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排序方式: 共有3397条查询结果,搜索用时 31 毫秒
11.
SV Filippov MD Rekhter RS Polishchuk SV Gurkin SN Voronov VI Cherviakov AA Mironov 《Canadian Metallurgical Quarterly》1993,35(9):62-65
It has been shown that changes in the orientation of arterial smooth muscle cells during a constant longitudinal stretching of the artery in vivo are not similar in different sections of the stretching zone. Cells in the proximal and distal sections keep their orientation but this orientation differs from that of smooth muscle cells in the control arteries. Cells in the central part of the stretching region lose their definite orientation to settle randomly. 相似文献
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PURPOSE: To determine the improvement in pancreatic enhancement at helical computed tomography (CT) performed with an early delay after administration of contrast material compared with that performed with a standard delay. MATERIALS AND METHODS: Dual-phase helical CT of the abdomen was performed in 120 patients with a 150-mL bolus of contrast material infused at 5 mL/sec. Early and standard delayed scanning was performed beginning at 20 seconds and 49-71 seconds, respectively. Regions of interest were measured in the head, body, and tail of the pancreas in 92 patients. The difference in enhancement between early and standard delayed scanning was calculated. RESULTS: Mean pancreatic enhancement was 82 HU +/- 3 (standard error) with an early delay, whereas enhancement on standard delay scans was 62 HU +/- 2 (P < .001). An improvement in enhancement greater than 10 HU was attained in 66 of 92 cases (72%). CONCLUSION: Pancreatic enhancement at helical CT with an early delay after contrast material administration is often significantly greater than the enhancement seen with a standard delay when a monophasic, rapidly infused bolus of contrast material is used. 相似文献
14.
Electrical field stimulation evoked a reproducible outflow of calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) from the dorsal half of the rat spinal cord, an effect which was abolished by prior application of capsaicin, tetrodotoxin or removal of extracellular Ca2+. Adenosine (EC50 3.2 microM) and the selective adenosine A1 receptor agonist N6-cyclohexyladenosine (EC50 8.2 nM) inhibited evoked CGRP-LI outflow, while the selective adenosine A2 receptor agonist CGS-21680 was ineffective up to 10 microM. The action of adenosine was prevented by the adenosine A1 receptor selective antagonist 8-cyclopentyl-1,3-dipropylxanthine (30 microM), which did not affect CGRP-LI release on its own. 相似文献
15.
PURPOSE: We investigated the association, treatment options and outcomes of patients with ureteropelvic junction obstruction and concomitant vesicoureteral reflux. MATERIALS AND METHODS: We analyzed 6,790 consecutive pediatric urology records at our university. Treatment options included observation, and primary pyeloplasty, ureteroneocystostomy and nephroureterectomy. Hydronephrosis, reflux and obstruction were judged as resolved, improved, unchanged or worse. RESULTS: A total of 1,140 patients had vesicoureteral reflux, 224 had ureteropelvic junction obstruction and 41 had both conditions (39 ipsilateral and 6 contralateral kidneys). There was no increased risk of obstruction in patients with reflux when all grades of reflux were grouped (odds ratio 1.26, confidence interval 0.91 to 1.71). In contrast, subgroup analysis of patients with high grade reflux demonstrated a 5-fold increased risk of obstruction (odds ratio 5.0, confidence interval 2.4 to 10.8). One patient was lost to followup. Observation of 6 kidneys led to resolution of reflux in 3 (50%), resolution of obstruction in 3 (50%) and resolution or improvement of hydronephrosis in 4 (67%). Primary pyeloplasty was done on 29 kidneys with 10 (35%) requiring subsequent ureteroneocystostomy. At latest followup hydronephrosis resolved or improved in 24 patients (83%), vesicoureteral reflux resolved or improved in 19 (66%) and ureteropelvic junction obstruction resolved in all. Primary ureteroneocystostomy was performed on 5 kidneys, all of which required subsequent pyeloplasty. Hydronephrosis resolved in 3 patients (60%), and reflux and obstruction resolved in all. Two patients treated with primary nephroureterectomy, and 1 who underwent concomitant pyeloplasty and ureteroneocystostomy have had no subsequent urological problems. One patient awaits primary pyeloplasty. CONCLUSIONS: High grade vesicoureteral reflux is associated with ureteropelvic junction obstruction. No association with low or intermediate grade reflux was demonstrated. While some patients may be monitored expectantly, in our series pyeloplasty or nephrectomy was required in 81% and ureteroneocystostomy was required in 36%. In no case did primary ureteroneocystostomy protect against the subsequent need for pyeloplasty. 相似文献
16.
JP Heiner SS Kohles PA Manley R Vanderby MD Markel 《Canadian Metallurgical Quarterly》1997,(341):233-240
In a canine model, the fixation stability of a prosthesis and proximal bone graft composite were measured relative to the distal femur. One group had the prosthesis graft composite cemented into the distal femur. The second group had the prosthesis graft composite press fit into the distal femur for biologic ingrowth. Displacements of the proximal femoral grafts relative to the host bone in each group were measured after ex vivo (acute with graft) implantation and 4 months after implantation. A third group with no osteotomy (acute intact) simulated perfect graft to host bone union. Relative displacements representing 6 degrees freedom (translation and rotation) were calculated from the displacement values measured by 9 eddy current transducers. Measurements of displacement were used to test the hypothesis that distal press fit fixation equals distal cement fixation at 4 months after implantation. In all cases the measured translations and rotations of the graft to implant construct were small and of a magnitude that should encourage bone ingrowth (< 0.05 mm and < 0.1 degree, respectively). The stability of the press fit group at 4 months was not significantly different from the cemented group in axial and transverse displacement during axial and transverse loading, respectively. There was no difference in stabilities at 4 months between distal press fit and cemented fixation in hip replacements requiring a proximal femoral graft. 相似文献
17.
Point prevalence of oropharyngeal carriage of fluconazole-resistant Candida in human immunodeficiency virus-infected patients 总被引:1,自引:0,他引:1
To estimate the prevalence of both clinically evident and asymptomatic carriage of fluconazole-resistant Candida, we prospectively surveyed 128 adults infected with human immunodeficiency virus (HIV). The patients had an average CD4 cell count of 206/mm3. Ninety-seven isolates of Candida were obtained from the oropharynx of 82 patients (64%). Of these 82 patients, 76% carried C. albicans alone; 18%, both albicans and non-albicans isolates; and 6%, non-albicans species alone. Oropharyngeal candidiasis was evident in only 38 (46%) of the 82 patients for whom a culture was positive and was never seen unless C. albicans was present. When MICs were measured by using the National Committee for Clinical Laboratory Standards M27-T methodology and grouped by using recently proposed breakpoints, we found that eight of the 38 patients with oropharyngeal candidiasis and six of the 44 patients who were asymptomatically colonized carried C. albicans isolates resistant to fluconazole (MIC, > or = 64 micrograms/mL); estimated rates of carriage were 21% (95% confidence interval, 10%-37%) and 14% (95% confidence interval, 5%-27%), respectively. Carriage of resistant isolates of C. albicans by HIV-infected adults is more common than previously suspected, and clinicians should be alert to the possible need for either higher doses of fluconazole or alternative treatment modalities. 相似文献
18.
MH Collins R Yang Q Liu A Cnaan MD Pescovitz JL Grosfeld 《Canadian Metallurgical Quarterly》1997,32(4):555-559
The spectrum of photoaging in human skin shows a recognizable progression from subtle to profound, reflecting the various anatomic and structural changes that appear with aging skin. Qualification and quantification of these changes on both the macroscopic and microscopic levels enable the physician to select and evaluate appropriate therapeutic approaches to the problem of chronic solar damage. Comparative studies remain to be done that will further refine our abilities to match the right solutions to the recognized problems. 相似文献
19.
Prostate enlargement in mice due to fetal exposure to low doses of estradiol or diethylstilbestrol and opposite effects at high doses 总被引:7,自引:0,他引:7
FS vom Saal BG Timms MM Montano P Palanza KA Thayer SC Nagel MD Dhar VK Ganjam S Parmigiani WV Welshons 《Canadian Metallurgical Quarterly》1997,94(5):2056-2061
On the basis of results of studies using high doses of estrogens, exposure to estrogen during fetal life is known to inhibit prostate development. However, it is recognized in endocrinology that low concentrations of a hormone can stimulate a tissue, while high concentrations can have the opposite effect. We report here that a 50% increase in free-serum estradiol in male mouse fetuses (released by a maternal Silastic estradiol implant) induced a 40% increase in the number of developing prostatic glands during fetal life; subsequently, in adulthood, the number of prostatic androgen receptors per cell was permanently increased by 2-fold, and the prostate was enlarged by 30% (due to hyperplasia) relative to untreated males. However, as the free serum estradiol concentration in male fetuses was increased from 2- to 8-fold, adult prostate weight decreased relative to males exposed to the 50% increase in estradiol. As a model for fetal exposure to man-made estrogens, pregnant mice were fed diethylstilbestrol (DES) from gestation days 11 to 17. Relative to controls, DES doses of 0.02, 0.2, and 2.0 ng per g of body weight per day increased adult prostate weight, whereas a 200-ng-per-g dose decreased adult prostate weight in male offspring. Our findings suggest that a small increase in estrogen may modulate the action of androgen in regulating prostate differentiation, resulting in a permanent increase in prostatic androgen receptors and prostate size. For both estradiol and DES, prostate weight first increased then decreased with dose, resulting in an inverted-U dose-response relationship. 相似文献
20.