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C Emde

Publications and source records attributed to C Emde.

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

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

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

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

Twenty-four-hour pattern of esophageal motility in asymptomatic volunteers.

Diurnal variations in the pattern of esophageal motility and acidity were studied in 14 healthy volunteers. Data from a two-channel manometry and one-channel pH-metry recording were stored in a portable 1-MByte, solid-state data logger for subsequent computerised analysis. Comparison of predefined nighttime, mealtime and nonmeal daytime periods showed that propagated contractions predominated during mealtimes (56% of all contractions) and nonmeal daytime periods (53.5% of contractions) and that their propagation velocity (2.98 cm/sec) was at its lowest and the AUC of all contractions (134.6 hectoPascal.sec) at its greatest during mealtime periods. During the night, propagated contractions (0.136/min) and simultaneous contractions (0.025/min) were significantly less frequent than during both meal (1.31/min and 0.172/min, respectively) and nonmeal daytimes (0.665/min and 0.133/min, respectively), whereas the nocturnal segmental contraction frequency (0.181/min) was not significantly lower than the nonmeal daytime contraction frequency (0.243/min). Median reflux time was in the normal range (1.2%), although two subjects had prolonged reflux times (9.5% and 14.5%). In conclusion, all subjects showed similar patterns of diurnal esophageal contractory activity determined partly by meal intake and partly by a characteristic clustering of nocturnal contractions that could not be explained by episodes of nocturnal gastroesophageal reflux. It may, therefore, be speculated that nocturnal contraction clusters are associated with rhythmic phenomena such as MMC or specific sleep stages.

Acid-Base Equilibrium↗
PubMed1990

Fate of antacid gel in the stomach. Site of action and interaction with food.

The site of action of a high-power Al-Mg antacid gel (buffering capacity 70 meq/10 ml) and its interaction with food was examined in 10 healthy volunteers. Combined pH-metries in antrum and corpus were performed in each volunteer on four occasions. In a randomized study design, antacid or placebo were given 1 hr after either a protein or a carbohydrate pancake, of which only the former had any acid-buffering capacity. Before the meal, pH was higher in the antrum than in the corpus (median antrum: 3.2, corpus 1.5). In the corpus, a protein pancake but not a carbohydrate pancake raised the pH (median pH after protein pancake: 3.5; after carbohydrate pancake: 1.4). In the antrum, the protein pancake had no effect, but the carbohydrate pancake decreased the pH (median pH after protein pancake: 3.1; after carbohydrate pancake: 2.0). The antacid had no effect in the corpus after either pancake. It raised intraluminal pH markedly in the antrum after a carbohydrate pancake (median antral pH before antacid: 2.0; after antacid: 3.3), whereas its effect in the antrum was weak after a protein pancake. In vitro experiments were conducted to explain the in vivo results: in contrast to a carbohydrate pancake, a protein pancake reduced the buffering capacity of the antacid by direct interaction. In conclusion, the effect of an antacid gel on intragastric pH is predominantly localized in the antrum and is attenuated in the presence of proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Outcome prediction models on admission in a medical intensive care unit: do they predict individual outcome?

Prospectively acquired data from 941 patients staying greater than 24 h in a medical ICU were analyzed to determine the relevance of scoring on ICU admission by the following methods of outcome prediction: Acute Physiology and Chronic Health Evaluation (APACHE II), Simplified Acute Physiology Score (SAPS), and Mortality Prediction Model (MPM). Analysis was performed separately for all patients (group A) and for a subsample (group B), obtained by excluding coronary care patients. Calculation of risk and classification of patients were carried out as recommended in the literature for MPM, APACHE II, and SAPS. In group A, sensitivities (correct prediction of hospital mortality) were 44.7%, 51.1%, and 21.2% and specificities (correct prediction of survival) were 84.5%, 85.4%, and 96.8%, respectively; overall correct classification rates were 73.3%, 75.8%, and 75.6%. In group B, sensitivities were slightly higher, but total correct classification rates did not reach group A levels. Goodness-of-fit testing showed low levels of fit for all methods in both groups. Application of APACHE II to diagnostic subgroups, using disease-adapted risk calculations, revealed marked inconsistencies between the estimated risk and the observed mortality. We conclude that the estimation of risk on admission by the three methods investigated might be helpful for global comparisons of ICU populations, although the lack of disease specificity reduces their applicability for severity grading of a given illness. The inaccuracy of these methods makes them ineffective for predicting individual outcome; thus, they provide little advantage in clinical decision-making.

Female↗
PubMed1990

Electrochemical aspects of pH electrodes.

When a pH electrode is applied intragastrically for long-term pH metry, problems may occur which are related to the specific conditions of gastric juice and to the possible difference between the temperature of buffer solutions and the body temperature. The fact that pH electrodes measure the activity of the hydrogen ion instead of its concentration may, in concentrated solutions (i.e. pH less than 2), lead to an error that is even compounded if other ions are present in high concentrations. This error normally does not influence comparisons between measurements obtained under the same conditions. It is, however, important to check which correction procedures are provided for the particular devices being used when comparing results obtained by different research groups. Calibration of the electrode at a temperature differing from body temperature may result in an important error. Complete correction for this error may be achieved for glass electrodes by a modified version of the Nernst equation; for monocrystalline antimony electrodes an empirically derived formula is available allowing for partial correction. In general, all types of electrodes should be calibrated using two different buffer solutions (one with a pH value between 6 and 8 and another with a pH of 2 or less) and the double-point interpolation method.

Antimony↗
PubMed1990

Graphical display and statistical evaluation of data gained by long-term ambulatory intragastric pH monitoring.

The graphical display of data gained by long-term ambulatory intragastric pH monitoring requires different methods to present (1) the circadian time course of each individual, (2) data from all individuals belonging to the same group, and (3) data from two or more groups in a summary plot. Data reduction is normally required in all three cases; for this purpose, it is advisable to use median values from consecutive time periods, e.g. of 10-20 min each. All data from a total group of comparable individuals may be displayed using a pseudo-3D-graph allowing for easy recognition of interindividual variability. Summary curves from all data of one group may be gained by calculating medians from time-equivalent pH values and plotted together in one graph. The study design should take into consideration that intraindividual reproducibility of intragastric pH metry is excellent, while large variations may occur between individuals. Therefore, repeated measurements in the same individual under the different conditions to be tested are highly recommended. If two measurements are performed in each individual, the data are statistically evaluated using Wilcoxon paired rank test; Friedman rank test and subsequent multiple comparison according to Wilcoxon-Wilcox are proposed in the case of more than two groups. Alternatively, multiple single tests may be used; this procedure, however, requires appropriate correction of the alpha-error which is best done using the exact versions of the test.

Circadian Rhythm↗
PubMed1990

Reproducibility of ambulatory gastric pH recordings in the corpus and antrum. Effect of food, time, and electrode position.

The reproducibility of simultaneous, long-term, ambulatory gastric pH recordings in the antrum and corpus was investigated in nine healthy subjects who underwent three separate, 27-h gastric double pH-metries. Intraindividual reproducibility for the entire 27-h recording period was good in the corpus (Kendall's concordance coefficient, W' = 0.6393, p less than 0.025) but not in the antrum (W' = 0.4806, NS). Analysis of predefined time periods showed that non-meal daytime pH was reproducible in the corpus (W' = 0.6531, p less than 0.025) but not in the antrum (W' = 0.3395, NS), whereas mealtime pH was reproducible in the antrum (W' = 0.7159, p less than 0.005) but not in the corpus (W' = 0.4954, NS); nocturnal pH was not reproducible in either the antrum or the corpus. These results reflect the functional separation of corpus and antrum and their differing responses to food. Thus, studies of gastric acidity over long periods should be conducted in the corpus, whereas studies of gastric acidity over shorter, meal-related periods should be conducted with a second electrode in the antrum.

Adult↗
PubMed1990

The effect of an anthraquinone laxative on colonic nerve tissue: a controlled trial in constipated women.

Anthraquinone containing laxatives have been accused to cause degenerative changes in the colonic nerve tissue; prospective studies, however, are not available. This article reports the result of a semiprolective study in 11 matched pairs of chronically constipated women. Each pair consisted of one women having regularly taken an anthraquinone containing laxative for at least one year and a control person without such a medication. Six endoscopic biopsies were taken from the left colon and rectum which were evaluated by electron microscopy and subsequent ultramorphometry for the ratio of damaged to intact neurons, density of neurosecretory vesicles, axonal diameter and number of lysosomes. Medians of the three colonic locations were calculated in each individual and for each variable, and they were compared by non-parametric statistics. Medians of the ratio of damaged to intact neurons in anthraquinone treated women and controls were 0.162 and 0.146 (p = 0.0326, one-tail), medians of the number of type I vesicles were 293 and 348.5 per 100 microns 2 (p = 0.0365, one-tail), respectively. None of the other variables were different between groups. These data do not support the hypothesis that anthraquinone containing laxatives are able to provoke relevant degenerative changes in the colonic nerve tissue since the variables are either similar in both groups or only slight differences could be found which are unlikely to be of pathophysiological relevance.

Adult↗
PubMed1990

[The protease inhibitor gabexate mesilate in experimentally-induced acute pancreatitis with early gram-negative infection in the Göttingen minipig: therapeutic efficacy and effects on blood coagulation and fibrinolysis].

Due to its biochemical properties, the newly developed low-molecular protease inhibitor gabexate mesilate is assumed to be efficient in the treatment of complicated acute pancreatitis. This thypothesis was tested using the model of the experimental taurocholate pancreatitis with early artificial E. coli infection in Göttingen mini pigs. Either gabexate mesilate or a placebo was given intravenously 150 min after induction of pancreatitis in a dosage of 2 mg/kg b.w. and h. Median survival time was 15 h in the gabexate mesilate treated animals (n = 7) as compared to 34 h in the placebo group (n = 7); this difference was not significant. The application of gabexate mesilate had no influence on the increased coagulation activity (decrease of prothrombin time, antithrombin III and platelet count) nor on the additional hyperfibrinolysis with concomitant decrease of plasminogen and antiplasmin. Prothrombin time and antithrombin III were less distinctly decreased in the placebo group; decrease of platelet count was more pronounced. On the basis of this study the hypothesis is not confirmed that treatment with gabexate mesilate for necrotizing experimental pancreatitis with additional gram-negative infection has a therapeutic efficiency.

Acute Disease↗
PubMed1989

[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↗
PubMed1989

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↗
PubMed1989

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↗
PubMed1989

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↗