Biomedical subjects
Publications and source records attributed to David Morgan.
Cr(III) complexes of tridentate SNS ligands have been prepared and evaluated as catalysts for ethylene trimerization, with several giving very high activity and excellent selectivity toward 1-hexene when activated with methylaluminoxane. The new complexes illustrate the potential of sulfur-based ligands on early transition metals for catalysis.
STUDY DESIGN: Prospective descriptive biomechanical analysis of shoulder motion in golf. OBJECTIVE: To characterize normal shoulder motion during the driving swing in male recreational golfers of various age groups. BACKGROUND: Shoulder trauma accounts for approximately 12% of all golf-related injuries. To design sport-specific rehabilitation programs for the injured golfer and exercise programs for the healthy golfer, clinicians and teachers need quantitative information describing range of motion requirements about the shoulder for the amateur player. METHOD AND MEASURE: Sixty-five male golfers were divided into 3 age groups: college, middle, and senior. A high-speed, 6-camera motion analysis system recorded 3-dimensional bilateral shoulder motion (vertical elevation, horizontal adduction, external rotation, and shoulder tum) for 3 swings of the driver. Group means for ranges and functional end points of motion were compared using a single-factor 1-way ANOVA (alpha = 0.05). RESULTS: All maximum values of shoulder motion were lower in the senior group than in the other 2 groups. At peak backswing, senior golfers exhibited 38 degrees less right-side shoulder external rotation than college golfers. However, from address, seniors horizontally abduct the right arm 18 degrees more than college golfers. In the older golfers, total range of motion was reduced for both shoulders in the vertical plane and for the left shoulder in the horizontal plane. CONCLUSIONS: This study describes shoulder motion for asymptomatic golfers of various age groups. These data may serve as a baseline reference for assessing disease- or injury-related changes in the golf swing and for designing sport-specific exercise and rehabilitation programs.
Homozygous inv mice lack a functional inversin protein and exhibit situs inversus plus severe cystic changes in the kidney and pancreas. Although the inversin sequence has provided few clues to its function, we and others have previously identified calmodulin as a binding partner. We now provide evidence that inversin interacts with the anaphase promoting complex protein Apc2. As expected of an Apc2 target, inversin possesses D-boxes and site-directed mutagenesis of the well-conserved D-box residues abrogates inversin-Apc2 interaction. An inversin-specific antibody reveals a dynamic expression pattern throughout the cell cycle and strong expression in the primary cilia of renal epithelium. Our data support a role for inversin in primary cilia and involvement in the cell cycle. Mutations of the proteins polaris, cystin and polycystin-2 which are expressed in renal epithelium primary cilia, lead to renal cystic changes. Aberrant cell proliferation is also involved in cyst development. The data reported here suggest that inversin may provide a link between these two mechanisms.
All vertebrates have a left-right body axis with invariant asymmetries of the heart and the positions of the abdominal viscera. Major advances have recently been made in defining molecular components of the pathway specifying the vertebrate left-right axis, but our knowledge of the early determinants is extremely limited. In the invmouse the left-right axis is consistently reversed, unlike other vertebrate mutants where randomisation of situs is apparent. The gene disrupted in this mouse encodes a 1062-amino-acid protein, inversin. We previously reported 16 tandem ankyrin repeats, spanning amino acids 13-557, and two putative nuclear localisation sequences, but otherwise the sequence offered few clues to the possible function. In order to identify regions likely to be functionally important, we have identified and characterised orthologous sequences in several species, including chick, Xenopus and zebrafish. Sequence comparisons show strong conservation of the ankyrin repeat region and also a lysine-rich domain spanning amino acids 558-604. Further analysis identified a highly conserved IQ calmodulin-binding domain in the latter region and another such domain in an otherwise poorly conserved C-terminal region. A yeast two-hybrid screen identified calmodulin in one third of the positive clones, and we confirmed this interaction by immunoprecipitation.
We describe a process for assisting seriously ill patients and their caregivers in prioritizing their preferences for care during advanced illness. Thirty-two seriously ill patients and their caregivers participated in seven 90-minute focus groups conducted cross-sectionally in Denver, Colorado; San Francisco, California; and Washington State. Fourteen expert-defined end-of-life quality indicators were presented to each group, and quantitative unweighted rankings were obtained through patient and caregiver preferences. Aggregated weightings were used to rank the top five quality measures for exploration of open-ended questions. Pain management was the most important quality indicator among all three groups. Overlap in preferences were found for at least two of the groups for symptom management, monitoring medical issues, advance care preferences and assessment of family and caregiver involvement. Caregivers were more focused on bereavement support. Variation in preferences for end-of-life care by patients and their caregivers reflects the need to understand the individual decision-making regarding end-of-life care. Quality improvement activities are beginning to address these needs.
Inhibiting platelet and endothelial nitric oxide production favours platelet adhesion and aggregation, and arterial vasoconstriction. This study investigated the effect of NG-nitro-l-arginine methyl ester (L-NAME), a stereospecific inhibitor of nitric oxide synthesis, on P-selectin expression on platelets, platelet-derived microparticles and platelet-leucocyte aggregates, and on soluble P-selectin levels. Twelve healthy male volunteers were infused intravenously with L-NAME and then with a 10% solution of either l- or d-arginine. Blood pressure responses were recorded and whole blood and serum collected at baseline and after each infusion. P-selectin expression was analysed in all samples by flow cytometry. Serum levels of soluble P-selectin were batch analysed using an enzyme-linked immunosorbent assay at the end of the study. P-selectin expression on platelets, platelet-derived microparticles and platelet-leucocyte aggregates did not vary significantly from baseline levels following the infusion of L-NAME or l- or d-arginine. However, endothelial nitric oxide synthase inhibition caused a marked elevation of arterial blood pressure (P < 0.01) that was restored to pretreatment values by l- but not d-arginine. Serum levels of the soluble form decreased significantly (P = 0.001) following the infusion of l- and d-arginine compared with samples taken at baseline and following L-NAME infusion. In conclusion, inhibition of constitutive nitric oxide synthase in the endothelium and platelets produced significant increases in blood pressure but did not alter platelet membrane expression of P-selectin.
BACKGROUND: Operation rates for common surgical procedures are known to vary widely both between areas within the same country and between countries. However, no studies in the United Kingdom have yet examined the variation in the use of important groups of surgical procedures among primary care groups. METHODS: Data were obtained from the NHS Executive and the Department of Health on each of the 66 primary care groups in London that existed on 1 April 1999. These were used to estimate indicators for six main groups of variables: population estimates, mortality rates, Census data, benefits data, practice characteristics, and hospital admissions. The data were used to generate a number of population and practice variables describing the characteristics of each primary care group in London. We also obtained information at ward level by age and sex on the number of patients admitted for coronary artery bypass grafting (CABG) and angioplasty (PTCA); cataract surgery; and hip replacement in patients aged 65 years and over during the period 1997-1998. These data were used with population estimates to estimate directly age-standardized annual operation rates for each primary care group for the study period. RESULTS: Operation rates for the three groups of procedures examined in this study varied widely between the 66 primary care groups. The directly standardized combined CABG and PtCA rate varied from 28 to 193 per 100,000 (mean 80); cataract surgery rates from 167 to 618 per 100,000 (mean 291); and hip replacement in people aged 65 years and over from 74 to 363 per 100,000 (mean 202). Correlations between operation rates and population and practice variables were relatively weak. Multifactorial models explained 57 per cent of the variation in CABG and PTCA rates, 34 per cent of the variation in cataract surgery rates, and 27 per cent of the variation in hip replacement rates. CONCLUSIONS: There are wide variations in the operation rates for important groups of surgical procedures among primary care groups. These variations are poorly explained by differences in the population and practice characteristics of primary care groups. The underlying reasons for variations in operation rates need to be better understood if the ambitious targets for access to elective surgery outlined in the NHS plan are to be met.
Two well-controlled trials were carried out to investigate the effectiveness of intravenous proton pump inhibitors (PPIs) to reduce peptic ulcer rebleeding after successful hemostasis. The results demonstrated that the PPI reduced the rate of rebleeding significantly. The recent availability of the first intravenous PPI formulation in the United States, intravenous pantoprazole, represents an alternative to intravenous histamine-2 receptor antagonists. The results of 16 randomized, controlled trials involving a total of >3,800 patients (1,892 receiving PPIs and 1,911 controls) suggest that bolus administration plus continuous infusion of PPIs is a more effective pharmacotherapy than bolus infusion alone in decreasing both rebleeding and the need for surgery. Optimal effect is achieved with an intravenous 80-mg bolus, followed by continuous infusion of 8 mg/hr for 3 days, after which therapy may be continued with an oral PPI. Intermittent bolus administration yielded a minimal benefit. A difference in mortality rates has not yet been demonstrated.
This study examined patterns of change and stability in religiosity over the life course. Open-ended interviews with 129 adults aged 65 and older provided a rich source of data for applying a life course perspective to the study of religion. Two theoretical constructs from the life course perspective (i.e., trajectories and transitions) were used as a framework for understanding religion and aging. The interviews were content analyzed to identify: 1) dimensions of religiosity that exhibit change; 2) patterns of religious trajectories; and 3) social forces that promote changes in religiosity. These analyses revealed four distinct patterns: stable, increasing, decreasing, and curvilinear trajectories. Several forces were involved with either increasing religiosity (e.g., child rearing, adverse life experiences) or decreasing religiosity (e.g., disillusionment with church members, adverse life experiences). Directions for future research are discussed.