Membrane wounding triggers ATP release and dysferlin-mediated intercellular calcium signaling.

Dysferlin is a Ca(2+)-binding protein found in many different cell types. It is required for membrane wound repair in muscle, but it is not known whether it has the same function in other cells. Here we report the activation of an intercellular signaling pathway in sea urchin embryos by membrane wounding that evokes Ca(2+) spikes in neighboring cells. This pathway was mimicked by ATP application, and inhibited by apyrase, cadmium, and omega-agatoxin-IVA. Microinjection of dysferlin antisense phosphorodiamidate morpholino oligonucleotides blocked this pathway, whereas control morpholinos did not. Co-injection of mRNA encoding human dysferlin with the inhibitory morpholino rescued signaling activity. We conclude that in sea urchin embryos dysferlin mediates Ca(2+)-triggered intercellular signaling in response to membrane wounding.

Two independent forms of endocytosis maintain embryonic cell surface homeostasis during early development.

Eukaryotic cells have multiple forms of endocytosis which maintain cell surface homeostasis. One explanation for this apparent redundancy is to allow independent retrieval of surface membranes derived from different types of vesicles. Consistent with this hypothesis we find that sea urchin eggs have at least two types of compensatory endocytosis. One is associated with retrieving cortical vesicle membranes, and formed large endosomes by a mechanism that was inhibited by agatoxin, cadmium, staurosporine and FK506. The second type is thought to compensate for constitutive exocytosis, and formed small endosomes using a mechanism that was insensitive to the above mentioned reagents, but was inhibited by phenylarsine oxide (PAO), and by microinjection of mRNA encoding Src kinase. Both mechanisms could act concurrently, and account for all of the endocytosis occurring during early development. Inhibition of either form did not trigger compensation by the other form, and phorbol ester treatment rescued the endocytotic activity blocked by agatoxin, but not the retrieval blocked by PAO.

[Benign esophageal strictures in toddlers and pre-school children. Results of endoscopic dilation]. / Estenosis esofágica benigna en pacientes lactantes y preescolares. Resultados de dilatación endoscópica.

BACKGROUND: The most frequent causes of dysphagia in children are benign strictures and therefore require special consideration. OBJECTIVE: To evaluate safety and efficacy of endoscopic dilation in children with benign esophageal strictures. MATERIAL-METHODS-RESULTS: Twenty four consecutive children of 1.5 to 5.5 years (mean 3.5), with benign esophageal strictures were evaluated in a prospective manner over a 3-year period. The most frequent causes of esophageal stricture were caustic ingestion (Group A) and in Group B were included other benign strictures. Dilation was done on a weekly base using Savary-Gilliard bougies and was considered adequate, if the esophageal lumen could be dilated to 11 mm with complete relief of dysphagia. Of the 24 patients, 16 had corrosive strictures, 6 complications of gastroesophageal reflux and 2 post surgical strictures. Group A required a significantly higher number of session (14.3 +/- 10.84 vs 7.0 +/- 2.94 p: > 0.05), less free-time dysphagia (1.1 +/- 0.39 vs 2.6 +/- 0.95 months p: < 0.01) and a higher number of recurrences (3.12 +/- 1.12 vs 1.25 +/- 0.95 p: < 0.01). Two esophageal perforations occurred during a total of 292 dilation sessions (0.68%). There was one fatality. CONCLUSIONS: Benign esophageal strictures in children can be treated effectively and with acceptable safety by means of endoscopic dilation.

[Colonic polyps in children. Experience with polypectomy]. / Pólipos colónicos en niños. Experiencia en polipectomía.

BACKGROUND: Colonic polyp, the most common gastrointestinal tumor in children, is considered a cause of rectal bleeding in the pediatric population. Colonoscopy is the "gold standard" procedure in diagnosis and therapeutic. OBJECTIVE: To know the incidence and symptomatology of colonic polyps in children to remark on the usefulness of the endoscopic examination. PATIENTS-METHODS AND RESULTS: Between 1985 and 1996, over 1,000 colonoscopies were performed on 50 children between 8 months and 14 years old. The patients had colonic polyps and lower gastrointestinal bleeding. In 40 cases polyps were solitary, 82% were located in rectum sigmoid, and 80% of polyps were found to be juvenile (retention). There were no complications associated with diagnostic and therapeutic endoscopy. CONCLUSIONS: The endoscopic method was shown to be very useful for diagnosis as well as treatment of the colonic polyps in children.

[Precut sphincterotomy: efficacy and complications]. / Esfinterotomía de precorte: eficacia y complicaciones.

BACKGROUND: The use of precut sphincterotomy has been criticized as potentially unsafe. Despite this, a number of tertiary referral center have reported their successful use of this technique to increase the rate of common bile duct cannulation and therapeutic procedures. AIM: To evaluate precut papillotomy and correlate the complication rate. METHODS-PATIENTS AND RESULTS: We performed precut sphincterotomy in 120 patients in whom attempts at standard common bile duct cannulation and sphincterotomy were unsuccessful. Bile duct diameters were correlated to the complication rate. Cannulation of the common bile duct and endoscopic sphincterotomy was successful immediately after precut sphincterotomy in 103 patients (86%), and was successful in 12 of the 17 patients who underwent repeat ERCP, for a total cannulation and sphincterotomy rate of 96%. Eight patients (6.9%) experienced complications: six bleeding, and two retroduodenal perforation. There was no procedure-related mortality, and complications were managed medically except on patient with bleeding who required surgical intervention. CONCLUSIONS: Precut sphincterotomy was effective and safe in facilitating cannulation and sphincterotomy in patients in whom standard cannulation attempts failed. Excluding patients with small duct size may further reduce the complication rate.

[Self-expanding metal prosthesis as palliative treatment in esophageal cancer]. / Prótesis metálicas auto-expandibles como tratamiento paliativo en cáncer de esófago.

BACKGROUND: Current non-surgical or endoscopic therapeutic modalities in esophageal cancer include dilatation, thermocoagulation, injection of alcohol or chemotherapeutic agents, photodynamic therapy, intracavitary irradiation, and placement of plastic or metallic prostheses. None of these procedures, however, has proved to be a simple and well-tolerated like the last one. AIM: Achieve palliation of dysphagia, in patients with nonresectable esophageal cancer treated with a metal self-expanding endoprosthesis. PATIENTS--METHODS AND RESULTS: Twelve patients (6 men and 6 women, mean age 58) with dysphagia caused by non-resectable esophageal cancer were treated with a metal self-expanding endoprosthesis. Prior to treatment, they had mean dysphagia grade of 3.5. Histologic diagnosis was squamous carcinoma in 4 cases, and adenocarcinoma in 8. Six tumors were located at the gastroesophageal junction, 4 in the distal esophagus, and 2 in the mid-esophagus. None of the patients had cervical esophageal tumor. All procedures were performed under mild intravenous sedation. Stent insertion was technically successful in 91.6%, and led to a reduction of dysphagia from a mean score of 3.5 to a mean score of 0.5 at first and 4th weeks. Ninety-one percent of the patients continued to swallow during follow-up (average follow-up: 10.5 weeks, range 1 day-35 weeks). Early complications (within 30 days) included retrosternal pain in 2 patients which resolved in a few days and one patient with recurrent bleeding from the tumor site. CONCLUSIONS: Self-expanding metal stents placement is a relatively simple and atraumatic procedure, it is safe and effective in treatment of malignant dysphagia.

[Endoscopic cholangiopancreatography (ERCP) in pediatric patients]. / Colangiopancreatografía endoscópica (CPE) en pacientes pediátricos.

BACKGROUND: While Endoscopic Retrograde Cholangio-Pancreatography (ERCP) is widely employed in the management of adult pancreaticobiliary disease, its use in children has been limited. AIMS: To evaluate if ERCP diagnostic and therapeutic, is a safe and useful procedure in the diagnosis and treatment of pancreatobiliary disorders in children. PATIENTS, METHODS AND RESULTS: We reviewed our experience with 72 ERCPs performed in 50 children (age 7-17 y, mean 14.5 y). The procedures were performed using standard adult side-viewing duodenoscopes. We used general anesthesia in 25 and conscious sedation in 47. In 38 patients we performed one, in 7/2, in 2/3, in 1/4 and in 2/5 ERCPs. The biliary or pancreatic ducts were successfully cannulated in 98%. Abnormal papilla accounted for the unsuccessful attempt. Abnormalities were found in biliary ducts in 54% and pancreatic duct in 24%, including choledocholithiasis (10), stenosis of the papilla (5), benign biliary stenoses (5), recurrent pancreatitis (4), pancreatic fistula (4), bile duct leak (3), cholelithiasis (3), chronic calcifying pancreatitis (2), pancreas divisum (2) and choledochal cyst (1). Endoscopic sphincterotomy was performed in 19 patients, 15 on biliary segment and four on pancreatic segment. Stents were placed in the biliary duct in nine patients and in pancreatic duct in six patients. Complications included abdominal pain and elevated amylase in three patients (6%), which resolved rapidly. CONCLUSIONS: ERCP in children and adolescents is a safe and underutilized diagnostic and therapeutic procedure.

[Endoscopic management of biliary fistula]. / Manejo endoscópico de la fístula biliar.

OBJECTIVE: To assess safety and efficacy of endoscopic therapy for patients with a postoperative biliary fistula. BACKGROUND: Biliary fistula that occur after operations on the biliary tract may be due to bile duct injury or distal bile duct obstruction. These fistulas has been managed with surgical correction. At present, endoscopic methods of improving biliary drainage has been found to be highly successful in the management of postsurgical biliary leaks. PATIENTS-METHODS-RESULTS: By endoscopic cholangiopancreatography (ERCP) we diagnosed 35 patients (23 females and 12 males) with postoperative biliary fistula. Four patients had history of laparoscopic cholecystectomy. We used endoscopic sphincterotomy (18 cases) or endoprosthesis placement (17 cases) in the treatment. Seventeen patients with fistula plus common bile duct (CBD) stones and one patient with benign papillary stenosis were treated with endoscopic sphincterotomy alone. Seventeen patients without CBD stones were treated with only endoprosthesis placement. A second ERCP confirmed healing of the leakage after 4-16 weeks. CONCLUSIONS: Postoperative bile leakage could be diagnosed safely and effectively by ERCP, subsequent endoscopic management in most cases is successful. Sphincterotomy alone is the preferred treatment for biliary fistula-complicating surgery for gallstone disease. Alternatively, when a fistula is large, endoscopic placement of an endoprosthesis can be proposed as the first treatment.

[Precut sphincterotomy in impacted choledocholithiasis at the Vater's ampulla]. / Esfinterotomía de precorte en coledocolitiasis impactada en el ampula de vater.

BACKGROUND: Endoscopic sphincterotomy is an established treatment for common bile duct stones. Stone impaction at the ampulla makes deep cannulation and standard sphincterotomy more difficult. The use of precut papillotomy may facilitate stone extraction, although risks may be greater. AIM: To evaluate precut papillotomy in impacted common bile duct stone at the ampulla of Vater. PATIENTS AND METHODS: Between October 1990 and September 1995, 27 of 345 patients with common bile duct stones underwent needle knife precut papillotomy after conventional sphincterotomy failed due to impacted ampullary stone. This facilitated deep cannulation and subsequent standard sphincterotomy in 12 patients. RESULTS: Eleven patients had spontaneous expulsion of the stone when precut papillotomy was extended. Oedema or bleeding precluded stone extraction in 3 patients, and these stones were removed at a second endoscopic retrograde cholangiopancreatography (ERCP) session. Mild bleeding occurred in one patient and hemotransfusion was necessary. There was no perforation or pancreatitis following the procedure. CONCLUSIONS: Precut papillotomy is effective in the treatment of impacted common bile duct stone at the ampulla of Vater. It's a technique that should be performed only by an experienced endoscopist and does not increase the complications risk.

[Extraction of foreign bodies in the esophagus. Experience in 215 cases]. / Extracción de cuerpos extraños en el esófago. Experiencia en 215 casos.

OBJECTIVE: To analyze our experience in management of foreign bodies in esophagus. BACKGROUND: At present, the flexible endoscope is usually the instrument of choice for foreign bodies of the esophagus. The rigid endoscope is less expensive, but the advantages of the flexible endoscope are numerous. MATERIAL, METHODS: Management of 215 foreign bodies of esophagus are reported. The flexible endoscope was used to manage these foreign bodies. The patients comprised 151 children and 64 adults. RESULTS: In children, coins were the commonest foreign bodies (119 cases), whereas in adults, the commonest cause was impacted meat (35 cases). Two hundred fourteen foreign bodies (99.5%) were successfully managed endoscopically. The surgery rate was 0.5%. There was no morbidity or mortality. In fifteen adults we diagnosed significant associated medical conditions: benign esophageal stricture in eleven, esophago-gastric junction carcinoma in one, two patients with esophageal motility disorders and remaining with Plummer-Vinson Syndrome. CONCLUSIONS: The forward-viewing flexible endoscope has became the instrument of choice in diagnosis and management of esophageal foreign bodies.