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Biomedical subjects

M Albrecht

Publications and source records attributed to M Albrecht.

At least 181 records · Page 10Linked to original sources
PubMed1983

Interrelation between lipid peroxidation and lysosomal enzyme release in the presence of carbon tetrachloride, cumene hydroperoxide or thioacetamide.

To study the relationship between lipid peroxidation (LPO) and the release of lysosomal enzymes as markers of liver injury three compounds were chosen which evoke lipid peroxidation (cumene hydroperoxide, CHP), hepatocellular injury (thioacetamide, TAA) or both (carbon tetrachloride, CCl4). Premitochondrial supernatants of phenobarbital-induced rat liver homogenates were incubated in the presence of either agent and an NADPH-regenerating system. Then, lipid peroxidation was assessed by measurement of malondialdehyde (MDA) formation and, after centrifugation at 105 000 g, released beta-glucuronidase was measured in the supernatant. While CCl4 and CHP promoted both events in a time and concentration dependent manner, TAA did not evoke either LPO or lysosomal enzyme release. Glutathione, dithiocarb and (+)-catechin inhibited both effects. Though LPO and lysosomal enzyme release proved to be related events, no strict correlation with the hepatotoxicity was found.

Acetamides↗
PubMed1983

Cell lines derived from human ovarian carcinomas: growth stimulation by gonadotropic and steroid hormones.

Carcinoma cell lines established from 5 patients with advanced tumors of ovarian location were characterized by karyotypes and growth properties in serum-free medium. In early passages of the cultivation, the growth of cell lines derived from tumors of fairly differentiated histology was stimulated by human follicle-stimulating hormone or human chorionic gonadotropin-human luteinizing hormone. Cells obtained from poorly differentiated carcinomas were unresponsive to gonadotropins. The proliferation of cell lines derived from a malignant clear cell carcinoma and from the ovarian metastasis of an advanced mammary carcinoma was enhanced by cortisol. The results imply that hormonal factors in concentrations physiologically occurring in human serum may support the in vivo growth of ovarian tumors.

Carcinoma↗
PubMed1983

Interrelationship between in vivo lipid peroxidation, microsomal Ca2+-sequestration activity and hepatotoxicity in rats treated with carbon tetrachloride, cumene hydroperoxide or thioacetamide.

To study the relationship between lipid peroxidation and cellular damage we studied three compounds known to evoke lipid peroxidation (cumene hydroperoxide, CHP), hepatocellular injury (thioacetamide, TAA) or both (carbon tetrachloride, CCl4). Phenobarbital-induced male rats were treated with one of the three agents and lipid peroxidation was monitored via the measurement of exhaled ethane. Treatment with both, CCl4 and CHP resulted in an increased ethane expiration, whereas TAA did not. When liver-specific serum enzyme activities (GPT, SDH) were investigated 24 h later, however, hepatotoxicity was evident only in rats treated with either CCl4 or TAA. The ATP-dependent Ca2+-sequestration activity of microsomal membranes, suggested to be a final common pathway leading to cellular death, was studied in microsomes isolated from rats treated with either agent. 2 h after treatment with CCl4 or TAA a clear inhibition was seen which persisted after 24 h in the case of CCl4 only. CHP did not affect the Ca2- -pump activity. Thus, a clear correlation between cellular damage and lipid peroxidation cannot be expected in every case. An impairment of the microsomal calcium-pump, however, seems to be a crucial event which leads to hepatocellular injury.

Animals↗
PubMed1982

Dark cells in human oral leukoplakias.

Dark basal keratinocytes, characterized by a strong affinity for basic dyes and by electron density of cytoplasm and nucleus, could be recognized in eleven oral leukoplakias. The percentage of dark cells was higher in the group comprising leukoplakias verrucosa, and erosiva (28% of the basal cells) than in the leukoplakia simplex group (10%). The presence of these cells is a good indicator of the degree of histological dysplasia and correlates well with the preneoplastic potential of these lesions.

Adult↗
PubMed1981

[Ancillary chemotherapy with trofosfamid, methotrexate and fluoro-uracil in cancer of the breast (author's transl)].

The results of adjuvant chemotherapy in the treatment of primary cancer of the breast is reported. During 44 months 401 patients were admitted to the prospective study. All patients with a cancer of the breast T1a-3a, N0-1b, M0 were operated by modification of the Patey procedure. N+ patients were treated for one year postoperatively with TMF chemotherapy (trofosfamid, methotrexate and Fluoro-uracil). Patients without lymph node metastases were not treated. After 44 months the recurrence rate in the TMF group was 16.2%, in the group without chemotherapy 9.8%. The recurrence rate in the treated group was 18.8% for post-menopausal patients and 13.8% in pre-menopausal patients. The number of distant metastases was higher than that of local recurrences. In the group without post-operative chemotherapy a higher number of recurrences occurred in the pre-menopausal patients (13.8%) than in the post-menopausal patients (7.5%). The proportion of local recurrences and distant metastases was the same in these patient groups. The experiences regarding the treatment plan and the side effects are the same as in comparable other studies of adjuvant chemotherapy. Several treatment plans are discussed which can lead to a reduction of the recurrence rate and to an improvement of the survival rates.

Breast Neoplasms↗
PubMed1981

Pharmacokinetics, bioavailability and ECG response of verapamil in patients with liver cirrhosis.

1 The pharmacokinetics, bioavailability and ECG response of verapamil was investigated in seven patients with liver cirrhosis and compared with six normal subjects, using stable labelled techniques whereby both the intravenous and oral dose are given simultaneously. 2 After intravenous administration, plasma concentrations were much higher in the patient group such that the total plasma clearance was reduced from a mean of 1258 ml/min in normals to 616 ml/min in the patient group (P less than 0.0025). The apparent volume of distribution nearly doubled (6.76 v 12.05 l/kg, P less than 0.025) and the terminal half-life was prolonged four fold (3.7 v 14.2 h, P less than 0.001). 3 Given orally, the peak plasma concentration was higher and occurred earlier in the liver cirrhotic patients. The absolute bioavailability more than doubled (22.0% normals v 52.3% liver cirrhotics, P less than 0.001) and apparent oral clearance was reduced to only 20% of normal (6.38 v 1.30 l/min, P less than 0.001). 4 The delta P-R interval in the patient group lagged behind the plasma concentration, in contrast to normal subjects. The maximum effect was much greater in the patients (15.4 v 41.6% increase, P less than 0.005) and persisted for a longer period of time. The slope of the plasma concentration-response curve was the same as in normals after intravenous administration. Plasma protein binding remained unchanged. 5 It is recommended that in liver cirrhotic patients the intravenous dose of verapamil be halved and the oral dose decreased by a factor of five in order to prevent untoward effects. As well as a steady-state plasma concentration will not be reached until approximately 2 days after the beginning of therapy.

Adult↗
PubMed1981

[Survival rates in lymphogranulomatosis related to different methods of primary treatment (author's transl)].

Between 1950 and 1979, 544 patients with Lymphogranulomatosis were treated in the Central Institute of Radiology in Karl-Marx-Stadt. In regard to the practice of the ray-therapy 4 groups can be compared. The survival rates rise demonstrably with the radicalism of the treatment. Using the present method--irradiation by telecobalt about 40 Gy for all the participated regions inclusive of the clinically negative neighbouring lymph node stations--a 5 years survival of 66.7 percent is found. The partly retrospective staging by the Ann Arbor classification is availably only in a qualified sense; in this way the importance of a careful diagnosis and its share in improving the results is emphasized. For interpreting the relatively favourable results in combination of radiologica treatment with chemotherapy in cases with a doubtful prognosis is referred to.

Dose-Response Relationship, Radiation↗
PubMed1980

[The scintigraphic features of cirrhosis of the liver (author's transl)].

A retrospective study of 101 patients with histologically confirmed cirrhosis of the liver and portal hypertension was carried out in order to evaluate the accepted scintigraphic criteria. In only 20% were all the essential criteria present. The absence of generally accepted important scintigraphic signs does not exclude the diagnosis of cirrhosis of the liver. Specificity of liver scintigraphy in cirrhosis of the liver is fairly low, but sensitivity of the method is almost 100%.

Colloids↗
PubMed1980

Scanning electron microscopic study of oral leukoplakia.

Biopsy specimens of buccal mucosa from six oral leukoplakia patients and one specimen of normal buccal mucosa were studied by scanning electron microscopy. The results showed: (1) There was a difference between the surfaces of normal and leukoplakic epithelial cells. (2) The appearance varied with the clinical type of leukoplakia: in leukoplakia verrucosa, epithelial cells appeared keratinized; in leukoplakia erosiva, epithelial cells were dissociated. (3) Histologically, dysplastic erosive leukoplakia was characterized by an atypical arrangement of superficial cytoplasmic projections of epithelial cells.

Adult↗
PubMed1980

Ultrastructure of different clinical forms of oral leukoplakia.

Twelve cases of oral leukoplakia were studied at the light and electron microscopic levels. In clinical leukoplakia simplex and verrucosa, both light and electron microscopic investigations revealed evidence of increased keratinization. Clinically erosive and histiologically dysplastic leukoplakias showed ultrastructural alterations characteristic of oral carcinomas in some instances.

Adult↗
PubMed1980

[Cirrhosis of the liver and esophageal bleeding after chronic vitamin A intoxication (author's transl)].

A female patient with congenital ichthyosis took vitamin A in an uncontrolled manner throughout 3 years totalling 60 Mill. IU. This lead to cirrhosis of the liver confirmed histologically after biopsy; vitamin A could be demonstrated in tissue of liver and spleen by fluorescence microscopy. Bleeding from esophageal varices could not be stopped by conventional means, but only by sclerosing the esophageal mucosa in the areas affected. A relapse of bleeding from varices of the fornix was stopped by disconnection according to Hassab-Paquet. The patient died from hepatic failure in advanced hepatic cirrhosis. A long time treatment with high doses of vitamin A seems to be a doubtful therapeutic procedure, especially in view of the fact, that side effects of this therapy cannot be monitored by laboratory measurements; when a disturbed liver function becomes evident, irreversible damage, e.g. cirrhosis or fibrosis and portal hypertension, is already present.

Adult↗