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51.
Superficial- and deep-tissue heating was measured in five dogs during high-specific-absorption-rate radiofrequency (RF) irradiation to see whether significant temperature changes could be produced by a 1.5-T clinical magnetic resonance imager. The RF power output employed was 6.3 times that required for routine imaging. Temperature probes were placed in both deep and superficial tissues, and temperatures were recorded before, during, and after exposure. In each dog, there was a linear temperature increase of several degrees during RF exposure; the maximal average change was 4.6 degrees C in the urinary bladder. The temperature increase was slightly greater in deep tissues than in superficial tissues. The calculated specific absorption rate, based on the temperature change, averaged 7.9 W/kg for all five dogs. These findings argue for continued caution in the design and operation of imagers capable of high specific absorption rates, particularly when they are used for imaging infants or patients with altered thermoregulatory capability. 相似文献
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B. KAPPEL J. NIELSEN K. BROGAARD HANSEN M. MIKKELSEN AA. J. THERKELSEN 《BJOG : an international journal of obstetrics and gynaecology》1987,94(1):50-54
Summary. The clinical significance of placental perforation and bloodstained amniotic fluid was studied in a group of 7238 Danish women undergoing mid-trimester amniocentesis for prenatal diagnosis under ultrasound guidance. The risk of spontaneous abortion was significantly increased both in pregnancies where the placenta was perforated and in those with blood-stained amniotic fluid. The risk estimate nearly doubled after placental perforation and more than doubled with a bloody tap. It is concluded that for women at relatively low risk of a fetal genetic abnormality, the indication of the amniocentesis should be reconsidered if a placental perforation is unavoidable. 相似文献
56.
Cornual heterotopic pregnancy: contemporary management options 总被引:9,自引:0,他引:9
Habana A Dokras A Giraldo JL Jones EE 《American journal of obstetrics and gynecology》2000,182(5):1264-1270
This review covers the clinical presentations, treatments, and outcomes of cornual heterotopic pregnancies reported in the literature. Infertile women with a history of ectopic pregnancy, tubal surgery, or disease are at increased risk for cornual heterotopic pregnancy when they undergo in vitro fertilization. Women who have undergone bilateral salpingectomy also seem to be predisposed to this condition when they undergo in vitro fertilization. We recommend that these patients be followed up closely after a successful in vitro fertilization cycle with monitoring of serum beta-human chorionic gonadotropin levels and serial transvaginal ultrasonography because of the high associated morbidity. Laparotomy remains the treatment of choice for rupture of a cornual heterotopic pregnancy. In the absence of cornual rupture, however, medical management is an option that eliminates the risk of surgery and anesthesia and results in outcomes similar to those associated with surgical treatment. Currently there is insufficient evidence to recommend any single treatment modality, and the decision should be based on such factors as clinical presentation, surgeon's expertise, side effects, overall cost, and the patient's preference. 相似文献
57.
Moderate and severe malnutrition are endemic in much of the developing world and in association with pockets of deprivation in the developed world. The cost in terms of individual and social development is high. The principles of effective management are clearly documented. A low cost, community based treatment programme for moderately and severely malnourished children under 3 years of age was established at a health centre in rural Jamaica. Children were followed up monthly and defaulters were rigorously recalled. Management consisted of carefully delivered dietary advice, antibiotics, anthelminthics, and vitamin supplements. All children improved and the response of 36 children, who were treated in the first year, showed an accelerated weight gain, with catch-up growth and the maintenance of length gain. There was a significant increase in the weight for age, at 1.9% per month over six months, which exceeds the rate reported with food supplementation programmes and nutrition rehabilitation centres. 相似文献
58.
Pathophysiologic considerations as well as non-comparative clinical results suggest that very high purity concentrates may slow immunologic deterioration in human immunodeficiency virus (HIV)-infected hemophiliacs. In an attempt to evaluate this hypothesis, we prospectively compared CD4 cell counts, skin testing responses, and changes of the clinical status in 20 asymptomatic HIV-positive hemophiliacs, randomly assigned to continue the treatment with an intermediate purity concentrate or to receive a very high purity product, purified by immunoaffinity chromatography with monoclonal antibodies. In the group switched to the very high purity concentrate there was no significant change of the CD4 cell counts over the 96-week follow-up period, whereas in the group continued on the intermediate purity concentrate, a highly significant decline was detected (P less than .013). Furthermore, in the very high purity group, four of six anergic patients at entry acquired reactivity to skin testing. The results of this study clearly support the use of very high purity concentrates for the replacement therapy of HIV-infected hemophiliacs. 相似文献
59.
Intimal hyperplasia as a cause of restenosis after percutaneous transluminal coronary angioplasty 总被引:1,自引:0,他引:1
We describe a patient who died 96 days after percutaneous transluminal coronary angioplasty was performed. The balloon-dilated segments of the left anterior descending artery and its first diagonal branch were found to be restenosed. Histologic examination of these arterial segments showed intimal hyperplasia without lipid deposition as the cause of restenosis, rather than common atherosclerotic plaque. 相似文献
60.
Masclee AA; Hopman WP; Corstens FH; Rosenbusch G; Jansen JB; Lamers CB 《Radiology》1989,173(2):407-410
Both ultrasonography (US) and cholescintigraphy are used to study gallbladder dynamics. The present study was undertaken to determine whether the two methods provide the same or different information relating to gallbladder emptying. Emptying was simultaneously studied with both methods during infusion of graded physiologic doses of cholecystokinin (CCK) in six healthy subjects. Infusion of stepwise increasing doses of CCK, ranging from 0.03 to 0.5 Ivy dog units per kilogram of body weight per hour (IDU/kg.h), induced significant dose-related increases in plasma CCK, decreases in gallbladder volume assessed with US, and gallbladder emptying assessed with cholescintigraphy. The threshold dose for inducing significant gallbladder emptying was 0.13 IDU/kg.h, as determined with both techniques, indicating similar detection limits. There was a highly significant correlation between decreases in gallbladder volume and decreases in radioactive counts over the gallbladder region, with a tendency toward greater gallbladder responses at sonography during the early phase of gallbladder contraction and toward greater responses at cholescintigraphy during the later phase of gallbladder contraction. It is concluded that these methods can be used interchangeably for the quantitation of gallbladder emptying. 相似文献