ICA-based denoising for ASL perfusion imaging.

Arterial Spin Labelling (ASL) imaging derives a perfusion image by tracing the accumulation of magnetically labeled blood water in the brain. As the image generated has an intrinsically low signal to noise ratio (SNR), multiple measurements are routinely acquired and averaged, at a penalty of increased scan duration and opportunity for motion artefact. However, this strategy alone might be ineffective in clinical settings where the time available for acquisition is limited and patient motion are increased. This study investigates the use of an Independent Component Analysis (ICA) approach for denoising ASL data, and its potential for automation. 72 ASL datasets (pseudo-continuous ASL; 5 different post-labeling delays: 400, 800, 1200, 1600, 2000 m s; total volumes = 60) were collected from thirty consecutive acute stroke patients. The effects of ICA-based denoising (manual and automated) where compared to two different denoising approaches, aCompCor, a Principal Component-based method, and Enhancement of Automated Blood Flow Estimates (ENABLE), an algorithm based on the removal of corrupted volumes. Multiple metrics were used to assess the changes in the quality of the data following denoising, including changes in cerebral blood flow (CBF) and arterial transit time (ATT), SNR, and repeatability. Additionally, the relationship between SNR and number of repetitions acquired was estimated before and after denoising the data. The use of an ICA-based denoising approach resulted in significantly higher mean CBF and ATT values (p < 0.001), lower CBF and ATT variance (p < 0.001), increased SNR (p < 0.001), and improved repeatability (p < 0.05) when compared to the raw data. The performance of manual and automated ICA-based denoising was comparable. These results went beyond the effects of aCompCor or ENABLE. Following ICA-based denoising, the SNR was higher using only 50% of the ASL-dataset collected than when using the whole raw data. The results show that ICA can be used to separate signal from noise in ASL data, improving the quality of the data collected. In fact, this study suggests that the acquisition time could be reduced by 50% without penalty to data quality, something that merits further study. Independent component classification and regression can be carried out either manually, following simple criteria, or automatically.

Shear Wave Elastography May Be Superior to Greyscale Median for the Identification of Carotid Plaque Vulnerability: A Comparison with Histology.

PURPOSE: There is a need to develop methods that reliably quantify characteristics associated with vulnerable carotid plaque. Greyscale median (GSM) and shear wave elastography (SWE) are two techniques that may improve individual plaque risk stratification. SWE, which quantifies Young's Modulus (YM) to estimate tissue stiffness, has been researched in the liver, breast, thyroid and prostate, but its use in carotid plaques is novel. MATERIALS AND METHODS: The aim of this study was to quantify YM and GSM of plaques and compare to histology. 25 patients (64% male) with a mean age of 76 underwent both clinical and SWE imaging. The mean GSM was quantified over a cardiac cycle. The mean YM was quantified in multiple regions within the plaque over 5 frames. Histological features were assessed following carotid endarterectomy. RESULTS: The mean YM of unstable plaques was significantly lower than that of stable plaques (50.0 kPa vs. 79.1 kPa; p = 0.027). The presence of intra-plaque hemorrhage, thrombus and increasing numbers of foam cells was also associated with a significantly lower YM. Plaque YM did not correlate well with plaque GSM (r =  .12). The mean plaque GSM was the same in both unstable and stable plaques. Fibrous plaques had a significantly higher GSM (p = 0.036). CONCLUSION: In conclusion, SWE provides additional information on plaque stiffness which may be of clinical benefit to help identify vulnerable plaque, and warrants further study.

A combined impact-process evaluation of a program promoting active transport to school: understanding the factors that shaped program effectiveness.

This mixed methods study was a comprehensive impact-process evaluation of the Ride2School program in metropolitan and regional areas in Victoria, Australia. The program aimed to promote transport to school for primary school children. Qualitative and quantitative data were collected at baseline and followup from two primary schools involved in the pilot phase of the program and two matched comparison schools, and a further 13 primary schools that participated in the implementation phase of the program. Classroom surveys, structured and unstructured observations, and interviews with Ride2School program staff were used to evaluate the pilot program. For the 13 schools in the second phase of the program, parents and students completed questionnaires at baseline (N = 889) and followup (N = 761). Based on the quantitative data, there was little evidence of an overall increase in active transport to school across participating schools, although impacts varied among individual schools. Qualitative data in the form of observations, interviews, and focus group discussions with students, school staff, and program staff provided insight into the reasons for variable program impacts. This paper highlights the benefits of undertaking a mixed methods approach to evaluating active transport to school programs that enables both measurement and understanding of program impacts.

Saturated- and n-6 polyunsaturated-fat diets each induce ceramide accumulation in mouse skeletal muscle: reversal and improvement of glucose tolerance by lipid metabolism inhibitors.

Lipid-induced insulin resistance is associated with intracellular accumulation of inhibitory intermediates depending on the prevalent fatty acid (FA) species. In cultured myotubes, ceramide and phosphatidic acid (PA) mediate the effects of the saturated FA palmitate and the unsaturated FA linoleate, respectively. We hypothesized that myriocin (MYR), an inhibitor of de novo ceramide synthesis, would protect against glucose intolerance in saturated fat-fed mice, while lisofylline (LSF), a functional inhibitor of PA synthesis, would protect unsaturated fat-fed mice. Mice were fed diets enriched in saturated fat, n-6 polyunsaturated fat, or chow for 6 wk. Saline, LSF (25 mg/kg x d), or MYR (0.3 mg/kg x d) were administered by mini-pumps in the final 4 wk. Glucose homeostasis was examined by glucose tolerance test. Muscle ceramide and PA were analyzed by mass spectrometry. Expression of LASS isoforms (ceramide synthases) was evaluated by immunoblotting. Both saturated and polyunsaturated fat diets increased muscle ceramide and induced glucose intolerance. MYR and LSF reduced ceramide levels in saturated and unsaturated fat-fed mice. Both inhibitors also improved glucose tolerance in unsaturated fat-fed mice, but only LSF was effective in saturated fat-fed mice. The discrepancy between ceramide and glucose tolerance suggests these improvements may not be related directly to changes in muscle ceramide and may involve other insulin-responsive tissues. Changes in the expression of LASS1 were, however, inversely correlated with alterations in glucose tolerance. The demonstration that LSF can ameliorate glucose intolerance in vivo independent of the dietary FA type indicates it may be a novel intervention for the treatment of insulin resistance.

Active transport to work in Australia: is it all downhill from here?

Physical inactivity is increasing in Australia and active forms of transportation may be one way to increase the working population's daily physical activity. We used travel-to-work data from employed persons aged 15 years and over participating in the 1996 (n = 7,636,319) and 2001 (n = 8,298,606) Australian censuses to determine prevalence and trends in walking and cycling to work by state and gender, and differences in prevalence by age. In 2001, 3.8% of Australians walked to work and < 1% cycled. Over 64% travelled to work by car. There have been small declines in walking (men and women) and cycling (men) over the 5-years from 1996 to 2001. People were more likely to walk or cycle to work if they lived in the Northern Territory, if they were male or if they were aged 15 to 24 years. They were more likely to travel by car if they lived in the Australian Capital Territory, if they were male, or if they were aged 45-54 years. Few people walk or cycle to work in Australia. Efforts to encourage active transportation are urgently needed.

Pharmacological and clinical aspects of antiepileptic drug use in the elderly.

In this article, epidemiological and clinical aspects related to the use of antiepileptic drugs (AEDs) in the elderly are highlighted. Studies have shown that people with epilepsy receiving AED treatment show important deficits in physical and social functioning compared with age-matched people without epilepsy. To what extent these deficits can be ascribed to epilepsy per se or to the consequences of AED treatment remains to be clarified. The importance of characterizing the effects of AEDs in an elderly population is highlighted by epidemiological surveys indicating that the prevalence of AED use is increased in elderly people, particularly in those living in nursing homes. Both the pharmacokinetics and the pharmacodynamics of AEDs may be altered in old age, which may contribute to the observation that AEDs are among the drug classes most commonly implicated as causing adverse drug reactions in an aged population. Age alone is one of several contributors to alterations in AED response in the elderly; other factors include physical frailty, co-morbidities, dietary influences, and drug interactions. Individualization of dosage, avoidance of unnecessary polypharmacy, and careful observation of clinical response are essential for an effective and safe utilization of AEDs in an elderly population.

Factors associated with antiepileptic drug use among elderly nursing home residents.

UNLABELLED: BACKGROUND. Epilepsy, a chronic condition defined as two or more recurrent, unprovoked seizures, has the highest incidence at the end of life. Antiepileptic drugs (AEDs) are the primary therapeutic mode. Approximately 10%-11% of elderly nursing home residents receive one or more AEDs, a higher prevalence than would be expected in this age group. In the research literature, there is not a clear explanation of variations in AED use in nursing homes. The purpose of this study was to examine the prevalence and variations in use of AEDs by resident characteristics, AEDs used, drug dosage, and AED combinations in treatment regimens. METHODS: This was a retrospective, cross-sectional study of residents (N = 21,551) in a convenience sample of nursing homes in 24 states and the District of Columbia. The unit of analysis was the individual resident. The study period was a single day in 1995. Bivariate and multivariate analyses were used to test differences. RESULTS: The prevalence of AED use was 10.5% across all elderly residents. In a multivariate analysis, factors associated with AED treatment included seizure indication, age group, and geographic region. AED use by age group showed declining use as the residents aged, from 65-74 to 75-84 to > or =85 years. CONCLUSIONS: The inverse relationship between AED use and age group was unexpected because the incidence of epilepsy increases with advancing age. This finding raises important questions about the future use of these drugs in elderly nursing home residents.

The role of depression in the association between self-rated physical health and clinically defined illness.

We enrolled 543 elderly participants of a managed care organization in a cross-sectional study to test whether the association between self-rated physical health and clinically defined illness differs for persons who are not depressed compared with persons with minor or serious depression. Depression was measured with the Diagnostic Interview Schedule (DIS). Clinically defined illness was measured with the Chronic Disease Score (CDS), a pharmacy-based measure. Additional variables included age, sex, and self-reported pain and physical function. Self-rated physical health was associated with both minor and serious depression, independent of clinically defined illness; minor depression was no longer significant when self-reported pain and physical function were added to the model. A significant negative correlation between self-rated physical health and clinically defined illness was observed for minor and no depression, but no correlation was seen for serious depression. These results confirm the association between depression and self-rated physical health and emphasize that, for persons with serious depression, self-rated health provides a less accurate picture of clinically defined illness at both ends of the spectrum. Also, a diagnosis of minor depression should not forestall investigation of inconsistencies between patient report and clinical evidence.

Clinical detection of depression among community-based elderly people with self-reported symptoms of depression.

BACKGROUND: Depression is under-diagnosed and under-treated in the primary care sector. The purpose of this study was to determine the association between self-reported indications of depression by community-dwelling elderly enrollees in a managed care organization and clinical detection of depression by primary care clinicians. METHODS: This was a 2-year cohort study of elderly people (n = 3410) who responded to the Geriatric Depression Scale (GDS) at the midpoint of the study period. A broad measure of clinical detection was used consisting of one or more of three indicators: diagnosis of depression, visit to a mental health specialist, or antidepressant medication treatment. RESULTS: Approximately half of the community-based elderly people with self-reported indications of depression (GDS > or = 11) did not have documentation of clinical detection of depression by health providers. Physician recognition of depression tended to increase with the severity of enrollees' self-reported feelings of depression. Men 65-74 years old and those > or = 85 years old were at highest risk for under-detection of depression by primary care providers. CONCLUSIONS: Clinical detection of depression of elderly people living in the community continues to be a problem. The implications of failure to recognize the possibility of depression among elderly White men suggest a serious public health problem.

Drug use management in board and care facilities.

The purpose of this study was to describe medication management in board and care facilities throughout Minnesota. A triangulation of data collection methods was used, including mail questionnaires (N = 98 facilities), telephone interviews (N = 64 facilities), and site visits (N = 15 facilities). Major issues examined included characteristics of board and care facilities, staffing, residents, and drug management systems. Results showed that staff in 86% of the board and care facilities surveyed provided medication storage, 83% gave medication reminders, and 69% administered medications to one or more residents. Site visits revealed a wide diversity in the characteristics of managers and their attitudes toward medication administration.

The impact of the 1987 federal regulations on the use of psychotropic drugs in Minnesota nursing homes.

OBJECTIVES: The purpose of this study was to examine prevalence rates of psychotropic drug use by elderly nursing home residents 3 years before and 1 year after implementation of the 1987 Omnibus Budget Reconciliation Act drug regulations throughout the United States on October 1, 1990. METHODS: A cohort study was conducted of elderly nursing home residents, for each of 4 study years (approximately 33,000 residents per year), of all nursing homes (n = 372) in Minnesota certified by Medicare and Medicaid. Data included (1) health status assessment and psychotropic drug use; (2) nursing home and care characteristics; and (3) county geographic and population characteristics. RESULTS: Annual rates of antipsychotic drug use declined by one third over the 4-year period (23%, 22%, 19%, and 15% from 3 years before enforcement of the regulations to 1 year afterward). All differences were statistically significant. Antianxiety use rates were 11%, 12%, 12%, and 12%, respectively, and antidepressant use rates were 14%, 15%, 16%, 16%, respectively, for the 4 years. The latter two classes of drugs were not affected directly by the regulations. CONCLUSIONS: Declines in the rates of antipsychotic drug use appear to be associated with anticipation of the regulations the year before and as the result of the regulations the year after the October 1990 implementation. A hypothesized medication shift to benzodiazepine drugs was not observed.

Does Life Education's drug education programme have a public health benefit?

The Life Education organization offers a drug education programme to an estimated one million Australian primary schoolchildren. It is believed the programme delays experimentation with or initiation into smoking, alcohol use and the taking of analgesics. This study examined the short-term public health effects on 3000 11- and 12-year-old students, of whom 1700 were exposed to 5 consecutive years of the programme. The other 1300 students were not exposed to the programme. After controlling for the known predictors of social drug use there was no evidence that Life Education students, when compared with students receiving conventional school-based drug education, were less likely to have smoked, were less likely to have drunk or were less likely to have used analgesics. Indeed, the evidence suggested that Life Education-students were slightly more likely to use these substances, and that the programme had different effects on boys' and girls' drug use. Given that these findings are consistent with previous research evaluating similar drug education programmes, it is hypothesized they are most likely to do with the design of the programme itself.

Comparison of injuries to children with and without disabilities in a day-care center.

Injury rates and characteristics of children with and without disabilities in separate day-care programs were studied retrospectively through a record review of injury logs. The study focused on three issues: (1) initial injury rates and multiple injury rates, with comparisons by gender and program; (2) the characteristics of children who were injured compared to those who were not injured; and (3) comparisons between programs on characteristics and consequences of injuries. Injury rates were calculated on the basis of children's exposure time in the day-care setting. Results showed that children with disabilities had higher rates of injury than those without disabilities. Injury prevention in day care should be tailored to the characteristics of children and the types of injuries that occur in this setting.

Differences between nursing home admissions and residents.

The use of a cross-sectional sample of nursing home residents rather than a sample of admissions to estimate admission characteristics carries a potential bias. The purpose of this study was to fill this void by comparing abstracted records data for an admissions cohort (n = 1,118) and a residents cohort (n = 830) residing in the same nursing homes. Compared to residents, admissions were significantly more dependent in their ability to get around and to dress themselves, received more clinical services, and had a higher rate of medication use. Over a 12-month period, admissions had a fivefold greater likelihood of being discharged to community, but about the same mortality rate as residents. Within both groups, those discharged to the community as well as those who died had expenditures that were almost twice as high as those of their counterparts who remained alive in the nursing home.

Injuries to preschool-age children in day-care centers. A retrospective record review.

OBJECTIVES: To increase our understanding of the epidemiologic nature of injuries to children in day-care settings by examining injury logs and to determine appropriate methods for calculating injury rates. DESIGN: Retrospective, with data collected through a review of 1 year's records. SETTING: Four suburban day-care centers in the upper Midwest. PARTICIPANTS: Five hundred twenty-seven preschool-age children, 275 of whom experienced one or more injuries during the study period. SELECTION PROCEDURE: Convenience sample. MEASUREMENTS/RESULTS: Injury rates were calculated based on the number of hours spent in day care in the study year. More than 1000 injuries were reported for 527 children. Injury rates ranged from 0.006 to 0.049 per child per standardized 8-hour day in a day-care center (or six to 49 injuries per 1000 children per 8 hours of exposure). However, most injuries were minor, and none resulted in a fatality or hospital admission. Using this method, injury rates were examined by gender and month. CONCLUSIONS: Future research should determine exposure time based on the actual number of hours a child spends in attendance to determine injury rates. Exposure time should also be carefully considered in determining product- and location-specific rates of injury.

Inadequate treatment of depressed nursing home elderly.

OBJECTIVE: To determine the prevalence of antidepressant drug treatment among nursing home elderly with major depression. DESIGN: Survey early and late in nursing home stay. SETTING: Sixty Medicaid/Medicare-certified skilled nursing homes. PARTICIPANTS: Admission cohort of 5,752 residents age 65 or older in 1976 through 1983. MEASURES: Chart review by nurse-abstractors of physicians' diagnoses, drug used, and alertness rating. Diagnosis of depression equivalent to DSM-III-R major depression. RESULTS: Of 868 persons with a diagnosis of depression in the medical record, only 10% were treated with antidepressant drugs. More received neuroleptics and benzodiazepines than received antidepressants, but most (52%) received no psychoactive drug at all. A subset of 258 depressed persons had positive notations in their records supporting a mental status rating of "alert and oriented." Of that subset, only 15% received antidepressants. When followed from admission to discharge or end of study the prevalence rate of antidepressant drug treatment increased by 4%. CONCLUSIONS: In the late 1970's and early 1980's, even when the primary care physician made and recorded a diagnosis of depression, most such nursing home residents remained untreated, incorrectly treated, or inadequately treated.