Magnetic tests for magnetosome chains in Martian meteorite ALH84001

Transmission electron microscopy studies have been used to argue that magnetite crystals in carbonate from Martian meteorite ALH84001 have a composition and morphology indistinguishable from that of magnetotactic bacteria. It has even been claimed from scanning electron microscopy imaging that some ALH84001 magnetite crystals are aligned in chains. Alignment of magnetosomes in chains is perhaps the most distinctive of the six crystallographic properties thought to be collectively unique to magnetofossils. Here we use three rock magnetic techniques, low-temperature cycling, the Moskowitz test, and ferromagnetic resonance, to sense the bulk composition and crystallography of millions of ALH84001 magnetite crystals. The magnetic data demonstrate that although the magnetite is unusually pure and fine-grained in a manner similar to terrestrial magnetofossils, most or all of the crystals are not arranged in chains.     

胃癌中iNOS与HIF-1α表达的相互关系及临床意义

目的:研究诱导型一氧化氮合酶(iNOS)与缺氧诱导因子-1α(HIF-1α)在胃癌中表达的相互关系,探讨他们在胃癌的发生发展、浸润和转移中的作用.方法:2001-01/2002-03手术切除,病理证实为腺癌的胃癌标本54例,患者术前均未行化疗或放疗,另取正常胃组织15例作对照.应用免疫组化SP法检测胃癌及正常胃组织中iNos和HIF-1α的表达,光镜下观察iNOS及HIF-1α蛋白表达,分析iNOS与HIF-1α的表达关系及临床意义.结果:胃癌中iNOS和HIF-1α的表达明显高于正常胃组织(66.67% vs 6.67%P<0.05;74.07%vs 0% P<0.01),其表达与胃癌TNM分期、肿瘤浸润深度和淋巴结转移显著相关(P<0.05或0.01).胃癌组织中iNOS与HIF-1α的表达呈正相关(r=0.596,P<0.05).结论:iNOS和HIF-1α在胃癌的发生发展中起重要作用,联合检测可作为判断胃癌恶性程度和预后的指标.     

HBV pre-X转染HepG2细胞后差异表达基因的筛选

目的:检测HBV Pre-X在真核表达栽体PcDNA3.1-myc-his-HBV pre-X转染的HepG2细胞中的表达,并筛选其中的代谢相关差异表达基因.方法:将构建的真核表达载体pcDNA3.1-mychis-HBV pre-X转染HepG2细胞后蛋白免疫印迹检测:将pcDNA3.1-myc-his-HBV pre-X和pcDNA3.1-myc-his载体分别转染HepG2细胞后,提取mRNA后逆转录为cDNA,运用基因表达谱芯片技术分析差异表达基因.结果:构建的真核表达载体经ApsI、BstXI双酶切鉴定,转染HepG2细胞后HBV pre-X表达经蛋白免疫印迹证实:经基因表达谱芯片分析发现,其中基因表达水平显著上调和下调的分别是200个和62个.结论:筛选HBV pre-X转染HepG2细胞后的代谢相关差异表达基因,从而为乙型肝炎病毒合并糖尿病、脂肪肝等代谢性疾病的分子生物学机制的研究提供了重要依据.     

Hypoxia appears at pre-arthritic stage and shows co-localization with early synovial inflammation in collagen induced arthritis

OBJECTIVE:The presence of hypoxia in rheumatoid synovium has been well known, but exact correlation between hypoxia and synovitis is unclear. The aim of our study was to investigate the time and spatial relationship and the correlation of severity between hypoxia and synovitis in pre-arthritic or early stage of inflammatory joint disease.METHODS:DBA/1J mice were injected intradermally with type II collagen and adjuvant solution to induce arthritis; mice injected with only adjuvant were used as a control group. CIA and control mice were sacrificed weekly after the injection to evaluate serial pathological changes. H&E stain and hydroxyprobe-1 stain were performed to look at the status of inflammation and hypoxia.RESULTS: In serial observations of tissue pathology, we could note the inflammation of synovium developing a week after the injection of type II collagen. Hypoxic change, measured by the hydroxyprobe-1 stain, was also identified in synovium as early as 1 week after the collagen injection, prior to clinically evident arthritis. In addition, we could observe that inflammation and hypoxia co-localize in the synovium and there was a positive correlation between the severity of hypoxia and the degree of synovitis.CONCLUSION:Our results demonstrate that hypoxia takes place in synovium at the pre-arthritic stage of disease and have a close spatial relationship and a positive severity correlation with synovitis.     

Differentiation of the Left‐ from Right‐Side Ventricular Septum in Acute Anterior Myocardial Infarction by Tissue Doppler Imaging

Objectives: This study was to evaluate the longitudinal and radial function of the left‐ and right‐side ventricular septum (Ls and Rs) in patients with acute anterior myocardial infarction (AMI) by tissue Doppler imaging. Methods: Thirty patients with anterior ST‐elevation AMI and revascularization and 20 age‐matched normal subjects were enrolled as controls. The longitudinal and radial systolic tissue velocity (TV), strain rate (SR) and strain (?) of both Ls and Rs were assessed. Results: In normal, there were no significant differences of longitudinal TV, SR and ? between the Ls and Rs. The radial TV was same directed, but larger in Ls than Rs (P < 0.001). The radial SR and ? were positive values of Ls and negative values of Rs, but the degrees were similar in both sides. In AMI, longitudinal and radial TV were significantly decreased in both sides. However, longitudinal and radial SR and ? were significantly decreased in Ls only (P < 0.001 in all). Fourteen patients with AMI who showed no functional recovery had more reduced radial ? of Ls (3.9 ± 1.5% vs. 5.5 ± 2.1%, P = 0.02), but not longitudinal ? of Ls than the other 16 patients with recovery. Conclusion: This study showed the ventricular septum can be functionally differentiated the Ls from the Rs, which can be well demonstrated by SR imaging. The impairment of radial rather than longitudinal function of the Ls was related to no functional recovery. (Echocardiography 2011;28:38‐43)     

Non-Invasive Index for Predicting Significant Liver Fibrosis: Comparison of Diagnostic Performances in Patients with Chronic Hepatitis B and C

Background/Aims

The majority of non-invasive markers of liver fibrosis have been developed in patients with chronic hepatitis C. We aimed to develop a formula for predicting significant fibrosis in patients with chronic viral hepatitis and to compare the usefulness of published models derived from the data obtained from patients with chronic hepatitis C.

Methods

Serum markers and the METAVIR stage of fibrosis in liver biopsy specimens were compared prospectively in patients with chronic hepatitis B and C (estimation set, 367; validation set, 159).

Results

In the estimation set, multiple forward stepwise logistic regression analysis identified ??-glutamyl transpeptidase, haptoglobin, ??2-macroglobulin, matrix metalloproteinase-2, and tissue inhibitor of metalloproteinase-1 as independent predictors of significant fibrosis. A formula termed the SF index was constructed with the aforementioned five variables. The areas under the receiver operating characteristic curves of the SF index for predicting significant fibrosis were 0.828, 0.776, and 0.827 in the estimation, validation, and total sets, respectively. Using cut-off scores of 2.2 and 3.3, significant fibrosis was predicted with considerable accuracy. The diagnostic performances of the SF index and the Zeng index derived from chronic hepatitis B patients were much better than indices derived from chronic hepatitis C patients, such as the APRI, Forns index, and FIB-4.

Conclusions

We developed a novel formula for predicting significant fibrosis in patients with chronic viral hepatitis. Serum indices from studies in patients with chronic hepatitis C were less accurate in patients with chronic hepatitis B for predicting significant fibrosis.     

Attenuation of pulmonary hypertension secondary to left ventricular dysfunction in the rat by Rho‐kinase inhibitor fasudil

Pulmonary hypertension (PH) in left ventricular dysfunction is attributable not only to backward failure of the left ventricle, but also to increased pulmonary vascular resistance (PVR) in some patients. Recently, Rho‐kinase has been known as a potent growth stimulator and mediator of vasoconstriction, and Rho‐kinase inhibitors could ameliorate PVR, little is known about the role of Rho‐kinase in left ventricular dysfunction‐induced PH. We utilized the ascending aortic‐banded rat and assessed the effect of Rho‐kinase inhibitor fasudil on the development of PH secondary to left ventricular dysfunction. Subsequently, in rats subjected to aortic banding for 6 weeks, there were increases in mean pulmonary arterial pressure, pulmonary arteriolar medial thickness, active RhoA, Rho‐kinase II, Rho‐kinase activity, endothelial nitric oxide synthase (eNOS) and endothelin‐1(ET‐1) concomitant with decreased levels in NO and cGMP in the lung. Treatment with fasudil at a dose of 30 mg/kg/day from days 1 to 28 or from days 29 to 42 decreased the mean pulmonary arterial pressure by 57% and 56%, right ventricular hypertrophy by 31% and 30%, pulmonary arteriolar medial thickness by 50% and 50%, and pulmonary expression of Rho‐kinase II by 41% and 28%, respectively, as well as augmented pulmonary expression of eNOS by 16% and 31% and NO by 50% and 76%, respectively, when compared with the vehicle controls. In conclusion, these results suggest that inhibition of Rho‐kinase may provide therapeutic potential for preventing and attenuating the development of PH in left ventricular dysfunction. Further translational study in human is needed to substantiate the findings. Pediatr Pulmonol. 2011; 46:45–59. © 2010 Wiley‐Liss, Inc.     

Application of Near-Infrared Fluorescence Imaging Using a Polymeric Nanoparticle-Based Probe for the Diagnosis and Therapeutic Monitoring of Colon Cancer

Background

Early and accurate detection of adenomatous colonic polyps is a major concern in the prevention of colon cancer. Near-infrared fluorescence (NIRF) imaging with optical probes targeting specific peptides enables the noninvasive visualization and characterization of lesions. Matrix metalloproteinases (MMPs) are known to play an important role in tumorigenesis and tumor progression.

Aim

To investigate the effectiveness of NIRF imaging, with a novel MMP-activatable probe based on a polymeric nanoparticle platform, in the colon cancer models.

Methods

We used an azoxymethane (AOM)-induced mouse colon cancer model resembling human sporadic colon cancer and an MMP-positive xenograft tumor model. MMP expression was evaluated by Western blotting, real-time PCR, and immunohistochemical staining. NIRF imaging was performed with a novel MMP-activatable probe, an MMP-inactivatable probe, and saline. In addition, we observed the change of NIRF signal intensity after intratumoral administration of an MMP-inhibitor.

Results

Multiple tumors with various sizes developed in AOM-treated mouse colons, progressing from adenomas to adenocarcinomas, with MMP expression progressively increasing in the normal-adenoma-adenocarcinoma sequence. In mice injected with the MMP-activatable probe, the NIRF signal also increased in this sequence and was highly correlated with MMP expression (p < 0.001). Tumor-background-ratios (TBR) of adenocarcinoma to adjacent normal mucosa by a novel probe were significantly higher than that of adenoma (p < 0.001). In both the AOM and xenograft models, NIRF signals of tumors decreased after treatment with an MMP-inhibitor.

Conclusions

NIRF imaging using a polymeric nanoparticle-based probe may be useful for detecting early stage disease and for assessing treatment response.     

Effect of Bowel Preparation with Polyethylene Glycol on Quality of Capsule Endoscopy

Background and Aims  

Capsule endoscopy (CE) has the problem that lumen visualization is impaired by bubbles, bile, and debris. The benefits of bowel preparation are still controversial and the best method remains to be determined. The objective of this study was to evaluate the effect of the method of bowel preparation on the quality of visualization and on transit time.     

Vertical Root Fracture in Buccal Roots of Bifurcated Maxillary Premolars from Condensation of Gutta-percha

Introduction

Maxillary premolars are among the teeth most susceptible to vertical root fracture (VRF) from lateral condensation of gutta-percha. These teeth are distinguished by a complex anatomy of the buccal root including a large depression in the dentin wall facing the bifurcation. It is hypothesized that tooth sectioning coupled with 2-dimensional fracture analysis is instrumental in understanding VRF in such teeth. VRF was examined by tooth sectioning following the development of a fracture mechanics analysis to predict VRF in such roots.