Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
3.
Bull Narc ; 57(1-2): 121-47, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-21338018

RESUMO

The present article describes the profiling process developed at the Institute of Forensic Science of the School of Crime Sciences of the Faculty of Law at the University of Lausanne. The technique is oriented towards an operational approach that can be applied directly by drug units of local law enforcement authorities. The background of the development of that technique and issues relating to data sources are outlined. Analytical, statistical and computerized methods for detecting, managing and visualizing linkages are examined in the context of drug profiling. Harmonization of methods and operational use of links are discussed and explained using examples. Finally, adequate communication of forensic information/intelligence is explored as an area of development. This endeavour has helped demonstrate the enormous potential that linking seizures made in different regional markets has for police investigations. The next stage is to focus on implementing this model in a more systematic manner and, if possible, at the national level and even the international level. That harmonization of methods should be pursued in order to maximize the potential of the detected linkages. In conclusion, links established through profiling, combined with traditional information, can be utilized to better understand the market's structure and implement medium- and long-term investigation strategies.


Assuntos
Comércio/legislação & jurisprudência , Controle de Medicamentos e Entorpecentes/legislação & jurisprudência , Controle de Medicamentos e Entorpecentes/organização & administração , Ciências Forenses/legislação & jurisprudência , Ciências Forenses/organização & administração , Drogas Ilícitas/legislação & jurisprudência , Polícia , Detecção do Abuso de Substâncias/legislação & jurisprudência , Cocaína/química , Comportamento Cooperativo , Bases de Dados como Assunto/legislação & jurisprudência , Contaminação de Medicamentos/legislação & jurisprudência , Humanos , Drogas Ilícitas/química , Disseminação de Informação/legislação & jurisprudência , Comunicação Interdisciplinar , Aplicação da Lei/métodos , Suíça
4.
Mol Pharmacol ; 58(4): 709-18, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10999940

RESUMO

The new olivacine derivative S16020-2 (NSC-659687) is a DNA topoisomerase II inhibitor endowed with a remarkable antitumor activity against various experimental tumors. In vitro physicochemical properties of this compound, in particular its interaction with DNA and DNA topoisomerase II, were very similar to those of ellipticine derivatives, except for a strictly ATP-dependent mechanism of cleavable complex induction. From the Chinese hamster lung fibroblast cell line DC-3F, a subline resistant to S16020-2, named DC-3F/S16, was selected by adding stepwise increasing concentrations of the drug to the cell growth medium. Whereas DC-3F/9-OH-E cells, a DC-3F subline resistant to 9-hydroxy-ellipticine, are cross-resistant to S16020-2, DC-3F/S16 cells are only very weakly cross-resistant to ellipticine derivatives, indicating that, despite their structural similarity, these compounds may differ in their mechanisms of action. Uptake and efflux rates of S16020-2 were identical in the resistant and the sensitive cells. Topoisomerase IIalpha was expressed at the same level in both sensitive and resistant cells, whereas expression of the beta-enzyme was approximately 50% lower in the resistant cells. Sequencing of both alpha- and beta-isoform cDNAs revealed a point mutation that converts Arg(486) to a Gly in the alpha cDNA, whereas the beta cDNA was not modified. This amino acid substitution in a highly conserved sequence of the enzyme appears to be responsible for the resistance to S16020-2. Comparative analysis of the properties of the ellipticine and S16020-2-resistant cells suggests that S16020-2, which is a DNA intercalator, might also interact with this enzyme amino acid sequence through its side chain.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Resistência a Múltiplos Medicamentos , Elipticinas/farmacologia , Inibidores da Topoisomerase II , Animais , Antimetabólitos Antineoplásicos/farmacologia , Testes de Carcinogenicidade , Clonagem Molecular , Cricetinae , DNA/efeitos dos fármacos , DNA/metabolismo , DNA Topoisomerases Tipo II/análise , DNA Topoisomerases Tipo II/metabolismo , Resistência a Múltiplos Medicamentos/fisiologia , Resistencia a Medicamentos Antineoplásicos , Elipticinas/metabolismo , Análise de Sequência de DNA , Células Tumorais Cultivadas
6.
J Neurol Neurosurg Psychiatry ; 65(3): 353-6, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9728948

RESUMO

OBJECTIVE: To evaluate psychopathological disturbances in patients with myotonic dystrophy (MD) and compare patients with MD to both patients with facioscapulohumeral dystrophy (FSHD) and healthy control subjects. METHODS: A semistructured interview was used to determine DSM III-R criteria for major depressive episodes, dysthymic episodes, and generalised anxiety. The Montgomery and Asberg and the Hamilton depressive scales, the Covi and Tyrer anxiety scales, the Abrams and Taylor scale for emotional blunting, and the depressive mood scale were all used in the study. Subjects were also asked to complete questionnaires for physical and social anhedonia. RESULTS: Fifteen patients with MD, 11 patients with FSHD, and 14 healthy subjects were studied. Patients with MD were not more depressed or anxious than healthy controls. Patients with FSHD were the most depressed and most anxious. However, patients with MD had significantly lower scores for expressiveness and significantly higher scores for anhedonia than the other two groups. CONCLUSION: Patients with MD did not present significant depressive or anxious symptomatology but rather an emotional deficit. This emotional deficit may be an adaptive reaction to the threatening implications of the disease, or the effect of the CNS lesions which occur with MD, or both.


Assuntos
Sintomas Afetivos/psicologia , Transtornos de Ansiedade/psicologia , Transtorno Depressivo Maior/psicologia , Transtorno Distímico/psicologia , Distrofia Miotônica/psicologia , Escalas de Graduação Psiquiátrica , Papel do Doente , Adaptação Psicológica , Adulto , Sintomas Afetivos/diagnóstico , Transtornos de Ansiedade/diagnóstico , Mecanismos de Defesa , Transtorno Depressivo Maior/diagnóstico , Diagnóstico Diferencial , Transtorno Distímico/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Distrofia Miotônica/diagnóstico
7.
Arch Neurol ; 55(5): 635-40, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9605719

RESUMO

BACKGROUND: Myotonic dystrophy (DM) is a multisystemic disease. The central nervous system is affected by cognitive, affective, and personality disturbances. A characteristic behavior was noted from the first clinical descriptions, but no definitive conclusions have been drawn despite extensive debate. As DM is a genetic disease of well-defined abnormality, it may be a good model for understanding the relative contributions of nature and nurture in the building of personality traits. OBJECTIVE: To investigate the possibility that there is a personality pattern that is characteristic of patients with DM. SUBJECTS AND METHODS: The personalities of 15 adult (age range, 20-53 years) patients with DM with no, or minimal, muscle weakness were studied by means of the International Personality Disorder Examination. The results were compared with those from 14 matched healthy subjects (age range, 20-54 years) and 12 patients (age range, 22-50 years) with a mild form of facioscapulohumeral dystrophy. SETTING: The Department of Neuromuscular Diseases, Hôpital de la Salpêtrière, Paris, France. RESULTS: Patients with DM exhibited a homogeneous personality profile, with statistically significant differences (P<.005) for avoidant, obsessive-compulsive, passive-aggressive, and schizotypic traits. In both groups of controls, the personality profiles were extremely heterogeneous. Personality disorders (avoidant personality) were found in 4 of 15 patients with DM. CONCLUSIONS: The findings of this study suggest that the personality pattern of patients with DM is related to their disease. Their personality disorders are not attributable to their adjustment to a disabling condition. By contrast, among the patients with DM, the high incidence of avoidant personality, a phenotype poorly represented in the general population, supports the idea that it is the expression of a primary phenomenon related to a genetic mutation.


Assuntos
Distrofia Miotônica/psicologia , Transtornos da Personalidade/diagnóstico , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Determinação da Personalidade , Transtornos da Personalidade/epidemiologia , Transtornos da Personalidade/etiologia
8.
Cancer Res ; 57(19): 4301-8, 1997 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-9331091

RESUMO

In the Chinese hamster lung cell line DC-3F/9-OH-E, made resistant to 9-OH-ellipticine and cross-resistant to other topoisomerase II inhibitors, the amount of topoisomerase II alpha is 4-5-fold lower than in the parental DC-3F cells. A mutation in position 1710 of topoisomerase II beta cDNA, generating a stop codon, completely abolishes the expression of this isoform in DC-3F/9-OH-E cells. To analyze the contribution of the loss of topoisomerase II beta to the resistance phenotype, DC-3F/9-OH-E cells were cotransfected with two plasmids, one conferring the resistance to G418, the other carrying the topoisomerase II beta cDNA. Among 200 G418-resistant clones, one was found to contain a topoisomerase II beta activity similar to that in the parental cells. These cells constitute an in vivo mammalian model to study the pharmacological role of topoisomerase II beta. In the transfected cells, different levels of cleavable complex formation and resistance reversion were observed with each topoisomerase II inhibitor examined. This work demonstrates that topoisomerase II beta is a pharmacological target for 9-OH-ellipticine, etoposide, or 4'-(9-acridinylamino)methanesulfon-m-anisidide and plays a role in the cytotoxicity of these agents. Furthermore, topoisomerase II beta is the preferential target for 4'-(9-acridinylamino)methanesulfon-m-anisidide. The loss of topoisomerase II beta activity in the DC-3F/9-OH-E cells is then in part responsible for their resistance to topoisomerase II inhibitors.


Assuntos
Elipticinas/farmacologia , Inibidores Enzimáticos/farmacologia , Fibroblastos/efeitos dos fármacos , Isoenzimas/antagonistas & inibidores , Inibidores da Topoisomerase II , Amsacrina/farmacologia , Animais , Linhagem Celular , Códon/genética , Cricetinae , Cricetulus , DNA Topoisomerases Tipo II/genética , DNA Topoisomerases Tipo II/fisiologia , Resistencia a Medicamentos Antineoplásicos , Etoposídeo/farmacologia , Fibroblastos/enzimologia , Genisteína/farmacologia , Isoenzimas/genética , Isoenzimas/fisiologia , Pulmão
9.
Neuroradiology ; 39(3): 166-70, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9106286

RESUMO

MRI was performed in 13 patients with the adult form of myotonic dystrophy (MD) and compared with that of sex- and age-matched normal controls. There was some cerebral atrophy in the patients and marked thickening of the skull in three of them, associated with ossification of the falx cerebri in two. We found high-signal areas on T2-weighted images in the white matter in 9 (70%) of the patients; five showed high-signal areas in the subcortical white matter of the temporal lobes. These findings were associated with intellectual impairment in only one patient, who had a history of a difficult birth and temporal lobe epilepsy.


Assuntos
Encéfalo/patologia , Imageamento por Ressonância Magnética , Distrofia Miotônica/diagnóstico , Adulto , Atrofia , Córtex Cerebral/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Exame Neurológico , Ossificação Heterotópica/diagnóstico , Crânio/patologia
10.
Biochem Pharmacol ; 53(1): 59-66, 1997 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-8960064

RESUMO

Chinese hamster lung cells resistant to the DNA topoisomerase II inhibitor 9-OH-ellipticine (DC-3F/9-OH-E) are cross resistant to various drugs through the expression of the MDR phenotype. The myc oncogene was approximately 10-fold amplified and 20-fold overexpressed in parental DC-3F cells as compared with DC-3F/9-HO-E cells. Transfection of the resistant cells with a mouse c-myc gene did not alter the resistance to topoisomerase II inhibitors and, in cells with a low multidrug (MDR) expression, reversed this phenotype. Northern and Western blot analyses revealed an increased expression of pgp1 in the DC-3F/9-OH-E cells, which was not modified in the myc-transfected clones. However, myc expression in these clones resulted in an increased expression of pgp3, roughly in proportion to the level of myc expression. Transfection of the DC-3F/9-OH-E cells with the human MDR3 gene, homologous to pgp3, also resulted in the reversion of the MDR phenotype. These results show that (1) expression of the transfected myc gene positively regulates pgp3 expression but has no effect on pgp1; (2) when observed, reversion of the MDR phenotype is proportional to the levels of myc and pgp3 expression; and (3) this reversion, resulting from pgp3 expression, is associated with a decreased functional activity of the pgp1 protein and might require an appropriate balance of pgp1 and pgp3 expression.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Antimetabólitos Antineoplásicos/farmacologia , Resistência a Múltiplos Medicamentos/genética , Elipticinas/farmacologia , Genes myc/fisiologia , Animais , Células Cultivadas , Cricetinae , Cricetulus , Humanos , Camundongos , Transfecção
11.
Genet Couns ; 7(4): 289-96, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8985733

RESUMO

The way of announcing a late-onset, heritable, disabling disease, and the impact of this realisation on the patient's life, were studied by means of unstructured interviews conducted with 10 neurologists and 22 patients. All physicians announced the name of the disease to the patient, and considered it important to do so. At the same time they also provided explanations concerning the unpredictable prognosis, the absence of curative therapy, and genetic transmission. It was extremely shocking for the patients to learn that their illness is a myopathy and furthermore that it is genetically transmissible. This shock was linked to the naming of the disease, which represented an abrupt transition in the patient's life. Patients feel that this moment marks the beginning of social exclusion. A strong disavowal of the disease is developed, regarding its disabling and heritable characteristics. This disavowal hampers reconstruction of the personality. A post-diagnostic follow-up by a genetic counsellor is highly recommended for patients and relatives alike. This should allow the patient to mourn his/her previous life, a prerequisite for positive rebuilding.


Assuntos
Músculos Faciais/fisiopatologia , Úmero/fisiopatologia , Distrofias Musculares/diagnóstico , Distrofias Musculares/fisiopatologia , Escápula/fisiopatologia , Adaptação Psicológica , Adulto , Idade de Início , Feminino , Aconselhamento Genético , Humanos , Masculino , Distrofias Musculares/genética , Autoimagem
12.
Biochim Biophys Acta ; 1264(2): 178-82, 1995 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-7495861

RESUMO

DNA topoisomerase II beta cDNAs from Chinese hamster lung cells sensitive (DC-3F) and resistant to 9-OH-ellipticine (DC-3F/9O-HE) were isolated. In the sensitive cells, the sequence defines an open reading frame of 4839 nucleotides, and extends over a 323 nucleotides untranslated region up to the putative polyadenylation site. The deduced amino acid sequence predicts a protein with 1612 amino acids in length and a calculated molecular mass of approx. 182 kDa. The cDNAs from the resistant cells only differs by one mutation at position length and a calculated molecular mass of approx. 182 kDa. The cDNAs from the resistant cells only differs by one mutation at position 1710 which converts a Trp codon (TGG) to a stop codon (TGA). This mutation accounts for the loss of DNA topoisomerase II beta in the 9-OH-ellipticine resistant cells.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , DNA Topoisomerases Tipo II/genética , Elipticinas/farmacologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Southern Blotting , Linhagem Celular , Clonagem Molecular , Códon/genética , Cricetinae , Cricetulus , DNA Complementar , Resistência a Medicamentos , Isoenzimas/genética , Pulmão , Dados de Sequência Molecular , Mutação Puntual , Triptofano
13.
Bull Cancer ; 81(5): 381-5, 1994 May.
Artigo em Francês | MEDLINE | ID: mdl-7749214

RESUMO

Chinese hamster lung cells resistant to 9-OH-ellipticine (DC-3F/9-OH-E) present a complex phenotype. These cells, which are about 150-fold resistant to 9-OH-E, display a cross-resistance to other topo-II inhibitors, such as m-AMSA or VP-16, which stabilize the cleavable complex. In addition, these cells display also a cross-resistance to suramin, which is also a topo-II inhibitor, but does not stabilize the cleavable complex. Finally, DC-3F/9-OH-E present a multidrug-resistant phenotype (MDR) which confers a cross-resistance to natural products such as actinomycin D, taxol or vincristine, due to a decrease of cellular accumulation of these drugs. Analysis of expression of the genes encoding topo-II alpha and beta, and the evaluation of both enzyme forms by immunoblotting, revealed that DC-3F cells contained about 20-fold less of the beta form than of the alpha form. The alpha form was decreased by about 4-5-fold in DC-3F/9-OH-E, whereas the beta form became undetectable. Purification and characterization of topo-II activities in sensitive and resistant cells is presently in progress. Analysis of the expression of pgp1, 2, 3 genes, involved in the MDR phenotype in hamster, by Northern blotting or by immunoblotting, has shown that the MDR phenotype in DC-3F/9-OH-E cells is due to the overexpression of pgp1 gene. In these cells, pgp3 expression is positively regulated by myc oncogene expression. Overexpression of the myc gene is followed by an overexpression of the pgp3 gene and is associated to a reversal of the MDR phenotype.


Assuntos
Resistência a Medicamentos/genética , Pulmão/enzimologia , Inibidores da Topoisomerase II , Animais , Antineoplásicos/antagonistas & inibidores , Antineoplásicos/farmacologia , Divisão Celular , Linhagem Celular , Cricetinae , DNA Topoisomerases Tipo II/genética , Resistência a Múltiplos Medicamentos/genética , Elipticinas/antagonistas & inibidores , Elipticinas/farmacologia , Regulação Enzimológica da Expressão Gênica , Pulmão/citologia , Células Tumorais Cultivadas/efeitos dos fármacos
14.
Rofo ; 158(4): 362-7, 1993 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8477078

RESUMO

Magnetic resonance imaging (MRI) is now considered the diagnostic study of choice for evaluation of patients with suspected acoustic schwannoma. This retrospective study of 118 MR examinations presents an analysis of the MR findings of 89 acoustic tumours in 86 patients. The method of examination included precontrast and gadolinium(Gd)-enhanced MRI in 72 and plain MRI in 14 patients. The common MR-appearances of acoustic schwannomas were: on T1-weighted images (WI) isointense (36%) or slightly hypointense (64%) relative to the brainstem; intense and homogeneous contrast enhancement in 62%; the shape of the tumour was round or oval in 71%; the tumour was centred at/or located in the internal auditory canal (IAC) in 80%. The small acoustic schwannomas were mostly round or oval in shape and showed homogeneous signal intensity (SI) both before and after Gd. The larger acoustic tumours were more heterogeneous in morphology and SI. The significance of these and other signs, early diagnosis and differential diagnosis are discussed.


Assuntos
Neuroma Acústico/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Meios de Contraste , Feminino , Gadolínio , Gadolínio DTPA , Compostos Heterocíclicos , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neuroma Acústico/epidemiologia , Compostos Organometálicos , Ácido Pentético , Estudos Retrospectivos
15.
Muscle Nerve ; 15(3): 295-302, 1992 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1557076

RESUMO

Class II MHC antigen expression has been investigated in muscle tissue and cultured cells from normal human skeletal muscle by light and electron immunocytochemistry. In muscle tissue, these antigens were detected in satellite cells, interstitial cells, and blood vessels. In cultures, muscle cells were stained with a pan-reactive anti-HLA class II antibody and with isotypes specific for DP, DQ, and DR. The staining was present on mononucleated cells and persisted on myotubes; it was stronger for DR and DQ isotypes than for DP. At the subcellular level, staining was located not only at the cell surface, but also next to the endoplasmic reticulum and in the cytosol. Thus, myosatellite cells and aneurally cultured cells from human normal skeletal muscle express class II MHC antigens. Moreover, the myotube staining and the presence of gold particles inside the cells suggested synthesis of these antigens after myoblast fusion.


Assuntos
Antígenos de Histocompatibilidade Classe II/análise , Músculos/imunologia , Imunofluorescência , Humanos , Imuno-Histoquímica , Microscopia Eletrônica
16.
Exp Cell Res ; 197(2): 176-82, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1720389

RESUMO

In the Chinese hamster lung fibroblast cell line DC-3F, the development of resistance to different drugs, through several mechanisms like MDR expression or alteration of the DNA topoisomerase II activity, has been shown to be associated with a decreased tumorigenicity. Multiple studies have shown that the myc oncogene, in cooperation with ras, plays a major role in the oncogenic transformation of fibroblasts. As an approach to a better understanding of the relationship between the different phenotypic traits, we analyzed the expression of myc and ras oncogenes in the drug-sensitive DC-3F cells and in variants resistant to 9-hydroxyellipticine (9-OH-E) (DNA topoisomerase II alteration) or to actinomycin D (AD) (multidrug (MDR) expression). Southern and Northern blot analyses revealed about a 10-fold amplification and a 20-fold overexpression of the c-myc gene in the DC-3F cells as compared to the normal lung fibroblasts. Both amplification and overexpression are markedly decreased in the two resistant variants, ras gene copy number and expression were found to be identical in all cell types. In order to analyze the contribution of the decreased myc expression on the different phenotypic traits, the DC-3F/9-OH-E cells were transfected with the plasmid pSV-c-myc, and six clones expressing high amounts of the transfected myc were isolated and characterized. Morphological and caryological alterations, as well as an increased cloning efficiency in soft agar, indicated that the myc gene product was made in these cells. However, the tumorigenicity of the sensitive parental cells was not restored, thus showing that the decreased myc expression alone does not account for the loss of tumorigenicity in the resistant cells. 9-OH-E resistance was not modified in the transfected cells, while the cross-resistance of these cells to MDR-sensitive drugs, such as vincristine, actinomycin D, and taxol, was reversed roughly in proportion of the expression of the transfected myc.


Assuntos
Antineoplásicos/farmacologia , Transformação Celular Neoplásica , Resistência a Medicamentos/genética , Genes myc , Animais , Northern Blotting , Southern Blotting , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Clonais , Cricetinae , Cricetulus , DNA/análise , DNA/genética , DNA/isolamento & purificação , Feminino , Citometria de Fluxo/métodos , Expressão Gênica , Genes ras , Pulmão , Camundongos , Camundongos Nus , Transplante de Neoplasias , RNA/genética , RNA/isolamento & purificação , Transfecção
17.
J Neurol Sci ; 105(2): 183-91, 1991 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1757795

RESUMO

Proliferation and differentiation of myoblasts from hypertrophic muscles were studied "in vitro" in two cases of syringomyelia with muscle hypertrophy (MH). Their myoblast growth was compared with that of muscle cells sampled on the contralateral side in the same patients and in control subjects. The effect of a circulating factor was tested using patient sera in place of fetal calf and horse sera. The results showed that MH cells were morphologically abnormal (giant and granular). MH myoblasts proliferated more rapidly than contralateral and normal myoblasts, their fusion was accelerated and the resulting myotubes synthesized higher levels of protein. MH sera increased these effects. Serum factors are therefore likely to be involved in "in vivo" muscle hypertrophy. These findings suggest that the pathogenesis of muscle hypertrophy in syringomyelia involves acquired abnormalities due to molecules released in response to neural lesions.


Assuntos
Músculos/patologia , Siringomielia/patologia , Adulto , Diferenciação Celular , Divisão Celular , Células Cultivadas , Meios de Cultura , Retículo Endoplasmático/ultraestrutura , Feminino , Humanos , Hipertrofia , Masculino , Microscopia Eletrônica , Músculos/citologia , Músculos/ultraestrutura , Valores de Referência , Siringomielia/sangue , Siringomielia/fisiopatologia , Vacúolos/ultraestrutura
18.
J Neurol Sci ; 95(1): 77-88, 1990 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-2338566

RESUMO

Cultured muscle cells from Duchenne muscular dystrophy (DMD) patients show altered growth from the mononucleated stage: abnormal morphology, decreased adhesiveness, reduced number of population doublings and delayed fusion. On the basis of these findings, a study was undertaken to observe cell shape and surface morphology by scanning electron microscopy and to define the immunocytochemical localization of 4 basal lamina components (type IV collagen, laminin, fibronectin, heparan sulfate proteoglycan (HSPG]. Eight DMD muscle cultures with fusion indices higher than 65% were compared to muscle cultures from 10 age-matched controls. The following results were noted for the dystrophic muscle cells: (1) the cell surface was smooth with a few slender cell processes and anchorage extensions; (2) distribution of type IV collagen and laminin was heterogenous, with large patches (type IV collagen) or a reticulum (laminin); (3) in contrast, fibronectin and HSPG levels were clearly decreased. These molecules did not form a network but rather were arranged in thick filaments and patches. Cell surface morphology may be related to the decreases in fibronectin and HSPG, which could reflect a more general decrease in basal lamina. Such findings could explain the low adhesiveness of the cells from dystrophic cultures and the delayed fusion of myoblasts. Although these abnormalities were maximally expressed after myoblast fusion, they were already present in mononucleated cells and their connection with the primary defect in DMD, i.e., lack of dystrophin, must now be clarified.


Assuntos
Membrana Basal/ultraestrutura , Distrofias Musculares/patologia , Membrana Basal/metabolismo , Células Cultivadas , Criança , Pré-Escolar , Colágeno/metabolismo , Fibronectinas/metabolismo , Humanos , Laminina/metabolismo , Masculino , Microscopia Eletrônica de Varredura , Distrofias Musculares/metabolismo
19.
Biochem Pharmacol ; 37(4): 613-9, 1988 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-3342098

RESUMO

9-OH-Ellipticine (9-OH-E)-resistant cells are not only resistant to the DNA topoisomerase II inhibitors, but also to some other antitumor agents, such as actinomycin D (AD), adriamycin (ADM), daunorubicin and vincristine. It was previously shown that a decreased uptake accounts for the cross-resistance of these cells to AD and ADM which then suggested that the 9-OH-E-resistant cells might display some of the properties usually associated with the multidrug resistance phenotype. In this work, we have examined the effects of verapamil, a drug which is known to overcome the multidrug resistance, on the toxicity and the cellular accumulation of four cytotoxic agents: 9-OH-E, 2N-methyl-9-hydroxy-ellipticinium (NMHE), AD and ADM, either on 9-OH-E resistant cells or on a multidrug resistant subline derived from the same sensitive parental cells. Verapamil inhibited the cellular accumulation of the ellipticine derivatives in the sensitive DC-3F cells, and the toxicity of these drugs on these cells was correspondingly decreased. On either one of the resistant cell lines, verapamil had no effect on the toxicity and the cellular accumulation of 9-OH-E. In contrast, in the presence of verapamil, the cellular accumulation of NMHE by the 9-OH-E and the multidrug resistant cells was about 50% and 300% increased, respectively. The increased NMHE cellular concentration in the multidrug resistant cells was associated with an 8-fold increased toxicity. The major structural characteristics which might account for this difference between the sensitivities of both ellipticine derivatives to the effects of verapamil on the multidrug resistant cells is the presence of a positive charge on the nitrogen in position 2 of the 6H-pyridocarbazole molecule. Finally, verapamil circumvented partially the cross-resistance of DC-3F/9-OH-E cells to AD and ADM by increasing the accumulation of these drugs inside the cells.


Assuntos
Alcaloides/farmacologia , Antineoplásicos/farmacocinética , Elipticinas/farmacologia , Verapamil/farmacologia , Animais , Antineoplásicos/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cricetinae , Resistência a Medicamentos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...