Isometric torso muscle endurance profiles in adolescents aged 15–18: normative values for age and gender differences

Objective: The aim of this study was to establish normative values for torso muscle endurance in adolescents aged 15–18 years. It was hypothesized that torso endurance profiles of adolescents differs between males and females and between adolescents and adults.

Background: Decreased torso muscle endurance has been identified as a potential personal risk factor for low back pain development in both adolescents and later years together with being detrimental for athletic performance.

Design: Measurement of torso muscle endurance, established through four tests performed in random order in a healthy adolescent population.

Setting: High school in Novi Sad, Province of Vojvodina, Republic of Serbia.

Methods: Two hundred and ninety-four adolescents from one high school (178 males and 116 females) were grouped into four age strata. Selected isometric torso muscle endurance tests were: Biering-Sørensen test for extensor endurance; Flexor endurance test; right and left Side Bridge tests. The mean, ratio, standard deviation and 25th, 50th and 75th percentile scores were determined for each gender/age strata.

Results and conclusion: Males had higher lateral torso endurance than females. Adolescents in general demonstrate their peak lifetime endurance as they appear more endurable than children and comparable adult groups. These data of endurance times, their ratios and percentiles in healthy normal subjects form a database bridging existing data for children and adults that may be useful for guiding training and rehabilitation.     

Modelling foetal growth in a bi-ethnic sample: results from the Born in Bradford (BiB) birth cohort

Background: Attempts to explain the increased risk for metabolic disorders observed in South Asians have focused on the “South Asian” phenotype at birth and subsequent post-natal growth, with little research on pre-natal growth.

Aim: To identify whether divergent growth patterns exist for foetal weight, head (HC) and abdominal circumferences (AC) in a sample of Pakistani and White British foetuses.

Subjects and methods: Models were based on 5553 (weight), 5154 (HC) and 5099 (AC) foetuses from the Born in Bradford birth cohort. Fractional polynomials and mixed effects models were employed to determine growth patterns from ～15 weeks of gestation-birth.

Results: Pakistani foetuses were significantly smaller and lighter as early as 20 weeks. However, there was no ethnic difference in the growth patterns of weight and HC. For AC, Pakistani foetuses displayed a trend for reduced growth in the final trimester.

Conclusion: As the pattern of weight and HC growth was not significantly different during the period under investigation, the mechanism culminating in the reduced Pakistani size at birth may act earlier in gestation. Reduced AC growth in Pakistanis may represent reduced growth of the visceral organs, with consequences for post-natal liver metabolism and renal function.     

Parturition lines in modern human wisdom tooth roots: do they exist,can they be characterized and are they useful for retrospective determination of age at first reproduction and/or inter-birth intervals?

Background: Parturition lines have been described in the teeth of a number of animals, including primates, but never in modern humans. These accentuated lines in dentine are comprised of characteristic dark and light component zones.

Aim: The aim of this study was to review the physiology underlying these lines and to ask if parturition lines exist in the third molar tooth roots of mothers known to have had one or more children during their teenage years.

Methods: Brief retrospective oral medical obstetric histories were taken from four mothers and compared with histological estimates for the timing of accentuated markings visible in longitudinal ground sections of their wisdom teeth.

Results: Evidence of accentuated markings in M3 root dentine matched the age of the mother at the time their first child was born reasonably well. However, the dates calculated for inter-birth intervals did not match well.

Conclusions: Parturition lines corresponding to childbirth during the teenage years can exist in human M3 roots, but may not always do so. Without a written medical history it would not be possible to say with confidence that an accentuated line in M3 root dentine was caused by stress, illness or was a parturition line.     

The role of physical activity,body mass index and maturity status in body-related perceptions and self-esteem of adolescents

Background: Adolescence represents a transitional period which is marked by physical, social and psychological changes. Changes in body shape and physical activity especially alter and shape the psychological well-being of adolescents.

Aim: The purpose of this study was to determine the role of physical activity level, body mass index and maturity status in body-related perception and self-esteem of 11–18 years old adolescents.

Subjects and methods: A total of 1012 adolescents participated in this study. The “Social Physique Anxiety Scale”, “Body Image Satisfaction Scale”, “Physical Self-Perception Profile for Children” and “Rosenberg Self-Esteem Inventory” were administered. Physical activity level and body mass index were assessed using the “Physical Activity Questionnaire” and “Bioelectrical Impedance Analyzer”, respectively.

Results: Regression analysis indicated that body mass index was the only predictor of perceived body attractiveness, social physique anxiety, body image satisfaction and self-esteem for female adolescents. For male adolescents, both physical activity and body mass index were correlated with perceived body attractiveness and social physique anxiety. Pubertal status were not correlated with self-esteem and body-related perceptions for both males and females adolescents.

Conclusion: In summary, body mass index and physical activity plays an important role in body-related perceptions and self-esteem of adolescents.     

IgA directly inhibits antigen-dependent B cell activation following distinctive distribution of the antigen in mice

Context: Serum IgA suppresses immune responses when exposed to antigens recognized by the antibody; however, the underlying mechanism remains unclear.

Objective: We herein clarified the relationships between changes in antigen distribution and antigen-dependent B cell activation in the presence or absence of IgA against the antigen in mice.

Materials and methods: DBA/1J and HR-1 mice were intravenously injected with ovalbumin (OVA) and anti-OVA monoclonal IgA OA-4. The distribution of the antigen and B cell responses were measured.

Results: B cell activation by injected OVA, namely, increases in anti-OVA IgG production and the populations of B220⁺GL7⁺ and B220⁺CD69^high splenocytes, was diminished by the co-injection of OA-4. Co-injected OA-4 increased OVA in the serum as well as in the bile and gut. This was coincident with its decrease in the urine due to the inhibition of OVA monomer secretion through the formation of immune complexes. The apparent similarities in the association between fluorescein isothiocyanate (FITC)-OVA and splenic B cells in the presence and absence of OA-4 in vivo appeared to be attributed to compensation between the two effects of OA-4; an increase in serum OVA in vivo and inhibition of the association between OVA and B cells, as suggested by in vitro experiments.

Discussion: Based on these results, the stimulation of B cells by OVA may be directly reduced, at least partly, by the neutralization of OVA by OA-4.

Conclusion: IgA may be an effective drug for the treatment of immune disorders due to its ability to blunt antigen-specific B cell activation.     

Lyophilized Turkey herpesvirus (HVT): Stability of vaccine and minimum protective dose

The research reported showed that:

the stability of cell‐free HVT vaccine, lyophilized and sealed under vacuum, is very high: after one year at 4°‐6°C and after 10 days at 37°C the titre decreased only about 0.4 log₁₀;

the stability of the vaccine, when reconstituted for use in the diluent (sucrose‐phosphate buffer), is high (80%) for at least 2 hours;

the degree of protection, found in 3 tests, was about 90% with an inoculum of 20 to 100 pfu, and the PD₅₀ was 4.9 pfu of virus per chick.     

Correlation of Proteinuria with Podocyte Foot Process Effacement in IgA Nephropathy: An Ultrastructural Study

Background: Proteinuria is an uncommon clinical manifestation of IgA nephropathy and is usually seen in cases with severe lesions like endocapillary proliferation. However, it is occasionally seen even with cases with mild glomerular manifestations and may even be of nephrotic range.

Predictor: Podocyte foot process effacement.

Outcome: Severity of proteinuria.

Measurements: Podocyte foot process effacement was measured. Morphometric analysis was performed on transmission electron microscope images using a computerized digital photomicrograph system (BioWizard 4.2 Image analysis software, New Delhi, India). Proteinuria was measured quantitatively assigned into five grades.

Results: It was found that as the extent of proteinuria increased, the effacement ratio also increased, and this was most significant between “no” proteinuria and the rest of the categories.

Conclusion: Nephrotic presentation in IgA nephropathy is a known phenomenon and in certain cases may show near normal glomerular morphology with severe foot process effacement on EM being the only significant finding to explain the proteinuria. Proteinuria in these cases shows a significant correlation with degree of foot process effacement. Renal biopsy is important in these cases because they are known to have a better prognosis and are usually steroid responsive.     

Long-term changes in body composition and prevalence of overweight and obesity in girls (aged 3–18 years) from Kraków (Poland) from 1983, 2000 and 2010

Background: Body mass disorders are an increasing problem, especially in industrialized countries.

Aim: Determination of time- and age-related differences in the prevalence of overweight, obesity and in body composition in girls from 1983, 2000 and 2010.

Subject and methods: In 2010 an anthropological study was conducted on 1970 girls aged 3–18 years living in Kraków (Poland). Data on selected skin-folds, BMI, muscle mass and bone mass were compared to two studies on analogous populations carried out in 1983 and 2000.

Results: Compared to 1983, the share of overweight girls in 2010 had decreased (from 12.4% to 11.2%), while the obesity rate had increased slightly from 2.3% to 3.2%. Girls from 2010 had lower overall body fat content than their peers studied in 1983. However, in 2010 suprailiac adiposity prevalence was higher, while triceps, subscapular and abdominal adiposity rates were lower. They also had higher muscle mass and lower bone mass.

Conclusion: The prevalence of overweight and obesity has not changed significantly over the last 30 years. However, significant changes have occurred in body composition. Girls measured in 2010 had lower total adipose tissue, although they also showed a tendency towards increased central adiposity.     

An investigation of the genetic diversity of the Kerkennah islands and Mahdia (Tunisia) using biparental markers

Background: Kerkennah is one of the main inhabited islands of Tunisia. The origin of the population of Kerkennah has not been established and no well-defined ethnic groups have been identified nor are genetic studies available. Mahdia, a Tunisian coastal city, has a long history dating back to ancient times.

Aim: To discover the genetic diversity of the two studied populations and analyse their relationships with other Mediterranean populations.

Subject and methods: Seven human-specific Alu insertion polymorphisms were typed in 99 individuals born in Kerkennah and Mahdia.

Results: A neighbour-joining tree and MDS multidimensional scaling analysis showed that these Tunisian populations are scattered amongst North African and Europeans populations, indicating their high genetic diversity and mosaic aspect. The important finding of this study was the proximity of Kerkennah to Moroccans. Hence, the actual gene pool of this insular population may descend from the ancestral population known to be of Moroccan origin. Concerning Mahdia, its closeness to Eurasian populations and some Tunisian groups reflected a high Eurasian genetic component for North African populations and confirmed their heterogeneity.

Conclusion: The strategic location of the two studied populations and their fortifications have allowed them to play a leading role in the Mediterranean basin.     

The epigenetic side of human adaptation: hypotheses,evidences and theories

Context: Epigenetics represents a still unexplored research field in the understanding of micro- and macro-evolutionary mechanisms, as epigenetic changes create phenotypic diversity within both individuals and populations.

Objective: The purpose of this review is to dissect the landscape of studies focused on DNA methylation, one of the most described epigenetic mechanisms, emphasizing the aspects that could be relevant in human adaptations.

Methods: Theories and results here considered were collected from the most recent papers published.

Results: The matter of DNA methylation inheritance is here described as well as the recent evolutionary theories regarding the role of DNA methylation—and epigenetics in a broader sense—in human evolution. The complex relation between (1) DNA methylation and genetic variability and (2) DNA methylation and the environmental stimuli crucial in shaping genetic and phenotypic variability through the human lineage—such as diet, climate and pathogens exposure—are described. Papers about population epigenetics are also illustrated due to their high relevance in this context.

Conclusion: Genetic, epigenetic and phenotypic variations of the species, together with cultural ones, are considerably shaped by a vast range of environmental stimuli, thus representing the foundation of all human bio-cultural adaptations.     

Milk immunity and reproductive status among Ariaal women of northern Kenya

Background: The immune factors in human milk protect infants from infection and promote immune development. Evidence suggests that the production of milk-specific immunoproteins is energetically costly, making them a form of maternal investment in offspring health that is subject to life history trade-offs.

Aim: This research tests the relationship between measures of reproductive effort and the production of milk immunoglobulin A (IgA) among Ariaal women, a settled northern Kenyan pastoralist population that experiences nutritional and disease stress.

Subjects and methods: Two hundred and forty-three lactating Ariaal women participated in a questionnaire, anthropometric measurement and milk collection. Milk IgA was analysed using ELISA.

Results: There was a significant U-shaped relationship between post-partum months and milk IgA, reflecting decreasing investment in the current offspring over the early post-partum period and subsequent recovery of maternal energy status near the end. There was also a significant inverse U-shaped relationship between milk IgA and parity, with high parity women showing a drop in milk IgA. In contrast, anthropometric measures of energy status were not associated with the production of milk IgA.

Conclusion: This research shows that patterns of reproductive investment can be demonstrated in milk IgA in the absence of measured energy changes.     

Sitting height as a better predictor of body mass than total height and (body mass)/(sitting height)3 as an index of build

Background: The Rohrer Index and the ratio of sitting height (SH) to height fall similarly with growth in early childhood, then level off and rise slightly towards adulthood. In adults the BMI correlates with SH/height. The mean cross-sectional areas of the legs of adults are correlated positively with upper body masses and negatively with leg lengths.

Aim: To find an index of body build that is less dependent on relative leg length and age in children and adults than are the BMI and the Rohrer Index.

Subjects and methods: Published data are analysed to establish the relative importance of SH and leg length as predictors of body mass and to investigate the age dependence of the ratio (body mass)/SH³.

Results: SH is a much better predictor of body mass than height, with leg length being barely relevant. Average values of (body mass)/SH³ vary very little over the age range of 1–25 years, despite small non-random fluctuations.

Conclusion: The ratio (body mass)/SH³ is proposed as a useful “sitting-height index of build” that is superior to the Rohrer Index and could prove better than the BMI as a predictor of adiposity. Further studies are needed, notably using individual data and fat-free masses.     

Secular trends in cranial morphological traits: a socioeconomic perspective of change and sexual dimorphism in North Americans 1849–1960

Background: The human body has undergone significant changes in stature and other areas, which reflect secular trends associated with socioeconomics.

Aim: To analyse cranial morphological traits for deciphering if they are subject to secular trends.

Subjects and methods: Two documented skeletal collections were sampled for a total of 525 individuals from 1849–1960. Cranial morphological traits were scored and input into time series statistics (logistic regression).

Results: In females, nuchal crests have enlarged, while glabella has decreased. In males, supraorbital margins have dulled, while glabella decreased. Sexual dimorphism increased in supraorbital margins.

Conclusion: The patterns in the data here reflect those found in other areas of the skeleton, namely height, as regards to secular trends. These findings can be extended to stature and cranial changes that parallel socioeconomic trends during the Industrial Revolution, antebellum period and after.     

Weight and height percentiles calculated by the LMS method in Argentinean schoolchildren. A comparative references study

Background: The Argentinean population is characterized by ethnic, cultural and socio-economic diversity.

Aim: To calculate the percentiles of weight-for-age (W/A) and height-for-age (H/A) of schoolchildren from Argentina employing the LMS method; and to compare the obtained percentiles with those of the international and national references.

Subjects and methods: Anthropometric data of 18 698 students (8672 girls and 10 026 boys) of 3–13 years old were collected (2003–2008) from Buenos Aires, Catamarca, Chubut, Jujuy, La Pampa and Mendoza. Percentiles of W/A and H/A were obtained with the LMS method. Statistical and graphical comparisons were established with the WHO (international reference) and with that published by the Argentinean Paediatric Society (national reference).

Results: Differences in W/A and H/A, regarding the references, were negative and greater at the highest percentiles and in most of the age groups. On average, the differences were greater for boys than girls and for national than international references.

Conclusion: The distribution of weight and height of schoolchildren, coming from most regions of the country, differs from those of national and international references. It should be advisable to establish a new national reference based on internationally recognized methodological criteria that adequately reflect the biological and cultural diversity of the Argentinean populations.     

Detecting chronotype differences associated to latitude: a comparison between Horne--Östberg and Munich Chronotype questionnaires

Background: Chronotype, phase preference to perform activities during a 24-hour day, represents distinct circadian temporal organization of living organisms. Morning and evening types can be identified by questionnaires such as Horne and Östberg (HO) and Munich Chronotype Questionnaire (MCTQ). Environmental factors, such as different light–dark cycles experienced at different latitudes, interact with the organisms’ circadian timekeeping system. Therefore, chronotype is expected to vary as a result of different geographical locations.

Aim: To identify differences in chronotype distribution in populations of two Brazilian cities, Natal and Sao Paulo, located at different latitudes.

Subjects and methods: Two specific questionnaires, the Horne and Östberg Questionnaire (HO) and the Munich Chronotype Questionnaire (MCTQ), were used to identify chronotypes of undergraduate students from São Paulo and Natal.

Results: The comparison of the curve distributions of HO and MCTQ scores between both cities allowed one to observe that, while HO curves of São Paulo and Natal overlapped, MCTQ curves showed a clear shift towards eveningness in São Paulo.

Conclusion: This experiment confirmed results from previous studies that the farther away from the equator, the longer the delay of the sleep phase. It was also concluded that MCTQ is better at detecting this phenomenon.     

A metabonomic analysis reveals novel regulatory mechanism of Huangqi injection on leucopenia mice

Context: Huangqi injection (HQI), extracted from Astragali Radix, which has capability on treating the leucopenia. However, the potential metabolic mechanism is poorly understood.

Objective: To investigate the effect of HQI on cyclophosphamide (Cy)-induced leucopenia in mice, the nuclear magnetic resonance (NMR)-based metabolomic profiling technique coupled with multivariate statistical analysis was applied.

Materials and methods: NMR analysis was used to identify the various compounds of HQI, and high-performance liquid chromatography was applied to determine the contents of major compounds. A experimental mice model of leucopenia induced by Cy and NMR-based metabolomic approach was used to evaluate the pharmacological effect of HQI and to investigate its probable acting mechanism on leucopenia.

Results: HQI increased body weight and elevated the white blood cell (WBC), monocytes (MO), neutrophils (NE), and lymphocyte (LY) levels of Cy-treated mice. In addition, the levels of most perturbed endogenous metabolites could be reversed after HQI treatment. Correlations between WBC, MO, NE, LY, and altered metabolite profiles in spleen were greater than that in serum, and the correlation in MO was more evident than those for WBC, NE, and LY.

Discussion and conclusion: HQI showed obvious efficacy on the mice model of leucopenia. And the drug action of HQI on leucopenia was probably related with regulating metabolic pathways of energy metabolism, amino acids metabolism, oxidative stress, and choline metabolism. However, various compounds were present in the HQI, and the bioactive compounds responsible for the drug actions should be further investigated.     

The timing of mandibular tooth formation in two African groups

Background: Ethnic differences in the timing of human tooth development are unclear.

Aim: To describe similarities and differences in the timing of tooth formation in two groups of Sudanese children and young adults.

Subjects and methods: The sample consisted of healthy individuals from Khartoum, Sudan, aged 2–23 years. The Northern group was of Arab origin (848 males, 802 females) and the Western group was of African origin (846 males, 402 females). Each mandibular left permanent tooth from first incisor to third molar was assessed from dental radiographs into one of 15 development stages. Mean ages at entry for 306 tooth stages were calculated using probit regression in males/females in each group and compared using a t-test.

Results: Mean ages were not significantly different in most tooth stage comparisons between ethnic groups for both males (61/75) and females (56/76), despite a tendency of earlier mean ages in the Western group. Mean ages for most tooth stage comparisons between males and females (137/155) were not significantly different within ethnic groups suggesting low sexual dimorphism.

Conclusion: The mean ages of most mandibular tooth formation stages were generally not significantly different between ethnic groups or between males and females in this study.     

Frequency of three prothrombotic polymorphisms among Syrian population: factor V G1691A,prothrombin G20210A and methylenetetrahydrofolate reductase C677T

Background: Thrombophilia is a multi-factorial disorder caused by inherited and acquired factors. Among the inherited factors are factor V G1691A, prothrombin G20210A and methylenetetrahydrofolate reductase (MTHFR) C677T single nucleotide polymorphisms (SNPs).

Aim: The main aim of this study was to assess the incidence of these three SNPs in the Syrian population.

Subjects and methods: A total of 200 unrelated healthy Syrians (100 males and 100 females) were recruited.

Results: The prevalence of factor V G1691A, prothrombin G20210A and MTHFR C677T SNPs among Syrians is 11.5%, 2.5% and 84.5%, respectively. Prevalence of factor V G1691A and prothrombin G20210A SNPs among apparently healthy Syrian individuals is very high.

Conclusion: To the best of the authors knowledge, the Syrian population harbours the highest prevalence of the MTHFR C677T polymorphism compared to all other populations reported so far.