RESUMO - RACIONAL: Disfunção do esfíncter esofágico inferior (EEI), doença do refluxo gastroesofágico e esofagite erosiva em pacientes submetidos à gastrectomia subtotal são ocorrências comumente reconhecidas, mas até agora as causas permanecem obscuras. OBJETIVO: A hipótese deste estudo é que a gastrectomia subtotal provoque alterações na pressão de repouso do EEI e na sua competência, devido ao dano anatômico desta, visto que as fibras oblíquas “Sling”, um dos componentes musculares do EEI, são seccionadas durante este procedimento cirúrgico. MÉTODOS: Sete cães adultos sem raça definida (18-30 kg) foram anestesiados e submetidos à transecção do estômago proximal. Em seguida, o remanescente gástrico proximal foi fechado por sutura. No intraoperatório, manometria lenta foi realizada em cada cão, em condições basais (com estômago intacto) e no remanescente gástrico proximal fechado. A média dessas medidas é apresentada, com cada cão servindo como seu próprio controle. RESULTADOS: A pressão média do EEI medida no remanescente gástrico proximal, em comparação com a pressão do EEI no estômago intacto, foi diminuída em cinco cães, aumentada em um cão e sem alterações no outro cão. CONCLUSÃO: A secção transversa superior do estômago e o fechamento do remanescente do estômago por sutura provocam alterações na pressão do EEI. Sugerimos que essas mudanças na pressão do EEI são secundárias à secção das fibras oblíquas “Sling” do esfíncter, um de seus componentes musculares. A sutura e o fechamento do remanescente gástrico proximal, reancora essas fibras com mais, menos ou a mesma tensão, modificando ou não a pressão do EEI.

ABSTRACT - BACKGROUND: Dysfunction of the lower esophageal sphincter (LES), gastroesophageal reflux disease, and erosive esophagitis in patients undergoing subtotal gastrectomy are commonly recognized occurrences, but until now the causes remain unclear. AIM: The hypothesis of this study is that subtotal gastrectomy provokes changes on the LES resting pressure and its competence, due to the anatomical damage of it, given that the oblique “Sling” fibers, one of the muscular components of the LES, are transected during this surgical procedure. METHODS: Seven adult mongrel dogs (18-30 kg) were anesthetized and admitted for transection of the proximal stomach. Later, the proximal gastric remnant was closed by a suture. Intraoperatively, slow pull-through LES manometries were performed on each dog, under basal conditions (with the intact stomach), and in the closed proximal gastric remnant. The mean of these measurements is presented, with each dog serving as its control. RESULTS: The mean LES pressure (LESP) measured in the proximal gastric remnant, compared with the LESP in the intact stomach, was decreased in five dogs, increased in one dog, and remained unchanged in other dogs. CONCLUSION: The upper transverse transection of the stomach and closing the stomach remnant by suture provoke changes in the LESP. We suggested that these changes in the LESP are secondary to transecting the oblique “Sling” fibers of the LES, one of its muscular components. The suture and closing of the proximal gastric remnant reanchor these fibers with more, less, or the same tension, whether or not modifying the LESP.

ABSTRACT Seagrasses are aquatic angiosperms that grow submerged in shallow marine and estuarine environments worldwide. Halodule wrightii is a circumtropically distributed seagrass species found primarily in the Atlantic Ocean, but also in parts of the Indian Ocean and eastern Pacific Ocean. Along the Pacific coast of Central America, large swaths of the reported distribution of H. wrightii are assumptions based on interpolation between known seagrass point locations, and despite confirmation of H. wrightii occurrence in Bahía de Jiquilisco in El Salvador, little is known about its distribution and associated species, which can hamper efforts to conserve this seagrass ecosystem. To address these gaps in data, we provide the first assessment of H. wrightii distribution and associated macroinvertebrate species in Bahía de Jiquilisco. We identified six areas where seagrasses occurred and two of these were selected for monitoring. At the two sampled areas, heterogeneous patches of H. wrightii covered 27.1 km2 with 22 associated macroinvertebrate species from three taxonomic groups in three phyla. We conclude by discussing local threats to H. wrightii, including implications for endangered hawksbill (Eretmochelys imbricata and green (Chelonia mydas agassizii) turtles that depend on these ecosystems, and describe opportunities for conservation in Bahía de Jiquilisco.

The studies related to dietary composition of anurans present in Chile are a field sparsely explored and allow to contribute with knowledge about the biology of the species. Alsodes coppingeri inhabits mountain streams in Nothofagus temperate forests, of Chilean Patagonia. These frogs have been found under logs in stream margins. In this study, 44 specimens of A. coppingeri from Laguna Caiquenes, Tortel and Villa O’Higgins (Aysen Region, Chile) were analyzed. The prey items were ranked at the ordinal level. The frequency of occurrence percentage and abundance of prey items and relative importance index (IRI) were estimated. The frequency of occurrence percentage was 70.5%, where the diet of A. coppingeri was mainly composed of arthropods. The most important preys were beetles, springtails, flies, spiders and isopods, with an obvious predominance of larval stages of beetles, flies and moths.

Los estudios relacionados con la composición dietaria de los anuros presentes en Chile son un campo escasamente explorado y que permiten aportar con conocimiento sobre la biología de las especies. Alsodes coppingeri habita los arroyos de montaña de los bosques templados de Nothofagus de la Patagonia chilena. Estos anuros han sido encontrados bajo troncos en los márgenes de arroyos. Para este estudio se analizaron 44 especímenes de A. coppingeri provenientes de Laguna Caiquenes, Caleta Tortel y Villa O’Higgins (Región de Aysén, Chile). Los ítems presa fueron clasificados a nivel ordinal y se estimó la frecuencia de ocurrencia, de abundancia e índice de importancia relativa (IRI). Se determinó un 70,5% de frecuencia de ocurrencia, donde la dieta de A. coppingeri estuvo compuesta principalmente de artrópodos. Las presas más frecuentes correspondieron a coleópteros, colémbolos, dípteros, arañas e isópodos, con un notorio predominio de estados larvales de coleópteros, dípteros y lepidópteros.

Background: Non cardiac chest pain can be caused by esophageal problems such as gastroesophageal reflux or smooth muscle motor disorders. Aim: To perform esophageal manometry in patients with non cardiac chest pain. Material and methods: One hundred patients with chest pain in whom coronary problems were discarded, were studied. A computerized esophageal manometry was performed in all and 24 hours esophageal pH measurement was done in 21 patients. Results: Esophageal manometry was normal in eight patients. Nutcracker esophagus was the most common finding, in 36 patients. Twenty eight had a hypotensive sphincter, 16 had unspecific motor disorders, nine had diffuse esophageal spasm, two had a non achalasic esophageal aperistalsis and one had a hypertensive sphincter. Conclusions: Only eight of 100 patients referred to esophageal manometry for non cardiac chest pain, had a normal study

Background: The nutcracker esophagus, a primary motor disorder, is frequently associated with noncardic chest pain. Aim: To study the clinical, endoscopic, manometric, and pathological features and 24 h acid reflux in patients with nutcracker esophagus. Patients and methods: Eighty patients (63 females, aged 26 to 70 years) with nutcracker esophagus, defined as the presence of contraction waves of more than 180 mmHg in the esophageal manometry, were studied. All were subjected to an upper gastrointestinal endoscopy, 24 h esophageal pH monitoring and a new manometric study. Results: Eighty percent of patients had symptoms suggestive of gastroesophageal reflux, 31% had retrosternal pain and 25% had dysphagia. Upper endoscopy was normal in 41% and showed erosive esophagitis or Barrett esophagus in 27%. Fifty percent of patients had an abnormal acid reflux. There were no significant differences in manometric parameters between patients with and without acid reflux. Conclusions: Symptoms of gastroesophageal reflux not necessarily mean that a pathological reflux is present. Primary motor disorders of the esophagus may cause similar symptoms (Rev Méd Chile 2004; 132: 160-4)

The primary clinical symptom of Paralytic Shellfish Poisoning is acute paralytic illness produced by paralyzing toxins. Paralytic shellfish poison is formed by a mixture of phycotoxins and their toxicity is due to its reversible binding to a receptor site on the voltage-gated sodium channel on excitable cells, thus blocking neuronal transmission. We studied the effect of the gonyautoxin 2/3 epimers by local infiltration in the anal internal sphincter of healthy voluntary adults in order to reduce anal tone. The toxin was injected after prior clinical evaluation, anoscopy and anorectal manometry. Post injection clinical examination, electromyography and anorectal manometry were performed. Resting and voluntary contraction pressures were measured and the anorectal inhibitory and anocortical reflexes were tested by manometry. Blood and urine samples were obtained from each participant, and hemogram, basic metabolic panel, and urinalysis were done both before and one week after the injection. This study shows, for the first time, that gonyautoxin 2/3 reduces the anal tone by relaxing the anal sphincters in 100 % of the participants. Manometric recordings showed a significant decrease in anal maximal voluntary contraction pressure after the toxin injection, dropping to 55.2 ± 6.2 % and 47.0 ± 6.8 % (Mean Value ± Std.Dev.) of the baseline values at 2 minutes and at 24 hours respectively after the injection. Post-injection electromyography showed that activity of the muscle was abolished. We conclude that local administration of gonyautoxin 2/3 to the anal sphincter produces immediate relaxation and a statistically significant decrease in the anal tone (p <0.001)