Corea secundaria a hiperglucemia no cetósica: a propósito de un caso / Chorea secondary to non-ketotic hyperglycaemia: presentation of a case

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Behavioral predictors of attrition in adolescents participating in a multidisciplinary obesity treatment program: EVASYON study.

The aims of this study were to identify the cognitive and behavioral predictors of dropping out and to estimate the attrition rate during different phases of an intervention program to treat overweight and obesity in adolescents. Overweight/obese adolescents (n=156, aged: 13-16 years; 71 male and 85 female subjects) were included in a multicomponent (diet, physical activity and psychological support) family-based group treatment program. At baseline and after 2 months (intensive phase) and 13 months (extensive phase) of follow-up, we measured adolescents' cognitive and behavioral dimensions, together with the parents' perception of their child's behavior. Of the 156 adolescents selected, 112 completed the full program (drop-out rate of 28.2%). The risk of dropping out during the extensive phase increased by 20% for each unit increase in the adolescent's social insecurity score (odds ratio=1.20, 95% confidence interval=1.07-1.34, P=0.002). The adolescents who had a high interoceptive awareness showed a significant decrease of 13.0% in the probability of dropping out (odds ratio=0.87, 95% confidence interval=0.77-0.99, P=0.040). Adolescents' social insecurity was the main predictor of drop-out in a multicomponent family-group-based obesity treatment program. To reduce attrition rates in these programs, the individual's social insecurity level needs to be reduced, whereas the family's awareness of eating-related behavior needs adjustment.

Group size, individual role differentiation and effectiveness of cooperation in a homogeneous group of hunters.

The emergence of cooperation in wolf-pack hunting is studied using a simple, homogeneous, particle-based computational model. Wolves and prey are modelled as particles that interact through attractive and repulsive forces. Realistic patterns of wolf aggregation readily emerge in numerical simulations, even though the model includes no explicit wolf-wolf attractive forces, showing that the form of cooperation needed for wolf-pack hunting can take place even among strangers. Simulations are used to obtain the stationary states and equilibria of the wolves and prey system and to characterize their stability. Different geometric configurations for different pack sizes arise. In small packs, the stable configuration is a regular polygon centred on the prey, while in large packs, individual behavioural differentiation occurs and induces the emergence of complex behavioural patterns between privileged positions. Stable configurations of large wolf-packs include travelling and rotating formations, periodic oscillatory behaviours and chaotic group behaviours. These findings suggest a possible mechanism by which larger pack sizes can trigger collective behaviours that lead to the reduction and loss of group hunting effectiveness, thus explaining the observed tendency of hunting success to peak at small pack sizes. They also explain how seemingly complex collective behaviours can emerge from simple rules, among agents that need not have significant cognitive skills or social organization.

Wolf-pack (Canis lupus) hunting strategies emerge from simple rules in computational simulations.

We have produced computational simulations of multi-agent systems in which wolf agents chase prey agents. We show that two simple decentralized rules controlling the movement of each wolf are enough to reproduce the main features of the wolf-pack hunting behavior: tracking the prey, carrying out the pursuit, and encircling the prey until it stops moving. The rules are (1) move towards the prey until a minimum safe distance to the prey is reached, and (2) when close enough to the prey, move away from the other wolves that are close to the safe distance to the prey. The hunting agents are autonomous, interchangeable and indistinguishable; the only information each agent needs is the position of the other agents. Our results suggest that wolf-pack hunting is an emergent collective behavior which does not necessarily rely on the presence of effective communication between the individuals participating in the hunt, and that no hierarchy is needed in the group to achieve the task properly.

Perception of aggression, personality disorders and psychiatric morbidity in nursing students.

OBJECTIVE: To determine the relationship between perception of aggression, personality disorders and psychiatric morbidity. METHOD: Ninety nursing students were interviewed. A two-stage transversal analysis was used, the first stage using the Spanish version of the general health questionnaire (GHQ-28), the true-false test of international personality disorders (IPDE) of Loranger, and the perception of aggression scale (POAS) of Jansen. For the second stage we used the Spanish version of the clinical interview schedule (CIS), and the full test of IPDE. RESULTS: Perception of aggression was mainly described as a violent reaction. There were no significant differences in the perception of aggression according to GHQ(+), CIS(+) and IPDE(+). There was a significant relationship between perception of aggression as violent reaction and gender. CONCLUSION: Aggression was perceived by our nursing students as a violent reaction. A significant relationship with gender was observed.

MCC and PSC, the putative protein import channels of mitochondria.

All but a small fraction of the hundreds of proteins in a mitochondrion are synthesized in the cytoplasm and imported into the organelle. Water-filled channels are integral to the process of translocating proteins since channels can provide an aqueous pathway through the hydrophobic environment of the membrane. The MCC (multiple conductance channel) and PSC (peptide-sensitive channel) are two high-conductance channels previously identified in electrophysiological studies of mitochondrial membranes. MCC and PSC are the putative pores of the import complexes of the inner and outer membranes, respectively. The genetic, biochemical, and biophysical evidence regarding these assignments are summarized herein. These findings support the identification of MCC and PSC as the protein import channels of mitochondria.

Effects of carbonyl cyanide phenylhydrazones on two mitochondrial ion channel activities.

The respiratory uncouplers carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) and carbonyl cyanide m-chlorophenylhydrazone (CCCP) affect the activities of two mitochondrial ion channels from mouse liver. At micromolar concentrations, the phenylhydrazones block the voltage-dependent 100-pS channel, mCS, and induce the multiple-conductance-level channel, MCC. The binding site(s) involved in perturbation of channel activities are probably distinct from the sites involved in uncoupling of oxidative phosphorylation which occurs at nanomolar concentrations of the phenylhydrazones. The effects of FCCP and CCCP on the mitochondrial ion channels could be partially reversed by washing with fresh media and were always reversed by perfusion with dithiothreitol. These results indicate that the effects of the phenylhydrazones on mitochondrial ion channels may be related to the ability of these compounds to act as sulfhydryl reagents and not to their protonophoric and uncoupling activity.

Biological activity of purpurogallin.

Purpurogallin showed antibacterial activity toward gram-positive bacteria. Strong activity against methicillin-resistant Staphylococcus aureus [minimal inhibitory concentration (MIC) against methicillin of 1600 micrograms/ml] was found, with MIC of 11.0 micrograms/ml. Purpurogallin inhibited the growth of all tested plants and decreased the chlorophyll content in the cotyledons of Brassica campestris subsp. rapa. It showed potent inhibitory activity against prolyl endopeptidase (the 50% inhibitory concentration was 1.6 x 10(-5) M), unlike its analogues, hinokitiol and tropolone.

Left ventricular function during exercise in athletes and in sedentary men.

Aim of this study was to evaluate left ventricular function during exercise in 10 male elite runners and in 10 sedentary males. End-diastolic (EDV) and end-systolic volume (ESV), left ventricular ejection fraction (EF), early peak transmitral flow velocity (peak E), time-velocity integral of mitral inflow (m-TVI); mitral cross sectional area (m-CSA); mitral stroke volume (SV), and cardiac output (CO) were measured by echo-Doppler. We simultaneously analyzed: VO2max by spirometric method, mean arterial blood pressure (MAP) by sphygmomanometer, and heart rate (HR) by ECG. The parameters were measured under basal conditions (level 1), at 50% of maximal aerobic capacity (level 2), at peak of exercise (level 3) and during recovery. Ejection fraction in athletes increased significantly at peak of exercise through Frank-Starling mechanism. Stroke volume and cardiac output increased significantly in athletes at peak of exercise. Left ventricular diastolic function was superior in athletes versus controls: in fact, higher peak E in athletes enhanced early diastolic ventricular filling. Therefore, the athletes showed complex cardiovascular adjustments induced by training, which allowed an higher peak working power, a greater cardiac output, and VO2max when compared with an untrained control population.

Evaluation of maximal left ventricular performance in elite bicyclists.

Aim of this work was to study in a group of elite cyclists, undergoing laboratory testing, the trend of the left ventricular systolic and diastolic function, echocardiographically and Doppler derived, simultaneously with the evaluation of ergospirometric parameters during maximal exercise. We studied a group of male subjects, consisting of 10 professional elite bicyclists (mean age: 25.1 +/- 3.2 years) during competitive activity (VO2/kg max: 78.5 +/- 7.7 ml.kg.min-1). The maximal exercise test, conducted with Wind Loaded Simulator for optimisation of ergometric capacity, showed, at the end of exercise, at a speed of 49.2 +/- 2.4 km/h, a VO2max of 5365 +/- 543.4 ml/min, with a calculated Cardiac Output (CO) of 19.3 +/- 3.7 l/min. A linear regression relationship was found between VO2max and CO (r = 0.84; p < 0.0001) as well as between VO2max and maximal reached speed (r = 0.97; p < 0.0001). During the aerobic period a slight but significant increase in End Diastolic Volume (EDV) was observed due to the greater venous return from exercising muscles. At stop, in anaerobic period, the EDV remained substantially constant. Ejection Fraction (EF) also increased during exercise through the Frank-Starling mechanism activation. The slight, but not significant, increase in EF at stop level may be explained by an activation of homeometric control of contractility with a sympathetic modulation on myocardial fibres. The early diastolic mitral flow velocity (Peak E) increased significantly during exercise, in comparison with basal upright values. The left ventricular diastolic compliance observed in athletes permits a good left ventricular filling, particularly in early diastolic phase; this allows an excellent left ventricular systolic performance. Based on echocardiography and pulsed Doppler measurements, calculated cardiac output is underestimated by approximately 20%.

Increased echodensity of myocardial wall in the diabetic heart: an ultrasound tissue characterization study.

OBJECTIVES: We sought to characterize myocardial echodensity in asymptomatic patients with insulin-dependent diabetes and normal conventional two-dimensional echocardiographic findings to determine whether ultrasound tissue characterization can detect ultrastructural changes in myocardium, such as an increase in collagen content. BACKGROUND: Fibrosis alters the acoustic properties of the heart in animals and humans, and these changes are detectable by cardiac tissue characterization with ultrasound. Early changes detected in the diabetic heart include increased interstitial collagen deposition. METHODS: Using two-dimensional echocardiography, we evaluated 26 asymptomatic patients with insulin-dependent diabetes with normal regional and global rest function, and 17 age- and gender-matched control subjects. By selection, all diabetic patients were normotensive and had negative maximal exercise stress test results to avoid the confounding effects of hypertension and coronary artery disease. Using an echocardiographic instrument implemented at the Institute of Clinical Physiology, we performed an on-line radiofrequency analysis to obtain quantitative operator-independent measurements of the integrated back-scatter signal of the ventricular septum and posterior wall. The integrated values of the radiofrequency signal from the myocardial wall were normalized for those from the pericardial interface and were expressed as percentages (integrated backscatter index). RESULTS: Diabetic patients showed a significant increase in myocardial echodensity both in the septum ([mean +/- SD] 36.6 +/- 8.1 vs. 23.6 +/- 4.4, p < 0.0001) and posterior wall (21.2 +/- 5.3 vs. 18.4 +/- 3.7, p < 0.001). By individual patient analysis, 17 patients exceeded the 95% confidence limits for normal myocardial echocardiographic reflectivity found in normal subjects, and only 3 had a relatively abnormal transmitral Doppler filling pattern (E/A ratio), mainly consisting of an abnormally increased late peak flow velocity (65% vs. 11%, p < 0.001). The increased myocardial intensity was similar in patients with (n = 16) and without (n = 10) noncardiac complications, such as retinopathy or nephropathy (37.5 +/- 7.9% vs. 35.0 +/- 8.3%, p = 0.35). CONCLUSIONS: Abnormally increased myocardial echodensity, possibly related to collagen deposition, can be detected in asymptomatic diabetic patients with normal rest function. Theoretically, this finding might be considered a very early preclinical alteration potentially related to subsequent development of diabetic cardiomyopathy.

Microalbuminuria and erythrocyte sodium-hydrogen exchange in essential hypertension.

Microalbuminuria (urinary albumin excretion between 20 and 200 micrograms/min) and abnormalities of red blood cell sodium-hydrogen exchange coexist in essential hypertensive patients. To evaluate how the two phenomena relate, we recruited 10 untreated microalbuminuric male essential hypertensive patients without diabetes to be compared with an equal number of matched essential hypertensive patients excreting albumin in normal amounts as well as 10 healthy control subjects. Sodium-hydrogen exchange values were increased to a comparable extent in microalbuminuric and normoalbuminuric hypertensive patients. Systolic and mean blood pressures were higher in microalbuminuric patients. Fasting insulin was greater and high-density lipoprotein cholesterol lower in patients than control subjects. Urinary albumin excretion correlated positively with both mean blood pressure and left ventricular mass values in the absence of a relationship with circulating lipid and insulin levels. In contrast with microalbuminuria, sodium-hydrogen exchange covaried only with high-density lipoprotein cholesterol and insulin levels. Thus, microalbuminuria and an abnormal sodium-hydrogen exchange are unrelated phenomena in essential hypertensive patients. Microalbuminuria appears to be a hemodynamically driven biological variable, while an accelerated sodium-hydrogen exchange seems primarily conditioned by the metabolic abnormalities of hypertension, possibly in the context of an insulin-resistant syndrome.

Forearm blood flow reserve and cardiac and renal indexes of pressure load in normotensive and hypertensive individuals.

In response to hypertension, arterioles remodel their structure, the heart develops myocardial hypertrophy, and the kidney reduces creatinine clearance and increases albuminuria. To better understand the interrelations among the target organs involved in hypertension, we evaluated minimal forearm vascular resistances--a hemodynamic index of arteriolar structure derived from mean blood pressure and maximal postischemic forearm blood flow--the echocardiographic indexes of cardiac structure, and urinary albumin excretion and creatinine clearance in 29 male mild to moderate non-macroalbuminuric essential hypertensive patients on no drugs and 11 age- and sex-matched normotensive control subjects. Minimal forearm resistances were elevated in hypertensive patients and correlated with left ventricular mass, wall thickness, and mean arterial pressure. Patients with abnormal minimal forearm resistances (2 SD above normal) were characterized by higher pressure, greater wall thickness, lower creatinine clearance, and higher albumin excretion, suggesting that maximal forearm flow capacity does relate to the hemodynamic load exerted on both the kidney and heart. However, the correlation with cardiac structure and mean arterial pressure explained only part of the variability of minimal forearm resistances. Furthermore, no correlation among these parameters was found when hypertensive patients were evaluated separately from normotensive subjects, possibly because of heterogeneous factors active on arteriolar structure and unrelated to the pressor load. Overall, the data suggest that the development of abnormal minimal forearm resistances in the course of the hypertensive process is related to the pressor load, but its details need further understanding.

Phytogrowth-inhibitory activities of 2-thiophenecarboxylic acid and its related compounds.

2-Thiophenecarboxylic acid (I) exhibited growth-inhibitory activity in five kinds of plants. In particular, I strongly inhibited the growth of the roots of Lactuca sativa L. var. longifolia LAM and Echinochloa utilis OHWI et YABUNO, even at the low concentration of 5.0 x 10(-3) M. Furthermore, all of the I-related compounds (II-V and VII-X) except for VI, showed more or less obvious inhibitory activity on the seeds of Sesamum indicum L. Compounds VII-X, in which the carboxyl group of I was replaced by acetic acid, propionic acid, butyric acid and acrylic acid, and exhibited more potent phytogrowth-inhibitory activity than I. Among these compounds, 2-thiophenebutyric acid (IX) showed the strongest activity. Esterification of the carboxyl group in I increased the inhibitory activity relative to that of I, while amidation and reduction of this group markedly decreased its inhibitory activity. The radicles of the plants treated with each of the compounds except for VI showed negative geotropism, even though germination occurred.