Objective: To determine the effect of a general group-based exercise programme on cognitive performance and mood among seniors without dementia living in retirement villages. Design: Randomised controlled trial. Setting: Four intermediate care and four self-care retirement village sites in Sydney, Australia. Participants: 154 seniors (19 men, 135 women; age range 62 to 95 years), who were residents of intermediate care and self-care retirement facilities. Intervention: Participants were randomised to one of three experimental groups: (1) a general group-based exercise (GE) programme composed of resistance training and balance training exercises; (2) a flexibility exercise and relaxation technique (FR) programme; or (3) no-exercise control (NEC). The intervention groups (GE and FR) participated in 1-hour exercise classes twice a week for a total period of 6 months. Main outcome measures: Using standard neuropsychological tests, we assessed cognitive performance at baseline and at 6-month re-test in three domains: (1) fluid intelligence; (2) visual, verbal and working memory; and (3) executive functioning. We also assessed mood using the Geriatric Depression Scale (GDS) and the Positive and Negative Affect Schedule (PANAS). Results: The GE programme significantly improved cognitive performance of fluid intelligence compared with FR or NEC. There were also significant improvements in the positive PANAS scale within both the GE and FR groups and an indication that the two exercise programmes reduced depression in those with initially high GDS scores. Conclusions: Our GE programme significantly improved cognitive performance of fluid intelligence in seniors residing in retirement villages compared with our FR programme and the NEC group. Furthermore, both group-based exercise programmes were beneficial for certain aspects of mood within the 6-month intervention period.

Background: Fall-related injuries, a major public health problem in long-term care, may be reduced by interventions that improve safety practices. Previous studies have shown that safety practice interventions can reduce falls however, in long-term care these have relied heavily on external funding and staff. The aim of this study was to test whether a training program in safety practices for staff could reduce fall-related injuries in long-term care facilities.Methods: A cluster randomization clinical trial with 112 qualifying facilities and 10 558 study residents 65 years or older and not bedridden. The intervention was an intensive 2-day safety training program with 12-month follow-up. The training program targeted living space and personal safety; wheelchairs, canes, and walkers; psychotropic medication use; and transferring and ambulation. The main outcome measure was serious fall-related injuries during the follow-up period.Results: There was no difference in injury occurrence between the intervention and control facilities (adjusted rate ratio, 0.98; 95% confidence interval, 0.83-1.16). For residents with a prior fall in facilities with the best program compliance, there was a nonsignificant trend toward fewer injuries in the intervention group (adjusted rate ratio, 0.79; 95% confidence interval, 0.57-1.10).Conclusion: More intensive interventions are required to prevent fall-related injuries in long-term care facilities.

Normative data on neuropsychological tests for very old adults living in retirement villages and hostels are under-represented in the literature. This study reports normative data on the Mini-Mental State Examination, Digit Span Forwards, Digit Span Backwards, the Digit Symbol Substitution Test, the Controlled Oral Word Association Test, the Stroop Neuropsychological Screening Test and the National Adult Reading Test. Age and education showed moderate correlations with neuropsychological test performance. For all tests except the Stroop, differences between residents of retirement villages and hostels were explained by age and education. Men performed better on the NART than women, but this difference was eliminated when education was controlled for statistically.

Specific location of 5′-nucleotidase in the heart has been uncertain, some authors citing evidence for an exclusively non-myocyte location, while other data point to the existence of cytoplasmic and membrane-bound fractions. Single myocytes isolated from mature rat heart, and free of endothelial or interstitial cells, have been used to establish that muscle cells of the myocardium are rich in 5′-nucleotidase, exhibiting activity sufficient to account for the total myocardial content of this enzyme. All 5′-nucleotidase is accessible to extracellular AMP. Inhibitors of 5′-nucleotidase and adenosine transport have been used to establish that only the adenosine component of adenine nucleotides is taken up by myocytes, but hydrolysis of AMP by 5′-nucleotidase does not commit the adenosine formed to transport across the sarcolemmal membrane. Myocytes also have ecto-phosphatases which hydrolyse ADP and ATP.

Adenine and hypoxanthine can be utilised by cardiac muscle cells as substrates for the synthesis of ATP. A possible therapeutic advantage of these compounds as high-energy precursors is their lack of vasoactive properties. Myocytes isolated from mature rat heart have been used to establish in kinetic detail the capacity of the heart to incorporate adenine, hypoxanthine and ribose into cellular nucleotides. Maximum rates of catalysis by enzymes on the salvage pathways have been established. Whilst the rate of incorporation of adenine into the ATP pool appears to depend upon intracellular concentrations of adenine and phosphoribosylpyrophosphate, for hypoxanthine the pattern is more complex. Hypoxanthine is salvaged at a slow rate compared with adenine, and is incorporated into GTP and IMP as well as into adenine nucleotides. The rate of incorporation of hypoxanthine into both IMP and ATP is accelerated in myocytes incubated with ribose. However, the rate-limiting reaction appears to be that catalysed by adenylosuccinate synthetase, for the rate of ATP synthesis is not accelerated when hypoxanthine concentration is increased from 10 to 50 microM, while the rate of IMP synthesis is more than doubled. Adenine and hypoxanthine phosphoribosyl transferases are present in equal catalytic amounts, but rat cardiac myocytes have very little adenylosuccinate synthetase activity. Exogenous ribose is incorporated into adenine nucleotides in amounts equimolar with adenine or hypoxanthine.

Reoxygenation of ischaemic, energy-depleted heart does not result in sufficiently rapid regeneration of normal adenine nucleotide concentrations for preservation of cardiac function and structure. Salvage of nucleoside as a mechanism for restoration of ATP in the post-ischaemic myocardium is limited by efflux of adenosine during ischaemia. Isolated cardiac myocytes have been used to establish the kinetics of uptake and salvage of adenosine and inosine, measuring the distribution of radioactive nucleoside incorporated into ATP, ADP and AMP. Maximum rates of catalysis of reactions on the salvage pathway, and of enzymes competing for substrates on the pathway, have been established in myocyte extracts. Myocytes have little capacity to salvage or catabolise inosine. Enzyme measurements indicate that salvage of adenosine should proceed at 7-8-times the rate exhibited by intact myocytes dependent upon extracellular adenosine as substrate. The data indicate that the rate of transport of adenosine is not determined by its metabolic utilization, but is the rate-limiting step in the salvage of adenosine.