The kinetic occipital (KO) region in man: an fMRI study

We used functional magnetic resonance imaging to explore, in individual subjects, the properties of the kinetic occipital (KO) region, which previous position emission tomography studies have shown to be involved in the processing of kinetic boundaries. The KO region was significantly activated in 23/25 subjects tested in the subtraction of uniform motion from kinetic gratings. The KO region is genuinely specialized for processing kinetic boundaries since it is significantly more activated by kinetic gratings than by luminance-defined gratings, uniform motion or transparent motion. This leaves only the kinetic boundaries, created by discontinuities in motion direction, as the specific stimulus aspect, activating the KO region. The KO region is anatomically and functionally distinct from areas MT/V5, V3 and V3A. It also has minimal overlap with the lateral occipital (LO) region. The selective activation of the KO region is robust and relatively immune to changes in stimulus size, spatial frequency and type of kinetic boundary. These results strongly argue for the view that the KO region is a new, separate, functional region in human occipital cortex.      

Electron microscopic evidence of persistent chlamydial infection following treatment

Chlamydia trachomatis infections of the female and male genital tracts are often asymptomatic and, thus, tend to become persistent. In the persistent state the typical Chlamydia life cycle is arrested and standard antibiotic regimens do not always eradicate this infection. We sought to relate treatment failures in men and women with persistent chlamydial genital tract infections to electron microscopic evidence of chlamydial persistence and with atypical morphological forms of the organism. Of 16 patients with chlamydial persistence following azithromycin treatment, morphological variants of this organism were observed by electron microscopy from one endocervical sample and one male urethral sample. We document the presence of intracellular inclusions containing only reticulate bodies, extracellular monomembrane and polymembrane phagosomes containing elementary bodies and reticulate bodies with abnormal outer membranes in the process of dividing extracellularly. These observations parallel previous in vitro studies of chlamydial persistence under adverse conditions. This capacity of C. trachomatis to undergo atypical morphological alterations in vivo may contribute to its persistence and relative resistance to antibiotics.     

Not all "quality-adjusted life years" are equal

BACKGROUND: There is evidence that utility elicitation methods used in the calculation of quality-adjusted life years (QALYs) yield different results. It is not clear how these differences impact economic evaluations. METHODS: Using a mathematical model incorporating data on efficacy, costs, and utility values, we simulated the experiences of 100,000 hypothetical rheumatoid arthritis patients over 10 years (50,000 exposed to infliximab plus methotrexate [MTX] and 50,000 exposed to MTX alone). QALYs, were derived from the Health Utilities Index 2 and 3 (HUI2 and HUI3), the Short Form 6-D (SF-6D), and the Euroqol 5-D (EQ-5D). Incremental cost-utility ratios were determined using each instrument to calculate QALYs and the results were compared using cost-effectiveness acceptability curves. RESULTS: Using the different utility measurement methods, the mean difference in QALYs between the infliximab plus MTX and MTX groups ranged from a high of 1.95 QALYs (95% CI=1.93-1.97) using the HUI3 to 0.89 QALYs (95% CI=0.88-0.91) using the SF-6D. Adopting the commonly cited value of society's willingness to pay for a QALY of $50,000, 91% of the simulations favored the cost utility of infliximab plus MTX when using the HUI3 to calculate QALYs. However, when using the EQ-5D, HUI2, or the SF-6D utility values to calculate QALYS, the proportion of simulations that favored the cost utility of infliximab were 63%, 45%, and 12%, respectively. CONCLUSION: Depending on the method for determining utility values used in the calculation of QALYs, very different incremental cost-utility ratios are generated.     

Minimal error in self-report of having had DXA, but self-report of its results was poor

OBJECTIVE: To examine the validity of both self-report of having had dual-energy x-ray absorptiometry (DXA) and self-reported DXA test results. METHODS: Participants were recruited in 2003 and 2004 from a population-based study of women aged 65-90 years examining osteoporosis management in Ontario, Canada (N=871). Women reporting having had a DXA were eligible and asked to report the results of their most recent test. Participant responses were compared against DXA reports obtained from physicians. RESULTS: We obtained 413 (81%) physician records among the 510 women who reported having had a DXA test. Of these, the positive predictive value for self-report of having had a DXA was 93%. The weighted kappa statistic for the agreement between self-report and actual DXA results was 0.42 (95% confidence interval=0.34-0.49). Although 84% of those with normal bone reported this, only 29% of those with osteopenia and 62% with osteoporosis reported their results correctly. Self-report of a clinical diagnosis of osteoporosis was better among those with a low trauma fracture, yet underestimated osteoporosis prevalence by 24%. CONCLUSION: There is minimal measurement error in self-report of having had a DXA test. Self-report of DXA results will underestimate osteoporosis prevalence and is not a good proxy for clinical diagnosis.     

脑利钠肽与超声心动图在川崎病诊断中的意义

目的探讨脑利钠肽(brain natriuretic peptide,BNP)与超声心动图在川崎病急性期及恢复期诊断中的临床意义。方法选取川崎病患儿35例为病例组,以发热、皮疹为主诉的肺炎支原体或病毒感染的48例患儿为对照组,测其急性期与恢复期脑利钠肽及左、右冠状动脉内径值,并做相关分析。结果川崎病患儿急性期脑利钠肽值明显高于恢复期,且差异有统计学意义;川崎病患儿恢复期冠状动脉内径值明显高于急性期,且差异有统计学意义。结论应用超声心动图检测冠状动脉扩张是在恢复期诊断川崎病的重要手段,而脑利钠肽可作为急性期诊断川崎病的生化指标之一。