Elevated Levels of Interferon-γ Production by Memory T Cells Do Not Promote Transplant Tolerance Resistance in Aged Recipients

Immunosenescence predisposes the elderly to infectious and autoimmune diseases and impairs the response to vaccination. We recently demonstrated that ageing also impedes development of transplantation tolerance. Unlike their young counterparts (8-12 weeks of age) aged male recipients (greater than 12 months of age) transplanted with a full MHC-mismatched heart are resistant to tolerance mediated by anti-CD45RB antibody. Surprisingly, either chemical or surgical castration restored tolerance induction to levels observed using young recipients. Based on the strong impact of endocrine modulation on transplant tolerance, we explored the impact of ageing and castration on the immune system. Here we report a significant increase in the percentage of T cells that produce interferon-γ (IFN-γ) in aged male versus young male animals and that the overall increase in IFN-γ production was due to an expansion of IFN-γ-producing memory T cells in aged animals. In contrast to IFN-γ production, we did not observe differences in IL-10 expression in young versus old male mice. We hypothesized that endocrine modulation would diminish the elevated levels of IFN-γ production in aged recipients, however, we observed no significant reduction in the percentage of IFN-γ+ T cells upon castration. Furthermore, we neutralized interferon-γ by antibody and did not observe an effect on graft survival. We conclude that while elevated levels of interferon-γ serves as a marker of tolerance resistance in aged mice, other as yet to be identified factors are responsible for its cause. Defining these factors may be relevant to design of tolerogenic strategies for aged recipients

Functional roles of two novel P450 genes in the adaptability of Conogethes punctiferalis to three commonly used pesticides

Introduction: Insect cytochrome P450 (CYP450) genes play important roles in the detoxification and metabolism of xenobiotics, such as plant allelochemicals, mycotoxins and pesticides. The polyphagous Conogethes punctiferalis is a serious economic pest of fruit trees and agricultural crops, and it shows high adaptability to different living environments.Methods: The two novel P450 genes CYP6CV1 and CYP6AB51 were identified and characterized. Quantitative real-time PCR (qRT-PCR) technology was used to study the expression patterns of the two target genes in different larval developmental stages and tissues of C. punctiferalis. Furthermore, RNA interference (RNAi) technology was used to study the potential functions of the two P450 genes by treating RNAi-silenced larvae with three commonly used pesticides.Results: The CYP6CV1 and CYP6AB51 genes were expressed throughout various C. punctiferalis larval stages and in different tissues. Their expression levels increased along with larval development, and expression levels of the two target genes in the midgut were significantly higher than in other tissues. The toxicity bioassay results showed that the LC50 values of chlorantraniliprole, emamectin benzoate and lambda-cyhalothrin on C. punctiferalis larvae were 0.2028 μg/g, 0.0683 μg/g and 0.6110 mg/L, respectively. After treating with different concentrations of chlorantraniliprole, emamectin benzoate and lambda-cyhalothrin (LC10, LC30, LC50), independently, the relative expressions of the two genes CYP6CV1 and CYP6AB51 were significantly induced. After the dsRNA injection, the expression profiles of the two CYP genes were reduced 72.91% and 70.94%, respectively, and the mortality rates of the larvae significantly increased when treated with the three insecticides independently at LC10 values.Discussion: In the summary, after interfering with the CYP6CV1 and CYP6AB51 in C. punctiferalis, respectively, the sensitivity of C. punctiferalis to chlorantraniliprole, emamectin benzoate and lambda-cyhalothrin was significantly increased, indicating that the two CYP6 genes were responsible for the adaptability of C. punctiferalis to the three chemical insecticides in C. punctiferalis. The results from this study demonstrated that CYP6CV1 and CYP6AB51 in C. punctiferalis play crucial roles in the detoxification of chlorantraniliprole, emamectin benzoate and lambda-cyhalothrin

Testicular Characteristics and the Block to Spermatogenesis in Mature Hinny

Most hinnies (female donkey×male horse) and mules (female horse×male donkey) are sterile with few reports of equine fertile hybrids. The main cause of this sterility is thought to be a meiotic block to spermatogenesis and oogenesis. This study compared the developmental features of the testes and a histological analyses of spermatogenesis in a male hinny with those of a normal, fertile stallion and Jack donkey. Hinny testes showed a thicker tunica albuginea, fewer blood vessels and more connective tissue in the testis parenchyma than those of the stallion and Jack donkey. Although the mean number of seminiferous tubules was significantly higher in stallion and hinny than Jack donkey (p<0.01), the mean proportion of seminiferous tubules was lower in the hinny (p<0.01) which resulted in a smaller diameter of seminiferous tubules. The mean number of spermatogonia and spermatocytes per unit area were significantly lower in hinny testis (p<0.01) and no spermatids or mature spermatozoa cells were found during immunofluorescent analyses. These results indicated that defects in seminiferous tubule development and structure occur in the testis of hinnies. Furthermore, most spermatogonia and spermatocytes cease development in synapsis during mid-meiosis of spermatocytes, which results in a block to spermatogenesis that prevents the formation of spermatids and matured spermatozoa during meiosis in male hinnies

Effect of Unit Cell Shape on Switchable Infrared Metamaterial VO2 Absorbers/Emitters

Metamaterial absorber/emitter is an important aspect of infrared radiation manipulation. In this paper, we proposed four simple switchable infrared metamaterial absorbers/emitters with Ag/VO2 disks on the Ag plane employing triangle, square, hexagon, and circle unit cells. The spectral absorption peaks whose intensities are above 0.99 occur at ~4 μm after structure optimization when VO2 is in insulating state and disappear when VO2 becomes metallic state. The simulated electromagnetic field reveals that the spectral absorption peaks are attributed to the excitation of magnetic polariton within the insulating VO2 spacer layer, whose values exceed 1.59 orders of magnitude higher than the incident magnetic field. Longer resonant wavelength would be excited in square arrays because its configuration is a better carrier of charges at the same spans. For absorption stability, the absorbers/emitters with square and circular structures do not have any change with the polarization angles changing from 0° to 90°, due to the high rotational symmetric structure. And four absorbers/emitters reveal similar shifts and attenuations under different incident angles. We believed that the switchable absorber/emitter demonstrates promising applications in the sensing technology and adaptive infrared system

A novel prevascularized tissue-engineered chamber as a site for allogeneic and xenogeneic islet transplantation to establish a bioartificial pancreas.

Although sites for clinical or experimental islet transplantation are well established, pancreatic islet survival and function in these locations remain unsatisfactory. A possible factor that might account for this outcome is local hypoxia caused by the limited blood supply. Here, we modified a prevascularized tissue-engineered chamber (TEC) that facilitated the viability and function of the seeded islets in vivo by providing a microvascular network prior to transplantation. TECs were created, filled with Growth Factor-Matrigel™ (Matrigel™) and then implanted into the groins of mice with streptozotocin-induced diabetes. The degree of microvascularization in each TECs was analyzed by histology, real-time PCR, and Western blotting. Three hundred syngeneic islets were seeded into each chamber on days 0, 14, and 28 post-chamber implantation, and 300, 200, or 100 syngeneic islets were seeded into additional chambers on day 28 post-implantation, respectively. Furthermore, allogeneic or xenogeneic islet transplantation is a potential solution for organ shortage. The feasibility of TECs as transplantation sites for islet allografts or xenografts and treatment with anti-CD45RB and/or anti-CD40L (MR-1) was therefore explored. A highly developed microvascularized network was established in each TEC on day 28 post-implantation. Normalization of blood glucose levels in diabetic mice was negatively correlated with the duration of prevascularization and the number of seeded syngeneic islets. Combined treatment with anti-CD45RB and MR-1 resulted in long-term survival of the grafts following allotransplantation (5/5, 100%) and xenotransplantation (16/20, 80%). Flow cytometry demonstrated that the frequency of CD4+Foxp3-Treg and CD4+IL-4+-Th2 cells increased significantly after tolerogenic xenograft transplantation, while the number of CD4+IFN-γ-Th1 cells decreased. These findings demonstrate that highly developed microvascularized constructs can facilitate the survival of transplanted islets in a TECs, implying its potential application as artificial pancreas in the future

Quantitative Analysis of HER2 Amplification by Droplet Digital PCR in the Follow-Up of Gastric Cancer Patients Being Treated with Trastuzumab after Surgery

Background. Circulating tumor DNA (ctDNA) derived from tumors is a promising biomarker for monitoring tumor status and evaluating therapeutic effects and prognosis. We studied the plasma human epidermal growth factor receptor 2 (HER2) amplification in gastric cancer (GC) patients by droplet digital PCR (ddPCR) during therapy with trastuzumab. Methods. A total of 12 patients were recruited after surgery. All patients received FOLFOX chemotherapy combined with trastuzumab as a treatment regimen. During the 12 months of the follow-up period, using elongation factor Tu GTP binding domain containing 2 (EFTUD2) as a reference gene, plasma HER2 to EFTUD2 ratios (the HER2 ratio) were determined for each patient every 2 months by ddPCR. Results. The concordance rate of HER2 amplification examined in plasma and formalin-fixed paraffin-embedded (FFPE) samples with ddPCR was 81.4%, with a sensitivity of 76.5% and a specificity of 83.8%. Plasma HER2 ratios were correlated with the primary tumor size (p<0.01). A significant decrease in the plasma HER2 ratio was found after two months of treatment (p<0.0001). Nine patients experienced partial response, and three patients had stable disease. Seven patients had progressive disease (PD) during follow-up, and four of them had died. The median progression-free survival (PFS) was 9.8 months. For each patient who developed PD, the plasma HER2 ratio was approximately 2.3-4.1 times higher than the cut-off value at the time of PD, which was the highest during the whole follow-up period. Conclusion. Longitudinal monitoring for the plasma HER2 ratio by ddPCR in the clinical courses of GC patients holds great promise for use as an indicator of tumor progression and treatment efficacy

Characterization of the single-cell derived bovine induced pluripotent stem cells

© 2017. Single-cell derived bovine induced pluripotent stem cells (iPSCs) were generated by the introduction of piggyBac transposons with CAG promoting transcription factors (Oct3/4, Sox2, Klf4 and cMyc). In the study, the bovine iPSCs colony from single cell could passage more than 50 passages after enzymatic dissociation into single cells. These bovine iPSCs cells kept the normal karyotype and displayed dome shaped clones similar to mouse embryonic stem cells. They showed pluripotency in many ways, including their expression of pluripotency markers, such as OCT3/4, NANOG, SOX2, SSEA1, SSEA4, and AP in immunofluorescence assay, Oct4, Nanog, Sox2, Klf4 and cMyc in RT-PCR. Additionally, single-cell derived bovine iPSCs formed embryoid bodies and teratomas that all subsequently gave rise to differentiated cells from all three embryonic germ layers. The results showed that our reprogramming method could obtain high efficiency single-cell cloning bovine iPSCs, and the efficiency of single cell cloning is 40%.Link_to_subscribed_fulltex

Droplet digital PCR-based circulating microRNA detection serve as a promising diagnostic method for gastric cancer

Abstract Background Novel non-invasive biomarkers for gastric cancer (GC) are needed, because the present diagnostic methods for GC are either invasive or insensitive and non-specific in clinic. The presence of stable circulating microRNAs (miRNAs) in plasma suggested a promising role as GC biomarkers. Methods Based on the quantitative droplet digital PCR (ddPCR), four miRNAs (miR-21, miR-93, miR-106a and miR-106b) related to the presence of GC were identified in plasma from a training cohort of 147 participants and a validation cohort of 28 participants. Results All circulating miRNA levels were significantly higher in the plasma of GC patients compared to healthy controls (P < 0.05). Through a combination of four miRNAs by logistic regression model, receiver operating characteristic (ROC) analyses yielded the highest AUC value of 0.887 in discriminating GC patients from healthy volunteers. Furthermore, miR-21, miR-93 and miR-106b levels were significantly related to an advanced TNM stage in GC patients. ROC analyses of the combined miRNA panel also showed the highest AUC value of 0.809 in discriminating GC patients with TNM stage I and II from stage III and IV. Through combining four miRNAs and clinical parameters, a classical random forest model was established in the training stage. In the validation cohort, it correctly discriminated 23 out of 28 samples in the blinded phase (false rate, 17.8%). Conclusions Using the ddPCR technique, circulating miR-21, miR-93, miR-106a and miR-106b could be used as diagnostic plasma biomarkers in gastric cancer patients