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排序方式: 共有852条查询结果,搜索用时 15 毫秒
1.
Intracranial circulation: pulse-sequence considerations in three- dimensional (volume) MR angiography 总被引:2,自引:0,他引:2
The technique and feasibility of magnetic resonance (MR) angiography of intracranial vessels were studied in 35 healthy volunteers. Variations in image orientation, repetition time (TR), and flip angle were evaluated to determine their effects on flow-related enhancement. Gradient modifications--including echo time (TE), motion compensation, bandwidth, and field of view--were also studied in an effort to reduce motion-induced phase shifts. Results indicated that a FISP (fast imaging with steady precession) sequence with a TR of 50 msec, TE of 15 msec, velocity compensation in the read and section-select directions, acceleration compensation in the read direction, anisotropic volume, and a 1.25-mm partition thickness produced three-dimensional angiographic MR images that were accurate and reproducible in the depiction of the major intracranial vessels. Difficulties with field of view, persistent signal void secondary to higher-order motion, and spatial resolution remain major problems requiring additional study. 相似文献
2.
Paediatric dacryocystorhinostomy 总被引:1,自引:0,他引:1
KN Hakin FRCS FRCOphth TJ Sullivan FRACO FRACS A Sharma FCOphth † RAN Welham FRCS FCOphth † 《Clinical & experimental ophthalmology》1994,22(4):231-235
Of 258 cases of dacryocystorhinostomy performed on children in the period September 1981 to September 1991, 130 were for simple, unresolved congenital nasolacrimal duct obstruction. Other indications for surgery included punctal agenesis, lacrimal fistula, post-traumatic and post-inflammatory canalicular obstruction. Of 177 children without canalicular pathology, 171 (96%) were relieved of symptoms with one operation, without canalicular intubation. Of 81 cases with canalicular disease, 55 of 70 (79%) who underwent DCR plus canalicular intubation, and 10 of 11 who underwent DCR plus Lester-Jones tube, were substantially improved with one operation. No child required peroperative or postoperative blood transfusion. Dacryocystorhinostomy in childhood, in experienced surgical hands, is a safe procedure, achieving relief of symptoms in most cases, particularly in the absence of canalicular disease. 相似文献
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The effects of a constant infusion of total parenteral nutrition on the histamine content of the hypothalamus was studied in adult male rats. Histamine content of the stomach, kidney, liver, and heart was also determined. The relationship between tissue histamine levels and duration of the infusion was examined. Rats receiving intravenous infusions of total parenteral nutrition had significantly higher (p less than 0.001) histamine levels in the hypothalamus than did orally-fed control rats. No difference was observed in the histamine level in the remainder of the brain. Animals receiving parenterally infused nutrient solutions had a higher histamine content in the kidneys but lower histamine levels in the stomach than did the control rats. No changes in the histamine content of liver or heart were observed. It appears that increases in histamine levels in the kidney and hypothalamus of rats given total parenteral nutrition persist up to 5 days and 9 days, respectively. The mechanisms responsible for and the consequences of the alterations of histamine content of these tissues remain to be established. 相似文献
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OBJECTIVE: The aim of this study was to assess the severity of epilepsy and
its effect on patients lives, and to describe patients' use of and
attitudes to health care. METHOD: A questionnaire was sent to 595 people
with epilepsy identified from 14 general practices in north-west Bristol.
All patients aged 16 years and over receiving anti-epileptic medication for
their epilepsy were included in the study. Areas investigated included
severity of epilepsy and its effect on quality of life, anti-epileptic
medication and its perceived effect, health care utilization and
preferences for health care. RESULTS: Seizure frequency was strongly
associated with adverse effects of epilepsy. Attacks of epilepsy were
experienced at least monthly by 20.4% (95% confidence intervals (Cl)
17.0-23.7%) of patients, 29.4% (25.4-33.4%) took more than one
anti-epileptic drug, 56.1% (50.1-62.2%) reported drug side effects, 74.1%
(70.3-77.8%) would prefer to receive all or most of their epilepsy care in
a general practice setting, and 69.8% (63.5- 76.2%) would like contact with
a primary care-based epilepsy specialist nurse. During the previous year
42.4% (35.9-48.8%) of patients had not seen a doctor about their epilepsy.
Of patients who had attended the general practice only 13.4% (9.6-17.2%)
had regular arrangements to see their GP about epilepsy. Patients receiving
both primary and secondary care had the greatest needs and wants for
improved care. CONCLUSIONS: Structured care, including regular
appointments, co-ordination of primary and secondary care, and increased
monitoring and discussion, may improve the quality of life of people with
epilepsy, but requires evaluation.
相似文献
7.
Factors influencing women to undergo screening mammography 总被引:2,自引:0,他引:2
8.
Brain histamine levels were determined in golden hamster hypothalamus and 'brain minus hypothalamus' on each of the 4 days of the estrous cycle and on selected days of pregnancy. The highest histamine content of the hypothalamus was observed on day 3 of the estrous cycle. The highest histamine content of the hypothalamus was observed on day 3 of the estrous cycle, which is the day prior to recurrence of heat on day 4. Day 4 terminates in ovulation. The histamine level in the remainder of the brain peaked on day 2. During gestation the histamine content of the 'brain minus hypothalamus' was greatest on day 5, while the maximum content of histamine in the hypothalamus was not reached until day 8. After the 8th day of pregnancy, there was an overall decline in brain histamine that continued until parturition. The hypothalamic histamine level in nonpregnant females was not different from that of males. However, in the remainder of the brain, histamine levels in females on days 1 and 2 of the estrous cycle were higher than in males. 相似文献
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