Regulation of Intracellular Structural Tension by Talin in the Axon Growth and Regeneration.

Intracellular tension is the most important characteristic of neuron polarization as well as the growth and regeneration of axons, which can be generated by motor proteins and conducted along the cytoskeleton. To better understand this process, we created Förster resonance energy transfer (FRET)-based tension probes that can be incorporated into microfilaments to provide a real-time measurement of forces in neuron cytoskeletons. We found that our probe could be used to assess the structural tension of neuron polarity. Nerve growth factor (NGF) upregulated structural forces, whereas the glial-scar inhibitors chondroitin sulfate proteoglycan (CSPG) and aggrecan weakened such forces. Notably, the tension across axons was distributed uniformly and remarkably stronger than that in the cell body in NGF-stimulated neurons. The mechanosensors talin/vinculin could antagonize the effect of glial-scar inhibitors via structural forces. However, E-cadherin was closely associated with glial-scar inhibitor-induced downregulation of structural forces. Talin/vinculin was involved in the negative regulation of E-cadherin transcription through the nuclear factor-kappa B pathway. Collectively, this study clarified the mechanism underlying intracellular tension in the growth and regeneration of axons which, conversely, can be regulated by talin and E-cadherin.

Feasibility study of low tube voltage technique and low concentration of contrast in CT pulmonary angiography by filtered back projection reconstruction / 中华放射医学与防护杂志

Objective To investigate the feasibility of CT pulmonary angiography (CTPA) with 80 kVp and contrast agent of iodixanol (270 mg I/ml) by filtered back projection(FBP) reconstruction.Methods In total,52 patients who underwent CTPA were randomly divided into two equally-sized groups,control group and experimental group.The volume computed tomography dose index (CTDIvol) and dose-length product (DLP)were recorded,and the weighted computed tomography dose index (CTDIw) and effective dose (E) were calculated.The image quality was visually evaluated and measured,and statistical analyses were performed on the image quality and the radiation dose.Results The sex,age,height,weight and body mass index (BMI) had no statistical difference between two groups (P ＞ 0.05).The average iodine dosage decreased by 22.9％ in the experimental group compared with the control group.Compared with the control group,the CTDIvol,DLP,CTDIw and E decreased by 73.5％,75.1％,73.5％ and 75.8％,respectively.The differences were statistically significant (t =＜0.001,30.5,＜ 0.001,-28.7,P ＜ 0.05).The image quality of the two groups met the requirement of diagnosis and there were no significant statistic differences between visually evaluating and objectively measuring the image quality (P ＞ 0.05).Conclusions Using 80 kVp and iodixanol for CTPA,FBP reconstruction image quality can meet diagnostic requirements.At the same time the radiation dose,the contrast agent dose and the X-ray tube wastage are reduced respectively.

Application of 64-slice spiral CT urography in diagnosis of urologic diseases / 中国介入影像与治疗学

ObjectiveTo investigate the value of 64-slice CT urography (CTU) in diagnosis of urologic diseases.Methods Sixty patients with suspected urinary system diseases underwent 64-slice CT volume scanning and 3D reconstructions.The diagnostic value of 64-slice CTU was evaluated.ResultsThere were 14 patients with urinary system cancers,2 with ureter polyp,9 with tuberculosis of urinary system,13 with urinary system calculus,13 with nonmalignant ureterostenosis combined with hydronephrosis,2 with ureterostenosis and hydronephrosis induced by nearby organic damage,2 with traumatism,1 with renal occlusion,as well as 4 after urinary tract surgeries and 2 without abnormality.Totally 28 cases was confirmed with surgery and pathology,the sensitivity,specificity and accuracy of MSCTU for upper tract tumor was 100％(14/14),85.71％ (12/14) and 92.86％ (26/28),respectively.ConclusionMSCTU is able to directly and clearly show urologic diseases.It can be regarded as the first choice in patients with clinically suspected urinary tract diseases,especially tumors.

The evidence-based evaluation of the safety of contrast media in patients with diabetes mellitus / 介入放射学杂志

Contrast-induced nephropathy (CIN) has now been the third most common cause of acquired renal failure. Diabetes mellitus (DM), the type of contrast agent used and the intra-arterial route of administration are three important risk factors inducing CIN. The incidence rate of CIN is very high in patients with DM or renal insufficiency after iodinated contrast was administered. Unfortunately, it has not yet attracted physicians’and radiologists’sufficient attention. This paper aims to make an evidence-based evaluation of the safety and rephrotoxicity of various contrast agents when they are used in patients with DM. Usually, intravenous administration of contrast media will not cause permanent damage to the kidney in highrisk patients. Low-osmolarity contrast media is relatively safe for patients with DM only, while it takes much risk of CIN when low-osmolarity contrast media is used in patients with diabetic nephropathy or in patients of DM accompanied with renal insufficiency, for such patients, the iso-osmolarity contrast media, iodixanol, can be used.

CT Diagnosis of Brachial Cleft Cyst and Fistula / 中国医学影像技术

Objective　 To improve the recognization and the diagnostic accuracy of brachial cleft cyst (BCC) by CT scan. Methods 　CT findings of 10 BCC proved surgically and pathologically were retrospectively reviewed. Results　 BCC，CT number 22～33 Hu；with the enhanced wall and the non-enhanced cystic part. If infections exist，the margin would be obscure and the internal density be increased. These cysts commonly located in the anterior triangle area of the neck or along the anterior border of the sternocleidomastoid muscle. The first brachial cleft fistula was not displayed. Conclusion　 CT scan can not only clearly show the location，enhanced characters and the relationship to the adjacent tissues of the BCC，but also can be possible to make the diagnosis of the BCC，but not the brachial cleft fistula.