Influence of Angiotensin II Subtype 2 Receptor (AT2R) Antagonist, PD123319, on Cardiovascular Remodelling of Aged Spontaneously Hypertensive Rats during Chronic Angiotensin II Subtype 1 Receptor (AT1R) Blockade

Cardiac AT2R expression is upregulated in the normal process of aging. In this study we determined the contribution of AT2R to chronic antihypertensive and remodelling effects of AT1R blockade in aged hypertensive rats. Adult (20 weeks) and senescent (20 months) spontaneously hypertensive rats (SHRs) were treated with either the AT1R antagonist, candesartan cilexetil (2 mg/kg/day), the AT2R antagonist, PD123319 (10 mg/kg/day), or a combination of the 2 compounds. Mean arterial pressure (MAP) and left ventricular volume were markedly decreased by candesartan cilexetil, however, simultaneous treatment with PD123319 had no additional effect on either parameter. Perivascular fibrosis was significantly reduced by candesartan cilexetil in aged animals only, and this effect was reversed by concomitant PD123319 administration. Vascular hypertrophy was reduced by candesartan cilexetil, and these effects were reversed by simultaneous PD123319. These results suggest that AT2R stimulation does not significantly influence the antihypertensive effect of chronic AT1R blockade, but plays a role in the regulation of vascular structure. The severe degree of cardiac perivascular fibrosis in senescent animals was regressed by AT1R blockade and this effect was reversed by simultaneous AT2R inhibition, demonstrating an antifibrotic role of AT2R stimulation in the aging hypertensive heart

Psychological Functioning in Adulthood: A Self-Efficacy Analysis

In the first edition of this handbook, we laid the foundation for a self-efficacy approach to understanding learning in adulthood. We examined self-efficacy applications to learning in adulthood from two broad-based theoretical perspectives: KAPA (knowledge and appraisal personality architecture; Cervone, 2004a) and SOC (selective optimization with compensation, Baltes, Lindenberger, & Staudinger, 2006). Both perspectives emphasize the dynamic interplay between dispositional, motivational, situational, and developmental contexts for successful functioning and adaptation in life. In this edition, we build upon earlier claims with new evidence regarding the central role of self-efficacy to adult development, aging, and well-being in memory, health, work, and everyday problem-solving contexts. Of these, the work context is new in this edition, and the sections on memory, problem solving, and health are expanded and updated.The unifying theme of our chapter is the individual\u27s ability to adapt flexibly to new learning opportunities that arise in adulthood and old age by relying on perceived self-efficacy as a coping resource for navigating the changing social, cognitive, and physical landscape of late adulthood

Low birth weight due to intrauterine growth restriction and/or preterm birth: effects on nephron number and long-term renal health

Epidemiological studies have clearly demonstrated a strong association between low birth weight and long-term renal disease. A potential mediator of this long-term risk is a reduction in nephron endowment in the low birth weight infant at the beginning of life. Importantly, nephrons are only formed early in life; during normal gestation, nephrogenesis is complete by about 32–36 weeks, with no new nephrons formed after this time during the lifetime of the individual. Hence, given that a loss of a critical number of nephrons is the hallmark of renal disease, an increased severity and acceleration of renal disease is likely when the number of nephrons is already reduced prior to disease onset. Low birth weight can result from intrauterine growth restriction (IUGR) or preterm birth; a high proportion of babies born prematurely also exhibit IUGR. In this paper, we describe how IUGR and preterm birth adversely impact on nephrogenesis and how a subsequent reduced nephron endowment at the beginning of life may lead to long-term risk of renal disease, but not necessarily hypertension

Britain’s highest bog: can we unlock its secrets?

The Glenfeshie Mòine Mhór (Great Moss) is Britain’s highest bog, the largest bog in the Cairngorm Mountains (Scotland) and a water source area for the River Spey. The area was managed primarily for sport hunting for about two centuries, but deer numbers have been heavily reduced in the last decade to allow regeneration of natural woodland and the return to more natural condition of all ecosystems including peatland. However, it may not be realistic to expect spontaneous improvement in peatland condition and ecosystem services provision in the harsh environment of the Mòine Mhór, which retains snow cover for more than half the year and differs floristically from lower-altitude bogs. To understand whether and where management intervention may be required, we need first to understand how the system works at scales ranging from microform to macrotope, and from sub-catchment to whole-system level. Multi-disciplinary condition and process studies (involving various collaborators) are in progress, with a current emphasis on streamflow generation and fluvial carbon loads. This presentation develops two sub-themes. First, ground survey and GIS analysis are used to address the questions: what are the special features of this bog; what is the nature and extent of degradation; and what are the implications for water delivered to the outflow streams? Secondly, a striking feature is the bare peat patches which were favourite resting places for deer on warm, dry summer days. The occurrence of seasonally extreme surface conditions seems a likely factor in preventing their recolonisation by bog plants now. Information about these conditions that cannot readily be accessed through direct observation, originating from temperature sensors and delivered at 60-minute intervals via a low power internet link, is explored in this context. Finally, we discuss aspects of the suitability of our investigation methods for remote and intermittently accessible field sites such as the Mòine Mhór

The epidemiology of chronic kidney disease (CKD) in rural East Africa: A population-based study.

BackgroundChronic kidney disease (CKD) may be common among individuals living in sub-Saharan Africa due to the confluence of CKD risk factors and genetic predisposition.MethodsWe ascertained the prevalence of CKD and its risk factors among a sample of 3,686 participants of a population-based HIV trial in rural Uganda and Kenya. Prevalent CKD was defined as a serum creatinine-based estimated glomerular filtration rate <60 mL/min/1.73m2 or proteinuria (urine dipstick ≥1+). We used inverse-weighting to estimate the population prevalence of CKD, and multivariable log-link Poisson models to assess the associations of potential risk factors with CKD.ResultsThe estimated CKD prevalence was 6.8% (95% CI 5.7-8.1%) overall and varied by region, being 12.5% (10.1-15.4%) in eastern Uganda, 3.9% (2.2-6.8%) in southwestern Uganda and 3.7% (2.7-5.1%) in western Kenya. Risk factors associated with greater CKD prevalence included age ≥60 years (adjusted prevalence ratio [aPR] 3.5 [95% CI 1.9-6.5] compared with age 18-29 years), HIV infection (aPR 1.6 [1.1-2.2]), and residence in eastern Uganda (aPR 3.9 [2.6-5.9]). However, two-thirds of individuals with CKD did not have HIV, diabetes, or hypertension as risk factors. Furthermore, we noted many individuals who did not have proteinuria had dipstick positive leukocyturia or hematuria.ConclusionThe prevalence of CKD is appreciable in rural East Africa and there are considerable regional differences. Conventional risk factors appear to only explain a minority of cases, and leukocyturia and hematuria were common, highlighting the need for further research into understanding the nature of CKD in sub-Saharan Africa

What women want from local primary care services for unintended pregnancy in rural Australia: a qualitative study from rural New South Wales

Background: Under the generalist model of health care in rural Australia, general practitioners (GPs) are often the first point of contact for women seeking health services for unintended pregnancy, including pregnancy decision-making support and options advice, antenatal or abortion care. Rural women are more likely to experience unintended pregnancy in Australia, yet little is known about how well local rural primary healthcare services currently meet their needs. Methods: To address this gap, this qualitative study explores through in-depth semi-structured interviews, the experiences of 20 rural women managing an unintended pregnancy, and their expectations of, and satisfaction with, the quality of care they received. The Framework Method was used to organise data and conduct an inductive thematic analysis. Results: Three themes related to management of unintended pregnancy in a rural primary care setting were identified: (1) women expect informed and efficient care once services are reached; (2) women desire greater choice and aftercare; and (3) comprehensive reproductive health should be part of rural primary care. Participants indicated an awareness of the limitations of the rural health system, yet a firm expectation that despite access delays, all of their reproductive health needs would be met. Choice, time efficiency, and aftercare were identified as gaps in the current primary care service experience. A desire for greater attention to rural reproductive health, including improved contraception, was also emphasised. Conclusions: Rural women with unintended pregnancy experienced gaps in service quality and described a lack of woman-centred care in their local rural health setting. This study offers insight into how rural primary care providers can better support women to make decisions about and reach their preferred services for unintended pregnancy

The effect of an acute bout of resistance exercise on carotid artery strain and strain rate

Arterial wall mechanics likely play an integral role in arterial responses to acute physiological stress. Therefore, this study aimed to determine the impact of low and moderate intensity double-leg press exercise on common carotid artery (CCA) wall mechanics using 2D vascular strain imaging. Short-axis CCA ultrasound images were collected in 15 healthy men (age: 21 ± 3 years; stature: 176.5 ± 6.2 cm; body mass; 80.6 ± 15.3 kg) before, during, and immediately after short-duration isometric double-leg press exercise at 30% and 60% of participants’ one-repetition maximum (1RM: 317 ± 72 kg). Images were analyzed for peak circumferential strain (PCS), peak systolic and diastolic strain rate (S-SR and D-SR) and arterial diameter. Heart rate (HR), systolic and diastolic blood pressure (SBP and DBP) were simultaneously assessed and arterial stiffness indices were calculated post hoc. A two-way repeated measures ANOVA revealed that during isometric contraction, PCS and S-SR decreased significantly (P < 0.01) before increasing significantly above resting levels post-exercise (P < 0.05 and P < 0.01 respectively). Conversely, D-SR was unaltered throughout the protocol (P = 0.25). No significant differences were observed between the 30% and 60% 1RM trials. Multiple regression analysis highlighted that HR, BP and arterial diameter did not fully explain the total variance in PCS, S-SR and D-SR. Acute double-leg press exercise is therefore associated with similar transient changes in CCA wall mechanics at low and moderate intensities. CCA wall mechanics likely provide additional insight into localized intrinsic vascular wall properties beyond current measures of arterial stiffness

Associations between neonatal nutrition and visual outcomes in 7-year-old children born very preterm

PURPOSE: There is uncertainty about the effect of increased neonatal protein intake on neurodevelopmental outcomes following preterm birth. The aim of this study was to assess the effect of a change in neonatal nutrition protocol at a major tertiary neonatal intensive care unit intended to increase protein intake on ophthalmic and visual development in school-age children born very preterm.METHODS: The study cohort comprised children (n = 128) with birthweight &lt;1500 g or gestational age &lt; 30 weeks born at Auckland City Hospital before (OldPro group, n = 55) and after (NewPro group, n = 73) a reformulation of parenteral nutrition that resulted in increased total protein intake during the first postnatal week and decreased carbohydrate, total parenteral fluid and sodium intake. Clinical and psychophysical vision assessments were completed at 7 years' corrected age, including visual acuity, global motion perception (a measure of dorsal stream function), stereoacuity, ocular motility and ocular health. Composite measures of favourable overall visual, binocular and functional visual outcomes along with individual vision measures were compared between the groups using logistic and linear regression models.RESULTS: Favourable overall visual outcome did not differ between the two groups. However, global motion perception was better in the NewPro group (p = 0.04), whereas the OldPro group were more likely to have favourable binocular visual outcomes (60% vs. 36%, p = 0.02) and passing stereoacuity (p = 0.02).CONCLUSIONS: These results indicate subtle but complex associations between early neonatal nutrition after very preterm birth and visual development at school age.</p