Concordance of in vivo microdialysis and in vitro techniques in the studies of adipose tissue metabolism

BACKGROUND

Adipose tissue metabolism can be investigated directly in vivo by microdialysis and indirectly in vitro using isolated adipocytes. The in vitro studies are relatively easy to make and they give information about specific tissue metabolism. The in vivo studies, on the other hand, are supposed to give relevant data about tissue physiology interacting with other metabolic systems at the body level.

OBJECTIVE

To investigate the concordance between the results on responsiveness to stimulation of lipolysis from in vivo microdialysis and in vitro isolated adipocytes.

SUBJECTS

Altogether 22 massively obese otherwise healthy subjects (seven men and 15 women, age 41 (26-55) y, BMI 51.5 (37.5-73.9)kg/m2, mean (range)) going through the gastric banding operation participated in the study.

METHODS

The microdialysis study was done after an overnight fast at rest. Lipolysis was stimulated with isoprenaline that was perfused into the subcutaneous abdominal adipose tissue. Local blood flow was estimated by ethanol dilution method. Adipose tissue biopsy for the in vitro study was taken from subcutaneous abdominal region during the operation. Lipolysis in freshly isolated adipocytes was stimulated with different concentrations of adrenaline or isoprenaline.

RESULTS

Significant positive correlations were observed between the values of relative stimulation of lipolysis in isolated adipocytes and in the microdialysis study. These correlations improved after correcting for cell size or fat mass.

CONCLUSION

The microdialysis study in vivo and lipolysis assay with isolated adipocytes in vitro provide concordant and complementary information of adipose tissue metabolism in the same individual.

Clinical evaluation of serum tumour markers CEA, CA 50 and CA 242 in colorectal cancer

The aim of the present prospective study was to evaluate the clinical value ol serum tumour markers CEA, CA 50 and CA 242 in patients with colorectal cancer (n = 138) and patients with benign gastrointestinal disease (n = 104). The cutoff levels (90% specificity) determined for each test were 2.5 ng/ml for CEA, 17 U/ml for CA 50 and 17 U/ml for CA 242. The diagnostic sensitivity of the CEA test was 0.63, that of the CA 50 test was 0.30 and 0.30 for the CA 242 test in detecting colorectal cancer. CEA, CA 50 and CA 242 tests were tested in a multivariate analysis to find the best combination of independent predictors of colorectal cancer. The most important predictor of colorectal cancer was CEA followed by CA 242. In order to calculate the contributions of tumour marker tests, a diagnostic score (DS) was developed. The sensitivity of the DS in detecting colorectal cancer was 0.47 with a specificity of 0.88 and an efficiency of 0.67. On the basis of this study, serum CEA and CA 242 seem to possess diagnostic value in preoperative evaluation of patients with colorectal cancer.

Effect of dihydroergotamine on leg blood flow during combined epidural and general anaesthesia and postoperative deep vein thrombosis after cholecystectomy

The effects of dihydroergotamine (DHE) on the circulation of the leg during combined epidural and general anaesthesia were studied to determine if DHE would enhance leg blood flow and prevent postoperative deep vein thrombosis in a double-blind trial of 40 elderly female patients subjected to cholecystectomy. Central and big toe temperature, arterial blood pressure, heart rate, calf volume and arterial inflow of the leg by electrical impedance plethysmography and the venous outflow by Doppler method were measured. DHE 0.5 mg subcutaneously reduced the volume of the leg, i.e. increased the electrical impedance, probably due to venous vasoconstriction. Simultaneously the need for etilefrine hydrochloride was reduced. No significant changes in the pulsatile inflow of the leg or the outflow were detected. Deep vein thrombosis (DVT) was detected by fibrinogen uptake test in five patients (three in DHEH and two in the control group) and verified by ascending phlebography in four patients. Intraoperative characteristics in patients with postoperative DVT were tachycardia (P < 0.001), enhanced need for etilefrine (P < 0.01) and a more rapid increase in big toe temperature (P < 0.05) after induction of epidural analgesia, compared with patients without DVT. Femoral vein flow velocity remained at the preinduction level, whereas pulsatile arterial inflow slightly increased. Together with a low basal impendance of the leg, the changes were indicative of a more intense vasodilatation, probably leading to stagnant flow and development of postoperative deep vein thrombosis.

Sucralfate as maintenance treatment for the prevention of duodenal ulcer recurrence

Eighty-eight patients with endoscopically proven and healed duodenal or pyloric ulcer were randomly allocated into a double-blind, placebo-controlled, 12-month maintenance trial to determine whether sucralfate, 1 g twice daily, can be used to prevent a recurrence of ulceration. The patients were assessed endoscopically at three, six, and 12 months, or earlier if a symptomatic relapse occurred. Serum aluminum levels were also monitored. Sixteen patients were excluded from the study during the follow-up: nine of 41 in the sucralfate group, and seven of 47 in the placebo group. The groups did not differ with respect to age, sex, or smoking. The cumulative relapse rates in the sucralfate group were 28 percent after three months, 33 percent after six months, and 45 percent after 12 months, as compared with 49 percent (p less than 0.05), 64 percent (p less than 0.01), and 68 percent (p less than 0.05), respectively, in the placebo group. It is concluded that 1 g sucralfate twice daily is more effective than a placebo and is safe for the maintenance treatment of duodenal and pyloric ulcer disease.

Ranitidine versus anticholinergic/antacid for duodenal ulcer. A randomized, endoscopically controlled, single-blind multicentre trial

One hundred and forty-nine patients with endoscopically documented duodenal or prepyloric ulcer were randomly allocated to treatment with ranitidine, 150 mg twice daily (75 patients), or glycopyrrobromide, 2 mg three times daily, and antacid suspension, 60 ml/day, with a buffering capacity of 480 mmol/day (74 patients). The patients underwent a thorough prestudy symptom analysis, and endoscopy was performed by an observer who was unaware of the treatment in use. After 4- and 8-week courses of treatment the patients were re-evaluated. Sixty-nine patients in the ranitidine group and 66 in the anticholinergic/antacid group completed the trial. Complete ulcer healing was obtained in 60 of the 69 patients (87%) in the ranitidine group and in 50 of the 66 patients (76%) in the anticholinergic/antacid group after 4 weeks of treatment and in 65 (94%) and in 61 (92%), respectively, after 8 weeks of treatment. Forty-three patients had troublesome side effects of either anticholinergic or antacid treatment, and three patients had to interrupt the treatment. There were no serious side effects of ranitidine. This study suggests that ranitidine causes faster ulcer healing than the combination of anticholinergic and antacid. The results show that ranitidine is an effective and safe drug for duodenal ulcer healing, with no troublesome side effects.

Sucralfate and alginate/antacid in reflux esophagitis

The efficacy of sucralfate and of an alginate/antacid compound was compared in a randomized, double-blind 6-week trial in patients with symptomatic, endoscopically confirmed macroscopic reflux esophagitis. Of the 68 patients who completed the study, 36 received sucralfate and 32 alginate/antacid. Significant symptomatic improvement occurred in both treatment groups: almost 70% of the patients became symptom-free or improved. Esophagitis healed completely in 53% of the patients receiving sucralfate and in 34% of the alginate/antacid patients, as measured with endoscopic criteria (p greater than 0.05). Our results indicate that sucralfate seems to be at least as effective as alginate/antacid in relieving symptoms and in healing macroscopic lesions. As a safe, locally active mucosal protecting agent, sucralfate is a promising new drug for the treatment of reflux esophagitis and deserves further trials over longer periods.

Effects of lumbar epidural analgesia and general anaesthesia on flow velocity in the femoral vein and postoperative deep vein thrombosis

The effect of lumbar epidural analgesia and of general anaesthesia on the peroperative velocity of flow in the femoral vein was measured with Doppler ultrasound technique in 38 patients undergoing retropubic prostatectomy. The patients were randomly allocated to the epidural or the general procedure. The 125I-fibrinogen test was used to detect deep vein thrombosis (DVT). Epidural analgesia was associated with a significant (ca. 120%) increase in the femoral venous flow velocity. The peak flow showed a moderate (47%) increase, whereas the minimum flow was greatly increased (188%). The increase was significant already 2 min after induction of the analgesia and the rate continued to rise for about 11 min. General anaesthesia significantly reduced the flow velocity in the femoral vein. Immediately after induction of the anaesthesia the velocity approached zero, but gradually rose, and after about 8 min was stabilized at level 40% below the preoperative velocity. The peak flow velocity in all patients of this group fell by 24 to 40%. Only 2 of 17 patients with epidural analgesia, but 11 of 21 with general anaesthesia had postoperative DVT. In the 11 patients with DVT the mean minimum velocity of flow was decreased (by 85%), but in the 10 without DVT it was increased (by 175%). The difference was not statistically significant. Increased velocity of flow in the femoral vein, especially of minimum flow, seems to counteract development of DVT.