Deformability study of breast cancer cells using microfluidics

Cell deformability is an important biomarker which can be used to distinguish between healthy and diseased cells. In this study, microfluidics is used to probe the biorheological behaviour of breast cancer cells in an attempt to develop a method to distinguish between non-malignant and malignant cells. A microfabricated fluidic channel design consisting of a straight channel and two reservoirs was used to study the biorheological behaviour of benign breast epithelial cells (MCF-10A) and non-metastatic tumor breast cells (MCF-7). Quantitative parameters such as entry time (time taken for the cell to squeeze into the microchannel) and transit velocity (speed of the cell flowing through the microchannel) were defined and measured from these studies. Our results demonstrated that a simple microfluidic device can be used to distinguish the difference in stiffness between benign and cancerous breast cells. This work lays the foundation for the development of potential microfluidic devices which can subsequently be used in the detection of cancer cells. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Expression and self-assembly of virus-like particles of infectious hypodermal and hematopoietic necrosis virus in <Emphasis Type="Italic">Escherichia coli</Emphasis>

Infectious hypodermal and hematopoietic necrosis virus (IHHNV) is one of the highly pathogenic shrimp viruses. In this study, IHHNV capsid protein (CP) was recombinantly expressed in Escherichia coli and found to self-assemble into virus-like particles (VLPs) with homogeneous size and shape similar to native IHHNV particles. Furthermore, we found that IHHNV-VLPs encapsidate RNA and DNA with a predominant size of 0.5 kb. Stability experiments revealed that the VLP could not be disassembled by EDTA, but its structure was completely disrupted by dithiothreitol (DTT). Non-reducing SDS/PAGE showed that no intermolecular disulfide bonds were formed between the CP molecules, suggesting that intra-CP disulfide bonds are essential for maintaining the structural integrity of the capsid. In addition, indirect immunofluorescence microscopy analysis showed that the VLPs could efficiently enter primary hemocytes of the shrimp Litopenaeus vannamei, which implied that IHHNV-VLPs may be promising vehicles for the delivery of antiviral agents. Luhong Hou and Hao Wu contributed equally to this paper.     

High-dose dexamethasone regulates interleukin-18 and interleukin-18 binding protein in idiopathic thrombocytopenic purpura

To evaluate the effects of high-dose dexamethasone (HD-DXM) on the balance of interleukin-18 (IL-18) and its endogenous antagonist IL-18 binding protein (IL-18BP) in ITP patients, IL-18, IL-18BP as well as IFN-γ, IL-4 plasma levels and platelet counts were determined in 17 ITP patients receiving DXM 40 mg/day for four consecutive days and in 24 healthy subjects. Using RT-PCR, the mRNA expression of IL-18, IL-18BP, IFN-γ, IL-4, T-box (T-bet) and GATA-binding protein 3(GATA-3) were studied in all subjects. The in vitro effects of DXM on IL-18BP and IL-18 of peripheral blood mononuclear cells (PBMCs) were studied by ELISA. HD-DXM administration increased IL-18BP and reduced IL-18 expression significantly (p<0.05), which resulted in a downregulation of IL-18/IL-18BP ratio p<0.05). In vitro, DXM had a significant effect on secretion of IL-18BP while diminishing IL-18 release from cultures of PBMCs. These results suggest that downregulation of IL-18/IL-18BP might account for its clinical efficacy of HD-DXM in active ITP.     

手背静脉网穿刺技术探讨

[目的]探讨手背静脉网的穿刺技术，提高静脉穿刺一次成功率。[方法]将1481例门诊、急诊输液病人和留观病人随机分为两组，试验组783例，采用自然状态静脉穿刺法。传统组698例，采用常规静脉穿刺法。[结果]传统组一次成功率低，且病人疼痛感较强；试验组一次成功率高。[结论]用试验组方法进行穿刺优于传统组。     

Creep-resistant elastomeric networks prepared by photocrosslinking fumaric acid monoethyl ester-functionalized poly(trimethylene carbonate) oligomers

Biodegradable elastomeric networks were prepared from ethyl fumarate-functionalized poly(trimethylene carbonate) oligomers. Photocrosslinkable macromers were synthesized by reacting three-armed, hydroxyl group-terminated poly(trimethylene carbonate) oligomers with fumaric acid monoethyl ester at room temperature using N,N-dicyclohexylcarbodiimide as a coupling agent and 4-dimethylamino pyridine as a catalyst. Poly(trimethylene carbonate) macromers with molecular weights ranging between 4500 and 13,900 were prepared and crosslinked by ultraviolet-initiated radical polymerization. The gel contents of the resulting transparent networks varied between 74% and 80%. All obtained networks had low glass transition temperatures, which varied between ?18 and ?13 °C. They showed rubber-like behavior and excellent mechanical properties, with tensile strengths and elongations at break of up to 17.5 MPa and 750%, respectively. Moreover, static- and dynamic creep experiments showed that these amorphous networks were highly elastic and resistant to creep. In cyclic tensile testing to 50% strain, the permanent deformation after 20 cycles was 0%, while static creep tests at 35% of the yield stress did not indicate creep or permanent deformation after removal of the load. Porous structures were prepared by photopolymerizing the macromers in the presence of salt particles, and subsequent leaching of the salt. Such networks, built up of non-toxic compounds and designed to release benign degradation products, may find application as tissue engineering scaffolds for dynamic cell culture.     

Roles of adipose restriction and metabolic factors in progression of steatosis to steatohepatitis in obese, diabetic mice

Background and Aims: We previously reported that steatohepatitis develops in obese, hypercholesterolemic, diabetic foz/foz mice fed a high‐fat (HF) diet for 12 months. We now report earlier onset of steatohepatitis in relation to metabolic abnormalities, and clarify the roles of dietary fat and bodily lipid partitioning on steatosis severity, liver injury and inflammatory recruitment in this novel non‐alcoholic steatohepatitis (NASH) model. Methods: Foz/foz (Alms1 mutant) and wild‐type (WT) mice were fed a HF diet or chow, and metabolic characteristics and liver histology were studied at 2, 6, 12 and 24 weeks. Results: After 12 weeks HF‐feeding, foz/foz mice were obese and diabetic with approximately 70% reduction in serum adiponectin. Hepatomegaly developed at this time, corresponding to a plateau in adipose expansion and increased adipose inflammation. Liver histology showed mild inflammation and hepatocyte ballooning as well as steatosis. By 24 weeks, HF‐fed foz/foz mice developed severe steatohepatitis (marked steatosis, alanine aminotransferase elevation, ballooning, inflammation, fibrosis), whereas dietary and genetic controls showed only simple steatosis. While steatosis was associated with hepatic lipogenesis, indicated by increased fatty acid synthase activity, steatohepatitis was associated with significantly higher levels of CD36, indicating active fatty acid uptake, possibly under the influence of peroxisome proliferator‐activated receptor‐γ. Conclusion: In mice genetically predisposed to obesity and diabetes, HF feeding leads to restriction of adipose tissue for accommodation of excess energy, causing lipid partitioning into liver, and transformation of simple steatosis to fibrosing steatohepatitis. The way in which HF feeding ‘saturates’ adipose stores, decreases serum adiponectin and causes hepatic inflammation in steatohepatitis may provide clues to pathogenesis of NASH in metabolic syndrome.     

佛鱼饮治疗29例慢阻肺病急性发作期患者的疗效观察

目的观察清热化痰活血法组方的佛鱼饮联合西药治疗慢阻肺病急性发作期的临床疗效。方法59例患者随机分为两组,治疗组29例在西医常规治疗基础上口服佛鱼饮;对照组30例,给予抗感染、祛痰止咳平喘等常规治疗。结果治疗14 d,治疗组的临床总有效率为69.69%,明显好于对照组;治疗组动脉血气较对照组明显好转（P〈0.05）;两组白细胞总数、中性粒细胞百分数均较疗前明显降低（P〈0.01）,淋巴细胞百分数明显升高（P〈0.01）,治疗组改善比对照组明显。结论佛鱼饮联合西药治疗慢阻肺病急性发作的疗效优于对照组,是治疗慢阻肺病急性发作的有效方,值得临床推广运用。     

Genetic alterations and their relationship in the phosphatidylinositol 3-kinase/Akt pathway in thyroid cancer.

PURPOSE: To investigate the overall occurrence and relationship of genetic alterations in the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in thyroid tumors and explore the scope of this pathway as a therapeutic target for thyroid cancer. EXPERIMENTAL DESIGN: We examined collectively the major genetic alterations and their relationship in this pathway, including PIK3CA copy number gain and mutation, Ras mutation, and PTEN mutation, in a large series of primary thyroid tumors. RESULTS: Occurrence of any of these genetic alterations was found in 25 of 81 (31%) benign thyroid adenoma (BTA), 47 of 86 (55%) follicular thyroid cancer (FTC), 21 of 86 (24%) papillary thyroid cancer (PTC), and 29 of 50 (58%) anaplastic thyroid cancer (ATC), with FTC and ATC most frequently harboring these genetic alterations. PIK3CA copy gain was associated with increased PIK3CA protein expression. A mutual exclusivity among these genetic alterations was seen in BTA, FTC, and PTC, suggesting an independent role of each of them through the PI3K/Akt pathway in the tumorigenesis of the differentiated thyroid tumors. However, coexistence of these genetic alterations was increasingly seen with progression from differentiated tumor to undifferentiated ATC. Their coexistence with BRAF mutation was also frequent in PTC and ATC. CONCLUSIONS: The data provide strong genetic implication that aberrant activation of PI3K/Akt pathway plays an extensive role in thyroid tumorigenesis, particularly in FTC and ATC, and promotes progression of BTA to FTC and to ATC as the genetic alterations of this pathway accumulate. Progression of PTC to ATC may be facilitated by coexistence of PI3K/Akt pathway-related genetic alterations and BRAF mutation. The PI3K/Akt pathway may thus be a major therapeutic target in thyroid cancers.