排序方式: 共有711条查询结果,搜索用时 15 毫秒
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LK Bogush IA Zharakhovich MM Shmelev NE Kubrik SK Rasshivalov 《Canadian Metallurgical Quarterly》1976,71(1):89-93
The single nephron glomerular filtration rate (SNGFR) was determined in superficial (S) and juxtamedullary (JM) nephrons of 10 anesthetized rabbits by the 14C ferrocyanide infusion technique. The length of the proximal tubules and the volume of the glomeruli were also determined for the same nephrons. SNGFR was higher in JM than in S: 28.6 +/- 3.4 versus 22.6 +/- 3.0 nl/min, P less than 0.001. In JM nephrons, glomeruli were larger than in S: 1.3 +/- 0.1 versus 0.9 +/- 0.1 nl, P less than 0.001, whereas there was no difference between proximal tubule length in either category (s, 8.7 +/- 0.3 and JM, 8.9 +/- 0.5 mm). In 6 out of 8 animals, SNGFR was significantly correlated to glomerular volume. Lack of correlation was observed between SNGFR and length of proximal tubule in all animals but one. These results show that the rabbit, as well as small rodents and the dog, has a higher SNGFR in juxtamedullary than superficial glomeruli. Although this functional difference is not related to the length of the proximal tubule in each individual animal, the ratio between the mean SNGFR value and the mean length of the proximal tubule in superficial rabbit nephrons is similar to the ratio found in other species. 相似文献
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Transillumination of the skull in infants is a simple technique which can be used to detect several major abnormalities of the central nervous system. The usefulness of transillumination has been limited, however, by the lack of standard techniques for its performance and by the absence of normal values, especially in premature infants. In healthy premature infants, there is a progressive increase in transillumination with increasing gestational age over three sites--the anterior fontanelle, the frontotemporal fossa, and the parieto-occipital eminence. 相似文献
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LK Katosova 《Canadian Metallurgical Quarterly》1977,13(3):403-404
Studies have been made on ontogenetic changes in the activity of succinic dehydrogenase, alpha-glycerophosphate dehydrogenase and acid phosphatase from the lymphocytes of rabbit blood. It was found that maturation of alpha-glycerophosphate dehydrogenase takes place at later stages as compared to other enzymes. The activity of succinic dehydrogenase gradually decreases. Acid phosphatase activity, being rather high in very young animals, also decreases with ageing. 相似文献
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PC Berquin JN Giedd LK Jacobsen SD Hamburger AL Krain JL Rapoport FX Castellanos 《Canadian Metallurgical Quarterly》1998,50(4):1087-1093
Clinical, neuroanatomic, neurobehavioral, and functional brain-imaging studies suggest a role for the cerebellum in cognitive functions, including attention. However, the cerebellum has not been systematically studied in attention-deficit hyperactivity disorder (ADHD). We quantified the cerebellar and vermal volumes, and the midsagittal areas of three vermal regions, from MRIs of 46 right-handed boys with ADHD and 47 matched healthy controls. Vermal volume was significantly less in the boys with ADHD. This reduction involved mainly the posterior inferior lobe (lobules VIII to X) but not the posterior superior lobe (lobules VI to VII). These results remained significant even after adjustment for brain volume and IQ. A cerebello-thalamo-prefrontal circuit dysfunction may subserve the motor control, inhibition, and executive function deficits encountered in ADHD. 相似文献
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JC Watson TH Shawker LK Nieman HL DeVroom JL Doppman EH Oldfield 《Canadian Metallurgical Quarterly》1998,89(6):927-932
OBJECT: Pituitary surgery has been reported to produce remission of Cushing's disease with preservation of pituitary function in only 60 to 70% of patients. The inability to identify an adenoma accounts for most failed sellar explorations. Most negative surgical explorations occur in patients in whom magnetic resonance (MR) imaging of the pituitary demonstrates normal findings, which happens in at least 35 to 45% of patients with Cushing's disease. METHODS: To examine the usefulness of intraoperative ultrasonography (IOUS) for identifying an adenoma in patients with no demonstrable tumor (negative findings) on pituitary MR imaging. we prospectively assessed the results of IOUS in 68 patients with a negative (59 patients) or equivocal (nine patients) MR image from a consecutive series of 107 patients with Cushing's disease (64%). We compared surgical findings and outcomes in these 68 patients with a group of 68 patients with Cushing's disease and negative findings on MR imaging in whom IOUS was not available. Intraoperative ultrasonography localized a tumor in 47 (69%) of 68 patients with negative findings on MR imaging. Surprisingly, the size of the adenomas that were detected with IOUS compared with the size of those not detected did not differ (6.8+/-3.4 mm compared with 6.1+/-2.8 mm [mean+/-standard deviation], respectively [p=0.51). In four patients, no adenoma was found at surgery or in the pathological specimen ("true negative"). In eight patients, nine abnormalities detected by IOUS that were suspected adenomas were negative on exploration ("false positive"). Thus, IOUS has a sensitivity of 73% and a positive predictive value of 84% for detecting pituitary adenomas in patients with Cushing's disease and negative findings on MR imaging. Compared with the 68 patients who did not undergo IOUS. remission after surgery was improved (61 patients [90%] compared with 57 patients [84%]), the number of tumors found on exploration was increased (61 tumors compared with 51 tumors, p=0.02), and the number of hemihypophysectomies was decreased (five compared with 15; p=0.02) with IOUS. When the groups were compared after excluding patients with prior pituitary surgery, tumors were found in 91% versus 72% (p=0.008), and remission occurred in 95% versus 87% of patients, respectively, in the groups that had or did not have IOUS. CONCLUSIONS: The IOUS is a sensitive imaging modality when used in patients with Cushing's disease in whom findings on pituitary MR imaging are negative. The improved ability to detect and localize these tumors by using IOUS positively affects surgical outcome. 相似文献
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LK DeNicola JL Falk ME Swanson MO Gayle N Kissoon 《Canadian Metallurgical Quarterly》1997,13(3):477-502
Drowning and near drowning remain a common cause of childhood death and disability. Toddlers aged one through four drown in private swimming pools. Submersions greater than 10 minutes and lack of CPR at the scene or the need for greater than 20 minutes of resuscitation portends a poor prognosis. Management of respiratory failure without neurologic impairment has the most successful outcome. Prevention of drowning morbidity is dependent on constant parental supervision, and immediate and expert CPR. 相似文献