The non-enzymatic formation of nitric oxide from soil and clay systems

Prevailing concepts relating to the non-enzymatic gaseous loss of nitrite from soil are thought to be inadequate as regards to the mechanisms involved. The conventional explanation for nitric oxide formation i.e., the acid decomposition of nitrite, is held to be insufficient in substrates of only mild or slight acidity. A criticism is presented wherein it is maintained that certain past practices in methodology have created rather than eliminated confusion. Positive suggestions are proposed which may help to eliminate confusion in future experiments. Evidence was obtained from soil and clay systems which attest to a mechanism of loss whereby nitrite may react with certain metals to yield nitric oxide as a primary gaseous product. A conventional half-cell reaction is presented wherein a transition-like metal is oxidized and nitrite is reduced to nitric oxide with the formation of water. It is implied that hydrogen ions may be necessary--acid conditions favor the reduced state of the metals which is a more active state with respect to the formation of nitric oxide--for such reactions, but that they are not sufficient in substrates of only mild acidity. An apparent corollary to this study is that the very conditions which favor classical denitrification from nitrate also favor metal-nitrite reactions. Under such conditions both nitrate and the metals involved would be expected to undergo reduction resulting in an increased possibility for nitric oxide formation. This possibility places in question the status of nitric oxide as a direct biochemical intermediate in the microbial formation of nitrogen gas. It is suggested that a mechanism involving transition -like metals may account for significant losses of mineral nitrogen from field soils capable of accumulating nitrite under conditions of moderate or slight acidity

Short- and Long-Term Results of Open Versus Laparoscopic Appendectomy

Clinical advantages of laparoscopic appendectomy have been shown in numerous trials and reviews. Most of these advantages are small and of limited clinical relevance, while laparoscopic operation costs are reported to be higher. The present study compares short- and long-term results of conventional appendectomy with or without diagnostic laparoscopy (OA), and laparoscopic appendectomy (LA). All adult patients who underwent appendectomy in our institution from 1995 to 2005 were included retrospectively. Patient data were retrieved from medical records, questionnaires sent by mail, and records of general practitioners. Primary outcome parameters were long-term complications, readmissions, and reinterventions (> 30 days postoperatively). Secondary outcome parameters were short-term complications, readmissions, and reinterventions (a parts per thousand currency sign30 days postoperatively). A total of 755 patients were included, 545 of whom underwent OA, with the remaining 210 undergoing LA. In the long term there were few complications noted, and there were no significant differences in complications between the two groups. Within 30 days postoperatively, LA was associated with a significantly higher incidence of abdominal abscesses with consequent diagnostic investigations, interventions, and readmissions. Although laparoscopic appendectomy is known to deliver clinical advantages, it is associated with a higher incidence of abdominal abscesses. Because the procedure is about to become the standard of care, future research must be directed at solving this issue. The expected lower incidence of incisional hernia and small bowel obstruction after laparoscopic appendectomy was not shown in the present stud

Adhesion Awareness: A National Survey of Surgeons

Contains fulltext : 87943.pdf (publisher's version ) (Closed access)BACKGROUND: Postoperative adhesions are the most frequent complication of abdominal surgery, leading to high morbidity, mortality, and costs. However, the problem seems to be neglected by surgeons for largely unknown reasons. METHODS: A survey assessing knowledge and personal opinion about the extent and impact of adhesions was sent to all Dutch surgeons and surgical trainees. The informed-consent process and application of antiadhesive agents were questioned in addition. RESULTS: The response rate was 34.4%. Two thirds of all respondents (67.7%) agreed that adhesions exert a clinically relevant, negative effect. A negative perception of adhesions correlated with a positive attitude regarding adhesion prevention (rho = 0.182, p < 0.001). However, underestimation of the extent and impact of adhesions resulted in low knowledge scores (mean test score 37.6%). Lower scores correlated with more uncertainty about indications for antiadhesive agents which, in turn, correlated with never having used any of these agents (rho = 0.140, p = 0.002; rho = 0.095, p = 0.035; respectively). Four in 10 respondents (40.9%) indicated that they never inform patients on adhesions and only 9.8% informed patients routinely. A majority of surgeons (55.9%) used antiadhesive agents in the past, but only a minority (13.4%) did in the previous year. Of trainees, 82.1% foresaw an increase in the use of antiadhesive agents compared to 64.5% of surgeons (p < 0.001). CONCLUSIONS: The magnitude of the problem of postoperative adhesions is underestimated and informed consent is provided inadequately by Dutch surgeons. Exerting adhesion prevention is related to the perception of and knowledge about adhesions.1 december 201

Bologna guidelines for diagnosis and management of adhesive small bowel obstruction (ASBO) : 2017 update of the evidence-based guidelines from the world society of emergency surgery ASBO working group

Background: Adhesive small bowel obstruction (ASBO) is a common surgical emergency, causing high morbidity and even some mortality. The adhesions causing such bowel obstructions are typically the footprints of previous abdominal surgical procedures. The present paper presents a revised version of the Bologna guidelines to evidence-based diagnosis and treatment of ASBO. The working group has added paragraphs on prevention of ASBO and special patient groups. Methods: The guideline was written under the auspices of the World Society of Emergency Surgery by the ASBO working group. A systematic literature search was performed prior to the update of the guidelines to identify relevant new papers on epidemiology, diagnosis, and treatment of ASBO. Literature was critically appraised according to an evidence-based guideline development method. Final recommendations were approved by the workgroup, taking into account the level of evidence of the conclusion. Recommendations: Adhesion formation might be reduced by minimally invasive surgical techniques and the use of adhesion barriers. Non-operative treatment is effective in most patients with ASBO. Contraindications for non-operative treatment include peritonitis, strangulation, and ischemia. When the adhesive etiology of obstruction is unsure, or when contraindications for non-operative management might be present, CT is the diagnostic technique of choice. The principles of non-operative treatment are nil per os, naso-gastric, or long-tube decompression, and intravenous supplementation with fluids and electrolytes. When operative treatment is required, a laparoscopic approach may be beneficial for selected cases of simple ASBO. Younger patients have a higher lifetime risk for recurrent ASBO and might therefore benefit from application of adhesion barriers as both primary and secondary prevention. Discussion: This guideline presents recommendations that can be used by surgeons who treat patients with ASBO. Scientific evidence for some aspects of ASBO management is scarce, in particular aspects relating to special patient groups. Results of a randomized trial of laparoscopic versus open surgery for ASBO are awaited.Peer reviewe