Diverging trends for onset of acute myocardial infarction, heart failure, stroke and mortality in young males: role of changes in obesity and fitness.

BACKGROUND: As opposed to the decreasing overall rates of coronary heart disease (CHD) incidence and overall cardiovascular disease (CVD) mortality, heart failure (HF) and stroke incidence are increasing in young people, potentially due to rising rates of obesity and reduced cardiorespiratory fitness (CRF). OBJECTIVES: We investigated trends in early major CVD outcomes in a large cohort of young men. METHODS: Successive cohorts of Swedish military conscripts from 1971 to 1995 (N = 1,258,432; mean age, 18.3 years) were followed, using data from the National Inpatient and Cause of Death registries. Cox proportional hazard models were used to analyse changes in 21-year CVD event rates. RESULTS: 21-year CVD and all-cause mortality and incidence of acute myocardial infarction (AMI) decreased progressively. Compared with the cohort conscripted in 1971-1975 (reference), the hazard ratios (HRs) for the last 1991-1995 cohort were 0.50 [95% confidence interval (CI) 0.42-0.59] for CVD mortality; 0.57 (95% CI 0.54-0.60) for all-cause mortality; and 0.63 (95% CI 0.53-0.75) for AMI. In contrast, the incidence of ischaemic stroke, intracerebral haemorrhage and HF increased with HRs of 1.43 (95% CI 1.17-1.75), 1.30 (95% CI 1.01-1.68) and 1.84 (95% CI 1.47-2.30), respectively. During the period, rates of obesity increased from 1.04% to 2.61%, whilst CRF scores decreased slightly. Adjustment for these factors influenced these secular trends only moderately. CONCLUSION: Secular trends of young-onset CVD events demonstrated a marked shift from AMI and CVD mortality to HF and stroke incidence. Trends were significantly, though moderately, influenced by changing baseline BMI and CRF.

Cognitive medicine - a new approach in health care science.

BACKGROUND: The challenges of today's society call for more knowledge about how to maintain all aspects of cognitive health, such as speed/attention, memory/learning, visuospatial ability, language, executive capacity and social cognition during the life course. MAIN TEXT: Medical advances have improved treatments of numerous diseases, but the cognitive implications have not been sufficiently addressed. Disability induced by cognitive dysfunction is also a major issue in groups of patients not suffering from Alzheimer's disease or related disorders. Recent studies indicate that several negative lifestyle factors can contribute to the development of cognitive impairment, but intervention and prevention strategies have not been implemented. Disability due to cognitive failure among the workforce has become a major challenge. Globally, the changing aging pyramid results in increased prevalence of cognitive disorders, and the diversity of cultures influences the expression, manifestation and consequences of cognitive dysfunction. CONCLUSIONS: Major tasks in the field of cognitive medicine are basic neuroscience research to uncover diverse disease mechanisms, determinations of the prevalence of cognitive dysfunction, health-economical evaluations, and intervention studies. Raising awareness for cognitive medicine as a clinical topic would also highlight the importance of specialized health care units for an integrative approach to the treatment of cognitive dysfunctions.

Gastrectomy alters emotional reactivity in rats: neurobiological mechanisms.

Gastrectomy (Gsx) is associated with altered emotional function and a predisposition to depression/anxiety disorders. Here we investigated the effects of Gsx on emotional reactivity in rats and explored the underlying neurobiological mechanisms. Gsx- and sham-operated rats were exposed to behavioural tests that explore anxiety- and depression-like behaviour (open field, black and white box, elevated plus maze, social interaction, forced swim) as well as memory (object recognition). The potential neurobiological mechanisms underlying these differences were explored by measuring (i) turnover of candidate neurotransmitter systems in the nucleus accumbens, (ii) hippocampal neurogenesis by BrdU labelling or by analysis of candidate genes involved in neuronal growth and (iii) changes in mRNA expression of candidate genes in dissected hippocampal and amygdala tissue. Data from individual behavioural tests as well as from multivariate analysis revealed differing emotional reactivity between Gsx- and sham-operated rats. Gsx rats showed reduced emotional reactivity in a new environment and decreased depression-like behaviour. Accumbal serotonin and dopamine turnover were both reduced in Gsx rats. Gsx also led to a memory deficit, although hippocampal neurogenesis was unaffected. Of the many candidate genes studied by real-time RT-PCR, we highlight a Gsx-associated decrease in expression of Egr-1, a transcription factor linked to neural plasticity and cognition, in the hippocampus and amygdala. Thus, Gsx induces an alteration of emotional reactivity and a memory/cognitive deficit that is associated with reduced turnover of serotonin and dopamine in the nucleus accumbens and decreased expression of Egr-1 in the hippocampus and amygdala.

Developmental dysregulation of adult neurogenesis.

Rather than a singular event that suddenly appears during adulthood, adult neurogenesis has long been recognized as the continuation of postnatal neurogenic activity. During the first postnatal weeks, significant cellular changes occur within and adjacent to germinal matrices of the subventricular zone and dentate gyrus. The majority of granule cells are generated during this period. In addition, radial glia are transformed into astrocyte-like stem cells, the ependymal layer is formed, and the highest rates of angiogenesis, gliogenesis and myelination are observed. The first postnatal weeks are critical as the brain growth rate is maximal, and changes during this period can have a great impact on neurogenesis levels and overall brain function later in life. This review chronicles cellular changes and some of the clinically relevant dysregulations that can occur during the postnatal period, and discusses the possible impact of these changes on neurogenesis and cognitive function later in life.

Peripheral growth hormone induces cell proliferation in the intact adult rat brain.

Growth hormone (GH) and insulin-like growth factor I (IGF-I) increase cell genesis in several regions of the brains of GH-IGF-I-deficient hypophysectomized rats. However, it is not known to what degree GH treatment stimulates adult cell genesis in pituitary-intact rodents. We investigated the effect of peripheral administration of bovine growth hormone (bGH) on cellular proliferation in various regions of the brains of normal adult female rats. To monitor cell division, bromodeoxyuridine (BrdU) was administered daily for 5 days. We studied the two areas of ongoing neurogenesis, the subventricular zone (SVZ) and the dentate gyrus (DG) of the hippocampus, as well as the corpus callosum, striatum, and the parietal and piriform cortices. After bGH treatment, the numbers of BrdU-positive cells increased 2.0- to 2.5-fold in all the brain regions, with the exception of the SVZ, in which there was no increase in the numbers of BrdU-positive cells. The present study shows for the first time that peripheral bGH administration increases the generation of new brain cells in normal adult female rats. Thus, bGH may stimulate cellular proliferation not only under GH-deficiency, but also under physiologic conditions. These findings have important implications for GH treatment strategies for patients who have normal or near-normal circulating levels of GH or IGF-I.

Irradiation to the immature brain attenuates neurogenesis and exacerbates subsequent hypoxic-ischemic brain injury in the adult.

Cranial radiotherapy is common in pediatric oncology. Our purpose was to investigate if irradiation (IR) to the immature brain would increase the susceptibility to hypoxic-ischemic injury in adulthood. The left hemisphere of postnatal day 10 (P10) mice was irradiated with 8 Gy and subjected to hypoxia-ischemia (HI) on P60. Brain injury, neurogenesis and inflammation were evaluated 30 days after HI. IR alone caused significant hemispheric tissue loss, or lack of growth (2.8 +/- 0.42 mm(3), p < 0.001). Tissue loss after HI (18.2 +/- 5.8 mm(3), p < 0.05) was synergistically increased if preceded by IR (32.0 +/- 3.5 mm(3), p < 0.05). Infarct volume (5.1 +/- 1.6 mm(3)) nearly doubled if HI was preceded by IR (9.8 +/- 1.2 mm(3), p < 0.05). Pathological scoring revealed that IR aggravated hippocampal, cortical and striatal, but not thalamic, injury. Hippocampal neurogenesis decreased > 50% after IR but was unchanged by HI alone. The number of newly formed microglia was three times higher after IR + HI than after HI alone. In summary, IR to the immature brain produced long-lasting changes, including decreased hippocampal neurogenesis, subsequently rendering the adult brain more susceptible to HI, resulting in larger infarcts, increased hemispheric tissue loss and more inflammation than in non-irradiated brains.