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Biomedical subjects

L Højgaard

Publications and source records attributed to L Højgaard.

108 records · Page 6Linked to original sources
PubMed1988

Gastric mucosal electrical potential difference and blood flow during high FFA/albumin ratios in anaesthetized Göttingen mini-pigs.

The gastric blood flow and the gastric mucosal potential difference (p.d.) was studied in anaesthetized Göttingen mini-pigs under normal conditions and during increased FFA/albumin ratios. The antrum mucosal p.d. was measured continuously with a newly developed intragastric microelectrode principle. The gastric blood flow was measured with the radioactive microsphere technique: at basal conditions, during high FFA/albumin ratios, and after normalization of the plasma lipids. The antrum p.d., expressed with gastric lumen negative, decreased during the increased FFA/albumin ratios; from -25 +/- 3 mV to -17 +/- 4 mV, (P less than 0.05). A further reduction to -12 +/- 3 mV (P less than 0.05) was observed during the normalization of the FFA/albumin ratios. The antrum and corpus mucosal blood flow values were reduced by 37 and 26% during the increased FFA/albumin ratios, and the gastric mucosal blood flow returned to initial values after normalization of the plasma lipids. The p.d. reduction during and after the increased FFA/albumin ratios could reflect a reduced active ion transport across the mucosa caused by a changed gastric mucosal metabolism.

Animals↗
PubMed1988

Epidural blood flow and regression of sensory analgesia during continuous postoperative epidural infusion of bupivacaine.

Epidural blood flow was measured in seven patients undergoing elective abdominal surgery during combined lumbar epidural and general anesthesia. After an initial dose of 20 ml plain bupivacaine 0.5%, a continuous epidural infusion of bupivacaine 0.5% (8 ml/hr) was given for 16 hours for postoperative pain relief. The epidural blood flow was measured by a local 133Xe clearance technique in which 15-35 MBq 133Xe diluted in 1 ml saline was injected through the epidural catheter on the day before surgery (no bupivacaine), 30 minutes after the initial dose of bupivacaine on the morning before surgery, and 8, 12, and 16 hours later during the continuous infusion. Initial blood flow was 6.0 +/- 0.7 ml/min per 100 g tissue (mean +/- SEM). After epidural bupivacaine, blood flow increased in all seven patients to 7.4 +/- 0.7 ml (P less than 0.02). Initial level of sensory analgesia was T4.5 +/- 0.17 (mean +/- SEM). Postoperatively, two patients maintained the initial level of sensory analgesia and low pain score throughout the 16-hour study. In these two patients epidural blood flow remained constant after the initial increase. Flow increased further to 10.3 +/- 0.8 ml/min per 100 g tissue (P less than 0.03) in the other five patients as the level of sensory analgesia regressed postoperatively. These data suggest that changes in epidural blood flow during continuous epidural infusion of bupivacaine, and thus changes in rates of vascular absorption of bupivacaine from the epidural space, may be an important factor contributing to differences in rates of regression of sensory analgesia.

Adult↗
PubMed1987

A new method for measurement of the electrical potential difference across the stomach wall. Clinical evaluation of the gastric mucosal integrity.

PD, the electrical potential difference across the gastric mucosa, is a variable used frequently in experimental studies. Existing methods for PD measurements are, however, unstable, and variations in the pH of the gastric juice causes liquid junction potentials between gastric juice and the PD measuring probe. A new PD measuring system has been developed with high stability, easy handling, and correction for the liquid junction potentials. PD was measured between a stomach microelectrode and an intravenous reference electrode connected to a millivoltmeter. pH was measured by an intragastric microelectrode. The liquid junction potential was calculated by using the pH measured in the gastric juice and the Henderson equation and was then subtracted from the measured PD to provide a better approximation of the PD across the mucosa. The liquid junction potential calculated as stated above correlated with the liquid junction potential calculated from precise ion determinations made in gastric juice samples (y = x; r = 0.92; p less than 0.05). The reliability of the PD measuring system was tested in vitro and in vivo and was satisfactory. In conclusion, a new, reliable, and easily applied method for gastric PD measurements corrected for the liquid junction potential between gastric juice and the PD measuring probe has been developed.

Action Potentials↗
PubMed1987

Gastritis--a clinical entity?

Clinicians, endoscopists, and pathologists define gastritis in different ways. Pathoanatomical gastritis is very common and the prevalence increases with age. Patients submitted to routine endoscopy were interviewed before endoscopy and biopsies were taken from gastric antrum and body. No correlation could be found between upper abdominal dyspepsia, endoscopic signs suggesting gastritis, and histological gastritis. Gastritis does not seem to constitute a clinical entity within non-ulcer dyspepsia.

Adolescent↗
PubMed1985

Effect of enterocoated cholestyramine on bowel habit after ileal resection: a double blind crossover study.

Ileal resection causes malabsorption of bile acid; the increased load of bile acids in the colon induces increased secretion of salt and water and hence diarrhoea. A study was carried out to test the effect of an enterocoated cholestyramine tablet designed to disintegrate in the colon and sequester the bile acids there, thereby minimising diarrhoea induced by bile acids while having no effect on malabsorption of bile acid and jejunal fat absorption. The study comprised 14 patients who had undergone ileal resection of 40-150 cm for Crohn's disease. A double blind crossover trial was performed with placebo and cholestyramine enterocoated with cellulose acetate phthalate. During treatment with cholestyramine the daily faecal output decreased, the number of defecations each week decreased, and the intestinal transit time increased. Acceptability of the tablets was high, in contrast with general clinical experience with cholestyramine powder. No change was observed in the total faecal output of bile acids or fat. Cholestyramine tablets caused a reduction in diarrhoea without noticeably interfering with the metabolism of fat or bile acid.

Adult↗
PubMed1983

Effect of oat bran on lithogenic index of bile and bile acid metabolism.

Epidemiological studies lend support to the hypothesis that high-fibre diets might prevent and low-fibre diets might facilitate the formation of cholesterol gall stones. In the present study, the bile compositions after ingestion of oat bran 18 g/day and placebo 18 g/day for 2 X 2 weeks were compared in a randomized, double-blind cross-over study in 6 healthy volunteers. The lithogenic index of bile was not influenced, whereas the following changes (0.05 less than p less than 0.10) occurred: the cholic acid pool was enlarged, the relative proportion of chenodeoxycholate in bile was increased and that of deoxycholate reduced, while cholate remained unchanged. It is concluded that oat bran seems to influence the metabolism of bile acids.

Adult↗
PubMed1982

Superficial eosinophilic squamous epithelial cells in vaginal smears from postmenopausal women.

19 500 vaginal smears from women aged 20-90 years were examined from August 1976 to November 1979. 3 000 were from women more than 55 years of age. 146 of these had smears with an increased proportion of superficial eosinophilic squamous epithelial cells (SESEC). The smears were divided into four groups, A-D with 0-25%, 25-50%, 50-75% and 75-100% of SESEC of the examined squamous epithelial cells. 39% of the 146 with increased proportions of SESEC were either undergoing treatment with estrogenic hormones, or else the possibility of estrogenic influence could not be ruled out. In group D the possibility of an estrogenic influence was more pronounced, here found to be 67%. In 32% of the 146 cases we believe that these cells were possibly the result of changed anatomical conditions in the cervix/vagina. Such an explanation seems most frequently probable in groups A and B. In 5% of the 146 cases the cells appeared changed, as can be seen in trichomoniasis. In 21% the discovery of the cells could not be explained. Finally, no explanation could be found for 5% in group D.

Age Factors↗
PubMed1981

Bile acid metabolism after intestinal bypass operations.

Intestinal bypass operation for obesity results in substantial weight loss only if the small bowel segment left in function is 50 cm or less. The anatomical changes induce interruption of the enterohepatic circulation of bile acids, which result in bile acid malabsorption. This review discusses the various aspects of the disturbed bile acid metabolism. A small number of controlled prospective studies have focused on the problems of the jejunoileal ratio (JIR) of the functioning segment in relation to the changes induced on the bile acid metabolism. 1:3 JIR results in a significantly: (1) lower bile acid pool size; (2) lower postprandial concentration of bile acid in the jejunum: (3) lower ratio of glycine to taurine conjugates; (4) higher cholesterol saturation index in bile, compared to 3:1 JIR. Thus, the studies mentioned have not only elucidated the changes in bile acid metabolism after jejunoileostomy, but also given support to a new hypothesis that a functioning upper jejunum is necessary for the bile acid synthesis as such. This hypothesis is further supported by the finding that 1:3 JIR at follow-up has a three fold higher rate of gallstones than 3:1 JIR (p less than 0.05).

Bile↗
PubMedDate not supplied

In vitro and in vivo accuracy of sonographic gallbladder volume determinations.

To assess gallbladder function, sonographic gallbladder volume determinations have been used with increasing frequency. This study presents a modified and automated procedure for gallbladder volume determinations using Simpson's rule of integration, Simpson's method. This method is a standard option in the data systems of many sonographic instruments. Simpson's method was validated in vitro and in vivo, and it was compared with the sum-of-cylinders method for gallbladder volume determinations. In vitro assessment indicated that the two methods were equally accurate, with Simpson's method being more precise. The absolute deviation was independent of the size of the volume and of the shape of the gallbladder. In vivo Simpson's method was validated on 11 patients with cholecystitis. The gallbladder volumes (mean 65 mL; Range 20 mL to 130 mL) measured by sonography differed from the aspirated volumes by 1.5 mL (SD 10.4 mL). Thus Simpson's method is an accurate, precise, and fast method for sonographic gallbladder volume determination.

Animals↗
PubMedDate not supplied

Coregulation of glucose uptake and vascular endothelial growth factor (VEGF) in two small-cell lung cancer (SCLC) sublines in vivo and in vitro.

We examined the relationship between (18)F- labeled 2-fluro-2-deoxy-d-glucose (FDG) uptake, and expression of glucose transporters (GLUTs) in two human small-cell lung cancer (SCLC) lines CPH 54A and CPH 54B. Changes in the expression of GLUTs and vascular endothelial growth factor (VEGF) during 12-, 18-, and 24 hours of severe hypoxia in vivo (xenografts) and in vitro (cell cultures) were recorded for both tumor lines. The two SCLC lines are subpopulations of the same patient tumor. In spite of their common genomic origin they represent consistently different metabolic and microenvironmental phenotypes as well as treatment sensitivities. There were higher levels of Glut-1 protein in 54B and a correspondingly higher FDG uptake in this tumor line (P<.001). During hypoxia a significant upregulation of in VEGF mRNA, GLUT-1 mRNA, and Glut-1 and -3 protein occurred with a distinctly different time course in the two cell lines. A similar co-upregulation of GLUT and VEGF was seen in hypoxic tumors of both lines. There were no significant changes of HIF-1alpha mRNA during hypoxia in either of the cell lines. A more detailed understanding of such correlations between glucose metabolism, angiogenesis, and microenvironmental phenotype of tumors, by positron emission tomography (PET) and molecular techniques might further sophisticate our interpretation of glycolytic predominance in tumors as seen by 18FFDG PET.

Animals↗
PubMedDate not supplied

Development of stress ulcers assessed by gastric electrical potential difference, pH of gastric juice, and endoscopy in patients in the intensive care unit.

OBJECTIVE: To assess measurement of gastric electrical potential difference, pH of gastric mucosa, and endoscopic findings in patients in intensive care units who are at risk of developing stress ulcers. DESIGN: Open comparison with age- and sex-matched control subjects. SETTING: Herlev Hospital, Denmark. SUBJECTS: Sixteen consecutive patients with no history of gastrointestinal haemorrhage, coagulopathy, or ulcer disease who had been admitted to the intensive care unit, and 16 age- and sex-matched outpatients with normal endoscopic findings. INTERVENTIONS: Upper gastrointestinal endoscopy, during which any lesions that were found were scored according to severity, the gastric potential difference, and the pH of gastric juice were measured. OUTCOME MEASURES: Correlation between the incidence of stress ulceration found at endoscopy, gastric potential difference, and gastric pH. RESULTS: Gastric potential difference was significantly reduced and gastric pH significantly increased in the patients in the intensive care unit (p less than 0.05 in both cases), all of whom had stress ulcers in more than one gastric segment. Nine of the patients had gastric pH readings of greater than 4. CONCLUSION: Gastric electrical potential difference may be useful measurement for the assessment of stress ulceration in patients in intensive care units.

Adult↗