Alpha-fetoprotein (AFP) is a serum protein highly produced during the fetal period. It is also known as a biomarker of various pathologies. Commonly, tumors requiring diagnosis and monitoring through AFP determination appear during the first year of life, with poorer outcomes when presenting in fetal life. Due to advancements in imaging technology, the detectability of ovarian masses in infants is higher. However, the use of AFP as a biomarker could improve diagnosis in cases when imaging and histological examinations are not sensitive enough to detect tumors. From the outcome of our investigation, it is possible to conclude that there is evidence of an association between increased AFP levels and ovarian masses. However, previous studies have presented contradictory and unverified results, with the authors emphasizing that future research is needed. In this article, an analysis of the available literature on AFP as a biomarker of ovarian masses in children was performed. Two types of literature were reviewed: guidance and published studies (clinical trials, reviews, and systematic reviews). We searched the Embase, PubMed, ScienceDirect, and Web of Science databases to collect essential data.

Hair cortisol concentration (HCC) has shown remarkable promise as a stable, non-invasive measure of systemic cortisol; however, despite methodological advances, the value that would typically be seen in healthy adults has not been established. Therefore, we sought to review the relevant literature to determine a reference value for HCC in healthy (i.e., non-clinical) adults. To this end, we conducted a systematic review of the PubMed, Scopus, and CINAHL databases for studies that measured healthy adult HCC using immunoassay methods, given that these are the most widely accessible analytical tools. To be eligible, studies were required to have been published in English, to have provided relevant descriptive statistics (i.e., means and standard deviations), and to have used a healthy adult human sample. We found 17 studies that met our inclusion criteria; the reports involved 1348 participants with a mean age of about 38 years. Since we identified a large amount of between-study heterogeneity, we completed a random-effect meta-regression analysis and found that test kit vendor was the only significant variable of the model. As a result, when using methodologies from traditional finite mixture distributions to determine reference values for mean and elevated HCC in individual healthy adults, we calculated these estimates for each of the major test kit vendors. Future work will need to determine whether our estimated reference values need to be modified, and these efforts will be greatly assisted by studies that account for potential moderating factors, such as age, sex, and ethnicity.

What are comfortable gait speed values for apparently healthy adults? How do these differ by age group, sex and geographical region?
Systematic review of observational studies with meta-analysis.
Apparently healthy, community-dwelling adults who have undergone measurement of comfortable gait speed.
Potentially relevant studies were identified in four databases. Extracted data from studies that satisfied the eligibility criteria were added to a database containing the same information from a meta-analysis published a decade ago.
The weighted mean comfortable gait speed was calculated along with the 95% confidence interval for each stratum of age/sex using a random-effects model. Mean gait speeds were further stratified by the continent where the study took place. Tests of homogeneity included I2 and prediction intervals.
Meta-analysis of data from 51,248 apparently healthy adults was stratified by age (in decades) and sex. Male gait speed slowed beyond age 50 years whereas female gait speed slowed beyond age 30 years. The weighted mean gait speed ranged from 97 cm/s (females aged ≥ 80 years) to 140 cm/s (males aged 40 to 49 years). The I2 values ranged from 0 to 34.07; prediction interval ranges varied from a low of 30 (125 to 155 cm/s; males aged 40 to 49 years) to a high of 77 (83 to 160 cm/s; females aged 60 to 69 years). There was considerable overlap in confidence intervals between continents for each sex/age group.
Comfortable gait speed slowed through the adult years, but males maintained a faster walking speed than females. Further stratification of comfortable gait speed by geographical region is not warranted.

The current critical review examines the application of 11 frequently used sedimentary metal indices in their ability to accurately assess the magnitude of human-induced change (enrichment) in the highly vulnerable and intensely developed coastal environment. The plethora and rapidly increasing number of sedimentary metal indices should, if not derived for special purposes, produce a consistent assessment on the basis that they use the same suite of metals and concentrations. Inconsistent numerical results produced by different index formulations should, when combined with their associated classification scheme, produce a common assessment of environmental condition. However, such a consistent outcome is seldom observed. Significant differences in assessment results are partly due to the historical evolution of indices and to the extraordinary diversity of background and reference values and materials being applied to account for pre-anthropogenic metal levels and confounding due to variable sediment characteristics. Size-normalised sample and background metal data used in the mCd and MEQ indices do not require reference values to account for textural variability and provide a quasi-direct measurement of enrichment with minimal computation (simple division). These priority indices should be combined into a single index (Enrichment Quotient, EQ). Results produced by the EF index were strongly correlated to mCd and MEQ and provide a similar classification and is recommended if normalised data are unavailable. Other indices assessed (MPI, PI, mPI, SEF, Igeo, PLI and Cf, original and current) provided a range of results, which either over- or under-estimated enrichment. The confusion concerning the choice and application of background and reference values in the assessment process is reviewed and their use in local and global assessment is clarified. Single- and combined-metal evaluations are recommended to provide detailed, local and more comprehensive assessments, respectively.

Objective: This study was conducted in order to determine the reference values for right ventricular (RV) volumes and ejection fraction (EF) using three-dimensional echocardiography (3DE) and to identify sources of variance through a systematic review and meta-analysis. Methods: This systematic review was preregistered with the International Prospective Register of Systematic Reviews (https://www.crd.york.ac.uk/PROSPERO/) (CRD42020211002). Relevant studies were identified by searches of the PubMed, Embase, and Cochrane Library databases through October 12, 2020. Pooled reference values were calculated using the random-effects model weighted by inverse variance. Meta-regression analysis and Egger\'s test were used to determine the source of heterogeneity. A subgroup analysis was performed to evaluate the reference values across different conditions. Results: The search identified 25 studies of 2,165 subjects. The mean reference values were as follows: RV end-diastolic volume, 100.71 ml [95% confidence interval (CI), 90.92-110.51 ml); RV end-systolic volume, 44.19 ml (95% CI, 39.05-49.33 ml); RV end-diastolic volume indexed, 57.01 ml/m2 (95% CI, 51.93-62.08 ml/m2); RV end-systolic volume indexed, 25.41 ml/m2 (95% CI, 22.58-28.24 ml/m2); and RVEF, 56.20% (95% CI, 54.59-57.82%). The sex- and age-specific reference values were assessed according to the studies reporting the values of different sexes and age distributions, respectively. In addition, the vendor- and software-specific reference values were analyzed. The meta-regression analysis revealed that sex, frame rate, pulmonary artery systolic pressure, and software packages were associated with variations in RV volumes (P < 0.05). Inter-vendor and inter-software discrepancies may explain the variability of RVEF. Conclusions: The reference values for RV volumes and RVEF using 3DE were assessed. The confounders that impacted the variability in RV volumes or RVEF contained the sex, frame rate, pulmonary artery systolic pressure, inter-vendor discrepancies, and inter-software discrepancies.

Thousands of publications in recent years have addressed the induction of metabolic syndrome (MetS) in rodents. However, the criteria and the reference values for diagnosing this disease have not been defined.
Our main objective was to carry out a systematic review to gather evidence about the criteria for biochemical and anthropometric parameters in which scientific studies have relied on to report that rats developed MetS from a previous dietary manipulation.
We compiled characteristics and findings of diet-induced MetS with high-fat, high-carbohydrate, high-fat/high-carbohydrates, and cafeteria diet from PubMed and Science Direct databases published in the last 5 years.
The results on the principal determinants for the syndrome, published in the reviewed articles, were chosen to propose reference values in the rat models of food induction.
The values obtained will serve as reference cut-of points in the development of the disease; in addition, the compilation of data will be useful in planning and executing research protocols in animal models.

In this paper, some significant problems, which were found frequently in the products of autoimmune in vitro diagnostic reagents, were summarized and analyzed in detail, and meanwhile a few relevant suggestions were put forward, which should be paid attention in the process of registration and application.

Results can vary between different free thyroxine (FT4) assays; global standardization would improve comparability of results between laboratories, allowing development of common clinical decision limits in evidence-based guidelines.
We summarize the path to standardization of FT4 assays, and challenges associated with FT4 testing in special populations, including the need for collaborative efforts toward establishing population-specific reference intervals. The International Federation of Clinical Chemistry and Laboratory Medicine Committee for Standardization of Thyroid Function Tests has undertaken FT4 immunoassay method comparison and recalibration studies and developed a reference measurement procedure that is currently being validated. Further studies are needed to establish common reference intervals/clinical decision limits. Standardization of FT4 assays will change test results substantially; therefore, a major education program will be required to ensure stakeholders are aware of the benefits of FT4 standardization, planned transition procedure, and potential clinical impact of the changes. Assay recalibration by manufacturers and approval process simplification by regulatory authorities will help minimize the clinical impact of standardization.
Significant progress has been made toward standardization of FT4 testing, but technical and logistical challenges remain.
Collaborative efforts by manufacturers, laboratories, and clinicians are required to achieve successful global standardization of the FT4 assays.

The timed up and go test (TUGT) was recently proposed as a strong predictor of adverse outcomes. Few reviews have been conducted to identify a standard for the TUGT in healthy older people, and the aims of this study were to explore the source of heterogeneity and evaluate the range of reference values for the TUGT in healthy people over 60 years old stratified by age and sex. The VIP, EMBASE, Web of Science and PubMed databases were searched from January 1, 2000, to December 31, 2018. A subgroup analysis and meta-regression were used to assess heterogeneity. Thirty-four eligible studies were included. The mean TUGT results for the total population, males and females in the sample were 9.21 s [95% CI (9.11, 9.31)], 9.33 s [95% CI (7.82, 11.08)] and 8.87 s [95% CI (8.40, 9.38)], respectively. The mean TUGT results for older people in their 60 s, 70 s, and 80 s were 7.91 s [95% CI (6.62, 9.20)], 8.67 s [95% CI (7.23, 10.12)] and 11.68 s [95% CI (8.11, 15.26)], respectively. The meta-regression analysis results showed that the heterogeneity was related to age (P < 0.01). Age affects the results of the TUGT, and it is necessary to take age into consideration when conducting stratified physical evaluations for the evaluation of older people individuals\' physical fitness.

Although uroflowmetry is a widely used diagnostic test, reference values of uroflowmetry parameters in women are lacking making it difficult to interpret the test results.
To quantify the range of results in uroflowmetry parameters in healthy women based on a systematic review.
A search was made in the International Continence Society standardization articles, PubMed, Embase and the Cochrane Library (from inception to 27 February 2014). Studies on uroflowmetry in healthy women were included. The selected articles were examined using a critical appraisal process based on the QUADAS-2 tool and the Critical Appraisal Skills Program.
Mean values of uroflowmetry parameters in healthy women (mean age 37.1 years) were: voided volume (VV) 338 ml (SD 161), maximum flow rate (Qmax) 23.5 ml/s (SD 10), average flow rate (Qave) 13 ml/s (SD 6), postvoid residual (PVR) 15.5 ml (SD 25), voiding time (VT) 29 sec (SD 17), and time to maximum flow rate (time to Qmax) 8 sec (SD 6). Qmax was dependent on VV. There was no clear relationship between Qmax and age, and no correlation between parity and Qmax. A normal shape of the uroflowmetry curve was seen in 70-80% of the flows.
This systematic review provides an overview of the range of results of uroflowmetry parameters in healthy women. Neurourol. Urodynam. 36:953-959, 2017. © 2016 Wiley Periodicals, Inc.