Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 45
Filtrar
1.
Abdom Radiol (NY) ; 46(1): 96-110, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-31950204

RESUMO

Elastography is an established technique in the evaluation of chronic liver diseases. While there is a large clinical experience and data available regarding the performance of elastography in native liver, elastography experience with liver grafts is limited and still growing. Both ultrasound-based elastography techniques and MR Elastography (MRE) are useful in the assessment of liver fibrosis in liver transplants. Technical modifications for performing elastography will be required for optimum evaluation of the graft. In general, caution needs to be exercised regarding the use of elastography immediately following transplantation as post-operative changes, perioperative conditions/complications, inflammation, and rejection can cause increased stiffness in the graft. In the follow-up, detection of increased stiffness with elastography is useful for predicting development of fibrosis in the graft. Adjunctive MRI or ultrasound with Doppler also provides comprehensive evaluation of anatomy, vascular anastomosis and patency, biliary tree, and stiffness for fibrosis. In this review, we provide a brief overview of elastography techniques available followed by the literature review of elastography in the evaluation of grafts and illustration with clinical examples.


Assuntos
Técnicas de Imagem por Elasticidade , Transplante de Fígado , Aloenxertos , Humanos , Fígado/diagnóstico por imagem , Cirrose Hepática/patologia
2.
Mol Cell Biol ; 18(7): 4347-57, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9632818

RESUMO

Gene targeting of transcription factor PU.1 results in an early block to fetal hematopoiesis, with no detectable lymphoid or myeloid cells produced in mouse embryos. Furthermore, PU.1(-/-) embryonic stem (ES) cells fail to differentiate into Mac-1(+) and F4/80(+) macrophages in vitro. We have previously shown that a PU.1 transgene under the control of its own promoter restores the ability of PU. 1(-/-) ES cells to differentiate into macrophages. In this study, we take advantage of our PU.1(-/-) ES cell rescue system to genetically test which previously identified PU.1 functional domains are necessary for the development of mature macrophages. PU.1 functional domains include multiple N-terminal acidic and glutamine-rich transactivation domains, a PEST domain, several serine phosphorylation sites, and a C-terminal Ets DNA binding domain, all delineated and characterized by using standard biochemical and transactivational assays. By using the production of mature macrophages as a functional readout in our assay system, we have established that the glutamine-rich transactivation domain, a portion of the PEST domain, and the DNA binding domain are required for myelopoiesis. Deletion of three acidic domains, which exhibit potent transactivation potential in vitro, had no effect on the ability of PU.1 to promote macrophage development. Furthermore, mutagenesis of four independent sites of serine phosphorylation also had no effect on myelopoiesis. Collectively, our results indicate that PU.1 interacts with important regulatory proteins during macrophage development via the glutamine-rich and PEST domains. The PU.1(-/-) ES cell rescue system represents a powerful, in vitro strategy to functionally map domains of PU.1 essential for normal hematopoiesis and the generation of mature macrophages.


Assuntos
Glutamina/fisiologia , Macrófagos/citologia , Proteínas Proto-Oncogênicas/fisiologia , Transativadores/fisiologia , Ativação Transcricional , Células 3T3 , Animais , Sítios de Ligação , Diferenciação Celular , Glutamina/genética , Humanos , Camundongos , Proteínas Proto-Oncogênicas/genética , Transativadores/genética
3.
Nat Biotechnol ; 19(7): 673-6, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11433281

RESUMO

RNA quantitation is becoming increasingly important in basic, pharmaceutical, and clinical research. For example, quantitation of viral RNAs can predict disease progression and therapeutic efficacy. Likewise, gene expression analysis of diseased versus normal, or untreated versus treated, tissue can identify relevant biological responses or assess the effects of pharmacological agents. As the focus of the Human Genome Project moves toward gene expression analysis, the field will require a flexible RNA analysis technology that can quantitatively monitor multiple forms of alternatively transcribed and/or processed RNAs (refs 3,4). We have applied the principles of invasive cleavage and engineered an improved 5'-nuclease to develop an isothermal, fluorescence resonance energy transfer (FRET)-based signal amplification method for detecting RNA in both total RNA and cell lysate samples. This detection format, termed the RNA invasive cleavage assay, obviates the need for target amplification or additional enzymatic signal enhancement. In this report, we describe the assay and present data demonstrating its capabilities for sensitive (<100 copies per reaction), specific (discrimination of 95% homologous sequences, 1 in > or =20,000), and quantitative (1.2-fold changes in RNA levels) detection of unamplified RNA in both single- and biplex-reaction formats.


Assuntos
RNA/análise , Espectrometria de Fluorescência/métodos , Sequência de Bases , Biotecnologia/métodos , HIV/metabolismo , Modelos Genéticos , Dados de Sequência Molecular , RNA/metabolismo , RNA Mensageiro/metabolismo , Proteínas Recombinantes/metabolismo , Homologia de Sequência do Ácido Nucleico
4.
Cancer Res ; 52(8): 2248-52, 1992 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-1559228

RESUMO

Ascitic fluid from human ovarian cancer patients often contains a large number of leukocytes along with tumor cells. Some of the recent evidence suggests that the ascitic fluid contains factors capable of inducing the growth of ovarian cancer cells in vitro and in vivo. While these factors have not yet been completely characterized, growth factors secreted by the tumor cells could influence the tumor growth by paracrine and autocrine mechanisms. Earlier, we reported that ovarian epithelial cancer cells produce macrophage colony-stimulating factor. It appears that these tumor cells produce more than one cytokine. Identifying the various products secreted by the tumor cells would provide valuable information needed to understand the biology of ovarian cancer. In the present study, evidence is provided for the first time that five different human ovarian epithelial tumor cell lines and tumor cells isolated from the ascitic fluid of four cancer patients express interleukin (IL) 1 alpha and beta genes constitutively. Production of the lymphokine was determined by analyzing the cellular RNA for IL-1-related transcripts and by immunological assays. Ovarian cancer cells also secrete another pleiotropic cytokine, IL-6, constitutively. In many systems, IL-1 induces the expression of the IL-6 gene. To determine whether the basal levels of IL-6 production are dependent on the endogenous IL-1, neutralization studies were carried out. Addition of antibodies to IL-1 did not decrease the levels of IL-6 secreted by the cancer cell lines. These results suggest that multiple cytokines are produced by ovarian cancer cells and that the endogenous IL-1 may not be directly involved in the regulation of IL-6 gene expression in these cells.


Assuntos
Interleucina-1/genética , Neoplasias Ovarianas/genética , RNA Mensageiro/análise , Líquido Ascítico/química , Feminino , Humanos , Interleucina-1/metabolismo , Interleucina-1/farmacologia , Interleucina-6/metabolismo , Neoplasias Ovarianas/metabolismo , Células Tumorais Cultivadas
5.
AIDS Res Hum Retroviruses ; 7(12): 1025-30, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1725958

RESUMO

Peripheral blood mononuclear cells from seronegative donors were stimulated with phytohemagglutinin and then infected with human immunodeficiency virus (HIV-1). Using this experimental system, the antiviral activity of two translation inhibitory proteins (pokeweed antiviral protein, PAP-S, and Luffa ribosomal inhibitory protein, LRIP-I) isolated from plants and a recombinant form of ricin A chain were studied. Previously, it had been shown that toxin polypeptides linked to monoclonal antibodies could inhibit HIV-infected cells. In the present study, the free, unconjugated, proteins were found to inhibit HIV replication at doses in which they were nontoxic to uninfected peripheral blood mononuclear cells. Among the inhibitory proteins, PAP-S and recombinant ricin A chain markedly reduced the reverse transcriptase activity and the expression of p24 core protein in infected cultures. Dose response studies indicate that the anti-HIV activity of PAP-S was comparable to AZT. The other ribosome inhibitory proteins (RIPs) showed moderate but significant antiviral activity.


Assuntos
HIV-1/efeitos dos fármacos , Leucócitos Mononucleares/microbiologia , N-Glicosil Hidrolases , Proteínas de Plantas/farmacologia , Inibidores da Síntese de Proteínas/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Transcriptase Reversa do HIV , HIV-1/enzimologia , HIV-1/fisiologia , Humanos , Leucócitos Mononucleares/citologia , Proteínas Recombinantes/farmacologia , Inibidores da Transcriptase Reversa , Proteínas Inativadoras de Ribossomos Tipo 1 , Ricina , Replicação Viral/efeitos dos fármacos , Zidovudina/farmacologia
6.
Br J Radiol ; 67(802): 951-7, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8000838

RESUMO

A study was undertaken to find out if there is a quantitative relationship between the development of contrast-associated nephrotoxicity (CAN) and the mean renal cortical attenuation (RCA) as seen on computed tomography (CT) examination of the kidneys 24 hours after injection of contrast medium. 96 patients undergoing aortography were selected, who were considered "high risk" either because of the presence of a baseline serum creatinine (Cr) of 123.76 mumol l-1 (1.4 mg dl-1) or higher, or who were 73 or older with or without elevated creatinine levels. A CT study of the kidneys at approximately 24 h was correlated with baseline serum creatinine as well as 24 h Cr (48-72 h Cr when available). Medical history and medications were recorded. Eight of 96 patients had RCA of 108-236 HU at 24 h CT and all developed significant CAN of varying degree; 3/96 had RCA ranging from 48 to 67 HU and had transient CAN; two other patients with RCA of 67-90 HU developed CAN; and there was increased incidence of CAN in patients: (a) with pre-existing renal insufficiency; (b) with diabetes with renal insufficiency; (c) on diuretics; (d) who were older; and (e) had a unilateral atrophic kidney. It was concluded that a 24 h CT study evaluating the RCA had better predictive value for the development of CAN than a 24 h creatinine level.


Assuntos
Meios de Contraste/efeitos adversos , Nefropatias/induzido quimicamente , Rim/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Aorta Torácica/diagnóstico por imagem , Creatinina/sangue , Feminino , Humanos , Nefropatias/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores de Tempo
7.
Diagn Cytopathol ; 19(3): 216-20, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9740999

RESUMO

Inflammatory pseudotumor, fibrohistiocytic type, also called benign fibrous histiocytoma, is a rare reactive entity usually found incidentally on routine chest roentgenography. We present a case of inflammatory pseudotumor, fibrohistiocytic type, initially diagnosed by fine-needle aspiration (FNA) cytology in a 39-yr-old woman with a history of breast carcinoma. Cytomorphologic characteristics were confirmed by a cell block examination and immunohistochemical findings. The differential diagnoses of the fine-needle aspiration cytology of this type of inflammatory pseudotumor are discussed.


Assuntos
Histiócitos/patologia , Pneumopatias/patologia , Granuloma de Células Plasmáticas Pulmonar/patologia , Adulto , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Biópsia por Agulha/métodos , Feminino , Histiócitos/metabolismo , Humanos , Técnicas Imunoenzimáticas , Pneumopatias/diagnóstico por imagem , Pneumopatias/metabolismo , Granuloma de Células Plasmáticas Pulmonar/diagnóstico por imagem , Granuloma de Células Plasmáticas Pulmonar/metabolismo , Tomografia Computadorizada por Raios X , alfa 1-Antitripsina/metabolismo
8.
Clin Imaging ; 15(3): 220-2, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1933654

RESUMO

A case with coexistent pancreatic adenocarcinoma and microcystic adenoma is presented. These diagnoses were suspected on the basis of their computed tomography (CT) appearances and confirmed with CT-guided fine-needle aspiration.


Assuntos
Adenocarcinoma/diagnóstico por imagem , Adenoma/diagnóstico por imagem , Neoplasias Primárias Múltiplas/diagnóstico por imagem , Neoplasias Pancreáticas/diagnóstico por imagem , Idoso , Feminino , Humanos , Tomografia Computadorizada por Raios X
9.
Clin Imaging ; 18(1): 1-3, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8180852

RESUMO

Inflammatory pseudotumor of the liver is a rare entity; fewer than 50 cases have been reported in the world literature. Its appearance on both computerized tomography (CT) and ultrasound have been previously described. To our knowledge, this is the first report of its appearance on magnetic resonance imaging (MRI). The lesion demonstrated increased signal intensity on T-1 and T-2 spin-echo and inversion recovery (STIR) sequences in relationship to normal liver. The signal characteristics, however, were nonspecific and diagnosis required biopsy confirmation. There was spontaneous resolution with conservative management, and this was documented on follow-up CT and MRI.


Assuntos
Granuloma de Células Plasmáticas/diagnóstico , Hepatopatias/diagnóstico , Imageamento por Ressonância Magnética , Biópsia , Diagnóstico Diferencial , Seguimentos , Granuloma de Células Plasmáticas/diagnóstico por imagem , Granuloma de Células Plasmáticas/patologia , Humanos , Hepatopatias/diagnóstico por imagem , Hepatopatias/patologia , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Radiografia Intervencionista , Tomografia Computadorizada por Raios X
12.
Theor Med Bioeth ; 20(1): 85-95, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10442056

RESUMO

The purpose of this exploratory and descriptive study was to examine old-age dementia in the Hmong community of Milwaukee, Wisconsin. Formal and informal Hmong leaders were interviewed to determine the prevalence of dementia in the Hmong community and how it is perceived and experienced. Interviews revealed few cases of dementia among the Hmong. Dementia was perceived as a natural part of the life cycle, rather than as a devastating disease that robs individuals of their autonomy. Treatment is not sought for dementia. Some of the common manifestations of dementia, such as wandering and combativeness, were rare or non-existent in the Hmong community. Individuals with dementia are cared for in their sons' homes. Nursing home placement in advanced dementia was only acceptable if sanctioned by the entire extended family. Further research on the Hmong perception of and experience with dementia needs to be conducted in other Hmong communities to validate the generalizability of these results.


Assuntos
Asiático , Demência/etnologia , Idoso , Doença de Alzheimer/etnologia , Doença de Alzheimer/psicologia , Comparação Transcultural , Demência/psicologia , Ética Médica , Humanos , Laos/etnologia , Wisconsin/epidemiologia
13.
Urol Radiol ; 12(4): 206-8, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-2042273

RESUMO

Contrast nephropathy (CN), a well-known complication of intravascular contrast medium, is associated with dense cortical nephrograms. These may be detected on unenhanced computed tomography (CT). We report the initial findings of a series of patients at risk for CN who received contrast for coronary arteriography or aortic arch angiography. Unenhanced CT scans were performed 22-26 h after contrast, and the mean cortical attenuation measured. These results were correlated with serial blood urea nitrogen (BUN) and serum creatinine measurements. The patients in this study, all of whom had either elevated baseline creatinine values, were over 73 years or both, had a high incidence of cortical contrast retention and contrast nephropathy.


Assuntos
Injúria Renal Aguda/induzido quimicamente , Meios de Contraste/efeitos adversos , Rim/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Injúria Renal Aguda/diagnóstico por imagem , Idoso , Diatrizoato/efeitos adversos , Feminino , Humanos , Iohexol/efeitos adversos , Rim/efeitos dos fármacos , Córtex Renal/diagnóstico por imagem , Masculino , Estudos Prospectivos
14.
Tech Urol ; 1(3): 141-9, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-9118383

RESUMO

The introduction of helical computed tomography (CT) has resulted in improved quality of multiplanar reformations and three-dimensional reconstructions in the chest and abdomen and has made CT angiography a clinical reality. These imaging techniques are useful for evaluating the urinary tract, adding a new dimension to its display, resulting in improved diagnosis of renal and perirenal disease. This article reviews the indications and techniques utilized for multiplanar and three-dimensional CT for urology. The advantages and limitations are discussed, and normal and pathologic findings in the urinary tract illustrated.


Assuntos
Intensificação de Imagem Radiográfica/métodos , Tomografia Computadorizada por Raios X/métodos , Urografia/métodos , Angiografia/métodos , Meios de Contraste , Apresentação de Dados , Humanos , Processamento de Imagem Assistida por Computador , Nefropatias/diagnóstico por imagem , Doenças Urológicas/diagnóstico por imagem
15.
Radiographics ; 11(2): 233-46, 1991 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2028062

RESUMO

Congenital and acquired abnormalities may alter the anatomy, size, or position of the azygos system. Computed tomography is often able to depict these abnormalities and in many cases indicate the cause. In this article, the normal anatomy of the azygos system is discussed and examples of congenital and acquired abnormalities are presented.


Assuntos
Veia Ázigos/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Veia Ázigos/anormalidades , Veia Ázigos/anatomia & histologia , Humanos , Tórax/irrigação sanguínea , Tomografia Computadorizada por Raios X/métodos , Doenças Vasculares/diagnóstico por imagem , Veia Cava Inferior/anormalidades , Veia Cava Inferior/diagnóstico por imagem
16.
Radiology ; 172(1): 125-9, 1989 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2740495

RESUMO

The prospective study involved 50 patients without known renal masses or previous renal surgery who received intravascular contrast medium for various radiologic procedures and subsequently underwent unenhanced computed tomography (CT) of the kidneys 22-26 hours later. In 42 patients, cortical readings did not exceed 50 HU and corticomedullary attenuation differences (CMADs) did not exceed 10 HU. In seven patients (intermediate group), there was persistent cortical enhancement (mean attenuation, 58.3-84.8 HU; CMAD, 10.3-40.3 HU), but there was no significant rise in levels of blood urea nitrogen or serum creatinine. A single patient had contrast nephropathy and exhibited a mean cortical attenuation of 141.6 HU and a mean CMAD of 85.8 HU on the 24-hour CT scan. The authors have seen two additional cases of contrast nephropathy presaged by mean cortical attenuations of 162 and 209 HU on the 24-hour CT scan. One of these patients had been in the intermediate group in the prospective study. A cortical attenuation of 55-110 HU on a 24-hour postcontrast scan may help identify a group of patients with subclinical renal impairment who are at high risk of nephropathy on subsequent exposure to contrast medium, while cortical attenuations in excess of 140 HU seem to be an early indicator of contrast nephropathy.


Assuntos
Meios de Contraste/efeitos adversos , Nefropatias/induzido quimicamente , Rim/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Nitrogênio da Ureia Sanguínea , Creatinina/sangue , Feminino , Humanos , Nefropatias/diagnóstico , Nefropatias/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
17.
Abdom Imaging ; 21(5): 470-2, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8832875

RESUMO

Polyorchidism is an uncommon congenital anomaly. It is associated with an increased frequency of testicular malignancy, cryptorchidism, inguinal hernia, and torsion. Sonography may be used to confirm the clinically suspected diagnosis. We present a case of polyorchidism in which a rete testis adenoma was present in one of the testicles. Sonographic and magnetic resonance findings are illustrated.


Assuntos
Adenoma/diagnóstico por imagem , Adenoma/diagnóstico , Imageamento por Ressonância Magnética , Neoplasias Testiculares/diagnóstico por imagem , Neoplasias Testiculares/diagnóstico , Testículo/anormalidades , Adulto , Meios de Contraste , Combinação de Medicamentos , Gadolínio , Gadolínio DTPA , Humanos , Aumento da Imagem , Masculino , Meglumina , Compostos Organometálicos , Ácido Pentético/análogos & derivados , Testículo/diagnóstico por imagem , Testículo/patologia , Ultrassonografia
18.
Abdom Imaging ; 18(4): 323-4, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8220028

RESUMO

Extramedullary plasmacytomas are an unusual manifestation of multiple myeloma. They occur most frequently in tissues or organs rich in reticulo-endothelial cells. Pancreatic plasmacytomas are rare, with only a few case reports in the literature. We present the ultrasound (US) and computed tomographic (CT) findings of two pancreatic plasmacytomas in a patient with multiple myeloma.


Assuntos
Mieloma Múltiplo/diagnóstico por imagem , Neoplasias Pancreáticas/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Idoso , Feminino , Humanos , Ultrassonografia
19.
Cardiovasc Intervent Radiol ; 16(5): 319-20, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8269431

RESUMO

A case of the rarely occurring partial anomalous pulmonary venous drainage of the right upper lobe into the azygos arch is presented. Computed tomography (CT) clearly demonstrated the abnormal vessel coursing through the right upper lobe and draining into the azygos arch.


Assuntos
Veia Ázigos/anormalidades , Veias Pulmonares/anormalidades , Tomografia Computadorizada por Raios X , Veia Ázigos/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Veias Pulmonares/diagnóstico por imagem
20.
Cancer ; 75(9): 2286-8, 1995 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-7712438

RESUMO

BACKGROUND: The Gynecologic Oncology Group (GOG) protocol #88 reported an 18.5% failure in inguinal lymph nodes of patients with vulvar cancer whose groins were treated with radiation alone. This high failure rate may be due to the study design. METHODS: In this study, the depths of inguinal lymph nodes were evaluated with computed tomography (CT) scans in 100 adult women without inguinal adenopathy or prior inguinal surgery. The dose that would have been delivered to the inguinal lymph nodes of these patients was determined using isodose curves constructed according to the guidelines in GOG protocol #88. RESULTS: Only 18% of women had all inguinal lymph nodes measured at a depth of 3 cm or less. CONCLUSIONS: More than one-half of all women in this study would have received less than 60% of the prescribed radiation dose because their inguinal lymph nodes were deeper than 5 cm, if the depth of their inguinal lymph nodes had not been measured before therapy.


Assuntos
Canal Inguinal/patologia , Linfonodos/patologia , Planejamento de Assistência ao Paciente , Neoplasias Vulvares/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Canal Inguinal/diagnóstico por imagem , Linfonodos/diagnóstico por imagem , Pessoa de Meia-Idade , Dosagem Radioterapêutica , Radioterapia de Alta Energia , Tomografia Computadorizada por Raios X , Falha de Tratamento
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa