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PubMed1982

Noncomparability of longitudinally and cross-sectionally determined annual change in spirometry.

Annual decline in lung function determined longitudinally is often compared with predicted decline determined cross-sectionally. To test this comparison, spirometric data were collected 5 times over 5 yr from 52 adult male Caucasians. The age regression coefficient for FEV1 and FVC, determined cross-sectionally at each visit, was more than twice the longitudinal annual change computed from the same data as the mean of the slopes of each subject's regression lines. The discrepancy persisted even when the first visit was deleted to reduce learning effects on longitudinal estimates. This discrepancy may be partly explained by the sensitivity of cross-sectional analyses to past noxious influences, whereas longitudinal analyses are sensitive only to influences that continue to affect annual decline during the study period. We also found historical evidence of an increase in height-specific VC, which would artifactually steepen cross-sectionally determined regression lines. Thus, observed longitudinal changes of study cohorts should be compared with control longitudinal data.

Adult↗

PubMed2004

Verbal memory decline and adverse effects on cognition in adult patients with pharmacoresistant partial epilepsy: a longitudinal controlled study of 36 patients.

The aim of this study was to delineate possible longitudinal cognitive changes in adult patients with a long history of pharmacoresistant partial epilepsy. Thirty-six patients and thirty healthy controls were investigated at baseline. A reassessment was conducted, with median test intervals of 4.8 years for the patients and 3.1 years for controls. A standardized battery was used for assessment of general cognitive level and memory. At baseline, patients performed at a significantly lower level on general cognition, immediate recall of pairs of associated words, and retention of learned words and visuospatial stimuli, compared with controls. Analyses of change over time in the patients disclosed significant verbal memory decline in retention of pairs of associated words. Group comparisons of change over time revealed adverse effects in the performance aspect of general cognition on the patients. Also, group comparisons indicated impaired performance across time for the patients in retention of pairs of associated words and retention of visuospatial stimuli. The adverse effect on memory and general cognition in this patient group over the period was clear-cut when compared with the longitudinal changes in an adequate control group.

Adult↗

PubMed2026

Digital Remote Assessment of Motor and Speech Changes in Amyotrophic Lateral Sclerosis: Longitudinal Observational Study.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with an active trial landscape that relies on the sensitivity of selected clinical trial endpoints. Traditional clinical outcome assessments perform well in trials but lack strong psychometric properties and may not detect small but clinically meaningful disease progression. Digital health technologies offer a promising alternative for tracking ALS disease progression. OBJECTIVE: This study assessed the feasibility of remote digital monitoring in ALS using a comprehensive battery of prescribed home-based assessments via a smartphone, a wearable device, and a computer-based mouse-clicking task. METHODS: Participants completed weekly remote assessments, including motor and speech tasks via a smartphone app and a computer mouse-clicking task for 24 weeks. They also participated in 3 remote telephone visits in weeks 1, 13, and 25. Reliability, minimal detectable change, and correlations with self-reported ALS Functional Rating Scale-Revised subdomain scores were calculated for 8 features across the speech, fine motor, and gross motor smartphone app tasks and for all 32 features from the computer mouse-clicking task. Sensitivity to longitudinal change was assessed for the 8 smartphone-derived features and for a representative subset of 8 computer mouse-clicking features. RESULTS: Forty-two participants (19 with ALS and 23 controls) completed 10,237 smartphone assessments and 459 computer mouse-clicking sessions. Baseline discriminative models differentiated ALS from controls with AUC values of 0.75-0.92. Digital measures correlated strongly with self-reported ALS Functional Rating Scale-Revised subdomain scores. Both participants with ALS and controls demonstrated improvement in fine motor and speech measures, with the exception of nondominant-hand pegboard performance, which declined in the ALS group. Improvements were smaller in participants with ALS, leading to increasing group differences over time, although only one feature showed a statistically significant separation over the 24 weeks. Gait and balance performance declined in both groups, with greater but nonsignificant separation observed for balance measures. CONCLUSIONS: These findings support the feasibility of digital remote assessments in ALS, demonstrate the ability to discriminate between ALS and controls based on certain features collected from speech, fine, and gross motor tasks, and in some cases, quantify functional decline over time. Further research is necessary to explore the natural history of these features longitudinally in larger cohorts of participants with ALS over extended periods to enable their potential integration into clinical trials.

Adult↗

PubMed2026

Effects of Fecal Microbiota Transplantation on Intestinal Microbial Characteristics and Clinical Phenotypes in Patients with Parkinson's Disease.

Alterations in the gut microbiota have been associated with Parkinson's disease (PD), but longitudinal microbial changes after fecal microbiota transplantation (FMT) and their clinical associations remain poorly understood. This single-center retrospective observational study included 6 patients with PD, stratified into high- and low-severity subgroups based on disease duration (>6 years vs ≤6 years). Thirty-six fecal samples were collected before FMT and monthly for five months afterward. Microbial diversity, community structure, taxonomic composition, and predicted functional profiles were assessed using 16S ribosomal RNA gene sequencing. Analyses included alpha and beta diversity, taxonomic abundance, linear discriminant analysis effect size, Tax4Fun2-based functional prediction, and Spearman rank correlations between microbial features and clinical indicators. Descriptive analyses indicated differences in microbial richness, diversity, community structure, and predicted functions between severity subgroups and across post-FMT time points. At baseline, the low-severity subgroup had greater microbial richness and diversity than the high-severity subgroup, with relatively higher abundances of taxa including Bifidobacterium and Lactobacillus. One month after FMT, richness and diversity increased from baseline in the high-severity subgroup, accompanied by changes in taxonomic composition. Both subgroups showed time-associated variation in microbial diversity and predicted Kyoto Encyclopedia of Genes and Genomes pathway enrichment after FMT. Predicted functions included carbohydrate and amino acid metabolism, secondary metabolite biosynthesis, membrane transport, and signal transduction. Several operational taxonomic units correlated with indicators of motor impairment, constipation, sleep quality, functional status, and neuropsychiatric symptoms. FMT was therefore associated with longitudinal changes in gut microbial diversity, composition, and predicted functions, and specific microbial features were associated with motor and non-motor indicators. Given the small retrospective cohort, these findings are preliminary and warrant confirmation in larger controlled studies. Future studies should determine whether these microbial alterations are reproducible, persist beyond five months, reflect donor engraftment, and correspond to measurable clinical improvement after transplantation in PD.

Humans↗

PubMed2006

Are serum leptin and the Gln223Arg polymorphism of the leptin receptor determinants of bone homeostasis in elderly men?

OBJECTIVE: Across studies it has been suggested that leptin intervenes as a regulator of bone metabolism. This study assesses the contribution in elderly men of leptin and the Gln223Arg leptin receptor gene (LEPR) polymorphism to the variation in bone homeostasis, in relation to body composition and free estradiol as major confounders. DESIGN: We performed cross-sectional (n = 270) and longitudinal (mean follow-up 3.4 years, n = 214) evaluations in elderly men. METHODS: Serum leptin, LEPR genotype, baseline bone mineral density (BMD), longitudinal BMD changes at the hip and forearm, and biochemical markers of bone turnover were determined. RESULTS: In cross-sectional analyses absolute fat mass was the index of body composition most strongly associated with leptin (r = 0.74; P < 0.001). LEPR genotypes and serum leptin were not associated. Serum bone-specific alkaline phosphatase (S-BAP) was associated with LEPR genotypes (P = 0.05) and urinary C-terminal telopeptides of type I collagen (U-CTX) were associated with leptin levels (P = 0.03), independently from age, fat mass and free estradiol. Baseline BMD at the hip and forearm was neither associated with leptin nor with LEPR genotypes. Prospectively assessed BMD loss was not associated with serum leptin at the hip, whereas BMD loss was positively associated with leptin at the forearm (P = 0.01), independently from age, fat mass and free estradiol. Longitudinal changes in hip or forearm BMD were not associated with LEPR genotypes. CONCLUSION: The findings suggest a possible role for leptin as determinant of bone homeostasis in elderly men, but with only modest impact independently from body composition and free estradiol.

Aged↗

PubMed2002

Longitudinal evaluation of both morphologic and functional changes in the same individuals with Alzheimer's disease.

UNLABELLED: Morphologic and functional imaging studies have not always given concordant results about brain areas showing atrophic changes and reduced flow or metabolism in Alzheimer's disease (AD). The aim of this study was to determine the initial abnormality and the longitudinal changes in both morphologic and functional measurements for the same individuals with AD. METHODS: We investigated 15 patients with mild AD and 25 age-matched healthy volunteers. The AD patients underwent both MRI and SPECT 3 times at intervals of approximately 1 y. The gray matter volume, as segmented from MRI, and the regional cerebral blood flow (rCBF), as measured by SPECT, of AD patients were compared with those of healthy volunteers using statistical parametric mapping, which is a voxel-based analysis in stereotactic space. RESULTS: Considerable discordance between areas of regional atrophy and areas of decreased rCBF was observed. The medial temporal areas showed a faster and more extensive reduction of gray matter volume than of rCBF. In comparison with the value at the baseline study, rCBF in the posterior cingulate gyrus and precuneus and the associative parietal cortex was extensively decreased. In contrast, the extent of significant decrease in this area continued to be much narrower for gray matter volume than for rCBF, even in the follow-up studies. Frontal areas, including the anterior cingulate gyrus and the orbitofrontal areas, showed a progressive reduction in both rCBF and gray matter volume. The reduction in rCBF was in a more posterior part of the associative temporal cortex than was the reduction in gray matter volume. CONCLUSION: These results indicate a distinct discordance between morphologic and functional changes in a longitudinal study of AD. Functional changes may be caused partly by remote effects from the morphologically involved areas with decreased connectivity and partly by a compensatory response by neuronal plasticity.

Aged↗

PubMed1989

Personality as modifier of the life change-distress relationship. A longitudinal modelling approach.

We present a structural equation model of the way in which personality factors may modify the response to changes in life situation, based on two-wave panel data from a random sample of 296 Dutch adults. Three definitions of vulnerability were studied: high neuroticism (N), low self-esteem (SE), and an external locus of control (LC). The multigroup LISREL analysis led to the following conclusions: First, previous symptom level was strongly related to current symptom level. The strength of this relationship was independent of SE and LC but modified by N. Secondly, the impact of life situation changes on distress level was moderately strong and similar to what others have reported. Thirdly, a marked modifier effect was found for neuroticism; responsiveness significantly increased with N level. For SE and LC we observed reduced responsiveness among low vulnerability subjects, but the differences did not reach statistical significance. The implications of the findings are discussed.

Adult↗

PubMed1991

Personality in advanced old age: continuity or change?

A longitudinal study of elderly persons found evidence of personality development even in advanced old age. Five traits, similar to traits found in younger persons, were identified. Although considerable continuity was found, change also was apparent. An increase in agreeableness was observed for the old-old, bringing their scores up to the level maintained by the oldest-old. Two traits were stable: satisfaction (65% did not change reliably) and intellect (63% did not change reliably). A decline in extraversion occurred in both age groups. Energetic, in which 40% declined, may be more affected than the other traits by external, environmental circumstances. The study confirms the findings of longitudinal studies of children and younger adults and extends them into the final stages of life.

Age Factors↗

PubMed1994

Cost-effective prostate cancer detection. Reduction of low-yield biopsies. Investigators of the American Cancer Society National Prostate Cancer Detection Project.

BACKGROUND: In hopes of limiting low-yield prostate biopsies, results of digital rectal examination (DRE), transrectal ultrasound (TRUS), prostate specific antigen (PSA) and age-related PSA values, gland-volume-adjusted PSA levels, and longitudinal PSA changes were analyzed to identify their cost-effectiveness as prognostic indicators in screening, biopsy, and follow-up of patients with prostate cancer. METHODS: Twenty-nine hundred men with complete data sets from an initial cohort of 2999 men with an annual follow-up for up to 5 years were examined. Intrapatient PSA and gland-volume variability, optimal PSA operating points (o.p.), and test performance scores were determined for each parameter. Decision analysis was then applied retrospectively to each parameter to determine the cancer detection yield, biopsy requirements, and costs for commonly used detection strategies. RESULTS: For the initial screening decision, the optimal PSA o.p. was 3.0 ng/ml but increased to 5.0 ng/ml in combination with DRE, whereas age-related PSA performed no better than did PSA. The mean intrapatient variability in TRUS gland volume (+5.5 cc) relative to mean volume (34 cc) was 16%, which was less than the 28% (0.64/2.3 ng/ml) relative variability for PSA. For biopsy decisions, using PSA density (PSAD) with a level of 0.12 ng/ml/cc there was no significant difference in accuracy compared with the systematic biopsy of all patients with elevated PSA or age-related PSA levels. Rather than perform systematic biopsy on all patients with PSA levels greater than 4 ng/ml, decision analysis showed that a 16-55% reduction in biopsies could be achieved with a respective cancer loss of 4-25% by limiting biopsy to patients with an increased PSAD level and/or abnormal results of DRE. Using age-related PSA criteria in combination with DRE reduced biopsies by 12% but resulted in minimal cost reductions. The greatest biopsy reduction relative to cancer yield and lowest cost per cancer detected occurred with PSAD-driven biopsy strategies. During follow-up, longitudinal changes in absolute PSA and PSAD levels were significantly better (P < 0.05) than the percentage change in PSA levels per year. CONCLUSIONS: Cost-effective prostate cancer detection with PSA as a parameter is better achieved if screening and biopsy decisions are not linked intimately. A tailored-biopsy approach for patients with disproportionately elevated PSA levels of suspicious DRE results in the greatest biopsy reduction by selecting lower risk groups for more conservative follow-up.

Age Factors↗

PubMed2000

Blood flow changes in the ovarian and uterine arteries in women with normal and polycystic ovaries.

This review summarizes the haemodynamic changes in the ovarian and uterine arteries, as revealed by transvaginal colour Doppler ultrasonography, (i) in women with normal ovaries (group 1), (ii) in women with the polycystic ovary syndrome who ovulate in response to clomiphene citrate (group 2) and (iii) in women with polycystic ovaries who have a regular ovulatory menstrual cycle (group 3). In each group blood flow velocities in the intraovarian arteries increased during the menstrual cycle in the dominant ovary and remained high in the mid-luteal phase. There was no significant change in pulsatility index. In group 2, the longitudinal haemodynamic changes in the intraovarian arteries were similar to those seen in women with normal ovaries. However, the follicular and ovarian stromal blood flow velocities were greater in group 2 compared with the normal group. There was a significant increase in the pulsatility index of the uterine artery during the follicular phase of the menstrual cycle and a subsequent decrease into the mid-luteal phase. Uterine artery pulsatility index was also significantly greater at the baseline ultrasound scan in group 2. In group 3, the longitudinal haemodynamic changes in the intraovarian arteries were similar to those in group 1. Furthermore, the intraovarian vascular changes were similar to those in group 2, but velocities were significantly greater than in group 1. There was an increase in uterine artery pulsatility index during the follicular phase of the menstrual cycle and a subsequent decrease into the mid-luteal phase. The uterine artery Doppler changes were similar to those seen in group 2. In conclusion, women with polycystic ovaries have significant differences in ovarian and uterine artery haemodynamics. Increased ovarian stromal blood flow within the polycystic ovary may help to explain the increased ovarian re-sponsiveness that women with polycystic ovaries show after administration of gonadotrophins.

Journal Article↗

PubMed1993

Change in social support after retirement: longitudinal findings from the Normative Aging Study.

Although retirement is generally thought to lead to a decline in social support due to a loss of social contacts with coworkers, the evidence for this is at best contradictory. This longitudinal study examined change in social support among 1,311 men, participants in the Veterans Administration Normative Aging Study, over a 3-year period. In general, long-term retirees reported the least quantitative social support, and the continuing full-time workers the most; however, change in workforce status produced no apparent effect on quantitative support over the duration of this study. In general, qualitative support showed no retirement effects. We also examined more specific patterns of coworker friendship and again found a pattern similar to that of general quantitative support. The findings support our earlier suggestion of a distinction between retirement as a transition and retirement as a state, and also support the convoy model of social support in late life and the selectivity theory of developmental adaptation to aging.

Adult↗

PubMed2000

Leaves as Shell Structures: Double Curvature, Auto-Stresses, and Minimal Mechanical Energy Constraints on Leaf Rolling in Grasses.

Grass leaves are natural examples of shell structures because they are thin and display a double curvature. An important mechanical property of shells is that changes in longitudinal and transverse curvatures are not independent. The basis of this mechanical coupling is presented using simple diagrams. The relevance of the structural constraints for the processes of hydronastic rolling and developmental unrolling in grass leaves is then reviewed. I show that mechanical constraints can explain a large part of the genetic and developmental variability of hydronastic rolling in grasses, without reference to specific anatomic features such as bulliform cells. Mechanical analysis of a rolled maize mutant also revealed that developmental unrolling is not limited to a pure transverse expansion of hinge cells and involves both longitudinal and transverse dimensional changes in the upper epidermis. Interest in using mechanical models as a tool to reveal structural interactions at the tissue and organ level is discussed, and the importance of Paul Green's biophysical approach to the study of plant morphogenesis is emphasized.

Journal Article↗

PubMed2000

Self-efficacy as a mediator between stressful life events and depressive symptoms. Differences based on history of prior depression.

BACKGROUND: Self-efficacy, a characteristic that is protective against depressive symptoms, may be undermined by stressful life events. AIMS: To estimate the effects of stressful life events on self-efficacy, and to examine self-efficacy as a mediator of the effect of stressful life events on symptoms of depression. METHOD: Using a sample of 2858 respondents from the longitudinal Americans' Changing Lives study, path analyses were used to evaluate interrelationships between self-efficacy, life events and symptoms of depression controlling for a variety of potentially confounding variables. Separate models were estimated for those with and without prior depression. RESULTS: For those with prior depression, dependent life events had a significant, negative impact on self-efficacy. For those without prior depression, life events had no effect on self-efficacy. CONCLUSIONS: For those with prior depression, self-efficacy mediates approximately 40% of the effect of dependent stressful life events on symptoms of depression.

Depression↗

PubMedDate not supplied

Testing keratolytic effect of carbamide in various vehicles.

BACKGROUND: Urea is a natural protein degradation product widely used in keratolytic preparations due to its property to promote fibrinogen decomposition and to act as a proteolytic agent dissolving and denaturing proteins. Preparations containing 20% or 40% urea in commercial ambiphylic bases are widely used to produce keratolysis. At such high concentration urea recrystallization occurs and is separated over the preparation mass, particularly if the urea content is 40%. This was the initial reason to look for a new preparation formulation that would not have the above-mentioned technological inadequacy. Considering urea's water solubility and its high content in the preparations, the most convenient form, in which recrystallisation would not occur, was gel. The aim of this work was to experimentally estimate the influence of the vehicle upon the proteolytic effect of urea on keratin in the human hair model. METHODS: Hair geometrical properties, the change in longitudinal mass, and the change of disruptive force and disruptive hair elongation were measured. RESULTS: The effect of 20% and 40% urea was estimated in three various vehicles, of which two were of organic hydrogel type, and one was an ambiphylic base of mixed type--Basiscreme. CONCLUSION: Keratin proteolysis effects of urea incorporated into various bases, as measured by human hair disruption forces, depended upon the base; preparations containing 20% and 40% urea in Basiscreme (ambiphylic base) had no desired proteolytic effect upon keratin fibers; proteolysis was best expressed bay urea preparations in 3.5% NaCMC gel, and proteolytic effect of these preparations was best expressed in the first hour.

Hair↗

PubMed1995

Prosocial development in late adolescence: a longitudinal study.

Change in prosocial moral reasoning over 15 years, gender differences in prosocial reasoning, and the interrelations of moral reasoning, prosocial behavior, and empathy-related emotional responses were examined with longitudinal data from 17-18- and 19-20-year-olds and data from adolescents interviewed for the first time. Hedonistic reasoning declined in use until adolescence, and then increased somewhat in early adulthood. Needs-oriented and stereotypic reasoning increased until mid-childhood or early adolescence and then declined in use. Direct reciprocity and approval reasoning, which appeared to be on the decline in mid-adolescence in previous follow-ups, showed no decline into early adulthood. Several modes of higher-level reasoning increased in use across adolescence and early adulthood. Females' overall reasoning was higher than males'. Scores on interview and objective measures of prosocial moral reasoning were positively correlated. Consistent with expectations, there was some evidence of relations among prosocial reasoning, prosocial behavior, sympathy, and perspective taking.

Adolescent↗

PubMed1989

Two-year follow-up of changes in clinical chemistry in Singaporean Norplant-2 rod acceptors: haemostatic changes.

A longitudinal study of coagulation parameters was carried out on 100 Singaporean acceptors using Norplant-2 rods for contraceptive purposes. At the end of 2 years of use, results from this study show a return of platelet count to preinsertion level while platelet aggregation remained significantly enhanced. Thus the net effect of these two changes on an increased tendency for thrombosis needs further evaluation. The PT and APTT continued to remain persistently shortened during the period of use. There was also a general fall in fibrinogen and most other coagulation factors during the two years of use. Thus, again, the net effect of these two changes on the exposed potential for hypercoagulation at the end of the first year needs further evaluation throughout the five years of Norplant-2 use.

Blood Coagulation↗

PubMed1990

Clinical report on longitudinal post-eruptive changes in fluorotic enamel observed in 10 cases over a 2 1/2 year period.

The present longitudinal study was conducted on ten children from age 5-6 years to determine the post-eruptive enamel changes of fluorosed permanent incisors. The children were born and reared in an area of Kenya with a water fluoride level of 14-45 parts per million. The incisors were examined and photographed periodically from the time of eruption over a period of 2 1/2 years. It was noted that the fluorosed incisor was intact as it erupted and then it underwent a variety of changes. In some there was mechanical breakdown (pitting) of the chalky white enamel which occurred rapidly initially and then the breakdown slowed down by 2 years. In others, there was smoothening of the pitted enamel resulting in a translucent appearance. Alternatively there was some degree of patchy staining of the enamel without surface breakdown. Much of the cervical 1/3 of the enamel remained intact even in teeth with severe breakdown. In most cases, these changes were bilaterally symmetrical. The possible reasons for these changes are discussed.

Child, Preschool↗

PubMed1997

Apparent change in caseness in longitudinal studies.

Unless positive responses are verified at a second stage of data collection, a questionnaire-based survey has limited ability to assess change in caseness in a longitudinal study of a condition of low prevalence, assuming imperfect validity of the survey instrument.

Health Surveys↗