Normal Reference Values Research Articles

Reference luminal diameters of the carotid arteries among healthy Nigerian adults.

The carotid arteries serve as major blood supply to the head and neck region of the body. Understanding their structure and function in the pathogenesis of stroke and in interventional neuroradiology due to luminal stenosis, atherosclerosis and wall stiffness is paramount. Doppler ultrasound scan plays key role in the early diagnosis of the pathologies of the arteries as it is an affordable, accessible, reliable and non-invasive clinical tool. Knowing normal average diameter of the carotid arteries among healthy individuals is important in making correct clinical diagnosis in any population. The aim of the study was to determine mean diameters of the carotid arteries among healthy adult Nigerians for reference. This was a prospective study involving 104 healthy Nigerians within the ages of 18 and 65 years who had their carotid arteries scanned on both sides and each diameter was measured. A 95% confidence level was used; a p-value of < 0.05 was significant. Of the studied population, 62 were males and 42 were females, and the average age of the subjects was 28.32 ± 9.09 years. From this study, the average luminal diameter of the common carotid artery = 0.61 ± 0.08 cm, internal carotid artery = 0.60 ± 0.08 cm and external carotid artery = 0.49 ± 0.10 cm. The results showed that although, there are differences in measurements between the two sexes (males slightly higher than females in common carotid artery) and between right and left sides (with right side slightly higher), they are not statistically significant. This sonographic study on healthy Nigerian adults has given us normal reference values of the luminal diameters of the carotid arteries among Nigerians, which clinicians can make reference to, when assessing carotid artery diameters of patients in Nigeria.

Normal References of Peak Oxygen Uptake for Cardiorespiratory Fitness Measured with Cardiopulmonary Exercise Testing in Chinese Adults.

Introduction: This study aims to establish normal reference values of peak oxygen uptake (VO2peak) for cardiorespiratory fitness (CRF) in Chinese adults using cardiorespiratory exercise testing (CPET). Methods: A cross-sectional study was done in four communities, two in the North (Beijing) and two in the South (Hezhou, Guangxi) of China from 1 January 2017 to 31 December 2018, with one urban and one rural in each region. Out of 1642 participants screened, 1114 were eligible and completed CPET using a cycle ergometer (Ergosana320F) without abnormal ECG and were included in the analysis. The 2nd and 98th percentiles of O2peak were used as the lower and upper limits of the normal reference values. Results: Significant difference in mean O2peak was shown between men (27.0 mL·min−1·kg−1) and women (23.7 mL·min−1·kg−1). The mean O2peak decreased with age in both sexes, from 35.8 mL·min−1·kg−1 in age 20–29 years to 20.5 mL·min−1·kg−1 in 70–79 years in men and from 29.2 mL·min−1·kg−1 to 17.0 mL·min−1·kg−1 in women. Thus, the age- and sex-specific normal reference values of O2peak were presented for each 10-year age group by men and women separately. Conclusions: This first community-based study in China provides age- and sex-specific normal references of O2peak as a measure of CRF in Chinese adults, which differed significantly from those established in Western populations. Future studies with national representative samples should be warranted.

A-222 Normative Reference Values for Crystallized-Fluid Discrepancy Scores for the NIH Toolbox Cognition Battery

Abstract Objective: To translate NIH Toolbox Cognition Battery (NIHTB-CB) Crystallized-Fluid discrepancy scores into research and clinical practice with adults by providing normative data for discrepancy scores for both age-adjusted standard scores and demographic-adjusted T-scores. Method: We included adult participants from the NIHTB-CB standardization sample who completed all seven neuropsychological tests and who denied having neurodevelopmental, medical, psychiatric, or neurological conditions (n=730; M=47.4 years-old, SD=17.6, range: 18-85; 64.4% women; 63.1% White). Descriptive statistics were calculated for the Fluid and Crystallized composite scores and the Crystallized-Fluid discrepancy score, along with the correlation between the two composite scores. Percentiles were calculated for the discrepancy score, with stratifications by gender, education, and Crystallized composite for the age-adjusted standard scores (SSs) and only the Crystallized composite for the demographic-adjusted T-scores (T). Results: Crystallized-Fluid discrepancy scores ranged from -40 to 44 (M=-0.63, SD=14.89, Mdn =-1, interquartile range=-11-10) for age-adjusted SSs and from -29 to 27 (M=-0.39, SD=10.49, Mdn=-1, IQR=-8-7) for demographic-adjusted T-scores. Using age-adjusted SSs and demographic-adjusted T-scores, Crystallized-Fluid discrepancy scores of SS=15 and T=11 were at the 16th percentile (1 SD below the mean) and discrepancy scores of SS=21 and T=15 were at the 7th percentile (1.5 SDs below the mean). Conclusions: Crystallized-Fluid discrepancy scores might prove to be, with future research, a useful within-person interpretive approach for detecting decline from pre-injury or pre-disease levels of cognitive functioning. These normative reference values assist clinicians and researchers in determining the frequency at which given Crystallized-Fluid discrepancy scores occurred among healthy adults in the normative sample.

The use of OCT to detect signs of intracranial hypertension in patients with sagittal suture synostosis: Reference values and correlations

PurposeTo obtain pediatric normative reference values and determine whether optical coherence tomography (OCT) corresponds better with clinical signs of intracranial hypertension (ICH) compared to the traditional screening method fundoscopy in a large cohort of one type of single suture craniosynostosis.MethodsControl subjects without optic nerve diseases and isolated sagittal synostosis patients aged 3–10 years who underwent fundoscopy and OCT were included in this prospective cohort study. Normative reference values were obtained through bootstrap analysis. Main outcome was the association between peripapillary total retinal thickness (TRT) and total retinal volume (TRV) and appearance on fundoscopy. Signs and symptoms suggestive of ICH, including skull growth arrest, fingerprinting, and headache, were scored.ResultsSixty-four healthy controls and 93 isolated sagittal synostosis patients were included. Normative cut-off values for mean TRT are < 256 μm and > 504 μm and for mean TRV < 0.21 mm3 and > 0.39 mm3. TRT was increased in 16 (17%) and TRV in 15 (16%) of 93 patients, compared to only 4 patients with papilledema on fundoscopy (4%). Both parameters were associated with papilledema on fundoscopy (OR = 16.7, p = 0.02, and OR = 18.2, p = 0.01). Skull growth arrest was significantly associated with abnormal OCT parameters (OR = 13.65, p < 0.01).ConclusionsThe established cut-off points can be applied to screen for ICH in pediatrics. The present study detected abnormalities with OCT more frequent than with fundoscopy, which were associated with skull growth arrest. Therefore, a combination of OCT, fundoscopy, and skull growth arrest can improve clinical decision-making in craniosynostosis.

Determination of Doppler velocimetric measurements of the median artery in horses

Considering the importance of equine culture for the northeast region, the objective was to determine the median artery Doppler velocimetry measurements in horses through Doppler ultrasonography and to correlate changes in these measurements with possible risk factors for laminitis and / or other foot diseases. The project was approved for its execution through protocol N°. 3769100419 granted by the UFPB Ethics Committee. The analyzes were performed at Horse Training Centers and at the Veterinary Hospital - CCA / UFPB, in Areia, Paraíba State. Fourteen animals were used, which were trichotomized at the time of the third metacarpal bone, medial face of both thoracic limbs. The sonoscape S2V ultrasound device with color Doppler coupled to a 7 MHz linear probe was placed at the height of the median artery, in which B was measured. Then, the color Doppler mode was used to determine the doppler velocimeter measurements. Thus, with a 95% confidence interval in mode B 0,509 ± 0,133 of the median artery diameter was determined and in Doppler mode 2,198 ± 1,451 of the pulsatility index and 0,734 ± 0,906 of the resistivity index (non-parametric data). as reference values ​​for normality of median artery vascularization. It is concluded that more studies need to be developed to attest to the reliability of these values. Moreover, they may help in the early diagnosis, improving the prognosis of these animals prone to laminitis and other foot diseases.

Hepatic artery and portal vein Doppler ultrasound reference values in children aged 0-17 years old.

Doppler ultrasound of the portal vein peak systolic velocity and hepatic artery peak systolic velocity and resistive index in children is often performed during abdominal ultrasound for the assessment of liver and other abdominal pathology. However, evidence-based reference values are not available. We aimed to determine these reference values and to investigate whether they are age-dependent. Children who underwent abdominal ultrasound between 2020 and 2021 were retrospectively identified. Patients without hepatic or cardiac abnormalities at the time of ultrasound or during at least 3 months follow-up were eligible for the study. Ultrasound without hepatic hilum portal vein peak systolic velocity and/or hepatic artery peak systolic velocity and resistive index measurements were excluded. Age-dependent changes were analyzed using linear regression. Normal range reference values were described using percentiles for all ages, and for age subgroups. One-hundred ultrasound examinations performed in 100 healthy children aged 0-17.9 years (median 7.8 years, interquartile range 1.1-14.1 years) were included. Ninety-nine portal vein peak systolic velocity and 80 hepatic artery peak systolic velocity and resistive index measurements were obtained. There was no significant association between portal vein peak systolic velocity and age (β = -0.056, p = 0.68). There were significant associations between age and hepatic artery peak systolic velocity, and between age and hepatic artery resistive index (β = -0.873, p = 0.04 and β = -0.004, p < 0.001, respectively). Detailed reference values were provided for all ages, and for age subgroups. Reference values for the hepatic hilum portal vein peak systolic velocity, hepatic artery peak systolic velocity, and hepatic artery resistive index in children were established. Portal vein peak systolic velocity is not age-dependent, whereas hepatic artery peak systolic velocity and hepatic artery resistive index decrease when children get older.

Muscle strength, aerobic capacity, and exercise tolerance are impaired in left ventricular assist devices recipients: A pilot study.

Background: Left ventricular assist devices (LVAD) are increasingly being used as a therapy for advanced heart failure, both as a bridge to heart transplant and, given the rapid advances in the LVAD’s functionality and safety, and constant lack in availability of donor organs, as long-term destination therapy. With the diffusion of such therapy, it is crucial to assess patients’ muscle strength, aerobic capacity and exercise tolerance, to improve their functional capacity. Methods: 38 LVAD recipients (33 men and five women) were included. Exercise testing including a maximal cardiopulmonary exercise test (CPET), handgrip, isometric and isokinetic strength testing of knee and ankle flexion/extension, and Romberg balance test in three conditions (eyes open, eyes closed, double task). Given the small and heterogeneous final sample size, a mostly descriptive statistical approach was chosen. Results: 12 participants were classified as “Obese” (BMI>29.9). The most common comorbidities were type II diabetes and chronic kidney disease. Only 12 participants were able to successfully complete all the assessments. CPET and isokinetic strength trials were the least tolerated tests, and the handgrip test the best tolerated. Mean VO2 peak was 12.38 ± 3.43 ml/kg/min, with 15 participants below 50% of predicted VO2 max, of which 6 below 30% VO2max. Mean handgrip strength was 30.05 ± 10.61 Kg; 25 participants were below the 25° percentile of their population’s normative reference values for handgrip strength, 10 of which were below the 5° percentile. Issues with the management of the external pack of the LVAD and its influence on the test limited the validity of the balance tests data, therefore, no solid conclusions could be drawn from them. VO2 peak did not correlate with handgrip strength or with any of the lower limb strength measures. Conclusion: LVAD recipients show greatly reduced functional capacity and tolerance to exercise and exercise testing, with low overall strength levels. As strength variables appear to be independent from VO2 peak, different lower limbs strength tests should be explored to find a tolerable alternative in this population, which is subjected to muscle wasting due to old age, reduced tissue perfusion, side effects from the pharmacological therapies, and prolonged periods of bedrest.

The Diagnostic Performance of the FEF 25%-75% in the Evaluation of 34 Cases of Asthmatic Children and Adolescents Sensitized and Non-Sensitized to House Dust Mites

The guidelines for asthma and spirometry do not mention the forced expiratory flow between 25% and 75% of forced vital capacity (FEF 25%-75%) in evaluation of airflow obstruction in asthma. The aim of this study was to assess the diagnostic performance of the FEF 25%-75% of children and adolescents with asthma sensitized to house dust mites (HDM). A retrospective case series was done in the Hospital Municipal Jesus, Rio de Janeiro, Brazil with 34 participants with asthma sensitized (n=26) and non-sensitized (n=8) to HDM. Standard reference value for FEF 25%-75% was considered abnormal if below at 65% of predicted. The percentages of 62% of sensitized participants and 38% of not sensitized to HDM had asthma with small airway obstruction by FEF 25-75% index and normal reference values for large airway flow in the spirometry report according to FEV 1/FVC ratio. The means of FEF 25%-75% for HDM and non-HDM were 44.27±9.96 vs. 56.62±13.56, respectively (t=1.86, P=0.0719). The results calculated were a positive predictive value of 80%, a sensitivity of 65%, and an accuracy of 62% amongst other significant parameters (P&lt;0.05). We concluded that the FEF 25%-75% had a high diagnostic performance in children and adolescents with asthma sensitized to HDM.

Establishing Normative Data for 10RM Strength Scores in College-Aged Females

Training recommendations for novice to intermediate lifters include loads that correspond to a 10RM, yet there has not been normative data established for college aged females. Therefore, the purpose of this study was to provide 10RM normative reference values for various strength exercises for 18 to 25-year-old females. The exercises for this study included were the Lat Pulldown, Bench Press, Seated Front Press, Preacher Curl, and the Leg Press. Every testing and training occurred using the same equipment and in the same facility. Testing occurred prior to the structured training program began and then again upon completion of 12 weeks of training. A total of 371 subjects (age = 19.86 +1.43years; height = 64.51 +2.90 inches; pre-test bodyweight = 151.19 +36.05 pounds; pre-test body fat percentage = 29.20 +8.89 percent body fat; post-test bodyweight = 153.66 +36.80 pounds; post-test body fat percentage = 30.76 +8.44 percent body fat; years of strength training experience = 2.28 +2.38 years), participated in the study. Bodyweight categories were derived based upon two established classification systems used in competitive lifting sports. Percentiles and performance rankings for each weight category were reported, where the weighted average method was used to determine the percentile break points. These norms provide a range of possible 10RM loads as well as a reference to the strength levels, which could be useful to more effectively assess and design resistance training programs.

Long-Term Quality of Life After Esophagectomy for Esophageal Cancer

BackgroundSurgery, as part of a multimodal approach, offers the greatest chance of cure for esophageal cancer. However, esophagectomy is often perceived as having a lasting impact on quality of life (QOL), biasing some physicians and patients toward nonoperative management. A comprehensive understanding of the dynamic changes in patient-centered outcomes is therefore important for decision making. Our objective was to determine the long-term QOL after esophagectomy. MethodsData were obtained from a prospectively collected (2006-2015) esophagectomy database at a high-volume center, and patients surviving 3 or more years were identified. Health-related QOL was evaluated using the Functional Assessment of Cancer Therapy-Esophageal Module (FACT-E) at diagnosis and every 3 to 6 months, and was stratified according to operative approach, stage, and complications. In addition, QOL scores were compared with normative population values. ResultsOf 480 patients, 47% (n = 226) survived 3 or more years and 70% (158 of 226) completed the health-related QOL assessments. Time of follow-up was 5.1 ± 2.8 years. After a reduction at 1 to 3 months, FACT-E increased from a baseline of 126 (95% CI, 121-131) to 133 (95% CI, 127-139) at 12 months, and to 147 (95% CI, 142-153) by 5 years. There was no difference in long-term FACT-E with respect to the surgical approach, clinical and pathologic stage, or postoperative complications. At long-term follow-up (more than 3 years), QOL did not differ significantly from the normative population reference values. ConclusionsThe long-term QOL of esophagectomy patients surviving at least 3 years is improved when compared with the time of diagnosis and does not differ from the general population.

Normative Reference Values and Validity for the 30-Second Chair-Stand Test in Healthy Young Adults

Background Clinicians often use physical performance tests (PPT) to measure performance measures in sports since they are easy to administer, portable, and cost-efficient. However, PPT often lack good or known psychometric properties. Perhaps, the 30-second chair-stand test (30CST) would be a good functional test in athletic populations as it has been shown to demonstrate good psychometric properties in older adults. Hypothesis/Purpose The purpose of this study was to determine normative values for and concurrent, convergent and discriminative validity of 30CST for healthy young adults aged 19-35 years. Study Design Cross-sectional Methods Eighty-one participants completed this study. All participants performed two trials of 30CST, 5-times sit-to-stand (5xSTS), and lateral step-up test (LSUT). Investigators used the International Physical Activity Questionnaire Leisure Domain (LD-IPAQ) to divide participants into insufficiently or sufficiently active groups based on the weekly metabolic equivalent of task per the Physical Activity Guidelines for Americans. Results Participants (Mean + SD age, 25.1 ± 3.4 years; body height, 1.71 ± 0.09 m; body mass, 72.6 ± 16.1 kg; females 47) performed an average of 33.0±5.4 30CST repetitions. The 30CST performance was negatively associated with 5xSTS (r=-0.79 p=0.01) and positively associated with LSUT performances (r=0.51, p=0.01) when using Pearson correlations. In addition, the sufficiently active group performed significantly greater 30CST repetitions than the insufficiently active group (mean difference = 2.5; p=0.04). Conclusions In addition to finding a reference value for 30CST performance in young adults, investigators found that the 30CST displayed concurrent and convergent validity in assessing functional lower extremity (LE) muscle strength and discriminated between those with sufficient and insufficient physical activity levels. Training and rehabilitation professionals could use the 30CST for testing functional LE muscle strength for athletes in pre-season or during rehabilitation. Future investigators should perform studies to determine if 30CST predicts sport performance. Level of Evidence Level 2

Normative healthy reference values for global and segmental 3D principal and geometry dependent strain from cine cardiac magnetic resonance imaging.

3-Dimensional (3D) myocardial deformation analysis (3D-MDA) enables novel descriptions of geometry-independent principal strain (PS). Applied to routine 2D cine cardiovascular magnetic resonance (CMR), this provides unique measures of myocardial biomechanics for disease diagnosis and prognostication. However, healthy reference values remain undefined. This study describes age- and sex-stratified reference values from CMR-based 3D-MDA, including 3D PS. One hundred healthy volunteers were prospectively recruited following institutional ethics approval and underwent CMR imaging. 3D-MDA was performed using validated software. Age- and sex-stratified global and segmental strain measures were derived for conventional geometry-dependent [circumferential (CS), longitudinal (LS), and radial (RS)] and geometry-independent [minimum (minPS) and maximum principal (maxPS)] directions of deformation. Layer-specific contraction angle interactions were determined using local minPS vectors. The average age was 43 ± 15years and 55% were women. Strain measures were higher in women versus men. 3D PS-based assessment of maximum tissue shortening (minPS) and maximum tissue thickening (maxPS) were greater than corresponding geometry-dependent markers of LS and RS, consistent with improved representation of local tissue deformations. Global maxPS amplitude best discriminated both age and sex. Segmental analyses showed greater strain amplitudes in apical segments. Transmural PS contraction angles were higher in females and showed a heterogeneous distribution across segments. In this study we provided age and sex-based reference values for 3D strain from CMR imaging, demonstrating improved capacity for 3D PS to document maximal local tissue deformations and to discriminate age and sex phenotypes. Novel markers of layer-specific strain angles from 3D PS were also described.

Femoral Head Coverage Assessment in Healthy Children Younger than 6 Years.

Introduction Developmental dysplasia of the hip (DDH) is one of the commonest hip joint pathologies in children; to treat it properly, hip surgeons should know the normal femoral head (FH) coverage by the acetabulum. This paper aims to assess the femoral head coverage in healthy children younger than 6 years. Methods 270 hip joint CT scans were selected, and digital pelvic models were created according to these scans. FH coverage by the five acetabular regions was assessed according to patient's age and sex. Results Normal reference values of FH coverage by different acetabular regions were obtained. It was found that the growth process of different acetabular regions occurs nonlinearly with the periods of acceleration. Anterior and superior-anterior acetabular regions grow more intensively in boys up to 3 years old and between 4 and 5 years old both in boys and girls; superior-posterior, posterior-superior, and posterior-inferior acetabular regions grow more intensively in boys and girls up to 3 years old and between 4 and 5 years old (p ≤ 0.005). The following sex differences in FH coverage by the acetabulum were found: more superior-anterior FH coverage was found in boys and posterior FH coverage in girls (p ≤ 0.005).

Normal Echocardiographic Reference Values of the Right Ventricular to Left Ventricular Endsystolic Diameter Ratio and the Left Ventricular Endsystolic Eccentricity Index in Healthy Children and in Children With Pulmonary Hypertension.

BackgroundAn accurate assessment of the right and left ventricle and their interaction is important in pediatric pulmonary hypertension (PH). Our objective was to provide normal reference values for the right ventricular to left ventricular endsystolic (RV/LVes) ratio and the LV endsystolic eccentricity index (LVes EI) in healthy children and in children with PH.MethodsWe conducted an echocardiographic study in 769 healthy children (median age: 3.36 years; range: 1 day—18 years) and validated abnormal values in 44 children with PH (median age: 2.1 years; range: 0.1 months—17.7 years). We determined the effects of gender, age, body length, body weight, and body surface area (BSA) on RV/LVes ratio and LVes EI values. The RV/LVes ratio and LVes EI were measured from the parasternal short axis view between papillary muscle from the endocardial to endocardial surfaces.ResultsBoth, the RV/LVes ratio and the LVes EI were highly age-dependent: (i) neonates RV/LVes ratio [median 0.83 (range 0.53–1.37)], LVes EI [1.21 (0.92–1.45)]; (ii) 12–24 months old: RV/LVes ratio: [0.55 (0.35–0.80)], LVes EI: [1.0 (0.88–1.13)]; iii) 18th year of life RV/LVes ratio: [0.53 (0.32–0.74)], LVes EI: [1.0 (0.97–1.07)]. Healthy neonates had high LVes EI and RV/LVes ratios, both gradually decreased within the first year of life and until BSA values of about 0.5 m2, body weight to about 15 kg and body length to about 75 cm, but were almost constant thereafter. Children (>1 year) and adolescents with PH had significantly higher RV/LVes ratio (no PH: median 0.55, IQR 0.49–0.60; PH: 1.02, 0.87–1.26; p < 0.001) and higher LVes EI values (no PH: 1.00, 0.98–1.00; PH: 1.53, 1.26–1.71; p < 0.001) compared to those without PH. To predict the presence of PH in children > 1 year, we found the following best cutoff values: RV/LVes ratio ≥ 0.67 (sensitivity: 1.00, specificity: 0.95) and LVes EI ≥ 1.06 (sensitivity: 1.00, specificity: 0.97).ConclusionWe provide normal echocardiographic reference values of the RV/LVes ratio and LVes EI in healthy children, as well as statistically determined cutoffs for the increased values in children with PH.

Cardiometabolic Risk Factors Among Insufficiently Active African American Women With Obesity: Baseline Findings From Smart Walk.

Low moderate-to-vigorous physical activity (MVPA) levels and obesity are associated with increased cardiometabolic disease risk. The aim of this study was to describe MVPA and cardiometabolic risk characteristics of insufficiently active African American women with obesity (N = 60) enrolled in a culturally tailored MVPA intervention. We assessed accelerometer-measured and self-reported MVPA, blood pressure, serum lipid profiles, cardiorespiratory fitness (VO 2 peak), and aortic pulse wave velocity. Participants (mean age, 38.4; mean body mass index, 40.6 kg/m 2 ) averaged 15 min/d of accelerometer-measured MVPA and 30 min/wk of self-reported MVPA. Systolic and diastolic blood pressure levels were elevated (135.4 and 84.0 mm Hg, respectively). With the exception of low-density lipoprotein cholesterol (121.4 mg/dL) and high-density lipoprotein cholesterol (47.6 mg/dL), lipid profiles were within reference ranges. Compared with normative reference values, average VO 2 peak was low (18.7 mL/kg/min), and pulse wave velocity was high (7.4 m/s). Our sample of insufficiently active African American women with obesity was at an elevated risk for cardiometabolic disease.

Influencing Factors on the Use of Tetrahydrobiopterin in Patients with Phenylketonuria.

Objective To explore and analyze the influencing factors of tetrahydrobiopterin therapy in patients with phenylketonuria. Methods 86 children with phenylketonuria (PKU) diagnosed and treated in our hospital from February 2019 to September 2021 were randomly enrolled. All the children underwent coenzyme hydroxybiopterin and urinary pterin spectrum analysis, and the children with deficiency received gene mutation testing. Results The results of urine pterin analysis showed that 82 patients had higher urinary N and B contents than the normal reference values, with the N/B slightly higher than the normal B% within the normal range. 4 patients had extremely high urinary N/B and B% <5% and were diagnosed as BH4 deficiency caused by 6-pyruvoyl-tetrahydropterin synthase (PTPS) deficiency, and a combined stress test was performed. The blood Phe level was (720–1200) μmol/L 3 h after Phe loading, and the blood Phe concentration decreased to (120–240) μmol/L 4–6 h after oral administration of 7.5 mg/kg BH4 tablet. After one week of treatment, the blood Phe concentration decreased significantly to 239 ± 173 μmol/L, with a decrease rate of 52.14 ± 25.28%. It shows that the application of tetrahydrobiopterin intervention therapy is effective in patients with PKU. The results of the full-length cDNA analysis of the PTPS gene showed that a total of 4 gene mutations were found. A C ⟶ T substitution occurred at the 259th base, and the 87th proline (Pro) in the coding region was converted to serine (Ser) (P87S). G ⟶ A substitution at base 286 converts aspartic acid (Asp) at position 96 of the coding region to asparagine (Asn) (D96N). A ⟶ G substitution occurs at the 155th base to convert asparagine (Asn) at position 52 of the coding region to serine (Ser) (N52S). G ⟶ C substitution occurs at the 430th base to convert glycine at position 144 (Gly) to arginine (Arg) (G144R). G144R is a new mutation type. The gene mutation types of the 4 patients were P87S/D96N, N52S/G144R, D96N/P87S, and P87S/P87S, all of which were from their parents, which conformed to the law of autosomal recessive inheritance. Conclusion PKU is caused by the defect of phenylalanine hydroxylase activity in children, which causes phenylalanine metabolism disorder, and tetrahydrobiopterin intervention therapy can affect the activity of phenylalanine hydroxylase, increase the decline rate of blood Phe, significantly reduce the level of phenylalanine in children, and promote intellectual recovery. The dose of tetrahydrobiopterin should be tailored, with small doses for mild phenotypes and long-term treatment using even smaller doses.

Normative Reference Values of Left Ventricular Mechanical Dispersion Assessed by Two-Dimensional Longitudinal Speckle-Tracking Strain in Normal Subjects

Normative Reference Values of Left Ventricular Mechanical Dispersion Assessed by Two-Dimensional Longitudinal Speckle-Tracking Strain in Normal Subjects

Assessment of cardiac function in children by strain imaging and its correlation with conventional echocardiographic parameter.

ABSTRACTBackground:The objectives of this study were to find out of normal reference value for age-dependent longitudinal strain values in children and find its correlation with conventional echocardiographic parameters.Methods:In total, 100 healthy normal children aged between 2 and 15 years were enrolled and divided into three age groups, namely, 2–5 years, 5–10 years, and 10–15 years. Using the GE Vivid 7 ultrasound platform with 4 or 7 MHz probes, both LV and RV global longitudinal strains and conventional echocardiographic parameters were acquired.Results:In normal healthy children, left ventricular GLS values were –20.10 to –19.68 (mean: –19.89), –21.93 to –21.02 (mean: –21.48), and –20.87 to –20.41 (mean: –20.64)) in children aged 2–5 years, 5–10 years, and 10–15 years and right ventricular GLS values were –16.80 to –16.44 (mean: –16.62), –27.85 to –27.27 (mean: –27.56), –28.44 to –27.93 (mean: –28.19) in the above three groups, respectively. No significant increase was noted in the left ventricular strain value from basal to the apical segment from age group 2 years to 15 years and no gender differences were seen. None of the conventional echocardiographic parameters commonly used to assess the left or right ventricular systolic function had a significant correlation with LVGLS and RVGLS.Conclusions:The mean LVGLS values were –19.89, –21.48, and –20.64 and RVGLS were –16.62, –27.56, and –28.19 in healthy normal children aged 2–5 years, 5–10 years, and 10–15 years, respectively, and conventional echocardiographic parameters did not have any significant correlation with these values.

Reference values of myocardial native T1 and T2 mapping values in normal Indian population at 1.5 Tesla scanner.

T1 and T2 mapping techniques on cardiovascular magnetic resonance (CMR) provide insights into the myocardial tissue characterisation. We sought to establish the normal reference values of native T1 and T2 mapping in Indian population which can be used subsequently in clinical practice for addressing various cardiac pathologies. This prospective study included consecutive healthy volunteers (18-60years) who underwent CMR on a 1.5 Tesla scanner using standard protocol. T1 mapping sequence was performed using MOLLI sequence with two different flip angles (FA) (35° and 50°). T2 mapping was performed using a hybrid gradient and spin-echo sequence sequence with two different FA (70° and 12°). Images were analysed with ROIs drawn in all the 16 AHA myocardial segments. 50 volunteers (average age-34years, males-72%) were included. All the scans were normal. The mean T1 value at 35-degree FA was 946.86 + 14.16ms and at 50-degree FA was 941.60 + 11.89ms. The mean T2 mapping value at 70-degree FA was 45.67 + 1.39ms and at 12-degree FA was 45.61 + 1.47ms. The mapping values were not statistically different between males and females (all p > 0.2). The T1 and T2 mapping values did not show any significant correlation with LVEF, age, BMI or heart rate (all r < 0.33). The T1 mapping values significantly differ at 35- and 50-degree FAs (p = 0.002). The results establish the normal reference T1 and T2 mapping value for Indian population in institutes using the same protocol and parameters at 1.5 Tesla and may guide future research.

Normative reference values and regression equations to predict the 6-minute walk distance in the Asian adult population aged 21-80 years.

The 6-min walk test (6MWT) is a widely used field walking test. This study reports the normative reference values (NRV) of distance walked during 6MWT (6MWD) in healthy Singaporeans (aged 21-80) and updates the 6MWD reference equations. This information may facilitate the interpretation of the 6MWD in clinical populations. The Singapore Institute of Technology-Institutional Review Board (SIT-IRB Project Number: 2019099) approved this study to be carried out from June 2019 to January 2021. All participants gave written informed consent before data collection began. The six-minute walk test (6MWT) is a widely adopted submaximal field-walking test to evaluate functional exercise capacity. This validated test is a reliable, safe, inexpensive, and straightforward assessment tool commonly used as an outcome measure, using the distance walked (6MWD) as the primary outcome. An earlier study has established the normative reference values (NRV) and equation in healthy Singaporeans - however, the small sample size and narrow age range curb adequate representation of the adult population profile. This study aims to update the NRV and reference equations to predict the distance walked during 6MWT (6MWD) for healthy Singaporeans aged 21-80. This cross-sectional study recruited community-dwelling healthy subjects aged 21-80 via convenience sampling. Each subject completed two trials of 6MWT according to the standard protocol. Primary outcome measures included 6MWD, pre-and post-test heart rate (HR), oxygen saturation, and blood pressure (BP). 172 healthy Singaporeans (, ) participated. The overall mean 6MWD was metres. The age-stratified mean 6MWD ranged from metres (aged 21-39) to metres (aged 60-80). Age, gender, and percentage maximum HR predicted (%PredHRmax) were the most significant variables (). 6MWD reference (HR reserve, bpm) (weight, kg), . Applying equations from other studies to the Singaporean population resulted in an overestimation of the 6MWD. This study updated the NRV and reference equations of 6MWD for healthy Singaporeans aged between 21-80 years. This update revises the local benchmarks of 6MWD in Singapore, a widely adopted outcome measure.