Homocysteine-induced peripheral microcirculation dysfunction in zebrafish and its attenuation by L-arginine

Elevated blood homocysteine (Hcy) level is frequently observed in aged individuals and those with age-related vascular diseases. However, its effect on peripheral microcirculation is still not fully understood. Using in vivo zebrafish model, the degree of Hcy-induced peripheral microcirculation dysfunction is assessed in this study with a proposed dimensionless velocity parameter (V) over bar (CV)/(V) over bar (PCV), where (V) over bar (CV) and (V) over bar (PCV) represent the peripheral microcirculation perfusion and the systemic perfusion levels, respectively. The ratio of the peripheral microcirculation perfusion to the systemic perfusion is largely decreased due to peripheral accumulation of neutrophils, while the systemic perfusion is relatively preserved by increased blood supply from subintestinal vein. Pretreatment with L-arginine attenuates the effects of Hcy on peripheral microcirculation and reduces the peripheral accumulation of neutrophils. Given its convenience, high reproducibility of the observation site, non-invasiveness, and the ease of drug treatment, the present zebrafish model with the proposed parameters will be used as a useful drug screening platform for investigating the pathophysiology of Hcy-induced microvascular diseases.111Ysciescopu

Spontaneous rupture of the lateral thoracic artery in patients with liver cirrhosis

Bleeding in patients with liver cirrhosis is primarily caused by gastroesophageal varix in association with extensive collateral circulation, portal hypertensive gastropathy, a Mallory-Weiss tear and peptic ulcer disease. The spontaneous rupture of an artery, as a result of coagulopathy, is extremely rare in patients with liver cirrhosis; however, we recently observed a case of a spontaneous rupture of the lateral thoracic artery in a 47 year-old male patient with alcoholic liver cirrhosis. The patient expired despite repeated transcatheter arterial embolization of the lateral thoracic artery and best supportive care. This is, to our knowledge, the first documented case of the spontaneous rupture of the lateral thoracic artery in a patient with liver cirrhosis

A Clinical Analysis of Twelve Cases of Ruptured Cerebral De Novo Aneurysms

Formation of cerebral de novo aneurysms (CDNA) is rare, and the pathogenesis remains obscure. In this study, we investigated the factors that contribute to the formation of CDNA and suggest guidelines for following patients treated for cerebral aneurysms. We retrospectively reviewed 2,887 patients treated for intracranial aneurysm at our institute from January of 1976 to December of 2005. Of those patients, 12 were readmitted due to recurrent rupture of CDNA, which was demonstrated by cerebral angiography. We assessed clinical characteristics, such as gender, size and site of rupture, past history, and the time to CDNA rupture. Of the 12 patients, 11 were female and 1 was male, with a mean age at rupture of the first aneurysm of 44.7 years (range: 30-69 years). The mean time between the first episode of subarachnoid hemorrhage (SAH) and the second was 8.9 years (range: 1.0-16.7 years). The most common site of ruptured CDNA was the internal carotid artery (5 patients, 41.7%), followed by basilar artery bifurcation (3 patients, 25.0%). In the remaining 4 patients, rupture occurred in the anterior communicating, middle cerebral, anterior cerebral (A1), or posterior cerebral (P1) arteries. In 5 cases (41.7%), the CDNA occurred contralateral to the initial aneurysm. Eleven patients (91.7%) had a past history of arterial hypertension. There was no history of habitual smoking or alcohol abuse in any of the patients. Eight patients underwent clipping for CDNA and three patients were treated with coiling. One patient who had multiple aneurysms was treated with clipping following intra-aneurysmal coiling. Assessment according to the Glasgow Outcome Scale (GOS) of the patients after the treatment was good in 10 cases (83.3%) and fair in 2 cases (16.7%). Although formation of CDNA after successful treatment of initial aneurysm is rare, several factors may contribute to recurrence. In our study, female patients with a history of arterial hypertension were at higher risk for ruptured CDNA. We recommend follow-up imaging studies every five years after treatment of the initial aneurysm, especially in women and those with a history of arterial hypertension

Radiofrequency Ablation of Benign Thyroid Nodules and Recurrent Thyroid Cancers: Consensus Statement and Recommendations

Thermal ablation using radiofrequency is a new, minimally invasive modality employed as an alternative to surgery in patients with benign thyroid nodules and recurrent thyroid cancers. The Task Force Committee of the Korean Society of Thyroid Radiology has developed recommendations for the optimal use of radiofrequency ablation for thyroid nodules. These recommendations are based on a comprehensive analysis of the current literature, the results of multicenter studies, and expert consensus

SiO2 나노입자 현탁액의 충동 및 퍼짐에 관한 실험적 연구

국내2

Wetting state and maximum spreading factor of microdroplets impacting on superhydrophobic textured surfaces with anisotropic arrays of pillars

The dynamic behaviors of microdroplets that impact on textured surfaces with various patterns of microscale pillars are experimentally investigated in this study. A piezoelectric inkjet is used to generate the microdroplets that have a diameter of less than 46 mu m and a controlled Weber number. The impact and spreading dynamics of an individual droplet are captured by using a high-speed imaging system. The anisotropic and directional wettability and the wetting states on the textured surfaces with anisotropically arranged pillars are revealed for the first time in this study. The impalement transition from the Cassie-Baxter state to the partially impaled state is evaluated by balancing the wetting pressure P-wet and the capillary pressure P-C even on the anisotropic textured surfaces. The maximum spreading factor is measured and compared with the theoretical prediction to elucidate the wettability of the textured surfaces. For a given Weber number, the maximum spreading factor decreases as the texture area fraction of the textured surface decreases. In addition, the maximum spreading factors along the direction of longer inter-pillar spacing always have smaller values than those along the direction of shorter inter-pillar spacing when a droplet impacts on the anisotropic arrays of pillars.X11129sciescopu

Hemodynamic characteristics of flow around a deformable stenosis

Clinical studies reported that some vulnerable stenoses deformed their shape in a blood vessel based on flow condition. However, the effects of shape variation on flow characteristics remain unclear. The flow characteristics are known to affect vulnerable stenosis rupture and fractional flow reserve (FFR) value which has been widely used as a diagnostic tool for stenosis. Vulnerable stenosis rupture occurs when the structural stress exerted on a fibrous cap exceeds its tolerable threshold. The stress magnitude is determined from the spatial distribution of static pressure around the stenosis. In the present study, the static pressure distribution and the FFR value in deformable stenosis were investigated with related other flow characteristics. Two phantom models were fabricated to mimic deformable and nondeformable stenoses using polydimethylsiloxane. The flow characteristics were observed under a steady flow condition at three Reynolds numbers (Re = 500, 1000, 1500) using a particle image velocimetry. The pressure drop across the stenosis models were measured using a pressure sensor to determine effects "of shape deformation on FFR value. Shape variations and jet deflections were clearly observed in the deformable stenosis model, and the effective severity of the stenosis increased up to 17.2%. The shape variations of deformable stenosis model increased the static pressure difference at the upstream and downstream sides of the stenosis. The pressure drop across the deformable stenosis model was significantly higher than that of the nondeformable stenosis model. The present results substantiate that stenosis deformability should be carefully considered to diagnose the rupture of vulnerable stenosis. (C) 2017 Elsevier Ltd. All rights reserved.111Nsciescopu