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排序方式: 共有632条查询结果,搜索用时 281 毫秒
1.
Prevalence of silent myocardial ischemia in asymptomatic individuals with subclinical atherosclerosis detected by electron beam tomography 总被引:3,自引:0,他引:3
Anand D. Vijay Lim Eric Raval Usha Lipkin David Lahiri Avijit 《Journal of nuclear cardiology》2004,11(4):450-457
BACKGROUND: Electron beam tomography coronary calcium imaging is an evolving technique for the early detection of coronary atherosclerosis, and recent studies have established its prognostic value in asymptomatic individuals. The relationship of coronary artery calcium scores (CAC) to obstructive coronary artery disease (CAD) has been poorly studied but is clinically relevant because it determines which individuals are likely to benefit from revascularization procedures. Hence, we prospectively evaluated the prevalence of myocardial ischemia in asymptomatic patients with cardiovascular risk factors and subclinical atherosclerosis. METHODS AND RESULTS: We studied 864 asymptomatic patients with no previous CAD but with cardiovascular risk factors, referred for electron beam tomography coronary calcium imaging to our institution over an 18-month period. From this group, 220 consecutive patients (85% men; mean age, 61 +/- 9 years; age range, 31-84 years) with moderate to severe atherosclerotic disease (coronary calcium score > or =100 Agatston units) were prospectively evaluated by technetium 99m sestamibi single photon emission computed tomography (SPECT). Patients were followed up (mean follow-up, 14 months) and data regarding their subsequent clinical management recorded. Of the 220 patients, 119 had moderate atherosclerosis (CAC score of 100-400 Agatston units) and 101 had severe atherosclerosis (CAC score > or =400 Agatston units). Abnormal SPECT findings were seen in 18% of patients with moderate atherosclerosis (n = 21) and 45% of patients with severe atherosclerosis (n = 45). Increasing severity of atherosclerosis was related to increasing ischemic burden (summed difference score = 1 +/- 0.2 for CAC score of 100-400 Agatston units and 3.2 +/- 0.5 for CAC score > or =400 Agatston units). In a multivariate linear regression model incorporating risk factors, CAC was the only predictor of silent ischemia. CONCLUSION: In comparison to previously published data, we detected a higher prevalence of silent ischemia even in patients with moderate coronary atherosclerosis (18%). This may reflect the differing risk factor profile of our patient population. When coronary calcium screening is used to preselect asymptomatic patients with cardiovascular risk factors for myocardial perfusion imaging, the optimum coronary calcium score threshold will depend on the population prevalence of risk factors and asymptomatic obstructive CAD. 相似文献
2.
Prafulla Raval Howard H. T. Hsu H. Clarke Anderson 《Journal of orthopaedic research》1996,14(4):605-610
Implants of defatted, freeze-dried Saos-2 human osteosarcoma cells grown to confluency induce de novo bone formation in athymic mice. These cells are also richly endowed with bone morphogenetic proteins and express mRNA for bone morphogenetic proteins 1, 2, 3, 4, and 6, as well as for transforming growth factor-β1. Our aim was to study whether the ability to induce bone formation is related to the level of expression of bone morphogenetic protein. We studied the osteoinductive abilities and levels of expression of bone morphogenetic protein of Saos-2 cells both during the growth phase and after confluency was reached. Subconfluent cells were at least 70% less effective in their osteoinductive ability than confluent cells. Comparison of bone morphogenetic protein mRNA expression in confluent and subconfluent cells revealed that the latter had lower expression of all the mRNAs studied. The expression of bone morphogenetic protein-1, bone morphogenetic protein-2, and bone morphogenetic protein-6 mRNAs was 2, 3, and 6 to 10-fold lower, respectively, in subconfluent cells. These results suggest that the ability of Saos-2 cells to induce de novo bone formation may be correlated with the relative expression of these proteins; the expression of bone morpho-genetic proteins in Saos-2 cells also may be dependent on the cell cycle. 相似文献
3.
The effects of the calcium antagonists verapamil and nifedipine on blood glucose levels, glucose tolerance, insulin secretion during glucose tolerance and hypoglycaemic effect of tolbutamide were studied in normal nondiabetic rabbits. Daily dosage of 40 mg/kg verapamil and 5 mg/kg nifedipine given orally up to 7 days did not affect blood glucose level, glucose tolerance, insulin secretion during glucose tolerance and hypoglycaemic activity of tolbutamide 250 mg/kg p.o. 相似文献
4.
A critically ill man suffered a respiratory arrest due to pulmonary air embolism after the exchange of central venous catheters over a guidewire. A pulmonary perfusion lung scan performed 90 min later demonstrated extensive perfusion defects which were interpreted as "high probability" for PTE. Pulmonary angiography 4.5 h later was normal. A second perfusion lung scan performed 24 h after the respiratory arrest was normal. Pulmonary air embolism can produce segmental (and larger) perfusion defects which may be indistinguishable from those caused by PTE. The rapid (24 h) resolution of the perfusion defects may help differentiate the two disorders. 相似文献
5.
Dai Z Weichenhan D Wu YZ Hall JL Rush LJ Smith LT Raval A Yu L Kroll D Muehlisch J Frühwald MC de Jong P Catanese J Davuluri RV Smiraglia DJ Plass C 《Genome research》2002,12(10):1591-1598
Knudson's two-hit hypothesis postulates that genetic alterations in both alleles are required for the inactivation of tumor-suppressor genes. Genetic alterations include small or large deletions and mutations. Over the past years, it has become clear that epigenetic alterations such as DNA methylation are additional mechanisms for gene silencing. Restriction Landmark Genomic Scanning (RLGS) is a two-dimensional gel electrophoresis that assesses the methylation status of thousands of CpG islands. RLGS has been applied successfully to scan cancer genomes for aberrant DNA methylation patterns. So far, the majority of this work was done using NotI as the restriction landmark site. Here, we describe the development of RLGS using AscI as the restriction landmark site for genome-wide scans of cancer genomes. The availability of AscI as a restriction landmark for RLGS allows for scanning almost twice as many CpG islands in the human genome compared with using NotI only. We describe the development of an AscI-EcoRV boundary library that supports the cloning of novel methylated genes. Feasibility of this system is shown in three tumor types, medulloblastomas, lung cancers, and head and neck cancers. We report the cloning of 178 AscI RLGS fragments via two methods by use of this library. 相似文献
6.
A case of multiple myeloma diagnosed by fine-needle aspiration (FNA) biopsy and confirmed by laboratory studies in a patient with a history of renal-cell carcinoma is presented. The patient was diagnosed with renal-cell carcinoma of the right kidney and a radical nephrectomy was performed. Eighteen months after this diagnosis was made, the patient developed chest wall pain and was found to have osteolytic bone lesions of the ribs and vertebral bodies. FNA of an osteolytic rib lesion disclosed multiple myeloma. Additional laboratory studies confirmed the diagnosis of multiple myeloma. This case report demonstrates the value of FNA as a diagnostic tool for the follow-up of cancer patients, the subsequent discrimination between metatastic lesions and a second primary malignancy, and the cytology of multiple myeloma. 相似文献
7.
Protein and diacylglycerol phosphorylation in the stimulus-secretion coupling of rat mast cells. 总被引:2,自引:0,他引:2
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The pattern of endogenous protein phosphorylation during stimulation of rat peritoneal mast cells by two types of agonists has been compared. Compound 48/80, substance P and histone, which do not require the presence of external Ca2+ to trigger histamine release, induced a similar profile of phosphorylation comprising an increased phosphorylation of a 35,000 molecular weight (MW) protein and dephosphorylation of a 15,000 MW protein. The same profile was seen when the cells were stimulated with phorbol-12-myristate-13-acetate. The phorbol ester also induced histamine release, although less than that caused by the other secretagogues. The pattern of phosphorylation shared by both the phorbol ester and the basic secretagogues represented only part of that observed when the cells were stimulated in a Ca2+-free medium with anti-IgE. Under those conditions, two additional proteins of 68,000 and 56,000 MW became phosphorylated. The phosphorylation of these two proteins increased when anti-IgE was applied in the presence of Ca2+. In contrast, the extent of phosphorylation of the 35,000 MW protein was diminished. Both the basic secretagogues and anti-IgE, but not the phorbol ester, also enhanced the production of phosphatidic acid, indicating that diacylglycerol was generated. This process was independent of the presence of external Ca2+. It is suggested that protein kinase C activation is responsible for the phosphorylation observed with the basic secretagogues but not entirely with IgE-directed ligands. 相似文献
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10.
Raval RC Bilimoria FE Patel HA 《Indian journal of dermatology, venereology and leprology》1995,61(3):137-139
Fifty cases with chronic idiopathic urticaria of more than 3 months duration were selected and divided into two groups. Group 'A' was given 10 mg loratadine once daily, while group 'B' was given pheniramine maleate 25 mg, twice daily for one month. All patients were followed for one month more. 48% excellent response was observed in group 'A' while 16% excellent response was observed in group 'B'. Good response was observed in 24% of patients in group 'A', while in group 'B' 16% of patients had good response. No side effects were observed in loratadine group, while drowsiness was observed in pheniramine group. 相似文献