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71.
Neostigmine injected intra-arterially to the superior cervical ganglion of the cat evoked an asynchronous postganglionic nervous discharge in both normal and denervated superior cervical ganglia. This asynchronous firing was enhanced by tubocurarine but blocked by small doses of atropine. In addition, the responses evoked by acetylcholine in ganglia treated with neostigmine were characterized by two components. The first was blocked by tubocurarine and the second by atropine. Asynchronous firing evoked by repetitive preganglionic nerve stimulation of ganglia treated with neostigmine was blocked by atropine but not tubocurarine. It is suggested that neostigmine (1) has actions on ganglia other than those attributable to inactivation of cholinesterase, (2) may possess both pre- and post-synaptic sites of action, and (3) may unmask a cholinoceptive site which can be blocked by atropine.  相似文献   
72.
The effect of 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), an alpha-amino-hydroxy-5-methyl-4-isoxazole propionate (AMPA) glutamate receptor antagonist, on bladder contractions was examined under isometric conditions in urethane anesthetized rats. Intravenous administration of CNQX (33 ng-50 micrograms/kg) inhibited or abolished bladder contraction. Before complete inhibition, the frequency of bladder contractions was reduced without altering the amplitude or duration. Intrathecal administration of CNQX (2 ng/kg-11 micrograms/kg) similarly inhibited bladder contractions. In contrast, CNQX did not affect bladder contractions in chronically spinalized animals (6.7 ng/kg-400 micrograms/kg i.v.), or contractions evoked by stimulation of the decentralized pelvic nerve (1-100 micrograms/kg i.v.).  相似文献   
73.
Wall structures of the arteries in the corpora cavernosa penis were observed in rabbits. The deep (central) arteries in the proximal part of the penis have five or more independent ridges of the wall which are formed by the internal layer of the media consisting of almost longitudinal muscle cell layers. Electron microscopy of these regions revealed that the endothelial cells are connected to each other by many maculae and zonulae adherentes, and that smooth muscle cells of the media are separated from one another by a wide intercellular space embedding abundant collagenous fibers. The epithelioid cells constituting the media of the helicine branches of the deep artery vary in their fine structure from close resemblance to muscle cells, to cells with easily identified special features. Frankly epithelioid cells have few scattered cytoplasmic filaments of a single type, 60–90 Å in diameter, abundant ribosomes, active Golgi, and other features different from the typical smooth muscle cells. There is no suggestion that these epithelioid cells are either degenerative or undifferentiated forms of smooth muscle cells, as postulated by light microscopists. Transitions froms muscle to epithelioid cells are consistent with, but not proved by, our data.  相似文献   
74.
75.
We performed a right upper lobectomy with prosthetic replacement of the superior vena cava (SVC) through a posterolateral thoracotomy in a 65-year-old man undergoing complete resection of a locally advanced non-small-cell lung cancer with invasion of the SVC. Instead of using a vascular shunt, the right atrium and a right brachiocephalic vein (BCV) were anastomosed using a ringed polytetrafluoroethylene (PTFE) graft. During the anastomosis, vascular flow was maintained through the left BCV. By using this technique, SVC resection and reconstruction during lung cancer surgery can be safely performed through a posterolateral thoracotomy without blood flow interruption.  相似文献   
76.
A 77-year-old man developed pulmonary tumor thrombotic microangiopathy (PTTM) 2 days after undergoing transurethral resection for urothelial carcinoma (G3) of the urinary bladder and died of respiratory failure 6 days later. Histological findings demonstrated marked intimal fibrocellular proliferation, fibrin thrombi, and both cancer cells and fibrin thrombi in the arteries of the lungs, findings consistent with PTTM. Prominent stenosis in arteries smaller than 300 ??m was also seen. The Ki-67 labeling index of primary and metastasized cancer cells was 62.4 % and 70.2 %, respectively. The membranes of metastasized cancer cells expressed E-cadherin, similar to membranes in the urinary bladder. An aggressive PTTM course is affected by intimal fibrocellular proliferation and the high cell proliferation of cancer cells. Furthermore, prominent stenosis in small arteries and membranous staining of E-cadherin of metastasized cells suggest that cancer cells formed clusters by maintaining adhesion molecules and migrated into the arteries of the lungs, where they easily caused damage to the endothelium of small arteries, in contrast to dispersed cancer cells.  相似文献   
77.
The protective effects of the glutathione peroxidase system against functional damage induced by perfusion of isolated hearts with adriamycin, an anthracycline antibiotic, were studied. We used selenium deficient rats, in which cardiac glutathione peroxidase activity was only 3% of control rats. Both contractile tension and coronary flow decreased during perfusion with the antibiotic. The degree of decline was significantly greater in the selenium deficient hearts than in the control hearts. The increase in malondialdehyde, a product of lipid peroxidation, induced by adriamycin perfusion was more evident in selenium deficient hearts, though the level of reduced glutathione was well maintained. Isolated mitochondrial function also decreased after aerobic adriamycin perfusion and the decrease was greater in selenium deficient rats. These observations indirectly suggest that the decrease in cardiac function induced by adriamycin is protected by the glutathione peroxidase system and that the decrease may be due, at least in part, to damage to the mitochondria caused by oxygen radicals generated by adriamycin.  相似文献   
78.
Advanced Glycation End-products (AGEs) are produced by the Maillard reaction, which causes cross-linking of collagen and results in changes in the mechanical properties of collagen tissues. Several types of AGE fluoresce, and measurement of this fluorescence is effective for determining the presence of AGEs. Because fluorescence intensity by steady-state fluorometry is affected by sample surface condition and light source, we focused on fluorescence lifetime measurement (FLM). We found that fluorescence lifetime of collagen gel decreased with glycation progress. In vivo application of FLM for determination of AGEs was confirmed in human dentin.OCIS codes: (000.1430) Biology and medicine, (030.5260) Photon counting, (170.1850) Dentistry, (170.2520) Fluorescence microscopy, (170.3650) Lifetime-based sensing  相似文献   
79.

Objective

We studied a racially diverse population and the relationship with colorectal adenomas (CA) further looking for risks related to BMI and metabolic factors.

Designs

Seven hundred seventy-nine patients who underwent screening colonoscopies between 2007 and 2009 meeting exclusion criteria were included. To evaluate the association between race, BMI, and other metabolic factors with having one or more CA detected at colonoscopy, adjusted odds ratios and 95 % CI were estimated using unconditional logistic regression models.

Outcomes

CA were detected in 167 out of 779 (21.4 %) patients. Compared to Whites, Hispanics were less likely to have one or more adenomas detected during a screening colonoscopy (OR?=?0.52, 95 % CI, 0.31–0.88; p?=?0.01). There was no significant statistical difference between Blacks and Whites, or other races and Whites. There was an association between the presence of CA and smoking (OR?=?1.57, 95 % CI, 1.02–2.43; p?=?0.04).

Conclusion

Our results showed that Hispanics were less likely to have an adenoma detected during a screening colonoscopy than Whites. No statistical significant difference was found between patients with metabolic factors and the presence of colorectal adenoma.  相似文献   
80.
PURPOSE: To compare the performance of the phased-array coil (PAC) with that of the single-loop coil (SLC) in magnetic resonance (MR) imaging of the breast. MATERIALS AND METHODS: MR imaging was performed with a 1.5T MR imager. A phantom study was performed with the right element of the two coils to obtain their signal-to-noise ratio (SNR). MR images of the breasts of 12 patients with breast lesions were obtained with the PAC and SLC, and these images were reviewed by five readers in a blind evaluation employing a scoring system for assessing overall image quality. RESULTS: In the phantom study, the SLC exhibited a SNR 1.82 times higher than that of the PAC at the center of the coil; however, the SLC exhibited an inhomogeneous sensitivity profile and its SNR varied with the distance from the center of the coil in the horizontal and vertical directions. In most of the 12 patients, the MR images obtained with the PAC showed more noise than did those obtained with the SLC, and the PAC obtained lower scores than the SLC in the assessment of overall image quality; however, the difference was significant (p < 0.05) only in coronal imaging. On the other hand, the uniformity of fat saturation in the MR images obtained with the PAC was judged to be significantly superior to that obtained with the SLC (p < 0.05). CONCLUSION: Compared with the SLC, the PAC exhibited a lower SNR and was less advantageous at depicting the breast. However, the PAC provided more homogeneous fat saturation and might be useful for reducing artifacts.  相似文献   
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