Physical activity patterns in chronic hemodialysis patients: comparison of dialysis and nondialysis days.

OBJECTIVE: To determine physical activity patterns in chronic hemodialysis patients with a specific emphasis on the difference between dialysis and nondialysis days. Design A cross-sectional single-center study. SETTING: Vanderbilt University Outpatient Dialysis Unit. PATIENTS: Twenty current chronic hemodialysis patients: 10 male, 10 female; 15 black, 5 white; mean age, 50.1 +/- 9.9 years; height, 164.5 +/- 10.9 cm; weight, 82.5 +/- 15.4 kg; length on dialysis, 57.3 +/- 45.3 months. METHODS: Minute-by-minute physical activity was assessed over a 7-day period using a triaxial accelerometer, which consists of raw numbers or counts calculated by the 3 axes of the accelerometer (PA counts). PA counts were extrapolated on a daily and hourly basis. Physical functioning tests included: sit-to-stand, 6-minute walk, and 1-repetition maximal leg press exercise. Laboratory values for serum concentrations of albumin, prealbumin, C-reactive protein, and cholesterol were also collected. MAIN OUTCOME MEASURE: PA counts. RESULTS: Total PA counts were significantly lower on dialysis days when compared with nondialysis days (128,279 +/- 74,009 versus 168,744 +/- 95,168, respectively, P = .025). The average PA counts during the 4-hour dialysis time period were significantly lower on dialysis days when compared with nondialysis days (3,086 +/- 3,749 versus 11,070 +/- 7,695, respectively, P = .001). At postdialysis hours 1 and 2, PA counts on dialysis days were significantly higher than on nondialysis days (11,410 +/- 5,340 versus 9,082 +/- 6,646, P = .008, and 14,048 +/- 9,728 versus 8,662 +/- 6,433, P = .016, respectively). By postdialysis hour 4, PA counts on dialysis days had significantly decreased when compared with nondialysis days (6,068 +/- 6,268 versus 10,512 +/- 7,420 PA counts, P = .01, respectively). From postdialysis hours 5 to 20, there was no significant difference in PA counts between dialysis and nondialysis days. CONCLUSION: This study shows that physical activity is lower on dialysis days when compared with nondialysis days, and this decrease is caused by the lack of activity during the 4-hour hemodialysis procedure. New behavior modification strategies involving physical activity, both during hemodialysis and on nondialysis days, must be examined in this patient population.     

Response of negative symptoms of schizophrenia to neuroleptic treatment.

BACKGROUND: In view of the inconclusive reports in the literature about the response to neuroleptics of chronic schizophrenics with negative symptoms, the authors further evaluated this issue. METHOD: A sample of 30 ambulatory chronic schizophrenics meeting DSM-III-R criteria who had to a marked degree at least two negative symptoms of the five on the Scale for the Assessment of Negative Symptoms (SANS) received various therapeutic dosages of thiothixene for 3 months. The average dose was 26.75 mg/day. Subjects were periodically evaluated with the Brief Psychiatric Rating Scale, Negative Symptoms Rating Scale (a modified version of the SANS), and the Randt Memory Test. The time effect on treatment was calculated by repeated measures of analysis of variance. The relationship between the positive and negative symptoms was tested by an analysis of covariance. RESULTS: Both negative and positive symptoms improved with treatment. The negative symptoms tended to respond to treatment predominantly independently of the positive ones. At the end of the study, 63% (N = 19) of patients had improved moderately, 16% (N = 5) had improved slightly, and 20% (N = 6) had not improved. CONCLUSION: The data require further support from a long-term follow-up study that may show the extent to which these gains are maintained over time.     

Common bile duct calculi: updated experience with dissolution with methyl tertiary butyl ether

The authors describe their experience with methyl tertiary butyl ether (MTBE) in a larger series of patients than previously reported in order to acquaint physicians with both its effectiveness for dissolution of common bile duct calculi and the limitations of its use. Ten patients with 13 biliary calculi underwent percutaneous stone dissolution treatment with the experimental cholesterol solvent, MTBE. Three stones completely dissolved within 30 minutes, seven were reduced in size, and three were visibly unaffected. All stones not completely dissolved were easily extracted by means of a stone basket except for one in a patient taken to surgery. Although MTBE perfusion is an effective technique for management of biliary calculi, practitioners should be aware that its use is quite time consuming and its odor difficult to control.     

The impact of HIV disease on an Irish prison population.

Between January 1987 and January 1991, 168 known HIV-infected prisoners have been incarcerated in Dublin's Mountjoy prison. This figure constitutes 16.6% of the total HIV-infected population in the Republic of Ireland over the same period. One hundred and forty-one (84%) of these prisoners have attended the Department of Genitourinary Medicine, St James's Hospital, Dublin. This group displayed considerable morbidity from HIV-related disease. Respiratory tract infection was the most frequent complication seen. Much additional morbidity was directly attributable to intravenous drug use. A survey of a representative group of inmates revealed that 64.7% were diagnosed HIV-positive in prison. The mean length of time spent incarcerated since the diagnosis of HIV infection was 38.9 months. Twenty-nine of 34 individuals who answered a questionnaire were imprisoned for drug-related crimes and 32 of 34 prisoners admitted to parenteral drug use within the prison. As the HIV epidemic unfolds in Dublin, increasing numbers of prisoners with symptomatic HIV disease will spend time incarcerated in Mountjoy prison. This will pose a considerable burden on prison and hospital medical services alike.     

Cardiovascular adaptations to transfusion/chelation therapy of homozygote sickle cell anemia

The effect of transfusion/chelation therapy on the cardiovascular adaptations to chronic anemia in pediatric and young adult patients with homozygous sickle cell disease is uncertain. This study compares left ventricular (LV) function indexes and thoracoabdominal aortic systolic and diastolic blood flow in nontransfused and transfused patients with homozygous sickle cell disease. The study population consisted of 29 nontransfused patients with homozygous sickle cell disease, ages 0.4 to 20.9 years (group 1) and 11 chronically transfused/chelated patients, ages 4.0 to 21.8 years (group 2). The mean total hemoglobin concentration in group 2 was 28% greater than that in group 1. The mean duration of transfusion/chelation therapy in group 2 was 3.7 years. The percent of predicted LV end-diastolic and end-systolic dimensions were significantly greater than the respective controls in both groups. There was no significant difference in percent of predicted LV end-diastolic dimension (group 1, 120 +/- 12%; group 2, 120 +/- 12%) or percent of predicted LV end-systolic dimension (group 1, 120 +/- 12%; group 2, 117 +/- 8) between the groups. The percent of LV shortening fraction was similar in study groups and control subjects. Aortic systolic blood flow (cc/min/m2) for group 1 (2,426 +/- 841) and 2 (2,374 +/- 1.004) were significantly greater than corresponding control values (1,683 +/- 442, 1,736 +/- 430, respectively). Aortic diastolic blood flow was significantly greater than corresponding control values for both group 1 (699 +/- 313 vs 488 +/- 212) and group 2 (1,080 +/- 607 vs 588 +/- 219).(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical MR imaging with a Helmholtz-type surface coil

Limited-field-of-view radio-frequency receiver antennas provide improved near-field sensitivity for magnetic resonance imaging by decreasing the antenna volume. The Helmholtz-type surface coil, consisting of two flat rings, is an organ-encompassing antenna that takes advantage of this principle to yield an improved signal-to-noise ratio (S/N). The coil was tested in a group of 50 patients and 16 healthy volunteers. Images obtained with the Helmholtz coil demonstrated quantitatively superior S/N of 2.2-fold or greater than that of comparison body coil images, as well as qualitatively superior anatomic resolution.