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21.
Calcium, calcineurin, and the control of transcription   总被引:17,自引:0,他引:17  
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Bone development is one of the key processes characterizing childhood and adolescence. Understanding this process is not only important for physicians treating pediatric bone disorders, but also for clinicians and researchers dealing with postmenopausal and senile osteoporosis. Bone densitometry has great potential to enhance our understanding of bone development. The usefulness of densitometry in children and adolescents would be increased if the physiological mechanisms and structural features of bone were given more consideration in the design and interpretation of densitometric studies. This review gives an overview on the most relevant techniques of quantitative noninvasive bone analysis. Furthermore it describes the relationship between bone biology, selected surrogates describing the biological processes and the possibilities of measuring these surrogates specifically and precisely by the different devices. The overall recommendation for researchers in this field is to describe firstly the biological process to be analyzed (bone growth in length, remodeling or modeling, or all together), secondly the bone parameter which describes this process, and thirdly the reason for selecting a special device.  相似文献   
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In recent studies from Sweden and the United States, a high vitamin A intake has been associated with low bone mineral density (BMD) and increased fracture risk. In Sweden and the United States, food items such as milk and breakfast cereals are fortified with vitamin A, whereas in Denmark there is no mandatory fortification with vitamin A. In the present study, we investigated relations between vitamin A intake and BMD and fracture risk in a Danish population consuming mostly unfortified food items. Within a population-based cohort study in 2,016 perimenopausal women, associations between BMD and vitamin A intake were assessed at baseline and after 5-year follow-up. Moreover, associations between baseline vitamin A intake and 5-year changes in BMD were studied. Finally, fracture risk was assessed in relation to vitamin A intake. In our cohort, dietary retinol intake (0.53 mg/day) was lower than the intake reported in recent studies form Sweden (0.78 mg/day) and the United States (1.66 mg/day). Cross-sectional and longitudinal analyses showed no associations between intake of vitamin A and BMD of the femoral neck or lumbar spine. Neither did BMD differ between those 5% who had the highest, and those 5% who had the lowest, vitamin A intake. During the 5-year study period, 163 subjects sustained a fracture (cases). Compared to 978 controls, logistic regression analyses revealed no difference in vitamin A intake. Thus, in a Danish population, average vitamin A intake is lower than in Sweden and the United States and not associated with detrimental effects on bone.  相似文献   
24.
PlasmoDB (http://PlasmoDB.org) is the official database of the Plasmodium falciparum genome sequencing consortium. This resource incorporates the recently completed P. falciparum genome sequence and annotation, as well as draft sequence and annotation emerging from other Plasmodium sequencing projects. PlasmoDB currently houses information from five parasite species and provides tools for intra- and inter-species comparisons. Sequence information is integrated with other genomic-scale data emerging from the Plasmodium research community, including gene expression analysis from EST, SAGE and microarray projects and proteomics studies. The relational schema used to build PlasmoDB, GUS (Genomics Unified Schema) employs a highly structured format to accommodate the diverse data types generated by sequence and expression projects. A variety of tools allow researchers to formulate complex, biologically-based, queries of the database. A stand-alone version of the database is also available on CD-ROM (P. falciparum GenePlot), facilitating access to the data in situations where internet access is difficult (e.g. by malaria researchers working in the field). The goal of PlasmoDB is to facilitate utilization of the vast quantities of genomic-scale data produced by the global malaria research community. The software used to develop PlasmoDB has been used to create a second Apicomplexan parasite genome database, ToxoDB (http://ToxoDB.org).  相似文献   
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BACKGROUND: Granular cell tumor (GCT) (granular cell "myoblastoma") is an uncommon neoplasm that may mimic carcinoma both clinically and morphologically. Fine needle aspiration diagnosis of vulvar GNT has been described on only one prior occasion. CASE: A 74-year-old, black female presented with a mass in the left labia. Fine needle aspiration biopsy revealed rare intact cells; abundant, granular, cytoplasmic fragments; and bland, ovoid, stripped nuclei. The intact cells were arranged in loose aggregates. Each sampling was exquisitely painful to the patient despite the use of local anesthesia. CONCLUSION: Cytologists should be aware of the distinctive clinical and morphologic appearance of GCT. The cytologic findings of vulvar, GCT are identical to those described at other body sites. Definitive diagnosis before extirpation permits definitive therapy.  相似文献   
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