Significant Age-related Variations Research Articles

Age-Related Variations in Clinical Profiles for Children with Sports- and Recreation-Related Concussions.

The purpose was to examine clinical profiles in concussed children aged 5-9 and 10-12 years and compare them with those of adolescents >12 years. This study included patients aged 5-18 years presenting to a specialty care concussion program with a sports- and recreation-related (SRR) concussion ≤28 days postinjury. Demographics, injury mechanisms, symptoms, and clinical features were assessed. Chi-squared tests, one-way ANOVA, and Kruskal-Wallis were used for comparisons across age groups. A total of 3280 patients with SRR concussion were included: 5.0% were 5-9 years, 18.4% were 10-12 years, and 76.6% were 13-18 years. Younger age groups had more males than females (5-9 years: 70.7% vs. 29.3%) and more commonly sustained their injury during limited- (28.7%), and non-contact (7.9%) activities compared to other age groups (p < 0.01). Younger children presented less symptoms frequently (p ≤ 0.042), but higher symptom severity in somatic and emotional domains (p ≤ 0.016). Fewer 5-9-year-olds reported changes in school (25.6%), sleep (46.3%), and daily habits (40.9%) than adolescents (p < 0.001). Among SRR-concussed children and adolescents, we found significant age-related variations in demographics, injury mechanism, symptoms, and clinical features. Recognizing these unique features in younger children may facilitate targeted management and treatment.

Comparison of facial skin ageing in healthy Asian and Caucasian females quantified by in vivo line-field confocal optical coherence tomography 3D imaging.

Quantitative biomarkers of facial skin aging were investigated in 109 healthy Asian female volunteers, aged 20 to 70 years. In vivo 3D Line-field Confocal Optical Coherence Tomography (LC-OCT) imaging, enhanced by Artificial Intelligence (AI)-based quantification algorithms, was utilized to compute various metrics, including stratum corneum thickness (SC), viable epidermal (VE) thickness, and Dermal-Epidermal Junction (DEJ) undulation along with cellular metrics for the temple, cheekbone, and mandible. Comparison with data from a cohort of healthy Caucasian volunteers revealed similarities in the variations of stratum corneum and viable epidermis layers, as well as cellular shape and size with age in both ethnic groups. However, specific findings emerged, such as larger, more heterogeneous nuclei in both layers, demonstrated by an increase in nuclei volume and their standard deviation, and increased network atypia, all showing significant age-related variations. Caucasian females exhibited a flatter and more homogeneous epidermis, evidenced by a decreased standard deviation of the number of layers, and a less dense cellular network with fewer cells per layer, indicated by a decrease in cell surface density. Ethnicity-wise comparisons highlighted distinct biological features specific to each population. Asian individuals showed significantly higher DEJ undulation, higher compactness, and lower cell network atypia compared to their Caucasian counterparts across age groups. Differences in stratum corneum and viable epidermal thickness on the cheekbone were also significant. LC-OCT 3D imaging provides valuable insights into the aging process in different populations and underscores inherent biological differences between Caucasian and Asian female volunteers.

Mobile assessment of visual function helps to prevent Re-Injury in elderly patients with recent hip fractures

IntroductionPatients undergoing surgery due to hip fracture face an elevated risk of a subsequent fall during rehabilitation. An important contributing factor to this risk is deteriorated visual function, often responsive to intervention. This study aims to explore differences in visual acuity (VA) and stereovision (SV) between individuals with a history of fall-related hip injuries (study group) and age-matched controls, utilizing a mobile application (EuvisionTab, ET) to distinguish age-related visual decline from pathological vision. Materials & MethodsA total of 32 and 71 participants were enrolled in the study and control groups, respectively (mean age: 74.9 years, range: 60–96). Monocular logMAR VA was measured using a tablet by means of an adaptive threshold-search algorithm. SV was assessed using low-dot density static and dynamic random dot stereograms. An age-dependent reference limit for VA was established. For ET stereotests, the number of correctly identified optotypes out of 10 random presentations served as the measure for further comparisons. Visually impaired status in the study group was determined if patients failed either the VA threshold or the SV criteria. ResultsIn the control group, an apparent but statistically nonsignificant decline in VA was observed, while stereovision remained stable and did not exhibit significant age-related variations based on ET stereotests. Conversely, the study group demonstrated significantly worse results in monocular VA (p = 0.0032) and for both stereotests (p = 0.018 for static, p = 0.036 for dynamic) according to paired samples t-test and chi-square test, respectively. Hip injuries were significantly associated with visual impairment (OR = 4.88, p = 0.0012). DiscussionThis study focuses on one possible risk factor of elderly falls, namely, vision impairment. Patients with visual decay present a higher incidence of hip injuries compared to age-matched controls. This data suggest that vision screening and, when feasible, restoration of visual function may contribute to the prevention of secondary falls, refractures, or contralateral fractures. A mobile-based screening protocol, executable as part of a postoperative bedside examination and independent of specialized eye care, can be proposed.

Fostering Transversal Skills through Open Schooling with the CARE-KNOW-DO Framework for Sustainable Education

This large cross-national study investigates the development of transversal skills in the context of open schooling—an educational approach integrating schools, universities, and communities to address real-world challenges—through the CARE-KNOW-DO framework. Utilising a mixed-methods approach across five countries, this research employs a novel validated self-report instrument to evaluate the perceptions of 12,074 underserved students concerning their learning experiences in open schooling environments. An exploratory factor analysis enabled us to explore quantitative insight into students’ skill development, while thematic analysis of 20 teachers’ reports contributed qualitative depth. The study identified six critical transversal skills: self-initiative, problem-solving, emotional engagement, scientific citizenship, authentic learning, and future prospects. Significant geographic, gender, and age-related variations were found, with notable disparities in skill perceptions among nonbinary students, indicating the need for more inclusive educational support. All countries showed high levels of perceived transversal skills, with 83% of Greek and 80% of Brazilian students leading, compared to 64% in Romania and the UK, and 62% in Spain. Trends suggest secondary students exhibit stronger global citizenship and authentic learning, although they report less confidence in problem-solving and self-initiative than their primary counterparts. These findings, viewed alongside 12 teaching competencies revealed through thematic analysis, underscore the effectiveness of open schooling, which is underexplored, in fostering key skills and call for pedagogical innovations that integrate real-life issues into the curriculum. The study contributes to Agenda 2030—quality of education by demonstrating the real-world applicability of the CARE-KNOW-DO framework for educational practice and policy towards equity and sustainability. Our comparative analysis of transversal skill development across diverse student populations, as well as teaching competencies, further advances the discourse on improving 21st-century education.

Histological and molecular difference in albumen quality between post-adolescent hens and aged hens

The decline in albumen quality resulting from aging hens poses a threat to the financial benefits of the egg industry. Exploring the underlying mechanisms from the perspective of cell molecules of albumen formation is significant for the efficient regulation of albumen quality. Two individual groups of Hy-Line Brown layers with ages of 40 (W40) and 100 (W100) wk old were used in the present study. Each group contained over 2,000 birds. This study assessed the egg quality, biochemical indicators and physiological status of hens between W40 and W100. Subsequently, a quantitative proteomic analysis was conducted to identify differences in protein abundance in magnum tissues between W40 and W100. In the W40 group, significant increases (P < 0.05) were notable for albumen quality (thick albumen solid content, albumen height, Haugh unit), serum indices (calcium, estrogen, and progesterone levels), magnum histomorphology (myosin light-chain kinase content, secretory capacity, mucosal fold, goblet cell count and proportion) as well as the total antioxidant capacity of the liver. However, the luminal diameter of the magnum, albumen gel properties and random coil of the albumen were increased (P < 0.05) in the W100 group. The activity of glutathione, superoxidase dismutase, and malondialdehyde in the liver, magnum, and serum did not vary (P > 0.05) among the groups. Proteomic analysis revealed the identification of 118 differentially expressed proteins between the groups, which comprised proteins associated with protein secretion, DNA damage and repair, cell proliferation, growth, antioxidants, and apoptosis. Furthermore, Kyoto Encyclopedia of Genes pathway analysis revealed that BRCA2 and FBN1 were significantly downregulated in Fanconi anemia (FA) and TGF-β signaling pathways in W100, validated through quantitative real-time PCR (qRT-PCR). In conclusion, significant age-related variations in albumen quality, and magnum morphology are regulated by proteins involved in antioxidant capacity.

R Radiological Risk Assessment Of 222 Radon Concentration And Annual Effective Dose Calculation In Groundwater From Zakho, Iraq

Radon, the heaviest of noble gases in the periodic table, is a naturally occurring radioactive nuclide found in rocks, soil, and water. It has gained increasing attention in recent research due to its association with cancer. This study focused on assessing the potential radioactive risks associated with water usage in Zakho, Iraq, by analyzing 16 groundwater samples collected from the primary water source. Alpha spectrometry with RAD7 and RAD-H2O accessories from Durridge CO was employed for assay purposes. The measured 222Rn concentrations ranged from 0.21 ± 0.1 to 19.75 ± 4.8 BqL−1, with an average of 8.90 Bq. −1. The recorded values indicate that 31% of the data surpasses the specified United States Environmental Protection Agency (USEPA) limit of 11.1 BqL−1. Notably, the evaluation of the total annual effective dose revealed significant age-related variations. Specifically, 62% of infant samples and 68% of children samples exceeded the acceptable limit of 100 μSv/y, while 25% of adult samples surpassed the World Health Organization (WHO) recommended threshold. The obtained data align with similar studies conducted globally, emphasizing the need for continuous radon monitoring during water consumption. The findings advocate for proactive measures to ensure the safety of these water sources, addressing the pressing concern of radon-related health risks.

Influence of skeletal classes and facial patterns on the positioning of the craniovertebral junction, dimensions of the pharyngeal airway space, and pre-vertebral soft tissue thickness: A cone beam computed tomography study

This study employed cone beam computed tomography (CBCT) to assess the influence of skeletal classes and facial patterns on the craniovertebral complex, pharyngeal airway space (PAS) dimensions, and pre-vertebral soft tissue thickness. The analysis of 150 CBCTs involved measurements between various vertebrae and layers of soft tissue. Significant findings included a lower odontoid process in Class II and hyperdivergent individuals, while hypodivergent subjects exhibited a larger area and volume in the PAS. A negative correlation between PAS size and pre-vertebral soft tissue thickness was observed. Gender differences were noteworthy, with males consistently displaying higher values. Significant age-related variations were also identified, with the age groups of 18-30 and 31-45 exhibiting distinct characteristics. The study underscores the impact of facial patterns and skeletal classes on the craniovertebral complex, emphasizing an inverse relationship between PAS and pre-vertebral soft tissue thickness. The intricate connections between gender and age highlight their influence on anatomical characteristics. Understanding how facial patterns and skeletal classes affect the craniovertebral complex has implications for respiratory disorders, including Obstructive Sleep Apnea and Hypopnea Syndrome (OSAHS).

A comparative analysis of colour-emotion associations in 16-88-year-old adults from 31 countries.

As people age, they tend to spend more time indoors, and the colours in their surroundings may significantly impact their mood and overall well-being. However, there is a lack of empirical evidence to provide informed guidance on colour choices, irrespective of age group. To work towards informed choices, we investigated whether the associations between colours and emotions observed in younger individuals also apply to older adults. We recruited 7393 participants, aged between 16 and 88 years and coming from 31 countries. Each participant associated 12 colour terms with 20 emotion concepts and rated the intensity of each associated emotion. Different age groups exhibited highly similar patterns of colour-emotion associations (average similarity coefficient of .97), with subtle yet meaningful age-related differences. Adolescents associated the greatest number but the least positively biased emotions with colours. Older participants associated a smaller number but more intense and more positive emotions with all colour terms, displaying a positivity effect. Age also predicted arousal and power biases, varying by colour. Findings suggest parallels in colour-emotion associations between younger and older adults, with subtle but significant age-related variations. Future studies should next assess whether colour-emotion associations reflect what people actually feel when exposed to colour.

Zooplankton Composition and Trophic Status of Aquatic Species in the Laptev and East Siberian Seas

The species composition, abundance, biomass, and distribution of zooplankton were studied on the shelf and slope of the northwestern Laptev Sea and the shelf of the East Siberian Sea in summer 2015. The trophic status of common zooplankton and fish species, as well as their position in the food webs of these two seas, has been determined based on stable carbon and nitrogen isotope analyses (δ13C and δ15N). Data of both stomach content and stable isotope analyses show significant age-related variations in the trophic status of the Arctic cod Boreogadus saida, which is the dominant fish species.

Age-related variations in corneal geometry and their association with astigmatism: The Yamagata Study (Funagata).

To investigate how aging affects corneal geometry in Japanese adults, and the association between corneal geometry and astigmatism.We included 421 participants who had undergone systemic and ophthalmological examinations in 2015 in Funagata town, Yamagata, Japan. Corneal topographic data were obtained using anterior-segment optical coherence tomography (CASIA SS-1000). Astigmatism was evaluated using power vector analyses where J0 represents the power of the orthogonal astigmatism. Positive values of J0 indicate with-the-rule astigmatism, while negative values indicate against-the-rule (ATR) astigmatism.Regarding age-related variations in corneal geometry, the anterior elevations at axis 0° and 180° decreased, and those at axis 90° and 270° increased with increasing age in linear regression analyses, demonstrating horizontal steepening and vertical flattening of the corneal surface. There were no significant age-related variations in posterior elevations and pachymetry findings, including central corneal thickness. Regarding age-related variations in orthogonal astigmatism, the mean values of J0 and corneal J0 (cJ0) decreased by –0.014 and –0.015 per year of increase in age, indicating astigmatic shift toward ATR. Regarding the correlation between corneal geometry and astigmatism, the shift toward ATR was positively correlated with horizontal steepening and vertical flattening, in accordance with the age-related corneal variations. In addition, the posterior surface of the cornea also has an association with this shift to some extent.The results of our population-based study demonstrated that the age-related variation in astigmatism is associated with geometrical changes in the cornea, especially those in the anterior surface of the cornea.

Normative Data for Left and Right Ventricular Systolic Strain in Healthy Caucasian Italian Children by Two-Dimensional Speckle-Tracking Echocardiography

There is an increasing interest in echocardiographic strain (ε) measurements for the assessment of ventricular myocardial function in children; however, pediatric nomograms remain limited. Our aim was to establish pediatric nomograms for the left ventricular (LV) and the right ventricular (RV) ε measured by two-dimensional speckle-tracking echocardiography (2D-STE) in a large cohort of healthy children prospectively enrolled. Echocardiographic measurements included STE LV longitudinal and circumferential and RV longitudinal global end-systolic ε. Age, weight, height, heart rate (HR), and body surface area (BSA) were used as independent variables in different analyses to predict the mean values of each measurement. Echocardiograms were performed by Philips-iE33 systems (Philips, Bothell, WA) and offline measurements on Philips-Q-Lab-9. In all, 721 subjects (age 31days to 17years; 48% female) were studied. Low coefficients of determination (R2) were noted among all of the ε parameters evaluated and adjusted for age, weight, height, BSA, and HR (i.e., R2 all≤0.10; range, 0.01-0.088). This hampered the possibility of performing z-scores with a sufficient reliability. Thus, we are limited to presenting data as mean values (±SD) stratified for age groups and divided by gender. LV longitudinal ε values decreased with age (P<.001), while no significant age-related variations were noted for RV longitudinal ε. A significant base-to-apex (lowest to highest) gradient in circumferential LV ε values was noted at all ages (P<.001). We report pediatric echocardiographic normative data for 2D-STE for the LV and RV ε by using vendor-specific software. Our results confirm previous observations, showing only little variations of strain parameters with age and gender.

Segmental morphometrics of the olive baboon (Papio anubis): a longitudinal study from birth to adulthood.

The linear dimensions and inertial characteristics of the body are important in locomotion and they change considerably during the ontogeny of animals, including humans. This longitudinal and ontogenetic study has produced the largest dataset to date of segmental morphometrics in a Catarrhini species, the olive baboon. The objectives of the study were to quantify the changes in body linear and inertial dimensions and to explore their (theoretical) mechanical significance for locomotion. We took full‐body measurements of captive individuals at regular intervals. Altogether, 14 females and 16 males were followed over a 7‐year period, i.e. from infancy to adulthood. Our results show that individual patterns of growth are very consistent and follow the general growth pattern previously described in olive baboons. Furthermore, we obtained similar growth curve structures for segment lengths and masses, although the respective time scales were slightly different. The most significant changes in body morphometrics occurred during the first 2 years of life and concerned the distal parts of the body. Females and males were similar in size and shape at birth. The rate and duration of growth produced substantial size‐related differences throughout ontogeny, while body shapes remained very similar between the sexes. We also observed significant age‐related variations in limb composition, with a proximal shift of the centre of mass within the limbs, mainly due to changes in mass distribution and in the length of distal segments. Finally, we observed what we hypothesize to be ‘early biomechanical optimization’ of the limbs for quadrupedal walking. This is due to a high degree of convergence between the limbs’ natural pendular periods in infants, which may facilitate the onset of quadrupedal walking. Furthermore, the mechanical significance of the morphological changes observed in growing baboons may be related to changing functional demands with the onset of autonomous (quadrupedal) locomotion. From a wider perspective, these data provide unique insights into questions surrounding both the processes of locomotor development in primates and how these processes might evolve.

Age and sex-related variations in facial soft tissue thickness in a sample of Pakistani children

A facial soft tissue thickness (FST) database forms the backbone of different facial reconstruction methods. Various studies have identified age, sex and ethnicity as the core factors affecting the FST of an individual. The aims of this study were to explore the changes in FST occurring during the adolescent growth period and to develop the FST database for Pakistani children. The lateral cephalograms of 231 children, aged 9–18 years, were analysed and FST was determined at the 11 midline points. Subjects were divided into five age groups (9–10, 11–12, 13–14, 15–16 and 17–18 years) to evaluate age-related variations in FST. To compare FST between males and females and among different age groups, multivariate analysis of variance (MANOVA) was used. Moreover, the FST of Pakistani children was compared with those of Japanese and Canadian-Caucasoid children. Significant age-related variations in FST were present at four landmarks in boys and at six landmarks in girls. Marked ethnic differences in FST (>2 mm) were also observed at five landmarks in some of the age groups. These age-related and ethnic variations in FST warrant the use of data of appropriate age groups for a specific population for reliable outcome of facial reconstruction.

Histological and immunohistochemical changes of the thyroid gland during the foetal and postnatal period of development in indigenous Large White crossbred pigs

The present study was carried out to ascertain the morphometric, histological and immunohistochemical changes (expression of calcitonin and somatostatin) in the thyroid gland of indigenous local pig crosses during the foetal and postnatal period of development. A total of thirty foetal thyroids (40) grouped into early and late foetal period, fifteeen (15) prepubertal and ten (10) pubertal thyroids obtained from slaughtered pigs in the local abattoir were used. Histomorphometrically, all the measured parameters increased with development in all thyroid age group. The mean values were significantly different at P˂0.05 among ages. Histologically, significant age-related variations in the structure of the foetal and postnatal thyroids were observed in the follicles, colloid, colloid vacuoles, follicular cells and interfollicular connective tissue. Calcitonin was demonstrated in the foetal and postnatal parafollicular cells, while somatostatin was only localised in the pubertal parafollicular cells. The study provides strong evidence of thyroid functionality during the late foetal period that changes with age during the development.

Age-related effects of major and trace element concentrations in rat liver and their mutual relationships

The concentrations of 22 major and trace elements in livers from rats aging from 5 to 113 weeks old were determined. The rats investigated were the same rats previously reported with respect to 29 elements in bones (femur) and 26 elements in kidneys. The samples were decomposed with high-purity nitric acid and hydrogen peroxide. Seven elements (Na, Mg, P, K, Ca, Fe and Zn) were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES), and 15 elements (Mn, Co, Cu, As, Se, Rb, Sr, Mo, Cd, Sn, Sb, Cs, Ba, Pb and Bi) were determined by inductively coupled plasma mass spectrometry (ICP-MS). Analysis of variance (ANOVA) for age variations indicated that the concentrations of many elements, such as Mg, P, K, Mn, Fe, Cu, Zn, Sr, Mo and Cd, were almost constant across the ages of the rats with the exception of 5 weeks old (p>0.05). Arsenic, Pb and Bi showed significant increasing trends, while Na and Co showed decreasing trends (p<0.01). Selenium showed a decreasing trend except at the initial stage of 5–9 weeks old. Calcium, Rb, Sn, Sb, Cs and Ba showed significant age-related variations, but their patterns were not monotonic. The liver clearly contrasts with the kidneys, in which many elements showed significant age-related variations with increasing trends. The concentration ranges of Mg, P, K, Mn, Cu, Zn, and Mo were controlled within 15% across all ages of rats. The homeostasis of the aforementioned elements may be well established in the liver. The toxic elements, such as Cd, Pb and Bi, showed a narrow concentration range among age-matched rats.

Cephalocaudal Variations in the Horizontal and Vertical Diameters of the Pedicles of the Lumbar Spine in the Turkish Population

Purpose: Racial morphometric differences in the pedicular structure of the vertebrae must be taken into account when using international transpedicular screw systems. In this study, we tried to figure out the differences, if any, in the size of the pedicles in a sample of the Turkish population. Methods: The horizontal and vertical diameters of the pedicles of the lumbar vertebrae were measured from the standardized anteroposterior radiographs of the lumbar spine in 100 subjects, aged from 20 to 40 years. Results: The mean horizontal width of the pedicles in our sample of the Turkish population was smaller than the subjects in other studies. The vertical diameter did not differ widely. There was a cephalocaudal increase in the horizontal diameters in both sexes. The vertical diameters did not increase. Significant differences between the pedicle diameters of the males and the females were noted at L2, L3 and L4 levels. No significant age-related variations were observed. Conclusion: Awareness of the racial variations in the size of the pedicles is very important when using international transpedicular screw systems. Preoperative determination of especially the horizontal diameter of the pedicles to be used for screw implantation from standardized anteroposterior X-rays is the easiest way.

CEPHALOCAUDAL VARIATIONS IN THE HORIZONTAL AND VERTICAL DIAMETERS OF THE PEDICLES OF THE LUMBAR SPINE IN THE TURKISH POPULATION

Purpose: Racial morphometric differences in the pedicular structure of the vertebrae must be taken into account when using international transpedicular screw systems. In this study, we tried to figure out the differences, if any, in the size of the pedicles in a sample of the Turkish population. Methods: The horizontal and vertical diameters of the pedicles of the lumbar vertebrae were measured from the standardized anteroposterior radiographs of the lumbar spine in 100 subjects, aged from 20 to 40 years. Results: The mean horizontal width of the pedicles in our sample of the Turkish population was smaller than the subjects in other studies. The vertical diameter did not differ widely. There was a cephalocaudal increase in the horizontal diameters in both sexes. The vertical diameters did not increase. Significant differences between the pedicle diameters of the males and the females were noted at L2, L3 and L4 levels. No significant age-related variations were observed. Conclusion: Awareness of the racial variations in the size of the pedicles is very important when using international transpedicular screw systems. Preoperative determination of especially the horizontal diameter of the pedicles to be used for screw implantation from standardized anteroposterior X-rays is the easiest way.

Age-related changes in the urinary excretion of aldehydes in ad libitum fed and food-restricted rats.

Age-related changes in the urinary excretion of aldehydes arising from lipid peroxidation have been investigated in male Sprague-Dawley rats aged 2, 4, 6, 12, 18, 24 and 27 months, fed ad libitum or subjected to two different regimens of calorie restriction (namely every-other-day ad libitum feeding--EOD--and 40% calorie restriction--40%DR). For only some age groups, results were compared with those obtained in ad libitum fed male Fisher 344 and Lewis rats. Results show that the urinary excretion of malondialdehyde (MDA) and formaldehyde (FA) significantly decreases, whereas that of propionaldehyde (PROP) progressively increases with age, and that urinary excretion of acetaldehyde (ACT) does not show any significant age-related variations. Dietary restriction significantly increases the urinary levels of MDA, FA and PROP without affecting their age-related modifications, and does not affect ACT urinary excretion. In conclusion, results indicate that the quantitative pattern of aldehyde production and urinary excretion may be altered by the process of aging.

Estimation of bone matrix apparent stiffness variation caused by osteocyte lacunar size and density.

The role of osteocyte lacunar size and density on the apparent stiffness of bone matrix was predicted using a mechanical model from the literature. Lacunar size and lacunar density for different bones from different gender and age groups were used to predict the range of matrix apparent stiffness values for human cortical and cancellous tissue. The results suggest that bone matrix apparent stiffness depends on tissue type (cortical versus cancellous), age, and gender, the magnitudes of the effects being significant but small in all cases. Males had a higher predicted matrix apparent stiffness than females for vertebral cancellous bone (p< I0(-7)) and the difference increased with age (p =0.0007). In contrast, matrix apparent stiffness was not different between males and females forfemoral cortical bone and increased with age in both males (p < 0.0001) and females (p < 0.0364). Osteocyte lacunar density and size may cause significant gender and age-related variations in bone matrix apparent stiffness. The magnitude of variations in matrix apparent stiffness was small within the physiological range of lacunar size and density for healthy bone, whereas the variations can be profound in certain pathological cases. It was proposed that the mechanical effects of osteocyte density be uncoupled from their biological effects by controlling lacunar size in normal bone.

Neurochemical parameters of the main neurotransmission systems in aging mice

The present work was designed to study the effect of aging on some parameters of the glutamatergic, aminergic and cholinergic neurotransmission, in the main brain areas of mice of the long-surviving BALB/c-nu strain. We have assayed: (1) the density of three ionotropic receptors for excitatory aminoacids (EAA) which selectively bind kainic acid (KA), N-methyl- d-aspartate (NMDA) and 2-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA); (2) the content of dopamine (DA), norepinephrine (NE) and serotonin (5-HT) and the levels of the DA metabolite dihydrophenylacetic acid (DOPAC) and the 5-HT metabolite 5-hydroxyindoleacetic acid (5-HIAA); (3) the level of the choline acetyltransferase (ChAT), the enzyme catalyzing the synthesis of acetylcholine. The parameters were measured in animals at the age of 6, 12, 18 and 24 months; the brain zones under test were the frontal cortex (FC), the corpus striatum (STR), the hippocampus (HIP), the medio-dorsal cortex (DC) and the cerebellum (CER). Significant age-related variations for the density of KA-type and NMDA-type receptors were found in STR and a decrease of the NMDA parameter was found in DC. Neither the monoamine and metabolite contents nor the ChAT levels showed any significant variation in all the tested areas. These findings suggest that an unbalance among different neurotransmission activities could take place with normal aging in rodents: it could be involved in the onset of the motor deficit which occurs in the elderly of these and other mammals.