ABSTRACT
Vitamin D (VD) is essential for bone health, and VD or its analogues are widely used in clinics to ameliorate bone loss. The targets and mode of VD anti-osteoporotic actions appear to be different from those of other classes of drugs modulating bone remodeling. VD exerts its biological activities through the nuclear VD receptor (VDR)-mediated transcriptional regulation of target mRNA and non-coding RNA genes. VD-induced gene regulation involves epigenetic modifications of chromatin conformation at the target loci as well as reconfiguration of higher-order chromosomal organization through VDR-mediated recruitment of various regulatory factors. Enhancer RNAs (eRNA), a class of non-coding enhancer-derived RNAs, have recently emerged as VDR target gene candidates that act through reorganization of chromatin looping to induce enhancer-promoter interaction in activation of mRNA-encoding genes. This review outlines the molecular mechanisms of VD actions mediated by the VDR and suggests novel function of eRNAs in VDR transactivation.
Subject(s)
Bone Remodeling , Chromatin , Epigenomics , Metabolism , Receptors, Calcitriol , RNA , RNA, Messenger , RNA, Untranslated , Transcriptional Activation , Vitamin D , VitaminsABSTRACT
Prosthetic grafts have been employed in a limited number of pediatric patients with peripheral vascular lesions. We treated an iatrogenic obstruction of bilateral external iliac arteries in a child. The patient was a six-year-old girl whose chief complaints were intermittent claudication, and lower limb pain when exposed to cold. She had a history of coarctation complex for which she had undergone repeated catheterizations by puncture of both femoral arteries in her infancy. At the age of four, two-stage operation was performed: resection of the coarctation and end-to-end anastomosis, and direct closure of ventricular septal defect. Angiography performed through the brachial artery demonstrated obstruction of the bilateral external iliac arteries. Both right and left femoral artery were visualized through the collateral artery from the ipsilateral internal iliac artery. Because she became afflicted with lower limb ischemia a revascularization procedure was indicated. A 6mm expanded polytetrafluoroethylene (ePTFE) bypass graft was implanted bilaterally between the internal iliac artery and the common femoral artery with end-to-side anastomosis. Ischemic symptoms disappeared postoperatively and MR-angiogram performed nine days after surgery also showed the patency of the graft. It is a great concern, however, that the length of the graft may become relatively shorter with the growth of the patient. It is also anticipated that the lower limbs may suffer relatively insufficient blood flow in the future.
ABSTRACT
Diagnosis of cardiac rupture caused by blunt trauma is sometimes difficult when multi-organ injuries are associated with profound shock. Only prompt diagnosis and urgent treatment can save the patients. We have encountered 16 cases of blunt cardiac rupture, including 4 that survived in the past 10 years. All cases of cardiopulmonary arrest on arrival were unable to be resuscitated. Also, all cases of profound hemorrhagic shock caused by multi-organ injury succumbed. Among the cases in which the region of cardiac rupture was identified, only cases of injury to the right heart chambers were saved. No case of rupture in the left heart chambers survived. It is definitely important to suspect cardiac injury and make a prompt diagnosis to save patients with blunt chest trauma. Ultrasonic cardiography is highly effective for urgent diagnosis of cardiac rupture because it can be performed readily, noninvasively and, therefore, repeatedly.
ABSTRACT
A 16-year-old girl with aortitis syndrome under treatment with a low dose of prednisolone was admitted because of severe headache and intermittent claudication. Angiography revealed diffuse stenosis of the thoracoabdominal aorta and the bilateral renal arteries. Extra-anatomical bypass grafting from the ascending to the abdominal aorta was first made with a 14mm woven Dacron graft through a midline sternolaparotomy. Bilateral renal arteries were difficult to dissect due to periarterial adhesion. Bypass grafting for the left renal artery could be performed with a 5mm external velour wrap-knit Dacron graft (Sauvage, Bionit); however, the right renal artery was so thin that bypass was made with a 4mm EPTFE graft which was demonstrated to be occluded by follow-up angiography 3 years after surgery. The postoperative course has been uneventful and she has been free from symptoms up to now. The good long-term function of the bypass graft from the ascending aorta holds promise for diffuse coarctation of the thoracoabdominal aorta due to aortitis syndrome.