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1.
J Radiol Prot ; 42(2)2022 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-35263727

RESUMEN

The threat caused by ionising radiation has resulted in the establishment of strict radiation protection guidelines. This is especially true for severe nuclear power plant (NPP) accident scenarios, which may involve the release of significant amounts of ionising radiation. However, we believe that the fine balance between the benefit of a certain protective action (e.g. evacuation) and its risks is not always accounted for properly. Deaths and mental health problems have been associated with protective actions (e.g. evacuation) implemented in the response to the Fukushima Daiichi (NPP) accident in 2011. The protective actions were implemented consistent with international recommendations, to reduce radiation-induced health effects, even though the off-site effective doses were too low to indicate that there would be any discernible radiation-induced health effects. In this paper, we will provide a first step for the development of tools to evaluate the risk of protective actions versus the radiation-induced health risk. Over 50 papers were selected as useful from more than 600 reviewed papers to characterise the health impact of protective actions taken during different emergencies (including, technical and natural emergencies). An analysis was performed comparing the radiation-induced health effects averted by protective actions with the health effects associated with the protective actions. We concentrated our analysis on deaths and mental health problems associated with protective actions compared with the inferred radiation-induced deaths averted by the protective actions. Our analysis is stated in terms of absolute risk (cases per 1000) of health effects to allow for a direct comparison. It indicates that taking protective actions consistent with dose criteria typically used in many countries could result in more excess deaths than the inferred radiation-induced deaths prevented, as well as resulting in mental health problems. We identified that residents of facilities for long stays and the elderly are particularly vulnerable and a significant number of the deaths among the general public are associated with a lack of emergency preparedness provisions.


Asunto(s)
Accidente Nuclear de Fukushima , Traumatismos por Radiación , Protección Radiológica , Anciano , Urgencias Médicas , Humanos , Japón , Plantas de Energía Nuclear , Dosis de Radiación , Traumatismos por Radiación/etiología , Traumatismos por Radiación/prevención & control , Protección Radiológica/métodos
2.
Proc Natl Acad Sci U S A ; 116(34): 16750-16759, 2019 08 20.
Artículo en Inglés | MEDLINE | ID: mdl-31350352

RESUMEN

In October 2017, most European countries reported unique atmospheric detections of aerosol-bound radioruthenium (106Ru). The range of concentrations varied from some tenths of µBq·m-3 to more than 150 mBq·m-3 The widespread detection at such considerable (yet innocuous) levels suggested a considerable release. To compare activity reports of airborne 106Ru with different sampling periods, concentrations were reconstructed based on the most probable plume presence duration at each location. Based on airborne concentration spreading and chemical considerations, it is possible to assume that the release occurred in the Southern Urals region (Russian Federation). The 106Ru age was estimated to be about 2 years. It exhibited highly soluble and less soluble fractions in aqueous media, high radiopurity (lack of concomitant radionuclides), and volatility between 700 and 1,000 °C, thus suggesting a release at an advanced stage in the reprocessing of nuclear fuel. The amount and isotopic characteristics of the radioruthenium release may indicate a context with the production of a large 144Ce source for a neutrino experiment.

3.
Environ Sci Technol ; 52(15): 8488-8500, 2018 08 07.
Artículo en Inglés | MEDLINE | ID: mdl-29979581

RESUMEN

Traces of particulate radioactive iodine (131I) were detected in the European atmosphere in January/February 2017. Concentrations of this nuclear fission product were very low, ranging 0.1 to 10 µBq m-3 except at one location in western Russia where they reached up to several mBq m-3. Detections have been reported continuously over an 8-week period by about 30 monitoring stations. We examine possible emission source apportionments and rank them considering their expected contribution in terms of orders of magnitude from typical routine releases: radiopharmaceutical production units > sewage sludge incinerators > nuclear power plants > spontaneous fission of uranium in soil. Inverse modeling simulations indicate that the widespread detections of 131I resulted from the combination of multiple source releases. Among them, those from radiopharmaceutical production units remain the most likely. One of them is located in Western Russia and its estimated source term complies with authorized limits. Other existing sources related to 131I use (medical purposes or sewage sludge incineration) can explain detections on a rather local scale. As an enhancing factor, the prevailing wintertime meteorological situations marked by strong temperature inversions led to poor dispersion conditions that resulted in higher concentrations exceeding usual detection limits in use within the informal Ring of Five (Ro5) monitoring network.


Asunto(s)
Contaminantes Radiactivos del Aire , Neoplasias de la Tiroides , Europa (Continente) , Humanos , Radioisótopos de Yodo , Federación de Rusia
4.
Phys Rev Lett ; 107(6): 060502, 2011 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-21902306

RESUMEN

We report strong coupling between an ensemble of nitrogen-vacancy center electron spins in diamond and a superconducting microwave coplanar waveguide resonator. The characteristic scaling of the collective coupling strength with the square root of the number of emitters is observed directly. Additionally, we measure hyperfine coupling to (13)C nuclear spins, which is a first step towards a nuclear ensemble quantum memory. Using the dispersive shift of the cavity resonance frequency, we measure the relaxation time of the NV center at millikelvin temperatures in a nondestructive way.

5.
Scand J Immunol ; 73(6): 508-11, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21352257

RESUMEN

Plasma cells sustain antibody production and hence are an essential part of immune protection. In the mucosa-associated lymphoid tissues plasma cells secrete IgA antibodies which protect the organism from invasion by pathogenic bacteria while in the bone marrow they produce the antibodies which guarantee long-term humoral immune protection. The various lymphoid organs provide specific microenvironments which support plasma cell survival. In particular, in the bone marrow, highly specialized survival niches are established by the underlying stromal reticular cells which permit plasma cells to survive for years. In some situations, however, the antibody may be detrimental to the organism. In those auto immune diseases, where plasma cells play a pathological role by producing the auto antibodies, new strategies are needed to interfere with the lifespan of plasma cells and thus to diminish their numbers. The recent finding that eosinophils are essential for the long-term survival of plasma cells in the bone marrow provides a new therapeutic target to modulate the plasma cell survival niche.


Asunto(s)
Supervivencia Celular/inmunología , Tejido Linfoide/citología , Células Plasmáticas/citología , Animales , Formación de Anticuerpos/inmunología , Humanos , Tejido Linfoide/inmunología , Células Plasmáticas/inmunología
6.
Gesundheitswesen ; 68(8-9): 535-44, 2006.
Artículo en Alemán | MEDLINE | ID: mdl-17039432

RESUMEN

PURPOSE: In autumn 2004 the local association of physicians (Arztlicher Kreis- und Bezirksverband München) performed a survey among employed physicians in Munich on working hours and working conditions. The aim of the study was to assess the extent to which the German law on working hours is actually implemented in employed physicians, and to obtain information about their work satisfaction. METHODS: A questionnaire was sent to all employed physicians in hospitals and medical practices. Participants were asked to give anonymous information and send it back per mail. RESULTS: In total, 2450 out of 5461 physicians took part in the survey. 45% reported that their working hours do not meet the German law on working hours of 1994. 44.4% stated that overtime is not fully recognized by their employers. 43.5% think the job would become more attractive if the law was implemented. 63.3% expect an income loss with the implementation. 53.7% are thinking about quitting their job. For 59.9% the burden of long working hours is an important reason for this. Women are more likely to be given a limited employment contract than men, and their overtime is more rarely recognized in full. CONCLUSION: Many employed physicians in Munich are dissatisfied with their job. The high burden of long working hours is a main reason for this.


Asunto(s)
Actitud del Personal de Salud , Satisfacción en el Trabajo , Cuerpo Médico de Hospitales , Médicos , Carga de Trabajo/legislación & jurisprudencia , Adulto , Recolección de Datos , Empleo , Femenino , Alemania , Humanos , Masculino , Cuerpo Médico de Hospitales/legislación & jurisprudencia , Persona de Mediana Edad , Médicos/legislación & jurisprudencia , Factores Sexuales , Sociedades Médicas , Encuestas y Cuestionarios , Factores de Tiempo , Tolerancia al Trabajo Programado
7.
Nervenarzt ; 76(12): 1524-6, 2005 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-15856151

RESUMEN

Exophiala species belong to the dematiaceous fungi. Occurring worldwide, they are a rare cause of human infection. We present the case of a 75-year-old immunocompetent patient with a cardiogenic embolic anterior cerebral artery infarction. Echocardiography revealed endocarditis of the aortic valve. Antibiotic therapy was initiated after susceptibility testing (blood cultures were positive for Staphylococcus aureus, and liquor was normal), with a subsequent fall in serologic markers of infection and resolution of the signs of endocarditis on echocardiography. However, 6 weeks after initiation of antibiotic therapy, abscesses were seen in the infarct region on CT scan, although antimicrobial treatment was still continued. At this stage, the CSF showed an inflammatory process, and Exophiala species, susceptible to voriconazol, could be detected in liquor cultures. However, antifungal therapy with voriconazol could not prevent severe sepsis and death from multiorgan failure. Autopsy revealed the clinically supposed Exophiala endocarditis with metastatic cerebral abscesses. In accordance with other published case reports, a fatal outcome in disseminated Exophiala infection might only be prevented by aggressive therapy consisting of early surgical removal of the foci and combined antifungal agents.


Asunto(s)
Absceso Encefálico/diagnóstico , Absceso Encefálico/etiología , Endocarditis/diagnóstico , Endocarditis/etiología , Exophiala/aislamiento & purificación , Micosis/complicaciones , Micosis/diagnóstico , Anciano , Humanos , Masculino , Enfermedades Raras/complicaciones , Enfermedades Raras/diagnóstico
9.
J Immunol ; 162(5): 3053-62, 1999 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-10072558

RESUMEN

Plasma cells are found surrounding the inflammatory infiltrates of macrophages, T, and B cells in the synovial tissue of patients with rheumatoid and reactive arthritis. This characteristic arrangement suggests that in the synovial tissue CD20+ B cells differentiate into plasma cells. To examine clonal relationships, we have used micromanipulation to separately isolate CD20+ B cells and plasma cells from single infiltrates. DNA was extracted, and from both populations the VH/VL gene repertoires was determined. The data show that in the inflamed synovial tissue activated B cells are clonally expanded. During proliferation in the network of follicular dendritic cells, V gene variants are generated by the hypermutation mechanism. Surprisingly, we do not find identical rearrangements between CD20+ B cells and plasma cells. Nevertheless, the finding of clonally related plasma cells within single infiltrates suggests that these cells underwent terminal differentiation in the synovial tissue. These results indicate that B cell differentiation in the synovial tissue is a dynamic process. Whereas CD20+ B cells may turnover rapidly, plasma cells may well be long lived and thus accumulate in the synovial tissue. The analysis of individual B cells recovered from synovial tissue opens a new way to determine the specificity of those cells that take part in the local immune reaction. This will provide new insights into the pathogenesis of chronic inflammatory diseases like rheumatoid or reactive arthritis.


Asunto(s)
Artritis Reactiva/inmunología , Artritis Reumatoide/inmunología , Centro Germinal/fisiología , Células Plasmáticas/fisiología , Membrana Sinovial/inmunología , Adolescente , Adulto , Anciano , Antígenos CD20/análisis , Femenino , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/genética , Masculino , Persona de Mediana Edad
10.
J Clin Invest ; 102(5): 938-46, 1998 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-9727062

RESUMEN

Structures resembling germinal centers are seen in the salivary glands of patients with Sjögren's syndrome, but it is not known whether the microenvironment of these cell clusters is sufficient for the induction of a germinal center response. Therefore, we cloned and sequenced rearranged Ig V genes expressed by B cells isolated from sections of labial salivary gland biopsies from two Sjögren's syndrome patients. Rearranged V genes from B cells within one cell cluster were polyclonal and most had few somatic mutations. Two adjacent clusters from another patient each contained one dominant B cell clone expressing hypermutated V genes. None of the rearranged V genes was found in both clusters, suggesting that cells are unable to migrate out into the surrounding tissue and seed new clusters. The ratios of replacement to silent mutations in the framework and complementarity determining regions suggest antigen selection of high-affinity mutants. These results show that an antigen-driven, germinal center-type B cell response is taking place within the salivary glands of Sjögren's syndrome patients. In view of the recent demonstration of a germinal center response within the rheumatoid synovial membrane and the existence of similar structures in the target tissues of other autoimmune diseases, we propose that germinal center- type responses can be induced in the nonlymphoid target tissues of a variety of autoimmune diseases.


Asunto(s)
Antígenos/inmunología , Enfermedades Autoinmunes/inmunología , Linfocitos B/metabolismo , Glándulas Salivales/inmunología , Síndrome de Sjögren/inmunología , División Celular/inmunología , Células Clonales/inmunología , Clonación Molecular , Centro Germinal/inmunología , Humanos , Región Variable de Inmunoglobulina/genética , Inmunohistoquímica , Glándulas Salivales/citología , Alineación de Secuencia , Análisis de Secuencia de ADN
12.
Eur J Immunol ; 24(10): 2393-400, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7925566

RESUMEN

In a T cell-dependent immune response the microenvironment of the germinal center plays a crucial role in the affinity maturation of the antigen-specific, immunoglobulins. In order to look at the development of antibody diversity we have isolated single germinal centers and sequenced light chains characteristic of 2-phenyl-oxazolone (phOx)-specific antibodies. Fourteen days after immunization we can demonstrate various stages of intraclonal diversity. There are germinal centers where B cells are practically unmutated, suggesting that in these cases a substantial clonal expansion has taken place prior to the activation of the hypermutation mechanism. In other germinal centers, sequences with a low number of randomly distributed somatic mutations were observed, indicating that these changes have been introduced recently and/or that they fail to generate high-affinity variants and hence provide no basis for affinity selection. Finally, germinal centers are found in which practically all sequences carry the amino acid substitutions characteristic of the high affinity phOx antibodies. In these latter cases the high-affinity variants have been preferentially expanded. We conclude that affinity selection is a process that operates right from the beginning of germinal center development. Those B cells with a relative high affinity for the antigen gain a proliferative advantage over other cells and will dominate the response and these are the cells which will be selected to differentiate into memory cells.


Asunto(s)
Diversidad de Anticuerpos , Linfocitos B/inmunología , Bazo/citología , Secuencia de Aminoácidos , Animales , Afinidad de Anticuerpos , Secuencia de Bases , Células Clonales , Cartilla de ADN/química , Reordenamiento Génico de Cadena Ligera de Linfocito B , Genes de Inmunoglobulinas , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , Mutación , Oxazolona/análogos & derivados , Oxazolona/inmunología , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Homología de Secuencia de Ácido Nucleico , Bazo/inmunología
13.
Wien Klin Wochenschr ; 105(6): 172-5, 1993.
Artículo en Alemán | MEDLINE | ID: mdl-8475629

RESUMEN

A pilot study was undertaken in Vorarlberg to determine the concentration of fluoride ions in drinking water. The results showed that 91.3% of the population was supplied by drinking water containing under 0.3 ppm fluoride and the remaining 8.7% by drinking water containing 0.3-0.6 ppm fluoride. Hence, the fluoride concentration was too low to prevent caries in all areas of Vorarlberg. Exogenous fluoridation of the drinking water or table salt in all districts of Vorarlberg is discussed. Measurements are planned for the whole of Austria, which may lead to a general recommendation for fluoridation of the water or salt nationwide.


Asunto(s)
Fluoruración , Adolescente , Adulto , Austria , Niño , Preescolar , Caries Dental/prevención & control , Humanos , Lactante , Proyectos Piloto
14.
Cancer Res ; 51(15): 3862-6, 1991 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-1855204

RESUMEN

We have previously reported on stimulation of clonal growth of cell lines from human solid tumors by recombinant human interleukin 3, recombinant human granulocyte-macrophage colony-stimulating factor, and recombinant human granulocyte colony-stimulating factor (W. E. Berdel et al., Blood, 73: 80-83, 1989; Exp. Hematol., 16: 510, 1988). Within an extensive screening program of hematopoietic growth factor activity on malignant cells, the effects of recombinant human interleukin 6 (rhIL-6) were tested on the growth (tritiated thymidine uptake and human tumor cloning assay) of 26 different human cell lines derived from a wide range of solid tumors (head and neck, 4; lung, 1; pancreatic, 1; gastric, 1; colorectal, 3; renal, 3; bladder, 1; prostate, 1; breast, 2; ovary, 2; choriocarcinoma, 1; sarcoma, 2; glioblastoma, 2; neuroblastoma, 2). rhIL-6 (dose range up to 10(4) IU/ml) caused no reproducible enhancement or inhibition of tritiated thymidine uptake by tumor cell lines from nonhematopoietic origin. Furthermore, 19 of the tumor cell lines were clonogenic in a capillary modification of the human tumor cloning assay. No reproducible stimulation of clonal growth by rhIL-6 was observed in any of the cells tested. Particularly, there was no sensitivity of those cell lines for rhIL-6, which were previously shown to be sensitive for recombinant human interleukin 3 and recombinant human granulocyte-macrophage colony-stimulating factor in this assay. On the other hand, there were no significant growth-inhibitory effects of rhIL-6 on the cell lines tested in this study. Further experiments showed no influence of neutralizing monoclonal anti-hIL-6 antibody on the growth of 3 kidney carcinoma cell lines, making autocrine growth-modulating loops for IL-6 in these lines unlikely. In conclusion, no major interactions between hIL-6 and the growth of the human malignant cell lines from nonhematopoietic origin tested were detected in this study.


Asunto(s)
Interleucina-6/farmacología , Neoplasias/tratamiento farmacológico , Anticuerpos/farmacología , Carcinoma de Células Renales/tratamiento farmacológico , Carcinoma de Células Renales/metabolismo , Carcinoma de Células Renales/patología , División Celular/efectos de los fármacos , Medios de Cultivo , Humanos , Interleucina-6/inmunología , Neoplasias Renales/tratamiento farmacológico , Neoplasias Renales/patología , Neoplasias/metabolismo , Neoplasias/patología , Timidina/metabolismo , Células Tumorales Cultivadas
15.
Cancer Res ; 51(1): 43-8, 1991 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-1988103

RESUMEN

Nine new platelet activating factor (PAF) antagonists from 4 different chemical classes (thiopyrimidines: SDZ 59-015; thioimidazolines: SDZ 61-813; imidazoisoquinolines: SDZ 62-434, SDZ 62-759, SDZ 63-135, SDZ 63-596; and imidazopiperidines: SDZ 61-638, SDZ 62-293, SDZ 62-694) have been tested for cytostatic/antiproliferative ([3H]thymidine uptake) and cytotoxic (trypan blue dye exclusion) activity in neoplastic human cell lines of different histology in vitro. The antiproliferative activity of 3 of the 9 PAF antagonists (SDZ 61-638, SDZ 61-813, SDZ 62-694) was not stable after freezing and thawing. SDZ 59-015 showed only minor cytotoxic or antiproliferative effects in a dose range of 2-40 microns after 24, 48, and 72 h of incubation. SDZ 62-434 showed varying activity. There were no significant differences between the activities of the other 3 PAF antagonists from the imidazoisoquinoline class, which showed drug concentrations inhibiting 50% of the activity studied (IC50) and drug concentrations yielding a 50% decrease of trypan blue dye exclusion (LC50) of less than or equal to 20 microM at greater than or equal to 48 h, even in the K-562 cell line, which is known to be rather resistant for a variety of cytotoxic drugs related to PAF. SDZ 62-293 showed the best antineoplastic properties with IC50 and LC50 values less than or equal to 10 microM at greater than or equal to 48 h including K-562. SDZ 62-434, SDZ 62-759, SDZ 63-135, SDZ 63-596, and SDZ 62-293 have been further tested in a human tumor cloning assay in 5 cell lines. Colony formation was reproducibly suppressed to less than 30% of the controls only by SDZ 63-135 (less than or equal to 40 microM) and SDZ 62-293 (less than or equal to 20 microM) during continuous exposure. There was no correlation between the IC50 values for the antiproliferative activity of the test compounds and their IC50 values for PAF-induced human platelet aggregation. Furthermore, the antiproliferative activity of the most active compound, SDZ 62-293, could not be antagonized by preincubation with the specific PAF antagonists WEB 2170 or WEB 2086 or PAF itself in noncytotoxic doses.(ABSTRACT TRUNCATED AT 400 WORDS)


Asunto(s)
Antineoplásicos , Supervivencia Celular/efectos de los fármacos , Factor de Activación Plaquetaria/antagonistas & inhibidores , Células Tumorales Cultivadas/efectos de los fármacos , Antineoplásicos/farmacología , Humanos , Imidazoles/farmacología , Isoquinolinas/farmacología , Piperidinas/farmacología , Agregación Plaquetaria/efectos de los fármacos
16.
Onkologie ; 13(6): 437-43, 1990 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-2092280

RESUMEN

We studied the influence of recombinant human (rh) interleukin-3 (IL-3) and rh granulocyte-macrophage colony-stimulating factor (GM-CSF) on the clonal growth of a human colorectal adenocarcinoma cell line in a methylcellulose assay for colony growth of solid tumor cell lines (HTCAMC) and a capillary modification of a human tumor cloning assay in agar (HTCAcap). Both growth factors stimulated the clonal growth of this cell line in a dose-dependent fashion. Neutralizing the monoclonal antibody abolished the effect of rhGM-CSF. There was an inverse correlation between the spontaneous plating efficacy (PE) of the cells and their susceptibility to the stimulation by the growth factors. From day 4 to 7 we found conditions in which clusters and colonies occurred preferentially in the growth factor-stimulated cultures. Single colonies taken from these cultures grew rapidly into macroscopically visible tumors in liquid cultures and had a high secondary PE (PE2) in the HTCAcap, both presenting an argument against a differentiating effect of the growth factors on this tumor cell line. Furthermore, we were able to define conditions in which rhGM-CSF significantly increased the cytotoxicity of 5-fluorouracil (5-FU). However, this effect was dependent on spontaneous PE of the cells, degree of stimulation by the factor, degree of cytotoxicity of 5-FU in the controls, as well as the therapeutic regimen. Since there were only narrow margins for a beneficial effect of rhGM-CSF in this setting when absolute numbers of surviving colonies were counted, it remains doubtful whether this approach will be exploitable in the clinical situation.


Asunto(s)
Adenocarcinoma/patología , División Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Neoplasias Colorrectales/patología , Fluorouracilo/farmacología , Factor Estimulante de Colonias de Granulocitos y Macrófagos/fisiología , Interleucina-3/fisiología , Células Tumorales Cultivadas/efectos de los fármacos , Ensayo de Tumor de Célula Madre , División Celular/fisiología , Línea Celular , Supervivencia Celular/fisiología , Terapia Combinada , Relación Dosis-Respuesta a Droga , Factor Estimulante de Colonias de Granulocitos y Macrófagos/farmacología , Humanos , Interleucina-3/farmacología , Proteínas Recombinantes/farmacología , Células Tumorales Cultivadas/fisiología
17.
J Lipid Mediat ; 2(5): 271-80, 1990.
Artículo en Inglés | MEDLINE | ID: mdl-2133272

RESUMEN

Hexadecylphosphocholine (HPC) was tested in comparison with the membrane-toxic reference ether lipid ET-18-OCH3 for cytotoxic (trypan blue dye exclusion) and cytostatic/antiproliferative [( 3H]thymidine uptake) activity in six cell lines of human hematologic malignancies, six cell lines of human solid tumors and four drug-resistant sublines and their respective non-resistant parent lines in vitro. HPC showed time- and dose-dependent antiproliferative and cytotoxic activity in almost all cell lines, including drug-resistant sublines over a dose range of 2-120 microM and after incubation times of 24, 48 and 72 h. However, ET-18-OCH3 showed a significantly higher activity than HPC, when both compounds were compared on an equimolar basis. The human tumor clonogenic assay confirmed these results. Furthermore, no cross-resistance for HPC with colchicine or methotrexate and partial cross-resistance for HPC with adriamycin was found in cell lines selected for drug resistance. In conclusion, HPC is cytotoxic for neoplastic cells of different histologies including drug-resistant sublines in vitro. Although its cytotoxicity starts at somewhat higher doses when compared to ET-18-OCH3, further testing as an experimental anticancer drug in vivo and comparative cytotoxicity studies with hematopoietic progenitor cells from bone marrow are recommended.


Asunto(s)
Fosforilcolina/análogos & derivados , Células Tumorales Cultivadas/efectos de los fármacos , Antineoplásicos/farmacología , División Celular/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Resistencia a Medicamentos , Humanos , Éteres Fosfolípidos/farmacología , Fosforilcolina/farmacología , Ensayo de Tumor de Célula Madre
18.
Cancer Chemother Pharmacol ; 26(6): 437-43, 1990.
Artículo en Inglés | MEDLINE | ID: mdl-2225315

RESUMEN

The synthetic ether lipids ET-18-OCH3 and BM41.440 and a derivative, hexadecylphosphocholine, were tested for inhibition of [3H]-thymidine uptake into a Chinese hamster ovarian cell line (AUXBl) and its multidrug-resistant subline selected for colchicine resistance (CHRC5). The activity of all three compounds against the multidrug-resistant subline was equal to or higher than that against the parent line. The same result was found for their activity against a human leukemic lymphoblastic cell line (CEM/O) and its methotrexate-resistant subline (CEM/MTX). In contrast, two multidrug-resistant cell lines selected for resistance to Adriamycin, the mouse leukemia cell line P388/ADR and the murine sarcoma cell line S180/ADR, expressed modest cross-resistance to the lipids as measured by thymidine uptake. Experiments performed using the trypan-blue dye-exclusion assay yielded comparable results, although this system revealed a slightly different sensitivity in showing the cytotoxicity of the drugs. By this assay, modest cross-resistance for ET-18-OCH3 and BM41.440 to Adriamycin was found only after 24 h incubation and decreased after 48 h incubation, with almost equal sensitivity to both drugs being shown by the parental (P388/W) and resistant lines (P388/ADR). Furthermore, findings from a human tumor-cloning assay were in accordance with these data, although they did not indicate cross-resistance for the P388/ADR cell line. These results suggest that certain ether lipids and derivatives might represent valuable anticancer drugs warranting further study in the setting of resistant disease.


Asunto(s)
Antineoplásicos/antagonistas & inhibidores , Células Cultivadas/efectos de los fármacos , Fosfolípidos/antagonistas & inhibidores , Células Tumorales Cultivadas/efectos de los fármacos , Animales , Línea Celular , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Células Cultivadas/metabolismo , Medios de Cultivo , Relación Dosis-Respuesta a Droga , Resistencia a Medicamentos , Cobayas , Humanos , Ratones , Timidina/metabolismo , Tritio , Células Tumorales Cultivadas/metabolismo , Ensayo de Tumor de Célula Madre
19.
Cancer Lett ; 46(2): 143-7, 1989 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-2752383

RESUMEN

Xanthate derivatives were shown previously to display antitumor activity against transformed fibroblasts and lymphoma cells in combination with monocarboxylic acids [1]. Various malignant cell lines of human origin were treated in vitro to explore the range of antitumoral activity of the compounds. The combination of tricyclodecan-9-yl-xanthogenate (D 609) with undecanoic acid (C11) exerted dose dependent cytotoxic and antiproliferative effects on cell lines both from solid tumors (glioblastomas, colon-carcinomas) and hematological diseases (lymphomas, CML/BC). Additionally, the combination of D 609/C11 was able to kill both methotrexate- and adriamycin-resistant L 1210 and S 180 cells, indicating that there is no cross-resistance for these drugs and D 609/C11 in vitro.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Neoplasias/tratamiento farmacológico , Hidrocarburos Aromáticos con Puentes/administración & dosificación , Resistencia a Medicamentos , Ácidos Grasos/administración & dosificación , Humanos , Norbornanos , Tiocarbamatos , Tionas/administración & dosificación , Células Tumorales Cultivadas
20.
Cancer Lett ; 46(2): 149-52, 1989 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-2752384

RESUMEN

The combinations of tricyclodecan-9-yl-xanthogenate (D 609) with undecanoic acid (C11) and D 609 with myristic acid (C14) were tested in 3 rodent tumor models in vivo. D 609 in combination with C11 or C14 did not show antitumoral efficacy in 3-Lewis lung carcinoma (3-LL) growing in syngeneic C57BL6-mice (primary tumor and metastasis) or in WEHI-3B myelomonocytic leukemia growing in Balb/c mice, when given in a dose range lower than the lethal dose for 10% of the treated animals (LD10). In L 1210 mouse lymphoid leukemia growing in CD2F1 mice the combination of D 609/C11 given intraperitoneally in a concentration of 100 mg/kg for more than 1 day effected a significant difference in the survival curves between the control and therapeutic groups in 1 out of 2 experiments. In conclusion, the treatment schedules of D 609/C11 or D 609/C14 used in this study has not revealed significant therapeutic effects in mouse tumors or leukemias in vivo.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Leucemia Experimental/tratamiento farmacológico , Neoplasias Experimentales/tratamiento farmacológico , Animales , Hidrocarburos Aromáticos con Puentes/administración & dosificación , Ácidos Grasos/administración & dosificación , Femenino , Leucemia L1210/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/secundario , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ácidos Mirísticos/administración & dosificación , Norbornanos , Tiocarbamatos , Tionas/administración & dosificación
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