Identification and Genetic Division of Fusarium graminearum and Fusarium asiaticum by Species‐Specific SCAR Markers

Fusarium head blight (FHB), also called scab, is a devastating and insidious disease of cereals including wheat (Triticum spp.) and barley (Hordeum vulgare L.) worldwide. Apart from direct yield losses, the most serious concern about FHB is the contamination of the crop with mycotoxins, which pose a health risk to human and livestock. Recent research reported that phylogenetic species F. asiaticum (Fa) and F. graminearum (Fg) were the major causal agents of FHB from infected wheat heads in China. To investigate the population structure of Fusarium species in China by species‐specific as well as the chemotype‐specific markers, sequence‐related amplified polymorphism (SRAP) markers were screened on representative isolates of F. asiaticum‐NIV, F. asiaticum‐ 3ADON and F. graminearum‐15ADON to find amplification products characteristic of either species or chemotypes. Selected amplified fragments were cloned and sequenced so that sequence‐characterized amplified region (SCAR) primer pairs could be developed which permit specific detection of Fusarium species using conventional PCR. Primer pairs SCAR‐Fa1 and SCAR‐Fg1 were confirmed to be able to amplify specific products only in F. asiaticum and F. graminearum isolates, respectively. These species‐specific primers were applied to determine genetic division of F. asiaticum and F. graminearum isolates collected in Yangtze–Huaihe valley. The results indicated that F. asiaticum was the predominant species causing FHB in this wheat production area. It is the first report that SRAP markers were adapted for species characterization in Fusarium isolates.     

High-level expression and characterization of bioactive human truncated variant of hepatocyte growth factor in Escherichia coli

Hepatocyte growth factor (HGF) is an effective anti-fibrotic factor because of its bioactivity in inhibiting fibrosis-related proteins in the development of hepatic fibrosis. However, high-level production of bioactive mature form HGF is difficult because of its complex structure. Here, we report a non-fusion protein expression system to obtain truncated variant of N-terminal hairpin and first kringle domains of HGF (tvNK1) in Escherichia coli to determine its anti-fibrotic effects on hepatic stellate cells (HSCs). Under the selected conditions of cultivation and isopropyl-β-D-1-thiogalactopyranoside induction, the expression level of tvNK1 accounted for approximately 65 % of the total cellular protein and 50 % of fusion protein in the supernatant of whole cell lysates. The recombinant protein could be purified in one step with Ni²⁺-affinity chromatograph. Finally, about 65 mg recombinant tvNK1 was obtained from 1 l fermentation culture with no <95 % purity. In vitro, the final purified tvNK1 was shown to inhibit the proliferation of HSCs and decrease the mRNA and protein expression levels of fibrosis-related COL1A1 and α-smooth muscle actin genes.     

The Role of N-Acetyltransferase 8 in Mesenchymal Stem Cell-Based Therapy for Liver Ischemia/Reperfusion Injury in Rats

Objective

To evaluate the impact of mesenchymal stem cells (MSCs) against hepatic I/R injury and explore the role of N-acetyltransferase 8 (NAT8) in the process.

Methods

We investigated the potential of injected MSCs systemically via the tail vein in healing injuried liver of the SD rat model of 70% hepatic I/R injury by measuring the biochemical and pathologic alterations. Subsequently, we evaluated the expression levels of NAT8 by western blotting in vivo. Concurrently, hydrogen peroxide (H₂O₂)-induced apoptosis in the human normal liver cell line L02 was performed in vitro to evaluate the protective effects of MSC conditioned medium (MSC-CM) on L02 cells. In addition, we downregulated and upregulated NAT8 expression in L02 cells and induced apoptosis by using H₂O₂ to study the protective role of NAT8.

Results

MSCs implantation led to a significant reduced liver enzyme levels, an advanced protection in the histopathological findings of the acutely injured liver and a significantly lower percentage of TUNEL-positive cells, which were increased after I/R injury. In vitro assays, MSC-CM inhibited hepatocyte apoptosis induced by H₂O_2. Moreover, overexpression or downregulation of NAT8 prevented or aggravated hepatocyte apoptosis induced by H₂O₂, respectively.

Conclusions

MSC transplantation provides support to the I/R-injured liver by inhibiting hepatocellular apoptosis and stimulating NAT8 regeneration.     

Comparison of Medial Temporal Measures between Binswanger's Disease and Alzheimer's Disease

Binswanger''s disease (BD) is a common cause of vascular dementia in elderly patients; however, few studies have investigated the medial temporal lobe (MTL) atrophy in BD, and the differences in the atrophic patterns between BD and Alzheimer''s disease (AD) remain largely unknown. Such knowledge is essential for understanding the pathologic basis of dementia. In this study, we collected structural magnetic resonance imaging (MRI) data from 16 normal controls, 14 patients with AD and 14 patients with BD. The volumes of the hippocampus and amygdala, and morphologic parameters (volume, surface area, cortical thickness and mean curvature) of the entorhinal cortex (ERC) and perirhinal cortex (PRC) were calculated using an automated approach. Volume reduction of the hippocampus, amygdala and ERC, and disturbance of the PRC curvature was found in both AD and BD patients compared with the controls (p<0.05, uncorrected). There were no significant differences among all the structural measures between the AD and BD patients. Finally, partial correlation analyses revealed that cognitive decline could be attributed to ERC thinning in AD and volume reduction of PRC in BD. We conclude that AD and BD exhibit similar atrophy patterns in the medial temporal cortices and deep gray matter but have distinct pathologic bases for cognitive impairments. Although atrophy of the MTL structures is a sensitive biomarker for AD, it is not superior for discrimination between AD and BD.     

Organic carbon burial in lake sediments in the middle and lower reaches of the Yangtze River Basin, China

Lakes are important in the global and regional carbon cycle, and lake sediments potentially store substantial quantities of organic carbon. The middle and lower reaches of the Yangtze River basin (MLYB) are some of the largest agricultural areas in China with an extremely high density of lakes and rivers. The lakes in the region have undergone dramatic changes over the past several decades. In this study, six cores from five lakes (the macrophyte-dominated: Shijiuhu Lake and Honghu Lake; the algae-dominated: Chaohu Lake, Taihu Lake, and Nanyihu Lake) in the MLYB were collected from 2002 A.D. to 2008 A.D. Mass accumulation rates (MARs) of sediment derived from ²¹⁰Pb and ¹³⁷Cs along with total organic carbon content (TOC) were used to determine organic carbon accumulation rates (OC ARs) over the last 100 years. The TOC in the five lakes exhibited a significant increase since the mid or late 20th century, which was consistent with the increase in the lake water trophic status due to nutrient input. The average organic carbon accumulation rates for the Taihu Lake, Nanyihu Lake, Chaohu Lake, Shijiuhu Lake, and Honghu Lake were calculated to be 16.6, 28.9, 9.8, 25.4, and 113.2 g C m^?2 year^?1, respectively, over the past 100 years. Based on the average OC AR of 32.1 g C m^?2 year^?1 from the five lakes, carbon burial in lake sediments may be as much as 6.8 × 10¹³ g C in the MLYB over the past 100 years.     

Dopamine D1 Receptor in the Nucleus Accumbens Modulates the Emergence from Propofol Anesthesia in Rat

Neurochemical Research - It has been reported that systemic activation of D1 receptors promotes emergence from isoflurane-induced unconsciousness, suggesting that the central dopaminergic system is...     

Mitochondrion-mediated apoptosis induced by Rana grylio virus infection in fish cells

A fish cell line, fathead minnow (FHM) cell, was used to investigate the alteration of mitochondrial dynamics and the mechanism of apoptosis under Rana grylio virus (RGV) infection. Microscopy observations, flow-cytometry analysis and molecular marker detection revealed the apoptotic fate of the RGV-infected cells. Some typical apoptotic characteristics, such as chromatin condensation, DNA fragmentation and mitochondrial fragmentation, were observed, and significantly morphological changes of mitochondria, including size, shape, internal structure and distribution, were revealed. The mitochondria in RGV-infected cells were aggregated around the viromatrix, and the aggregation could be blocked by colchicine. Moreover, the Δψm collapse was induced, and caspase-9 and caspase-3 were activated in the RGV-infected cells. In addition, NF-κB activation and intracellular Ca²⁺ increase were also detected at different times after infection. The data revealed the detailed dynamics of mitochondrion-mediated apoptosis induced by an iridovirus, and provided the first report on mitochondrial fragmentation during virus-induced apoptosis in fish cells.     

Shedding of syndecan-1 by stromal fibroblasts stimulates human breast cancer cell proliferation via FGF2 activation

The cell surface heparan sulfate proteoglycan syndecan-1 is induced in stromal fibroblasts of breast carcinomas and participates in a reciprocal feedback loop, which stimulates carcinoma cell growth in vitro and in vivo. To define the molecular mechanism of carcinoma growth stimulation, a three-dimensional co-culture model was developed that combines T47D breast carcinoma cells with immortalized human mammary fibroblasts in collagen gels. By silencing endogenous syndecan-1 induction with short interfering RNA and expressing mutant murine syndecan-1 constructs, it was determined that carcinoma cell mitogenesis required proteolytic shedding of syndecan-1 from the fibroblast surface. The paracrine growth signal was mediated by the syndecan-1 heparan lfate chains rather than the ectodomain of the core protein and required fibroblast growth factor 2 and stroma-derived factor 1. This paracrine pathway may provide an opportunity for the therapeutic disruption of stromaepithelial signaling.     

Late marine isotope stage 3 palaeoclimate for East Asia: A data–model comparison

Climate prediction under impact of anthropological greenhouse-gas emission is impossible to validate, but it can be inferred from past climate and modeling. In East Asia, a general warm–wet period at late Marine Isotope Stage 3, ca. 30–40 ky BP has been identified based upon extensive geological records; this provides an arid/humid reference for possible future warming caused by human activities. Based upon syntheses of geological evidence and the AGCM + SSiB modeling, this paper presents climate simulations focused on 35 ky BP, using forcing of insolation, glaciation and land surface conditions for East Asia. Results of the simulation can be compared with geological records and show that (1) the climate patterns of 35 ky BP were warm–wet conditions in northern China, but with warm–dry conditions in southern China compared to today; (2) mean annual temperatures were higher in most mid-low latitude areas, mainly contributed to by increased winter temperatures, suggesting that insolation has generated significant climate effects through the coupling in atmospheric circulation with land surface patterns; (3) Quaternary ice sheets in the Northern Hemisphere played an important role in temperature decrease at the mid-high-latitudes, and also enhanced the south–north temperature gradients, which in turn, increased moisture transport from low to high latitudes and increased monsoonal precipitation over the Tibetan Plateau; and (4) Vegetation changes in East Asia resulted from an increased temperature in the low latitudes, extended rain-belt northwards into China, and an enlarged area of increased precipitation inland.