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Biomedical subjects

W Bakker

Publications and source records attributed to W Bakker.

At least 19 recordsLinked to original sources
PubMed1992

Clearance of 99mTc-DTPA and experimentally increased alveolar surfactant content.

We measured clearance of 99mTc-labeled diethylenetriamine pentaacetic acid (99mTc-DTPA) in rabbits with experimentally increased alveolar surfactant content. In one group of animals, surfactant production was increased by treatment with ambroxol, and another group of animals was treated with tracheal instillation of natural surfactant. A group of untreated control animals and animals treated with instillation of saline were also studied. Clearance was measured during standard conditions of mechanical ventilation and during ventilation with large tidal volumes. In ambroxol- and surfactant-treated groups, clearance rate was reduced compared with untreated control animals. In contrast, clearance rate increased after saline instillation. The differences were observed at both modes of ventilation. The findings indicate that the pulmonary surfactant system is a rate-limiting factor for the clearance of 99mTc-DTPA and that the volume dependence of clearance is not explained by stretching of the alveolar wall only.

Ambroxol↗
PubMed1992

Nutritional state and lung disease in cystic fibrosis.

The life expectancy of patients with cystic fibrosis (CF) is largely dependent on the severity and progress of the pulmonary involvement associated with the disease. Many data support the view that malnutrition and deterioration of lung function are closely interrelated and interdependent, with each affecting the other, leading to a spiral decline in both. The occurrence of malnutrition appears to be associated with poor lung function and poor survival, and conversely prevention of malnutrition appears to be associated with better lung function and improved survival. Nutritional intervention may lead to an improvement in body weight, lung function and exercise tolerance, provided that the intervention is combined with exercise training in order to increase both respiratory and other muscle mass. These improvements can be preserved when patients have the stamina to continue with a high-energy, high-fat diet and daily exercise training at home.

Cystic Fibrosis↗
PubMed1991

Omeprazole enhances the efficacy of pancreatin (pancrease) in cystic fibrosis.

We studied the effect of the addition of omeprazole (20 mg once a day) to treatment with pancreatin (Pancrease, Cilag, Herentals, Belgium), two or four capsules three times a day, on fecal fat excretion in a double-blind, crossover fashion in nine patients with cystic fibrosis having persistent steatorrhea while taking Pancrease, two capsules three times a day (mean fecal fat excretion, 22.3%; range, 12% to 44%). Neither doubling of the dose of Pancrease nor addition of omeprazole to the lower dose of Pancrease significantly reduced fecal fat excretion (mean, 19.6% [range, 10% to 34%]; mean, 16.4% [range, 6% to 32%], respectively). However, addition of omeprazole to the higher dose of Pancrease (four capsules three times a day) significantly reduced fecal fat excretion when compared with the two doses of Pancrease alone (mean, 10.7%; range, 4% to 25%; P less than 0.01). We conclude that adjunct therapy with omeprazole reduces fecal fat excretion in cystic fibrosis provided that a high dose of Pancrease is supplied.

Adult↗
PubMed1991

Oxygen-assisted exercise training in adult cystic fibrosis patients with pulmonary limitation to exercise.

Exercise training has been considered suitable only in cystic fibrosis (CF) patients with mild to moderate pulmonary dysfunction without progressive hypoxaemia during exercise. We trained 16 CF patients, all with advanced lung disease (mean standardized forced expiratory volume in 1 s (FEV1), 30% pred.), with a ventilatory limitation to exercise and a progressive hypoxaemia and hypercapnia at low maximal exercise capacity, Wmax (mean Wmax, 50% pred). Exercise training was performed on a cycle ergometer twice a day for 20 min at approximately 75% of the maximal predicted heart rate for at least 3 weeks. Supplemental oxygen was administered to reach a haemoglobin oxygen saturation of 90% during training. Patients considered malnourished because of a Quetelet Index of less than 20 kg m-2 received hyperalimentation orally or by duodenal tube (total 3500-4000 kcal day-1). Evaluation directly after the training period showed a statistically significant improvement in Wmax, maximal oxygen consumption, maximal minute ventilation, pulse, PaCO2 at rest, FEV1 and body weight. None of the pretraining variables was able to predict the outcome of the training programme in the individual patient. We detected no adverse effects of the programme. This study shows that oxygen-assisted exercise training in combination with correction of the nutritional status is safe and beneficial in CF patients with severe lung disease.

Adult↗
PubMed1991

Cystic fibrosis: MR imaging of the pancreas.

The appearance of the pancreas in 17 adult patients with cystic fibrosis was evaluated with magnetic resonance (MR) imaging. The pancreas was abnormal in 15 patients. Three patterns were observed: (a) lobulated enlarged pancreas with complete replacement by fatty tissue (n = 9), (b) small atrophic pancreas with partial replacement by fat tissue (n = 5), and (c) diffuse atrophy of the pancreas without fatty replacement (n = 1). Replacement of the pancreas by fat tissue was seen on T1-weighted images with, characteristically, a very high signal intensity. The sensitivity of MR imaging in depicting pancreatic abnormality in cystic fibrosis is 94%, which is comparable to that of computed tomography.

Adolescent↗
PubMed1990

Pulmonary clearance of 99mTc-DTPA during halothane anaesthesia.

We studied the integrity of the alveolo-capillary barrier during different forms of anaesthesia by measuring the pulmonary clearance of inhaled 99mTc-DTPA. We studied four groups of rabbits. Groups I and II were anaesthetized with nembuthal only and the fractional concentration of inspired oxygen (F1O2) was 0.30 and 1.00, respectively. Groups III and IV were anaesthetized with 1% halothane and F1O2 was 0.30 and 0.99, respectively. 99mTc-DTPA was administered as a fine aerosol and the clearance of the tracer from the lungs was subsequently measured with a gamma camera. The mean half-life of the tracer in the lungs in Groups I-IV was 60, 58, 59 and 26 min, respectively. The rapid pulmonary clearance of 99mTc-DTPA in Group IV indicates that halothane in combination with high oxygen concentration increases the permeability of the alveolo-capillary barrier. This may be due to effects on the pulmonary surfactant system and/or the alveolar epithelium.

Anesthesia, Inhalation↗
PubMed1990

Ranitidine compared with the dimethylprostaglandin E2 analogue enprostil as adjunct to pancreatic enzyme replacement in adult cystic fibrosis.

In a double-blind cross-over randomized study adjunct therapy with ranitidine (2 x 150 mg) was compared with enprostil (2 x 35 micrograms) in eight adult cystic fibrosis (CF) patients receiving a fixed dose of enteric-coated microsphere capsules of pancreatin (Pancrease). The study consisted of two consecutive 14-day treatment periods. All patients kept a fixed daily fat intake during the last 5 days of each treatment period and performed 72-h faecal collections during the last 3 days of each treatment period. Gastrointestinal complaints were scored at the end of each treatment period. During treatment with ranitidine there was less faecal fat excretion (18.9% versus 25.1%; NS), less faecal weight (263 versus 303 g/day; NS), and a lower gastrointestinal complaints score (5.3 versus 3.1; P less than 0.05) compared with the treatment with enprostil. One patient dropped out during the treatment period with enprostil because of very severe diarrhoea and abdominal discomfort. We conclude from this study that adjunct therapy with ranitidine has significantly less side effects and may give a better reduction of faecal fat excretion and daily faecal weight in CF.

Adult↗
PubMed1989

Adriamycin affects glomerular renal function: evidence for the involvement of oxygen radicals.

The early nephrotoxic effect of the antitumor drug adriamycin (ADR) is suggested to be related to the generation of oxygen free radicals. Therefore the O2-dependence and the influence of free radical scavengers were studied in the model of the isolated perfused single glomerulus of Myxine glutinosa and by histochemical demonstration of the glomerular ATP-ase. In Myxine, the glomerular ATP-ase activity was decreased after injection of ADR (5 mg/kg, i.v.). Both ADR-treated Myxine and controls were exposed for 48 h to an artificial atmosphere of 20% O2/80% N2 or 80% O2/20% N2, respectively. After 10 days a significant decrease of the hydraulic conductivity (k) was measured in the experimental group exposed to 80% O2 (k-values expressed as nl/s.mm Hg.mm2: controls (7): 0.059 +/- 0.017; ADR (7): 0.033 +/- 0.026). The reduction of k following the administration of ADR (20 mg/kg) could be prevented by the sulphydryl donor N-acetylcysteine (NAC). The sieving coefficient for albumin (phi) was significantly increased in ADR-treated animals, showing no O2-dependence (phi x 10(-2): controls (7) 1.3 +/- 0.2; ADR 20% O2 (8): 8.1 +/- 9.6; ADR 80% O2 (7): 6.9 +/- 6.7). phi was not affected by NAC. The lipid peroxide levels in liver, kidney and heart of Myxine increased after the administration of ADR, peaking by day 2 to 5. The circulation disorders of ADR-treated Myxine were not due to an accumulation of the drug in the heart, but rather to a lack of the intracellular antioxidant glutathione. It is concluded that the early nephrotoxic effect of ADR, as reflected by a decreased glomerular ATP-ase activity, is mediated by free radical formation. Oxidative stress on membrane compounds seems to reduce the water permeability of the glomerular barrier, while the ADR-induced sieving defect may be due to oxygen independent pathological mechanisms.

Adenosine Triphosphatases↗
PubMed1989

Is diaphragmatic elevation a serious complication of open-heart surgery?

Diaphragmatic elevation or paralysis after open-heart surgery was retrospectively analyzed in 370 consecutive operations performed on 365 adult patients. The incidence of the complication was 7.2%. It was significantly correlated with ipsilateral pleural effusion and lower-lobe atelectasis, but no predisposing or causal factors could be identified. Diaphragmatic elevation did not prolong the hospital stay. Actuarial analysis of data from follow-up chest radiograms showed normalization of the diaphragmatic position within 6 months in 44% and within a year in 90% of the patients.

Adolescent↗
PubMed1987

The use of ciprofloxacin in the treatment of patients with cystic fibrosis.

The use of ciprofloxacin for the treatment of pulmonary infection in cystic fibrosis patients was investigated. Therapy was successful in six patients and unsuccessful in three patients. In one patient therapy had to be stopped because serum transaminase levels showed a 5- to 8- fold increase. During therapy resistance developed in Haemophilus influenzae, Staphylococcus aureus and Pseudomonas aeruginosa.

Adult↗
PubMed1987

A long term scintigraphic bone abnormality after trauma: a pitfall in the survey for metastatic disease.

A solitary bone lesion was detected by 99mTc bone scintigraphy during a survey for metastatic disease. A trauma in this region which had occurred 47 years previously, was mentioned by the patient on questioning. This case report emphasizes the need for a precise history of traumatic events, no matter how long has passed, before a survey for metastatic disease or when an atypical lesion is noted on the bone scan.

Bone Neoplasms↗
PubMed1987

Retreatment with the induction regimen in small cell lung cancer relapsing after an initial response to short term chemotherapy.

In 37 patients with small cell lung cancer treatment with five cycles of cyclophosphamide, doxorubicin and etoposide (CDE), resulted in 23 complete (CR) and 14 partial responses (PR). Median response duration was 34 weeks. At relapse all patients were retreated with CDE. In 23 (62%) patients this gave a second response (6 CR, 17 PR). Factors influencing the occurrence of a second response were: 1. a CR after the first five cycles of CDE; 18 out of 23 CR patients responded again whereas only five of the 14 PR patients responded (P less than 0.01). 2. 15 out of 19 patients with a first response duration greater than 34 weeks reached a second response and in eight of the other 18 patients retreatment was successful (P less than 0.05). Reinduction at relapse, after short term chemotherapy and a treatment-free interval, with the induction regimen is an effective second line treatment in patients with an initial CR and a first response duration of greater than 34 weeks.

Adult↗
PubMed1986

Post-operative intrapleural BCG in lung cancer: a 5-year follow-up report.

Of a total study group of 99 patients 56 received intrapleural BCG in three different dosages (5 patients 16 X 10(6), 25 patients 32 X 10(6), and 26 patients 64 X 10(6) culturable particles) following resection treatment for lung cancer. This study group was compared with an historical control population, very closely matched with regard to age, sex, stage of disease, histology and type of operation. Although the clinical condition of the patients selected for BCG treatment was above average, no survival benefit ensued from the intrapleural BCG. On the contrary, disease-free survival in BCG receivers with stage I and II squamous cell carcinoma was shortened significantly at 2 years follow-up due to the earlier appearance of local recurrences, with the same tendency still present after 5 years. This observation suggests an enhancement of tumour growth by the intrapleural BCG treatment. This alarming phenomenon could be a warning to clinicians when planning clinical immunotherapy trials to be aware of the potentially deleterious effects of such treatment.

Aged↗