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There are numerous studies on systems comprising an enzyme encapsulated in unilamellar liposomes and its substrate initially present in the external aqueous media. Most of these studies are focused on enzyme stability and activity in a restricted media. However, the rate of the process is also determined by the capacity of the substrate to permeate towards the liposome inner pool. In spite of this, there are few studies aimed at a quantitative evaluation of the substrate permeation rate and its lifetime inside the liposome pool. In the present work, we describe, in terms of a very simple mechanism, the permeation of glucose and hydrogen peroxide in DPPC unilamellar liposomes. To this aim, we evaluated the rate of the process employing encapsulated glucose oxidase and catalase in the kinetic diffusion controlled limit. Under this condition, the rate of the process becomes zero order in the enzyme and allows a direct evaluation of the rate constant for the permeation process and the lifetime of a substrate molecule incorporated into the liposome inner pool.

Obesity, is a chronic, biological, preventable, and treatable disease. The accumulation of fat mass causes physical changes (adiposity), metabolic and hormonal changes due to adipose tissue dysfunction (adiposopathy), and psychological changes. Bariatric endocrinology was conceived from the need to address the neuro-endocrinological derangements that are associated with adiposopathy, and from the need to broaden the scope of the management of its complications. In addition to the well-established metabolic complications of overweight and obesity, adiposopathy leads to hyperinsulinemia, hyperleptinemia, hypoadiponectinemia, dysregulation of gut peptides including GLP-1 and ghrelin, the development of an inflammatory milieu, and the strong risk of vascular disease. Therapy for adiposopathy hinges on effectively lowering the ratio of orexigenic to anorexigenic signals reaching the the hypothalamus and other relevant brain regions, favoring a lower caloric intake. Adiposopathy, overweight and obesity should be treated indefinitely with the specific aims to reduce fat mass for the adiposity complications, and to normalize adipose tissue function for the adiposopathic complications. This paper defines the principles of medical practice in bariatric endocrinology-the treatment of overweight and obesity as means to treat adiposopathy and its accompanying metabolic and hormonal derangements.

The decomposition of hydrogen peroxide catalyzed by catalase entrapped in the pool of dipalmitoylphosphatidyl choline unilamellar liposomes has been studied. The rate of the process was evaluated by following the production of oxygen as a function of time. Under the experimental conditions employed the rate of oxygen production was controlled by the diffusion of hydrogen peroxide, allowing for the estimation of the diffusion coefficient of hydrogen peroxide across the liposome bilayer. The rate of diffusion across the bilayer increases with the temperature and the presence of fluidizers (n-nonanol), according with changes in the bilayer fluidity, as sensed by 1,6-diphenyl hexatriene (DPH) fluorescence anisotropy. A peculiar aspect of the data is the fast hydrogen peroxide diffusion observed at the bilayer phase transition temperature. This fast diffusion is associated to rafts fluctuations that take place in the partially melted bilayer. These fluctuations have no effect on the microviscosity sensed by DPH., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Approximately 170 million inhabitants of the American continent live at risk of malaria transmission. Although the continent's contribution to the global malaria burden is small, at least 1-1.2 million malaria cases are reported annually. Sixty percent of the malaria cases occur in Brazil and the other 40% are distributed in 20 other countries of Central and South America. Plasmodium vivax is the predominant species (74.2%) followed by P. falciparum (25.7%) and P. malariae (0.1%), and no less than 10 Anopheles species have been identified as primary or secondary malaria vectors. Rapid deforestation and agricultural practices are directly related to increases in Anopheles species diversity and abundance, as well as in the number of malaria cases. Additionally, climate changes profoundly affect malaria transmission and are responsible for malaria epidemics in some regions of South America. Parasite drug resistance is increasing, but due to bio-geographic barriers there is extraordinary genetic differentiation of parasites with limited dispersion. Although the clinical spectrum ranges from uncomplicated to severe malaria cases, due to the generally low to middle transmission intensity, features such as severe anemia, cerebral malaria and other complications appear to be less frequent than in other endemic regions and asymptomatic infections are a common feature. Although the National Malaria Control Programs (NMCP) of different countries differ in their control activities these are all directed to reduce morbidity and mortality by using strategies like health promotion, vector control and impregnate bed nets among others. Recently, international initiatives such as the Malaria Control Program in Andean-country Border Regions (PAMAFRO) (implemented by the Andean Organism for Health (ORAS) and sponsored by The Global Fund to Fight AIDS, Tuberculosis and Malaria (GFATM)) and The Amazon Network for the Surveillance of Antimalarial Drug Resistance (RAVREDA) (sponsored by the Pan American Health Organization/World Health Organization (PAHO/WHO) and several other partners), have made great investments for malaria control in the region. We describe here the current status of malaria in a non-Amazonian region comprising several countries of South and Central America participating in the Centro Latino Americano de Investigación en Malaria (CLAIM), an International Center of Excellence for Malaria Research (ICEMR) sponsored by the National Institutes of Health (NIH) National Institute of Allergy and Infectious Diseases (NIAID)., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The effect of human serum albumin (HSA) addition on the rate of hydrolysis of N-glutaryl-L-phenylalanine p-nitroanilide (GPNA) catalyzed by α-chymotrypsin has been measured in phosphate buffer saline at pH = 7.4. The presence of HSA (up to 200 μM) leads to a decrease in the rate of the process. The reaction follows a Michaelis-Menten mechanism under all the conditions employed. To take into account the effect of substrate depletion due to its binding to albumin ultrafiltration experiments were carried out from which the binding of GPNA to HSA was derived. After correction of the kinetic data taking into account the binding of GPNA to HSA, the activity of the enzyme, and the derived Michaelis constant and catalytic rate constant tends to remain almost independent of the presence of albumin, indicating that the depletion of the substrate due to its binding to HSA is the main factor affecting the enzyme activity.

Introduction: The enzootic focus of subtype ID of Venezuelan equine encephalitis (VEE) virus in the Central Magdalena region (central Colombia) occasionally produces human cases. The report of a VEE infection in a three-year-old girl in the small Chingalé, municipalitype of Puerto Wilches, Santander, motivated this study., Objective: The village of Chingalé was evaluated as the probable site of infection., Materials and Methods: In June 2005, mosquitoes were collected with CDC light traps in and outside of dwellings in the village. Trinidad traps were placed in nearby vegetation, and hamsters were used as sentinel animals near homes., Results: One hundred and seven samples, consisting of 14,423 mosquitoes of 35 species were collected. The relative abundance of incriminated vectors of subtype ID of VEE, Culex (Melanoconion) pedroi and Cx. (Mel.) ocossa, was generally low (<4%), but both species were more frequent outside of dwellings than indoors. Cx. (Mel.) ocossa was collected in CDC traps and was more frequent indoors,whereas Cx. (Mel.) pedroi was found in the Trinidad traps. In addition, Psorophora confinnis was present, recognized as a potential vector of the epidemo/epizootic subtype. Mansonia indubitans, another recognized vector, was present at high frequency within dwellings. The exposed hamsters did not become infected., Conclusion: The child may have been infected in or near her home, although the epidemiologic cycle of the virus was not demonstrated within the village of Chingalé. Possibly, infected Culex mosquitoes of the subgenus Melanoconion carried the virus into the village from a neighboring habitat.

Social isolation in rodents is the most well characterized animal model for early stressful experiences and their neurobehavioral consequences. The present study analyzed the effects of early social isolation on the expression of the calcium binding protein calbindin-D28k (CAD) and dendritic arborization in the medial prefrontal cortex (mPFC) of the rat. Sprague-Dawley male rats were reared either under isolation or social conditions from 21 to 51 postnatal days. At the end of this period the animals were behaviorally evaluated in the open-field test, sacrificed, and mPFC serial sections were processed either for immunocytochemical labeling against CAD or Golgi-Cox-Sholl staining. Isolated-reared rats exhibited a dramatic decrease in the number of CAD immunoreactive neurons and a significant dendritic atrophy of layer II/III pyramidal cells in association with a reduced exploratory behavior.

Background: Pretreatment with statins reduces early ischemic events after percutaneous coronary interventions, primarily in patients with a high level of inflammation markers. We sought to examine the association between preoperative statin therapy, systemic inflammation, and myocardial ischemia with the occurrence of early cardiac complications after coronary artery bypass grafting surgery., Methods: One hundred forty-one consecutive patients who underwent coronary artery bypass grafting surgery from two university tertiary hospitals were stratified according to their preoperative status of statin therapy (87 treated and 54 nontreated). Preoperative blood samples were collected for measurement of lipid parameters, C-reactive protein, interleukin-6, and troponin T. The evaluated primary endpoint was a composite of death and myocardial infarction at 30 days., Results: Patients undergoing preoperative statin therapy showed a reduced incidence of death (2.3% versus 13.0%, p = 0.012), myocardial infarction (5.7% versus 18.5%, p = 0.017), and primary combined endpoint (8.0% versus 22.2%, p = 0.017). In the multivariate model, preoperative troponin T greater than 0.01 ng/mL (odds ratio 6.85, p = 0.001) and nonstatin therapy (odds ratio 4.2, p = 0.01) predicted a higher risk of primary endpoint. Statins showed a significant interaction with troponin T status and benefited primarily those patients with positive troponin T. Among 19 patients with troponin T greater than 0.01 ng/mL, the primary endpoint occurred in all 6 nonstatin-treated patients, but it occurred in only 1 of 13 statin-treated patients (p < 0.001). Neither C-reactive protein nor interleukin-6 predicted early complications, nor did they interact with statin therapy (p = not significant)., Conclusions: Preoperative statin therapy reduces early complications and offers additional protection in patients with positive troponin T status, regardless of inflammatory markers.

Atrial fibrillation (AF) is a common complication after coronary artery bypass grafting. Atrial remodeling has been observed in AF and has been associated with the development of this arrhythmia. Because 3-hydroxy-3-methylglutaryl coenzyme A inhibitors (statins) have been demonstrated to modify remodeling, we hypothesized a protective role of statins against postoperative AF. We also hypothesized that extracellular matrix turnover and brain natriuretic peptide (BNP) might be related to such atrial remodeling. We studied 234 consecutive patients who underwent coronary artery bypass grafting (173 men; 65 +/- 9 years of age) in whom the occurrence of postoperative AF was monitored. In a subgroup of 66 patients, we measured plasma levels of matrix metalloproteinase-1 (MMP-1), its inhibitor, tissue inhibitor matrix metalloproteinase-1 (TIMP-1; as indexes of extracellular matrix remodeling), and N-terminus pro-BNP (related to left ventricular function) at baseline and at 24 hours after surgery. Of 234 patients, 66 (28.2%) developed postoperative AF. In multivariate analysis, previous AF was related to an increase in the development of AF (odds ratio 11.92, 95% confidence interval 2.37 to 59.98, p = 0.026), whereas statin use was related to a decrease in arrhythmia (odds ratio 0.52, 95% confidence interval 0.28 to 0.96, p = 0.038). A higher TIMP-1/MMP-1 ratio at 24 hours after surgery was present in those who did not develop postoperative AF (p = 0.043). Statin use was associated with increased TIMP-1 levels and TIMP-1/MMP-1 ratio (p = 0.027 and 0.036, respectively). No significant relations to N-terminus pro-BNP were seen. In conclusion, previous AF and nonuse of statins are significantly associated with AF after coronary artery bypass grafting. Statin use may be protective against AF after coronary artery bypass grafting, possibly due to alterations in the extracellular matrix and remodeling after coronary artery bypass grafting.

Introduction and Objectives: The clinical profile of patients with acute myocardial infarction (AMI) who have reinfarction (REAMI) during their stay in the intensive cardiologic care unit (ICCU) is not well known. The aim of this study was to identify factors predictive of REAMI, as well as its global incidence and mortality., Patients and Method: All patients with AMI admitted to the ICCU of 17 hospitals in the Comunidad de Valencia (Spain) in the period 1995-2000 (PRIMVAC Registry) were included. Differential characteristics between patients with or without REAMI were determined, and odds ratios (OR) for possible predictive factors were estimated with their 95% confidence intervals by logistic regression., Results: A total of 12,071 patients were included. Mean age of the patients was of 65.5 years, the percentage of women was 23.8%, and the incidence of REAMI was 2.8%. The REAMI group was significantly older than the non-REAMI group. Female sex was significantly more common in the REAMI group. More diagnostic and therapeutic procedures were carried out, more drugs were used and there were more complications in the REAMI group. Mortality was significantly higher in the REAMI group (37.8% vs 12.6%). Only age, diabetes mellitus, previous myocardial infarction and the appearance of Q waves in the electrocardiogram were independently associated with the presence of REAMI., Conclusions: REAMI in the ICCU was associated with high mortality. Some clinical factors present during the first few hours after AMI were associated independently with the appearance of REAMI.

Background and Objective: We intended to estimate the prevalence of varicose veins in the mature population of the Valencia Community and to analyze its relationship with socio-demographic variables, self-reported health status, body mass index and the presence of hemorrhoids, tobacco smoking, alcohol consumption and physical activity., Subjects and Method: Information on self-reported varicose veins was collected from 1,778 adults older than 14 years (819 men and 959 women) who participated in the Health and Nutrition Survey of the Valencia Community (Spain). We estimated the prevalence of varicose veins by age groups and sex. To explore the association between varicose veins and variables, we estimated adjusted odds ratios (OR) with 95% confidence intervals (CI 95%) by multiple logistic regression., Results: The overall prevalence of varicose veins was 16.4%, with a much higher prevalence in women that in men (26.7% versus 5.5%) and with older age. Gender and age were the 2 strongest predictors of varicose veins in multivariate analysis. Women had seven times more risk than men (OR = 7.01; CI 95%, 4.52-10.87) and those older than 35 years almost tripled the risk with respect to those aged 15-24 years. A body mass index of 30 kg/m2, a poor self-reported health status and hemorrhoids were significantly associated with the presence of varicose veins. Employers showed higher risk than workers. A moderate alcohol consumption (< or = 1 drink/day) was associated with a protective effect (OR = 0.50; CI 95%, 0.28-0.88). Tobacco smoking and physical activity were not associated with varicose veins., Conclusions: Although being a woman and having an advanced age were the strongest predictors of varicose veins, other factors such as a high BMI, poor health status, hemorrhoids and some professional categories may be also important factors in their presentation. A moderate alcohol consumption seems to have a protective effect.

Background and Objective: The aim of this study was to determine the mortality due to acute myocardial infarction in the coronary units from Comunidad Valenciana (Spain) and the prognostic factors associated with a higher mortality., Patients and Method: Demographic characteristics, coronary risk factors, electrocardiographic ischemic signs, complications and mortality of patients with acute myocardial infarction admitted in the coronary units were collected. The study period comprised January 1995-December 1999. Death incidence was measured during coronary unit's stay. Factors associated with poor prognosis were analyzed., Results: 10.213 patients entered into the study. Mean age at admission was 65 12 years. 23.8% were females (76.2% males). Global mortality in coronary units was 13.3%. Independent variables associated with higher mortality were (p < 0.05): advanced age (OR=1.06 [1.05-1.06]), female sex (OR=1.45 [1.26-1.66]), diabetes mellitus (OR=1.53 [1.35-1.74]), previous myocardial infarction (OR=1.46 [1.23-1.70]), previous angor pectoris (OR=1.29 [1.13-1.49]) and Q-wave infarction (OR=1.23 [1.03-1.43]). Factors associated with lower mortality were: hypercholesterolemia (OR=0.76 [0.66-0.78]), smoking (OR=0.65 [0.57-0.74]) and thrombolysis (OR=0.85 [0.78-0.92])., Conclusions: At present, in the reperfusion therapy era, acute myocardial infarction has a high mortality after coronary unit admission. Several clinical factors are associated with a worse prognosis.

The ecology of Venezuelan equine encephalitis (VEE) virus transmission was compared at three enzootic foci: two forest sites in the Catatumbo region of western Venezuela that have yielded small numbers of virus isolates since the 1970s, and another focus in the middle Magdalena Valley of Colombia that has consistently yielded many VEE virus isolates. Our results demonstrated dramatic differences in VEE virus isolation rates from sentinel hamsters, as well as differences in mosquito species composition and captured mammals with antibodies to VEE virus, between the Colombian and Venezuelan study sites. The higher isolation rate of enzootic VEE virus in the Colombian site was associated with a more abundant fauna of spiny rats (Proechimys spp.), known reservoir hosts of enzootic VEE virus. Mosquito collections demonstrated that the Colombian forest had a higher mosquito diversity and species evenness than either of the Venezuelan forests. The Colombian focus was especially richer in its Culex (Melanoconion) spp. fauna, a subgenus that includes all proven enzootic vectors for VEE virus. Our results suggest that the greater abundance, diversity, and stability of enzootic vector populations, combined with the greater density of rodent reservoir hosts, explains the higher levels of VEE virus circulation in the Colombian focus compared with the Venezuelan forests.

Background: Frequently, the use of insulin is considered for metabolic control in postoperative patients with non-insulin-dependent diabetes mellitus (NIDDM). We sought to determine the best method for control of glucose in NIDDM non-insulin patients during postoperative care., Methods: Two algorithms were developed: subcutaneous administration of insulin (SC), and continuous intravenous infusion (IV). A randomized, controlled clinical trial was designed. In addition, both experimental groups were compared with a non-concurrent routinely managed group (RM) with insulin administration under no predetermined algorithm. Eligible patients were those subjected to major surgery under general anesthesia or spinal blockade. They were followed for 48 h after surgery. Target variables were capillary and central blood glucose, insulin dose administered, urine glucose and ketone strip determination, and development of hyper- or hypoglycemia., Results: A total of 62 patients were studied (RM = 25, SC = 19, IV = 18). Results for both experimental algorithms were similar except for the IV group that required less insulin per hour compared to SC (0.64 vs. 0.34 U/h; p = 0.0003). The RM control group showed poor control in all capillary glucose measurements (194.9 +/- 26.8 mg/dL) compared with the two experimental algorithms (SC = 129.9 +/- 21; IV = 131.6 +/- 20.4) (p <0.05). More hyperglycemia events appeared in the RM group (p = 0.016). Only one hypoglycemia event occurred in the IV group., Conclusions: Postoperative control of NIDDM is similar with both tested methods. The use of any of the algorithms studied improves metabolic control substantially because it standardizes postoperative management of the diabetic patient with timely determination of capillary blood glucose and insulin administration. However, IV administration has the advantage of accomplishing adequate control with a smaller insulin dose.

Surgery continues to be the only curative therapy for gallbladder cancer, but useful in very few patients. Mean survival of patients with gallbladder cancer, that are out of the reach of surgery, is 3 months. The few clinical trials of chemotherapy for this disease, report very low success rates. We report four patients with advanced gallbladder cancer, treated with gemcitabine in an intravenous dose of 1000 mg/m2, given in 30 min, once a week during three consecutive weeks, every 28 days. There was a partial response that lasted 40.3 23.2 weeks with a mean survival of 59.75 17 weeks. One patient survives without evidences of disease after 17 months of the diagnosis of an advanced cancer. In all patients, symptoms were alleviated, functional status and quality of life improved. Toxicity was mild and did not require reduction in doses or delay in therapy. Therefore, this medication deserves further investigation for the treatment of gallbladder cancer.

Objective: Lactobacilli are considered cariogenic micro-organisms. As oral species of lactobacilli have not been thoroughly described, the aim of this work was to isolated and identify these organisms from teeth, tongue, saliva and gum of healthy patients and to describe some of their surface properties., Subjects: Forty-four subjects from Tucumán, Argentina, with D, d and M, m indices equal to 0., Materials and Methods: Samples were obtained from different areas of the oral cavity. Microorganisms were cultured in lactobacilli selected media (LBS) and identified morphologically and biochemically. Hydrophobicity was analysed by partition in organic solvents, acidity by affinity with chloroform and basicity with ethyl acetate (MATH method), aggregation and coaggregation in presence of (NH4)2SO4, and haemagglutination with ABO erythrocytes in microplates., Results: Eighty-five lactobacilli were isolated; 29.4% were homofermenter, 44.7% facultative heterofermenter and 25.9% obligate heterofermenter. Predominant species were L. fermentum, L. plantarum, L. salivarius, and L. rhamnosus. Most of the strains showed moderate to high hydrophobicity and demonstrated high acid and basic surface charges with almost 40% showing salt aggregation. Few strains haemagglutinated., Conclusions: A variety of Lactobacillus species were isolated from healthy mouths, some of whom showed adhesion-related properties such as high hydrophobicity and charged surfaces. Probable mechanisms related to the ecological behaviour of lactobacilli in the oral cavity are discussed.

The purpose of this study was to investigate the neural networks involved when using an ultrasonic echolocation device, which is a substitution prosthesis for blindness through audition. Using positron emission tomography with fluorodeoxyglucose, regional brain glucose metabolism was measured in the occipital cortex of early blind subjects and blindfolded controls who were trained to use this prosthesis. All subjects were studied under two different activation conditions: (i) during an auditory control task, (ii) using the ultrasonic echolocation device in a spatial distance and direction evaluation task. Results showed that the abnormally high metabolism already observed in early blind occipital cortex at rest [C. Veraart, A.G. De Volder, M.C. Wanet-Defalque, A. Bol, C. Michel, A.M. Goffinet, Glucose utilization in human visual cortex is, respectively elevated and decreased in early versus late blindness, Brain Res. 510 (1990) 115-121.] was also present during the control task and showed a trend to further increase during the use of the ultrasonic echolocation device. This specific difference in occipital cortex activity between the two tasks was not observed in control subjects. The metabolic recruitment of the occipital cortex in early blind subjects using a substitution prosthesis could reflect a concurrent stimulation of functional cross-modal sensory connections. Given the unfamiliarity of the task, it could be interpreted as a prolonged plasticity in the occipital cortex early deprived of visual afferences., (Copyright 1999 Elsevier Science B.V.)

Recognition tasks of simple visual patterns have been used to assess an early visual--auditory sensory-substitution system, consisting of the coupling of a rough model of the human retina with an inverse model of the cochlea, by means of a pixel-frequency relationship. The potential advantage of the device, compared with previous ones, is to give the blind the ability to both localise and recognise visual patterns. Four evaluation sessions assessed the performance of twenty-four blindfolded sighted subjects using the device. Subjects had to recognise twenty-five visual patterns, one at a time, using a head-mounted small camera and interpreting the corresponding sounds given by the device. Half the subjects were trained by means of a correction feedback procedure during ten one-hour training sessions embedded in between the evaluation sessions. Results revealed extremely successful training effects. Performance of trained subjects significantly increased with practice compared with the untrained control group. The improvement was also observed for new patterns, demonstrating a learning-process generalisation. The negative correlation observed between scores and processing time showed that the subjects' response accuracy was related to their speed. In conclusion, simple pattern recognition is possible with a fairly natural vision-to-audition coding scheme, given the possibility for the subjects to have sensory--motor interactions while using the device.

Background: Maternal smoking negatively affects birth weight, breast milk volume and growth at one month of age., Aim: To study the effect of maternal smoking on the growth of three month old infants., Subjects and Methods: Ten smoking and 10 non smoking mothers with one month old children, under exclusive breast feeding, were selected for the study. Urinary cotinine levels in the mothers and children were measured to assess smoking. Two months later, children were reassessed., Results: Smoking mothers consumed a mean of 6.5 cigarettes/day. Compared to non smokers, urinary cotinine levels were higher in these mothers (60 +/- 21 and 1428 +/- 716 ng/ml respectively, p < 0.001) and their offspring (21 +/- 20 and 156 +/- 101 ng/ml respectively p < 0.001). Compared with smokers, at three months of age, children of non smoking mothers had a higher average weight (5829 +/- 498 and 6325 +/- 427 g, p < 0.02)., Conclusions: Measurement of urinary cotinine levels is a reliable and objective measure of maternal smoking and nicotine transfer to the offspring. It also allows the assessment of passive smoking. Maternal smoking adversely affects child growth at three months of age.

Objective: Our aim was to study the behavior and validity of PEFR and FEV1 in the free-running exercise test in order to diagnose exercise-induced asthma during childhood., Patients and Methods: We studied 30 asthmatic children and 30 healthy children as controls. A provocation test was performed by means of free-running exercise in an indoor sports center. Environmental temperature and humidity were equal in both groups. Forced breathing spirometry and the "Mini-Wright peak flow meter" test were recorded before and two, five, fifteen and twenty minutes after the exercise challenge. The spirometric values representing two standard deviations below the mean for each variable studied in the control group were considered as reference values (FEV1 > or = 83.5% and PEFR > or = 81.5%)., Results: There was a decrease in FEV1 in 17 asthmatic children (56.7%) and a decrease in PEFR occurred in 14 children (46.7%). No statistically significant differences were found in either test. Specificity was 100% for FEV1 and 96.7% for PEFR. The greatest decrease in both spirometric parameters occurred at five minutes., Conclusions: According to our results, in a free-running provocation test if we maintain previously controlled environmental conditions and exercise intensity "forced breathing spirometry" and "Mini-Wright peak flow" can be used interchangeably in order to diagnose exercise-induced asthma.

Oleuropein, tyrosol, squalene and the fraction of sterols and triterpenoid dialcohols from the unsaponifiable fraction obtained from virgin olive oil have been tested for possible cytostatic activity against McCoy cells, using 6-mercaptopurine as a positive control. The samples of sterols and triterpenic dialcohols showed a strong activity.

Background: Exercise is one of the most common precipitating factors of acute asthmatic crises in childhood. Although it has been described as more frequent among children, this is probably due to their more abundant physical activity. Nevertheless, it also occurs at other ages., Objective: The aim of this study is to assess possible differences in postexercise spirometry after treadmill and free running provocation tests., Methods: We compared the results obtained in a treadmill test performed by 30 asthmatic children and 30 healthy children with the results obtained with these same children in a free running test, keeping similar environmental conditions (temperature and humidity), exercise intensity (assessed by heart rate), and airway status at the time of the test., Results: Seventy-three percent of the patients had positive treadmill tests and 63.3% had positive free running tests. For the spirometric parameters studied, there were no significant differences in the percent decrease in postexercise performance after either of the provocation tests. For FEV1, which is the most sensitive diagnostic parameter, the sensitivity was 53.3% in treadmill running and 56.7% in free running, with a specificity of 100% in both tests., Conclusions: If environmental conditions, exercise intensity, and airway status are controlled at the time of the test, treadmill and free running can be used indistinctly as asthma-inducing exercises.

Objective: The aim of this study was to evaluate ribavirin therapy for acute bronchiolitis caused by viral syncytial respiratory infection., Patients and Methods: Ninety-seven patients with acute bronchiolitis in which respiratory syncytial virus was identified by direct immunofluorescence and admitted to the hospital between October 1990 and May 1995 were studied. Data pertaining to age, sex, weight, respiratory frequency at admission, respiratory frequency on the fourth day, day in which respiratory ausculation was normal, day in which there were no thoracic retractions, number of days that the infants needed oxygen, duration of hospital stay, and whether or not they were treated with ribavirin were collected retrospectively., Results: At admission there were no statistically significant differences in patients treated or not with ribavirin or in age, sex or weight, but the respiratory frequency was higher in those patients treated with ribavirin than in those who were not. The number of days of oxygen therapy was statistically different between these groups, with infants treated with ribavirin requiring oxygen for 2.7 days and the nontreated group requiring 1.7 days. However, we think that this difference is not clinically relevant., Conclusions: We did not find any difference of clinical relevance between patients treated or not with ribavirin.

Perspectives of cholera vaccines with emphasis in their possible usage in Latin American countries are discussed. Microbiology, antigenicity, relevant aspects of traditional serology, protective immune responses and epidemiological data up to December, 1991, are presented. Indications of parenteral vaccines are discussed. Finally, perspectives of usage of cholera vaccines in Latin America are analyzed.

Alcoholism is a major health problem in Spain. Frequently, the first drink is offered in the home. We report the results of a poll in which parents were asked when they offer alcohol to their children. We found that 76.1% offered alcohol anytime. Furthermore, 15% of the mothers answered that this may be of benefit to their children. Drinks with a higher level of alcohol (brandy, punch, anis) were offered more frequently after seven years of age and to those children whose mother had offered the first alcoholic beverage at an earlier age.

Myasthenia gravis is an inmunological disease infrecuent during childhood. In recent years, thymectomy has gained increasing acceptance as the most effective treatment for acheiving sustained improvement in patients affected of myasthenia gravis. We report our experience in five children treated by trassternal radical thymectomy in the last five years. This patients were clinically staged following Osserman's classification as stage IIB (three cases) and stage III (two cases). All of them are in complete remission after a mean postoperative period of thirty three months. We add a review of the literature comparing the differents surgical approaches for thymectomy and its results in children.

In order to know the importance and epidemiology of childhood accidents, a prospective study was made in a Spanish region, this study was founded in death certificates and 3,344 questionnaires from children under 7 years old, accidented in 1986 and attended in emergency departments in our region. The information was coded and analysed by computer of the Murcia University. Accidents are the main cause of death in children aged over 1 year, as a common cause of assistance in emergency departments. Its characteristic are common to most countries, but the authors find some differences in our region. It is necessary to dedicate bigger effort to study and prevention of childhood accidents.

The DUHAMEL operation is widely used for the treatment of HIRSCHSPRUNG disease. Recently, technical modifications using stapled instruments have been introduced. The results of 12 patients treated between 1985 and 1989, performing the DUHAMEL procedure are reviewed. We perform with mechanical sutures, both surgical stages, e.g. abdominal and perineal. The technique for the procedure is described. Since we introduce the technique, we have observed several advantages consisting in a shorter surgical time, earlier normal life pattern, less postoperative complications and better results in clinical evolution.

The relation between cigarette smoking and obstetrical history, characteristics of skin and voice, presence of hirsutism and newborn weight/height index was studied in 100 hospitalized women. 45 had never smoked, 36 were present and 19 former smokers. No differences were found in the average age of menarche, number of live births or stillborns. Abortions were twice as frequent in women smoking more than 10 cigarettes a day. Menopause occurred an average of 5 years earlier among smokers. A significant increase in hoarseness and face hirsutism was detected, the relative risk for heavy smokers (more than 10 cigarettes per day) being 14.2 for hoarseness, 5.6 for facial hirsutism and 2.8 for other locations of hirsutism. Obesity was twice as common among smokers. These findings, related to hormonal disturbance, should be used in education efforts in the anti-smoking campaign among Chilean women.