Ecotoxicology and environmental safety toxicity of pyrethroid cypermethrin on the freshwater snail Chilina parchappii: Lethal and sublethal effects.

The aim of the present work was to study the effect of the pyrethroid cypermethrin (CYP) on the non-target freshwater snail Chilina parchappi. Initially, the sensitivity of adult snails to CYP was evaluated via the 96-h LC50 test. Then, snails were exposed to subtethal CYP concentrations (0.1 and 10 mg/l) for 1, 4 and 10 days and the digestive glands were dissected for biomarkers analyses. Enzymatic activity of catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST), as well as total glutathione reduced (GSH) levels, were determined. Histological analyses of morphology, intracellular accumulation of lipofucsins and neutral lipids accumulation in the digestive gland were also evaluated. As compared to other molluscs, C. parchappi showed high resistance to CYP exposure evidenced by the 96-h LC50 value (44.59 mg/l). Snails exposed to sublethal CYP concentrations showed a statistically significant increase (p < 0.01) in GST (79-116%) and GPx (45-190%) activities with respect to controls. However, CAT activity showed a tendency to decrease with CYP treatment but was not statistically significantly different compared to control. Only high CYP concentration caused a statistically significant increase (p < 0.01) in GSH content (95-196%). There was evidence of structural changes in the digestive gland of snails exposed to CYP, showing a dose-dependent response. In exposed snails, some of the main symptoms included a reduction in the thickness of the epithelium, vacuolisation of the digestive cells and an increase in the number of excretory cells. Accumulation of lipofuscins (933-1006%) and neutral lipids (403%) were statistically significantly higher (p < 0.05) in snails exposed to CYP compared to control. This study showed that C. parchappii is quite tolerant to CYP exposure and that at sublethal concentrations, GSH metabolism could play a protective role against the pesticide harm in snails. Therefore, it would be interesting to study the response of this organism to other environmental stressors to assess its potential use in monitoring programs.

Impact of acute stress on itch sensation and scratching behaviour in patients with atopic dermatitis and healthy controls.

BACKGROUND: Patients with atopic dermatitis (AD) often report that stress aggravates their itch. However, no study has investigated if and how acute stress influences itch sensation and scratching behaviour in these patients. OBJECTIVES: We evaluated the impact of acute stress on experimentally induced cowhage itch perception and scratching behaviour in 16 healthy subjects and 15 patients with AD. METHODS: The Trier Social Stress Test (TSST) was used to induce acute stress. The itch sensation, provoked by applying cowhage to the forearms, and off-site scratching behaviour (not directed at the cowhage application site) were compared before and after performing the TSST or the control condition (watching a video of landscape scenes). RESULTS: In patients with AD, stress induced by TSST caused a significant reduction of cowhage-evoked itch but significantly increased off-site scratching behaviour. Such changes in itch perception and scratching behaviour were not observed in healthy controls. In addition, a significant positive correlation was noted between stress induced by TSST and clinical severity of eczema. CONCLUSIONS: We speculate that psychological stress increases spontaneous scratching in patients with AD, which may enhance the vicious cycle of itching and scratching, resulting in aggravation of the skin eczema. These results provide new insights on the mechanism of acute stress-related exacerbation of itch in patients with AD.

Desarrollo de ecuaciones antropométricas para predecir el porcentaje de grasa corporal total en niños y adolescentes chilenos / Development of anthropometric equations for predicting total body fat percentage in Chilean children and adolescents

Introducción: estudiar el porcentaje de grasa corporal (%GC) en niños y adolescentes es muy relevante, puesto que un elevado nivel de grasa corporal en la infancia y la adolescencia representa sobrepeso y obesidad. Objetivo: identificar los indicadores antropométricos que se relacionan con el %GC y validar ecuaciones de regresión para predecir el %GC de niños y adolescentes a partir del uso de la absorciometría de rayos X de doble energía (DXA) como método de referencia. Métodos: se diseñó un estudio descriptivo (transversal) en 1126 escolares (588 hombres y 538 mujeres) de la región del Maule (Chile). El rango de edad oscila desde los 6,0 hasta los 17,9 años. Se evaluaron el peso, la estatura, dos pliegues cutáneos (tricipital y subescapular) y la circunferencia de la cintura (CC). Se calcularon el índice de masa corporal (IMC), el índice ponderal (IP) y el índice cintura-estatura (ICE). Se evaluó el porcentaje de grasa corporal (%GC) por medio del escaneo DXA. Resultados: las relaciones entre Σ (Tricipital + Subescapular), IP e ICE con el %GC (DXA) fueron de R2 = 52-54 % en hombres y R2 = 41-49 % en mujeres. Las ecuaciones generadas para los hombres fueron: %GC = 9,775 + [(0,415 * (Tr + SE)] + (35,084 * ICE) - (0,828 * edad), R2 = 70 %, y %GC = 20,720 + [(0,492 * (Tr + SE)] + (0,354 * IP) - (0,923 * edad), R2 = 68 %; y para mujeres: %GC = 8,608 + [(0,291 * (Tr + SE)] + (38,893 * ICE) - (0,176 * edad), R2 = 60 %, y %GC = 16,087 + [(0,306 * (Tr + SE)] + (0,818 * IP) - (0,300 * edad), R2 = 59 %. Conclusión: este estudio demostró que la sumatoria de los pliegues cutáneos tricipital y subescapular, el IP y el ICE son adecuados predictores del %GC. Estos indicadores permitieron desarrollar dos ecuaciones de regresión aceptables en términos de precisión y exactitud para predecir el %GC en niños y adolescentes de ambos sexos (AU)

Introduction: studying the percentage of body fat (%BF) in children and adolescents is very relevant, since a high level of body fat in childhood and adolescence represents overweight and obesity. Objective: to identify the anthropometric indicators related to %BF and to validate regression equations to predict %BF in children and adolescents using dual-energy X-ray absorptiometry (DXA) as a reference method. Methods: a descriptive study (cross-sectional) was designed in 1126 schoolchildren (588 males and 538 females) from the Maule region (Chile). The age range ranged from 6.0 to 17.9 years. Weight, height, two skinfolds (tricipital and subscapular and waist circumference (WC) were evaluated. Body mass index (BMI), triponderal mass index (TMI), waist height index (WHtR) were calculated. Body fat percentage (%BF) was assessed by DXA scanning. Results: the relationships between Σ (Tricipital + Subscapular), TMI and WHtR with %BF (DXA) ranged from R2 = 52 % to 54 % in men, and from R2 = 41 % to 49 % in women. The equations generated for men were: %BF = 9.775 + [(0.415 * (Tr + SE)] + (35.084 * WHtR) - (0.828 * age), R2 = 70 %, and %BF = 20.720 + [(0.492 * (Tr + SE)] + (0.354 * TMI) - (0.923 * age), R2 = 68 %], and for women: %BF = 8.608 + [(0.291 * (Tr + SE)] + (38.893 * WHtR) - (0.176 * age), R2 = 60 %, and %BF = 16.087 + [(0.306 * (Tr + SE)] + (0.818 * TMI) - (0.300 * age), R2 = 59 %. Conclusion: this study showed that the sum of tricipital and subscapular skinfolds, IP and WHtR are adequate predictors of %BF. These indicators allowed the development of two regression equations acceptable in terms of precision and accuracy to predict %BF in children and adolescents of both sexes (AU)

Redox properties of nanostructured lanthanide-doped ceria spheres prepared by microwave assisted hydrothermal homogeneous co-precipitation.

In this work, nanostructured LnxCe(1-x)O2-δ (Ln: Gd and Pr; x = 0.1 and 0.2) spheres were synthesized by microwave assisted hydrothermal homogeneous co-precipitation and their properties were characterized by synchrotron radiation XRD, X-ray absorption near-edge spectroscopy (XANES) and scanning and high-resolution electron microscopy (SEM and HRTEM). In situ XRD and XANES experiments were carried out under reducing and oxidizing conditions in order to investigate the redox behaviour of these materials. The nanostructured mixed oxide spheres were found to have a cubic crystal structure (Fm3m space group). The spheres were composed of nanoparticles with an average crystallite size of about 10 nm. The Ln(0.1)Ce(0.9)O2-δ compositions exhibited the highest specific surface area (∼ 60 m(2) g(-1)). In situ XRD experiments showed an increase in lattice parameters upon reduction, which was attributed to the reduction of Ce(4+) and Pr(4+) cations to Ce(3+) and Pr(3+), which have larger radii, and to the associated increase in VO concentration. This increase in lattice parameters was considerably more pronounced for PrDC than GDC, and was explained by the considerably larger change in ionic radius for Pr upon reduction. XANES absorption experiments at the Ce and Pr L3-edge showed that the changes observed upon reduction of the Pr-containing samples resulted mostly from the formation of Pr(3+) rather than Ce(3+), and supported the previously reported proposal that Pr(3+) has a stabilizing effect on Ce(4+).

Correlation between the clinical classification of bronchial asthma severity and the methacholine test in children.

The purpose of this study was to validate the Methacholine Bronchial Challenge Test in its different degrees and to compare them with the different clinical classifications of bronchial asthma. Fifty-four child asthmatic patients over 6 years of age from the Respiratory Outpatient Clinic at La Union Hospital (Chile) were submitted to the clinical classification of bronchial asthma and later to the Methacholine Bronchial Challenge Test, which classified the children as mildly, moderately or severely hyperreactive to the test. In mildly asthmatic children, the Methacholine Test showed both a high sensitivity (100%) and specificity (92.3%). In moderately asthmatic children, the sensitivity decreased to 84.5%, whilst the specificity was maintained (92.3%). In severely asthmatic children, however, the sensitivity decreased to 53.5%, whilst the specificity increased 97.2%. The latter could be explained as a consequence of the previous exposure of this group of children to either inhaled or oral corticoids. According to our experience, the Methacholine Test is not only useful for the diagnosis of bronchial hyperreactivity in dubious cases, but also for contributing together with the clinical findings to the adequate classification of these patients.

Ten-year follow-up in pediatric patients with allergic bronchial asthma: evaluation of specific immunotherapy.

Specific immunotherapy as a treatment for bronchial asthma has been a controversial field. A collaborative study was designed in an attempt to further define the possible contribution of specific immunotherapy in a pediatric population. One hundred and sixty-six patients were treated with immunotherapy and 248 received no immunotherapy. The results were compared during 10 years of follow-up in both groups. There was a significant decrease in the number of acute crisis in the treated group (p < 0.05). However, no differences were seen in the number of hospital admissions or in the quality of life between the treated and untreated groups. The treated group required significantly fewer drugs (p < 0.05). Thus, it is probable that the untreated group shows the same clinical indexes as the treated group due to their increased use of medication. Specific immunotherapy represents an effective treatment that changes the natural course of allergic bronchial asthma in pediatric patients.

[Antiribosomal antibodies and the neurological manifestations in systemic lupus erythematosus]. / Anticuerpos antirribosómicos y manifestaciones neurológicas en el lupus eritematoso sistémico.

BACKGROUND: The possible positive correlation between the presence of antiribosomic antibodies and neurologic and neuropsychiatric manifestations in patients with systemic lupus erythematosus, cited in the literature, was analyzed. METHODS: Neurological involvement (current or previous) was evaluated in 71 successive patients. The anti-ENA antibodies (extractable nuclear antigens) were studied with special attention to the antiribosomic antibodies by: a) indirect immunofluorescence (IFI) on triple rat substrate, Hep2 and Crithidia luciliae; b) counter immunoelectrophoresis (CIE); c) double immunodiffusion (DI), and d) Western blot (WB) in the Molt-4 cell line. The statistical study was performed by the Fisher exact test. RESULTS: RibosomAL dyeing was observed in only 2 patients by IFI on triple rat substrate and HEp2. With CIE and DI, 14 patients (20%) were anti-ENA positive. Detectable bands were obtained with WB in 47 patients (66%) with 9 corresponding to antiribosomic antibodies. No statistical differences were found (p > 0.3) in relation with the presence of antirobosomic antibodies in particular and anti-ENA in general, between the groups with and without neurologic involvement. CONCLUSIONS: No relation was observed between antiribosomic antibodies and neurolupus by determinations of anti-ENA antibodies by Western blot (superior method--p < 0.0001--to direct immunofluorescence, counter immunoelectrophoresis and double immunodiffusion in the comparative study of sensitivity.

[Biodegradability in soil of residual hydrocarbons in petroleum tank bottoms]. / Biodegradabilidad en suelo de hidrocarburos residuales en fondos de tanques de almacenamiento de petróleo.

Biodegradability of hydrocarbons on soils can be applied to the treatment of residues (land treatment) from petroleum refinery as well as the cleaning of contaminated soils (bioremediation). In this paper we have studied the biodegradability of hydrocarbons from petroleum tank bottom sludges on soil by the autochthonous microbial community. Lab assays were conducted in 1l-beakers under the following conditions: hydrocarbon load 5.3%, total aerobic microorganisms 2.7 x 10(7) CFU/g, hydrocarbon degrading microorganisms (HDM) 2.5 x 10(5) cells/g, incubation temperature 25 degrees C, pH 7.0-7.6, and moisture 10-15%. Soil had the following composition: sand 25%, silt 15%, and clay 20%. Different levels and kind of fertilizers were evaluated. Fertilization increased the rate and the quantity of hydrocarbons degraded. It was degraded about 40% of hydrocarbons in 30-90 days according to the fertilization effected. During biodegradation, the HDM increased 760 times. Assays conducted outdoor on trays showed a similar limit of biodegradation. Changes with time in the fungi population, hydrocarbon class, carbon level, and saturated hydrocarbon profiles were measured too. Data suggests the use of microorganisms having a greater metabolic capacity, specially to degrade those hydrocarbon classes that they have shown to be more resistant to biodegradation (aromatics, resins and asphaltenes).

Occurrence of heterotrophic bacteria and fungi in an aviation fuel handling system and its relationship with fuel fouling.

Clean, dry and contaminant-free fuel is necessary for safe and economical aircraft operation. Microbial growth in aviation fuel handling systems can alter the quality of the product. This paper reports the occurrence of heterotrophic bacteria and fungi in a handling system of jet A-1 aviation turbine fuel. A total of 350 samples were collected during 1990-1996. The aerobic microorganisms in fuel samples were mainly fungi, 85% of samples containing < or = 100 cfu/l (range 0 (< 1 cfu/l) to 2000 cfu/l). The predominant fungi were Cladosporium and Aspergillus. Water was observed mainly in samples extracted from the drainage pipes of two tanks used frequently as intermediate storage tanks. The aerobic heterotrophic microorganisms found in water samples were mostly bacteria, counts varying from 100 to 8.8 x 10(7) cfu/ml, with 85% of samples containing 10(4)-10(7) cfu/ml. There was a preponderance of Pseudomonas spp. Bacterial contaminants belonging to the genus Flavobacterium and Aeromonas were also identified. Sulphate reducing bacteria were detected in 80% of water samples. It was not possible to assign a maximum microbial contamination level above which maintenance is required and it is suggested that analysis of successive samples from the same site are necessary for this purpose. Microbial sludges produced in the laboratory and collected from a contaminated tank bottom were analysed chemically. The data are presented and discussed. Samples collected from the supply pipes of tanks and refueller trucks during the period surveyed always met the standard specifications.

[Usefulness of brain stem auditory evoked potentials]. / Utilidad de potenciales evocados auditivos del tronco cerebral.

The neonates, children under 4 years and patients with central nervous system pathology are a population that need a screening test to estimate the hearing threshold. ABR-test (auditory brainstem response) is a viable and effective tool for identification a hearing impairment.

Prognostic factors for amputation in severe burn patients.

INTRODUCTION: Amputation is a rare procedure among burned patients. However, it has significant physical and psychological consequences which impact quality of life. OBJECTIVE: To study the incidence, etiology and prognostic factors associated with amputation among burned patients in Chile. METHODS: Cohort study of patients admitted to the Reference Burn Center of Chile from 2006 to 2011. Association of demographic, event and injury variables with the likelihood of amputation were evaluated by using multivariable analysis. RESULTS: Amputation incidence was 5.8% in 1090 admitted patients. Male amputee patients were significantly more frequent (p=0.01), with more electrical and high voltage burns (p<0.01) and had greater frequency of impaired consciousness (p=0.03). Multivariable analysis identified electrical burns (OR 13.7; 95% CI 6.7-28.1) and impaired consciousness (OR 2.8; 95% CI 1.4-5.7) as prognostic factors for amputation. CONCLUSION: Amputation is a low incidence procedure among burned patients. Patients who underwent amputations are frequently at working age. Patients with high-voltage electrical burns and impaired consciousness are more likely to undergo amputation. Since these are highly incapacitating injuries, it is very important to implement preventive measures.

Ethanol production from eucalyptus wood hemicellulose hydrolysate by Pichia stipitis.

Ethanol production was evaluated from eucalyptus wood hemicellulose acid hydrolysate using Pichia stipitis NRRL Y-7124. An initial lag phase characterized by flocculation and viability loss of the yeast inoculated was observed. Subsequently, cell regrowth occurred with sequential consumption of sugars and production of ethanol. Polyol formation was detected. Acetic acid present in the hydrolysate was an important inhibitor of the fermentation, reducing the rate and the yield. Its toxic effect was due essentially to its undissociated form. The fermentation was more effective at an oxygen transfer rate between 1.2 and 2.4 mmol/L h and an initial pH of 6.5. The hydrolysate used in the experiences had the following composition (expressed in grams per liter): xylose 30, arabinose 2.8, glucose 1.5, galactose 3.7, mannose 1.0, cellobiose 0.5, acetic acid 10, glucuronic acid 1.5, and galacturonic acid 1.0. The best values obtained were maximum ethanol concentration 12.6 g/L, fermentation time 75 h, fermentable sugar consumption 99% ethanol yield 0.35 g/g sugars consumed, and volumetric ethanol productivity 4 g/L day. (

Coupled saccharification and fermentation of pre-treated Eucalyptus wood: a simple kinetic model.

Coupled saccharification and fermentation of Eucalyptus globulus wood, pre-treated by acid hydrolysis and sodium hypochlorite, was carried out in two column reactors: one for enzymatic hydrolysis of the substrate at 50°C and the other for fermentation of sugars with calcium alginate-immobilized Saccharomyces cerevisiae at 30°C. A buffered solution containing cellulases at pH 4.8 was recycled through both reactors. The maximum yields were about 0.26 g ethanol per g of substrate. The results were reproduced reasonably well using a simple kinetic model consisting of two successive pseudo-first-order reactions.

[Prevalence of asthma in Chilean students. Descriptive study of 24,470 children. ISAAC-Chile]. / Prevalencia del asma en escolares chilenos. Estudio descriptivo de 24.470 niños. ISAAC-Chile.

BACKGROUND: There is little information about the prevalence of asthma in Latin American children. AIM: To determine the prevalence of asthma among Chilean school age children. SUBJECTS AND METHODS: The prevalence of respiratory symptoms related to asthma in schoolchildren aged 7 and 13 years, coming from South Santiago, Central Santiago, Valdivia and Punta Arenas, was determined using the methodology of the International Study on Asthma and Allergies in Childhood (ISMC). A random sample of school children aged 6-7 and 13-14 years from each locality was selected. This resulted in 24)470 surveyed children (11,723 aged 6-7 years and 12,747 aged 13-14 years). RESULTS: The current prevalence of wheezing ("wheezing in the last 12 months") ranged from 16.5% to 20.0% in children aged 67 years, and from 6.8% to 11.7% in children aged 13-14 years. The cumulative prevalence of asthma ("asthma ever"), ranged from 9.7% and 16.5% in the 6-7 years group and from 7.3% to 12.4% in those aged 13-14 years. CONCLUSIONS: This study found much higher figures for prevalence of respiratory symptoms related to asthma in school children than those previously reported in this country, with a significant variability between centers (p < 0.05). The prevalence of asthma in Chilean schoolchildren is as high and variable as that reported in industrialized countries.

[Hodgkin's disease in children. Modified COPP combined treatment and radiotherapy in advanced stages]. / Enfermedad de Hodgkin en el niño. Tratamiento combinado COPP modificado y radioterapia en estadios avanzados.

Twenty two children, under 15 years of age, from southern Chile's Tenth Region, with advanced stages of Hodgkin's disease (8 III-A, 6 III-B and 8 IV-B) were treated with chemotherapy (modified COPP protocol) and radiotherapy between 1976 and 1985 at Valdivia's Regional Hospital. Overall survival rate was 77.3% and disease-free survival rate was 64.5% after a follow-up period from 3 to 13 years (median 70 months). Five patients died during the first two years. One relapsed 10 years after beginning of therapy, but achieved a second complete remission. The survival rate in patients with lymphocytic depletion type (5 cases) was 20.0%, whereas that of the mixed cellularity type (14 cases) was 92.9% (p less than 0.01). No cases of second neoplasms related to chemotherapy and radiotherapy were seen in this series.

Enfermedad celíaca del adulto: hallazgos endoscópicos en pacientes con atrofia de mucosa duodenal histológica: comparación inter-observadores y correlación con histología / Celiac disease in the adult: endoscopic findings in patients with histological atrophy in duodenal mucosa: interobserver comparison and correlation with histology

Celiac disease diagnosis (CD) is based on clinical, serological and histological studies. Endoscopy is of great help in clinically suspicious celiac disease patients showing digestive symptoms related to this exam. Objective: To describe endosopic lesions in 70 videos of celiac disease patients, to analyze concordance among endoscopists and correlate with histology. Materials and methods: Seventy videos are edited, corresponding to 20 Marsh III A patients; 25 Marsh III B; and 25 Marsh III C. Five endoscopists reviewed the duodenal bulb and the second portion, checking for markers such as reduction in the number of duodenal folds; scalloping of folds; mucosal fissures or cracks; Mosaic pattern to the mucosa; Nodes and Vascular Augmentation. The presence of a lesion was assigned 1 point; 0 points in case of no lesion. Results: Videos correspond to 57 women (81.4 percent) and 13 men; 90 percent between 21-60 years old. Lesions were observed in the bulb in 55 (78.5 percent) cases (78.2 percent nodes; 9 percent vascular augmentation and 12.7 percent nodes and vascular augmentation). In the second portion, 100 percent presented a lesion: scalloping of folds (60 percent); reduction in the number of folds (58.5 percent); mucosal fissures or cracks (45.7 percent); Nodes (31.4 percent); Mosaic pattern (12.8 percent) and vascular augmentation (11.4 percent). Two or more lesions were detected en 53 cases (75 percent). Concordance among endoscopists was 72.1 percent. Average score assigned by the endoscopists to Marsh III A was 9.05; 11.2 to Marsh III B, and 13.6 to Marsh III C; p < 0,001 between III A and III C; non-significant between III A and B, and III B and III C. Conclusions: All patients present a type of lesion of the second portion and 78 percent also in the bulb. The most frequently occurring are scalloping of folds and reduction in the number of folds; most of the cases present two or more markers...

El diagnóstico de la enfermedad celíaca (EC) se basa en la clínica, la serología e histología. Se considera a la endoscopia de gran ayuda en la sospecha de EC, en pacientes con sintomatología digestiva derivados para este examen. Objetivo: Describir las lesiones endoscópicas en 70 videos de pacientes celíacos, analizar la concordancia entre endoscopistas, y correlacionar con la histología. Material y Método: Se editan 70 videos correspondiente a 20 pacientes Marsh III A; 25 casos Marsh III B; y 25 casos Marsh III C. Cinco endoscopistas revisaron el bulbo duodenal y la segunda porción, evaluando la presencia de marcadores como disminución de pliegues (DP); Festoneado (F); Surcos (S); Mosaico (M); Nódulos (N) y Aumento de vasculatura (AV). A la presencia de una lesión se le asignó 1 punto y la ausencia 0 puntos. Resultados: Los videos corresponden a 57 mujeres (81,4 por ciento) y 13 hombres; el 90 por ciento tiene 21 a 60 años. En el bulbo se observaron lesiones en 55 (78,5 por ciento) casos (78,2 por ciento nódulos; 9 por ciento AV y 12,7 por ciento N+AV). En la segunda porción, el 100 por ciento presentaba alguna lesión: F en 60 por ciento; DP (58,5 por ciento), S (45,7 por ciento); N (31,4 por ciento); M (12,8 por ciento) y AV (11,4 por ciento). Se detectaron dos o más lesiones en 53 casos (75 por ciento). La concordancia entre endoscopistas fue de 72,1 por ciento. El puntaje promedio asignado por los endoscopistas a los Marsh III A fue de 9,05; 11,2 a los III B y 13,6 a los Marsh III C; p < 0,001 entre III A y III C, no significativo entre III A y B, y III B y III C. Conclusiones: Todos los pacientes presentan algún tipo de lesión de la segunda porción y 78 por ciento además en el bulbo. Las más frecuentes son el festoneado y la disminución de pliegues, y la mayoría de los casos presentan más de dos marcadores. Mientras más daño histológico de la mucosa, se observó un mayor número de lesiones...