Reference Range Research Articles

Circulating Nucleated Red Blood Cells: An Updated Reference Interval.

Nucleated red blood cells (nRBCs) are not identified in the peripheral blood in healthy individuals beyond the neonatal period. Their presence in children and adults is traditionally considered pathologic. Contemporary hematology analyzers measure nRBCs at very low levels compared to traditional manual morphometric methods. The original launch of the Sysmex XN analyzer in this study's clinical laboratory verified the previously used nRBC reference interval of 0.00 to 0.01 × 106/μL. However, nRBC results from apparently healthy patients were flagged as abnormal (high), subsequently causing patient anxiety and increased subspecialty referrals. To determine whether current reference intervals (RIs) for nRBCs were clinically relevant. We performed a prospective analysis of 405 300 specimens from nonhospitalized individuals who received a complete blood count. Applying inclusion/exclusion criteria produced a total specimen pool of 66 498. Of the 66 498 samples with otherwise normal complete blood count results from healthy, nonhospitalized individuals, 338 showed results outside the previously established RI; 336 of 66 498 (0.5%) had nRBC results greater than 0.01 × 106/μL. Two samples had nRBC values greater than 0.10 ×106/μL. Based on statistical analysis of our results, we concluded that the upper limit of the RI could be updated from 0.01 × 106/μL to 0.10 × 106/μL. Increasing the upper limit of normal for the nRBC RI should decrease patient consternation from an abnormal laboratory value and significantly decrease costs through reducing unnecessary follow up care, and without causing patient harm.

Seasonally adjusted laboratory reference intervals to improve the performance of machine learning models for classification of cardiovascular diseases

BackgroundVariation in laboratory healthcare data due to seasonal changes is a widely accepted phenomenon. Seasonal variation is generally not systematically accounted for in healthcare settings. This study applies a newly developed adjustment method for seasonal variation to analyze the effect seasonality has on machine learning model classification of diagnoses.MethodsMachine learning methods were trained and tested on ~ 22 million unique records from ~ 575,000 unique patients admitted to Danish hospitals. Four machine learning models (adaBoost, decision tree, neural net, and random forest) classifying 35 diseases of the circulatory system (ICD-10 diagnosis codes, chapter IX) were run before and after seasonal adjustment of 23 laboratory reference intervals (RIs). The effect of the adjustment was benchmarked via its contribution to machine learning models trained using hyperparameter optimization and assessed quantitatively using performance metrics (AUROC and AUPRC).ResultsSeasonally adjusted RIs significantly improved cardiovascular disease classification in 24 of the 35 tested cases when using neural net models. Features with the highest average feature importance (via SHAP explainability) across all disease models were sex, C- reactive protein, and estimated glomerular filtration. Classification of diseases of the vessels, such as thrombotic diseases and other atherosclerotic diseases consistently improved after seasonal adjustment.ConclusionsAs data volumes increase and data-driven methods are becoming more advanced, it is essential to improve data quality at the pre-processing level. This study presents a method that makes it feasible to introduce seasonally adjusted RIs into the clinical research space in any disease domain. Seasonally adjusted RIs generally improve diagnoses classification and thus, ought to be considered and adjusted for in clinical decision support methods.

Reference data on estrogen metabolome in healthy pregnancy

IntroductionEstrogen hormones and their metabolites are implicated in the maintenance of healthy pregnancy and adequate fetal development. Abnormal levels were related to increased risk of pregnancy complications, particularly preeclampsia. Our aims were (1) to develop a methodological platform for the comprehensive assessment of estrogen metabolome in pregnancy; (2) to collect healthy reference data for relevant elements of estrogen metabolome in each trimester; (3) to assess unconjugated fractions of the estrogen metabolome, (4) to assess the dominant metabolic pathways of estrogen compounds. MethodsWe enrolled healthy pregnant mothers between gestational week 5–15 (on the confirmation of pregnancy; 79 samples), gestational weeks 19–27 (70 samples), and gestational week 34–39 (54 samples). A method employing liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed to assess estrone, 17-beta-estradiol, estriol levels, and their metabolites as conjugated and unconjugated forms. Descriptive statistics were used to characterize the level of compounds in each trimester. ResultsEstrone, 17-beta-estradiol and estriol levels are dramatically increasing with the advancement of pregnancy. Measured levels were in a very wide range. 17-beta-estradiol is neither glucuronated nor sulphated. To the contrary, estriol and estrone are significantly conjugated; unconjugated fraction is <15% of total hormone levels in any trimester. Regarding metabolism, 4-methoxy-estradiol and 17-epiestriol were not detected. ConclusionWe concluded that (1) the levels of estrogen compounds and metabolites increase with advancing gestational age; (2) the wide ranges of levels challenge the establishment of a healthy reference range for clinical purposes; (3) 17-beta-estradiol is not conjugated significantly; (4) 4-methylation and 17-epimerization pathways of estrogens are negligible with our LC-MS/MS method.

(267) Penile Length and Circumference in Vietnamese Men

Abstract Introduction Penile size has long been an important fixation in men's lives. Establishing what the normal size of the penis is very important to have a yardstick for men, which is a challenge and depends on the culture, race, and form of measurement applied. Objective To evaluate the size of the penis in flaccidity, erection, and stretch of Vietnamese men. Methods A total of 259 men who visited the Andrology and Fertility Hospital of Hanoi, VietNam were involved in the study between October 2022 and April 2023. Penile measurements (flaccid, erect length/circumference, stretched length) were predominantly taken by 1 investigator using a tape measure and the same measurement technique. All statistical analyses were completed using STATA 17.0. Statistical analysis was performed with the Spearman correlation as tested by the Kolmogorov–Smirnov test (p&amp;lt;0.05). Results The mean age of 259 patients was 29,24 (range: 15–48). The mean penile lengths were: flaccid length 9.21 cm (SD 1.71 cm), flaccid circumference at the middle of the shaft 8.25 cm (SD 0.96 cm), erect length 13.22 (SD 1.46cm), erect circumference at the middle of the shaft 10.42 cm (SD 0.94 cm), and stretched length 12.47 cm (SD 1.61 cm). The mean testicular volume was 12.47 mL (SD 6.37 mL) and 12.65 (SD 4.03 mL) for the left and right testicles, respectively. Stretched length is most closely correlated with erect length with r=0.68. We also observed that the testicular volume, erect length was a significant inverse correlation with age, which ranged from r = -0.14 to -0.21. Conclusions The results of this study help to establish a reference range for male genital size in Vietnam, which should be helpful for urologists and andrologist in counseling patient Disclosure No.

Hematological and Serum Biochemical Reference Intervals for Alphaxalone Sedated Common Marmosets (Callithrix jacchus).

Marmosets are routinely used in biomedical research, therefore there is an increasing need for updated reference intervals calculated using a large sample size, correct statistics, and considering different variables. Hematological and biochemical values from 472 healthy common marmosets sedated with alphaxalone were collected over a ten-year period (2013-2023). The variables assumed to have influenced the blood-based parameters were compared, i.e., sex, age, housing condition, pregnancy, and contraceptive use. Reference intervals were calculated based on observed percentiles without parametric assumptions, and with parametric assumptions following Box-Cox transformation. Juvenile marmosets showed increased ALP, phosphate, WBC, lymphocyte count, and basophil count and decreased levels of GGT and Fe compared to adults. Marmosets housed strictly indoors showed increased ALT and GGT levels and decreased levels of total bilirubin and neutrophil count compared to marmosets housed with outdoor access. Pregnant marmosets showed increased ALP, total bilirubin, neutrophil count, monocyte count, and basophil count, and decreased levels of AST, ALT, cholesterol, Fe, and lymphocyte count compared to non-pregnant marmosets. Etonogestrel contracepted marmosets showed decreased P-LCR compared to females who were not contracepted. Updated reference intervals will aid researchers and veterinarians in identifying physiological and pathological changes, as well as improve the reproducibility of research in this species.

Thyroid volume and its correlation with thyroid function in Central India

Objectives Due to its strong correlation with age, gender, anthropometric parameters, and geographic location, thyroid gland volume varies widely. Finding the reference range of a healthy individual’s normal thyroid gland volume has become crucial for every community. Thus, the public will be better able to grade goiter, and large-scale iodine monitoring initiatives will be guided by this. Ultrasound (US) eliminates the issues of overestimation of goiter prevalence and significant interobserver variability associated with palpation estimates, as it is more accurate than clinical examination in diagnosing enlarged thyroid glands. This research aimed to use ultrasonography to determine reference ranges for total thyroid volume in the normal adult population in central India and to connect the results with thyroid function tests. Material and Methods A tertiary-care hospital hosted a prospective cross-sectional study. There were 410 healthy subjects in total. B-Grey scale imaging US was utilized to assess the overall thyroid volume by adding the volume of both lobes, which was calculated using the ellipsoid formula. In order to examine thyroid function, blood samples were obtained. Age-appropriate thyroid volume reference values were found. Results The average thyroid gland volume across all research participants was 6.90 ± 1.74 ml. The gland volume of males was considerably greater (7.30 ± 1.86 ml) than that of females (6.63 ± 1.61 ml) (P&lt;0.001). In both genders, the right lobe’s volume was considerably higher than the left lobe’s (3.76 ± 0.96 ml vs. 3.14 ± 0.89 ml, P &lt; 0.001). There was no discernible relationship between thyroid function tests and gland volume. Conclusion We made an effort to help set the reference values for our community, but more extensive research is needed to set the thyroid gland volume reference values for the entire country.

Evaluation of taurine and carnitine concentrations in whole blood, plasma, skeletal muscle and cardiac muscle in dogs.

Little is known about how plasma and whole blood taurine and plasma carnitine correlate to concentrations in skeletal and cardiac muscle and the effects of diet in dogs. The purpose of this study was to evaluate the correlation among plasma, skeletal and cardiac muscle carnitine and taurine and whole blood taurine and determine the effect of diet. The study protocol was approved by the Pet Food Solutions Institutional Animal Care and Use Committee. Thirty-three mixed-breed hounds and 32 beagles were evaluated at Day 0 then removed from their baseline diet and randomized to a test diet: high animal protein, grain-inclusive (HA-GI), low animal protein, grain-free (LA-GF), low animal protein, grain-inclusive (LA-GI), or high animal protein, grain-free (HA-GF). Blood was drawn every 30 days and endomyocardial (mixed breeds only) and skeletal muscle biopsies were collected at Days 0 and 180. The correlations between plasma and whole blood taurine, or plasma carnitine and skeletal and cardiac muscle concentrations were weak (p < 0.01-0.05). Mixed-breed hounds had increased (p = 0.029) whole blood taurine compared to beagles. Plasma taurine was lower with diet HA-GF, (p = 0.009) however, all diets had increased taurine from Day 0 and were, on average within the laboratory reference range. Dogs fed the HA-GI diet had increased cardiac muscle carnitine esters (p = 0.014). Increased carnitine esters were also appreciated in cardiac muscle in all diets from Day 0 to 180 (p = 0.0001). On Day 180 mixed-breed hounds had increased skeletal total carnitine (p < 0.001) compared to all time points and breeds. This study observed no correlation between plasma, whole blood, skeletal and cardiac muscle taurine concentrations but noted some effects between time, breed and diet.

Clot time ratio (CTR) and relation to treatment outcome in patients with atrial fibrillation treated with Rivaroxaban

BackgroundThere are situations where information about the anticoagulant effects of Rivaroxaban could be clinically useful. Methods for measuring Rivaroxaban concentrations are not available at all medical laboratories while the test MRX PT DOAC for measuring the functional effects of Rivaroxaban, in CTR (Clot Time Ratio), can be made available around the clock. The objectives of this study were to investigate CTR in trough and peak samples during Rivaroxaban treatment of atrial fibrillation and to correlate the findings to bleeding episodes.Methods3 trough- and 3 peak samples from 60 patients (30 on 20 mg daily and 30 on 15 mg daily) were analyzed with PT DOAC. Patients were monitored for 20 months, and bleeding and thrombotic events were documented. Descriptive statistics were used to summarize the data and non-parametric t-test for comparison between groups. ROC curves for the prediction of DOAC plasma levels > 50 ng/mL as determined with LC-MS/MS and anti-FXa methods were computed.ResultsThere was a significant difference between trough and peak CTR (median CTR 1.33 vs. 3.57, p < 0.001). 28 patients suffered bleeds. Patients on 20 mg Rivaroxaban with bleeds had higher mean peak CTR than patients without bleeds (CTR 4.11 vs. CTR 3.47, p = 0.040). There was no significant difference in mean CTR between patients on 15 mg Rivaroxaban with or without bleeds (CTR 3.81 vs. 3.21, p = 0.803), or when considering all patients (CTR 3.63 vs. 3.56, p = 0.445). Five out of seven patients on Rivaroxaban 20 with mean peak CTR above the dose specific first to third quartile range (Q1-Q3) suffered bleeds, while 7/16 patients with mean peak CTR within, and 1/7 patients with mean peak CTR below the Q1-Q3 suffered bleeds. The area under the ROC curve was > 0.98 at the upper limit of the PT DOAC reference interval and the negative predictive value of PT DOAC for the prediction of DOAC plasma levels > 50 ng/mL was > 0.96.ConclusionsThe sample size was too low to draw any firm conclusions but is seems that MRX PT DOAC might be a useful laboratory test in situations where the effect of Rivaroxaban needs evaluation.

A Role for Thyroid Testing in Slipped Capital Femoral Epiphysis? 32% Rate of Abnormal Values in Tested Patients.

Hypothyroidism is a known risk factor for slipped capital femoral epiphysis (SCFE), and prior studies of hypothyroid-associated SCFE have demonstrated an incidence of up to 6%. However, there is limited evidence and no formal practice guidelines regarding whether patients presenting with SCFE should undergo screening for endocrine disorders. This study aims to investigate the incidence of abnormal thyroid function studies in patients presenting with SCFE. This was a retrospective review of all patients aged 0 to 18 years treated for SCFE at a single pediatric hospital from January 2015 to July 2022. On presentation, patients' BMI, thyroid-stimulating hormone (TSH), free T4, vitamin D, creatinine, BUN, and HbA1c levels were documented. Follow-up and treatment for any identified endocrinopathies were noted. In addition, the chronicity, stability, and severity of their slips were recorded. Ninety-eight patients with 106 hips were included in this study. TSH was obtained at the time of initial presentation in 66% (n=65/98) of patients. Median TSH was 2.99 (range: 0.02 to 919, std dev: 132.4). The normal reference range for our institution is 0.5 to 4.5mcIU/mL. Thirty-two percent (n=21/65) of patients with a documented TSH had an abnormal value. Of those patients who had an elevated TSH, 3 were diagnosed with clinical hypothyroidism and went on to treatment with levothyroxine (n=3/19, 16%), 2 patients had been started on levothyroxine before presentation (n=2/19, 11%), and 2 patients were followed in endocrinology clinic until their TSH levels had normalized without further intervention (n=2/19, 11%). Screening of our SCFE population revealed a 32% incidence of thyroid abnormalities which affected treatment in 24% of those patients. This is a much higher incidence of hypothyroid-associated SCFE than previously demonstrated in the literature and has prompted us to start including thyroid screening studies as a routine part of our workup for all patients with SCFE. Level III.

The Role and Limitations of the Reference Interval Within Clinical Chemistry and Its Reliability for Disease Detection.

Reference intervals (RIs) are a range of values that are supplied alongside laboratory measurements for comparison to allow interpretation of this data. Historically, RIs were referred to as the normal range. However, the perception of what is normal can lead to confusion in clinicians and unnecessary emotional distress in patients. RIs can be acquired using several methods. Laboratories may quote published studies or derive their own using established direct or indirect methods. Alternatively, laboratories may verify RIs provided by assay manufacturers using in-house studies. RIs have several limitations that clinicians should be aware of. The statistical methodology associated with establishment of RIs means that approximately 5% of "disease free" individuals will fall outside the RI. Additionally, the higher the number of tests requested, the higher the probability that one will be abnormal, and repeat results in an individual may show regression to the mean. Completion of studies for establishment of RIs can be expensive, difficult, and time consuming. Method bias and differences in populations can greatly influence RIs and prevent them from being transferable between some laboratories. Differences in individual characteristics such as age, ethnicity, and sex can result in large variation in some analytes. Some patients, such as those whose gender differs from that which was presumed for them at birth, may require their own RIs. Alternatively, a decision will need to be made about which to use. Overall, the issue common to these factors lies within interpretation. As such, RIs can be improved with better training in their use, combined with a better understanding of influences that affect them, and more transparent communication from laboratories in how RIs were derived.

Using forest plots to interpret covariate effects in pharmacometric models.

The inclusion of covariates in pharmacometric models is important due to their ability to explain variability in drug exposure and response. Clear communication of the impact of covariates is needed to support informed decision making in clinical practice and in drug development. However, effectively conveying these effects to key stakeholders and decision makers can be challenging. Forest plots have been proposed to meet these communication needs. However, forest plots for the illustration of covariate effects in pharmacometrics are complex combinations of model predictions, uncertainty estimates, tabulated results, and reference lines and intervals. The purpose of this tutorial is to outline the aspects that influence the interpretation of forest plots, recommend best practices, and offer specific guidance for a clear and transparent communication of covariate effects.

Risk factors contributing to infection with SARS-CoV-2 are modulated by sex.

Throughout the early stages of the COVID-19 pandemic in Mexico (August-December 2020), we closely followed a cohort of n = 100 healthcare workers. These workers were initially seronegative for Immunoglobulin G (IgG) antibodies against SARS-CoV-2, the virus that causes COVID-19, and maintained close contact with patients afflicted by the disease. We explored the database of demographic, physiological and laboratory parameters of the cohort recorded at baseline to identify potential risk factors for infection with SARS-CoV-2 at a follow-up evaluation six months later. Given that susceptibility to infection may be a systemic rather than a local property, we hypothesized that a multivariate statistical analysis, such as MANOVA, may be an appropriate statistical approach. Our results indicate that susceptibility to infection with SARS-CoV-2 is modulated by sex. For men, different physiological states appear to exist that predispose to or protect against infection, whereas for women, we did not find evidence for divergent physiological states. Intriguingly, male participants who remained uninfected throughout the six-month observation period, had values for mean arterial pressure and waist-to-hip ratio that exceeded the normative reference range. We hypothesize that certain risk factors that worsen the outcome of COVID-19 disease, such as being overweight or having high blood pressure, may instead offer some protection against infection with SARS-CoV-2.

Feasibility of using real-world free thyroxine data from the US and Europe to enable fast and efficient transfer of reference intervals from one population to another

ObjectivesThe direct approach for determining reference intervals (RIs) is not always practical. This study aimed to generate evidence that a real-world data (RWD) approach could be applied to transfer free thyroxine RIs determined in one population to a second population, presenting an alternative to performing multiple RI determinations. Design and methodsTwo datasets (US, n = 10,000; Europe, n = 10,000) were created from existing RWD. Descriptive statistics, density plots and cumulative distributions were produced for each data set and comparisons made. Cumulative probabilities at the lower and upper limits of the RIs were identified using an empirical cumulative distribution function. According to these probabilities, estimated percentiles for each dataset and estimated differences between the two sets of percentiles were obtained by case resampling bootstrapping. The estimated differences were then evaluated against a pre-determined acceptance criterion of ≤7.8% (inter-individual biological variability). The direct approach was used to validate the RWD approach. ResultsThe RWD approach provided similar descriptive statistics for both populations (mean: US = 16.1 pmol/L, Europe = 16.4 pmol/L; median: US = 15.4 pmol/L, Europe = 15.8 pmol/L). Differences between the estimated percentiles at the upper and lower limits of the RIs fulfilled the pre-determined acceptance criterion and the density plots and cumulative distributions demonstrated population homogeneity. Similar RI distributions were observed using the direct approach. ConclusionsThis study provides evidence that a RWD approach can be used to transfer RIs determined in one population to another.

Comparison of plasma l-lactate between jugular and cephalic veins in healthy and systemically ill horses using a point-of-care device.

To compare plasma l-lactate (LAC) values between samples collected from jugular and cephalic venipuncture in healthy horses and systemically ill horses. Prospective, experimental study. Large animal university teaching hospital. Thirty healthy adult university-owned horses and 43 client-owned horses presenting to the large animal hospital for elective surgical procedures or for emergent medical evaluation of systemic illness. Blood samples were collected from the jugular vein (JV) and cephalic vein (CV) and placed in EDTA blood tubes prior to any medical therapy. LAC values were obtained with a handheld lactate meter at the time of blood collection. LAC was higher in CV samples than JV samples in healthy horses (P<0.001); however, all values were within the normal reference range. Similarly, LAC was higher in CV samples than JV samples in systemically ill horses (P<0.001), but the median JV value was within normal reference range (1.9mmol/L [17.1mg/dL]), while the median CV value was outside the normal reference range (2.9mmol/L [26.1mg/dL]). The CV is an alternative venipuncture site for assessing plasma LAC if the JV is not accessible or to preserve the JV for subsequent catheterization. However, in ill horses, the CV value may be outside the reference range when the corresponding JV value would have been within the reference range.

Reference Ranges for Regional Cerebral Oxygen Saturation with Masimo O3® after Birth and Differences with Other Devices.

Cerebral oximetry using near-infrared spectroscopy (NIRS) is a noninvasive optical technology widely used in neonatology. The present study aimed to define reference ranges for cerebral tissue oxygen saturation (crSO2) with a new four-wavelength NIRS device, Masimo O3® oximeter, during immediate transition after birth and compare values with those obtained previously with NIRO 200NX®. This was a prospective observational study using Masimo O3 device to measure crSO2 and regional cerebral fractional tissue oxygen extraction (cFTOE) in healthy term newborns delivered by primary cesarean section, during the 15 minutes after cord clamping. The neonates who required any medical support were excluded. The NIRS sensor was placed on the right forehead. Peripheral oxygen saturation and heart rate were continuously measured by pulse oximetry. Previous studies which established centiles for crSO2 with NIRO 200NX were used for comparison. A total of 44 newborns were included. The median crSO2 and cFTOE (interquartile range) at 2, 5, and 7 minutes was 54% (49-54), 71% (64-86), and 79% (73-84) and 0,25 (0,18-0,33), 0,19 (0,15-0,23), and 0,16 (0,12-0,21), respectively, with no further changes afterwards. The crSO2 measurements were significantly higher with Masimo O3 compared with NIRO-200NX. The present observational study presented reference ranges for crSO2 and cFTOE measured with Masimo O3 oximeter during the immediate neonatal transition. Values obtained with O3 were higher than those obtained with other oximeters. For this reason, crSO2 is device-specific so there must be known reference values for each oximeter to define therapeutic interventions based on crSO2 and assess cerebral oxygenation in clinical studies. · Masimo O3 uses four wavelengths to measure regional oxygen saturation value.. · O3 values of crSO2 and cFTOE differ with other neonatal oximeters at birth.. · Knowledge of reference range of O3 at birth is essential to guide resuscitation..

A Bayesian nonparametric meta-analysis model for estimating the reference interval.

A reference interval represents the normative range for measurements from a healthy population. It plays an important role in laboratory testing, as well as in differentiating healthy from diseased patients. The reference interval based on a single study might not be applicable to a broader population. Meta-analysis can provide a more generalizable reference interval based on the combined population by synthesizing results from multiple studies. However, the assumptions of normally distributed underlying study-specific means and equal within-study variances, which are commonly used in existing methods, are strong and may not hold in practice. We propose a Bayesian nonparametric model with more flexible assumptions to extend random effects meta-analysis for estimating reference intervals. We illustrate through simulation studies and two real data examples the performance of our proposed approach when the assumptions of normally distributed study means and equal within-study variances do not hold.

Improvement of the methodology for predicting gas-dynamic phenomena on the basis of modern sound-capturing equipment

The object of the study is the sound accompaniment of the processes of stress redistribution in the bottom part of the coal seam, which precede the release of rock, coal, and gas. Among the hazards of underground coal mining, gas-dynamic phenomena (GDP) are the most complex in nature and the most dangerous in terms of consequences of high dynamic power and the release of a large amount of mechanical energy in the form of fractures and gas in a short period of time. This leads to accidents due to sudden gassing and blockages of workings with coal and rock, as well as explosions of methane and coal dust, destruction of the workings' support, damage to machinery and mechanisms, equipment, and devices. The greatest hazard among GDPs is posed by sudden releases of coal and gas, rock and gas, gas releases with destruction of host rocks and with destruction of the ground of the workings, as well as gas breakthroughs from tectonic fault zones. Therefore, the accuracy of predicting possible gas-dynamic phenomena significantly affects the level of safety of miners. The acoustic emission (AE) method is used to predict the gas-dynamic activity of a rock massif. The analysis of acoustic emission studies based on archival data in coal seams subject to gas-dynamic activity has made it possible to substantiate the possibility of improving the accuracy of the forecast of emission hazard, which has a social and economic effect. On the basis of exploratory research and production tests, the software for automated calculations of the GDP forecast was improved and an improved Methodology for forecasting gas-dynamic phenomena based on modern sound-capturing equipment was developed. A scientific justification for the reference interval of AE observations in the conditions of a particular longwall was developed. The developed software and the forecasting methodology were tested in the conditions of the Tsentralna mine of the Toretskugol State Enterprise (Toretsk, Donetsk region, Ukraine). The practical significance of the work is that a method for predicting explosion hazard has been developed, taking into account the modern capabilities of equipment and methods of input data processing, which allows to increase the productivity of mining and tunneling operations in coal seams without reducing the safety of miners.

Familial cases with adult-onset FGF23-related hypophosphatemic osteomalacia -A PHEX 3’-UTR change as a possible cause-

Excessive actions of FGF23 cause several kinds of hypophosphatemic rickets/osteomalacia. It is possible that there still remain unknown causes or mechanisms for FGF23-related hypophosphatemic diseases. We report two male cousins who had been suffering form FGF23-related hypophosphatemic osteomalacia. Sequencing of exons and exon-intron junctions of known causative genes for FGF23-related hypophosphatemic diseases and whole genome sequencing were conducted. Luciferase assay was used to evaluate the effect of a detected nucleotide change on mRNA stability. Two cousins showed hypophosphatemia with impaired proximal tubular phosphate reabsorption and high FGF23. Serum phosphate of their mothers was within the reference range. Exome sequencing of the proband detected no mutations. Whole genome sequencing of the patients and their mothers identified a nucleotide change in the 3’-UTR of phosphate-regulating gene with homologies to endopeptidases on the X chromosome (PHEX) gene (c.*1280_*1287dupGTGTGTGT) which is heterozygous in the mothers and hemizygous in the patients. While sixteen is the most prevalent number of GT repeats, this family had twenty repeats. Luciferase assay indicated that mRNA with 3’-UTR of PHEX with 20 GT repeats was more unstable than that with 16 repeats. Sequencing of exons and exon-intron junctions of known causative genes for FGF23-related hypophosphatemic diseases cannot identify all the genetic causes. Our results strongly suggest that changes of PHEX expression by a nucleotide change in the 3’-UTR is a novel mechanism of FGF23-related hypophosphatemic osteomalacia.

Assay validation and determination of the reference interval for symmetric dimethylarginine in healthy rabbits

BackgroundChronic kidney disease (CKD) is common in older rabbits. The renal biomarkers blood urea and creatinine can be insensitive as indicators of renal disease in rabbits. Symmetric dimethylarginine (SDMA) has been shown to be an earlier and more sensitive biomarker for the assessment of glomerular filtration rate and the evaluation of CKD in several animal species. An immunoassay for SDMA has been validated in a number of species. The purpose of this study was to validate the SDMA immunoassay for rabbit serum and plasma and to determine the normal rabbit reference interval (RI) for SDMA. MethodsClinically healthy rabbits (n=167) between 5 months and 8 years of age, of any breed or sex, participated in the study. Heparinized plasma or serum was collected for clinical chemistry and used for assay validation. Analytical validation of the SDMA immunoassay for rabbit serum and plasma was performed and included assessment of assay accuracy, precision, analytical sensitivity, linearity, interference testing, and plasma/ serum bias. The SDMA reference interval (RI) was determined. ResultsThe SDMA immunoassay met all set quality requirements assessed in analytical validation. The RI for SDMA was determined to be between 4 - 18 µg/dL. Conclusions and clinical relevanceThe SDMA immunoassay demonstrated acceptable performance in both rabbit serum and heparinized plasma as determined by the validation criteria. Although the utility of SDMA as a biomarker of renal disease in rabbits has not been determined, validation of the SDMA immunoassay should facilitate evaluation of SDMA levels in rabbits with confirmed renal disease.

A novel XNA-based Luminex assay to detect UBA1 somatic mutations associated with VEXAS syndrome

ObjectivesPatients with VEXAS syndrome carry mutations of UBA1 gene coding for the E1 enzyme. The three most frequent mutations are p.M41T(122T > C), p.M41V (c.121A > G), and p.M41L (c.121A > C) in codon 41 of exon 3. Currently, sanger sequencing was mainly used to detect these mutations, which has low sensitivity and low throughput. There is a need of high sensitivity, simple and high throughput method to characterize patients with VEXAS syndrome. MethodsBased on our proprietary XNA technology, we have developed a QClamp® Plex platform to detect eight mutations in a single reaction using the Luminex xMap technology. The assay sensitivity, specificity and precision were subsequently evaluated. Furthermore, the reference interval and clinical sensitivity/specificity were estimated using clinical healthy/positive DNA samples and the sanger sequencing method was used for comparison. ResultsWith spiking synthetic mutant DNA in wildtype GM24385 cell line DNA, this assay can detect UBA1 mutations with a detection limit of variant allele frequency (VAF) at 0.1–5%. Our assay shows 100% concordance with Sanger sequencing results when used for analyzing 15 positive and 19 negative clinical samples. ConclusionsThe QClamps® Plex UBA1 Mutation Detection Assay is a quicker, simpler, and more sensitive assay that can accurately detect the UBA1 mutations even at early stages with low mutation frequency.