Verbal working memory encodes phonological and semantic information differently.

Working memory (WM) is often tested through immediate serial recall of word lists. Performance in such tasks is negatively influenced by phonological similarity: People more often get the order of words wrong when they are phonologically similar to each other (e.g., cat, fat, mat). This phonological-similarity effect shows that phonology plays an important role for the representation of serial order in these tasks. By contrast, semantic similarity usually does not impact performance negatively. To resolve and understand this discrepancy, we tested the effects of phonological and semantic similarity for the retention of positional information in WM. Across six experiments (all Ns = 60 young adults), we manipulated between-item semantic and phonological similarity in tasks requiring participants to form and maintain new item-context bindings in WM. Participants were asked to retrieve items from their context, or the contexts from their item. For both retrieval directions, phonological similarity impaired WM for item-context bindings across all experiments. Semantic similarity did not. These results demonstrate that WM encodes phonological and semantic information differently. We propose a WM model accounting for semantic-similarity effects in WM, in which semantic knowledge supports WM through activated long-term memory.

Physical functioning in patients with chronic kidney disease.

BACKGROUND: Patients with chronic kidney disease (CKD) treated with dialysis have reduced levels of physical functioning. Little is known of the physical functioning in patients prior to initiation of renal replacement therapy (RRT). The purpose of the study was 2-fold: (i) to document physical functioning of patients with CKD not requiring RRT, using objective laboratory tests, physical performance measures and self-reported functioning; and (ii) to determine the correlations between these measures of physical functioning and renal function. METHODS: Thirty-two patients with CKD (mean estimated glomerular filtration rate [eGFR] 29.9 +/- 17.0) were recruited for the study. Subjects completed symptom-limited treadmill test (peak oxygen uptake [VO2peak]), physical performance measures (gait speed, sit-to-stand and 6-minute walk) and the SF-36 Health Status Questionnaire (physical functioning scale [PF] and physical composite scale [PCS]). Descriptive and correlational analyses were performed on the data. RESULTS: VO2peak (O2 17.8 +/- 6.7 ml/kg body weight per minute), physical performance measures and self-reported functioning were reduced compared with sedentary age-predicted norms. Significant correlations were found between VO2peak and all other physical functioning measures; however, only maximal gait speed and PCS correlated significantly with eGFR. CONCLUSIONS: Patients with CKD have reduced physical functioning as measured using objective laboratory tests (VO2peak), physical performance measures and self-reported functioning. Given that low physical functioning predicts outcomes in dialysis patients, interventions to maintain or improve physical functioning are warranted prior to initiation of dialysis.

A randomized trial of exercise and dietary counseling after liver transplantation.

We report results of a randomized clinical trial of a combined intervention of exercise and dietary counseling (ExD) after orthotopic liver transplantation (OLT). Of the 151 patients randomized into ExD or usual care (UC), 119 completed testing 2, 6 and 12 months post-OLT. Testing included assessment of exercise capacity (VO(2peak)), quadricep muscle strength, body composition (DXA), nutritional intake (Block 95) and health-related quality of life (SF-36). The intervention consisted of individualized counseling and follow-up to home-based exercise and dietary modification. Repeated measure ANOVA was performed to determine differences over time between ExD and UC with a secondary analysis to determine differences over time between adherers (Adh), nonadherers (Nadh) to the intervention and UC. The ExD group showed greater increases in VO(2peak) (p = 0.036), and self-reported general health (p = 0.038) compared to UC. Both groups demonstrated increases in muscle strength, body weight, body fat and other SF-36 scale scores. Adherence to the intervention was 37% with positive trends in VO(2peak) and body composition observed in Adh compared to Nadh and UC. These data suggest improvements in exercise capacity and body composition are achieved with nutrition and exercise behavior modifications initiated early after OLT and with regular follow-up.

Alterations in skeletal muscle structure are minimized with steroid withdrawal after renal transplantation.

BACKGROUND: Limitations in exercise capacity in kidney transplant recipients are thought to result in part from changes in muscle structure and function associated with immunosuppression therapy. METHODS: We compared the percent distribution of skeletal muscle fiber types, cross-sectional areas, and ultrastructural morphologies in kidney transplant recipients treated with standard prednisone maintenance therapy (n=21) to those undergoing rapid withdrawal of prednisone using Simulect (interleukin 2 receptor inhibitor) (n=13). Skeletal muscle biopsy specimens from the vastus lateralis were analyzed at 3 and 12 months after transplantation and compared with sedentary controls (n=15). RESULTS: Compared with the control group, the group receiving prednisone maintenance therapy had a significantly lower percentage of type I fibers and a higher percentage of type IIB/x fibers, evident at 3 and 12 months. Fiber type distribution in patients withdrawn from prednisone did not differ from controls. In patients withdrawn from prednisone, the cross-sectional areas of type I and IIA fibers were lower and the area of type IIB/x fibers was higher compared with controls. Likewise, ultrastructural studies revealed reduced volume densities of myofibrils and higher densities of interfibrillar and subsarcolemmal mitochondria. At 12 months there were no ultrastructural differences between the patients withdrawn from prednisone and controls. CONCLUSIONS: We conclude that prednisone maintenance therapy contributes to the lower exercise capacity by altering the ratio of type I to type IIB/x fibers and by reducing myofilament density. The increase in mitochondria in patients receiving prednisone may reflect a switch from carbohydrate to lipid metabolism resulting from the glucocorticoid therapy.

Health-related fitness and quality of life following steroid withdrawal in renal transplant recipients.

BACKGROUND: Exercise capacity increases significantly soon after transplantation; however, over time it does not further improve and patients remain low compared to normal levels. The limitations to exercise following transplantation have not been identified, but may be related to immunosuppression therapy regimens that include prednisone. METHODS: We studied health-related fitness measures (cardiorespiratory fitness, muscle strength, and body composition) and quality of life in renal transplant recipients randomized into two groups: those using standard maintenance immunosuppression, including prednisone therapy (N = 14); and those undergoing rapid withdrawal of steroids using Simulect[interleukin-2 (IL-2) receptor inhibitor] (N = 9). Testing was done at 3 and 12 months following transplant and the 12-month data were compared to 15 normal sedentary controls. RESULTS: Compared to those maintained on steroids, the steroid withdrawal group showed greater gains in VO2peak (P = 0.05) and quadriceps peak torque (P = 0.05) and greater gains in the vitality score and the Physical Composite Scale on the SF-36 questionnaire (P < 0.05). At 1 year, all patients had significantly lower exercise capacity compared to the sedentary controls (P = 0.01). No differences were observed in body composition, with both patient groups increasing in body weight (primarily body fat) over time. At 12 months, all patients were not different in body fat percentage compared to the sedentary controls. CONCLUSION: We conclude that prednisone is not the cause for increased body fat following transplantation; however, it may contribute to lower spontaneous improvements in exercise capacity possibly by limiting increases in muscle strength. The low exercise capacity in all transplant recipients studied at 1 year suggests a need for exercise training to optimize physical functioning following transplant.

Age, sex, race, initial fitness, and response to training: the HERITAGE Family Study.

Effects of age, sex, race, and initial fitness on training responses of maximal O(2) uptake (VO(2 max)) are unclear. Data were available on 435 whites and 198 blacks (287 men and 346 women), aged 17-65 yr, before and after standardized cycle ergometer training. Individual responses varied widely, but VO(2 max) increased significantly for all groups. Responses by men and women and by blacks and whites of all ages varied widely. There was no sex difference for change (Delta) in VO(2 max) (ml. kg(-1). min(-1)); women had lower initial values and greater relative (%) increases. Blacks began with lower values but had similar responses. Older subjects had a lower Delta but a similar percent change. Baseline VO(2 max) correlated nonsignificantly with DeltaVO(2 max) but significantly with percent change. There were high, medium, and low responders in all age groups, both sexes, both races, and all levels of initial fitness. Age, sex, race, and initial fitness have little influence on VO(2 max) response to standardized training in a large heterogeneous sample of sedentary black and white men and women.

Physical activity and health-related quality of life in liver transplant recipients.

The US Surgeon General's Report on Physical Activity and Health recommends that people of all ages engage in regular physical activity, and that significant health benefits can be obtained through a moderate amount of physical activity. Physical activity appears to improve health-related quality of life (HRQOL) by enhancing physical functioning in persons compromised by poor health. The Medical Outcomes Study Short Form-36 (SF-36) Health Status Questionnaire was sent to all patients who were 5 years or more post-liver transplantation at the University of California at San Francisco. Additional questions related to coexisting medical conditions and participation in regular physical activity were included. SF-36 scale scores were compared between active and inactive patients. Regression analysis was also performed to determine the contributions of coexisting medical conditions and physical activity to the physical scales of the SF-36 questionnaire. Patients who participated in regular physical activity had significantly higher scores on all physical scales and the physical component scale (PCS). The regression model, which included age, sex, time posttransplantation, retransplantation, recurrence of hepatitis C, number of comorbid conditions, and physical activity participation showed that both the number of comorbid conditions and participation in physical activity were significant independent contributors to the physical functioning scale and PCS. This study indicates that physical activity is related to HRQOL after liver transplantation independent of other coexisting medical conditions.

Adaptation to a standardized training program and changes in fitness in a large, heterogeneous population: the HERITAGE Family Study.

PURPOSE: This paper describes the variations in response to a standardized, computer-controlled training program. METHODS: Steady-state heart rate (HR) and oxygen intake (VO2) of 614 healthy, sedentary men and women aged 16-65 yr were measured during three cycle ergometer exercise tests. The HR associated with 55, 65, 70, and 75% of each subject's pretraining VO2max was used to prescribe exercise intensity. Subjects exercised three times a week, beginning at a HR associated with 55% VO2max for 30 min. Duration and intensity was gradually increased over 20 wk of training. The duration and HR of each training session were controlled by a computer. RESULTS: Using the linear relationship between HR, VO2 and power output (PO), PO were predicted for each of 60 training sessions at the respective programmed HR. The average ratio of the actual training HR to programmed HR was 0.99. It was hypothesized that participants whose actual training PO exceeded their predicted PO would improve VO2max more than those whose actual PO was less than their predicted PO. Using the ratio of actual/predicted PO determined after the training was over, participants were arbitrarily assigned to three groups: 128 participants had low (LO) ratios (0.65-0.84), 408 had average (AV) ratios (0.85-1.14), and 78 had high (HI) ratios (1.15-1.34). Secondary analysis showed that the training program significantly increased mean VO2max of all three groups. Those who had a smaller increase in training PO (LO) had significantly less increase in VO2max than those with larger increases in PO (HI). CONCLUSION: People who exercise at a HR associated with the same %VO2max can vary substantially in their training PO, in their rate of increase in PO over a 20-wk training program, and in improvement of their VO2max.

The magnitude and duration of ambulatory blood pressure reduction following acute exercise.

The purpose of this study was to observe the magnitude and duration of the ambulatory blood pressure (BP) reduction following exercise and to identify the peak intervals of BP reduction throughout the 24-h diurnal period. Subjects were 25 normo- (N = 116.7/ 78.2+/-10.0/7.2 mm Hg) and 21 hypertensive (H = 140.8/96.9+/-13.9/9.6 mm Hg) adults. Twenty-four hour ambulatory blood pressures (SBP = systolic and DBP = diastolic) were recorded following exercise (E = 50 min @ 50% VO2 max) and during a non-exercise control day (C). The 24-h pressures were compared between the E and C days for (1) duration and magnitude of the BP reduction following exercise, and for (2) the time of day for the diurnal patterns to exhibit reductions in BP. No BP differences were found for N between E and C days. Significant reductions in BP were found for 24-h average SBP (decrease 6.8 mm Hg) and DBP (decrease 4.1 mm Hg), daytime (06.00-22.00 hrs) SBP (decrease 6.9 mm Hg) and DBP (decrease 3.3 mm Hg), and sleep (22.00-06.00) SBP (decrease 5.1 mm Hg) and DBP (decrease 4.4 mm Hg) for H subjects only. H also demonstrated an 11 h reduction in SBP (chi = decrease 8.3+/-2.2 mm Hg) and 4h reduction in DBP (chi = decrease 6.0+/-1.7 mm Hg) following exercise. For the diurnal variation, the peak interval of reduction in SBP (chi = 17.0+/-2.6 mm Hg) was for 11 h; from 11.00-21.00 hrs. For DBP, a significant reduction (chi = decrease 5.7+/-0.7 mm Hg) was found for 5 h; from 11.00-15.00 h. Thus, exercise reduces both systolic and diastolic BP for a significant length of time postexercise as well as reduces pressures during the time of day that typically exhibits higher diurnal pressures.

The physiological consequences of bed rest and inactivity.

Most dialysis patients experience prolonged periods of physical inactivity and often bedrest. The physiological consequences of bed rest and inactivity are many and detrimentally affect the functioning of many bodily systems, several of which affect physical functioning. Reductions in plasma volume reduce cardiac filling, stroke volume, and cardiac output. Skeletal muscle fiber size, diameter, and capillarity are reduced, as is bone density. These changes result in profound reductions in physical work capacity. The effects of bed rest and inactivity in patients with chronic renal failure may have more serious consequences, in that they may exacerbate the pathophysiology of renal failure such as cardiac dysfunction, anemia, muscle wasting, muscle weakness, neuropathy, glucose intolerance, and reduced bone density.

Papular-purpuric gloves and socks syndrome associated with acute parvovirus B19 infection: case report and review.

The papular-purpuric gloves and socks syndrome (PPGSS) was first described in 1990. This syndrome is characterized by fever, acral pruritus, edema, petechiae, and oral erosions. Subsequently, parvovirus B19 has been implicated, in most cases, as the causative agent of this syndrome. To date, with two exceptions, all published cases of PPGSS have been from Europe and the Middle East and have been mainly reported in the dermatology literature. Herein, we report what we believe to be only the second case of documented parvovirus B19-associated PPGSS occurring in the United States. The patient presented with the typical clinical syndrome, and the diagnosis of acute parvovirus B19 infection was documented by serial serologies that demonstrated development of IgM antibody to virus during the acute phase of infection and seroconversion to IgG antibody in the convalescent period. We then review the existing literature on this unusual syndrome and its association with parvovirus B19.

A comparison of 24-h average blood pressures and blood pressure load following exercise.

Although the use of 24-h ambulatory blood pressure monitoring has been recommended in the study of blood pressure and exercise, consistent results have not been found for average 24-h systolic or diastolic blood pressures. Systolic load and diastolic load (the percentage of pressures >140/90 mm Hg during daytime hours and >120/80 mm Hg during sleep) have recently been identified as an important variable, but has had limited use with exercise. The purpose of this study was to compare the average systolic and diastolic pressures to systolic and diastolic loads from 24-h data recorded after a 50-min treadmill walk at 50% VO2max to data from a nonexercise control day. Subjects were 36 normotensive (116.9 +/- 10.7/77.0 +/- 8.9 mm Hg) and 25 hypertensive (141.0 +/- 13.7/96.6 +/- 9.0 mm Hg) adults. No significant differences were found for systolic and diastolic pressures or loads between the control and exercise days for normotensives. Even though no significant changes were found for any of the average systolic and diastolic pressures between the control and exercise days for the hypertensives, significant reductions were found in systolic load for 24-h (-25.7%), day (6 AM to 10 PM, -23.1%), work (6 AM to 5 PM, -22.9%), and leisure (5 PM to 10 PM, -26.7%) periods; and in diastolic load for the work (-22.5%) period. Thus, the measurement of systolic and diastolic load may be more sensitive than average systolic and diastolic blood pressures for the detection of 24-h ambulatory blood pressure changes with exercise in borderline hypertension.

Inflammatory cutaneous metastases from cloacogenic carcinoma of the anus.

BACKGROUND: There are a few tumors that exhibit inflammatory cutaneous metastases. This pattern is particularly difficult to diagnose since it can mimic erysipelas or lymphangitis. OBJECTIVE: This is a presentation of a 69-year-old woman diagnosed with poorly differentiated cloacogenic carcinoma who simultaneously was noted to have an abdominal rash. A biopsy confirmed cutaneous metastasis of her carcinoma. METHODS: Previously published literature on cutaneous metastases were reviewed and summarized. RESULTS: This is the first reported case of an inflammatory cutaneous metastasis arising from cloacogenic carcinoma. CONCLUSION: Cutaneous metastases can present in various forms, including the inflammatory pattern. Because this form mimics other conditions, it is prudent to biopsy any suspicious skin lesion in cancer patients, as it may considerably affect prognosis.

Meeting psychosocial and developmental needs of children during prolonged intensive care unit hospitalization.

In order to optimize psychosocial and cognitive development and family function of chronically ill patients who are acutely stable in a pediatric intensive care unit, the philosophy of care was changed. Psychosocial development was enhanced by practices that develop trust in caregivers, including change in visiting policies and consistency in caregivers. Cognitive development was enhanced by increasing interaction with the environment outside of the Pediatric Intensive Care Unit bed. Family function was maintained by communication and family participation.

Eating and drinking: An economic analysis.

Food-deprived rats were exposed to various schedules of food delivery; water-deprived rats were exposed to various schedules of water delivery. Eating and drinking were measured over sessions and at points throughout sessions. The symmetries and asymmetries of food and water consumption were explored in terms of: (1) substitutability of food versus water, and of food and water on the one hand versus leisure on the other, (2) constraints imposed by various schedules of food and water, and (3) the tendency of rats to maximize utility within the imposed constraints.