57 resultados para Hubbard, Christopher


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Purpose: To evaluate the ability of the GDx Variable Corneal Compensation (VCC) Guided Progression Analysis (GPA) software for detecting glaucomatous progression. Design: Observational cohort study. Participants: The study included 453 eyes from 252 individuals followed for an average of 46 +/- 14 months as part of the Diagnostic Innovations in Glaucoma Study. At baseline, 29% of the eyes were classified as glaucomatous, 67% of the eyes were classified as suspects, and 5% of the eyes were classified as healthy. Methods: Images were obtained annually with the GDx VCC and analyzed for progression using the Fast Mode of the GDx GPA software. Progression using conventional methods was determined by the GPA software for standard automated achromatic perimetry (SAP) and by masked assessment of optic disc stereophotographs by expert graders. Main Outcome Measures: Sensitivity, specificity, and likelihood ratios (LRs) for detection of glaucoma progression using the GDx GPA were calculated with SAP and optic disc stereophotographs used as reference standards. Agreement among the different methods was reported using the AC(1) coefficient. Results: Thirty-four of the 431 glaucoma and glaucoma suspect eyes (8%) showed progression by SAP or optic disc stereophotographs. The GDx GPA detected 17 of these eyes for a sensitivity of 50%. Fourteen eyes showed progression only by the GDx GPA with a specificity of 96%. Positive and negative LRs were 12.5 and 0.5, respectively. None of the healthy eyes showed progression by the GDx GPA, with a specificity of 100% in this group. Inter-method agreement (AC1 coefficient and 95% confidence intervals) for non-progressing and progressing eyes was 0.96 (0.94-0.97) and 0.44 (0.28-0.61), respectively. Conclusions: The GDx GPA detected glaucoma progression in a significant number of cases showing progression by conventional methods, with high specificity and high positive LRs. Estimates of the accuracy for detecting progression suggest that the GDx GPA could be used to complement clinical evaluation in the detection of longitudinal change in glaucoma. Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references. Ophthalmology 2010; 117: 462-470 (C) 2010 by the American Academy of Ophthalmology.

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Replication-defective adenoviruses have been utilized as candidate HIV vaccine vectors Few studies have described the international epidemiology of pre-existing immunity to adenoviruses We enrolled 1904 participants in a cross-sectional serological survey at seven sites in Africa, Brazil, and Thailand to assess neutralizing antibodies (NA) for adenovirus types Ad5, Ad6, Ad26 and Ad36 Clinical trial samples were used to assess NA titers from the US and Europe The proportions of participants that were negative were 14 8%(Ad5), 31 5%(Ad6),41 2%(Ad26) and 53.6% (Ad36) Adenovirus NA titers varied by geographic location and were higher in non-US and non-European settings, especially Thailand In multivariate logistic regression analysis, geographic setting (non-US and non-European settings) was statistically significantly associated with having higher Ad5 titers, participants from Thailand had the highest odds of having high Ad5 titers (adjusted OR = 3 53,95% CI 224,557) Regardless of location. titers of Ad5NA were the highest and Ad36 NA were the lowest Coincident Ad5/6 titers were lower than either Ad5 or Ad6 titers alone Understanding pre-existing immunity to candidate vaccine vectors may contribute to the evaluation of vaccines in international populations (C) 2009 Published by Elsevier Ltd

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OBJECTIVE. The purpose of the study was to investigate patient characteristics associated with image quality and their impact on the diagnostic accuracy of MDCT for the detection of coronary artery stenosis. MATERIALS AND METHODS. Two hundred ninety-one patients with a coronary artery calcification (CAC) score of <= 600 Agatston units (214 men and 77 women; mean age, 59.3 +/- 10.0 years [SD]) were analyzed. An overall image quality score was derived using an ordinal scale. The accuracy of quantitative MDCT to detect significant (>= 50%) stenoses was assessed using quantitative coronary angiography (QCA) per patient and per vessel using a modified 19-segment model. The effect of CAC, obesity, heart rate, and heart rate variability on image quality and accuracy were evaluated by multiple logistic regression. Image quality and accuracy were further analyzed in subgroups of significant predictor variables. Diagnostic analysis was determined for image quality strata using receiver operating characteristic (ROC) curves. RESULTS. Increasing body mass index (BMI) (odds ratio [OR] = 0.89, p < 0.001), increasing heart rate (OR = 0.90, p < 0.001), and the presence of breathing artifact (OR = 4.97, p = 0.001) were associated with poorer image quality whereas sex, CAC score, and heart rate variability were not. Compared with examinations of white patients, studies of black patients had significantly poorer image quality (OR = 0.58, p = 0.04). At a vessel level, CAC score (10 Agatston units) (OR = 1.03, p = 0.012) and patient age (OR = 1.02, p = 0.04) were significantly associated with the diagnostic accuracy of quantitative MDCT compared with QCA. A trend was observed in differences in the areas under the ROC curves across image quality strata at the vessel level (p = 0.08). CONCLUSION. Image quality is significantly associated with patient ethnicity, BMI, mean scan heart rate, and the presence of breathing artifact but not with CAC score at a patient level. At a vessel level, CAC score and age were associated with reduced diagnostic accuracy.

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Objective: Natural killer T (NKT) cells are efficiently targeted by HIV and severely reduced in numbers in the circulation of infected individuals. The functional capacity of the remaining NKT cells in HIV-infected individuals is poorly characterized. This study measured NKT cell cytokine production directly ex vivo and compared these responses with both the disease status and NKT subset distribution of individual patients. Methods: NKT cell frequencies, subsets, and ex-vivo effector functions were measured in the peripheral blood mononuclear cells of HIV-infected patients and healthy controls by flow cytometry. We measured cytokines from NKT cells after stimulation with either a-galactosyl ceramide-loaded CD1d dimers (DimerX-alpha GalCer) or phorbol myristate acetate and ionomycin. Results: The frequencies of NKT cells secreting interferon-gamma and tumor necrosis factor-alpha were significantly lower in HIV-infected patients than healthy controls after DimerX-alpha GalCer treatment, but responses were similar after treatment with phorbol myristate acetate and ionomycin. The magnitude of the interferon-gamma response to DimerX-alpha GalCer correlated inversely with the number of years of infection. Both interferon-gamma and tumor necrosis factor-alpha production in response to DimerX-alpha GalCer correlated inversely with CD161 expression. Conclusion: The ex-vivo Th1 responses of circulating NKT cells to CD1d-glycolipid complexes are impaired in HIV-infected patients. NKT cell functions may be progressively lost over time in HIV infection, and CD161 is implicated in the regulation of NKT cell responsiveness. (C) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins

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PURPOSE. To assess whether baseline Glaucoma Probability Score (GPS; HRT-3; Heidelberg Engineering, Dossenheim, Germany) results are predictive of progression in patients with suspected glaucoma. The GPS is a new feature of the confocal scanning laser ophthalmoscope that generates an operator-independent, three-dimensional model of the optic nerve head and gives a score for the probability that this model is consistent with glaucomatous damage. METHODS. The study included 223 patients with suspected glaucoma during an average follow-up of 63.3 months. Included subjects had a suspect optic disc appearance and/or elevated intraocular pressure, but normal visual fields. Conversion was defined as development of either repeatable abnormal visual fields or glaucomatous deterioration in the appearance of the optic disc during the study period. The association between baseline GPS and conversion was investigated by Cox regression models. RESULTS. Fifty-four (24.2%) eyes converted. In multivariate models, both higher values of GPS global and subjective stereophotograph assessment ( larger cup-disc ratio and glaucomatous grading) were predictive of conversion: adjusted hazard ratios (95% CI): 1.31 (1.15 - 1.50) per 0.1 higher global GPS, 1.34 (1.12 - 1.62) per 0.1 higher CDR, and 2.34 (1.22 - 4.47) for abnormal grading, respectively. No significant differences ( P > 0.05 for all comparisons) were found between the c-index values ( equivalent to area under ROC curve) for the multivariate models (0.732, 0.705, and 0.699, respectively). CONCLUSIONS. GPS values were predictive of conversion in our population of patients with suspected glaucoma. Further, they performed as well as subjective assessment of the optic disc. These results suggest that GPS could potentially replace stereophotograph as a tool for estimating the likelihood of conversion to glaucoma.

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The purpose of this study was to evaluate the newly formed bone, comparing two different carriers for rhBMP-2, using the decortication and nondecorticatication surgical technique in Wistar rat mandibles, evaluated by radiographic densitometry method. It was used fifty six animals according to specific treatment, which were sacrificed after 3 and 6 weeks after this. It was concluded that the decortication surgical technique was able to optimize the osteoinduction properties of the rhBMP-2, independently of the material carrier used and the period of time, according to radiographic densitometry technique.

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To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specific variations in genes associated with lactation and immune responsiveness. Genes involved in metabolism are generally highly conserved, although five metabolic genes are deleted or extensively diverged from their human orthologs. The cattle genome sequence thus provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.

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Large, long-lived species experience more lifetime cell divisions and hence a greater risk of spontaneous tumor formation than smaller, short-lived species. Large, long-lived species are thus expected to evolve more elaborate tumor suppressor systems. In previous work, we showed that telomerase activity coevolves with body mass, but not lifespan, in rodents: telomerase activity is repressed in the somatic tissues of large rodent species but remains active in small ones. Without telomerase activity, the telomeres of replicating cells become progressively shorter until, at some critical length, cells stop dividing. Our findings therefore suggested that repression of telomerase activity mitigates the increased risk of cancer in larger-bodied species but not necessarily longer-lived ones. These findings imply that other tumor suppressor mechanisms must mitigate increased cancer risk in long-lived species. Here, we examined the proliferation of fibroblasts from 15 rodent species with diverse body sizes and lifespans. We show that, consistent with repressed telomerase activity, fibroblasts from large rodents undergo replicative senescence accompanied by telomere shortening and overexpression of p16(Ink4a) and p21(Cip1/Waf1) cycline-dependent kinase inhibitors. Interestingly, small rodents with different lifespans show a striking difference: cells from small shorter-lived species display continuous rapid proliferation, whereas cells from small long-lived species display continuous slow proliferation. We hypothesize that cells of small long-lived rodents, lacking replicative senescence, have evolved alternative tumor-suppressor mechanisms that prevent inappropriate cell division in vivo and slow cell growth in vitro. Thus, large-bodied species and small but long-lived species have evolved distinct tumor suppressor mechanisms.

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Plasmids are mobile genetic elements of bacteria that can impart important adaptive traits, such as increased virulence or antibiotic resistance. We report the existence of plasmids in Rickettsia (Rickettsiales; Rickettsiaceae) species, including Rickettsia akari, ""Candidatus Rickettsia amblyommii,"" R. bellii, R. rhipicephali, and REIS, the rickettsial endosymbiont of Ixodes scapularis. All of the rickettsiae were isolated from humans or North and South American ticks. R. parkeri isolates from both continents did not possess plasmids. We have now demonstrated plasmids in nearly all Rickettsia species that we have surveyed from three continents, which represent three of the four major proposed phylogenetic groups associated with blood-feeding arthropods. Gel-based evidence consistent with the existence of multiple plasmids in some species was confirmed by cloning plasmids with very different sequences from each of two ""Ca. Rickettsia amblyommii"" isolates. Phylogenetic analysis of rickettsial ParA plasmid partitioning proteins indicated multiple parA gene origins and plasmid incompatibility groups, consistent with possible multiple plasmid origins. Phylogenetic analysis of potentially host-adaptive rickettsial small heat shock proteins showed that hsp2 genes were plasmid specific and that hsp1 genes, found only on plasmids of ""Ca. Rickettsia amblyommii,"" R. felis, R. monacensis, and R. peacockii, were probably acquired independently of the hsp2 genes. Plasmid copy numbers in seven Rickettsia species ranged from 2.4 to 9.2 per chromosomal equivalent, as determined by real-time quantitative PCR. Plasmids may be of significance in rickettsial evolution and epidemiology by conferring genetic plasticity and host-adaptive traits via horizontal gene transfer that counteracts the reductive genome evolution typical of obligate intracellular bacteria.

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Introduction The objective of the present study was to assess the craniocervical posture and the positioning of the hyoid bone in children with asthma who are mouth breathers compared to non-asthma controls. Methods The study was conducted on 56 children, 28 of them with mild (n = 15) and moderate (n = 13) asthma (14 girls aged 10 79 +/- 1 31 years and 14 boys aged 9 79 +/- 1.12 years), matched for sex, height, weight and age with 28 non-asthma children who are not mouth breathers The sample size was calculated considering a confidence interval of 95% and a prevalence of 4% of asthma in Latin America. Eighteen variables were analyzed in two radiographs (latero-lateral teleradiography and lateral cervical spine radiography), both obtained with the head in a natural position The independent t-test was used to compare means values and the chi-square test to compare percentage values (p < 0 05) Intraclass correlation coefficient (ICC) was used to verify reliability. Results. The Craniovertebral Angle (CVA) was found to be significantly smaller in asthma than in control children (106.38 +/- 766 vs. 111 21 +/- 7.40. p = 0 02) and the frequency of asthma children with an absent or inverted hyoid triangle was found to be significantly higher compared to non-asthma children (36% vs 7%, p = 0.0001). The values of the inclination angles of the superior cervical spine in relation to the horizontal plane were significantly higher in moderate than in mild asthma children (CVT/Hor 85 10 +/- 725 vs. 90 92 +/- 6.69, p = 0 04 and C1/Hor. 80 93 +/- 5.56 vs 85 00 +/- 4 20, p = 0 04) Conclusions These findings revealed that asthma children presented higher head extension and a higher frequency of changes in hyoid bone position compared to non-asthma children and that greater the asthma severity greater the extension of the upper cervical spine. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

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The aim of this study was to analyze if the presence of impacted third molars, and their positions in the mandibular angle, can change the bone quality in this area, considering the measure of the cortical thickness in this region as representative or not for mandible fracture risk. Software was used to analyze 50 digital images from panoramic radiographs of patients who had one or two impacted third molars in the mandible, and 30 digital images of patients with agenesis of the mandibular third molar. The thickness of the cortical region of the mandible was measured; it was possible to draw a parallel line to the posterior portion of the mandible and a parallel line to the body of this bone on each side of the image. At the intersection of these lines near the distal portion of the second molar, another line was set up to serve as reference in the cortical thickness measurement. It could be concluded that the cortical thickness of the mandibular angle in male patients without impacted third molars was greater than the thickness in patients with these teeth, and no difference in thickness was found for the female group.

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For the purposes of this report, ""systemic disease"" will be interpreted as conditions that are spread out within the body rather than localized strictly to the tissues of the oral cavity. Since it would take many volumes to review all such conditions, the intent of the authors is to review a few examples of conditions where initial panoramic radiographic findings suggested widespread disease of significance enough to affect the quality of life and longevity of the patient.