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排序方式: 共有8082条查询结果,搜索用时 11 毫秒
11.
We present 2 cases of superficial siderosis of the central nervous system secondary to chronic subarachnoid bleeding. The diagnosis was made with MR and cerebrospinal fluid (CSF) examination. MR showed, in T2-weighted images, superficial hypointensity of the cervical cord, brainstem, cerebellum, and basal cisterns due to hemosiderin deposits. CSF was xanthochromic, with increased protein content. In 1 of the 2 cases also the CT examination was positive, showing a hyperdense rim around the brainstem. A complete neuroradiological evaluation (MR, CT, angiography and myelography) did not permit to detect the source of the bleeding. 相似文献
12.
H Nasrat D Bloxam U Nicolini N Williams Y Tannirandorn P Nicolaides C H Roedeck 《British journal of obstetrics and gynaecology》1992,99(8):646-650
OBJECTIVE: To determine plasma zinc concentrations in normally and abnormally growing fetuses. DESIGN: Prospective observational study. SETTING: Fetal Medicine Unit, Queen Charlotte's Maternity Hospital. SUBJECTS: 53 pregnant women attending for fetal blood sampling at between 18 and 40 weeks gestation. 27 fetuses were normal (central group), 11 fetuses were growth retarded and 15 were malformed. MAIN OUTCOME MEASURES: Plasma zinc concentrations in maternal and fetal blood at time of fetal blood sampling. RESULTS: In normally growing fetuses, between 18 and 40 weeks gestation, there was no fall in maternal plasma zinc concentration; the fetal level fell by 36%. In 10 fetuses with symmetrical growth retardation, plasma zinc concentration tended to be low, but was not significantly different from that in the normal control fetuses. CONCLUSION: The results suggest that (i) placental transfer of zinc is an uphill secretory process and that it is a rate-limiting step in the accumulation of zinc by the fetus and (ii) in fetuses with symmetrical intrauterine growth retardation, a low plasma zinc is probably a parallel phenomenon and not necessarily an aetiological factor. 相似文献
13.
N M Fisk D Ronderos-Dumit Y Tannirandorn U Nicolini D Talbert C H Rodeck 《British journal of obstetrics and gynaecology》1992,99(1):18-22
OBJECTIVE: To characterize amniotic pressure (AP) in pregnancies with normal amniotic fluid volume. DESIGN: Observational study, mainly cross-sectional. SETTING: Fetal medicine unit within a tertiary referral hospital. SUBJECTS: Patients undergoing transamniotic invasive procedures in whom amniotic fluid volume was subjectively assessed as normal on ultrasound. Those beyond 16 weeks with a deepest vertical pool on ultrasound less than 3.0 or greater than 8.0 cm were excluded. Overall 194 pregnancies were studied on 232 occasions between 7 and 38 weeks gestation. INTERVENTIONS: Manometry readings referenced to the top of the maternal abdomen were obtained via a fluid-filled line from the needle hub and either connected to a pressure transducer (n = 190) or held vertically against a ruler (n = 42). MAIN OUTCOME MEASURES: AP in mm Hg, AP corrected for gestational age (z scores), semi-quantitative ultrasonic indices of amniotic fluid volume, clinical variables. RESULTS: AP in singleton pregnancies increased with advancing gestation (P less than 0.001), and the sigmoid-shaped regression curve plateaued in the mid-trimester. AP z scores were not influenced by volume-related phenomena such as twin gestation, the deepest vertical pool, or amniotic fluid index, nor by maternal age, parity, gravidity, fetal sex, or subsequent spontaneous preterm delivery. CONCLUSIONS: These findings suggest that AP is not principally determined by intrauterine volume. We speculate that AP, which reflects change in uterine tension as a function of radius, may instead be determined by gestation-specific anatomical and hormonal influences on gravid uterine musculature. A reference range for AP has been constructed for use in amnioinfusion and amnioreduction procedures. 相似文献
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Onelio Geatti Brahm Shapiro Pier Giuseppe Orsolon Gianni Proto Ugo Paolo Guerra Francesco Antonucci Daniele Gasparini 《European journal of nuclear medicine and molecular imaging》1994,21(1):17-22
Technetium-99m methoxyisobutylisonitrile (MIBI), like thallium-201, has recently been introduced as a myocardial perfusion agent and is now also showing very promising results in parathyroid scintigrapy. The results of 201Tl/99mTc-pertechnetate and 99mTc-MIBI/99mTc-pertechnetate subtraction scintigraphy, ultrasonography and computed tomography are presented in a series of 43 patients operated on for hyperparathyroidism. All four imaging modalities were confirmed to be reliable, scintigraphy being the most accurate. Sensitivities ranged from 81% to 95%, that of 99mTc-MIBI being the highest. Moreover this tracer, which has more favourable physical and also biochemical properties, yielded images of superior quality. This allowed localization of the lesion by visual inspection only in as many as 86% of the patients with positive 99mTc-MIBI/99mTc-pertechnetate subtraction scintigraphy. We believe that the higher sensitivity, superior image quality and lower cost of 99mTc-MIBI imaging will make 99mTc-MIBI the new radiopharmaceutical of choice for parathyroid scintigraphy (when one takes into account the stability of labelling with large activities it is possible to perform three or four cardiac studies together with one parathyroid scintigraphic examination using one lyophililzed vial). 相似文献
16.
Myocardial protection in adult cardiac surgery: current options and future challenges 总被引:3,自引:0,他引:3
Francesco Nicolini Cesare Beghi Claudio Muscari Andrea Agostinelli Alessandro Maria Budillon Igino Spaggiari Tiziano Gherli 《European journal of cardio-thoracic surgery》2003,24(6):986-993
Current techniques of myocardial protection are evolving with the use of less conventional modalities of cardioplegia and have reduced the morbidity and mortality of cardiac operations. Blood cardioplegic solutions appear superior to cold cardioplegia in terms of myocardial protection and adjuncts as glutamate/aspartate enhancement, antioxidant supplementation, nitric oxide donors and maintenance of calcium homeostasis seem effective. In the near future, further experimental and clinical investigations about pharmacological preconditioning, sodium–hydrogen exchangers inhibition and gene therapy need to be addressed to well define their potential role in the improvement of current techniques of myocardial protection that are suboptimal in high-risk clinical settings. 相似文献
17.
The complex dielectric constant of small quantities of liver nuclei in various functional states was measured in the frequency range of 50-2,000 MHz using an Automatic Network Analyzer. From these measurements, through an electric model of macromolecules in solution, several quantities such as ion content, bound water, and free water have been estimated. Unique changes in the physical state of intranuclear water and ions were then apparent in the resting liver nuclei immediately following induced cell proliferation, as compared to nuclei either from early carcinogen-altered hepatocytes or from late selected carcinogen-initiated hepatocytes. Possible implications of these findings are discussed in terms of the molecular events controlling chemically-induced neoplastic transformation. 相似文献
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19.
Carlo Alberto Maggi Riccardo Patacchini Paolo Santicioli Sandro Giuliani Damiano Turini Gabriele Barbanti Patrizia Beneforti Daniele Misuri Alberto Meli 《Naunyn-Schmiedeberg's archives of pharmacology》1989,339(4):415-423
Summary (1) Longitudinal muscle strips from the human small intestine (jejunum/ileum) responded to electrical field stimulation (1–50 Hz) with frequency-related primary contractions which were largely atropine- (3 M) sensitive. When the tone was raised by addition of galanin (0.3 – 1 M), prostaglandin (PG) E2 (1–10 M) or neurokinin A (NKA, 0.1 M), a frequency-related relaxation was evident which was potentiated by atropine. All the responses to field stimulation were abolished by tetrodotoxin (1 M), thus indicating their neural origin. (2) The atropine-sensitive primary contraction to field stimulation was virtually abolished by omega conotoxin fraction GVIA (CTX, 0.1–0.3 M) while the relaxations were CTX-resistant. The field stimulation-induced relaxations, which were observed in the presence of atropine and guanethidine (3 M), were also unaffected by apamin (0.1 M). (3) NKA and substance P (SP) produced a concentration- (1 nM–1 M for both peptides) related contraction, NKA being about 53 times more potent than SP. [Pro9]SP sulphone and [MePhe7]-NKB, selective agonists of the NK-1 and NK-3 receptor, respectively, were barely effective. On the other hand, [\Ala8]NKA(4–10), a selective NK-2 receptor agonist, had a potent contractile activity, similar to that of NKA. (4) Galanin (1 nM–1M) produced an atropine- and tetrodotoxin-resistant concentration-related contraction of longitudinal muscle of human isolated small intestine. The response to galanin did not show any sign of fading and was particularly suitable to study the evoked relaxations. (5) Calcitonin gene-related peptide (CGRP) (10–100 nM) consistently inhibited the nerve-mediated contractions of strips from the ileum while the effect on the jejunum was less pronounced. Vasoactive intestinal polypeptide (VIP, 0.1–1 M) inhibited nerve-mediated contractions both in the ileum and the jejunum. (6) These experiments indicate that both cholinergic excitatory and non-adrenergic non-cholinergic nerves affect motility of the longitudinal muscle of the human small intestine. Furthermore, several neuropeptides produce potent motor effects, the contractile response to tachykinins being apparently mediated by activation of NK-2 receptors. 相似文献
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