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Biomedical subjects

D Taylor

Publications and source records attributed to D Taylor.

At least 91 records · Page 5Linked to original sources

A systematic review and meta-analysis of Hypericum perforatum in depression: a comprehensive clinical review.

The herbal remedy St John's wort is widely used as an antidepressant but its efficacy has not been systematically investigated. Meta-analyses and systematic reviews of published trials strongly suggest St John's wort is more effective than placebo although comparative efficacy to standard antidepressants is less clearly established. We updated and expanded previous meta-analyses of St John's wort, scrutinised the validity of published reports and examined possible mechanisms of action. Twenty-two randomised controlled trials were identified. Meta-analysis showed St John's wort to be significantly more effective than placebo (relative risk (RR) 1.98 (95% CI 1.49-2.62)) but not significantly different in efficacy from active antidepressants (RR 1.0 (0.90-1.11)). A sub-analysis of six placebo-controlled trials and four active comparator trials satisfying stricter methodological criteria also suggested that St John's wort was more effective than placebo (RR 1.77 (1.16-2.70)) and of similar effectiveness to standard antidepressants (RR 1.04 (0.94-1.15)). There was no evidence of publication bias. Adverse effects occurred more frequently with standard antidepressants than with St John's wort. The mechanism of action of St John's wort remains unknown. Future research should include large scale, appropriately powered comparisons of St John's wort and standard antidepressants.

Anthracenes↗

Outcome of lens aspiration and intraocular lens implantation in children aged 5 years and under.

AIMS: To determine the visual outcome and complications of lens aspiration with intraocular lens implantation in children aged 5 years and under. METHODS: The hospital notes of all children aged 5 years and under, who had undergone lens aspiration with intraocular lens implantation between January 1994 and September 1998, and for whom follow up data of at least 1 year were available, were reviewed. RESULTS: Of 50 children who underwent surgery, 45 were eligible based on the follow up criteria. 34 children had bilateral cataracts and, of these, 30 had surgery on both eyes. Cataract was unilateral in 11 cases; thus, 75 eyes of 45 children had surgery. Cataracts were congenital in 28 cases, juvenile in 16, and traumatic in one case. The median age at surgery was 39 months (range 11-70 months). Follow up ranged from 12-64 months (median 36 months). Of 34 children with bilateral disease, 25 (73.5%) had a final best corrected visual acuity of 6/12 or better, while seven (20.5%) achieved 6/18 or less; in one child the vision improved from UCUSUM to CSM but another, who had only one eye operated on, was unable to fix or follow with this eye preoperatively or 2 years postoperatively. Of 11 children with unilateral cataract, five (45.5%) had a final best corrected visual of 6/12 or better, and six (54.5%) 6/18 or less. A mild fibrinous uveitis occurred in 20 (28.2%) eyes in the immediate postoperative period, but resolved with topical steroids. One child had a vitreous wick postoperatively requiring surgical division. Glaucoma, endophthalmitis, or retinal detachment have not been observed so far in any patient postoperatively. CONCLUSION: From this series the authors suggest that, in children aged 5 years and under, lens aspiration with intraocular lens implantation is a safe procedure, with a good visual outcome in the short term. Further studies are needed to investigate these outcomes in the long term.

Anti-Inflammatory Agents↗

Left ventricular wall stress during leg-press exercise performed with a brief Valsalva maneuver.

STUDY OBJECTIVES: To assess the effects of leg-press (LP) exercise performed with a brief (2 to 3 s) Valsalva maneuver on left ventricular (LV) systolic function and LV wall stress in five healthy men (mean +/- SD age, 27.6 +/- 2.9 years). METHODS AND MEASUREMENTS: Subjects performed submaximal (80% one repetition maximum [1RM], 337.9 +/- 109.1 kg; 95% 1RM, 400.6 +/- 129.8 kg) and maximal LP exercise (420 +/- 118.6 kg) during which central arterial pressure, intrathoracic pressure, and two-dimensional echocardiographic analysis of LV systolic function and LV wall stress were measured. RESULTS: Compared with baseline, LP exercise resulted in an increase in intrathoracic pressure (baseline, 1.7 +/- 2.9 mm Hg; 80% 1RM, 111.7 +/- 20.2 mm Hg; 95% 1RM, 112.2 +/- 21.1 mm Hg; 100% 1RM, 111.0 +/- 21.3 mm Hg; p < 0.05) and LV end-systolic pressure (baseline, 120.0 +/- 13.2 mm Hg; 80% 1RM, 251.6 +/- 15.3 mm Hg; 95% 1RM, 255.3 +/- 12.2 mm Hg; 100% 1RM, 242.8 +/- 16.5 mm Hg; p < 0.05) with no changes in LV end-systolic transmural pressure (baseline, 118.3 +/- 12.6 mm Hg; 80% 1RM, 140.0 +/- 6.1 mm Hg; 95% 1RM, 143.1 +/- 16.1 mm Hg; 100% 1RM, 131.8 +/- 29.7 mm Hg; p > 0.05), LV end-systolic wall stress (baseline, 91.7 +/- 20.2 kilodyne/cm(2); 80% 1RM, 78.0 +/- 24.4 kilodyne/cm(2); 95% 1RM, 81.4 +/- 25.3 kilodyne/cm(2); 100% 1RM, 85.9 +/- 20.1 kilodyne/cm(2); p > 0.05), or LV fractional area change (baseline, 0.48 +/- 0.03; 80% 1RM, 0.52 +/- 0.11; 95% 1RM, 0.53 +/- 0.06; 100% 1RM, 0.52 +/- 0.05; p > 0.05). CONCLUSION: LP exercise performed with a brief Valsalva maneuver is not associated with an alteration in LV wall stress or LV systolic function in healthy young men.

Adult↗

Effects of ground surface deformability, trimming, and shoeing on quasistatic hoof loading patterns in horses.

OBJECTIVE: To determine whether solar load distribution pattern on a solid nondeformable ground surface is the product of contact erosion and is the mirror image of load distribution on a deformable surface in horses. ANIMALS: 30 clinically normal horses. PROCEDURES: Solar load distribution was compared among 25 clinically normal horses during quasistatic loading on a solid nondeformable surface and on a highly deformable surface. Changes in solar load distribution patterns were evaluated in 5 previously pasture-maintained horses housed on a flat nondeformable surface. Changes in solar load distribution created by traditional trimming and shoeing were recorded. RESULTS: Unshod untrimmed horses had a 4-point (12/25, 48%) or a 3-point (13/25, 52%) wall load distribution pattern on a flat solid surface. Load distribution on a deformable ground surface was principally solar and located transversely across the central region of the foot. Ground surface contact areas on solid (24.2 +/- 8.62 cm2) and deformable (69.4 +/- 22.55 cm2) surfaces were significantly different. Maintaining unshod horses on a flat nondeformable surface resulted in a loss of the 3- and 4-point loading pattern and an increase in ground surface contact area (17.9 +/- 2.77 to 39.9 +/- 12.77 cm2). Trimming increased ground surface contact area (24.2 +/- 8.60 to 45.7 +/- 14.89 cm2). CONCLUSION AND CLINICAL RELEVANCE: In horses, the solar surface is the primary weight-loading surface, and deformability of ground surface may have a role in foot expansion during loading. Increased surface area induced by loading on deformable surfaces, trimming, and shoeing protects the foot.

Animals↗

Impaired left ventricular systolic function after a half-ironman race.

OBJECTIVE: To assess the effects of prolonged strenuous exercise in the form of a half-ironman (HI) race (2 km swim, 90 km bike ride and a 21 km run) on left ventricular systolic function. METHODS AND RESULTS: The study participants consisted of nine male triathletes (mean age +/- SD 32+/-5 years) who competed in the Great White North HI race. Two-dimensional transthoracic echocardiograms were obtained two to three days before the HI (prerace), immediately after completion of the HI (postrace) and 24 h after cessation of exercise. Compared with before the race, performing an HI was associated with a decline in systolic blood pressure (prerace 127.2+/-15.0 mmHg compared with after the race 116.1+/-10.2 mmHg, P<0.05), the systolic blood pressure to end-systolic cavity area ratio (a surrogate for left ventricular contractility - prerace 14.3+/-3.0 mmHg/cm(2) compared with postrace 11.0+/-2.2 mmHg/cm(2), P<0.05) and the fractional area change (prerace 54.1+/-3.8% compared with postrace 47.4+/-5.5%, P<0.05). There was also a concomitant increase in heart rate (prerace 56.3+/-9.4 beats/min compared with postrace 74.1+/-10.7 beats/min, P<0.05), the end-systolic cavity area (prerace 9.2+/-2.2 cm(2) compared with postrace 10.8+/-1.9 cm(2), P<0.05) and the end-systolic cavity area to end-systolic myocardial area ratio (prerace 0.39+/-0.08 compared with postrace 0.51+/-0.1, P<0.05), which returned toward baseline values 24 h after cessation of the HI. CONCLUSIONS: Performing an HI appears to be associated with a transient impairment in left ventricular contractility and a subsequent decline in left ventricular systolic function that tends to return toward normal values within 24 h after cessation of exercise.

Adult↗

What we know and how we know it: contributions from nursing to women's health research and scholarship.

In this first chapter, we trace the historical roots of nursing research and scholarship focused on protecting and promoting women's health. Beginning with Florence Nightingale, modern nursing's first researcher, who focused on the health impact of women's daily lives through her detailed observations of human behavior. More recently, nursing's contributions to women's health over the past 30 years have redefined women's health, proposed new frameworks for understanding women's health; provided reviews of the women's health literature across disciplines; developed communities of nurse scholars and researchers focused on new areas of women's health research; generated and expanded the knowledge base for women's health practice and education; promoted a global view of women's health; and proposed new models for women's health care delivery. Clearly, a community of nursing scholars, developed over the past 25 years, has contributed to advancing women's health knowledge and improving the health and well-being of women. Without the benefit of a crystal ball, we suggest that nursing will continue to provide leadership in the conduct and the application of research to improve women's health and women's lives.

Female↗

Simultaneous assessment of occupational exposures from multiple worker groups.

The methods developed by Rappaport et al. [Ann. Occup. Hyg. 39 (1995) 469] and Lyles et al. [J. Agri. Bio. Environ. Stat. 2 (1997a) 64; Ann. Occup. Hyg. 41 (1997b) 63]) for assessing workplace exposures on a group-by-group basis are extended to allow for the simultaneous assessment of data from multiple worker groups within the same industry. These extended methods allow models to be fit simultaneously to data on all groups in a study, even when some of the groups might not contribute adequate information to be modeled separately. We assume that the exposures are log-normally distributed, and that they can be adequately modeled by a mixed effects regression model with parameters for exposure levels and for between- and within-worker variance components. Simultaneously analyzing data from multiple groups is only advantageous when at least one of these variance components can be assumed to be homogeneous across the groups. Here, we advocate testing an assumption of homogeneous within-worker variance components, sigma(2)(w,h), using a likelihood ratio test to choose between a full model (distinct sigma(2)(w,h) for each group) and a reduced model (common sigma(2)(w) across groups). We then develop a procedure, which is conditional on the results of the likelihood ratio test, for testing whether or not each group of workers is overexposed to the contaminant of interest. This modeling and testing procedure was applied to 39 different data sets, each containing data for multiple groups, from a wide variety of industries. For these data, the testing procedure generally resulted in the same conclusion regarding overexposure under both models, even in those data sets where the within-worker variance components appeared to be quite heterogeneous. We also conducted a small simulation study to estimate the significance level of the proposed testing procedure, and found that the significance levels tended to be adequately close to the specified nominal level when a likelihood ratio test with significance level of at least 0.01 was used as a preliminary test. Additionally, we make specific recommendations for designing studies and suggest a method for determining whether engineering and administrative controls or individual-level interventions would be of most benefit to an overexposed group of workers.

Humans↗

Effectiveness of thin-layer preparations vs. conventional Pap smears in a blinded, split-sample study. Extended cytologic evaluation.

OBJECTIVE: To further evaluate the effectiveness of the AutoCyte PREP thin-layer slide preparation (TriPath Imaging, Inc., Burlington, North Carolina) as compared to conventional Pap smears. STUDY DESIGN: A split-sample, blinded evaluation of matched thin-layer preparations and conventional smears from 2,438 patients was performed. This material was enriched by including 260 cases of high grade squamous intraepithelial lesions (HSILs) and cancer cases from an earlier study. Many of these cases were difficult to diagnose, containing very few abnormal cells on one or both matching slides. The preparations were evaluated multiple times by both thin-layer-inexperienced and -experienced cytology professionals to better compare performance related to preparation quality alone. RESULTS: The initial evaluations of the slides by personnel with only brief training in thin-layer interpretation demonstrated equivalent performance for the two preparations. The reevaluation study by cytology professionals with several months of thin-layer experience demonstrated a statistically significant improvement in detection of both LSIL and HSIL lesions using AutoCyte PREP slides. There was also a statistically significant improvement in the number of satisfactory samples using the AutoCyte PREP method. CONCLUSION: The study demonstrated that the AutoCyte PREP thin-layer slide preparation is at least equivalent to conventional Pap smears in the detection of LSIL and HSIL, even when evaluated by cytology professionals who have been newly trained in the thin-layer method and that, with increased experience, the thin-layer AutoCyte PREP slide preparation method showed a statistically significant improvement in disease detection.

Female↗

Long-term effects of cholesterol lowering and angiotensin-converting enzyme inhibition on coronary atherosclerosis: The Simvastatin/Enalapril Coronary Atherosclerosis Trial (SCAT).

BACKGROUND: This long-term, multicenter, randomized, double-blind, placebo-controlled, 2 x 2 factorial, angiographic trial evaluated the effects of cholesterol lowering and angiotensin-converting enzyme inhibition on coronary atherosclerosis in normocholesterolemic patients. METHODS AND RESULTS: There were a total of 460 patients: 230 received simvastatin and 230, a simvastatin placebo, and 229 received enalapril and 231, an enalapril placebo (some subjects received both drugs and some received a double placebo). Mean baseline measurements were as follows: cholesterol level, 5.20 mmol/L; triglyceride level, 1.82 mmol/L; HDL, 0.99 mmol/L; and LDL, 3.36 mmol/L. Average follow-up was 47.8 months. Changes in quantitative coronary angiographic measures between simvastatin and placebo, respectively, were as follows: mean diameters, -0.07 versus -0.14 mm (P:=0.004); minimum diameters, -0.09 versus -0.16 mm (P:=0. 0001); and percent diameter stenosis, 1.67% versus 3.83% (P:=0.0003). These benefits were not observed in patients on enalapril when compared with placebo. No additional benefits were seen in the group receiving both drugs. Simvastatin patients had less need for percutaneous transluminal coronary angioplasty (8 versus 21 events; P:=0.020), and fewer enalapril patients experienced the combined end point of death/myocardial infarction/stroke (16 versus 30; P:=0.043) than their respective placebo patients. CONCLUSIONS: This trial extends the observation of the beneficial angiographic effects of lipid-lowering therapy to normocholesterolemic patients. The implications of the neutral angiographic effects of angiotensin-converting enzyme inhibition are uncertain, but they deserve further investigation in light of the positive clinical benefits suggested here and seen elsewhere.

Adult↗

Scaling effects in the fatigue strength of bones from different animals.

The bones of vertebrates are all made from the same basic material, despite a huge variation in size from one species to another. This introduces a problem: large structures are more prone to fatigue failure (stress fracture) than smaller structures made of the same material. This implies that bones in larger animals cannot withstand as much stress in daily use as bones in smaller animals. In fact, this is not the case, because all bones experience approximately the same stresses and strains in use. This implies a variation in the underlying material: bone material in large animals must have superior fatigue properties to offset the disadvantages of size. This hypothesis is tested here by reference to fatigue data from the literature, taken from a range of animals from cows to mice. Fatigue strength was plotted as a function of stressed volume and modelled mathematically using a Weibull distribution. This shows a general tendency for fatigue strength to reduce as volume increases. But when the volume effect is taken into account, there remains a tendency for bones from smaller animals to have lower fatigue strength. This can be modelled by a simple variation in one of the parameters in the Weibull equation, which defines the intrinsic fatigue strength of the material. When extrapolated to the size of the whole bone for each animal, all bones were found to have the same fatigue strength. This resolves the anomaly and implies a complex system in which the underlying structure of bone varies with animal size in order to cancel out scaling effects.

Animals↗

The distribution of mercury and other trace metals in the sediments of the Mersey Estuary over 25 years 1974-1998.

Mercury and other heavy metals have been monitored in the surface sediments of the Mersey Estuary in NW England for a period of 25 years, using a consistent methodology and sampling grid. This has produced one of the most comprehensive data sets available in the literature and demonstrated some of the difficulties associated with undertaking long-term environmental monitoring. The data indicate that the concentration of mercury and other metals in the sediments of this estuary are strongly correlated to the organic matter and particle size content. This has resulted in the metal distribution patterns reflecting the sediment characteristics and dynamics, irrespective of the position of the input sources. The trend data has indicated a continual, although somewhat uneven, decline in the concentration of most of the metals studied. Remobilisation of previously consolidated saltmarsh sediments can cause significant perturbations in contaminant reduction trends, and needs to be considered in the design of long term monitoring programmes.

Aluminum↗

Oculo-ectodermal syndrome: report of two further cases.

We describe the clinical findings in two previously unreported, unrelated cases with aplasia cutis congenita and epibulbar dermoids, similar to the cases reported by Toriello et al. [1993]. In addition, one patient had bladder exstrophy with epispadias. These cases provide further evidence for the identification of the oculo-ectodermal syndrome as a distinct entity.

Bladder Exstrophy↗