Coronary artery bypass grafts and MDCT imaging: what to know and what to look for

Multi-detector row CT (MDCT) scanners with high spatial and temporal resolutions are now available and are increasingly used for non-invasive assessment of vascular disease, including coronary arteries and coronary artery bypass grafts (CABG). Follow-up of patients who have previously undergone surgical revascularization for coronary artery disease is nowadays one of the main applications of MDCT. Thanks to the continuous technical evolution of the CT scanners, it is now possible to scan the heart and the full anatomic extent of grafts with sub-millimeter slice-thickness within a single breath-hold. In the evaluation of these patients, it is important for the radiologist to be familiar with the different types of grafts and surgical techniques to know the main characteristics of each graft type and what to look for in the assessment of a patient who has undergone coronary artery surgical revascularization. This review summarizes some surgical aspects, the biological characteristics of conduits, and the main technical MDCT features, and describes the CABG anatomy together with some typical CT findings.     

Ruptured aneurysms of the abdominal aorta: from the First Aid to the Operating Room. Changing concepts

Worldwide literature review from PubMed indicate that progress has been made in first aid assistance, diagnosis and treatment of ruptured abdominal aortic aneurysms, which led to a reduced operative mortality. Nevertheless, ruptured aneurysms may present atipically in about half of the cases, thus leading to an initially uncorrect diagnosis up to 25% of cases. Mean survival interval from onset of symptoms and death is 10-14 hours, thus indicating that time exists to consider the new imaging techniques in 80% of patients, particularly the TC multislice. This, when is strategically located close to the emergency or the operative room, can rapidly allow a correct diagnosis and provide an accurate morphological evaluation, thus enabling the surgeon to plan the most adequate treatment with open or endovascular repair.     

Protein-tyrosine phosphatase 1B-deficient myocytes show increased insulin sensitivity and protection against tumor necrosis factor-alpha-induced insulin resistance

Protein-tyrosine phosphatase (PTP)1B is a negative regulator of insulin signaling and a therapeutic target for type 2 diabetes. In this study, we have assessed the role of PTP1B in the insulin sensitivity of skeletal muscle under physiological and insulin-resistant conditions. Immortalized myocytes have been generated from PTP1B-deficient and wild-type neonatal mice. PTP1B(-/-) myocytes showed enhanced insulin-dependent activation of insulin receptor autophosphorylation and downstream signaling (tyrosine phosphorylation of insulin receptor substrate [IRS]-1 and IRS-2, activation of phosphatidylinositol 3-kinase, and serine phosphorylation of AKT), compared with wild-type cells. Accordingly, PTP1B(-/-) myocytes displayed higher insulin-dependent stimulation of glucose uptake and GLUT4 translocation to the plasma membrane than wild-type cells. Treatment with tumor necrosis factor-alpha (TNF-alpha) induced insulin resistance on glucose uptake, impaired insulin signaling, and increased PTP1B activity in wild-type cells. Conversely, the lack of PTP1B confers protection against insulin resistance by TNF-alpha in myocyte cell lines and in adult male mice. Wild-type mice treated with TNF-alpha developed a pronounced hyperglycemia along the glucose tolerance test, accompanied by an impaired insulin signaling and increased PTP1B activity in muscle. However, mice lacking PTP1B maintained a rapid clearance of glucose and insulin sensitivity and displayed normal muscle insulin signaling regardless the presence of TNF-alpha.     

Videosialoendoscopic assessment of bilateral atresia of the Wharton's duct orifice in an infant

Atresia of the submandibular ducts (particularly the duct orifice) is a rare occurrence that is mainly observed in newborns or infants; moreover, its differential diagnosis with other anomalies of the oral floor is sometimes difficult. Given the lack of data concerning the differences between atresia of the orifice of Wharton's duct and other anomalies of the submandibular duct system, we describe here the findings of videosialoendoscopic assessment of the salivary duct system in an infant who underwent traditional surgery for bilateral atresia of the orifice of Wharton's duct. During sialoendoscopy, a trifurcation of the main duct, a normal variant of the more common bifurcation of the secondary branches of the salivary duct system, was observed bilaterally. No other ductal anomalies were encountered. Complete resolution of the symptoms and complete patency of both ducts at 19-month follow-up evaluation were observed. In conclusion, although spontaneous resolution of the disease during feeding is possible, minimal incision of the orifice of the imperforated submandibular duct together with diagnostic videosialoendoscopy of the main salivary duct system may be considered as part of the modern approach to salivary obstructive disorders in pediatric age as is currently the case for sialolithiasis and recurrent juvenile parotitis.     

The age-related changes of trunk responses to Achilles tendon vibration

The contribution of different sensory modalities to balance control is modified by age. Postural responses to Achilles tendon vibration were investigated in order to understand the influence of age on proprioceptive input from lower legs in human stance. Postural responses to bilateral vibrations of Achilles tendon with 10 s duration were recorded at three frequencies (40, 60 and 80 Hz) in 9 healthy young (range, 24–27 years) and in 9 healthy older adults (59–70 years). Subjects were instructed to keep standing on firm surface with eyes closed. They performed three trials in each of three vibration frequencies. Postural responses were characterized by displacement of the centre of foot pressure (CoP) and by kinematics of body segments in the anterior–posterior direction. Bilateral vibrations of Achilles tendon induced backward body lean increasing with frequency of vibration and with age. The leg angle response to vibration was found similar in both groups of subjects. Slight trunk tilts from vertical position were induced by vibration in young subjects while in older subjects the trunk tilted backward together with the whole body. This observation was supported also by the minimal change of hip angle in older subjects contrary to increased hip activity in young subjects. The findings showed that the trunk and hip angle responses to proprioceptive stimulation might be a good indicator of age-related destabilization in balance control.