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121.
Cortical spreading depression is a wave of electrical and biochemical changes that spreads across the cerebral cortex. It has been hypothesized to be an important underlying cause of the visual disturbances occurring during the migraine aura, but this is difficult to test in animals or humans. We created a computational model of cortical spreading depression and found that during the wave of biochemical changes the spatial pattern of neural activity broke up into irregular patterns of lines and small patches of highly activated elements. The corresponding visual disturbances that would be produced by these patterns of neural activity resemble the hallucinations reported during the migraine aura, providing strong support for the cortical spreading depression hypothesis of migraine. The model also makes the testable prediction that these hallucinations move at an exponentially increasing speed across the visual field.  相似文献   
122.
We used certain physiologic maneuvers to perturb the autonomic nervous system (ANS) in an attempt to detect a link between the ANS and pain. In the unperturbed state, we found no difference in the electrodermal response among normal controls, preoperative patients (increased stress without pain) and postoperative patients (increased stress and pain). The electrodermal response elicited by autonomic maneuvers was significantly attenuated in postoperative patients but not in preoperative patients or in normal control subjects.  相似文献   
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Postoperative adhesions account for a significant morbidity after abdominal, gynecological, or cardiac surgery. A large number of compounds have been suggested to prevent such adhesions, but none is generally accepted. We have compared eight different substances that could be beneficial for the prevention of postoperative adhesions in a new standardized rabbit model with measurement of the areas of adhesion. In 10 groups of 20 rabbits an area of abrasion of the serosa of the ileum, the appendix, and the abdominal wall measuring 10,000 mm2 was created by an emery piston during celiotomy. The controls received no medication. The treatment groups received a single intraperitoneal administration of 1 ml per 100 g body wt of normal saline (NaCl), 5 mg taurolidine (T), 0.5 U plasmin/300 U DNase (PD), 2000 IU streptokinase/500 IU streptodornase (SS), 7 mg phosphatidylcholine (PC), 4 mg hyaluronic acid (HA), 7 mg sphingolipid (SL), 7 mg galactolipid (GL), or 0.5 ml tetrachlorodecaoxide (TCDO), respectively. Ten days later the extent of adhesions was quantified by morphometry. The total area of adhesions (+/- SEM) was found to be 1998 +/- 124 mm2 in controls. The application of NaCl reduced the adhesions to 1368 +/- 58 mm2, of T to 1012 +/- 48 mm2, of PD to 673 +/- 33 mm2, of SS to 360 +/- 44 mm2, of PC to 335 +/- 84 mm2, of HA to 328 +/- 76 mm2, of SL to 278 +/- 80 mm2, of GL to 261 +/- 67 mm2, and of TCDO to 240 +/- 45 mm2. The effects of PD, SS, PC, HA, SL, GL, and TCDO were significant in comparison to controls and NaCl. Our experimental data suggest that the two new lipid substances, SL and GL, are the most likely candidates for routine clinical use in the prevention of postsurgical adhesions.  相似文献   
125.
BACKGROUND: We have previously observed a potentiation of the metabolic response to cachectin/tumor necrosis factor (TNF) by total parenteral nutrition (TPN) but not in anorexic orally fed animals. We hypothesized that nutritional status might affect TNF clearance kinetics. METHODS: We compared the clearance of a bolus of labeled TNF in TPN-fed animals given sufficient nutrients to grow called weight-gaining rats (WGR) with those given 50% of the WGR called weight-losing rats (WLR) and with orally fed rats (OFR). Data were analyzed using a two-compartment open system model and by linear systems analysis. RESULTS: The data from both types of analysis indicator that although metabolic clearance was similar, WGR had a slower fractional TNF clearance rate (FCR) as well as a larger volume of distribution than WLR or OFR. Further analysis showed that an increased proportion of the total mass of TNF resided in a plasma-associated compartment in WGR compared with WLR and OFR. In addition, WGR had reduced uptake of labeled TNF by the kidney. CONCLUSION: The data suggest that nutrition support influences either the distribution of TNF or the FCR, resulting in a greater retention in the plasma-associated compartment with intact absolute removal rates. This study has important implications concerning the type of nutrition support provided to the critically ill patient because our data suggest that clinical states with increased circulating TNF levels may be adversely affected by currently available nutritional practices.  相似文献   
126.
The results of different investigators show that lack of p105 expression is relatively common in human myeloid leukemias, especially in monocytic leukemias. This suggests that loss of p105 expression could contribute to the altered growth control of these cells. So far no clear data exist which show that low p105 levels in AML blasts predict a poor therapy outcome. Therefore it is not very likely that p105 expression will become a strong prognostic factor for the different treatment strategies in AML.  相似文献   
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Peripheral T cell lymphoma encompasses lymphomas with a variety of histologic appearances and clinical patterns. Recently, it has been suggested that almost all of the histologic features described under the name of polymorphic reticulosis(PR), lethal midline granuloma, and midline malignant reticulosis can be included in those generally described for malignant lymphomas of peripheral T cell origin(PTCL). There have been few studies of pathogenesis or tissue damage mechanism in PR patients. The need for a precise mechanism for tissue damage has important therapeutic implications. Using immunohistochemical methods with polyclonal anti IL-6 antibody, the authors describe 5 cases of PR with clinically and pathologically typical PR demonstrating a high expression of IL-6. According to classification, 2 cases of grade 1 PR showed the highest expressions, and 2 cases of grade 2 PR with atypical lymphoid cells showed moderate activity, but one case progressed into frank lymphoma(grade 3) and lost IL-6 expression. This strongly implies that some cases of PR have a different mechanism of tissue damage from frank PTCL, despite the one disease spectrum. Further studies on more cases may help clarify the pathogenesis.  相似文献   
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Nasal mucociliary clearance (NMC) is a biomarker of nasal mucosal function. Tobacco smokers have been shown to have abnormal NMC, but the acute effect of environmental tobacco smoke (ETS) on nonsmokers is unknown. This study evaluated acute tobacco smoke-induced alterations in NMC in 12 healthy adults. Subjects were studied on 2 days, separated by at least 1 week. Subjects underwent a 60-min controlled exposure at rest to air or sidestream tobacco smoke (SS) (15 ppm CO) in a controlled environmental chamber. One hour after the exposure, 99mTc-sulfur colloid was aerosolized throughout the nasal passage and counts were measured with a scintillation detector. Six out of 12 subjects showed more rapid clearance after smoke exposure than after air exposure, and 3/12 had rapid clearance on both days. However, substantial decreases in clearance occurred in 3/12 subjects, all of whom had a history of ETS rhinitis. In two subjects, more than 90% of the tracer remained 1 hr after tracer administration (2 hr after smoke exposure). Understanding the basis for biologic variability in the acute effect of tobacco smoke on NMC may advance our understanding of pathogenesis of chronic effects of ETS.  相似文献   
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