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61.
We have evaluated the ''two minute walking distance'' in children with cystic fibrosis as an objective measurement of exercise tolerance. There was a strong correlation between walking distance and height in 89 normal children (r = 0.72). Fifty children with cystic fibrosis showed a similar correlation (r = 0.56) with a mean result of 94% of that expected for height compared with the normal children. There was a training effect in the normal children with the second walk being significantly better than the first, but this was not evident in children with cystic fibrosis. The test was reproducible with no significant change in 12 children retested after one to three months. Sixteen children with cystic fibrosis admitted for treatment of chest disease showed a significant improvement in walking distance with treatment. Children as young as 5 years old can perform a walking distance test. It seems to be an objective way of assessing exercise tolerance and can help in evaluating response to treatment.  相似文献   
62.
In a double blind crossover trial, we compared sodium cromoglycate, ipratropium bromide, and water in 23 asthmatic children less than 2 years old (mean age 11.8 months). Each child received nebulised solutions containing 20 mg of sodium cromoglycate, 250 micrograms of ipratropium bromide, or 2 ml water three times a day for three two month periods. Daily symptom scores did not show significant differences between the treatments but parental preferences indicated that both sodium cromoglycate and ipratropium bromide were superior to placebo. Sodium cromoglycate was prophylactic and was more likely to help the older patients. Ipratropium bromide produced an immediate clinical benefit and the response was not age dependent. We were unable to pick responders from non-responders on the basis of lung function tests performed on a routine outpatient basis. Both ipratropium bromide and sodium cromoglycate help some but not all asthmatic children aged less than 2 years.  相似文献   
63.
BACKGROUND: Hemostatic complications are not uncommon after bone marrow transplantation (BMT). However, little is known about the frequency, localization, determinants, and outcome of hemostatic events in autologous and allogeneic BMT. METHODS: Four hundred forty-seven patients (364 allogeneic, 83 autologous transplants) were evaluated retrospectively for the presence of hemostatic complications (bleeding, thrombosis, hepatic veno-occlusive disease [VOD], microangiopathic hemolytic anemia) from the start of conditioning therapy until June 2000. RESULTS: A total of 83.2% of the patients presented with at least one hemostatic complication during the investigational period. Most bleeding episodes occurred within the first 4 weeks after transplantation and were relatively mild. However, 27.1% of the patients hemorrhaged severely, generally doubling the overall mortality of the BMT recipients. Fatal gastrointestinal or intracerebral hemorrhages contributed to 1.1% of the events. Bleeding was strongly associated with prolonged thrombocytopenia and graft-versus-host disease (GVHD). Hemorrhagic cystitis may additionally have been triggered by the preceding conditioning regimens containing cyclophosphamide. Thromboembolic events occurred most frequently in allogeneic transplant recipients, for whom the incidence was 14.6%. Chronic GVHD and treatment with steroids were the major determining factors. The incidence of hepatic VOD in 4.7% of the allogeneic transplant recipients was associated with a high fatality rate. Busulfan conditioning increased the VOD risk 2.6-fold. Moderate or severe microangiopathic hemolytic anemia was associated with GVHD and occurred in 14.6% of the allogeneic transplant recipients, leading to an increased overall mortality. CONCLUSION: Hemostatic disturbances, commonly found in the course of transplantation, are associated with a high transplantation risk and closely related to thrombocytopenia and immunologic complications.  相似文献   
64.
Microfocus X-ray scattering provides a powerful nondestructive technique capable of providing important information about the size, habit, and arrangement of mineral crystals in bone. The technique is capable of probing textural differences in a sample at a micron scale resolution. The study presented here involved the analysis of a number of archaeological bones by microfocus X-ray scattering at the ESRF Grenoble in order to determine local changes in mineral durability. The results showed that regions of bone with a modified microscopic morphology contained a greater dispersion of crystal shape when compared with more intact regions and control contemporary bone samples, but the crystal thickness values showed similar consistency. We speculate that the persistence of collagen in the archaeological bone may allow diagenetic remodeling of bone in terms of crystallite shape but defines the size of remodelled crystallites. The ability to detect such local changes in texture has wide potential for determining crystal characteristics in healthy and diseased bone samples.  相似文献   
65.
BACKGROUND: This study evaluated the prognostic value of a three-grade staging system of spinal involvement using magnetic resonance imaging (MRI) in patients with multiple myeloma and determined its usefulness as an independent parameter in the staging system of Durie and Salmon. METHODS: Seventy-seven previously untreated patients with multiple myeloma underwent MRI of the thoracic and lumbar spine with unenhanced T1-weighted spin echo and short-tau inversion time inversion recovery sequences. The patients were evaluated according to their infiltration patterns and the extent of bone marrow involvement was staged using a three-grade scale: Stage I, no focal or diffuse infiltration; Stage II, 1-10 foci or mild diffuse infiltration; Stage III, more than 10 foci or strong diffuse infiltration. RESULTS: The infiltration patterns had no significant effect on survival. Of 77 patients, 25 would have been understaged using the standard staging system of Durie and Salmon without the findings of MRI and 8 patients would have been understaged if the staging was based only on MRI. The combination of the staging system of Durie and Salmon and MRI was highly significant with respect to survival (P < 0.0001, log rank analysis). MRI staging I-III was independent of the staging system of Durie and Salmon (Cox regression model). CONCLUSIONS: A three-grade staging of spinal MRI provides a significant prognostic tool for patients with multiple myeloma. The authors propose including it in the staging system of Durie and Salmon.  相似文献   
66.
Former exploratory investigations of sleep alterations due to global system for mobile communications (GSM) signals have shown a hypnotic and REM-suppressive effect under field exposure. This effect was observed in a first study using a power flux density of 0.5 W/m(2), and the same trend occurred in a second study with a power flux density of 0.2 W/m(2). For the present study, we applied a submaximal power flux density of 50 W/m(2). To investigate putative effects of radio frequency electromagnetic fields (EMFs) of cellular GSM phones on human sleep EEG pattern, all-night polysomnographies of 20 healthy male subjects both with and without exposure to a circularly polarized EMF (900 MHz, pulsed with a frequency of 217 Hz, pulse duration 577 microseconds) were recorded. The results showed no significant effect of the field application either on conventional sleep parameters or on sleep EEG power spectra.  相似文献   
67.
68.
The putative role of the opioid system in cognitive and memory functions prompted us to search for possible changes in the cohort of the major opioid receptors, mu, delta and kappa, in Alzheimer's disease. The present study examines alterations in opioid receptor levels by quantitative autoradiography. These experiments were carried out on coronal sections of postmortem brains from Alzheimer's disease patients and from aged-matched, dementia-free individuals. Brain sections were labeled with the tritiated forms of mu-, delta- and kappa-opioid ligands; DAMGO ([D-Ala(2),N-Me-Phe(4),Gly-ol(5)]-enkephalin), DPDPE ([D-Pen2,5]-enkephalin) and bremazocine (in the presence of mu- and delta-ligands), respectively. Nonspecific binding was determined in the presence of naloxone (10 microM). Brain areas analyzed were caudate, putamen, amygdaloid complex, hippocampal formation and various cerebral and cerebellar cortices. Image analyses of autoradiographs show, that in comparison to the same areas in control brain, statistically significant reductions in mu-opioid receptor binding occur in the subiculum and hippocampus of Alzheimer's disease brains. Binding of delta-opioid receptors is also decreased in the amygdaloid complex and ventral putamen of Alzheimer's disease brains. In contrast, large increases of kappa-opioid receptor binding are found in the dorsal and ventral putamen as well as in the cerebellar cortex of Alzheimer's disease brains. Levels of mu- delta- and kappa-opioid receptor binding are unaltered in the caudate, parahippocampal gyrus and occipito-temporal gyrus. These results may suggest an involvement of the endogenous opioid system in some of the multitude of effects that accompany this dementia.  相似文献   
69.
Defining the specific cause of pain in patients with cancer often has substantial therapeutic and prognostic implications. This process often requires the use of specific diagnostic investigations. Here we critically review the diagnostic investigations used in the evaluation of common pain problems in patients with cancer. Familiarity with this information facilitates the development of efficient and rational diagnostic strategies.  相似文献   
70.
Measurement of myocardial perfusion is important for the functional assessment of heart in vivo. Our approach is based on the modification of the longitudinal relaxation time T1 induced by magnetic spin labeling of endogenous water protons. Labeling is performed by selectively inverting the magnetization within the detection slice, and longitudinal relaxation is measured using a fast gradient echo MRI technique. As a result of blood flow, nonexcited spins enter the detection slice, which leads to an acceleration of the relaxation rate. Incorporating this phenomenon in a mathematical model that describes tissue as two compartments yields a simple expression that allows the quantification of perfusion from a slice-selective and a global inversion recovery experiment. This model takes into account the difference between T1 in blood and T1 in tissue. Our purpose was to evaluate the feasibility and reproducibility of this technique to map quantitatively myocardial perfusion in vivo in rats. Quantitative maps of myocardial blood flow were obtained from nine rats, and the reproducibility of the technique was evaluated by repeating the whole perfusion experiment four times. Evaluation of regions of interest within the myocardium yielded a mean perfusion value of 3.6 ± .5 ml min?1 g-1 over all animals, which is in good agreement with previously reported literature values.  相似文献   
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