Diffusion MRI improves the accuracy of preoperative diagnosis of common pediatric cerebellar tumors among reviewers with different experience levels

BACKGROUND AND PURPOSE

Although utility of diffusion MR imaging in the preoperative diagnosis of common pediatric cerebellar tumors is generally recognized, its added value has not been systematically studied previously. The purpose of this study was to evaluate the impact of diffusion MR imaging on the accuracy of preoperative diagnosis of common pediatric cerebellar tumors among reviewers with different experience levels.

MATERIALS AND METHODS

Review of the neuro-oncology data base yielded 96 patients whose preoperative brain MR imaging included both diffusion MR imaging (b = 1000 s/mm(2)) and ADC maps. There were 38 pilocytic astrocytomas, 33 medulloblastomas, 17 ependymomas, and 8 atypical teratoid/rhabdoid tumors. Six reviewers (4 residents, 2 neuroradiologists) evaluated the examinations. Two sessions were conducted with each reviewer, without and with diffusion MR imaging data on 2 separate days. The impact of diffusion MR imaging on accuracy of diagnoses was assessed.

RESULTS

In choosing the correct diagnosis of the 4 alternatives, performances of 5 of the 6 reviewers improved significantly with inclusion of the diffusion MR imaging data, from 63%-77% (P = .0003-.0233). The performance of 1 reviewer also improved, but the difference did not attain statistical significance (P = .1944). Inclusion of diffusion MR imaging data improved the likelihood of rendering a correct diagnosis (odds ratio = 3.16, 95% confidence interval = 2.07-4.00) over all tumor types. When embryonal tumors were regarded as a single group, the rate of correct diagnosis increased from 66%-83% with diffusion MR imaging data, and performances of all of the reviewers improved significantly (P = .0001-.05). The improvement in performances resulted from increased correct diagnoses of pilocytic astrocytomas, medulloblastomas, and atypical teratoid/rhabdoid tumors. There was no improvement in the correct diagnoses of ependymomas with inclusion of the diffusion MR imaging data.

CONCLUSIONS

Diffusion MR imaging improves accuracy of preoperative diagnosis of common pediatric cerebellar tumors significantly among reviewers with differing experience levels.

Automated image segmentation of haematoxylin and eosin stained skeletal muscle cross-sections

The ability to accurately and efficiently quantify muscle morphology is essential to determine the physiological relevance of a variety of muscle conditions including growth, atrophy and repair. There is agreement across the muscle biology community that important morphological characteristics of muscle fibres, such as cross-sectional area, are critical factors that determine the health and function (e.g. quality) of the muscle. However, at this time, quantification of muscle characteristics, especially from haematoxylin and eosin stained slides, is still a manual or semi-automatic process. This procedure is labour-intensive and time-consuming. In this paper, we have developed and validated an automatic image segmentation algorithm that is not only efficient but also accurate. Our proposed automatic segmentation algorithm for haematoxylin and eosin stained skeletal muscle cross-sections consists of two major steps: (1) A learning-based seed detection method to find the geometric centres of the muscle fibres, and (2) a colour gradient repulsive balloon snake deformable model that adopts colour gradient in Luv colour space. Automatic quantification of muscle fibre cross-sectional areas using the proposed method is accurate and efficient, providing a powerful automatic quantification tool that can increase sensitivity, objectivity and efficiency in measuring the morphometric features of the haematoxylin and eosin stained muscle cross-sections.

Plasma chemerin level in metabolic syndrome

To investigate the chemerin level in the Chinese Han population with metabolic syndrome and its relationship with each metabolic syndrome component [body mass index (BMI), blood pressure, blood lipids, and blood glucose], we selected 30 patients with metabolic syndrome and 30 healthy control subjects. The chemerin level was measured by enzyme immunoassay in these 2 groups. The subjects' weight, blood pressure, BMI, waist circumference, fasting blood glucose, fasting insulin, lipids, and glycated hemoglobin were simultaneously detected. The t-test, correlation analysis, and multiple regression analysis were used to perform statistical analysis. We found that plasma chemerin level was higher in the metabolic syndrome group than that in the control group (97.61 ± 6.49 vs 70.26 ± 6.97, t = 15.73, P < 0.05). The plasma chemerin level was positively correlated with systolic blood pressure, waist circumference, BMI, waist-to-hip ratio, fasting blood glucose, fasting insulin, and glycated hemoglobin (r = 0.548, 0.442, 0.359, 0.556, 0.613, 0.581, and 0.572, respectively; all P < 0.05). However, it was negatively correlated with high-density lipoprotein cholesterol (r = -0.378, P < 0.05). Therefore, we concluded that plasma chemerin level was correlated with obesity, blood pressure, and high-density lipoprotein cholesterol, suggesting that it may play a role in the pathogenesis of metabolic syndrome.

A clinical study of HBsAg-activated dendritic cells and cytokine-induced killer cells during the treatment for chronic hepatitis B

We aim to study the therapeutic effects of HBsAg-activated DCs and cytokine-induced killer (CIK) cells as adoptive immunotherapy in patients with Chronic Hepatitis B (CHB). Autologous HBsAg-activated DC-CIK cells were infused into patients with CHB to evaluate their effect on HBV-DNA, HBsAg, ALT, etc. The viral load in the treatment group decreased significantly (P < 0.001), while that in the control group did not decrease (P > 0.05). Twenty-one patients (63.6% efficiency) in the treatment group had a viral response (≥2 log decrease in viral load), while four patients (14.8% efficiency) from the control group had a viral response. There were significant differences in the viral responses of the two groups (the control group 63.6% versus the control group 14.8%, P < 0.001). We concluded that the immunity was enhanced after HBsAg activation in DCs and CIK cells. Reinfusion of autologous HBsAg-activated DC-CIK cells inhibited HBV proliferation in 21 of 33 (63.6%) patients.

Microstructure, mechanical and corrosion properties of Mg-Dy-Gd-Zr alloys for medical applications

In previous investigations, a Mg-10Dy (wt.%) alloy with a good combination of corrosion resistance and cytocompatibility showed great potential for use as a biodegradable implant material. However, the mechanical properties of Mg-10Dy alloy are not satisfactory. In order to allow the tailoring of mechanical properties required for various medical applications, four Mg-10(Dy+Gd)-0.2Zr (wt.%) alloys were investigated with respect to microstructure, mechanical and corrosion properties. With the increase in Gd content, the number of second-phase particles increased in the as-cast alloys, and the age-hardening response increased at 200°C. The yield strength increased, while the ductility reduced, especially for peak-aged alloys with the addition of Gd. Additionally, with increasing Gd content, the corrosion rate increased in the as-cast condition owing to the galvanic effect, but all the alloys had a similar corrosion rate (~0.5 mm year(-1)) in solution-treated and aged condition.

Production of a monoclonal antibody and development of an immunoassay for detection of Cr(III) in water samples

In this study we report the production of a monoclonal antibody (Mab) specific for Cr(III)-chelate and the development of a competitive immunoassay for detection of Cr(III) in water samples. In the assay, the complete antigen (Cr(III)-ITCBE-BSA) was used as coating antigen, and Cr(III)-ITCBE as competitor competes with coating antigen to bind with Mab. Using this approach, the spiked water samples with Cr(III) were detected. The linear range of the detection was 0.7-12.4 ng mL(-1). The limit of the detection (LOD) was 0.51 ng mL(-1). The spiked results were also confirmed by ICP-MS, which showed a good correlation (R(2)=0.997) between the two methods. The results indicated that the developed assay was reliable and suitable for the detection of Cr(III) in water samples.

Process of aerenchyma formation and reactive oxygen species induced by waterlogging in wheat seminal roots

The development and regulation of aerenchyma in waterlogged conditions were studied in the seminal roots of wheat. Evans blue staining and the first cell death position indicated that the cortical cell death began at the root mid-cortex cells in flooding conditions. Continuous waterlogging treatment caused the spread of cell death from the mid-cortex to the neighboring cells and well-developed aerenchyma was formed after 72 h. Meanwhile, the formation of radial oxygen loss barrier was observed in the exodermis owing to the induction of Casparian bands and lignin deposition. Analysis of aerenchyma along the wheat root revealed that aerenchyma formed at 10 mm from the root tip, significantly increased toward the center of the roots, and decreased toward the basal region of the root. In situ detection of radial oxygen species (ROS) showed that ROS accumulation started in the mid-cortex cells, where cell death began indicating that cell death was probably accompanied by ROS production. Further waterlogging treatments resulted in the accumulation of ROS in the cortical cells, which were the zone for aerenchyma development. Accumulation and distribution of H₂O₂ at the subcellular level were revealed by ultracytochemical localization, which further verified the involvement of ROS in the cortical cell death process (i.e., aerenchyma formation). Furthermore, gene expression analysis indicated that ROS production might be the result of up-regulation of genes encoding for ROS-producing enzymes and the down-regulation of genes encoding for ROS-detoxifying enzymes. These results suggest that aerenchyma development in wheat roots starts in the mid-cortex cells and its formation is regulated by ROS.

Suppression of hepatoma tumor growth by systemic administration of the phytotoxin gelonin driven by the survivin promoter

Hepatocellular carcinoma (HCC) is one of the most common types of cancer worldwide. However, there is currently no effective therapy strategy in the clinical practice. Recombinant phytotoxin gelonin fused to other factors have been used to treat different cancers. But there have been no reports of gelonin gene therapy. In this study, we have constructed a recombinant plasmid which contained a tumor-specific survivin promoter to drive phytotoxin gelonin (pSur-Gel). And the cytotoxicity effects of pSur-Gel in HCC were also validated both in vitro and in vivo. The expression level of survivin was detected in different liver cancer cell lines and normal liver cell lines by western blot analysis, and a survivin promoter-driven green fluorescent protein (GFP) expression vectors (pSur-GFP) was also tested in liver cancer cell line HepG2 and normal liver cell line LO2. Moreover, phytotoxin gelonin expression experiment and cytotoxicity experiment of pSur-Gel was performed in HepG2 cells and LO2 cells in vitro. Furthermore, anti-tumor effect of pSur-Gel against HepG2 xenografts and toxicity of this gene were evaluated in the mice model. Finally, LDH release assay, apoptosis assay and immunoblot analyse LC3 conversion (LC3-I to LC3-II) were tested. We found that the expression of survivin protein was higher in liver cancer cell lines compared with the normal liver cells. Further study showed that the pSur-GFP and pSur-Gel was expressed specially in liver cancer cell other than in normal liver cells. pSur-Gel plasmid could effectively inhibit the proliferation of liver cancer cells (*P<0.05), and significantly repress the growth of HepG2 xenografts via intravenous in vivo (*P<0.05). Otherwise, compared to cytomegalovirus promoter-driven gelonin expression vectors (pCMV-Gel), no significantly systemic toxicity or organ injuries had been observed in pSur-Gel treated mice. Further studies revealed that the phytotoxin gelonin induced cell death might be mediated by apoptosis and the damage of cell membrane. Taken together, treating hepatocellular carcinoma with the pSur-Gel may be a novel and interesting cancer gene therapy protocol and is worthy of further development for future clinical trials.

KEYWORDS

liver cancer, gelonin, survivin promoter, gene therapy.

Effects of seasonal change and parity on raw milk composition and related indices in Chinese Holstein cows in northern China

This study was to investigate the effects of seasonal change and parity on milk composition and related indices, and to analyze the relationships among milk indices in Chinese Holstein cows from an intensive dairy farm in northern China. The 6,520 sets of complete Dairy Herd Improvement data were obtained and grouped by natural month and parity. The data included daily milk yield (DMY), milk solids percentage (MSP), milk fat percentage (MFP), milk protein percentage (MPP), milk lactose percentage (MLP), somatic cell count (SCC), somatic cell score (SCS), milk production loss (MPL), and fat-to-protein ratio (FPR). Data analysis showed that the above 9 indices were affected by both seasonal change and parity. However, the interaction between parity and seasonal change showed effects on MLP, SCS, MPL, and DMY, but no effects on MFP, MPP, MSP, and FPR. Duncan's multiple comparison on seasonal change showed that DMY (23.58 kg/d), MSP (12.35%), MPP (3.02%), and MFP (3.81%) were the lowest in June, but SCC (288.7 × 10(3)/mL) and MPL (0.69 kg/d) were the lowest in January; FPR (1.32) was the highest in February. Meanwhile, Duncan's multiple comparison on parities showed that MSP, MPP, and MLP were reduced rapidly in the fourth lactation, but SCC and MPL increased with increasing parities. The canonical correlation analysis for indices showed that SCS had high positive correlation with MPL (0.8360). Therefore, a few models were developed to quantify the effects of seasonal change and parity on raw milk composition using the Wood model. The changing patterns of milk composition and related indices in different months and parities could provide scientific evidence for improving feeding management and nutritional supplementation of Chinese Holstein cows.

ASCL1 and RET expression defines a clinically relevant subgroup of lung adenocarcinoma characterized by neuroendocrine differentiation

ASCL1 is an important regulatory transcription factor in pulmonary neuroendocrine (NE) cell development, but its value as a biomarker of NE differentiation in lung adenocarcinoma (AD) and as a potential prognostic biomarker remains unclear. We examined ASCL1 expression in lung cancer samples of varied histologic subtype, clinical outcome and smoking status and compared with expression of traditional NE markers. ASCL1 mRNA expression was found almost exclusively in smokers with AD, in contrast to non-smokers and other lung cancer subtypes. ASCL1 protein expression by immunohistochemical (IHC) analysis correlated best with synaptophysin compared with chromogranin and CD56/NCAM. Analysis of a compendium of 367 microarray-based gene expression profiles in stage I lung adenocarcinomas identified significantly higher expression levels of the RET oncogene in ASCL1-positive tumors (ASCL1(+)) compared with ASCL1(-) tumors (q-value <10(-9)). High levels of RET expression in ASCL1(+) but not in ASCL1(-) tumors was associated with significantly shorter overall survival (OS) in stage 1 (P=0.007) and in all AD (P=0.037). RET protein expression by IHC had an association with OS in the context of ASCL1 expression. In silico gene set analysis and in vitro experiments by ASCL1 shRNA in AD cells with high endogenous expression of ASCL1 and RET implicated ASCL1 as a potential upstream regulator of the RET oncogene. Also, silencing ASCL1 in AD cells markedly reduced cell growth and motility. These results suggest that ASCL1 and RET expression defines a clinically relevant subgroup of ∼10% of AD characterized by NE differentiation.

Cell wall degradation and the dynamic changes of Ca2+ and related enzymes in the developing aerenchyma of wheat (Triticum aestivum L.) under waterlogging

This research was aimed to study the cell wall degradation and the dynamic changes of Ca2+ and related enzymes in developing aerenchyma of wheat root under waterlogging. An examination of morphological development by light and electron microscope revealed that the structure of cell wall in middle cortical cells remained intact after 12 h of waterlogging and turned thinner after waterlogging for 24 h. At 48 h, the aerenchyma has been formed. The cellulase activity gradually increased in middle cortical cells within 24 h of waterlogging, and decreased with the formation of aerenchyma. Fluorescence detection and subcellular localization of Ca2+ showed the dynamic changing of Ca2+ at the cellular and subcellular levels during the development of aerenchyma. The activity of Ca2+-ATPase enhanced markedly in intercellular space, plasma membrane and tonoplast of some middle cortical cells after 8 h of waterlogging and remained high after 24 h, but it decreased after 48 h of waterlogging. All these suggests that cellulase, Ca2+ and Ca2+-ATPase show a dynamic distribution during the aerenchyma development which associated with the cell wall degradation of middle cortical cells. Moreover, there is a feedback regulation between Ca2+ and Ca2+-ATPase.

High prevalence of early childhood infection by Kaposi's sarcoma-associated herpesvirus in a minority population in China

In China, KSHV seroprevalence varies considerably among different regions and ethnicities. But in Xinjiang province, located in the northwestern China, there is a very high seroprevalence of KSHV in adults of Kazak and Ughur ethnicities. However, KSHV prevalence in children and the risk factors associated with the acquisition of infection are currently not known. The aim of this study was to investigate the prevalence of KSHV infection and identify associated socioeconomic or behavioural risk factors and the humoral immune response among children in this population. This is a cross-sectional study (N = 178) to screen children and their caregivers from Xinjiang for total KSHV antibodies, KSHV neutralizing antibodies and HIV infection. Structured questionnaires were utilized to investigate risk factors associated with KSHV prevalence. KSHV seroprevalence in children and caregivers in Xinjiang was 48.3% and 64.7%, respectively. Neutralizing antibody was detected in most seropositive caregivers (93.8%) but was detected in only 5.8% of the infected children. A significant association was observed between child KSHV seroprevalence and sharing of food among family members. These results suggest that similar to other endemic areas in Africa, KSHV infection in the minority populations of Xinjiang is likely to be occurring during early childhood, probably via horizontal transmission through saliva, and results in high seroprevalence in the adult population.

PTEN hypermethylation profiles of Chinese Kazakh patients with esophageal squamous cell carcinoma

Aberrant DNA methylation of promoter region CpG islands may serve as an alternative mechanism to genetic defects in the inactivation of tumor suppressor genes (TSGs) in human malignancies. The aim of this study was to examine the promoter methylation status of the PTEN TSG and its association with esophageal squamous cell carcinoma (ESCC) carcinogenesis in a Chinese Kazakh population, which is known to have a relatively high ESCC incidence and mortality. The methylation status of the PTEN promoter region was determined in patients with ESCC (n = 95) and healthy individuals (n = 65) using highly sensitive Sequenom Epityper assays. The methylation level of the PTEN gene was significantly higher in patients with ESCC than in healthy controls. The median methylation level was 10.0% (interquartile range [IQR]: 7.0-11.0%) in patients with ESCC and 6.0% in controls (IQR: 4.0-9.0%; P = 0.001). PTEN methylation levels were higher in male patients with ESCC than in male controls, whereas a trend toward significance was observed between female patients with ESCC and female controls (P = 0.005 and P = 0.086, respectively). The PTEN methylation level was associated with histopathological grade and lymph node metastasis in patients with ESCC (P = 0.002 and P = 0.009, respectively). To our knowledge, this is the first report to show the presence of PTEN promoter CpG hypermethylation in ESCC and its association with tumor metastasis.

Large-scale development of PIP and SSR markers and their complementary applied in Nicotiana

PIP (Potential Intron Polymorphism) and SSR (Simple Sequence Repeats) were used in many species, but large-scale development and combined use of these two markers have not been reported in tobacco. In this study, a total of 12,388 PIP and 76,848 SSR markers were designed and uploaded to a web-accessible database (http://yancao.sdau.edu.cn/tgb/). E-PCR analysis showed that PIP and SSR rarely overlapped and were strongly complementary in the tobacco genome. The density was 3.07 PIP and 1.72 SSR markers per 10 kb of the known sequences. A total of 153 and 166 alleles were detectedby 22 PIP and 22 SSR markers in 64 Nicotiana accessions. SSR produced higher PIC (polymorphism information content) values and identified more alleles than PIP, whereas PIP could identify larger numbers of rare alleles. Mantel testing demonstrated a high correlation coefficient (r = 0.949, P < 0.001) between PIP and SSR. The UPGMA dendrogram created from the combined PIP and SSR markers was clearer and more reliable than the individual PIP or SSR dendrograms. It suggested that PIP and SSR can make up the deficiency of molecular markers not only in tobacco but other plant.