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31.
To investigate the role of the sympathetic nervous system in angiotensin II (AngII)-stimulated medial and neointimal smooth muscle cell (SMC) replication, we sympathectomized rats with 6-hydroxydopamine (6-OHDA) in which the left carotid artery was injured by a balloon catheter. Balloon injury is associated with a loss of specific [3H]-prazosin binding. AngII (250 ng/kg/min), infused 2 weeks after balloon injury of the rat left carotid artery, increased systolic blood pressure by approximately 70 mm Hg. There was no effect of 6-OHDA on this pressor response. AngII increased the cumulative 5-bromo-2'-deoxyuridine (BrdU) labeling fraction (LF) in the uninjured right carotid media and the injured left carotid neointima as compared to controls (5.7+/-1.6% vs. 0.4+/-0.1%, p<0.05; 10.6+/-0.9% vs. 5.0+/-0.8%, p<0.05, respectively). 6-OHDA decreased the AngII-induced increase in LF in the media of the uninjured right carotid artery (AngII/6-OHDA 0.9+/-0.2% vs. AngII 5.7+/-1.6%, p < 0.05). 6-OHDA did not decrease the AngII-induced increase in LF in both the injured left carotid media and neointima at 4 weeks after balloon injury. The effects of chemical sympathectomy were comparable with those obtained 12 weeks after balloon injury. Thus, the data show that the sympathetic nervous system mediates the AngII-induced increase in SMC DNA synthesis, but only in the uninjured carotid media. This indicates a differential regulation of AngII-induced SMC replication in injured and uninjured vessels.  相似文献   
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The authors studied the permeability of the blood-brain barrier (CEB) to two nootropics: calcium ketogomopantothenate (KRA-Ca), a GABA derivative, and and calcium salt of oxybutyrate (OB-Ca), a derivative of GOBA. It was established that both preparations penetrate the CEB easily and are found in the brain at different intervals after their administration. However, essential differences in the distribution constant of these drugs were disclosed: KPA-Ca permeated the CEB more intensively and was accumulated in larger amounts in the late-term intervals.  相似文献   
34.
BACKGROUND: Chylothorax is a rare primary or secondary condition the optimum management of which remains uncertain. METHODS: Twenty cases of chylothorax, including ten of primary chylothorax and ten secondary to either malignancy, subclavian vein thrombosis or lymphangioma treated between 1956 and 1986 have been reviewed. RESULTS: Open pleurectomy was the most successful treatment in preventing reaccumulation of the effusion. Three patients had thoracic duct-azygous vein anastomoses, but all anastomoses were probably occluded within a year of surgery. Three patients have been lost to follow-up and five died within 2 years of their treatment, but 12 patients were alive and free from an effusion 3-22 years after treatment. CONCLUSION: Patients with chylothorax should undergo lymphangiography to identify the cause and site of the lymphatic abnormality. Conservative treatment is successful in some patients but should be abandoned if the fluid loss exceeds 1.5 l/day for more than 5-7 days in an adult or more than 100 ml/day in a child. Parietal pleurectomy is the most successful treatment when no distinct chylous leak can be identified. Less commonly, an isolated chylous leak either in the chest or in the abdomen may be identified and this should be treated by direct ligation.  相似文献   
35.
As part of a continued push for high permittivity dielectrics suitable for use at elevated operating temperatures and/or large electric fields, modifications of BaTiO3 with Bi(M)O3, where M represents a net‐trivalent B‐site occupied by one or more species, have received a great deal of recent attention. Materials in this composition family exhibit weakly coupled relaxor behavior that is not only remarkably stable at high temperatures and under large electric fields, but is also quite similar across various identities of M. Moderate levels of Bi content (as much as 50 mol%) appear to be crucial to the stability of the dielectric response. In addition, the presence of significant Bi reduces the processing temperatures required for densification and increases the required oxygen content in processing atmospheres relative to traditional X7R‐type BaTiO3‐based dielectrics. Although detailed understanding of the structure–processing–property relationships in this class of materials is still in its infancy, this article reviews the current state of understanding of the mechanisms underlying the high and stable values of both relative permittivity and resistivity that are characteristic of BaTiO3‐Bi(M)O3 dielectrics as well as the processing challenges and opportunities associated with these materials.  相似文献   
36.
In this work, lithium and diurea greases formulated by poly-alpha-olefin were aged up to 1,200 h in an oven at 120°C and periodically taken out for testing. Scanning electron microscopy (SEM) and infrared (IR) spectra proved that both physical and chemical degradation occurred during the thermal aging process, such as a decrease in apparent viscosity, thickener destruction, and change in chemical species. Diurea grease showed much better anti-oxidation performance during thermal aging than lithium grease. A dual effect of thermal aging on the grease lubricity was observed and analyzed. Results showed that early oxidation might reduce grease lubricity due to the formation of ketones and aldehydes, and the decrease in grease viscosity and oil bleeding due to thickener destruction would contribute to better replenishment.  相似文献   
37.
This special issue of the Transactions is a compilation of the most important papers presented at the 17th IEEE International Symposium on Applications of Ferroelectrics (ISAF). This was a joint meeting with the Electronics Division of the American Ceramics Society that was held at the Eldorado Hotel and Spa in Santa Fe, New Mexico, from February 24?27, 2008. The meeting was host to over 300 conference attendees and over 250 technical presentations. Presentations covered a wide range of technical topics, including processing, advanced characterization, theory and modeling of ferroelectrics, FERAM devices, capacitors, piezoelectrics, ultrasonics, multiferroics, and energy harvesting materials and devices.  相似文献   
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Blood samples from 740 Egyptian Nationals working in the tourism industry at two sites in the South Sinai governorate were screened for markers of infection with hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and Treponema pallidum. Study subjects included 467 individuals from a rural seashore tourist village and 273 persons at two hotels in a well-established resort town. Subjects' ages ranged from 15 to 70 years; 99.3% were male. The prevalence of serologic markers for currently asymptomatic or past HBV infection alone was 20.7% (n = 153), of markers for past or chronic HCV infection alone was 7.4% (n = 55), and of markers for both HBV and HCV was 6.9% (n = 51). Of the 204 individuals positive for anti-HBV core antibody, 12 (5.9%) were also positive for hepatitis B surface antigen. Two individuals (0.3%) had a serologic market suggestive of an active syphilitic infection. No subject was found to be HIV-seropositive. History of prior injections and number of injections were associated with infection with HCV. Primary residence in the Nile delta and valley areas where schistosomiasis is highly endemic, was also a statistically significant risk factor for HCV, but not HBV infection.  相似文献   
40.
Amiodarone is a benzofuran derivative with a chemical structure similar to thyroxine. Originally introduced to treat angina pectoris, amiodarone was found to have antiarrhythmic properties, and in 1985, was approved in the United States for treatment of life-threatening ventricular arrhythmias. It is now used for various ventricular and supraventricular arrhythmias refractory to conventional first-line medications, and as a result, side effects have been observed with increased frequency. The most severe and potentially life-threatening of these side effects is the development of pulmonary toxicity. Typically, amiodarone pulmonary toxicity (APT) is manifested by acute pneumonitis and chronic fibrosis. Amiodarone-associated hemoptysis (AAH) is a rare occurrence. The authors describe a case of AAH successfully treated with cessation of drug and steroid therapy.  相似文献   
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