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D Arndt

Publications and source records attributed to D Arndt.

At least 55 records · Page 3Linked to original sources
PubMed1985

[Liposomes from hydrogenated egg yolk lecithin].

Egg yolk lecithin is a lipid, frequently been used for the liposome preparation. Such liposomes, however, are sensitive to oxidation and relatively permeable to encapsulated substances. The catalytic hydrogenation of egg yolk lecithin is one possibility to modify the properties mentioned. The authors deal with preparation and characterization of hydrogenated egg yolk lecithin. Liposomes from native and hydrogenated egg yolk lecithin--also in combination with cholesterol--are compared. Liposomes with hydrogenated egg yolk lecithin as phospholipid component exhibit a significantly increased encapsulation capacity and an essentially improved stability. The permeation of electrolytes, carboxyfluorescein and of the cytostatic drug daunorubicin is studied.

Animals↗
PubMed1984

Cardiotoxicity of free and liposomally encapsulated rubomycin (daunorubicin) in mice.

Different serum enzyme levels (creatine kinase, CK; lactate dehydrogenase, LDH; alanine amino-transferase, ALAT; aspartate aminotransferase, ASAT) were determined after treatment of mice with rubomycin in free or liposomally encapsulated form. Especially increase in CK activity, measure for cardiac toxicity, was significantly altered in animals that were treated with rubomycin-containing liposomes. Organ distribution studies showed a significantly lower uptake of encapsulated drug in heart tissues. Electron microscopic studies confirmed these results by indicating only small anthracycline-induced cardiac lesions using the liposomal form.

Alanine Transaminase↗
PubMed1984

[Significance of radiotherapy for the treatment of primary bone and soft tissue sarcomas].

Recent data from the literature as well as our own treatment results of soft tissue sarcomas and primary bone tumours with the exception of osteosarcomas indicate, that: 1. A conservative, limb sparing therapy should be attempted in peripheral bone tumours and soft tissue sarcomas. This may be achieved in 85% to 97%. 2. The recurrence rate is in a range of 3% to 22%, which does not exceed the results of ablative surgery. 80% of possible recurrences can be controlled by consecutive surgery. 3. After the development of improved treatment techniques, the complication rate is less than 10%. 4. Conservative limb sparing treatment does not decrease the survival rate. However, these results are not derived from randomised studies. 5. Apart from osteosarcomas and Ewing sarcomas adjuvant chemotherapy is recommended for G3 tumours. The time interval for evidence of metastases may be doubled by this treatment modality. 6. There is some evidence that neutron-boost therapy may improve local control rates in T2 and T3 soft tissue sarcomas.

Bone Neoplasms↗
PubMed1984

[Radiotherapy and combined modality treatment of advanced gastrointestinal tumors. Analysis of morbidity in 101 patients].

Despite numerous reports about combined therapy of gastrointestinal tumours no detailed analysis of considerably manifold side effect has been established. In this study the therapeutic results and morbidity of irradiation in 64 patients are compared with 37 courses of combined therapy for recurrences and/or metastases. Modalities in combined therapy consisted of radiotherapy and hyperthermia or chemotherapy, or chemotherapy and hyperthermia respectively. Toxicity from combined therapy was seen more frequently and pronounced, requiring variations in therapy management up to 54% versus 17% in patients irradiated. Dose reductions (15% vs. 8%), intervals (30% vs. 14%) and its duration (14 vs. 6 days) extended the overall treatment times. In 21% combined therapy was interrupted totally (vs. 11% mainly caused by non therapy specific other diseases, respectively rapid tumour progression) or in another 13% continued sequentially. No improved results were seen following combined therapy, but an intolerably high risk of serious complications (up to 71% in combination of radio- and chemotherapy). With the dosages, fractionations and techniques used combined therapy can be performed only in a sequential course for palliation of advanced gastrointestinal tumours. We assume that morbidity of hyperthermia in most cases is considerably higher than its therapeutic gain.

Aged↗
PubMed1983

[Is radiotherapy indicated in cases of metastatic brain tumors? A retrospective analysis of 35 cases].

The results of 35 patients who got whole brain irradiation for metastatic disease are analysed in terms of relief of symptoms, quality of remission and survival time. Patients are distinguished in a group with known and in a group with unknown primary tumor. The results of the first group are indicated in brackets. The mean survival time for patients with unknown primary tumor is 7,5(4,2) and the median survival time is 3(2,2) months. 12 months after radiotherapy, 25% (9%) of the patients are still alive. More than 75% (55%) show considerable relief of symptoms. The proportion of failures is approximately 20% for both groups. These results indicate that radiotherapy of brain metastases gives good palliation even for patients with unknown primary tumor.

Adult↗
PubMed1983

[Preparation, properties and therapeutic effect of Daunorubicin-containing liposomes].

Preparation and analytic characterization of uni- and multilamellar lipid vesicles with different lipid composition, charge and size, containing Daunorubicin are described. A critical review is given for the methods of preparation of lipids and other amphiphilic compounds. Variations of the lipid composition, charge and size of the liposomes do not alter the therapeutic effectiveness.

Animals↗
PubMed1983

[Alternative contrasexual hormone treatment following fibrosing breast irradiation in prostatic carcinoma. Retrospective analysis of 123 patients].

Symptoms and objective parameters of gynecomastia are analysed in 113 patients, who received prophylactic irradiation of the breast (12 Gy in 3 fractions) prior to estrogen therapy of prostatic carcinoma. Another 10 patients were treated equally after estrogens had caused severe complaints. Symptoms increased from 10% to 100% in relation to 4 classes of gynecomastia. They were mild in 27.5%, moderate in 23.9% and severe in 8.8%. A correlation between metric classification and graded symptoms became more evident when only 2 groups were distinguished. With a maximum diameter of 3.5 cm only 17% of the patients had mostly slight discomfort in contrast to 70% of the patients with a gland of more than 3.5 cm in diameter; they revealed moderate or serious complaints. These results indicate that prophylactic radiotherapy may reduce severe complications to less than 10% as compared to 70-80% without irradiation. If gynecomastia has developed, regression by subsequent radiotherapy seems to be impossible; but the intensity of complaints could be reduced in our ten patients. Provided that irradiation precedes estrogen application, this sequence may be considered as a reasonable alternative to expensive antiandrogen therapy.

Breast↗
PubMed1983

[Analysis of morbidity from simultaneous 5-fluorouracil therapy and radiation therapy in advanced gastrointestinal tumors. Report of results].

Simultaneous application of 5-fluorouracil and radiotherapy is generally accepted in the treatment of gastrointestinal tumours. However, in 10 patients with metastatic gastrointestinal tumours we observed intolerable toxicity during this combined treatment regimen. Because of gastrointestinal and haematological toxicity the combined modality was interrupted in all patients. Given sequentially, this regimen was tolerated. Our experience indicates that an intolerable high rate of toxicity has to be taken into consideration in case of the simultaneous combination of 5-fluorouracil and radiotherapy.

Colonic Neoplasms↗
PubMed1982

[Cisplatin as a radiosensitizer in the treatment of solid tumours--a clinical pilot study].

A variety of experimental tumour models have shown that cisplatin in combination with ionizing radiation enhances tumour regression. To evaluate the feasibility, efficacy and toxicity of a combined regimen, 25 patients with different solid tumours were treated with cisplatin and photon irradiation. A local tumour control was achieved in 22 cases. Thirteen patients with squamous cell carcinoma of the lung (T1-3, N1-2, M0) received cisplatin (20 mg/m2 per day) on 5 consecutive days with NaCl hyperhydratation (0,9% NaCl, 2400 ml/24 hours as continuous infusion) in the first and last week of radiotherapy (5 X 2 Gy/week, 56 Gy target volume dose). 12 of 13 patients have shown local tumour control. Increased clinically evident side effects were not observed. From the underlying data the conclusion is drawn that the experimental results are reproducable under clinical conditions and that improved local tumour response rates can be achieved.

Adult↗
PubMed1981

Therapeutic evaluation of liposome-encapsulated Daunoblastin in murine tumor models.

Daunoblastin in free and liposome-encapsulated form was tested in the L1210 murine leukemia and the intramuscularly transplanted 276A sarcoma. Both therapeutic (% ILS, tumor volume inhibition) and toxicologic (leukocytes, body weight difference) parameters were evaluated. The liposome preparations showed similar therapeutic effects as the free substance but caused a lower toxicity with a lower mortality rate, higher leukocyte values and smaller body weight reduction. Longer sonication time with the output of more smaller unilamellar vesicles had no influence on the parameters in the solid model, but resulted in shorter ILS values in the L1210 model. Administration of empty liposomes immediately before liposomal Daunoblastin did not result in better antineoplastic activity but yielded higher leukocyte values.

Animals↗
PubMed1978

[An evaluation of the risks of pulmonary scintigraphy (author's transl)].

Scintipulmography is a method for testing cardiopulmonary function in diagnosis and control. Standardized X-ray examinations are preferable from a radio-hygienic view. In perfusion scintigraphy microspheres are better for examining terminal vessels and are of lower risk. Short-lived radionuclides, e.g., 99mTc or 113mIn, should be used as markers. Recent physiologic findings indicate injection by bolus during the middle phase of inspiration while the patient holds his breath. General and individual risks and the diagnostic advantages of this method are discussed. Normally, the advantages outweigh the risks, as demonstrated in a case of artificial pulmonary embolism. For high-risk patients, however, inhalation scintigraphy should be made available as a standard radiologic method.

Humans↗
PubMed1978

Experiments to increase the selectivity of tumor chemotherapy by means of in vivo activation of transport forms of cancerostatics by exogenous enzymes.

A significant tumor damaging effect (growth inhibition) on transplanted syngeneic sarcoma in mouse was obtained by means of pH-dependent activation of a transport form of a cancerostatic drug by an enzyme foreign to the organism. This effect was achieved by combined administration of 8-0-(alpha-L-arabinofuranosyl)beta-peltatin-A as a transport form of beta-peltatin-A and the exogenous enzyme alpha-L-arabinofuranosidase from Aspergillus niger and additional increase of the acidity of the tumor by injection of glucose. The combined application of the transport form plus enzyme showed a more favorable effect on selectivity than free peltatin when a quantitative comparison was made between the tumor growth inhibition and the damage to the blood picture.

Animals↗
PubMed1978

[Suspension cultures of human malignant lymphoma in the leukocyte migration test].

The effects of supernatants of primary and secondary malignant human lymphoma cell cultures were analyzed as parameters of spontaneous secretion of factors by these cells using the leukocyte migration test (LMT). Spontaneous cultivation for up to five weeks was successful in four cases. The postulated production of mediators, i.e. the inhibitory and stimulating effects on leukocyte migration were characterized by testing the influence of (a) concentration, (b) temperature and (c) absorption with normal blood leukocytes on the effect. Reproducible stimulatory and inhibitory effects on the migration of normal leukocytes were dependent on concentration and temperature and were apparently mediated by one or more factors. The supernatants of a lymphoblastic lymphosarcoma of the T-cell type and of a lymphoblastic lymphosarcoma clearly revealed congruous and reproducible inhibitory effects. A further case of lymphoblastic lymphosarcoma that could not exactly be defined with immunological methods either and a case of centroblastic/centrocytic lymphosarcoma exhibited stimulating effects which could be reduced in a time-dependent manner through preincubation with blood leukocytes. The results of these studies support the assumption that malignant lymphoma cells are capable not only of secreting immunoglobulin, but also of other biologically effective secretion. The effects of such secretion are differentiated into stimulating and inhibitory ones. They might be important for the spreading of a tumor or for resistance of the organism to the disease.

Cell Migration Inhibition↗
PubMed1978

[Tissue extracts of malignant human lymphomas in the leukocyte migration test].

Water-soluble lymph node extracts and sera from 23 patients with benign and malignant lymphomas and tissue extracts from liver, spleen, kidney, and muscle of one patient without any lymphatic disease were analyzed using the direct leukocyte migration test (LMT). The leukocytes were obtained from healthy persons. 10 of the lymphomas and 3 of the tissue extracts varied the leukocyte migration. In most cases of chronic nonspecific lymphadenitis, in 2 cases of Hodgkin's disease, and in extracts of liver, spleen and muscle inhibitory effects were found. Stimulating effects could be demonstrated in 2 cases of immunocytoma and in 4 cases of Hodgkin's disease. The results indicate that in cases of stimulation the target cells might be influenced by a pathological migration inhibitory factor.

Cell Migration Inhibition↗