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Biomedical subjects

M Molls

Publications and source records attributed to M Molls.

At least 109 records · Page 6Linked to original sources
PubMed1990

Clinical results and the Essen concept of TBI.

Total body irradiation (TBI) prior to bone marrow transplantation (BMT) is applied for treatment of 230 patients in the period 1975-1988. The clinical results of 169 patients treated by four different TBI dosage and treatment techniques are analysed. The risk of leukemic relapse is low after fractionated TBI (9%) as well as after single dose TBI (14%). The lowest frequency of interstitial pneumonitis (21%) occurred when the patient translation technique was used for fractionated homogeneous pa/ap TBI with 10 Gy (8 Gy lung dose) in 4 fractions in 4 days. Prophylaxis of GVHD and the modus of protective environment were two other factors which influence the risk of IP.

Adult↗
PubMed1990

Radiation response in 10 high-grade human soft tissue sarcoma xenografts to photons and fast neutrons.

From a panel of 48 human soft tissue sarcomas growing as permanent xenografts, 10 tumor lines (five leiomyosarcomas, three malignant fibrous histiocytomas, two neurofibrosarcomas) have been selected to determine the radiation response to photons and fast neutrons. Using the specific growth delay (SGD) as an end-point, considerable variability of inherent radiosensitivity was observed. Isoeffective radiation doses varied by a factor of 27 for photons and of 9.4 for neutrons at a specific growth delay level of 0.5. The heterogeneity of the relative biological effectiveness (RBE) at this specific growth delay-level differed by a factor of 8. Relative biological effectiveness values for clamped tumors exceeded those of the normal tissues (RBE approximately 3) in 6 out of 10 tumor lines. Assuming a ratio of 0.5 for oxygen enhancement ratio-values of neutrons and photons, a therapeutic gain for neutrons existed in 4 out of 10 tumor lines under oxic conditions. No correlation between volume doubling times and relative biological effectiveness was seen.

Animals↗
PubMed1988

[Breast carcinoma in men: radiotherapy and treatment results].

The treatment of 34 men with stage T1 N0 M0 to T3/4 N1 M0 mammary carcinomas was followed by a five-year survival rate of 70%. Three patients suffering from initial remote metastases died after 2 to 3.5 years. The probability of a five-year survival decreases with increasing tumor growth and axillary involvement. The prognostic effect of receptor state and grading could not be investigated in our patients. Our own data as well as recent data from literature suggest that, with respect to TNM stages in mammary carcinoma, there is no prognostic difference between men and women. It is not very clear at present if postoperative irradiation exerts a favorable influence on the survival rate. However, it reduces the local recurrence risk for men and women. 45 Gy in five weeks should be considered as a minimum dose. The indications for postoperative irradiation are discussed.

Adenocarcinoma↗
PubMed1988

[Computed tomography guided positioning of catheters for temperature measurement in hyperthermia of malignant tumors].

Prior to a combined treatment with ionizing radiation and hyperthermia, 38 patients with superficial, semi-deep, and deep tumors received catheters for temperature measuring probes which were introduced under CT control. After having established a localization diagnosis and determined the angle for the puncture as well as the length of the puncture canal, a puncture needle containing a closed teflon catheter was introduced subsequent to local anaesthesia and puncture incision of the skin. None of the patients needed a general analgetic and sedative treatment. 10% of the patients presented a dislocation making necessary a reimplantation. Local infections at the catheter insertion point were observed in three cases, a phlegmonous inflammation was seen only in one patient who had undergone an immunosuppression by means of cytostatic drugs. In one patient a temporary bleeding led to a slight haemoglobin reduction which, however, did not require further therapeutic measures. The insertion of catheters for intratumoral temperature measurement was well tolerated by the patients. It could be performed in out-patients with good general condition and no further risk factors.

Adolescent↗
PubMed1988

[Radiation and hyperthermia in the treatment of superficial and semi-deep tumors: heat profile, heat doses, tumor remission].

Between August, 1986 and October, 1987, 364 hyperthermia treatments combined with radiotherapy were performed in mostly locally advanced and recurrent tumors. Half of the patients could only be exposed to relatively small radiation doses of 20 to 36 Gy. The therapy results of 24 patients with 26 treated tumor sites showed complete remission in 22% and partial remission in 42% of the sites. The dependence of tumor remission on the dose of radiation and heat and the inhomogeneity of the temperature distribution are discussed.

Breast Neoplasms↗
PubMed1988

[Results of whole lung irradiation and chemotherapy in comparison with partial lung irradiation in metastasizing, undifferentiated soft tissue sarcomas].

The poor prognosis of patients with unresectable pulmonary metastases of soft tissue sarcoma is well known. In order to evaluate the beneficial effect of radiotherapy, we have treated 44 patients with pulmonary metastases of grade 3 soft tissue sarcoma from 1980 to 1986. In 36 patients the treatment volume was restricted to the single metastases up to a dose of 50 to 60 (9 to 10 Gy/week). The survival rate at one year was 18% and at two years 6%. Eight patients were treated with a combined regimen, consisting of cisplatin and ifosfamide with simultaneous whole lung irradiation. Irradiation was performed with 8 or 16 MV photons at a hyperfractionation of 2 x 0.8 Gy/day (8 Gy/week). After a dose of 12 Gy, the single metastases were boosted up to 50 to 60 Gy, with a second course of chemotherapy. In six of eight patients complete remissions were achieved, one patient showed a partial remission. The survival rate at 27 months was 50%. The patients with partial remission died from pulmonary progression at 23 months. One patient died after twelve months from a loco-regional recurrence in the tonsillar fossa without evidence of pulmonary disease. Side effects included alopecia and moderate bone marrow suppression approximately twelve days after each chemotherapy cycle. Pulmonary fibrosis was observed only at the high dose volume without impairment of respiratory function. From these observations the conclusion is drawn that whole lung irradiation simultaneously with cisplatin and ifosfamide chemotherapy provides good palliative results without relevant morbidity in patients with high grade unresectable pulmonary metastases of soft tissue sarcomas.

Adult↗
PubMed1987

Radiotoxicities of [3H]thymidine and of [3H]arginine compared in mouse embryos in vitro.

Tritium that is bound to organic molecules is of special risk for living systems, in particular when such molecules are components of the cell nucleus. Therefore, [3H]thymidine and [3H]arginine were studied for radiotoxicity in early mammalian embryo development. Starting with the two-cell stage, mouse embryos were incubated in vitro with [3H]thymidine or [3H]arginine at either 370 Bq/ml (10 nCi/ml) or 925 Bq/ml (25 nCi/ml). Development in vitro was followed up to the formation of the inner cell mass at 192 h postconception (p.c.). There was no difference in radiotoxicity of the two substances with respect to cell proliferation; however, formation of blastocysts, hatching of blastocysts, trophoblast outgrowth, and formation of inner cell mass were impaired more strongly by [3H]arginine than by [3H]thymidine when the external exposure concentrations were the same. Similarly, micronuclei were seen in blastocysts at 96 h p.c. at higher frequency after incubation with [3H]arginine. However, uptake of [3H]arginine by the embryos was considerably faster than that of [3H]thymidine, and this most probably accounts for the apparent difference in radiotoxicity.

Animals↗
PubMed1986

The incidence of interstitial pneumonitis: comparison of total body irradiation schedules for allogenic bone marrow transplantation.

Interstitial pneumonitis (IP) is one of the major causes of death following bone marrow transplantation (BMT). This report deals with a comparison between data compiled from six centers concerning the essential factors responsible for the development of IP. Special concern has been paid to the idiopathic form of disease where TBI is thought to be the most important factor in its pathogenesis. Our own experience using different TBI modalities shows that the instantaneous dose rate seems to be an important factor in the development of IIP. Comparing the data from various centers it is not possible at the present time to recommend one optimal modality.

Bone Marrow Transplantation↗
PubMed1986

Total body irradiation: the lung as critical organ.

The pathogenesis of interstitial pneumonitis (IP) after chemoradiotherapy and subsequent bone marrow transplantation is not completely understood. Total body irradiation (TBI) with a dose of about 10 Gy significantly contributes to this very serious complication. The radiation induced morphological alterations especially of the crucial targets, namely the pneumocytes type II and capillaries are described. Investigations in animals and in humans reveal that pneumonitis occurs over a very short range of doses. In humans a single dose of 9.3 Gy given at a high dose rate leads to an incidence of 50%. Reduction of the dose by shielding the lungs, fractionation of irradiation and decreasing the dose rate are considered to be the main possibilities which diminish the risk of pneumonitis after TBI. The role of further factors involved in the development of IP such as cytomegalovirus, age, reduced lung volume, immunological mechanisms and others is discussed. Especially chemotherapeutic agents may increase lung morbidity by interacting with TBI.

Animals↗
PubMed1985

Estimation of absorbed dose in cell nuclei due to DNA-bound 3H.

The average absorbed dose due to DNA-bound 3H in a cell nucleus was estimated by a Monte Carlo simulation for a model nucleus which was assumed to be spheroidal. The shape of the cell nucleus was found to be of minor importance in determining the average absorbed dose. The volume of the cell nucleus was the major dose-determining factor for cell nuclei which have the same DNA content and the same specific activity of DNA. This result was applied to estimating the accumulated dose in the cell nuclei of organs of young mice born from mother mice which ingested 3H-thymidine with drinking water during pregnancy. The values of dose-modifying factors for the accumulated dose due to DNA-bound 3H compared to the dose due to an assumed homogenous distribution of 3H in organ were found to be between about 2 and 6 for the various organs.

Animals↗
PubMed1984

The influence of G2 progression on X-ray sensitivity of two-cell mouse embryos.

Naturally synchronous, two-cell mouse embryos were X-irradiated in vitro. In experiment 1, irradiation was either in the early or in the late G2 phase, which lasts about 14 hours. In experiment 2, irradiation of all the embryos was in late G2 but embryos with different intervals between irradiation and the first mitosis after irradiation were separated and investigated independently. After 2 Gy the time interval between irradiation in late G2 and the first mitosis post-irradiation was on the average about 9 hours; after irradiation in the early G2 phase about 13.5 hours. Development (hatching of blastocysts) and cell proliferation (cell number per embryo at the stage of the hatched blastocyst) was most impaired and the frequency of micronuclei (determined in four- or eight-cell embryos) was highest in the case of a short interval between irradiation in G2 and the first mitosis post-irradiation. It is concluded that a longer interval allows a longer period of DNA repair. The results also demonstrate a positive correlation between the extent of chromosomal damage (micronuclei) and the extent of cell death as well as the impairment of the development of the whole biological system.

Animals↗