Variations in seasonal solar insolation are associated with a history of suicide attempts in bipolar I disorder

Background: Bipolar disorder is associated with circadian disruption and a high risk of suicidal behavior. In a previous exploratory study of patients with bipolar I disorder, we found that a history of suicide attempts was associated with differences between winter and summer levels of solar insolation. The purpose of this study was to confirm this finding using international data from 42% more collection sites and 25% more countries. Methods: Data analyzed were from 71 prior and new collection sites in 40 countries at a wide range of latitudes. The analysis included 4876 patients with bipolar I disorder, 45% more data than previously analyzed. Of the patients, 1496 (30.7%) had a history of suicide attempt. Solar insolation data, the amount of the sun’s electromagnetic energy striking the surface of the earth, was obtained for each onset location (479 locations in 64 countries). Results: This analysis confirmed the results of the exploratory study with the same best model and slightly better statistical significance. There was a significant inverse association between a history of suicide attempts and the ratio of mean winter insolation to mean summer insolation (mean winter insolation/mean summer insolation). This ratio is largest near the equator which has little change in solar insolation over the year, and smallest near the poles where the winter insolation is very small compared to the summer insolation. Other variables in the model associated with an increased risk of suicide attempts were a history of alcohol or substance abuse, female gender, and younger birth cohort. The winter/summer insolation ratio was also replaced with the ratio of minimum mean monthly insolation to the maximum mean monthly insolation to accommodate insolation patterns in the tropics, and nearly identical results were found. All estimated coefficients were significant at p < 0.01. Conclusion: A large change in solar insolation, both between winter and summer and between the minimum and maximum monthly values, may increase the risk of suicide attempts in bipolar I disorder. With frequent circadian rhythm dysfunction and suicidal behavior in bipolar disorder, greater understanding of the optimal roles of daylight and electric lighting in circadian entrainment is needed

Exploratory study of ultraviolet B (UVB) radiation and age of onset of bipolar disorder

Background: Sunlight contains ultraviolet B (UVB) radiation that triggers the production of vitamin D by skin. Vitamin D has widespread effects on brain function in both developing and adult brains. However, many people live at latitudes (about > 40 N or S) that do not receive enough UVB in winter to produce vitamin D. This exploratory study investigated the association between the age of onset of bipolar I disorder and the threshold for UVB sufficient for vitamin D production in a large global sample. Methods: Data for 6972 patients with bipolar I disorder were obtained at 75 collection sites in 41 countries in both hemispheres. The best model to assess the relation between the threshold for UVB sufficient for vitamin D production and age of onset included 1 or more months below the threshold, family history of mood disorders, and birth cohort. All coefficients estimated at P ≤ 0.001. Results: The 6972 patients had an onset in 582 locations in 70 countries, with a mean age of onset of 25.6 years. Of the onset locations, 34.0% had at least 1 month below the threshold for UVB sufficient for vitamin D production. The age of onset at locations with 1 or more months of less than or equal to the threshold for UVB was 1.66 years younger. Conclusion: UVB and vitamin D may have an important influence on the development of bipolar disorder. Study limitations included a lack of data on patient vitamin D levels, lifestyles, or supplement use. More study of the impacts of UVB and vitamin D in bipolar disorder is needed to evaluate this supposition

Effects of node mobility on energy balancing in wireless networks

Having a direct effect on network lifetime, balanced energy consumption is one of the key challenges in wireless networks. In this paper, we investigate the effects of node mobility on energy balancing in wireless networks. We construct a Linear Programming (LP) framework that jointly captures data routing, mobility, and energy dissipation aspects. We explore the design space by performing numerical analysis using the developed LP framework. Our results show that mobility has significant effects on the energy dissipation trends of wireless nodes. Mobility can improve the energy balancing up to a certain level, however extreme mobility may lead to a degradation in energy balancing of wireless networks. (C) 2014 Elsevier Ltd. All rights reserved

Activated protein C attenuates intestinal reperfusion-induced acute lung injury: an experimental study in a rat model

Background: Activated protein C (APC) is a serine protease with anticoagulant and anti-inflammatory activities. APC has been shown to attenuate local deleterious effects of ischemia/reperfusion (I/R) injury in many organs. We aimed to investigate the effects of APC on lung reperfusion injury induced by superior mesenteric occlusion. Methods: Male Wistar-Albino rats were allocated into 4 groups: (1) sham-operated group, laparotomy without I/R injury (n = 12); (2) sham + APC group, identical to group 1 except for APC treatment (n = 12); (3) intestinal I/R group, 60 minutes of ischemia followed by 3 hours of reperfusion (n = 12); and (4) I/R + APC-treated group, 100 μg/kg injection of APC intravenously, 15 minutes before reperfusion (n = 12). Evans blue dye was injected into half of the rats in all groups. We assessed the degree of pulmonary tissue injury by measuring activities of oxidative and antioxidative enzymes, as well as nitrate (NO3-)/nitrite (NO2-) levels, biochemically. We evaluated acute lung injury (ALI) by establishing pulmonary neutrophil sequestration and ALI scoring histopathologically. Pulmonary edema was estimated by using Evans blue dye extravasation and wet/dry ratios. The plasma levels of proinflammatory cytokines and D-dimer were measured. Results: APC treatment significantly reduced activities of oxidative enzymes and nitrate/nitrite levels in the lung tissues, and plasma levels of proinflammatory cytokines and D-dimer, and also significantly increased activities of antioxidative enzymes (P < .05). Pulmonary neutrophil sequestration and ALI scores were decreased significantly with APC administration (P < .05). In addition, APC treatment significantly alleviated pulmonary edema (P < .05). Conclusions: This study clearly showed that APC treatment significantly attenuated the lung reperfusion injury. Further clinical studies are required to clarify whether APC has a useful role in the reperfusion injury during particular surgeries in which I/R-induced organ injury occurs. © 2008 Elsevier Inc. All rights reserved

colonic anastomoses: an experimental study in the murine model

BACKGROUND: Activated protein C (APC) is a serine protease with anticoagulant and antiinflammatory activities. The delaying effects of remote reperfusion injury on the wound-healing process in colonic anastomoses have been previously shown. In this study, we aimed to investigate whether APC protects against deleterious systemic effects of intestinal ischemia/reperfusion (I/R) injury on colonic anastomotic wound healing process

Evaluation of the Effects of Different Surface Configurations on Stability of Miniscrews

Introduction. The aim of this study was to analyze the effects of screw design and force application on the stability of miniscrews, using RTT, SEM, and histomorphometric analyses. Materials and Methods. Eighty cylindrical, self-drilling, and Ti6Al4V alloy miniscrews (1,6 × 6 mm) were used. Four mini-screws were inserted in fibulas of each rabbit, and 115 G of force was immediately applied. Four miniscrews were inserted in the other fibula, on which no force was applied. Eight weeks after insertion, osseointegration between miniscrew and the surrounding bone was evaluated by the histomorphometric analyses, SEM, and RTT. Kruskal-Wallis and the paired t-tests were used for statistical analysis. Results. Values obtained from Group I were significantly higher than those of the other loaded groups (). There were no differences in RTT scores among Groups II, III, and IV. Similar findings were also observed for unloaded mini-screws. There was no significant difference between Groups I and , while the differences between loaded and unloaded controls for each miniscrew were statistically significant. Conclusions. Immediate loading of miniscrews does not impair screw stability. Also, the diameter of miniscrew and more frequent thread pitches have a positive effect on stability; however, length of miniscrews does not have a significant effect on the stability

Activated protein C prevents deleterious effects of remote reperfusion injury caused by intestinal ischemia on wound healing in the left colonic anastomoses: an experimental study in the murine model.

BACKGROUND: Activated protein C (APC) is a serine protease with anticoagulant and antiinflammatory activities. The delaying effects of remote reperfusion injury on the wound-healing process in colonic anastomoses have been previously shown. In this study, we aimed to investigate whether APC protects against deleterious systemic effects of intestinal ischemia/reperfusion (I/R) injury on colonic anastomotic wound healing process. METHODS: Male Wistar-albino rats were randomly allocated into 4 groups, and a left colonic anastomosis was performed in all animals: (1) sham-operated group, simultaneously with left colonic anastomosis, the superior mesenteric artery and collateral branches were divided from the celiac axis, and the inferior mesenteric artery were isolated but not occluded (group 1, n = 12), (2) sham + APC group, identical to group 1 except for APC treatment (100 microg/kg, intravenously, 15 minutes before construction of the colonic anastomosis), (group 2, n = 12), (3) intestinal I/R group, 60 minutes of superior mesenteric ischemia followed by reperfusion (group 3, n = 12), and (4) APC-treated group, (100 microg/kg, intravenously, 15 minutes before reperfusion) (group 4, n = 12). All animals were sacrificed, and colonic anastomotic bursting pressures were measured in vivo on day 7. Tissue samples were obtained for analysis of hydroxyproline contents, nitrate/nitrite levels, and activities of oxidative and antioxidative enzymes. The plasma levels of proinflammatory cytokines and D-dimer were also measured. RESULTS: Intestinal I/R led to significant decreases in colonic anastomotic bursting pressures, tissue hydroxyproline contents, and activities of antioxidative enzymes, along with increases in tissue nitrate/nitrite levels, activities of oxidative enzymes, and plasma levels of proinflammatory cytokines and D-dimer (P < .05). However, APC treatment led to significant increases in colonic anastomotic bursting pressures, tissue hydroxyproline contents, and activities of antioxidative enzymes, along with decreases in tissue nitrate/nitrite levels, activities of oxidative enzymes, and plasma levels of proinflammatory cytokines and D-dimer (P < .05). CONCLUSION: This study clearly showed that APC treatment prevented the delaying effects of remote I/R injury on colonic anastomotic wound healing process. Further clinical studies are required to determine whether APC has a useful role in the enhancement of colonic anastomotic wound healing after particular operations in which I/R injury occurs