Genetic diversity of Phytophthora capsici (Pythiaceae) isolates in Anhui Province of China based on ISSR-PCR markers

Phytophthora capsici is a plant pathogenic oomycete that damages numerous crops worldwide. Consequently, interest in research on the genetic structure of this species has grown in recent decades. However, there is little information about P. capsici in eastern China. We investigated the genetic diversity of P. capsici isolates from three large regions of Anhui Province in eastern China based on ISSR-PCR technology. Thirteen random primers were screened and used to amplify DNA from 51 samples. We obtained 158 reproducible ISSR fragments, of which 90% were polymorphic, revealing a high degree of polymorphism among the isolates. Genetic similarity coefficients among all the isolates ranged from 0.56 to 0.94, with a mean of 0.84 based on the ISSR data, indicating a high level of genetic variation in these P. capsici isolates. Cluster analysis using UPGMA indicated that the Anhui isolates were divided into seven groups according to the DNA fingerprints, although there was no correlation between the ISSR group and geographic origin. Isolates from the same location showed no clustering based on the year of sampling. AMOVA partitioned variability among (13.6%) and within populations (86.4%). The gene flow among populations ranged from 2.804 to 4.937, with a mean of 3.545, indicating highly frequent gene exchange. Genetic distances and genetic differentiation were negatively correlated with geographic distances. These results lead us to suggest that this pathogen has considerable evolutionary potential, which will enable it to adapt to and overcome management strategies over time.

LCA data quality: sensitivity and uncertainty analysis

Life cycle assessment (LCA) data quality issues were investigated by using case studies on products from starch-polyvinyl alcohol based biopolymers and petrochemical alternatives. The time horizon chosen for the characterization models was shown to be an important sensitive parameter for the environmental profiles of all the polymers. In the global warming potential and the toxicity potential categories the comparison between biopolymers and petrochemical counterparts altered as the time horizon extended from 20 years to infinite time. These case studies demonstrated that the use of a single time horizon provide only one perspective on the LCA outcomes which could introduce an inadvertent bias into LCA outcomes especially in toxicity impact categories and thus dynamic LCA characterization models with varying time horizons are recommended as a measure of the robustness for LCAs especially comparative assessments. This study also presents an approach to integrate statistical methods into LCA models for analyzing uncertainty in industrial and computer-simulated datasets. We calibrated probabilities for the LCA outcomes for biopolymer products arising from uncertainty in the inventory and from data variation characteristics this has enabled assigning confidence to the LCIA outcomes in specific impact categories for the biopolymer vs. petrochemical polymer comparisons undertaken. Uncertainty combined with the sensitivity analysis carried out in this study has led to a transparent increase in confidence in the LCA findings. We conclude that LCAs lacking explicit interpretation of the degree of uncertainty and sensitivities are of limited value as robust evidence for decision making or comparative assertions.

Inflammation and oxidative stress induced by cigarette smoke in Lewis rat brains

Exposure to cigarette smoke has been associated with an increased risk of neurological diseases such as stroke, Alzheimer's disease and multiple sclerosis. In these studies, serum and brain sections from Lewis rats or those exposed to cigarette smoke and control rats were examined for evidence of increased inflammation and oxidative stress. Immunocytochemical staining of brain sections from CS-exposed rats showed increased expression of class II MHC and, in ELISA, levels of IFN-gamma and TNF-α were higher than for non-exposed rats. In polymerase chain reaction assays there was increased interferon-gamma, TNF-α, IL-1α, IL-1β, IL-23, IL-6, IL-23, IL-17, IL-10, TGF-β, T-bet and FoxP3 gene expression with CS exposure. There was also markedly elevated MIP-1α/CCL3, less prominent MCP-1/CCL2 and no elevation of SDF-1α gene expression. Analysis of samples from CS-exposed and control rats for anti-oxidant expression showed no significant difference in serum levels of glutathione and, in brain, similar levels of superoxide dismutase and decreased thioredoxin gene expression. In contrast, there was increased brain gene expression for the pro-oxidants iNOS and the NADPH components NOX4, dual oxidase 1 and p22(phox). Nrf2 expression, which is typically triggered as a secondary response to oxidative stress, was also increased in brains from CS-exposed rats with nuclear translocation of this protein from cytoplasm demonstrated in astrocytes in association with increased expression of the aryl hydrocarbon receptor gene, an Nrf2 target. These studies, therefore, demonstrate that CS exposure in these animals can trigger multiple immune and oxidative responses that may have important roles in the pathogenesis of CNS inflammatory neurological diseases.

First Report of Medical Tree Peony Root Rot Caused by Fusarium solani in Tongling, China

Tree peony bark, a main component of Chinese traditional medicine used for alleviating fever and dissipating blood stasis, is mainly produced in Tongling, China. Recently, tree peony cultivation in this area was seriously affected by root rot, with approximately 20 to 30% disease incidence each year. The disease severely affects yield and quality of tree peony bark. During the past 2 years, we collected 56 diseased tree peony plants from Mudan and Fenghuang townships in Tongling. We found reddish brown to dark brown root rot in mature roots, especially on those with injuries. Plant samples collected were disinfected with 2% sodium hypochlorite and isolations were conducted on potato sucrose agar (PSA). Eleven isolates were obtained and all had white fluffy aerial hypha on PSA. Two types of conidia were produced; the larger, reaphook-shaped ones had three to five septa and the smaller, ellipse-shaped ones had one or no septum. The reaphook-shaped conidia were 20.15 to 37.21 × 3.98 to 5.27 μm and the ellipse-shaped conidia were 6.02 to 15.52 × 2.21 to 5.33 μm in size. Chlamydospores were produced, with two to five arranged together. Biological characteristics of the fungi indicated that the optimum temperature for the mycelial growth on PSA was 25 to 30°C and the optimum pH range was 5.5 to 7.0. The above morphological characteristics point the fungal isolates to be Fusarium solani. To confirm pathogenicity, 30 healthy 1-year-old tree peony seedling plants were grown in pots (25 cm in diameter) with sterilized soil and a conidial suspension from one isolate (FH-1, 5 × 10⁵ conidia/ml) was used for soil inoculation. Inoculated seedlings were maintained at 28°C in a greenhouse with a 12-h photoperiod of fluorescent light. Seedlings inoculated with distilled water were used as controls. After 3 weeks, the roots were collected and rinsed with tap water. Dark brown lesions were observed in the inoculated mature roots but not in the control roots. To confirm the identity of the pathogen, F. solani strains were reisolated from the lesions and total genomic DNA was extracted with the cetyltriethylammnonium bromide method from the mycelia of the reisolated strains (1). PCR was performed using the fungal universal primers ITS4 (5'-TCCTCCGCTTATTGATATGC-3') and ITS5 (5'-GGAAGTAAAAGTCGTAACAAGG-3') to amplify a DNA fragment of approximately 590 bp. The purified PCR products were sequenced (Invitrogen Co., Shanghai, China) and shared 100% sequence identity with each other. A comparison of the sequence (JQ658429.1) by the Clustal_W program (2) with those uploaded in GenBank confirmed with the fungus F. solani (100% sequence similarity to isolate S-0900 from the Great Plains of the United States; EU029589.1). To our knowledge, this is the first report of F. solani causing medical tree peony root rot in China. The existence of this pathogen in China may need to be considered for developing effective control strategies. References: (1). C. N. Stewart et al. Biotechniques 14:748, 1993. (2). J. D. Thompson et al. Nucleic Acids Res. 22:4673, 1994.

Strong magnetic field effects on solid-liquid and particle-particle interactions during the processing of a conducting liquid containing non-conducting particles

The behavior of micrometer-sized weak magnetic insulating particles migrating in a conductive liquid metal is of broad interest during strong magnetic field processing of materials. In the present paper, we develop a numerical method to investigate the solid-liquid and particle-particle interactions by using a computational fluid dynamics (CFDs) modeling. By applying a strong magnetic field, for example, 10 Tesla, the drag forces of a single spherical particle can be increased up to around 15% at a creeping flow limit. However, magnetic field effects are reduced when the Reynolds number becomes higher. For two identical particles migrating along their centerline in a conductive liquid, both the drag forces and the magnetic interaction will be influenced. Factors such as interparticle distance, Reynolds number and magnetic flux density are investigated. Shielding effects are found from the leading particle, which will subsequently induce a hydrodynamic interaction between two particles. Strong magnetic fields however do not appear to have a significant influence on the shielding effects. In addition, the magnetic interaction forces of magnetic dipole-dipole interaction and induced magneto-hydrodynamic interaction are considered. It can be found that the induced magneto-hydrodynamic interaction force highly depends on the flow field and magnetic flux density. Therefore, the interaction between insulating particles can be controlled by applying a strong magnetic field and modifying the flow field. The present research provides a better understanding of the magnetic field induced interaction during liquid metal processing, and a method of non-metallic particles manipulation for metal/ceramic based materials preparation may be proposed.

Role of growth hormone, glutamine and enteral nutrition in pediatric short bowel syndrome: a pilot follow-up study

OBJECTIVE

Aim of the study was to evaluate whether growth hormone (GH), glutamine (Gln), and enteral nutrition (EN) have a positive effect on intestinal adaptation in pediatric patients with short bowel syndrome (SBS).

METHOD

7 pediatric patients with SBS (small bowel remnant length: 60.57 ± 15.18 cm; mean ± SEM) were treated with GH (0.05 mg/kg/day), supplemental Gln (0.45 g/kg/day), plus EN for 3 weeks. After 3 weeks of treatment, GH was discontinued, and patients were maintained on Gln and EN or additionally received a high-carbohydrate-low-fat diet. Repeat treatment was given at regular intervals. Changes in weight and height increase, intestinal absorptive capacity and blood indices were evaluated.

RESULT

All patients completed the treatment. The intestinal absorptive capacity and plasma levels of proteins were significantly improved after treatment. There were no major adverse effects in any patient and no death occurred. Growth velocity was also well maintained on follow-up. 6 patients were weaned off PN and lived on HCLF diet supplement with EN, while the last patient required less volume of PN.

CONCLUSION

Multiple treatment approaches with GH, Gln, and EN at an early stage significantly improved intestinal adaptation in pediatric patients with SBS. Furthermore, the positive effect appeared to be sustained even after GH was discontinued.

Optimization of factors affecting Agrobacterium-mediated transformation of Micro-Tom tomatoes

Micro-Tom is the smallest known variety of tomatoes. An orthogonal experimental design L(16) (4(5)) was used to optimize Agrobacterium-mediated transformation of cotyledon explants of Lycopersicon esculentum cv. Micro-Tom. Four parameters were investigated to determine their effect on transformation frequency: the concentration of bacterial suspension, time of dip in bacterial suspension, co-cultivation time, and concentration of carbenicillin. We also examined the effect of these parameters on contamination rate, necrosis rate, mortality, cut-surface browning rate, and undamaged explant rate. Both the bacterial and carbenicillin concentrations had a significant influence on the rate of infected explants. The time of co-cultivation also had a significant influence on the transformation parameters. The optimal transformation protocol consisted of an Agrobacterium suspension of 0.5 × 10(8) cells/mL (OD(600) = 0.5) and an infection time of 5 min, one day of co-cultivation and 500 mg/L carbenicillin. Under these conditions, the transformation efficiency of the shoots reached 5.1%; the mean transformation frequency was 3.9% (N = 838).

Forebrain glutamatergic neurons mediate leptin action on depression-like behaviors and synaptic depression

The glutamatergic system has been implicated in the pathophysiology of depression and the mechanism of action of antidepressants. Leptin, an adipocyte-derived hormone, has antidepressant-like properties. However, the functional role of leptin receptor (Lepr) signaling in glutamatergic neurons remains to be elucidated. In this study, we generated conditional knockout mice in which the long form of Lepr was ablated selectively in glutamatergic neurons located in the forebrain structures, including the hippocampus and prefrontal cortex (Lepr cKO). Lepr cKO mice exhibit normal growth and body weight. Behavioral characterization of Lepr cKO mice reveals depression-like behavioral deficits, including anhedonia, behavioral despair, enhanced learned helplessness and social withdrawal, with no evident signs of anxiety. In addition, loss of Lepr in forebrain glutamatergic neurons facilitates NMDA-induced hippocampal long-term synaptic depression (LTD), whereas conventional LTD or long-term potentiation (LTP) was not affected. The facilitated LTD induction requires activation of the GluN2B subunit as it was completely blocked by a selective GluN2B antagonist. Moreover, Lepr cKO mice are highly sensitive to the antidepressant-like behavioral effects of the GluN2B antagonist but resistant to leptin. These results support important roles for Lepr signaling in glutamatergic neurons in regulating depression-related behaviors and modulating excitatory synaptic strength, suggesting a possible association between synaptic depression and behavioral manifestations of depression.

Anaerobic digestion of starch-polyvinyl alcohol biopolymer packaging: biodegradability and environmental impact assessment

The digestibility of a starch-polyvinyl alcohol (PVOH) biopolymer insulated cardboard coolbox was investigated under a defined anaerobic digestion (AD) system with key parameters characterized. Laboratory results were combined with industrial operational data to develop a site-specific life cycle assessment (LCA) model. Inoculated with active bacterial trophic groups, the anaerobic biodegradability of three starch-PVOH biopolymers achieved 58-62%. The LCA modeling showed that the environmental burdens of the starch-PVOH biopolymer packaging under AD conditions on acidification, eutrophication, global warming and photochemical oxidation potential were dominated by atmospheric emissions released from substrate degradation and fuel combustion, whereas energy consumption and infrastructure requirements were the causes of abiotic depletion, ozone depletion and toxic impacts. Nevertheless, for this bio-packaging, AD of the starch-PVOH biopolymer combined with recycling of the cardboard emerged as the environmentally superior option and optimization of the energy utilization system could bring further environmental benefits to the AD process.

Establishment and characterization of a new cell line derived from kidney of grouper, Epinephelus akaara (Temminck & Schlegel), susceptible to Singapore grouper iridovirus (SGIV)

A marine fish cell line derived from the kidney of red-spotted grouper, Epinephelus akaara, designated as EAGK was established and characterized. The EAGK cells multiplied well in Leibovitz's L-15 medium containing 10% foetal bovine serum at 25 °C and have been subcultured for more than 90 passages. Karyotyping, chromosomal typing and ribosomal RNA (rRNA) genotyping analysis revealed that EAGK had a modal diploid chromosome number of 82 and was a fibroblast cell line originated from grouper. A severe cytopathic effect was observed in EAGK cells incubated with Singapore grouper iridovirus (SGIV), but not with soft-shelled turtle iridovirus, viral nervous necrosis virus or spring viraemia of carp virus. SGIV replication was further confirmed by immunofluorescence, electron microscopy and virus titre determination. Bright fluorescence was observed after transfection with fluorescent protein reporter plasmids, indicating that EAGK cells can be used to identify gene functions in vitro. In addition, the cell organelles including mitochondria and endoplasm reticulum changed and aggregated around virus factories after SGIV infection, suggested that the EAGK cell line could be an important tool for investigation of iridovirus-host interactions.

Successful cutaneous delivery of the photosensitizer silicon phthalocyanine 4 for photodynamic therapy

BACKGROUND

 Photodynamic therapy (PDT) has been shown to be effective in the treatment of malignancies of a variety of organ systems, including the lungs, bladder, gastrointestinal tract and skin. Cutaneous lesions serve as ideal targets of PDT because of the accessibility of the skin to light. To achieve optimum results, the photosensitizer must be delivered effectively into the target layers of the skin within a practical timeframe, via noninvasive methods.

AIM

To determine whether topical application of a second-generation photosensitizer, silicon phthalocyanine (Pc) 4 [SiPc(OSi(CH3)2 (CH2)3 N(CH3)2)(OH)], results in effective penetration of the skin barrier.

METHODS

Penetration of Pc 4 was evaluated using standard Franz-type vertical diffusion cell experiments on surrogate materials (silicone membranes) and laser-scanning confocal microscopy of normal skin biopsy samples from human volunteers.

RESULTS

The Franz diffusion data indicate that Pc 4 formulated in an ethanol/propylene glycol solution (70/30%, v/v) can penetrate the membrane at a flux that is appreciable and relatively invariant. Using the same formulation, Pc 4 uptake could be detected in human skin via laser-scanning confocal microscopy.

CONCLUSION

After topical application, Pc 4 is absorbed into the epidermis in as little as 1 h, and the absorption increased with increasing time and dose. Pc 4 can be effectively delivered into human skin via topical application. The data also suggest that the degree of penetration is time- and dose-dependent.

Multipoint laser Doppler vibrometry with single detector: principles, implementations, and signal analyses

A 20-point laser Doppler vibrometer with single photodetector is presented for noncontact dynamic measurement. A 5×4 beam array with various frequency shifts is generated by a 1.55 μm distributed feedback laser and four acousto-optic devices, and illuminating different points on vibrating objects. The reflected beams are coupled into a single-mode fiber by a pigtailed collimator and interfere with a reference beam. The signal output from a high-speed photodetector is amplified and then digitized by a high-speed analog-to-digital converter with a sampling rate of 1 gigasample per second (1 GS/s). Several methods are introduced to avoid the cross talk among different frequencies and extract the vibration information of 20 points from a one-dimensional signal. Two signal processing algorithms based on Fourier transform and windowed Fourier transform are illustrated to extract the vibration signals at different points. The experimental results are compared with that from a commercial single-point laser vibrometer. The results show simultaneous vibration measurement can be realized on multiple points using a single laser source and a single photodetector.

Engagement of activated Notch signalling in collagen II-specific T helper type 1 (Th1)- and Th17-type expansion involving Notch3 and Delta-like1

Our previous study demonstrated that T helper (Th) cells from patients with rheumatoid arthritis (RA) display an altered expression profile of Notch receptors and enhanced activation of Notch signalling. The aim of this study was to investigate the role of distinct Notch receptors and ligands in the activation and differentiation of collagen II (CII)-reactive Th cells upon antigen-specific restimulation. Spleen mononuclear cells (SMNCs) from CII-immunized DBA/1J mice were restimulated by culturing with CII. CII-specific proliferation and differentiation of T cells were determined by tritiated thymidine ((3) [H]-TdR) incorporation and flow cytometric analysis, respectively. The mRNA expression of Notch receptors and Hes1 was assessed by real-time polymerase chain reaction (PCR). There was a clear increase in the percentage of Th1 cells and Th17 cells after CII restimulation. No significant difference was observed in the percentage of regulation T cells (T(reg) ) in SMNCs with or without CII restimulation. CII restimulation induced up-regulated transcript levels of Hes1 in CII-reactive CD4(+) T cells. The mRNA level of Notch3 was also up-regulated significantly, while the levels of the other three Notch receptors were not increased. Inhibition of Notch signalling by N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT) and Notch3 antibody decreased the collagen-specific T cell proliferation and attenuated Th1- and Th17-type responses, while treatment with Notch ligand Delta-like 1 promoted such a response. The present study demonstrates that Notch signalling is engaged in CII-specific Th1- and Th17-type expansion in which Notch3 and Delta-like1 were involved. Selective inhibition of Notch signalling mediated by Notch3 or Delta-like1 may offer a new strategy for the treatment of RA.

Trans-acting dosage effects on the expression of model gene systems in maize aneuploids

The reduction in vigor of aneuploids was classically thought to be due to the imbalance of gene products expressed from the varied chromosome relative to those from the remainder of the genome. In this study, the dosage of chromosomal segments was varied, but the transcript level of most genes encoded therein showed compensation for the number of copies of the gene. Genes whose dosage was not altered were affected by aneuploidy of unlinked chromosomal segments. The phenotypic effects of aneuploidy and of a substantial fraction of quantitative variation are hypothesized to be the consequence of an altered dosage-sensitive regulatory system.

Expansion of mouse sertoli cells on microcarriers

BACKGROUND

Sertoli cells (SCs) have been described as the 'nurse cells' of the testis whose primary function is to provide essential growth factors and create an appropriate environment for development of other cells [for example, germinal and nerve stem cells (NSCs), used here]. However, the greatest challenge at present is that it is difficult to obtain sufficient SCs of normal physiological function for cell transplantation and biological medicine, largely due to traditional static culture parameter difficult to be monitored and scaled up.

OBJECTIVE

Operational stirred culture conditions for in vitro expansion and differentiation of SCs need to be optimized for large-scale culture.

MATERIALS AND METHODS

In this study, the culturing process for primary SC expansion and maintaining lack of differentiation was optimized for the first time, by using microcarrier bead technology in spinner flask culture. Effects of various feeding/refreshing regimes, stirring speeds, seed inoculum levels of SCs, and concentrations of microcarrier used for expansion of mouse SCs were also explored. In addition, pH, osmotic pressure and metabolic variables including consumption rates of glucose, glutamine, amino acids, and formation rates of lactic acid and ammonia, were investigated in culture.

RESULTS

After 6 days, maximal cell densities achieved were 4.6 x 10(6) cells/ml for Cytodex-1 in DMEM/FBS compared to 4.8 x 10(5) cells/ml in static culture. Improved expansion was achieved using an inoculum of 1 x 10(5) cells/ml and microcarrier concentration of 3 mg/ml at stirring speed of 30 rpm. RESULTS indicated that medium replacement (50% changed everyday) resulted in supply of nutrients and removal of waste products inhibiting cell growth, that lead to maintenance of cultures in steady state for several days. These conditions favoured preservation of SCs in the undifferentiated state and significantly increased their physiological activity and trophic function, which were assessed by co-culturing with NSCs and immunostaining.

CONCLUSION

Data obtained in this study demonstrate the vast potential of this stirred culture system for efficient, reproducible and cost-effective expansion of SCs in vitro. The system has advantages over static culture, which has major obstacles such as lower cell density, is time-consuming and susceptible to contamination.

Ex-vivo expansion of CFU-GM and BFU-E in unselected PBMC cultures with Flt3L is enhanced by autologous plasma

BACKGROUND

Previous ex-vivo expansion studies in our laboratory, comparing unselected and CD34(+)-selected PBMC, have shown no advantage for CD34(+) cell selection, in terms of the expansion achieved. Our goal was to develop procedures for consistent generation of large numbers of hematopoietic progenitor and post-progenitor cells from unselected PBMC.

METHODS

Unselected PBMC, collected from cancer patients undergoing apheresis prior to high-dose chemotherapy and autologous stem cell rescue, were expanded ex vivo in static cultures, without a stromal layer, in the presence of Flt3 ligand (Flt3L), a recombinant GM-CSF/IL-3 fusion protein (PIXY321), G-CSF and GM-CSF for 10 days.

RESULTS

The addition of 2% autologous plasma to this cytokine combination enhanced expansion of total cell numbers (3.2 fold versus 1.9 fold; p < 0.01), colony-forming units granulocyte-macrophage (CFU-GM) (22.0 fold versus 8.1 fold, p < 0.01) and burst-forming units erythroid (BFU-E) (17.6 fold versus 7.0 fold, 0.01 < p < 0.02). The optimal seeding density for a given specimen was inversely related to the frequency of CD34(+) cells in the sample. CFU-GM expansion with the Flt3L-containing cytokine cocktail was equivalent to that obtained with IL-3, IL-6, G-CSF and SCF, whether or not the cultures were supplemented with autologous plasma. In plasma-free cultures, BFU-E expansion was significantly higher with IL-3, IL-6, G-CSF and SCF than with Flt3L, PIXY321, G-CSF and GM-CSF. In the presence of autologous plasma, however BFU-E expansion was higher in the Flt3L-containing media. In comparison studies, autologous plasma suppressed BFU-E expansion in SCF-containing cultures. Consistent with our colony assay results, dual-parameter flow cytometric analysis of the expanded cell population revealed that supplementation with autologous plasma yielded a significant increase in the numbers of myeloid progenitors in Flt3L-containing cultures.

DISCUSSION

Unselected PBMC from cancer patients can be effectively expanded ex vivo in Flt3L, PIXY321, G-CSF and GM-CSF, supplemented with autologous plasma, yielding high numbers of myeloid and erythroid progenitors.

The radiation protection and therapy effects of mesenchymal stem cells in mice with acute radiation injury

The aim of this study was to investigate the effects and mechanisms of mesenchymal stem cells (MSCs) on haematopoietic reconstitution in reducing bone marrow cell apoptosis effects in irradiated mice, and to research the safe and effective dosage of MSCs in mice with total body irradiation (TBI). After BALB/c mice were irradiated with 5.5 Gy cobalt-60 gamma-rays, the following were observed: peripheral blood cell count, apoptosis rate, cell cycle, colony-forming unit-granulocyte macrophage (CFU-GM) and colony-forming unit-fibroblast (CFU-F) counts of bone marrow cells and pathological changes in the medulla. The survival of mice infused with three doses of MSCs after 8.0 Gy or 10 Gy TBI was examined. The blood cells recovered rapidly in the MSC groups. The apoptotic ratio of bone marrow cells in the control group was higher at 24 h after radiation. A lower ratio of G0/G1 cell cycle phases and a higher ratio of G2/M and S phases, as well as a greater number of haematopoietic islands and megalokaryocytes in the bone marrow, were observed in the MSC-treated groups. MSCs induced recovery of CFU-GM and CFU-GM and improved the survival of mice after 8 Gy TBI, but 1.5 x 10(8) kg(-1) of MSCs increased mortality. These results indicate that MSCs protected and treated irradiated mice by inducing haematopoiesis and reducing apoptosis. MSCs may be a succedaneous or intensive method of haematopoietic stem cell transplantation under certain radiation dosages, and could provide a valuable strategy for acute radiation syndrome.

Spatially encoded multibeam laser Doppler vibrometry using a single photodetector

A laser Doppler vibrometer with single photodetector is introduced to measure the vibration on multiple points of target simultaneously. A 2 x 5 beam array with various frequency shifts is generated by three acousto-optic devices, illuminating different points on a vibrating object. The reflected beams interfere with a reference beam on a high-speed photodetector, and the signal is amplified and digitized with a rate of 500 megasamples/s. To extract vibration information of different points, the carrier frequencies of each beam are elaborately designed so that they can be separated from cross-talk regions in the spectrum. The experimental results are compared with that from a commercial single-point vibrometer, and the comparison shows that it is possible to do a precise measurement on multiple points simultaneously using a single photodetector.

Expression analysis of Notch-related molecules in peripheral blood T helper cells of patients with rheumatoid arthritis

OBJECTIVE

Expression of Notch homologues in local tissue inflammation in rheumatoid arthritis (RA) and cultured synoviocytes has been reported, but the expression profile of Notch-related molecules in peripheral lymphocytes in RA remains unclear. In this study, we measured the expression of Notch receptors and downstream molecules in peripheral lymphocytes from RA patients.

METHODS

Expression of Notch receptors in peripheral lymphocytes of RA patients was assessed by both flow cytometry and real-time polymerase chain reaction (PCR). Expression of the representative Notch target gene HES-1 and the regulatory gene NUMB in purified T helper cells from RA patients was determined by real-time PCR, and expression of Notch intracellular domain (ICD) was determined by immunoblot analysis.

RESULTS

There was an increased expression of Notch 2, Notch 3, and Notch 4 in T helper cells from active RA patients, among which increased expression of Notch 3 was mainly by activated T cells. Notably, expression of Notch 3 in T cells decreased in inactive RA patients and the level was similar to that of healthy controls (HC). Notch receptors were rarely observed on B cells and no difference in expression was found between RA patients and HC. T helper cells from RA patients exhibited increased expression of the target gene HES-1 but decreased expression of the negative modulation gene NUMB of Notch signalling. There was also an increased nuclear translocation of Notch-ICD in T helper cells from active RA disease.

CONCLUSION

The present study demonstrated that T helper cells from RA patients display a significantly altered expression profile of Notch receptors and enhanced activation of Notch signalling compared with HC.

Exercise preconditioning reduces neuronal apoptosis in stroke by up-regulating heat shock protein-70 (heat shock protein-72) and extracellular-signal-regulated-kinase 1/2

Exercise preconditioning induces neuroprotection after stroke. We investigated the beneficial role of heat shock protein-70 (HSP-70) and phosphorylated extracellular-signal-regulated-kinase 1/2 (pERK 1/2), as they pertain to reducing apoptosis and their influence on Bcl-x(L), Bax, and apoptosis-inducing factor (AIF) in rats subjected to ischemia and reperfusion. Adult male Sprague-Dawley rats were subjected to 30 min of exercise on a treadmill for 1, 2, or 3 weeks. Stroke was induced by a 2-h middle cerebral artery (MCA) occlusion using an intraluminal filament. Protein levels of HSP-70, pERK 1/2, Bcl-x(L), Bax, and AIF were analyzed using Western blot. Neuroprotection was based on levels of apoptosis (TUNEL) and infarct volume (Nissl staining). Immunocytochemistry was used for cellular expression of HSP-70 and pERK 1/2. Significant (P<0.05) up-regulation of HSP-70 and pERK 1/2 after 3 weeks of exercise coincided with significant (P<0.05) reduction in neuronal apoptosis and brain infarct volume. Inhibition of either one of these two factors showed a significant (P<0.05) reversal in the neuroprotection. Bax and AIF were down-regulated, while levels of Bcl-x(L) were up-regulated in response to stroke after exercise. Inhibiting HSP-70 or pERK 1/2 reversed this resultant increase or decrease. Our results indicate that exercise diminishes neuronal injury in stroke by up-regulating HSP-70 and ERK 1/2.

Exploratory analysis describing ultrasonic (US) evaluation of spleen size during peripheral blood progenitor cell (PBPC) mobilization by filgrastim in normal donors

7102

Background: Filgrastim is used to mobilize CD34+ cells into the peripheral blood that are collected by apheresis for allogeneic transplantation. We prospectively evaluated spleen size during PBPC mobilization Methods: Donors ≥18 yrs eligible to be PBPC donors per institutional guidelines enrolled. Splenic assessments were done before, during, and after PBPC mobilization. Filgrastim dose and schedule and leukapheresis (LK) procedures were per local practice. Spleen size by US was measured in 3 dimensions: longitudinal (craniocaudal), transverse, and diagonal (perpendicular to transverse). Splenic volume was estimated by taking the cross-product of 3 dimensions and multiplying by 0.52, approximating an ellipse volume. Stiff (ASH 2007) reported the primary endpoint, fold change from baseline in splenic volume during mobilization. Exploratory analyses, including a linear regression evaluating the effect of age and baseline spleen size on fold-change, were performed. Results: 309 enrolled, median age 44yrs, 56% male. Median fold volume change from baseline to first LK was 1.47, resolving to near baseline 1 week after last LK. No significant clinical sequelae, including splenic rupture, were reported. Older donors appeared to have the smallest baseline spleen volume and the largest fold change (table). Linear regression analyses indicated age was a significant predictor for both baseline spleen volume (p=0.0031) and spleen volume fold change from baseline at first LK (p=0.0499). Conclusions: During mobilization, spleen volume transiently increased from baseline to day of 1st LK and returned to near baseline 1 week after last LK. Older donors tended to have smaller baseline splenic volume and greater fold changes in spleen size. Preclinical models suggest decreasing hematopoietic stem cell homing after mobilization with aging (Morrison 1996; Wagers 2002), which could result in splenic accumulation of progenitor and stem cells.

[Table: see text]

[Table: see text]

Efficient generation of multi-copy strains for optimizing secretory expression of porcine insulin precursor in yeast Pichia pastoris

AIMS

This study attempted to fully explore the expression potentials of Pichia pastoris for producing porcine insulin precursor (PIP) through PIP copy number optimization.

METHODS AND RESULTS

Multi-copy strains were screened employing a highly efficient improved in vivo method and their copy numbers were quantified by real-time qPCR. A range of Mut(+)P. pastoris strains harbouring 0, 1, 3, 6, 12, 18, 29, 52 copies of PIP were obtained. After 96 h methanol induction, a bell-shaped correlation curve was observed between gene dosage and protein yield, and the maximum PIP expression level of 181 mg l(-1) was achieved by a 12-copy strain. Specific growth rate and methanol utilization capacity were found to decrease remarkably for high copy strains (>12 copies). Transcriptional analysis of KAR2 suggested higher copy strains were suffering more from ER stress.

CONCLUSIONS

A copy number around 12 is optimal for secretory expression of PIP in P. pastoris. Excess PIP gene dosage (>12 copies) significantly impaired the growth of P. pastoris hosts.

SIGNIFICANCE AND IMPACT OF THE STUDY

The methods developed and the discoveries made by this systematical investigation will be helpful to the application and understanding of Pichia pastoris expression system for heterologous overexpression.

Pre-ischemic exercise reduces matrix metalloproteinase-9 expression and ameliorates blood-brain barrier dysfunction in stroke

Exercise reduces ischemia and reperfusion (I/R) injury in the rat stroke model. We investigated whether pre-ischemic exercise ameliorates blood-brain barrier (BBB) dysfunction in stroke by reducing matrix metalloproteinase (MMP)-9 expression and strengthening basal lamina. Adult male Sprague-Dawley rats were subjected to a 30 min exercise program on a treadmill 5 days a week for 3 weeks. Stroke was induced by a 2-h middle cerebral artery (MCA) occlusion using an intraluminal filament in the exercised and non-exercised groups. Brain infarction was measured and neurological deficits were scored. BBB dysfunction was determined by examining brain edema and Evans Blue extravasation. Expression of collagen IV, the major component of basal lamina essential for maintenance of the endothelial permeability barrier, was quantitatively detected by Western blot and immunocytochemistry. Ex vivo techniques were used to compare collagen IV-labeled vessels in response to ischemic insult. Temporal relationship of expression of MMP-9 and its endogenous inhibitor, the tissue inhibitors of metalloproteinase-1 (TIMP-1), was determined by real-time PCR for mRNA and Western blot for protein during reperfusion. Brain edema and Evans Blue leakage were both significantly (P<0.01) reduced after stroke in the exercised group, in association with reduced brain infarct volume and neurological deficits. Western blot analysis indicated that exercise enhanced collagen IV expression and reduced the collagen loss after stroke. Immunocytochemistry demonstrated that collagen IV-labeled vessels were significantly (P<0.01) increased in exercised rats. In the ex vivo study, after exercised brains were incubated with ischemic brain tissue, a significantly (P<0.01) higher level of collagen IV-labeled vessels was observed as compared with non-exercised brains following the same treatment. The ex vivo study also revealed a key role of MMP-9 in exercise-strengthened collagen IV expression against I/R injury. TIMP-1 protein levels were significantly (P<0.01) increased by exercise. Our results indicate that pre-ischemic exercise reduces brain injury by improving BBB function and enhancing basal lamina integrity in stroke. This study suggests that the neuroprotective effect of physical exercise is associated with an imbalance of MMP-9 and TIMP-1 expression.

Meniscus-climbing behavior and its minimum free-energy mechanism

Some insects can climb up the top of the meniscus surface generated by a hydrophilic wall by fixing their posture without moving their appendages [Baudoin, R. Bull. Biol. Fr. Belg. 1955, 89, 16. Hu, D. L.; Bush, J. W. M. Nature 2005, 437, 733]. To better understand this interesting phenomenon, we did meniscus-climbing experiments of bent copper sheets. It was found that the sheets do not always climb up the top of the meniscus surface but may stop and stably stay at various positions on the meniscus surface, depending upon their curvatures and masses, and that bent copper sheets can self-assemble into an oriented array (or an anisotropic form) through self-rotating on the water surface. The minimum energy mechanism of meniscus-climbing and self-rotating was then numerically studied. It was further shown that the meniscus-climbing and the rotating behavior is not only a general phenomenon for floating objects with hydrophilic surfaces, even those with fairly large sizes and weights (e.g., a metal bottle cap), but is also conditionally realizable for floating objects with hydrophobic surfaces.

Evolutionary tree reconstruction using structural expectation maximization and homotopy

The evolutionary tree reconstruction algorithm called SEMPHY using structural expectation maximization (SEM) is an efficient approach but has local optimality problem. To improve SEMPHY, a new algorithm named HSEMPHY based on the homotopy continuation principle is proposed in the present study for reconstructing evolutionary trees. The HSEMPHY algorithm computes the condition probability of hidden variables in the structural through maximum entropy principle. It can reduce the influence of the initial value of the final resolution by simulating the process of the homotopy principle and by introducing the homotopy parameter beta. HSEMPHY is tested on real datasets and simulated dataset to compare with SEMPHY and the two most popular reconstruction approaches PHYML and RAXML. Experimental results show that HSEMPHY is at least as good as PHYML and RAXML and is very robust to poor starting trees.

Hypoxia-mimetic agents desferrioxamine and cobalt chloride induce leukemic cell apoptosis through different hypoxia-inducible factor-1alpha independent mechanisms

Hypoxia presents pro-apoptotic and anti-apoptotic biphasic effects that appear to be dependent upon cell types and conditions around cells. The substantial reports demonstrated that commonly used hypoxia-mimetic agents cobalt chloride (CoCl(2)) and desferrioxamine (DFO) could also induce apoptosis in many different kinds of cells, but the mechanism was poorly understood. In this work, we compare the apoptosis-inducing effects of these two hypoxia-mimetic agents with acute myeloid leukemic cell lines NB4 and U937 as in vitro models. The results show that both of them induce these leukemic cells to undergo apoptosis with a loss of mitochondrial transmembrane potentials (DeltaPsi m), the activation of caspase-3/8 and the cleavage of anti-apoptotic protein Mcl-1, together with the accumulation of hypoxia-inducible factor-1 alpha (HIF-1alpha) protein, a critical regulator for the cellular response to hypoxia. Metavanadate and sodium nitroprusside significantly abrogate DFO rather than CoCl(2)-induced mitochondrial Delta Psi m collapse, caspase-3/8 activation, Mcl-1 cleavage and apoptosis, but they fail to influence DFO and CoCl(2)-induced HIF-1alpha protein accumulation. Moreover, inducible expression of HIF-1alpha gene dose not alter DFO and CoCl(2)-induced apoptosis in U937 cells. In conclusion, these results propose that although both DFO and CoCl(2)-induced leukemic cell apoptosis by mitochondrial pathway-dependent and HIF-1alpha-independent mechanisms, DFO and CoCl(2)-induced apoptosis involves different initiating signal pathways that remain to be investigated.

HbA(1c) as a screening tool for detection of Type 2 diabetes: a systematic review

AIM

To assess the validity of glycated haemoglobin A(1c) (HbA(1c)) as a screening tool for early detection of Type 2 diabetes.

METHODS

Systematic review of primary cross-sectional studies of the accuracy of HbA(1c) for the detection of Type 2 diabetes using the oral glucose tolerance test as the reference standard and fasting plasma glucose as a comparison. RESULTS Nine studies met the inclusion criteria. At certain cut-off points, HbA(1c) has slightly lower sensitivity than fasting plasma glucose (FPG) in detecting diabetes, but slightly higher specificity. For HbA(1c) at a Diabetes Control and Complications Trial and UK Prospective Diabetes Study comparable cut-off point of > or = 6.1%, the sensitivity ranged from 78 to 81% and specificity 79 to 84%. For FPG at a cut-off point of > or = 6.1 mmol/l, the sensitivity ranged from 48 to 64% and specificity from 94 to 98%. Both HbA(1c) and FPG have low sensitivity for the detection of impaired glucose tolerance (around 50%). CONCLUSIONS HbA(1c) and FPG are equally effective screening tools for the detection of Type 2 diabetes. The HbA(1c) cut-off point of > 6.1% was the recommended optimum cut-off point for HbA(1c) in most reviewed studies; however, there is an argument for population-specific cut-off points as optimum cut-offs vary by ethnic group, age, gender and population prevalence of diabetes. Previous studies have demonstrated that HbA(1c) has less intra-individual variation and better predicts both micro- and macrovascular complications. Although the current cost of HbA(1c) is higher than FPG, the additional benefits in predicting costly preventable clinical complications may make this a cost-effective choice.

A likelihood approach to estimating sensitivity and specificity for binocular data: application in ophthalmology

Binocular data typically arise in ophthalmology where pairs of eyes are evaluated, through some diagnostic procedure, for the presence of certain diseases or pathologies. Treating eyes as independent and adopting the usual approach in estimating the sensitivity and specificity of a diagnostic test ignores the correlation between eyes. This may consequently yield incorrect estimates, especially of the standard errors. The paper proposes a likelihood-based method of accounting for the correlations between eyes and estimating sensitivity and specificity using a model for binocular or paired binary outcomes. Estimation of model parameters via maximum likelihood is outlined and approximate tests are provided. The efficiency of the estimates is assessed in a simulation study. An extension of the methodology to the case of several diagnostic tests, or the same test measured on several occasions, which arises in multi-reader studies, is given. A further extension to the case of multiple diseases is outlined as well. Data from a study on diabetic retinopathy are analysed to illustrate the methodology.

Reproducibility of the Penn predictive score of tumor lysis syndrome (PPS-TLS) in acute myelogenous leukemia (AML)

6577

Background: In a previous retrospective study of 194 patients undergoing AML induction chemotherapy, we described a TLS predictive model entitled the Penn Predictive Score for Tumor Lysis Syndrome (PPS-TLS). TLS incidence was 9.8%. The PPS-TLS is defined as the sum of the scores for pre-induction lactate dehydrogenase (LDH), uric acid (UA), and gender (see table ). The area under the receiver operator characteristic (ROC) curve for this cohort was 89% (SD 4%). Methods: To validate the PPS-TLS, we retrospectively analyzed a second dataset of 166 AML patients undergoing induction chemotherapy from 2003–2006 at our institution. All patients received TLS prophylaxis. TLS was defined as (i) doubling of baseline serum creatinine (Cr) in association with elevated serum phosphate, UA, or potassium or (ii) elevations in 2 of the above electrolytes within 7 days of initiation of therapy. Potential TLS predictive factors were analyzed for statistical significance. Results: In this new dataset, TLS incidence is 9.6%. Significant in univariate analysis are male sex (OR=6.0, CI 1.31–27.15), Cr (OR=13.0, CI 2.88–58.23), UA (OR=48.6, CI 5.78–408.95), and LDH (OR=1.2, CI 1.03–1.48). In multivariate analysis, LDH (OR=1.3, CI 1.04–1.70) and Cr (OR=6.8, CI 1.48–30.89) remain significant. PPS-TLS scores were calculated and tested for their ability to predict TLS in this dataset. The area under the ROC curve for the PPS-TLS in this dataset was 75% (CI 61%-89%), indicating that the probability that a patient with TLS would have a higher PPS-TLS score than one without TLS is 75%. The current result is not statistically significantly different from the area under the ROC curve in the initial dataset (89%). Conclusions: The PPS-TLS is the first TLS predictive model in AML. The reproducibility of this model is supported by this study. A prospective multisite study is being designed to further validate this model. This analysis may lay the groundwork for the first evidence-based guidelines for TLS monitoring and management in AML.

[Table: see text]

No significant financial relationships to disclose.

Identification of mutations that disrupt phosphorylation-dependent nuclear export of cyclin D1

Although cyclin D1 is overexpressed in a significant number of human cancers, overexpression alone is insufficient to promote tumorigenesis. In vitro studies have revealed that inhibition of cyclin D1 nuclear export unmasks its neoplastic potential. Cyclin D1 nuclear export depends upon phosphorylation of a C-terminal residue, threonine 286, (Thr-286) which in turn promotes association with the nuclear exportin, CRM1. Mutation of Thr-286 to a non-phosphorylatable residue results in a constitutively nuclear cyclin D1 protein with significantly increased oncogenic potential. To determine whether cyclin D1 is subject to mutations that inhibit its nuclear export in human cancer, we have sequenced exon 5 of cyclin D1 in primary esophageal carcinoma samples and in cell lines derived from esophageal cancer. Our work reveals that cyclin D1 is subject to mutations in primary human cancer. The mutations identified specifically disrupt phosphorylation of cyclin D1 at Thr-286, thereby enforcing nuclear accumulation of cyclin D1. Through characterization of these mutants, we also define an acidic residue within the C-terminus of cyclin D1 that is necessary for recognition and phosphorylation of cyclin D1 by glycogen synthase kinase-3 beta. Finally, through construction of compound mutants, we demonstrate that cell transformation by the cancer-derived cyclin D1 alleles correlates with their ability to associate with and activate CDK4. Our data reveal that cyclin D1 is subject to mutations in primary human cancer that specifically disrupt phosphorylation-dependent nuclear export of cyclin D1 and suggest that such mutations contribute to the genesis and progression of neoplastic growth.