The choroidal artery to the fourth ventricle and its radiological significance

The choroidal artery to the fourth ventricle has been studied in 25 brain specimens and 100 normal posterior fossa angiograms, including 25 angiotomograms. Its variable origin, course and radiological significance have been stressed.     

Radiological evaluation of post-tracheostomy lesions

Post-tracheostomy lesions are becoming more commonplace and surgical techniques for definitive repair of these abnormalities are being developed. These lesions, in general, occur at two sites, the proximal lesions at the tracheostomy incision and the distal lesions 1·5 to 2·5 cm inferior in the area of the tracheostomy balloon cuff. Granuloma formation, stenosis, tracheomalacia, and perforation of the tracheal wall have been encountered in our experience. Clinical symptoms depend upon the type and location of the lesion as well as on the patient's awareness and physical activity. Radiological evaluation offers an accurate method to depict the anatomical and physiological alterations. This radiological assessment should begin with routine postero-anterior and lateral chest radiographs followed by fluoroscopy. Laminograms and special oblique views are often helpful. Contrast tracheograms using powdered tantalum allow good mucosal detail as well as excellent delineation of structural and physiological abnormalities.     

Phlebotomy-related lateral antebrachial cutaneous nerve injury

Although phlebotomy is a common and widespread procedure, the medical literature provides limited information in terms of the documented complications of venipuncture. Documentation of phlebotomy-related nerve injuries is even more limited. The authors present a case report of a phlebotomy-induced lesion of the lateral antebrachial cutaneous nerve. According to our literature search, this is the first case in which electrodiagnostic studies were used to document venipuncture-related injury of the lateral antebrachial cutaneous nerve. Specific electrodiagnostic testing is used to definitively diagnose this rare injury and to track recovery. Electrodiagnostic testing can be helpful in evaluating cases of sensory disturbance after phlebotomy.     

ISOLA器械治疗小儿脊柱侧凸

目的定期随访评价ISOLA器械治疗小儿脊柱侧凸.方法41例小儿脊柱侧凸患儿,特发性脊柱侧凸32例,神经肌肉性脊柱侧凸5例,其他类型的脊柱侧凸4例,术前、术中、术后均摄X线片,记录Cobb角,顶椎的移位及旋转,躯干偏离中线程度.结果Cobb角术前平均为66°,术后1年为36°,术后2年为36°.1年后,所有患儿的脊柱均完全融合.顶椎的偏离改善了14mm.躯干偏离改善了5mm.特发性脊柱侧凸患儿1年后有基本的正常活动.术后4例出现并发症,1例深部感染,1例骶尾部褥疮,1例横钩脱落,1例L3椎弓根螺丝钉脱落.结论目前有多种后路器械治疗小儿脊柱侧凸.严格掌握手术指征及ISOLA的原理,该术式能获得较为满意的疗效.     

A 2015 focus on preventing drug-induced arrhythmias

Drug-induced Torsade de Pointes arrhythmia is a life-threatening adverse effect feared by pharmaceutical companies. For the last decade, the cardiac safety guidelines have imposed human ether-a-go-go-related gene channel blockade and prolongation of QT interval as surrogates for proarrhythmic risk propensity of a new chemical entity. Suffering from a lack of specificity, this assessment strategy led to a great amount of false positive outcomes. Therefore, this review will discuss new pharmaceutical strategies: the cardiac safety proposal that recently emerged, the Comprehensive in vitro Proarrhythmia Assay, combining in vitro assays that integrate effects on main cardiac ion channels, with computational models of human ventricular action potential as well as assays using human stem cell-derived cardiomyocytes for an improved prediction of drug’s proarrhythmic liability, alternative pharmacological perspectives as well as the current treatment of drug-induced long QT syndrome.     

Physics of ultrasound

Ultrasound is a form of non-ionizing radiation that uses high-frequency sound waves to image the body. It is a real-time investigation which allows assessment of moving structures and also facilitates measurement of velocity and directionality of blood flow within a vessel. It can be used for a variety of purposes in the intensive care setting, for example to aid central venous catheter and pleural drain insertion. When using this imaging modality it is vital to understand the relevant physical principles and how the images are created. This article will explain these principles, including the use of Doppler ultrasound and the interpretation of common artefacts.     

Enhanced expression of transforming growth factor beta during megakaryoblastic differentiation of K562 leukemia cells

Platelet alpha granules contain several growth factors such as the transforming growth factor beta (TGF-beta) that are released during blood clotting and are thought to participate in the repair of tissue injury; however, the site of synthesis of platelet TGF-beta has not been demonstrated. We studied TGF-beta expression during megakaryoblastic differentiation of the chronic myeloid leukemia cell line K562 in vitro. These cells have mainly erythroid characteristics but acquire several megakaryoblastic properties when treated with the phorbol diester 12-0-tetradecanoyl-13-phorbolacetate (TPA). During four subsequent days of megakaryoblastic differentiation the amount of the 2.5-kilobase (kb) TGF-beta mRNA increased about eightfold, and a novel 2.3-kb mRNA species was induced in the K562 cells. This occurred concomitantly with distinct induction patterns of platelet-derived growth factor A (PDGF-A) and c-sis (PDGF-B chain) RNAs and several platelet antigens. The expression of erythroid markers such as glycophorin A decreased. Culture media of TPA-differentiated K562 cells also contained TGF-beta polypeptides as shown by a sensitive radioreceptor assay and by immunoprecipitation after metabolic labeling of the cells. These polypeptides were not seen in culture media from dimethyl sulfoxide- or sodium butyrate-treated cells. Unlike in several other cells, exogenously added TGF-beta 1 or 2 affected neither TGF- beta nor PDGF RNA expression in K562 cells.     

Anterior commissure: anatomic-MR correlation and use as a landmark in three orthogonal planes

Correlation of cryomicrotomic and myelin-stained sections of human cadaver heads with spin-echo magnetic resonance (MR) images documents that MR imaging routinely displays the anterior commissure in three orthogonal planes as a distinct white-matter tract that resembles bicycle handlebars. The anterior commissure crosses the midline at the upper end of the lamina terminalis, just anterior to the anterior columns of the fornices. To each side of midline, it curves antero-inferolaterally and then postero-inferolaterally through the lateral nucleus of the globus pallidus to course with the white matter of the external and extreme capsules toward the middle and inferior temporal gyri. Because the anterior commissure is easily recognizable in all three planes at differing pulse sequences, the commissure has proved to be a major landmark for identification of the complex anatomy of this region, especially in sagittal sections.