Development and characterization of an anthropomorphic breast phantom for permanent breast seed implant brachytherapy credentialing

PurposeTo develop an anthropomorphic breast phantom for use in credentialing of permanent breast seed implant brachytherapy.Methods and MaterialsA representative external contour and target volume was used as the basis of mold manufacturing for anthropomorphic breast phantom development. Both target and normal tissue were composed of gel-like materials that provide suitable computed tomography and ultrasound contrast for brachytherapy delivery. The phantoms were evaluated for consistency in construction (target location) and Hounsfield unit (computed tomography contrast). For both target and normal tissue, the speed of sound was measured and compared to the image reconstruction algorithm's expectation value. Five phantoms were imaged preimplant and postimplant to assess interphantom similarity as well as to evaluate the uncertainty in quantifying seed position.ResultsThe average Hounsfield units of the target and normal tissue gels is −146 ± 5 and 23 ± 1, respectively. The average speed of sound of the target and normal tissue gels is 1485 ± 7 m/s and 1558 ± 9 m/s, respectively, resulting in an estimated 0.4 mm uncertainty in image guidance. The registration/deformation uncertainty was determined to be 0.8 mm. The standard combined uncertainty in assessing seed position spatial accuracy, also including a 0.9 mm estimate based on literature for seed localization, is estimated to be 1.3 mm.ConclusionsThe development of the anthropomorphic breast phantom and evaluation of both the consistency as well as overall seed position uncertainty illustrates the suitability of this phantom for use in brachytherapy end-to-end delivery and implant accuracy evaluation. When evaluating a user's implant accuracy, we estimate a standard combined uncertainty of 1.3 mm.     

超声功能成像在脂肪性肝病研究中的应用进展

脂肪性肝病(Fatty Liver Disease)是我国目前最常见的肝脏病变,主要与过多脂肪蓄积在肝细胞内有关。患者早期常无明显临床表现,晚期有进展为肝硬化的风险。因此,应着眼于早期诊断和预后的判断。超声检查具有无创、便捷、实时、廉价及无辐射等特点,在临床工作中应用广泛。随着超声检查新技术的不断发展,以超声检查新技术为基础的功能成像在脂肪性肝病诊断方面显示出较大的优势,本文主要针对超声功能成像在脂肪性肝病中的应用予以总结分析。     

Phaeophyceae and rhodophyceae macroalgae from the Antarctic: A source of selenium

This study reports the development of a voltammetric method applied for Se determination in Phaeophyceae (A. utricularis, C. jacquinotii, A. mirabilis, D. anceps, H. grandifolius) and Rhodophyceae (G. confluens, C. racovitzae, I. cordata) macroalgae from the Antarctic. Evaluation of the instrumental parameters showed the square wave cathodic stripping voltammetry provided greater sensitivity (deposition potential, -0.4 V; deposition time, 420 s; amplitude, 0.08 V; frequency, 60 Hz) than influence of differential pulse cathodic stripping voltammetry. The matrix effect and the influence of Cu concentration on the determinations were also assessed. After microwave-assisted digestion of the samples, the quantification limit was from 5.21 × 10⁻³ (G.confluens) to 9.85 × 10⁻³ mg kg^-1 (I. cordata). The quantification of Se was carried out over the concentration range from 0.23 (C. jacquinotii) to 1.22 mg kg^-1 (A. mirabilis). The method accuracy was by analysing the reference material of peach leaves (SRM 1547).     

Molecular characterization,isolation, pathology and pathotyping of peafowl (Pavo cristatus) origin Newcastle disease virus isolates recovered from disease outbreaks in three states of India

Disease outbreak investigations were carried out in three states of Northern India namely Haryana (Rewari), Uttar Pradesh (Noida) and Delhi, where a total of 110 Indian peafowls (Pavo cristatus) showed sudden onset of nervous signs and died within a period of two weeks during June, 2012. The F (fusion) gene-based RT-PCR detection of Newcastle disease virus (NDV) in affected tissues confirmed the presence of the virus. Three NDV isolates were selected (one from each area under investigation) and further characterized. They were found to be of virulent pathotype (velogenic NDV) based on both pathogenicity assays (MDT, ICPI and IVPI) and partial F gene sequence analysis. Additionally, the phylogenetic analysis revealed that the isolates belonged to the genotype VIIi and XIII of class II avian Paramyxovirus serotype1 (APMV-1) and related closely to new emerging sub-genotypes. This is the first report regarding the presence of the fifth panzootic vNDV genotype VIIi from India. In this scenario, extensive epidemiological studies are suggested for surveillance of NDV genotypes in wild birds and poultry flocks of the country along with adopting suitable prevention and control measures.     

Vasospastic Angina with J‐Wave Pattern and Polymorphic Ventricular Tachycardia Effectively Treated with Quinidine

Background: Myocardial ischemia during coronary spasm may generate malignant ventricular arrhythmias. The J‐wave pattern was suggested to be a marker of a disorder associated with life‐threatening arrhythmias. Results: We report the case of a patient with vasospastic angina and J‐wave pattern in inferior and lateral leads associated with polymorphic ventricular tachycardia which was effectively treated only with quinidine—vasodilating drugs were not able to prevent the arrhythmia although they were effective in preventing ischemic events. Conclusion: The J‐wave pattern in inferolateral leads may be a sign of electrical vulnerability to lethal ventricular arrhythmia in patients suffering from vasospastic angina—quinidine can effectively prevent such arrhythmias in these patients.     

Disruption of beta-catenin pathway or genomic instability define two distinct categories of liver cancer in transgenic mice

BACKGROUND & AIMS: Human liver cancer can be divided into 2 categories that are characterized by activation of beta-catenin and genomic instability. Here we investigate whether similar categories exist among 5 transgenic models of liver cancer, including c-myc, transforming growth factor-alpha, E2F-1, c-myc/transforming growth factor-alpha, and c-myc/E2F-1 mice. METHODS: The random amplified polymorphic DNA method was used to assess the overall genomic instability, and chromosomal loci affected by genomic alterations were determined by microsatellite analysis. beta-Catenin mutations and deletions were analyzed by polymerase chain reaction and sequencing screening. Cellular localization of beta-catenin and expression of alpha-fetoprotein, a prognostic marker of hepatocellular carcinoma, were investigated by immunohistochemistry. RESULTS: Liver tumors from the transgenic mice could be divided into 2 broad categories characterized by extensive genomic instability (exemplified by the c-myc/transforming growth factor-alpha mouse) and activation of beta-catenin (exemplified by the c-myc/E2F-1 mouse). The c-myc/transforming growth factor-alpha tumors displayed extensive genomic instability with recurrent loss of heterozygosity at chromosomes 1, 2, 4, 6, 7, 9, 12, 14, and X and a low rate of beta-catenin activation. The genomic instability was evident from the early dysplastic stage and occurred concomitantly with increased expression of alpha-fetoprotein. The c-myc/E2F-1 tumors were characterized by a high frequency of beta-catenin activation in the presence of a relatively stable genome and low alpha-fetoprotein levels. CONCLUSIONS: We have identified 2 prototype experimental models, i.e., c-myc/transforming growth factor-alpha and c-myc/E2F-1 mice, for the 2 categories of human hepatocellular carcinoma characterized by genomic instability and beta-catenin activation, respectively. These mouse models will assist in the elucidation of the molecular basis of human hepatocellular carcinoma.