Reference values of gait parameters in healthy Chinese university students: A cross-sectional observational study

BACKGROUND Gait is influenced by race,age,and diseases type.Reference values for gait are closely related to numerous health outcomes.To gain a comprehensive understanding of gait patterns,particularly in relation to race-related pathologies and disorders,it is crucial to establish reference values for gait in daily life considering sex and age.Therefore,our objective was to present sex and age-based reference values for gait in daily life,providing a valuable foundation for further research and clinical applications.AIM To establish reference values for lower extremity joint kinematics and kinetics during gait in asymptomatic adult women and men.METHODS Spatiotemporal,kinematics and kinetics parameters were measured in 171 healthy adults(70 males and 101 females)using the computer-aided soft tissue foot model.Full curve statistical parametric mapping was performed using independent and paired-samples t-tests.RESULTS Compared with females,males required more time(cycle time,double-limb support time,stance time,swing time,and stride time),and the differences were statistically significant.In addition,the step and stride lengths of males were longer.Compared to males,female cadence was faster,and statures-per-second and stride-per-minute were higher.There were no statistical differences in speed and stride width between the two groups.After adjusting for height,it was observed that women walked significantly faster than men,and they also had a higher cadence.However,in terms of step length,stride length,and stride width,both genders exhibited similarities.CONCLUSION We established reference values for gait speed and spatiotemporal gait parameters in Chinese university students.This contributes to a valuable database for gait assessment and evaluation of preventive or rehabilitative programs.

Defining laboratory reference values and decision limits＇ populations, intervals, and interpretations

This article provides a brief overview of various approaches that may be utilized for the analysis of human semen test results. Reference intervals are the most widely used tool for the interpretation of clinical laboratory results. Reference interval development has classically relied on concepts elaborated by the International Federation of Clinical Chemistry Expert Panel on Reference Values during the 1980s. These guidelines involve obtaining and classifying samples from a healthy population of at least 120 individuals and then identifying the outermost 5% of observations to use in defining limits for two-sided or one-sided reference intervals. More recently, decision limits based on epidemiological outcome analysis have also been introduced to aid in test interpretation. The reference population must be carefully defined on the basis of the intended clinical use of the underlying test. To determine appropriate reference intervals for use in male fertility assessment, a reference population of men with documented time to pregnancy of 〈 12 months would be most suitable. However, for epidemiological assessment of semen testing results, a reference population made up ofunselected healthy men would be preferred. Although reference and decision limits derived for individual semen analysis test results will undoubtedly be the interpretational tools of choice in the near future, in the long term, multivariate methods for the interpretation of semen analysis alone or in combination with information from the female partner seem to represent better means for assessing the likelihood of achieving a successful pregnancy in a subfertile couple.

Normal Reference Value of Red Blood Cell Count of Chinese Presenile Men and Geographical Factors

This paper aims at providing a scientific basis for unifying the normal reference value standards of red blood cell count of Chinese presenile men. The paper, using microscopical counting method, studies the relationship between the normal reference values of 38,061 samples of red blood cell count of presenile men and eight geographical factors in 297 units in China. It is found that the correlation of geographical factors and the normal reference value of red blood cell count of presenile men is quite significant （F=303.00, P=-0.000）. By using the method of stepwise regression analysis, one regression equation is inferred. It is concluded that if geographical data are obtained in a certain area, the normal reference value of red blood cell count of presenile men in this area can be reckoned by using the regression analysis. Furthermore, according to the geographical factors, China can be divided into eight regions： Northeast China Region, North China Region, Shanxi-Shaanxi-Irmer Mongolia Region, Middle and Lower Reaches of the Changjiang River Region, Southeast China Region, Northwest China Region, Southwest China Region and Qinghai-Tibet Plateau Region.

Normal reference value of hemoglobin of young women and geographical factors in China

A research is conducted on the relationship between the normal reference value of 20,475 examples of hemoglobin of young women and five geographical factors in 208 areas in China, the normal reference value is determined by the hemoglobincyanide method. It is found that the correlation of geographical factors and the normal reference value of hemoglobin of young women are quite significant (F=142.81). By using the method of multiple linear regression analysis, one regression equation is inferred. If geographical values are obtained in some areas, the normal reference value of hemoglobin of young women of this area can be reckoned by using the regression equation. Furthermore, depending on the geographical factors, China can be divided into six regions: Qinghai-Tibet (Qingzang) Plateau, Southwest, Northwest, Southeast, North and Northeast China.

Reference value of old people's hematocrit and geographical factors

This paper is written in order to provide a scientific basis for a unified standard of the reference value of Chinese healthy old people's hematocrit. It studies the relationship between the reference values of healthy old people's hematocrit, tested according to the Wintrobe Laws and five geographical factors. It is found that the altitude is the most important factor affecting the reference value of old people's hematocrit. As the altitude gradually increases, the reference value of their hematocrit also increases, the relationship is quite significant. By using the method of stepwise regression analysis, two multivariate regression equations are deduced:1=50.2+0.00248X1-0.0534X3-0.388X4+0.00383X5±2.2, 2=44.5+0.00231X1-0.0600X3-0.260X4+0.00341X5±2.1. If the geographical index values in a particular area in China are known, the reference value of old people's hematocrit in this area can be established by means of the regression equations. Furthermore, according to the dependent relationship of the reference value of old people's hematocrit on geographical factors, China can be divided into six regions: Qinghai-Tibet, Plateau, Southwest, Northwest, Southeast, North and Northeast.

Normal reference value of forced vital capacity of Chinese younger women and geographical factors

Objective To supply a scientific basis for standardizing the normal reference value of forced vital capacity(FVC)of Chinese younger women.Methods We studied the relationship between the normal reference value of 21767 samples of FVC of younger women and eight geographical factors in 157 areas in China.Results It was found that the correlation between geographical factors and the normal reference value of FVC of younger women was quite significant(F=5.884,P=0.000).By adopting the method of mathematical regression analysis,one regression equation was inferred:=3.146+0.00006919X1+0.01315X4-0.006966X6+0.09524X8±0.254.In the above equation,is the normal reference value of younger women’ FVC(L);X1 is the altitude(m);X4 is the annual mean air temperature(℃);X6 is the annual mean relative humidity(%);X8 is the annual mean wind speed(m/s);0.254 is the value of the residual standard deviation.Conclusion If geographical values are obtained in a certain area,the normal reference value of FVC of younger women in this area can be obtained by using the regression equation.Furthermore,according to the geographical factors,China can be divided into eight regions:Northeast China Region,North China Region,Shanxi-Shaanxi-Inner Mongolia Region,middle and lower reaches of the Yangzte River Region,Southeast China Region,Northwest China Region,Southwest China Region,and Qinghai-Tibet Plateau Region.

The Reference Value for Biomonitoring in Chemicals Risk Area in Thailand

The workers’biological standard value(WBSV)is generally used to assess chemicals health risks in community.It may cause the deviate biomonitoring.Therefore,this study was aimed to set the pilot reference value for exposed people to chemicals.The study was divided into three phases:the two phases for field-study method and one phase for stakeholder’s adoption.Phase I was proceeded in one industrial zone in Thailand during the years 2012-2014 to collect blood and urine samples of 402 working-age people in community accompanied with in-depth interview.The 4 heavy metals(arsenic,cadmium,lead,mercury)in blood and urine were analyzed by atomic absorption spectroscopy(AAS)analysis and inductively coupled plasma mass spectrometry(ICP-MS).The metabolites of 4 volatile organic compounds(VOCs,benzene,toluene,styrene,xylenes)in urine were analyzed by high performance liquid chromatography(HPLC)analysis.The 8 chemicals concentrations of the volunteers’average chemicals concentration(VACC)were calculated.Phase II was proceeded during the years 2015-2016 to compare risk group identification between usage of VACC and usage of WBSV.The results were presented in mean value,standard deviation,percentage,and significant.The results showed approximately 90 percent of VACCs were lower than WBSV.The exceptional result was volunteers’average urinary arsenic concentration.It was clearly higher than WBSV.The comparative results showed the adjusted amount of risk people by VACC was higher than the adjusted amount risk people by WBSV.Phase III was proceeded in the year 2017 for stakeholder’s adoption.This study indicated that general people’s average chemicals concentration should be used as the reference value for biomonitoring and active health surveillance.

Reference values of carotid intima-media thickness and arterial stiffness in Chinese adults based on ultrasound radio frequency signal:A nationwide,multicenter study

Background:Carotid intima-media thickness(IMT)and diameter,stiffness,and wave reflections,are independent and important clinical biomarkers and risk predictors for cardiovascular diseases.The purpose of the present study was to establish nationwide reference values of carotid properties for healthy Chinese adults and to explore potential clinical determinants.Methods:A total of 3053 healthy Han Chinese adults(1922 women)aged 18-79 years were enrolled at 28 collaborating tertiary centers throughout China between April 2021 and July 2022.The real-time tracking of common carotid artery walls was achieved by the radio frequency(RF)ultrasound system.The IMT,diameter,compliance coefficient,βstiffness,local pulse wave velocity(PWV),local systolic blood pressure,augmented pressure(AP),and augmentation index(AIx)were then automatically measured and reported.Data were stratified by age groups and sex.The relationships between age and carotid property parameters were analyzed by Jonckheere-Terpstra test and simple linear regressions.The major clinical determinants of carotid properties were identified by Pearson’s correlation,multiple linear regression,and analyses of covariance.Results:All the parameters of carotid properties demonstrated significantly age-related trajectories.Women showed thinner IMT,smaller carotid diameter,larger AP,and AIx than men.Theβstiffness and PWV were significantly higher in men than women before forties,but the differences reversed after that.The increase rate of carotid IMT(5.5µm/year in women and 5.8µm/year in men)and diameter(0.03 mm/year in both men and women)were similar between men and women.For the stiffness and wave reflections,women showed significantly larger age-related variations than men as demonstrated by steeper regression slopes(all P for age by sex interaction<0.05).The blood pressures,body mass index(BMI),and triglyceride levels were identified as major clinical determinants of carotid properties with adjustment of age and sex.Conclusions:The age-and sex-specific reference values of carotid properties measured by RF ultrasound for healthy Chinese adults were established.The blood pressures,BMI,and triglyceride levels should be considered for clinical application of corresponding reference values.

Normal sperm head morphometric reference values in fertile Asian males

Sperm head morphology is crucial for male factor infertility diagnosis and assessment of male reproductive potential.Severalcriteria are available to analyze sperm head morphology,but they are limited by poor methodology comparability and populationapplicability.This study aimed to explore comprehensive and new normal morphometric reference values for spermatozoa heads infertile Asian males.An automated sperm morphology analysis system captured 23152 stained spermatozoa from confirmed fertilemales.Of these samples,1856 sperm head images were annotated by three experienced laboratory technicians as“normal”.Weemployed 14 novel morphometric features to describe sperm head size(head length,head width,length/width ratio,and girth),shape(ellipse intersection over union,girth intersection over union,short-axis symmetry,and long-axis symmetry),area(head,acrosome,postacrosomal areas,and acrosome area ratio),and degrees of acrosome and nuclear uniformity.This straight-forwardmethod for the morphometric analysis of sperm by accurate visual measurements is clinically applicable.The measured parameterspresent valuable information to establish morphometric reference intervals for normal sperm heads in fertile Asian males.Thepresented detailed measurement data will be valuable for interlaboratory comparisons and technician training.In vitro fertilizationand andrology laboratory technicians can use these parameters to perform objective morphology evaluation when assessing malefertilization potential.

Reference Interval of Thyroidal Function of Women in the Early,Middle and Late Pregnancy in Jingzhou City,Hubei Province

[Objectives]To study the reference value of thyroid function in healthy women of childbearing age during different pregnancies(early,middle and late pregnancy)in Jingzhou City.[Methods]362 healthy women of childbearing age during different pregnancies(early,middle and late pregnancy)were selected as the study group,and 360 non-pregnant women were selected as the control group.Serum thyroid hormone levels in the two groups were detected,and the reference value was expressed as the median(M)and 95%confidence interval(CI).On this basis,the chart of changing trend of thyroid hormone in the early,middle and late pregnancy were plotted.[Results]Compared with the control group,FT3,TT4,TT3,FT4and TSH in the early,middle and late pregnancy were significantly different in the study group(P<0.05).In the study group,there were significant differences in the early,middle and late pregnancy(P<0.05).[Conclusions]This trend chart has certain reference value in the screening,diagnosis and treatment of thyroid diseases in healthy women of childbearing age during different pregnancies(early,middle and late pregnancy)in Jingzhou City of Hubei Province.

Reference values of brachial-ankle pulse wave velocity for Northern Chinese

Background Brachial-ankle pulse wave velocity （baPWV） is a reliable method for measuring arterial elasticity, but the absence of reference value for baPWV has limited its wide use. We conducted an epidemical study in north China to investigate the reference value of baPWV for Chinese people and its influential factors. Methods A total of 974 identified healthy subjects were recruited in this study. The values of baPWV were evaluated noninvasively with an automatic device. Results For healthy population, the mean value of baPWV was higher for male （P 〈0.001）. Multiple regression analysis demonstrated that both age and systolic blood pressure were positively associated with baPWV for male and female （P 〈0.001）. BaPWV value was higher in male than in female in younger group （〈50 years） but not in older group （P〈-0.001）. The upper limits of baPWV were 1394/1264 cm/s, 1435/1361 cm/s, 1552/1433 cm/s, 1597/1609 cm/s and 1798/1915 cm/s for healthy male/female at 10 years interval （age range 20-70 years）. Conclusions Aging is the most important reason of arterial stiffness, but the effect of age on baPWV augmentation is greater for healthy female than their male counterpart. The reference values of baPWV by sex and age are very useful for clinical and preventive medicine.

Reference value of long-time exercise test in the diagnosis of primary periodic paralysis

Background The long-time exercise test （ET） is used to diagnose the primary periodic paralyses （PPs）.However the reference values of ET are many and various.This study aimed to investigate the reference value of long-time ET in the diagnosis of PPs.Methods We recruited 108 healthy subjects,68 patients with PPs,and 72 patients with other diseases for the study.The procedure of ET was made on the basis of the McManis＆#39; method.Electrical responses were recorded from right abductor digiti minimi （ADM） muscle when stimulation of the ulnar nerve at the wrist.After the compound muscle action potential （CMAP） was monitored,subjects were then asked to contract the muscle as strongly as possible for 5 minutes.CMAPs were recorded for 2 seconds immediately after cessation of exercise,then every 5 minutes for 10 minutes,and finally every 10 minutes for 50 minutes.In general,the CMAP amplitudes will fall below the pre-exercise levels in an hour.The largest decrease was calculated and used as results of ET.Results The CMAP amplitude decreases had no significant differences between groups when the healthy adults were grouped according to age,gender,height,weight and test time.Decreases in PPs patients （57.76%） were significantly more than in healthy subjects （15.21%） and other disease patients （18.10%,P 〈0.001）.Receiver operating characteristic （ROC） curve analysis showed that the best threshold is 35.50%.Conclusions In the long-time exercise test,threshold of 35.50% for the CMAP amplitude decrease was identified for abnormal.The result is not influenced by age,gender,height,weight,and test time.About 7.4% of healthy subjects were abnormal in ET.

VALIDITY OF SPIROMETRIC REFERENCE VALUES FOR HEALTHY ADULTS IN SHANGHAI

Objective To evaluate the validity of current spirometric reference values for healthy adults in Shanghai.Methods Healthy non-smoking adults without respiratory diseases were randomly enrolled in the study.Gender,age,standing height,body weight and spirometric parameters were obtained.The parameters were compared with reference values from current prediction equations with or without conversion factors.Results A total of 127 healthy adults (60 males and 67 females) aged 18-57 years participated in the study.In the study,pulmonary function parameters of healthy adults,especially of female adults were higher than predicted values,according to prediction equations from Chinese subjects in Shanghai.There were discrepancies between measuring values and reference values from foreign prediction equations with or without conversion factors.Conclusion Spirometric parameters of healthy adults,especially female population in Shanghai might be underestimated by present reference values from Chinese subjects.Foreign reference values and their conversion factors are not able to match measuring values.Validity of spirometric reference values for adults in Shanghai should be reassessed.

Age-specific reference ranges of prostatespecific antigen in the elderly of Amirkola: A population-based study

Objective:To determine the age-specific reference ranges of prostate-specific antigen(PSA)in the older men in the city of Amirkola.Methods:This cross-sectional study is a part of Amirkola Health and Ageing Project(AHAP)which has been conducted as a cohort study since 2011 in Amirkola,a city in northern Iran.The demographic information of all men aged 60 and older were collected through questionnaires and interviews and the PSA measurements were performed using ELISA and Diametra kit.The acquired data were analyzed afterwards.Results:A number of 837 elderly men with a mean age of 69.99±7.72 years participated in this study.The serum PSA level(95th percentile)was determined to be 0.9(0-4.89)ng/mL in the age group of 60-64 years,1.1(0-4.88)ng/mL in the age group of 65-69 years,0.93(0-9.01)ng/mL in the age group of 70-74 years,1.3(0-7.95)ng/mL in the age group of 75-79 years,1.9(0-11.98 ng/mL)in the age group of 80-84 years,and 1.45(0-33.17)ng/mL in the 85 and older group.The serum PSA level was significantly correlated with age(p=0.000).Conclusion:This study indicated that there is a direct correlation between the age and serum PSA levels.The use of age-specific reference range could guide clinicians on the incidence of prostate cancer in this population and perhaps reduce the number of unnecessary tests in this population group.

Allowance of the Emission Quota Using Life Cycle Assessment for the Creation of a National Carbon Market: Framework Developed for Hydroelectric Projects in Cameroon

The lack of synergy between infrastructure financing mechanisms and mechanisms for combating climate change does not favor the definition of sustainable infrastructure in Cameroon. The definition of a sustainable infrastructure could meet the requirements of these mechanisms, thanks to the control of Greenhouse Gas (GHG) emissions during its installation, in relation to a predefined value. However, the promotion of efforts to reduce emissions from new infrastructures is not subject to a local market. This situation is a limit in the implementation of the policies defined in the Nationally Determined Contribution (NDC). This article proposes a framework for promoting reduction efforts for a national carbon market, in favor of hydroelectric infrastructures. Thanks to the Life Cycle Assessment (LCA) environmental assessment tool, we are going to determine the carbon quota for a specific power. The study carried out on the hydroelectric power station of Mekin (HydroMekin) leads us to a reduction effort of 68.2% compared to the threshold defined at 14.057 gCO2eq/kWhe. The framework, developed, contributes to defining the environmental parameters in the decarbonation strategy during the implementation of new hydroelectric infrastructures and the market carbon design elements special to the construction phase of these infrastructures.

Effects of hepatitis B virus infection on human sperm chromosomes

AIM: To evaluate the level of sperm chromosome aberrations in male patients with hepatitis B, and to directly detect whether there are HBV DNA integrations in sperm chromosomes of hepatitis B patients.METHODS: Sperm chromosomes of 14 tested subjects (5healthy controls, 9 patients with HBV infection, including 1with acute hepatitis B, 2 with chronic active hepatitis B, 4with chronic persistent hepatitis B, 2 chronic HBsAg carriers with no clinical symptoms) were prepared using interspecific in vitro fertilization between zona-free golden hamster ova and human spermatozoa, and the frequencies of aberration spermatozoa were compared between subjects of HBV infection and controls. Fluorescence in situ hybridization (FISH) to sperm chromosome spreads was carried out with biotin-labeled full length HBV DNA probe to detect the specific HBV DNA sequences in the sperm chromosomes.RESULTS: The total frequency of sperm chromosome aberrations in HBV infection group (14.8%, 33/223) was significantly higher than that in the control group (4.3%,5/116). Moreover, the sperm chromosomes in HBV infection patients commonly presented stickiness, clumping, failure to staining, etc, which would affect the analysis of sperm chromosomes. Specific fluorescent signal spots for HBV DNA were seen in sperm chromosomes of one patient with chronic persistent hepatitis. In 9 (9/42) sperm chromosome complements containing fluorescent signal spots, one presented 5 obvious FISH spots, others presented 2 to 4signals. There was significant difference of fluorescence intensity among the signal spots. The distribution of signal sites among chromosomes was random.CONCLUSION: HBV infection can bring about mutagenic effects on sperm chromosomes. Integrations of viral DNA into sperm chromosomes which are multisites and nonspecific, can further increase the instability of sperm chromosomes. This study suggested that HBV infection can create extensively hereditary effects by alteration genetic constituent and/or induction chromosome aberrations, as well as the possibility of vertical transmission of HBV via the germ line to the next generation.

Plasma matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 as biomarkers of ulcerative colitis activity

AIM:Overexpression of mucosal metalloproteinases(MMP) has been demonstrated recently in inflammatory bowel disease.Their activity can be counterbalanced by the tissue inhibitor of metalloproteinases(TIMP).The aim of this study was to evaluate the effect of ulcerative colitis(UC)on MMP- 1 and TIMP-1 plasma concentrations,as two possible biomarkers of the disease activity. METHODS:MMP-1 and TIMP-1 plasma concentrations were measured with an enzyme immunoassay in 16 patients with endoscopically confirmed active UC. RESULTS:Plasma concentrations of both MMP-1(13.7±0.2 ng/ml)and TIMP-1(799±140 ng/ml)were significantly elevated in UC patients in comparison to healthy controls (11.9±0.9 ng/ml and 220±7 ng/ml respectively).There was no correlation between TIMP-1 and MMP-1 concentrations (r=0.02).TIMP-1 levels revealed significant positive correlations with scored endoscopic degree of mucosal injury, disease activity index and clinical activity index values as well as C-reactive protein concentration.There was no correlation between MMP-1 and laboratory,clinical or endoscopic indices of the disease activity.CONCLUSION: These results confirm the role of both MMP- 1 and TIMP-1 in the pathogenesis of ulcerative colitis. However only TIMP-1 can be useful as a biomarker of the disease activity, demonstrating association with clinical and endoscopic pictures.

PCR analysis of Yq microdeletions in infertile males, a study from South India

AIM: To estimate the frequency of microdeletions in the long arm of Y-chromosome of 20 infertile males from South India. METHODS: Polymerase chain reaction (PCR) amplification using Y-specific STS of azoospermia factor (AZF) regions i.e., SY 84 for AZFa, SY 127 for AZFb and SY 254 for AZFc. RESULTS: Of the 20 infertile subjects 3 (15 %), one azoospermic and two oligozoospermic, showed microdeletions in the AZF region of Y-chromosome. CONCLUSION: The frequency of deletions involving AZF region of the Y-chromosome is 15 % in azoospermic and severely oligozoospermic infertile men. PCR amplification of AZF locus is useful for the diagnosis of microdeletions in the Y-chromosome.

Semen analysis from an epidemiologic perspective

The fifth edition of the World Health Organization （WHO） manual for semen analysis includes for the first time reference values for human semen characteristics. This paper considers whether such values will help to resolve the intensely debated data indicating temporal and geographical shifts in sperm counts and hypotheses that anthropogenic activities that result in the release of chemicals into the environment are detrimental to male reproductive health. The reasons that these reference values will not fulfil these purposes are also explained. Although established reference values for semen characteristics are of limited value in analytical epidemiologic research, the WHO guidelines are of utmost importance for supporting the development of appropriate research protocols. Moreover, in spite of its limitations, semen analysis is still a useful research tool in epidemiological research, and no superior alternatives are on the horizon.

Healthy ranges of serum alanine aminotransferase levels in Iranian blood donors

AIM: The healthy ranges for serum alanine aminotransferase(ALT) levels are less well studied. The aim of this study was to define the upper limit of normal (ULN) for serum ALT levels, and to assess factors associated with serum ALT activity in apparently healthy blood donors. METHODS: A total of 1 939 blood donors were included.ALT measurements were performed for all cases using the same laboratory method. Healthy ranges for ALT levels werecomputed from the population at the lowest risk for liver disease. Univariate and multivariate analyses were performed to evaluate associations between clinical factors and ALT levels.RESULTS: Serum ALT activity was independently associated with body mass index (BMI) and male gender, but not associated with age. Association of ALT with BMI was more prominent in males than in females. Upper limit of normal for non-overweight women (BMI of less than 25) was 34 U/L,and for non-overweight men was 40 U/L.CONCLUSION: Serum ALT is strongly associated with sex and BMI. The normal range of ALT should be defined for male and female separately.