Genome sequence of the plant pathogen and biotechnology agent Agrobacterium tumefaciens C58

Agrobacterium tumefaciens is a plant pathogen capable of transferring a defined segment of DNA to a host plant, generating a gall tumor. Replacing the transferred tumor-inducing genes with exogenous DNA allows the introduction of any desired gene into the plant. Thus, A. tumefaciens has been critical for the development of modern plant genetics and agricultural biotechnology. Here we describe the genome of A. tumefaciens strain C58, which has an unusual structure consisting of one circular and one linear chromosome. We discuss genome architecture and evolution and additional genes potentially involved in virulence and metabolic parasitism of host plants.

Preoperative biliary drainage of severely jaundiced patients increases morbidity of pancreaticoduodenectomy: results of a case-control study

BACKGROUND

Recent studies have indicated that preoperative biliary drainage (PBD) should not be routinely performed in patients suffering from obstructive jaundice before surgery. The severity of jaundice that mandates PBD has yet to be defined. Our aim was to investigate whether PBD is truly justified in severely jaundiced patients before pancreaticoduodenectomy. The parameters evaluated were overall morbidity, length of hospital stay, and total in-hospital mortality.

METHODS

From January 2000 to December 2012, a total of 240 patients underwent pancreaticoduodenectomy for periampullary tumors. Group A comprised 76 patients with preoperative serum bilirubin ≥15 mg/dl who did not undergo PBD before surgery. Group B comprised another 76 patients, matched for age and tumor localization (papillary vs. pancreatic head) who underwent PBD 2-4 weeks before pancreaticoduodenectomy and were identified from the same database.

RESULTS

Less operative time was required in the 'no PBD' group compared with the 'PBD' group (210 vs. 240 min). Total intraoperative blood loss and blood transfusions were also significantly less in the 'no PBD' group. There was no difference detected in the rate of pancreatic fistula or biliary fistula formation. Group A patients demonstrated significantly lower morbidity than group B (24 vs. 36 %, respectively) and therefore required briefer hospitalization (11 vs. 16 days). Mild infectious complications appear to be the main factor that enhanced morbidity in the PBD group. However, total in-hospital mortality was not significantly different between the two groups.

CONCLUSIONS

Even severe jaundice should not be considered as an indication for PBD before pancreaticoduodenectomy, as PBD increases infections and postoperative morbidity, therefore delaying definite treatment.

High-dose pantoprazole continuous infusion is superior to somatostatin after endoscopic hemostasis in patients with peptic ulcer bleeding

BACKGROUND

The best antisecretory treatment after endoscopic hemostasis in patients with ulcer bleeding is still in quest.

OBJECTIVES

To compare pantoprazole and somatostatin continuous infusion after endoscopic hemostasis in patients with bleeding peptic ulcers.

PATIENTS AND METHODS

A total of 164 consecutive patients with a bleeding peptic ulcer, after successful endoscopic hemostasis, were randomly assigned to receive, double blindly, continuous IV infusion of pantoprazole 8 mg/h for 48 h after a bolus of 40 mg (group P) or somatostatin 250 microg/h for 48 h after a bolus of 250 microg (group-S). Twenty-four-hour pH-metry was performed in the last 30 patients in each group. Endoscopy was performed, in case of bleeding nonrecurrence, every 48 h until disappearance of stigmata.

RESULTS

Bleeding recurrence: group S 14 patients (17%) versus group P 4 (5%) (P=0.046). In multivariate analysis, bleeding recurrence was 4.57 (CI 1.31-15.91) times more frequent in group S (P=0.02). There was no difference in the need for surgery and mortality. Acid suppression over pH 6: group S 82.9% of the time versus group P 81.5% (P=0.97). Acid suppression over pH 6 for >85% of the time: group S 14 (47%) patients versus group P 17 (57%) (P=0.44). Disappearance of endoscopic stigmata after 48 h: group S 25/68 patients (37%) versus group P 72/78 (92%) (P<0.0001). No major side effects identified in either study group.

CONCLUSIONS

In patients with a bleeding ulcer, after successful endoscopic hemostasis, despite equipotent acid suppression, pantoprazole continuous infusion was superior to somatostatin to prevent bleeding recurrence and quick disappearance of the endoscopic stigmata. Nevertheless, no differences were seen in the need for surgery and mortality.

Retained surgical sponges: what the practicing clinician should know

Retained surgical sponges (RSS) are an avoidable complication following surgical operations. RSS can elicit either an early exudative-type reaction or a late aseptic fibrous tissue reaction. They may remain asymptomatic for long time; when present, symptomatology varies substantially and includes septic complications (abscess formation, peritonitis) or fibrous reaction resulting in adhesion formation or fistulation into adjacent hollow organs or externally. Plain radiograph may be useful for the diagnosis; however, computed tomography is the method of choice to establish correct diagnosis preoperatively. Removal of RSS is always indicated to prevent further complications. This is usually accomplished by open surgery; rarely, endoscopic or laparoscopic removal may be successful. Prevention is of key importance to avoid not only morbidity and even mortality but also medicolegal consequences. Preventive measures include careful counting, use of sponges marked with a radiopaque marker, avoidance of use of small sponges during abdominal procedures, careful examination of the abdomen by the operating surgeon before closure, radiograph in the operating theater (either routinely or selectively), and recently, usage of barcode and radiofrequency identification technology.

Current trends in the management of infected necrotizing pancreatitis

Severe acute pancreatitis is a potentially life-threatening disease. Pancreatic necrosis is associated with an aggravated prognosis, while superimposed infection is almost always lethal without surgery. Bacterial translocation mainly from the gut is the most widely accepted mechanism in the pathogenesis of infected pancreatic necrosis. Infected pancreatic necrosis should be suspected in the presence of the usual markers of systemic inflammation (i.e., fever and leukocytosis), organ failure, or a protracted severe clinical course. The diagnostic method of choice to confirm the diagnosis of pancreatic necrosis is contrast-enhanced computed tomography, where necrotic areas are evidenced as regions without enhancement. The presence of pancreatic necrotic infection should be based on a combination of clinical manifestations, results of laboratory investigation (mainly increased levels of CRP and / or procalcitonin), and can be confirmed by image-guided fine-needle aspiration and gram stain /culture of the aspirates. Surgery remains the treatment of choice for the management of infected pancreatic necrosis and involves open necrosectomy (debridement) and wide drainage of the peripancreatic areas, often in association with continuous irrigation. Planned reoperations may be required to achieve complete removal of the necrotic / infected material. The timing of surgery is of paramount importance; ideally, surgery should be performed after 2 or 3 weeks from the onset of pancreatitis. Recently, various minimally invasive approaches have been described, but they have not been compared in prospective trials with the classical open surgery. Antibiotic therapy is routinely used in patients with infected necrotizing pancreatitis, in conjunction with surgical debridement; its role, however, in the management of patients with sterile necrosis is recently questioned. Nutritional support should be taken into consideration in these patients; enteral nutrition should be preferred over total parenteral nutrition to improve the anatomical and functional integrity of the gut mucosa, thereby preventing bacterial translocation.

External Branch of the Superior Laryngeal Nerve: Applied Surgical Anatomy and Implications in Thyroid Surgery

The external branch of the superior laryngeal nerve (EBSLN) is the only motor supply to the cricothyroid muscle and has an important role during phonation in high frequencies. Iatrogenic injury of the EBSLN, most commonly during thyroid surgery, is associated with varying levels of alterations in phonation, which may have an impact on a patient's life, especially when his or her career depends on the full range of voice. EBSLN injury incidence after thyroid surgery ranges widely in the literature (0 to 58%). Despite this wide variation, it appears that EBSLN injury is a not uncommon, and frequently overlooked, complication of thyroid surgery. An in-depth knowledge of the surgical anatomy of the EBSLN is therefore required from the part of the operating surgeon to protect this nerve during thyroid surgery.

Interval routine appendectomy following conservative treatment of acute appendicitis: Is it really needed

Conservative management of acute appendicitis (AA) is gradually being adopted as a valuable therapeutic choice in the treatment of selected patients with AA. This approach is based on the results of many recent studies indicating that it is a valuable and effective alternative to routine emergency appendectomy. Existing data do not support routine interval appendectomy following successful conservative management of AA; indeed, the risk of recurrence is low. Moreover, recurrences usually exhibit a milder clinical course compared to the first episode of AA. The role of routine interval appendectomy is also questioned recently, even in patients with AA complicated by plastron or localized abscess formation. Surgical judgment is required to avoid misdiagnosis when selecting a conservative approach in patients with a presumed “appendiceal” mass.

Necrotizing acute pancreatitis current status - emerging new strategies in surgical management

Despite that pancreatic necrosis complicates only 15 % of cases of acute pancreatitis (AP), it is associated with high morbidity and considerable mortality. In an attempt to improve prognosis, many surgical strategies have been described during the last few decades. Currently, necrosectomy remains the cornerstone in the surgical treatment of infected pancreatic necrosis and in selected cases of sterile necrotizing pancreatitis. Following necrosectomy, continuous closed lavage is recommended by many authors, while closed abdominal packing /drainage and repeated planned necrosectomies- commonly using the zipper technique-are also acceptable alternative strategies. Open abdomen (laparostomy) is rarely indicated in carefully selected cases (typically in abdominal compartment syndrome associated with necrotizing AP). During the last decade, minimally invasive techniques (including percutaneous drainage, retroperitoneal endoscopic approach, transgastric endoscopic approach etc) have been extensively studied by some groups not only in the management of pancreatic abscesses and / or pseudocysts, but also as primary methods of treatment of necrotizing AP. Results have been impressive, but experience currently is limited to only a few centers around the world.

External branch of the superior laryngeal nerve: applied surgical anatomy and implications in thyroid surgery

The external branch of the superior laryngeal nerve (EBSLN) is the only motor supply to the cricothyroid muscle and has an important role during phonation in high frequencies. Iatrogenic injury of the EBSLN, most commonly during thyroid surgery, is associated with varying levels of alterations in phonation, which may have an impact on a patient's life, especially when his or her career depends on the full range of voice. EBSLN injury incidence after thyroid surgery ranges widely in the literature (0 to 58%). Despite this wide variation, it appears that EBSLN injury is a not uncommon, and frequently overlooked, complication of thyroid surgery. An in-depth knowledge of the surgical anatomy of the EBSLN is therefore required from the part of the operating surgeon to protect this nerve during thyroid surgery.