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21.
Metastasis (the spread of cancer from a primary tumor to secondary organs) is responsible for most cancer deaths. The ability to follow the fate of a population of tumor cells over time in an experimental animal would provide a powerful new way to monitor the metastatic process. Here we describe a magnetic resonance imaging (MRI) technique that permits the tracking of breast cancer cells in a mouse model of brain metastasis at the single-cell level. Cancer cells that were injected into the left ventricle of the mouse heart and then delivered to the brain were detectable on MR images. This allowed the visualization of the initial delivery and distribution of cells, as well as the growth of tumors from a subset of these cells within the whole intact brain volume. The ability to follow the metastatic process from the single-cell stage through metastatic growth, and to quantify and monitor the presence of solitary undivided cells will facilitate progress in understanding the mechanisms of brain metastasis and tumor dormancy, and the development of therapeutics to treat this disease.  相似文献   
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Lasers in Medical Science - Melasma is a chronic, dark brown–pigmented patches and macules commonly on the face. Many treatment modalities for melasma have been used as hydroquinone, laser...  相似文献   
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OBJECTIVE: To investigate the relationship between the extent of sinus disease in chronic sinusitis as detected radiologically by computed tomography (CT) scan and the population of cilia (ciliary area) both before and after functional endoscopic sinus surgery (FESS). In a simple way this is a trial to statistically prove that the CT scan could be a valid indicator and a mirror of the histological status of the sinus mucosa. DESIGN: Twenty adult patients were enrolled in this study. Radiological extension of the sinus disease was quantitated using the classification proposed by Kennedy in 1992 and the ciliary population was studied using scanning electron microscopy and image analysis softwares. RESULTS AND CONCLUSION: The more advanced the sinusitis, as evidenced by CT scans, the more the expected reduction in the ciliary area (CA) and in the ciliary count. But after FESS the degree of ciliary regeneration does not depend statistically on the radiological condition of the sinuses and the degree of opacity prior to intervention, i.e. a statistically valid inverse relationship exists between the radiological stage of sinusitis and the ciliary population pre-operatively but the same relation does not extend to the ciliary population post-operatively.  相似文献   
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OBJECTIVES/HYPOTHESIS: Electromagnetic therapy has been used with reported success in multiple clinical settings, including the treatment of seizure disorders, brain edema, migraine headaches, revascularization of burn wounds, and diabetic ulcers. The purpose of the study was to investigate the effect of pulsed high-frequency electromagnetic therapy on chronic tinnitus. STUDY DESIGN: A randomized, prospective, double-blind, placebo-controlled pilot study was conducted to evaluate the effectiveness of high-frequency pulsed electromagnetic energy using the Diapulse device in the treatment of chronic tinnitus. Thirty-seven adult patients with chronic tinnitus of at least 6 months' duration were recruited and randomly assigned to either a treatment or a placebo group. METHODS: Patients received 30-minute treatments with the Diapulse device three times a week for 1 month. The unit was set to deliver electromagnetic energy at a frequency of 27.12 MHz at a repetition rate of 600 pulses per second. All subjects had pretreatment and post-treatment audiological testing, including tinnitus frequency and intensity matching. They responded to a tinnitus rating questionnaire and the Tinnitus Handicap Inventory before and after treatment. RESULTS: There was no significant change in the pretreatment and post-treatment audiometric thresholds in either group. There were no significant differences between the pretreatment and post-treatment Tinnitus Handicap Inventory scores or the tinnitus rating scores in either subject group (Student t test). No diagnosis-specific differences were identified. CONCLUSION: High-frequency pulsed electromagnetic energy (Diapulse) at the settings used in the study showed no role in the therapy of patients with chronic tinnitus.  相似文献   
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The bone-anchored hearing aid (BAHA) is an effective means of intervention, its use being well documented in persons with chronic conductive pathology and congenital aural anomalies. This article describes the standard guidelines (both auditory and extraauditory aspects) for patient selection and expands the criteria to include bilateral BAHA implantation, unilateral conductive hearing loss, and unilateral profound sensorineural hearing loss. The BAHA's development, design features, and patient outcomes are also reviewed. Suggestions are presented for fitting, counseling, and following BAHA users.  相似文献   
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Clopidogrel is an inhibitor of platelet ADP P2Y12 receptors and currently used for prevention of stent thrombosis. Despite certain clinical benefit using this drug in patients undergoing percutaneous coronary intervention (PCI), some patients do not attain adequate antiplatelet effects. In this study, we investigated the role of three genetic factors (P2Y12, CYP3A5, CYP2C19), demographic characteristics, and pathologic condition on clopidogrel response variability in Iranian patients after PCI. Patients who were candidate for elective PCI were enrolled in this study. All patients had received aspirin 80-325 mg daily for ≥ 1 week before PCI. Blood samples were taken from patients at baseline, 2 h after taking a 600-mg loading dose of clopidogrel, 24h and 30 days after PCI. Platelet aggregation was measured by turbidimetric aggregation assay with two different concentrations of ADP (5 and 20 μM). CYP2C19*2(rs4244285), CYP2C19*3(rs4986893), CYP3A5 (A6986G), and P2Y12 (T744C) genotypings were performed by PCR-RFLP. One hundred and twelve patients were included in this study. Maximum clopidogrel non-responsiveness (25.90%) occurred at 2 h after taking 600 mg of the loading dose of clopidogrel. Although there were no significant associations between clopidogrel responsiveness and polymorphisms of CYP2C19, CYP3A5, and P2Y12 (P > 0.05), subjects who were CYP3A5 genotype expressor had a greater inhibition of platelet aggregation. No significant associations were observed between environmental factors and clopidogrel responsiveness (P > 0.05). Our results showed that P2Y12, CYP3A5, and CYP2C19 polymorphisms along with non-genetic factors were not responsible for the interindividual variability in response to clopidogrel in Iranian population.  相似文献   
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As a preliminary step toward incorporating a tobacco education and intervention program into our undergraduate medical curriculum, this study was designed to assess students' smoking-related behaviour, knowledge and attitudes towards tobacco, and perceptions of their future role as doctors in smoking intervention. A cross-sectional, study was conducted in the university year 2001/2002 on a representative sample of male medical students enrolled in 4th and 5th years at Alexandria University. A total of 320 students across the 2 years completed the survey. The smoking rate among medical students was 17.5% (10.9% smoked daily and 6.6% occasionally). The awareness of harmful effects of smoking and knowledge about the causal role of tobacco in the development of specific diseases were deficient. The intention to perform smoking intervention in the future as doctors seemed unsatisfactory. About 85% of the students thought that doctors should carry out smoking cessation advice depending on the disease, while the rate of those who thought so irrespective of the disease did not reach 44%. Current smokers thought less actively about smoking intervention than non-smokers. Nearly two-thirds of students (65.3%) felt they were not sufficiently prepared for caring or counseling smokers, and only 31.9% of students were convinced of the effectiveness of the doctor's advice to stop smoking. Seventy-seven and half percent of them desired specific training in smoking intervention. Non-smokers were more in favour of legislative actions to discourage tobacco use than current smokers. These findings suggest that medical school authorities should design and implement an appropriate basic training aimed at better preparing medical students for their future role in prevention of smoking. Specific teaching of medical students about smoking-related diseases and a patient-centered smoking cessation intervention is required to provide future medical practitioners with the knowledge and skills they need to effectively intervene with smokers.  相似文献   
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