Since there is a need for a widely applicable non-invasive test to assess gastric emptying in diabetic patients, we evaluated the sensitivity, specificity, and reproducibility of the [13C]octanoic acid breath test as compared with scintigraphy. Moreover, we examined the relationship between the breath test indices and gastric symptoms, cardiovascular autonomic function, and metabolic parameters. Forty healthy control subjects and 34 diabetic patients were studied. Three indices of gastric emptying, assessed by the breath test, were computed: half-emptying time (t1/2breath), gastric emptying coefficient (GEC), and lag phase. Furthermore, the half-emptying time, measured by scintigraphy (t1/2scint), was calculated and gastric symptoms and cardiovascular autonomic neuropathy (CAN) were scored. The coefficients of variation of day-to-day reproducibility in 10 healthy subjects were 29.6% for t1/2breath, 7.4% for GEC, and 46.5% for lag phase. An abnormal delay for t1/2scint (> 100 min) or t1/2breath (> 200 min) was noted in 12 patients. Based on the results for t1/2scint, the sensitivity of t1/2breath and GEC was 75% and the specificity was 86%. Both t1/2breath (rs = 0.523; p < 0.05) and GEC (r2 = -0.594; p < 0.05) were significantly associated with the gastric symptom score. A significant relationship to the CAN score was demonstrated for t1/2breath (rs = 0.448; p < 0.05), GEC (rs = -0.467; p < 0.05), and t1/2scint (rs = 0.602; p < 0.05). There were no significant associations of the breath test indices with the blood glucose levels during the test, HbA1c, age, and duration of diabetes. In patients with abnormal t1/2scint (n = 12) not only was t1/2breath significantly prolonged and GEC reduced, but also the scores of CAN and gastric symptoms were significantly increased as compared with those who had a normal t1/2scint (n = 22). We conclude that the [13C]octanoic acid breath test represents a suitable measure of delayed gastric emptying in diabetic patients which is associated with the severity of gastric symptoms and CAN but not affected by the blood glucose level.

SummaryPatients received 2,000 ml of dialysate intraperitoneally with five exchanges per day during continuous peritoneal dialysis (CAPD) for the treatment of terminal renal insufficiency. During a dwell time of 4 h the dialysate reached a total protein concentration up to 100 mg/dl by mass transfer of intravascular proteins. The composition is dependent on the molecular weight of the proteins. This results in an intraperitoneal hemostatic system of low concentration and different composition.We found an intraperitoneal fibrinogen cleavage and thrombin- antithrombin Ill-complex formation leading to increased levels of fibrinopeptide A (FPA: 33.3 ± 7.0 ng/ml) and thrombin-antithrombin Ill-complex (TAT: 4.7 ± 0.4 ng/ml) in plasma by mass transfer from dialysate to plasma. t-PA (tissue plasminogen activator) and PAI-1 (plasminogen activator inhibitor type 1) concentrations in plasma were within the normal range. The dialysate concentrations indicated a low local secretion. The fibrinolytic fibrin fragment D-dimer and the fibrinogen degradation product concentrations in plasma were greater than in dialysate. But the relations of the proteins between plasma and dialysate refer to a local intraperitoneal production as well.The results show that intraperitoneal coagulation predominates over fibrinolysis which is accompanied by an intravascular fibrinolysis in patients undergoing CAPD. Neoantigens produced in dialysate and diffused to plasma are comparable to changes seen in disseminated intravascular coagulation.

In 6 patients on continuous ambulatory peritoneal dialysis we investigated the inhibition of intraperitoneal fibrin formation by heparin. A continuous addition of 500 U of heparin per liter dialysate was used for 52 h. In plasma no heparin activity could be detected, even 52 h after intraperitoneal administration of heparin. The fibrin formation was determined by fibrinopeptide A, a thrombin-induced split product of fibrinogen. In patients under regular continuous ambulatory peritoneal dialysis we determined the fibrinopeptide A concentrations in plasma. The values were comparable with the fibrinopeptide A concentrations measured in disseminated intravascular coagulopathy. They decreased during intraperitoneal administration of heparin from 63.2 ± 11.8 to 4.9 ± 1.7 ng/ml. The fibrinopeptide A concentration in the 4-hour intraperitoneal dialysate (155.8 ± 15.7 ng/ml) decreased after heparin administration to 8.5 ± 2.0 ng/ml and was always higher than in plasma. We conclude that 500 U heparin per liter dialysate prevents the intraperitoneal fibrin formation. The low antithrombin III concentration (0.44 ± 0.13 mg/dl) in protein-poor dialysate seems to be sufficient to inhibit the thrombin activity after acceleration by heparin.

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Bile salts, when instilled into the intestine at pH 6, stimulate pancreatic exocrine secretion in man and cat. We investigated if the surface tension as a major physicochemical property of bile acids might be responsible for this effect. In anesthetized cats, either conjugated taurocholate (TC) or unconjugated ursodesoxycholate (UDC) as steroidal detergents or oleate as nonsteroidal detergent were perfused into the duodenum. The critical micellar concentration (CMC) and the surface tension (γ) were as follows: for oleate 18.6 mmol/l and 27.7 dyn·cm^-1, for UDC 10.75 mmol/l and 46.5 dyn·cm^-1, for TC 14.5 mmol/l and 58.6 dyn cm^-1. The intraduodenal perfusion of the three solutions at 30 mmol/l and pH 8 evoked an equal pancreatic flow (about 300 mg/15 min) and bicarbonate secretion. It is suggested that the free ionized form of TC perfused intraduodenally is responsible for stimulation of the pancreatic exocrine secretion. We show that the stimulatory effect seems to be independent of the detergency of these molecules.