首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Traumatic injury to the central nervous system induces delayed neuronal death, which may be mediated by acute and chronic neurochemical changes. Experimental identification of these injury mechanisms and elucidation of the neurochemical cascade following trauma may provide enhanced opportunities for treatment with novel neuroprotective strategies.  相似文献   

3.
Central nervous system (CNS) disease in Langerhans cell histiocytosis (LCH) is a poorly understood complication of yet unknown frequency. By far the most common manifestation is in the hypothalamic-pituitary system with diabetes insipidus as the leading sign, followed by other endocrinopathies and hypothalamic dysfunction. However, essentially all other parts of the CNS may be involved. On the one hand, space-occupying histiocytic infiltrates may lead to size- and site-depending symptoms, extending from adjacent bone lesions or arising from the meninges or choroid plexus. On the other hand, a progressive neurological deterioration can occur with mainly cerebellar-pontine symptoms. In this article, these clinical patterns are described in correlation with the morphology on MR imaging and histopathology. Further, the therapeutic strategies are reviewed critically, and guidelines for the management of patients with LCH-related CNS disease are presented.  相似文献   

4.
Central nervous system aspergillosis in two young adults   总被引:1,自引:0,他引:1  
Unusual and unique features were present in the cases of two patients with central nervous system aspergillosis: One had a previously unreported complication of aspergillosis, extracranial internal carotid artery thrombosis documented by angiography, and in the other patient, cerebral granulomas developed from Aspergillus fumigatus in association with intravenous narcotic abuse. The latter etiologic mechanism was suggested once before. Neither of these patients showed other underlying disease. A detailed neuropathologic examination correlated the salient clinical findings with formation of aspergillosis cerebral granulomata, basilar meningitis, and arterial occlusion. Diagnostic and therapeutic methods in this disease are limited.  相似文献   

5.
6.
Central cholinergic nervous system play important role in many physiological and behavioral functions in humans. The activity of the cholinergic nervous system depends upon the production and fate of acetylcholine and all compounds influenced its biosynthesis, storage, release, hydrolysis, interaction with different subtypes of cholinergic receptors, etc., there are very important drugs and therapeutics. This paper summarizes current views on many compounds which can interact with different parts of central cholinergic nervous system.  相似文献   

7.
8.
Stimulation of sites in the midbrain reticular formation and in the posterior hypothalamus of the cat resulted in a large to modest rise of arterial pressure and the induction of cardiac dysrhythmias. Most frequently, these arrhythmias developed upon cessation of brain stem stimulation but also occurred during the stimulus period in 5 of 23 cats studied. The arrhythmias disappeared upon cooling and reappeared upon rewarming the vagus nerves. The ventricular dysrhythmias also were abolished by methylscopolamine, by bilateral vagatomy, or by extirpation of the stellate ganglia. Simultaneous stimulation of both distal end of the cut right vagus nerve and the decentralized right stellate ganglion caused arrhythmias similar to those observed after diencephalic stimulation. These data are interpreted to indicate that the cardiac arrhythmias evoked by brain stem stimulation result from the interplay of both sympathetic and parasympathetic influences on the heart. The response patterns of a population of medullary neurons activated by carotid sinus nerve stimulation were modified by condition stimuli to posterior hypothalamic sites. From studies on unit activity of brain stem areas known to participate in cardiovascular adjustment, a schema is proposed of hypothalamic-medulla interaction as a central mechanism that may account for the development of ventricular arrhythmias.  相似文献   

9.
Orthodontic bands form retention areas which create favourable conditions for growth of lactobacilli. This study deals with the numbers and specific species of lactobacilli in the oral cavity of teenage orthodontic patients. High numbers of lactobacilli were obtained (log 6.398 +/- 0.761 cfu/ml) and the buffer capacity of saliva indicated a high caries risk amongst these individuals but the actual DMFT values were relatively low. Homofermentative lactobacilli predominated in both plaque and saliva and particularly L. salivarius and L. casei. These two lactobacilli species indicated that these patients are at a high caries risk. Several other homofermentative and heterofermentative lactobacilli were isolated which indicated the complexity of the oral lactobacilli community in saliva and plaque.  相似文献   

10.
Infections of the nervous system remain a significant source of morbidity and mortality in patients with cancer. This paper reviews the main pathogens and emphasizes some of the principles of diagnosis and management of nervous system infections in cancer patients. Due to immunosuppression, diagnosis is more difficult in this group, secondary to the multitude of potential pathogens, and often by their atypical presentations. Fever or headache are often the only symptoms. Clinical history and general examination should guide appropriate studies such as neuroimaging. CSF analysis, cultures, and brain biopsy. Diagnostic evaluation should be pursued rapidly and aggressively since specific treatments can often reduce morbidity and mortality. Bacterial infections are generally due to break-down of the natural barriers and neutropenia. In neutropenia, Pseudomonas aeruginosa, and Enterobacteriae are the most frequent etiology. If all causes of immunodepression are included, Listeria monocytogenes meningitis is the main bacterial infection encountered. Fungal infections have emerged as a major cause of death among cancer patients. The prognosis of cryptococcosis and histoplasmosis meningitis are markedly improved with new antifungal therapy. Aspergillosis and Mucormycosis, which may cause cerebral abcesses and secondary vascular complications, are almost always fatal. The incidence of meningo-cerebral Candidiasis is often underestimated. Similar to Histoplasmosis, it is frequently disseminated. Viral infections are mainly seen in patients with T-lymphocyte defects. Herpes-simplex virus and Varicella-Zoster virus encephalitis should quicky lead to intravenous treatment with Acyclovir. As in AIDS patients, cerebral toxoplasmosis is the most frequent parasitic infection and appropriate therapy greatly reduces morbidity. It should be emphasized that multitude pathogens are often seen in cancer patients. Despite development of new therapeutic agents, central nervous system infections should still be considered life-threatening. Therefore, antibacterial, antifungal, and antiviral prophylaxis should be the rule for all cancer patients.  相似文献   

11.
Few well-documented cases of central nervous system involvement in patients with hepatitis C virus infection have been reported. We describe three patients (two men and one woman) with cerebral involvement (ischemia and/or hemorrhage). Hepatitis C virus infection was confirmed in all patients by polymerase chain reaction detection of hepatitis C virus RNA. These three cases document the occurrence of central nervous system involvement in patients with hepatitis C virus infection and mixed cryoglobulinemia. Cerebral involvement may be the initial manifestation of hepatitis C virus infection.  相似文献   

12.
The internalization of basic fibroblast growth factor (FGF-2) was studied in Chinese hamster lung fibroblasts (CCL39). Recombinant FGF-2 was derivatized with a photoactivable agent, N-hydroxysuccinimidyl-4-azidobenzoate (HSAB), iodinated, and used to visualize intracellular FGF-2-affinity-labeled molecules after internalization at 37 degrees C. Iodinated HSAB-FGF-2 maintained the properties of natural FGF-2 such as affinity for heparin, binding to Bek and Fig receptors, interaction with high- and low-affinity binding sites, and reinitiating of DNA synthesis in CCL39 cells. Affinity-labeling experiments at 4 degrees C with 125I-HSAB-FGF-2 led to the detection of several FGF-cell surface complexes with apparent molecular mass of 80, 100, 125, 150, 170-180, 220, 260, and about 320 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), whereas two specific bands at 80 and 130-160 kDa were obtained using the homobifunctional cross-linking reagent, disuccinimidyl suberate. When the cells, preincubated with 125I-HSAB-FGF-2 at 4 degrees C and then washed, were shifted to 37 degrees C, irradiation of the internalized labeled FGF-2 led to detection of a similar but fainted profile with one major specific band at 80 kDa. Heparitinase II treatment of the cells reduced binding of 125I-HSAB-FGF-2 to its cell surface sites by 80% and internalization by 55%, indicating the involvement of heparan sulfate proteoglycans in these processes. Among the heparitinase-sensitive bands was the 80-kDa complex.  相似文献   

13.
The increase in mesolimbic dopamine (DA) release observed during the first 40 min of 120 min restraint in naive rats is not evident in repeatedly stressed animals (daily 60 min restraint, for 5 days). However, repeatedly stressed rats show a significant decrease in DA release from 80 min of restraint onwards which is not observable in naive rats. These results indicate that repeated stressful experiences do not produce habituation but alter the response of mesolimbic DA system to the stressor. Moreover, they point to a possible neuronal mechanism underlying stress-induced depression.  相似文献   

14.
The central nervous system is generated from neural stem cells during embryonic development. These cells are multipotent and generate neurons, astrocytes and oligodendrocytes. The last few years it has been found that there are populations of stem cells also in the adult mammalian brain and spinal cord. In this paper, we review the recent development in the field of embryonic and adult neural stem cells.  相似文献   

15.
Cathepsin D, an aspartic proteinase, correlates with invasion and metastasis in breast cancer and with poor prognosis. In the present study, we examined the immunohistological expression of cathepsin D in both primary (5 cases) and skin-metastatic breast cancers (13 cases) and compared it to those in gastric (2 cases) and lung (4 cases), and primary eccrine cancers (3 cases). All breast and gastric cancers were adenocarcinomas. The 2 gastric cancers were poorly differentiated, while the 4 lung cancers consisted of 2 poorly differentiated adenocarcinomas, 1 poorly differentiated large cell carcinoma, and 1 moderately to poorly differentiated squamous cell carcinoma. We also surveyed the immunohistological distribution of cathepsin B, carcinoembryonic antigen, gross cystic disease fluid protein-15, c-erbB-2, and estrogen receptor. In almost all breast cancer samples, the cancer cells demonstrated strong expression of cathepsin D in the cytoplasm, but weak staining patterns with other antibodies. Gastric and lung cancer cells did not respond with cathepsin D (except one metastatic lung cancer) or the other immunohistological markers. Since cathepsin D is strongly expressed in primary and metastatic lesions of breast cancer, cathepsin D could be useful as an adjunct to a panel of immunohistochemical stains in determining the primary site of origin of metastatic cancer in the skin.  相似文献   

16.
OBJECTIVES: To evaluate variables instrumental in central nervous system infections after military missile head wounds, using uni- and multivariate analysis in 964 patients during the 8-year Iran-Iraq War. METHODS: Factors considered in this retrospective study were: the types of projectile, mode of injury, paranasal sinus involvement, number of lobes involved, transventricular injuries, place of exploration (base hospital or Nemazee Hospital), cerebrospinal fluid (CSF) fistulas, Glasgow Coma Scale (GCS) score, retained bone, and retained shell fragments. RESULTS: During the study period, 105 patients (11%) developed central nervous system infections, including 20 abscesses, 1 case of cerebritis, 2 cases of fungus cerebri, and 82 cases of meningitis. gram-negative organisms, especially Klebsiella pneumoniae, were the most frequent offending organisms. Forty-one percent of the 133 deaths were due to infections, but the death rate from infection was only 4.4%. Univariate analysis showed mode of injury, number of lobes involved, ventricular penetration, paranasal sinus involvement, CSF fistulas, place of exploration, GCS score, and retained bone fragments to have significant bearing on the incidence of central nervous system infections. On the other hand, multivariate regression analysis disclosed the following factors each enhancing infection: CSF fistulas (chi2 = 46.526), transventricular injuries (chi2 = 13.4790), and paranasal petrous sinuses involvement (chi2 = 4.2221). When compared with primary exploration at the Nemazee Hospital, both exploration at a base hospital and no exploration at all were associated with increased chances of infection (chi2 = 4.7629 and 8.3220, respectively). Additionally, when tangential, crossed penetrating, and uncrossed penetrating injuries were compared with through-and-through injuries, the uncrossed penetrating mode was associated with less infection (chi2 = 0.1652, 2.6353, and 5.0817, respectively). Only two patients were readmitted for new evidence of infection 3 and 5 months after missile head wounds, one definitely due to and the other on suspicion of CSF fistulas. One hundred and thirty-seven of 587 patients with retained bone fragments were followed a mean of 42 months with no evidence of delayed infection. CONCLUSION: In this study, CSF fistulas and transventricular and paranasal sinus injuries all were associated with increased chances of central nervous system infections after military missile head wounds. Infection rate was lower in penetrating injuries not crossing into another dural compartment. Exploration at the Nemazee Hospital, despite delays in evacuation, had less incidence of infection than surgery at a base hospital within the first 24 hours of injury. Retained bone and metal fragments, a lower GCS score at the time of admission, secondary exploration at the Nemazee Hospital, and number of lobes involved were less important when evaluated in a multivariate regression model.  相似文献   

17.
We set out to determine whether the increases in intracranial pressure (ICP) associated with CO2 insufflation had any metabolic effect on the central nervous system in a head injury when compared with gasless laparoscopy (GL). To test this hypothesis, we looked at both the ICP and jugular bulb venous saturation (JVS), with and without a coexisting cerebral mass lesion. Twenty-five kilogram male pigs had tracheostomy, epidural balloon, pulmonary arterial catheter, arterial line, and jugular bulb catheter placed. Intravenous Pentobarbital was used for anesthesia. Either CO2 laparoscopy (CL; n=7) or GL (n=7) were performed both with and without an epidural balloon inflated to a baseline ICP of 25. Data were analyzed using the Student's t test with a P value <0.05 being significant. Cerebral perfusion pressure and most hemodynamic values did not differ. Both central venous pressure and peak inspiratory pressure were significantly elevated whenever CO2 insufflation took place, reflecting an increased intrathoracic pressure. When comparing both study groups, the partial pressure of CO2 did not differ. CL increases ICP significantly above the gasless group in our head injury model. This is most likely secondary to increased intrathoracic pressure. The question still remains whether these changes are clinically significant. We could not demonstrate significant metabolic effects secondary to laparoscopy. In patients suffering head injury, GL rather than CL might be safer to avoid ICP elevation. Additional studies looking at central nervous system metabolic and objective histopathologic effects should be undertaken with larger numbers of study animals.  相似文献   

18.
19.
The secondary structure and global fold of the AVR9 elicitor protein of Cladosporium fulvum has been determined by 2D NMR and distance-geometry protocols. The protein consists of three anti-parallel strands forming a rigid region of beta-sheet. On the basis of the NMR-derived parameters and distance geometry calculations, it is evident that the AVR9 protein is structurally very homologuous to carboxy peptidase inhibitor (CPI) of which the X-ray structure is known. The AVR9 protein reveals the presence of a cystine knot, which consists of a ring formed by two disulfide bridges and the interconnecting backbone through which the third disulfide bridge penetrates. This structural motif is found in several small proteins such as proteinase inhibitors, ion channel blockers and growth factors. The implications of the structural relationship between AVR9 and other biologically active proteins are discussed.  相似文献   

20.
Systemic lupus erythematosus (SLE) is an inflammatory disease in which up to two thirds of the patients present neurological symptoms. The diagnosis of the disease is based on clinical findings and the presence of autoantibodies, and the pathogenesis is unclear. The purpose of this study was to determine if the pathogenesis was partly mediated via nitric oxide (NO) formation. Cerebrospinal fluid (CSF) samples from 15 patients with cerebral SLE were analyzed for the NO metabolites nitrite and nitrate using capillary electrophoresis. The severity of neurological symptoms was scored by dividing the patients into two groups with either mild or moderate/severe CNS involvement. All patients with cerebral SLE showed increased levels of NO metabolites. In CSF, there was a relationship between signs of NO production and clinical results showing that increased levels of nitrite and nitrate were associated with more severe neurological symptoms. These findings may shed new light on the pathogenesis of cerebral SLE, and analysis of nitrate and nitrate may prove to be of value in monitoring the activity of the disease.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号