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Biomedical subjects

A L Blum

Publications and source records attributed to A L Blum.

At least 19 recordsLinked to original sources
PubMed1992

The effect of continuous enteral nutrition on gastric acidity in humans.

The effect of continuous intraduodenal enteral nutrition on gastric pH was compared with the effects of fasting and of parenteral and standard nutrition control regimens containing equal amounts of carbohydrate, protein, and lipid. Eleven healthy volunteers underwent four 24-hour intragastric pH-metry studies; serum glucose, calcium, immunoreactive insulin and gastrin levels were determined during fasting and enteral and parenteral regimens. Median 24-hour gastric pH during enteral nutrition (group median pH 1.4) was lower than during parenteral nutrition (pH 1.9; P = 0.0039 vs. enteral) but was not different from fasting (pH 1.4) or standard nutrition (pH 1.6) values. Median 24-hour serum glucose levels during enteral nutrition (group median, 4.8 mmol/L) were higher than during fasting (4.0 mmol/L; P = 0.00098 vs. enteral) and lower than during parenteral nutrition (5.3 mmol/L; P = 0.0039 vs. enteral). Median 24-hour serum insulin levels during enteral nutrition (group median, 22.9 mU/L) were higher than during fasting (group median, 9.2 mU/L; P = 0.00098 vs. enteral) but similar to levels during parenteral nutrition (23.3 mU/L). Neither median 24-hour gastrin levels nor calcium levels were affected by any nutrition regimen. Thus, continuous enteral nutrition produces gastric pH values similar to those seen with fasting or standard nutrition, suggesting that, under most physiological conditions, gastric acidity is subject to close feedback control. Parenteral nutrition increases gastric pH, suggesting that systemic nutrients may influence this feedback mechanism.

Adult↗
PubMed1992

Healing and relapse of duodenal ulcer during ranitidine therapy in the elderly. The RUDER Study Group.

A total of 2,109 outpatients with active duodenal ulcer (DU) entered an open, prospective study in order to investigate factors influencing healing and relapse during 2 years of ranitidine therapy (300 mg daily for healing, 150 mg as maintenance treatment). In a retrospective analysis, we evaluated the influence of age. Symptoms related to DU in 1,899 evaluable cases in patients over 65 years of age (n = 185) were identical to those of DU patients younger than 65 years old (n = 1,714). Rapid healing within 2 weeks of ranitidine therapy was less frequent in the elderly (32.5%) than in younger patients (40.7%) though identical healing rates (94.1%) in each group were achieved by continuation of ranitidine therapy for 8 weeks. Cumulative recurrence rates during the 2 years of long-term therapy were lower (17.3%) in old age than in patients under 65 years of age (23.3%). Adverse events were rare in both age groups. We conclude that DU healing during ranitidine is delayed in old age. Additional differences in relapse rates in favor of the elderly suggest that DU disease has a different course in the elderly.

Adult↗
PubMed1992

Oesophageal pH-metry: should meals be standardized?

To assess the effect of a late-evening, high-fat meal on nocturnal supine gastro-oesophageal reflux, eight healthy volunteers (aged 20 to 38 years) underwent two ambulatory oesophageal pH-metry recordings, the first after a standardized light meal at 1930 h and the second after a high-fat meal including peppermint and chocolate, at 2130 h. Between 2300 and 0700 h, when subjects were supine, the median acid exposure time (percentage recording with pH less than 4) increased from 0.0% (range, 0.0-6.8%) after the standardized meal to 7.9% (0.0-17.8%) after the high-fat meal (p = 0.031). Similarly, the median number of reflux episodes increased from 0 (0 to 11) after the standardized meal to 7 (0 to 26) after the high-fat meal (p = 0.031). Reflux occurred after both meals, but, in general, persistent nocturnal reflux was observed only after the high-fat meal. Thus, the analysis of oesophageal pH recordings should consider the effects of meal composition and timing on oesophageal acid exposure.

Adult↗
PubMed1992

[Therapy of the acute ulcer attack].

Medical treatment of acute ulcers can be optimized by paying attention to risk factors for slow healing and for rapid recurrence. Therapy-resistant ulcers have become virtually unknown with modern drugs, so elective ulcer surgery is nowadays rarely needed for this reason. While drug therapy of acute ulcer hemorrhage is probably of little, if any, benefit for stopping bleeding, endoscopic treatment reduces the risk of continuous or recurrent bleeding, the need for emergency surgery, and mortality of this most common complication.

Acute Disease↗
PubMed1992

[Prevention of recurrence of ulcer disease: indications and choice of procedure].

In this contribution we discuss the relapse prophylaxis of ulcers by nonmedicamentous measures, by long-term drug therapy and, in particular, with inhibitors of secretion, by eradication therapy of Helicobacter pylori and by surgical therapy. Besides secondary prophylaxis (prevention of ulcer relapses), primary prophylaxis (prevention of the first episode) is also briefly treated.

Anti-Ulcer Agents↗
PubMed1992

Diagnostic assessment of gastroesophageal reflux disease: what is possible vs. what is practical?

The diagnosis of gastroesophageal reflux disease (GERD) entails the identification of patients with esophagitis and its complications as well as patients who have symptoms but no mucosal disease. Endoscopy is mandatory to establish a diagnosis of reflux esophagitis, to exclude other esophageal disease and to permit directed biopsy if columnar metaplasia, dysplasia or carcinoma is suspected. The lesions of reflux esophagitis--erosions, ulceration, stricturing and metaplasia--should be identified and graded independently, using a classification system such as the recently described "MUSE" (Metaplasia, Ulcer, Stricture, Erosions) system. Fluoroscopy can identify associated structural changes such as stricturing or esophageal shortening. Measures of esophageal acid exposure time may be used to quantify reflux before and after treatment; however, if the patient has typical symptoms but no esophagitis, a temporal association between symptoms and episodes of esophageal acidification should be sought. Ambulatory 24-hour esophageal pH-monitoring with accurate event-marking provides recordings suitable for an objective statistical analysis, which was evaluated prospectively in 14 patients. Computerized analysis of 24-hour esophageal pH recordings diagnosed 5 patients as having acid-related symptoms although only 3 of 5 patients fulfilling the criteria for pathological reflux had pH-related chest pain. This finding was confirmed by 5 experts who analyzed all recordings visually, unaware of the result of the computer analysis. The Bernstein test should be reserved for patients whose symptoms are too infrequent to permit an objective assessment of symptom occurrence during pH monitoring. In conclusion, i) endoscopy is the test of choice for the diagnosis of esophagitis but it should be supplemented by a standardized and reliable scoring system for disease severity; ii) ambulatory esophageal pH recording with accurate event-marking is the test of choice for the diagnosis of GER-related symptoms, but it should be supplemented by an objective assessment of the temporal relationship between symptoms and esophageal pH; and iii) esophageal manometry is the test of choice for evaluating esophageal peristalsis and LES (lower esophageal sphincter) function but, in the context of GERD, its main indication is the assessment of GERD patients who are being considered for surgery. The widespread use of other tests for clinical purposes must await a better understanding of the pathophysiological mechanisms which can lead to the development of GERD.

Esophagitis, Peptic↗
PubMed1991

Diclofenac delays healing of gastroduodenal mucosal lesions. Double-blind, placebo-controlled endoscopic study in healthy volunteers.

The effects of the water-soluble and delayed-release formulations of a nonsteroidal antiinflammatory drug, diclofenac, on the healing of gastroduodenal mucosal lesions were compared in a double-blind, double cross-over, placebo-controlled endoscopic study conducted in 14 healthy volunteers. Severe endoscopic lesions (petechiae, erosions, ulcers, and esophageal candidiasis) were found only in the group taking the soluble formulation of diclofenac (P less than 0.05 vs placebo). The endoscopic healing of biopsies at one week was delayed by both preparations in comparison to placebo (P less than 0.05 vs placebo). Neither formulation produced significantly more histological inflammation or minor endoscopic lesions (erythema, red striae) than placebo. Both formulations were equally well tolerated and produced no more symptoms than placebo. This study suggests that soluble diclofenac acts topically to delay gastroduodenal healing and produce gastroduodenal injury; it thus provides a model for future studies of the production, perpetuation, and healing of peptic lesions.

Adult↗
PubMed1991

Reproducibility of long-term ambulatory esophageal combined pH/manometry.

Long-term ambulatory esophageal manometry is used increasingly, but normal values and data on the reproducibility of the method are not available. Thus, studies were conducted using paired 24-hour recordings, separated by 1-4 weeks, in 24 healthy volunteers (aged 19-50). Computerized analysis of each two-channel pressure recording (5 and 15 cm above lower esophageal sphincter) determined mean contraction amplitude, duration, area under the curve, contractility and propagation velocity, and the proportion of propagated contractions during day and night periods. A combined glass pH electrode (5 cm above lower esophageal sphincter) was used to register acid reflux. Visual analysis of the 24-hour contractility patterns showed marked intraindividual reproducibility but, although most subjects showed similar meal-associated increases and sleep-associated decreases in contraction frequency and amplitude, considerable interindividual variation was observed. This was confirmed by comparing the variation between subjects in the first and second recordings with the variation between recordings in the same subject; for all pH and manometry variables, the coefficient of variation was two to three times greater between subjects than between recordings in the same subject. The recordings were highly reproducible within subjects (nighttime contraction duration, P less than 0.05; all other variables, P less than 0.01). Thus, computerized ambulatory pH manometry is reproducible and because healthy volunteers have a characteristic individual pattern of esophageal motility, the method is perfectly suitable for repeated-measure design physiological and pharmacological studies. However, generally applicable normal values are difficult to define.

Adult↗
PubMed1991

The ion sensitive field effect transistor (ISFET) pH electrode: a new sensor for long term ambulatory pH monitoring.

Intraluminal pH monitoring in man should be performed with disposable multichannel assemblies that allow recordings at multiple sites and prevent transmission of infection. Currently available glass electrodes are unsuitable for this purpose because of their size and price. We have thus constructed and tested a small, combined ion sensitive field effect transistor (ISFET) pH electrode incorporating an integral reference electrode. In vitro studies showed that both ISFET and glass electrodes (440-M4, Ingold, Switzerland) have a linear response over the pH range 1.3-8.0 and that they are comparable with regard to response time and 24 hour drift. Twenty one hour intragastric pH recordings were performed simultaneously in eight healthy volunteers using a glass electrode and an ISFET electrode, placed no more than 2 mm apart in a combined assembly. This was located in the gastric corpus under fluoroscopic control. The 21 hour pH curves recorded by each electrode type showed identical patterns: an early morning rise in pH with three meal-associated pH peaks lasting for about two to three hours. The means of the 21 hour pH medians were 2.09 and 2.07 as measured by the glass and the ISFET electrodes respectively. Thus, ISFETs are suitable for the construction of inexpensive and hence disposable multichannel pH monitoring assemblies of small diameter. Provided that they can be produced in large numbers with appropriate technical support, ISFETs have the potential to replace glass electrodes for long term monitoring of gastrointestinal luminal acidity.

Evaluation Studies as Topic↗
PubMed1990

Treatment of acid-related disorders with gastric acid inhibitors: the state of the art.

Since their introduction in 1976, and until recently, the H2-receptor antagonists have been the 'state-of-the-art' gastric acid inhibitors, but the advent of omeprazole, the acid pump inhibitor, has necessitated a reassessment of therapy for acid-related diseases. In making this reassessment, the following therapeutic goals should be considered: rapid and reliable therapeutic effect, safety, simple treatment regimen, resolution of recurrence, and cost-effectiveness. Extensive clinical evidence indicates that omeprazole offers an advance over the H2-receptor antagonists in achieving these goals. A series of meta-analyses shows that omeprazole gives more rapid symptom relief and more reliable healing than H2-receptor antagonist, ranitidine, in uncomplicated duodenal ulcer (DU), in uncomplicated gastric ulcer (GU) and in reflux oesophagitis (RO). By contrast with the H2-receptor antagonists, refractoriness leading to failure to heal is virtually unknown with omeprazole. Omeprazole also fulfils the goal of therapeutic safety, and this has been documented in extensive short- and long-term clinical and laboratory studies. Omeprazole has a simple treatment regimen: 20 mg once daily is recommended in the routine treatment of DU, GU and RO. As a result of its high therapeutic success rate, omeprazole is also cost-effective. Taking all these factors into account, it is concluded that omeprazole approaches the therapeutic targets set for the treatment of acid-related disorders.

Gastric Acid↗
PubMed1990

Current and future drugs for acid-peptic disease: a plethora of opinions on possible mechanisms of action.

Sixty-seven invited participants involved in the development, evaluation, and use of therapies for acid-peptic disorders participated in a meeting to discuss the scientific basis for healing actions of ulcer drugs and the prospects for future developments ("Realities of Mucosal Protection in the Upper Gastrointestinal Tract," Lausanne, Switzerland, November 8-10, 1987). Eighty-one key statements were prepared and subsequently analyzed on the basis of a voting system. Of the 45 statements that dealt with existing therapies, only 3 statements showed positive consensus (agreement of two-thirds or more of voters) about mechanisms of ulcer healing. Participants agreed that both (1) hydrogen/potassium adenosine triphosphatase inhibitors and (2) histamine H2 antagonists healed ulcers solely by acid inhibition, and (3) that sucralfate works by topical action. Substantial uncertainty about the mechanisms by which bismuth compounds and antacids heal ulcers was noted as well as their wide range of effects. The mechanism of ulcer healing by prostaglandins and the clinical relevance of antiulcer effects of drugs demonstrated in acute studies with animals were also controversial. There was greater agreement among participants about unexplored drug effects that might produce ulcer healing. Of the 36 such mechanisms surveyed, the most support went to therapies aimed at enhancement of mucosal blood flow, epithelial restitution, and mucosal alkaline secretion or inhibition of luminal pepsin activity. The diversity of opinions among participants suggests a high level of empiricism in the development of ulcer healing drugs apart from those that inhibit acid secretion. This empiricism probably arises from inadequate understanding of processes of mucosal injury and repair.

Drug Design↗