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41.
Children with no known prior vitamin A deficiency exhibited a significant decline in their serum retinol levels during the acute phase of measles. This decline in circulating retinol was associated with increased duration of fever, higher hospitalization rates, and decreased antibody titers.  相似文献   
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We have shown that stress fractures can be induced in the tibial diaphysis of an animal model by the repeated application of non-traumatic impulsive loads. The right hind limbs of 31 rabbits were loaded for three to nine weeks and changes in the bone were monitored by radiography and bone scintigraphy. The presence of stress fractures was confirmed histologically in some cases. Most animals sustained a stress fracture within six weeks and there was a positive correspondence between scintigraphic change and radiological evidence. Microscopic damage was evident at the sites of positive bone scans. The progression, location, and time of onset of stress fractures in this animal model were similar to those in clinical reports, making the model a useful one for the study of the aetiology of stress fractures.  相似文献   
45.
Relationships between serum cholesterol and coronary heart disease (CHD) were investigated in Tecumseh men and women who were 45 to 92 years old and initially free of CHD. Recruitment continued through three cycles of examinations over a period of 10 years, beginning in 1959. Follow-up for mortality ended in 1986 to 1987. Age-adjusted relative risks for CHD death for cholesterol levels of 5.2 to 6.2 mmol/L and greater than 6.2 mmol/L, compared with levels less than 5.2 mmol/L for men aged 45 to 64 years, were 1.2 and 1.7; for older men they were 1.0 and 1.8. Comparable relative risks for CHD death by cholesterol level were .7 and 1.4 for 45- to 64-year-old women and .8 and .7 for older women. Coefficients for cholesterol were significant for fatal CHD in men under and those 65 years and older when age, systolic blood pressure, body mass index, cigarette smoking status, and glucose intolerance were controlled in proportional hazards models. Cholesterol was a significant predictor of fatal CHD plus nonfatal myocardial infarction in middle-aged, but not elderly women. Relative risks for total mortality were lowest for middle-aged men and women with cholesterol levels of 5.2 to 6.2 mmol/L and the difference was significant in men.  相似文献   
46.
The syndrome of senile gait   总被引:1,自引:0,他引:1  
Summary Infrared computed stroboscopic photometry was used to quantify the kinematic profiles of walking in 10 elderly patients with symmetrical neurological disturbances of gait and in 19 age-matched neurologically healthy people. Clinical examination of the patients revealed similar profiles of walking even though their diagnoses were vascular dementia (2), normal pressure hydrocephalus (2), Alzheimer dementia with possible normal pressure hydrocephalus (2), mixed Alzheimer and vascular dementia (1), peripheral neuropathy (1), Alzheimer dementia with parkinsonian features (1), and un determined (1). Quantitatively, the patients' gait kinematics deviated greatly from control values, but these deviations were statistically attributable to reductions in stride. We suggest that many gait disturbances in elderly people are similar, regardless of etiology, because the characteristics of these gait disturbances are heavily veiled by nonspecific stride-dependent changes that comprise the syndrome of senile gait.  相似文献   
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Experiments were done to investigate the cause of the cranial (mesencephalic) flexure of the chick brain during stages 10 to 14. Measurements of the length and thickness of the roof and floor of the mesencephalon gave values similar to the values obtained previously by others. The labeling index was determined in the roof and floor of the prosencephalon, mesencephalon, and rhombencephalon as a preliminary measure of cell division. The labeling index was about the same in all regions, and was high enough to suggest that most of the cells were dividing. The labeling indices did not suggest that differential growth was caused by differential rates of cell division in the roof and floor of the mesencephalon. It was found through time lapse photography that the foregut and heart remained stationary along the rostrocaudal axis, whereas the prosencephalon moved rostrally and the mesencephalon underwent flexure. Measurements suggested that the neural tube cranial to the otic primordium grew in volume exponentially at a rate consistent with the labeling index. The rostral tip of the neural tube was observed to be linked to the rostral tip of the foregut by the ectoderm that formed Rathke's pouch at the neural tube and the pharyngeal membrane (prospective stomodeum) at the foregut. As the neural tube grew in length, the link between the neural tube and the foregut did not. We suggest that because of this link, the growing neural tube had to bend around the foregut, forming the cranial flexure, and the ectoderm folded where it attached to the prosencephalon, forming Rathke's pouch. © 1994 Wiley-Liss, Inc.  相似文献   
48.
In the present study we have examined the interaction between the selective cholecystokinin (CCK)A and CCKB receptor antagonists, devazepide and L365-260 on morphine conditioned place preference (CPP). Using an unbiased procedure, morphine (1.5 mg/kg) produced a reliable CPP which was observed irrespective of the conditioning compartment type. Pretreatment with devazepide (0.001-0.01 mg/kg s.c.) produced a dose related attenuation of this response. At higher doses (0.1-1 mg/kg) this antagonism became variable and dependent on the training compartment with blockade only observed when conditioning was to the white/rough textured environment. This profile has also been reported for the serotonin (5-HT)3 receptor antagonist ondansetron. The CCKB antagonist L365-260 (0.000001-0.01 mg/kg) failed to antagonize the morphine CPP, if anything a mild potentiation was observed. To study this further we examined the interaction between L365-260 (0.01 mg/kg) and a subthreshold dose of morphine (0.3 mg/kg). At these doses neither drug elicited CPP, however when co-administered a significant CPP was recorded. Finally, L365-260 at 1 mg/kg induced a mild but significant CPP when administered alone. These results suggest a differential role of CCK receptor subtypes on reward-related behaviour and complement previous studies suggesting bimodal effects of CCK systems on mesolimbic dopamine function.  相似文献   
49.
For 75 consecutive days, 54 Ss with rheumatoid arthritis supplied daily reports of their mood and joint pain. After aggregating daily reports, the relation between chronic mood and chronic pain remained statistically significant when controlling for neuroticism, depression, disease activity, disability, and characteristic responses to increasing pain. Findings of a path analysis suggest that (a) individuals higher in neuroticism experience more chronic distress regardless of their responses to pain, their pain intensity, and depressive symptomatology, and (b) the relation between neuroticism and chronic pain is mediated by the propensity of high-neuroticism individuals to catastrophize their pain. Within-subject analyses that controlled for autocorrelation and linear trends in the time series revealed that 40% of the Ss experienced significantly worse moods on more painful days. Although individuals higher in neuroticism reported more intense pain and more negative mood, their daily mood was less strongly linked to their daily pain.  相似文献   
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