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991.
Interactions between atrial natriuretic peptide (ANP) and bradykinin (BDK) on norepinephrine (NE) uptake were demonstrated in the adrenal medulla of the rat. One hundred nM ANP and 10 nM BDK increased total NE uptake. Subthreshold concentration of ANP (1nM) or BDK (1nM) reverted the effects of thre shold concentrations of both peptides (10 nM BDK and 100 nM ANP respectively). Effective concentrations of ANP and BDK acting simultaneously did not induce additive effects on total NE uptake. Threshold concentrations of both peptides increased neuronal NE uptake only. These results suggest interactions between ANP and BDK at the neuronal uptake level. They confirm that ANP and BDK take part in the regulation of the sympathetic activity in the adrenal medulla of the rat.  相似文献   
992.
Gastric cancer continues to be a major global health problem. In the American College of Surgeons Patient Care study on gastric cancer, 5-year disease-specific survival was 26%, with an overall survival of 14%. Improvements in survival will require both earlier diagnosis and new therapeutic strategies. The ability of surgical oncologists to understand the natural history of the disease, accurately define its extent, and provide the most effective treatment places them in a key position to see that improvements in outcome are brought about expeditiously.  相似文献   
993.
Vocal fold scarring: current concepts and management   总被引:1,自引:0,他引:1  
Scarring of the vocal folds can occur as the result of blunt laryngeal trauma or, more commonly, as the result of surgical, iatrogenic injury after excision or removal of vocal fold lesions. The scarring results in replacement of healthy tissue by fibrous tissue and can irrevocably alter vocal fold function and lead to a decreased or absent vocal fold mucosal wave. The assessment and treatment of persistent dysphonia in patients with vocal fold scarring presents both diagnostic and therapeutic challenges to the voice treatment team. The common causes of vocal fold scarring are described, and prevention of vocal fold injury during removal of vocal fold lesions is stressed. The anatomic and histologic basis for the subsequent alterations in voice production and contemporary modalities for clinical and objective assessment will be discussed. Treatment options will be reviewed, including nonsurgical treatment and voice therapy, collagen injection, fat augmentation, endoscopic laryngoplasty, and Silastic medialization.  相似文献   
994.
A variety of developmental accounts of intentionality, arising from disparate theoretical perspectives, can now be found in the literature. This paper argues that this diversity is undermining the ability of developmental psychologists to construct a coherent developmental account of the capacity and that it would be more productive to pursue an integrated approach. To this end, the dominant theoretical positions on the development of intentionality are reviewed and evaluated: intentionality as goal-directedness, a result of parental scaffolding, an innate capacity for intersubjectivity, and behavioral object-directedness. Particular attention is given to comparing three key features of each position: the definition of intentionality adopted, the types of behaviors considered to be evidence of intentionality, and the proposed developmental sequence. The possibility of constructing an integrated approach based on these components is explored.  相似文献   
995.
996.
A quantitative structure-activity relationship (QSAR) study on some sulfolanes and arylthiomethanes acting as human immunodeficiency virus-1 (HIV-1) protease inhibitors reveals that in the case of sulfolanes an octahydropyrindene ring and a five-membered 3(S)-sulfolane ring with a hydrophobic 2-substituent (cis to 3-substituent) will be crucial for the inhibition activity. The binding of a sulfolane, which is a nonpeptidic molecule, with the enzyme is shown to partly mimic the binding of a peptidic inhibitor. The 2-substituent is found to have strong hydrophobic interaction with the receptor. Similarly, in the case of arylthiomethanes, one of the substituents of the methane is found to have strong hydrophobic interaction with the enzyme, while the aryl substituent (4-hydroxy-6-phenyl-2-oxo-2H-pyran-3-yl) is assumed to be involved in the hydrogen bondings.  相似文献   
997.
998.
In order to evaluate the interference of hepatitis delta virus (HDV) in hepatitis B viral particle (HBsAg, HBcAg) expression in the liver of chronic HDV patients, 39 and 81 liver biopsies of HBsAg carriers seropositive for anti-HDV and anti-HDV negative controls, respectively, were studied. HBcAg was positive in 16.7% of the HBeAg-positive patients with HDAg in the liver and in 91,4% of controls. In contrast, in HBeAg- and anti-HDV negative patients the intrahepatic expression of HBcAg was detected in 32.6%. In anti-HDV negative patients the HBcAg liver expression correlated significantly with the HBeAg in serum (p < 0.00001). The distribution of HBcAg was exclusively cytoplasmatic in 30% of HDV-infected patients but mixed nuclear and cytoplasmic in 38.3% of the controls. The nuclear expression of HBcAg was decreased in chronic HDV infection. HBsAg was positive in 70.3% of patients who were anti-HDV positive and in 82.3% of controls. The membranous expression of HBsAg was detected less frequently in HDV-infected patients (p < 0.05) than in controls, while associated with HBeAg in serum of HBV carriers without HDV superinfection (p < 0.00001). The prevalence and the HBsAg cytoplasmic expression was not different for the chronic HDV infection or controls. Our results show: 1) decreased intrahepatic expression of HBcAg and membranous HBsAg in HBV carriers superinfected with HDV, suggesting decreased HBV replication in the liver of these patients. 2) the changing of HBcAg and HBsAg expression in the liver of HDV-infected patients, suggest not so much a decrease but rather a modulation in HBV replication.  相似文献   
999.
The authors report a case of rhabdomyoma of the right ventricular cavity with outlet obstruction in a three-months old infant. The diagnosis was established by echocardiography. Bidimensional echocardiography study showed a polypoid tumor of the right ventricle. During the systole it was projected through the pulmonary valve, obstructing part of it. The Doppler study showed an important gradient between the right ventricle and the pulmonary artery. The resection was performed with success. The diagnosis of cardiac rhabdomyoma was made by microscopic study. It is emphasized the importance of the echocardiographic study in an infant with oligosymptomatic cardiac murmurs.  相似文献   
1000.
South America's Pantanal, the world's largest tropical wetland, contains hundreds of thousands of geochemically diverse lakes, ranging from dilute to brackish to saline in composition. These lakes form the backbone of the habitat that supports the highly diverse flora and fauna of the Pantanal, yet the natural processes that create and destroy them are largely unknown. The quantities and types of lakes in the Pantanal and their spatial distribution are therefore essential, but missing information required to understand the dynamics of the Pantanal ecosystem.RADARSAT S1 and S7, and JERS-1 imagery were integrated with field measurements of water geochemistry and characteristics of emergent aquatic vegetation for fresh and brackish lakes of the Nhecolândia region of the Brazilian Pantanal. A supervised classification was used to classify forest, pasture, bare soil, and lakes. A mask is then applied to produce an image of only lakes. The radar backscattering values were found to have a strong relationship with the emergent aquatic plant assemblages of the lakes—S1 imagery was the most useful. The plant assemblages, in turn, were observed to be strongly controlled by the total dissolved solids (TDS) and pH of the lakes. The relationships between backscattering values, plant assemblages, and geochemistry were then exploited to map the type and distribution of the lakes in the study area.Threshold rules were used to perform Level 1 and Level 2 classifications of the lakes. For the Level 1 classification, the σo values of RADARSAT S1 effectively separated brackish (10,000 > TDS > 1000 mg/kg) from fresh water lakes (TDS < 1000 mg/kg) with a total accuracy of 91%. For the Level 2 classification, the σo values of RADARSAT S1 effectively separated lakes into three geochemical groups: brackish (10,000 > TDS > 1000 mg/kg), hard with only Typha (1000 > TDS > 100 mg/kg), and fresh water lakes (TDS mg/kg < 100 mg/kg) with a total accuracy of 83%. Considering that the area is very remote and the lakes are very numerous, this may be the most feasible way to map lake type in the Pantanal.  相似文献   
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