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41.
Estimating medical costs with censored data   总被引:6,自引:0,他引:6  
Bang  H; Tsiatis  AA 《Biometrika》2000,87(2):329-343
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Drug delivery through the vagina is a novel and effective approach for treating embryonic diseases. Magnetic nanoparticles (MNPs) currently are used as drug delivery systems. The safety of MNPs for use with embryonic tissues remains unclear. We used pregnant mice to investigate the possible toxicity of MNPs toward neonatal liver at three embryonic ages using histochemical and immunohistochemical techniques. MNPs were instilled through the vaginas of pregnant mice at days 12 (E12), 15 (E15) and 17 (E17) after fertilization. We found MNPs in the neonatal liver parenchyma after delivery of the pups on day 20. We observed that MNPs caused mild apoptosis of hepatocytes, cytoplasmic vacuolation and lymphocytic infiltration in the neonatal liver after treatment at E15 compared to instillation at E12 and E17. We observed also that MNPs increased the production of caspase proteins and tumor necrosis factor receptor 2 proteins, which are indicators of apoptosis, in the neonatal liver after instillation of MNPs at E15 compared to instillation at E12 and E17. MNPs also increased the number of collagen fibers and the amounts of connective tissue growth factors in the neonatal liver parenchyma after instillation at E15 compared to instillation at E12 and E17. The general carbohydrates in the neonatal liver were decreased in a time-dependent manner after instillation at E17, E15 and E12 owing to the presence of MNPs in the parenchyma. Overall, we determined that MNPs were mildly toxic to neonatal liver.  相似文献   
44.
The liver is a target for toxic chemicals such as cadmium (Cd). When the liver is damaged, hepatic stellate cells (HSC) are activated and transformed into myofibroblast-like cells, which are responsible for liver fibrosis. Curcuma longa has been reported to exert a hepato-protective effect under various pathological conditions. We investigated the effects of C. longa administration on HSC activation in response to Cd induced hepatotoxicity. Forty adult male albino rats were divided into: group 1 (control), group 2 (Cd treated), group 3 (C. longa treated) and group 4 (Cd and C. longa treated). After 6 weeks, liver specimens were prepared for light and electron microscopy examination of histological changes and immunohistochemical localization of alpha smooth muscle actin (αSMA) as a specific marker for activated HSC. Activated HSC with a positive αSMA immune reaction were not detected in groups 1 and 3. Large numbers of activated HSC with αSMA immune reactions were observed in group 2 in addition to Cd induced hepatotoxic changes including excess collagen deposition in thickened portal triads, interlobular septa with hepatic lobulation, inflammatory cell infiltration, a significant increase in Kupffer cells and degenerated hepatocytes. In group 4, we observed a significant decrease in HSC that expressed αSMA with amelioration of the hepatotoxic changes. C. longa administration decreased HSC activation and ameliorated hepatotoxic changes caused by Cd in adult rats.  相似文献   
45.
Two patients suffering from aneurysms of the internal carotid artery simulating pituitary tumours are reported. One of these was a 17-year-old boy with a mycotic aneurysm of the right internal carotid artery causing failure of growth and pubertal maturation. The second was a 53-year-old woman with a left internal carotid artery aneurysm, probably of atherosclerotic origin, who had evidence of anterior pituitary insufficiency.In both cases there was paresis of extraocular muscles and one patient had bitemporal hemianopsia. While lateral radiographs of the skull suggested intrasellar calcification in each case, further roentgenological investigation established that this calcification was actually extrasellar, and carotid arteriograms demonstrated the presence of an internal carotid aneurysm in each case. Investigations of the endocrine system confirmed the presence of anterior pituitary insufficiency in both patients, and diabetes insipidus became evident in one patient after cortisone therapy was commenced.This lesion, while rare, may be difficult to differentiate from a pituitary tumour. It is likely that this syndrome depends on aneurysmal expansion to the region of the sella turcica with compression of the pituitary gland itself, as well as the optic fibres.  相似文献   
46.
The interaction of amphotericin B with ergosterol was studied in aqueous solutions of propanol. The mode of the interaction was found to be related to the aggregation state of amphotericin B. Ergosterol does not react (or reacts extremely slowly) with monomeric amphotericin B. Traces of a small aggregate, probably a dimer, enable a cooperative reaction. At high concentrations of the dimer, the reaction is immediate and the concentration of amphotericin B complexed with ergosterol is twice as high as the amount of added sterol. The interaction with ergosterol is hindered when the antibiotic is in micellar form. The pharmaceutical form, Fungizone, behaves similarly to the pure amphotericin B. Fungizone's greater solubility in water does not modify either the extent or the mode of interaction with ergosterol.  相似文献   
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Journal of Molecular Histology - End-stage liver disease (ESLD) is a term used clinically in reference to a group of liver diseases with liver transplantation as the choice of treatment. Due to the...  相似文献   
49.
Sport hunting may help in controlling cervid populations over large areas. As with natural predators, several environmental factors can influence sport harvest. A better understanding of the environmental variables that limit the efficiency of sport hunting could provide guidelines for more efficient wildlife management using hunting. We studied white-tailed deer (Odocoileus virginianus) hunting on a high deer density island where hunting was the sole form of predation. Our objective was to study the behavior of sport hunters and determine the habitat characteristics (e.g., abundance of deer forage, visibility of the deer from the hunter's point of view, and accessibility of the territory to hunters) that are associated with a successful harvest. We collected movements and harvest site location data from 477 hunters equipped with handheld Global Positioning System (GPS) units. Harvest sites were visited and characterized, along with a paired random site, to determine the environmental conditions associated with a successful hunt. We also developed a model to predict the daily number of deer seen by hunters considering weather conditions, hunter characteristics (e.g., age, experience), and date of hunting. We used the mean number of deer seen per hunter per day as a relative index of local density in each hunted territory. At both the site and landscape scales, the combination of visibility and access had a positive effect on the distribution of harvested deer. Habitat types with less visual obstruction from vegetation enabled hunters to see more deer in a given day. At the site scale, harvested deer were located in areas with a lower density of access routes compared to areas where hunters travelled throughout the day. Using an innovative approach of studying hunter behavior with GPS technology, digital maps, and questionnaires, we highlighted the factors associated with hunter success. Our study suggests that habitat characteristics could be modified to increase harvest by improving accessibility and visibility near roads. Creating openings in mature and regenerating forest near access roads could make sport hunting a more efficient management tool, but the potential impact of increased forage availability in forest openings should not be overlooked. © 2012 The Wildlife Society.  相似文献   
50.
With no further intervention, relapse rates in detoxified alcoholics are high and usually exceed 80% of all detoxified patients. It has been suggested that stress and exposure to priming doses of alcohol and to alcohol-associated stimuli (cues) contribute to the relapse risk after detoxification. This article focuses on neuronal correlates of cue responses in detoxified alcoholics. Current brain imaging studies indicate that dysfunction of dopaminergic, glutamatergic and opioidergic neurotransmission in the brain reward system (ventral striatum including the nucleus accumbens) can be associated with alcohol craving and functional brain activation in neuronal systems that process attentional relevant stimuli, reward expectancy and experience. Increased functional brain activation elicited by such alcohol-associated cues predicted an increased relapse risk, whereas high brain activity elicited by affectively positive stimuli may represent a protective factor and was correlated with a decreased prospective relapse risk. These findings are discussed with respect to psychotherapeutic and pharmacological treatment options.  相似文献   
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