The effect of different potassium, calcium and magnesium concentrations in the perfusate on the hormone secretion of the isolated dog pancreas was investigated. A potassium concentration above 15 mMol/l shortly stimulates the insulin and glucagon secretion. Potassium ions (greater than or equal to 15 mMol/l) completely inhibit the early phase of glucose-induced insulin release. At a low Ca2+-level (0.25 mMol/l) the glucose-stimulated insulin secretion is reduced to basal values. On the other hand, the glucagon release is stimulated under these conditions. An increase of magnesium ions from 1.0 mMol/l to 2.5-7.5 mMol/l strikingly inhibits insulin and glucagon release by approximately 50%, which is compensated for insulin by increasing the Ca2+-content of the medium. Perfusates for normothermic pancreas perfusion should contain electrolyte concentrations within the physiological range.

Der Stofftransport im Oesophagus wird wechselseitig durch peristaltische Wanddruckkräfte und sphinktere Verschlußdruckkräfte bewirkt. Dabei sind die Funktionsmechanismen des oberen und unteren Oesophagussphinkters verschieden. Mit Hilfe der simultanen Videoradiografie und Manometrie werden die unterschiedlichen Funktionen sichtbar und meßbar, so daß Modellbildungen der biomechanischen Transportund Verschlußfunktionen zunehmend realistischer werden.

Article Simultane Darstellung von Struktur und Funktion klinisch relevanter Hohlorgane was published on January 1, 1997 in the journal Biomedical Engineering / Biomedizinische Technik (volume 42, issue s2).

Wir kombinierten ein neu entwickeltes fiberoptisches ambulantes Meßsystem zur Bestimmung von intragastralem Bilirubin (Bilitec 2000®, Synectics Medical Inc., Schweden) mit der gastroduodenalen Langzeitmanometrie bei 10 gesunden Probanden und 10 beschwerdefreien Patienten nach Billroth-I-Resektion (BI-Resektion). Im Vergleich zur Kontrollgruppe war die circadiane Bilirubinexposition und die Anzahl exzessiver Schwankungen der intragastralen Bilirubinkonzentration (mehr als 20 % und länger als 5 min) bei den BI-resezierten Patienten signifikant erhöht (p < 0,05). Der interdigestive Motilitätszyklus (IMC) war bei den Patienten durch das gehäufte Auftreten verschiedener Typen abnormal propagierter Phase-III-Aktivitätsfronten gekennzeichnet. 90,1 % aller Bilirubinanstiege gingen in der Patientengruppe zeitlich mit abnormalen propagierten Phase-III-Aktivitätsfronten einher. In Fällen eines erhöhten duodenogastralen Refluxes erscheint die ambulante intragastrale Bilirubinbestimmung in Kombination mit der gastroduodenalen Langzeitmanometrie als praktikable Methode zum circadianen Monitoring von Motilität und Reflux.

We combined a newly developed ambulatory fiberoptic system for detecting intragastric bilirubin (Bilitec 2000, Synectics Medical Inc., Sweden) with prolonged measurement of gastroduodenal motility in 10 healthy volunteers and 10 patients followed BI resection. Circadian intragastric bilirubin exposure and the total number of tremendous changes of bilirubin absorption (more than 20%, over a period of at least 5 min) were significantly increased in the BI-resected patients (P < 0.05). In patients the interdigestive motility cycle (IMC) was characterized by the appearance of several types of abnormally propagated phase III activity fronts. Of the tremendous increases of bilirubin absorption in the patient group, 90.1% were associated with abnormally propagated phase III activity fronts. In cases of increased duodenogastric reflux, the combination of ambulatory intragastric bilirubin measurement and long-term manometry seems to be feasible to assess motility and reflux simultaneously.

Article Die Impedanzspektroskopie, eine Methode zur Bestimmung der Zellkonzentration und zum Monitoring der zellulären Vitalität was published on January 1, 1996 in the journal Biomedical Engineering / Biomedizinische Technik (volume 41, issue s1).

Two factors are to determine increasing lower esophageal sphincter pressure during intragastric pressure rising mainly: 1. the active intrinsic muscle tone and 2. the efficiency of the law by La Place. The purpose of the study was to estimate the part of both of them in this measurable phenomenon. We investigated 15 healthy volunteers and 5 patients post Nissen fundoplication. A simultaneous manometric examination of gaster and LES was carried out during gradual compression of abdominal wall. Analysis of dependence of LES-pressure on intragastric pressure, based on computer usage, was established. A linear equation described this dependence with the best correlation coefficient (r = 0.98) followed by potential and exponential equation. Fundoplication caused a steeper ascent without any changing of linear character of function. Considering linear equation is compatible with the law by La Place out not with a simultaneous pressure depending change of intrinsic muscle tone, these results indicate that the law by La Place has major importance in the measurable rising of high pressure zone during intragastric pressure increasing.

A group of 20 urinary continent postmenopausal women and two stress incontinent groups in the age of 60-69 and 70-79 years have been examined concerning standardized conditions without and with stress. The measurements using the pneumatic-hydraulic pump perfusion were recorded under standardized conditions. The whole pressure profile without stress decreased with increasing age and with stress incontinence. The maximum urethra closure pressure has been displaced in the distal part of the urethra. The stress profile demonstrated a shortening of the continence zone, a clear decrease of the urethra closure pressure and a bad pressure transmission in the whole urethra, especially in its distal part. These fluctuations make us expect, that there are only a few promising possibilities of conservative treatment in stress incontinent postmenopausal women over 70 years.

Well defined results can be obtained quickly by in vitro test concerning the preservation effect of the preserved dog's pancreas. Clinical and chemical parameters were received during the hypothermic perfusion respectively during the refrigerant storage. The in vitro function tests were carried out after the preservation by insulin and glucagon stimulation. The results showed that the A and B cells of the dog's pancreas are completely able to function after a preservation of 24 hours. Thereby a strong formation of edemas by releasing high enzyme activities is caused during the mechanical perfusion of the organs. The simple refrigerant storage of the pancreata therefore, is the more suitable preservation form for organ transplantations.

Measurements of the pressure in the urethra were performed under standardized conditions with the aid of perfused catheters in 20 fertile and 20 postmenopausal women, from it 12 women after local estrogen therapy by means of Ostriol-Ovula. Hormone-cytological swabs from the urethra, vagina and from the urinary cells were done. Proliferation of the urogenital epithelialia under the estriol-therapy and an ascent of the MUP and MUCP in the urethra pressure profile under resting conditions could be achieved. The maximum of the pressure profile could be displaced proximaly. In the urethra pressure profile the distal pressure transmission increased. Estriol therapy was without secondary effects and is suitable for the conservative therapy of the stress incontinence type I to III.