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Biomedical subjects

E Verbeken

Publications and source records attributed to E Verbeken.

At least 73 records · Page 4Linked to original sources
PubMed1994

Shunt properties of large intrathoracic airways.

The impedance of the wall of human intrathoracic trachea and central airways was measured by submitting preparations of excised airways to forced oscillations at various frequencies from 2 to 32 Hz. Both real (resistance) and imaginary (reactance) parts of wall impedance demonstrate a marked frequency dependence, varying with transmural pressure. These variations of resistance and reactance are related and are linked to the static elastic properties of the airways. The data allow us to calculate the total shunt impedance of the central intrathoracic airways. When the latter shunt values are used to correct measurements of impedance values of excised emphysematous lungs, it turns out that the shunt does not modify markedly the observed frequency dependence of resistance and compliance of those lungs, at least at transpulmonary pressures > 0.2 kPa. A model study suggests, in addition, that the latter frequency characteristics cannot be explained satisfactorily by parallel mechanical inhomogeneities. We submit that the frequency dependence of resistance and compliance of excised emphysematous lungs is determined mainly by the visco- and/or plastoelastic properties of lung tissue itself.

Adult↗
PubMed1994

New Na(+)-H+ exchange inhibitor HOE 694 improves postischemic function and high-energy phosphate resynthesis and reduces Ca2+ overload in isolated perfused rabbit heart.

BACKGROUND: Experiments were carried out using the new Na(+)-H+ exchange inhibitor (3-methylsulfonyl-4-piperidinobenzoyl)guanidine methanesulfonate (HOE 694) to assess the role of Na(+)-H+ exchange in myocardial ischemic and reperfusion injury. METHODS AND RESULTS: Three groups of rabbit hearts (n = 5 in each) were perfused with blood and were subjected to 45 minutes of global normothermic (37 degrees C) ischemia, followed by 1 hour of reperfusion. Group 1 was the control group (vehicle only); in group 2, HOE 694 (1 mumol/L) was administered before ischemia (pretreatment group); and in group 3, HOE 694 was given only during reperfusion to separate actions exerted during ischemia from those specifically obtained during reperfusion. End-diastolic pressure rise at 1 hour of reperfusion was reduced by administration of HOE 694 starting before ischemia (from 52.2 +/- 8.5 mm Hg in group 1 to 17.6 +/- 4.5 mm Hg in group 2, P < .01) or starting on reperfusion (28.8 +/- 5.4 mm Hg in group 3, P < .05 versus group 1). Left ventricular developed pressure (LVDP) and its derivative (dP/dt) recovered better in HOE 694-pretreated hearts (LVDP, 79 +/- 9.9 mm Hg in group 2 versus 24.8 +/- 10 mm Hg in group 1; dP/dt, 1580 +/- 198 mm Hg/s versus 340 +/- 221 mm Hg/s, P < .01). In hearts treated only on reperfusion, some improvement was observed, which, however, did not reach statistical significance. Coronary flow on reperfusion was higher in groups 2 and 3 compared with controls, and no "no-reflow" was observed. Two additional groups of hearts were perfused with phosphate-free Krebs-Henseleit solution to enable studies with 31P nuclear magnetic resonance (NMR). ATP was better preserved in HOE 694-pretreated (62 +/- 4.9% of preischemic value) than in control hearts (44 +/- 3.3%) at the end of 30 minutes of reperfusion, and phosphocreatine resynthesis was higher (109 +/- 3.7% versus 86 +/- 5.4%). HOE 694 did not affect the time course of intracellular acidosis during ischemia but suppressed a small alkaline overshoot occurring early in reperfusion (pH 6.96 +/- 0.02 in HOE 694-pretreated hearts versus 7.14 +/- 0.05 in control hearts). Electron microscopy with Ca2+ staining of the blood-perfused hearts showed that clumping of Ca2+ aggregates in mitochondria was prevented by HOE 694. CONCLUSIONS: Postischemic dysfunction was associated with a rise in end-diastolic pressure. This rise was effectively blocked by HOE 694. The drug was most effective when hearts were treated before ischemia, although partial protection was observed when administration was started on reperfusion. The action of HOE 694 strengthens the idea that Na(+)-H+ exchange during both ischemia and reperfusion contributes to contractile dysfunction.

Adenosine Triphosphate↗
PubMed1994

Transcarinal needle aspiration biopsy in the staging of lung cancer.

Lung cancer without distant metastasis often requires an invasive surgical procedure to document inoperability. In order to determine how often puncture biopsy was a valid substitute for a surgical procedure, we investigated the performance of endoscopic staging by means of transcarinal needle aspiration biopsy during rigid bronchoscopy. Eighty lung cancer patients with subcarinal lymph nodes visible on computed tomography (CT) scan were studied. Specimens were of histological quality (i.e. lymph node tissue) in 59 out of 80 (74%) patients, and showed malignant invasion of this lymph node tissue in 43 cases. Specimens of cytological quality (i.e. lymph node cells) were obtained in 13 out of 80 (16%) patients, and showed malignancy in 7 cases. Therefore, adequate evaluation of the subcarinal lymph nodes was possible in 72 out of 80 (90%) patients. In 50 of these 72, malignant mediastinal spread was proven, and further invasive surgical staging could be avoided. Subgroup analysis showed that this outcome tended to be more likely in patients with abnormal endoscopic appearance of the main carina, with locally extensive tumours, and with nonsquamous histology. These results indicate that transbronchial needle aspiration biopsy of subcarinal lymph nodes can be a valuable alternative to more invasive surgical staging in patients selected by CT scan.

Adult↗
PubMed1994

Completely reversible respiratory insufficiency with persisting ultrastructural ciliary abnormalities.

A male nonsmoker, born in 1946, suffered from hypersecretory bronchitis and recurrent upper and lower respiratory tract infections since adolescence. In 1983 he developed pulmonary insufficiency. In 1984, some months after daily occupational exposure to printing inks and glues, forced expiratory volume in one second (FEV1) was 1.1 l (28% pred) and arterial oxygen tension (PaO2) 44 mmHg (5.9 kPa). Open lung biopsy showed a centri-acinar bronchiolitis-alveolitis suggestive of an airborne toxic pathology. Ultrastructural examination of the bronchial mucosa revealed microtubular abnormalities in about 10% of the cilia. Treatment consisted of stopping work from December 1985, oral corticosteroids until 1988, bronchodilators on a regular basis and intermittent antibiotics (1 week/month). The evolution was remarkable because: 1) from a severe pulmonary insufficiency, refractory to bronchodilators and corticosteroids for several years, lung function slowly improved to supernormal values, without residual functional signs of small airways disease; and 2) a repeat ultrastructural nasal mucosa examination in 1992 still showed persisting microtubular abnormalities in about 10% of the cilia, which disappeared on sequential monolayer-suspension culture, thus indicating secondary ciliary abnormalities.

Bronchi↗
PubMed1994

Cardiac transplantation in giant cell myocarditis. A case report.

The present report describes a 15-year-old boy who underwent an urgent cardiac transplantation for giant cell myocarditis because of fulminant progressive heart failure, complicated by ventricular tachycardia, unresponsive to classical inotropic medical treatment. The physiopathology and the treatment are discussed.

Adolescent↗
PubMed1993

Adenine nucleotide degradation in ischemic rabbit lung tissue.

The aim of the study was to determine the pathways and site of adenosine triphosphate (ATP) catabolism during lung ischemia, which thus far are largely unknown. For this purpose we used the isolated rabbit lung. Rabbit lungs were flushed in situ with a modified Krebs-Henseleit solution (60 ml/kg), the deflated heart lung blocks were isolated, immersed in saline solution, and stored at 37 degrees C. In group I (normothermic ischemia; n = 6) tissue content of ATP decreased progressively from 9.42 +/- 0.58 mumol/g dry wt to 3.42 +/- 0.24 mumol/g dry wt after 30 min of ischemia and further to 0.51 mumol/g dry weight after 4 h. Hypoxanthine was the major catabolite (92% of the nucleoside and purine base fraction at 4 h ischemia). Adenosine did not accumulate (preischemic 0.08 +/- 0.02 mumol/g dry weight vs. 0.13 +/- 0.01 mumol/g dry weight; P > 0.05). AMP accumulated, but also inosine monophosphate (IMP), which was undetectable before ischemia, increased significantly during ischemia. To determine the breakdown pathway of AMP, 400 microM of the adenosine deaminase inhibitor EHNA was added to the flush solution in group II (n = 6). During ischemia, ATP breakdown was unaltered but adenosine became the major catabolite (2.8 times the concentration of hypoxanthine at 4 h ischemia). By pretreatment of the rabbits with the nucleoside transport inhibitor R 75231 (group III; n = 6) no effect was observed on the concentrations during ischemia of inosine and hypoxanthine and only a minor increase of adenosine was found. Cytochemical localization of nucleoside phosphorylase revealed activity predominantly in the endothelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenine Nucleotides↗
PubMed1990

Growing bone cysts in long-term hemodialysis.

All patients with chronic renal failure undergoing hemodialysis for more than 10 years in the university hospitals of Leuven were selected for this study. The medical records and radiographs of these 21 patients were studied retrospectively. Skeletal surveys were examined for the presence and location of subchondral cysts. The predialysis films and the films taken after 5, 10, 15 and 20 years of dialysis were reviewed. Subchondral cysts that grew in size and number were found in the wrist, humeral head, hip, and patella. Accurate measurements were made of cysts in the wrist and compared with a control group. In the dialysis group, cystic involvement of the wrist was more common and the size and number of the cysts were larger. Soft tissue swelling was seen in the dialysis group but not in controls. Soft tissue swelling was assessed on shoulder radiographs by measuring the acromiohumeral distance (ACD) and in the knees by ultrasonic measurement of synovial thickness. In 11 patients synovial or bone biopsies or aspirated synovial fluid were available. All these patients had swollen joints and multiple subchondral periarticular cysts. Amyloid deposition was found in ten of these patients, and this proved to be composed of B2 microglobulins in seven.

Amyloidosis↗
PubMed1990

Rapidly fatal progression of cobalt lung in a diamond polisher.

Interstitial lung disease was diagnosed in a 52-yr-old male diamond polisher, who worked with polishing disks containing cobalt. After a further 7 months of probably high occupational exposure without any specific treatment, he had to quit work because of dyspnea. Despite treatment with systemic corticosteroids and continuous oxygen administration, he died 3 months later in respiratory distress. Postmortem examination of the lung tissue showed a typical giant-cell interstitial fibrosis, with active inflammatory cell infiltration superimposed on an established centrilobular fibrosis. The lung tissue contained 2.1 micrograms cobalt/g wet weight (more than 100-fold the normal concentration); cobalt particles, mainly localized in macrophages, were identified by transmission electron microscopy and energy-dispersive X-ray analysis. We speculate that the rapid deterioration and fatal outcome resulted from the continued exposure to cobalt, leading to a high pulmonary concentration of cobalt, and from the oxygen treatment because cobalt promotes the formation of hydroxyl free radicals.

Air Pollutants, Occupational↗
PubMed1989

Uneven lipomatosis: a pitfall in pancreatic sonography.

A marked difference in echogenicity between the anterior and posterior parts of the pancreatic head was demonstrated by pancreatic ultrasound in 4 patients. This finding could not be related to local pancreatic or peripancreatic pathology. In all patients the dorsal portion of the head, including the uncinate process, appeared less echogenic than the ventral part of the head, body, and tail. The level of demarcation was identical in all 4 cases, coinciding with the expected fusion line of the embryological dorsal and ventral pancreatic origin. Pathology available in 1 patient showed an uneven lipomatosis as an explanation for this hitherto unreported observation.

Aged↗
PubMed1989

Pulmonary migration following periurethral polytetrafluoroethylene injection for urinary incontinence.

We report a case of clinically significant migration of polytetrafluoroethylene (Teflon) paste particles to the lungs after periurethral injection. These particles were identified by standard and polarized light microscopy. Since the long-term effects in humans are not sufficiently known, we strongly warn against the use of polytetrafluoroethylene paste in children or young adults with a normal life expectancy.

Adult↗
PubMed1989

Carcinosarcoma of the lung. Report of two cases and review of the literature.

Two cases of carcinosarcoma of the lung are presented. Until now, 76 cases have been recorded in the literature. The lesion contains an epithelial and a mesenchymal component, both with cytologic features of malignancy. A central endobronchial and a peripheral invasive type have been described. Fiberoptic biopsies usually show no tumour at all or contain only one of the two components. Treatment consists of lobectomy or pneumonectomy. Prognosis is not better for this tumour than for non-small cell bronchogenic carcinoma, and may even be worse.

Aged↗
PubMed1989

[Pulmonary pathology due to cobalt and hard metals].

For forty years, cases of interstitial pneumonia and bronchial asthma have been described in hard metal workers (i.e., alloys of tungsten carbide and cobalt). Recently we have reported comparable pulmonary lesions in workers in the diamond industry who were exposed to cobalt unassociated with tungsten carbide. The exposure came from the diamond cobalt discs used for polishing diamonds, which had as the hard element microdiamonds, cemented in an alloy of pure cobalt. The hard metals on the other hand consisted of cobalt and tungsten carbide. Forty-seven diamond cutters (i.e., nearly 1% of those exposed) presented with broncho-pulmonary pathology due to cobalt. Nineteen had a fibrosing alveolitis, sometimes documented by a pulmonary biopsy and more often by a broncho-alveolar lavage which revealed characteristic multinucleated giant cells. Thirteen had occupational asthma, often proved by specific inhalation provocation tests to cobalt or by lung function measurements at the place of work. Two patients had mixed forms and in thirteen a probable diagnosis was suggested. The pathogenesis of cobalt might be explained by cytotoxic action such as has been demonstrated in animal experiments. Either results suggest a sensitising or allergic action. Tungsten carbide does not produce pulmonary lesions but its association with cobalt intensifies the effects of the latter.

Alloys↗
PubMed1988

Surgical treatment of bronchogenic carcinoma: a retrospective study of 720 thoracotomies.

Seven hundred and twenty patients with primary bronchogenic carcinoma were operated on at the Pellenberg Clinic, K.U. Leuven, Belgium, between January 1, 1970, and January 1, 1985. Almost 45% of the resections were pneumonectomies and 47% were lobectomies. Mortality was 6.9% and 2.9%, respectively. Patients with squamous cell carcinoma (Stages I and II) who underwent lobectomy or pneumonectomy had an absolute 5-year survival rate of 52.8% (93/176); it was 21% (4/19) in the T3 N0/N1 subgroup. Patients with adenocarcinoma who underwent a lobectomy had a 5-year survival rate of 49% (26/53) in the T1/T2 N0 group and of 27% (3/11) in the T1/T2 N1 group. Only 13.6% (3/22) of patients survived 5 years if a pneumonectomy had to be performed. Only 1 in 22 N2 patients survived 5 years after resection.

Adult↗
PubMed1987

Postoperative biliocutaneous fistula: successful treatment by insertion of an endoprosthesis.

An elderly patient with a postoperative biliocutaneous fistula, the persistence of which was due to an unrecognized fibro-malignant stricture of the distal common bile duct, was treated by the insertion of an endoscopic biliary endoprosthesis. Immediately after the procedure, bile discharge through the fistula ceased completely, and the fistula closed in three days. Endoscopic treatment methods are worth trying before surgical revision of a biliocutaneous fistula is performed.

Aged↗
PubMed1987

Adult linear IgA bullous dermatosis with bronchial involvement.

A 54-year-old man is described, suffering from adult linear IgA bullous dermatosis with involvement of the bronchial mucosa. The main respiratory symptoms were recurring haemoptysis, episodic narrowing of the airways and persistent non-specific bronchial hyperreactivity. On CT scan the trachea had a saber-sheath shape with tracheal ring calcification. Endoscopically the tracheo-bronchial mucosa was diffusely purpuric and hyperaemic and also showed pale elevated plaques, bullous lesions and ulceration. Histological examination of biopsies of skin and nasal and tracheo-bronchial mucosa showed subepithelial blister formation associated with an accumulation of polymorphonuclear cells at the epithelial-subepithelial junction, and linear IgA deposits on direct immunofluorescence.

Bronchi↗
PubMed1987

Recurrent aneurysms of the upper arteries of the lower limb: an atypical manifestation of fibromuscular dysplasia--a case report.

Fibromuscular dysplasia (syn. arterial dysplasia, fibromuscular hyperplasia, medial fibroplasia) is an arteriopathy of unknown etiology, most frequently involving the renal arteries. The string-of-beads appearance of these lesions seems to be a characteristic angiographic finding. We report atypical angiographic findings at an unusual site, which proved to correspond to fibromuscular dysplasia at histological examination.

Adult↗