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1.
Eur Radiol ; 29(11): 6227-6235, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31115623

RESUMO

PURPOSE: We aimed to estimate the incremental cancer detection rate achieved by adding three-dimensional functional infrared imaging (3DIRI) to digital mammography in women with dense breasts. MATERIALS AND METHODS: In this prospective study conducted between December 2014 and April 2016, 1727 women (median age 56) with percentage volumetric breast density > 6% were recruited at routine screening mammography to undergo additional 3DIRI. The 3DIRI findings were classified as negative or positive. Women with a negative mammography but positive 3DIRI were referred to dynamic contrast-enhanced MRI, whereas all other women underwent routine follow-up based on the mammography finding. Diagnosis of breast cancer was verified by histopathologic examination. The number of women diagnosed with a malignancy formed the basis of our statistical analysis. RESULTS: Mammography detected 7 cancers in 7 women. Of 1692 women with negative mammography, 222 women (13%) had a positive 3DIRI of which 219 underwent MRI. An additional 6 cancers were identified in 5 women, increasing the diagnostic yield from 7 of 1727 (0.41%) to 12 of 1727 (0.69%). The incremental cancer detection rate associated with using 3DIRI to select women for MRI was 5 of 222 (22.5 additional cancers per 1000). CONCLUSION: The use of 3DIRI to select women for an additional MRI can result in the detection of additional cancers in women with dense breasts, but at the expense of additional false positives and considerably lower positive predictive value of the combined examinations. Additional studies are necessary to evaluate the role of 3DIRI as an adjunct to mammography. KEY POINTS: • Use of three-dimensional functional infrared imaging to select women for an MRI in addition to screening mammography has the potential to improve breast cancer detection in women with dense breasts.


Assuntos
Densidade da Mama , Neoplasias da Mama/diagnóstico por imagem , Detecção Precoce de Câncer/métodos , Mamografia/métodos , Espectrofotometria Infravermelho/métodos , Adulto , Idoso , Neoplasias da Mama/patologia , Feminino , Humanos , Imageamento Tridimensional/métodos , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos
2.
Eur Radiol ; 23(5): 1191-8, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23223805

RESUMO

OBJECTIVE: We evaluated a functional three-dimensional (3D) infrared imaging system (3DIRI) coupled with multiparametric computer analysis for risk assessment of breast cancer. The technique provides objective risk assessment for the presence of a malignant tumour based on automated parameters derived from a clinically known training set. METHODS: Following institutional review board approval, we recruited 434 women for this prospective multicentre trial, including 256 healthy woman undergoing routine screening mammography with BI-RADS-1 results and 178 women with newly diagnosed breast cancer. This was a two-phase study: an initial training and calibration phase, followed by a two-armed blinded evaluation phase (52 healthy and 66 with breast cancer). 3DIRI data sets were acquired using a non-contact, no radiation system. RESULTS: The sensitivity and specificity of functional infrared imaging in providing the correct risk for the presence of breast cancer were 90.9 % and 72.5 %, respectively. The area under the ROC curve was 86 %. Forty-two of the 60 (70 %) cancers in women correctly classified by the system as suspicious were smaller than 20 mm in size. CONCLUSION: The preliminary blinded results of this novel technology show sufficient performance of functional infrared imaging in providing risk assessment for breast cancer to warrant further clinical studies. KEY POINTS: • 3D functional infrared imaging (3DIRI) provides new metabolic signatures from breast lesions. • 3DIRI offers high sensitivity for risk assessment of breast cancer. • It also has reasonable specificity. • This initial experience warrants further evaluation in larger clinical trials.


Assuntos
Neoplasias da Mama/diagnóstico , Neoplasias da Mama/epidemiologia , Imageamento Tridimensional/instrumentação , Imageamento Tridimensional/estatística & dados numéricos , Modelos de Riscos Proporcionais , Termografia/instrumentação , Termografia/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Raios Infravermelhos , Israel/epidemiologia , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , Reprodutibilidade dos Testes , Medição de Risco , Sensibilidade e Especificidade , Método Simples-Cego , Termografia/métodos , Adulto Jovem
3.
Jpn J Ophthalmol ; 53(4): 345-51, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19763751

RESUMO

The Retinal Function Imager (RFI; Optical Imaging, Rehovot, Israel) is a unique, noninvasive multiparameter functional imaging instrument that directly measures hemodynamic parameters such as retinal blood-flow velocity, oximetric state, and metabolic responses to photic activation. In addition, it allows capillary perfusion mapping without any contrast agent. These parameters of retinal function are degraded by retinal abnormalities. This review delineates the development of these parameters and demonstrates their clinical applicability for noninvasive detection of retinal function in several modalities. The results suggest multiple clinical applications for early diagnosis of retinal diseases and possible critical guidance of their treatment.


Assuntos
Diagnóstico por Imagem/métodos , Angiofluoresceinografia , Oxigênio/sangue , Retina/fisiologia , Vasos Retinianos/fisiologia , Animais , Velocidade do Fluxo Sanguíneo/fisiologia , Meios de Contraste/administração & dosagem , Diagnóstico por Imagem/instrumentação , Humanos , Oximetria , Fluxo Sanguíneo Regional/fisiologia
4.
Ann N Y Acad Sci ; 1173: 343-9, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19758171

RESUMO

Patients with neurological disease of unknown etiology sometimes present with antigliadin and antitissue transglutaminase antibodies. The association between these antibodies and multiple sclerosis has been previously suggested. The purpose of this study was to determine the prevalence of these antibodies in multiple sclerosis patients. We determined the level of serum immunoglobulin A and immunoglobulin G antigliadin and antitissue transglutaminase antibodies in 98 patients with multiple sclerosis. We found a highly significant increase in titers of immunoglobulin G antibodies against gliadin and tissue transglutaminase in the multiple sclerosis patients. Seven patients had a positive IgG AGA, whereas only 2 controls presented positive titers (P = 0.03). Four patients had positive IgG anti-tTG while all the controls tested negative (P = 0.02). However, immunoglobulin A antibodies against gliadin and tissue transglutaminase were not statistically higher in the multiple sclerosis group in comparison to the control group. Our findings support the associations between antibodies against gliadin and tissue transglutaminase to multiple sclerosis. The specific role of these antibodies in the pathogenesis of multiple sclerosis remains uncertain and requires additional research. A gluten free diet should be considered in specific cases of patients who present with gluten antibodies.


Assuntos
Autoanticorpos/sangue , Glutens/imunologia , Esclerose Múltipla/sangue , Adulto , Estudos Transversais , Feminino , Gliadina/imunologia , Humanos , Imunoensaio/métodos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/imunologia , Transglutaminases/imunologia
5.
Autoimmun Rev ; 7(8): 621-5, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18603025

RESUMO

BACKGROUND: The etiology of autoimmune diseases is not fully clarified and the mechanisms underlying their initiation and progression are still obscure. It is becoming clear that in a genetic susceptible individual an environmental trigger such as infectious agent in general and viruses in particular could initiate the development of an autoimmune disease. Hepatitis B virus (HBV) is notorious in its association with diverse autoimmune diseases. Therefore, we aimed to determine the presence of hepatitis B core antibody (HBcAb), a seromarker for past or present infection with HBV, in a large number of sera collected from patients with different autoimmune diseases. METHODS: A cohort of 675 sera samples of 5 different autoimmune diseases and healthy donors were screened for evidence of a prior infection with HBV. All samples were tested for hepatitis B core antibody (IgG) using the Monolisa anti-HBc PLUS commercial kit (Bio-Rad, Hercules, San Francisco, USA). RESULTS: Lower percentage of HBcAb was found in sera of the autoimmune diseases when compared to normal controls. Fifteen (10.7%) from 140 normal controls were found positive for the presence of HBcAb. Two (2%) out of 98 multiple sclerosis (MS) sera were positive for the presence of HBcAb (OR: 0.17, 95%CI: 0.03-0.77, p=0.01), 3 (2.5%) out of 117 systemic lupus erythematosus (SLE) sera (OR: 0.2, 95%CI: 0.06-0.77, p=0.01), 4 (4.5%) out of 89 type 1 diabetes (T1D), 5 (6.1%) from 82 Sjogren's syndrome (SS) sera and 12 (8%) from 149 rheumatoid arthritis (RA) sera were positive for the presence of HBcAb. CONCLUSIONS: Our data divulge an unexpected low percentage of antibodies to HBcAg in patients with SLE, MS and T1D in comparison to healthy matched donors. This finding may raise a protective role to HBV in some autoimmune diseases i.e. hygiene theory.


Assuntos
Doenças Autoimunes/prevenção & controle , Doenças Autoimunes/virologia , Vírus da Hepatite B/imunologia , Hepatite B/imunologia , Doenças Autoimunes/sangue , Doenças Autoimunes/imunologia , Hepatite B/sangue , Anticorpos Anti-Hepatite B/sangue , Humanos
6.
Proc Natl Acad Sci U S A ; 103(24): 9006-11, 2006 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-16751267

RESUMO

The drive toward more sensitive single-molecule manipulation techniques has led to the recent development of optical tweezers capable of resolving the motions of biological systems at the subnanometer level, approaching the fundamental limit set by Brownian fluctuations. One successful approach has been the dual-trap optical tweezers, in which the system of study is held at both ends by microspheres in two separate optical traps. We present here a theoretical description of the Brownian limit on the spatial resolution of such systems and verify these predictions by direct measurement in a Brownian noise-limited dual-trap optical tweezers. We find that by detecting the positions of both trapped microspheres, correlations in their motions can be exploited to maximize the resolving power of the instrument. Remarkably, we show that the spatial resolution of dual optical traps with dual-trap detection is always superior to that of more traditional, single-trap designs, despite the added Brownian noise of the second trapped microsphere.


Assuntos
Lasers , Micromanipulação/métodos , Microesferas , DNA/química , Matemática , Modelos Teóricos , Movimento (Física) , Tamanho da Partícula
7.
Annu Rev Biochem ; 73: 705-48, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15189157

RESUMO

Mechanical processes are involved in nearly every facet of the cell cycle. Mechanical forces are generated in the cell during processes as diverse as chromosomal segregation, replication, transcription, translation, translocation of proteins across membranes, cell locomotion, and catalyzed protein and nucleic acid folding and unfolding, among others. Because force is a product of all these reactions, biochemists are beginning to directly apply external forces to these processes to alter the extent or even the fate of these reactions hoping to reveal their underlying molecular mechanisms. This review provides the conceptual framework to understand the role of mechanical force in biochemistry.


Assuntos
Bioquímica , Fenômenos Biomecânicos , Animais , Fenômenos Bioquímicos , Catálise , Enzimas/química , Cinética , Conformação Molecular , Proteínas Motores Moleculares/química , Termodinâmica
8.
Proc Natl Acad Sci U S A ; 99(18): 11682-7, 2002 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-12193647

RESUMO

Escherichia coli RNA polymerase translocates along the DNA discontinuously during the elongation phase of transcription, spending proportionally more time at some template positions, known as pause and arrest sites, than at others. Current models of elongation suggest that the enzyme backtracks at these locations, but the dynamics are unresolved. Here, we study the role of lateral displacement in pausing and arrest by applying force to individually transcribing molecules. We find that an assisting mechanical force does not alter the translocation rate of the enzyme, but does reduce the efficiency of both pausing and arrest. Moreover, arrested molecules cannot be rescued by force, suggesting that arrest occurs by a bipartite mechanism: the enzyme backtracks along the DNA followed by a conformational change of the ternary complex (RNA polymerase, DNA and transcript), which cannot be reversed mechanically.


Assuntos
RNA Polimerases Dirigidas por DNA/metabolismo , Escherichia coli/enzimologia , RNA Polimerases Dirigidas por DNA/química , Cinética , Transcrição Gênica
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