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Biomedical subjects

W Bakker

Publications and source records attributed to W Bakker.

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

Vindesine, cisplatin, and bleomycin combination chemotherapy in non-small cell lung cancer: survival and quality of life.

Although combination chemotherapy is applied on a large scale in advanced non-small cell lung cancer (NSCLC), we still lack evidence indicating in which subsets of patients survival or quality of life might be improved. We studied these issues among a sample of 28 NSCLC patients with a high performance status, who received a tri-weekly vindesine, cisplatin, and bleomycin combination. Treatment was extended for an additional two courses only if a response was observed after the initial three courses. An overall response rate of 13/27 evaluable patients (48%) was found (complete response 1/27 and partial response 12/27) with a median response duration of 24 weeks. Median survival was 33 weeks (47 for responders and 26 for non-responders). Toxicity was primarily related to cisplatin, including severe nausea and vomiting and nephrotoxicity in 68% and 21% of the patients, respectively. Performance status and body weight dropped significantly during chemotherapy both among responders and non-responders. Performance status after discontinuation of chemotherapy approached pre-treatment scores in responders only. While the antitumor effect of this drug combination was confirmed, we conclude that treatment-associated toxicity and deterioration of the patients' well-being offset any potential survival advantage for the majority of patients.

Adult↗
PubMed1986

Calcified lymph node metastases in bronchioloalveolar carcinoma.

A 45-year-old man was found by cytopathologic examination of bronchial washings to have bronchioloalveolar carcinoma. A computed tomography (CT) scan of the chest showed diffuse calcifications in the consolidated left upper lobe. Similar calcifications were seen in several mediastinal lymph nodes; these were shown by biopsy to be metastases with calcified psammoma bodies. When CT demonstrates diffuse calcifications in a bronchioloalveolar carcinoma, the finding of identical calcifications in the mediastinal lymph nodes should raise a strong suspicion of metastatic involvement.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1986

The value of the forced expiration technique with and without postural drainage in adults with cystic fibrosis.

The effect of the Forced Expiration Technique (FET) with or without Postural Drainage (PD) was examined in eight adults with cystic fibrosis. On four mornings the patients followed a 30-min physiotherapy session consisting in a randomized order of either FET in a sitting position following a night of horizontal sleep ("FET"), or FET in a postural drainage position following sleep including postural drainage ("FET/PD"). The lung function parameters studied did not change during either of the two treatments. Sputum yield over 22.5 h before the physiotherapy sessions and over 24 h increased with PD during sleep in patients with more than 30 g of sputum per 24 h (p less than 0.05). PD during the treatment sessions did not further increase sputum production. This study indicates that sleeping head-down improves expectoration in patients with copious sputum. PD during FET is not needed after sleeping in the head-down position.

Adolescent↗
PubMed1985

An in vivo clonogenic assay for human tumors using plasma clot diffusion chambers implanted in mice.

A modification of the in vivo tumor clonogenic assay using plasma clot diffusion chambers has been described which allows improved study of the cytological characteristics of the colonies cultured. Seventy-five percent of the tumors derived from malignant ascites could be cultured successfully (more than 30 small and large colonies per diffusion chamber). The cloning efficiency ranged from 0.01 to 10%. The addition of 2-mercaptoethanol, horse serum and insulin to the diffusion chambers did not affect colony formation, whereas the effect of cell-free malignant ascites added to the diffusion chambers was unpredictable. Colony growth was comparable when fresh or cryopreserved tumor cells were cultured. A linear relationship between the number of tumor cells inoculated and the number of colonies cultured was apparent in the range 10(2)-10(4) cells. Colony formation was stimulated by pre-irradiation (8 Gy) of the host animal and by weekly transplantation of the diffusion chambers in new mice. Intravenously administered doxorubicin penetrated the plasma clot and caused inhibition of colony formation in two experiments with melanoma cells.

Animals↗
PubMed1984

Combined modality treatment of short duration in small cell lung cancer.

Fifty-seven patients with small cell lung cancer (SCLC) (limited disease = LD in 23, extensive disease = ED in 34) received the combination of CCNU, cyclophosphamide, vincristine and methotrexate (CCOM). A mean number of only 6 (range 1-17) courses of chemotherapy were given. All LD patients received consolidation locoregional radiation (30 Gy) after two courses of chemotherapy. A complete response (CR) was obtained in 61% of LD and 12% of ED patients, and a partial response in 22 and 35% respectively. Median survival was 54 and 34 weeks for LD and ED respectively. Five LD patients survived more than 2 yr, three of them remaining disease-free 4 yr after the cessation of treatment. A subset of 12 LD patients achieving a CR after two courses of chemotherapy was randomized to receive maintenance chemotherapy or observation only after the consolidation radiotherapy. In this small-sized randomized trial maintenance treatment showed a significant decrease of the patients' quality of survival compared to no maintenance treatment. We conclude that combined modality treatment of short duration proved effective in SCLC. Future randomized studies are necessary to show whether prolonged chemotherapy has a meaningful impact on survival, or otherwise the resulting morbidity will plead against it.

Adult↗