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Biomedical subjects

G Methlin

Publications and source records attributed to G Methlin.

At least 37 records · Page 2Linked to original sources
PubMed1984

Proteinases and sialyltransferase in human breast tumors.

Proteolytic and sialyltransferase activities were determined in extracts of 65 human primary breast tumors, 6 lymph node metastases, 6 fibroadenomas and 27 normal tissues. Using proteins and synthetic selective substrates, we observed the presence of collagen-peptidases, plasminogen activator, cathepsin-B and cathepsin-D-like enzymes, and sialyltransferase. No active or trypsin-activatable type-IV collagenase activity was detected. Although individual variations between tumors were large, proteinase and sialyltransferase contents were significantly elevated in malignant breast tissues. Enzyme activities were found to be related to the epithelial volume of the tumor. No significant correlation was found between the proteinase or sialyltransferase activities and the degree of differentiation of the tumor cells, or the degree to which tumors had metastasized to regional lymph nodes. Since large variations of enzyme levels apparently reflect the heterogeneity of epithelial cell densities in tumor samples, proteolytic or sialyltransferase activities cannot therefore be used as a measure of quantitative evaluation of invasive properties in breast cancer.

Adenocarcinoma↗
PubMed1984

Relationship between pulmonary artery mean pressure and the vertical gradient of perfusion in chronic respiratory diseases.

The relationship between mean pulmonary artery pressure (PPA) and the regional distribution of perfusion, investigated with 133Xe, was studied in 67 patients with chronic respiratory diseases, including 57 patients with chronic obstructive pulmonary disease. The vertical gradient of perfusion, assessed by the ratio upper/lower perfusion (RQ), was considered as normal when RQ was less than or equal to 0.85. Patients were divided into three groups: no pulmonary hypertension, mild hypertension, moderate to severe hypertension. RQ was normal in the majority of patients, even in the group with PPA greater than 30 mm Hg. The average values of RQ did not significantly differ from one group to another. There was no correlation between PPA or pulmonary vascular resistance and RQ. These results suggest that the vertical gradient of perfusion is generally conserved and that the distribution of perfusion cannot provide any reliable prediction of pulmonary hypertension in chronic obstructive pulmonary disease.

Adult↗
PubMed1984

Detection of right ventricular pressure overloading by thallium-201 myocardial scintigraphy. Results in 57 patients with chronic respiratory diseases.

The diagnostic value of thallium 201 (201Tl) myocardial imaging was studied in 57 patients with chronic respiratory diseases, most with COPD (n = 46), by comparing the results to hemodynamic findings. In healthy subjects, the right ventricle (RV) is not visualized; therefore, any recorded activity of the RV was considered as indicating RV hypertrophy due to RV pressure overloading (RVPO). RV activity was graded from 0 (no activity) to 3 (activity greater than or equal to that of the left ventricle). Patients were divided into three groups according to the level of the pulmonary artery mean pressure (PPA): PPA less than or equal to 20 mm Hg (no pulmonary arterial hypertension [PAH] ) = group 1, n = 20; PPA ranging from 21 to 30 mm Hg (mild to moderate PAH) = group 2, n = 20; PPA greater than 30 mm Hg (marked PAH) = group 3, n = 17. RV was visualized in 14 patients in group 3 (82 percent) and in 13 patients in group 2 (65 percent). For all patients with PAH (2 + 3) the sensitivity of 201Tl imaging for the diagnosis of RVPO was of 73 percent, higher than that of ECG and echocardiography (both 51 percent). The sensitivity of 201Tl, even if moderate (65 percent) was better than that of ECG (30 percent) or echo (40 percent) in patients with mild-to-moderate PAH (group 2). A high RV activity (grade 3) was observed in only three patients. The specificity of this method (obtained from results in group 1) was of 80 percent vs 89 percent for echo and 100 percent for ECG. These results suggest that 201Tl myocardial imaging is a rather sensitive method and could be of interest for the noninvasive diagnosis of RVPO in COPD patients.

Adult↗
PubMed1981

[Regional pulmonary function in unilateral sero-fibrinous pleural effusions and changes under the influence of treatment (author's transl)].

The regional distribution of ventilation (Vr), perfusion (Qr) (expressed in absolute values) and the regional distribution of ventilated lung volume, of ventilation and of perfusion (expressed as %) were studied using Xenon 133 in 13 subjects with a unilateral pleural effusion of proven or presumed tuberculous origin. The examinations were performed in a sitting position. The initial examination was carried out after as complete an evacuation as possible of the fluid effusion. Eight subjects underwent a follow-up examination after two months treatment with tuberculostatic agents combined with daily respiratory physiotherapy. The initial results emphasized the following points: - in absolute values, a deficit in ventilation on the involved side affecting the 3 regions explored without any similar change in perfusion ; a hyperventilation on the controlateral upper and middle regions ; - in relative values, a slight deficit in ventilated volume and perfusion localised at the base, whilst the deficit in ventilation was more marked and more extensive. After treatment the contribution to ventilation of the involved side increased on average by 6%. However this improvement only concerned the lower territory. The mechanisms of impairment of regional function and its improvement under the influence of treatment are discussed.

Adolescent↗
PubMed1980

Immunoradiometric assay for human thyroglobulin and variations in thyroid pathology.

A specific and sensitive double antibody radioimmunoassay for measuring human serum thyroglobulin (Tg) has been developed. Serum Tg levels are reported for patients with differentiated and undifferentiated thyroid carcinomas, post-treated and untreated hyperthyroidism, thyroiditis, and cold nodular goiters. We have studied results of serum Tg levels in the follow-up and care of patients who have undergone total thyroidectomy for differentiated thyroid carcinomas. Tg has no diagnostic value in the detection of thyroid cancer, but is a reliable index of metastatic growth in the follow-up of patients with differentiated carcinomas. In addition, serum Tg determination might be helpful in the aetiological diagnosis of bone or lung metastases of unknown origin.

Carcinoma↗
PubMed1979

Radionuclide computerized ventilation studies.

Studies of regional lung function have developed rapidly in the last few years. Xenon -133 is the most frequently used isotope because of its physiocochemical and biologic properties. Fixed counters are being replaced by the scintillation camera interfaced to a computer allowing easy acquisition and interpretation of results and numerical data. The use of isotopes other than 133Xe, such as 81mKr, is less widespread. In this article, a method is described for studying regional ventilation in which the isotope used is 133Xe, the radioactivity is recorded by a scintillation camera, interfaced to a computer andsix (or 12) regions for both lungs are selected and investigated. The regional ventilation is expressed as an absolute value in ml/min/ml of ventilated volume as well as the relative contribution in percent of each zone to the total ventilation and volume. To illustrate this method, the results are reported for healthy subjects and for patients with chronic bronchitis and emphysema. Scintigraphs of individual cases are presented. Certain theoretic problems related to calculation of regional ventilation are discussed.

Bronchitis↗
PubMed1978

[The regional exploration of pulmonary function using xenon 133. Value of the gamma camera connected to a computer (author's transl)].

Regional isotopic exploration of ventilation and pulmonary perfusion is not yet widely applied in clinical practice, by virtue of the complexity of the equipment required, but also because of the complicated and lengthy analysis of the results. In this respect, connection of the scintillation camera to a computer represents a major advance which other authors have already emphasized. Our own experience in this area and our method of exploration are described. The results of regional exploration in a group of 43 cases of chronic obstructive lung disease (33 patients of the chronic bronchitis type, 10 patients with emphysema) are analysed and discussed. The results indicate the following : in chronic bronchitis, a very marked fall in ventilation of the bases with inversion of the normal vertical ventilation gradient, and a fall in the ventilation/perfusion ratio of the bases; in emphysema, a fall in ventilation, but also and above all in regional perfusion of all territories with preservation of normal or even increased regional ventilation/perfusion ratios. Regional exploration may also be of value in the detection of early stages of obstructive lung disease, and in pre-operative assessment in thoracic surgery.

Bronchitis↗
PubMed1977

Regional pulmonary function in sarcoidosis.

In 26 subjects with a confirmed histological diagnosis of thoracic sarcoidosis regional lung function was studied with Xenon 133. All subjects also underwent overall lung function studies including CO steady state (TCO SS) and single breath (TCO SB) diffusing capacity. Regional ventilation (Vr) was on the average increased in stages I (isolated hilar adenopathies) and II (pulmonary infiltration) and appeared normal in stage III (pulmonary fibrosis). Regional perfusion (Qr) was on the average normal in stages I and II and decreased in stage III. There were no appreciable differences between average values in stages I and II. Abnormalities of Vr and Qr were frequently found in individual cases. A distinction was made between the total number of abnormalities and deficiency abnormalities. The total number of abnormalties was high in all three stages. Deficiency abnormalities were relatively rare in stages I and II, and frequent in stage III. The correlation between radiological and regional functional abnormalities was low. TCO SB/VA was found significantly lower (P less than 0.005) in subjects with regional deficiency abnormalities (mostly perfusion abnormalities). These data probably indicate that a lowered diffusing capacity may be due to the loss of pulmonary capillaries and not only to ventilation - perfusion disparities.

Adolescent↗