Plasma exosomes protect against cerebral ischemia/reperfusion injury via exosomal HSP70 mediated suppression of ROS

AIMS

Ischemic stroke is the leading cause of severe disability and death worldwide. As the pathogenesis of stroke has not been clearly elucidated and the ability of current therapeutic drugs on crossing the blood-brain barrier (BBB) is extremely low, there is no effective strategy to treat stroke. We aim at investigating the specific advantages of using plasma exosomes (Pla-Exo) for targeting ischemic brain and exploring its underlying mechanism in neuroprotection.

MAIN METHODS

Pla-Exo was obtained by a gradient ultracentrifugation of fresh plasma. The quantification of penetrated Pla-Exo through BBB was investigated in vitro BBB model, furthermore, the effects of Pla-Exo and exosomal HSP70 on cerebral ischemia/reperfusion injury were evaluated.

KEY FINDINGS

Pla-Exo enhanced BBB crossing by specific interaction between Pla-Exo inherited heat shock protein 70 (HSP70) and endothelial Toll-like receptor 4 (TLR4). As expected, Pla-Exo increased HSP70 expression in the ischemic region through the transfer of HSP70, and led to HSP70 mediated suppression of ROS, thus alleviating cerebral ischemia/reperfusion (I/R) injury by attenuating the deterioration of BBB and preventing mitochondria damage.

SIGNIFICANCE

These findings indicated that Pla-Exo can provide protection against ischemia-reperfusion injury via the regulation of HSP70 and it should be further studied as a potential candidate for protection against ischemic injury.

Association study of SNCA gene polymorphisms with schizophrenia in a Chinese North Han population

OBJECTIVE

Previous studies suggested that the alpha-synapse protein (SNCA) gene and its coding product α-synuclein (α-Syn) may play a role in the pathogenesis of neurodegenerative diseases. The mutation of SNCA can influence the formation of nerve fibers and the function of dopaminergic neurons, and that may be related to addictive behavior, such as alcohol dependence. SNCA may overlap with the pathogenesis of schizophrenia and Parkinson's disease or alcohol dependence associated with the dopamine pathway. The aim was to determine the association between three SNCA SNPs (rs3822086C/T, rs11931074G/T, and rs356219A/G) and schizophrenia in a Chinese North Han population.

PATIENTS AND METHODS

A total of 878 subjects, with or without schizophrenia, were included in our study. DNA purification, Polymerase Chain Reaction (PCR) amplification, and subsequent restriction fragment length polymorphism (RFLP) analysis were manipulated to determine genotypes.

RESULTS

Between the schizophrenia group and healthy group, neither the genotype nor allele frequencies of rs3822086C/T, rs11931074G/T, or rs356219A/G differed significantly in either the total sample or the subgroups. In the haplotype analysis, the ATT and GTT haplotype frequencies differed significantly between the patients and controls in the total sample (χ2=6.052, p=0.0139; χ2=4.508, p=0.0337). In the female subgroup, the ATT haplotype frequency differed significantly between the patients and controls (χ2=4.219, p=0.04).

CONCLUSIONS

There was no association between SNCA polymorphisms and schizophrenia in the North Han Chinese population, and the ATT haplotype may be a susceptibility factor for schizophrenia.

Characterization of lncRNA-Associated ceRNA Network to Reveal Potential Prognostic Biomarkers in Lung Adenocarcinoma

Lung adenocarcinoma (LUAD) is one of the most fatal malignant tumors harmful to human health. The complexity and behavior characteristics of long-non-coding RNA (lncRNA)-associated competing endogenous RNA (ceRNA) network in LUAD patients are still unclear. The purpose of this study was to elucidate the regulatory networks of dysregulated RNAs, view, and identify potential prognosis signatures involved in LUAD. The expression profiles of mRNAs, lncRNAs, and miRNAs were obtained from the TCGA database. In total, 2078 DEmRNAs, 257 DElncRNAs, and 101 DEmiRNAs were sorted out. A PPI network including 45 DEmRNAs was constructed. Ten hub genes in the PPI network associated with cell cycle-related pathways were identified and they played key roles in regulating cell proliferation. A total of three DEmiRNAs, seven DElncRNAs, and six DEmRNAs were enrolled in the ceRNA network. Except for certain genes without any published study reports, all the genes in the ceRNA network played an essential role in controlling tumor cell proliferation and were associated with prognosis in LUAD. Finally, based on step regression and Cox regression survival analysis, we identified four candidate biomarkers, including miR490, miR1293, LINC01740, and IGF2BP1, and established a risk model based on the four genes. Our study provided a global view and systematic dissection of the lncRNA-associated ceRNA network, and the identified four genes might be novel important prognostic factors involved in LUAD pathogenesis.

Brassinosteroids are involved in ethylene-induced Pst DC3000 resistance in Nicotiana benthamiana

Plant immunity is regulated by a huge phytohormone regulation network. Ethylene(ET) and brassinosteroids (BRs) play critical roles in plant response to biotic stress; however, the relationship between BR and ET in plant immunity is unclear. We used chemical treatments, genetic approaches and inoculation experiments to investigate the relationship between ET and BR in plant defense against Pst DC3000 in Nicotiana benthamiana. Foliar applications of ET and BR enhanced plant resistance to Pst DC3000 inoculation, while treatment with brassinazole (BRZ, a specific BR biosynthesis inhibitor) eliminated the ET induced plant resistance to Pst DC3000. Silencing of DWARF 4(DWF4, a key BR biosynthetic gene), BRASSINOSTEROID INSENSITIVE 1 (BRI1, aBR receptor) and BRASSINOSTEROID-SIGNALING KINASE 1 (BSK1, downstream of BRI1) also neutralised the ET-induced plant resistance to Pst DC3000. ET can induce callose deposition and reactive oxygen species (ROS) accumulation to resistPst DC3000, BRZ-treated and gene-silenced were completely eliminate this response. Our results suggest BR is involved in ET-induced plant resistance, the involvement of ET in plant resistance is possibly by the induction of callose deposition and ROS accumulation, in a BR-dependent manner.

LncRNA LINC00628 overexpression inhibits the growth and invasion through regulating PI3K/Akt signaling pathway in osteosarcoma

OBJECTIVE

Osteosarcoma (OS) is the most common primary malignancy, mainly arising from the metaphysic of the long bones of adolescents and young adults. Although osteosarcoma has been studied widely, the underlying molecular mechanism remains unclear. Increasing evidence shows that abnormal long non-coding RNAs (LncRNAs) expression is involved in tumorigenesis. The aim of this study was to identify the detailed role of LncRNA LINC00628 in osteosarcoma.

MATERIALS AND METHODS

The relative mRNA expression level of LINC00628 in adjacent tissues, osteosarcoma tissues with or without metastasis and osteosarcoma cell lines were detected by qRT-PCR. Overall survival curves for two groups defined by high and low expression level of LINC00628 in osteosarcoma patients. The cell proliferation, invasion and migration in osteosarcoma cells after transfection with lncRNA- NC or lncRNA-LINC00628 were detected. The cell cycle distribution and apoptosis rate in osteosarcoma cells after transfection with lncRNA- NC or lncRNA-LINC00628 were measured using the Flow cytometry analysis. The relative protein expression level of p-PI3K, p-Akt, P53 and Bcl-2 in osteosarcoma cells after transfection with lncRNA- NC or lncRNA-LINC00628 were detected by Western blot.

RESULTS

LINC00628 expression was significantly decreased in osteosarcoma tissues compared with adjacent tissues. Meanwhile, osteosarcoma tissues with metastasis were significantly associated with a low expression level of LINC00628 and the low expression level of LINC00628 has a lower overall survival rate. LINC00628 expression was increased in osteosarcoma cell lines after transfection with lncRNA-LINC00628 and the cell proliferation, invasion and migration in osteosarcoma cells after transfection with lncRNA-LINC00628 were significantly inhibited. Moreover, the cell cycle was arrested in G0/G1 phase and the apoptosis rate was increased in osteosarcoma cells after transfection with lncRNA-LINC00628. Mechanistically, the relative protein expression level of p-PI3K, p-Akt and Bcl-2 were significantly increased and the relative expression of P53 was significantly decreased in osteosarcoma cells after transfection with lncRNA-LINC00628.

CONCLUSIONS

LINC00628 expression was decreased in osteosarcoma. The overexpression of LINC00628 inhibited the proliferation, invasion and migration and promoted cell apoptosis in osteosarcoma cells through the inactivation of PI3K/Akt signaling pathway. This lncRNA may be involved in the development and progression of osteosarcoma.

Pyrococcus furiosus Argonaute-mediated nucleic acid detection

We demonstrate that short single-stranded DNA generated by Pyrococcus furiosus Argonaute (PfAgo) can initiate a second round of cleavage. Based on this principle, we established a molecular diagnostic method, termed PfAgo-mediated Nucleic acid Detection (PAND). This method could detect DNA at attomolar sensitivities, distinguish single-nucleotide mutants and accomplish multiplexed detection.

Considerations for Clinical Review of Cellular Therapy Products: Perspectives of the China Food and Drug Administration Center for Drug Evaluation

With increasing numbers of technical developments and clinical studies, pioneering cellular/gene therapies are now available that could cure life-threatening disease. Cellular/gene therapy products are broad-ranging and complicated, and thereby bring challenges for clinical review by regulatory agencies. This review discusses principles for the clinical review of cellular therapy products, including protection of clinical trial populations, pharmacodynamics, pharmacokinetics, dose evaluation, clinical efficacy, clinical safety, and risk-management plans. Based on these principles, key points in the clinical review of chimeric antigen receptor T-cell therapy are also discussed.

Exosomes from LPS-stimulated macrophages induce neuroprotection and functional improvement after ischemic stroke by modulating microglial polarization

Inflammation occurs throughout the progression of cerebral ischemia/reperfusion and mediates myriads of pathological events following an ischemic insult.

Rapid and Error-Free Site-Directed Mutagenesis by a PCR-Free In Vitro CRISPR/Cas9-Mediated Mutagenic System

The quality and efficiency of any PCR-based mutagenesis technique may not be optimal due to, among other things, amino acid bias, which means that the development of efficient PCR-free methods is desirable. Here, we present a highly efficient in vitro CRISPR/Cas9-mediated mutagenic (ICM) system that allows rapid construction of designed mutants in a PCR-free manner. First, it involves plasmid digestion by utilizing a complex of Cas9 with specific single guide RNA (sgRNA) followed by degradation with T5 exonuclease to generate a 15 nt homologous region. Second, primers containing the desired mutations are annealed to form the double-stranded DNA fragments, which are then ligated into the linearized plasmid. In theory, neither the size of the target plasmid nor the unavailable restriction enzyme site poses any problems that may arise in traditional techniques. In this study, single and multiple site-directed mutagenesis were successfully performed even for a large size plasmid (up to 9.0 kb). Moreover, a PCR-free site-saturation mutagenesis library on single site and two adjacent sites of a green fluorescent protein was also generated with promising results. This demonstrates the great potential of the ICM system for creating high-quality mutant libraries in directed evolution as an alternative to PCR-based saturation mutagenesis, thus facilitating research on synthetic biology.

IL-37 inhibits IL-4/IL-13-induced CCL11 production and lung eosinophilia in murine allergic asthma

BACKGROUND

IL-37 is emerging as an anti-inflammatory cytokine, particularly in innate inflammation. However, the role of IL-37 in Th2-mediated allergic lung inflammation remains uncertain. We sought to determine the role and the underlying mechanisms of IL-37 in the development of house dust mites (HDM)-induced murine asthma model.

METHODS

We examined the effect of IL-37 administration during the sensitization or challenge phase on Th2-mediated allergic asthma induced by inhaled HDM. Cellular source of CCL11 and distribution of IL-37 receptors, IL-18Rα and IL-1R8, were determined in HDM-exposed lungs. Finally, we examined the effect of IL-37 on CCL11 production and STAT6 activation in different primary lung structural cell types upon IL-4/IL-13 stimulation.

RESULTS

IL-37 had no effect on HDM sensitization, but when administrated during the challenge phase, significantly attenuated pulmonary eosinophilia, CCL11 production, and airway hyper-reactivity (AHR). Interestingly, IL-37 treatment had no significant effects on lung infiltrating T cells and Th2 cytokine production. Intranasal co-administration of CCL11 reversed the inhibiting effect of IL-37 on HDM-induced pulmonary eosinophilia and AHR. Furthermore, we demonstrated that CCL11 was primarily expressed by fibroblasts and airway smooth muscle cells (AMSC), while IL-37 receptors by tracheobronchial epithelial cells (TEC). In vitro study showed that IL-37 inhibited IL-4/IL-13-induced STAT6 activation and CCL11 production by fibroblasts and AMSC, which was dependent on its direct action on TEC. Moreover, cell contact was required for the inhibitory effect of IL-37-treated TEC.

CONCLUSIONS

IL-37 attenuates HDM-induced asthma, possibly by inhibiting IL-4/IL-13-induced CCL11 production by fibroblasts and AMSC via its direct act on TEC.

Synthesizing value-added products from methane by a new Methylomonas

AIMS

Methane and methanol are potential carbon sources of industrial micro-organisms in addition to crop-derived bio-carbon sources. Methanotrophs that can utilize these simple, stable and large amounts chemicals are expected to be developed into 'cell factories' for the production of specific chemicals. In this study, a methanotroph that can synthesize lycopene, C₃₀ carotenoid and exopolysaccharides (EPS) with relative better performances from C1 substrates was isolated, and its performances were evaluated.

METHODS AND RESULTS

The isolated strain was identified as Methylomonas sp. ZR1 based on 16S rRNA sequence analysis. Its maximum specific growth rate achieved 0·200 h^-1 under flask culture conditions, and 0·386 h^-1 in bubble column reactors. ZR1 was able to utilize 35 g l^-1 of methanol and even exhibited slight growth in the presence of 40 g l^-1 of methanol. Furthermore, ZR1 was proved to synthesize lycopene (C₄₀ carotenoids) besides the C₃₀ carotenoids through HPLC-DAD and HPLC-MS/MS analysis methods. Its carotenoid extracts exhibited excellent antioxidative activities measured by the ABTS⁺ method. Plenty of polysaccharides were also synthesized by ZR1, the components of the polysaccharides were identified as glucose, mannose and galactose with a proportion of 1 : 2 : 1 by GC-MS, and its yield achieved 0·13 g g^-1 cell dry weight.

CONCLUSIONS

The isolated strain has great potential for the production of value-added bioproducts from C1 compounds because of its excellent C1 substrate utilizing abilities and its abilities to naturally synthesize lycopene, C₃₀ carotenoids and EPS.

SIGNIFICANCE AND IMPACT OF THE STUDY

In this study, we isolated a fast-growing methanotroph, its C1 carbon substrate utilizing ability is excellent in comparison with reported methanotrophs. Furthermore, besides polysaccharides and C₃₀ carotenoids which were commonly synthesized by methanotrophs, our findings suggested that C₄₀ lycopene could also be naturally synthesized from methane by methanotrophs.

Effects of heparin catheter-sealing solution for implantable venous access ports on D-dimer levels in older cancer patients

OBJECTIVE

To investigate the effects of different concentrations of heparin catheter-sealing solution for implantable venous access ports (VAPs) on D-dimers (D-D) in older cancer patients.

PATIENTS AND METHODS

A total of 208 older cancer patients who received intravenous chemotherapy for the first time were randomly divided into four groups: the normal saline group, the low concentration heparin group (25 U/ml), the medium concentration heparin group (50 U/ml), and the high concentration heparin group (75 U/ml), with 52 patients in each group. VAPs were sealed by the positive pressure technique every day before and after perfusion, as well as at the end of a course of chemotherapy when the butterfly needle was removed. The patients were followed-up for three courses of chemotherapy, and comparisons of the clinical effects were conducted.

RESULTS

Before treatment and at the end of follow-up, no significant differences among groups were found in platelet count, prothrombin time, thrombin time, or activated partial thromboplastin time (p>0.05). At the end of follow-up, the high concentration heparin group had reduced fibrinogen (FIB) and increased D-D compared with the other groups, and the differences were statistically significant (p<0.05). The other three groups showed no significant differences in FIB or D-D before treatment or at the end of follow-up (p>0.05). The high concentration heparin group had higher local bleeding rate, while the saline group had higher partial and complete prevalence of blockage compared with the other groups. The differences were statistically significant (p<0.05).

CONCLUSIONS

25-50 U/ml heparin catheter-sealing solution had little effect on blood circulation and coagulation. Additionally, it did not increase the risk of local bleeding or thrombotic blockage.

Negative pressure wound therapy inhibits inflammation and upregulates activating transcription factor-3 and downregulates nuclear factor-κB in diabetic patients with foot ulcerations

BACKGROUND

Negative pressure wound therapy (NPWT) is one of the most important treatments for diabetic foot, but the underlying mechanisms of its benefits still remain elusive. This study aims to evaluate the inflammatory signals involved in the effects of negative pressure therapy on diabetic foot ulcers.

METHODS

We enrolled 22 patients with diabetic foot ulceration, 11 treated with NPWT and the other 11 treated with traditional debridement. All patients were treated and observed for 1 week. Granulation tissues were harvested and analyzed in both groups, and then were histologically and immunohistochemically analyzed. Enzyme-linked immunosorbent assay, Western blot analysis, and real-time PCR were performed to evaluate the expression of interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), inducible nitric oxide synthase (iNOS), nuclear factor-κB (NF-κB) p65, I_k B-α, and activating transcription factor-3 (ATF-3).

RESULTS

After 7 days of treatment, NPWT could obviously promote diabetic wound healing because of the mild inflammation and the dense cell-deposited matrix. Meanwhile, NPWT significantly decreased the expression of TNF-α, IL-6, and iNOS (all P < .05). The result of Western blotting and real-time PCR indicated that NPWT obviously decreased the level of I_k B-α and NF-κB p65, and increased the level of ATF-3 (all P < .05).

CONCLUSION

NPWT exerts an anti-inflammatory effect, possibly through the suppression of proinflammatory enzymes and cytokines resulting from I_k B-α inhibition and ATF-3 activation, which may prevent the activation of the NF-κB pathway in human diabetic foot wounds.

Incorporating 131I into a PAMAM (G5.0) dendrimer-conjugate: design of a theranostic nanosensor for medullary thyroid carcinoma

We report the synthesis and purification of a targeting probe for Medullary Thyroid Carcinoma (MTC) by incorporating ¹³¹I into PAMAM (G5.0) dendrimers.

[Current status of antiarrhythmic drug use and safety assessment in Chinese patients with atrial fibrillation]

Objective: To investigate the current status of antiarrhythmic drugs (AADs) use in Chinese patients with atrial fibrillation(AF) and assess the safety of AADs in this patient cohort. Methods: From January 2011 to December 2013, a total of 4 008 AF patients treated with AADs was enrolled in this study and patients were followed up for 24 months. Detailed information of prescribed drug, the causes of drug discontinuation and side effects were recorded. Results: Amiodarone was prescribed to 64.3%(2 579 cases) and propafenone to 31.1%(1 247 cases) of the enrolled patients, only 148 patients(3.7%) were treated with sotalol and 34 patients (0.8%) were treated with moracizine. The prevalence of heart failure (4.0%(102/2 579) vs. 1.4%(17/1 247, P<0.001), coronary heart disease (13.5% (348/2 579) vs. 7.4%(93/1 247), P<0.001) and non-ischemic cardiomyopathy (3.1%(78/2 579) vs. 0.7%(9/1 247), P<0.001) was significantly higher in patients treated with amiodarone than in the patients treated with propafenone. During the follow-up period, the discontinuation rate of amiodarone, propafenone, sotalol and moracizine was 28.8%(743/2 579), 25.1%(313/1 247), 14.2%(21/148) and 32.4%(11/34) respectively. The reasons of discontinuing amiodarone were: follow physicians' decision (75.7%, 563 cases), no effect (3.0%, 22 cases), side effects (4.3%, 32 cases) and patients' own decision (17.0%, 126 cases). The side effects of amiodarone included thyroid dysfunction (56.3%, 18 cases), bradycardia (12.5%, 4 cases), interstitial pneumonitis/pulmonary interstitial fibrosis (6.2%, 2 cases) and others (gastrointestinal symptom, rash, hepatic dysfunction, etc.). Conclusions: Amiodarone and propafenone are the most common AADs used in Chinese patients with atrial fibrillation. The prescription of AADs is essentially in accordance to the guideline of AF treatment. However, the discontinuation rates of AADs are high in Chinese AF patients. Lacking of better AADs is still a major problem in AF pharmacotherapy. Clinical Trial Registry Chinese Clinical Trial Registry, ChiCTR-OCH-13003729.

Genetic diversity and variability in populations of the white wax insect Ericerus pela, assessed by AFLP analysis

The white wax insect Ericerus pela Chavannes (Hemiptera: Coccoidea) is an economically valuable insect species that has been used for over a thousand years in China. The present study focuses on assessing the genetic variability in different populations of E. pela collected from seven Chinese provinces. The amplified fragment length polymorphism technique was used to generate DNA fingerprints of individuals from each population using nine primer combinations (EcoRI-MseI). A total of 435 polymorphic loci were generated; fragment sizes ranged from 200 to 1000 bp. The percentage of polymorphic loci was 85.29%. Nei's genetic diversity and Shannon index indicated consistency in the results, which showed that the Sichuan population had the highest diversity, followed by Yunnan and Zhejiang populations. Dendrogram analysis showed the shortest genetic distance between the Sichuan and Yunnan populations, suggesting that they probably form sister groups. High genetic differentiation between population values among all sampled populations indicated a low degree of genetic variability within each population (40.85%) and higher variation among populations (59.15%). Gene flow estimate values were low in all samples, suggesting low gene flow from events such as interbreeding and migration. Low gene flow values also suggested that populations among species of E. pela might become genetically heterogeneous, due to counteracting forces such as strong differential selection. Our data support the probability that E. pela will remain localized, and has a low potential to spread beyond current habitats.

Comparison of Axxent-Xoft, (192)Ir and (60)Co high-dose-rate brachytherapy sources for image-guided brachytherapy treatment planning for cervical cancer

OBJECTIVE

To evaluate the dosimetric differences and similarities between treatment plans generated with Axxent-Xoft electronic brachytherapy source (Xoft-EBS), (192)Ir and (60)Co for tandem and ovoids (T&O) applicators.

METHODS

In this retrospective study, we replanned 10 patients previously treated with (192)Ir high-dose-rate brachytherapy. Prescription was 7 Gy × 4 fractions to Point A. For each original plan, we created two additional plans with Xoft-EBS and (60)Co. The dose to each organ at risk (OAR) was evaluated in terms of V(35%) and V(50%), the percentage volume receiving 35% and 50% of the prescription dose, respectively, and D(2cc), highest dose to a 2 cm(3) volume of an OAR.

RESULTS

There was no difference between plans generated by (192)Ir and (60)Co, but the plans generated using Xoft-EBS showed a reduction of up to 50% in V(35%), V(50%) and D(2cc). The volumes of the 200% and 150% isodose lines, however, were 74% and 34% greater than the comparable volumes generated with the (192)Ir source. Point B dose was on average only 16% of the Point A dose for plans generated with Xoft-EBS compared with 30% for plans generated with (192)Ir or (60)Co.

CONCLUSION

The Xoft-EBS can potentially replace either (192)Ir or (60)Co in T&O treatments. Xoft-EBS offers either better sparing of the OARs compared with (192)Ir or (60)Co or at least similar sparing. Xoft-EBS-generated plans had higher doses within the target volume than (192)Ir- or (60)Co-generated ones.

ADVANCES IN KNOWLEDGE

This work presents newer knowledge in dosimetric comparison between Xoft-EBS, (192)Ir or (60)Co sources for T&O implants.

Vitamin D deficiency increases the risk of retinopathy in Chinese patients with type 2 diabetes

AIMS

To investigate the relationship between vitamin D deficiency and diabetic retinopathy.

METHODS

In total, 1520 patients with Type 2 diabetes were recruited and divided into three groups according to their fundus oculi results: no diabetic retinopathy (n = 625, 41.12%); non-sight-threatening diabetic retinopathy (n = 562, 36.97%); and sight-threatening diabetic retinopathy (n = 333, 21.91%). Vitamin D deficiency was defined as a serum circulating 25-hydroxyvitamin D level < 20 ng/ml. Clinical characteristics and biochemical parameters were detected and compared.

RESULTS

The patients with sight-threatening diabetic retinopathy had significantly lower serum 25-hydroxyvitamin D concentrations and higher prevalence of vitamin D deficiency than other two groups (all P < 0.05). In addition, there was a downward trend in average 25-hydroxyvitamin D level with the increased stages of diabetic retinopathy (P < 0.01). The prevalence of diabetic retinopathy and sight-threatening diabetic retinopathy in patients with vitamin D deficiency was also higher than in those without vitamin D deficiency (both P < 0.01). After adjusting for all potential confounders, vitamin D deficiency was still associated with increased risk of diabetic retinopathy (odds ratio 1.93) and sight-threatening diabetic retinopathy (odds ratio 2.42) (both P < 0.01). Logistical regression analysis further revealed that vitamin D deficiency was an independent risk factor for diabetic retinopathy (β = 0.66) and sight-threatening diabetic retinopathy (β = 0.93) (both P < 0.01). ROC analysis indicated that a serum 25-hydroxyvitamin D level < 15.57 ng/ml suggested the occurrence of sight-threatening diabetic retinopathy (odds ratio 2.38, P < 0.01).

CONCLUSIONS

Vitamin D deficiency is an independent risk factor for diabetic retinopathy and sight-threatening diabetic retinopathy. The prevalence of sight-threatening diabetic retinopathy doubles when the serum 25-hydroxyvitamin D level is < 15.57 ng/ml.

Morphometry-based measurements of the structural response to whole-brain radiation

PURPOSE

Morphometry techniques were applied to quantify the normal tissue therapy response in patients receiving whole-brain radiation for intracranial malignancies.

METHODS

Pre- and Post-irradiation magnetic resonance imaging (MRI) data sets were retrospectively analyzed in N = 15 patients. Volume changes with respect to pre-irradiation were quantitatively measured in the cerebrum and ventricles. Measurements were correlated with the time interval from irradiation. Criteria for inclusion included craniospinal irradiation, pre-irradiation MRI, at least one follow-up MRI, and no disease progression. The brain on each image was segmented to remove the skull and registered to the initial pre-treatment scan. Average volume changes were measured using morphometry analysis of the deformation Jacobian and direct template registration-based segmentation of brain structures.

RESULTS

An average cerebral volume atrophy of -0.2 and -3% 3% was measured for the deformation morphometry and direct segmentation methods, respectively. An average ventricle volume dilation of 21 and 20% was measured for the deformation morphometry and direct segmentation methods, respectively.

CONCLUSION

The presented study has developed an image processing pipeline for morphometric monitoring of brain tissue volume changes as a response to radiation therapy. Results indicate that quantitative morphometric monitoring is feasible and may provide additional information in assessing response.

Chemerin suppresses murine allergic asthma by inhibiting CCL2 production and subsequent airway recruitment of inflammatory dendritic cells

BACKGROUND

Chemerin has been implicated to play opposing roles, either pro-inflammatory or anti-inflammatory, in various tissue inflammation processes primarily through the regulation of tissue recruitment of immune cells. However, the effect of chemerin in allergic asthma has not yet been explored. We sought to investigate the role of chemerin in the murine model of allergic asthma and explore the underlying mechanism.

METHODS

We examined the effect of intranasal (i.n.) administration of chemerin during antigen challenge in murine models of asthma. Moreover, we examined whether administration of CCL2 or bone marrow-derived dendritic cells (BMDCs) transfer reversed the effects of chemerin on ovalbumin-induced asthma. We finally examined the effect of chemerin on CCL2 expression in activated lung epithelial cells in vitro.

RESULTS

The administration of chemerin attenuated allergic airway inflammation and airway hyperreactivity during antigen challenge. Chemerin treatment caused significant decreases in BALF CD4(+) T-cell accumulation and mRNA expression of Th2-attracting chemokines, CCL17 and CCL22, which was accompanied by significantly decreased BALF CD11c(+) CD11b(+) inflammatory DC accumulation and CCL2 production. Furthermore, airway administration of exogenous CCL2 or adoptive transfer of CD11c(+) CD11b(+) BMDCs abrogated the suppressive effects of chemerin on allergic asthma. Finally, in vitro study showed that chemerin inhibited CCL2 secretion by low-dose LPS-stimulated lung epithelial cells, which led to decreased chemotaxis of BMDCs.

CONCLUSIONS

Our study demonstrates that chemerin plays a protective role in allergic asthma by suppressing airway recruitment of inflammatory CD11c(+) CD11b(+) DCs through the inhibition of CCL2 secretion by active lung epithelial cells.

A red tide of Alexandrium fundyense in the Gulf of Maine

In early July 2009, an unusually high concentration of the toxic dinoflagellate Alexandrium fundyense occurred in the western Gulf of Maine, causing surface waters to appear reddish brown to the human eye. The discolored water appeared to be the southern terminus of a large-scale event that caused shellfish toxicity along the entire coast of Maine to the Canadian border. Rapid-response shipboard sampling efforts together with satellite data suggest the water discoloration in the western Gulf of Maine was a highly ephemeral feature of less than two weeks in duration. Flow cytometric analysis of surface samples from the red water indicated the population was undergoing sexual reproduction. Cyst fluxes downstream of the discolored water were the highest ever measured in the Gulf of Maine, and a large deposit of new cysts was observed that fall. Although the mechanisms causing this event remain unknown, its timing coincided with an anomalous period of downwelling-favorable winds that could have played a role in aggregating upward-swimming cells. Regardless of the underlying causes, this event highlights the importance of short-term episodic phenomena on regional population dynamics of A. fundyense.

A red tide of Alexandrium fundyense in the Gulf of Maine

In early July 2009, an unusually high concentration of the toxic dinoflagellate Alexandrium fundyense occurred in the western Gulf of Maine, causing surface waters to appear reddish brown to the human eye. The discolored water appeared to be the southern terminus of a large-scale event that caused shellfish toxicity along the entire coast of Maine to the Canadian border. Rapid-response shipboard sampling efforts together with satellite data suggest the water discoloration in the western Gulf of Maine was a highly ephemeral feature of less than two weeks in duration. Flow cytometric analysis of surface samples from the red water indicated the population was undergoing sexual reproduction. Cyst fluxes downstream of the discolored water were the highest ever measured in the Gulf of Maine, and a large deposit of new cysts was observed that fall. Although the mechanisms causing this event remain unknown, its timing coincided with an anomalous period of downwelling-favorable winds that could have played a role in aggregating upward-swimming cells. Regardless of the underlying causes, this event highlights the importance of short-term episodic phenomena on regional population dynamics of A. fundyense.

Perfusion deficits detected by arterial spin-labeling in patients with TIA with negative diffusion and vascular imaging

BACKGROUND AND PURPOSE

A substantial portion of clinically diagnosed TIA cases is imaging-negative. The purpose of the current study is to determine if arterial spin-labeling is helpful in detecting perfusion abnormalities in patients presenting clinically with TIA.

MATERIALS AND METHODS

Pseudocontinuous arterial spin-labeling with 3D background-suppressed gradient and spin-echo was acquired on 49 patients suspected of TIA within 24 hours of symptom onset. All patients were free of stroke history and had no lesion-specific findings on general MR, DWI, and MRA sequences. The calculated arterial spin-labeling CBF maps were scored from 1-3 on the basis of presence and severity of perfusion disturbance by 3 independent observers blinded to patient history. An age-matched cohort of 36 patients diagnosed with no cerebrovascular events was evaluated as a control. Interobserver agreement was assessed by use of the Kendall concordance test.

RESULTS

Scoring of perfusion abnormalities on arterial spin-labeling scans of the TIA cohort was highly concordant among the 3 observers (W = 0.812). The sensitivity and specificity of arterial spin-labeling in the diagnosis of perfusion abnormalities in TIA was 55.8% and 90.7%, respectively. In 93.3% (70/75) of the arterial spin-labeling CBF map readings with positive scores (≥2), the brain regions where perfusion abnormalities were identified by 3 observers matched with the neurologic deficits at TIA onset.

CONCLUSIONS

In this preliminary study, arterial spin-labeling showed promise in the detection of perfusion abnormalities that correlated with clinically diagnosed TIA in patients with otherwise normal neuroimaging results.