Phagocytosis of Hemozoin (Native and Synthetic Malaria Pigment), and Plasmodium falciparum Intraerythrocyte-Stage Parasites by Human and Mouse Phagocytes

Hemozoin, the detoxification product of hemoglobin heme, piles up as electron-dense material in the food vacuole (FV) of intraerythrocytic malaria parasites (malaria pigment). In infected individuals, pigment is internalized by both circulating and resident phagocytes, thus modulating their functions. Synthetic beta-hematin, prepared in vitro from hematin (ferriprotoporphyrin IX hydroxide) in acidic condition, is spectroscopically identical to hemozoin. In this electron microscopy study, native and synthetic hemozoin also prove to be morphologically indistinguishable (large polygonal crystals with apparent transverse banding) and to undergo the same process when internalized by phagocytes (primarily a direct uptake of crystals, similar to what is described for asbestos fibers). On the contrary,whole parasites appear to follow a classical endocytic pathway. This suggests that there may be differences between the ingestion of free particles and whole parasites in terms of modulation of phagocytes' functions.     

螺旋弯曲管中血液两相流动分析

目的 经典的单相牛顿血液流动模型忽略了红细胞与血浆之间的相互作用以及血液剪切变稀性质。为了解决这些问题,采用多相的非牛顿模型研究冠状动脉模型的血流动力学参数。方法 把血液考虑为血浆和红细胞的混合体,并用螺旋弯曲血管模型模拟冠状动脉,分析冠状动脉内红细胞的运动以及红细胞体积分数的分布情况,并与单相非牛顿血液模型的模拟结果进行对比。结果 单相和多相血液模型模拟下的截面壁面剪切力平均值差别不明显,但是在两相流模拟中,螺旋弯曲管下底壁面处存在明显的红细胞聚集现象,同时还分布着较低的壁面剪切力。结论 引用多相流数值模拟得到了螺旋弯曲管中的血流动力学参数,同时发现红细胞在螺旋弯曲管下底面处聚集的现象,这很容易诱发血栓形成,与临床上所观察到的粥样硬化斑块经常出现在冠状动脉弯曲内侧是相符合的,可进一步说明动脉粥样硬化病变的发生机制。     

Risk assessment of atherosclerotic plaques based on global biomechanics

We present the results of a computational study of the entire left coronary system simulated both at Newtonian level and at red blood cell resolution for a sizeable number of physiological conditions. We analyze the cardiovascular implications of stenotic plaques and show that the standard clinical criterion for surgical or percutaneous intervention, based on the fractional flow reserve (FFR), is significantly affected by system-dependent, local hemodynamic factors. A refined version, based on the new notion of local FFR response to stenotic growth, and accounting for statistical uncertainties due to flow heterogeneity, is suggested and illustrated.     

The effect of red light on backward masking in individuals with psychometrically defined schizotypy

Introduction. Previous research has suggested that individuals with schizophrenia and their relatives show a change in backward masking performance with a red background that is in the opposite qualitative direction as that found in nonpsychiatric controls. The present study examines this effect in individuals with psychometrically defined schizotypy to explore the potential of this effect to be a useful new qualitative endophenotype for schizophrenia-spectrum traits.

Methods. The Abbreviated Youth Psychosis At-Risk Questionnaire was used to screen a large number of undergraduates for schizotypy symptoms. A sample of 23 participants scoring high on this measure were compared to a sample of 26 controls on a location backward masking task that was presented on both red and green backgrounds.

Results. Consistent with findings in patients with schizophrenia, the participants reporting a high number of schizotypy features showed a decrease in performance to the red (compared to green) background and the controls showed a nonsignificant increase in performance—although this finding was limited to the stimulus–onset asynchrony (SOA) value that approximated the SOA with the largest effect size in the previous schizophrenia study (69 ms).

Conclusions. Although limited to one SOA, results extend earlier findings approximating this SOA to include a psychometrically defined schizotypy sample.     

UPLC-QTOF-MS fingerprinting combined with chemometrics to assess the solvent extraction efficiency,phytochemical variation,and antioxidant activities of Beta vulgaris L.

Accurate assays of plant antioxidants and other phytochemicals require efficient extraction conditions and enable rigorous assessments of crop varieties and production systems. This study assessed the extraction of phytochemicals and antioxidants from conventionally or organically grown red and golden beets (Beta vulgaris L.), using twenty solvent (S1–S20) mixtures containing water, methanol, and ethanol alone or with acids (ascorbic, formic, acetic). Red beetroot extracted with methanol with or without acid had the highest betanin content (2791.0 μg/g and 8222.3 μg/g of fresh weight [FW], respectively) and golden beetroot extracted with methanol/ascorbic acid/water had the highest vulgaxanthin I (193.7 μg/g and 15.0 μg/g of FW, respectively). The radical-scavenging activity and total phenolics in beetroot extracts reflected the different extraction efficiency of each solvent. UHPLC-QTOF-MS was used to identify twenty-seven phytochemicals, including 23 betalains, 2 amino acids, and 2 phenolic acids. Chemometric approaches discriminated the beet varieties and different extracts within one variety based on the composition and abundance of the key phytochemicals. The red beetroot extracted with aqueous ethanol with or without acid (S5, S7, S8, S9), and golden beetroot extracted with methanol-containing solvents (S15 for conventionally and S20 for organically) had the highest levels of phytochemicals, suggesting that these conditions efficiently extract key phytochemicals.     

Predicting the risk of extinction from shared ecological characteristics

Understanding the ultimate causes of population declines and extinction is vital in our quest to stop the currently rampant biodiversity loss. Comparison of ecological characteristics between threatened and nonthreatened species may reveal these ultimate causes. Here, we report an analysis of ecological characteristics of 23 threatened and 72 nonthreatened butterfly species. Our analysis reveals that threatened butterflies are characterized by narrow niche breadth, restricted resource distribution, poor dispersal ability, and short flight period. Based on the characteristics, we constructed an ecological extinction risk rank and predicted which of the currently nonthreatened species are at the highest risk of extinction. Our analysis reveals that two species currently classified as nonthreatened are, in fact, at high risk of extinction, and that the status of a further five species should be reconsidered.     

慢性肝病患者红细胞免疫功能的研究

目的 探讨慢性肝病患者红细胞免疫粘附功能的变化。方法 检测73例慢性乙型肝炎及肝硬化患者红细胞C_3b受体花环形成率(RBC-C_3bRR)、红细胞免疫复合物花环形成率(RBC-ICRR)及患者的循环免疫复合物(CIC)水平。结果 与正常对照组相比,RBC-C_3bRR在慢性肝炎中、重度及肝硬化患者中明显下降(P<0.01),在慢性肝炎轻度也有显著下降(P<0.05)。而RBC-ICRR在慢性肝炎中重度及肝硬化患者中明显升高(P<0.05)。各型肝病患者CIC均明显升高。结论 慢性肝炎患者的红细胞免疫粘附功能有明显改变,其意义有待进一步研究。     

改变硒、维生素E饮食摄入量对红细胞变形性的影响

饲予大鼠不同硒（Ｓｅ）、维生素Ｅ（ＶＥ）含量的饲料１０周。低Ｓｅ低ＶＥ组红细胞变形性、全血谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）、血清谷胱甘肽转硫酶（ＧＳＴ）、红细胞中铜锌超氧化物歧化酶（Ｃｕ、Ｚｎ－ＳＯＤ）活力降低，而血清脂质过氧化物（ＬＰＯ）含量增高。结果提示，饮食中适量的Ｓｅ和ＶＥ能够增强红细胞的变形能力，其机制可能是：①Ｓｅ维持Ｓｐｅｃｔｒｉｎ与红细胞膜骨架结合；②Ｓｅ和ＶＥ的抗氧化作用，减弱了ＬＰＯ对细胞膜的损伤。     

Assessments of the associations of thrombus localization with accompanying disorders,risk factors,D-dimer levels,and the red cell distribution width in pulmonary embolism

OBJECTIVE:

Pulmonary embolisms occur as a wide spectrum ranging from clinically asymptomatic thrombi to massive thrombi that lead to cardiogenic shock. The purpose of this study was to determine the associations of thrombus localization with risk factors, accompanying disorders, D-dimer levels and the red blood cell distribution width in patients with pulmonary embolism.

MATERIAL AND METHODS:

In 148 patients diagnosed with pulmonary embolism, the presence and anatomical localization of the thrombus were assessed via computed tomographic pulmonary angiography. The accompanying disorders, risk factors, serum D-dimer levels, and red blood cell distribution width of the patients were retrospectively evaluated. ClinicalTrials.gov: NCT02388841.

RESULTS:

The mean age of the patients was 54±16.0 years, and 48 patients were ≥65 years of age. The most frequent accompanying disorders were chronic obstructive pulmonary disease (22%) and malignancy (10.1%), and the most frequent risk factors were recent operation (14.1%) and immobilization (18.2%). Thrombi were most frequently observed in the right pulmonary artery (37.8%). In 31% of the patients, the thrombus was localized to the main pulmonary arteries. Immobile patients exhibited a higher proportion of thrombi in the main pulmonary arteries than mobile patients. The mean D-dimer level and the mean red blood cell distribution width in the patients with thrombi in the main pulmonary arteries were higher than those in the patients with thrombi in more distal pulmonary arterial branches.

CONCLUSION:

Significant associations of proximally localized thrombi with immobilization, the D-dimer levels, and the red blood cell distribution width were observed.