Interobserver and interstudy variability of myocardial blood flow and flow-reserve measurements with nitrogen 13 ammonia-labeled positron emission tomography

Background  

Experimental studies have shown that positron emission tomography (PET) with ¹³N-labeled ammonia provides accurate quantification of regional myocardial blood flow (MBF) under rest and stress conditions. To establish the clinical utility of this method, the interobserver variability and the temporal variability of serial measurements of blood flow and coronary flow reserve (CFR) must be known. This study investigated the interobserver and temporal reproducibility of ¹³N-labeled PET for measurement of MBF and CFR.     

新生儿骨矿质含量及影响因素的研究

应用双光子及单光子吸收测定技术，检测了９２名出生３ｄ内的新生儿骨矿质含量，其中巨大儿３０名，正常体重儿３２名，低出生体重儿３０名，其孕龄分别是４０．１±０．７、３９．１±１．５和３７．４±１．２孕周。结果表明，巨大儿、正常体重儿、低出生体重儿的全身骨矿质含量分别是１０１．６±２８．８、８５．２±１９．８、５９．９±２７．２ｇ／ｃｍ２，巨大儿骨矿质含量最高，正常体重儿次之，低出生体重儿最低，差异有显著性（Ｐ＜０．０１）。颅骨、肱骨、股骨的骨矿质含量与全身的骨矿质含量有高度的相关性，相关系数分别是０．９４３、０．８７９和０．７４５（Ｐ＜０．０１）。全身的骨矿质含量与出生体重、孕龄及头围有高度相关性，相关系数分别是０．７５５、０．５９６和０．５５６（Ｐ＜０．０１）。提示颅骨、肱骨及股骨的任一部位均可代表全身的骨矿质含量，肱骨是确定全身骨矿质含量较好的部位，新生儿骨矿质含量受出生体重、孕龄及头围的影响较大。     

Clinicopathologic correlation of pigmented epiretinal membranes

We performed clinicopathologic correlation on ten surgically removed pigmented epiretinal membranes causing macular pucker. All cases occurred in eyes with existing retinal holes or tears, including eight cases of macular pucker after previous retinal detachment. These cases probably represented a limited form of proliferative vitreoretinopathy. All membranes contained pigment epithelial cells with polarity, basement membrane, and melanosomes. Cytoplasmic melanin granules accounted for the clinical feature of pigmentation in these eyes.     

Quantitative MRI volume changes in late onset schizophrenia and Alzheimer''s disease compared to normal controls

Volumes of medial and lateral temporal lobe structures were assessed using magnetic resonance imaging (MRI) in 11 patients with late-life onset schizophrenia (LOS), 18 normal elderly controls and 12 patients with moderate cognitive impairment due to Alzheimer's disease (AD) who had no non-cognitive symptoms. While both patient groups has smaller volumes of several medial temporal regions (e.g. entorhinal cortex, left hippocampus), schizophrenics had significantly smaller anterior superior temporal gyri (STG) than normal controls, but AD patients did not. We have previously demonstrated anterior STG volume to be reduced in early life onset schizophrenia.     

Lymphogranuloma venereum: biopsy, serology, and molecular biology.

A 21 year old woman presented with painful groin lymphadenopathy and malaise. Lymph node biopsy, to exclude atypical infection and malignancy, suggested the diagnosis of lymphogranuloma venereum. This diagnosis was confirmed by serology and polymerase chain reaction, with the patient subsequently admitting to a casual sexual contact within the United Kingdom. Alternative methods of investigation of this disease are discussed.     

Distinct mechanisms of splicing regulation in vivo by the Drosophila protein Sex-lethal

The protein Sex-lethal (SXL) controls pre-mRNA splicing of two genes involved in Drosophila sex determination: transformer (tra) and the Sxl gene itself. Previous in vitro results indicated that SXL antagonizes the general splicing factor U2AF⁶⁵ to regulate splicing of tra. In this report, we have used transgenic flies expressing chimeric proteins between SXL and the effector domain of U2AF⁶⁵ to study the mechanisms of splicing regulation by SXL in vivo. Conferring U2AF activity to SXL relieves its inhibitory activity on tra splicing but not on Sxl splicing. Therefore, antagonizing U2AF⁶⁵ can explain tra splicing regulation both in vitro and in vivo, but this mechanism cannot explain splicing regulation of Sxl pre-mRNA. These results are a direct proof that Sxl, the master regulatory gene in sex determination, has multiple and separable activities in the regulation of pre-mRNA splicing.