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V Poxon

Publications and source records attributed to V Poxon.

18 recordsLinked to original sources
PubMed1997

Comparison of serum, salivary, and rapid whole blood diagnostic tests for Helicobacter pylori and their validation against endoscopy based tests.

BACKGROUND: A rapid, reliable, and accurate test for the diagnosis of infection with Helicobacter pylori is needed for screening dyspeptic patients before referral for endoscopy. AIM: To compare a new rapid whole blood test (Helisal rapid blood, Cortecs), two serum enzyme linked immunosorbent assays (ELISAs; Helico-G, Shield and Helisal serum, Cortecs), and a salivary assay (Helisal saliva, Cortecs), with slide biopsy urease, 13C-urea breath test, and histology. METHODS: Three hundred and three consecutive dyspeptic patients attending for gastroscopy underwent two antral biopsies for histology, and one for rapid slide biopsy urease test for assessment of H pylori status. Blood and saliva were also collected. One hundred of the patients also underwent a 13C-urea breath test. Gold standard positives were defined as those with at least two positive tests among slide urease, breath test, or histology, and gold standard negatives as those with all these (or two when the breath test was not done) negative. RESULTS: Of 300 patients (median age 63, range 28-89) eligible for analysis, 137 (46%) were gold standard positives, of which Helisal rapid blood identified 116, Helico-G 129, Helisal serum 130, and Helisal saliva 120; 137 (46%) were gold standard negatives of which the number falsely identified as positive was 30 by Helisal rapid blood, 45 by Helico-G, 41 by Helisal serum, and 41 by Helisal saliva. Sensitivities and specificities were: for the whole blood test 85% and 78% respectively; for Helico-G 94% and 67%, for Helisal serum 95% and 70%, and for Helisal saliva 84% and 70%. CONCLUSIONS: If endoscopy had been undertaken only on patients with positive tests two of 16 duodenal ulcers would have been missed if the Helisal rapid blood test was used, and one if any of the ELISA tests were used. None of the blood tests would have missed any of six gastric ulcers, but the salivary test would have missed one.

Adult↗
PubMed1995

Helicobacter pylori eradication in a clinical setting: success rates and the effect on the quality of life in peptic ulcer.

BACKGROUND: Helicobacter pylori eradication for peptic ulcer has been widely taken up. Evidence for the efficacy of different regimens is often derived from small series in clinical trials but there is little reporting of everyday practice with unselected patients. Freedom from ulcer relapse has been demonstrated, but not whether this equates with clinical success. METHODS: We report on a series of 706 patients with H. pylori infection who, between January 1991 and April 1995, received eradication therapy followed by assessment of H. pylori status. Two-hundred and seven of these patients were followed-up by postal questionnaire, validated by parallel questionnaires to their general practitioners, covering clinical outcome measures. RESULTS: The overall eradication rate was 81.7%, and a 1-week course of omeprazole plus two antibiotics was significantly better than a 2-week course of standard triple therapy (85.0% vs. 78.0%, P < 0.05). Amongst 21 first-time failures, a 7-day course of a clarithromycin-containing triple therapy succeeded in 18. The questionnaire replies indicate that, following successful H. pylori eradication, ulcer patients are less likely to consult with ulcer symptoms (P < 0.0005), take medication (P < 0.0005), require further prescription (P < 0.0005), or lose work-time because of their ulcer (P < 0.005). They are more likely to have a subjective sense of ulcer cure (P < 0.0005). CONCLUSIONS: In addition to clear cost savings, social benefits are now demonstrated when H. pylori is eradicated. A well-tolerated 1 week regimen is genuinely effective in everyday practice.

Adult↗
PubMed1994

Mucosal glucosamine synthetase activity in inflammatory bowel disease.

Abnormalities in colonic glycoprotein synthesis have been implicated in the pathogenesis of ulcerative colitis and Crohn's disease. Glucosamine synthetase is the rate-limiting step in the biosynthesis of gastrointestinal glycoprotein and has been measured in control subjects (N = 23) and patients with ulcerative colitis (N = 26) or Crohn's disease of the colon (N = 20) classified according to the macroscopic status of the rectum. Glucosamine synthetase activity was relatively constant around the normal colon but lower levels were found in the terminal ileum. In ulcerative colitis, glucosamine synthetase activity was similar to controls (24.0 +/- 1.9) mmol/g wet (wt/hr) irrespective of disease activity (quiescent: N = 13, = 27.3 +/- 1.9; active N = 16, = 26.2 +/- 2.3). Rectal glucosamine synthetase activity was normal in the presence of active Crohn's proctocolitis (29.4 +/- 3.1) but raised in patients with Crohn's colitis and rectal sparing (37.2 +/- 4.9 P < 0.02). Glucosamine synthetase activity was strongly influence by the degree of epithelial preservation.

Colitis, Ulcerative↗
PubMed1994

Faecal diversion for Crohn's colitis: a model to study the role of the faecal stream in the inflammatory process.

The high incidence of clinical remission after faecal diversion for Crohn's colitis suggests the faecal stream may play a part in the inflammatory mechanism. The effect of faecal diversion (n = 22) and restoration of intestinal continuity (n = 10) was assessed in patients with Crohn's colitis and compared with controls. Faecal diversion produced significant improvement in the disease activity index mean (SEM) (before 176 (9); after 114 (9), p < 0.01) and serum albumin concentrations (before 33 (3.0); after 38 (3.0), p < 0.05) in all patients with Crohn's colitis. The crypt cell production rate (CCPR) was maintained after faecal diversion for Crohn's colitis but fell in the control group (before = 3.6 (0.8)), at two (1.4 (0.4), p < 0.02), and six weeks (1.6 (0.4), p < 0.05). Mucosal glucosamine synthetase activity, reflecting glycoprotein synthesis, was significantly lower in patients with Crohn's colitis (analysis of variance p < 0.05) after diversion but was maintained in the control group. Restoration of intestinal continuity failed to produce reciprocal changes. The sustained cellular proliferation and fall in glycoprotein synthesis in Crohn's colitis after faecal diversion may represent the end of an exaggerated protective response and regenerative hyperplasia after exclusion of the faecal stream. This study suggests the faecal stream may participate in the inflammatory process in Crohn's colitis. The underlying mechanism is unknown.

C-Reactive Protein↗
PubMed1993

The influence of ileal pouch-anal anastomosis for ulcerative colitis on ileal glycoprotein synthesis.

Restorative proctocolectomy and ileal pouch-anal anastomosis are frequently associated with the onset of low-grade inflammation, colonic metaplasia, and pouchitis. The influence of intestinal adaptation and inflammatory activity on ileal glycoprotein synthesis (GS) has been assessed. Ileal GS activity in controls (n = 13, 28.9 +/- 3.6) was similar to that of patients with ulcerative colitis (n = 18, 26.4 +/- 3.6) irrespective of the presence of backwash ileitis (n = 6, 22.0 +/- 4.0). Ileoanal pouch construction was not associated with a significant change in ileal GS activity regardless of the presence of low-grade inflammation (n = 19, 25.9 +/- 2.2), frank pouchitis (n = 5, 24.4 +/- 4.6), or transformation to a colonic type of mucosa (n = 6, 25.4 +/- 5.2). The transformation of ileal mucosa from an absorptive to a storage function is associated with characteristic morphologic and inflammatory changes but does not produce a protective response mediated by increased GS.

Adaptation, Physiological↗
PubMed1993

A pathophysiologic study of diversion proctitis.

Diversion proctitis occurs with variable frequency after exclusion of the fecal stream. Its importance lies in the inability to differentiate it from other types of proctitis that may result in inappropriate therapy and a reluctance to recommend stoma closure. The effect of fecal diversion (n = 18) and restoration of intestinal continuity (n = 10) on human rectal mucosa in patients without inflammatory intestinal disease has been prospectively evaluated. Fecal diversion was associated with macroscopic inflammation in 55 percent of the patients and histologic inflammation in 72 percent, with a variable incidence of aphthoid ulceration, crypt abscess formation and submucosal nodularity. Restoration of continuity was associated with improvement in histologic features in all patients, but the mucosa returned to normal in only 50 percent of the patients. Onset or resolution of diversion proctitis was not associated with any significant changes in colonic cellular proliferation, glycoprotein synthesis or mucosa-associated or luminal flora. The only diagnostic feature of defunctioned proctitis remains its resolution on reintroducing the fecal stream.

Diagnosis, Differential↗
PubMed1988

Gastric juice factors after Roux-Y reconstruction compared with Billroth II partial gastrectomy.

Gastric juice was studied in five patients after Billroth II partial gastrectomy, in six patients after Roux-Y reconstruction, and in eight healthy control subjects. Juice was obtained over a 24 hour period by hourly nasogastric aspiration prior to measurement of pH, total and stable N nitrosocompounds, nitrites, bile acids (total and free), and bacterial count. Large variations in almost all compounds were seen during the 24 hour period in individual patients, and in addition, there were large variations between patients within the clinical groups. The gastric juice pH concentration was higher in the Billroth II group, as was the bacterial flora count (median 3 X 10(6) organisms/ml). Although Roux-Y bile diversion reduced the exposure to bile acids, it did not prevent it, and bacterial proliferation was increased (1 X 10(7) organisms/ml). No significant differences or sizeable trends were seen in N nitrosocompounds or nitrite concentrations.

Anastomosis, Roux-en-Y↗
PubMed1986

Incidence of bile reflux in gastric ulcer and after partial gastrectomy.

Duodenogastric bile reflux (DGBR) is reported to be increased in patients with gastric ulcer (GU) and following Billroth I partial gastrectomy (BIPG). pH, total bacterial counts, and total and free bile acids were measured in gastric juice aspirated hourly for 24 h in 6 patients with GU, 7 patients with a BIPG performed for GU and in 8 healthy normal controls. Intragastric pH was significantly higher in the BIPG group during the day (P less than 0.001) and at night (P less than 0.001) compared with normals and the GU group. There were no differences between GUs and normal patients. Bile acid concentrations in the gastric juice were not significantly different between GU and control groups over the 24 h. Median and range values were 0.14 (0.06-0.52) mmol l-1 in GU patients and 0.14 (0.05-0.67) mmol l-1 in the normals. However total bile acid concentrations were significantly greater in the BIPG group (0.23, 0.04-0.84) compared with GU or controls. (P = 0.04, P = 0.02). Our data do not support the role of DGBR in the pathogenesis of GU, but deoxycholic acid was detected in significantly greater amounts in BIPG subjects than controls (chi 2 = 12.94, P less than 0.001) or GU subjects (none detected) and may be important in the pathogenesis of gastric stump cancer.

Adult↗
PubMed1984

Intragastric N-nitrosation is unlikely to be responsible for gastric carcinoma developing after operations for duodenal ulcer.

Three groups of patients studied after operations which had cured their duodenal ulcer were compared with a control group (no operation, n = 8). The surgical procedures included: proximal gastric vagotomy (n = 7), truncal vagotomy and pyloroplasty (n = 7), truncal vagotomy and antrectomy (n = 8). Samples of gastric juice were aspirated half hourly or hourly over 24 hours for measurement of pH, counts of all identified bacteria, nitrite and total N-nitrosocompounds. Although the pH over 24 hours was significantly higher after proximal gastric vagotomy (p less than 0.05) and truncal vagotomy and antrectomy (p less than 0.001) than controls, there was no difference between truncal vagotomy and pyloroplasty and controls. Counts of nitrate reducing bacteria over 24 hours were also significantly higher after truncal vagotomy and antrectomy than controls (p less than 0.1) but no differences were observed between the other groups. Only after truncal vagotomy and antrectomy was nitrite over 24 hours significantly increased compared with controls (p less than 0.01). Despite these higher values after truncal vagotomy and antrectomy, there was no significant difference in total N-nitrosocompounds between any of the four groups. Whereas bacterial counts and nitrite increased with pH, no correlation was found between total N-nitrosocompounds and pH. These results provide no evidence that exposure to total N-nitrosocompounds is increased after operations for duodenal ulcer.

Bacteria↗
PubMed1984

The importance of the distal stomach in gastric emptying of liquids in man.

The effects of pyloroplasty and vagal denervation of the distal stomach on gastric emptying of 10% dextrose have been compared. In a randomized trial, 38 male patients having elective surgery were treated by proximal gastric vagotomy (PGV, N = 10), proximal gastric vagotomy and pyloroplasty (PGV + P, N = 9), total gastric vagotomy (TGV, N = 9), and total gastric vagotomy and pyloroplasty (TGV + P, N = 10). Gastric emptying was recorded using an external scanning technique before and after operation. Compared with before operation, all four procedures resulted in significantly faster emptying during ingestion of the meal (the filling phase). This is attributable to failure of receptive relaxation of the proximal stomach. The emptying phase (after ingestion of the meal) was unchanged by PGV, but was significantly altered by PGV + P, TGV, and TGV + P (Principal Component Analysis). Before operation and after PGV, emptying fitted a monoexponential curve. In contrast, after PGV + P, TGV, and TGV + P, the emptying phase fitted a double exponential curve. Emptying was precipitate initially, but slowed later, leaving a large residual volume. We conclude that, when the proximal stomach is denervated, the intact, innervated distal stomach can restore the emptying of hypertonic dextrose to normal; however, when the distal stomach is denervated or pyloroplasty has been performed emptying remains uncontrolled. Since pyloroplasty and vagal denervation have the same effect, it is concluded that the mechanism retarding the emptying of hypertonic dextrose is an active mechanism that resides in the terminal antrum or pylorus.

Adult↗
PubMed1983

Effects of nutrient liquids on human gastroduodenal motor activity.

The effects of intragastric infusion of 10% Intralipid and 10% dextrose on the intraluminal pressures in the antrum, pylorus and duodenal bulb have been examined. Ten studies with each infusate have been performed in 10 normal subjects and the results compared with those obtained previously in 22 studies during intragastric infusion of isotonic saline. During saline infusion, contractile activity varied. In six studies fasting motor activity persisted; in the remainder, variable activity, without recognisable pattern was recorded. With saline, the gastroduodenal region usually functioned as a unit and the pylorus was the least autonomous part. Neither a sustained rise of basal pressure nor rhythmic, independent contractions were recorded from the pylorus. The contractile activity of the gastroduodenal region with Intralipid and dextrose was more uniform than with saline. Fasting motor activity was always abolished. The gastroduodenal region ceased to contract as a unit and the pylorus acquired autonomous activity. Rhythmic, independent contractions of the pylorus were recorded in nine of 10 studies during Intralipid infusion and six of 10 studies with dextrose. In addition, a sustained rise in pyloric basal pressure was recorded in eight of 10 studies with Intralipid and three of 10 studies with dextrose. Pyloric motility indices were significantly greater with fat than with dextrose. The observed differences in gastroduodenal motility are consistent with a role for the pylorus in the control of emptying of liquid from the stomach.

Duodenum↗
PubMed1983

Biliary excretion of piperacillin.

1. The excretion of piperacillin sodium in bile was studied after intravenous injection of 2 g (n = 5) and 4 g (n = 7). All patients had undergone cholecystectomy and exploration of the common bile duct for cholelithiasis. Bile, serum and urine concentrations were measured by a microbiological technique. 2. Peak concentrations of piperacillin were found in bile at 150 minutes after 4 g and at 210 minutes after 2 g. 3. Both the concentration of piperacillin in bile at the end of a 6 1/2 hour study and the calculated mean bile concentration of piperacillin were above the minimum inhibitory concentration (MIC) of this drug for organisms commonly found in acute biliary tract infections. We believe piperacillin may be useful in the management of such conditions.

Adolescent↗
PubMed1981

A study of motility of normal human gastroduodenal region.

A method of recording continuously and simultaneously the intraluminal pressure in the antrum, pylorus, and duodenal bulb has been used to study gastroduodenal motility during intragastric infusion of saline. Twenty-two studies were performed in 15 normal individuals. Two types of contraction were recorded: (1) independent contractions of the individual parts of the gastroduodenal region, and (2) related contractions of the antrum, pylorus, and duodenal bulb, resulting in a concerted contraction of the whole region. The majority of pyloric contractions were part of a concerted contraction of the whole gastroduodenal region during which the pylorus behaved as the terminal part of the antrum. The majority of duodenal contractions were not associated with pyloric contractions, only 21.7% of duodenal contractions coincided with closure of the pylorus. This suggests that under the conditions of this study the pylorus was not acting as a barrier to reflux. An elevated basal pressure was never recorded from within the pylorus; apart from a brief closure during contraction, the pylorus is always open.

Adult↗