ObjectiveTo identify case definitions for chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME), and explore how the validity of case definitions can be evaluated in the absence of a reference standard.DesignSystematic review.SettingInternational.ParticipantsA literature search, updated as of November 2013, led to the identification of 20 case definitions and inclusion of 38 validation studies.Primary and secondary outcome measureValidation studies were assessed for risk of bias and categorised according to three validation models: (1) independent application of several case definitions on the same population, (2) sequential application of different case definitions on patients diagnosed with CFS/ME with one set of diagnostic criteria or (3) comparison of prevalence estimates from different case definitions applied on different populations.ResultsA total of 38 studies contributed data of sufficient quality and consistency for evaluation of validity, with CDC-1994/Fukuda as the most frequently applied case definition. No study rigorously assessed the reproducibility or feasibility of case definitions. Validation studies were small with methodological weaknesses and inconsistent results. No empirical data indicated that any case definition specifically identified patients with a neuroimmunological condition.ConclusionsClassification of patients according to severity and symptom patterns, aiming to predict prognosis or effectiveness of therapy, seems useful. Development of further case definitions of CFS/ME should be given a low priority. Consistency in research can be achieved by applying diagnostic criteria that have been subjected to systematic evaluation.

Table of comparisons Characteristics of included studies Characteristics of excluded studies Table 01 Percentage recruitment (number of patients entered into trial/total screened) References to studies included in this review References to studies excluded in this review Additional references

A noninvasive method to obtain high-resolution images of tumor blood perfusion is needed for individualized cancer treatments. In this study we investigated the potential usefulness of dynamic contrast-enhanced MRI (DCE-MRI), using human melanoma xenografts as models of human cancer. Gadopentetate dimeglumine (Gd-DTPA) was used as the contrast agent, and DCE-MRI was performed at a voxel size of 0.5 ؋ 0.2 ؋ 2.0 mm 3 with spoiled gradient-recalled sequences. We obtained images of E ⅐ F (where E is the extraction fraction, and F is perfusion) by subjecting DCE-MR images to Kety analysis. We obtained highly reproducible E ⅐ F images, which we verified by imaging heterogeneous tumors twice. We hypothesized that the extraction fraction of Gd-DTPA would be high and would not vary significantly in tumor tissue, implying that E ⅐ F should be a well-suited parameter for describing tumor blood perfusion. Observations consistent with this hypothesis were made by comparison of E ⅐ F-images with immunostained histological preparations from the imaged sections. The E ⅐ F images mirrored the histological appearance of the tumor tissue perfectly. Quantitative studies showed that E ⅐ F was highest in nonhypoxic tissue with high microvascular density, second highest in nonhypoxic tissue with low microvascular density, third highest in hypoxic tissue, and lowest in necrotic tissue. Moreover, the radial heterogeneity in E ⅐ F was almost identical to that in the blood supply, as assessed by the use of Na 99m TcO 4 as a perfusion tracer. Taken together, our observations show that highresolution images reflecting tumor blood perfusion can be obtained by DCE-MRI. Magn Reson Med 52:269 -276, 2004.

CONTEXT: Survival of infants born at the limit of viability varies between high-income countries. OBJECTIVE: To summarize the prognosis of survival and risk of impairment for infants born at 22 + 0/7 weeks’ to 27 + 6/7 weeks’ gestational age (GA) in high-income countries. DATA SOURCES: We searched 9 databases for cohort studies published between 2000 and 2017 in which researchers reported on survival or neurodevelopmental outcomes. STUDY SELECTION: GA was based on ultrasound results, the last menstrual period, or a combination of both, and neurodevelopmental outcomes were measured by using the Bayley Scales of Infant Development II or III at 18 to 36 months of age. DATA EXTRACTION: Two reviewers independently extracted data and assessed the risk of bias and quality of evidence. RESULTS: Sixty-five studies were included. Mean survival rates increased from near 0% of all births, 7.3% of live births, and 24.1% of infants admitted to intensive care at 22 weeks’ GA to 82.1%, 90.1%, and 90.2% at 27 weeks’ GA, respectively. For the survivors, the rates of severe impairment decreased from 36.3% to 19.1% for 22 to 24 weeks’ GA and from 14.0% to 4.2% for 25 to 27 weeks’ GA. The mean chance of survival without impairment for infants born alive increased from 1.2% to 9.3% for 22 to 24 weeks’ GA and from 40.6% to 64.2% for 25 to 27 weeks’ GA. LIMITATIONS: The confidence in these estimates ranged from high to very low. CONCLUSIONS: Survival without impairment was substantially lower for children born at <25 weeks’ GA than for those born later.

Analysis 1.15. Comparison 1 Exercise therapy versus treatment as usual, relaxation or flexibility, Outcome 15 Self-perceived changes in overall health (follow-