How to formulate research recommendations.
Explore the source record for details and available documents.
Biomedical Research↗
Biomedical subjects
Mark Fenton
Publications and source records attributed to Mark Fenton.
Early atherogenesis in senescence-accelerated mice.
We studied atheromatous lesion formation in an animal model of accelerated ageing. The senescence-accelerated prone mouse (SAM-P) has a reduced life-span and exhibits clinical features characteristic of human ageing. Our aim was to establish whether these mice are more susceptible to atherosclerosis than a related strain, senescence-accelerated resistant mice (SAM-R), which age normally. We fed a Western-type diet to 14 SAM-P/8 and 14 SAM-R/1 mice for 17 weeks, starting at 28 weeks of age, measuring their serum lipid profiles before and after this diet. We stained aortic root cryostat cross-sections with Oil red O, and assessed lipid deposition morphometrically. We used immunohistochemistry to detect macrophages in the aortic roots. We found that despite showing similar alterations in lipid profile, SAM-P/8 mice developed more prevalent and extensive fatty lesions than SAM-R/1 mice. Furthermore, the lipid lesions in SAM-P/8 mice showed a greater frequency of invasion by macrophages. We conclude that mice, which age at an accelerated rate, are more prone to early atherogenesis than mice which age normally. We suggest that this increased susceptibility may result from abnormalities in the oxidative status and cellular replicative capacity of these mice.
Aging↗
Gross Domestic Product (GDP) and productivity of schizophrenia trials: an ecological study.
BACKGROUND: The 5000 randomised controlled trials (RCTs) in the Cochrane Schizophrenia Group's database affords an opportunity to research for variables related to the differences between nations of their output of schizophrenia trials. METHODS: Ecological study--investigating the relationship between four economic/demographic variables and number of schizophrenia RCTs per country. The variable with closest correlation was used to predict the expected number of studies. RESULTS: GDP closely correlated with schizophrenia trial output, with 76% of the total variation about the Y explained by the regression line (r = 0.87, 95% CI 0.79 to 0.92, r2 = 0.76). Many countries have a strong tradition of schizophrenia trials, exceeding their predicted output. All nations with no identified trial output had GDPs that predicted zero trial activity. Several nations with relatively small GDPs are, nevertheless, highly productive of trials. Some wealthy countries seem either not to have produced the expected number of randomised trials or not to have disseminated them to the English-speaking world. CONCLUSIONS: This hypothesis-generating study could not investigate causal relationships, but suggests, that for those seeking all relevant studies, expending effort searching the scientific literature of Germany, Italy, France, Brazil and Japan may be a good investment.
Cross-Cultural Comparison↗
Further in vivo evidence that cellular senescence is implicated in vascular pathophysiology.
Explore the source record for details and available documents.
Animals↗
Progressive supranuclear palsy diagnosis and confounding features: report on 16 autopsied cases.
We evaluated 16 (15 men, 1 woman) autopsy-verified progressive supranuclear palsy (PSP) cases during 31 years (1969-2000) for clinical diagnosis and the course of the disease. The onset was gait difficulty or postural instability in 9 (56.3%), general motor slowing in 3 (18.8%), and tremor in 2. One case had onset with cognitive decline and 1 as hemidystonia. Four cases had supranuclear ophthalmoplegia (SNO) at the first assessment and were diagnosed as PSP. By last assessment, PSP diagnosis was made in 4 additional cases, but in 8 (50%) who never manifested ophthalmoplegia (mean 9.8 years after onset), PSP diagnosis was not made. Other manifestations included bulbar symptoms in 13 (81.3%), and cognitive impairment in 10 (62.5%) during the course of illness. Fifteen cases received levodopa, amantadine, anticholinergics, dopamine agonists, and selegiline in different combinations with symptomatic benefit in 9 of 15 (60%). Five had some improvement on levodopa alone and 3 showed more improvement when a dopamine agonist was added to levodopa. In general, the benefit was minimal and occurred only early in the course of illness. The mean age at onset was 63.7 (range, 53-85) years. Mean duration at PSP diagnosis was 4.8 (range, 2-11) years. Mean survival was 8.6 (range, 3-24) years and mean age at death was 72.3 (range, 60-89) years. When the different diagnostic criteria recommended in the literature were used, the accuracy of clinical diagnosis did not improve substantially.
Aged↗
Battling America's epidemic of physical inactivity: building more walkable, livable communities.
The US surgeon general recommends a minimum of 30 minutes of physical activity a day for adults to reduce the risk of chronic disease and an early death. Yet only about 1 in 4 American adults meets that recommendation through leisure-time physical activity and/or conscious exercise. One result is the so-called obesity epidemic, but a sedentary lifestyle also increases the risk of chronic diseases, such as diabetes, cardiovascular disease, osteoporosis, and cancer. We must create environments in which physical activity becomes a routine part of the day for more Americans. Encouraging routine walking and bicycling appears to be especially promising because of a growing understanding of how to create bicycle- and pedestrian-friendly settings. Everyone, not just those working in public health, must ally themselves with community leaders to pursue programs and policies to create settings with 4 key attributes: more compact neighborhoods with a mix of land uses; a comprehensive network of pathways, trails, bike lanes, and mass transit to allow "active" transportation; site designs that welcome cyclists and pedestrians; and an umbrella of safety that encourages people to get out of their cars. Many specific resources and programs are recommended to advance this agenda. Finally, we all must become role models by walking and cycling whenever possible and inviting others to do so with us.
Bicycling↗
The relationship between convenience of destinations and walking levels in older women.
PURPOSE: To examine the relationship between physical activity and (1) convenience of destinations, measured by whether destinations (such as a park, trail, businesses, and services) are within walking distance of the home, and (2) participants' perception of the quality of their neighborhood surroundings for walking, captured with a global neighborhood "walkability" rating. DESIGN: Cross-sectional analysis of data obtained in 1999. SETTING: Community in southwest Pennsylvania. SUBJECTS: Older Caucasian women (n = 149, mean age = 74.2 years). Response rate = 79%. MEASURES: Walking levels, leisure-time physical activity, and features of the neighborhood environment were measured with interviewer-administered questionnaires. Physical activity was also measured objectively with a pedometer. RESULTS: Living within walking distance (defined as within a 20-minute walk of home) of a park; biking or walking trail; or department, discount, or hardware store was related to higher pedometer readings (p < .01). In addition, there was a positive trend between the sum of destinations within walking distance of home and activity levels measured by pedometer and questionnaire (p < .01). There was also a positive trend between participants' neighborhood "walkability" rating and activity levels measured by pedometer and questionnaire (p < .01). CONCLUSION: These findings suggest that the ability to make utilitarian walking trips from home and the perception of having favorable neighborhood surroundings for walking are associated with increased physical activity levels in older women.
Aged↗