A Comparison of Immediate and Short-Term Defensive Responses to Phytophthora Species Infection in Both Susceptible and Resistant Walnut Rootstocks.

Clonal rootstocks are one alternative used by the walnut industry to control damage caused by Phytophthora species, traditionally using plants grafted on susceptible Juglans regia rootstock. Vlach, VX211, and RX1 are clonal rootstocks with a degree of resistance to Phytophthora species. The resistance to pathogens in these rootstocks depends on the resistance mechanisms activated by the presence of the pathogen and subsequent development of responses in the host. In this work, we analyzed how plants of J. regia, Vlach, VX211, and RX1 responded to inoculation with Phytophthora cinnamomi or Phytophthora citrophthora isolates obtained from diseased English walnut plants from Chilean orchards. After inoculation, plants of Vlach, VX211, and RX1 showed canopy and root damage indexes that did not differ from noninoculated control plants. In contrast, plants of J. regia, which is susceptible to P. cinnamomi and P. citrophthora, died after inoculation. Vlach, VX211, and RX1 plants inoculated with P. cinnamomi or P. citrophthora showed greater root weight and volume and greater root growth rates than their respective controls. These results suggest that short-term carbohydrate dynamics may be related to the defense mechanisms of plants; they are immediately activated after inoculation through the production of phenolic compounds, which support the further growth and development of roots in walnut clonal rootstocks. To our knowledge, this is the first study that comprehensively characterizes vegetative and radicular growth and the dynamics of sugars and phenols in response to infection with P. cinnamomi or P. citrophthora in walnut rootstocks.

[Bouveret's syndrome. Case report]. / Síndrome de Bouveret. Reporte de un caso.

INTRODUCTION: Bouveret's syndrome is characterized by piloro-duodenal obstruction following the implant of a giant gallstone with gallstone ileus origin. It constitutes the less common variety of gallstone ileus (1-3%), mainly affecting elderly patients with chronic degenerative illnesses, possibly with high mortality. OBJECTIVE: We report the case of a patient with a less common variety of gallstone ileus. The patient was treated at a third-level care hospital. CLINIC CASE: Patient is a 52-year-old male with gastric obstruction and secondary dehydration. Studies were supported by a series of esophagus-gastric-duodenal and broad endoscopy. Piloro-duodenal obstruction by a giant gallstone was reported which could not be extracted by endoscopy. The patient was taken to surgery where a giant gallstone lying in the duodenal site was found and biliary vesicular scleroatrophic. Gastrotomy is effected with the extraction of the gallstone and gastrography. Gallstone duodenal fistula is then identified with support analysis. CONCLUSIONS: Bouveret's syndrome is a rare entity whose diagnosis has a high sensitivity and specificity with a supported radiographic diagnosis. Endoscopy is difficult in the case of a giant impacted gallstone, making surgery the best therapeutic choice.