IPSI- and contralateral changes in acetylcholinesterase and choline acetyltransferase activities in the hippocampus following unilateral septal lesions in the rat

Unilateral, left electrocoagulative septal lesions of the rat brain were performed. Acetylcholinesterase and choline acetyltransferase activities in the left and right hippocampi were measured 6–8 and 14–17 days postoperatively.Small lesions, damaging mainly the nucleus lateralis evoked a small (10–20%) decrease in the activity of both enzymes on the ipsilateral and side a tendency to an increase in the enzymatic activity on the contralateral side. No differences were observed between values obtained on the sixth-eighth and the fourteenth-seventeenth days after the operation. Larger lesions, including the nucleus fimbriatus and the nucleus of the diagonal band evoked on the sixth-eighth day a decrease (40–50%) in the activity of both enzymes on the ipsilateral side, but on the fourteenth-seventeenth day a significant recovery in the enzymatic activity was noted. Contralaterally, following larger lesions, an initial decrease on the sixth-eighth day in choline acetyltransferase activity was followed by an overshoot in comparison to controls on the fourteenth-seventeenth day; acetylcholinesterase activity remained unchanged on the sixth-eighth day, but also surpassed the control value on the fourteenth-seventeenth day.It is suggested that the post-lesion changes in enzyme activity in the ipsilateral hippocampus occur mainly within the cholinergic system, while in the contralateral hippocampus they may be the result of damage to non-cholinergic fibres followed by sprouting of cholinergic axons.     

Obstructive sleep apnea and hypertension

There is growing evidence of a causal relationship between obstructive sleep apnea (OSA) and hypertension. Untreated OSA may have direct and deleterious effects on cardiovascular function and structure through several mechanisms, including sympathetic activation, oxidative stress, inflammation, and endothelial dysfunction. OSA may contribute to or augment elevated blood pressure levels in a large proportion of the hypertensive patient population. It is important to consider OSA in the differential diagnosis of hypertensive patients who are obese. OSA should be especially considered in those hypertensive patients who respond poorly to combination therapy with antihypertensive medications.     

Attempt to eliminate health inequalities in Poland arising at the time of political and economic transformation: Polish 400 Cities Project.

AIM: Epidemiological data show that citizens of small towns and villages have presented worse trends in cardiovascular mortality during the political, social and economic transformation in Poland during past 15 years than citizens of large towns. To try to eliminate these inequalities the Polish 400 Cities Project (P400CP), a large educational and interventional project, was prepared. The project consists of two arms: medical and social interventions. MATERIAL AND METHODS: The main aim of the medical screening intervention in P400CP is to increase detection and control of cardiovascular risk factors in inhabitants of 418 small cities (<8000 inhabitants) and surrounding villages, particularly in men and people of lower education. In 2003 and 2004 the P400CP covered 123 cities. All together, 36 696 subjects aged between 18 and 98 years were examined. In all participants, blood pressure (BP), anthropometric measurements, laboratory tests and questionnaire interviews were performed. The social arm of P400CP is one of multi-level educational intervention. Modern techniques of social psychology and marketing were involved to increase participation in interventions. RESULTS: Only 12.5% of all subjects had normal BP, cholesterol (<190 mg/dl) and glucose (<100 mg/dl in whole capillary blood) levels. During the first screening visit 65.5% of all examined subjects had BP>/=140 mmHg or >/=90 mmHg. The fasting glucose level was increased in 19% of women and 26% of men. Almost two-third of all subjects had a total cholesterol level above the norm. CONCLUSIONS: The prevalence of cardiovascular risk factors in participants of the screening programme P400CP in small towns in Poland was very high. High prevalence and low control of risk factors in participants of the P400CP confirm the decision to target this programme at citizens of small towns and villages.     

Mining Knowledge of Respiratory Rate Quantification and Abnormal Pattern Prediction

The described application of granular computing is motivated because cardiovascular disease (CVD) remains a major killer globally. There is increasing evidence that abnormal respiratory patterns might contribute to the development and progression of CVD. Consequently, a method that would support a physician in respiratory pattern evaluation should be developed. Group decision-making, tri-way reasoning, and rough set–based analysis were applied to granular computing. Signal attributes and anthropomorphic parameters were explored to develop prediction models to determine the percentage contribution of periodic-like, intermediate, and normal breathing patterns in the analyzed signals. The proposed methodology was validated employing k-nearest neighbor (k-NN) and UMAP (uniform manifold approximation and projection). The presented approach applied to respiratory pattern evaluation shows that median accuracies in a considerable number of cases exceeded 0.75. Overall, parameters related to signal analysis are indicated as more important than anthropomorphic features. It was also found that obesity characterized by a high WHR (waist-to-hip ratio) and male sex were predisposing factors for the occurrence of periodic-like or intermediate patterns of respiration. It may be among the essential findings derived from this study. Based on classification measures, it may be observed that a physician may use such a methodology as a respiratory pattern evaluation-aided method.

     

Personality type and neural circulatory control

Psychosocial factors, including type A personality, anger, hostility, and anxiety, have been implicated in the pathogenesis of cardiovascular disease. Abnormal sympathetic responses to stress may help explain the link between certain behavior patterns and cardiovascular disease. We tested the hypothesis that in normal humans, type A personality characteristics are associated with exaggerated heart rate, pressor, and sympathetic nerve responses to mental and physical stress. We measured heart rate, blood pressure, and muscle sympathetic nerve activity (obtained with direct intraneural recordings) at rest and during stress in 45 healthy subjects (19 men and 26 women, age 29.2+/-8.7 years) who had no chronic diseases and were taking no medications. Subjects were divided into tertiles based on type A scores. There were no significant differences in sympathetic or hemodynamic reactivity among the 3 different intensity levels of type A characteristics. Baseline measures and responses to stress tests were similar across the 3 groups. Sympathetic and hemodynamic changes during stress tests were also similar in subject groups stratified according to anger scale and cynicism scale. Sympathetic nerve and hemodynamic measurements at rest and during stress were not different in normal subjects with type A characteristics. Abnormalities in sympathetic or cardiovascular reactivity are unlikely to be implicated in any excess of cardiovascular disease in people with type A personality characteristics.     

Effects of obstructive sleep apnea on endothelin-1 and blood pressure

OBJECTIVE: To evaluate blood pressure and humoral vasoconstrictor responses to recurrent episodes of obstructive sleep apnea and the effects of therapy by means of continuous positive airway pressure. PATIENTS AND METHODS: We prospectively evaluated overnight changes in hemodynamics, oxygen saturation, the apnea-hypopnea index, circulating endothelin-1, norepinephrine and plasma renin activity in 22 patients with severe obstructive sleep apnea before and after successful therapy using continuous positive airway pressure therapy (three measurements). Measurements of endothelin-1 and blood pressure were also obtained on three occasions, at similar times, in 12 healthy control subjects without sleep disturbances. RESULTS: Mean arterial pressure and endothelin-1 concentrations increased significantly after 4 h of untreated obstructive sleep apnea, and decreased after 5 h of continuous positive airway pressure. Changes in endothelin-1 levels were correlated with changes in mean arterial pressure (r = 0.44, P < 0.02) and with changes in oxygen saturation (r = 0.37, P < 0.05). Norepinephrine levels and plasma renin activity did not change significantly in patients with obstructive sleep apnea, and were not correlated with changes in blood pressure or oxygen saturation. In controls, blood pressure measurements at similar times during the night showed changes directionally opposite to that seen in obstructive sleep apnea, while endothelin-1 levels remained unchanged. CONCLUSIONS: Sleep apnea elicits increases in blood pressure and endothelin-1, with reductions in both after treatment. Vasoconstrictor and mitogenic effects of endothelin-1 may be implicated in increased cardiovascular risk in patients with obstructive sleep apnea.     

Cobalt-based Catalysts for Ammonia Decomposition

An effect of promoters such as calcium, aluminium, and potassium oxides and also addition of chromium and manganese on the structure of cobalt catalysts was examined. Studies of the catalytic ammonia decomposition over the cobalt catalysts are presented. The studies of the ammonia decomposition were carried out for various ammonia-hydrogen mixtures in which ammonia concentration varied in the range from 10% to 100%. Co(0) catalyst, promoted by oxides of aluminium, calcium, and potassium, showed the highest activity in the ammonia decomposition reaction. Contrary to expectations, it was found that chromium and manganese addition into the catalysts decreased their activity.     

Effects of sleep deprivation on neural circulatory control

Effects of sleep deprivation on neural cardiovascular control may have important clinical implications. We tested the hypothesis that sleep deprivation increases heart rate, blood pressure, and sympathetic activity and potentiates their responses to stressful stimuli. We studied 8 healthy subjects (aged 40+/-5 years, 6 men and 2 women). Blood pressure, heart rate, forearm vascular resistance, and muscle sympathetic nerve activity were measured at rest and during 4 stressors (sustained handgrip, maximal forearm ischemia, mental stress, and cold pressor test). Measurements were obtained twice, once after normal sleep and once after a night of sleep deprivation. All measurements were obtained in a blinded, randomized manner. In comparison with normal sleep, sleep deprivation resulted in an increase in blood pressure (normal sleep versus sleep deprivation=82+/-8 versus 86+/-7 mm Hg, mean+/-SEM, P=0.012) and a decrease in muscle sympathetic nerve activity (normal sleep versus sleep deprivation=28+/-6 versus 22+/-6 bursts/min, P=0.017). Heart rate, forearm vascular resistance, and plasma catecholamines were not significantly changed by sleep deprivation, nor did sleep deprivation affect autonomic and hemodynamic responses to stressful stimuli. Sleep deprivation results in increased resting blood pressure, decreased muscle sympathetic nerve activity, and no change in heart rate. Thus, the pressor response to sleep deprivation is not mediated by muscle sympathetic vasoconstriction or tachycardia.     

Interamygdaloid connections in the rat studied by the horseradish peroxidase method

Neurons of the rat amygdaloid body were labeled with horseradish peroxidase following its injection into contralateral nuclei of the amygdala. The results strongly suggest that there is a contralateral amygdaloid projection from the basal (dorsal and ventral) nuclei of amygdala; it terminates in the medial, central and lateral nucleus. True commissural connections were found only between posterior parts of the cortical nuclei of amygdala and between homonymous areas of the piriform cortex.