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PubMed1993

Comparative imaging techniques and models.

In vitro modeling remains an effective method of assessing the effect of hemodynamic variables and instrumentation settings on the display characteristics of imaging modalities. Most emphasis has been placed on the quantitative estimation of mitral regurgitation using the zone of flow convergence proximal to the regurgitant orifice on color Doppler flow mapping. Comparative studies of cardiac ultrasound imaging and flow-related magnetic resonance imaging have led to an improved understanding of the appearance of flow voids on cine magnetic resonance imaging and the shape of flow velocity fields on color Doppler flow mapping. We review recent advances in the above areas and introduce some of the more innovative recent research in the area of cardiac imaging. The results of evaluating imaging techniques using in vitro and animal models provide useful insights into the basic display characteristics of these often quite different modalities and supply a valuable basis for the interpretation of these images in the clinical setting. Comparative clinical observations of a variety of cardiac imaging techniques such as transesophageal and transthoracic echocardiography, magnetic resonance imaging, and computed tomography scanning can often highlight and explain differences in their individual characteristics and clinical utility.

Echocardiography↗
PubMed1999

Incidence and predictors of drug-induced parkinsonism in older psychiatric patients treated with very low doses of neuroleptics.

The available literature suggests that a sizable proportion of patients placed on neuroleptics develop acute and subacute extrapyramidal side effects, including neuroleptic-induced parkinsonism (NIP). The presence of mild, spontaneous extrapyramidal signs in the elderly makes it difficult to accurately estimate the incidence of NIP in this subgroup of patients. We examined the incidence of NIP in 56 older, newly medicated, psychiatric patients. Fifteen age-comparable, unmedicated psychiatric patients underwent 2 assessments to estimate natural fluctuation in extrapyramidal signs, and 49 normal, healthy, elderly individuals were also studied to establish age-comparable norms for the assessment of parkinsonism. Potential pretreatment predictor variables included instrumental measures of motor function, age, cognitive status, and psychiatric diagnosis. After controlling for spontaneous parkinsonism, 32% of patients met strict criteria for NIP after receiving an average of 43 mg/day chlorpromazine equivalents of a typical neuroleptic. Factors contributing to the development of NIP included older age, instrumentally derived tremor, baseline extrapyramidal signs, type of neuroleptic, and severity of dementia. The use of risperidone in a small subsample was not associated with NIP. These findings indicate that even after controlling for spontaneous extrapyramidal signs at baseline and their natural fluctuations, there is a substantial risk of NIP in older patients who are treated with very low doses of typical neuroleptics.

Aged↗
PubMed1994

Outcome of lumbar fusion in Washington State workers' compensation.

STUDY DESIGN: This study covered a large, population-based cohort of workers in the Washington State workers' compensation system who received lumbar fusion between August 1, 1986 and July 31, 1987 to determine work disability status, reoperation rate, and patient satisfaction. OBJECTIVES: To use predictors of outcome of lumbar fusion to design clearer clinical guidelines for lumbar fusion in injured workers. METHODS: Logistic regression analysis was used to determine the predictors of work disability and risk of reoperation after fusion. RESULTS: The lumbar fusion incidence rate was 41.7/100,000 workers a year (n = 388 patients). Overall, 68% were work disabled and 23% required further lumbar spine surgery 2 years post-fusion. Five markers of severity predicted worse work disability outcome (older age at injury, longer time from injury to fusion, increased increased time on work disability before fusion, increased number of prior low back operations, and increased number of levels fused). Even after adjusting for these variables, receiving instrumentation with fusion doubled the risk of reoperation. Most patients reported that back pain (67.7%) was worse and overall quality of life (55.8%) was no better or worse than before surgery. CONCLUSIONS: Outcome of lumbar fusion performed on injured workers was worse than reported in published case series. Prospective studies should be conducted to determine the biologic indications that might lead to improved outcomes in this disabled population.

Adult↗
PubMed1990

Blood gas analysis as a determinant of occupationally related disability.

Arterial blood gas analysis is one of the criteria used by the Department of Labor to award total and permanent disability for coal workers' pneumoconiosis (Black Lung). We have observed that Black Lung claimants often undergo several blood gas analyses with widely differing results that sometimes range from complete normality to life-threatening hypoxemia in the same subject. We concluded that blood gas analysis in occupationally related disability determination is unreliable, in that quality control and instrumentation are variable; that severe hypoxemia is rare in coal workers' pneumoconiosis; and that such hypoxemia is nonspecific and correlates poorly with breathlessness.

Blood Gas Analysis↗
PubMed2004

Qualitative perspectives in translational research.

The rapid uptake of qualitative approaches in translational research can be best understood in the context of recent innovations in health services research, as well as an overarching concern with improving the quality of health care. Qualitative approaches highlight the human dimension in health care by foregrounding the perceptions, experiences, and behaviors of both consumers and providers of care. As such, these methods are particularly useful for addressing the complex issues related to improving health care quality and implementing system change. This overview traces a brief history of the factors contributing to the recent and rapid growth of qualitative methods in health research in general and translational research in particular; describes the varieties of qualitative approaches employed in this research; and illustrates the utility of these approaches for variable identification, instrument development, description/explanation of patient/provider perceptions and behaviors, individual/organizational change, and theory refinement.

Attitude of Health Personnel↗
PubMed2003

Factors influencing quality of life in people with chronic illness in Korea.

PURPOSE: To identify factors influencing quality of life based on health-promoting behavior in patients with chronic illness. DESIGN AND METHODS: This descriptive study was conducted over 8 months in 2001 on 1,748 chronic adult outpatients at a university hospital in Seoul, Korea. Study variables and instruments were health perception, perceived benefits of action, perceived barriers to action, self-esteem, self-efficacy, social support, commitment of planned action, activity-related affect, health-promoting behavior, and quality of life. RESULTS: The data indicated a statistically significant positive correlation among health-promoting behavior, perceived benefits of action, self-efficacy, social support, self-esteem, health perception, activity-related affect, and quality of life. A statistically significant negative correlation was found between perceived barriers to action and quality of life. Stepwise multiple regression showed that the most powerful predictor of quality of life was health-promoting behavior. The combination of health-promoting behavior, activity-related affect, self-esteem, health perception, commitment to planned action, social support, and perceived barriers to action accounted for 57% of the variance in quality of life. CONCLUSIONS: Multiple social, psychological, and health-related factors were associated with quality of life.

Adult↗
PubMed1996

Measuring psychosocial variables that predict older persons' oral health behaviour.

The importance of recognising psychosocial characteristics of older people that influence their oral health behaviours and the potential success of dental procedures is discussed. Three variables and instruments developed and tested by the author and colleagues are presented. A measure of perceived importance of oral health behaviours has been found to be a significant predictor of dental service utilization in three studies. Self-efficacy regarding oral health has been found to be lower than self-efficacy regarding general health and medication use among older adults, especially among non-Western ethnic minorities. The significance of self-efficacy for predicting changes in caries and periodontal disease is described. Finally, a measure of expectations regarding specific dental procedures has been used with older people undergoing implant therapy. Studies with this instrument reveal that patients have concerns about the procedure far different than those focused on by dental providers. All three instruments can be used in clinical practice as a means of understanding patients' values, perceived oral health abilities, and expectations from dental care. These instruments can enhance dentist-patient rapport and improve the chances of successful dental outcomes for older patients.

Aged↗
PubMed1999

Prevalence of depression in patients with chronic obstructive pulmonary disease: a systematic review.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) have repeatedly been characterised as a population of chronically ill patients with a higher than normal prevalence of depression. Susceptibility for depression has been noted in patients with certain other chronic conditions. This systematic review was conducted to achieve a more definite answer to the question: do patients with COPD show a higher than normal prevalence of depression? METHODS: Studies in English language journals were retrieved by an electronic search over the period from 1966 to December 1997 and by an extended search of reference lists, and were included or excluded according to a system of diagnostic and methodological criteria. RESULTS: Ten studies were included, of which only four had a case-control design. Three of the case-control studies reported an increased prevalence of depression among patients with COPD which was statistically significant in only one. The fourth controlled study found a significantly increased depression score among COPD patients. Of the remaining six uncontrolled studies three found a high baseline prevalence of depression among their study group. CONCLUSIONS: An association between COPD and depression was found in the four controlled studies. The two methodologically best conducted studies that did not detect a statistically significant higher prevalence lacked power. The two studies that did find a significant association used a questionable depression measure. The prevalence of depression was high compared with general population figures in three of six non-controlled studies. The empirical evidence for a significant risk of depression in patients with COPD remains inconclusive, due to the poor methodological quality of most of the published studies, the lack of studies with an adequate sample size, and variability in instruments and cut off scores used to measure depression.

Aged↗
PubMed1986

Intracranial lesions: flow-related enhancement on MR images using time-of-flight effects.

Many physico-anatomic variables and instrument parameters influence the relative magnetic resonance signal intensity of vascular channels. The interaction of these mechanisms is complex, but their composite effects can be accounted for by two main categories of flow phenomena: time-of-flight effects and spin-phase changes. Of these two mechanisms only the time-of-flight effect known as flow-related enhancement produces augmentation of intravascular signal. Flow-related enhancement can potentially provide positive contrast of diagnostic value in terms of anatomic depiction of vascular detail as well as physiologic characterization of blood flow. The authors have used a single-section, selectively irradiated, spin-echo pulse sequence to maximize flow-related enhancement within a variety of intracranial lesions, as a supplement to their regular imaging. The technique was found to be diagnostically useful in improving the conspicuity of vascular lesions, in determining vessel patency, in distinguishing flow void from calcification, and in obtaining semiquantitative information about flow dynamics.

Brain Diseases↗
PubMed1981

Blood oxygen content in microliter samples using an easy-to-build galvanic oxygen cell.

We have designed a simple, inexpensive, easy-to-build and operate apparatus for measuring blood oxygen content. The galvanic oxygen cell (fuel cell) requires as little as 1 microliter of blood and has a measuring time of 1-3 min. It is well suited for measuring oxygen content in fluids low in oxygen inasmuch as the sensitivity of the instrument is variable. Either air or water (at a known temperature and oxygen tension) can be used for calibration. No significant differences in blood oxygen content measured with our cell or the Van Slyke manometric method were found.

Blood Gas Analysis↗
PubMed1996

Performance of the 'unaffected' upper extremity of elderly stroke patients.

BACKGROUND AND PURPOSE: The main objective of this study was to compare the sensorimotor performance of the unaffected upper extremity (UE) of elderly stroke patients with that of healthy elderly people. METHODS: The group of stroke patients was composed of 43 hemiplegic/paretic subjects who had had a cerebrovascular accident at least 6 months earlier. They were > or = 60 years old, were right-handed before the stroke, had visual perception within normal limits, and showed no major cognitive impairments. A group of 43 healthy subjects matched for dominance, age, and sex was used for comparison. The main parameters of the performance of the unaffected UE of the stroke subjects and of the same side of the healthy subjects were measured with valid, reliable instruments. Some variables potentially related to the unaffected UE were also measured: affected UE motor function, functional independence, length of time since the stroke, self-perceived health status, activity level, and hand anthropometry. RESULTS: Statistical analyses showed significant deficits in the unaffected UE of hemiplegic/paretic subjects compared with normal subjects with regard to the following parameters: gross manual dexterity, fine manual dexterity, motor coordination, global performance, and kinesthesia (P < .01 to P < .0001). No significant clinical or statistical difference was found for grip strength (P < .81), static and moving two-point discrimination (P = .21 and P = .12), or touch/pressure threshold (P < .91). CONCLUSIONS: Many factors (frequency of use of the unaffected hand, sensorimotor interaction tasks, severity of the deficits in corticifugal projections, and deficits in postural stabilization) could interact to provide the clinical picture obtained in the present study.

Aged↗
PubMed1998

Validation of automated sleep analysis in normal children.

With the aim of determining normal reference values for our sleep laboratory and evaluating the reliability of automated analysis for scoring polysomnographic studies in children, we recorded polysomnograms in 16 healthy boarding-school children. Sleep recordings were obtained with a computer system (Medilog SAC, Oxford Instruments). Polysomnographic variables were monitored continuously on a 16-channel recorder equipped with a video. Data were acquired on optical disk for computer-assisted data interpretation. Sleep stages and respiratory events were also scored visually by operator. Comparison with visual scores showed that the computer system significantly overscored wakefulness (W) (p<0.02) and stage IV (p<0.001) and underscored stage II (p<0.001) and rapid eye movement (REM) sleep (p<0.001). It also assigned respiratory events a higher score than did visual scoring, as shown by the higher apnoea index (AI) and hypopnoea index (HI) (AI p<0.03; HI p<0.001). Regression analysis showed a significant correlation between visual and automated scores for central (r=0.679; p<0.004) and obstructive apnoea (r=0.631; p<0.008). Computer apnoea scores did not correlate with visual scores. Much remains to be done before computer-based scoring systems can be relied upon, without visual scoring, for polysomnographic sleep studies in children. Their main advantage at present is that they offer a convenient means of saving paper, space and time.

Apnea↗
PubMed2000

Smoking behavior and opinions of French general practitioners.

This report examines smoking prevalence, sociodemographic factors, and the opinions of French general practitioners (GPs) about tobacco control policies. Data from the CFES (Comité Français d'Education pour la Santé) national survey on general practitioners included 1013 respondents. The questionnaire was administered by telephone and a response rate of 65% was attained. Instrumentation included variables related to medical practice, sociodemographic characteristics, and opinions about health behavior. Thirty-four percent of physicians were current smokers. A higher proportion of males smoked compared to women (36.1% vs. 24.9%, p < 0.01), and they consumed on average more cigarettes per day (11.2 vs. 8 cigarettes/day, p < 0.05). Slightly more than 52% of physicians regarded their role in reducing nicotine addiction to be important. Doctors who believed that the physician's role was limited were less likely to advise pregnant women to stop smoking (odds ratio = 0.39, p < 0.001), and nonsmokers were more supportive of bans on smoking in public places. Despite the high prevalence of smoking among French physicians, they can still play an important role in reducing smoking among their patients. Medical school curriculum and continuing medical education programs focusing on prevention and cessation in France should be strengthened to help reduce smoking rates among physicians and the general population.

Adult↗
PubMed2003

A compact ECG R-R interval, respiration and activity recording system.

An ECG R-R interval, respiration and activity recording system has been developed for monitoring variability of heart rate and respiratory frequency during daily life. The recording system employs a variable gain instrumentation amplifier, an accelerometer, a low power 8-bit single-chip microcomputer and a 1024 KB EEPROM. It is constructed on three ECG chest electrodes. The R-R interval and respiration are detected from the ECG. Activity during walking and running is calculated from an accelerator. The detected data are stored in an EEPROM and after recording, are downloaded to a desktop computer for analysis.

Acceleration↗
PubMed2006

A mobile phone-based ECG monitoring system.

We have developed a telemedicine system for monitoring a patient's electrocardiogram during daily activities. The recording system consists of three ECG chest electrodes, a variable gain instrumentation amplifier, a low power 8-bit single-chip microcomputer, a 256 KB EEPROM and a 2.4 GHz low transmitting power mobile phone (PHS). The complete system is mounted on a single, lightweight, chest electrode array. When a heart discomfort is felt, the patient pushes the data transmission switch on the recording system. The system sends the recorded ECG waveforms of the two prior minutes and ECG waveforms of the two minutes after the switch is pressed, directly in the hospital server computer via the PHS. The server computer sends the data to the physician on call. The data is displayed on the doctor's Java mobile phone LCD (Liquid Crystal Display), so he or she can monitor the ECG regardless of their location. The developed ECG monitoring system is not only applicable to at-home patients, but should also be useful for monitoring hospital patients.

Amplifiers, Electronic↗
PubMed2005

Measure of glycosylated hemoglobin.

Glycosylated hemoglobin (HbA1c) is a marker of evaluation of long-term glycemic control in diabetic patients and predicts risks for the development and/or progression of diabetic complications. Glycosylation process depends on the exposure to glucose, so on the half-life of erythrocyte. It was demonstrated, however that metabolic control concerning the last 90-120 days had only a 10% effect on the result of HbAlc; mean blood glucose of the last 30 days contributes for 50% of HbA1c value. Blood glucose value in the afternoon and in the evening better correlate with HbA1c levels if compared with blood glucose values in the morning. It is important to know that there may be, in the evaluation of HbAlc, interference in the dosage, due to a condition of uremia, hyperlipemia, bad conservation and hemolysis of the sample, increase of leucocytes and presence of anomalous hemoglobins. Moreover the use of different methods, the lack of a common calibration concerning the same methods and the variability of instrumentation do not make reproducible results yet, in different laboratories.

Artifacts↗