Three new teosintes (Zea spp., Poaceae) from México.

PREMISE OF THE STUDY: Teosinte species are the closest relatives of maize and represent an important but increasingly rare genetic resource for maize improvement and the study of evolution by domestication. Three morphologically and ecologically distinct teosinte populations were recently discovered in México. The taxonomic status of these rare and endangered populations was investigated by detailed comparisons to previously characterized wild Zea species. • METHODS: Three new teosinte populations were compared to known teosinte taxa on the basis of morphological, ecogeographic, cytological, and molecular characteristics. Phenetic and phylogenetic analyses were performed using morphological and molecular data, respectively. • KEY RESULTS: The newly discovered populations are distinct from each other and from other Zea species to represent three new entities based on their unique combinations of morphological, ecological, ploidy, and DNA markers. A perennial diploid population from Nayarit is distinguished by early maturing plants, and having male inflorescences with few tassel branches and long spikelets. A perennial tetraploid population from Michoacán is characterized by tall and late maturing plants, and having male inflorescences with many branches. An annual diploid population from Oaxaca is characterized by having male inflorescences with fewer branches and longer spikelets than those found in the sister taxa Z. luxurians and Z. nicaraguensis, plants with high thermal requirements, and very long seed dormancy. • CONCLUSIONS: Evidence from multiple independent sources suggests placement of the three new populations of teosinte as distinct entities within section Luxuriantes of the genus Zea. However, more extensive DNA marker or sequence data are required to resolve the taxonomy of this genus.

Use of fully covered self-expanding metal stents for the management of benign biliary conditions.

BACKGROUND AND AIM: biliary self-expanding metal stents (SEMS) have the advantage of being inserted undeployed with very small sizes and provide, when fully opened, large diameters for biliary drainage. However, their use in benign conditions has been very limited, mainly because of difficulty in their extraction. We present our initial experience with a fully covered SEMS (Wallflex) for the management of benign problems of the bile duct. PATIENTS AND METHODS: in a prospective study, stents of 8 mm in diameter and 4, 6 or 8 cm long were inserted by means of ERCP. These SEMS were chosen when according to medical judgement it was thought that diameters greater than 10 French (3.3 mm) were needed for proper biliary drainage. Stents were extracted also endoscopically, several months later when deemed clinically appropriate. RESULTS: twenty biliary SEMS were inserted. Reasons for insertion were: large intrahepatic biliary fistula after hydatid cyst surgery (1), perforation of the papillary area following endoscopic sphincterotomy (2), coaxial insertion to achieve patency in obstructed uncovered stents inserted in benign conditions (3), benign strictures (7), multiple and large common bile duct stones that could not be extracted because of tapering and stricturing of the distal common bile duct (7). In all cases, successful biliary drainage was achieved and there were no complications from insertion. Stents were easily extracted after a mean time of 132 days (36-270) in place. Complete resolution of biliary problems was obtained in 14 patients (70%). CONCLUSIONS: in our initial experience, the fully covered Wallflex biliary stent was removed without any complication after being in place in the common bile duct for a mean time of over four months. Therefore, it could be used in the management of benign biliary conditions.

Biliary sphincterotomy dilation for the extraction of difficult common bile duct stones.

BACKGROUND AND AIM: Endoscopic retrograde cholangiopancreatography (ERCP) with biliary sphincterotomy (BS) is the usual method for extracting common bile duct stones. However, following BS and by means of extraction balloons and Dormia baskets a complete bile duct clearance cannot be achieved in all cases. We present a study on the impact that hydrostatic balloon dilation of a previous BS (BSD) may have in the extraction rate of choledocholithiasis. PATIENTS AND METHODS: A prospective study which included 91 consecutive patients diagnosed with choledocholithiasis who underwent ERCP. For stone removal, extraction balloons and Dormia baskets were used, and when necessary BSD was employed. RESULTS: Complete bile duct clearance was achieved in 86/91 (94.5%) patients. BSD was used in 30 (33%) cases. In these cases, extraction was complete in 29/30 (97%); 23 (76%) patients in the BSD group had anatomic difficulties or bleeding disorders. The most frequently used hydrostatic balloon diameter was 15 mm (60%). There were 7 (7.6%) complications: two self-limited hemorrhage episodes in the BSD group and one episode of cholangitis, one of pancreatitis, and three of bleeding in the group in which BSD was not used. CONCLUSIONS: BSD is a very valuable tool for extracting common bile duct stones. In our experience, there has been an increase in the extraction rate from 73% (Rev Esp Enferm Dig 2002; 94: 340-50) to 94.5% (p = 0.0001, OR 0.1, CI 0.05-0.45), with no increase in complications.

[Palliative management of malignant gastric outlet obstruction with endoscopically inserted self-expanding metal stents].

AIM AND BACKGROUND: the insertion of self-expanding metal stents to palliate malignant gastric outlet obstruction is a minimally invasive procedure that is being increasingly used. We discuss experience with this technique in a level-II hospital in the Spanish National Health System. PATIENTS AND METHODS: a retrospective five-year study (2003-2007) was conducted in 23 patients who underwent 27 procedures aimed at resolving malignant gastric outlet obstruction (mean, 0.45 procedures per month) using endoscopically inserted noncovered stents (Wallstent and Wallflex). RESULTS: insertion was technically feasible in all 27 (100%) attempts, with satisfactory clinical results in 25 cases (92.5%). Endoscopy alone was used 10 times (37%), and both endoscopy and fluoroscopy on 17 (63%) occasions. After stent insertion, one patient was intervened for treatment, and a patient with an unsuccessful prosthesis received a palliative surgical bypass. Four stents became obstructed by tumoral ingrowth, and patency was reestablished by inserting a new stent. Obstructive jaundice caused by stents covering the papilla of Vater occurred in three cases. There were no other complications or mortality due to the procedure. Mean survival was 104 days (range 28-400, SD +/- 94). CONCLUSIONS: in our experience endoscopic insertion of self-expanding metal stents appears to be a safe and efficient palliative method for malignant gastric outlet obstruction, and can be performed successfully in a center with our characteristics.

Long-term follow-up of patients with small-bowel angiodysplasia on capsule endoscopy. Determinants of a higher clinical impact and rebleeding rate.

BACKGROUND: the clinical impact of small-bowel angiodysplasia has not been defined. We present a prospective study to determine the features of individuals with a higher risk of rebleeding or a worse clinical outcome. PATIENTS AND METHODS: thirty patients with angiodysplasia found on CE were included and followed for 12 months. Angiodysplasia were classified by their size as small ( 10 mm). We also studied angiodysplasia lesion numbers in each patient. Rebleeding was defined as a hemoglobin drop of more than 2 g/dl in the absence of melena or hematochezia in the case of occult GI bleeding, or with any or both manifestations. RESULTS: a therapeutic procedure was carried out in 13 patients (43.4%). Individuals with large angiodysplasia had higher transfusion requirements, a higher proportion of therapeutic procedure performed after CE, lower hemoglobin concentration, and a lower rebleeding rate. Patients with ten or more angiodysplasia lesions had also higher transfusion requirements and lower hemoglobin levels, but we found no differences in the number of therapeutic procedures or rebleeding rate between both groups. On follow up rebleeding was detected in 5 patients (16.7%), all of them with small angiodysplasias. Rebleeding was more frequent in patients who did not receive further interventions (23.53 vs. 7.69%; p = 0.037). CONCLUSIONS: angiodysplasia size >or= 10 mm determines a worse clinical impact and more possibilities of receiving a therapeutic procedure. Our findings support that patients with large lesions would benefit from therapeutic interventions with a reduction in rebleeding rate.

Extracción de cálculo coledociano de gran tamaño con esfinterotomía biliar seguida de dilatación de la papila con balón hidrostático / No disponible

No disponible

Outcomes of bile duct drainage by means of ERCP in geriatric patients / Resultados del drenaje de la vía biliar por CPRE en pacientes con edad geriátrica.

BACKGROUND AND OBJECTIVE: Endoscopic retrograde cholangiopancreatography (ERCP) is usually the procedure of choice for relieving bile duct obstruction. a large number of patients undergoing this intervention are geriatric population (aged 75 years of age and older). Our aim was to assess the efficacy of ERCP in this group of patients as compared to younger ones. PATIENTS AND METHODS: A retrospective study. All patients in whom a therapeutic biliary endoscopy had been performed over a four-year period of time (2002-2005) were included. RESULTS: 178 geriatric patients and 159 younger ones underwent ERCP. No differences were found in successful biliary drainage (97.7 vs. 98.7%), complication number (11.8 vs. 14.4%), or mortality rate (1.1 vs. 0.6%). On the other hand, more common bile duct stones were found in geriatric patients (57.3 vs. 39.6%, p = 0.004), and also more self-expanding metal stents were employed to drain malignant obstructive jaundice (47 vs. 8%, p = 0.0035). In the youngest group, more ERCPs were repeated in the same patients (4 vs. 10%, p = 0.001). CONCLUSIONS: The geriatric population showed similar success and morbidity and mortality rates when compared to younger patients in draining their bile duct by means of ERCP. Common bile duct stones were more frequently found in geriatric patients. No patients needing an ERCP should be excluded only because of their age.

Distensión de la vesícula biliar por obstrucción tumoral coledociana (signo de Courvoisier) / Gallbladder distension caused by tumoral obstruction of the common bile duct (Courvoisier's sign)

No disponible

El aceite de oliva es un excelente lubricante para el dilatador tipo Witzel / Olive oil is a good lubricating agent for the Witzel dilator

No disponible

Coledococele de pequeño tamaño como causa de dolor epigástrico crónico: diagnóstico y tratamiento mediante CPRE / Small size choledochocele as a cause of chronic epigastric pain: diagnosis and treatment by means of ERCP

El coledococele pertenece al tipo III de los quistes biliares según la clasificación de Alonso-Lej, y son considerados los quistes menos frecuentes entre ellos. La definición habitual del coledococele es la de una dilatación quística de la porción distal intramural del colédoco que protruye en la luz duodenal. La CPRE es una de las pruebas de elección tanto para su diagnóstico como para su tratamiento, especialmente cuando son pequeños y la cavidad quística está habitualmente colapsada. La distensión de la papila (“ballooning”) durante la inyección de contraste en la CPRE se considera un signo diagnóstico. Presentamos un paciente con dolor epigástrico crónico a causa de un pequeño coledococele. La Colangiografía por Resonancia Magnética no fue diagnóstica. La CPRE proporcionó el diagnóstico y el tratamiento mediante una esfinterotomía biliar

Choledochocele belongs to type III Alonso-Lej’s classification of biliary cysts and they are considered the less frequent of such cysts. The definition most often given of choledochocele is a cystic dilation of the distal intramural portion of the bile duct, protruding into the duodenal lumen. ERCP is one of the diagnostic and therapeutic procedures of choice, specially when they are small and the cystic cavity is usually collapsed. The ballooning of the papilla during contrast injection in ERCP is thought to be a diagnostic sign. We present a patient suffering from chronic epigastric pain due to a small choledochocele. Magnetic Resonance Cholangiopancreatography failed to diagnose it. ERCP offered both diagnosis and treatment by means of biliary sphincterotomy

[Small size choledochocele as a cause of chronic epigastric pain: diagnosis and treatment by means of ERCP]. / Coledococele de pequeño tamaño como causa de dolor epigástrico crónico: diagnóstico y tratamiento mediante CPRE.

Choledochocele belongs to type III Alonso-Lej's classification of biliary cysts and they are considered the less frequent of such cysts. The definition most often given of choledochocele is a cystic dilation of the distal intramural portion of the bile duct, protruding into the duodenal lumen. ERCP is one of the diagnostic and therapeutic procedures of choice, specially when they are small and the cystic cavity is usually collapsed. The ballooning of the papilla during contrast injection in ERCP is thought to be a diagnostic sign. We present a patient suffering from chronic epigastric pain due to a small choledochocele. Magnetic Resonance Cholangiopancreatography failed to diagnose it. ERCP offered both diagnosis and treatment by means of biliary sphincterotomy.

[Treatment of malignant colorectal obstruction by means of endoscopic insertion of self-expandable metallic stents]. / Tratamiento de la obstrucción neoplástica del colon meciante la inserción endoscópica de prótesis metálicas autoexpandibles.

BACKGROUND AND AIM: Self-expandable metallic stents are being used increasingly to treat the obstruction of different segments of the digestive tract and biliary tree. We present our centre experience on the initial resolution of malignant colorectal obstruction by means of this type of stents. PATIENTS AND METHODS: During a 18-month period, 13 patients patients suffering from malignant obstruction at the level of rectum, sigmoid or descending colon tried to be initially treated by means of endoscopic insertion of stents (non covered enteral Wallstents). Ten procedures were performed with both endoscopy and fluroscopy and three with only endoscopy. RESULTS: In 12 of the 13 patients (92,3%) the obstruction was solved by means of correct stent insertion. All the exclusively endoscopic procedures (without fluoroscopy) were successful. Six (50 %) patients with tumours at the rectosigmoid underwent later scheduled surgery. In the remaining six ones (a patient with an ovarian carcinoma and five with colonic adenocarcinoma) the stents were considered to be a palliative definitive treatment. Stent migration was observed in two of these patients and both were extracted endoscopically. Only one patient needed to have another stent inserted. A tumoural colo-vesical fistula developed in another patient in the palliative group, inside the previous inserted stent, and was treated by coaxial insertion of an esophageal Ultraflex. There were no other complications or mortality related to the endoscopic procedures. CONCLUSIONS: Self-expandable metallic stents might be considered, in general, as the initial treatment for the malignant obstruction at the level of rectum, sigmoid and descending colon

Maintenance of rat taste buds in primary culture.

The differentiated taste bud is a complex end organ consisting of multiple cell types with various morphological, immunocytochemical and electrophysiological characteristics. Individual taste cells have a limited lifespan and are regularly replaced by a proliferative basal cell population. The specific factors contributing to the maintenance of a differentiated taste bud are largely unknown. Supporting isolated taste buds in culture would allow controlled investigation of factors relevant to taste bud survival. Here we describe the culture and maintenance of isolated rat taste buds at room temperature and at 37 degrees C. Differentiated taste buds can be sustained for up to 14 days at room temperature and for 3-4 days at 37 degrees C. Over these periods individual cells within the cultured buds maintain an elongated morphology. Further, the taste cells remain electrically excitable and retain various proteins indicative of a differentiated phenotype. Despite the apparent health of differentiated taste cells, cell division occurs for only a short period following plating, suggesting that proliferating cells in the taste bud are quickly affected by isolation and culture.