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排序方式: 共有1094条查询结果,搜索用时 218 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.
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
3.
Mohamad H Yamani Daniel J Cook E Murat Tuzcu Philip Paul Norman B Ratliff Yang Yu Robert Hobbs Gustavo Rincon Corinne Bott-Silverman Nicholas Smedira James B Young Randall C Starling 《The Journal of heart and lung transplantation》2005,24(8):1014-1018
BACKGROUND: Recipients of hearts from donors with spontaneous intracerebral hemorrhage (ICH) are at increased risk of allograft vasculopathy compared with trauma donors. We have recently shown that the vitronectin receptor (integrin alpha(V)beta3) is upregulated in transplant vasculopathy. We hypothesized that donor ICH is associated with systemic activation of alpha(V)beta3 in the donor before transplantation. METHODS: We evaluated mRNA expressions of alpha(V)beta3 (TaqMan PCR) in endomyocardial biopsy samples at 1-week post-transplant in 20 recipients from ICH donors and 20 recipients from trauma donors. To investigate whether systemic activation of alpha(V)beta3 was present in the donor before transplantation, alpha(V)beta3 expression was also evaluated in the corresponding donor spleen lymphocytes. All patients underwent serial coronary intravascular ultrasound to evaluate for coronary vasculopathy. The baseline characteristics were similar except for increased donor age in the ICH Group. RESULTS: The ICH Group showed significant increased mRNA expression of alpha(V)beta3 in the heart biopsy samples (3.8-fold, p = 0.012) and in the corresponding donor spleen lymphocytes (3.5-fold, p = 0.014) compared with the Trauma Group. At 1 year, the ICH Group also showed increased progression of coronary vasculopathy. Multivariate regression analysis found that donor lymphocytic alpha(V)beta3 mRNA expression was independently associated with increased risk of vasculopathy (odds ratio, 1.9; 95% CI, 1.21-3.98, p = 0.03). CONCLUSIONS: Our report demonstrates the presence of systemic activation of alpha(V)beta3 in donors with spontaneous intracerebral hemorrhage and its association with the subsequent development of allograft vasculopathy in the recipient. 相似文献
4.
5.
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
6.
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
7.
8.
Patients' Expectations of Asthma Treatment 总被引:1,自引:0,他引:1
Carol A. Mancuso Melina Rincon Laura Robbins Mary E. Charlson 《The Journal of asthma》2003,40(8):873-881
A multicomponent model has been developed to explain patients' unmet expectations of medical care. The model proposes that expectations are related to patients' personal experiences with illness, perceived vulnerability to disease, transmitted knowledge, and perceived severity of disease. The objective of this cross-sectional study was to determine whether this model can be applied to patients' unrealistic expectations of treatment outcomes, specifically expecting to be cured of asthma. In total, 230 patients observed in a primary care practice in New York City were interviewed in person with open-ended questions about their expectations of asthma treatment. Responses were analyzed with qualitative techniques to generate categories of expectations. Patients had a mean age of 41 ± 11 years, 21% were white, 30% African American, 42% Latino, and 7% other groups. Major categories of expectations were generated from patients' responses and included symptom relief (expected by 52%), cure (36%), improved physical function (21%), and improved psychological well-being (15%). The category of expecting a cure was assessed with patients' responses to the following items representing components of the model: 1) resource utilization and medication requirements for asthma (representing severity of disease); 2) perceived quality of asthma care and satisfaction with care (representing past asthma experiences); 3) the Asthma Self-Efficacy Scale (representing perceived vulnerability to exacerbations); and 4) experiences of social network contacts with asthma and the Check Your Asthma IQ survey (representing transmitted knowledge). In bivariate analysis, patients who expected a cure were more likely to be Latino or Native American or Asian (p = 0.02), to have never required oral corticosteroids (p = 0.004), to be dissatisfied with the status of their asthma (p = 0.008), to know others who were limited by asthma (p = 0.03), to have worse Asthma Self-Efficacy Scale scores (p = 0.002), to have worse Check Your Asthma IQ scores (p = 0.04), and to currently be taking inhaled corticosteroids (p = 0.03). In multivariate analysis, worse asthma self-efficacy (p = 0.008), never having required oral corticosteroids (p = 0.005), and currently taking inhaled corticosteroids (p = 0.05) remained associated with expecting a cure. As a result of this study, we found that patients have multiple expectations of asthma treatment, including realistic expectations such as symptom relief and improved function, as well as unrealistic expectations, specifically to be cured of asthma. A multicomponent model of patient and disease characteristics was associated with this unrealistic expectation. These findings indicate that clinicians can intervene in diverse areas to foster realistic expectations of treatment outcomes among asthma patients. 相似文献
9.
Kursad Erinc Mohamad H Yamani Randall C Starling Tim Crowe Robert Hobbs Corinne Bott-Silverman Gustavo Rincon James B Young Jingyuan Feng Daniel J Cook Nicholas Smedira E Murat Tuzcu 《The Journal of heart and lung transplantation》2005,24(8):1033-1038
BACKGROUND: Hypertension is a potential risk factor for allograft coronary vasculopathy. We evaluated the efficacy of angiotensin-converting enzyme (ACE) inhibitors and calcium antagonists, and their combined use, on the development of coronary vasculopathy in hypertensive heart transplant recipients. METHODS: Eighty-two heart transplant recipients underwent serial intravascular ultrasound (IVUS) analysis at baseline (within 1 month) and at 1 year after transplantation and were evaluated for the development of coronary vasculopathy. Patients were divided into 4 groups. Nineteen normotensive recipients received no treatment, control (Group A). Hypertensive patients were treated with either ACE inhibitors (Group B, n = 37), calcium antagonists (Group C, n = 16), or both (Group D, n = 10). RESULTS: We found a significant reduction in IVUS indices of coronary vasculopathy in heart transplant recipients who used a combination of an ACE inhibitor and a calcium antagonist compared with recipients who used either drug alone (p < 0.05). This synergistic efficacy was independent of the baseline indices evaluated in a multivariate regression analysis model and was noted despite comparable mean arterial pressure among the 3 hypertensive groups at 1 year, thus suggesting the presence of a synergistic anti-proliferative effect beyond the anti-hypertensive efficacy. CONCLUSIONS: The combined use of an ACE inhibitor and a calcium antagonist is more effective than the individual use of either drug alone on the development of coronary vasculopathy in cardiac transplant recipients. Large randomized clinical trials are warranted to evaluate such a synergistic efficacy. 相似文献
10.