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PubMed1998

A longitudinal study of the pathophysiological changes in single human thenar motor units in amyotrophic lateral sclerosis.

The sequence of pathophysiological changes in amyotrophic lateral sclerosis (ALS) at the single motor unit (MU) level is not well understood. Using a recently described technique, a comprehensive range of physiological properties in two thenar MUs in ALS were intensively studied. In the first MU, despite a marked decline in the ability of the subject to voluntarily recruit the MU, the physiological properties of this MU remained remarkably stable over a 2-year period. In contrast, the physiological properties of the other MU declined rapidly over 5 months despite the fact that this MU could be recruited with ease throughout the study period. These differences between the progressively dysfunctional changes in these two MUs illustrates the value of such longitudinal studies of specific MUs in improving our understanding of the evolution of changes in single motoneurons in ALS. The broader application of longitudinally tracking the pathophysiological changes of the surviving MUs may prove to be a sensitive measure of disease progression and in evaluating the effectiveness of treatments.

Action Potentials↗
PubMedDate not supplied

Changes in diagnosis in a 9-year national longitudinal sample.

Studied are changes in diagnosis in a random sample of 10% of all first admissions to psychiatric hospitals and psychiatric wards of general hospitals in Israel from 1983 to 1990 with follow-up evaluation to 1991. This included 4,570 hospitalizations of 2,220 patients. Data were extracted from the National Psychiatric Case Registry of the Ministry of Health. Almost 59% of the sample had one admission, 18% had two, 9% had three, and 14% had four or more. From the first admission to the last discharge (a mean of 2.15 years), 59.2% of the patients' diagnoses did not change. In 89.46% of the cases in which the diagnosis changed, the changes took place during the first admission. Diagnostic change differed between diagnostic groups. In descending order of stability in diagnosis from the first admission to the last discharge were neurotic and personality disorder (73.6%), mental retardation (73.5%), schizophrenia (73.0%), organic conditions (70.6%), affective disorders (66.2%), substance abuse (65.6%), childhood disorders (60%), paranoid disorder (43.6%), other nonorganic psychosis (30.3%), and V-codes (25.0%). The average level of diagnostic agreement between the first admission and the last discharge was a kappa of .52. The average length of stay for patients whose diagnosis became more severe was considerably longer than for patients whose diagnosis became less severe or did not change in level of severity. Older age was related to less change in diagnosis. For patients aged less than 18 years, diagnosis changed in 46.7% of the cases, for patients aged 19 to 44, 31.2%, and for patients older than 45, 27.8%.

Adolescent↗
PubMedDate not supplied

Adrenoceptor and cholinoceptor mediated effects in the isolated urethra of cat and guinea-pig.

1. Preparations of isolated bladder-urethral junction from cats and guinea-pigs were suspended in Krebs solution (37 degrees C) which was bubbled with carbogen. The urethral lumen was perfused at a very low rate (1-3 ml/h) with Krebs solution. Resistance to flow and changes in longitudinal tension (initial setting 0-5 g) were recorded. In additional experiments, tension changes in urethral circular muscle preparations were registered. 2. The urethral preparations had a basal resistance to flow within the range 5-20 cm H2O. They had a spontaneous contractile activity that was unaffected by atropine 0-1 mug/ml, phenoxybenzamine 0-1 mug/ml, and tetrodotoxin 0-1-0-5 mug/ml, suggesting it was of myogenic origin. 3. The basal characteristics and the drug-induced changes in the perfused urethras were independent of whether the longitudinal tension was recorded isometrically or isotonically, or whether the perfusion was made retrograde or antegrade. Passive changes in longitudinal tension between 0-5 and 2-0 g did not affect the resistance to flow through the urethra. 4. Adrenaline and noradrenaline, 0-01-1 mug/ml, increased longitudinal tension and resistance to flow in the perfused preparations. The effects, which were sustained and concentration-related, were blocked or reversed into inhibition in the presence of phenoxybenzamine, 0-1 mug/ml. This finding suggests that the stimulatory effects were mediated via alpha-receptors. 5. Isoprenaline, 0-001-0-005 mug/ml, relaxed and inhibited the activity in the cat urethral smooth muscle and decreased the resistance to flow both under basal conditions and when the urethra was contracted by noradrenaline or acetylcholine. The inhibitory effects were blocked by propranolol, 0-1 mug/ml, suggesting that they were mediated via beta-receptors. In guinea-pig preparations, no effect of isoprenaline was observed. 6. Acetylcholine, 0-02-0-5 mug/ml, increased the longitudinal tension and the resistance to flow through the urethras. The latter effect was less pronounced than that produced by noradrenaline, especially in the guinea-pig preparations. Noradrenaline was also more effective than ecetylcholine in contracting the circular muscle of the urethra. The effect of acetylcholine was blocked by atropine, 0-1 mug/ml, suggesting that the contractions were mediated through muscarinic cholinoceptors.

Acetylcholine↗
PubMedDate not supplied

Analysis of longitudinal marginal deterioration of ceramic inlays.

This study quantitatively and morphologically analyzed and clarified the longitudinal marginal changes of ceramic inlays and determined the mechanism for those changes. Epoxy replicas of 15 Class II ceramic inlays in permanent premolars prepared at baseline, 6, 12, 24, 48, 72 and 96 months after placement were selected. A CCD optical laser scanner was employed to measure quantitative changes in the occlusal surfaces of restored teeth. Longitudinal cross-sections of marginal areas of a ceramic inlay were computed, and two profiles of the same location obtained at different periods were superimposed using software. The area enclosed by the two profiles obtained at different periods was defined as the quantitative marginal change, and both the area and maximum depth in the area enclosed were calculated with picture analysis software. The marginal deterioration pattern was analyzed by drawing a longitudinal curve of quantitative change for each restoration. Morphological observation was carried out by scanning electron microscopy at magnifications from 20x to 75x. Quantitative measurement and morphological observation identified a sequential three-stage pattern of marginal deterioration; initial rapid progress of wear of resin composite cement in the first stage, followed by a second stage without any remarkable visible change, then rapid progression of microfractures of ceramics and/or enamel in the third stage. Boundaries between the first and second stage were found in the six and 21-month period, and those between the second and third stage at 72 months. It was concluded that longitudinal marginal deterioration of fired ceramic inlays progressed in a sequential three-stage pattern.

Dental Porcelain↗
PubMed1977

[Relations between weight changes and various biological parameters. Results of a longitudinal epidemiological survey].

Weight changes over a three year period were measured on a group of about 1400 working men aged 46 to 52 years and related to several biological parameters (cholesterolemia, triglyceridemia, uricemia, glycemia and blood pressure). We observed: a) a slight increase in mean weight over the three year period; b) significant correlations between weight change and changes in these biological parameters. These results are compared to those found in cross sectional studies. Their implications for public health and prevention of ischemic heart disease are discussed.

Blood Glucose↗
PubMed2003

A longitudinal study of antenatal changes in lung function tests and importance of postpartum exercises in their recovery.

A study of changes in lung function tests during pregnancy was undertaken in fifty pregnant women beginning from third month of gestation. Fifty nonpregnant age and height matched women formed the controls. Forced Vital Capacity (FVC), Timed Vital Capacity (FEV1), Inspiratory Capacity (IC), Expiratory Reserve Volume (ERV) and peak Expiratory Flow Rate (PEFR) were performed in each month of pregnancy. However ten subjects were not available for follow-up during postpartum period. Remaining forty women were divided into two groups of twenty each. Group I performed daily graded active exercises to strengthen the anterior abdominal wall muscles. Group II women did not perform any exercises. It was observed that the antenatal changes in percent FVC and FEV1 were insignificant, but the decline in ERV and PEFR were very highly significant (P < 0.001) and the increment in IC was significant (P < 0.05). In the postpartum period the percentage variation of values in group I was less than 5% from controls (P > 0.05) and in group II it was 15-20% from controls (P < 0.05), resulting in a significant variation in group II women as compared to the controls. It is concluded that there are adaptive changes in lung functions in the antenatal period. We stress the importance of regular graded active exercises in the postpartum period for the speedy recovery of these changes.

Adult↗
PubMed1990

A longitudinal study of respiratory changes in normal human pregnancy with cross-sectional data on subjects with pregnancy-induced hypertension.

Respiratory frequency, tidal volume, minute ventilation, oxygen consumption, carbon dioxide production, and end-tidal carbon dioxide tension were measured longitudinally during pregnancy and post partum in 20 normal subjects with a computer-assisted mass spectrometer. Resting tidal volume, minute ventilation, oxygen consumption, and carbon dioxide production increased during pregnancy. End-tidal carbon dioxide tension fell progressively during pregnancy. Respiratory exchange ratio was 0.9 at 36 to 39 weeks' gestation and 0.8 at 5-13 weeks post partum. Respiratory frequency did not change during pregnancy. The increase in minute ventilation is in excess of the increase of carbon dioxide production and the resultant fall in end-tidal carbon dioxide tension reflects a fall in systemic arterial blood carbon dioxide tension. The greater respiratory exchange ratio during late pregnancy as compared with post partum also reflects this hyperventilation during pregnancy. Fourteen subjects with pregnancy-induced hypertension studied cross-sectionally failed to show any difference in the respiratory variables measured when compared with normotensive subjects at a similar length of gestation.

Adult↗
PubMed1996

[Longitudinal study on the determinants of career choice among young women: to continue or change jobs].

This longitudinal study over the five-year period of 1988-1993 seeks to ascertain the determinants of young women's career choice-continued employment with same organization or changing employment organization. Another purpose of the study is to compare the characteristics between two types of career choices. The sample consists of 204 employed women with a variety of occupations who are in their 20s and early 30s. They previously or currently work in Tokyo. Using chi-square tests, t-tests, and canonical discriminant analyses it is found that the determinant to continue employment with same organization is the desire for a lifetime career. The determinants of changing employment organization are shorter-educational-training professional jobs and high income. The comparison of the characteristics of the two types of women in 1993 shows that a woman who continues employment with the same organization for 7-8 years has a higher egalitarian sex role attitude, higher income, is a mother, and is in a managerial position. The woman who changes employment organization is older and has a shorter-educational-training-professional job.

Age Factors↗
PubMed2006

Changes in surgical therapy for Crohn's disease over 33 years: a prospective longitudinal study.

INTRODUCTION: Changes in surgery for Crohn's disease were analyzed in a single institution over a period of 33 years. MATERIALS AND METHODS: The data of all patients undergoing abdominal surgery for Crohn's disease between 1970 and 2002 were collected prospectively in an electronic database. The study period was divided into three periods of 11 years, each (group 1, 1970-1980; group 2, 1981-1991; group 3, 1992-2002). RESULTS: There was an increase in patients' age at time of hospital admission from 32.0+/-0.9 to 32.4+/-0.5 and 37.7+/-0.7 years, in the duration of disease from 4.9+/-0.3 to 7.3+/-0.3 and 8.8+/-0.5 years, and in the number of drug-induced remissions before surgery from 3.1+/-0.5 to 6.1+/-0.2 and 4.9+/-0.3 in groups 1, 2, and 3, respectively (p<0.01). The rates of elective surgery compared to urgent or emergency surgery increased from 69.5 to 81.4 and 80.9% in the corresponding groups (p<0.01). A significant decrease in hospital mortality was observed. The analysis of Crohn's complications demanding surgery revealed a significant increase of rates of stenosis and subileus. Furthermore, there was a significant increase in serious acute complications like free bowel perforations and peritonitis. CONCLUSION: Improved medical treatment may lead to higher rates of elective operations. However, prolonged conservative treatment may also increase the number of serious complications before surgery. Therefore, a multidisciplinary approach with early involvement of the surgeon is important to avoid any delay in indication to surgery.

Adult↗
PubMed1996

A longitudinal study of biological changes with age among the Brahmins of Calcutta.

In this paper, the individual biological sequence of change with age in a sample taken in metropolitan city, Calcutta, West Bengal, is discussed. The study comprises a few anthropometric measurements (stature, weight, biacromial breadth, nasal length, nasal breadth, upper facial height) taken on the same population at an interval of five years (first in the year 1982 and again in the year 1987). The study reveals that the amount of increment or decrement of some characters (the above mentioned traits) are different for different chronological age; and these differences can only be identified with the help of a longitudinal study which is free from the effect of secular change in the younger generations.

Adult↗
PubMed1994

Seven-year longitudinal population study of change in gamma-glutamyltransferase: the Tromsø Study.

The determinants of individuals changes in gamma-glutamyltransferase (GGT) were examined in 1,171 males and 1,267 females in Tromsø, Norway, according to a 7-year longitudinal design. The basis for the study was two comprehensive population surveys in 1979-1980 and 1986-1987. In both sexes, increase in GGT displayed a strong association with increase in body mass index and hours fasting. In males, increase in GGT also showed a strong association with increase in frequency of inebriation and with decrease in physical activity. In females, increased systolic blood pressure, starting to use oral contraceptives, the occurrence of menopause, and decrease in consumption of boiled coffee were associated with increase in enzyme levels. The strengths of the associations were considerably greater in this longitudinal design compared with earlier cross-sectional studies.

Adult↗
PubMed1998

Changes in throwing by older adults: a longitudinal investigation.

This investigation examined change in a motor pattern requiring multisegmented coordination in older adults. The overarm throw was observed longitudinally in 8 elderly individuals over 7 years. Data were evaluated using Roberton's (Roberton & Halverson, 1984) movement components. Contrasting the assumed pattern of aging, only small declines in movement form were observed. Individual cases revealed additional, noncategorizable declines within component categories, including slower movement speed and decreased range of motion. Increased trial-to-trial variability also was associated with change. These changes suggested that elderly participants coordinated their movements in a manner similar to younger participants but controlled them differently. The small changes observed in this investigation suggest that performance, at least for some skills, is more stable than traditionally assumed.

Aged↗
PubMed2001

Changes in the Epilimnetic Bacterial Community Composition, Production, and Protist-Induced Mortality along the Longitudinal Axis of a Highly Eutrophic Reservoir.

We studied changes in the epilimnetic bacterial community composition (BCC), bacterial biomass and production, and protistan succession and bacterivory along the longitudinal axis of the canyon-shaped, highly eutrophic Sau Reservoir (NE Spain) during two sampling campaigns, in April and July 1997. Longitudinal changes in BCC from the river inflow to the dam area of the reservoir were detected by using oligonucleotide probes targeted to the kingdom Bacteria, to the alpha, beta, and gamma subclasses (ALFA, BETA, and GAMA) of the class Proteobacteria, and to the Cytophaga/Flavobacterium (CF) cluster. In general, the inflow of the organically loaded Ter river, with highly abundant allochthonous bacterial populations, induced a clearly distinguishable longitudinal succession of the structure of the microbial food web. The most dynamic changes in microbial parameters occurred at the plunge point, the mixing area of river water and the reservoir epilimnion. Changes within members of BETA and CF were the most important in determining changes in BCC, bacterial abundance and biomass. Much less relevant changes occurred within the less abundant ALFA and GAMA bacteria. From the plunge point downstream, we described a significant shift in BCC in the form of decreased proportions of BETA and CF. This shift spatially coincided with the highest values of heterotrophic nanoflagellate bacterivory (roughly doubled the bacterial production). CF numerically dominated throughout the reservoir without any marked longitudinal changes in their mean cell volume. In contrast, very large cells affiliated to BETA clearly dominated in the allochthonous bacterial biomass brought by the river. BETA showed a marked downstream trend of decreasing mean cell volume. We conclude that the observed BCC shift and the longitudinal shift in food web structure (bacteria-heterotrophic nanoflagellates-ciliates) resulted from highly complex interactions brought about by several major factors: varying hydrology, the high localized allochthonous input of organic matter brought by the river, downstream changing substrate availability, and selective protistan bacterivory.

Journal Article↗
PubMed1999

Cross-sectional versus longitudinal estimates of cognitive change in nondemented older people: a CERAD study. Consortium to Establish a Registry for Alzheimer's Disease.

OBJECTIVES: To investigate the effect of increasing age on cognition in nondemented older people. DESIGN: A cross-sectional and longitudinal analysis. PARTICIPANTS: A total of 454 control subjects for Alzheimer's cases from the cohort assembled by the Consortium to Establish a Registry for Alzheimer's Disease (CERAD). MEASUREMENT: The Mini-Mental State Examination (MMSE) to assess cognitive function. RESULTS: Cross-sectional estimates were derived by generalized linear models and longitudinal estimates by generalized estimating equations. The cross-sectional model indicated a small but significant decline in MMSE of -.4 points per 10 years. The longitudinal model indicated a small but significant increase in MMSE of about +.6 points per 10 years. Evidence of an early learning effect and nonrandom dropout exists. CONCLUSIONS: The question of "normal" aging can be approached by considering cross-sectional information and, usually separately, longitudinal information. This study does both using recently developed statistical methods. We conclude that there is a small but significant decline in scores on the MMSE with increasing population age. The effect can be masked in longitudinal cohorts by a learning effect (especially early in follow-up) and other factors associated with repeated testing.

Aged↗