Subjects Of Different Age Groups Research Articles

Heights of the lumbar intervertebral discs related to age in Turkish individuals.

The present study investigated the changes in the heights and anteroposterior diameters of human intervertebral discs by means of measurements from radiographs, to determine age changes of lumbar intervertebral discs in Turkish people. Measurements of anterior and posterior disc heights and disc depths were made for 200 clinic subjects of different age groups from lateral radiographs. The height of the intervertebral disc increases with aging only in males and the disc depth in both sexes. Our findings generally corroborate previous studies. It is suggested that the different findings from the present study might be peculiar to the society.

X Chromosome Inactivation Patterns in Normal Females

ABSTRACT: Since one of the two X chromosomes is randomly inactivated at an early stage of female embryonic development, X-linked markers have been used to study the origin and development of various neoplastic disorders in affected heterozygous women; clonality assays have provided a useful tool to the understanding of the mechanisms underlying the development of neoplasia. Recently, a technique of clonal analysis has been devised that takes advantage of a highly polymorphic short tandem repeat within the X-linked human androgen receptor (AR) gene, resulting in a heterozygosity rate approaching 90%. The rapid expansion of the number of women now suitable for X inactivation analysis has however given rise to new controversies, one of the more troublesome being the possibility of a modification of the pattern of X- chromosome inactivation pattern in blood cells of elderly women. In the present study we analyze with the AR assay a group of 166 healthy females aged between 8 and 94 years, with no history of genetic or neoplastic familial disorders. We failed to find any correlation between age and X- chromosome inactivation pattern (r= 0.17), even subdividing the subjects in different age groups according to the criteria used by other researchers, and therefore reaffirm that, when tested for with well-standardized and accurate criteria, extremely unbalanced inactivation of the X chromosome is a truly uncommon phenomenon in normal women.

Age-related performance of human subjects on saccadic eye movement tasks.

We measured saccadic eye movements in 168 normal human subjects, ranging in age from 5 to 79 years, to determine age-related changes in saccadic task performance. Subjects were instructed to look either toward (pro-saccade task) or away from (anti-saccade task) an eccentric target under different conditions of fixation. We quantified the percentage of direction errors, the time to onset of the eye movement (saccadic reaction time: SRT), and the metrics and dynamics of the movement itself (amplitude, peak velocity, duration) for subjects in different age groups. Young children (5-8 years of age) had slow SRTs, great intra-subject variance in SRT, and the most direction errors in the anti-saccade task. Young adults (20-30 years of age) typically had the fastest SRTs and lowest intra-subject variance in SRT. Elderly subjects (60-79 years of age) had slower SRTs and longer duration saccades than other subject groups. These results demonstrate very strong age-related effects in subject performance, which may reflect different stages of normal development and degeneration in the nervous system. We attribute the dramatic improvement in performance in the anti-saccade task that occurs between the ages of 5-15 years to delayed maturation of the frontal lobes.

Interaction of screen distances, screen letter heights and source document distances

An experiment was conducted to investigate the main and interaction effects of screen distances (600 mm and 900 mm), screen letter heights (for visual angles of 16, 20, and 30 minutes of arc), and source document distances (same as the screen distance and closer than the screen distance) on visual performance and subjective preference in text proofreading tasks. Thirty subjects in different age groups participated in the experiment. The experimental results revealed that the subjects' performance improved from the letter height of 16 minutes of arc to the letter height of 20 minutes of arc for the 600 mm screen distance, but from 20 minutes of arc to 16 minutes of arc for the 900 mm screen distance. The subjects generally preferred a screen distance slightly higher than 600 mm, a letter height at the 22 minutes of arc, and a small difference between the visual angle of screen letters and the visual angle of source letters.

Age Dependent Physical and Anatomical Indian Data for Application in Internal Dosimetry

The data on physical, anatomical, physiological and metabolic human characteristics of the Indian population in various age groups were obtained for application in internal dosimetry. Only the physical and anatomical characteristics of the Indian population in age groups 0, 1, 5, 10, 15 y and adult are considered here. A comparison of the adult Indian data with that of ICRP Reference Man, clearly showed that with the exception of a few smaller organs, the body size as well as the organ weights of Indian subjects are, in general, smaller. With the exception of brain, a statistically significant linear correlation (p<0.01) was observed between the body weights and the corresponding organ weights of Indian subjects in different age groups.

An improved procedure for assessing ABR latency in young subjects based on a new normative data set

Auditory brainstem response (ABR) latencies in normal young and very young subjects are longer than in mature subjects. Use of adult norms in the assessment of young subjects may therefore result in the erroneous reporting of abnormalities in subjects who are in no way impaired. In this study a new normative data set was established by measuring ABR absolute and interpeak latencies in 374 subjects in different age groups with normal ABR and no risk factor for hearing impairment or neurological abnormality. Double exponential functions were fitted to a number of latency measures derived from the data and from those functions a table of correction values was computed. The variability in the measurements of the children is greater than that of the adults. Procedures are proposed which enable the assessment of abnormality of ABR latencies to be made for all subjects regardless of age.

Rapid Diagnosis of Long Chain and Medium Chain Fatty Acid Oxidation Disorders Using Lymphocytes

A method based on the release of tritiated water from [9,10(n)-3H] palmitic and myristic acids previously described for fibroblasts, was adapted for lymphocytes for the rapid diagnosis of fatty acid oxidation disorders. Optimal concentrations for both substrates and linearity of the assay were established. Normal values were established in control subjects of different age groups (58 children and 117 adults) and 16 patients with known fatty acid oxidation disorders were tested. Tritiated water production from patients' lymphocytes was expressed as a ratio between residual oxidations of palmitate and myristate and the results show that this method allows good differentiation between long chain and medium chain fatty acid oxidation defects.

Age- and sex-dependent change in stratum corneum sphingolipids.

We measured six stratum corneum sphingolipid species (ceramides 1-6) in 26 males and 27 females, and found a significant change in their percentage composition only among female subjects of different age groups. There was a significant increase in ceramide 1 and 2 with a corresponding decrease in ceramide 3 and 6 from prepubertal age to adulthood. Thereafter the ratio of ceramide 2 to total sphingolipids decreased with age in contrast to ceramide 3 which showed an increase. Such a pattern of change in the aging population is different from that observed in scaly skin experimentally induced by tape stripping. The present results suggest a significant influence of female hormones on the composition of stratum corneum sphingolipids. Moreover, the different patterns of change in sphingolipid composition of stratum corneum lipids between scales from inflammatory skin and those from aged skin also suggest that epidermal biosynthesis of sphingolipids is influenced by epidermal proliferative activity.

Assessment by echocardiogram of left ventricular diastolic function in healthy subjects using the atrioventricular plane displacement

Recent echocardiographic studies have shown that the atrioventricular (AV) valve plane displacement toward the apex in systole plays an important role in the pump function of the left ventricle. 1–6 The method of recording the AV plane displacement is simple and the magnitude of the AV plane displacement can be used to assess left ventricular systolic function in patients with acute myocardial infarction, coronary artery disease and severe chronic congestive heart failure. 5–7 At the start of diastole, the AV plane begins to ascend rapidly toward the atrium away from the apex. Atrial systole also contributes to ventricular filling by further displacing the AV plane in the same direction, and this is noticed in the last part of the diastolic phase of AV plane displacement and is associated with the P wave of the electrocardiogram. 8 The purpose of this study was to evaluate the diastolic function in healthy control subjects of different age groups by relating the motion of the AV plane due to atrial systole to the total diastolic ascent of the AV plane.

Frequency of micronuclei induced in peripheral lymphocytes by trimethyltin chloride

The clastogenicity of trimethyltin chloride was evaluated in human peripheral blood lymphocytes with micronucleus counts (MNC) as the endpoint. Two concentrations (0.5μg and 1.0 μg) of trimethyltin chloride were added to lymphocytes of healthy male and female subjects of different age groups, in mitogen-stimulated and serum-supplemented culture medium (RPMI 1640, Gibco) for 48 h at 37°C. A significant increase in micronucleus counts was observed with both doses, which was more pronounced with the lower dose. ANOVA in male and female donors revealed significant differences between age groups ( P<0.001), chemical concentrations ( P<0.001) and for the interaction of these 2 factors ( P< O.05 in females only). However, no regular increase or decrease in MNC frequencies was observed with the donor's age. Higher frequencies of MNC enhancement were observed in male individuals than in females.

Intrathecal synthesis of beta-2-microglobulin in multiple sclerosis and aseptic meningo-encephalitis

Beta-2-microglobulin (beta 2m) levels were studied in the cerebrospinal fluid (CSF) and plasma of 52 patients with clinically definite multiple sclerosis (MS) and of 14 with aseptic meningo-encephalitis (AM). Reference values for beta 2m were defined in 72 subjects of different age groups with tension headache (TH). Plasma levels of beta 2m increased with age in TH controls, particularly in the older age group, while no significant age variation could be detected for CSF beta 2m. Increased levels of beta 2m were found in the CSF and plasma of AM patients and in the CSF in MS. Calculations of CSF/plasma beta 2m ratios showed higher values in AM, reflecting intrathecal beta 2m synthesis, while only borderline alterations were evident in MS. Demonstration of intrathecal production of beta 2m is an additional CSF finding that may be useful in evaluating, among others, inflammatory nervous system disorders, but it has limited importance in the study of MS patients.

Impaired performance in a saccadic tracking task in schizophrenic patients

The performance of schizophrenic patients in a task which requires a sequence of saccades guided by visuospatial cues is reported. A previous study recording eye movements determined a highly increased number of fixations necessary for this task in acute schizophrenic patients compared with normal controls. The performance of normal control subjects of different age groups and the correlation between the performance in the tracking task and the results of a clinical psychological test battery are described. Schizophrenic patients in a partly remitted state and in a remitted or mildly chronic state performed this task worse than matched control subjects; this was particularly indicated by the time score. The relation to the lifetime dosage of neuroleptic medication is considered.

Probing depth, attachment loss and gingival recession. Findings from a clinical examination in Ushiku, Japan.

The present investigation describes probing pocket depth, probing attachment level and recession data from 319 randomly selected subjects, aged 20-79 years, from Ushiku, Japan. The findings are reported as mean values, frequency distributions and percentile plots of the 3 parameters at buccal, interproximal and lingual surfaces of single rooted (incisors, canines, premolars) and molar teeth. Inter-as well as intra-examiner errors for probing pocket depth and probing attachment levels were assessed and found to be small. The data reported revealed that practically all subjects studied had one or more sites in the dentition affected by destructive periodontal disease and that the severity of disease increased with age. It was further observed that in each age group, molars had suffered more attachment loss than single rooted teeth and that the interproximal surfaces as a rule had lost more periodontal tissue support than corresponding buccal and lingual surfaces. The attachment loss difference observed between different surfaces of a given tooth or a group of teeth, however, was comparatively small. In the age groups between 20-59 years, advanced destructive periodontal disease was found in a small subgroup of the subject sample, while after the age of 60 years, widespread destructive periodontitis was common. An attempt was made to examine the progression of destructive disease with age by comparing the frequency distributions of sites with attachment loss of greater than or equal to 3 mm in subjects of different age groups. The data suggested that in younger subject groups, progression was confined to a subset of individuals, while in older age groups, more subjects and sites became involved. A major feature of destructive periodontal disease in older individuals was the accompaniment of attachment loss with recession at the gingival margin. Deep pockets were relatively infrequently detected, while advanced loss of attachment (with recession) occurred at many sites.

Serologic markers of hepatitis A and B in the population of Bali, Indonesia.

A total of 343 sera from Balinese subjects in different age groups and geographic locations were tested by radioimmunoassay (RIA) for serum antibodies to hepatitis B surface antigen (anti-HBs) and hepatitis B core antigen (anti-HBc); most sera were also tested for hepatitis B surface antigen (HBsAg), and for antibody to hepatitis A virus (anti-HAV). One hundred percent of the adult population was found to have anti-HAV, with antibody acquisition beginning in early childhood and reaching a level of 95% by the age of 10 years. Antibodies to hepatitis B virus were also frequent in young children, rapidly peaking to near 80% in older children and adolescents, then declining to a plateau that fluctuated between 40% and 60% throughout adult life. Overall, anti-HBc (49%) was detected slightly more often than anti-HBs (45%), but the relative frequencies of the 2 antibodies varied considerably from group to group. Despite these high antibody prevalences, HBsAg was detected in only 1.5% of the general population, and in no woman of child-bearing age. In utero infection is thus far less likely to account for the early acquisition of antibody to hepatitis B virus than inapparent percutaneous transmission occurring under conditions of close personal contact.

Autoantibodies in healthy subjects of different age groups

Autoantibody determinations in 1284 healthy Caucasian subjects of various age groups were made by indirect immunofluorescence for anti-nuclear, anti-gastric, and anti-thyroglobulin antibodies. A sex-dependent relationship between age and prevalence of anti-gastric and anti-thyroglobulin antibodies was found. No association was found between age and anti-nuclear antibodies.

Taste acuity of the human palate: III. Studies with taste solutions on subjects in different age groups

The taste acuity at the midline of the hard and soft palate near their junction and, for comparison, on representative areas of the tongue was determined in 80 subjects aged 11-79 years by applying test solutions of the four basic tastes. Twenty-one subjects (26%) could identify at least one taste on the hard palate but none could recognize all four tastes. Seventy subjects (87%) could identify at least one taste on the soft palate and 37 subjects (46%) could recognize all four tastes. Taste thresholds were much higher on the hard palate than on the tongue and were in most cases higher on the soft palate than on the tongue. The ability to recognize all four tastes was less frequent in older than in younger subjects and the difference was greatest on the soft palate and least at the foliate papillae. The differences were greatest for citric acid and least for sucrose. There was a tendency to lower thresholds for women compared to men for all four tastes on all areas examined which was most pronounced on the soft palate. No differences in taste thresholds were found between denture wearers and subjects with natural dentition. Smokers had higher thresholds than non-smokers only for salt on the soft palate and the base of the tongue.

Taste acuity of the human palate: II. Studies with electrogustometry on subjects in different age groups

The electrical taste acuity on the hard and soft palate and the tip of the tongue was determined in 140 subjects aged 13-81 years using an electrogustometer constructed for the study. The possible influence of several variables including age, sex, wearing of a full upper denture, smoking as well as medical and social factors on the threshold values was also studied. Taste perception was demonstrated on the soft palate and on an area of the hard palate close to the junction of the hard and soft palate in most subjects. No perception of the electrical taste was found in eleven subjects (8%) on either the hard or the soft palate and in an additional 33 subjects (24%) on the hard palate alone and 2 subjects (1%) on the soft palate alone. The taste thresholds on the hard palate were very high compared to those on the soft palate and those on the tongue. Older subjects generally had higher thresholds than did younger subjects and the differences were greater for the thresholds on the hard and soft palate than for those on the tongue. No statistically significant differences in threshold values were found between women and men, denture wearers and non-denture wearers or smokers and non-smokers.

Influence of age on glucose tolerance in normal subjects.

Glucose tolerance, plasma FFA and insulin response following an oral glucose load (1 g/kg body weight) were studied in normal healthy subjects of different age groups. Although there was no obvious loss of glucose tolerance, the peak and 120 min blood glucose levels, and the glucose area under the glucose curve in the sixth decade were significantly higher than in the other decades. Fasting plasma FFA levels were also significantly elevated in the sixth decade but the insulin response was normal. The subtle degree of loss of glucose tolerance observed in the sixth decade could be either due to decreased sensitivity to insulin produced by elevated plasma FFA or atherosclerotic changes interfering with ready availability of circulating insulin to the tissues.