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Biomedical subjects

J B Knudsen

Publications and source records attributed to J B Knudsen.

At least 55 records · Page 3Linked to original sources
PubMed1986

The Copenhagen case-control study of bladder cancer. II. Effect of coffee and other beverages.

During the years 1979-1981 a population-based case-control study of bladder cancer including papilloma was performed in greater Copenhagen. A total of 371 patients (280 males; 91 females), and a comparable age- and sex-stratified group of 771 controls (577 males; 194 females) remained for logistic regression analysis. Controls were selected at random from the general population of the study area. All persons were questioned about their drinking habits with respect to coffee, tea and other beverages, as well as their exposure to a number of known or suspected risk factors for bladder cancer. After adjustment for tobacco smoking, the relative risk of bladder cancer in relation to coffee drinking was not statistically significant among either men or women. A significant association was found between bladder cancer and tea drinking among men, but with no regular trend for increasing consumption. An association was found between risk of bladder cancer and both total daily liquid intake and non-cola soft drinks. This population-based case-control study provides no evidence of an isolated influence of coffee drinking or caffeine intake on bladder cancer risk.

Adult↗
PubMed1986

Effect of metoprolol and propranolol on platelet aggregation and cAMP level in hypertensive patients.

Ten patients with uncomplicated moderate essential hypertension were recruited to evaluate the effect of the non-selective beta-blocker propranolol and the beta 1-selective beta-blocker metoprolol on platelet aggregation and cAMP formation. Five patients began treatment with propranolol 80 mg b.i.d. and 5 with metoprolol 100 mg b.i.d., and after 2 weeks the treatments were exchanged. ADP- and adrenaline-induced platelet aggregation and the basal level of platelet cAMP were measured at the end of each treatment period. Platelet aggregation was tested turbidometrically, using the threshold value for irreversible aggregation, and cAMP measurements were performed using a protein-binding assay. Both ADP and adrenaline threshold values were significantly lower after propranolol than after metoprolol. The basal cAMP level was lower during propranolol than metoprolol treatment. The results indicate that platelet aggregation and basal cAMP level are influenced by beta-blockers in proportion to their affinity to different beta-adrenoceptors. This may be of value in the beta-blocker treatment of patients at high thrombotic risk.

Adenosine Diphosphate↗
PubMed1986

Streptokinase therapy in the routine management of deep venous thrombosis in the lower extremities. A retrospective study of phlebographic results and therapeutic complications.

One hundred and eight patients with phlebographically verified deep venous thrombosis were treated with streptokinase. Total or partial thrombolysis was phlebographically demonstrated in 60 patients (55.6%). Three patients died during treatment, all from pulmonary embolism. Six patients developed clinical signs suggestive of pulmonary embolism. In 16 patients (14.8%), major bleeding complicated the treatment. One patient had anaphylactic shock, while various allergic reactions were recorded in 22. Streptokinase therapy in the routine management of deep venous thrombosis carries an acceptable efficacy and safety similar to what has been achieved under research conditions.

Adolescent↗
PubMed1986

The difference between non-selective and beta 1-selective beta-blockers in their effect on platelet function in migraine patients.

Platelet function has been postulated as playing a role in the pathogenesis of migraine. This study aimed to investigate to what extent beta 1-selective and non-selective beta-blockers interfere with the platelet function in migraine patients. Twelve patients with classical migraine were included. After a 2-week drug-free period, the patients were randomly allocated to either beta 1-selective metoprolol (50 mg b.i.d.) or non-selective propranolol (40 mg b.i.d.) treatment for one month. After a wash-out period, the patients were changed to the corresponding beta-blocker for one month. ADP-induced platelet aggregability, platelet cAMP, ATP and ADP levels, plasma cAMP and TxB2 concentration, as well as the serum production of TxB2 were measured before and after each treatment period. After propranolol treatment, the patients showed lower ADP threshold values for producing irreversible platelet aggregation and lower platelet and plasma cAMP levels as compared to metoprolol. Neither of the beta-blockers induced any change in the plasma concentration or serum production of TxB2. In conclusion, non-selective beta-blockade (propranolol) significantly increases the platelet aggregability compared to beta 1-selective blockade (metoprolol).

Adenosine Diphosphate↗
PubMed1986

Clinical aspects of second-look laparotomy in ovarian cancer.

Second-look laparotomy was performed in 56 patients with ovarian cancer, who presented no clinical evidence of disease after completion of a treatment program with chemotherapy. At the second-look laparotomy 31 of the patients were found to have residual disease, and 25 patients had no residual tumour. During the second-look operations we found it difficult to evaluate macroscopically whether there was any residual disease. 21% of the patients were estimated as false negative and 6% as false positive. This stresses the importance of taking multiple biopsies in the absence of clearly visible residual disease confirmed by frozen sections.

Adolescent↗
PubMed1985

The effect of ticlopidine on platelet functions in acute myocardial infarction. A double blind controlled trial.

A group of 43 consecutive patients with AMI were randomized to treatment with a novel platelet inhibitor, ticlopidine, or placebo in a double blind study. Treatment was started within 12 hr after onset of precordial pain. Patients who had taken drugs with known platelet inhibitory effect prior to the onset of therapy were excluded. Platelet survival time (PS) was measured 24-36 hr after onset of precordial pain and after 3 months of treatment in both groups. In the early phase of AMI CK-MB and ASAT were taken twice daily for estimation of infarction size. Platelet function, coagulation factors and fibrinolysis parameters were followed sequentially for 21 days and repeated after 3 months. In the placebo group a significant reduction in PS (5.62 +/- 1.63 S. D. days) was measured in the acute phase of AMI compared to PS 3 months after infarction (8.03 +/- 1.20 S.D. days). In the ticlopidine group PS was normal during the acute phase (8.35 +/- 1.82 S.D. days). After 3 months of treatment PS was normal in both groups. During the first two weeks after AMI significant changes in coagulation parameters and fibrinolysis indicated an increased risk of thrombosis in both groups. These parameters were unaffected by the platelet inhibitory therapy. Estimated by peak CK-MB and ASAT, infarction size was significantly reduced in the ticlopidine group.

Adult↗
PubMed1985

Inhibition of human platelet aggregation by dihydropyrano- and dihydrofuranocoumarins, a new class of cAMP-phosphodiesterase inhibitors.

Certain esters of dihydropyranocoumarin and dihydrofuranocoumarin alcohols have previously been shown to inhibit the cAMP-phosphodiesterase from bovine heart. We now report that these naturally occurring coumarins inhibit the high affinity (Km = 1.1 microM) cAMP-phosphodiesterase from human platelets with activities that closely correlate with those obtained using phosphodiesterase from bovine heart tissue. Additionally the coumarins inhibit the aggregation of human platelets induced with ADP, adrenaline and collagen with activities comparable to those of dipyridamole. A lack of significant correlation between these metabolic and functional activities indicates that there exist, besides cAMP-phosphodiesterase inhibition, additional mechanisms of action for the platelet aggregation inhibitory effect of dihydropyrano- and dihydrofuranocoumarins.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1985

Effect of specific thromboxane-synthetase inhibition on thromboxane and prostaglandin synthesis in stable angina induced by exercise test.

14 patients with effort induced angina pectoris were treated with a specific TxB2 inhibitor Dazoxiben or verapamil for two weeks with a wash-out period of 14 days between the two regimens. A sub-maximal bicycle test was performed before treatment and at the end of each treatment period. The bicycle test induced a significant increase in serum TxB2 in patients without treatment and during verapamil therapy. This increase was significantly inhibited by Dazoxiben treatment. No alterations in plasma TxB2 or 6-keto-PGF1 alpha were observed on either regimen. Dazoxiben had no clinical effect, while verapamil caused a highly significant prolongation of exercise time.

Aged↗
PubMed1985

Red cell 2,3-DPG, ATP, and mean cell volume in highly trained athletes. Effect of long-term submaximal exercise.

20 male elite long distance runners were compared to a control group of blood donors to determine the effect of training on red blood cells. The acute effects of exercise on red cells were investigated in 11 of the runners following a race of 15-30 km. The runners had elevated resting values of red cell 2,3-DPG (P less than 0.05) and mean cell volume (P less than 0.01); blood Hb and ATP were not different from concentrations in the control group. The red cell status of the athletes may be explained by an increased proportion of young erythrocytes in runners. No statistically significant changes in red cell 2,3-DPG, ATP, mean cell volume or blood Hb were found post exercise.

2,3-Diphosphoglycerate↗
PubMed1985

Postoperative survival of patients with potentially curable cancer of the colon.

The association between histopathologic findings and postoperative survival in 442 patients with potentially curable carcinomas of the colon has been analyzed using Cox's regression model. The prognostic variables included in the study were age, sex, stage of disease according to Dukes' classification and Broders' grading, as well as presence/absence at the time of operation of venous and nerve invasion. The overall five-year postoperative survival rate was 46.6 percent. Using a model including all prognostic factors, sex and Dukes' classification were not found to be associated with survival. Broders' grading and/or nerve invasion yielded only a borderline statistical significance in the model that included all factors. The invasion of veins was almost always associated with invasion of nerves.

Adult↗
PubMed1985

Second cancer following cancer of the urinary system in Denmark, 1943-80.

The risk of second primary cancer was evaluated in 29,128 patients who developed tumors of the urinary tract, including benign and malignant tumors of the renal pelvis and ureter and bladder papillomas in Denmark between 1943 and 1980. Among 9,162 persons with kidney cancer, 416 developed a second primary tumor [relative risk (RR) = 1.4]. Among 19,966 persons with bladder cancer, 1,423 developed a second primary tumor against 1,239 expected (RR = 1.1). The risk of bladder cancer was increased following kidney cancer in both men (RR = 6.3) and women (RR = 10.1), and kidney cancer was increased in both men (RR = 2.9) and women (RR = 4.5) following bladder cancer. These risks were particularly pronounced for cancers occurring in the ureter and renal pelvis. Etiologic similarities are likely explanations for these observations, which also emphasize the role of host factors and the multifocal nature of urothelial tumors. A decrease in relative risks since diagnosis of the first primary cancer was seen that may partly be attributed to a lessening of the intensity of medical surveillance with time. Among long-term survivors with kidney cancer, increased risks were observed for colon and pancreatic cancers, which may be related to treatment; approximately 25% received radiotherapy. Among bladder cancer patients, increased risks of cancers of the lung and larynx occurred, probably due to tobacco smoking. A slight elevation of prostate cancer (RR = 1.3) may be attributable to medical surveillance. Unexpected findings were the significant deficits of cancers of the stomach and rectum among patients with bladder cancer and stomach cancer among those with kidney cancer.

Denmark↗
PubMed1983

The survival of pig to rabbit renal xenografts during inhibition of thromboxane synthesis.

Five rabbits treated with the thromboxane synthetase inhibitor Dazoxiben and five control rabbits received pig renal xenografts. Plasma albumin, complement factor C3, TXB2, 6-keto-PGF1 alpha, and serum TXB2 and 6-keto-PGF1 alpha were determined before and 1/2 hour after transplantation. The xenograft survival was significantly decreased in the Dazoxiben treated animals compared to the placebo treated animals determined as time to total cyanosis of the graft, total urine production, and time to stop of urine production. Lack of TXB2 production during blood coagulation confirmed inhibition of platelet thromboxane synthesis. The other determined variables showed no significant differences between the treated and the placebo animals.

6-Ketoprostaglandin F1 alpha↗
PubMed1983

Artificial sweeteners and absence of bladder cancer risk in Copenhagen.

During the years 1979 to 1981 a population-based case-control study of bladder cancer including papillomas was performed in Greater Copenhagen. After exclusions some 388 patients (290 males; 98 females) and an age- and sex-matched group of 787 controls (592 males; 195 females) remained for analysis. Controls were selected at random from the general population of the study area. All persons were interviewed concerning use of artificial sweeteners in addition to their exposure to a number of other known or suspected risk factors for bladder cancer. Fifty-five male bladder cancer patients (19.4%) and 150 controls (25.7%) had at some time used artificial sweeteners regularly. Among females 27.1% of cases and 25.9% of controls regularly used sweeteners. In neither sex was the relative risk significantly increased in users compared with non-users of artificial sweeteners. The relative risk of 0.78 in the two sexes combined was not significantly different from 1.0 (95% C.I.: 0.58-1.05). There was no indication of a regular increase in risk with increasing daily consumption of table-top sweeteners nor was there any indication of an increase in risk with a duration of regular use of artificial sweeteners. Taking into account a possible latency period between first regular use and bladder cancer development did not change the finding of an absence of association between use of artificial sweeteners and the risk of bladder cancer. Neither saccharine nor cyclamate users had an increased risk of bladder cancer. This population-based case-control investigation provides further evidence that it is highly unlikely that the consumption of artificial sweeteners has contributed to current bladder cancer rates in man.

Beverages↗
PubMed1983

Venous and nerve invasion as prognostic factors in postoperative survival of patients with resectable cancer of the rectum.

The histopathologic and clinical findings in 682 patients with carcinoma of the rectum have been analyzed. Invasion of veins and nerves by primary growth was found in 38.9 and 34.9 per cent, respectively. The five-year survival rate for patients with resectable tumors was 49 per cent. The age, Dukes' staging, and presence and/or absence of liver metastases, of venous invasion, and of nerve invasion were found to be of statistically significant importance for the prognosis. Sex was found to be on the borderline of significance and Broders' grading was even less significant. Invasion of veins was found statistically significant more frequently than nerve invasion, but the present investigation revealed the importance of the invasion of veins as well as of nerves. When venous invasion was observed, liver metastases developed over three times as frequently in these patients as when metastases were not demonstrated. In contrast to Dukes' staging. Broders' grading can be applied to tumor biopsies preoperatively. The importance of venous and nerve invasion for the selection of patients for adjuvant therapy after termination of surgical treatment is discussed.

Adolescent↗