Role of RFRP-3 in the development of cold stress-induced polycystic ovary phenotype in rats

RFamide-related peptide (RFRP-3) is a regulator of GnRH secretion from the brain, but it can also act in human ovary to influence steroidogenesis. We aimed to study the putative local role of RFRP-3 in the ovary and its potential participation in the development of a polycystic ovary phenotype induced by chronic sympathetic stress (cold stress). We used adult Sprague­Dawley rats divided into control and stressed groups. In both groups, we studied the effect of intraovarian exposure to RFRP-3 on follicular development and plasma ovarian steroid concentrations. We also tested the effect of RFRP-3 on ovarian steroid production in vitro. Chronic in vivo intraovarian exposure to RFRP-3 decreased basal testosterone concentrations and cold stress-induced progesterone production by the ovary. In vitro, RFRP-3 decreased hCG-induced ovarian progesterone and testosterone secretion. Immunohistochemistry and mRNA expression analysis showed a decrease in Rfrp and expression of its receptor in the ovary of stressed rats, a result which is in line with the increased testosterone levels found in stressed rats. In vivo application of RFRP-3 recovered the low levels of secondary and healthy antral follicles found in stressed rats. Taken together, our data indicate a previously unknown response of hypothalamic and ovarian RFRP-3 to chronic cold stress, influencing ovarian steroidogenesis and follicular dynamics. Thus, it is likely that RFRP-3 modulation in the ovary is a key component of development of the polycystic ovary phenotype.

Single-laboratory validation of an LC-MS/MS method for determining florfenicol (FF) and florfenicol amine (FFA) residues in chicken feathers and application to a residue-depletion study.

A suitable analytical method is required to study the behaviour of florfenicol (FF) and its metabolite florfenicol amine (FFA) in broiler's feathers. An LC-MS/MS method was developed, assessed and intra-laboratory-validated for FF and FFA analyses. We chose cloramphenicol-d5 as an internal standard, acetone as a solvent for the extraction of the analytes and dichloromethane for the clean-up. Through LC-MS/MS analysis, we established a detection limit of 20 µg kg-1, as well as calculated quantification limits of 24.4 and 24.5 µg kg-1 for FF and FFA, respectively. Validation parameters such as linearity, recovery and precision were calculated following Commission Decision 2002/657/EC. For linearity, all standard curves showed a standard coefficient greater than 0.99. Recoveries ranged from 99% to 102% for all studied concentrations. The results show that this analytical method is precise and reliable. For the depletion study, 64 Ross 308 broilers were treated with a therapeutic dosage of 10% FF during 5 consecutive days and their feathers were then analysed. Samples were drawn on days 5, 10, 15, 20, 25, 30, 35 and 40 post-treatments. As for the control group, 16 broiler chickens were raised under the same regime. Throughout the whole study, the detected concentrations of FF and FFA in feather samples were above 100 µg kg-1. In fact, even on day 30 post-treatment we detected concentrations of 221.8 and 28.8 µg kg-1 for FF and FFA, respectively. Based on these results, we conclude that these analytes will persist for a long time and will deplete slowly in feathers of treated broiler chickens.

Neonatal exposure to estradiol valerate increases dopamine content in nigrostriatal pathway during adulthood in the rat.

Research in programming has focused in the study of stimuli that affect sensitive periods of development such as prenatal and neonatal stage. We previously showed that exposure to estradiol valerate to female rats during the first 12 h of life increased catecholamine content in ventromedial-arcuatus hypothalamus of the adult rat. However, changes in others dopaminergic circuits have not been studied. The purpose of this work was to determine the neurotransmitters changes induced by neonatal estradiol valerate (0.1 mg/50 µl s. c. per rat) administration on nigrostriatal pathway of adult female rats. Sesame oil (50 µl s. c. per rat) was administered in a control parallel group. EV-1 adult rats presented effective markers of long-term estrogenization as decreased serum levels of progesterone and a reduction in the size of estrogen-sensitive organs. In the brain, neonatal estradiol valerate administration led to a significant increase in dopamine content in striatum, substantia nigra and ventral tegmental area. With respect to the contents of dopamine metabolites, only 3-methoxytyramine content increased in substantia nigra and ventral tegmental area. In addition, the content of noradrenaline increased only in striatum. Interestingly, estrogenized rats lacked locomotor activity induced by acute dose of amphetamine (1 mg/kg i. p.). Altogether, these results show that neonatal exposure to estradiol valerate permanently modified the content of monoamine neurotransmitters in nigrostriatal pathway and amphetamine-induced locomotor activity of adult female rats. This might imply that estrogenized rats could have changes in the expression of key proteins in dopaminergic regulation, as tyrosine hydroxylase and dopamine transporter.

Intoxicación familiar por mercurio elemental: caso clínico / Family poisoned by elemental mercury: a case report

Introduction: mercury is a heavy metal widely dispersed in nature, occurring in three chemical forms. Exposure to mercury at work sites and even at home may be clinically significant. Objective: to update the knowledge about the risks of this toxic element. Case report: the case of a teenager and his family poisoned by elemental mercury is reported. The diagnostic process was difficult, mainly due to an initial presumption of probable infectious etiology, unavailability of key anamnestic data and unusual clinical behavior, with signs and symptoms of multisystem compromise (neurological, hepatic, renal and dermatological compromise). Discussion: the study was based on literature review of various clinical presentations regarding this poisoning and its management, emphasizing the need for dimercaptosuccinic acid chelator. As a major public health problem, the importance of education and implementation of public policies to have a mercury-free environment is discussed.

Introducción: el mercurio es un metal pesado ampliamente distribuido en el medio ambiente, en sus tres formas químicas. La exposición a dicho metal en recintos laborales e incluso en el hogar, puede llegar a ser clínicamente significativa. Objetivo: actualizar el conocimiento acerca de los riesgos de este tóxico. Caso clínico: se presenta el caso clínico de un adolescente y su familia intoxicados por mercurio elemental, cuyo proceso diagnóstico fue difícil, principalmente por la presunción inicial de una probable etiología infecciosa, falta de disponibilidad de datos anamnésticos claves y el inusual comportamiento clínico, con signos y síntomas de compromiso multisistémico (neurológico, hepático, renal y dermatológico). Discusión: se revisa la literatura en relación a las diversas formas de presentación clínica de esta intoxicación y su manejo, destacando la utilidad del quelante ácido dimercaptosuccínico. Por ser un importante problema de salud pública, se destaca la trascendencia de la educación e implementación de políticas públicas por un ambiente libre de mercurio.

Eryptosis and oxidative damage in type 2 diabetic mellitus patients with chronic kidney disease.

It has been suggested that oxidative stress may participate in the progression of diabetes and its complications. Long-term complications of type 2 diabetes mellitus (T2DM) include retinopathy, atherosclerosis, shortened life span of erythrocytes, nephropathy, and chronic kidney disease (CKD). Oxidative damage has been associated with erythrocyte apoptosis induction in other pathological conditions. Our aim was to study the presence of eryptosis and its possible relationship with oxidative damage in patients with T2DM without CKD (T2DM/CKD(-)) and in patients with T2DM and CKD (T2DM/CKD(+)).Oxidative damage of lipids erythrocytes were increased in diabetic patients. The highest lipoperoxidation was found in T2DM/CKD(+). Likewise, the lower plasma total antioxidant capacity, GSH/GSSG ratio, and GSH in erythrocytes were found in T2DM/CKD(+) patients. A negative correlation was found between plasma total antioxidant capacity and oxidative damage. Phosphatidylserine (PS) externalization was measured in erythrocytes to evaluate eryptosis. Annexin binding in erythrocytes of T2DM/CKD(+) patients was higher than in healthy subjects and T2DM/CKD(-) patients. A positive correlation between lipoperoxidation and PS externalization in erythrocytes was found. This work showed that the erythrocytes of diabetic patients have increased oxidative damage, a reduction of antioxidant systems and more erythrocyte PS externalization. The duration of diabetes and the presence of CKD increase both oxidative damage and eryptosis. It is possible that a longer time of evolution induces an increase in erythrocyte oxidative damage and the consumption of blood antioxidant systems, adding to the osmotic stress in CKD and so contributes to an increase in PS externalization in diabetic patients.

Predicting mortality in hospitalized patients with 2009 H1N1 influenza pneumonia.

BACKGROUND: Community-acquired pneumonia (CAP) severity scores can identify patients at low risk for mortality who may be suitable for ambulatory care. Here, we follow the clinical course of hospitalized patients with CAP due to 2009 H1N1 influenza. OBJECTIVE: To evaluate the role of CAP severity scores as predictors of mortality. METHODS: This was a secondary data analysis of patients hospitalized with CAP due to 2009 H1N1 influenza confirmed by reverse transcriptase polymerase chain reaction enrolled in the CAPO (Community-Acquired Pneumonia Organization) international cohort study. CAP severity scores PSI (Pneumonia Severity Index), CURB-65 (confusion, urea, respiratory rate, blood pressure, age ≥ 65 years) and CRB-65 (confusion, respiratory rate, blood pressure, age ≥ 65 years) were calculated. Actual and predicted mortality rates were compared. A total of 37 predictor variables were evaluated to define those associated with mortality. RESULTS: Data from 250 patients with CAP due to 2009 H1N1 influenza were analyzed. Patients with low predicted mortality rates (0-1.5%) had actual mortality rates ranging from 2.6% to 17.5%. Obesity and wheezing were the only novel variables associated with mortality. CONCLUSIONS: The decision to hospitalize a patient with CAP due to 2009 H1N1 influenza should not be based on current CAP severity scores, as they underestimate mortality rates in a significant number of patients. Patients with obesity or wheezing should be considered at an increased risk for mortality.

Fetal and postnatal pulmonary circulation in the Alto Andino.

Lowland mammals at high altitude constrict the pulmonary vessels, augmenting vascular resistance and developing pulmonary arterial hypertension. In contrast, highland mammals, like the llama, do not present pulmonary arterial hypertension. Using wire myography, we studied the sensitivity to norepinephrine (NE) and NO of small pulmonary arteries of fetal llamas and sheep at high altitudes. The sensitivity of the contractile responses to NE was decreased whereas the relaxation sensitivity to NO was augmented in the llama fetus compared to the sheep fetus. Altogether these data show that the fetal llama has a lower sensitivity to a vasoconstrictor (NE) and a higher sensitivity to a vasodilator (NO), than the fetal sheep, consistent with a lower pulmonary arterial pressure found in the neonatal llama in the Andean altiplano. Additionally, we investigated carbon monoxide (CO) in the pulmonary circulation in lowland and highland newborn sheep and llamas. Pulmonary arterial pressure was augmented in neonatal sheep but not in llamas. These sheep had reduced soluble guanylate cyclase and heme oxygenase expression and CO production than at lowland. In contrast, neonatal llamas increased markedly pulmonary CO production and HO expression at high altitude. Thus, enhanced pulmonary CO protects against pulmonary hypertension in the highland neonate. Further, we compared pulmonary vascular responses to acute hypoxia in the adult llama versus the adult sheep. The rise in pulmonary arterial pressure was more marked in the sheep than in the llama. The llama pulmonary dilator strategy may provide insights into new treatments for pulmonary arterial hypertension of the neonate and adult.

Influenza pneumonia: a comparison between seasonal influenza virus and the H1N1 pandemic.

We compared clinical presentation, complications and outcome in patients with influenza A (H1N1) and seasonal influenza pneumonia. The group of patients with influenza A (H1N1) pneumonia consisted of 75 patients. 52 patients with pneumonia associated with seasonal influenza were included for comparison. Patients with pneumonia associated with novel H1N1 influenza were younger (mean age 39.7 yrs versus 69.6 yrs) and had fewer chronic comorbidities and less alcoholism. Infiltrates were more extensive and frequently interstitial. Respiratory failure was more frequent (those with an arterial oxygen tension/inspiratory oxygen fraction ratio <200 28% versus 12%, p = 0.042), leading to a higher rate of intensive care unit (ICU) admission and mechanical ventilation (29.3% versus 7.7% (p<0.0030) and 18.7% versus 2% (p<0.0045)). Mortality was twice as high in patients with novel H1N1 (12% versus 5.8%; p = 0.238), although this was not significant, and was attributable to pneumonia in most instances (77.8% versus 0%; p = 0.046). Younger age, fewer comorbidities, more extensive radiographic extension and more severe respiratory compromise, and ICU admissions are key features of the clinical presentation of patients with novel H1N1-associated pneumonia compared with seasonal influenza pneumonia.

Characteristics of hospitalised patients with 2009 H1N1 influenza in Chile.

As the pandemic of 2009 H1N1 influenza A virus progressed, more patients required hospitalisation. The objective of this study is to describe the characteristics and clinical course of hospitalised patients with 2009 H1N1 virus infection in Chile. This was a prospective, observational study of 100 consecutive hospitalised patients with RT-PCR-confirmed 2009 H1N1 influenza A, admitted to Puerto Montt General Hospital (Puerto Montt, Chile). Information was obtained regarding contact history, demographics, laboratory values and clinical course. The primary reason for hospitalisation was pneumonia, in 75% of patients. Rapid influenza A test was positive in 51% of patients. Prior exposure to 2009 H1N1 virus was documented in 21% of patients. Clinical failure, documented in 18% of cases, was characterised by respiratory failure and acute respiratory distress syndrome. Failure was more common in patients with obesity, tachypnoea, confusion and multilobar infiltrates. When evaluating a patient hospitalised with influenza-like illness, a negative rapid test for influenza A or negative contact with a suspected case should not alter physicians' considerations regarding the likelihood of 2009 H1N1 virus infection. Patients with 2009 H1N1 virus infection with obesity, tachypnoea, confusion and multilobar infiltrates should be closely monitored since they are at high risk for clinical failure.

Behavioral phenotype of maLPA1-null mice: increased anxiety-like behavior and spatial memory deficits.

Lysophosphatidic acid (LPA) has emerged as a new regulatory molecule in the brain. Recently, some studies have shown a role for this molecule and its LPA(1) receptor in the regulation of plasticity and neurogenesis in the adult brain. However, no systematic studies have been conducted to investigate whether the LPA(1) receptor is involved in behavior. In this study, we studied the phenotype of maLPA(1)-null mice, which bear a targeted deletion at the lpa(1) locus, in a battery of tests examining neurologic performance, habituation in exploratory behavior in response to low and mild anxiety environments and spatial memory. MaLPA(1)-null mutants showed deficits in both olfaction and somesthesis, but not in retinal or auditory functions. Sensorimotor co-ordination was impaired only in the equilibrium and grasping reflexes. The mice also showed impairments in neuromuscular strength and analgesic response. No additional differences were observed in the rest of the tests used to study sensoriomotor orientation, limb reflexes and co-ordinated limb use. At behavioral level, maLPA(1)-null mice showed an impaired exploration in the open field and increased anxiety-like response when exposed to the elevated plus maze. Furthermore, the mice exhibit impaired spatial memory retention and reduced use of spatial strategies in the Morris water maze. We propose that the LPA(1) receptor may play a major role in both spatial memory and response to anxiety-like conditions.

A leptin serum concentration less than 10 ng/ml is a predictive marker of outcome in patients with moderate to severe secondary peritonitis.

INTRODUCTION: Leptin is involved in the sepsis syndrome. A possible relationship exists between low leptin levels and peritonitis severity and a poorer prognosis. OBJECTIVES: We aimed to corroborate the relationship between low leptin serum levels and death in patients with peritonitis and to explore the associations between leptin and interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-13 (IL-13), tumor necrosis factor-alpha (TNF-alpha) and C-reactive protein (CRP). METHODS: In 230 adult patients with surgically confirmed secondary peritonitis, the Mannheim Peritonitis Index and the serum concentrations of leptin, IL-6, IL-10, IL-13, TNF-alpha and CRP were determined. Two cohorts were established (leptin < or = 10 ng/ml and > 10 ng/ml). Death or survival was followed through 30 days. The relationship between leptin (< or = 10 ng/ml) and death was evaluated using the accumulated incidence ratio (AIR). The association of leptin (dependent variable) with IL-6, IL-10, IL-13, TNF-alpha and CRP (independent variables) was studied by regression analysis. RESULTS: The general mortality rate was 7.8% and the death AIR was 3.15 (p nonsignificant). A subsample of patients with a Mannheim Peritonitis Index > or = 21 was studied, showing a significant AIR of 4.26 (p = 0.017). Regression analysis determined an association only between leptin and IL-6 (p < 0.001), IL-10 (p < 0.047) and CRP (p < 0.001). DISCUSSION: A serum leptin below the threshold of 10 ng/ml is an adverse prognostic marker in patients with moderate to severe secondary peritonitis. The results of the regression analysis suggest that the mechanisms involved are opposing, in that leptin associated with IL-6 has a proinflammatory effect and, through IL-10 and CRP production, restrains the inflammatory response.

Comportamiento clínico y costos de la gastroenteritis por rotavirus en lactantes: adquisición comunitaria versus nosocomial / Clinical features and costs of rotavirus gastroenteritis in infants: community versus nosocomialy acquired infection

Este estudio observacional prospectivo describe elementos clínicos y costos directos de lactantes hospitalizados (julio 2003 a junio 2004), con diarrea confirmada por rotavirus de adquisición comunitaria (G-1, n = 78) y otros de adquisición nosocomial (G-2, n = 52). Se les aplicó una escala de gravedad de gastroenteritis, según Rennels 1996, de 0 a 17 puntos y asignó costos directos según arancel FONASA. Un 26,9 % de pacientes del G-1 tuvo puntaje > a 14 v/s 9,6 % del G-2 (p < 0,015). Así también los lactantes del G-1 presentaron menor nivel de bicarbonato plasmático (p < 0,001) y mayor frecuencia de shock o requerimiento de expansión de volumen (p < 0,023). El costo promedio total fue de $143.805 (US 277) para un caso de rotavirosis adquirida en la comunidad y $139.423 (US 268) para la de origen nosocomial. Hubo un gasto de $ 7.250.010 (US 13.900) en esta infección nosocomial, lo que amerita la implementación de un programa activo de prevención y control.

[Clinical features and costs of rotavirus gastroenteritis in infants: community versus nosocomialy acquired infection]. / Comportamiento clínico y costos de la gastroenteritis por rotavirus en lactantes: Adquisición comunitaria versus nosocomial.

This is a prospective 12 month (July 2003-June 2004) cohort study in one large tertiary hospital of Santiago, Chile aimed to describe clinic features and calculate the direct costs of hospitalization associated to community-acquired (n = 78) and nosocomially-acquired (n = 52) rotavirus infection. A gastroenteritis severity score after Rennels 1996, (0 to 17 points) was applied and costs where calculated based on those assigned by the Chilean National Funds for Health (FONASA). Severe gastroenteritis manifested by a score > 14 occurred in 26.9% and 9.6% of community and nosocomially-acquired cases respectively (p < 0.015). The former had lower bicarbonate levels (p < 0.001), and required more volume expansion compared to the latter (p < 0.023). The average cost was US 277 per case for community acquired rotavirus and US 268 for nosocomial infection. In this hospital the cost of nosocomial rotavirus infection was approximately 13,900 US dollars for a 12 month period. These results should stimulate the implementation of active prevention and control programs.

Sensorineural hearing loss in insulin-like growth factor I-null mice: a new model of human deafness.

It has been reported that mutations in the gene encoding human insulin-like growth factor-I (IGF-I) cause syndromic hearing loss. To study the precise role of IGF-I in auditory function and to hypothesize the possible morphological and electrophysiological changes that may occur in the human inner ear, we have analysed the auditory brainstem response in a mouse model of IGF-I deficiency. We show here that homozygous Igf-1(-/-) mice present an all-frequency involved bilateral sensorineural hearing loss. Igf-1(-/-) mice also present a delayed response to acoustic stimuli; this increases along the auditory pathway, indicating a contribution of the central nervous system to the hearing loss in Igf-1(-/-) mice. These results support the use of the Igf-1(-/-) mouse as a new model for the study of human syndromic deafness.

TeenSTAR: una opción de madurez y libertad. Programa de educación integral de la sexualidad, orientado a adolescentes / Effects of Teenstar, an abstinence only sexual education program, on adolescent sexual behavior

Background: Urgent measures are required to stop the increase in the frequency of pregnancies and sexually transmitted diseases among teenagers. A means of facing this problem is promoting sexual abstinence among youngsters. There are studies that confirm the efficacy of this approach. Aim: To show the results of the application of a holistic sexuality program (TeenSTAR) among Chilean teenagers. Subjects and Methods: Students attending basic or high school were divided into a control or study group. The control group (342 students) received the usual education on sexuality given by their schools and the study group (398 students) participated in twelve TeenSTAR sessions lasting 1.5 hours each, given by a trained professor. Assessment of achievements was made using an anonymous questionnaire answered at the start and end of the program. Results: The rates of sexual initiation among control and study groups were 15 and 6.5%, respectively. Among sexually active students, 20% of those in the study group and 9% of those in the control group discontinued sexual activity. Conclusions: A higher proportion of students in the TeenSTAR program retarded their sexual initiation or discontinued sexual activity and found more reasons to maintain sexual abstinence than control students.

Susceptibility and exposure biomarkers in people exposed to PAHs from diesel exhaust.

Xenobiotic metabolizing enzymes, especially CYP1A1 and GSTM1, are involved in the activation and conjugation of PAHs and are controlled by polymorphic genes. PAHs released from diesel emissions in many cities of the world, especially in developing countries, contribute significantly to the toxic effects of airborne inhalable particles. We have evaluated the gene-environment interaction in Santiago of Chile, studying the contribution of CYP1A1 and GSTM1 polymorphisms on 1-OH-P urinary levels used as the PAHs exposure biomarker. The study was performed on 59 diesel exposed (38 diesel revision workers and 21 subjects working in an urban area as established street vendors) and 44 non-exposed subjects living in a rural area. The 1-OH-P urinary levels of the urban (P=0.043) and rural (P=0.040) populations showed, without considering the genotypes, significant differences between smokers and non-smokers, but no significant differences were found between smokers and non-smokers among the diesel plant workers (P=0.33). Non-smoking subjects of the diesel plants and the urban area showed similar 1-OHP levels (P=0.466) which were significantly higher than those of the subjects living in the rural area (P<0.05). When 1-OH-P levels were related with genotypes, an association was observed for the CYP1A1*2A genotype, so that the diesel-exposed workers carrying the CYP1A1*2A allele showed significantly higher 1-OH-P levels than the subjects from the rural area with the same genotype (P=0.008). On the other hand, there was no significant correlation between urinary 1-OH-P levels and GSTM1 null genotype, although higher levels of the urinary metabolite were found in individuals carrying the combined CYP1A1*2A and GSTM1 null genotype (P=0.055). These results may suggest an association between levels of the exposure biomarker 1-OH-P and presence of the CYP1A1*2A genotype, a potential genetic susceptibility biomarker which might be useful in identifying individuals at higher risk among people exposed to high PAH levels in diesel exhaust.

Prevalence of sexual dysfunction in a cohort of middle-aged women: influences of menopause and hormone replacement therapy.

In order to determine the prevalence of sexual dysfunction (SD) and related risk factors in a cohort of middle-aged women the Laumann's test (DSM-IV) was passed to 534 healthy women between 40 and 64 years old (mean: 52.4+/-5.7) attending the Southern Metropolitan Health Service in Santiago de Chile. Of all the women, 82.8% were peri- or postmenopausal, 23% had received hormone replacement therapy (HRT) and 79.2% were sexually active. Among those who were sexually active a total of 51.3% presented SD. The prevalence of SD increased with age (from 22.2% in the 40-44-year age group to 66% in the 60-64-year age group). HRT users and healthy women presented a lower risk of SD (OR: 0.1 CI: 0.0-0.1 and OR: 0.6 CI: 0.3-0.9, respectively). The risk increased after the menopause (OR: 3.3 CI: 1.6-6.9) and with age older than 49 years (OR: 3.4 CI: 1.8-6.4), hysterectomy (OR: 3.7 CI: 1.3-10.6) and when male partners presented erectile dysfunction (OR: 3.2 CI: 1.2-8.6). In conclusion sexual dysfunction affects more than 51% of middle-aged women who are sexually active and increases with age. Ovarian function and HRT significantly influence sexual activity.

Effectiveness of rubber band ligation in haemorrhoids and factors related to relapse.

PURPOSE: to assess the effectiveness of ambulatory rubber band ligation (RBL) in the treatment of symptomatic internal haemorrhoids and to identify factors related to relapse. PATIENTS AND METHODS: prospective study of 232 patients treated with rubber band ligation for symptomatic haemorrhoids (grade I-III or grade IV with severe contraindication for surgery) from November 1996 to November 2000 at the outpatient clinic. Ligation was performed with a Stille AB (Comedic) ligator and suction pump, placing 1-3 bands per session and with up to three sessions per patient. Effectiveness of treatment was defined as the absence of symptoms and was confirmed by anoscopy by checking the residual scar after the cushions' detachment. Categorical variables were compared using the shi-squared test, whereas Student's t-test was used for continuous variables. Logistic regression was employed to identify clinical factors related to relapse. RESULTS: a total of 331 bands were placed during 235 sessions in the 163 patients who completed follow-up (70%). Mean age was 45.6 years, with males accounting for 64.4%. Most patients (86.5%) had grade II or grade III haemorrhoids. Overall morbidity was 6%. The most frequent complications were rectal tenesmus (11%), slight or mild anal pain (7.4%), dysuria (4.3%) and transient anal bleeding (3.7%). The treatment was effective in 86% of patients after a mean follow-up of 32 months. Efficacy was high for grades I and II (100% and 97.4% ) but decreased for grade III (69.8%; p<0.001) and grade IV (0%; p<0.001). Most relapses occurred within the first 24 months (87%) and were not significantly related to age, gender, duration of symptoms, itching, bleeding, pain, tenesmus or bowel habit, but were significantly related to the presence of prolapse and its grade (p<0.001), and to the involvement of left posterior, right lateral and anterior pedicles (p<0.05). CONCLUSIONS: ambulatory RBL is a safe and effective treatment for grade I, II and III symptomatic haemorrhoids, and is associated with low morbidity. Recurrence is uncommon and occurs mainly within the first 24 months, being related to the presence and grade of prolapse as well as to its location, but bears little relation to the rest of factors analysed.