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Biomedical subjects

W Bakker

Publications and source records attributed to W Bakker.

67 records · Page 4Linked to original sources
PubMed1984

Influence of rifampicin treatment on antipyrine clearance and metabolite formation in patients with tuberculosis.

The influence of an 8-day therapy with rifampicin (600 mg daily) was studied on antipyrine plasma clearance and metabolite formation in seven patients with tuberculosis (age 18-79 years), who were also treated with isoniazid and pyrazinamide. After rifampicin treatment the elimination half-life of antipyrine had decreased in all patients from 12.9 +/- 5.0 to 8.8 +/- 2.0 h (P less than 0.05). Antipyrine clearance had increased from 2.2 +/- 0.9 to 2.9 +/- 0.7 l/h (P less than 0.05), while no change in apparent volume of distribution was observed. The increase in antipyrine clearance was primarily due to a selective increase in the rate of formation of norantipyrine by 80% from 6.9 +/- 3.4 to 12.4 +/- 3.4 ml/min. Rifampicin seems to induce preferentially the cytochrome P-450 (iso-) enzyme(s) involved in the demethylation of antipyrine to norantipyrine. Other pathways of antipyrine metabolism were hardly affected. This provides further evidence for the involvement of different iso-enzymes of the cytochrome P-450 system in antipyrine metabolism in man.

Adolescent↗
PubMed1982

Complications of postoperative intrapleural BCG in lung cancer.

Sixty-four patients received bacillus Calmette- Guérin (BCG) in different dosages intrapleurally through a chest drain following resection for lung cancer. In 27 patients this procedure was followed by fever for a few days; the fever was attributed to the BCG. Late complications attributable to the BCG included recurrent fever in 4 patients, abscesses at the site of the drain in 4, wound infections in 2, consolidations on the chest roentgenogram in 3, 1 of whom had subsequent cavitation, and hemoptysis in 2. Side-effects were not dose-dependent. No relationship was found between the preoperative tuberculin response and the frequency or severity of complications. Treatment with isoniazid and rifampin failed to induce an apparent clinical response in patients with complications. We conclude that the intrapleural administration of BCG is not a safe procedure. The side-effects may considerably impair the patient's quality of life.

Adult↗
PubMed1982

Transpleural lung biopsy by the thoracoscopic route in patients with diffuse interstitial pulmonary disease.

Thoracoscopy was carried out in 81 cases of diffuse pulmonary disease in order to obtain lung tissue for biopsy. After we established artificial pneumothorax, the thoracoscope was introduced under local anesthesia, multiple biopsy specimens (theta 3 mm) were obtained under visual control, and an underwater sealed drain was left in place. The method was used to determine the cause of x-ray shadowing and respiratory distress in 26 immunocompromised patients. Within 2-48 hours, all biopsy specimens provided sufficient microbiologic and morphologic information to guide management, eg, specific antimicrobial drugs, decreasing or intensifying immunosuppression, or cytostatic therapy. Thoracoscopy was tolerated better than fiberoptic bronchoscopy, especially in hypoxic patients. Persisting or recurring pneumothoraces were seen in four patients and was not a major complication. In one very ill patient, the spleen was punctured accidentally before biopsy specimens were taken. Of 63 nonimmunocompromised patients, a histologic diagnosis was obtained in 57 (90 percent). In most of these patients, previous biopsy procedures had produced inconclusive results. Also in this group persisting or recurring pneumothoraces were seen in four patients, but closed eventually in a conservative way.

Biopsy, Needle↗
PubMed1981

Postoperative intrapleural BCG in lung cancer: lack of efficacy and possible enhancement of tumour growth.

Fifty-six patients out of a group of 99 with lung cancer received postoperative intrapleural BCG (Pasteur strain) in three different dosages (16 X 10(6) culturable particles (cp), 32 X 10(6) cp, and 64 X 10(6) cp). When comparing the whole group of 99 patients with a historical control group of 126 patients no statistically significant differences were found in survival and disease-free interval. The two groups were well matched in respect of age, sex, histology, stage of disease, and type of operation. Patients with epidermoid carcinoma stage I receiving BCG, however, did significantly worse than those who had not received BCG in terms of disease-free interval. This unfavourable trend was caused by earlier local recurrences rather than metastases. The possible phenomenon of enhanced tumour growth noted in or patients with epidermoid carcinoma stage I might be related to the dosages used in this study, but the different BCG strain used hinders comparison with other studies. We conclude that BCG has no beneficial effect on survival or on disease-free interval; possible enhancement of tumour growth in stage I epidermoid carcinoma was found.

Aged↗
PubMed1980

A matched-pair study of the leukocyte elastase-like activity in normal persons and in emphysematous patients with and without alpha 1-antitrypsin deficiency.

The elastase-like activities in whole cell extracts of neutrophilic polymorphonuclear leukocytes of 10 emphysematous patients with alpha 1-antitrypsin deficiency (PiZ) and of 7 subjects with alpha 1-antitrypsin deficiency (PiZ or PiSZ) without emphysema were the same as the activities of healthy nondeficient subjects (PiMM) matched according to age, sex, and smoking history. In 16 emphysematous patients without alpha 1-antitrypsin deficiency (PiMM) however, the leukocyte elastase-like activity tended to be higher than that of normal control subjects. We concluded that in persons with alpha 1-antitrypsin deficiency, the leukocyte elastase-like activity is not a deciding factor in the development of emphysema. In persons without alpha 1-antitrypsin deficiency, however, the leukocyte elastase-like activity may be a contributing factor in the development of this disease. Variations in specific anti-leukocyte-elastase-like activity of alpha 1-antitrypsin, which might play a role in the pathogenesis of emphysema, were not found.

Adult↗
PubMed1978

ST-vector orientation and location of myocardial perfusion defects during exercise.

In 34 patients with chest pain the spatial orientation of the ST-vectors in the exercise electrocardiogramm 30 and 80 msec after the end of QRS were compared with the location of exercise induced local defects of myocardial uptake of 201Tl. The following results were obtained: 1. The sensitivity and specifity of myocardial perfusion imaging after exercise were the same as those of exercise electrocardiograms; 2. No relation could be observed between the location of reduced 201Tl uptake during exercise and the spatial orientation of the ST-vectors.

Angina Pectoris↗
PubMedDate not supplied

Relationships between the lung-heart ratio assessed from post-exercise thallium-201 myocardial tomograms, myocardial ischemia and the extent of coronary artery disease.

Uptake of thallium (Tl)-201 in the lungs has been proposed as a measure of left ventricular dysfunction. In this study we were interested in pursuing two goals: 1) to assess possible relationships between the post-exercise Tl-201 lung-heart (LH)-ratio determined from the anterior view during SPECT-acquisition, myocardial ischemia and the extent of coronary artery disease; and 2) to explore the effects of coronary revascularisation procedures on the LH-ratio. The study group consisted of 145 patients with early and late postexercise Tl-201 tomograms, including 32 PTCA-patients with pre- and post-PTCA studies and 20 patients who underwent coronary artery bypass surgery (CABG) with corresponding pre- and post-CABG studies. Ischemia was defined as evoked angina during the exercise test in combination with greater than or equal to 1 mm horizontal or downsloping ST-depression on the ECG. The severity of coronary obstructions was assessed from coronary angiograms with a PC-based digital caliper technique; a stenosis was defined to be significant when its severity exceeded 50% diameter stenosis. The LH-ratio was defined by the ratio of the mean pulmonary counts and the mean myocardial counts assessed from corresponding regions of interest (ROI's) positioned over the left lung and the heart, respectively in the anterior view of a tomographic data acquisition procedure. Our results made clear that the LH-ratio was not significantly different between patients with and without ischemia during exercise, and between patients with single vs. multiple vessel disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Artery Bypass↗