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Biomedical subjects

R Loddenkemper

Publications and source records attributed to R Loddenkemper.

At least 127 records · Page 7Linked to original sources

Debrisoquine hydroxylation phenotype, acetylation phenotype, and ABO blood groups as genetic host factors of lung cancer risk.

Bronchogenic carcinoma is closely associated with cigarette smoking although additional environmental or individual factors might regulate a person's susceptibility to that disease. To further define such risk factors, the prevalence of the genetic debrisoquine 4-hydroxylation deficiency was determined before therapeutic intervention in 270 lung cancer patients. Nineteen homozygous carriers of this defect (poor metabolizers) were found (7.0%, 95% confidence limits 4.3%-10.8%), a number being lower than 30 out of 270 reference patients (11.1%, 95% confidence limits 7.6%-15.5%). The odds ratio of 0.61 was of marginal statistical significance (P = 0.067). Subdividing the collective according to histology revealed a trend towards underrepresentation of poor metabolizers especially among patients with adenocarcinoma (1 out of 37, P = 0.086) and among young patients not older than 50 years (none out of 32, P = 0.028). All poor metabolizers (PMs) in the cancer group were smokers. In 18 patients the phenotype assignment was confirmed by a second test several weeks after surgical or other treatment. In 220 of the lung cancer patients the N-acetyltransferase polymorphism was evaluated by means of the molar ratio of 5-acetylamino-6-formylamino-3-methyluracil and 1-methylxanthine in urine after ingestion of caffeine (coffee). There were 111 (50.5%) slow acetylators and 109 (49.5%) fast acetylators. A statistically significant clustering of either phenotype after stratification according to histology, or debrisoquine hydroxilator status was lacking. Moreover, there was no difference in the ratio of both phenotypes as compared to the reference collective of 245 patients (53.5% slow and 46.5% fast acetylators). As a third genetic host factor the AB0 blood group frequencies were evaluated in 263 lung cancer patients. The frequency ratio of A/O was significantly higher as compared to 41,423 blood donors (odds ratio 1.37, 95% confidence limits 1.02-1.84, P less than 0.05). A/O tended to be especially high in young patients not older than 50 years. The ratio B/O in bronchial cancer was significantly higher than expected. The results suggest that the debrisoquine hydroxilator status might have an impact on an individual's susceptibility to lung cancer. This association is either a weak one and/or is restricted to certain histological cancer types or to patients with certain characteristics. The acetylator phenotype could not be established as a risk factor, whereas AB0 blood groups seem to influence lung cancer susceptibility.

ABO Blood-Group System↗

[Prospective comparison of the diagnostic value of cytology and immunocytology in pleural effusion studied by thoracoscopy and biopsy].

Two issues have been elaborated: the value of immunocytochemistry in the diagnosis of pleural effusions, and the reactivity of the investigated antibodies with different classes of cells in pleural effusions. Effusions of unknown origin from 38 patients were investigated using thoracoscopy, pleural biopsies, conventional cytology, and immunocytochemistry. The following antibodies were used: those monoclonal against various leukocyte antigens, macrophage antigens, epithelial membrane antigen (EMA), various cytoskeleton antigens, and melanoma antigens; those polyclonal against CEA and ferritin. All of the techniques used showed 18 patients (48%) as having a tumor-cell negative effusion. A pleural tumor with a malignant effusion showed in 13 patients (34%); in 12 of these immunocytochemistry also revealed tumor cells. Seven patients (18%) had a tumor of the pleura with a tumor-cell negative effusion; in 2 of these immunocytochemistry revealed a tumor-cell positive effusion. There was no difference with regard to the number of NK cells in patients with inflammation of the pleura and negative cytology and patients with tumor of the pleura and malignant effusion (3% vs 4.5%). Tumor cells were mainly stained by EMA, cytokeratin, and CEA. CEA was the only antibody to be tumor-cell specific, while EMA and cytokeratin were expressed by mesothelial cells also. The antibody against ferritin was a significant marker for mesothelial cells.

Antibodies, Monoclonal↗

[Magnetic resonance tomography of intrathoracic tumors].

65 patients suspected of having intrathoracic masses were studied using magnetic resonance imaging (MRI) and computed tomography (CT). The intensity difference between mass and adjacent normal tissue or mediastinal fat was greater on MRI than on CT images. MRI was superior to CT in differentiating bronchogenic carcinomatous tumours from postobstructive pneumonia and/or lobar collapse. MRI images most clearly depicted obstructed mediastinal vessels and were also able to indicate intravenous flow reductions. The latter could be demonstrated by an increase of signal intensity within venous structures proximal to the obstruction. In patients with lung cancer no significant differences were found between the two imaging methods for the evaluation of tumour extent or node involvement.

Bronchogenic Cyst↗

[Nuclear magnetic resonance tomography of superior vena cava obstruction].

The potential of magnetic resonance tomography (MRT) to demonstrate the mediastinal veins was evaluated retrospectively in 6 patients with superior vena cava obstruction. In each instance, MRT provided detailed information about the extent of venous obstruction and the precise site of the causative oncological pathology. Transaxial images most clearly and unequivocally depicted obstructed superior vena cava. MRT was also able to indicate some secondary effects of superior vena cava obstruction such as slow intravenous flow. The latter could be demonstrated by a significant increase of signal intensity within venous structures proximal to the obstruction. Peripheral venous collaterals in the chest wall were better seen with contrast enhanced computed tomography scans.

Collateral Circulation↗

[New methods in the radiotherapy of bronchial carcinoma. Endobronchial small-field irradiation using the iridium-129 high-dose afterloading technic in combination with the neodymium-YAG laser].

106 patients with inoperable malignant tumours constricting the central bronchial tree underwent endobronchial small-field radiotherapy with iridium-192 at high dose between June 1983 and September 1985. Treatment was performed using the computer-guided after-loading technique and a flexible bronchoscope under local anaesthesia. In complete occlusion of a bronchus by the tumour, a neodymium YAG-laser was applied (57 patients) to allow insertion of the after-loading probe. Endoscopy showed tumour regression in 75% of the patients, accompanied by clinical improvement. Pulmonary function tests, arterial blood gas analyses and pulmonary perfusion scans yielded a highly significant improvement of data after treatment. The procedure also proved effective upon exhaustion of external radiation. Apart from its positive palliation, endobronchial small-field radiotherapy using high doses of iridium-192 also has a curative effect, thus opening up a new approach to the therapy of advanced bronchial carcinoma.

Aged↗

Computed tomography in CNS tuberculosis.

Computed tomography (CT) was performed in 14 cases of tuberculous meningitis (TBM), 12 of which were examined during the acute phase of the disease. CT findings in these cases included internal hydrocephalus (6/12), internal combined with external hydrocephalus (2/12), focal lesions consistent with localized encephalitis (3/12), diffuse brain edema (1/12), and middle cerebral artery infarction (1/12). In comparison to 32 cases of nonspecific bacterial meningitis, internal hydrocephalus was found significantly more often in TBM than in nonspecific meningitis (p less than 0.01) making CT an additional tool for the differentiation of these conditions in doubtful cases. In addition, CT features of 2 cases of cerebral tuberculoma are presented.

Adolescent↗

[Anaerobic bacterial meningitis with multiple brain abscesses].

The improvement of bacteriological techniques for isolation and identification of anaerobes has led to an increased interest in anaerobic infections. However, anaerobes have only rarely been found in cases of purulent meningitis, representing less than 1 percent of all isolated pathogens. We observed anaerobic meningitis in a patient suffering from multiple lung abscesses from which anaerobic bacteria spread to the brain, causing formation of anaerobic brain abscesses and consecutive meningitis. Microbiological examinations for anaerobes should be performed in those cases of meningitis in which purulent infections of other organs with known or suspected anaerobic etiology are present or in which a traumatic lesion of the subarachnoid space has preceded the development of meningitis.

Adult↗

Criteria of functional operability in patients with bronchial carcinoma: preoperative assessment of risk and prediction of postoperative function.

In this prospective study of 433 patients undergoing surgery for bronchial carcinoma 3 main factors influencing the operative risk were identified: (1) extent of resection, (2) pulmonary function and (3) age. The 30-day mortality rate was 8.3% in the whole group which comprised a high percentage of patients over 70 years of age (27%) and with a disturbed pulmonary function (45%). The value of various functional criteria proposed in the extensive literature is assessed and compared with the results of the study in which the use of FEV1 and quantitative regional analysis by perfusion scanning and 'regions of interest' proved to be highly efficient, allowing, in addition, the prediction of postoperative lung function even in sleeve resections. A new formula for estimation of the additional loss of function in the early postoperative phase after lobectomies is proposed along with a flow sheet for routine preoperative evaluation of pulmonary function.

Age Factors↗