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Determination of peak expiratory flow.

It is still unknown whether peak expiratory flow (PEF) is determined by "wave speed" flow limitation in the airways. To investigate the influences of airway mechanical properties on PEF, five healthy adults performed maximal forced expiratory effort (MFEE) manoeuvres, in the standard manner and following breathholds at total lung capacity (TLC) of 2 s and 10 s. Oesophageal pressure (Poes) was measured as an index of respiratory effort. Subjects also performed a MFEE following a 10 s breathhold during which intrathoracic pressure was voluntarily raised by a Valsalva manoeuvre, which would increase transmural pressure and cross-sectional area of the extrathoracic airway. Additional MFEEs were performed with the neck fully flexed and extended, to change longitudinal tracheal tension. In separate studies, PEF was measured with a spirometer and with a pneumotachograph. Breathholds at TLC (2 s and 10 s), and neck flexion reduced PEF by a mean of 9.8% (SD 2.9%), 9.6% (SD 1.6%), and 8.7% (SD 2.8%), respectively, when measured with the spirometer. The same pattern of results was seen when measured with the pneumotachograph. These reductions occurred despite similar respiratory effort. Voluntarily raising intrathoracic pressure during a 10 s breathhold did not reverse a fall in PEF. MFEE manoeuvre with neck extension did not result in an increase in PEF, the group mean % changes being -3.0% (SD 5.0%). We conclude that these results do not allow the hypothesis that "wave-speed" (Vws) is reached at PEF to be rejected. A breathhold at TLC could increase airway wall compliance by allowing stress-relaxation of the airway, thus reducing the "Vws" achievable.

Adult↗

Terminal decline and cognitive performance in very old age: does cause of death matter?

Cross-sectional differences and longitudinal changes in cognitive functioning in relation to mortality across a 7-year follow-up period, with 3 times of measurement, were examined in a population-based sample of very old adults. The authors also sought to determine whether cause of death (cerebro/cardiovascular disease [CVD]; non-CVD) modified the magnitude of mortality-related cognitive deficits. Cognitive performance was indexed by tests of general cognitive ability, episodic memory, primary memory, verbal fluency, and visuospatial ability. Results indicated cross-sectional differences on all domains of functioning, with persons who would die within 3 years after baseline testing performing more poorly. Longitudinally, greater decrements were observed on all domains for persons who would die after the first follow-up period, as compared with survivors. Cause of death failed to modify the magnitude of the cross-sectional and longitudinal deficits. The pattern of results point to the general nature of this phenomenon.

Aged↗

Lung function in military oxygen divers: a longitudinal study.

It is increasingly recognized that professional diving may elicit adverse long-term effects on the lungs, but conflicting results have been reported from distinct diving cohorts. This study reports the longitudinal change in lung function in professional divers who employ closed-circuit oxygen rebreathing apparatuses. All oxygen divers who attended the German Naval Medical Institute between 1994 and 1999 for regular medicals underwent spirometry and were entered if they had at least two follow-up examinations. Forced expiratory flows and volumes at baseline and at maximum follow up were compared. There were 39 divers who presented at least 3 times during a median period of 5.8 (2.7-8) yr. Forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) amounted to 4.86 +/- 0.62 L and 5.89 +/- 0.67 L at baseline, and 4.83 +/- 0.64 L and 5.87 +/- 0.69 L at maximum follow up, respectively. The change over time was statistically not significant. Substantial exposure to elevated oxygen partial pressure while diving is not associated with an accelerated decline in lung function. Factors other than hyperoxia (e.g., venous gas microemboli and altered breathing gas characteristics) may account for the long-term effects that have been found in professional divers.

Adult↗

Discrepancies between longitudinal and cross-sectional change in ventilatory function in 12 years of follow-up.

We compared the age dependence of cross-sectional and longitudinal changes in ventilatory function. FEV1, FVC, and data on chronic respiratory symptoms were obtained from 4,395 adults in a longitudinal survey of normal populations in two different areas in the Netherlands. They participated in up to five surveys at 3-yr intervals between 1972 to 1973 and 1984 to 1985. The ventilatory function in the oldest cohorts is substantially lower than might have been expected from the longitudinal change in the youngest cohorts. This holds for males and females, smokers and nonsmokers, subjects with or without symptoms, and for both survey populations. The robustness of the findings is demonstrated by various data-analytic strategies or omitting one or two of the five surveys from the analysis. Selective loss to follow-up cannot explain the discrepancy. It is concluded that the main differences between our longitudinal and cross-sectional findings may be due to a cohort effect. The implication is that in longitudinal studies of populations at risk, reference equations based on cross-sectional surveys may overestimate longitudinal change and hence lead to underestimating effects of exposure. Similarly, in clinical studies, accelerated decline in ventilatory function may be underrated if it is compared with cross-sectional standards. In older people at any one age the ventilatory function seems to improve in successive birth cohorts.

Adult↗

Individual trajectories of cognitive decline in patients with dementia of the Alzheimer type.

The course of decline was studied in 16 patients with probable or definite dementia of the Alzheimer type (DAT) over 2.7 to 6.8 years from first to last evaluation. Overall severity of dementia was measured with the Wechsler Adult Intelligence Scale (WAIS), the Dementia Rating Scale (DRS), and the Mini-Mental State Examination (MMSE), at approximately annual intervals. An initial plateau phase, during which language and cognitive functions did not change for periods of 9 to 35 months, was observed in 5 patients who initially had an isolated memory impairment without significant impairment of nonmemory language or visuospatial function. Once nonmemory functions began to decline, the rate of decline was remarkably steady in most individual patients but varied markedly among patients. The initial rate of decline after the plateau phase, as measured with the WAIS and DRS, was a significant predictor of subsequent rate in individual patients (r = .66, p less than .01, and r = .67, p less than .01, for the WAIS and DRS, respectively). The MMSE was a less reliable measure of longitudinal change in dementia severity and did not predict future rates of decline (r = .29). These results demonstrate a biphasic trajectory of decline in patients with DAT. Stable interindividual differences in rate of decline may provide a basis for designing more sensitive studies of treatments intended to slow or halt the progress of DAT.

Adult↗

Neuroanatomical abnormalities before and after onset of psychosis: a cross-sectional and longitudinal MRI comparison.

BACKGROUND: Psychotic disorders, such as schizophrenia, are associated with neuroanatomical abnormalities, but whether these predate the onset of symptoms or develop progressively over the course of illness is unclear. We investigated this issue with MRI to study people with prodromal symptoms who are at ultra high-risk for the development of psychosis. METHODS: We did two comparisons, cross-sectional and longitudinal. For the cross-sectional comparison, 75 people with prodromal signs of psychosis were scanned with MRI. After at least 12 months of follow-up, 23 (31%) had developed psychosis and 52 (69%) had not. Baseline MRI data from these two subgroups were compared. For the longitudinal comparison, 21 of the ultra high-risk individuals were scanned again with MRI after at least 12 months. Ten of these had developed psychosis and 11 had not. MRI data from baseline and follow-up were compared within each group of people. FINDINGS: In the cross-sectional comparison, compared with people who did not develop psychosis, those who did develop the disorder had less grey matter in the right medial temporal, lateral temporal, and inferior frontal cortex, and in the cingulate cortex bilaterally. In the longitudinal comparison, when re-scanned, individuals who had developed psychosis showed a reduction in grey matter in the left parahippocampal, fusiform, orbitofrontal and cerebellar cortices, and the cingulate gyri. In those who had not become psychotic, longitudinal changes were restricted to the cerebellum. INTERPRETATION: Some of the grey-matter abnormalities associated with psychotic disorders predate the onset of frank symptoms, whereas others appear in association with their first expression.

Adult↗

Alterations in temporal patterns of heart rate variability after coronary artery bypass graft surgery.

BACKGROUND: Preliminary studies have indicated that autonomic nervous system dysfunction may be present in patients after cardiac surgery. The purpose of this study was to evaluate cardiac autonomic nervous system function, as assessed by analysis of heart rate variability (HRV), in adult patients undergoing uncomplicated coronary artery bypass graft surgery. METHODS: Longitudinal changes in HRV were determined perioperatively by continuous electrocardiographic monitoring in 40 adult patients undergoing elective coronary artery bypass graft surgery and were compared with HRV in two groups of control subjects: 15 patients undergoing nonthoracic major vascular surgery and 19 healthy volunteers. Exclusion criteria were diabetes, renal failure, recent or perioperative myocardial infarction, or use of inotropic drugs. HRV data during electrocardiographically documented episodes of myocardial ischemia were omitted. RESULTS: There were no differences in any measurement of preoperative HRV between groups during the day, but HRV was greater at night (12:00 AM to 5:00 AM) in volunteers than in patients in either surgical group. In the hour after induction of anesthesia (before cardiopulmonary bypass), the components of HRV were decreased compared with those in the preoperative daytime but were similar in the two surgical groups. After surgery, HRV in the group undergoing nonthoracic vascular surgery remained at about the same level as that observed after induction of anesthesia, whereas in the group undergoing coronary artery bypass graft surgery, HRV was further reduced and was approximately 40-50% less than that in the vascular surgery group (P < 0.05). In the coronary artery bypass group, the reduction in HRV compared with the preoperative daytime measurements persisted on postoperative day 5. CONCLUSIONS: HRV is reduced after uncomplicated coronary artery bypass graft surgery. Although we cannot exclude the effects of uncontrolled variables in this reduction of postoperative HRV, the observed changes in HRV did not appear to result from general anesthesia, perioperative stress responses, and other factors associated with the early postoperative period. These data are consistent with the supposition that cardiac autonomic nervous system function is impaired after cardiac surgery.

Autonomic Nervous System↗

Trends in blood pressure levels, prevalence, awareness, treatment, and control of hypertension in the Czech population from 1985 to 2000/01.

OBJECTIVE: To assess trends in blood pressure (BP) levels, prevalence, awareness, and control of hypertension in the Czech population from 1985 to 2000/01. DESIGN: Five independent cross-sectional population surveys conducted in 1985, 1988, 1992, 1997/98, and 2000/01. SETTING: Six, mostly rural, districts of the Czech Republic (Praha-východ, Benesov, Pardubice, Chrudim, Cheb, and Jindrichův Hradec). PARTICIPANTS: Men and women aged 25-64 years randomly selected from six districts using the National Population Register/General Health Insurance Company Register (covering, by law, all citizens). The total number of participants was 11 726. MAIN OUTCOME MEASURES: We assessed the mean systolic BP, diastolic BP and pulse pressure, prevalence of hypertension (systolic BP > or = 140 mmHg and/or diastolic BP > or = 90 mmHg, or current treatment with antihypertensive drugs), awareness, treatment, and control of hypertension. RESULTS: Mean systolic BP, diastolic BP, and pulse pressure decreased significantly over a period of 15/16 years. This was associated with a significant decrease in the prevalence of hypertension (from 47.1 to 39.1%, P < 0.001) and with an increase in its awareness (from 49.5 to 67.2%, P < 0.001), use of antihypertensive medication (from 29.3 to 49.3%, P < 0.001), and hypertension control (from 3.9 to 17.0%, P < 0.001). Despite having lower BP values and prevalence of hypertension, females showed higher awareness of the disease, and were more frequently taking antihypertensive medication, and their hypertension was better controlled. CONCLUSION: The reduction in population BP and improved control of hypertension may have contributed to the decrease in cerebrovascular and coronary heart disease mortality in the Czech Republic. The positive longitudinal changes seen in the MONICA regions need not necessarily reflect the situation in the country as a whole. The situation is far from being optimal; a major problem is inadequate treatment of hypertension

Adult↗

Longitudinal analysis of lactate threshold in male and female master athletes.

PURPOSE: The lack of relationship between lactate threshold (LT) and running performance in older runners, and the increase in LT with age, has not been previously studied in a longitudinal design. We evaluated the cross-sectional and longitudinal changes in LT with age and compared the changes in LT with changes in performance variables. METHODS: Fifty-one male and 23 female runners (39-77 yr) performed two graded treadmill exercise tests with minute-by-minute venous blood lactate analysis, separated by 5.8 +/- 1.6 yr (mean +/- SD). Body composition was determined by hydrodensitometry and training history by questionnaire. RESULTS: There was no change in LBM over time, but significant decreases in [OV0312]O(2max) and training volume irrespective of age and gender (P < 0.05). LT as a percent of [OV0312]O(2max) increased with age (P < 0.05), demonstrated poor stability over time (r = 0.29, P = 0.01) compared with other parameters measured, and changes in LT were not related to changes in fitness or performance. CONCLUSION: Based upon these findings, we conclude that the LT may be less precise than [OV0312]O(2max) or performance in the prescription of exercise intensities or as an evaluation tool in older individuals.

Adaptation, Physiological↗

Teaching and learning end-of-life care: evaluation of a faculty development program in palliative care.

PURPOSE: To evaluate the effectiveness of the Program in Palliative Care Education and Practice (PCEP), an intensive faculty development program at Harvard Medical School. METHOD: PCEP is a two-week program offered annually with two on-site sessions in Boston, MA, and an interim period distance-learning component. Training integrates palliative care clinical skill development, learning theory and teaching methods, and leadership and organizational change. Longitudinal surveys (preprogram, retrospective preprogram, and postprogram) of participants from 2000-03 assessed self-reported preparation in providing and teaching palliative care; teaching and patient care practices; and satisfaction with program. RESULTS: The response rate was 96% (n=149) for Session I and 72% for both Session I and II (n=113). Questionnaire responses demonstrated statistically significant improvements with large effect sizes (range 0.7-1.8) on nearly all measures. Preparation increased from 3.0+/-1.1 to 4.2+/-0.7 for providing end-of-life care (1=not well prepared, 5=very well prepared), and from 2.6+/-1.0 to 4.3+/-0.7 for teaching this topic. Respondents reported behavioral changes in patient care and teaching; e.g., after the program, 63% noted that, specifically as a result of attending the course, they encouraged learners to reflect on their emotional responses to dying patients, and 57% conducted experiential exercises (e.g., role-play). Eighty-two percent rated the experience as "transformative," and many responses to open-ended items described powerful learning experiences. Participants rated the program highly (4.9+/-0.1, 1=lowest, 5=highest rating). CONCLUSIONS: Integrating clinical content with learning about educational methods is an efficient and effective approach to enhancing clinical faculty's capacity to model and teach clinical care. This program offers an educational model that engages practitioners, stimulates changes in practice, and offers opportunities for reflection and professional revitalization.

Academic Medical Centers↗

Increased intracranial pressure after coronal suturectomy in craniosynostotic rabbits.

It has been suggested that the complications associated with intracranial hypertension in craniosynostotic infants may be managed with surgical release of the synostosed sutures. However, both postoperative increases and decreases in intracranial pressure (ICP) have been reported in heterogeneous samples of infants with syndromic and nonsyndromic craniosynostoses. The present study was designed to describe longitudinal changes in ICP in a homogeneous sample of rabbits with uncorrected and corrected familial coronal suture synostosis and compare them with age-matched normal control rabbits. Fifty-three rabbits were divided into three groups: normal rabbits (n = 28), rabbits with uncorrected bilateral coronal suture synostosis (n = 9), and rabbits with bilateral coronal suture synostosis with coronal suturectomy at 25 days of age (n = 16). ICP was measured at 25 and 42 days of age using a Codman epidural microtransducer. Results revealed that rabbits with uncorrected craniosynostosis had significantly (P < 0.05) higher ICP at 25 days of age than normal control rabbits by approximately 86%. However, by 42 days of age, ICP in normal rabbits increased by 75%, whereas ICP in rabbits with uncorrected craniosynostosis decreased by 69% over the same time. Synostotic rabbits with coronal suturectomy showed a 50% decrease in ICP immediately after surgical release and then followed the normal, age-related ICP pattern, which significantly increased by 75% at 42 days of age. Results suggest that, in the rabbit model, the postsuturectomy rise in ICP may simply be normal, age-related changes, although a longer follow-up will be needed to determine the recurrence of pathological ICP. Possible multifactorial explanations for intracranial decompression and compensation in the craniosynostotic rabbit model are also discussed.

Analysis of Variance↗

Stability of prevalences of mental disorders in a normal population cohort followed for 16 years.

Results from the Finnish UKKI study on longitudinal changes in prevalences of different mental disorder categories in a population cohort (n = 723) are presented. The subjects were investigated three times: in the original survey during 1969-71, and in two follow-ups (5 and 16 years after the original survey). The prevalence of all mental disorders was about 30% in all phases of the study, although the prevalence of psychoses increased from 1.1% to 3.5%. A special focus of interest was the changes in different 10-year birth cohorts during the 16 years. The results indicated that the youngest birth cohort (born in 1945-54) did not reach the same prevalence level of all mental disorders combined as the birth cohort 10 years older upon reaching the same age.

Adolescent↗

Personality characteristics as predictors and sequelae of surgical and conventional orthodontics.

The aims of this study were to determine the effects of surgical and conventional orthodontics on patients' body image and self-esteem and the association between personality characteristics and postoperative reports of pain, paresthesia, swelling, and satisfaction among 90 patients who underwent surgical orthodontics. Patients who underwent surgery completed questionnaires before their operations and up to 6 months after surgery. Self-esteem and body image were compared longitudinally between these patients and 33 persons who were undergoing orthodontic treatment only and 33 persons who had decided against treatment. Results suggest that patients' self-esteem, body image, and degree of extroversion are unrelated to postsurgical satisfaction and discomfort. Neuroticism was correlated with satisfaction, so that patients who scored in the higher range on a scale of neuroticism were less satisfied immediately after surgery and at removal of fixation wires. Neurotic patients also were more likely to complain of pain and swelling 6 months after surgery. Surgical patients held a more negative facial image and were more introverted than those in the other two groups but were similar in other personality traits before surgery. Both surgical and orthodontic patients improved significantly in body image over time, with the greatest increase among the former. Similar shifts in self-esteem occurred for the three groups, suggesting that surgery per se may not be the major determinant of longitudinal changes in self-esteem. Notably, the positive effect of surgery and orthodontic treatment on body image is an important motive for many persons seeking treatment. Results of this study provide important insights into how to prepare and counsel patients undergoing orthodontic treatment with and without surgery.

Body Image↗

Body awareness and medical care utilization among older adults in an HMO.

This study investigated the association between the disposition of body awareness and medical care utilization among older adult members of a health maintenance organization (HMO). Results indicated that higher levels of body awareness are associated significantly with longitudinal increases in the volume of patient-initiated illness visits to the HMO, and with a greater likelihood of patient-initiated contact with the hospital emergency room, controlling for prior utilization, self-reported health status, and other factors. In contrast, body awareness was not associated significantly with longitudinal changes in physician-initiated follow-up visits, internal referrals, external referrals, or hospital inpatient days. Other findings indicated that higher levels of patient-initiated utilization were associated with greater physician-initiated utilization, controlling for prior utilization. These results illustrate how patient-initiated utilization may influence subsequent physician-initiated utilization.

Aged↗

Integration of quantitative DCE-MRI and ADC mapping to monitor treatment response in human breast cancer: initial results.

PURPOSE: The objective of this study was to assess changes in the water apparent diffusion coefficient (ADC) and in pharmacokinetic parameters obtained from the fast-exchange regime (FXR) modeling of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) during neoadjuvant chemotherapy in breast cancer. MATERIALS AND METHODS: Eleven patients with locally advanced breast cancer underwent MRI examination prior to and after chemotherapy but prior to surgery. A 1.5-T scanner was used to obtain T1, ADC and DCE-MRI data. DCE-MRI data were analyzed by the FXR model returning estimates of K(trans) (volume transfer constant), v(e) (extravascular extracellular volume fraction) and tau(i) (average intracellular water lifetime). Histogram and correlation analyses assessed parameter changes post-treatment. RESULTS: Significant (P < .05) changes or trends towards significance (P < .10) were seen in all parameters except tau(i), although there was qualitative reduction in tau(i) values post-treatment. In particular, there was reduction (P < .035) in voxels with K(trans) values in the range 0.2-0.5 min(-1) and a decrease (P < .05) in voxels with ADC values in the range 0.99 x 10(-3) to 1.35 x 10(-3) mm2/s. ADC and v(e) were negatively correlated (r = -.60, P < .02). Parameters sensitive to water distribution and geometry (T(1), v(e), tau(i) and ADC) correlated with a multivariable linear regression model. CONCLUSION: The analysis presented here is sensitive to longitudinal changes in breast tumor status; K(trans) and ADC are most sensitive to these changes. Relationships between parameters provide information on water distribution and geometry in the tumor environment.

Antineoplastic Agents↗

Follow-up study of peritoneal fluid kinetics in infants and children on peritoneal dialysis.

OBJECTIVES: To study longitudinal changes in transcapillary ultrafiltration (TCUF) and marker clearance (MC), as a reflection of lymphatic absorption, in children on peritoneal dialysis (PD). To present data on fluid kinetics in infants younger than 2.5 years, using an intraperitoneal volume of 1200 mL/m2 body surface area (BSA). DESIGN: The study involved a 4-hour dwell of 1200 mL/m2 BSA of dialysis fluid containing 3.86% glucose with Dextran 70 as volume marker. Cumulative TCUF and cumulative MC were measured. SETTING: A tertiary-care university hospital. PATIENTS: A follow-up period of 33 months of serial (1 - 4) peritoneal equilibration tests (PETs) was studied in 20 children with a median age of 6.4 years (range 2.1 - 15.4 years). Fluid kinetics in 5 additional infants with a median age of 1.4 years (range 0.5 - 2.5 years) was measured. RESULTS: Cumulative TCUF was 1041 mL/1.73 m2 at 1 - 3 months after start of PD, 1026 mL/1.73 m2 at 7 - 9 months, 1021 mL/1.73 m2 at 11 - 13 months, and 756 mL/1.73 m2 at 26 - 33 months (NS). Cumulative MC was 235 mL/1.73 m2 at 1 - 3 months after start of PD, 311 mL/1.73 m2 at 7 - 9 months, 395 mL/1.73 m2 at 11 - 13 months, and 509 mL/1.73 m2 at 26 - 33 months (NS). In infants, cumulative TCUF was 755 +/- 237 mL/1.73 m2; cumulative MC was 400 +/- 214 mL/1.73 m2. CONCLUSIONS: Transcapillary ultrafiltration and marker clearance do not change in children > 2.5 years during the period studied. Fluid kinetics does not differ between infants < 2.5 years and older children when intraperitoneal volumes of 1200 mL/m2 BSA are used.

Absorption↗

The value of the macerated skull as a model used in orthopaedic research.

In this study a method was developed to enable the measurement of initial bone displacement in vivo, post-mortem, and in vitro. Speckle interferometry was used as measuring technique. Through the construction of the centres of rotation, the different orthopaedic effects could easily be compared. Also the magnitude of the bone displacement could be calculated. The initial post-mortem displacement of the maxilla corresponds very well with the initial in vivo displacement. After maceration and drying of the skull, however, clear differences from the in vivo displacement were found. The orthopaedic effects on a macerated skull can be manipulated considerably by changing, for instance, the degree of humidity. Only a limited number of skulls was examined in these experiments and probably still other variables exert an influence on the bone displacement in the macerated skull. Nevertheless, it is certain now that the dry skull cannot reliably be used as a model to simulate the initial bone displacement in vivo. The experimental set-up of this study will be used in the future to evaluate the effect of environmental factors (humidity, temperature, etc.) in an attempt to improve the value of the skull as a model for orthopaedic research. Moreover, this technique permits investigation of the link between initial displacements in vivo and longitudinal changes.

Aging↗

Longitudinal analysis of the effects of the aging process on neuropsychological test performance in the healthy young-old and oldest-old.

A sample of 33 young-old (ages 65 to 74) and 20 oldest-old (ages 84 to 93) healthy elderly without dementia were assessed with neuropsychological tests annually over a 4-year period to examine longitudinal changes in cognitive functioning. Significant age-group differences existed at baseline in participants' performances on tests of immediate memory and visuospatial skills. There were no age-group differences in the rate of change over the 4-year interval on any neuropsychological tests. Within each age-group, the amount of change over time was minimal for most tests though some practice effects were apparent, and on some tests mild decline was observed. Results suggest that healthy old adults, including the oldest-old, do not experience measurable declines in cognitive functioning over a 4-year period.

Age Factors↗