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Biomedical subjects

J A Windsor

Publications and source records attributed to J A Windsor.

At least 37 records · Page 2Linked to original sources
PubMed1999

Small bowel ischaemia-reperfusion increases plasma concentrations of oxidised proteins in rats.

OBJECTIVES: To find out whether plasma concentrations of protein carbonyl (a specific marker of oxidative damage of proteins) are increased during intestinal ischaemia-reperfusion and whether they are correlated with von Willebrand's factor (vWF, a marker of endothelial injury) or myeloperoxidase (a marker of neutrophil activation). DESIGN: Randomised experimental study. SETTING: University department of surgery, New Zealand. ANIMALS: Thirty anaesthetised adult Wistar rats. INTERVENTIONS: The sham operated group (n = 10) had laparotomy and isolation of the superior mesenteric artery without clamping. The ischaemia-reperfusion group (IR, n = 10) had the superior mesenteric artery clamped for 1 hour and reperfusion for 15 minutes. The control group (n = 10) had direct puncture of the heart to sample blood. MAIN OUTCOME MEASURES: Plasma concentrations of protein carbonyl, vWF, and myeloperoxidase. RESULTS: Plasma protein carbonyl concentrations were significantly higher in the IR group than in the sham group (p < 0.02, Mann-Whitney test, median (range) 0.187 (0.141-0.242) compared with 0.144 (0.121-0.185) nmol/mg) and in the control group (p < 0.01, Mann-Whitney test, median (range) 0.187 (0.141-0.242) compared with 0.136 (0.108-0.175) nmol/mg). There was a significant correlation between protein carbonyl and vWF concentrations (r = 0.54, F = 10.9, p < 0.003, linear regression) but not with those of myeloperoxidase. CONCLUSION: Intestinal ischaemia-reperfusion caused an increase in the plasma protein carbonyl concentration, which is possibly produced by endothelial cells.

Animals↗
PubMed1999

Anti-inflammatory cytokine response and clinical outcome in acute pancreatitis.

OBJECTIVE: To test the hypothesis that elevated interleukin (IL)-10 plasma concentration relative to IL-6 and IL-8 in patients with acute pancreatitis is associated with improved clinical outcome. DESIGN: Case series. SETTING: University hospital surgical and intensive care unit. PATIENTS: Patients with mild (n = 18) and severe (n = 14) acute pancreatitis were recruited within 12 hrs of admission and studied for 5 days. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The plasma concentration of IL-10 was significantly elevated in patients with severe pancreatitis during the 5 days and especially so in those who died compared with survivors on day 5 (p <.03). The ratio of IL-10/IL-6 was decreased in patients with severe pancreatitis on day 5 (p < .01). There was a significant decrease in the ratio of IL-10/IL-8, but not of IL-10/IL-6, during the first 5 days (p < .014). CONCLUSIONS: The findings are consistent with the hypothesis that an increase in plasma IL-10 relative to IL-6 or IL-8 is associated with improved clinical outcome.

Acute Disease↗
PubMed1999

Intestinal ischaemia-reperfusion increases plasma amylin concentration in rats.

Intestinal ischaemia-reperfusion and hyperamylinaemia are both associated with severe acute pancreatitis. The aim of this study was to examine the relationship between intestinal-ischaemia reperfusion and plasma amylin in an experimental model. Wistar rats (n = 24, 400-450 g) were divided into three groups: (1) a sham (S)-operated group (n = 7) that underwent laparotomy and isolation (without clamping) of the superior mesenteric artery, (2) an ischaemia-reperfusion (IR) group (n = 7) that had clamping of the superior mesenteric artery for 60 min followed by 15 min reperfusion, and (3) a control (C) group (n = 10) that underwent no surgery. Amylin was significantly elevated in the IR group (median 39 pM, range 30-44) compared with the S group (19 pM, range 15-45; Mann-Whitney U, p < 0.05) and the C group (24 pM, range 15-55; p < 0. 01). Insulin was significantly elevated in the IR group (2,060 pM, range 1,000-4,650) compared with the S group (558 pM, range 424-2, 020; p < 0.01). There was a significant positive correlation between amylin and insulin (R = 0.82, F = 46.6, p < 0.0001), but not between amylin and glucose or insulin and glucose. Intestinal histology was consistent with an ischaemia-reperfusion injury, whereas pancreatic histology was normal. The unique finding that plasma amylin concentration is increased with intestinal ischaemia-reperfusion injury warrants further investigation.

Amyloid↗
PubMed1998

The role of surgery in the management of obesity.

This article reviews the role of surgery in the management of obesity. Surgery is discussed in the context of the different approaches to conservative treatment. Although there are no randomised trials, the available data suggest that open surgery is the most effective treatment for severe obesity when offered to carefully selected patients who are managed by a multidisciplinary team, committed to long-term follow-up. Results from ongoing, randomised controlled trials are awaited. Laparoscopic adjustable gastric banding is a promising technique which offers the benefits of less invasive surgery, appears to be as effective as open surgery but its diffusion should follow more rigorous evaluation.

Aftercare↗
PubMed1998

An audit of pancreatic pseudocyst management and the role of endoscopic pancreatography.

BACKGROUND: A rational algorithm for the management of symptomatic pancreatic pseudocysts is necessary with the increasing availability of radiological, surgical and endoscopic methods of treatment. METHODS: A retrospective audit of the management and outcome of all patients who presented with symptomatic pancreatic pseudocysts to the Auckland Hospital over a 9-year period (1988-96) was made. RESULTS: There were 44 patients (28 men, 16 women; median age 50; range 18-81) in this series. Initial management was not based on pseudocyst size, duration, location, wall thickness, the patients' symptoms and comorbidity, or the aetiology of pancreatitis. Of the 27 patients who had initial conservative management, 15 pseudocysts (56%) completely resolved. Of the 17 patients who were initially or subsequently treated with percutaneous catheter drainage (PCD), 10 pseudocysts (59%) completely resolved without additional treatment. Of the 13 patients initially or subsequently treated by surgery, all but one completely resolved after the first procedure. Two patients were successfully treated with endoscopic pancreatic stent placement. Complications arose in eight patients treated with PCD (47%) and four patients treated with surgery (31%). There was no mortality. The decision for active treatment was not preceded by delineation of the pancreatic duct by ERCP (endoscopic retrograde cholangiopancreatography) in 60% of patients. CONCLUSIONS: More than one-third of all patients with symptomatic pancreatic pseudocysts can be managed conservatively. Surgery yields excellent results but PCD has a high failure rate in patients with an underlying pancreatic duct stricture. A rational management algorithm is presented, based on pre-intervention ERCP, which should improve patient selection and outcome.

Adolescent↗
PubMed1998

Laparoscopic biliary injury: more than a learning curve problem.

BACKGROUND: The increase in the incidence of iatrogenic injury to the extrahepatic biliary tree that has been documented since the introduction of laparoscopic cholecystectomy (LC) has been explained as a 'learning curve' problem. The early New Zealand experience has been published and the present study was undertaken to determine whether there had been any change in the incidence, nature and management of laparoscopic biliary injuries (LBI) after further experience with LC. METHODS: A nationwide audit was undertaken in 1995 by two confidential postal questionnaires: to all active general surgeons (n=184, response rate 60%), and to all endoscopists performing endoscopic retrograde cholangiopancreatography (ERCP) (n=18, response rate 100%). RESULTS: The total number of LBI was 21, compared with 41 for 1991-92. The site and nature of the injuries were similar for the two survey periods. More of the injuries appeared to be diagnosed after the operation and prior to discharge (25% vs 47%). Calculating the national incidence of LBI was not possible without complete reporting, but in the subset of surgeons responsible for the LBI there was no apparent decrease in the incidence of all LBI (2.8% vs 2.9%), those requiring active re-intervention (2.4% vs 2.7%) and major duct injury (1.1% vs 0.7%), despite a significant increase in the surgeons' prior experience with LC (20% vs 61% of surgeons had performed more than 100 LC). There were some concerning trends in management: a less frequent use of ERCP in patients with LBI diagnosed after surgery (76% vs 65%) and a higher proportion of patients with minor injuries managed by re-operation (26% vs 50%). CONCLUSIONS: The present study indicates that iatrogenic biliary injury is a persistent problem in New Zealand, despite increasing experience with LC, and suggests the need for more intensive scrutiny of operative technique and training. There is scope to manage more patients with minor duct injuries conservatively.

Bile Ducts, Extrahepatic↗
PubMed1997

Manganese superoxide dismutase: a marker of ischemia-reperfusion injury in acute pancreatitis?

Recent evidence has suggested that ischemia-reperfusion injury is fundamental to the pathogenesis of acute pancreatitis. This study was designed to determine whether acute pancreatitis is associated with elevated serum manganese superoxide dismutase (MnSOD), a key antioxidant enzyme, considered a marker of ischemia-reperfusion injury in myocardial infarction. Thirty-four patients with acute pancreatitis had measurements of MnSOD on days 0, 2, and 5 after recruitment. The patients were recruited within 12 h of admission to hospital and had measurements of MnSOD on days 0, 2, and 5. Patients with severe acute pancreatitis had significantly elevated serum MnSOD concentrations on days 2 and 5 compared with patients with mild acute pancreatitis, but not on the day of recruitment. Elevated serum MnSOD correlated with peripheral plasma markers of lipid peroxidation (malondialdehyde) and neutrophil activation (myeloperoxidase) and was associated with decreased plasma ascorbic acid concentrations. The serial measurement of serum MnSOD may prove useful as a marker of the effectiveness of treatment designed to limit ischemia-reperfusion injury in patients with severe acute pancreatitis.

Acute Disease↗
PubMed1997

Gastric intramucosal pH predicts death in severe acute pancreatitis.

BACKGROUND: This study tested the hypothesis that gastric intramucosal pH (pHi) can predict death in severe acute pancreatitis. METHODS: Seventeen consecutive patients with predicted severe acute pancreatitis were studied prospectively. Four died from complications related to pancreatitis. Gastric pHi was measured by nasogastric tonometry at least every 12 h for the first 48 h after admission and then on a daily basis during the first week. RESULTS: The lowest pHi recorded during the first 48 h was significantly less in those admitted to the intensive care unit than that in those who remained on the surgical ward (P = 0.0015) and in nonsurvivors compared with the survivors (P = 0.009). A receiver-operator characteristic curve defined a pHi of 7.25 as the optimal cut-off point to predict death (sensitivity 100 per cent, specificity 77 per cent, overall predictive value 82 per cent). CONCLUSION: These results suggest that splanchnic ischaemia may be an important determinant of outcome in patients with severe acute pancreatitis.

Acute Disease↗
PubMed1995

Inguinal hernia repair by laparoscopic surgeons: early experience and attitudes.

The introduction of laparoscopic inguinal hernia repair (LIHR) has been controversial. A questionnaire was sent to all general surgeons in New Zealand to document the early experience with LIHR and attitudes towards it. Of the 118 replies (response rate 55%), 74 were from laparoscopic surgeons, 26 of whom had performed 564 (201 public, 363 private) LIHR (23 bilateral) until January 1994. Only nine (35%) of these surgeons had assisted an experienced surgeon before performing an LIHR, and only four (15%) were supervised by an experienced surgeon during their first case. The transabdominal preperitoneal technique of LIHR was used by 14 (54%) surgeons, the extraperitoneal technique by eight (31%), and the transabdominal onlay technique by four (15%). There were 29 (5%) recurrences, 17 (3%) neuropathies, seven (1.2%) conversions, four (0.7%) major perforations, and one (0.17%) death. Of the 26 surgeons who performed LIHR, 20 (77%) were concerned about the absence of long-term results, 14 (54%) considered that the optimal technique had not been established, 13 (50%) were concerned about the unique complications associated with LIHR, 11 (42%) were less enthusiastic about performing LIHR than previously, 10 (38%) were doubtful about its advantages, and six (23%) were uncertain about its future and considered that it should only be performed within the context of a controlled trial. This study highlights a number of issues that need to be addressed before the role of LIHR can be determined.

Attitude to Health↗
PubMed1994

Early laparoscopic biliary injury: experience in New Zealand.

Data on the incidence, nature and management of early laparoscopic biliary injury up to January 1993 were obtained by a postal questionnaire sent to all New Zealand general surgeons (n = 214; response rate 71 percent) and to all endoscopists who perform endoscopic retrograde cholangiography (n = 16; response rate 100 percent). A total of 41 injuries (surgeons' survey, 22; endoscopists' survey, 19) occurred in an estimated 4000 laparoscopic cholecystectomies; 16 involved the common bile and hepatic ducts, and 25 the cystic and segment V ducts. Operative cholangiography was performed in one patient. The diagnosis of injury was made after operation in 31 of 41 patients and after discharge in 21. Conservative management was undertaken in only 19 patients. This prospective audit documents an increase in the incidence of early biliary injury after the introduction of laparoscopic cholecystectomy in New Zealand. The results highlight the need for further study to determine the best way to ensure early and accurate diagnosis of biliary injury and to define optimal conservative and operative management.

Biliary Tract↗
PubMed1994

Early experience with minimally invasive surgery: a New Zealand audit.

The clinical and economic impact of minimally invasive surgery in New Zealand, especially laparoscopic cholecystectomy, has been profound but uncharted. A postal questionnaire was sent to all general surgeons in New Zealand (n = 214), in order to document the current levels of experience, adequacy of training, levels of equipment and sources of funding. In the case of laparoscopic cholecystectomy, further details were obtained relating to operative technique, complication rates and approaches to the management of choledocholithiasis. The response rate was 71%. From 27 centres, 71 of 106 active general surgeons were performing minimally invasive surgery. Of the 34 different procedures audited, cholecystectomy (3056), herniorrhaphy (178), and appendicectomy (141) were performed most often. Primary funding came from Area Health Boards (71%) and private hospital funds (25%) with 4% coming from other sources. Ten different camera/insufflator systems were used. Training was perceived to be adequate by the majority of surgeons (89%), although seven surgeons had received no specific training. Laparoscopic cholecystectomy technique included: prophylactic antibiotics (89% of surgeons), patients supine (80%), wound infiltration (80%), routine use of diathermy within triangle of Calot (36%) and a routine peritoneal drain (13%). Routine operative cholangiography was used rarely (7%) and 72% of surgeons had deliberately changed their policy with respect to its use. Twenty-two cases of laparoscopic biliary injury were identified by the survey, none of whom had operative cholangiography. The conversion rate was 13% for acute and 4% for elective laparoscopic cholecystectomy. This survey indicated the broad scope of minimally invasive surgery that is being undertaken, and highlights potentially important variations in surgical practice.

Cholangiography↗
PubMed1993

Role of serum endotoxin and antiendotoxin core antibody levels in predicting the development of multiple organ failure in acute pancreatitis.

It has been proposed that endotoxin contributes to the development of multiple organ failure (MOF) in acute pancreatitis. Endotoxaemia is transient and may not be detected by intermittent blood sampling. By contrast, not only can changes in the patient's endogenous antiendotoxin core antibody pool persist for many days, but depletion of this pool may be a key event in determining the physiological significance of endotoxaemia. A series of 33 patients with acute pancreatitis had daily measurement of Acute Physiology Score (APS) and levels of C-reactive protein, interleukin 6, endotoxin, immunoglobulin (Ig) G and IgM antiendotoxin core antibodies, and prospective documentation of complications. Endotoxin was detected in the serum of 13 patients, while a significant change in levels of endogenous antiendotoxin core antibodies was detected in all those with severe pancreatitis and in 28 overall. MOF developed in seven patients, five of whom died. The combination of a rising APS over the first 48 h of admission and a significant fall in endogenous IgG antibody level was observed in all patients who developed MOF (seven of seven), but in only one of 16 without MOF (P = 0.00003; overall predictive value 91 per cent). This study suggests that measuring the initial trend in APS and the concentration of endogenous IgG antiendotoxin core antibody provides a means of identifying patients with acute severe pancreatitis who are at high risk of developing MOF. This group might benefit from passive immunotherapy with antiendotoxin antibodies.

Acute Disease↗