Obesity and vulnerability of the CNS

AbstractThe incidence of obesity is increasing worldwide, and is especially pronounced in developed western countries. While the consequences of obesity on metabolic and cardiovascular physiology are well established, epidemiological and experimental data are beginning to establish that the central nervous system (CNS) may also be detrimentally affected by obesity and obesity-induced metabolic dysfunction. In particular, data show that obesity in human populations is associated with cognitive decline and enhanced vulnerability to brain injury, while experimental studies in animal models confirm a profile of heightened vulnerability and decreased cognitive function. This review will describe findings from human and animal studies to summarize current understanding of how obesity affects the brain. Furthermore, studies aimed at identifying key elements of body–brain dialog will be discussed to assess how various metabolic and adipose-related signals could adversely affect the CNS. Overall, data suggest that obesity-induced alterations in metabolism may significantly synergize with age to impair brain function and accelerate age-related diseases of the nervous system. Thus, enhanced understanding of the effects of obesity and obesity-related metabolic dysfunction on the brain are especially critical as increasing numbers of obese individuals approach advanced age

Storm intensity and old-growth forest disturbances in the Amazon region

We analyzed the pattern of large forest disturbances or blow-downs apparently caused by severe storms in a mostly unmanaged portion of the Brazilian Amazon using 27 Landsat images and daily precipitation estimates from NOAA satellite data. For each Landsat a spectral mixture analysis (SMA) was applied. Based on SMA, we detected and mapped 279 patches (from 5 ha to 2,223 ha) characteristic of blow-downs. A total of 21,931 ha of forest were disturbed. We found a strong correlation between occurrence of blow-downs and frequency of heavy rainfall (Spearman\u27s rank, r2 = 0.84, p \u3c 0.0003). The recurrence intervals of large disturbances were estimated to be 90,000 yr for the eastern Amazon and 27,000 yr for the western Amazon. This suggests that weather patterns affect the frequency of large forest disturbances that may produce different rates of forest turnover in the eastern and western Amazon basin

Clinical Effectiveness of Family Therapeutic Interventions in the Prevention and Treatment of Perinatal Depression: a Systematic Review and Meta-Analysis

Background: Family therapy is a potential strategy to increase family support for those suffering from perinatal depression. Family therapeutic interventions for this population typically target depressed women and their adult family members to improve family functioning and reduce depressive symptoms. Objective: This systematic review and meta-analysis is a synthesis of the current evidence on the usefulness of family therapy interventions in the prevention and treatment of perinatal depression and impacts on maternal depressive symptoms and family functioning. Methods: This study used the Cochrane Collaboration guidelines for systematic reviews and meta-analyses. Six electronic databases were searched for randomized controlled trials and cluster randomized trials. The primary outcomes included maternal depressive symptoms and family functioning. Results: Seven studies were included in the qualitative and quantitative analyses. Fixed effects models showed statistically significant reductions in depressive symptoms at post-intervention in intervention group mothers. Intervention intensity and level of family involvement moderated intervention impacts on maternal depression. A fixed effects model showed a trend in improving family functioning at post-intervention in intervention group couples. Conclusion: Although a limited number of controlled trials on family therapeutic interventions for this population exist, the findings show that these types of interventions are effective in both the prevention and treatment of perinatal depression. Recommendations for future research are addressed

Non-Invasive Technique for Assessing the Population Parameters of Metacercariae of Clinostomum marginatum in Smallmouth Bass (Micropterus dolomieu)

Clinostomllm marginatum is a trematode that uses a fish as its final intennediate host. The wonns in the fish are in metacercarial cysts and are known as yellow grub. Yellow grubs give the fish\u27s flesh a wonny, unappetizing appearance and are a problem for commercial fish fanners in that heavily infected fish are not suitable for marketing. The parasite is common in smallmouth bass (Micropterus dolomieu) living in upland streams of Arkansas where the bass may serve as a wild reservoir for contamination of commercial fish ponds. Because smallmouth bass are a prized game fish, it would be desirable to be able to assess the extent of yellow grub infections by a non-invasive method whereby the fish could be examined and returned to its habitat without destructive necropsy. In this study strong correlations were found between the parasites seen in the orobranchial region and the rest of the host body. These correlations were found for all of the population parameters usually reported. The significance of these findings are mainly three fold: (I) The correlations allowed a reasonable estimate of yellow grub loads in populations of smallmouth bass using only orobranchial counts, (2) in situ examination of the mouth and gills alone allows the fish to be returned unharmed to the stream and (3) similar anatomical-site density correlations applied to other parasitic infections might dramatically reduce the amount of necropsy time needed for estimating total parasite numbers. Examples for the latter are given from other studies with Clinostomum complanatum and Proteocephalus ambloplitis species that show similar anatomical site density relationships in their respective hosts

Vascular Expression of Hemoglobin Alpha in Antarctic Icefish Supports Iron Limitation as Novel Evolutionary Driver

Frigid temperatures of the Southern Ocean are known to be an evolutionary driver in Antarctic fish. For example, many fish have reduced red blood cell (RBC) concentration to minimize vascular resistance. Via the oxygen-carrying protein hemoglobin, RBCs contain the vast majority of the body’s iron, which is known to be a limiting nutrient in marine ecosystems. Since lower RBC levels also lead to reduced iron requirements, we hypothesize that low iron availability was an additional evolutionary driver of Antarctic fish speciation. Antarctic Icefish of the family Channichthyidae are known to have an extreme alteration of iron metabolism due to loss of RBCs and two iron-binding proteins, hemoglobin and myoglobin. Loss of hemoglobin is considered a maladaptive trait allowed by relaxation of predator selection since extreme adaptations are required to compensate for the loss of oxygen-carrying capacity. However, iron dependency minimization may have driven hemoglobin loss instead of a random evolutionary event. Given the variety of functions that hemoglobin serves in the endothelium, we suspected the protein corresponding to the 3’ truncated Hbα fragment (Hbα-3’f) that was not genetically excluded by icefish may still be expressed as a protein. Using whole mount confocal microscopy, we show that Hbα-3’f is expressed in the vascular endothelium of icefish retina, suggesting this Hbα fragment may still serve an important role in the endothelium. These observations support a novel hypothesis that iron minimization could have influenced icefish speciation with the loss of the iron-binding portion of Hbα in Hbα-3’f, as well as hemoglobin β and myoglobin

Distribution of Clinostomum marginatum (Yellow Grub) Metacercaria in Smallmouth Bass Populations from Crooked Creek in North Central Arkansas

Four hundred thirty-three smallmouth bass (Micropterus dolomieui) were collected from ten sites on Crooked Creek in North Central Arkansas from just below the city of Harrison to the White River in the summers of 1988-90. Necropsy of these hosts for yellow grub (Clinostomum marginatum) metacercariae showed a range of mean abundance (average/fish) from 1.4 ±1.9 (SD) at a far up stream site to 105 ± 368 at the White River juncture. An increasing mean abundance of C. marginatum was seen from the uppermost sites of the creek downstream to the White River. Relating stream mileage with mean abundance gave a correlation coefficient (r) of 0.78, with P= \u3c0.01. Maximum abundance (maximum number of parasites in a single host from a site) ranged from 7 to 2500 and also showed a positive correlation with stream mileage (r=0.77,P=\u3c0.01). Prevalence (% fish infected) at the different sites ranged from 61 to 91% but showed no significant correlation with stream distance. The increasingly heavier infections seen in the downstream sites are not due to poor water quality but probably to the combination of the greater presence of the definitive host, the great blue heron, and large intermediate host (smallmouth) populations