The effect of selenium and vitamin E on microvascular permeability of rat organs

The effects of dietary sodium selenite and vitamin E on the microvascular permeability of rat organs such as heart, brain, kidney, liver and eye were investigated by using the Evans blue leakage method. Combined deficiency of selenium and vitamin E caused an increase in the permeability of the heart and eye with respect to their controls while it had no considerable effect on the permeability of other organs. On the other hand, toxic levels of selenium (4.2 mg/kg) in diet decreased the permeabilities in kidney, liver, and eye whereas this parameter of brain increased in the same animal group. These results suggested that low or high sodium selenite and vitamin E contents in diet could alter the microvascular permeability of different organs in different manners. It might be important to give reasonable explanations for the pathophysiology of some diseases that are characterized with organ damage and /or disfunction originated from selenium deficiency or toxicity.     

Chronic effects of cadmium on kidney,liver, testis,and fertility of male rats

Male Wistar rats (n:20), at 5 wk of age, were given cadmium in drinking water (10 mg/L water) for 52 wk; 8 males and 20 female rats, as controls, were given tap water. At the end of 28 and 40 wk, some of the cadmium-treated males and control group male rats were sacrificed for the histopathological examination of testis, kidney, and liver. At the end of 56 wk, histopathological examinations were performed in the same way. Liver, kidney, and testis cadmium levels were also determined by atomic absorption spectrophotometry. All the cadmium-treated male rats showed pathological testicular alterations, and liver and kidney damage after chronic exposure. Cadmium levels were found to be highest in the kidney (1.009 +/- 0.034 microgram/g wet tissue in the infertile group). At the end of the 52-wk period, reproductive capacity of the cadmium-treated rats was investigated and was found to be lost in 39.89% of the animals.     

Karyomorphology and nuclear DNA content of sixteen Ophrys L. taxa from Turkey

Karyotypes in 16 representative taxa of the Ophrys genus are compared, based on Feulgen-stained somatic metaphase chromosomes. The karyotypes of O. omegaifera subsp. israelitica, O. ulupinara, O. lycia, O. argolica subsp. lucis, O. argolica subsp. lesbis, O. climacis and O. reinholdii subsp. reinholdii are described for the first time. Karyological analyses indicate relationships among the species with respect to their asymmetry indices. All Ophrys taxa studied were diploid with 2n = 2x = 36 chromosomes. One B chromosome has been detected among the chromosomes of O. argolica subsp. lucis. All karyotypes are symmetrical, consisting of metacentric and submetacentric chromosomes. The longest chromosomes of all the investigated specimens contain a secondary constriction. It is determined that there is a correlation between the total number of chromosomes having secondary constrictions and the evolutionary development order of the taxa. Based on nuclear DNA content, analysis was carried out by flow cytometer using propodium iodide as fluorochrome, 2C nuclear DNA content of 16 Ophrys species varying between 20.80 pg (O. argolica subsp. lucis) and 23.11 pg (O. omegaifera subsp. israelitica). Karyotype asymmetry relationships are discussed according to the bidimensional scatter plots of A₁–A₂, CV_CL–CV_CI, CV_CL–M_CA and CV_CI–M_CA.     

Recovery of Dynamics and Function in Spiking Neural Networks with Closed-Loop Control

There is a growing interest in developing novel brain stimulation methods to control disease-related aberrant neural activity and to address basic neuroscience questions. Conventional methods for manipulating brain activity rely on open-loop approaches that usually lead to excessive stimulation and, crucially, do not restore the original computations performed by the network. Thus, they are often accompanied by undesired side-effects. Here, we introduce delayed feedback control (DFC), a conceptually simple but effective method, to control pathological oscillations in spiking neural networks (SNNs). Using mathematical analysis and numerical simulations we show that DFC can restore a wide range of aberrant network dynamics either by suppressing or enhancing synchronous irregular activity. Importantly, DFC, besides steering the system back to a healthy state, also recovers the computations performed by the underlying network. Finally, using our theory we identify the role of single neuron and synapse properties in determining the stability of the closed-loop system.     

Trends in suicidal behaviour and use of mental health services in Canadian military and civilian populations

Background:In the context of the Canadian mission in Afghanistan, substantial media attention has been placed on mental health and lack of access to treatment among Canadian Forces personnel. We compared trends in the prevalence of suicidal behaviour and the use of mental health services between Canadian military personnel and the general population from 2002 to 2012/13.Methods:We obtained data for respondents aged 18–60 years who participated in 4 nationally representative surveys by Statistics Canada designed to permit comparisons between populations and trends over time. Surveys of the general population were conducted in 2002 (n = 25 643) and 2012 (n = 15 981); those of military personnel were conducted in 2002 (n = 5153) and 2013 (n = 6700). We assessed the lifetime and past-year prevalence of suicidal ideation, plans and attempts, as well as use of mental health services.Results:In 2012/13, but not in 2002, military personnel had significantly higher odds of both lifetime and past-year suicidal ideation than the civilian population (lifetime: adjusted odds ratio [OR] 1.32, 95% confidence interval [CI] 1.17–1.50; past year: adjusted OR 1.34, 95% CI 1.09–1.66). The same was true for suicidal plans (lifetime: adjusted OR 1.64, 95% CI 1.35–1.99; past year: adjusted OR 1.66, 95% CI 1.18–2.33). Among respondents who reported past-year suicidal ideation, those in the military had a significantly higher past-year utilization rate of mental health services than those in the civilian population in both 2002 (adjusted OR 2.02, 95% CI 1.31–3.13) and 2012/13 (adjusted OR 3.14, 95% CI 1.86–5.28).Interpretation:Canadian Forces personnel had a higher prevalence of suicidal ideation and plans in 2012/13 and a higher use of mental health services in 2002 and 2012/13 than the civilian population.Suicide is a leading cause of death around the world in military and civilian populations. ^1–3 There has been increased attention paid to suicidal behaviour in Canada, and a number of initiatives are being put in place to prevent suicide through better recognition and treatment of mental disorders.⁴ Examples of major Canadian initiatives include creation of a national Mental Health Commission of Canada,⁵ development of a federal framework for suicide prevention,⁶ large investments in military and veteran mental health services, and targeted efforts to formulate comprehensive suicide prevention strategies among military and veteran populations.^4,7 Despite these initiatives, the prevalence of suicide in Canada has not changed appreciably in recent years.^8,9A recent report on suicides in the Canadian Forces did not find an overall increase in the prevalence of suicide between 1995 and 2014.¹⁰ However, the prevalence increased substantially over that time in the subgroup of male army personnel in the Regular Force.¹⁰ In the United States, the army has observed steady increases in the prevalence of suicide attempts and completed suicide by soldiers since 2004, whereas the prevalence of suicide has remained unchanged in the general population.^3,11,12 Findings from the US are not generalizable to the Canadian military because of differences in recruitment, deployment policies and health care systems.¹³Suicidal ideation, plans and attempts are strong risk factors for death by suicide.¹⁴ A history of suicide attempt is the strongest predictor of future attempts.¹⁵ Suicidal ideation is also an important target for intervention because previous work has shown a rapid transition from first-onset suicidal ideation to plans and attempts within the same year.¹⁶ It remains unknown whether nonfatal suicidal behaviour in military and civilian populations in Canada has changed over time.Another area of major public health concern is that most people with suicidal behaviour do not receive mental health services. In nationally representative civilian samples in Canada and 21 other countries, most respondents with suicidal behaviours (60%) did not receive mental health services. ^17,18 The use of such services among Canadian military personnel with suicidal behaviours remains unknown. The media has recently been critical of the Canadian Armed Forces and Veterans Affairs Canada about insufficient services available to military personnel and veterans.¹⁹We compared trends in the prevalence of suicidal behaviours and help-seeking between Canadian civilian and military populations over a 10-year period from 2002 to 2012/13 using data from 4 nationally representative surveys.     

Mediators of glucagon-like peptide 2-induced blood flow: responses in different vascular sites

The aims of the present study were: to characterize the mechanisms of hemodynamic alterations induced by GLP-2, and, to compare the responses elicited in the superior mesenteric artery (SMA) to other vascular beds. Anesthetized rats were infused at the doses of 0.9, 2.3, 4.6 and 9.3 nmol/kg into the jugular vein for 60 min. Blood flow in the various arteries was measured by the ultrasonic transit time technique. Some animals were pretreated with indomethacin (5 mg/kg, ip), L-NAME (9, 18, 36 and 72 micromol/kg, iv), atropine sulfate (1-2 mg/kg, iv), CCK-1 and CCK-2 receptor antagonists (L-364,718 and L-365,260, 1 mg/kg, iv), exendin (9-39) amide (35 nmol/kg, iv) and lidocaine (74 micromol/kg, iv) prior to the infusion of GLP-2 (4.6 nmol/kg). In another group, capsaicin was applied either systematically (125 mg/kg, sc) or vagally (1 mg/rat). GLP-2 administration at all doses significantly increased the SMA blood flow throughout the experiments. GLP-2 (4.6 nmol/kg) infusion significantly increased blood flow of inferior mesenteric artery and carotid artery but not in any other vessel measured. Only the pretreatments with L-NAME and lidocaine were ineffective in preventing the GLP-2-induced responses. These results implicate that GLP-2-induced blood flow alterations are most significant in the SMA and are not mediated by prostaglandins, muscarinic, GLP-1 or CCK receptors. Our results also suggest that the stimulatory effect of GLP-2 on SMA blood flow is NO-dependent and mediated via intrinsic, non-cholinergic enteric neurons.