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71.
A 9-year-old male child had a IV ventricular medulloepithelioma of classical histology, showing tubulopapillary and undifferentiated areas. The unusual feature, however, was the presence of melanin pigmentation in the cells, which was further confirmed by electron microscopy. So far 28 cases of medulloepithelioma have been reported in the English literature. However, none of them showed melanin pigmentation. To the best of our knowledge this is the first case of pigmented medulloepithelioma in the English literature.  相似文献   
72.
Daily injections of amphetamine during 3 weeks into the rat caudal and rostral neostriatum impaired avoidance conditioning of rats in shuttle box. The data obtained suggests involvement of both parts of the neostriatum's dopaminergic system in avoidance conditioning and complex behavioural actions in rats.  相似文献   
73.
The cell death response known as the hypersensitive response (HR) is a central feature of gene-for-gene plant disease resistance. A mutant line of Arabidopsis thaliana was identified in which effective gene-for-gene resistance occurs despite the virtual absence of HR cell death. Plants mutated at the DND1 locus are defective in HR cell death but retain characteristic responses to avirulent Pseudomonas syringae such as induction of pathogenesis-related gene expression and strong restriction of pathogen growth. Mutant dnd1 plants also exhibit enhanced resistance against a broad spectrum of virulent fungal, bacterial, and viral pathogens. The resistance against virulent pathogens in dnd1 plants is quantitatively less strong and is differentiable from the gene-for-gene resistance mediated by resistance genes RPS2 and RPM1. Levels of salicylic acid compounds and mRNAs for pathogenesis-related genes are elevated constitutively in dnd1 plants. This constitutive induction of systemic acquired resistance may substitute for HR cell death in potentiating the stronger gene-for-gene defense response. Although cell death may contribute to defense signal transduction in wild-type plants, the dnd1 mutant demonstrates that strong restriction of pathogen growth can occur in the absence of extensive HR cell death in the gene-for-gene resistance response of Arabidopsis against P. syringae.  相似文献   
74.
OBJECTIVE: To measure the actual concentrations of dopamine, dobutamine, and epinephrine in infusates prepared for patients, and to compare these concentrations with those of the dopamine HCl, dobutamine, and epinephrine HCl infusates that had been prescribed to evaluate drug preparation accuracy. DESIGN: Prospective, unblind study. SETTING: Pediatric intensive care unit in a tertiary-care teaching hospital. PARTICIPANTS: All dopamine, dobutamine, and epinephrine infusions ordered for patients during the 2-month study period were eligible for inclusion in the study. MEASUREMENTS: Daily samples of dopamine, dobutamine, and epinephrine infusates that were prepared for 41 pediatric patients were obtained; the infusate catecholamine concentration was measured by HPLC and compared with the ordered concentration. The concentration than was multiplied by the rate of infusion to determine the catecholamine dose. MAIN RESULTS: There were significant differences between the measured doses of dopamine, dobutamine, and epinephrine and the dopamine HCl, dobutamine, and epinephrine HCl doses (p = 0.0001, p = 0.039, and p = 0.0009, respectively) that had been ordered because of preparation inaccuracies. Failure to account for the HCl salt in the stock drug accounted for some, but not all, of the inaccuracy of the dopamine HCl and epinephrine HCl infusates. There was a wide interday variability in the measured catecholamine dosage in patients receiving the same dose for 3 days or more. CONCLUSIONS: There are daily fluctuations in the preparation of dopamine, dobutamine, and epinephrine infusates that could alter the amount of drug actually delivered to critically ill patients and potentially contribute to their hemodynamic instability.  相似文献   
75.
P-selectin expressed on the surface of endothelium mediates leukocyte adhesion in vitro and rolling in vivo. Several inducers of cell-surface P-selectin expression on endothelial cells (EC) have previously been identified, all of which yield transient cell-surface expression of P-selectin lasting minutes to a few hours. We now show that a T-lymphocyte product, interleukin-3 (IL-3), stimulates the long-term endothelial cells (HUVEC). IL-3 induced cell-surface P-selectin expression in two phases. An initial peak at 10 minutes was followed by a prolonged upregulation beginning 16 hours after IL-3 addition and lasting at least 4 days. The level of P-selectin expression induced by IL-3 added for 48 hours was similar to that induced by treatment of HUVEC for 10 minutes with thrombin, and the effect of adding IL-3 for 48 hours followed by thrombin for 10 minutes was additive. Induction of cell-surface P-selectin expression by IL-3 was blocked by pretreatment of EC with a blocking monoclonal antibody against the IL-3 receptor alpha-chain. Lipopolysaccharide (LPS), tumor necrosis factor alpha (TNF alpha) and a mutant form of IL-3 with decreased potency did not induce cell-surface P-selectin expression after 48 hours' incubation with HUVEC, suggesting that the effect was specific to IL-3. The increase in cell-surface P-selectin expression occurring after 16 hours of incubation with IL-3 was accompanied by a similar prolonged increase in the steady-state mRNA level that was not observed at 10 minutes after IL-3 addition. As T-lymphocyte infiltration is a hallmark of chronic inflammation, our observations suggest that the secretion of IL-3 by T lymphocytes may serve to maintain the inflammatory state during chronic inflammation.  相似文献   
76.
Nuclear medicine imaging techniques are an important adjunct to other currently used modalities in the evaluation of patients with fever of unknown origin. Bone scanning performed with technetium-labeled phosphonate agents may identify osteomyelitis when plain radiography fails and may disclose sites of joint inflammation or unsuspected osseous tumor metastasis. Indium-labeled autologous leukocytes localize at sites of inflammation in the same manner as unlabeled leukocytes. Gallium citrate accumulates in areas of inflammation and in some tumors, most notably lymphomas. In most cases, scintigraphy is best used to determine the location of a lesion rather than to specifically identify the pathologic process.  相似文献   
77.
The incidence of dementia: a meta-analysis   总被引:1,自引:0,他引:1  
OBJECTIVE: To carry out a meta-analysis of the age-specific incidence of all dementias, including AD and vascular dementia. BACKGROUND: Several meta-analyses have been carried out on dementia prevalence, but none on its incidence. METHODS: We used loess-curve fitting to analyze data from 23 published studies reporting age-specific incidence data. RESULTS: The incidence of both dementia and AD rose exponentially up to the age of 90 years, with no sign of leveling off. The incidence rates for vascular dementia varied greatly from study to study, but the trend was also for an exponential rise with age. There was no sex difference in dementia incidence (p = 0.21), but women tended to have a higher incidence of AD in very old age, and men tended to have a higher incidence of vascular dementia at younger ages. East Asian countries had a lower incidence of dementia than Europe (p = 0.0004), and also tended to have a lower incidence of AD. CONCLUSIONS: The incidence of dementia rises exponentially to the age of 90 years. Any sex differences are small, and incidence is lower in East Asia than in Europe.  相似文献   
78.
Subsurface perfusion to lung parenchyma underlying the pleura is difficult to assess in live ventilated animals. The purpose of this study was to assess applicability of a newly developed laser Doppler grid scanning imaging technology that measures perfusion of pleural subsurface lung regions in intact normal and abnormal animal lungs. Eighty-six Doppler grid perfusion measurements were performed in five New Zealand White Rabbits (3-5 kg); four with unilateral bullous lung disease, one normal control. Left upper lobe lung surface was exposed to 10 1-sec spot Nd:YAG exposures (70 W/cm2). One week following laser exposure, all rabbits underwent sequential bilateral open thoracotomy. Unaffected left lower lobes in these animals and all four lobes of a previously untreated rabbit were used as controls. Pleural subsurface perfusion measurements were recorded over a contiguous 900-pixel square surface grid using quantitative noncontact laser Doppler imaging during open thoracotomy procedures. Scans were obtained in a normal volume ventilation mode, at 30 cm of inspiratory hold airway pressure, and postinflation. A perfusion-pressure response curve was obtained in normal lung at 10-, 20-, and 30-cm static airway pressure. Post mortem measurements were used as 0 flow controls. Normal lung tissue was found to have relatively high pleural subsurface perfusion (1362 +/- 328 corrected units on a scale of 0-4095). Areas of atelectasis had decreased perfusion (659 +/- 512 U., 48.4 +/- 12.5% compared to normal lung, p < 0.02), but returned to normal levels after inflation of the lung (1253 +/- 363 U., p = 0.21 compared to normal). Pleural subsurface perfusion decreased uniformly and progressively as lung inflation pressure increased (p < 0.0001). Perfusion increased immediately to supranormal values following release of high inspiratory inflation pressure holds (1603 +/- 626 U., 117 +/- 18% compared to normal lung, p = 0.03). Bullae had markedly decreased perfusion (541 +/- 68 U.) that was not further reduced by increased inflation pressures. Noncontact laser Doppler grid perfusion imaging appears to provide a new tool for measuring pleural subsurface perfusion over a large area of lung surface in clinical experimental settings. Results are rapid, reproducible, and consistent. Sampling errors inherent in current point sampling Doppler flow techniques are reduced by the multiple contiguous measurements. We have used this technique to demonstrate inspiratory pressure-related reduction in pleural subsurface perfusion in normal lung, reversible decreased perfusion in atelectatic regions, and reduced perfusion in bullous and laser-treated lung regions.  相似文献   
79.
The authors report a case of a 13-year-old girl with Barrett's esophagus who underwent antireflux surgery and was subsequently treated with endoscopic thermal coagulation using bipolar electrocoagulation. Follow-up endoscopy 15 months after completion of the endoscopic therapy showed normal esophageal mucosa without intestinal metaplasia. Longer follow-up is needed to assess the long-term effects of endoscopic treatment of the Barrett's mucosa with thermal coagulation, and this procedure should still be considered under investigation.  相似文献   
80.
As part of the Norwegian Medical Association's quality assurance programme for the primary health care sector we have investigated the lasting quality of the specimens drawn for determination of Thrombotest. Blood drawn into siliconated glass tubes resulted in varying Thrombotest values, depending on the time of analysis after specimen collection. Reliable Thrombotest values are needed to be able to administer the correct dosage of warfarin. Thrombotest analysis should therefore be performed within two hours, or after 48 hours of specimen collection.  相似文献   
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