Surgery for pancreatic ductal adenocarcinoma.

Surgical resection is the only potentially curative option in the treatment of pancreatic ductal adenocarcinoma. Preoperative radiological imaging allows to rule out the presence of metastases. Three resectability categories are established based on the radiological findings depending on the degree of contact between the tumor and the blood vessels. Histological confirmation of malignancy is only required in cases of borderline or non-resectable tumors, prior to neoadjuvant treatment initiation. Diagnostic laparoscopy is recommended in the presence of large tumors of the body or tail and in borderline tumors to explore the possibility of resection and to apply treatment with curative intent, as well as in those cases with high level of biomarkers to rule out peritoneal involvement. Prior to surgery preoperative nutritional measures as well as endoscopic biliary drainage can be applied to optimize patient's conditions. Cephalic pancreaticoduodenectomy is the recommended surgical technique in tumors located in the head of the pancreas. The benefits from pyloric preservation, type or reconstruction (one vs. two loops), type of anastomosis (pancreaticojejunostomy vs. pancreaticogastrostomy), intraoperative biopsy of the pancreatic resection margin or the use of intraperitoneal drainages are inconclusive. Total pancreatectomy and/or portal resection should only be performed in particular cases; however, arterial resections have shown no benefits. Radical antegrade modular pancreaticosplenectomy, that can be performed laparoscopically, is the technique used for those tumors located in the pancreatic body-tail.

Consensus guidelines for diagnosis, treatment and follow-up of patients with pancreatic cancer in Spain.

The management of patients with pancreatic cancer has advanced over the last few years. We convey a multidisciplinary group of experts in an attempt to stablish practical guidelines for the diagnoses, staging and management of these patients. This paper summarizes the main conclusions of the working group. Patients with suspected pancreatic ductal adenocarcinoma should be rapidly evaluated and referred to high-volume centers. Multidisciplinary supervision is critical for proper diagnoses, staging and to frame a treatment plan. Surgical resection together with chemotherapy offers the highest chance for cure in early stage disease. Patients with advanced disease should be classified in treatment groups to guide systemic treatment. New chemotherapeutic regimens have resulted in improved survival. Symptomatic management is critical in this disease. Enrollment in a clinical trial is, in general, recommended.

Ultrasound characteristics of connective tissue around porous hydroxyapatite hypodermic implants in rats.

Adults Sprague-Dawley rats were implanted with porous hydroxyapatite (Interpore 200), following a procedure different from that of Kawaguchi et al (1992). Instead of implanting hydroxyapatite (Ha) in periodontal osseus defects, we introduced Ha-implants in the hypodermis of rats. Animals were sacrificed on days 30, 90 and 150 (six in each stage). The interface between the Ha and connective tissue was studied by transmission electron microscopy, with the aim of understanding the biocompatibility and mechanisms of union of both parts. The connective tissue reaction to the Ha implant was characterized by fibrovascular proliferation, with abundant fibroblasts, macrophages, multinucleated giant cells, and by the formation of a capsule surrounding the implant. The multinucleated giant cells were observed in the interface along all stages and exhibited: (a) a progressive increase in mitochondria, ribosomes, rough endoplasmic reticulum and vesicles containing particles of Ha; and b) an electronlucent material of variable aspect in vesicles contained in their cytoplasmic expansions. The prominent cytologic aspects of the multinucleated giant cells in the juxta-Ha zone may indicate that both, the biocompatibility and the intimate union between connective tissue and Ha, are strongly dependent on the presence of these cells.

Ultrasound characteristics of connective tissue around porous hydroxyapatite hypodermic implants in rats

Adults Sprague-Dawley rats were implanted with porous hydroxyapatite (Interpore 200), following a procedure different from that of Kawaguchi et al (1992). Instead of implanting hydroxyapatite (Ha) in periodontal osseus defects, we introduced Ha-implants in the hypodermis of rats. Animals were sacrificed on days 30, 90 and 150 (six in each stage). The interface between the Ha and connective tissue was studied by transmission electron microscopy, with the aim of understanding the biocompatibility and mechanisms of union of both parts. The connective tissue reaction to the Ha implant was characterized by fibrovascular proliferation, with abundant fibroblasts, macrophages, multinucleated giant cells, and by the formation of a capsule surrounding the implant. The multinucleated giant cells were observed in the interface along all stages and exhibited: (a) a progressive increase in mitochondria, ribosomes, rough endoplasmic reticulum and vesicles containing particles of Ha; and b) an electronlucent material of variable aspect in vesicles contained in their cytoplasmic expansions. The prominent cytologic aspects of the multinucleated giant cells in the juxta-Ha zone may indicate that both, the biocompatibility and the intimate union between connective tissue and Ha, are strongly dependent on the presence of these cells

[Microscopic analysis of the effects of ultrasonic instrumentation on the root surface of molar furcations]. / Análisis microscópico de los efectos de la instrumentación ultrasónica sobre la superficie radicular del área de furcaciones de molares.

Twenty molars, 10 from the maxilla and 10 from the mandible with furcation areas type II (Staffileno) were instrumented in their inter-radicular area with P10 instrument of Cavitron. It was established that the furcations of easier access instrumentation were the lingual o lower teeth and the buccal of the upper, and the most difficult accessibility were the distal of upper molars. The instrumentation can leave grooves or deformations, depending on the instrument to the area. It was concluded that ultrasonic instrument are useful removing supragingival calculus and bacterial plaque, and it must be limited to perform such procedures.