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排序方式: 共有152条查询结果,搜索用时 10 毫秒
51.
辽西蜂胶中一新的桂皮酸酯成分的分离与鉴定 总被引:1,自引:0,他引:1
A new cinnamate ester drivitive (II) and three flavonoids (I, III, IV) were isolated from Liaoxi propolis. Their chemical structures were established as benzyl caffeate (II), 7-O-methylchrysin (I), genkwanin (III) and rhamnazin (IV) by spectral analysis. II is a new natural compound; I, III and IV were found from the propolis for the first time. 相似文献
52.
Three patients with histologically confirmed sarcoidosis with spinal cord involvement were examined with high-field-strength magnetic resonance imaging (1.5 T) before and after the administration of gadolinium diethylenetriaminepentaacetic acid. In addition to intramedullary expansion, areas of patchy, multifocal, parenchymal enhancement and areas of linear peripheral enhancement were seen in all three patients; these findings have not been previously reported and are unusual for other more common spinal cord lesions. This observation led to a correct diagnosis and a limitation of the extent of biopsy in two of the cases. Unfortunately, this enhancement pattern is not specific for sarcoidosis, as the authors have observed similar findings in two cases of biopsy-proved myelitis and multiple sclerosis. The peripheral enhancement is thought to be located in the leptomeninges due to leptomeningeal involvement, which was proved histologically in one case. This pattern of involvement, while not specific, is certainly consistent with and, in the appropriate clinical setting, highly suggestive of sarcoidosis. 相似文献
53.
54.
Rennick DM; Thompson-Snipes L; Coffman RL; Seymour BW; Jackson JD; Hudak S 《Blood》1990,76(2):312-316
Bone marrow of mice parasitized with Nippostrongylus brasiliensis showed increased numbers of eosinophils as early as 4 days after infection. By day 7, their bone marrow also contained elevated numbers of progenitors that form small eosinophil colonies (20 to 50 cells) in soft agar cultures supplemented with interleukin-5 (IL-5). However, when mice were infused with anti-IL-5 antibodies at the time of infection, the number of recognizable eosinophils present in bone marrow remained low and eventually dropped below normal levels. The antibody treatment also prevented increased generation of IL-5- responsive precursors capable of differentiating into mature eosinophils in liquid culture and inhibited the generation of progenitor cells capable of forming small eosinophil colonies or clusters in soft agar cultures. The results of these in vivo experiments directly show that IL-5 is an essential regulatory molecule required for the bone marrow-dependent phase of a parasite-induced eosinophilia. 相似文献
55.
Cryptic structural lesions in refractory partial epilepsy: MR imaging and CT studies 总被引:4,自引:0,他引:4
Ormson MJ; Kispert DB; Sharbrough FW; Houser OW; Earnest F th; Scheithauer BW; Laws ER Jr 《Radiology》1986,160(1):215-219
Results of contrast material-enhanced computed tomography (CT) and T2-weighted spin-echo magnetic resonance (MR) imaging were correlated with pathologic findings in 25 patients treated surgically for refractory partial epilepsy. Of 12 lesions present, ten (83%) were detected by MR imaging and seven (58%) by CT scanning. Of nine low-grade gliomas, eight were detected by MR imaging and four by CT scanning. One posttraumatic scar and one case of temporal lobe atrophy were better demonstrated by MR imaging. A small, thrombosed arteriovenous malformation was the only lesion detected by CT scanning but not by MR imaging. No lesions were detected in 13 patients with mild gliosis and one patient with a 1.2-cm grade 1 astrocytoma. Although more sensitive than CT for detection of structural lesions in patients with refractory partial epilepsy, MR imaging resulted in a 25% false-negative diagnostic rate when a repetition time of 2,000 msec and echo time of 60 msec were used. Multi-echo imaging with at least one long echo time may be needed to increase the sensitivity of MR imaging in these patients. 相似文献
56.
Rotator cuff sonography: a reassessment 总被引:4,自引:0,他引:4
This study is both a retrospective and prospective evaluation of the clinical usefulness of shoulder sonography. Ninety-eight patients suspected of having rotator cuff tears underwent sonography of both shoulders. Sixty-two patients underwent double-contrast arthrography performed on the same day as sonography, and 38 patients underwent surgery after sonography. A comparison of the results from ultrasound and arthrography, using published diagnostic criteria, demonstrated a sensitivity of 75% and a specificity of 43% for detection of a rotator cuff tear. In this study, use of more restricted criteria, a subset of the published criteria, yielded a sensitivity of 68% and a specificity of 90%. A comparison of sonography with surgery, using this study's criteria, demonstrated a sensitivity of 57% and a specificity of 76%. This report shows that shoulder sonography is less reliable than previously reported and appears to have a very limited role in the evaluation of rotator cuff injuries. 相似文献
57.
Seventy-five spot compression views of equivocally suspicious lesions detected at routine mammographic examination of 72 women were reviewed in this retrospective study. Sixty-five of the 75 lesions appeared less suspicious on spot compression views, two did not change, and eight appeared more suspicious. Biopsy findings confirmed that the eight more suspicious lesions were cancer. The adjunctive use of spot compression helped characterize equivocal findings seen on routine mammographic views and improved the accuracy of mammographic interpretation. 相似文献
58.
Paranasal sinuses: CT imaging requirements for endoscopic surgery 总被引:17,自引:0,他引:17
Zinreich SJ; Kennedy DW; Rosenbaum AE; Gayler BW; Kumar AJ; Stammberger H 《Radiology》1987,163(3):769-775
Recent advances in the understanding of mucociliary activity and the pathophysiology of the nasal cavity and paranasal sinuses have revolutionized the surgical management of chronic and/or recurrent sinusitis. Meticulous radiographic delineation of the small structures in this region, coupled with endoscopic evaluation, provides detailed preoperative information regarding morphology and pathology. This information has led to more focused endoscopic surgical procedures, which have dramatically reduced patient morbidity. As a consequence, there is now worldwide interest among otolaryngologists in the radiologic definition of paranasal regional anatomy. For effective interactions between radiologist and otolaryngologist, the former must be prepared to render interpretations that address these "microanatomic" locales. This communication is directed at familiarizing the radiologist with these observations and concepts, considering both normal and disturbed anatomy with their attendant pathophysiologic and therapeutic implications. 相似文献
59.
The accuracy of single serum progesterone measurement in the diagnosis of ectopic pregnancy: a meta-analysis 总被引:4,自引:2,他引:4
Mol BW; Lijmer JG; Ankum WM; van der Veen F; Bossuyt PM 《Human reproduction (Oxford, England)》1998,13(11):3220-3227
Serum progesterone measurement has been advocated as a diagnostic tool in
the non-invasive diagnosis of ectopic pregnancy. To assess the accuracy of
a single serum progesterone measurement in the diagnosis of ectopic
pregnancy, a meta-analysis was performed incorporating 26 studies
evaluating the performance of single serum progesterone measurement in the
diagnosis of ectopic pregnancy. A distinction was made in the diagnosis of
pregnancy failure of any type versus viable intrauterine pregnancy and the
diagnosis of ectopic pregnancy versus non-ectopic pregnancy. The reported
sensitivity and specificity differed between the studies. Since there was a
clear negative correlation between sensitivity and specificity, summary
receiver- operating characteristic (ROC) curves could be estimated. The ROC
curve for the diagnosis of pregnancy failure versus viable intrauterine
pregnancy showed a good discriminative capacity. Single serum progesterone
measurement could not discriminate between ectopic pregnancy and
non-ectopic pregnancy. It is concluded that serum progesterone measurement
can identify patients at risk for ectopic pregnancy, who need further
evaluation, but its discriminative capacity is insufficient to diagnose
ectopic pregnancy with certainty.
相似文献
60.
A de Jonge BY van der Goes ACJ Ravelli MP Amelink-Verburg BW Mol JG Nijhuis J Bennebroek Gravenhorst SE Buitendijk 《BJOG : an international journal of obstetrics and gynaecology》2009,116(9):1177-1184
Objective To compare perinatal mortality and severe perinatal morbidity between planned home and planned hospital births, among low-risk women who started their labour in primary care.
Design A nationwide cohort study.
Setting The entire Netherlands.
Population A total of 529 688 low-risk women who were in primary midwife-led care at the onset of labour. Of these, 321 307 (60.7%) intended to give birth at home, 163 261 (30.8%) planned to give birth in hospital and for 45 120 (8.5%), the intended place of birth was unknown.
Methods Analysis of national perinatal and neonatal registration data, over a period of 7 years. Logistic regression analysis was used to control for differences in baseline characteristics.
Main outcome measures Intrapartum death, intrapartum and neonatal death within 24 hours after birth, intrapartum and neonatal death within 7 days and neonatal admission to an intensive care unit.
Results No significant differences were found between planned home and planned hospital birth (adjusted relative risks and 95% confidence intervals: intrapartum death 0.97 (0.69 to 1.37), intrapartum death and neonatal death during the first 24 hours 1.02 (0.77 to 1.36), intrapartum death and neonatal death up to 7 days 1.00 (0.78 to 1.27), admission to neonatal intensive care unit 1.00 (0.86 to 1.16).
Conclusions This study shows that planning a home birth does not increase the risks of perinatal mortality and severe perinatal morbidity among low-risk women, provided the maternity care system facilitates this choice through the availability of well-trained midwives and through a good transportation and referral system. 相似文献
Design A nationwide cohort study.
Setting The entire Netherlands.
Population A total of 529 688 low-risk women who were in primary midwife-led care at the onset of labour. Of these, 321 307 (60.7%) intended to give birth at home, 163 261 (30.8%) planned to give birth in hospital and for 45 120 (8.5%), the intended place of birth was unknown.
Methods Analysis of national perinatal and neonatal registration data, over a period of 7 years. Logistic regression analysis was used to control for differences in baseline characteristics.
Main outcome measures Intrapartum death, intrapartum and neonatal death within 24 hours after birth, intrapartum and neonatal death within 7 days and neonatal admission to an intensive care unit.
Results No significant differences were found between planned home and planned hospital birth (adjusted relative risks and 95% confidence intervals: intrapartum death 0.97 (0.69 to 1.37), intrapartum death and neonatal death during the first 24 hours 1.02 (0.77 to 1.36), intrapartum death and neonatal death up to 7 days 1.00 (0.78 to 1.27), admission to neonatal intensive care unit 1.00 (0.86 to 1.16).
Conclusions This study shows that planning a home birth does not increase the risks of perinatal mortality and severe perinatal morbidity among low-risk women, provided the maternity care system facilitates this choice through the availability of well-trained midwives and through a good transportation and referral system. 相似文献