Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
S Afr Med J ; 111(11): 1070-1073, 2021 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-34949271

RESUMO

BACKGROUND: Globally there is increasing awareness of the need for end-of-life care and palliative care in hospitalised patients who are in their final year of life. Limited data are available on palliative care requirements in low- and middle-income countries, hindering the design and implementation of effective policies and health services for these patients. OBJECTIVES: To determine the proportion of patients who die within 1 year of their date of admission to public hospitals in South Africa (SA), as a proxy for palliative care need in SA. METHODS: This was a retrospective cohort study using record linkage of admission and mortality data. The setting was 46 acute-care public hospitals in Western Cape Province, SA. RESULTS: Of 10 761 patients (median (interquartile range (IQR)) age 44 (31 - 60) years) admitted to the 46 hospitals over a 2-week period in March 2012, 1 570 (14.6%) died within 1 year, the majority within the first 3 months. Mortality rose steeply with age. The median (IQR) age of death was 57.5 (45 - 70) years. A greater proportion of patients admitted to medical beds died within 1 year (21.3%) compared with those admitted to surgical beds (7.7%). CONCLUSIONS: Despite a median age <60 years at admission, a substantial percentage of patients admitted to public sector hospitals in SA are in the final year of their lives. This finding should be seen in the context of SA's high communicable and non-communicable disease burden and resource-limited public health system, and highlights the need for policy development, planning and implementation of end-of-life and palliative care strategies for hospitals and patients.


Assuntos
Necessidades e Demandas de Serviços de Saúde , Mortalidade Hospitalar , Hospitalização , Cuidados Paliativos , Adulto , Fatores Etários , Idoso , Feminino , Hospitais Públicos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , África do Sul
2.
Skin Health Dis ; 1(3): e57, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35663138

RESUMO

We present a case of a 54-year-old male with multiple myeloma (MM) who presented with widespread pruritic erythematous lesions following ixazomib treatment. This occurred after his third cycle of treatment with ixazomib, thalidomide and dexamethasone and was controlled by potent steroids and temporary cessation of ixazomib. The strong correlation between the timeline of the rash, ixazomib treatment and subsequent cessation led to a diagnosis of a drug-induced rash. Skin biopsy histology, immunochemistry and the absence of monoclonal T-cell receptor gene rearrangement further confirmed the diagnosis of a T-cell pseudolymphoma secondary to ixazomib. Ixazomib is an oral proteasome inhibitor used in the treatment of MM. Other proteasome inhibitors have been reported to trigger cutaneous adverse effects. However, to our knowledge, this is the first report of pseudolymphoma following proteasome inhibitor use. Dermatologists should be aware of this potential effect and the possible management pathways such as cessation and dose reduction.

4.
Int J Popul Data Sci ; 4(2): 1143, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-32935043

RESUMO

INTRODUCTION: The Western Cape Provincial Health Data Centre (PHDC) consolidates person-level clinical data across government services, leveraging sustained investments in patient registration systems, a unique identifier, and maturation of administrative and clinical digital health systems. OBJECTIVES: The PHDC supports clinical care directly through tools for clinicians which integrate patient data or identify patients in need of interventions, and indirectly through supporting operational and epidemiological analyses. METHODS: The PHDC is housed entirely within government. Data are processed from a range of source systems, usually daily, through distinct harmonisation and curation, beneficiation, and reporting processes. Linkage is predominantly through the unique identifier which doubles as a pervasive folder number, augmented by other identifiers. Further data processing includes triangulation of multiple data sources for enumerating health conditions, with assignment of certainty levels for each enumeration. Outputs include patient-specific email alerts, a web-based consolidated patient clinical viewing platform, filterable line-listings of patients with specific conditions and associated characteristics and outcomes, management reports and dashboards, and data releases in response to operational and research data requests. Strict architectural, administrative and governance processes ensure privacy protection. RESULTS: In the past decade 8 million unique people are recorded as having sought healthcare in the provincial public sector health services, with current utilisation at 15 million attendances or admissions a year. Cross-sectional enumeration of health conditions includes over 430 000 people with HIV, 500 000 with hypertension, 235 000 with diabetes. Annually 110 000 pregnancies and 54 000 patients with tuberculosis are enumerated. Over 50 data requests are processed each year for internal and external requesters in accordance with data request and release governance processes. CONCLUSIONS: The single consolidated environment for person-level health data in the Western Cape has created new opportunities for supporting patient care, while improving the governance around access to and release of sensitive patient data.

6.
Dermatol Online J ; 22(2)2016 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-27267199

RESUMO

Rosacea fulminans is a rare disorder of unknown cause, almost exclusively affecting women. There are only a few reported cases in men. The condition is characterized by the abrupt onset of pustules and nodules predominantly affecting the cheeks or chin without any systemic upset. We report the case of a 37-year-old man who presented with papulopustules, predominantly localized to his nose. Histopathological features were consistent with rosacea fulminans. The patient was managed with treatments including oral prednisolone, isotretinoin, and trimethioprim.


Assuntos
Dermatoses Faciais/diagnóstico , Dermatoses Faciais/tratamento farmacológico , Rosácea/diagnóstico , Rosácea/tratamento farmacológico , Adulto , Anti-Infecciosos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Fármacos Dermatológicos/uso terapêutico , Quimioterapia Combinada , Dermatoses Faciais/patologia , Humanos , Isotretinoína/uso terapêutico , Masculino , Nariz , Prednisolona/uso terapêutico , Rosácea/patologia , Trimetoprima/uso terapêutico
7.
Lupus ; 25(3): 325-30, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26405020

RESUMO

BACKGROUND: The prevalence and severity of systemic lupus erythematosus (SLE) differs between ethnic groups and geographical regions. Although initially reported as rare, there is growing evidence that SLE is prevalent and runs a severe course in Africa. There is a paucity of prospective studies on African SLE patients. OBJECTIVE: The African Lupus Genetics Network (ALUGEN) is a multicentred framework seeking to prospectively assess outcomes in SLE patients in Africa. Outcomes measured will be death, hospital admission, disease activity flares, and SLE-related damage. We will explore predictors for these outcomes including clinical, serological, socio-demographic, therapeutic and genetic factors. Further, we will investigate comorbidities and health-related quality of life amongst these patients. METHODS: Data of patients recently (≤ 5 yrs) diagnosed with SLE will be collected at baseline and annual follow-up visits, and captured electronically. The ALUGEN project will facilitate standardized data capture for SLE cases in Africa, allowing participating centres to develop their own SLE registries, and enabling collaboration to enrich our understanding of inter-ethnic and regional variations in disease expression. CONCLUSION: Comprehensive, high-quality multi-ethnic data on African SLE patients will expand knowledge of the disease and inform clinical practice, in addition to augmenting research capacity and networking links and providing a platform for future biomarker and interventional studies.


Assuntos
População Negra/genética , Lúpus Eritematoso Sistêmico/etnologia , Lúpus Eritematoso Sistêmico/genética , Sistema de Registros , África/epidemiologia , Bases de Dados Genéticas , Seguimentos , Predisposição Genética para Doença , Humanos , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/terapia , Fenótipo , Prevalência , Prognóstico , Estudos Prospectivos , Projetos de Pesquisa , Fatores de Risco , Índice de Gravidade de Doença , Fatores de Tempo
9.
Lupus ; 23(1): 102-11, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24174511

RESUMO

The epidemiology of systemic lupus erythematosus (SLE) in Africa is largely undetermined, and the perception persists that the incidence of SLE on the continent is very low. Recent studies as well as our own experience, however, suggest that this is not the case. We have conducted a survey amongst medical practitioners in Africa to determine their experiences of diagnosing and treating SLE patients, and the results suggest that significant numbers of African patients are presenting with SLE. The apparent low incidence rate in Africa may be the result of underdiagnosis due to poor access to health care, low disease recognition within primary health care settings, limited access to diagnostic tools and inadequate numbers of specialist physicians. Treatment of SLE in Africa is also restricted by availability and affordability of immunosuppressive drugs. We have established the African Lupus Genetics Network (ALUGEN), an informal network of clinicians and researchers in Africa who have an interest in SLE, in order to facilitate combined clinical and research efforts towards improved outcomes for African SLE patients.


Assuntos
Redes Comunitárias , Lúpus Eritematoso Sistêmico/epidemiologia , África/epidemiologia , Humanos , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/terapia
10.
Lupus ; 21(9): 1017-24, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22451603

RESUMO

There are few published studies on biopsy proven lupus nephritis (LN) from sub-Sahara Africa, mainly due to lack of expertise and pathology back-up for performing and interpreting renal biopsies in many centres. The purpose of this study was to document factors associated with biopsy proven LN and to determine clinical and laboratory models that best predict proliferative LN in South Africans. Of the 251 patients studied, 84.1% were females and 79.3% were of mixed ancestry. There were more observed cases of proliferative LN (63%) than non-proliferative LN. Factors associated with proliferative LN were male gender (p = 0.049), haematuria on dipstix (p < 0.0001), proteinuria on dipstix (p = 0.042), low serum albumin (p = 0.032), low complement C3 (p < 0.0001), low complement C4 (p = 0.009) and positive double-stranded DNA (p = 0.039). Using four models designed from various combinations of the factors associated with proliferative LN, the specificity and positive predictive values were highest for the model that combined gender (male), presence of dipstix haematuria and proteinuria, hypoalbuminaemia, low C3 and low C4 and positive double-stranded DNA (100% respectively). Further study is recommended to identify the value of using these demographic and laboratory parameters in identifying patients with proliferative LN in resource limited centres where the performance of a biopsy is not possible.


Assuntos
Nefrite Lúpica/patologia , Adulto , Idoso , Biópsia , Proliferação de Células , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Caracteres Sexuais
11.
J Plast Reconstr Aesthet Surg ; 65(9): 1267-9, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22364661

RESUMO

Epidermoid cysts are commonly encountered in clinical practice and while the majority are benign, isolated cases of premalignant and malignant conditions have been identified in their walls. We report four cases of squamous cell carcinoma arising in the walls of epidermoid cysts and review the literature.


Assuntos
Carcinoma de Células Escamosas/patologia , Transformação Celular Neoplásica/patologia , Cisto Epidérmico/patologia , Neoplasias Cutâneas/patologia , Idoso , Biópsia por Agulha , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/cirurgia , Intervalo Livre de Doença , Cisto Epidérmico/cirurgia , Feminino , Seguimentos , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neoplasias Cutâneas/mortalidade , Neoplasias Cutâneas/cirurgia , Resultado do Tratamento
12.
Colorectal Dis ; 11(1): 89-93, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18400041

RESUMO

INTRODUCTION: The implementation of bowel cancer screening in the UK requires the maintenance of high standards in colonoscopy. Part of this quality control requires the reliable documentation of complete colonoscopy that can be externally audited and assessed. It has been suggested that terminal ileal biopsy is the only definitive and reliable method of confirming caecal intubation, but it is not cost-effective and may now be contraindicated because of potential prion infection. OBJECTIVE: To determine how reliable routine terminal ileal images were as an independent predictor of complete colonoscopy and whether their interpretation was aided with water insufflation or indigo-carmine dye-spraying. Method Forty-nine histologically confirmed terminal ileal images were obtained from a single endoscopist's database; 19 were conventional white-light images, 15 were taken with water insufflation and 15 were taken using chromoscopy enhancement. The images were transferred onto CD-ROM and sent as a questionnaire to 42 colonoscopists who were asked to identify the images as terminal ileum or not. RESULTS: Twenty questionnaires were returned resulting in a total of 980 responses. Overall, the accuracy of positive identification was 53.4%. Water insufflation and chromoscopy improved the accuracy to 68.3% and 63% respectively. Experience of (> 1000 colonoscopies) did not increase overall accuracy. Less experienced endoscopists had an increased accuracy rate with dye-spraying (76.7%vs 59.3%, P < 0.05) but experienced endoscopists had an increased accuracy rate with water insufflation (67.4%vs 63.3%, P > .05). CONCLUSION: Currently, terminal ileal imaging is not a reliable mode of documenting complete colonoscopy. Using water insufflation or dye-spraying coupled with modifications in image acquisition technique may improve its reliability but these methods require further investigation before they can replace the use of caecal landmarks as completion parameters.


Assuntos
Neoplasias do Colo/diagnóstico , Colonoscopia/normas , Íleo/anatomia & histologia , Garantia da Qualidade dos Cuidados de Saúde , Colonoscopia/métodos , Documentação , Humanos , Variações Dependentes do Observador , Fotografação , Reino Unido
13.
Colorectal Dis ; 10(9): 891-7, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18355372

RESUMO

OBJECTIVE: A prospective technical feasibility study of cap assisted ESD for 'curative intent' in patients with residual or local neoplastic recurrence following EMR. Primary end points were second stage R0 resection rate, safety and recurrence. METHOD: Salvage ESD was performed using the Olympus GIF-XQ240 gastroscope and KD-630L insulation tipped knife. Thirty-day mortality, re-admission rates, complications and histological resection status were collected prospectively up to 9 months following index resection. RESULTS: Thirty patients met eligibility criteria. Index R0 resection was achieved in 25/30 (83%) lesions. One patient underwent surgical excision with a second receiving a curative second stage dissection. Ninety-six per cent (29/30) patients were discharged within 24 h of the procedure with a 0% 30-day mortality and re-admission rate. Bleeding occurred in 5/30 (16%) treated successfully with endoluminal haemostasis. There were no perforations. Overall 'cure' rates at short-term follow-up [median 6/12 (range; 3-18)] was 96%. CONCLUSION: This novel application of ESD for first line 'salvage' therapy in treating residual or locally recurrent neoplastic disease may be a safe, minimally invasive and cost effective alternative to direct surgical resection in a select patient cohort.


Assuntos
Carcinoma in Situ/cirurgia , Neoplasias Colorretais/cirurgia , Mucosa Intestinal/cirurgia , Recidiva Local de Neoplasia/cirurgia , Terapia de Salvação , Idoso , Idoso de 80 Anos ou mais , Procedimentos Cirúrgicos do Sistema Digestório , Dissecação/métodos , Endoscopia , Endoscopia do Sistema Digestório , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasia Residual , Estudos Prospectivos
14.
Br J Surg ; 95(5): 636-45, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18324640

RESUMO

BACKGROUND: Conventional colonoscopy has a significant false-negative rate for intraepithelial neoplasia. Chromoendoscopy increases sensitivity but lacks specificity. The aim was to assess prospectively the clinical applicability and predictive power of the EC3870CIFK confocal laser endomicroscope (CLE) for the in vivo diagnosis of intraepithelial neoplasia during colonoscopy. METHODS: Lesions were identified using chromoscopy followed by CLE imaging and graded according to vascular and cellular changes. CLE imaging of circumscribed lesions and four segmental 'normal' colorectal quadrants was performed. Targeted biopsy specimens were then compared with histopathological results. RESULTS: Forty patients completed the protocol (22 men and 18 women; median age 62 (range 39-82) years). The median duration of ileal intubation and total procedure time were 12 (range 5-26) and 55 (range 28-92) min respectively. Chromoscopic colonoscopy revealed 162 lesions in 39 patients. CLE imaging was obtained on all 162 lesions. Some 5422 confocal images were compared with 802 targeted biopsy specimens. Intraepithelial neoplasia was predicted with an accuracy of 99.1 per cent (sensitivity 97.4 per cent and specificity 99.3 per cent) (P = 0.711). CONCLUSION: Confocal laser endomicroscopy permits high-quality cellular, subsurface vascular and stromal imaging, enabling prediction of intraepithelial neoplasia with a high level of accuracy.


Assuntos
Colonoscopia/métodos , Neoplasias Colorretais/patologia , Mucosa Intestinal/patologia , Microscopia Confocal/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia/métodos , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Estudos Prospectivos , Sensibilidade e Especificidade
15.
Endoscopy ; 40(2): 110-4, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18253905

RESUMO

BACKGROUND AND AIMS: Loss of mucosal 'lift' prior to submucosal dissection or endoscopic mucosal resection (EMR) increases the risk of complications. We conducted a randomized controlled trial comparing dextrose solution with sodium hyaluronic acid (SHA) for the EN BLOC resection of Paris type I/0-II and lateral spreading lesions of the colorectum. PATIENTS AND METHODS: Patients with Paris type I/0-II or lateral spreading tumor lesions of < 30 mm were randomized in a 1 : 1 ratio to undergo EMR using either dextrose solution or SHA. The primary study outcome was complete resection. Secondary outcomes were endoscopic complications (i. e. perforation or bleeding) and polyp recurrence rates. RESULTS: A total of 174 patients were randomized. R0 resection was achieved in 59 of the 82 lesions (72 %) in the dextrose group and 56 of the 81 lesions (69 %) in the SHA group ( P > 0.1), with no significant difference in median lesion diameter ( P > 0.1). The median number of post resection surveillance colonoscopies was 3 (range 2 - 7) in the dextrose group and 4 (range 2 - 6) in the SHA group ( P = NS). The median post index EMR resection follow-up period was 20 months (range 4 - 26) in the DS group and 18 months (range 3 - 22) in the SHA group ( P = NS). Recurrence rates were 1/82 (1.21 %) in the dextrose group and 1/81 (1.23 %) in the SHA group ( P = NS). CONCLUSIONS: EMR using dextrose solution is as effective as SHA in terms of resection completion, recurrence rates, and complications.


Assuntos
Adenoma/cirurgia , Colonoscopia/métodos , Neoplasias Colorretais/cirurgia , Glucose/farmacologia , Ácido Hialurônico/farmacologia , Mucosa Intestinal/cirurgia , Adenoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia por Agulha , Distribuição de Qui-Quadrado , Neoplasias Colorretais/patologia , Método Duplo-Cego , Feminino , Humanos , Imuno-Histoquímica , Injeções Intralesionais , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Probabilidade , Medição de Risco , Sensibilidade e Especificidade , Resultado do Tratamento
16.
Histopathology ; 52(4): 417-26, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17903203

RESUMO

Recently, miniaturization of a novel confocal laser endomicroscope (Optiscan Pty, Notting Hill, Victoria, Australia) has permitted functional integration into the distal tip of a conventional video colonoscope (Pentax EC3870K; Pentax, Tokyo, Japan) enabling imaging of the surface epithelium and the underlying lamina propria during ongoing video endoscopy. Using endomicroscopy and intravenous sodium fluorescein as a contrast agent, 'virtual histology' can be created, which allows visualization of both the surface epithelium, and some of the lamina propria (down to a quarter of a millimetre), including the microvasculature. Confocal endomicroscopy may have major implications in the future of colonoscopy as uniquely it allows in vivo diagnosis of colonic intraepithelial neoplasia and carcinoma enabling 'smart' biopsy targeting and hence potentially influencing 'on table' management decisions. Initial pilot data have now shown that confocal imaging in vivo using the newly developed EC3870K has high overall accuracy for the immediate diagnosis of intraepithelial neoplasia and carcinoma in sporadic screened cohorts, but also has a role in the detection of intraepithelial neoplasia detection in chronic ulcerative colitis cancer screening when used in conjunction with methylene blue chromoscopy. We discuss the current evidence in support of confocal endomicroscopy in the colorectum and explore the new diagnostic possibilities for this technology.


Assuntos
Adenoma/patologia , Carcinoma in Situ/patologia , Colonoscopia/métodos , Neoplasias Colorretais/patologia , Microscopia Confocal/métodos , Adenoma/complicações , Biópsia , Colite Ulcerativa/complicações , Colite Ulcerativa/patologia , Neoplasias Colorretais/complicações , Humanos , Período Intraoperatório , Microscopia Confocal/instrumentação , Miniaturização
17.
Br J Cancer ; 89(2): 327-32, 2003 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-12865925

RESUMO

Rhabdomyosarcoma (RMS) is a common paediatric soft tissue sarcoma that resembles developing foetal skeletal muscle. Tumours of the alveolar subtype frequently harbour one of two characteristic translocations that juxtapose PAX3 or PAX7, and the forkhead-related gene FKHR (FOXO1A). The embryonal subtype of RMS is not generally associated with these fusion genes. Here, we have quantified the relative levels of chimaeric and wild-type PAX transcripts in various subtypes of RMS (n=34) in order to assess the relevance of wild-type PAX3 and PAX7 gene expression in these tumours. We found that upregulation of wild-type PAX3 is independent of the presence of either fusion gene and is unlikely to contribute to tumorigenesis. Most strikingly, upregulated PAX7 expression is almost entirely restricted to cases without PAX3-FKHR or PAX7-FKHR fusion genes and may contribute to tumorigenesis in the absence of chimaeric PAX transcription factors. Furthermore, as myogenic satellite cells are known to express PAX7, this pattern of PAX7 expression suggests this cell type as the origin of these tumours. This is corroborated by the detection of MET (c-met) expression, a marker for the myogenic satellite cell lineage, in all RMS samples expressing wild-type PAX7.


Assuntos
Regulação da Expressão Gênica , Proteínas de Homeodomínio/biossíntese , Músculo Esquelético/citologia , Rabdomiossarcoma Embrionário/genética , Rabdomiossarcoma Embrionário/patologia , Células Satélites de Músculo Esquelético , Animais , Proteínas de Ligação a DNA/biossíntese , Modelos Animais de Doenças , Proteína Forkhead Box O1 , Fatores de Transcrição Forkhead , Humanos , Camundongos , Proteínas Musculares , Proteínas do Tecido Nervoso , Fator de Transcrição PAX3 , Fator de Transcrição PAX7 , Fatores de Transcrição Box Pareados , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rabdomiossarcoma Embrionário/etiologia , Fatores de Transcrição/biossíntese , Células Tumorais Cultivadas , Regulação para Cima
19.
Br J Cancer ; 85(11): 1746-52, 2001 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-11742497

RESUMO

The MDM2 protein is known to be overexpressed in some sarcomas including rhabdomyosarcoma. However, the extent to which the MDM2 protein influences sensitivity to chemotherapeutic drugs is unclear. We have analysed this further using stable transfection of the mdm2 gene into 4 well-characterised human paediatric rhabdomyosarcoma cell lines. Transfection with the mdm2 gene resulted in increased levels of the MDM2 protein in all the cell lines. In 2 of the lines, SCMC and RD, the mdm2 gene caused between 2-fold and 61-fold increase in resistance to vincristine, etoposide and doxorubicin but not to cisplatin. In these lines there was an increase in expression of the mdr-1 gene which encodes P-glycoprotein, but not the mrp1 gene which encodes the multidrug resistance protein (MRP). The resistance was reversible using the MDR modulator PSC833, confirming the presence of P-glycoprotein. We conclude that MDM2 overexpression may be a mechanism by which multidrug resistance is regulated in some rhabdomyosarcomas.


Assuntos
Proteínas Nucleares , Proteínas Proto-Oncogênicas/metabolismo , Rabdomiossarcoma/patologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos/farmacologia , Divisão Celular/efeitos dos fármacos , Criança , Cisplatino/farmacologia , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Etoposídeo/farmacologia , Regulação Neoplásica da Expressão Gênica , Humanos , Concentração Inibidora 50 , Plasmídeos/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-mdm2 , Rabdomiossarcoma/genética , Rabdomiossarcoma/metabolismo , Transfecção , Células Tumorais Cultivadas/efeitos dos fármacos , Vincristina/farmacologia
20.
Clin Cancer Res ; 7(10): 3193-8, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11595714

RESUMO

We have established preclinical models for the development of drug resistance to vincristine (a major drug used in the treatment of pediatric rhabdomyosarcoma) using cell lines. The RD cell line has a mutant P53 phenotype and does not have detectable P-glycoprotein (P-gp) or multidrug resistance-related protein (MRP) despite expressing low levels of mdr-1 mRNA, which encodes P-gp and mrp1 mRNA. Resistant variants of RD were derived by exposure to increasing concentrations of vincristine. This was repeated on six occasions, resulting in three cell lines which could tolerate 64 x the IC(50) concentration. Six independent agents were tested for their ability to prevent the development of resistance in this model. Despite at least 10 attempts, resistance did not develop in the presence of the multidrug resistance (MDR) modulators PSC833, VX710, and XR9576. This strongly suggests that these agents may delay or even prevent the development of resistance to vincristine. This was also confirmed in a second rhabdomyosarcoma cell line, Rh30. In contrast, the agents indomethacin (MRP1 modulator), CGP41251 (protein kinase C inhibitor), and dexrazoxane (putative MDR prevention agent) did not affect the development of resistance in the RD model. Characterization of the resistant cell lines indicated the presence of increased mdr-1 and P-gp expression, which resulted in resistance to the agents doxorubicin, etoposide, and vincristine but not cisplatin. The resistance could be modulated using PSC833 or VX710, confirming that functional P-gp is present. No apparent differences were seen between the resistant cell lines derived in the absence and presence of the various agents. These experiments strongly suggest that the development of MDR may be preventable using modulators of MDR and merit clinical studies to test this hypothesis.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Rabdomiossarcoma/patologia , Estaurosporina/análogos & derivados , Antineoplásicos/farmacologia , Criança , Cisplatino/farmacologia , Ciclosporinas/farmacologia , Doxorrubicina/farmacologia , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Etoposídeo/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Indometacina/farmacologia , Concentração Inibidora 50 , Piperidinas/farmacologia , Piridinas/farmacologia , Quinolinas/farmacologia , RNA Neoplásico/genética , RNA Neoplásico/metabolismo , Razoxano/farmacologia , Rabdomiossarcoma/tratamento farmacológico , Rabdomiossarcoma/genética , Estaurosporina/farmacologia , Fatores de Tempo , Células Tumorais Cultivadas , Vincristina/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA