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Biomedical subjects

W J Owen

Publications and source records attributed to W J Owen.

At least 19 recordsLinked to original sources
PubMed2004

A review of the atypical manifestations of gastroesophageal reflux disease.

Manifestations of atypical gastroesophageal reflux disease (GORD) are varied, and the presentation of atypical symptoms may occur in the absence of typical symptoms. The most sensitive and specific investigation for GORD is pH monitoring, and its application in atypical disease is utilized throughout this paper as a basis for correlating disease and pathogenesis. The less well-known areas of laryngeal manifestations, particularly chronic hoarseness and globus, are discussed in addition to recent work on orodental manifestations. Well-known areas of cardiac and respiratory manifestations, which include chronic cough and asthma, are also reviewed. Evidence from clinical trials indicates that aggressive anti-reflux therapy in patients with atypical symptoms can be effective. Where appropriate, medical therapy may involve long-term proton pump inhibitor, although further research outlining the roles of other therapies such as surgery is awaited.

Chest Pain↗
PubMed2001

Reproducibility and intragastric variation of duodenogastric reflux using ambulatory gastric bilirubin monitoring.

Duodenogastric reflux has long been considered to be important in the pathogenesis of many gastric disorders that exhibit regional variation within the stomach. Ambulatory gastric bilirubin monitoring is a new technique and, although extensively validated, reproducibility and gastric regional variation have not been specifically addressed. Fourteen patients with symptoms of gastroesophageal reflux and 12 healthy subjects underwent 24-h ambulatory gastric bilirubin monitoring with the bilirubin sensor in the upper stomach. Gastric bilirubin monitoring with two simultaneous bilirubin probes, one in the upper stomach and the other in the antrum, was performed on a separate occasion. Gastric bilirubin exposure in the initial and repeat studies showed a good correlation (R = 0.60, P < 0.01). Gastric bilirubin exposure in the upper stomach and the antrum showed a high degree of correlation (R = 0.90, P < 0.01). In conclusion, reproducible results are obtained with ambulatory gastric bilirubin monitoring and duodenogastric reflux does not exhibit significant regional variation within the stomach.

Adult↗
PubMed2001

The extent of duodenogastric reflux in gastro-oesophageal reflux disease.

BACKGROUND: It is known that duodenogastro-oesophageal reflux (DGOR) increases with worsening gastro-oesophageal reflux disease (GORD). It is unclear whether this is accompanied by increasing duodenogastric reflux (DGR). OBJECTIVE: To investigate the extent of DGR in a control group and 66 patients with GORD, using the technique of ambulatory gastric bilirubin monitoring. METHODS: Sixty-six patients with reflux symptoms (30 grade 0 or 1 oesophagitis (group 1), 16 grade 2 or 3 oesophagitis (group 2), 20 Barrett's oesophagus (group 3)) and 17 healthy controls were studied. All underwent oesophageal manometry followed by 24-h ambulatory oesophageal and gastric pH monitoring and gastric bilirubin monitoring. RESULTS: Median per cent total oesophageal acid exposure (pH < 4) was significantly less in the control group (0.6%) than in group 1 (2.8%, P< 0.05) and groups 2 and 3 (7.5% and 7.8% respectively, P< 0.001). There was no significant difference between any group in median per cent total time gastric pH was greater than 4. There was no significant difference in median per cent total gastric bilirubin exposure (absorbance > 0.14) between any group. However, in each group gastric bilirubin exposure was greater in the supine position than the upright position, being significantly greater in the control group (P< 0.05) and group 1 (P < 0.001). CONCLUSIONS: Gastric bilirubin exposure is similar across the spectrum of GORD severity. It is greater in the supine than in the upright position.

Adult↗
PubMed2001

Gastro-oesophageal reflux and duodenogastric reflux before and after eradication in Helicobacter pylori gastritis.

OBJECTIVE: Helicobacter pylori and duodenogastric reflux (DGR) are both associated with chronic gastritis, peptic ulcer and gastric cancer. The nature of their interrelationship remains unclear. H. pylori eradication has also been reported to result in new or worsening acid gastro-oesophageal reflux (GOR). The aim of this study was to investigate the relationship between GOR, DGR and H. pylori infection. METHOD: 25 patients with H. pylori gastritis underwent ambulatory 24-hour oesophageal and gastric pHmetry and gastric bilirubin monitoring before and 12 weeks after H. pylori eradication, confirmed by 14C urea breath testing (UBT). Ten healthy subjects served as a control group. RESULTS: There were no differences between patient and control groups for gastric alkaline exposure or gastric bilirubin exposure (P> 0.25 in all categories). Oesophageal acid reflux was higher in the study group (P< 0.02). No differences were detected in oesophageal acid reflux, gastric alkaline exposure, or gastric bilirubin exposure (P = 0.35, 0.18 and 0.11, respectively) before and after eradication. CONCLUSIONS: Acid GOR is not increased by H. pylori eradication. DGR in patients with H. pylori gastritis is similar to that in healthy, non-infected subjects. H. pylori eradication produces no change in GOR or DGR. In patients with chronic gastritis, H. pylori infection and DGR appear to be independent of each other.

Adult↗
PubMed2001

Persistent post-transplant autonomous hyperparathyroidism despite 23 years of excellent renal allograft function.

Hyperparathyroidism is a common problem for patients on renal replacement therapy programs. Many long-term dialysis patients require parathyroidectomy while on dialysis. Some patients, however, despite severe renal osteodystrophy, are transplanted, and in these a large proportion show a slow resolution of bony problems, in the context of the removal of the uremic stimulus to abnormal bone metabolism. A proportion of these patients become hypercalcaemic after renal transplantation, sometimes with symptoms. There is not a consensus on how these patients should be managed, with opinions varying from early parathyroidectomy to later parathyroidectomy and to conservative treatment. We present the case of a lady who underwent 23 years of conservative management of her post-transplant hyperparathyroidism. She was hypercalcaemic for almost all of that period, despite excellent renal transplant function. Finally, after 23 years she underwent surgical parathyroidectomy with autografting with prompt sustained resolution of her symptomatic hypercalcaemia.

Adult↗
PubMed2000

Oesophageal lichen planus.

We present a case of lichen planus affecting the oesophagus of an 80-year-old woman. Symptomatically, the lesions manifested themselves as dysphagia requiring repeated oesophageal dilatations. The patient was unable to tolerate several conventional treatments and so pulsed methylprednisolone was given with some beneficial short-term effects. Due to potential for malignant change in lichen planus of the mucous membranes it is important to remember this complication and investigate patients with oesophageal symptoms.

Aged↗
PubMed2000

Primary malignant melanoma of the esophagus.

is a rare disease, with only 200 cases being reported since this condition became an established clinical entity in 1963. This tumor, which accounts for only 0.1-0.2% of all esophageal neoplasms, is typically aggressive and disseminates early via the bloodstream and lymphatics, with only some 30% of patients surviving > 1 year after diagnosis. Management of patients with esophageal melanomata is unsatisfactory, as most tumors are advanced at diagnosis, and therapeutic options are limited by inaccessibility and early dissemination of the neoplasms. Poor survival rates reflect the inoperability of many tumors and the ineffectiveness of radiation and chemotherapy in eradicating advanced tumors and metastases. We present two patients with primary melanoma of the esophagus and discuss the treatment options currently available.

Aged↗
PubMed2000

Parathyroid carcinoma in a dialysis patient.

A 75-year-old woman who had been receiving dialysis for 3 years and had a long history of chronic renal failure attributable to reflux nephropathy was investigated for progressive hypercalcemia in the context of very high intact parathormone (iPTH) levels. Imaging showed two functional parathyroid glands in the neck. At parathyroidectomy, four variously enlarged parathyroid glands were found and completely resected, without autotransplantation. The histology of one of the glands showed invasive parathyroid carcinoma. Parathyroid carcinoma is a very rare condition, with only 16 previous cases involving dialysis patients described in the literature. We review the literature to draw together presentational and therapeutic information on the management of this problem in the setting of renal replacement therapy.

Aged↗
PubMed2000

Investigation of gastro-oesophageal reflux in patients with an intact stomach: is oesophageal bilirubin monitoring a useful addition to pH monitoring?

OBJECTIVES: Ambulatory bilirubin monitoring has helped to establish the role of duodenal contents in gastro-oesophageal reflux disease. This study aims to define the clinical role of oesophageal bilirubin monitoring in reflux patients with an intact stomach. METHODS: In total, 113 consecutive patients with reflux symptoms were prospectively studied using combined ambulatory oesophageal pH and bilirubin monitoring. Patients were categorized as follows: no pathological reflux, isolated acid reflux, isolated bilirubin reflux, combined acid and bilirubin reflux. RESULTS: Thirty-eight patients (33%) had no pathological reflux, 49 patients (44%) had combined pathological acid and bilirubin reflux, and 17 patients (15%) had isolated pathological acid reflux. Only nine patients (8%) had isolated pathological bilirubin reflux. In these nine, the extent of pathological bilirubin reflux was small (median total bilirubin exposure time 12.2%, range 6.5%-20.7%) and mucosal damage was minimal (five had grade 1 oesophagitis, four had a normal oesophagus). In one patient, symptoms were temporally related to acid reflux, and in none were symptoms temporally related to bilirubin reflux. CONCLUSIONS: Isolated oesophageal bilirubin reflux in patients with an intact stomach is uncommon. In these patients mucosal injury is minimal, and reflux symptoms are not related to bilirubin reflux episodes. Further work is needed to define the role for oesophageal bilirubin monitoring in the investigation of reflux disease in patients with an intact stomach.

Bilirubin↗
PubMed2000

Effect of omeprazole on antral duodenogastric reflux in Barrett oesophagus.

BACKGROUND: The effect of long-term acid suppression therapy in Barrett oesophagus remains unknown, but the high intragastric pH generated has been shown to increase the cytotoxicity of duodenal refluxate on foregut mucosa. However, recent work suggests that duodenogastric reflux (DGR) may be reduced by omeprazole. AIM: To investigate the effect of omeprazole on the reflux of duodenal contents into the gastric antrum in Barrett patients and healthy subjects. METHOD: Fifteen patients with Barrett oesophagus and 14 healthy subjects underwent oesophageal manometry followed by 24-h ambulatory oesophageal and gastric pH and gastric bilirubin monitoring. The bilirubin sensor (modified by the addition of a weighted tip to facilitate manoeuvrability) was sited in the gastric antrum under fluoroscopic control. Combined ambulatory pH and bilirubin monitoring was repeated after 2 weeks on omeprazole 20 mg b.d. RESULTS: Changes in oesophageal acid reflux and gastric alkaline shift due to omeprazole were as expected (P < 0.001). There was no difference in total antral DGR between the Barrett and control groups (P = 0.56), and omeprazole had no significant effect on DGR in either group (P = 0.77 and 0.27, respectively). CONCLUSIONS: DGR into the antrum is of a similar level in Barrett patients and healthy controls. Omeprazole does not reduce the reflux of duodenal contents across the pylorus. Further work is required on the increased cytotoxic potential of continuing DGR in those on long-term acid suppression.

Adolescent↗
PubMed2000

Effect of cholecystectomy on gastroesophageal and duodenogastric reflux.

OBJECTIVE: The majority of patients experience resolution of their symptoms after cholecystectomy, but a minority either find their symptoms unchanged or complain of new upper GI symptoms. It has been suggested that the effect of cholecystectomy on upper GI motility, sphincter function, or bile delivery may account for these postoperative symptoms. We aimed to determine whether cholecystectomy affects gastroesophageal reflux or duodenogastric reflux by using 24-h ambulatory pH and gastric bilirubin monitoring before and after surgery. METHODS: Seventeen symptomatic patients with gallstones underwent 24-h ambulatory esophageal and gastric pH-metry and gastric bilirubin monitoring. Helicobacter pylori status was ascertained in all patients by 14C urea breath test and serology. Combined pH and bilirubin monitoring was repeated 3 months after cholecystectomy. Eleven healthy subjects served as a control group. RESULTS: Three (17%) patients complained of persistent or new symptoms after surgery, whereas 14 (83%) patients were asymptomatic. Two patients (12%) underwent open cholecystectomy, and (88%) had the operation performed laparoscopically. No significant differences were detected in esophageal acid exposure (pH < 4), gastric alkaline shift (pH > 4), or gastric bilirubin exposure (absorbance > 0.14) after surgery. Three (17%) patients tested positive for Helicobacter pylori; the presence of infection did not appear to affect pre- or postoperative values. CONCLUSIONS: Cholecystectomy does not result in increased bile reflux into the stomach or increased gastroesophageal acid reflux. Those patients who had increased postoperative duodenogastric reflux were entirely asymptomatic. The symptoms of postcholecystectomy syndrome are unlikely to be related to increased duodenogastric reflux after surgery.

Adult↗
PubMed2000

Validation of scanning laser Doppler flowmetry against single point laser Doppler flowmetry in the measurement of human gastric serosal/muscularis perfusion.

BACKGROUND: Single point laser Doppler (LDF) has been employed intra-operatively to measure gastro-intestinal tissue perfusion, but despite reports that it may have a role in predicting post-operative complications consequent upon hypo-perfusion, methodological drawbacks have prevented its routine clinical application. Scanning laser Doppler flowmetry (SLDF) may address these drawbacks, but this new development has not been previously validated in human gastro-intestinal tissue. AIMS: This study assessed the ability of Scanning laser Doppler flowmetry to measure human gastric perfusion. METHODS: 10 patients undergoing oesophageal resection were studied. In each 6 measurements of gastric corporal serosal/muscularis were made over 30 seconds using the previously validated single point LDF technique. A single 1 cm2 SLDF scan was made of the same area prior to any vascular division. These measurements were repeated after partial gastric devascularisation and the two techniques' measurements then compared. RESULTS: Correlation between the 2 methods was good (coefficient of correlation was 0.955 (p<0.01). The mean bias (scan - single point PUs) was -3 PUs (95% CIs 16.3 to 45 PUs) and the limits of agreement were -64 to 58 PUs. The coefficients of variation for the 6 sets of single point measurements made in each patient ranged between 3.0% and 30.4% (mean = 12.5%). CONCLUSION: These results validate SLDF as a method of measuring gastric tissue perfusion intra-operatively.

Esophagectomy↗
PubMed1999

Intraoperative scanning laser Doppler flowmetry in the assessment of gastric tube perfusion during esophageal resection.

BACKGROUND: Ischemia from tissue hypoperfusion in the gastric tube after esophagectomy is believed to contribute significantly to postoperative complications associated with anastomotic failure. This study assessed the ability of the new technique of laser Doppler flowmetry to measure differential levels of blood flow in human gastric tubes during esophagectomy. STUDY DESIGN: Gastric perfusion was measured in 16 patients undergoing esophagectomy by making laser Doppler scans of the stomach before mobilization and after formation of the gastric tube. Mean perfusion was calculated within the whole anterior surface of the stomach or tube and within 1 cm2 regions of interest, each of which contained 1,750 individual measurements of perfusion. These regions represented the cephalic end of the gastric tube, 10 adjacent 1 cm2 regions distally along the tube, and the proposed anastomosis site. Results were expressed as mean perfusion units, and tissue blood flow from each scan in each region was compared. RESULTS: There were significant decreases in gastric perfusion measured with the scanning laser Doppler in all patients after formation of the gastric tube. Mean perfusion of the stomach fell 41% (p<0.0005) after mobilization. In all patients there was a gradient of perfusion from the proximal end of the tube where flow was poor, to more distal areas where it was higher. At the proximal end of the tube perfusion fell by a mean of 72%, 5 cm distally the mean fall was 44%, and 10 cm from the proximal end of the tube the mean fall was 28%. At the anastomosis site mean perfusion fell 55%. CONCLUSIONS: This new technique can be used intraoperatively and appears to overcome the limitations of single point laser Doppler flowmetry. It has measured large differences in perfusion at different sites within the gastric tubes and could therefore have widespread clinical applications.

Adult↗
PubMed1999

Accelerated test models for system strength based on Birnbaum-Saunders distributions.

Recent research in cumulative damage models for strengths of systems has yielded various statistical distributions that incorporate a system size variable and follow a generalized Birnbaum-Saunders form. These models can be unified as a three-parameter Birnbaum-Saunders-type family of distributions, where the third parameter arises from the size variable through the cumulative damage approach. In this paper, the generalized three-parameter Birnbaum-Saunders distribution is characterized, and examples of cumulative damage models for system strength that fit this form are given. Also, estimation and asymptotic theory are developed for the generalized distribution, and illustrations are presented for experimental strength data for carbon composite materials.

Carbon Compounds, Inorganic↗
PubMed1999

Reading speech and hearing print: constraining models of visual word recognition by exploring connections with speech perception.

Current models of reading and speech perception differ widely in their assumptions regarding the interaction of orthographic and phonological information during language perception. The present experiments examined this interaction through a two-alternative, forced-choice paradigm, and explored the nature of the connections between graphemic and phonemic processing subsystems. Experiments 1 and 2 demonstrated a facilitation-dominant influence (i.e., benefits exceed costs) of graphemic contexts on phoneme discrimination, which is interpreted as a sensitivity effect. Experiments 3 and 4 demonstrated a symmetrical influence (i.e., benefits equal costs) of phonemic contexts on grapheme discrimination, which can be interpreted as either a bias effect, or an equally facilitative/inhibitory sensitivity effect. General implications for the functional architecture of language processing models are discussed, as well as specific implications for models of visual word recognition and speech perception.

Cognition↗
PubMed1999

Investigation of oesophageal reflux symptoms after gastric surgery with combined pH and bilirubin monitoring.

BACKGROUND: Little is known about the role of bile in gastro-oesophageal reflux disease in patients with previous gastric surgery. This has partly been due to a lack of suitable techniques for identifying bile reflux objectively. METHODS: Some 28 patients with reflux symptoms and previous gastric surgery underwent oesophageal manometry, and 24-h ambulatory oesophageal pH and bilirubin monitoring. RESULTS: A wide variety of operations had been performed, most commonly Pólya gastrectomy (seven patients), vagotomy and pyloroplasty (six) and vagotomy and gastrojejunostomy (four). Three patients had isolated acid reflux, eight had isolated bile reflux, six had combined acid and bile reflux, and 11 patients had no reflux. Two-thirds of heartburn symptoms were not associated with reflux. However, one-quarter were associated with acid reflux and only 7 per cent with bile reflux. Erosive oesophagitis was present in five patients: two with combined acid and bile reflux, and three with isolated bile reflux. CONCLUSION: Acid and/or bile reflux can be present after a wide variety of gastric operations. Symptoms are more frequently associated with acid reflux than with bile reflux. Erosive oesophagitis can occur in the presence of isolated bile reflux. Combined pH and bilirubin monitoring determines the nature of the refluxate, and may help in the management of these patients.

Adult↗