Adrenergic influences on the control of blood-brain barrier permeabilit

Summary The central adrenergic innervation of the cerebral microvessels may play a role in the control of blood-brain barrier permeability. To pursue the study of this hypothesis we investigated the effect of noradrenaline on both the permeability of the blood-brain barrier to sodium fluorescein and on the pinocytotic activity of cerebral endothelial cells in the rat. Noradrenaline, stereotactically injected in the right lateral cerebral ventricle, significantly increased the cerebral extraction ratio of sodium fluorescein in a dose-dependent way. The same effect was induced by phenylephrine. Prostaglandin F₂ had no significant effect on the passage of sodium fluorescein through the blood-brain barrier.The effect of noradrenaline (150 µg) on the cerebral extraction ratio of sodium fluorescein was totally blocked by phenoxybenzamine (25 mg/kg i.p., 24 h before noradrenaline). Noradrenaline (150 µg) significantly increased the pinocytotic activity of cerebral endothelial cells. Phenoxybenzamine (as above) reduced the effect of noradrenaline on pinocytosis.It is concluded that noradrenaline increases the blood-brain barrier's permeability to sodium fluorescein, most probably through an effect on alpha adrenoceptors. The increase induced in the blood-brain barrier's permeability by noradrenaline seems to be due, at least in part, to an increase in the pinocytotic activity of endothelial cells. Send offprint requests to A. Sarmento at the above address     

Saphenous vein graft bypass in the treatment of giant cavernous sinus aneurysms: report of two cases

Two cases of giant intracavernous aneurysms treated by high flow bypass with saphenous vein graft between the external carotid artery (ECA) and branches of the middle cerebral artery (MCA) are presented. Very often these aneurysms are unclippable because they are fusiform or have a large neck. Occlusion of the internal carotid artery (ICA) is the treatment of choice in many cases. This procedure has however a high risk of brain infarction. Revascularization of the brain by extra-intracranial anastomosis between the superficial temporal artery (STA) and branches of the MCA is frequently performed. This procedure provides however a low flow bypass and brain infarction may occur. We report two cases of giant cavernous sinus aneurysms treated by high flow bypass and endovascular balloon occlusion of the ICA. Immediate high flow revascularization of MCA branches was achieved and the patients showed no ischemic events. Follow-up of 8 and 14 months after operation shows patency of the venous graft and no neurological deficits. Angiographic control examination showed complete aneurysm occlusion in both cases.     

Growth of asthmatic children is slower during than before treatment with inhaled glucocorticoids

Reports on the influence of inhaled glucocorticoids on growth have been controversial. We studied the growth of prepubertal asthmatic children prior to and during glucocorticoid therapy. We collected retrospectively the notes of 201 asthmatic children aged 1–11 years receiving inhaled beclomethasone dipropionate or budesonide. We calculated their height and height velocity standard deviation scores (HSDS and HVSDS, respectively) before the treatment and up to 5 years during the treatment and compared those with the growth of healthy peers. The dose of the medication was calculated and the severity of asthma was assessed. The asthmatic children grew similarly to their healthy peers before treatment with inhaled glucocorticoids: the mean HSDS was +0.02 and the mean HVSDS +0.01 for boys and -0.16 and +0.13 for girls, respectively. Growth retardation took place soon after the start of the treatment, the most profound decrease in the growth velocity (the change in the mean HVSDS from +0.05 to -0.88) occurring during the first year of treatment. The growth-retarding effect of inhaled glucocorticoids was not dose dependent. In the covariance analysis the increasing severity of asthma had a significant interaction with repeated measurements, showing more growth retardation along with more severe asthma, especially during long-term treatment. Asthma per se does not impair growth, but inhaled glucocorticoids may do so. Careful monitoring of the growth of all asthmatic children receiving inhaled glucocorticoids is necessary because the growth-retarding effect of the medication is not dose dependent. Individual sensitivity might explain the differences seen in the growth patterns of children receiving inhaled glucocorticoids.     

Associations of substance use, abuse, and dependence with subsequent suicidal behavior

General population survey data are used to disaggregate the associations of substance use disorders with suicide attempts in order to evaluate a number of hypotheses about the processes leading to these associations. Data are from the US National Comorbidity Survey (1990-1992). Discrete-time survival analysis is used to study the effects of retrospectively reported temporally prior substance use, abuse, and dependence in predicting first onset of suicidal behavior. Alcohol and drug use predict subsequent suicide attempts after controlling for sociodemographics and comorbid mental disorders. Previous use is not a significant predictor among current nonusers. Abuse and dependence are significant predictors among users for three of the 10 substances considered (alcohol, inhalants, and heroin). The number of substances used is more important than the types of substances used in predicting suicidal behavior. Disaggregation shows that the effects of use are largely on suicidal ideation and nonplanned attempts among ideators. In comparison, the effects of use on suicide plans and planned attempts among ideators are not significant. Clinicians need to be aware that current substance use, even in the absence of abuse or dependence, is a significant risk factor for unplanned suicide attempts among ideators.     

Suicide attempts in a sample of patients from a general hospital

BACKGROUND: Suicide in Mexico has risen steadily in recent years, increasing by 156% in the last two decades. The study of suicide precursors, such as suicide attempts, has also become an important public health topic. The aim of this study is to establish the prevalence of suicide attempts in a general hospital setting and its association with alcohol, depression, and other factors. METHODS: A cross-sectional survey of a sample of patients was carried out in all three service units (inpatient, outpatient, and the emergency room) of a general hospital in Mexico City. All patients were randomly selected to participate regardless of the reason for initial hospital admission. Each patient was administered a series of psychological and demographic scales including the Beck Depression Inventory, the Beck Hopelessness Inventory, the General Health Questionnaire, a suicide assessment scale, a scale for alcohol consumption, and several measurements of alcohol-related problems. RESULTS: The final sample was made up of 1,094 patients of both genders (68% women), aged 18-65 years. A lifetime prevalence of suicide attempts of 6.1% (95% confidence interval [CI] of 4.7-7.7%) was found. Multiple logistic regression was used to obtain estimations of the association between lifetime suicide attempt and other factors. Marital status, age, depressed mood, hopelessness, Goldberg's 30-item version of the General Health Questionnaire, and high levels of alcohol consumption were all associated with the suicide attempt. CONCLUSIONS: Prevalence of lifetime suicide attempts was mainly related to being young, divorced, or widowed, and to feeling depressed, hopeless, and under undesirable psychological distress.