12%. The pooled estimate for the difference in overall survival favored early therapy but was significant only at 10 years when few patients had survived [OR = 1.16 (95% CI: 0.90 to 1.49) at 1 year, 1.08 (95% CI: 0.89 to 1.33) at 2 years, 1.19 (95% CI: 0.95 to 1.50) at 5 years, and 1.50 (95% CI: 1.04 to 2.16) at 10 years]. The pooled estimate of prostate cancer specific survival at 2, 5, and 10 years favored early therapy though the confidence intervals were wide and the results not statistically different. The risk differences at 2, 5, and 10 years were 2.7%, 5.8%, and 4.6%. Although each study used unique definitions of progression free survival, all studies found progression free survival was consistently better in the early intervention group at all time points. Complications due to disease progression were only reported in one study but were more frequent in the deferred treatment group. Adverse events due to treatment were also only reported in one study but occurred more frequently in the early treatment group. REVIEWER'S CONCLUSIONS: The evidence from randomized controlled trials is limited by the variability in study design, stage of cancer and subjects enrolled, interventions utilized, definitions and reporting of outcomes and the lack of PSA testing for diagnostic and monitoring purposes. However, the available information suggests that early androgen suppression for treatment of advanced prostate cancer reduces disease progression and complications due to progression. Early androgen suppression may provide a small but statistically significant improvement in overall survival at 10 years. There was no statistically significant difference in prostate cancer specific survival but a clinically important difference could not be excluded. These outcomes need to be evaluated with the evidence suggesting higher costs and more frequent treatment related adverse effects with early therapy. Additional studies are required to evaluate more definitively the efficacy and adverse effects of early versus delayed androgen suppression in men with prostate cancer. In particular trials should evaluate patients with advanced prostate cancer diagnosed by PSA testing and men with persistent or rising PSA levels following treatment options (e.g. radical prostatectomy, radiation therapy or observation) for clinically localized disease.

Androgen Antagonists↗

Terazosin for benign prostatic hyperplasia.

BACKGROUND: Lower urinary tract symptoms associated with benign prostatic obstruction (BPO) occur in up to 70% of men over the age of 60 years. To relieve these bothersome symptoms, treatment options include alpha-antagonists, also know as alpha-blockers. OBJECTIVES: We conducted a systematic review to evaluate the effectiveness and adverse effects of the alpha-blocker, terazosin, for treatment of urinary symptoms associated with BPO. SEARCH STRATEGY: Trials were searched in computerized general and specialized databases (MEDLINE, Cochrane Library), by checking bibliographies, and by contacting manufacturers and researchers. SELECTION CRITERIA: Studies were included if they (1) were randomized trials of at least 1 month duration, and (2) included men with symptomatic BPO and compared terazosin with placebo or active controls. DATA COLLECTION AND ANALYSIS: Study, patient characteristics and outcomes data were extracted in duplicate onto standardized forms utilizing a prospectively developed protocol. The main outcome measure for comparing the effectiveness of terazosin with placebo or other BPO medications was change in urological symptoms as measured by validated symptom scores. Secondary outcomes included urodynamic measures. The main outcome measure for adverse effects was the number of men reporting side effects. We also evaluated the number of men withdrawing from treatment and the number withdrawing due to adverse effects. MAIN RESULTS: 17 studies involving 5,151 subjects met inclusion criteria (placebo-controlled (10); alpha-blockers (7); finasteride alone or in combination with terazosin as well as placebo (1); microwave therapy (TUMT) (1). Study duration ranged from 4-52 weeks. Mean age was 65 years and 82% of men were white. Baseline urologic symptom scale scores and flow rates demonstrated that men had moderate BPO. Efficacy outcomes were rarely reported in a fashion that allowed for data pooling but indicated that terazosin improved symptom scores and flow rates more than placebo or finasteride and similarly to other alpha antagonists. The pooled mean percentage improvements for the Boyarsky symptom score was 37% for terazosin versus 15% for placebo (n=4 studies). The mean percentage improvement for the American Urological Association symptom score (AUA) was 38% compared to 17% and 20% for placebo and finasteride, respectively (n = 2 studies). The pooled mean improvement in the International Prostate Symptom Score (IPSS) (40%) was similar to tamsulosin (43%). Peak urine flow rates improved greater with terazosin (22%), than placebo (11%) and finasteride (15%) but did not differ significantly from the other alpha-blockers. The percentage of men discontinuing terazosin was comparable to men receiving placebo and finasteride but was greater then with other alpha-antagonists. Adverse effects were greater than placebo and included dizziness, asthenia, headache and postural hypotension. REVIEWER'S CONCLUSIONS: The available evidence suggests that terazosin improves urinary symptoms and flow measures associated with BPO. Effectiveness is superior to placebo or finasteride, similar to other alpha-blockers but less than TUMT. Adverse effects were generally mild but more frequent than other alpha-blockers and associated with between a two-four fold increase in treatment discontinuation.

Adrenergic alpha-Antagonists↗

Terazosin for treating symptomatic benign prostatic obstruction: a systematic review of efficacy and adverse effects.

OBJECTIVE: To systematically review and evaluate the effectiveness and adverse effects of the alpha-antagonist, terazosin, for treating urinary symptoms associated with benign prostatic obstruction (BPO). METHODS: Studies were sought and included in the review if they were randomized trials of at least 1 month duration, involved men with symptomatic BPO and compared terazosin with placebo or active controls. The study, patient characteristics and outcome data were extracted in duplicate onto standardized forms using a prospectively developed protocol. RESULTS: Seventeen studies involving 5151 men met the inclusion criteria, i.e. placebo-controlled (10), alpha-blockers (seven), finasteride alone or combined with terazosin and placebo (one), and microwave therapy (one). The study duration was 4-52 weeks; the mean age of the men was 65 years and 82% were white. Baseline urological symptom scale scores and flow rates showed that men had moderate BPO. Efficacy outcomes were rarely reported in a way that allowed for data pooling, but indicated that terazosin improved symptom scores and flow rates more than did placebo or finasteride, and similarly to other alpha-antagonists. The pooled mean percentage improvement for the Boyarsky symptom score was 37% for terazosin and 15% for placebo (four studies). The mean percentage improvement for the American Urological Association symptom score was 38%, compared with 17% and 20% for placebo and finasteride, respectively (two studies). The pooled mean improvement in the International Prostate Symptom Score of 40% was similar to that with tamsulosin (43%). Peak urinary flow rates improved more with terazosin (22%) than with placebo (11%) and finasteride (15%), but did not differ significantly from the other alpha-antagonists. The percentage of men discontinuing terazosin was comparable with those receiving placebo and finasteride, but greater than with other alpha-antagonists. Adverse effects were greater than with placebo and included dizziness, asthenia, headache and postural hypotension. CONCLUSIONS: The available evidence indicates that terazosin improves the symptoms and flow rates associated with BPO; it was more effective than placebo or finasteride and similar to other alpha-antagonists. Adverse effects were generally mild but more frequent than with other alpha-antagonists and associated with a two- to four-fold increase in treatment discontinuation.

Adrenergic alpha-Antagonists↗

Practising evidence-based medicine: the design and implementation of a multidisciplinary team-driven extubation protocol.

BACKGROUND: Evidence from recent literature shows that protocol-directed extubation is a useful approach to liberate patients from mechanical ventilation (MV). However, research evidence does not necessarily provide guidance on how to implement changes in individual intensive care units (ICUs). We conducted the present study to determine whether such an evidence-based strategy can be implemented safely and effectively using a multidisciplinary team (MDT) approach. METHOD: We designed a MDT-driven extubation protocol. Multiple meetings were held to encourage constructive criticism of the design by attending physicians, nurses and respiratory care practitioners (RCPs), in order to define a protocol that was evidence based and acceptable to all clinical staff involved in the process of extubation. It was subsequently implemented and evaluated in our medical/ surgical ICU. Outcomes included response of the MDT to the initiative, duration of MV and stay in the ICU, as well as reintubation rate. RESULTS: The MDT responded favourably to the design and implementation of this MDT-driven extubation protocol, because it provided greater autonomy to the staff. Outcomes reported in the literature and in the historical control group were compared with those in the protocol group, and indicated similar durations of MV and ICU stay, as well as reintubation rates. No adverse events were documented. CONCLUSION: An MDT approach to protocol-directed extubation can be implemented safely and effectively in a multidisciplinary ICU. Such an effort is viewed favourably by the entire team and is useful in enhancing team building.

Adult↗

High-throughput development and characterization of a genomewide collection of gene-based single nucleotide polymorphism markers by chip-based matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

We describe here a system for the rapid identification, assay development, and characterization of gene-based single nucleotide polymorphisms (SNPs). This system couples informatics tools that mine candidate SNPs from public expressed sequence tag resources and automatically designs assay reagents with detection by a chip-based matrix-assisted laser desorption/ionization time-of-flight mass spectrometry platform. As a proof of concept of this system, a genomewide collection of reagents for 9,115 gene-based SNP genetic markers was rapidly developed and validated. These data provide preliminary insights into patterns of polymorphism in a genomewide collection of gene-based polymorphisms.

Alleles↗

The use of glass wool as an attachment surface for studying phenotypic changes in Pseudomonas aeruginosa biofilms by two-dimensional gel electrophoresis.

Two-dimensional polyacrylamide gel electrophoresis was used to demonstrate phenotypic differences between Pseudomonas aeruginosa biofilm cells and the planktonic counterpart cells under defined culture conditions. Glass wool was used as a substratum for cell attachment as it affords a large surface-to-volume ratio (1 g with a mean diameter of 15 microns = 1300 cm2), supports the growth of biofilms, allows for free movement of cells between the inter-strand spaces, and it facilitates the exchange of nutrients and oxygen. It also allows for the separation of the biofilm biomass from the surrounding surface influenced planktonic (SIP) cells for further characterization. Comparative analysis of the respective proteomes indicated striking differences in the protein patterns of planktonic, biofilm and SIP cells. We selected 41 proteins, the levels of which varied in a significant and reproducible way in the respective protein profiles. In the biofilm cells, a general up-regulation of the spots was seen, but in SIP cells expression of these spots were generally down-regulated. Altogether six unique proteins were seen in the planktonic cells, while the biofilm and SIP cells contained five and two unique proteins, respectively. Glass wool, therefore, appears to be an ideal attachment surface for the study of biofilm development.

Bacterial Adhesion↗