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1.
World J Urol ; 41(5): 1285-1291, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36971827

RESUMO

PURPOSE: To analyse the pathological features and survival of patients with a PI-RADS 5 lesion on pre-biopsy MRI. METHODS: We extracted from a European multicentre prospectively gathered database the data of patients with a PI-RADS 5 lesion on pre-biopsy MRI, diagnosed using both systematic and targeted biopsies and subsequently treated by radical prostatectomy. The Kaplan-Meier model was used to assess the biochemical-free survival of the whole cohort and univariable and multivariable Cox models were set up to study factors associated with survival. RESULTS: Between 2013 and 2019, 539 consecutive patients with a PI-RADS 5 lesion on pre-biopsy MRI were treated by radical prostatectomy and included in the analysis. Follow-up data were available for 448 patients. Radical prostatectomy and lymph node dissection specimens showed non-organ confined disease in 297/539 (55%), (including 2 patients with a locally staged pT2 lesion and lymph node involvement (LNI)). With a median follow-up of 25 months (12-39), the median biochemical recurrence-free survival was 54% at 2 years (95% CI 45-61) and 28% at 5 years (95% CI 18-39). Among the factors studied, MRI T stage [T3a vs T2 HR 3.57 (95%CI 1.78-7.16); T3b vs T2 HR 6.17 (95% CI 2.99-12.72)] and PSA density (HR 4.47 95% CI 1.55-12.89) were significantly associated with a higher risk of biochemical recurrence in multivariable analysis. CONCLUSION: Patients with a PI-RADS 5 lesion on pre-biopsy MRI have a high risk of early biochemical recurrence after radical prostatectomy. MRI T stage and PSA density can be used to improve patient selection and counselling.


Assuntos
Antígeno Prostático Específico , Neoplasias da Próstata , Masculino , Humanos , Prognóstico , Imageamento por Ressonância Magnética , Estudos Retrospectivos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/cirurgia , Prostatectomia
2.
Prog Urol ; 33(5): 265-271, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36740508

RESUMO

OBJECTIVES: To compare the correlation of Gleason score (GS) and ISUP grade determined by prostate biopsies (PBx) and radical prostatectomy (RP) specimens according to the biopsy technique: ultrasound randomised (RBx) vs. MRI/ultrasound fusion targeted (TBx). MATERIALS AND METHODS: Between March 2013 and June 2018, we retrospectively included patients who underwent RP for prostate cancer (PCa) histopathologically proven by RBx and/or TBx. All patients had a prebiopsy MRI by a single radiologist (using PI-RADS score), then transrectal RBx (12cores, blinded to MRI lesions) and TBx (2-4 cores/target) with elastic MRI/ultrasound fusion (UroStation™, Koelis, Grenoble, France). Histological findings were compared: PBx vs. RP. RESULTS: One hundred and four patients underwent RP after RBx and/or TBx. ISUP concordance rate was better with the association RBx+TBx 49% (51/104) vs. 43.3% with TBx (P=0.07) and 43.3% with RBx (P=0.13). With RBx, 50% of the patients were downgraded (52/104) against 42.3% (44/104) with TBx (P=0.088). The association RBx+TBx significantly decreased the rate of downgrading of the ISUP score compared to the ISUP score of RP 35.6% (37/104) vs. RBx (50%, P=0.0001) and vs. TBx (42.3%, P=0.016). CONCLUSION: In half of cases, the ISUP score was underestimated in RBx compared to RP specimens. Adding TBx to RBx significantly reduced downgrading. The combination of both biopsy techniques appeared to be the best protocol to get closer to ISUP score and GS of the RP specimens. LEVEL OF EVIDENCE: C.


Assuntos
Próstata , Neoplasias da Próstata , Humanos , Masculino , Biópsia Guiada por Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Gradação de Tumores , Próstata/diagnóstico por imagem , Próstata/cirurgia , Próstata/patologia , Prostatectomia/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/cirurgia , Neoplasias da Próstata/patologia , Estudos Retrospectivos
3.
Health Policy ; 129: 104702, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36588068

RESUMO

The systematic use of patient-reported measures (PRMs) [i.e., patient-reported outcome measures (PROMs) and patient-reported experience measures (PREMs)] is advocated as an effective way to improve care practices. However, whether PRMs can lead to the performance assessment of healthcare organisations (HCOs) through valid quality indicators (QIs) for national purposes (i.e., public reporting and paying for performance) is open to debate. This study undertakes a scoping review to examine the use of PRMs as QIs for health policy purposes and to identify the challenges faced in the emblematic case of oncology. According to PRISMA guidelines, published papers, websites and reports published by national and international initiatives were analysed using five online databases (Web of Science, Scopus, PubMed, JSTOR and Google Advanced Search), and then studied using the same keywords. We selected 61 articles and 19 websites/reports and identified 29 PREMs and 48 PROMs from 14 countries and two international initiatives that routinely used them as QIs for HCOs' comparisons. Four types of barriers to this specific use were identified relating to the definition of a standard set, scientific soundness, data collection, and the actionability of such measures. Despite current developments, different barriers still must be overcome before PRMs can be used for health policy purposes in oncology. Future research is needed to ensure that valid QIs related to PRMs are applied at a national level.


Assuntos
Medidas de Resultados Relatados pelo Paciente , Indicadores de Qualidade em Assistência à Saúde , Humanos , Coleta de Dados , Atenção à Saúde , Oncologia
4.
Artigo em Inglês | MEDLINE | ID: mdl-38114598

RESUMO

BACKGROUND: Current prostate biopsy (PBx) protocol for prostate cancer (PCa) diagnosis is to perform systematic biopsies (SBx) combined with targeted biopsies (TBx) in case of positive MRI (i.e. PI-RADS ≥ 3). To assess the utility of performing SBx in combination with TBx, we determined the added value of SBx brought to the diagnosis of PCa according to their sextant location and MRI target characteristics. METHODS: In our local prospectively collected database, we conducted a single-center retrospective study including all patients with a suspicion of PCa, who underwent transrectal ultrasound-guided (TRUS) prostate biopsies (PBx) with a prior MRI and a single lesion classified as PI-RADS ≥ 3. We have characterized the SBx according to their location on MRI: same sextant (S-SBx), adjacent sextant (A-SBx), ipsilateral side (I-SBx) and contralateral side (C-SBx). The added value of SBx and TBx was defined as any upgrading to significant PCa (csPCa) (ISUP ≥2). RESULTS: 371 patients were included in the study. The added value of SBx was 10% overall. Regarding the lesion location and the SBx sextant, the added value of SBx was: 5.1% for S-SBx, 5.4% for A-SBx, 4.9% for I-SBx and 1.9% for C-SBx. The overall added value of SBx was 6.8% for PI-RADS 3 lesions, 14% for PI-RADS 4 lesions and 6.7% for PI-RADS 5 lesions (p = 0.063). The added value of SBx for contralateral side was 1.9% (2/103), 3.1% (5/163) and 0% (0/105) for PI-RADS 3, PI-RADS 4 and PI-RADS 5 lesions, respectively (p = 0,4). The added value of SBx was lower when the number of TBx was higher (OR 0.57; CI 95% 0.37-0.85; p = 0.007). CONCLUSIONS: Our results suggest that the utility of performing SBx in the contralateral lobe toward the MRI lesion was very low, supporting that they might be avoided.

9.
J Stomatol Oral Maxillofac Surg ; 120(4): 279-288, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31254638

RESUMO

AIM AND SCOPE: Artificial intelligence (AI) in medicine is a fast-growing field. The rise of deep learning algorithms, such as convolutional neural networks (CNNs), offers fascinating perspectives for the automation of medical image analysis. In this systematic review article, we screened the current literature and investigated the following question: "Can deep learning algorithms for image recognition improve visual diagnosis in medicine?" MATERIALS AND METHODS: We provide a systematic review of the articles using CNNs for medical image analysis, published in the medical literature before May 2019. Articles were screened based on the following items: type of image analysis approach (detection or classification), algorithm architecture, dataset used, training phase, test, comparison method (with specialists or other), results (accuracy, sensibility and specificity) and conclusion. RESULTS: We identified 352 articles in the PubMed database and excluded 327 items for which performance was not assessed (review articles) or for which tasks other than detection or classification, such as segmentation, were assessed. The 25 included papers were published from 2013 to 2019 and were related to a vast array of medical specialties. Authors were mostly from North America and Asia. Large amounts of qualitative medical images were necessary to train the CNNs, often resulting from international collaboration. The most common CNNs such as AlexNet and GoogleNet, designed for the analysis of natural images, proved their applicability to medical images. CONCLUSION: CNNs are not replacement solutions for medical doctors, but will contribute to optimize routine tasks and thus have a potential positive impact on our practice. Specialties with a strong visual component such as radiology and pathology will be deeply transformed. Medical practitioners, including surgeons, have a key role to play in the development and implementation of such devices.


Assuntos
Aprendizado Profundo , Redes Neurais de Computação , Algoritmos , Ásia , América do Norte
10.
Cancer Res ; 42(5): 1950-4, 1982 May.
Artigo em Inglês | MEDLINE | ID: mdl-6950813

RESUMO

The kinetics of uptake by cells and nuclear incorporation of aclacinomycin A was studied in Friend leukemia cells. It was shown that uptake is a very rapid process. The intracellular concentration is maximum in 10 min and mainly (about 75%) localized in the nucleus. Most of the incorporated drug will disappear from the cell by a two-step mechanism: (a) efflux from the nucleus to the cytoplasm; and (b) deglycosidation at C-7 to the alkavinone form in the cytoplasmic fraction. The cellular uptake was temperature dependent but was not prevented by sodium azide treatment. We assumed, therefore, that it is related to the composition and to the dynamic structure of the cell surface membrane. Nuclear outward transport and deglycosidation were inhibited by sodium azide and low temperatures; this suggests that they are regulated by an active transport process and by an enzymatic activity, respectively.


Assuntos
Leucemia Experimental/metabolismo , Infecções Tumorais por Vírus/metabolismo , Aclarubicina , Animais , Azidas/farmacologia , Linhagem Celular , Membrana Celular/metabolismo , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Vírus da Leucemia Murina de Friend , Naftacenos/farmacologia , Temperatura
11.
Cancer Res ; 44(12 Pt 1): 5544-9, 1984 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-6498816

RESUMO

Cross-resistance to rhodamine 123 (Rho-123) has been found in Adriamycin (ADM)-resistant and daunorubicin (DNR)-resistant Friend leukemia cell variants. Cytotoxicity in sensitive cells correlates with the intracellular amount of Rho-123, as determined by high-pressure liquid chromatography. Differential resistance coincides with Rho-123 accumulation which in sensitive cells was 20-fold higher than in resistant cells after 180 min of treatment. Sodium azide, which has been shown to inhibit ADM efflux and consequently increase drug accumulation in ADM-resistant cells, did not inhibit Rho-123 efflux. The difference in Rho-123 accumulation between sensitive and resistant cells correlates with cytotoxicity, which is in contrast to what has been found in these cells when treated with either ADM or DNR. Moreover, in contrast to the known effects of ADM and DNR on macromolecular synthesis, Rho-123 in sensitive cells was found to inhibit protein synthesis but had no effect on DNA or RNA synthesis. At Rho-123 doses which inhibited protein synthesis, drug localization changed from mitochondrial specific to generalized cytoplasmic. This effect was never achieved in resistant cells, even with prolonged drug exposure. The relevance of these findings is that different mechanisms of resistance to different drug types can be identified in the same cells even though similar resistance occurs. The similarity in resistance need not share a common mechanism. Although the drugs are effluxed more efficiently in resistant cells, the mechanisms for resistance in each case seem to differ. In the case of ADM and DNR, it appears to be multifactorial, whereas with Rho-123, total intracellular accumulation seems to be most important.


Assuntos
Daunorrubicina/toxicidade , Doxorrubicina/toxicidade , Leucemia Experimental/patologia , Rodaminas/toxicidade , Xantenos/toxicidade , Animais , Transporte Biológico , Linhagem Celular , Resistência a Medicamentos , Cinética , Camundongos , Rodamina 123 , Rodaminas/metabolismo
12.
Cancer Res ; 49(18): 5123-9, 1989 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-2788496

RESUMO

The purpose of these studies was to investigate whether the cell-differentiating effect of anthracyclines can trigger an over-production and secretion of molecules that may interfere with the tumor-host relationship. We exposed mouse hybridoma B-cells, which are devoted to immunoglobulin production, to doxorubicin (10-40 ng/ml). We found that most doxorubicin-treated cells secreted 3- to 5-fold higher amounts of immunoglobulin than untreated cells, along with an accumulation of 50% of them in the G2+M phase of the cell cycle. The antigenic specificity of the immunoglobulin and its size pattern as determined by polyacrylamide gel electrophoresis were similar whether or not cells were treated with doxorubicin. The enhancement of immunoglobulin secretion by doxorubicin was associated with an increase of the intracellular pool of heavy and light chains of the immunoglobulin. Furthermore, an elevated synthesis of immunoglobulin was observed. The synthesis of other proteins also appeared to be modified in these circumstances. These data suggest that doxorubicin can potentiate the biological functions of target cells when used at low concentrations, elevating the production and secretion of effector molecules that interfere with the tumor-host relationship.


Assuntos
Linfócitos B/imunologia , Doxorrubicina/farmacologia , Hibridomas/imunologia , Imunoglobulinas/biossíntese , Animais , Linfócitos B/citologia , Linfócitos B/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Hibridomas/citologia , Hibridomas/efeitos dos fármacos , Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Cinética , Camundongos , Biossíntese de Proteínas
13.
Cancer Res ; 50(15): 4698-701, 1990 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-2164445

RESUMO

The mechanism of action of 3'-deamino-3'-morpholino-13-deoxo-10-hydroxycarminomycin (MX2) was examined in a human leukemia cell line (K562) and its Adriamycin (ADM)-resistant subline (K562/ADM). ADM and MX2 showed an equivalent antitumor effect against K562. K562/ADM was highly resistant to ADM. In cellular pharmacokinetic studies, MX2 showed faster and greater influx than did ADM in both K562 and K562/ADM. The efflux of ADM was rapid in K562/ADM but not in K562. On the other hand, the efflux of MX2 was rapid in both cell lines. The formation of DNA single-strand breaks and double-strand breaks by ADM was significantly lower in K562/ADM than K562. On the other hand, formation of those breaks by MX2 was not decreased. Although some of the DNA breaks induced by MX2 were resealed, there was no difference in the degree of resealing in K562 and K562/ADM cells. On the other hand, most of the small number of DNA breaks in K562/ADM induced by ADM were resealed. The topoisomerase II activity in K562 and K562/ADM was not significantly different. It is concluded that MX2 conquers multidrug resistance by rapid influx following a higher frequency of formation of DNA single- and double-strand breaks in K562/ADM cells.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Carrubicina/análogos & derivados , Dano ao DNA , DNA de Neoplasias/efeitos dos fármacos , Daunorrubicina/análogos & derivados , Resistência a Medicamentos , Células Tumorais Cultivadas/metabolismo , Transporte Biológico , Carrubicina/metabolismo , Carrubicina/farmacologia , Linhagem Celular , Núcleo Celular/enzimologia , Sobrevivência Celular/efeitos dos fármacos , DNA Topoisomerases Tipo II/metabolismo , DNA de Cadeia Simples/efeitos dos fármacos , Doxorrubicina/metabolismo , Humanos , Cinética , Leucemia Mielogênica Crônica BCR-ABL Positiva , Células Tumorais Cultivadas/citologia , Células Tumorais Cultivadas/efeitos dos fármacos
14.
Biochem Pharmacol ; 32(12): 1819-24, 1983 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-6576787

RESUMO

The relationship between the structure and activity of aclacinomycin-A (ACM) metabolites was investigated in vitro in Friend leukaemia cells (FLC). The cytotoxic effect was related to the ease with which ACM and its metabolites accumulate in the nucleus. Cellular uptake and nuclear incorporation are influenced by the hexopyranoses linked to aklavinone (AKV) and by the two methyls linked to the L-rhodosamine amino groups. The effect of ACM and its metabolites on macromolecular synthesis depended on the drug concentrations and the exposure time. ACM was the most active in the inhibition of nucleic acid synthesis whereas it had no direct effect on protein synthesis even at high drug concentrations. When cells were treated for a short time with low drug concentrations (1 microM), RNA synthesis was inhibited to a greater extent than DNA synthesis. But when incubated for longer periods, inhibition of DNA synthesis increased further. RNA and DNA syntheses were both inhibited to about the same extent only when cells were exposed to the higher drug concentrations (10 microM). We conclude therefore that at low drug concentrations the effect on DNA synthesis is probably a consequence of RNA synthesis inhibition. The early DNA synthesis inhibition which occurs at higher drug concentrations may result from the direct action on the cellular genome.


Assuntos
Divisão Celular/efeitos dos fármacos , Substâncias Macromoleculares , Aclarubicina , Animais , Células Cultivadas , DNA de Neoplasias/biossíntese , Vírus da Leucemia Murina de Friend , Leucemia Experimental/metabolismo , Naftacenos/metabolismo , Naftacenos/farmacologia , RNA Neoplásico/biossíntese
15.
Leuk Res ; 10(6): 651-8, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3713252

RESUMO

Chromosome analysis was performed on adriamycin-sensitive and resistant Friend leukemia cells. Resistance to ADM is associated with an increased number of metacentric chromosomes. With increasing level of drug resistance additional metacentric chromosomes and several chromosomal markers were observed. Furthermore, the C-banding patterns and the heterochromatin distribution differed in resistant, as compared to sensitive cells. When sensitive cells were exposed to a toxic dose of ADM, multiple chromosomal breaks were observed in 62% of cells. In contrast, when ADM resistant cells were exposed to cytotoxic concentrations, the pulverization phenomenon was not observed and 75-80% of cells were without breaks. This striking difference suggests a different mechanism for cytotoxicity in sensitive and resistant cells.


Assuntos
Leucemia Experimental/genética , Animais , Linhagem Celular , Bandeamento Cromossômico , Cromossomos/efeitos dos fármacos , Doxorrubicina , Resistência a Medicamentos , Vírus da Leucemia Murina de Friend , Cariotipagem , Camundongos
16.
Leuk Res ; 12(5): 411-8, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3164087

RESUMO

Variants of Friend leukemia cells (FLC) selected for resistance to either adriamycin (ADM), daunorubicin (DNR) or aclacinomycin A (ACM) by step-wise exposure to each drug, were found to be cross-resistant to ADM and DNR but not to ACM. In addition, an epithelial cell line isolated from normal monkey kidney (CV-1) was found to be intrinsically resistant to ADM and DNR but not to ACM. In contrast, a human breast carcinoma cell line (MCF-7) was found to be sensitive to all three compounds. In these latter cell lines as well as in the FLC variants, lowered intracellular amounts of ADM and DNR correlated with resistance, but ACM levels were the same in sensitive and resistant cells. When cells with either acquired or intrinsic resistance were treated with ACM in combination with ADM or DNR, significant increases in the intracellular amounts of these latter compounds were found. Increased drug accumulation in resistant cells treated this way was accompanied by increased cytotoxicity. When resistant cells were exposed to ACM in combination with other anthracyclines, similar results were obtained. In comparison, these phenomena were not observed when either one of the sensitive cell types (parental FLC and MCF-7) were treated similarly. Since ADM and DNR resistant cells are sensitive to ACM and their resistance circumvented by ACM, this drug may have important clinical applications when used in combination with other anthracyclines.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Doxorrubicina/farmacologia , Células Tumorais Cultivadas/efeitos dos fármacos , Aclarubicina , Animais , Neoplasias da Mama/tratamento farmacológico , Daunorrubicina/farmacologia , Daunorrubicina/toxicidade , Resistência a Medicamentos , Sinergismo Farmacológico , Células Epiteliais , Humanos , Rim/patologia , Leucemia Experimental/tratamento farmacológico , Naftacenos/farmacologia
17.
Leuk Res ; 9(2): 289-96, 1985.
Artigo em Inglês | MEDLINE | ID: mdl-3990336

RESUMO

The relationship between the intracellular amount of a new anthracycline derivative, 4'-O-tetrahydropyranyl-adriamycin (THP-ADM) and its cytotoxic activity in Friend leukemia cells (FLC) was investigated. By comparison to adriamycin (ADM), the uptake of THP-ADM is a very rapid process reaching maximal levels within 5 min. Both drugs are accumulated and retained in the nuclear fraction. The two main consequences associated to these different uptake rate are: following short-time cell exposure to comparable drug concentration, the higher cytotoxic effect of THP-ADM correlates to the ease with which it crosses the cell membrane; the intracellular amount of THP-ADM but not of ADM decreases with the cell density. These results emphasize the importance of considering drug uptake kinetics and its relationship to cytotoxicity. Studies comparing uptake and efflux of both drugs in ADM-resistant cells showed that THP-ADM extrusion correlate more to cytotoxicity than that of ADM. The relevance of these in vitro findings to clinical application is considered.


Assuntos
Doxorrubicina/análogos & derivados , Leucemia Experimental/patologia , Animais , Contagem de Células , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Relação Dose-Resposta a Droga , Doxorrubicina/metabolismo , Doxorrubicina/farmacologia , Resistência a Medicamentos , Vírus da Leucemia Murina de Friend , Cinética , Leucemia Experimental/metabolismo , Camundongos , Fatores de Tempo
18.
Anticancer Res ; 6(2): 203-8, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3707056

RESUMO

Chromosome analysis was performed on Friend leukemia cells sensitive and resistant to doxorubicin. With increasing levels of resistance, increased numbers, of metacentric chromosomes and several chromosomal markers were observed. When sensitive cells were exposed to a toxic dose of doxorubicin, multiple chromosomal breaks were observed in 62% of cells. In contrast, when doxorubicin resistant cells were exposed to cytotoxic concentrations, the pulverization phenomenon was not observed. This striking difference suggests a different mechanism for cytotoxicity in sensitive and resistant cells. Moreover, when logarithmically growing cells were grafted subcutaneously in DBA2 mice, the tumorigenic property was related to the level of doxorubicin resistance.


Assuntos
Aberrações Cromossômicas , Doxorrubicina/toxicidade , Leucemia Experimental/etiologia , Animais , Resistência a Medicamentos , Vírus da Leucemia Murina de Friend , Cariotipagem , Leucemia Experimental/genética , Leucemia Experimental/patologia , Camundongos , Camundongos Endogâmicos DBA
19.
Anticancer Res ; 6(5): 1073-6, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3800316

RESUMO

Mitochondrial damage was found in Friend leukemia cells treated with rhodamine 123 (Rho 123). In contrast, when cells resistant to the drug were similarly treated, mitochondria were unaffected. These results correlated with higher levels of Rho 123 in sensitive as compared to resistant cells. However, when resistant cells were co-treated with verapamil, intracellular Rho 123 levels reached those of sensitive cells. At these levels mitochondrial damage and subsequent cytotoxicity in resistant cells were the same as in sensitive cells. These data suggest that differences in Rho 123 mitochondrial damage and subsequent cytotoxicity in sensitive and resistant cells result entirely from increased intracellular drug levels and not from differences in mitochondrial sensitivity or other mechanisms.


Assuntos
Doxorrubicina/farmacologia , Mitocôndrias/efeitos dos fármacos , Rodaminas/farmacologia , Verapamil/farmacologia , Xantenos/farmacologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Resistência a Medicamentos , Sinergismo Farmacológico , Vírus da Leucemia Murina de Friend , Leucemia Experimental/ultraestrutura , Camundongos , Microscopia Eletrônica , Rodamina 123
20.
Anticancer Res ; 6(4): 649-52, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3752944

RESUMO

Friend leukemia cells (FLC) resistant to different concentrations of doxorubicin were used to investigate the biochemical and biophysical changes associated with resistance. We have found that fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene analyzed on single cell level increased in resistant as compared to sensitive FLC. Furthermore, phospholipid analysis of sensitive and doxorubicin-resistant cells revealed changes in ratios of phosphatidyl-choline to phosphatidyl-ethanolamine and phosphatidyl-choline to sphingomyelin. These results correlate with decreased electrophoretic mobility in resistant cells. Our results indicate that changes in cell structure occur with the level of resistance to doxorubicin. These changes are probably the consequence rather than the cause of resistance.


Assuntos
Doxorrubicina/farmacologia , Leucemia Experimental/análise , Fosfolipídeos/análise , Células Cultivadas , Resistência a Medicamentos , Eletroforese , Polarização de Fluorescência , Vírus da Leucemia Murina de Friend
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