Investigate Age Related Changes Research Articles

Investigation of Age-Related Alterations in Brain and Serum Samples in a Healthy Aging Rat Model

Male albino rats of Wistar strain (n=24) were assigned to three groups 2-month old (GRP I), 9-month old (GRP II) and 15-month old (GRP III) ,(n=8 in each ) in order to investigate age related changes in serum and brain samples. Malondialdehyde (MDA), reduced glutathione (GSH), acetylcholinesterase (AChE) and paraoxanase (PON) enzyme activites , soluble and aggregated amyloid β1-42 (Aβ1-42) levels were analyzed in brain tissues. Tissues were also stained with Congo-red dye in order to observe fibrillation. Serum total cholesterol, uric acid and triglyceride levels and PON activites were investigated. Serum uric acid levels were significantly decreased (p

Voice Onset Time in Healthy Young and Old Adults

Objectives: This study aimed to investigate age related changes in articulatory control by examining whether there were differences between young and elderly adults in their voice onset time (VOT). Methods: 16 adults over the age of 65 and 16 adults aged between 18-39 years old participated in this study. The experimental task consisted of 9 plosives, categorized by place of articulation and phonation type, paired with the vowel /a/ to form 2 syllable VCV non-words. Participants’ voice samples were analyzed using Praat. VOT mean was used to examine group differences in VOT and coefficient of variation (CoV) was used to examine group differences in VOT variability. Results: There were significant differences in VOT mean according to age group, phonation type, and place of articulation. The elderly adults had a longer VOT compared to the young adults with significant differences for place of articulation in velar plosives and significant differences for phonation type in aspirated plosives. There were significant differences in VOT CoV according to age group and phonation type. The elderly adults had higher VOT and CoV compared to the young adults with a significant difference in lenis plosives. Conclusion: The results of this study show that elderly adults have longer VOT durations and irregular articulatory control, reflected by higher VOT variability, compared to younger adults. These results may reflect age related declines in the coordination of the speech mechanism and reduced oral motor control.

Skeletal Muscle Cells Derived From Old Donors Show Altered Mitochondrial Morphology And Reduced Respiratory Capacity

With age, skeletal muscle mitochondria lose their oxidative capacity and their ability to respond to energy demand. These phenomena can lead to a reduction in skeletal muscle oxygen consumption, atrophy, and increased risk of developing age-related diseases such as sarcopenia. Whether age-derived changes in mitochondrial function correspond to structural changes in the mitochondrial reticulum remains unknown. PURPOSE: Investigate age-related changes in mitochondrial morphology and function using primary skeletal muscle cells derived from healthy young and old men. METHODS: Primary skeletal muscle progenitor cells (SkM) derived from the Rectus abdominis muscle of healthy active 18-19-year-old men (SkM Young), and 66-69-year-old men (SkM Old) were obtained from Cook MyoSite Inc. (Pittsburgh, PA). The mitochondrial network was analyzed in live cells using confocal microscopy. Oxygen Consumption Rate (OCR) was measured in intact cells using extracellular flux assays and a Seahorse analyzer (Agilent Technologies; Santa Clara, CA). RESULTS: Primary cells derived from SkM Young revealed a higher Basal and Maximal OCR compared to SkM Old (Basal: 23.20 ± 1.49 vs. 11.34 ± 2.31; Maximal: 41.50 ± 4.72 vs. 18.36 ± 1.65 pmol/min/protein). SkM Young also had higher ATP production and Spare Respiratory Capacity (ATP: 19.08 ± 1.21 vs. 9.19 ± 2.10; SRC: 18.30 ± 3.47 vs. 7.03 ± 1.29 pmol/min/protein). No differences were revealed in morphology (Individuals: 37.80 ± 23.18 vs. 46.67 ± 22.43 counts; Networks: 10.20 ± 2.48 vs. 15.33 ± 5.75 counts; Mean Branches per Network: 15.52 ± 6.41 vs. 11.27 ± 3.67 counts). CONCLUSIONS: These preliminary results show primary skeletal muscle progenitor cells derived from healthy young donors have higher respiration, produce more ATP, and have a greater capacity to adapt to energy demands when compared to SkM derived from Old donors. Further analyses can give us an insight into human skeletal muscle-derived cellular physiological capacity. Technology to observe human muscle mitochondrial dysfunction in vitro helps us understand the effects of aging on skeletal muscle mitochondria and whole-body declines of resting and exercise metabolic rates. Additional studies will be required on aging individuals to determine if predicted decrements in energy coupling efficiency occur with aging in vivo.

Age-related changes in the EEG in an eyes-open condition: I. Normal development

This study investigated age related changes in the EEG of normal children in an eyes-open condition, in order to provide developmental norms for the study of children and adolescents with Attention-Deficit/Hyperactivity Disorder (AD/HD) – see our companion paper (Mason et al., submitted). EEG was recorded at 17 sites from 75 children (63 boys and 12 girls, in the approximately 5:1 ratio common in AD/HD) between the ages of 5 and 16 years. They comprised three groups, each of 25 children (21 boys and 4 girls), divided into Young (5–8 years), Middle (9–12 years), and Old (13–16 years). The EEG was recorded during an eyes-open resting condition and Fourier transformed to provide estimates for total power, and absolute and relative power in the delta, theta, alpha and beta bands. Total power and absolute delta, theta, alpha, and beta decreased with increasing age, as did relative delta, while relative alpha increased with increasing age. Changes occurred faster in the posterior regions for total power, absolute theta and alpha, relative theta, and in frontal regions for absolute and relative beta. Some lateral developmental effects differed with band. These results indicate that maturation effects observed in the eyes-open EEG show some similarities to those reported in eyes-closed conditions, although substantial differences are apparent in the maturation of fast wave activity, particularly alpha. The data provide simple age-norms for eyes-open investigations of EEG differences in young clinical groups, particularly AD/HD. They encourage further investigations of the activational effects of this simple eyes-closed/eyes-open manipulation, which may aid understanding of the energetics of behaviour.

Diffusion tensor-based analysis of white matter in the healthy aging canine brain

White matter dysfunction and degeneration have been a topic of great interest in healthy and pathological aging. While ex vivo studies have investigated age-related changes in canines, little in vivo canine aging research exists. Quantitative diffusion MRI such as diffusion tensor imaging (DTI) has demonstrated aging and neurodegenerative white matter changes in humans. However, this method has not been applied and adapted in vivo to canine populations. This study aimed to test the hypothesis that white matter diffusion changes frequently reported in human aging are also found in aged canines. The study used Tract Based Spatial Statistics (TBSS) and a region of interest (ROI) approach to investigate age related changes in fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AxD) and radial diffusivity (RD). The results show that, compared to younger animals, aged canines have significant decreases in FA in parietal and temporal regions as well as the corpus callosum and fornix. Additionally, AxD decreases were observed in parietal, frontal, and midbrain regions. Similarly, an age- related increase in RD was observed in the right parietal lobe while MD decreases were found in the midbrain. These findings suggest that canine samples show commonalities with human brain aging as both exhibit similar white matter diffusion tensor changes with increasing age.

Assessing the Age-Specific Phagocytic Ability of Adult Drosophila melanogaster Hemocytes using an In Vivo Phagocytosis Assay.

Phagocytosis is an essential function of the innate immune response. This process is carried out by phagocytic hemocytes whose primary function is to recognize a wide range of particles and destroy microbial pathogens. As organisms age, this process begins to decline, yet little is known about the underlying mechanisms or the genetic basis of immunosenescence. Here, an injection based in vivo phagocytosis assay is used to assess age related changes in different aspects of phagocytosis, such as binding, engulfment, and degradation of internalized particles, by quantifying phagocytic events in hemocytes in adult Drosophila. Drosophila melanogaster has become an ideal model to investigate age related changes in innate immune function for many reasons. For one, many genetic components and functions of the innate immune response, including phagocytosis, are evolutionarily conserved between Drosophila and mammals. Because of that, results obtained from using this protocol are likely to be widely relevant to understanding the age related changes in immune function in a variety of organisms. Additionally, we note that this method provides quantitative estimates of hemocyte phagocytic ability, which could be useful for a variety of research topics, and need not be limited to studies of aging.

Neurodevelopmental changes in the responsiveness of systems involved in top down attention and emotional responding

In this study, we aimed to investigate age related changes in systems implicated in top down attention and the implications of this for amygdala responses to emotional distracters. Fifty-one healthy subjects including 18 children (aged 10–14), 15 adolescents (aged 14–18), and 18 young adults (aged 18–25) completed the affective Stroop paradigm while undergoing functional MRI. While achieving comparable behavioral performance, children, relative to adolescents and adults, showed increased activation in areas including anterior cingulate gyrus and precentral gyrus in task relative to view trials. In addition, children showed increased activation within the amygdala and fusiform gyrus in response to emotional stimuli. Notably, the group difference within the amygdala was particularly pronounced during task trials. Also children showed increased connectivity between amygdala and superior frontal gyrus and bilateral postcentral gyrii in response to negative task trials. These data are consistent with previous work indicating less consolidated functional integrity in regions implicated in top down attention in children relative to older participants and extend this work by indicating that this less consolidated functional integrity leads to reduced automatic emotion regulation as a function of top down attention. Given that reduced automatic emotion regulation as a function of top down attention is considered a risk factor for the development of anxiety disorders, these data may contribute to an understanding of the increased risk for the development of these disorders at this age.

Investigation of microstructure of bone tissue in mandibles of newborn rats after maternal treatment with antiretroviral drugs

High-resolution imaging has become a powerful tool for measurements in clinics, laboratory and animal studies, etc. In the present study, we aimed to investigate age related changes in bone development, and the effect of two antiretroviral agents (zidovudine and indinavir), which were administered during pregnancy, on the microstructure and bone mineral density (BMD) in newborn rats (7-, 14- and 28-day-old), with the use of X-ray microcomputed tomography (XMT). Fifty-four mandible bones were collected and divided into 3 groups: group 1 and 2: newborns after maternal treatment of zidovudine and indinavir respectively, group 3: control animals. The specimens were XMT scanned with the resolution of 7μm and with a density phantom. Histomorphometric parameters and BMD were calculated to assess bone development depending on the administered drug. A statistical analysis was carried out to compare the differences among the control, zidovudine and indinavir groups. The analysis of the microstructure revealed disturbances in the development of the bone tissue in newborn rats. Indinavir seems to have a greater impact on bone microstructure than zidovudine.

Age-related differences in diffusion tensor indices and fiber architecture in the medial and lateral gastrocnemius.

To investigate age related changes in diffusion tensor indices and fiber architecture of the medial and lateral gastrocnemius (MG and LG) muscles using diffusion tensor imaging (DTI). The lower leg of five young and five senior subjects was scanned at 3 Tesla and DTI indices extracted using three methods: region of interest, histogram, and tract based. Tracked fibers were automatically edited to ensure physiologically relevant tracks. Pennation angles were measured with respect to the deep and superficial aponeuroses of both muscles. The three methods provided internally consistent measures of the DTI indices (correlation coefficient in the range of 0.90-0.99). The primary, secondary, and tertiary eigenvalues in the MG and LG increased significantly in the senior cohort (P < 0.05), while the small increase in fractional anisotropy with age was not significant (MG/LG: P = 0.39/0.85; 95% confidence interval: [-0.059/-0.056, 0.116/0.064]). Fiber lengths of MG fibers originating distally were significantly decreased in seniors (P < 0.05) while pennation angles decreased with age in the MG and LG but this was not significant. Fiber atrophy and increased fibrosis have opposing effects on the diffusion indices resulting in a complicated dependence with aging. Fiber architectural changes could play a role in determining aging muscle function.

Effect of Aging on Storage and Voiding Function in Women with Stress Predominant Urinary Incontinence

We investigated age related changes in urodynamic parameters in 2 large cohorts of women planning stress urinary incontinence surgery. Using a standardized protocol we obtained urodynamic parameters for participants in SISTEr (Stress Incontinence Surgical Treatment Efficacy Trial) and TOMUS (Trial of Mid-Urethral Slings) undergoing baseline noninvasive flow followed by filling cystometrogram and pressure flow study. The bladder contractility index (defined as detrusor pressure at maximum flow+5×maximum flow) and detrusor hypocontractility (defined as detrusor pressure at maximum flow less than 10 cm H2O) were also characterized. Patients excluded from analysis had undergone prior stress urinary incontinence surgery or had prolapse stage greater than II. Propensity score analysis controlled for the potential bias of combining participants from 2 clinical trials. Linear and logistic regression analysis adjusting for propensity score quintile was done to assess the association of age and an age cutoff (less than 65 vs 65 or greater years) with urodynamic parameters. A total of 945 women (468 in SISTEr and 477 in TOMUS) were included in analysis. Mean age was 50 years in SISTEr (range 27 to 75) and 51 years (range 24 to 82) in TOMUS. Noninvasive maximum urinary flow decreased significantly with age (26.2 vs 22 ml per second, p=0.002). Noninvasive flow voiding time increased 2.7 seconds for each 10-year age increment and detrusor pressure at maximum flow decreased 2.1 cm H2O for each 10-year increase in age (each p=0.003). Hypocontractility was more likely in women 65 years old or older (OR 2.89, 95% CI 1.59, 5.27). The bladder contractility index was inversely related to age, decreasing a mean±SD of 7.68±1.96 cm H2O for each 10-year age increase (p<0.001). In these 2 cohorts the observed changes in voiding parameters suggest that detrusor contractility and efficiency decrease with age.

Variation in the gaze, caloric test and vestibular-evoked myogenic potential with advancing age

Objectives: The present study was aimed to investigate age related changes on Caloric test, Gaze Test and Vestibular Evoked Myogenic Potential (cVEMP). Materials and Methods: The participants included 50 individuals ranging from 20-70 years having no complaint of dizziness or any major illness. The basic audiological test battery was carried out followed by Caloric test, Gaze Test and the VEMP. Results: There was no consistent pattern seen on the caloric test and gaze test with advancing age while VEMP showed significant increase in latency and decrease in amplitude of both P13 and N23 as the age advances. Discussion: The comparison of the mean SPV values do not show an age related pattern because the caloric test does not challenge the semicircular canal system enough so as to reveal its defects. The age related changes in the cVEMP parameters could be attributed to the age related degeneration in the vestibular sense organ

Effect of age on test performance in community dwelling elderly people: 6 minutes walk test and ten steps test

The data available in literature for test performance in elderly people are less and insufficient for use as a basis of comparison. The aim of the study was to investigate age related changes in functional performance tests and to determine criterion values depending on age in older adults who are functioning independently in the community.

Precision in isometric precision grip force is reduced in middle-aged adults

We investigated age related changes in the control of precision grip in 29 healthy adults spanning early adulthood to middle age (21-67 years). Subjects performed a visually guided, isometric precision grip ramp-and-hold force-tracking task. Target force levels were 3, 6, and 9 N. Precision and performance of force regulation was quantified. Larger errors were made during the ramp than during the hold phase. Age correlated positively with the amount of error at the lowest (3 N) force level in both phases. Force onsets were systematically earlier in middle-aged subjects and the average slope of the force during the ramp decreased with increasing age. The results show that precision during low grip force control decreases already during middle age and those subjects may modify their force generation strategies to compensate for early and subtle degenerative changes in the motor system before decline in grip strength is apparent.

Region and age dependent differences in α 1-adrenergic responsiveness of rat seminal vesicle and vas deferens

Because age dependent differences occur in the incidence of ejaculatory dysfunction with α 1-adrenoceptor antagonists used to treat lower urinary tract symptoms secondary to benign prostatic hyperplasia, we investigated age related changes in the functional, biochemical and molecular properties of α 1-adrenoceptor in the rat seminal vesicle and vas deferens. The characteristics of α 1-adrenoceptor in the seminal vesicle and epididymal and prostatic portion of vas deferens of 3 and 22-month-old rats were determined using an isolated muscle bath, radioligand receptor binding and real-time reverse transcription-polymerase chain reaction techniques. Old rats had significantly higher body weight and lower testosterone than young rats. Although there was no significant age dependent difference in the properties of α 1-adrenoceptor in the prostatic portion of vas deferens, the maximum contractile responses to phenylephrine, total α 1-adrenoceptor density and mRNA expression of all 3 α 1-adrenoceptor subtypes were significantly lower in the seminal vesicle and epididymal portion of vas deferens of 22 vs 3-month-old rats. Age dependent differences in the molecular, biochemical and functional properties of α 1-adrenoceptors in the rat seminal vesicle and vas deferens may indicate potential differences in the response to α 1-adrenoceptor antagonists with aging.

Age Related Changes in the Functional, Biochemical and Molecular Properties of α 1-Adrenoceptors in the Rat Genitourinary Tract

Because age related changes occur in the properties of alpha(1)-adrenoceptor in several mammalian tissues and alpha(1)-adrenoceptor antagonists are extensively used to treat lower urinary tract symptoms secondary to benign prostatic hyperplasia, we investigated age related changes in the functional, biochemical and molecular properties of alpha(1)-adrenoceptor in the rat genitourinary tract. The characteristics of alpha(1)-adrenoceptor in the ventral and dorsolateral prostate, and bladder base and dome of 3 and 22-month-old rats were determined using an isolated muscle bath, radioligand receptor binding and real-time reverse transcriptase-polymerase chain reaction techniques. Old rats had significantly higher body weight, lower testosterone, a smaller ventral prostate and a larger bladder dome than young rats. Although there was no significant age dependent difference in the properties of alpha(1)-adrenoceptor in the bladder base and dome, total alpha(1)-adrenoceptor density, mRNA expression of all 3 alpha(1)-adrenoceptor subtypes (alpha(1A), alpha(1B) and alpha(1D)) and the maximum contractile responses to phenylephrine were significantly lower in the ventral and dorsolateral prostate of 22 vs 3-month-old rats. Age related differences in the molecular, biochemical and functional properties of alpha(1)-adrenoceptors in the rat genitourinary tract may indicate potential differences in the response to alpha(1)-adrenoceptor antagonists with aging, ie a decrease in the therapeutic response in old vs young rats in the response to alpha(1)-adrenoceptor antagonists when used to treat lower urinary tract symptoms secondary to benign prostatic hyperplasia.

Multivariate analysis of second trimester midfacial morphology in normal and cleft lip and palate human fetal specimens.

To better understand the contribution of congenital dysmorphogenesis to postnatal midfacial dysplasia in individuals with complete cleft lip and palate (CLP), a series of studies were undertaken to investigate age related changes in a number of midfacial components for a sample of 20 normal and 9 complete CLP second trimester fetal specimens. Using data from this sample, the present study assessed the complex multivariate relationships among these variables which represent the fetal normal and CLP midface. Ten variables were standardized relative to crown-rump length and used in Canonical Discriminant Function Analysis (CDFA). CDF analysis revealed that five variables best described the midface and accounted for 72% of the overall variance. These included nasal capsule length, nasal airway volume, premaxillary length, premaxillary volume, and tongue volume. Classification using the CDFA coefficients resulted in correct group membership assignment for 26 of 29 total specimens (89.66%), 8 of 9 cleft (88.9%), and 18 of 20 normal specimens (90.0%). These results suggest that by as early as the second trimester CLP fetuses have a significantly distinct set of midfacial morphological relationships. Some or all of these factors may be responsible for postnatal growth dysplasias noted in CLP individuals.

Age related changes in cardiac output, cephalic and cerebral blood flow in the rat

Two isotope techniques have been used to investigate age related changes in cardiac output, cephalic and cerebral blood flow in the rat. Between 6 and 18 months of age, the cardiac output was reduced by 39.81%, while the cerebral blood flow was only reduced by 25.81%. This observation indicates a redistribution of the cardiac output to the brain, at the expense of other organs. This is best exemplified by the age related changes in the total blood flow to the total cephalic region, which showed a 51.81% fall over the same time period. The blood flow to the brain was approximately 36% of the flow to the cephalic region. Possible mechanims responsible for the redistribution of the cardiac output to the brain are discussed.