768 resultados para Mallette, Rick


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Respiratory diseases are a major cause of mortality and morbidity worldwide. Current treatments offer no prospect of cure or disease reversal. Transplantation of pulmonary progenitor cells derived from human embryonic stem cells (hESCs) may provide a novel approach to regenerate endogenous lung cells destroyed by injury and disease. Here, we examine the therapeutic potential of alveolar type II epithelial cells derived from hESCs (hES-ATIICs) in a mouse model of acute lung injury. When transplanted into lungs of mice subjected to bleomycin (BLM)-induced acute lung injury, hES-ATIICs behaved as normal primary ATIICs, differentiating into cells expressing phenotypic markers of alveolar type I epithelial cells. Without experiencing tumorigenic side effects, lung injury was abrogated in mice transplanted with hES-ATIICs, demonstrated by recovery of body weight and arterial blood oxygen saturation, decreased collagen deposition, and increased survival. Therefore, transplantation of hES-ATIICs shows promise as an effective therapeutic to treat acute lung injury.

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The complement C3a anaphylatoxin is a major molecular mediator of innate immunity. It is a potent activator of mast cells, basophils and eosinophils and causes smooth muscle contraction. Structurally, C3a is a relatively small protein (77 amino acids) comprising a N-terminal domain connected by 3 native disulfide bonds and a helical C-terminal segment. The structural stability of C3a has been investigated here using three different methods: Disulfide scrambling; Differential CD spectroscopy; and Reductive unfolding. Two uncommon features regarding the stability of C3a and the structure of denatured C3a have been observed in this study. (a) There is an unusual disconnection between the conformational stability of C3a and the covalent stability of its three native disulfide bonds that is not seen with other disulfide proteins. As measured by both methods of disulfide scrambling and differential CD spectroscopy, the native C3a exhibits a global conformational stability that is comparable to numerous proteins with similar size and disulfide content, all with mid-point denaturation of [GdmCl](1/2) at 3.4-5M. These proteins include hirudin, tick anticoagulant protein and leech carboxypeptidase inhibitor. However, the native disulfide bonds of C3a is 150-1000 fold less stable than those proteins as evaluated by the method of reductive unfolding. The 3 native disulfide bonds of C3a can be collectively and quantitatively reduced with as low as 1mM of dithiothreitol within 5 min. The fragility of the native disulfide bonds of C3a has not yet been observed with other native disulfide proteins. (b) Using the method of disulfide scrambling, denatured C3a was shown to consist of diverse isomers adopting varied extent of unfolding. Among them, the most extensively unfolded isomer of denatured C3a is found to assume beads-form disulfide pattern, comprising Cys(36)-Cys(49) and two disulfide bonds formed by two pair of consecutive cysteines, Cys(22)-Cys(23) and Cys(56)-Cys(57), a unique disulfide structure of polypeptide that has not been documented previously.

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Alveolar epithelial type II (ATII) cells are small, cuboidal cells that constitute approximately 60% of the pulmonary alveolar epithelium. These cells are crucial for repair of the injured alveolus by differentiating into alveolar epithelial type I cells. ATII cells derived from human ES (hES) cells are a promising source of cells that could be used therapeutically to treat distal lung diseases. We have developed a reliable transfection and culture procedure, which facilitates, via genetic selection, the differentiation of hES cells into an essentially pure (>99%) population of ATII cells (hES-ATII). Purity, as well as biological features and morphological characteristics of normal ATII cells, was demonstrated for the hES-ATII cells, including lamellar body formation, expression of surfactant proteins A, B, and C, alpha-1-antitrypsin, and the cystic fibrosis transmembrane conductance receptor, as well as the synthesis and secretion of complement proteins C3 and C5. Collectively, these data document the successful generation of a pure population of ATII cells derived from hES cells, providing a practical source of ATII cells to explore in disease models their potential in the regeneration and repair of the injured alveolus and in the therapeutic treatment of genetic diseases affecting the lung.

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In vivo induced antigen technology (IVIAT) is an immuno-screening technique that identifies bacterial antigens expressed during infection and not during standard in vitro culturing conditions. We applied IVIAT to Bacillus anthracis and identified PagA, seven members of a N-acetylmuramoyl-L-alanine amidase autolysin family, three P60 family lipoproteins, two transporters, spore cortex lytic protein SleB, a penicillin binding protein, a putative prophage holin, respiratory nitrate reductase NarG, and three proteins of unknown function. Using quantitative real-time PCR comparing RNA isolated from in vitro cultured B. anthracis to RNA isolated from BALB/c mice infected with virulent Ames strain B. anthracis, we confirmed induced expression in vivo for a subset of B. anthracis genes identified by IVIAT, including L-alanine amidases BA3767, BA4073, and amiA (pXO2-42); the bacteriophage holin gene BA4074; and pagA (pXO1-110). The exogenous addition of two purified putative autolysins identified by IVIAT, N-acetylmuramoyl-L-alanine amidases BA0485 and BA2446, to vegetative B. anthracis cell suspensions induced a species-specific change in bacterial morphology and reduction in viable bacterial cells. Many of the proteins identified in our screen are predicted to affect peptidoglycan re-modeling, and our results support significant cell wall structural remodeling activity during B. anthracis infection. Identification of L-alanine amidases with B. anthracis specificity may suggest new potential therapeutic targets.

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Ultrasound contrast agents are gas-filled microbubbles that enhance visualization of cardiac structures, function and blood flow during contrast-enhanced ultrasound (CEUS). An interesting cardiovascular application of CEUS is myocardial contrast echocardiography, which allows real-time myocardial perfusion imaging. The intraoperative use of this technically challenging imaging method is limited at present, although several studies have examined its clinical utility during cardiac surgery in the past. In the present review we provide general information on the basic principles of CEUS and discuss the methodology and technical aspects of myocardial perfusion imaging.

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OBJECTIVES Emdogain, containing an extract of fetal porcine enamel matrix proteins, is a potent stimulator of in vitro osteoclastogenesis. The underlying molecular mechanisms are, however, unclear. MATERIAL AND METHODS Here, we have addressed the role of transforming growth factor-beta receptor type 1 (TGF-βRI) kinase activity on osteoclastogenesis in murine bone marrow cultures. RESULTS Inhibition of TGF-βRI kinase activity with SB431542 abolished the effect of Emdogain on osteoclastogenesis induced by receptor activator of nuclear factor kappa-B ligand or tumor necrosis factor-alpha. SB431542 also suppressed the Emdogain-mediated increase of OSCAR, a co-stimulatory protein, and dendritic cell-specific transmembrane protein and Atp6v0d2, the latter two being involved in cell fusion. Similar to transforming growth factor-beta1 (TGF-β), Emdogain could not compensate for the inhibition of IL-4 and IFNγ on osteoclast formation. When using the murine macrophage cell line RAW246.7, SB431542 and the smad-3 inhibitor SIS3 blocked Emdogain-stimulated expression of the transcription factor NFATc1. CONCLUSIONS Taken together, the data suggest that TGF-βRI kinase activity is necessary to mediate in vitro effects of Emdogain on osteoclastogenesis. CLINICAL RELEVANCE Based on these in vitro data, we can speculate that at least part of the clinical effects of Emdogain on osteoclastogenesis is mediated via TGF-β signaling.

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BACKGROUND Ductal carcinoma in situ (DCIS) is a noninvasive breast lesion with uncertain risk for invasive progression. Usual care (UC) for DCIS consists of treatment upon diagnosis, thus potentially overtreating patients with low propensity for progression. One strategy to reduce overtreatment is active surveillance (AS), whereby DCIS is treated only upon detection of invasive disease. Our goal was to perform a quantitative evaluation of outcomes following an AS strategy for DCIS. METHODS Age-stratified, 10-year disease-specific cumulative mortality (DSCM) for AS was calculated using a computational risk projection model based upon published estimates for natural history parameters, and Surveillance, Epidemiology, and End Results data for outcomes. AS projections were compared with the DSCM for patients who received UC. To quantify the propagation of parameter uncertainty, a 95% projection range (PR) was computed, and sensitivity analyses were performed. RESULTS Under the assumption that AS cannot outperform UC, the projected median differences in 10-year DSCM between AS and UC when diagnosed at ages 40, 55, and 70 years were 2.6% (PR = 1.4%-5.1%), 1.5% (PR = 0.5%-3.5%), and 0.6% (PR = 0.0%-2.4), respectively. Corresponding median numbers of patients needed to treat to avert one breast cancer death were 38.3 (PR = 19.7-69.9), 67.3 (PR = 28.7-211.4), and 157.2 (PR = 41.1-3872.8), respectively. Sensitivity analyses showed that the parameter with greatest impact on DSCM was the probability of understaging invasive cancer at diagnosis. CONCLUSION AS could be a viable management strategy for carefully selected DCIS patients, particularly among older age groups and those with substantial competing mortality risks. The effectiveness of AS could be markedly improved by reducing the rate of understaging.

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This thesis analyzes the sportswriting genre as a form of personal essay. It explores the art over time through writers Red Smith, A.J. Liebling, Roger Angell, George Plimpton, Bart Giamatti, Frank Deford, and Rick Reilly, as well as anthologized writers from 2008 and blogs.

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Genital human papillomavirus (HPV) is of public health concern because persistent infection with certain HPV types can cause cervical cancer. In response to a nationwide push for cervical cancer legislation, Texas Governor Rick Perry bypassed the traditional legislative process and issued an executive order mandating compulsory HPV vaccinations for all female public school students prior to their entrance in the sixth grade. By bypassing the legislative process Governor Perry did not effectively mitigate the risk perception issues that arose around the need for and usefulness of the vaccine mandate. This policy paper uses a social policy paradigm to identify perception as the key intervening factor on how the public responds to risk information. To demonstrate how the HPV mandate failed, it analyzes four factors, economics, politics, knowledge and culture, that shape perception and influence the public's response. By understanding the factors that influence the public's perception, public health practitioners and policy makers can more effectively create preventive health policy at the state level. ^

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Background. HPV is the underlying cause of cervical cancer, a malignant tumor of the female genital tract. Each year, cervical cancer is newly diagnosed in approximately 10,000 women, and over 3,000 women die from the malignancy. In addition, HPV is implicated as a cause of other cancers involving the genital tract, male and female, and the head and neck. ^ Gardasil, a vaccine against HPV, was licensed by the FDA in June 2006. Early study results have shown Gardasil to be safe and effective at preventing HPV infections that are commonly associated with the development of cervical cancer, as well as other HPV-related cancers and genital warts. The vaccine is most effective when administered in childhood, before initial exposure to HPV, which typically occurs shortly after the onset of sexual activity. Accordingly, the CDC's Advisory Committee on Immunization Practices (ACIP) has recommended routine vaccination of females aged 11-12 years. ^ Taking the ACIP recommendation one step further, many states have considered school-based mandates of the HPV vaccine in an attempt to reduce the burden of HPV-related illness, in particular to reduce the disparately high incidence of cervical cancer in medically underserved populations. These mandate attempts have sparked heated debate—highlighting public concerns regarding adolescent sexuality, corporate greed, and vaccines in general. ^ Methods. My research focuses on publicly available sources of information such as medical journals, government reports (federal and state), NGO reports, newspapers, and books. I begin with a background discussion of HPV, cervical cancer, and the HPV vaccine. I then discuss public health policy issues related to vaccines, vaccine mandates, and HPV-related illness. Specifically, I discuss the public health benefit of previous vaccine mandates, the legality of vaccine mandates, and the undue corporate influence on the politics of instituting HPV vaccine mandates. In addition, I examine some of the causes behind the anti-vaccine movement and the controversy surrounding adolescent sexuality as it pertains to the HPV vaccine. In the final section, I focus on the recent failed attempt by Governor Rick Perry to mandate the HPV vaccine in Texas. A retrospective analysis of Governor Perry's policy decisions is undertaken and recommendations are made regarding future attempts to mandate the HPV vaccine, or other vaccines under development for similar sexually transmitted viral diseases such as HIV and herpes simplex. ^ Results. In Texas, as in other states across the country, HPV vaccine mandates faced opposition from those who, while they may support mandates of other vaccines, oppose mandates for the HPV vaccine based largely on the idea that HPV is a sexually transmitted disease—they see responsible sexual behavior as the appropriate method for preventing HPV-related illness. A second major group of opposition comes from those who are generally opposed to all vaccine mandates, due to concerns that mandates are intended primarily for the financial benefit of the pharmaceutical industry or due to concerns—largely unfounded—that vaccines pose a greater health threat than the illnesses they are designed to prevent. ^ Conclusion. In order to reduce opposition to vaccine mandates, care must be taken to educate the public regarding the benefits of vaccination by mobilizing the public health sector, avoid the impression that the decision to institute mandates is rash or pressured by allowing time for open debate, and minimize lobbying efforts by vaccine manufacturers. ^

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Escrito en el apogeo de la Revolución Cubana, “Tengo," que comparte el nombre del libro donde aparece, es una celebración eufórica del triunfo del hombre común y corriente. También documenta el punto de cambio de la doxa, al mostrar cómo “Juan sin nada" se convirtió en “Juan con todo". Esta investigación utiliza la teoría bourdieusiana para documentar cómo los cambios sociales deben aparecer en el nivel de habitus antes de manifestarse en el nivel físico. Este fallo tiene consecuencias muy importante para el poeta como “maestro de memes".