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Biomedical subjects

J Bredesen

Publications and source records attributed to J Bredesen.

At least 19 recordsLinked to original sources
PubMed2001

Gastric emptying: the validity of the paracetamol absorption test adjusted for individual pharmacokinetics.

An algorithm for the paracetamol absorption test for gastric emptying, adjusting for individual pharmacokinetics, was recently developed. The aim of the present study was to validate the use of this algorithm. Furthermore, the algorithm was applied to elucidate whether a gastric tube interferes with the rate of gastric emptying. A caloric liquid meal with paracetamol was administered orally to nine healthy volunteers on two separate days. On one occasion, the subjects were intubated with a nasogastric tube and the meal was aspirated from the stomach 45 min after meal intake. The percentage of the meal retained in the stomach at the time of aspiration was determined by analyses of paracetamol in the aspirate and compared with calculations by the algorithm. On the other examination day, the same meal was ingested without tube and aspiration. The median percentage of the meal retained in the stomach at aspiration was 47% (range 33-70%) calculated by the algorithm and 48% (range 23-61%) based on the aspiration data. The correlation between the emptying parameters was r=0.97 (P < 0.001). The median of gastric emptying parameters was similar when the number of samples included in the calculation by the algorithm was reduced, but the range tended to increase. The gastric tube moderately inhibited gastric emptying during the period 20-40 min after meal intake (P < 0.05), but for the period from meal intake until start of aspiration, no inhibition was found. The present study demonstrates that the novel algorithm for the paracetamol absorption test provides valid estimates for gastric emptying.

Acetaminophen↗
PubMed2000

Response to changing plasma concentrations of isosorbide-bound NO2 during acute and sustained treatment with isosorbide dinitrate in patients with coronary artery disease.

BACKGROUND: The mechanisms behind development of tolerance to nitrate effects during sustained, asymmetric isosorbide dinitrate (ISDN) therapy are not fully understood. HYPOTHESIS: The study was undertaken to investigate the changes of the relationships between left ventricular (LV) function and plasma concentrations of ISDN and its vasoactive metabolites (2- and 5-ISMO) during acute and sustained, asymmetric ISDN therapy. METHODS: Left ventricular function and plasma concentrations of ISDN, 2- and 5-isosorbide mononitrates (P-ISDN, P-2- and 5-ISMO) were measured at rest and at supine exercise before and for 4 h after peroral 30 mg ISDN in 15 patients with coronary artery disease, all with initial exercise pulmonary artery wedge pressure (PAWP) > 25 mmHg. Seven patients were untreated (acute group), while eight received 30 mg ISDN b.i.d. for 2 weeks before the invasive study. P-ISDN and the concentration of available isosorbide-bound nitrate (NO2) in plasma (P-ISDN.2 + P-2-ISMO + P-5-ISMO) (P-NO2) were used as measures of the nitric oxide (NO) offer to the tissues. RESULTS: Throughout the study, after administration of medication, all plasma concentrations, in particular P-ISDN, were higher in the chronic than in the acute group. Peak P-ISDN was reached after 15 min in the chronic group and after 25 min in the acute group, while P-2- and 5-ISMO reached maximum only after 40 min in both groups. At rest, the full effect on PAWP was observed after 10 min in both groups, but at markedly higher levels of P-ISDN and P-NO2 in the chronic group. Afterward, no further changes in PAWP were observed. During exercise, 1 h after medication, PAWP and stroke index to PAWP ratio (SI/PAWP) were normal in both groups. Thereafter, at slowly declining P-NO2, PAWP rose and SI/PAWP declined toward the initial level in the chronic group, but remained unchanged in the acute group, in spite of higher P-NO2 and greater NO release in the former. CONCLUSIONS: Patients receiving sustained, asymmetric 30 mg ISDN b.i.d. dosing had the same immediate beneficial effects on LV function during exercise after a morning dose as did untreated patients. However, in spite of higher P-NO2 and higher rate of NO release during sustained treatment, the effects deteriorated gradually 2 to 3 h after medication. The changes in metabolism and/or distribution of isosorbide-bound NO2 may possibly be part of the tolerance induced by long-term treatment, even with asymmetric dosing.

Aged↗
PubMed2000

Stimulation of the small intestine by nutrients in relation to phase of the migrating motor complex.

BACKGROUND: The relationship between the preceding phase of the migrating motor complex (MMC) and postprandial motility in the small intestine was studied. METHODS: In eight healthy subjects small-bowel manometry was performed, and a 55-ml caloric liquid bolus (280 kJ) containing paracetamol and 14C-D-xylose was instilled into the duodenum during phase I and late phase II of the intestinal MMC, respectively, in randomized order. Blood samples were drawn at regular intervals and analysed for insulin, gastrin, glucose, paracetamol, and 14C-D-xylose. RESULTS: After bolus administration during late phase II a phase-III-like activity succeeded by quiescence occurred in the duodenum in seven of eight subjects, whereas administration during phase I initiated irregular contractions in seven of eight subjects (P < 0.05). The caloric bolus induced a significant increase in serum insulin and gastrin. Areas under the curves for serum insulin, gastrin, glucose, paracetamol, and 14C-D-xylose were not modulated by the preceding phase of the MMC. CONCLUSIONS: The present study shows that a nutrient bolus instilled into the intestinal lumen induces MMC-like activity when administered during late phase II. These findings provide further evidence of interference between MMC and postprandial motility.

Acetaminophen↗
PubMed1999

Delay of gastric emptying by duodenal intubation: sensitive measurement of gastric emptying by the paracetamol absorption test.

AIMS: To examine the influence of duodenal intubation on gastric emptying measured by the paracetamol absorption test using a new algorithm developed to estimate emptying parameters, and to determine the sensitivity of this test. METHODS: A caloric liquid meal with paracetamol as marker of emptying was administered orally to eight healthy volunteers during phase I and phase II of the migrating motor complex (MMC) and without intubation on 3 separate days, and to 10 patients with partial gastrectomy. RESULTS: Healthy subjects: With duodenal tube, time until 25% of the meal had emptied (t25%) was 24+/-7 (phase I, P<0.02) and 21+/-6 min (phase II, P<0.02) compared with 14+/-4 min for meal intake without intubation. Time until 50% of the meal had emptied (t50%) was 45+/-8 (phase I, P<0.001) and 35+/-8 min (phase II, P<0.02) compared with 26+/-9 min for meal intake without intubation. Intraduodenal instillation of 10-20 mL of the liquid meal was reliably detected. PATIENTS: In 9 out of 10 patients with partial gastrectomy t25% was below the lower limit of the range for healthy controls, and t25% detected accelerated emptying with a higher degree of sensitivity than the commonly applied pharmacokinetic parameters Cmax and Tmax. CONCLUSIONS: A duodenal tube delays gastric emptying of a caloric liquid meal. The paracetamol absorption test emerges as a sensitive method suitable for detecting both delayed and accelerated gastric emptying of caloric liquid meals.

Acetaminophen↗
PubMed1995

The migrating motor complex modulates intestinal motility response and rate of gastric emptying of caloric meals.

The present study elucidates whether the phase of the migrating motor complex (MMC) present at the moment of food intake modulates postprandial motor response and rate of gastric emptying of caloric meals. Eight healthy male volunteers with a mean age of 26 years were examined twice. During water-perfused gastroduodenal manometry, a liquid meal with paracetamol added as a marker was orally administered during phase I and late phase II. Paracetamol appeared in serum 14.1 +/- 3.8 min and 9.1 +/- 4.0 (mean +/- SD) min, respectively, after intake of the meal (P < 0.02). The area under the curve of s-paracetamol until 25 min after intake was 232 +/- 169 mumol l-1 min and 362 +/- 130 (P < 0.05), respectively. When taken during late phase II, a phase III-like activity occurred within 2.1 +/- 1.3 min in the duodenum, and was succeeded by quiescence. During phase I, the meal invariably initiated irregular contractions within 4 min. The phase of MMC during which a caloric meal is ingested modulates duodenal motor response and rate of gastric emptying during the initial postprandial period. Initial postprandial motor activity thus represents the combined effect of nutrient stimulation and the underlying enteric biorhythm as reflected by phase of MMC.

Acetaminophen↗
PubMed1994

[Postoperative mortality after cholecystectomy. A survey of all cholecystectomies among women in 1977-1981].

This paper assesses the risk of dying within thirty days of admission among 13,854 women who had a cholecystectomy performed as the principal operation during the period 1977-81. The overall crude mortality rate was 1.2%. Women who had a simple elective cholecystectomy performed had a mortality rate (0.2%) similar to women who had a simple hysterectomy, but significantly higher than in the general female population. High age, acute admission, admission to hospital in the three months prior to the index admission, the number of discharge diagnoses, and the geographical region were significantly associated with increased mortality. The higher mortality associated with exploration of the common bile duct disappeared when number of discharge diagnoses was taken into account. As regards early mortality, it is concluded that simple elective cholecystectomy is a safe procedure before the age of 50-60 years. Exploration of the common bile duct may not be as important an independent factor as previous assumed.

Adult↗
PubMed1989

[Regional differences in the use of cholecystectomy in Denmark during the period 1977-1985].

In a register-based study of all cholecystectomized patients in Denmark during the period from 1977-85 (37,048 patients) an account is given of the regional variations observed in connection with the intervention. The cholecystectomy operation is sub-divided into four types of operation dependent on whether the intervention is merely a matter of cholecystectomy or it involves the choledocus, the duodenum, the small intestine or other organs. The variation analysis is based on a division of the country into 75 areas, each primarily served by a single hospital. The method highly reflects the differences in clinical treatment strategies. The summarized rate of cholecystectomy for this period of time was 8.2 per 10,000 persons. In areas with the highest and the lowest rates of operation the figures were 12.3 per 10,000 and 5.1 per 10,000, respectively. In 18 areas, the rates of operation were significantly higher than average and in 18 other areas significantly higher than average and in 18 other areas significantly below average. SCV-score (X100) 2.19. There is no systematic correlation between the degree of specialisation in the operating department and the frequency in employing the operation. Areas with an operation index significantly above average had the same rate of more complicated operations than simple cholecystectomy as the other areas. Possible causes of national as well as international variations in the use of cholecystectomy are discussed, and the need for a radical evaluation of this kind of treatment is emphasized.

Adult↗
PubMed1988

A comparative study of transitional cell tumors of the bladder and upper urinary tract.

In two groups composed of 228 patients with bladder tumors and 37 patients with upper urinary tract (UUT) tumors, we compared the transitional cell carcinoma in respect to sex, age, grade of dysplasia, staging, and survival. No differences could be established between the two groups, and we found the same 5-year survival rates of approximately 26% and 29%, respectively, for the invasive carcinomas.

Carcinoma, Transitional Cell↗
PubMed1988

Prognostic significance of hereditary predisposition on the outcome of colorectal cancer as expressed by increased in vitro tetraploidy.

Seventy colorectal cancer patients operated on in the period 1981-1984 were consecutively investigated for in vitro tetraploidy in dermal fibroblasts, as an increased number of tetraploids is considered a marker of genetic predisposition for colorectal cancer. The difference in disease-free survival rates of increased (IVT+) and normal (IVT-) in vitro tetraploidy was not statistically significant (0.1 less than p less than 0.2), but the decrease in the disease-free survival rate of IVT+ was 1.6 times that of IVT-. To exclude the influence of other prognostic factors, a Cox multivariate regression analysis was used, with Dukes C carcinoma and poor differentiation as co-variables for IVT+. In this analysis IVT+ did not show any independent prognostic significance. A genetic predisposition for colorectal cancer, as expressed by the presence of IVT+ in skin fibroblasts, does not seem to influence the survival of patients with colorectal cancer.

Adult↗
PubMed1988

Relationship between blood groups and tumors of the upper urinary tract.

Comparing the relationship between upper urinary tract tumors and blood group ABO and the rhesus system showed that patients with blood group A and blood type rhesus positive had more invasive tumors with a higher grade of dysplasia than patients with blood group O and blood type rhesus negative.

ABO Blood-Group System↗
PubMed1988

Medical treatment of stomal ulcers.

Thirty-five patients with anastomotic ulcer after gastric resection for benign ulcer disease were treated with sucralfate (Antepsin) and endoscopically controlled over a 6-month period after termination of the medical treatment. The healing frequency of 75% makes this model a suitable alternative in the treatment of stomal ulcers.

Adult↗
PubMed1988

Appendicitis and enterobiasis in children.

The importance of Enterobius vermicularis in the pathogenesis of appendicitis is not known. The authors found Enterobius in 38 (12.5%) of 303 appendices removed from children. No evidence was obtained for a pathogenic effect of the parasite in appendicitis: Negative laparotomy was significantly more common in the infested group than in the other children. The findings support the theory that E. vermicularis can cause symptoms resembling true appendicitis viz. appendicopathia oxyurica.

Animals↗
PubMed1987

Primary carcinoma of the upper urinary tract.

Thirty-seven patients with upper urinary tract tumours were evaluated for grade, stage, histological type, location, presence or absence of vascular invasion, abnormalities in the urothelium adjacent to the tumours, tumour multiplicity and patient survival. A good correlation between tumour grade and stage was found in the transitional cell tumours. Squamous cell carcinomas and adenocarcinomas were high-stage tumours. Vascular invasion was present in most high-grade tumours, squamous cell carcinoma and adenocarcinomas. Four patients had multifocal tumours of both pelvis and ureter. Three developed ureteric stump carcinomas and 13 had further development of bladder carcinomas. The cumulative 5 and 10 year survival rates were 43 and 23% respectively.

Adenocarcinoma↗