[When can a patient with artificial nutrition be discharged home?].
Explore the source record for details and available documents.
Continuity of Patient Care↗
Biomedical subjects
C Emde
Publications and source records attributed to C Emde.
[The effect of a calcium carbonate-bismuth subsalicylate combination on intragastric acidity over the course of 24 hours. A randomized study of healthy probands].
Bismuth salts are successfully used for the treatment of campylobacter-pylori-associated gastritis. It cannot be excluded, however, that calcium carbonate, which is present in one of the recommended preparations (calcium carbonate/bismuth subsalicylate, Jatrox), may have an additional therapeutic effect due to an increase of intragastric pH. Therefore, the in-vitro H+ buffering capacity of Jatrox was determined in comparison to other antacids using the pH-stat technique, and its effect on intragastric acidity was tested in 15 healthy volunteers using ambulatory 24-hour pH-metry (combined glass electrode in gastric corpus, solid state memory recorder, sampling rate 30/min). At two study sessions, the volunteers received standardized normal meals (8:00 a.m., 12:00 noon, 6:00 p.m.) and, in randomized order, either Jatrox (three times 2 tablets one hour before meals) or no medication. Under in-vitro conditions, the buffering capacity of Jatrox amounts to 7.82 mmol H+ per tablet (equivalent to 47 mmol H+/24 h at recommended dosage), which is relatively low. Under in-vivo conditions, gastric pH only increases significantly during the first hour after medication. This short-lasting effect, however, has no influence on the 24-hour median pH. It is concluded from these results that the calcium carbonate contained in Jatrox probably does not contribute directly towards its therapeutic effect in promoting the healing of gastritis.
Adult↗
Combined esophageal and gastric pH-metry in healthy volunteers. Influence of cable through LES and effect of misoprostol.
In order to evaluate whether combined esophageal and gastric pH-metry is feasible without interference due to the transcardial cable, four 24-hr ambulatory esophageal pH-metries were carried out in seven healthy volunteers in a randomized order. In two studies only one glass electrode was used. It was placed 5 cm above the lower esophageal sphincter. In the two other studies an additional electrode was placed in the corpus region 10 cm below the lower esophageal sphincter. In order to obtain a wide range of pH values, misoprostol (400 micrograms) was given at 9 AM and 9:15 PM in two studies. In the two other studies placebo was given. Misoprostol exerted only a weak and short-lasting effect on gastric acidity. The four measuring conditions did not differ with respect to medians of esophageal reflux time and duration of single reflux episodes, Kendall's coefficient of concordance yielded a high reproducibility for both variables (P less than 0.0025). Thus, combined esophageal and gastric pH-metry is feasible and highly reproducible.
Adult↗
High amount of dietary carbohydrate does not cause an adaptational increase of stimulated human pancreatic amylase secretion.
In order to investigate whether the human pancreas is capable of adapting to a diet with high-carbohydrate, low-fat, and normal protein content, 10 healthy volunteers were given a defined elemental diet (60% of calories as carbohydrates, 22% as fat, and 18% as protein) for 7 d. For the next 7 d they received an elemental diet with a further increased carbohydrate content (76% of calories) and a decreased fat content (10% of calories). A complete secretin-pancreozymin test was carried out at the end of the first wk and at d 14. The results show that an increase in dietary carbohydrate does not provoke an adaptational response of stimulated secretion rates of amylase, trypsin, and chymotrypsin in humans, as expected from animal experiments.
Acclimatization↗
Early dinner reduces nocturnal gastric acidity.
This study examines whether eating food at different times has differential effects on intragastric pH. Experiments were done in 23 healthy volunteers (12 men). Intragastric acidity was monitored by ambulatory 22 hour pH-metry. Composition of meals was standardised: breakfast and lunch at 7 am and 12 noon respectively, and dinner at 6 or 9 pm, in random order. The time of going to bed and getting up was also standardised. With early dinner nocturnal pH was higher, than with late dinner (pH median: 1.67 and 1.39, p less than 0.001). During the remaining time periods, pH values were similar. Thus early dinner may be helpful in conditions where low intragastric acidity is desirable.
Adult↗
Recommendations for long-term oesophageal pH monitoring.
Ambulatory 24-h pH monitoring in the distal oesophagus represents a widely accepted tool in the diagnosis of gastro-oesophageal reflux disease. When this method was first established, most attention was drawn to the definition of normal oesophageal pH values; various studies correlated morphological findings in the distal oesophagus with the extent of gastro-oesophageal reflux. We have compared different reflux-related variables under different measuring conditions; reflux time (percentage of time with pH below 4) was found to be much more reliable than variables derived from the recognition of single reflux episodes. The special advantage of long-term ambulatory pH monitoring is, however, in our opinion, its capacity for identifying gastro-oesophageal reflux as the primary cause of chest pain in those patients whose oesophagus has an endoscopically normal appearance. For this purpose, it is vital that the recording system be equipped with a reliable event marker; the oesophageal origin is confirmed by detection of a high coincidence between pain attacks and reflux episodes. The evaluation software for ambulatory pH monitoring must therefore allow for diagrammatic display of a complete 24-h recording where the onset of pain attacks is visible within the pH curve.
Chest Pain↗
Basic principles of pH registration.
Normally, pH-sensitive electrodes are used for measuring the acidity of an aqueous solution. A second electrode is required as reference and can be integrated in the pH-sensitive electrode (combined electrode); separate reference electrodes must be used, however, when combined ones are not available. Types of electrodes are: glass, antimony, ISFET and polymeric membranes; only glass and antimony electrodes are commercially available. Different factors determine the accuracy of a pH measurement, the most important being: (1) electrical and mechanical properties of the electrodes; (2) ionic strength, temperature and background activity of the test solution; and (3) electrical properties of the pH amplifier and display. The highest accuracy of about 0.1 pH units can be obtained with the glass electrode; the error of measuring systems equipped with antimony electrodes does not normally exceed 0.5 pH units. It is important to define the required accuracy prior to measurement. If, for example, long-term oesophageal pH monitoring is performed in newborns or infants, the best compliance is achieved with the relatively small and flexible antimony electrode. If, on the other hand, the effect of an allegedly weak drug on gastric acidity is to be tested in a volunteer study, only glass electrodes will be appropriate.
Antimony↗
Effect of a slow-release formula of trimoprostil on intragastric acidity in healthy volunteers.
We investigated the effect of a slow-release formula of trimoprostil, a prostaglandin E2 analogue, at a dose of 3 mg b.d. on circadian intragastric acidity in nine healthy volunteers using ambulatory pH-metry in a placebo-controlled study. The effect of trimoprostil was long lasting (8 hours during the night). However, it lowered gastric pH on average only by 0.4 pH units. In four of the six women severe side-effects occurred in the form of abdominal cramping, metrorrhagia, and/or diarrhoea. These disadvantages may limit the clinical use of this drug.
Adult↗
Exponential function for calculating saturable enzyme kinetics.
Enzyme kinetics are usually described by the Michaelis-Menten equation, where the time-dependent decrease of substrate (-dS/dt) is a hyperbolic function of maximal velocity (Vmax), Michaelis constant (Km), and amount of substrate (S). Because the Michaelis-Menten function in its most general meaning requires an assumption of steady-state, it is less curvilinear than true enzyme kinetics. A saturation-type exponential function is more curvilinear than the hyperbolic function and more closely approximates enzyme kinetics: -dS/dt = Vmax [1 - exp(-S/Km)]. The mathematical representation of enzyme kinetics can be further improved by introducing a deceleration term (Vdec), to make the assumption of a steady state unnecessary. For the action of chymotrypsin on N-acetyltyrosylethylester, the Michaelis-Menten equation yields the following: Vmax = 3.74 mumol/min and Km = 833 mumol. According to decelerated enzyme kinetics, the values Vmax = 4.80 mumol/min, Vdec = 0.0118 mumol/min, and the association constant (Ka) = 0.00111/mumol are more nearly accurate for this reaction (where 1/Ka = 901 mumol approximately Km).
Chymotrypsin↗
Transfer of large data sets from biomedical research: proposal for a universal data header (UNIDAT 1.0).
A universal data header for computerized data transfer between different research centers has been developed and successfully tested. The structure of this data header allows for data interchange irrespective of the internal data representation of the processor used. The first 128 byte are used for description of data structure followed by dynamically allocated space for string variables, event data, and measured data. Test programs written in Turbopascal and C are available on floppy disk (formatted for MS-DOS or OS/9) from the authors upon request.
Information Systems↗
Lessons from prolonged gastric pH monitoring.
Intragastric pH monitoring has shown that the distribution of acidity within the stomach is not homogeneous. Not only is it affected by meals but it also has a circadian rhythm in which nocturnal pH falls to very acid levels in normal subjects. Although results of pH monitoring are highly reproducible within individuals, considerable inter-individual variation has been shown. Duodenal ulcer patients do not appear to possess the normal buffering reaction to meals, but their night-time acidity is within the normal range. In these patients, antacids and pirenzepine have a small acid-neutralizing effect in the stomach; cimetidine is less potent than ranitidine and famotidine. Clinicians can choose between a single dose of either ranitidine or famotidine in the evening with dinner and a twice-daily regimen.
Gastric Acid↗
Does smoking interfere with the effect of histamine H2-receptor antagonists on intragastric acidity in man?
The interaction between smoking and the effect of histamine H2-antagonists on intragastric acidity was examined in a double blind double dummy placebo controlled study. Healthy volunteers, 11 smokers and 10 non-smokers, were given, on four separate days at least one week apart, either placebo or cimetidine 800 mg nocte or ranitidine 2 X 150 mg per day or ranitidine 300 mg nocte. Tablets were taken at 2115 and 0900 h. Smokers smoked a cigarette hourly from 0700 to 2300 h. Breakfast, lunch, and dinner were standardised. Intragastric acidity was measured with a combined intragastric glass electrode and a solid state recorder. The subjects were fully ambulatory. The three histamine H2-receptor antagonist regimens were less effective (p = 0.04) in smokers than in non-smokers, but the difference between acidity of smokers and non-smokers was small. Means of medians of pH during a 24-h period with placebo, cimetidine 800 mg, ranitidine 2 X 150 mg and ranitidine 300 mg were 1.6, 2.3, 3.1, and 2.7 in smokers and 1.5, 2.7, 3.2, and 3.1 in non-smokers, respectively. In a second part of the study seven chronic smokers were reexamined after acutely stopping smoking: inhibition of gastric acidity by histamine H2-receptor antagonists was similar before and after withdrawal. Smoking does not affect intragastric acidity in untreated volunteers and only slightly decreases the effectiveness of histamine H2-receptor antagonists on intragastric acidity. This effect best in part explains the unfavourable effect of smoking on healing of peptic ulcer in patients treated with these drugs.
Adult↗
Technical aspects of intraluminal pH-metry in man: current status and recommendations.
Explore the source record for details and available documents.
Digestive System↗
Reduction of gastric acidity with ranitidine or famotidine: early evening dosage is more effective than late evening dosage.
The antisecretory effect of a once daily dose of ranitidine and famotidine was examined after administration of the drugs either immediately after dinner or 3 h after dinner. A placebo-controlled multiple cross-over study was performed in 7 healthy ambulatory volunteers. They were given, on 6 separate days at least 1 week apart, either placebo, ranitidine 300 mg or famotidine 40 mg, either immediately after dinner or 3 h later. Breakfast, lunch and dinner were standardized. 24-Hour intragastric acidity was measured with a combined glass electrode. Duration of secretory inhibition by a drug was defined as the nighttime period between the first rise of pH above and the final fall below 3.5. This value represents the 95% upper confidence limit of nighttime pH values during placebo treatment. Secretory inhibition with early and late administration of ranitidine lasted for 10.7 and 7.3 h, respectively (p = 0.012). With famotidine it lasted for 10.1 and 7.1 h, respectively (p = 0.005). Gastric acidity after dinner was decreased by early but not late intake of ranitidine and famotidine. Thus, both ranitidine and famotidine were more effective when taken early, immediately after dinner, than when taken late in the evening. This observation might affect the mode of ulcer treatment with these drugs.
Adult↗
It is wise to prescribe NSAIDs with modern gastroprotective agents?
The administration of non-steroidal anti-inflammatory drugs (NSAIDs) leads to mucosal lesions in the upper gastrointestinal tract. Furthermore, NSAIDs increase the risk of ulcer bleeding and perforation, but the overall risk of fatal complications is relatively small (about 21 per one million prescriptions). Therefore, in asymptomatic patients, it is not justified to prescribe NSAIDs together with gastroprotective agents. The following recommendations can be given with respect to the management of peptic lesions in patients taking NSAIDs: (i) Fibre endoscopy should be performed even when there are relatively mild symptoms since mucosal lesions in rheumatic patients under NSAIDs produce minor or no symptoms. (ii) "Modern" NSAIDs might produce less gastric lesions than aspirin. (iii) Rheumatic patients with peptic disorders should be treated with an H2-antagonist. (iv) After complications such as ulcer bleeding or after rapid recurrence of peptic lesions, maintenance treatment with an H2-antagonist is advisable.
Anti-Inflammatory Agents, Non-Steroidal↗
[Long-term pH-metry and manometry: methods and value in the differential diagnosis of retrosternal pain].
Explore the source record for details and available documents.
Diagnosis, Differential↗
[Mechanical aids and technics in enteral tube feeding].
Explore the source record for details and available documents.
Endoscopy↗
Immune transfer studies in canine allogeneic marrow graft donor-recipient pairs.
Transfer of immunity occurring with bone marrow grafting was studied using the dog as a preclinical model. Allogeneic bone marrow transplantation (BMT) was performed between DLA-identical beagle litter-mates. The donors were immunized with tetanus toxoid (TT) or sheep red blood cells (SRBC), and their humoral response was monitored by hemagglutination. The recipients of bone marrow from TT-immunized donors showed a marked increase of antibody titer one week posttransplantation, while in the recipients of marrow from SRBC immunized donors the antibody titers were considerably lower. Within the following 60 days the antibody titers in both groups diminished gradually to pregrafting levels. Control experiments in which cell-free plasma from donors immunized with TT and SRBC respectively was transfused indicated that the initial rise of specific antibody titers after marrow grafting is likely to be due to a passive transfer of humoral immunity. A single challenge of these marrow graft recipients with the respective antigen 15-18 weeks posttransplantation led to a secondary type of humoral immune response. In addition, it could be demonstrated that transfer of memory against TT or SRBC was independent from the actual antibody titer and the time of vaccination of the donor. One dog was immunized with TT after serving as marrow donor. When the donor had shown an antibody response, a peripheral blood leukocytes (PBL) transfusion was given to his chimera. Subsequent challenge of the latter resulted in a secondary type of specific antibody response. This indicates that specific cellular-bound immunological memory can be transferred after BMT from the donor to his allogeneic bone marrow chimera by transfusion of peripheral blood leukocytes. The data presented may be of importance in clinical BMT to protect patients during the phase of reduced immune reactivity by transfer of memory cells from histocompatible immunized donors.
Animals↗