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Biomedical subjects

D G Colin-Jones

Publications and source records attributed to D G Colin-Jones.

At least 19 recordsLinked to original sources
PubMed1995

The role and limitations of H2-receptor antagonists in the treatment of gastro-oesophageal reflux disease.

Gastro-oesophageal reflux disease (GERD) occurs in up to 44% of adults in the USA. Most individuals do not seek medical help, self-medicating with antacids. Manifestations of GERD range from symptoms without oesophagitis, which constitute the bulk of patients who self-medicate, to active oesophagitis and then to complications such as stricture and ulceration. It is the more severe cases who tend to come to the gastroenterologist, but it must be remembered that reflux symptoms are probably around 5-10 times more common than actual oesophagitis. Since acid in the refluxate is responsible for the bulk of the symptoms and mucosal damage, antacids are often used for quick relief--which of course may not be sustained. More prolonged suppression of acid secretion, such as by a histamine H2-receptor antagonist (H2RA) or a proton pump inhibitor (PPI), is required to give long-lasting symptomatic relief and heal any inflammatory change. H2-receptor antagonists inhibit acid secretion with an effect that lasts for 4-8 h with a single dose, decreasing stimulated acid secretion by around 70%. When treating oesophagitis, the H2RAs suffer from the disadvantage of their relatively short duration of action (compared with PPIs), development of tolerance, and incomplete inhibition of acid secretion in response to a meal. Therefore, it is not easy for the H2RAs to achieve optimum conditions for healing the more severe forms of oesophagitis--even very high doses may fail. In mild GERD the H2RAs have been shown to be effective in relieving symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Risks of bleeding peptic ulcer associated with individual non-steroidal anti-inflammatory drugs.

Treatment with non-steroidal anti-inflammatory drugs (NSAIDs) is associated with an increased risk of peptic ulcer complications, but it is not clear whether some drugs are more likely than others to cause such complications. We compared previous use of NSAIDs in 1144 patients aged 60 and older admitted to hospitals in five large cities with peptic ulcer bleeding and in 1126 hospital controls and 989 community controls matched for age and sex. Peptic ulcer bleeding was strongly associated with use of non-aspirin NSAIDs of any type during the 3 months before admission (411 cases, 351 controls; odds ratio 4.5 [95% CI 3.6 to 5.6]). The odds ratios for peptic ulcer bleeding were lowest for ibuprofen (2.0 [1.4-2.8]) and diclofenac (4.2 [2.6-6.8]), and intermediate for indomethacin, naproxen, and piroxicam (11.3 [6.3-20.3], 9.1 [5.5-15.1], and 13.7 [7.1-26.3]). Azapropazone and ketoprofen carried the highest risks (31.5 [10.3-96.9] and 23.7 [7.6-74.2]). Risks also increased with drug dose (low dose 2.5 [1.7-3.8], intermediate 4.5 [3.3-6.0], and high 8.6 [5.8-12.6]) for all drugs combined. Appropriate clinical strategies could prevent many episodes of peptic ulcer bleeding: NSAIDs should be used only in patients who do not respond to other analgesics; the lowest possible doses should be used; and the least toxic NSAIDs should be selected.

Aged↗
PubMed1992

Oesophageal motor function before and after healing of oesophagitis.

Forty three patients with reflux oesophagitis were studied to investigate the effect of healing on oesophageal function. All patients underwent oesophageal manometry and transit studies before and after complete healing of oesophagitis. Oesophagitis was treated with omeprazole 40 mg/day for a median duration of 12 weeks. Twenty three patients also had an acid clearance test before and after healing. Thirty eight of the 43 patients had 24 hour oesophageal pH monitoring before treatment and this was repeated after healing (while on omeprazole) in 31 of them. Thirty four volunteers served as controls. All volunteers underwent manometry, 33 had oesophageal transit studies, and 23 had acid clearance test. Patients had significantly reduced lower oesophageal sphincter pressures and distal and middle oesophageal amplitudes, longer durations of contraction, and slower velocity of propagation than the controls (16.5 v 22.5 mm Hg; 52 v 92 mm Hg; 46 v 79 mm Hg; 3.1 v 2.7 seconds; and 3.3 v 4.1 cm/second respectively with the corresponding p values = 0.017; 0.0001; 0.0001; 0.017; and 0.006). Patients had significantly longer transit times (9 v 7 and 17 v 11 seconds: p = 0.027 and 0.002 for erect and supine postures respectively). They also had longer acid clearance times (350 v 288 and 536 v 405 seconds: p = 0.044 and 0.016 for sitting and supine postures respectively). There was no significant change in any of the indices of oesophageal function after healing of oesophagitis (lower oesophageal sphincter pressure = 16.5 v 20; distal amplitude = 52 v 60; middle amplitude = 46 v 49; duration of contraction = 3.1 v 3.1; velocity = 3.3 v 3.3; erect transit time = 9 v 9; supine transit time = 17 v 24; acid clearance test (sitting) = 350 v 371; acid clearance test (supine) = 536 v 645). These results indicate that oesophageal motor dysfunction in reflux oesophagitis is a primary phenomenon.

Adult↗
PubMed1992

Postmarketing surveillance of the safety of cimetidine: 10 year mortality report.

A total of 9928 cimetidine users were identified from prescriptions in four centres and followed for 10 years. The 'all-cause' mortality ratio fell from 1.9 in year 1 to 1.0 in years 8 to 10. Most of the early excess in mortality was attributable to cimetidine being given in the late stages of many diseases, often to counter adverse gastric effects of other drugs. Specific causes of mortality during years 5-10 of the study, were generally unremarkable. Significant increases in mortality ratios were apparent, however, for oesophageal cancer (years 5-7, 2.3; years 8-10, 1.9); lung cancer (years 5-7, 1.1; years 8-10, 1.7); diseases of the oesophagus, stomach, and duodenum (years 5-7, 3.3; years 8-10, 2.3); and chronic liver disease (years 5-7, 2.4; years 8-10, 3.3). None of these increases in mortality seems to be attributable to an adverse effect of cimetidine use. Data are also presented for mortality from diseases of the nervous system. Eight deaths (of which one was miscoded) were certified as being from motor neurone disease, representing a mortality ratio of 2.6 for years 2-10 of the study which is of borderline statistical significance. This study confirms that cimetidine is safe. Mortality from some diseases increased over the study period, but selection rather than any adverse effect of the drug is likely to be the explanation.

Cimetidine↗
PubMed1991

Post-cimetidine surveillance for up to ten years: incidence of carcinoma of the stomach and oesophagus.

The long-term effects of cimetidine on the occurrence of gastric and oesophageal cancer were assessed in a prospective cohort study of 9928 patients who had been prescribed cimetidine. They were first identified between 1978 and 1980, and cancer registrations and deaths were identified among them over a period of up to 10 years. One hundred and eleven cancers were identified after the start of cimetidine treatment: 71 were adenocarcinomas of the stomach, 27 were carcinomas of the cardia and/or oesophagus (22 adenocarcinomas, five unknown histology) and the remaining 13 tumours were squamous cell cancers of the oesophagus. Only six patients presented with early gastric cancers. Over a period of eight years the ratio of observed to expected (O/E) gastric cancer deaths has fallen from 10.7 (p < 0.001) to 1.2 (NS). The O/E ratio of oesophageal cancer deaths also fell over the first six years of study, from 5.4 (p < 0.01) to 1.4 (NS) but it has risen slightly in years 7 and 8 to 3.7 (p < 0.05). These findings do not suggest that there is an increased risk of developing oesophageal or gastric cancer from cimetidine treatment, and are generally consistent with cimetidine being used inadvertently to treat the early symptoms of gastric and oesophageal cancer. The slight rise in oesophageal cancer deaths in years 7 and 8 was unexpected and will be the subject of further observation.

Adenocarcinoma↗
PubMed1990

The evaluation of a gastric bile probe.

The purpose of this study was to validate a new technique for measuring duodenogastric bile reflux in the human subject. A custom built cadmium telluride gamma detector (Radiation Monitoring Devices, Mass), small enough to be passed into the oesophagus and stomach, was developed and tested for sensitivity to 99Tcm and 75Se radioisotopes. When immersed in radiolabelled water, the detector was capable of measuring gamma radiation in quantities as low as 0.1 microCi (0.0037 MBq) per ml. Two patients (A and B) with endoscopically proven bile reflux, and three normal volunteers (C, D and E) underwent oesophageal manometry to map the position of the lower oesophageal sphincter (LOS). The gamma probe was passed via the nose, to a position in the gastric fundus, 5 cm below the LOS. Each subject was placed supine under a gamma camera (Siemens LFOV 37 ZLC head), centred on the epigastrium. A 4 mCi (148 MBq) dose of radiolabelled 99Tcm-HIDA was administered intravenously, and simultaneous internal/external scanning was performed for between 45 and 90 min. Internal gamma probe data was transferred by a screened cable to a Memolog 600 portable recorder, using a 5 s counting interval, and from the gamma camera to a Nodecrest Micas III computer, using a 15 s counting interval. Gamma camera counts from a region of interest over the fundus of the stomach were then correlated with counts from the internal probe using a linear regression analysis program on the Nodecrest. The internal gamma probe functioned well at body temperature in the acidic gastric environment. Radiolabelled bile refluxed into the stomach during HIDA scanning in three out of the five subjects (one patient and two normal volunteers). There was a strong correlation between internal and external gamma counts (A, r = +0.79; C, r = +0.53; E, r = +0.54; P greater than 0.01). In the other two cases, there was no bile reflux, but still a significant correlation between internal and external gamma counts (B, r = +0.89; D, r = +0.75; P greater than 0.01). The mean correlation coefficient for the series of five cases was +0.70. We conclude firstly that the newly developed internal gamma detector is capable of measuring the reflux of radiolabelled bile into the human stomach and, secondly, that bile reflux may occur in normal subjects as well as those with upper gastrointestinal pathology.

Aged↗
PubMed1990

Future needs for ERCP: incidence of conditions leading to bile duct obstruction and requirements for diagnostic and therapeutic biliary procedures.

Although the development of endoscopic methods of treatment for biliary obstruction has proceeded rapidly in recent years, endoscopic retrograde cholangiopancreatographic (ERCP) services are patchily distributed. A recent survey by the British Society of Gastroenterology has shown that almost half the district general hospitals questioned did not have a sphincterotomy service available locally. To assess the level of provision required, two investigations have been undertaken. Firstly, an epidemiological study of bile duct obstruction has been carried out in the South Western Region. Secondly, the actual surgical and endoscopic workload in treating obstructive jaundice has been analysed in two health districts. Using present incidence and treatment rates at least 50 ERCPs per 100,000 of the population per year are estimated to be required in the future. Surgical treatment rates can be expected to fall as the number of therapeutic ERCPs increases. The implications of this estimate in equipment and staffing terms are discussed.

Aged↗
PubMed1989

Studies on the pathogenesis of the early dumping syndrome induced by intraduodenal instillation of hypertonic glucose.

A reaction indistinguishable from the early dumping syndrome was induced in four of nine normal volunteers by intraduodenal instillation of a hypertonic glucose meal. Tachycardia and marked peripheral vasodilatation were demonstrated in 'dumpers' by Doppler ultrasound measurements of the arterial blood flow signal. The dumping reaction was not detectably altered by the addition of guar to the meal. Plasma VIP concentration rose and plasma volume fell to a similar degree in 'dumpers' and 'non-dumpers', suggesting that neither event is an integral component of the dumping mechanism. In contrast, the rates of rise of blood glucose and enteroglucagon concentration were markedly greater in 'dumpers'. The results are inconsistent with the conventional explanation that the early dumping syndrome is caused by a large osmotic fluid shift, but are compatible with a mechanism involving an initial period of intestinal hypermotility.

Blood Flow Velocity↗
PubMed1989

Campylobacter pylori. An advance in understanding of dyspepsia and gastritis.

The prevalence of Campylobacter pylori (CP) rises with age, as does gastritis. There is now convincing evidence that CP is causative in the majority of cases of active chronic gastritis and that its eradication substantially improves the severity of the gastritis, even back to normal in some cases. A small minority of people may have other factors causing their gastritis, bile reflux, or anti-inflammatory drugs, for example, CP causes temporary dyspeptic symptoms when an individual receives an acute infection for the first time, but what is much less certain is whether or not CP is responsible for chronic dyspeptic symptoms, and whether eradication of CP will improve dyspepsia. At present the therapeutic trials are too few and too small to be sure, but some individuals may benefit.

Acute Disease↗
PubMed1988

Pharmacological response to cimetidine and healing of duodenal ulceration: effects of high-dose cimetidine and combination of cimetidine with pirenzepine.

Overnight gastric secretion was studied in 32 patients with acute duodenal ulcers before treatment and whilst taking cimetidine 400 mg b.d. After 6 weeks of treatment with cimetidine 400 mg b.d. 13 patients had healed ulcers, seven patients had healed ulcers but a persistent erosive duodenitis, and 12 patients had persisting ulceration. Inhibition of nocturnal gastric secretion by cimetidine 400 mg b.d. was most profound in patients who healed their ulcers completely; a less profound inhibition of nocturnal gastric secretion was seen in the non-healing and duodenitis groups. In patients with persisting ulcers and poor inhibition of nocturnal gastric secretion by cimetidine, gastric secretion could be suppressed by either cimetidine 400 mg b.d. in combination with pirenzepine 50 mg b.d., or by cimetidine 1600 mg nocte, but suppression of nocturnal gastric secretion was more effective with cimetidine 1600 mg than cimetidine with pirenzepine.

Adolescent↗
PubMed1988

Routine practice in the diagnosis of adenocarcinoma of the stomach: a survey of tumours diagnosed in the Portsmouth and Oxford Health Districts 1979-1980.

If the poor prognosis for patients with adenocarcinoma of the stomach is to be improved, it is important to make the diagnosis at an early stage. In order to evaluate our routine diagnostic practice, we have performed a retrospective study of patients in the Portsmouth and Oxford Health Districts who were diagnosed as having adenocarcinoma of the stomach during 1979 and 1980. Three hundred and forty-two patients were identified; the great majority had advanced disease at the first presentation. Only 9 patients (2.6%) were identified as having early gastric carcinoma and a total of 46 patients (13.4%) had either Stage 1 or 2 disease. Despite the provision of an endoscopy service, gastric carcinoma is still being diagnosed at an advanced stage. Initial false negative investigations caused a delay in diagnosis in 18.4% of patients. During the year preceding diagnosis (when tumour was likely to have been present), the false negative rate for barium meal examination was 25.5% and for endoscopy 13.5%. Negative results should not deter us from pursuing the diagnosis of tumour in those patients with persisting symptoms.

Adenocarcinoma↗
PubMed1988

Acid-related disorders: what are they?

'Acid-related disorders' is a term used to describe a whole range of conditions from the Zollinger-Ellison syndrome, where acid is entirely responsible for the problems, to aerophagia and motility-type non-ulcer dyspepsia, where acid plays little if any role in the dyspeptic symptoms. Careful evaluation of the patient's symptoms is required to establish the basis for the dyspepsia and from that, careful selection can be made for any investigations that might be needed. These symptoms are the basis for advising on the most effective management--but as many doctors and patients erroneously attribute dyspepsia solely to acid, it is all too easy for inappropriate treatment to be offered. Acid is not the only cause of dyspeptic symptoms. Dyspepsia is a very common complaint with many causes. Acid and pepsin are often held responsible for these symptoms, by both the medical profession and the lay public. The term, 'acid-related disorders' is used to embrace this wide variety of conditions in which acid may play a part. However, in spite of current folklore, it is a spectrum of conditions ranging from situations where acid is crucial to conditions where acid may play little part.

Digestive System Diseases↗