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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.
Letitia Lancaster 《European Journal of Oncology Nursing》2004,8(1):30-39
Despite advances in brachytherapy techniques in recent years, patients still experience a variety of treatment-related complications. Vaginal stenosis is a recognised toxicity of brachytherapy for the treatment of gynaecological cancer. It can result in long-term sexual dysfunction and painful vaginal examinations; however, it is generally accepted that it may be prevented by regular sexual intercourse or the use of vaginal dilators. The incidence of vaginal stenosis is variably reported in the literature, while preventative strategies and compliance are infrequently described and rarely evaluated. A telephone survey of radiation oncology centres in Australia was undertaken as a quality improvement activity to determine best practice for the use of vaginal dilators for the prevention of vaginal stenosis, by way of identifying similarities of practice. The results revealed a lack of consistency for all variables, including which patients are advised to use vaginal dilators, the time to initiate use, frequency of use, insertion time and duration of use. These findings suggest that current methods for preventing radiation-induced vaginal stenosis warrant formal evaluation in order to establish an evidence base for practice. 相似文献
3.
Maxillary sinusitis in adults: an evaluation of placebo-controlled double-blind trials 总被引:1,自引:0,他引:1
BACKGROUND: In general practice, acute sinusitis is frequently diagnosed
and treated with antibiotics. OBJECTIVE: This study aimed to determine the
evidence for the effectiveness of antibiotic treatment in acute maxillary
sinusitis in adults by assessing the methodological quality of
placebo-controlled double-blind randomized trials. METHOD: An evaluation by
four raters through a 35-item scoring-scale for internal and external
validity of all placebo-controlled double-blind randomized trials on acute
sinusitis found between January 1966 and July 1996. RESULTS: Eighty-five
trials were excluded because they were not placebo-controlled,
double-blind, randomized, or were carried out in patients with chronic
sinusitis or in children. The three remaining trials were performed in
different populations (one in general practice) between 1973 and 1978. Only
one study claimed superiority of antibiotic treatment. Different inclusion
criteria and major outcome measures were used by the authors. The
reliability of major outcome events was reported poorly or not at all and
in two studies outcome measures were clinically inappropriate. The studies
scored 30-62% of the maximum attainable score for internal validity and
10-20% for external validity. CONCLUSION: The effectiveness of antibiotic
treatment in acute maxillary sinusitis in a general practice population is
not based sufficiently on evidence.
相似文献
4.
Lofepramine is a tricyclic antidepressant that is structurally similar to imipramine and is extensively metabolised to desipramine. In the absence of other major pharmacological effects it appears that its antidepressant activity stems from the facilitation of noradrenergic neurotransmission by uptake inhibition, and possibly by the additional facilitation of serotoninergic neurotransmission. The overall therapeutic efficacy of lofepramine is comparable to that of imipramine, amitriptyline, clomipramine, maprotiline and mianserin in patients with depression of varying severity, and coexisting anxiety. Dry mouth is the most commonly reported side effect of usual therapeutic doses of lofepramine, but the incidence of this and other anticholinergic side effects is less among patients treated with lofepramine than with imipramine. Lofepramine has not been associated with adverse effects on cardiac function even in cases of attempted suicide by overdose. Thus, providing its apparent favourable side effect profile is confirmed in practice, lofepramine may be a valuable alternative for treatment of the depressed patient where a tricyclic is indicated. 相似文献
5.
Effectiveness of training health professionals to provide smoking cessation interventions: systematic review of randomised controlled trials. 下载免费PDF全文
OBJECTIVE--To assess the effectiveness of interventions that train healthcare professionals in methods for improving the quality of care delivered to patients who smoke. DESIGN--Systematic literature review. SETTING--Primary care medical and dental practices in the United States and Canada. Patients were recruited opportunistically. SUBJECTS--878 healthcare professionals and 11,228 patients who smoked and were identified in eight randomised controlled trials. In each of these trials healthcare professionals received formal training in smoking cessation, and their performance was compared with that of a control group. MAIN MEASURES--Point prevalence rates of abstinence from smoking at six or 12 months in patients who were smokers at baseline. Rates of performance of tasks of smoking cessation by healthcare professionals, including offering counselling, setting dates to stop smoking, giving follow up appointments, distributing self help materials, and recommending nicotine gum. METHODS--Trials were identified by multiple methods. Data were abstracted according to predetermined criteria by two observers. When possible, meta-analysis was performed using a fixed effects model and the results were subjected to sensitivity analysis. RESULTS--Healthcare professionals who had received training were significantly more likely to perform tasks of smoking cessation than untrained controls. There was a modest increase in the odds of stopping smoking for smokers attending health professionals who had received training compared with patients attending control practitioners (odds ratio 1.35 (95% confidence interval 1.09 to 1.68)). This result was not robust to sensitivity analysis. The effects of training were increased if prompts and reminders were used. There was no definite benefit found for more intensive forms of counselling compared with minimal contact strategies. CONCLUSIONS--Training health professionals to provide smoking cessation interventions had a measurable impact on professional performance. A modest, but non-robust, effect on patient outcome was also found, suggesting that training alone is unlikely to be an effective strategy for improving quality of care, unless organisational and other factors are also considered. 相似文献
6.
Drinking patterns of male and female Long-Evans rats were compared during a 15-day drinking period. All animals were tested for preference for alcohol for 24 h during which food, water, and beer containing 5% ethanol were freely available. Animals drinking 50 ml or more of beer were chosen for the experiments. On days 1-5, animals were offered food, water, and beer containing 5% ethanol (v/v). On days 6-15, the concentration of ethanol in the beer was doubled to 10% (v/v). Preference ratios (beer/total fluid) were higher for females than males, and females consumed more grams of alcohol per unit of body weight. When alcohol concentration was doubled, females increased alcohol intake (g/kg), while males tended to titrate alcohol intake to levels consumed at 5% concentration. Female patterns of drinking differed from male patterns of drinking. 相似文献
7.
8.
The interlocking intramedullary nail has greatly expanded the indications for closed intramedullary nailing of the femur. We describe a complication caused by the presence of a calcified lesion located at the proximal metaphyseal-diaphyseal junction of the femur. This lesion could not be penetrated by hand reamers. We used a long 3.5-mm drill bit to place a hole in the infarct, which then allowed passage of the hand reamer. The operation then proceeded in the standard fashion without complications. 相似文献
9.
H Angus-Leppan GA Lambert J Michalicek 《Cephalalgia : an international journal of headache》1997,17(6):625-630
Co-existence of facial and occipital pain may occur in occipital neuralgia, migraine and cluster headache; suggesting convergence of trigeminal and cervical afferents. Such convergence has been shown in humans and other animals, but the site and extent of this are uncertain. In anaesthetized adult cats, the superior sagittal sinus and occipital nerve were stimulated electrically, and extracellular recordings made in the dorsolateral area of the upper cervical cord using glass-coated tungsten electrodes. Of 49 units in 10 cats, 33 (67%) had input from the superior sagittal sinus and the occipital nerve. Thirteen (27%) had superior sagittal sinus input and 3 (6%) had occipital nerve input. Convergent receptive fields were identified mechanically in 7 units. These experiments in cats show convergent input from occipital nerve and superior sagittal sinus on dorsolateral area units in two-thirds of cases studied. This experimental site of trigeminocervical convergence may relate to referral of pain in occipital neuralgia and other headaches. 相似文献
10.
In patients with PG-dependent renal function, NSAID administration
constantly reduces GFR and RBF in a dose-dependent fashion. In this
situation, the risk of overt acute renal failure is high and should be
taken into proper account. In contrast, the incidence of NSAID-related
renal structural alterations appears to be very low, yet the absolute
number of patients may be significant considering the wide use of such
drugs. Concerning the antiproteinuric effect of NSAIDs, the unfavourable
ratio risk/benefit does not seem to support their indication in proteinuric
nephropathies. The development of PGHS-2 selective inhibitors is promising,
and may open new therapeutical strategies in the treatment of the
progression of renal disease.
相似文献