Influence of histological degree of seminiferous tubular degeneration and stage of seminiferous cycle on the proliferation of spermatogonia in aged Syrian hamster (Mesocricetus auratus)

The ageing testis is associated with germ loss in the seminiferous epithelium and a decrease in spermatogonia proliferation. In this work, we study whether the stages of the seminiferous epithelium cycle and/or the degree of histological tubular degeneration resulting from ageing is related with this decrease in spermatogonia proliferation. Eleven hamsters were used, five aged 6 months and six aged 24 months. In both groups, the proliferative activity was studied by BrdU immunostaining. The number of BrdU-positive and BrdU-negative cells was measured, providing the overall proliferation index in adult and aged testes. The mean number of BrdU-positive cells was also determined for each degree of histological degeneration of seminiferous epithelium, and a spermatogonia proliferation index was obtained for each stage of the seminiferous cycle. Ageing caused an overall decrease in the BrdU-positive cell percentage and a decrease in the number of BrdU-positive cells in the tubular sections with hypospermatogenesis, the sloughing of germ cells and maturation arrest, these changes being similar in both young and old animals. The spermatogonia proliferation index was only seen to be significantly lower in ageing hamster in stages VII-VIII of the seminiferous epithelium cycle. In conclusion, the overall decrease in proliferation observed in aged seminiferous epithelium is correlated with an increase in the number of degenerated sections of the seminiferous tubules, and this decrease is a phenomenon which occurs in specific stages of the seminiferous cycle.

Neuroregeneration and dementia: new treatment options

In the last years, physiological aging became a general concept that includes all the changes that occur in organism with old age. It is obvious now, that in developing and developed countries, new health problems concerning older population appear. One of these major concerns is probably dementia. Sooner or later, all forms of dementia lead to learning deficit, memory loss, low attention span, impairment of speech and poor problem solving skills. Normal ageing is a physiological process that also involves a lot of neurological disorders with the same type of symptoms and effects that many researchers are trying to minimize in demented patients. In this review we try to highlight some of the newest aspects of therapeutic strategies that can improve natural neuroregeneration.

Effect of cell senescence on the impedance measurement of adipose tissue-derived stem cells

Label-free and real-time monitoring of stem cells based on electrical impedance measurement is increasingly utilized for the quality control of the isolated stem cells to be used in stem cell-based tissue therapy or regenerative medicine. In spite of that the proliferative capacity and multipotency of stem cells are dependent on the type and age of the source tissue, however, the effect of the cell senescence on the impedance measurement of stem cells has not yet been studied. We investigated whether the senescence of adipose tissue-derived stem cells (ADSCs) can be detected by electrical impedance spectroscopy. For this, ADSCs at passage 9 and 31 were prepared and those genetic characteristics and growth kinetics were evaluated by quantitative polymerase chain reaction and cell counting. While the identified ADSCs were grown on the indium tin oxide electrodes, the impedance spectra were measured and interpreted by fitting analysis with an equivalent circuit model. ADSCs at passage 9 adhered on the electrode were small and spindle-shaped whereas the cells at passage 31 were flattened and larger than younger cells. At the beginning of culture time when the cell adhesion occurred, the resistance at 4.6kHz of passage 31 cells was higher than passage 9 due to the larger size of older cells. Afterwards, the value of passage 9 cells increased higher than passage 31, since younger cells proliferated more than old cells. Therefore, the impedance measurement could characterize the proliferative capacity of ADSCs during expanded culture.

A diet based on multiple functional concepts improves cognitive performance in healthy subjects

Background

Disorders such as the metabolic syndrome (MetS), impaired glucose tolerance and diabetes, are associated with increased risk of cognitive decline. Also several of the individual key features that define the MetS, e.g. hypertension, impaired glucose regulation, dyslipidemia, obesity, and inflammation, are related to an increased risk of cognitive decline. Consequently, a diet that prevents metabolic disorders might be expected to prevent cognitive decline. The purpose of the present study was to, in overweight but otherwise healthy subjects, investigate effects on cognitive functions of a dietary regime combining multiple functional concepts potentially beneficial to risk markers associated with MetS. The purpose was in addition to evaluate cognitive performance in relation to results on cardiometabolic risk variables (BMI, blood pressure, glucose, insulin, cholesterol, triglycerides, free fatty acids, lipoprotein A-1 and B, hs-CRP, HbA1c, interleukin-6, TNF-α, and PAI-1).

Methods

Fourty-four healthy women and men (50–73 years, BMI 25–33, fasting glycemia ≤ 6.1 mmol/L) participated in a randomized, controlled crossover intervention, comparing a multifunctional diet (active diet (AD)) including foods with a potential anti-inflammatory action, with a control diet (CD) devoid of the “active” components. Both diets were composed in close agreement with the Nordic dietary recommendations. Each diet was consumed during 4 wk, separated by a 4 wk washout period. Cognitive tests were performed at fasting and in the postprandial period after a standardized breakfast, after each diet period.

Results

In comparison with the CD, the AD improved performance in the Rey Auditory-Verbal Learning test (recognition test, p < 0.05, ANOVA, n = 42) and significantly improved performance in test of selective attention, which also included aspects of working memory (p < 0.05, n = 40). Performance in cognitive tests was inversely associated with plasma concentrations of cardiometabolic risk markers (fasting cholesterol, blood glucose, blood pressure) and cardiovascular risk scores (Framingham and Reynols), and positivly associated with apolipoprotein A1 (p < 0.05).

Conclusions

The results indicate that diet characteristics may modulate cognitive performance. A relationship seems to exist between cardiometabolic risk markers and cognitive performance in apparently healthy subjects. The results provide additional motives for diet based prevention of metabolic disturbances related to the MetS.

Neurodegeneration after transient brain ischemia in aged mice: beneficial effects of bilobalide

Bilobalide, an active constituent of Ginkgo biloba, has neuroprotective properties in experimental stroke models, but nearly all published studies were carried out in young animals. As ischemic strokes in humans are much more frequent in old age, we investigated bilobalide's effects in aged mice (age 18-22 month) using a model of transient ischemia induced by occlusion of the middle cerebral artery (MCAO) for 60 min. When bilobalide was administered locally into the striatum via microdialysis, a significant reduction of infarct size by almost 70% was observed. Concomitantly, the extensive, twelve-fold increase of extracellular glutamate which was observed in untreated animals was strongly reduced during the infusion of bilobalide. Glucose levels, in contrast, were not affected by bilobalide. In further experiments, bilobalide was given as an intraperitoneal injection (10/mg/kg) 1h before MCAO onset. ATP levels (measured in brain homogenates) were significantly reduced by transient MCAO but pretreatment with bilobalide prevented this loss. In ex vivo experiments with isolated mitochondria from aged mice, we found that the activity of the mitochondrial respiratory chain was only slightly impaired after 60 min of ischemia, and bilobalide showed no benefit in this experiment. However, aged mitochondria proved to be very sensitive to calcium-induced swelling which was significantly increased after ischemia. In this assay, pretreatment with bilobalide lowered the extent of swelling nearly to control levels. In behavioural tests, pretreatment of aged mice with bilobalide significantly improved the outcome in the Rotarod and the Corner test. In conclusion, aged mice show some differences in their response to transient ischemia when compared with young mice. Bilobalide has prominent neuroprotective properties in mice of all ages.

Age-related changes in cellular electrophysiology and calcium handling for atrial fibrillation

This study was to investigate whether or not the dysfunction of atrial repolarization and abnormality of the intracellular Ca²⁺ handling protein was augmented with ageing. Four groups of dogs were studied, adult and aged dogs in sinus rhythm (SR) and atrial fibrillation (AF) induced by rapid atrial pacing. We used whole cell patch clamp recording techniques to measure L-type Ca²⁺ current in cardiomyocytes dispersed from the left atria. Expressions of the Ca²⁺ handling protein were measured by real-time quantitative reverse transcription-polymerase chain reaction and Western blot methods. Cardiomyocytes from old atria showed longer action potential (AP) duration to 90% repolarization, lower AP plateau potential and peak L-type Ca²⁺ current densities at both age groups in SR. AF led to a higher maximum diastolic potential, an increase of amplitude of phase 0, decreases of AP duration to 90% repolarization, plateau potential and peak L-type Ca²⁺ current densities. Compared to the adult group, mRNA and protein expressions of the L-type calcium channel a1c were decreased, whereas expressions of calcium adenosine triphosphatase were increased in the aged group. Compared to SR group, expressions of Ca²⁺ handling protein except for phospholamban were significantly decreased in both age groups with AF. We conclude that these ageing-induced electrophysiological and molecular changes showed that general pathophysiological adaptations might provide a substrate conducive to AF.

Metabolomic markers reveal novel pathways of ageing and early development in human populations

BACKGROUND

Human ageing is a complex, multifactorial process and early developmental factors affect health outcomes in old age.

METHODS

Metabolomic profiling on fasting blood was carried out in 6055 individuals from the UK. Stepwise regression was performed to identify a panel of independent metabolites which could be used as a surrogate for age. We also investigated the association with birthweight overall and within identical discordant twins and with genome-wide methylation levels.

RESULTS

We identified a panel of 22 metabolites which combined are strongly correlated with age (R(2) = 59%) and with age-related clinical traits independently of age. One particular metabolite, C-glycosyl tryptophan (C-glyTrp), correlated strongly with age (beta = 0.03, SE = 0.001, P = 7.0 × 10(-157)) and lung function (FEV1 beta = -0.04, SE = 0.008, P = 1.8 × 10(-8) adjusted for age and confounders) and was replicated in an independent population (n = 887). C-glyTrp was also associated with bone mineral density (beta = -0.01, SE = 0.002, P = 1.9 × 10(-6)) and birthweight (beta = -0.06, SE = 0.01, P = 2.5 × 10(-9)). The difference in C-glyTrp levels explained 9.4% of the variance in the difference in birthweight between monozygotic twins. An epigenome-wide association study in 172 individuals identified three CpG-sites, associated with levels of C-glyTrp (P < 2 × 10(-6)). We replicated one CpG site in the promoter of the WDR85 gene in an independent sample of 350 individuals (beta = -0.20, SE = 0.04, P = 2.9 × 10(-8)). WDR85 is a regulator of translation elongation factor 2, essential for protein synthesis in eukaryotes.

CONCLUSIONS

Our data illustrate how metabolomic profiling linked with epigenetic studies can identify some key molecular mechanisms potentially determined in early development that produce long-term physiological changes influencing human health and ageing.

Mobility impairment is associated with urge but not stress urinary incontinence in community-dwelling older women: results from the Ossébo study

OBJECTIVE

To assess the association between functional limitations related to mobility and urinary incontinence (UI) in elderly women.

DESIGN

An observational cross-sectional study.

SETTING

Nine 'balance' workshops in France.

POPULATION

A total of 1942 community-dwelling women aged 75-85 years, who were invited, based on voter registration lists, to a 'balance assessment'.

METHODS

Mobility and balance test results for incontinent women were compared with those for continent women according to the severity and type of incontinence.

MAIN OUTCOME MEASURES

Data on UI were collected using a self-administered questionnaire (International Consultation on Incontinence Questionnaire-Short Form). Motor-related physical abilities were assessed using standardised balance and functional gait tests.

RESULTS

Forty-two per cent of women had involuntary urine leakage, with daily leaks in 57% of them; 24% had stress UI, 31% had urge UI, and 37% had mixed UI. Results for each functional test were poorer for women with UI and the limitation was more pronounced when the incontinence was severe. Multivariate logistic regression analyses showed that balance and gait impairments were significantly and independently associated with urge UI (walking speed, lower versus higher quartile, odds ratio (OR) 2.2; 95% confidence interval (95% CI) 1.4-3.5; walking balance, unable versus able to do four tandem steps (OR 1.6; 95% CI 1.2-2.2) but not with stress UI.

CONCLUSIONS

In this large population of older women living at home, there was a strong association between limitation of motor and balance skills and UI, which was proportional to the severity of incontinence and related specifically to urge incontinence. These results offer new perspectives on the prevention and treatment of urge incontinence in elderly women.

Revisiting the age-prospective memory-paradox: the role of planning and task experience

The present study aimed at investigating age-related differences in prospective memory performance using a paradigm with high ecological validity and experimental control. Thirty old and 30 young adults completed the Dresden Breakfast task; a meal preparation task in the lab that comprises several subtasks including event- and time-based prospective memory tasks. Participants were required to plan how to perform the task. Results showed that young adults outperformed old adults: they completed more subtasks, showed better event- and time-based prospective memory performance and planning quality. In contrast, old adults adhered to their plans more closely than young adults. Further exploratory gender-specific analyses indicated that old women did not differ from young men in time-based prospective memory performance, general task performance and time monitoring in contrast to old men. Possibly, differences in experience in breakfast preparation might account for these differential findings.

The relationship between informal caregiving and mortality: an analysis using the ONS Longitudinal Study of England and Wales

BACKGROUND

Many studies have suggested that caregiving has a detrimental impact on health. However, these conclusions are challenged by research which finds evidence of a comparative survivorship advantage, as well as work which controls for group differences in the demand for care.

METHODS

We use a large record linkage study of England and Wales to investigate the mortality risks of carers identified in the 2001 Census. The analysis focuses on individuals aged 35-74 living with others in private households and a distinction is made between those providing 1-19 and 20 or more hours of care per week. Logit models identify differences in carers' health at baseline and postcensal survival is analysed using Cox proportional hazards models.

RESULTS

12.2% of study members reported providing 1-19 h of care and 5.4% reported providing 20 or more hours. While carers were significantly more likely to report poorer health at baseline, survival analyses suggested that they were at a significantly lower risk of dying. This comparative advantage also held when the analyses were restricted to individuals living with at least one person with poor health.

CONCLUSIONS

The comparative mortality advantage revealed in this analysis challenges common characterisations of carers' health and draws attention to important differences in the way carers are defined in existing analyses. The survival results are consistent with work using similar data for Northern Ireland. However, the study also affords more uniform conclusions about carers' baseline health and this provides grounds for questioning existing hypotheses about the reasons for this advantage.

Employment Status, Quality of Matching, and Retirement in Korea: Evidence from Korean Longitudinal Study of Aging

This paper explores the differing probabilities of retirement for self-employed and wage-and-salary workers. It finds self-employed workers are less likely to retire than wage-and-salary ones, and that differences in retirement incomes, health, productivity, job characteristics, and compulsory retirement practices do not explain the disparity. The difference between self-employed and wage-and-salary workers in the quality of matching between the job and the worker (i.e., between required and desired amount of work) explains the later retirement of the self-employed. We note the implications of these findings for labor-force participation at older ages and how policies might boost employment of the elderly.

Deficiency of senescence marker protein 30 exacerbates angiotensin II-induced cardiac remodelling

AIMS

Ageing is an important risk factor of cardiovascular diseases including heart failure. Senescence marker protein 30 (SMP30), which was originally identified as an important ageing marker protein, is assumed to act as a novel anti-ageing factor in various organs. However, the role of SMP30 in the heart has not been previously explored. In this study, our aim was to elucidate the functional role of SMP30 on cardiac remodelling.

METHODS AND RESULTS

SMP30 knockout (KO) mice and wild-type (WT) mice were subjected to continuous angiotensin II (Ang II) infusion. After 14 days, the extent of cardiac hypertrophy and myocardial fibrosis was significantly higher in SMP30-KO mice than in WT mice. Echocardiography revealed that SMP30-KO mice had more severely depressed systolic and diastolic function with left ventricular dilatation compared with WT mice. Generation of reactive oxygen species related with activation of nicotinamide adenine dinucleotide phosphate-oxidase was greater in SMP30-KO mice than in WT mice. The number of deoxynucleotidyl transferase-mediated dUTP nick end-labelling positive nuclei was markedly increased in SMP30-KO mice with activation of caspase-3, increases in the Bax to Bcl-2 ratio and phosphorylation of c-Jun N-terminal kinase compared with WT mice. Furthermore, the number of senescence-associated β-galactosidase-positive cells was significantly increased via up-regulation of p21 gene expression in SMP30-KO mice compared with WT mice.

CONCLUSION

This study demonstrated the first evidence that deficiency of SMP30 exacerbates Ang II-induced cardiac hypertrophy, dysfunction, and remodelling, suggesting that SMP30 has a cardio-protective role in cardiac remodelling with anti-oxidative and anti-apoptotic effects in response to Ang II.

Effects of a short-term whole body vibration intervention on bone mass and structure in elderly people

OBJECTIVES

We aimed to clarify whether a short-term whole body vibration training has a beneficial effect on bone mass and structure in elderly men and women.

DESIGN

Randomised controlled trial.

METHODS

A total of 49 non-institutionalised elderly (20 men and 29 women) volunteered to participate in the study. Participants who met the inclusion criteria were randomly assigned to one of the study groups (whole body vibration or control). A total of 24 elderly trained squat positioned on a vibration platform 3 times per week for 11 weeks. Bone-related variables were assessed by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography. Two-way repeated measures one-way analysis of variance (group by time) was used to determine the effects of the intervention on the bone-related variables and also to determinate the changes within group throughout the intervention period. Analysis of covariance was used to test the differences between groups for bone-related variables in pre- and post-training assessments and in the percentage of change between groups. All analysis were carried out including age, height, subtotal lean mass and daily calcium intake as covariates.

RESULTS

11 weeks of whole body vibration training led to no changes in none of the bone mineral content and bone mineral density parameters measured by dual-energy X-ray absorptiometry through the skeleton. At the tibia, total, trabecular and cortical volumetric bone mineral density decreased significantly in the whole body vibration group (all P<0.05).

CONCLUSIONS

A short-term whole body vibration therapy is not enough to cause any changes on bone mineral content or bone mineral density and it only produces a slight variation on bone structure among elderly people.

A latent class analysis of friendship network types and their predictors in the second half of life

OBJECTIVES

Friendships contribute uniquely to well-being in (late) adulthood. However, studies on friendship often ignore interindividual differences in friendship patterns. The aim of this study was to investigate such differences including their predictors.

METHOD

The study builds on Matthews's qualitative model of friendship styles. Matthews distinguished 3 approaches to friendship differing by number of friends, duration of friendships, and emotional closeness. We used latent class analysis to identify friendship network types in a sample of middle-aged and older adults aged 40-85 years (N = 1,876). Data came from the German Aging Survey (DEAS).

RESULTS

Our analysis revealed 4 distinct friendship network types that were in high congruence with Matthews's typology. We identified these as a discerning style, which focuses on few close relationships, an independent style, which refrains from close engagements, and 2 acquisitive styles that both acquire new friends across their whole life course but differ regarding the emotional closeness of their friendships. Socioeconomic status, gender, health, and network-disturbing and network-sustaining variables predicted affiliations with network types.

DISCUSSION

We argue that future studies should consider a holistic view of friendships in order to better understand the association between friendships and well-being in the second half of life.

Safety and tolerability of intensified, N-terminal pro brain natriuretic peptide-guided compared with standard medical therapy in elderly patients with congestive heart failure: results from TIME-CHF

AIMS

NT-proBNP-guided therapy results in intensification of medical heart failure (HF) therapy and is suggested to improve outcome. However, it is feared that an intensified, NT-proBNP-guided therapy carries a risk of adverse effects. Therefore, the safety and tolerability of NT-proBNP-guided therapy in the Trial of Intensified vs standard Medical therapy in Elderly patients with Congestive Heart Failure (TIME-CHF) was assessed.

METHODS AND RESULTS

A total of 495 chronic HF patients, aged ≥60, with an LVEF ≤45%, NYHA class ≥II, randomized to NT-proBNP-guided or symptom-guided therapy and ≥1 month follow-up were included in the present safety analysis. All adverse events (AEs) were recorded during the 18-month trial period. A total of 5212 AEs were noted, 433 of them serious. NT-proBNP-guided therapy led to a higher up-titration of HF medication and was well tolerated, with a dropout rate (12% vs. 11%, P = 1.0) and AE profile [number of AEs/patient-year 4.7 (2.8-9.4) vs. 5.4 (2.7-11.4), P = 0.69; number of severe AEs/patient-year 0.7 (0-2.7) vs. 1.3 (0-3.9), P = 0.21] similar to that of symptom-guided therapy, although most subjects in both treatment groups (96% vs. 95%, P = 0.55) experienced at least one AE. Age and number of co-morbidities were associated with AEs and interacted with the safety profile of NT-proBNP-guided therapy: positive effects were more frequent in younger and less co-morbid patients whereas potential negative effects-although small and related to non-severe AEs only-were only seen in the older and more co-morbid patients.

CONCLUSIONS

NT-proBNP-guided therapy is safe in elderly and highly co-morbid HF patients. Trial registration ISRCTN43596477.

Older HIV-infected patients--an underestimated population in northern Greece: epidemiology, risk of disease progression and death

OBJECTIVES

HIV prevalence among older people is on the increase. The aim of this study was to evaluate the epidemiological and clinical features at diagnosis and survival of older patients.

METHODS

This was a retrospective analysis of the data of 558 newly diagnosed antiretroviral-naïve patients between January 1998 and December 2008. Patients were divided into two groups according to their age at diagnosis: ≥50 years (n=103) and 18-49 years (n=455).

RESULTS

The most common risk factor for older patients was heterosexual contact (p<0.013). Older patients were more likely to suffer from hypertension (33.0% vs. 5.1%, p<0.0005), cardiovascular disease (20.4% vs. 2.9%, p<0.0005), neurological disorders (11.7% vs. 5.5%, p=0.02), renal dysfunction (12.6% vs. 5.3%, p=0.01), and infections (66.0% vs. 49.7%, p=0.003) than their younger counterparts, and to have more hospital admissions during follow-up (47.5% vs. 19.6%, p<0.0005). Older patients had a shorter survival time (p<0.0005). A statistically significant increase in CD4+ cell number through time was observed in both groups (p<0.0005). Younger patients reached higher magnitudes of absolute numbers of CD4+ cells during follow-up (p<0.0005) after the initiation of antiretroviral therapy. The total number of patients with clinical AIDS from baseline throughout the study period was also higher in the older age group (35.9% vs. 25.0%).

CONCLUSIONS

HIV-infected people aged ≥50 years differ in epidemiological and clinical features to younger HIV-infected people. The issue of increasing prevalence of HIV infection is a matter of concern due to existing comorbidities, which probably lead to higher mortality rates and faster progression to clinical AIDS.

Morphological and mechanical examination of the atrial 'intima'

AIMS

To examine morphology and mechanical properties of the atrial 'intima', which we defined as the tissue interposed between atrial endocardium and myocardium, in patients without known cardiovascular disease.

METHODS AND RESULTS

Post-mortem right and left atrial tissue was obtained from male infants (<1 year, n = 4), children (10-19 years, n = 4), and adults (58-69 years, n = 7). Using light microscopy and an ocular micrometer, atrial intimal (AIT) thickness was measured. Intimal collagen bundle thickness was measured using electron microscopy. Passive atrial wall stiffness was measured using a planar biaxial testing device. Among infants, left AIT (0.2 ± 0.2 mm) and right (0.2 ± 0.1 mm) AIT were not significantly different (P = 0.84). Among children, left AIT (0.6 ± 0.2 mm) was significantly greater than right (0.2 ± 0.1 mm) AIT (P = 0.03), and left AIT was marginally greater than in infants (P = 0.07). Among adults, with the exception of the appendage region, left AIT (1.0 ± 0.2 mm) was markedly greater than right AIT (0.3 ± 0.1 mm; P < 0.05), and left AIT was significantly greater than that in other age groups (P < 0.05). There were no differences in right AIT among age groups. Left intimal collagen bundle thickness was greater in adults (0.0512 ± 0.0056 µm) than infants (0.0432 ± 0.0071 µm) or children (0.0435 ± 0.0013 µm), and bundles were less organized. Wall stiffness was attributable primarily to the intima (1245 ± 132, vs. 260 ± 45 N/m(2) for the remaining atrial wall).

CONCLUSION

The left atrial intima, but not the right, thickens with age, becomes more disorganized ultrastructurally, and is responsible for the majority of atrial wall stiffness.

Male reproductive traits of full-sibs of different age classes in three-spined sticklebacks (Gasterosteus aculeatus)

The process of ageing is associated with negative effects of mutations acting late in life, which range from those affecting cells to those affecting the whole organism. In many animal taxa, the deterioration of the phenotype with age also affects traits such as males’ primary and secondary sexual characteristics. In three-spined sticklebacks (Gasterosteus aculeatus), males usually reproduce at one or two years of age. To see whether sexual selection has the potential to differ between young and old males, full-sib brothers of different age classes were compared, which were bred and raised under standardised laboratory conditions. During two simulated, successive breeding seasons males were allowed to build their nest in single tanks either in the first (“young males”) or in the second (“old males”) breeding season. A comparison of reproductively active brothers of the first and second breeding season showed that older males produce more but smaller sperm, which might be of lower quality. The fact that older males stored more sperm is size dependent as the results show that larger males possess a greater absolute testis mass, which is inextricably linked to sperm number. However, independent of body size, old males had a lower intensity of red/orange and UV breeding coloration as well as a reduced testis melanisation, which might have consequences in female mate choice and sperm competition.

The role of young users in determining long-term care expenditure in Norway

AIMS

In Norway, it is the responsibility of the country's 429 municipalities to provide long term care (LTC) services to their residents. Recent years have seen a sharp rise in the number of LTC users under the age of 65. This article aims to explore the effect of this rise on LTC expenditure.

METHODS

Panel data models are used on data from municipalities from 1986 to 2011. An instrumental variable approach is also utilized to account for possible endogeneity related to the number of young users.

RESULTS

The number of young users appears to have a strong effect on LTC expenditure. There is also evidence of municipalities exercising discretion in defining eligibility criteria for young users in order to limit expenditure.

CONCLUSIONS

The rise in the number of young LTC users presents a long-term challenge to the sustainability of LTC financing. The current budgeting system appears to compensate municipalities for expenditure on young LTC users.

The Right and Wrong of Growing Old: Assessing the Argument from Evolution

One argument which is frequently levelled against the enhancement of human biology is that we do not understand the evolved function of our bodies well enough to meddle in our biology without producing unintended and potentially catastrophic effects. In particular, this argument is levelled against attempts to slow or eliminate the processes of human ageing, or 'senescence', which cause us to grow decrepit before we die. In this article, I claim that even if this argument could usefully be applied against attempts to enhance other human traits, it cannot be valid in the case of attempts to enhance the various processes that constitute senescence. I begin by reviewing the biology of ageing to show how it consists of a number of unrelated traits. Then, following the arguments of a number of evolutionary biologists, I explain that every one of these traits is a product of evolutionary 'neglect' rather than 'intent'. Finally, I consider the strongest version of the argument against enhancing senescence, which acknowledges these facts about the evolution of ageing but insists that we have nevertheless have prudential reasons to avoid enhancement wherever there is some uncertainty about the genetics or evolutionary function of a trait. I provide two reasons for rejecting this version of the argument as well, even in the case of human senescence, where such uncertainty is currently significant.

Chemical composition and meat quality attributes of indigenous sheep and goats from traditional production system in Tanzania

The aim of the study was to compare chemical composition and quality attributes of meat between male long fat tailed sheep (n = 17) and Small East African goats (n = 17) existing in Tanzania. Animals of 1.5 to 2 yrs in age and live body weight of 22.59±0.50 kg were purchased from livestock auction markets. Animals were fasted for 18 h and slaughtered according to standard halal procedure. Left carcasses were dissected into muscles, fat and bone and the muscle and fat were mixed together and chemically analysed. Meat quality attributes were measured based on Muscle longissimus thoracis et lumborum excised from right sides of carcasses. Goat carcasses had significant higher (p = 0.0302) moisture content (70.65% vs 66.96%) and lower (p = 0.0027) ether extract (2.49% vs 5.82%) than sheep but there was no significant species differences in protein and ash content. Sheep had lower (p = 0.0157) ultimate pH (5.74 vs 5.88) and higher (p = 0.0307) temperature (3.77°C vs 3.15°C) than goat carcasses. Sheep meat had lower (p = 0.0021) shear force values (29.83 N vs 34.07 N) than goat. Within species, at day 9 of ageing, meat tenderness improved (p = 0.0001) by 44.63% and 34.18% for sheep and goat. Pooled data showed that at d 9 of ageing, meat tenderness improved (p = 0.0001) by 39.25% (from 39.54 N to 24.02 N) compared to tenderness of meat which was not aged at day one of slaughter. The present study demonstrated the differences in chemical composition and quality attributes of meat existing between sheep and goats originated from East Africa.

Fear of crime in old age: precautious behaviour and its relation to situational fear

This study aimed to provide further insight into the question of why older adults show a higher precautionary behaviour regarding crime (behavioural fear), although they do not estimate their victimisation risk as higher than young adults and they do not experience fear more often. In two cross-sectional studies, the hypothesis was tested that the age-related increase in precautionary behaviour is an expression of higher dispositional fear with age. The vignette technique was employed to induce situational fear of crime across various situations as a proxy for dispositional fear. In contrast to the hypothesis, in Study 1 (young: 18-30 years, N = 179 vs. middle-aged: 50-64 years, N = 106), only younger adults reported higher situational fear in two vignettes. In Study 2 (young: 18-30 years, N = 129 vs. young-old: 65-84 years, N = 114), younger adults indicated higher situational fear again; however, young-old adults reported higher situational fear in other vignettes. The findings suggest that there is no general increase in the intensity of situational fear of crime with age and thus no age-related change in dispositional fear. Moreover, situational fear did not serve as mediator in the relationship between age and precautionary behaviour. Alternative accounts for the increase in behavioural fear of crime are discussed as well as emotion regulation mechanisms in response to the induction method.

I'm not just fat, I'm old: has the study of body image overlooked "old talk"?

BACKGROUND

Research indicates that body dissatisfaction is correlated with and often predictive of both physical and mental health problems. "Fat talk," a well-studied form of body image talk in adolescents and university-aged women, has been implicated as contributing to body dissatisfaction and mediating the relationship between body dissatisfaction and other mental health problems. Limited research, however, has investigated fat talk across the female lifespan. Further, consistent with most body image research, fat talk research solely focuses on the thin dimension of idealized female attractiveness, even though other dimensions may contribute to body dissatisfaction in women.

METHOD

The current study investigated whether or not "old talk," a hereto un-described form of body image talk, appears to be a parallel, but distinct, form of body image talk that taps into the young dimension of the thin-young-ideal standard of female beauty. An international, internet sample of women (aged 18-87, N = 914) completed questionnaires aimed at assessing fat talk, old talk, body image disturbance, and eating disorder pathology.

RESULTS

Results indicated that both fat talk and old talk were reported by women across the lifespan, although they evidenced different trajectories of frequency. Like fat talk, old talk was significantly correlated with body image disturbance and eating disorder pathology, albeit at a lower rate than fat talk in the total sample. Old talk was more highly correlated with ageing appearance anxiety than fat talk, and the correlation between old talk and body image disturbance and ED pathology increased with women's ages.

CONCLUSION

Results suggest that old talk is a form of body image talk that is related to but distinct from fat talk. Old talk appears to be similarly problematic to fat talk for women whose age increases their deviation from the thin-young-ideal. Further research into the phenomenon of old talk is warranted as is increased attention to fat talk across the full lifespan of women.

Reference intervals for common carotid intima-media thickness measured with echotracking: relation with risk factors

AIMS

Common carotid artery intima-media thickness (CCIMT) is widely used as a surrogate marker of atherosclerosis, given its predictive association with cardiovascular disease (CVD). The interpretation of CCIMT values has been hampered by the absence of reference values, however. We therefore aimed to establish reference intervals of CCIMT, obtained using the probably most accurate method at present (i.e. echotracking), to help interpretation of these measures.

METHODS AND RESULTS

We combined CCIMT data obtained by echotracking on 24 871 individuals (53% men; age range 15-101 years) from 24 research centres worldwide. Individuals without CVD, cardiovascular risk factors (CV-RFs), and BP-, lipid-, and/or glucose-lowering medication constituted a healthy sub-population (n = 4234) used to establish sex-specific equations for percentiles of CCIMT across age. With these equations, we generated CCIMT Z-scores in different reference sub-populations, thereby allowing for a standardized comparison between observed and predicted ('normal') values from individuals of the same age and sex. In the sub-population without CVD and treatment (n = 14 609), and in men and women, respectively, CCIMT Z-scores were independently associated with systolic blood pressure [standardized βs 0.19 (95% CI: 0.16-0.22) and 0.18 (0.15-0.21)], smoking [0.25 (0.19-0.31) and 0.11 (0.04-0.18)], diabetes [0.19 (0.05-0.33) and 0.19 (0.02-0.36)], total-to-HDL cholesterol ratio [0.07 (0.04-0.10) and 0.05 (0.02-0.09)], and body mass index [0.14 (0.12-0.17) and 0.07 (0.04-0.10)].

CONCLUSION

We estimated age- and sex-specific percentiles of CCIMT in a healthy population and assessed the association of CV-RFs with CCIMT Z-scores, which enables comparison of IMT values for (patient) groups with different cardiovascular risk profiles, helping interpretation of such measures obtained both in research and clinical settings.

Interstitial Cells of Cajal: Pathology, injury and repair

Interstitial cells of cajal (ICC) are specialised cells located within the musculature of the gastrointestinal tract (GIT). Although they form only 5% of the cells in the musculature of the GIT, they play a critical role in regulating smooth muscle function and GIT motility in coordination with the enteric nervous system. C-kit is a transmembrane glycoprotein that plays a critical role in ICC development and maturation. Physiological conditions such as ageing, as well as pathological conditions that have different disease processes, negatively affect ICC networks and function. Absent or disordered ICC networks can be associated with disorders in GIT motility. This review highlights the mechanism of ICC recovery from various types of injury which entails understanding the development of ICC and the factors affecting it. ICC transformation into malignant tumours (gastrointestinal stromal tumours) and their potential as contributors to therapeutic resistance is also discussed.

Cohort profile: the English longitudinal study of ageing

The English Longitudinal Study of Ageing (ELSA) is a panel study of a representative cohort of men and women living in England aged ≥50 years. It was designed as a sister study to the Health and Retirement Study in the USA and is multidisciplinary in orientation, involving the collection of economic, social, psychological, cognitive, health, biological and genetic data. The study commenced in 2002, and the sample has been followed up every 2 years. Data are collected using computer-assisted personal interviews and self-completion questionnaires, with additional nurse visits for the assessment of biomarkers every 4 years. The original sample consisted of 11 391 members ranging in age from 50 to 100 years. ELSA is harmonized with ageing studies in other countries to facilitate international comparisons, and is linked to financial and health registry data. The data set is openly available to researchers and analysts soon after collection (http://www.esds.ac.uk/longitudinal/access/elsa/l5050.asp).

Immunosenescence, inflammation and Alzheimer's disease

Ageing impacts negatively on the development of the immune system and its ability to fight pathogens. Progressive changes in the T-cell and B-cell systems over the lifespan of individuals have a major impact on the capacity to respond to immune challenges. The cumulative age-associated changes in immune competence are termed immunosenescence that is characterized by changes where adaptive immunity deteriorates, while innate immunity is largely conserved or even upregulated with age. On the other hand, ageing is also characterized by “inflamm-ageing”, a term coined to explain the inflammation commonly present in many age-associated diseases. It is believed that immune inflammatory processes are relevant in Alzheimer’s disease, the most common cause of dementia in older people. In the present paper we review data focusing on changes of some immunoinflammatory parameters observed in patients affected by Alzheimer’s disease.

Values and adult age: findings from two cohorts of the European Social Survey

Human values are assessed biannually in a multinational sample as part of the European Social Survey (ESS). Based on theories of adaptive ageing, it was predicted that ten lower order values and four higher order values would show age differences that would be invariant across (a) two sample cohorts (2002 and 2008), (b) gender and (c) 12 industrialised nations. The value categories measured by the ESS are the following: conservative values (tradition, conformity and security), openness to change values (self-direction, hedonism and stimulation), self-transcendent values (universalism, benevolence) and self-enhancement values (power, achievement). Of the ten lower order values, tradition shows the strongest positive relation with adult age, while the value of stimulation shows the strongest negative relation with age. With regards to the four higher order value categories, conservative values increased across age groups, while openness to change values decreased. Neither of these value types showed cohort or gender differences. Self-transcendence values were greater in midlife and older adults compared with young adults, were higher in women than in men, and higher in the 2008 compared with the 2002 cohort. Self-enhancement values showed a negative relation with age, with men of all age groups scoring higher in this value type than women. Age effects on the four higher order value types were replicated across all 12 countries in the sample, with the single exception of self-enhancement values in Spain, which show no relation with age.

Creatinine, urea, uric acid, water and electrolytes renal handling in the healthy oldest old

Renal physiology in the healthy oldest old has the following characteristics, in comparison with the renal physiology in the young: a reduced creatinine clearance, tubular pattern of creatinine back-filtration, preserved proximal tubule sodium reabsorption and uric acid secretion, reduced sodium reabsorption in the thick ascending loop of Henle, reduced free water clearance, increased urea excretion, presence of medulla hypotonicity, reduced urinary dilution and concentration capabilities, and finally a reduced collecting tubules response to furosemide which expresses a reduced potassium excretion in this segment due to a sort of aldosterone resistance. All physiological changes of the aged kidney are the same in both genders.

Diet, sex, and death in field crickets

Senescence is shaped by age-dependent trade-offs between fitness components. Because males and females invest different resources in reproduction, the trade-offs behind age-dependent reproductive effort should be resolved differently in the sexes. In this study, we assess the effects of diet (high carbohydrate and low protein vs. equal carbohydrate and protein) and mating (once mated vs. virgin) on lifespan and age-dependent mortality in male and female field crickets (Teleogryllus commodus), and on male calling effort. Females always had higher actuarial ageing rates than males, and we found a clear lifespan cost of mating in females. Mated males, however, lived longer than virgin males, possibly because virgins call more than mated males. The fastest age-dependent increases in mortality were among mated males on the high-carbohydrate diet. Males on a high-carbohydrate diet showed a faster increase in calling effort earlier in life, and a more pronounced pattern of senescence once they reached this peak than did males on a diet with equal amounts of protein and carbohydrates. Our results provide evidence that the cost of mating in this cricket species is both diet and sex-dependent, and that the underlying causes of sex differences in life-history traits such as lifespan and senescence can be complex.

Red blood cell microparticles: clinical relevance

SUMMARY

Microparticles are small phospholipid vesicles of less than 1 µm released into the blood flow by various types of cells such as endothelial, platelet, white or red blood cells. They are involved in many biological and physiological processes including hemostasis. In addition, an elevated number of microparticles in the blood is observed in various pathological situations. In the context of transfusion, erythrocyte-derived microparticles are found in red blood cell concentrates. Their role is not elucidated, and they are considered as a type of storage lesion. The purpose of this review is to present recent data showing that erythrocyte-derived microparticles most likely play a role in transfusion medicine and could cause transfusion complications.

A systematic review of the histological and molecular changes in rotator cuff disease

Introduction

The pathogenesis of rotator cuff disease (RCD) is complex and not fully understood. This systematic review set out to summarise the histological and molecular changes that occur throughout the spectrum of RCD.

Methods

We conducted a systematic review of the scientific literature with specific inclusion and exclusion criteria.

Results

A total of 101 studies met the inclusion criteria: 92 studies used human subjects exclusively, seven used animal overuse models, and the remaining two studies involved both humans and an animal overuse model. A total of 58 studies analysed supraspinatus tendon exclusively, 16 analysed subacromial bursal tissue exclusively, while the other studies analysed other tissue or varying combinations of tissue types including joint fluid and muscle. The molecular biomarkers that were altered in RCD included matrix substances, growth factors, enzymes and other proteins including certain neuropeptides.

Conclusions

The pathogenesis of RCD is being slowly unravelled as a result of the significant recent advances in molecular medicine. Future research aimed at further unlocking these key molecular processes will be pivotal in developing new surgical interventions both in terms of the diagnosis and treatment of RCD.

Later life health in Europe: how important are country level influences?

In this article, we examine the extent and pattern of country level differences in later life health in Europe and compare five competing explanations for this variation. We used data from 14 European countries, drawn from Northern (Denmark and Sweden), Western (Austria, France, Ireland, Germany Belgium, the Netherlands and Switzerland), Mediterranean (Spain, Italy and Greece) and Eastern (Poland and Czechia) regions of Europe, N = 33,528. Our results suggest that about a quarter (24%) of the overall variation in later life health in Europe appears to be due to country level differences. The Scandinavian countries along with Germany, the Netherlands and Switzerland appear to have the best health, whereas Spain, Italy and Poland had the lowest health score. Country level influences on health were largely associated with differences in the level of egalitarianism of each country as measured by the Gini coefficient, with more inequality being associated with poorer health. Differences in health-related lifestyle, as approximated by the prevalence of obesity in each country, also had a substantial macrolevel influence on later life health, with a lower national prevalence of obesity being associated with better health. Our results indicate the presence of systematic macrolevel health variation in Europe and suggest that policies to reduce income inequality as well as population interventions to promote healthier lifestyles and decrease the prevalence of obesity have the potential to improve population health and potentially offset some of the challenges posed by population ageing in Europe.

Dahi containing Lactobacillus acidophilus and Bifidobacterium bifidum improves phagocytic potential of macrophages in aged mice

The present study investigated the effect of Dahi containing potential probiotic bacterial strains on macrophage functions in ageing mice. Probiotic Dahi was prepared by co-culturing Dahi bacteria (Lactococcus lactis ssp. cremoris and Lactococcus lactis ssp. lactis biovar diacetylactis) along with Lactobacillus acidophilus LaVK2 (La-Dahi) or combined L. acidophilus LaVK2 and Bifidobacterium bifidum BbVK3 (LaBb-Dahi) in buffalo milk. The effect of ageing on phagocytic function was evaluated on 4 mo, 12 mo and 16 mo old mice. The effect of probiotic Dahi was evaluated for macrophage functions in ageing mice (12 mo old) fed La-Dahi or LaBb-Dahi supplements for 4 months. The production of extracellular superoxide and H2O2 declined in peritoneal macrophages but enhanced in splenic macrophages, while intracellular superoxide declined in both peritoneal and splenic macrophages with ageing in mice. A decline in phagocytic activity of peritoneal macrophages was also observed in aged mice. Supplementation of diet with La-Dahi or LaBb-Dahi for 4 months improved production of reactive oxygen species and phagocytic and adherence indices of peritoneal macrophages in aged mice. These results suggest that oral administration of La-Dahi or LaBb-Dahi has potential to improve immune functions in ageing individuals.

Can pervasive sensing address current challenges in global healthcare?

Important challenges facing global healthcare include the increase in the number of people affected by escalating healthcare costs, chronic and infectious diseases, the need for better and more affordable elderly care and expanding urbanisation combined with air and water pollution. Recent advances in pervasive sensing technologies have led to miniaturised sensor networks that can be worn or integrated within the living environment without affecting a person’s daily patterns. These sensors promise to change healthcare from snapshot measurements of physiological parameters to continuous monitoring enabling clinicians to provide guidance on a daily basis. This article surveys several of the solutions provided by these sensor platforms from elderly care to neonatal monitoring and environmental mapping. Some of the opportunities available and the challenges facing the adoption of such technologies in large-scale epidemiological studies are also discussed.

Natural and constrained language production as a function of age and cognitive abilities

Although it is often claimed that verbal abilities are relatively well maintained across the adult lifespan, certain aspects of language production have been found to exhibit cross-sectional differences and longitudinal declines. In the current project age-related differences in controlled and naturalistic elicited language production tasks were examined within the context of a reference battery of cognitive abilities in a moderately large sample of individuals aged 18-90. The results provide support for age-related increases in lexical sophistication and diversity at the discourse level, and declines in grammatical complexity in controlled and naturalistic contexts. Further, age-related decreases in facility with complex grammatical constructions in controlled sentence production were statistically independent of the cognitive abilities assessed in this project.

Effects of ageing on otoacoustic emission

To study the effects of ageing on otoacoustic emission (OAE) in individuals with normal pure tone audiogram (PTA). Tertiary/Medical College Hospital. Descriptive/Prospective study. We screened healthy individuals: (1) 50 persons in the age group of 20-25 years. (2) Fifty persons in the age group of 45-50 years. (3) Fifty persons in the age group of 55-60 years. (1) The individuals in the age group of 20-25 years showed absent/decreased distortion product OAE (DPOAE) in two cases (2/50) with normal PTA. (2) The individuals in the age group of 45-50 years showed absent/decreased DPOAE in eleven cases (11/50) with normal PTA. (3) The individuals in the age group of 55-60 years showed absent/decreased DPOAE in 47 cases (47/50) with normal PTA. Just like any other organ in the body which exhibits the process of ageing, the cochlea too undergoes similar changes to the ageing process. The DPOAE is the first sign to disappear in presbyacusis. The many factors which hasten the onset of presbyacusis-like nutrition, lifestyle, environment and occupational hazards, infection and illness, drug intake, hereditary etc.; can be modified for prolonging a healthy natural hearing.

A multi-state model for the analysis of changes in cognitive scores over a fixed time interval

In this article, we present the novel approach of using a multi-state model to describe longitudinal changes in cognitive test scores. Scores are modelled according to a truncated Poisson distribution, conditional on survival to a fixed endpoint, with the Poisson mean dependent upon the baseline score and covariates. The model provides a unified treatment of the distribution of cognitive scores, taking into account baseline scores and survival. It offers a simple framework for the simultaneous estimation of the effect of covariates modulating these distributions, over different baseline scores. A distinguishing feature is that this approach permits estimation of the probabilities of transitions in different directions: improvements, declines and death. The basic model is characterised by four parameters, two of which represent cognitive transitions in survivors, both for individuals with no cognitive errors at baseline and for those with non-zero errors, within the range of test scores. The two other parameters represent corresponding likelihoods of death. The model is applied to an analysis of data from the Canadian Study of Health and Aging (1991-2001) to identify the risk of death, and of changes in cognitive function as assessed by errors in the Modified Mini-Mental State Examination. The model performance is compared with more conventional approaches, such as multivariate linear and polytomous regressions. This model can also be readily applied to a wide variety of other cognitive test scores and phenomena which change with age.

[Does Alzheimer's disease exist in all primates? Alzheimer pathology in non-human primates and its pathophysiological implications (II)]

INTRODUCTION

In the ageing process there are some species of non-human primates which can show some of the defining characteristics of the Alzheimer's disease (AD) of man, both in neuropathological changes and cognitive-behavioural symptoms. The study of these species is of prime importance to understand AD and develop therapies to combat this neurodegenerative disease.

DEVELOPMENT

In this second part of the study, these AD features are discussed in the most important non-experimental AD models (Mouse Lemur -Microcebus murinus, Caribbean vervet -Chlorocebus aethiops, and the Rhesus and stump-tailed macaque -Macaca mulatta and M. arctoides) and experimental models (lesional, neurotoxic, pharmacological, immunological, etc.) non-human primates. In all these models cerebral amyloid neuropathology can occur in senility, although with different levels of incidence (100% in vervets;<30% in macaques). The differences between normal and pathological (Alzheimer's) senility in these species are difficult to establish due to the lack of cognitive-behavioural studies in the many groups analysed, as well as the controversy in the results of these studies when they were carried out. However, in some macaques, a correlation between a high degree of functional brain impairment and a large number of neuropathological changes ("possible AD") has been found.

CONCLUSIONS

In some non-human primates, such as the macaque, the existence of a possible continuum between "normal" ageing process, "normal" ageing with no deep neuropathological and cognitive-behavioural changes, and "pathological ageing" (or "Alzheimer type ageing"), may be considered. In other cases, such as the Caribbean vervet, neuropathological changes are constant and quite marked, but its impact on cognition and behaviour does not seem to be very important. This does assume the possible existence in the human senile physiological regression of a stable phase without dementia even if neuropathological changes appeared.

Grandparents in multigenerational households: the case of Portugal

Population ageing has paved the way for important and lasting multigenerational bonds, particularly between grandparents and grandchildren. Proximity is a powerful enhancer of relations, and co-residence, by involving continual proximity and long-term commitment, is particularly facilitative of significant linkages between generations. Although co-residence has generally been decreasing in Western societies, in the last decades of the millennium, a trend reversal was identified in the proportion of multigenerational households in the USA. Using data drawn from the European Community Household Panel, 1994-2001, some descriptive insights are provided that were considered to be missing in regard to the socio-demographic composition of extended households with grandparents in Portugal. Additionally, this study finds a rising trend in the proportion of multigenerational households, specifically those that include both grandparents and grandchildren. Portugal is possibly the European country that has the highest probability of exhibiting this pattern of evolution, because of the combination of its being a welfare state with limited resources, its historical reliance on family solidarity and its high level of participation of women in the labor market. Co-residence is a type of intergenerational transfer that can benefit any of the generations involved, but the direction of its net flow is still open to debate. A breakdown is made of its trend into age, period and cohort effects, in order to contribute to the discussion of the relative importance of the different generations in the shared living arrangement. Our findings suggest a mixture of interests, as well as a predominant influence of contemporary circumstances in the observed trend. These contemporary circumstances may be persistent or transient, but co-residence with grandparents is certainly an enduring mechanism, which households use in order to meet their needs.

Advances and developments in the use of human mesenchymal stem cells - a few considerations

One less visited area in musculoskeletal stem cell research is the effects of donor age on quality of stem cells. The prevalence of degenerative orthopaedic conditions is large, and the older population is likely to receive great benefit from stem cell therapies. There are many known growth factors involved in controlling and influencing stem cell growth which are also related to cell senescence. Of which, expressions are found to be altered in mesenchymal stem cells from older donors. Considerations must also be taken of these mechanisms which also have a role in cell cycle and tumour suppression.

Ageing and its implications

Ageing processes are defined as those that increase the susceptibility of individuals, as they grow older, to the factors that eventually lead to death. It is a complex multi-factorial process, where several factors may interact simultaneously and may operate at many levels of functional organization. The heterogeneity of ageing phenotype among individuals of the same species and differences in longevity among species are due to the contribution of both genetic and environmental factors in shaping the life span. The various theories of ageing and their proposed roles are discussed in this review.

Effect of ageing on colonic mucosal regeneration

The physiologic and pathologic cellular and molecular changes occurring with age in the human colon affect both the inflammatory process leading to mucosal injury and the regenerative capacity of the epithelium. On the one hand, age-related telomere shortening and inflamm-ageing may lead to the development of colonic inflammation, which results in epithelial damage. On the other hand, the altered migration and function of regenerative stem cells, the age-related methylation of mucosal healing-associated genes, together with the alterations of growth factor signaling with age, may be involved in delayed mucosal regeneration. The connections of these alterations to the process of ageing are not fully known. The understanding and custom-tailored modification of these mechanisms are of great clinical importance with regard to disease prevention and modern therapeutic strategies. Here, we aim to summarize the age-related microscopic and molecular changes of the human colon, as well as their role in altered mucosal healing.

Pharmacokinetic considerations for digoxin in older people

OBJECTIVE

This review aims to arm readers with a deep understanding of pharmacokinetics of digoxin.

DATA SOURCES

Pharmacology and pharmacokinetic references texts, and peer reviewed medical journal manuscripts indexed on Medline included based on currency, accuracy and appropriateness.

RESULTS

Physiologic changes and disease associated with aging have an impact on pharmacokinetics and pharmacodynamics of medications. Altered drug response and increased adverse reactions are common amongst the elderly. The narrow therapeutic index of digoxin and pharmacokinetic changes associated with aging increases the risk of toxicity. In the aging population, a number of factors combine to increase the risk, severity and likelihood of hospitalisation or death due to adverse drug effects: changes to absorption, distribution, metabolism and excretion,increased susceptibility to drug sensitivity,co-existing pathology,polypharmacy.

CONCLUSION

A thorough understanding of digoxin pharmacokinetics in the older person is essential for improved therapeutic outcomes, improved compliance, reduced morbidity and improved quality of life.

Three layers of working memory: Focus-switch costs and retrieval dynamics as revealed by the N-count task

Two experiments explored the process of switching items in and out of the focus of attention using a new paradigm, the N count task (adapted from Garavan, 1998; N varied from 1 to 4). This task yielded a focus size of one, indicated by a substantial focus switch cost for 2 count. Additionally, the focus switch costs in response time increased with working memory load, indicating an effortful search process occurring at a speed of about 240 ms/item. Maintaining and switching to and from a passive load did not increase the focus switch costs or decrease memory accuracy, indicating that there is no crosstalk between passive and active items. The results support a concentric theory of working memory: a small focus at its core, a surrounding area of (at least) three readily available items referred to as the outer store, and a still wider region of passive storage, possibly more long term memory than working memory.

Reduced P2x(2) receptor-mediated regulation of endocochlear potential in the ageing mouse cochlea

Extracellular adenosine triphosphate (ATP) has profound effects on the cochlea, including an effect on the regulation of the endocochlear potential (EP). Noise-induced release of ATP into the endolymph activates a shunt conductance mediated by P2X(2) receptors in tissues lining the endolymphatic compartment, which reduces the EP and, consequentially, hearing sensitivity. This may be a mechanism of adaptation or protection from high sound levels. As inaction of such a process could contribute to hearing loss, this study examined whether the action of ATP on EP changes with age and noise exposure in the mouse. The EP and the endolymphatic compartment resistance (CoPR) were measured in mice (CBA/CaJ) aged between 3 and 15 months. The EP and CoPR declined slightly with age with an associated small, but significant, reduction in auditory brainstem response thresholds. ATP (100-1,000 muM) microinjected into the endolymphatic compartment caused a dose-dependent decline in EP correlated to a similar decrease in CoPR. This was blocked by pyridoxal-phosphate-6-azophenyl-2',4'-disulfonate, consistent with a P2X(2) receptor-mediated shunt conductance. There was no substantial difference in the ATP response with age. Noise exposure (octave-band noise 80-100 decibels sound pressure level (dBSPL), 48 h) in young animals induced an upregulation of the P2X(2) receptor expression in the organ of Corti and spiral limbus, most noticeably with the 90-dB exposure. This did not occur in the aged animals except following exposure at 90 dBSPL. The EP response to ATP was muted in the noise-exposed aged animals except following the 90-dB exposure. These findings provide some evidence that the adaptive response of the cochlea to noise may be reduced in older animals, and it is speculated that this could increase their susceptibility to noise-induced injury.

Transitions in health and social service system at the end of life

This study focuses on the amount and types of transitions in health and social service system during the last 2 years of life and the places of death and among Finnish people aged 70-79, 80-89 and 90 or older. The data set, derived from multiple national registers, consists of 75,578 people who died between 1998 and 2001. The services included university hospitals, general hospitals, health centres and residential care facilities. The most common place of death was the municipal health centre: half of the whole research population died in a health centre. The place of death varied by age and gender: men and people in younger age groups died more often in general or in university hospital or at home, while dying in health centres or in residential care homes was more common among women or the very old. Number of transitions varied from zero to over a hundred transitions during the last 2 years. Number of transitions increased as death approached. Men and younger age groups had more transitions than women and older age groups. Among men and younger age groups transitions between home and general or university hospital were common while transitions between home and health centre or residential care were more common to women and older people. The results indicate that municipal health centres have a major role as care providers as death approaches. Differences between gender and age in numbers and types of transitions were clear. Future research is needed to clarify the causes to these differences.

Free radicals, antioxidants and functional foods: Impact on human health

In recent years, there has been a great deal of attention toward the field of free radical chemistry. Free radicals reactive oxygen species and reactive nitrogen species are generated by our body by various endogenous systems, exposure to different physiochemical conditions or pathological states. A balance between free radicals and antioxidants is necessary for proper physiological function. If free radicals overwhelm the body's ability to regulate them, a condition known as oxidative stress ensues. Free radicals thus adversely alter lipids, proteins, and DNA and trigger a number of human diseases. Hence application of external source of antioxidants can assist in coping this oxidative stress. Synthetic antioxidants such as butylated hydroxytoluene and butylated hydroxyanisole have recently been reported to be dangerous for human health. Thus, the search for effective, nontoxic natural compounds with antioxidative activity has been intensified in recent years. The present review provides a brief overview on oxidative stress mediated cellular damages and role of dietary antioxidants as functional foods in the management of human diseases.