Attenuation Coefficient Estimation of Normal Placentas

Attenuation coefficient estimation has the potential to be a useful tool for placental tissue characterization. A current challenge is the presence of inhomogeneities in biological tissue that result in a large variance in the attenuation coefficient estimate (ACE), restricting its clinical utility. In this work, we propose a new Attenuation Estimation Region Of Interest (AEROI) selection method for computing the ACE based on the (i) envelope signal-to-noise ratio deviation and (ii) coefficient of variation of the transmit pulse bandwidth. The method was first validated on a tissue-mimicking phantom, for which an 18%–21% reduction in the standard deviation of ACE and a 14%–24% reduction in the ACE error, expressed as a percentage of reported ACE, were obtained. A study on 59 post-delivery clinically normal placentas was then performed. The proposed AEROI selection method reduced the intra-subject standard deviation of ACE from 0.72 to 0.39 dB/cm/MHz. The measured ACE of 59 placentas was 0.77 ± 0.37 dB/cm/MHz, which establishes a baseline for future studies on placental tissue characterization.     

鲜天南星水提取物对小鼠子宫纤维瘤的抑制作用和对小鼠雌激素的影响

【摘要】目的 探讨鲜天南星水提取物对小鼠子宫纤维瘤的抑制作用及对小鼠雌激素水平的影响。方法 选取SD健康雌性小鼠30只,随机分为正常组、模型组、实验组3组,每组各10只,对模型组、实验组进行子宫纤维瘤模型建立,正常组不作处理。实验组小鼠予以鲜天南星水提取物进行干预,正常组、模型组小鼠注射等体积生理盐水。对小鼠子宫重及子宫系数进行统计计算,酶联免疫吸附试验法检测雌二醇（Estradiol,E2）、孕酮（Progesterone,P）、卵泡刺激素（Follicle stimulating hormone,FSH）、黄体生成激素（Luteinizing Hormone,LH）水平。结果 干预后,模型组及实验组小鼠子宫重及子宫系数均高于正常组,实验组小鼠子宫重及子宫系数均低于模型组（P＜0.05）;干预后,模型组及实验组小鼠血清E2、P、FSH、LH水平均高于正常组,但实验组小鼠血清E2、P、FSH、LH水平均低于模型组（P＜0.05）。结论 鲜天南星水提取物可对小鼠子宫纤维瘤起到一定的抑制作用,并能对E2、P、FSH、LH等激素水平进行调控,为子宫纤维瘤的临床治疗提供一定的理论依据,值得临床借鉴。     

黄连素对子宫肌瘤大鼠模型血液黏度、子宫系数、平滑肌厚度和炎性细胞浸润的影响

目的分析黄连素对子宫肌瘤大鼠模型血液黏度、子宫系数、平滑肌厚度和炎性细胞浸润的影响。方法取32只成年SPF级SD大鼠,随机分为对照组、模型组、低剂量黄连素组、高剂量黄连素组,每组各8只。除对照组外,其余三组均给予苯甲酸雌二醇注射液+黄体酮注射液肌内注射建立子宫肌瘤模型。对照组和模型组均给予等量生理盐水,低剂量黄连素组采用黄连素10 mg/kg进行灌胃,高剂量黄连素组采用黄连素20 mg/kg进行灌胃。比较各组大鼠血液黏度、血清肿瘤坏死因子α(TNF-α)、白介素6(IL-6)、α干扰素(INF-α)、子宫重量、子宫系数和平滑肌厚度,经病理学染色观察各组大鼠子宫形态学状况。结果模型组大鼠红细胞聚集指数、血浆黏度、全血黏度均明显高于对照组,低剂量黄连素组、高剂量黄连素组大鼠红细胞聚集指数、血浆黏度、全血黏度均明显低于模型组(P<0.05)。相比对照组,模型组大鼠血清TNF-α和IL-6水平显著增高,INF-α水平显著降低(P<0.01);低剂量黄连素组和高剂量黄连素组血清TNF-α和IL-6水平均明显低于模型组,INF-α水平均明显高于模型组(P<0.01)。模型组大鼠子宫重量、子宫系数和平滑肌厚度较对照组均明显增加,低剂量黄连素组和高剂量黄连素组大鼠子宫重量、子宫系数和平滑肌厚度较模型组均明显下降(P<0.05)。相比对照组,模型组、低剂量黄连素组和高剂量黄连素组出现不同程度的炎性细胞浸润,其中高剂量黄连素组的炎症程度较轻。结论黄连素对子宫肌瘤模型大鼠具有良好的治疗效果,能降低其血液黏度、子宫系数、平滑肌厚度和炎性细胞浸润程度,作用机制可能在于黄连素具有改善大鼠体内炎性因子水平的效果。     

Noise-Optimized Virtual Monoenergetic Dual-Energy CT Improves Diagnostic Accuracy for the Detection of Active Arterial Bleeding of the Abdomen

Purpose

To evaluate diagnostic accuracy of a noise-optimized virtual monoenergetic imaging (VMI+) reconstruction technique for detection of active arterial abdominal bleeding on dual-energy (DE) CT angiography compared with standard image reconstruction.

Arterial spin labeling hyperperfusion in Rasmussen's encephalitis: Is it due to focal brain inflammation or a postictal phenomenon?

Background and purpose

The study evaluated the utility of arterial spin labeling (ASL) perfusion imaging in Rasmussen's encephalitis (RE).

Establishment of hormone reference intervals for infants born < 30 weeks' gestation

Objective

Preterm infants, especially those born very preterm (< 32 weeks' gestation), suffer a number of morbidities. Immaturity of the endocrine system and its potential impact on morbidity is the subject of numerous studies. Hormone concentrations are sometimes measured in very preterm infants, however there are little normative data available to be able to interpret the results. The aim of this study was to describe age appropriate hormone reference intervals for babies born less than 30 weeks' gestation.

Study design

Samples were collected at 1, 4, 7, 14, 21, 28 and 42 days after birth from babies born 23–29 weeks' gestation. The serum was analyzed for seven hormones by automated chemiluminescent immunoassay (Siemens Immulite 2000). Results from the 107 infants who survived beyond 40 weeks' corrected gestational age were included in the data analysis.

Results

Cortisol, dehydroepiandrosterone sulfate, growth hormone and progesterone levels were highest during the first seven days with levels up to 10,801 nmol/L; 26.6 μmol/L; 343 mU/L; and > 63.6 nmol/L respectively. Free thyroxine levels were as low as < 2.6 pmol/L for the first 28 days with the nadir at 7 days. Estradiol levels ranged from < 73 to 1626 pmol/L over the six weeks. Reference intervals for IGF-1 could not be established as the levels were below the analyzer's sensitivity. There were no differences in reference intervals between male and female infants.

Conclusions

We describe gestation appropriate reference intervals for six hormones measured in babies born < 30 weeks' gestation. Utilization of these reference intervals permits the correct and timely interpretation of results to the clinician.     

Regional differences in the prevalence of sensitization to environmental allergens: Analysis on IgE antibody testing conducted at major clinical testing laboratories throughout Japan from 2002 to 2011

BackgroundIdentification of sensitized allergens for patients with respiratory allergy is an important step in disease care and environmental allergen control. The Japanese archipelago belongs to various climate categories due to its length from north to south which transverse the subarctic in the north to the subtropical in the south, suggesting substantial regional differences in dominant environmental allergens. However, few studies have assessed the regional differences in the prevalence of sensitization to environmental allergens.MethodsWe requested three major clinical testing laboratories to provide us with summarized results of antigen-specific IgE-antibody (Ab) measurements. These measurements were collected for clinical purposes throughout Japan from 2002 through 2011. The prevalence of positivity for IgE-Ab against 19 environmental allergens was calculated for each prefecture in order to evaluate regional differences.ResultsTest data on specific IgE-Ab of 19,969,753 orders were analyzed. The prevalence of positivity for house dust mites was high and the regional difference was low, whereas apparent regional differences were found for pollen, insects, and fungi. The prevalence of positivity for Japanese cedar was low in Hokkaido and Okinawa, while those to alder was highest in Hokkaido. Higher prevalence for insects was observed in southern areas (Okinawa and prefectures in Kyusyu).ConclusionsFindings of this study clearly demonstrated regional differences in the prevalence of sensitization to environmental allergens in Japan and the study also provides useful information for the clinician when deciding which allergens should preferentially be measured for IgE-Ab after considering regional difference.     

基于敏感性定理的EIT重构算法仿真研究

为了研究性能更好的EIT图像重构算法，我们对基于敏感性定理的EIT图像重构算法进行了计算机仿真研究，并与几种常用图像重构算法进行比较，提出对基于敏感性定理的EIT图像重构算法的改进措施。