Evaluation Of Age-related Changes Research Articles

Magnetic resonance diffusion-weighted imaging: quantitative evaluation of age-related changes in healthy liver parenchyma

The purpose of this study was to verify in healthy liver parenchyma the possible influence of age on DwI-related parameters: apparent diffusion coefficient (ADC), perfusion fraction (PF), diffusion and pseudodiffusion coefficient ( D and D ⁎). Forty healthy adult volunteers (age range 26–86 years), divided into four age groups, were prospectively submitted to a breath-hold magnetic resonance diffusion imaging (MR-DwI) (two b values, 0–300 and 0–1000 s/mm 2). A smaller cohort of 16 subjects underwent a free-breath multi- b acquisition (16 b values, 0–750 s/mm 2). Quantitative analysis was performed by two observers with manually defined regions of interest, on the most homogeneous portion of the right liver lobe. Individual and group statistical analysis of data was performed: ANOVA to establish differences between groups and Pearson correlation coefficient to investigate the association between DwI parameters and age. The mean, S.D. and 95% limits of agreement of ADC values for each age-defined group are reported. ANOVA showed no significant differences between group means ( P always >.05). No significant correlation between subjects' age and DwI parameters was established, both in breath-hold and free-breath acquisitions, on the whole range of adopted b values. Our study conducted on healthy liver parenchyma shows that there are no significant differences in ADC, PF, D and D ⁎ of younger or older subjects.

Integrated Evaluation of Age-Related Changes in Structural and Functional Vascular Parameters Used to Assess Arterial Aging, Subclinical Atherosclerosis, and Cardiovascular Risk in Uruguayan Adults: CUiiDARTE Project

This work was carried out in a Uruguayan (South American) population to characterize aging-associated physiological arterial changes. Parameters markers of subclinical atherosclerosis and that associate age-related changes were evaluated in healthy people. A conservative approach was used and people with nonphysiological and pathological conditions were excluded. Then, we excluded subjects with (a) cardiovascular (CV) symptoms, (b) CV disease, (c) diabetes mellitus or renal failure, and (d) traditional CV risk factors (other than age and gender). Subjects (n = 388) were submitted to non-invasive vascular studies (gold-standard techniques), to evaluate (1) common (CCA), internal, and external carotid plaque prevalence, (2) CCA intima-media thickness and diameter, (3) CCA stiffness (percentual pulsatility, compliance, distensibility, and stiffness index), (4) aortic stiffness (carotid-femoral pulse wave velocity), and (5) peripheral and central pressure wave-derived parameters. Age groups: ≤20, 21–30, 31–40, 41–50, 51–60, 61–70, and 71–80 years old. Age-related structural and functional vascular parameters profiles were obtained and analyzed considering data from other populations. The work has the strength of being the first, in Latin America, that uses an integrative approach to characterize vascular aging-related changes. Data could be used to define vascular aging and abnormal or disease-related changes.

Microarray Evaluation of Age-related Changes in Human Dental Pulp

Introduction The dental pulp undergoes age-related changes that could be ascribed to physiological, defensive, or pathological irritant-induced changes. These changes are regulated by pulp cell activity and by a variety of extracellular matrix (ECM) macromolecules, playing important roles in growth regulation, tissue differentiation and organization, formation of calcified tissue, and defense mechanisms and reactions to inflammatory stimuli. The aim of this research was to better understand the genetic changes that underlie the histological modification of the dental pulp in aging. Methods The gene expression profile of the human dental pulp in young and older subjects was compared by RNA microarray analysis that allowed to simultaneously analyze the expression levels of thousands of genes. Data were statistically analyzed by Significance Analysis of Microarrays (SAM) Ingenuity Pathway Analysis (IPA) software. Semiquantitative and real-time reverse-transcriptase polymerase chain reaction analyses were performed to confirm the results. Results Microarray analysis revealed several differentially expressed genes that were categorized in growth factors, transcription regulators, apoptosis regulators, and genes of the ECM. The comparison analysis showed a high expression level of the biological functions of cell and tissue differentiation, development, and proliferation and of the immune, lymphatic, and hematologic system in young dental pulp, whereas the pathway of apoptosis was highly expressed in older dental pulp. Conclusions Expression profile analyses of human dental pulp represent a sensible and useful tool for the study of mechanisms involved in differentiation, growth and aging of human dental pulp in physiological and pathological conditions.

Metrics for Evaluation of Age-Related Changes in Erectile Capacity in a Rodent Model

Stimulation of the cavernous nerve elicits increases in intracavernosal pressure (ICP) and visible penile erection (VPE) in rats. The observed penile erection can be characterized by the change in ICP and the ratio of ICP over blood pressure (BP; systemic blood pressure). We evaluated correlations between ICP, BP, ICP/BP, and VPE, and the magnitude of the nerve stimulation required to elicit those responses in order to evaluate age-related changes in erectile function in a rodent model. Nine young (3 months) and 10 old (18 months) rats were used. Under anesthesia cavernous nerve stimulation was performed at stimulation strengths ranging from 0.1 to 10 mA. The ICP, BP, ICP/BP, and VPE responses to cavernous nerve stimulation were quantified and compared. Significant correlations were observed between ICP and ICP/BP in both young (r(2) = 0.886) and old (r(2) = 0.962) rats. If the ratio ICP/BP was taken as a metric of VPE and non-erection, then the threshold value for observing a VPE in the majority of animals was > or =0.5 in both young and old rats. However, higher current stimulation was required in the old than in the young animals to achieve erections. Moreover, both the maximal ICP and ICP/BP ratios achieved during erection were also lower in the old (85 +/- 2 cmH(2)O and 0.6 +/- 0.02, respectively) than young (106 +/- 3 cmH(2)O and 0.75 +/- 0.02, respectively) rats (P < 0.0001). Old rats without obvious comorbidities were capable of penile erections, but those erections were accompanied by reduced ICP responses to cavernous nerve stimulation, implying apparently reduced penile rigidity. Taken together our current observations indicate that ICP, ICP/BP, and VPE provide useful metrics/indices of erectile capacity/function, and, moreover, that improved understanding of the inter-relationships among these parameters provides a frame work for further exploration of the mechanistic basis for age-related erectile dysfunction.

Evaluation of age-related changes in the structure of the equine tarsometatarsal osteochondral unit

To investigate effects of age on thickness and morphologic characteristics of hyaline cartilage, calcified cartilage, total cartilage, and subchondral bone (SCB) in the equine tarsometatarsal joint. 23 tarsal joints from cadavers of 23 ponies (11 days to 25 years old); ponies were limited to pasture exercise and euthanatized for reasons not related to this study. Procedures-Tarsi were allocated into several age groups (11 days old [n = 3], 6 to 9 months old [4], 2 to 3 years old [3], 6 to 8 years old [4], 11 to 17 years old [6], and 20 to 25 years old [3]). Histologic examination and histomorphometric measurement of hyaline cartilage, calcified cartilage, total cartilage, and SCB were performed at medial and lateral sites. A significant decrease was detected in thickness of hyaline cartilage and total cartilage with increasing age, but there was a significant increase in thickness of calcified cartilage and SCB with increasing age. Differences in chondrocyte and collagen fiber arrangement, tidemark, and osteochondral junction morphology were evident among age groups. These findings suggested that the various tissues of the osteochondral unit change in different ways with age. The response of each tissue may be related to relative response of the tissues to strains induced by pasture exercise but could have an influence on how the overall properties of the osteochondral unit change with age. The findings may also be suggestive of changes that develop prior to the onset of osteoarthritis.

Age-related changes of serum tartrate-resistant acid phosphatase 5b and the relationship with bone mineral density in Chinese women

Osteoclastic activity is mainly assessed by measurement of urinary markers (eg C-terminal cross-linked telopeptides of type I collagen, N-terminal crosslinked telopeptides of type I collagen, etc), the levels of which could often be affected by renal clearance. Recently, serum tartrate-resistant acid phosphatase 5b (TRACP5b) has been used as an alternative serum marker to evaluate osteoclastic activity. We investigated the age-related changes of TRACP5b level and its association with bone mineral density (BMD) in Chinese women. Seven-hundred and twenty-two Chinese mainland women aged 20-79 years were recruited in the study. Serum TRACP5b level was measured using immunoassay to evaluate the state of bone resorption. Bone mineral density (BMD) (g/cm2) at lumbar spine 1-4 and proximal femur were measured by duelenergy X-ray absorptiometry. The serum TRACP5b level reached a bottom value in premenopausal women aged 30-39, gradually increased in women aged 40-49, rapidly rose in women aged 50-59, and culminated with a maximum value in women aged 60-69 before a slow drop in women aged 70- 79. The average level of TRACP5b was significantly higher in postmenopausal women [(3.29+/-1.07) U/L] than in premenopausal women ([1.70+/-0.59] U/L). The levels of TRACP5b were inversely correlated with BMD at all measured sites (P<0.001). Furthermore, the level of TRACP5b was obviously higher in women with osteoporosis and osteopenia than those with normal bone mass (P<0.001). We have established the reference values of serum TRACP5b in Chinese mainland women, and found that postmenopausal women had higher TRACP5b concentration than younger women. The results showed that serum TRACP5b was a sensitive and useful parameter for the evaluation of age-related changes of bone absorption.

Influence of age and regional differences on skin elasticity as measured by the Cutometer®

Aging of skin is accompanied by decrease of skin elasticity. Using the noninvasive suction device Cutometer, we evaluated the age and regional body differences of the viscoelastic properties of human skin. The objectives of this study were to evaluate the correlation between age and the biomechanical parameters and the regional skin variations. A total of 96 healthy women aged 20-75 years were included in this study. The biomechanical properties of the skin were measured by using the Cutometer. Measurements were made on the face, upper arm and back. The age of subjects showed significant positive correlation with R4 and R6, and negative correlation with R2, R5 and R7. The face showed bigger changes of elastic properties than the arm and the back. Especially, the R7 of face was most significantly decreased with aging. We could estimate the so-called 'skin age' by using a correlation equation for this parameter. The viscoelastic properties were significantly influenced by aging. Also, significant regional variations in the viscoelastic properties were observed. Skin elasticity measurement is useful for the quantitative evaluation of age-related changes.

Histological evaluation of age-related changes in human respiratory mucosa of the middle turbinate.

Though the lining of the healthy human nose is subject of numerous investigations, age-related changes have attracted little attention. Furthermore, varying sampling sites complicate the evaluation of the available information. Reference is needed for evaluation of abnormal conditions, e.g. in persons with sleep apnea. Biopsy samples from the middle turbinate of 40 healthy humans aged 5 to 75 years were examined. Tissue samples were fixed immediately in glutaraldehyde and embedded in Epon for semi-thin sectioning and blind histological evaluation. In all age groups, patchy arrangement of different epithelial types were found. Ciliated epithelium decrease with age. Stratified and atrophic epithelial types show striking changes. Thin atrophic epithelium with conspicuously thickened basement membranes is only seen above the age of 40 years and is frequently found in older subjects. Stratified epithelial types initially increase with age, but decrease above 50 years. In the middle aged group (26 to 50 years) we found a remarkably high amount of squamous metaplasia, resulting in overall thicker epithelium becoming thinner in older subjects. In contrast, basement membranes are thinnest in the middle aged group. In conclusion, evaluating the histology of nasal respiratory epithelium must take pronounced age-related physiological changes into account.

Ultrafast three-dimensional ultrasound: application to carotid artery imaging.

Three-dimensional (3-D) vascular ultrasound can be expected to improve qualitative evaluation of vessel pathology and to provide quantitative data on vascular morphology and function. The objective of this study was to develop an ultrafast 3-D vascular system and to validate its performance for quantitation of atherosclerosis and assessment of regional arterial distensibility. The quantitative analysis of focal atherosclerotic lesions was validated in vitro on 27 phantoms of fibroadipous plaques of known volume (range, 100 to 600 mm3). In vivo reproducibility of plaque volume measurement was tested in 33 patients who had a total of 47 predominantly fibroadipous carotid plaques. Distensibility assessment was validated indirectly through the evaluation of age-related changes in distensibility of common carotid artery in healthy and hypertensive subjects (25 men in each group). The volume of plaque phantoms measured from the 3-D data set showed a very close correlation with the true volume (r=0.99; y=0.96x+12.38; P<0.01), with the mean difference between the 2 measurements being -3.12+/-15.1 mm3. High reproducibility was found for measurement of carotid plaque volume in vivo: the mean difference between measurements from 2 observers for the same data set was 0.60+/-11.2 mm3. Indexes of arterial distensibility decreased with age in healthy population, whereas this relationship was lost in hypertensive subjects. Ultrafast 3-D ultrasound imaging of carotid artery demonstrates good accuracy and reproducibility for atherosclerotic plaque volume measurements. The system also allows the study of age-related degenerative vascular changes.

Scanning electron microscopic evaluation of age-related changes in the rat vestibular epithelium

Scanning electron microscopic evaluation of age-related changes in the rat vestibular epithelium

Similar age-related changes of free intracellular calcium in lymphocytes and central neurons: effects of Alzheimer's disease.

Several studies suggest that alterations of cytosolic free calcium concentration ([Ca2+]i) are involved in the pathophysiology of aging and Alzheimer's disease (AD). However, only few data are presently available giving detailed information about specific characteristics of age-related or AD-specific changes in cellular Ca(2+)-homeostasis. To allow a comprehensive evaluation of age-related changes in [Ca2+]i we performed parallel investigations in central mouse brain cells and mouse spleen lymphocytes of young and aged animals and also in human lymphocytes and granulocytes of young and aged donors and additionally of AD patients. In aged animals, basal [Ca2+]i was decreased in brain cells but increased in spleen lymphocytes. No age-related alterations in baseline [Ca2+]i was found in human lymphocytes or granulocytes. However, comparison of activation-induced rise in [Ca2+]i revealed parallel age-related changes in the different cell-types investigated. The increase in [Ca2+]i after depolarization of mouse brain cells with KCl and after stimulation of mouse lymphocytes with phytohaemagglutinin (PHA) was significantly impaired in aged animals. Moreover, activation of human lymphocytes with PHA also revealed a reduced increase in [Ca2+]i in cells of aged donors. In lymphocytes of AD-patients there was a tendency to higher basal [Ca2+]i compared to their aged matched controls, but no specific alterations in [Ca2+]i could be found after stimulation with PHA. Also no age-related or AD-specific changes were found in granulocytes after stimulation with N-formyl-methionyl-leucyl-phenylalanine (fMLP).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical evaluation of age-related changes of bone mineral content of cortical and trabecular bones by dual energy QCT

The potential capability of a new dual energy (DE) quantitative computed tomography (QCT) method, 4-equation 4-unknown method (DEQCT4E-4U), was evaluated for estimation of bone mineral density (BMD) as well as bone mineral content/cm width (BMC) in trabecular bone of lumbar vertebrae. Cortical BMD and BMC were also estimated by the single energy QCT method (SEQCT 80 kVp) and the age-related change of cortical BMD and the cortical BMC/trabecular BMC ratio was also studied. The result indicated that the estimation of the BMD combining analysis of BMC in trabecular bone obtained by the present method provides further knowledge concerning vertebral trabecular bone mineral status. The profiles of the age-related changes of the cortical BMD and cortical BMC/trabecular BMC ratio in females were markedly different from those in males. These results indicated that our method combining analysis of BMC (BMD) of cortical bone and trabecular bone was also found to provide valuable information to evaluate the vertebral bone mineral status.

Evaluation of age-related changes of physicochemical properties and functional activity of rat adipose plasma membranes and their possible relationship

Studies were carried out to evaluate structural state of adipose plasma membranes (PM) from mature adult and aged Wistar rats and its possible relation to functional changes in aging. PM lipids were probed by fluorescence of 1,6-diphenyl-1,3,5-hexatriene (DPH) and pyrene. The data on DPH anisotropy, pyrene excimerization and induction resonance energy transfer (IRET) from PM proteins to pyrene provided the evidence for age-dependent decrease in PM lipid phase fluidity inclusive of that of annular lipid. Interaction between PM lipids and integral proteins also changed in aging. The observed structural changes were due to age-related lipid compositional modification. Evidence for this conclusion was provided by the following data: (i) DPH anisotropy was increased in aging both in PM and liposomes from the same PM lipids; (ii) both saturation/unsaturation fatty acid ratio and relative content of phosphatidylethanolamine (PE) increased in aged PM, whereas cholesterol/phospholipid and lipid/protein ratios were age-independent; (iii) PM polypeptide composition remained practically unchanged during aging. Age-related changes of the PM structure were accompanied by a twofold decrease of high affinity insulin binding sites and elevation of their affinity to insulin. It was suggested that age-related changes of physicochemical properties of PM lipid phase might affect protein molecular conformation and function through either changes in bulk lipid fluidity or through specific lipid-protein interactions.

Liquid-chromatographic evaluation of age-related changes in the urinary excretion of free catecholamines in pediatric patients.

Pediatric patients (to age 18) without neuroblastoma show an age-related decrease in urinary excretion of each of the catecholamines--epinephrine, norepinephrine, and dopamine--in relation to creatinine excretion. From these data, I have developed reference intervals for pediatric age groups. Application of these ranges to seven patients with neuroblastoma and ganglioneuroblastoma indicated a high clinical sensitivity for the urinary dopamine determination but significant false-negative results for epinephrine and norepinephrine.