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71.
All multi-cellular organisms undergo change with time. Conception heralds the onset of growth and development, leading to reproductive competence and propagation of the species. With time, organisms age, leading to death as a final end-point. Whilst our knowledge and definitions of growth and reproduction are firmly established, the concept of ageing remains less well understood. One of the reasons for the lack of a singular definition of ageing is that it can be considered in many different ways, according to social, behavioural, physiological, morphological, cellular and molecular changes. Research has led to a number of theories being proposed that may explain the ageing process. In this chapter, we will review some of these theories and address some of the following fundamental questions: What is ageing? How can ageing be measured? When does ageing begin? When is an organism defined as old? 相似文献
72.
Agalactosyl IgG: an aid to differential diagnosis in early synovitis 总被引:10,自引:0,他引:10
A Young N Sumar K Bodman S Goyal H Sinclair I Roitt D Isenberg 《Arthritis and rheumatism》1991,34(11):1425-1429
Sixty consecutive patients presenting with early-onset synovitis were studied by measuring rheumatoid factor (RF) titers and the percentage of oligosaccharide chains attached to the C gamma 2 domain of IgG that lack galactose (GAL[0]). After 2 years of followup, 39 patients (65%) had developed rheumatoid arthritis (RA), and 21 had developed a variety of other inflammatory joint diseases. A combination of RF positivity and GAL(0) levels above the age-corrected mean gave a positive predictive value for a diagnosis of RA in 94% of these patients. These observations may well have clinical utility. 相似文献
73.
Veldhuyzen van Zanten SJ Chiba N Armstrong D Barkun A Thomson A Smyth S Escobedo S Lee J Sinclair P 《The American journal of gastroenterology》2005,100(7):1477-1488
BACKGROUND: The management of Helicobacter pylori negative patients with dyspepsia in primary care has not been studied in placebo-controlled studies. METHODS: H. pylori negative patients with dyspepsia symptoms of at least moderate severity (> or =4 on a seven-point Likert scale) were recruited from 35 centers. Patients were randomized to a 4-wk treatment of omeprazole 20 mg od, ranitidine 150 mg bid, cisapride 20 mg bid, or placebo, followed by on-demand therapy for an additional 5 months. Treatment success was defined as no or minimal symptoms (score < or = 2 out of 7), and was assessed after 4 wk and at 6 months. RESULTS: Five hundred and twelve patients were randomized and included in the intention-to-treat (ITT) analysis. At 4 wk, success rates (95% CI) were: omeprazole 51% (69/135; 43-60%), ranitidine 36% (50/139, 28-44%), cisapride 31% (32/105, 22-39%), and placebo 23% (31/133, 16-31%). Omeprazole was significantly better than all other treatments (p < 0.05). The proportion of patients who were responders at 4 wk and at 6 months was significantly greater for those receiving omeprazole 31% (42/135, 23-39%) compared with cisapride 13% (14/105, 7-20%), and placebo 14% (18/133, 8-20%) (p= 0.001), but not ranitidine 21% (29/139, 14-27%) (p= 0.053). The mean number of on-demand study tablets consumed and rescue antacid used was comparable across groups. Economic analysis showed a trade-off between superior efficacy and increased cost between omeprazole and ranitidine. CONCLUSION: Treatment with omeprazole provides superior symptom relief compared to ranitidine, cisapride, and placebo in the treatment of H. pylori negative primary care dyspepsia patients. 相似文献
74.
A comparative study on alcohol-preferring rat lines: effects of deprivation and stress phases on voluntary alcohol intake 总被引:6,自引:0,他引:6
Vengeliene V Siegmund S Singer MV Sinclair JD Li TK Spanagel R 《Alcoholism, clinical and experimental research》2003,27(7):1048-1054
BACKGROUND: Voluntary alcohol intake in rats can be influenced by alcohol deprivation phases and stress. We investigated the magnitude of the effects of both deprivation and stress (forced swimming in cold water and foot-shock had been chosen as stressors distinct in their physical and psychological features) on alcohol intake and the influence of these experiences on the time course of alcohol drinking behavior. For the alcohol drinking procedure, a long-term model of alcohol self-administration originally developed for heterogeneous Wistar rats was used and was compared with different alcohol-preferring rat lines. METHODS: Adult male Alko alcohol (AA), alcohol-preferring (P), high-alcohol-drinking (HAD), and unselected Wistar rats were given ad libitum access to water, 5%, and 20% alcohol solutions for 6 months. A deprivation phase of 14 days was performed after 8 weeks of access to alcohol. After 16 weeks and 22 weeks of alcohol access, all animals were subjected to forced swimming and foot-shock, respectively, for 3 consecutive days, while alcohol intake was still being measured. RESULTS: Alcohol deprivation led to a significant increase in alcohol intake in Wistar rats and P rats. No alcohol deprivation effect was observed in HAD and AA rats; after deprivation, however, their preference for the 20% alcohol solution increased, immediately in the HAD rats and gradually over time in the AA rats. Repeated swim stress caused an increase in alcohol intake in Wistar rats but no changes in the alcohol-preferring rat lines. Foot-shock stress increased alcohol consumption in all lines of rats, but the most pronounced effects were observed in HAD and P rats. CONCLUSIONS: Wistar, HAD, P, and AA rats differentially respond to alcohol deprivation and stress, showing that the genetic background of these different rat lines profoundly affects relapse-like drinking and stress-induced drinking. 相似文献
75.
76.
Williams Rachel C. Dawson Deborah A. Horsburgh Gavin J. Sinclair William 《Conservation Genetics Resources》2015,7(1):107-111
Conservation Genetics Resources - A microsatellite-enriched genomic library was created from a single Nautilus pompilius individual and clones/fragments sequenced using Sanger and Illumina MiSeq... 相似文献
77.
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79.
Hunt PW Brenchley J Sinclair E McCune JM Roland M Page-Shafer K Hsue P Emu B Krone M Lampiris H Douek D Martin JN Deeks SG 《The Journal of infectious diseases》2008,197(1):126-133
BACKGROUND: Although untreated human immunodeficiency virus (HIV)-infected patients maintaining undetectable plasma HIV RNA levels (elite controllers) have high HIV-specific immune responses, it is unclear whether they experience abnormal levels of T cell activation, potentially contributing to immunodeficiency. METHODS: We compared percentages of activated (CD38(+)HLA-DR(+)) T cells between 30 elite controllers, 47 HIV-uninfected individuals, 187 HIV-infected individuals with undetectable viremia receiving antiretroviral therapy (antiretroviral therapy suppressed), and 66 untreated HIV-infected individuals with detectable viremia. Because mucosal translocation of bacterial products may contribute to T cell activation in HIV infection, we also measured plasma lipopolysaccharide (LPS) levels. RESULTS: Although the median CD4(+) cell count in controllers was 727 cells/mm(3), 3 (10%) had CD4(+) cell counts <350 cells/mm(3) and 2 (7%) had acquired immunodeficiency syndrome. Controllers had higher CD4(+) and CD8(+) cell activation levels (P < .001 for both) than HIV-negative subjects and higher CD8(+) cell activation levels than the antiretroviral therapy suppressed (P = .048). In controllers, higher CD4(+) and CD8(+) T cell activation was associated with lower CD4(+) cell counts (P = .009 and P = .047). Controllers had higher LPS levels than HIV-negative subjects (P < .001), and in controllers higher LPS level was associated with higher CD8(+) T cell activation (P = .039). CONCLUSION: HIV controllers have abnormally high T cell activation levels, which may contribute to progressive CD4(+) T cell loss even without measurable viremia. 相似文献
80.