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1.
Diagn Cytopathol ; 25(4): 258-61, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11599112

RESUMO

Tumoral calcium pyrophosphate dihydrate deposition disease (TCPPD, tumoral or tophaceous pseudogout) is a rare nonneoplastic entity which mimics soft-tissue or skeletal malignancy. We present here the fine-needle aspiration cytology findings of a unique case of TCPPD in a 76-yr-old woman, with a large paraischial soft-tissue mass diagnosed as a malignant neoplasm. The difficulty in diagnosing such lesions by fine-needle aspirates is discussed and reviewed in the context of known cases from the literature.


Assuntos
Neoplasias Ósseas/diagnóstico , Condrocalcinose/diagnóstico , Condrossarcoma/diagnóstico , Idoso , Biópsia por Agulha , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/patologia , Pirofosfato de Cálcio/metabolismo , Condrocalcinose/diagnóstico por imagem , Condrocalcinose/metabolismo , Condrocalcinose/patologia , Condrossarcoma/diagnóstico por imagem , Condrossarcoma/metabolismo , Condrossarcoma/patologia , Diagnóstico Diferencial , Feminino , Humanos , Radiografia
2.
Mol Pharmacol ; 60(5): 907-15, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11641418

RESUMO

Mitochondria play an important role in the cell death induced by many drugs, including hepatotoxicity from overdose of the popular analgesic, acetaminophen (APAP). To investigate mitochondrial alterations associated with APAP-induced hepatotoxicity, the subcellular distribution of proapoptotic BAX was determined. Based on the antiapoptotic characteristics of BCL-2, we further hypothesized that if a BAX component was evident then BCL-2 overexpression may be hepatoprotective. Mice, either with a human bcl-2 transgene (-/+) or wild-type mice (WT; -/-), were dosed with 500 or 600 mg/kg (i.p.) APAP or a nonhepatotoxic isomer, N-acetyl-m-aminophenol (AMAP). Immunoblot analyses indicated increased mitochondrial BAX-beta content very early after APAP or AMAP treatment. This was paralleled by disappearance of BAX-alpha from the cytosol of APAP treated animals and, to a lesser extent, with AMAP treatment. Early pathological evidence of APAP-induced zone 3 necrosis was seen in bcl-2 (-/+) mice, which progressed to massive panlobular necrosis with hemorrhage by 24 h. In contrast, WT mice dosed with APAP showed a more typical, and less severe, centrilobular necrosis. AMAP-treated bcl-2 (-/+) mice displayed only early microvesicular steatosis without progression to extensive necrosis. Decreased complex III activity, evident as early as 6 h after treatment, correlated well with plasma enzyme activities at 24 h (AST r(2) = 0.89, ALT r(2) = 0.87) thereby confirming a role for mitochondria in APAP-mediated hepatotoxicity. In conclusion, these data suggest for the first time that BAX may be an early determinant of APAP-mediated hepatotoxicity and that BCL-2 overexpression unexpectedly enhances APAP hepatotoxicity.


Assuntos
Acetaminofen/toxicidade , Analgésicos não Narcóticos/toxicidade , Fígado/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Animais , Complexo III da Cadeia de Transporte de Elétrons/efeitos dos fármacos , Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Humanos , Immunoblotting , Fígado/patologia , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/fisiologia , Frações Subcelulares , Proteína X Associada a bcl-2
3.
Clin Orthop Relat Res ; (391): 234-8, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11603674

RESUMO

Bone is a common site of metastasis from lung cancer. Metastasis to the patella, however, is rare. A 76-year-old man presented with knee pain caused by an isolated patellar metastasis from squamous cell carcinoma of the lung. Treatment was delayed secondary to delay in diagnosis. In cases of bone pain that are unexplained or out of proportion to a traumatic event, more extensive diagnostic studies should be done.


Assuntos
Neoplasias Ósseas/secundário , Carcinoma de Células Escamosas/secundário , Neoplasias Pulmonares/patologia , Patela , Idoso , Neoplasias Ósseas/diagnóstico , Carcinoma de Células Escamosas/diagnóstico , Humanos , Masculino
4.
J Clin Oncol ; 19(13): 3203-9, 2001 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-11432887

RESUMO

PURPOSE: To determine whether treatment-induced pathologic necrosis correlates with local recurrence and overall survival in patients who receive neoadjuvant therapy for high-grade extremity soft tissue sarcomas. PATIENTS AND METHODS: Four hundred ninety-six patients with intermediate- to high-grade extremity soft tissue sarcomas received protocol neoadjuvant therapy. All patients underwent surgical resection after neoadjuvant therapy and had pathologic assessment of tumor necrosis in the resected specimens. RESULTS: The 5- and 10-year local recurrence rates for patients with > or = 95% pathologic necrosis were significantly lower (6% and 11%, respectively) than the local recurrence rates for patients with less than 95% pathologic necrosis (17% and 23%, respectively). The 5- and 10-year survival rates for the patients with > or = 95% pathologic necrosis were significantly higher (80% and 71%, respectively) than the survival rates for the patients with less than 95% pathologic necrosis (62% and 55%, respectively). Patients with less than 95% pathologic necrosis were 2.51 times more likely to develop a local recurrence and 1.86 times more likely to die of their disease as compared with patients with > or = 95% pathologic necrosis. The percentage of patients who achieved > or /= 95% pathologic necrosis increased to 48% with the addition of ifosfamide as compared with 13% of the patients in all the other protocols combined. CONCLUSION: Treatment-induced pathologic necrosis is an independent predictor of both local recurrence and overall survival in patients who receive neoadjuvant therapy for high-grade extremity soft tissue sarcomas. A complete pathologic response (> or = 95% pathologic necrosis) correlated with a significantly lower rate of local recurrence and improved overall survival.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Terapia Neoadjuvante/efeitos adversos , Recidiva Local de Neoplasia/epidemiologia , Sarcoma/tratamento farmacológico , Neoplasias de Tecidos Moles/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Criança , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Doxorrubicina/administração & dosagem , Doxorrubicina/efeitos adversos , Feminino , Seguimentos , Humanos , Ifosfamida/administração & dosagem , Ifosfamida/efeitos adversos , Los Angeles/epidemiologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Necrose , Recidiva Local de Neoplasia/diagnóstico , Prognóstico , Risco , Sarcoma/diagnóstico , Sarcoma/epidemiologia , Sarcoma/patologia , Neoplasias de Tecidos Moles/diagnóstico , Neoplasias de Tecidos Moles/epidemiologia , Neoplasias de Tecidos Moles/patologia , Taxa de Sobrevida
5.
Clin Orthop Relat Res ; (385): 186-91, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11302313

RESUMO

Echinococcosis (hydatid cyst disease) is a zoonotic infection caused by the parasitic tapeworm Echinococcus. The larval stage of this parasite can implant in many organs of the body, most commonly the liver, and create internal budding cystic masses. Echinococcal cysts also can implant in soft tissues; however, a review of the literature revealed no published case with the patient initially presenting with a soft tissue mass. Two such cases are reported in the current study. Physicians who evaluate soft tissue masses, particularly in patients from Echinococcus-endemic areas, need to include echinococcosis in their differential diagnoses. The current treatment of choice for soft tissue echinococcosis is wide resection combined with perioperative medical therapy.


Assuntos
Equinococose/cirurgia , Infecções dos Tecidos Moles/parasitologia , Infecções dos Tecidos Moles/cirurgia , Adulto , Equinococose/diagnóstico , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Infecções dos Tecidos Moles/diagnóstico , Tomografia Computadorizada por Raios X
6.
Plast Reconstr Surg ; 107(1): 135-9, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11176611

RESUMO

Injury to the triangular fibrocartilage complex (TFCC) is frequently implicated in the etiology of ulnar-sided wrist pain. This study examines the nervous anatomy of the TFCC using a nitric acid maceration technique and attempts to correlate this information with known tear patterns. Ten fresh frozen cadaveric specimens were studied in detail. Gross dissection of each upper-extremity specimen included removal of all flexor and extensor tendons. After identification and labeling with permanent color of the ulnar nerve, dorsal sensory branch of the ulnar nerve, posterior interosseous nerve, anterior interosseous nerve, and median nerve, an en bloc excision of the distal radioulnar region was performed. Digestion of the soft tissue was performed with nitric acid at sequential concentrations of 50% and 33% for 9 of 10 specimens. The digestion was halted by immersing the specimen in a mixture of 10% formaldehyde and 1% glycerine. After removal of bone, the specimens were fixed in paraffin, sectioned, and stained with hematoxylin and eosin. Nine of the 10 specimens were studied microscopically to determine the contribution of the grossly identified nerves to each zone of the triangular fibrocartilage complex as defined by Palmer's classification of acute TFCC tears. The anterior interosseous, median, and superficial radial nerves did not contribute to the innervation of the TFCC. The intraarticular course of the peripheral nerves could not be defined in the one specimen that was not digested with nitric acid. Nitric acid maceration is a rediscovered technique for identifying the nervous anatomy of soft tissues. The study showed that the triangular fibrocartilage complex is innervated by branches of the posterior interosseous, ulnar, and dorsal sensory ulnar nerves in a fairly consistent manner. Improved treatment of TFCC tears may result from an enhanced understanding of the supporting structures' innervation and mechanical function.


Assuntos
Cartilagem Articular/inervação , Articulação do Punho/inervação , Cartilagem Articular/anatomia & histologia , Dissecação/métodos , Humanos , Ligamentos Articulares/anatomia & histologia , Ligamentos Articulares/inervação , Ácido Nítrico , Nervos Periféricos/anatomia & histologia , Articulação do Punho/anatomia & histologia
7.
Cancer Res ; 60(22): 6457-64, 2000 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-11103813

RESUMO

The cytokine interleukin-12 (IL-12) has shown potent antitumor activity in several tumor models. Recently, natural killer (NK) T cells have been proposed to mediate the antitumor effects of IL-12. In this study, the antitumor response of IL-12 was investigated in a gene therapeutic model against s.c. growing mouse hepatocellular carcinomas using an adenoviral vector expressing murine IL-12 (AdVmIL-12). An adenoviral-based system was chosen because of the ability of adenoviruses to transduce dividing and nondividing cells and because of their high transduction efficiencies. Our goals were to examine the efficacy of AdVmIL-12 in a hepatocellular carcinoma model and to investigate the mechanism of the AdVmIL-12-mediated antitumor response with specific interest in the role of NK T cells. Our studies demonstrate that intratumoral AdVmIL-12-mediated regression of s.c. hepatocellular tumors is associated with rapid antitumor responses. AdVmIL-12 treatment was associated with an immune cellular infiltrate consisting of CD4 and CD8 T lymphocytes, macrophages, NK cells, and NK T cells. Antibody ablation of CD4 and CD8 T cells and use of NK cell-defective beige mice failed to abrogate the response to AdVmIL-12. Studies in T-cell- and B-cell-deficient severe combined immunodeficient and recombinase activating gene-2-deficient mice and T-cell-, B-cell-, and NK cell-defective severe combined immunodeficient/beige mice also failed to abrogate this response. AdVmIL-12 retained potent antitumor activity in mice with specific genetic defects in immune cellular cytotoxicity (perforin knockout mice) and costimulation (CD28 knockout mice). Use of mice with specific NK T cell deficiencies, Valpha14 T-cell receptor and CD1 knockout mice, also failed to abrogate the response to AdVmIL-12. Histological and immunohistochemical studies of AdVmIL-12-treated tumors showed extensive inhibition of neovascularization and a marked decrease in factor VIII-stained endothelial cells. Our studies indicate that the antitumor response of AdVmIL-12 is independent of direct cytotoxic cellular immunity (specifically, the function of NK T cells) and suggest that the initial mechanisms of AdVmIL-12-mediated tumor regression involve inhibition of angiogenesis.


Assuntos
Antígenos CD1/imunologia , Interleucina-12/imunologia , Células Matadoras Naturais/imunologia , Neoplasias Hepáticas Experimentais/imunologia , Linfócitos T/imunologia , Adenoviridae/genética , Adenoviridae/imunologia , Animais , Antígenos CD28/imunologia , Citotoxicidade Imunológica , Modelos Animais de Doenças , Humanos , Hospedeiro Imunocomprometido/imunologia , Interleucina-12/genética , Neoplasias Hepáticas Experimentais/terapia , Glicoproteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos SCID , Neovascularização Patológica/prevenção & controle , Perforina , Proteínas Citotóxicas Formadoras de Poros
8.
Surg Oncol ; 9(2): 71-5, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11094326

RESUMO

Gastrointestinal stromal sarcomas, formerly categorized as leiomyosarcomas of gastrointestinal origin, have a common pattern of intraperitoneal dissemination. Despite surgical resection with or without adjuvant systemic chemotherapy the vast majority of these patients succumb to intraperitoneal sarcomatosis and/or hepatic metastases. In an attempt to improve upon the morbidity and mortality associated with this disease we and several other centers have begun treating these patients with intraperitoneal chemotherapy. We have found that aggressive surgical resection with postoperative intraperitoneal chemotherapy has significantly lowered the peritoneal recurrence rate in patients with recurrent gastrointestinal stromal sarcomas as compared to those who have undergone surgical resection alone. However, this treatment approach has proven to be ineffective in preventing hepatic metastases, and thus has had little effect upon overall survival. With the treatment of primary rather than recurrent disease we hope to interrupt the disease process at an earlier stage further decreasing peritoneal recurrences and potentially improving survival.


Assuntos
Neoplasias Gastrointestinais/tratamento farmacológico , Mitoxantrona/administração & dosagem , Recidiva Local de Neoplasia/prevenção & controle , Sarcoma/tratamento farmacológico , Antineoplásicos/administração & dosagem , Quimioterapia Adjuvante , Feminino , Neoplasias Gastrointestinais/patologia , Neoplasias Gastrointestinais/cirurgia , Humanos , Injeções Intraperitoneais , Neoplasias Hepáticas/secundário , Masculino , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Sarcoma/patologia , Sarcoma/secundário , Sarcoma/cirurgia , Taxa de Sobrevida , Resultado do Tratamento
9.
Skeletal Radiol ; 29(8): 474-6, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11026717

RESUMO

Although osteosarcoma is the most common primary bone malignancy of childhood and adolescence that is not related to marrow cells, involvement of the short tubular bones is uncommon. In contrast to more conventional sites, where the tumor is usually high grade and found in adolescents, osteosarcoma of the small bones is more likely to be low grade, and is often seen in older individuals. We present a case of low-grade primary osteosarcoma of a metatarsal bone in a 25-year-old woman.


Assuntos
Neoplasias Ósseas/diagnóstico , Ossos do Metatarso , Osteossarcoma/diagnóstico , Adulto , Neoplasias Ósseas/diagnóstico por imagem , Feminino , Humanos , Osteossarcoma/diagnóstico por imagem , Radiografia
11.
Ann Surg Oncol ; 6(7): 645-50, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10560849

RESUMO

BACKGROUND: Recurrent abdominal sarcomas have an extremely high rate of recurrence and poor overall survival. A prospective study was initiated to assess the feasibility, toxicity, and benefit of surgical resection and intraperitoneal chemotherapy for improving local control of disease and overall survival. METHODS: Fifty-four patients underwent surgical excision of all gross disease and postoperative intraperitoneal chemotherapy with mitoxantrone. Thirty-five patients had peritoneal disease only (stage II), and 19 patients had peritoneal disease with hepatic metastases (stage III). RESULTS: Nine (17%) patients remain free of disease with a mean follow-up of 37 months. The remaining 45 patients (83%) have had recurrence, with a mean interval to recurrence of 11 months. Stage (P = .001) and grade (P = .005) were the only two variables found to significantly affect recurrence. There was an overall peritoneal recurrence rate of 48% and an overall hepatic failure rate of 69%. Nineteen (35%) of the patients are alive, with a mean follow-up of 46 months. The overall 5-year survival was 31%. The 5-year survival for stage II patients was 46%; for stage III patients, it was only 5%. Stage (P = .001) and grade (P = .056) were the only two variables found to significantly affect survival. There were no treatment-related deaths, and only 5 patients (9%) developed local complications. CONCLUSIONS: Aggressive surgical resection and intraperitoneal chemotherapy for recurrent abdominal sarcomas is a feasible treatment approach with minimal toxicity. Although this treatment had little effect on the hepatic spread of this disease and thus overall survival, it appears to have significantly lowered the rate of peritoneal recurrence and may provide a survival benefit for patients with disease limited to the peritoneum.


Assuntos
Neoplasias Abdominais/tratamento farmacológico , Neoplasias Abdominais/cirurgia , Antineoplásicos/uso terapêutico , Mitoxantrona/uso terapêutico , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/cirurgia , Sarcoma/tratamento farmacológico , Sarcoma/cirurgia , Adulto , Idoso , Terapia Combinada , Estudos de Viabilidade , Feminino , Humanos , Infusões Parenterais , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/secundário , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Prospectivos , Análise de Sobrevida
12.
J Med Assoc Thai ; 82(8): 839-43, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10511795

RESUMO

The incidence and mortality rate of bladder carcinoma remains high and is in fact increasing despite the application of new treatment strategies. Transitional cell carcinoma (TCC) is the most common carcinoma of the bladder (> 90% of cases). We report a case of a 60 year-old man with multiple bony metastases of TCC affecting the humerus, femur, spine, iliac wing, and ribs. The metastases were discovered within a year after first presentation of hematuria with a subsequent biopsy diagnosis of TCC of bladder, Grade 3 of 3 with no definite muscle invasion. Metastasis of TCC of bladder to bone is an uncommon occurrence when compared with breast and prostate carcinoma. This may be due to intrinsic properties of tumor cells and/or mechanisms of metastases. Recent studies confirm that bone is the preferred site of metastasis (35%) of TCC outside of the pelvis, with the spine being the most common site (40% of bony metastases). Histologic grading, emphasizing the presence of invasion, is generally accepted as being very important prognostically. The importance of diagnostic screening tests including urothelial biomarkers profile in reducing the mortality rate from first onset of hematuria is discussed such as tumor-associated antigen M344 and DD23.


Assuntos
Neoplasias Ósseas/secundário , Carcinoma de Células de Transição/secundário , Neoplasias da Bexiga Urinária/patologia , Biópsia por Agulha , Neoplasias Ósseas/diagnóstico , Neoplasias Ósseas/terapia , Carcinoma de Células de Transição/diagnóstico , Carcinoma de Células de Transição/terapia , Terapia Combinada , Evolução Fatal , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias da Bexiga Urinária/terapia
13.
Radiology ; 212(3): 682-6, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10478232

RESUMO

PURPOSE: To analyze the effectiveness of core-needle biopsy for evaluation of possible primary musculoskeletal neoplasms, which often are evaluated with open biopsy. MATERIALS AND METHODS: Core-needle biopsy was performed at a tertiary care institution in 141 patients suspected of having a mesenchymal neoplasm. In 85 patients, the lesion was in soft tissue; in 56 patients, the lesion was in bone. Eighty-nine patients had a malignant lesion, and 52 had a benign lesion. Twenty-eight patients had undergone previous surgery. RESULTS: In 105 (74%) patients, core-needle biopsy results were concordant with results from specimens subsequently obtained at surgery with respect to tumor histologic features and grade, or they provided sufficient diagnostic information to obviate surgery. In 36 (26%) patients, inaccurate core-needle biopsy results were obtained: In nine, results were imprecise about exact histologic features; in three, results were correct about histologic features but incorrect about tumor grade. In 25 (18%) patients, open biopsy was performed after core-needle biopsy. The accuracy and rate of performance of open biopsy for soft-tissue lesions were not significantly different from those for bone lesions. CONCLUSION: Percutaneous core-needle biopsy can be an effective alternative to open biopsy in the evaluation of possible mesenchymal neoplasms of either bone or soft tissue. Needle biopsy of such lesions, however, is best performed as part of a multidisciplinary team approach to tumor management.


Assuntos
Biópsia por Agulha , Neoplasias Ósseas/patologia , Neoplasias Musculares/patologia , Biópsia , Osso e Ossos/patologia , Diagnóstico Diferencial , Humanos , Mesenquimoma/patologia , Músculos/patologia , Sensibilidade e Especificidade , Neoplasias de Tecidos Moles/patologia
14.
Biochemistry ; 38(25): 8159-66, 1999 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-10387061

RESUMO

N-acetyl-p-benzoquinone imine (NAPQI), a reactive metabolite of acetaminophen (APAP), can arylate and oxidize protein and nonprotein thiols in the pathogenesis of APAP-induced hepatotoxicity. We report the first direct evidence for the formation of a labile ipso adduct between glutathione (GSH) and NAPQI using a combination of techniques including liquid chromatography/tandem mass spectrometry and liquid chromatography/NMR spectroscopy. Decomposition kinetics of the GSH-NAPQI ipso adduct and product ratios suggested that the ipso adduct was readily reversible back to NAPQI under neutral and basic conditions. The significance of the ipso adduct is that it may migrate from its site of formation to other cell compartments where it can either oxidize protein thiols or covalently modify them. Ipso adduct formation with protein thiols was demonstrated with a cysteine protease, papain, whose catalytic activity relies on the presence of an active site cysteinyl thiol. The formation and reactions of cysteinyl thiol ipso adducts of NAPQI provides significant new insights into possible reactions of quinone imines with cellular peptides and proteins.


Assuntos
Benzoquinonas/química , Cisteína/química , Iminas/química , Proteínas/química , Compostos de Sulfidrila/química , Acetaminofen/química , Ácido Ascórbico/química , Benzoquinonas/metabolismo , Cisteína/metabolismo , Glutationa/química , Glutationa/metabolismo , Meia-Vida , Iminas/metabolismo , Substâncias Macromoleculares , Papaína/antagonistas & inibidores , Papaína/química , Proteínas/metabolismo , Compostos de Sulfidrila/metabolismo
15.
Surg Oncol ; 8(4): 211-4, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11128835

RESUMO

Limb salvage is now possible for the majority of patients with extremity sarcomas. Although overall prognosis is primarily based on tumor size and histologic grade, complete surgical excision and local control is essential for cure. There are, however, certain anatomic locations such as the flexor fossae in which a complete surgical margin is difficult to attain, and surgery without adjuvant therapy has a high local failure and amputation rate. We have found that preoperative adjuvant therapy consisting of chemotherapy and radiation followed by surgical excision with tumor-free margins has been successful in treating flexor fossa sarcomas with high limb salvage (96%), local control (89%) and overall survival rates (70%). These results are comparable to patients with similar large, high-grade extremity tumors in other compartmental locations.


Assuntos
Sarcoma/cirurgia , Neoplasias de Tecidos Moles/cirurgia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Axila/cirurgia , Terapia Combinada , Fracionamento da Dose de Radiação , Doxorrubicina/administração & dosagem , Cotovelo/cirurgia , Virilha/cirurgia , Humanos , Ifosfamida/administração & dosagem , Joelho/cirurgia , Terapia Neoadjuvante , Sarcoma/tratamento farmacológico , Sarcoma/radioterapia , Neoplasias de Tecidos Moles/tratamento farmacológico , Neoplasias de Tecidos Moles/radioterapia
16.
J Chromatogr B Biomed Sci Appl ; 708(1-2): 75-85, 1998 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-9653949

RESUMO

A method for the quantification of subnanomolar levels of in vitro metabolites of caffeine by an isotope dilution gas chromatographic-mass spectrometric (GC-MS) assay has been developed and applied. Trideuteromethylated analogs of each primary metabolite were synthesized and added after incubations of caffeine with human liver microsomes high in cytochrome P4501A2. HPLC separation of the metabolites prior to GC-MS quantification allowed the isolation of theobromine and paraxanthine which coeluted by GC and enabled quantification over a larger dynamic range. Quantitative analysis was performed on the n-propylated derivatives by selected-ion monitoring of either the M+. ions for the dimethylxanthines or [M-C3H6]+. ions for 1,3,7-trimethyluric acid. For the least abundant metabolite (1,3,7-trimethyluric acid), the detection level on column was 200 pg. Replicate analyses exhibited intra- and inter-day variability of 4.2 and 7.9%, respectively. This assay has been successfully used in the quantification of caffeine's primary metabolites in more than 180 incubations, at varying substrate concentrations and with multiple enzyme sources.


Assuntos
Cafeína/metabolismo , Cromatografia Gasosa-Espectrometria de Massas/métodos , Cromatografia Líquida de Alta Pressão , Humanos , Técnicas In Vitro , Microssomos Hepáticos/metabolismo , Sensibilidade e Especificidade
17.
Drug Metab Dispos ; 26(7): 701-4, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9660853

RESUMO

(R)-(+)-Menthofuran is a potent, mechanism-based inactivator of human liver cytochrome P450 (CYP or P450) 2A6. Menthofuran caused a time- and concentration-dependent loss of CYP2A6 activity. The inactivation of CYP2A6 was characterized by a Ki of 2.5 microM and a kinact of 0.22 min-1 for human liver microsomes and a Ki of 0.84 microM and a kinact of 0.25 min-1 for purified expressed CYP2A6. Addition of various nucleophiles, a chelator of iron, or scavengers of reactive oxygen species or extensive dialysis failed to protect CYP2A6 from inactivation. An antibody to metallothionein conjugates of a suspected reactive metabolite of menthofuran was used to detect reactive menthofuran metabolite adducts with CYP2A6. These adducts were formed only in the presence of NADPH-P450 reductase and NADPH. Glutathione, methoxylamine, and semicarbazide did not prevent adduction of reactive menthofuran metabolites to CYP2A6, however. The menthofuran metabolite formation/CYP2A6 inactivation partition ratio was determined to be 3.5 +/- 0.6 nmol/nmol of P450. Menthofuran was unable to inactivate CYP1A2, CYP2D6, CYP2E1, or CYP3A4 in a time- and concentration-dependent manner.


Assuntos
Hidrocarboneto de Aril Hidroxilases , Inibidores das Enzimas do Citocromo P-450 , Inibidores Enzimáticos/farmacologia , Oxigenases de Função Mista/antagonistas & inibidores , Monoterpenos , Terpenos/farmacologia , Animais , Citocromo P-450 CYP2A6 , Humanos , NADP/farmacologia , Coelhos
18.
Toxicol Lett ; 95(2): 123-9, 1998 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-9635416

RESUMO

1,3-Butadiene (BD) is a gas used widely in the rubber and plastics industry as an intermediate in production processes and has been detected in automobile exhaust and cigarette smoke. BD requires metabolic activation to exert toxicity and has been shown to be carcinogenic in rodents. IARC has classified BD as a group 2A (probably carcinogenic to humans) carcinogen. The initial oxidation of BD to butadiene monoxide (BMO) occurs primarily via cytochrome P450 2E1 and two stereoisomers of BMO (R and S) can be formed. (R) and (S)-BMO are metabolized differently and demonstrate markedly different toxicities in isolated rat hepatocytes. This work examined the generation of (R) and (S)-BMO from BD by cytochrome P450 2E1 from rabbit, rat and human. BMO level was measured by GC-MS analysis and enantiomeric composition was determined by GC-FID. The greatest rate of formation of BMO from BD was obtained with rabbit cytochrome P4502E1 followed by human and then by rat. Enantiomeric distribution of R and S-BMO produced by the three species demonstrated no significant differences.


Assuntos
Butadienos/metabolismo , Carcinógenos/metabolismo , Citocromo P-450 CYP2E1/metabolismo , Compostos de Epóxi/metabolismo , Animais , Humanos , Técnicas In Vitro , Fígado/citologia , Fígado/enzimologia , Oxirredução , Coelhos , Ratos , Estereoisomerismo
19.
Cancer ; 82(9): 1704-8, 1998 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-9576292

RESUMO

BACKGROUND: The sentinel lymph node is defined as the first lymph node to receive drainage from a primary tumor. Based on this concept, the authors set out to evaluate whether the status of the sentinel lymph node can accurately predict whether breast tumor cells have metastasized to the axillary lymphatic basin. METHODS: Radiolabeled dextran was injected into the site of the breast tumor. In the operating room, a portable gamma detector probe was used to identify the exact location of the sentinel lymph node(s). After identifying and excising the radioactive sentinel lymph node specimens, a routine axillary lymph node dissection was performed. All lymph nodes were then subjected to hematoxylin and eosin (H & E) staining, and the sentinel lymph nodes were subjected to additional cytokeratin immunohistochemistry. RESULTS: Of the 41 patients who participated in the study, 18 had tumor metastasis to their axillary lymph nodes. In all 18 of these cases, the sentinel lymph node(s) contained cancer detected by either H & E staining or cytokeratin immunohistochemistry. CONCLUSIONS: The status of the sentinel lymph node(s) appears to predict accurately whether breast tumor cells have metastasized to the axillary lymphatic basin. This new, minimally invasive technique for staging breast carcinoma should be further validated in a large, multi-institutional clinical trial.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Dextranos , Linfonodos/diagnóstico por imagem , Linfonodos/patologia , Compostos de Organotecnécio , Compostos Radiofarmacêuticos , Feminino , Humanos , Linfonodos/cirurgia , Metástase Linfática , Estadiamento de Neoplasias , Cintilografia
20.
Chem Res Toxicol ; 11(4): 295-301, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9548799

RESUMO

Acetaminophen (APAP), a widely used analgesic and antipyretic agent, is bioactivated by cytochromes P450 to cause severe hepatotoxicity. APAP is oxidized by two pathways to form a toxic intermediate, N-acetyl-p-benzoquinone imine (NAPQI), and a nontoxic catechol metabolite, 3-hydroxy-APAP (3-OH-APAP). We investigated the role of P450 2E1 and 2A6 in APAP oxidation by using baculovirus-expressed and highly purified forms of human P450 2E1 and 2A6. An electrochemical HPLC assay was developed to quantify both oxidative metabolites simultaneously. For the first time, it was demonstrated that human P450 2E1 selectively oxidized APAP to NAPQI (assayed as its glutathione conjugate, GS-APAP), whereas human P450 2A6 selectively oxidized APAP to 3-OH-APAP. At 1 mM APAP, the relative ratio for the formation of GS-APAP vs 3-OH-APAP with human P450 2E1 was approximately 6:1, whereas the ratio with human P450 2A6 was 1:3. Apparent Km and Vmax values for the formation of GS-APAP by human P450 2E1 were 1.3 mM and 6.9 nmol/min/nmol of P450, respectively, whereas they were 4.6 mM and 7.9 nmol/min/nmol of P450 for P450 2A6. Apparent Km and Vmax values for the formation of 3-OH-APAP by human P450 2E1 were 4.0 mM and 2.5 nmol/min/nmol of P450, respectively, whereas they were 2.2 mM and 14.2 nmol/min/nmol of P450, respectively, for P450 2A6. Thus, although at toxic doses of APAP P450 2E1 is the more efficient catalyst for the formation of the toxic metabolite NAPQI, P450 2A6 also can contribute significantly to NAPQI production.


Assuntos
Acetaminofen/metabolismo , Analgésicos não Narcóticos/metabolismo , Hidrocarboneto de Aril Hidroxilases , Citocromo P-450 CYP2E1/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Oxigenases de Função Mista/metabolismo , Baculoviridae/enzimologia , Citocromo P-450 CYP2A6 , Humanos
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