Role of a mixed type, moderate intensity exercise programme after peripheral blood stem cell transplantation.

OBJECTIVES: To evaluate the effect of peripheral blood stem cell transplantation on functional capacity, and to determine the role of a mixed type, moderate intensity exercise programme in the recovery of patients after intensive cancer treatment. METHODS: Peak aerobic capacity and muscular strength (upper body, lower body, and handgrip strength) measures were assessed before (PI) and after (PII) transplant and after a 12 week intervention period (PIII). After PII, 12 patients aged 16-64 years were allotted in equal numbers to a control group or exercise intervention group. RESULTS: Mean peak aerobic capacity and muscular strength were reduced after the transplant, with significant (p<0.05) decreases for upper body strength. No change was found in aerobic capacity and muscular strength between PII and PIII for the control group. In contrast, participation in the exercise programme led to significant improvements in peak aerobic capacity (p<0.05) and upper and lower body strength (p<0.01). In addition, values recorded after the three month intervention period were significantly higher than before treatment for peak aerobic capacity (litres/min (p<0.05) and ml/kg/min (p<0.01)) and lower body strength (p<0.01). CONCLUSION: Intensive treatment for cancer can adversely affect aerobic capacity and muscular strength. A mixed type, moderate intensity exercise programme can help patients to regain fitness and strength within three months. No exercise can exacerbate physical losses resulting from treatment.

Nifedipine blocks retention of a visual discrimination task in chicks.

Reports that the dihydropyridine Ca2+ channel antagonists may facilitate memory led to the present study of the behavioral effects of nifedipine. Ninety-two 4-day-old male chicks received 0, 100 nM, 100 microM, or 10 mM nifedipine. Drugs were administered in volumes of 2 microliters into the fourth cerebral ventricle 5 min before training on a visual discrimination task. Nifedipine did not produce any detectable changes in behavior during acquisition trials. Retention, however, was impaired 24 h after training in the 100 nM and 100 microM nifedipine-treated chicks, which made significantly more errors than controls. Nifedipine did not affect the amount of time required to complete the task. No effects on body weight gain were detected, suggesting that the memory impairment was not due to a change in feeding behavior. These data are discussed in terms of the role of calcium-dependent processes in memory.

Vortex gas lens.

A vortex gas lens concept is presented. Such a lens has a potential power density capability of 10(9)-10(10) w/cm(2). An experimental prototype was constructed and the divergence half angle of the exiting beam was measured as a function of the lens operating parameters. Reasonably good agreement is found between the experimental results and theoretical calculations. The expanded beam was observed to be steady, and no strong, potentially beam-degrading jets were found to issue from the ends of the lens. Estimates of random beam deflection angles to be expected due to boundary layer noise are presented; these angles are very small.

Effect of low-intensity hippocampal stimulation on spatial versus working memory in rats.

A series of experiments was performed to investigate differing predictions from the spatial mapping hypothesis of hippocampal function proposed by O'Keefe and Nadel (1978) and the working memory hypothesis proposed more recently by Olton and his colleagues (Olton, Becker, & Handelmann, 1979). Each of two groups of rats was trained to use a different strategy to locate a submerged platform in a tank of opaque water. The MAP group used a spatial mapping strategy to reach a platform in a fixed location over trials; whereas the CUE group used a guidance strategy, which involved following a cue that signaled the location of a randomly placed platform on each trial. Following acquisition, one-half of each group was given low-level unilateral electrical stimulation of the dentate gyrus and immediately tested on the water maze task. The results of Experiment 1 showed that both the MAP and CUE groups were impaired by stimulation. However, it was observed that there was an inadvertent spatial element involved in the CUE task. When this element was eliminated in Experiment 3, the same CUE animals were not affected by a second series of stimulation trials, whereas the MAP animals continued to show impairment. These results are interpreted as strongly supporting the cognitive mapping hypothesis, while at the same time providing little support for the working memory hypothesis of hippocampal function.

ROC and contrast detail image evaluation tests compared.

Using both contrast detail and receiver operating characteristic (ROC) evaluation tests, we evaluated different quality images, produced with different film-screen combinations. ROC curves were obtained for six observers who were attempting to detect lung nodules and pulmonary infiltrates. The contrast detail curves were obtained from images of regular circular test patterns of differing contrast, which had been presented to the observers. Our results indicate that contrast detail tests can be used for relative ranking of image systems prior to detailed ROC testing.

Radionuclide thyroid studies: a survey of practice in the United States in 1981. Special report.

A survey was conducted to determine the radiopharmaceuticals and radionuclide imaging methods used for thyroid studies in the U.S. in 1981. The final sample, made up of 299 hospitals, was taken from a random sample consisting of 10% (337) of U.S. hospitals performing nuclear medicine studies. The survey showed that over one half of thyroid scans were obtained with Tc-99m pertechnetate and over one half of uptake studies were performed with I-131. Uptake determinations accompanied 78% of scans. Only 8% of the uptake studies were performed without scans. I-123 was more commonly used on the west coast and in the northeast, and there was interest in a more readily available and less expensive supply of I-123. Thyroid studies accounted for 6.7% of all nuclear imaging procedures. Approximately 7,760,000 nuclear medicine imaging procedures were performed in the U.S. in 1981.

Anticrossover emulsions evaluated by observer performance tests.

Observer performance in the detection of pulmonary nodules and infiltrates was measured using film coated with anticrossover emulsion, a recent innovation in radiographic film that is expected to produce sharper images because of improved resolution. Test radiographs of an anthropomorphic phantom were shown to six experienced observers. Radiographs containing pseudonodule and pseudoinfiltrate images were obtained with the anticrossover film and the same type of film without the anticrossover coating. Test images contained single nodules, single infiltrates, or both; approximately 45% of the test radiographs were normal. Individual receiver operating characteristic (ROC) curves were formed, and sensitivity and specificity values were calculated. The results demonstrated an improvement in observer performance with the anticrossover film as measured by sensitivity and the area under the average ROC curves.

Segmental renal artery emboli treated with low-dose intra-arterial streptokinase.

Herein we describe a sixty-one-year-old man with unilateral segmental renal artery emboli treated with renal intra-arterial streptokinase infusion. The initial infusion rate was 9,000 units/hr. which was decreased to 5,000 units/hr. over the next six hours. Periodic arteriography demonstrated progressive lysis and virtual complete resolution after fifty-two hours of infusion. Intravenous pyelogram (IVP) six weeks later showed almost complete return of functional compared with IVP obtained six years earlier. We have demonstrated successful clot lysis at an infusion rate of 5,000 units/hr., compared with reported rates of 25,000 units/hr. and without the frequently utilized initial large intravenous bolus. Such low-dose streptokinase infusion should, theoretically, limit the incidence of recognized dose-related complications and permit its use in clinical settings where higher dosages are contraindicated. Intra-arterial streptokinase therapy seems particularly suitable for the high surgical risk patient and in arterial lesions not amenable to surgery. The availability of this potentially efficacious therapy suggests that aggressive diagnostic studies be pursued early in patients suspected of having an acute renal arterial embolus.

Directed versus free search for nodules in chest radiographs.

Nodule detection in chest radiographs was compared under free-search and directed-search conditions. In directed search, the observer was told which quadrant of the chest to examine. Each of five observers read a test series of 96 radiographs seven times. Results were analyzed in terms of signal detection theory. NOdule detection was found to be significantly more accurate in directed search than in free search. The results were compared with those of previous experiments which found no such effect or an opposite effect. The present results do not support a previously hypothesized preattentive visual mechanism with better detection capabilities than focused visual attention.