Search PubMed⌕ Search

Biomedical subjects

C Emde

Publications and source records attributed to C Emde.

51 records · Page 3Linked to original sources
PubMed1985

[Continuous intragastric pH-metry].

Ambulatory intragastric pH-metry is a suitable method of assessing gastric acidity under conditions of normal daily life. A detailed profile of intragastric acidity is given which is a reproducible individual characteristic. There is a circadian rhythm of gastric acidity in which pH rises during the night and after meals. pH-metry was used to determine the effects of H2-antagonists and antacids, and the results are the basis for the clinical use of intragastric pH-metry.

Antacids↗
PubMed1985

Three-day continuous drainage of pancreatic juice in the cortisone-treated conscious rat: analysis of enzyme activities and ultrastructural changes.

We have investigated the short-term effects of hydrocortisone (60 mg/kg per day) and placebo on basal and stimulated pancreatic secretion in the conscious rat. Volume and enzyme secretion were determined; fine structural changes were examined simultaneously. The pancreatic and bile ducts were cannulated separately; pancreatic juice was drained via an isolated fistula, and bile was recirculated into the duodenum. The application of hydrocortisone led to an almost complete inhibition of the secretory response of the exocrine pancreas when stimulated with 0.25 U secretin in combination with 5 X 10(-8) g caerulein per h. It strongly affected the secretion rates of volume, protein, lipase, chymotrypsin, trypsin and carboxypeptidase, whereas the secretion rate of alpha-amylase continued to show a slight increase after stimulation. After stimulation with secretin and caerulein, the hydrocortisone-treated animals showed a higher density of zymogen granules in the acinar cell and an increase in the number of autophagic vacuoles in comparison to the equally stimulated placebo-treated rats. It is concluded that the short-term inhibition of pancreatic secretion by hydrocortisone occurs largely as a result of an inhibition of cellular enzyme discharge.

Animals↗
PubMed1985

Lack of adaptive changes in human pancreatic amylase and lipase secretion in response to high-carbohydrate, low-fat diet applied by a 10-day continuous intraduodenal infusion.

In order to investigate whether the human exocrine pancreas is capable of adapting to a diet with a high-carbohydrate, low-fat, and normal protein content, 10 healthy subjects were given a continuous intraduodenal infusion of such a dietary composition (8760 kJ in 2400 ml/day) via a portable infusion pump over a period of 10 days. The diet consisted of 76% of calories as carbohydrates (80% oligosaccharides, 20% mono- and disaccharides), 10% as fat (more than 90% C18 fatty acids) and 14% as protein (oligo- and polypeptides; 11.8 g nitrogen per day). A complete pancreozymin-secretin test was carried out before and after the experimental period. The results show that the above dietary regimen leads to a significant (P less than 0.05) increase in the stimulated secretion rates of trypsin and chymotrypsin, whereas, in contrast to the findings in animal experiments, no change could be measured in the secretion rates of amylase and lipase.

Adaptation, Physiological↗
PubMed1984

[Tolerance of intraduodenal tube feeding. Prospective studies of the tolerance of a 10-day, continuous intraduodenal administration of a peptide diet and its effects on various serum parameters in healthy subjects].

Filiform nasoduodenal nutrition tubes in connection with portable infusion pumps are now available and by this way continuous enteral nutrition is given to a certain number of patients, thus avoiding expensive parenteral nutrition which demands a great deal of nursing care and bears a greater risk of complications. In order to study the acceptance and effects of this nutrition, 10 healthy persons were fed by the new system with a fiber-free, low molecular peptide diet. The probands had to write a daily protocol and, at the end of the test, had to answer a questionnaire regarding the effectivity and social consequences of the system and their subjective sensations. Before and after the enteral nutrition phase, different serum parameters were also determined. The results show that a continuous intraduodenal nutrition by tube can be achieved outside the clinic allowing to exercise the profession. The general well-being of the probands was moderately disturbed only by the tube whereas the other points from the questionnaire were less disturbing. Regarding the serum parameters only a reduction in the serum potassium was remarkable.

Adolescent↗
PubMed1984

[Simplified procedure for endoscopic administration of enteral feeding catheters].

Due to the immobilisation of patients in intensive care units or to pathologic alterations in the upper gastrointestinal tract caused by stenosis or anastomosis, the insertion of feeding tubes into the duodenum has been difficult in some cases. For this reason an enteral feeding tube has been developed which can be introduced through the biopsy channel of an endoscope so that it is possible to place the tube under visual control. This method has been used in more than 20 patients; in each case the positioning of the tube and the consecutive nutrition were free of complications. The required material is now commercially available.

Critical Care↗
PubMed1984

[Manometric study on the effect of Hedenstedt's selective proximal vagotomy on the lower esophageal sphincter].

A manometric examination of the oesophagus was carried out before and after selective proximal vagotomy according to Hedenstedt in 20 patients in whom operations were performed at the Dept. of Surgery of the Steglitz Medical Center within the period from 1980 to 1982. The resting pressure of the lower oesophageal sphincter could be shown to be unaltered postoperatively (preoperative median 17,5 mm Hg, postoperative 18 mm Hg, p greater than 0,1 non-significant). Likewise, the other manometric findings were normal and postoperatively unaltered. Thus, it was possible to demonstrate that the modification of the vagotomy according to Hedenstedt has no other effect on oesophageal motility than that already known for other types of selective proximal vagotomy.

Adult↗
PubMed1984

Exponential function of chymotrypsin action.

Enzyme kinetics are usually described by the hyperbolic Michaelis-Menten equation, but they can also be described by the following exponential function: -dS/dt = Vm [1 - exp (-S/Km)]. The time-dependent decrease of the substrate (-dS/dt) is an exponential function of maximal velocity (Vm), the Michaelis constant (Km) and the actual substrate value (S). This exponential function is based on the assumption that the association of the substrate-enzyme complex is a concentration-dependent process, whereas the transformation of the substrate-enzyme complex is time-dependent. It can be shown that this exponential function is a more general solution of which the hyperbolic Michaelis-Menten equation is a special derivative under the conditions of low substrate (S) and high constant (Km) values. If the association process is time-dependent, the decline in substrate values will show a more concave curve. However, exponential functions in general are more concave than hyperbolic functions. Probably, therefore, the enzyme action of chymotrypsin could be described more appropriately by the present exponential function than by the conventional hyperbolic function.

Chymotrypsin↗
PubMed1981

Early changes in brush border disaccharidase kinetics in rat jejunum following subcutaneous administration of tetraiodothyronine: a quantitative histochemical study on villi revealing normal morphology.

In order to test the influence of thyroid hormones on small intestine function, adult female Wistar rats were injected daily with either 100 microgram/100 g body weight tetraiodothyronine or placebo. After 12 days, jejunal segments were removed and processed for morphometric analysis of mucosal architecture and quantitative histochemical determinations of the apparent Km- and Vmax-values of lactase/beta-glucosidase and neutral alpha-glucosidase at constant basal and apical measuring positions along the villi. The villus-crypt-architecture was the same in both experimental groups. At the cellular level, however, application of tetraiodothyronine resulted in a marked decrease in the apparent Vmax of lactase/beta-glucosidase at both villus positions, maintaining the normal activity gradient along the villi. In comparison with the controls, a less pronounced but significant reduction in activity was also demonstrated for the neutral alpha-glucosidase. Substrate affinity, however, was only increased for this enzyme, the apparent Km of lactase/beta-glucosidase not being affected by the hormone. The results indicate a direct effect of tetraiodothyronine on jejunal brush border disaccharidases of the rat. The alternative mechanism, an effect mediated by an altered enterocyte turnover is unlikely to occur.

Animals↗
PubMed1980

Quantification of alpha-glucosidases along the villus of the small intestine in man. Introduction of a computerized histochemical method.

A method is introduced which enables the two-dimensional detection and analysis of absorbancy-values from continuous dye-deposites with rather low data storage capacity. Applied to histochemical reactions this method is used for kinetic analysis of enzymes along the intestinal villus. Its main part consists of two programs for two dimensional scanning, i.e. along the villus and at right angle from the lumen across the brush-border membrane to the apical cytoplasma. Two further programs serve as prerequisites: the automatical detection of mean values and the description of absorbancy spectra in the tissue section. The measurements are carried out with a MPVII Leitz in connection with a Hewlett Packard 9815 A calculator. The study of alpha-glucosidases of the human small intestine is taken to demonstrate the value of the method. It is shown that a similar Vmax-gradient along the villus can be demonstrated as by microchemical methods. Thus this method enables the description of the kinetic properties of a distinct enzymatic activity in preserved tissue sections on the cellular level and the possible alterations of Vmax and Km in context to the morphological pattern.

Computers↗
PubMedDate not supplied

Subjective distress during continuous enteral alimentation: superiority of silicone rubber to polyurethane.

A small-bore feeding tube of silicone rubber was developed in order to improve the acceptance of enteral feeding. The insertion procedure was facilitated by providing a double guidewire which allows continuous adjustment of tip rigidity. The usefulness of this tube was tested in a short-term and a long-term volunteer study as well as in a prospective follow-up of patients receiving enteral nutrition. The volunteer study showed that the newly developed tube significantly reduced subjective distress (rank value 14) when compared to a conventional tube made of polyurethane (rank value 20). In the patient study, 131 silicone rubber tubes were used in 85 patients who received enteral nutrition for a total period of 2080 days and complained about foreign-body feeling and rhinorrhea in only 3.7% and 0.5% of the days, respectively. The rate of inadvertent removals was relatively low (32%), mainly due to restricted mental status of the patients.

Enteral Nutrition↗
PubMedDate not supplied

Reduction of 24-hour gastric acidity by different dietary regimens: a randomized controlled study in healthy volunteers.

Evidence from animal experiments suggests that intraduodenal infusion of nutrients leads to an inhibition of gastric acid secretion via an enterogastric feedback mechanism. Detailed data are lacking, however, on the difference in circadian gastric acidity between gastric and intraduodenal alimentation in man. We conducted a randomized study in 10 healthy volunteers (5 men, 5 women, age 22-30 yr). From 8:00 am of the first study day until 4:00 pm of the next day, either a standardized normal meal or a liquid polymer diet (Fresubin) was given orally at 8:00 am, noon, and 6:00 pm. In a third experiment, a liquid hydrolysed diet (Survimed OPD) was continuously applied to the duodenum using a portable pump. Daily caloric intake and main nutrient components were comparable in all three diets. From 2:00 pm of the first day until 4:00 pm of the next day, an intragastric pH-metry was performed with a combined glass pH-electrode in the gastric corpus. Median pH-values from predefined time periods (whole day, prandial, interdigestive, nocturnal) were compared between the three groups. The orally applied liquid polymer diet led to a significantly stronger increase in 24-hr and prandial gastric pH than the normal diet. Twenty-four-hr, interdigestive, and nocturnal pH-median values were significantly higher during continuous intraduodenal application of the liquid hydrolysed diet than during the normal diet.

Adult↗