Evaluation of cloned cells, animal model, and ATRA sensitivity of human testicular yolk sac tumor

The testicular yolk sac tumor (TYST) is the most common neoplasm originated from germ cells differentiated abnormally, a major part of pediatric malignant testicular tumors. The present study aimed at developing and validating the in vitro and vivo models of TYST and evaluating the sensitivity of TYST to treatments, by cloning human TYST cells and investigating the histology, ultra-structure, growth kinetics and expression of specific proteins of cloned cells. We found biological characteristics of cloned TYST cells were similar to the yolk sac tumor and differentiated from the columnar to glandular-like or goblet cells-like cells. Chromosomes for tumor identification in each passage met nature of the primary tumor. TYST cells were more sensitive to all-trans-retinoic acid which had significantly inhibitory effects on cell proliferation. Cisplatin induced apoptosis of TYST cells through the activation of p53 expression and down-regulation of Bcl- expression. Thus, we believe that cloned TYST cells and the animal model developed here are useful to understand the molecular mechanism of TYST cells and develop potential therapies for human TYST

Bone-marrow derived cells do not contribute to new beta-cells in the inflamed pancreas

The contribution of bone-marrow derived cells (BMCs) to a newly formed beta-cell population in adults is controversial. Previous studies have only used models of bone marrow transplantation from sex-mismatched donors (or other models of genetic labeling) into recipient animals that had undergone irradiation. This approach suffers from the significant shortcoming of the off-target effects of irradiation. Partial pancreatic duct ligation (PDL) is a mouse model of acute pancreatitis with a modest increase in beta-cell number. However, the possibility that recruited BMCs in the inflamed pancreas may convert into beta-cells has not been examined. Here, we used an irradiation-free model to track the fate of the BMCs from the donor mice. A ROSA-mTmG red fluorescent mouse was surgically joined to an INS1Cre knock-in mouse by parabiosis to establish a mixed circulation. PDL was then performed in the INS1Cre mice 2 weeks after parabiosis, which was one week after establishment of the stable blood chimera. The contribution of red cells from ROSA-mTmG mice to beta-cells in INS1Cre mouse was evaluated based on red fluorescence, while cell fusion was evaluated by the presence of green fluorescence in beta-cells. We did not detect any red or green insulin+ cells in the INS1Cre mice, suggesting that there was no contribution of BMCs to the newly formed beta-cells, either by direct differentiation, or by cell fusion. Thus, the contribution of BMCs to beta-cells in the inflamed pancreas should be minimal, if any

Effects of aging and macrophages on mice stem Leydig cell proliferation and differentiation in vitro

BackgroundTestosterone plays a critical role in maintaining reproductive functions and well-beings of the males. Adult testicular Leydig cells (LCs) produce testosterone and are generated from stem Leydig cells (SLCs) during puberty through adulthood. In addition, macrophages are critical in the SLC regulatory niche for normal testicular function. Age-related reduction in serum testosterone contributes to a number of metabolic and quality-of-life changes in males, as well as age-related changes in immunological functions. How aging and testicular macrophages may affect SLC function is still unclear.MethodsSLCs and macrophages were purified from adult and aged mice via FACS using CD51 as a marker protein. The sorted cells were first characterized and then co-cultured in vitro to examine how aging and macrophages may affect SLC proliferation and differentiation. To elucidate specific aging effects on both cell types, co-culture of sorted SLCs and macrophages were also carried out across two ages.ResultsCD51+ (weakly positive) and CD51++ (strongly positive) cells expressed typical SLC and macrophage markers, respectively. However, with aging, both cell types increased expression of multiple cytokine genes, such as IL-1b, IL-6 and IL-8. Moreover, old CD51+ SLCs reduced their proliferation and differentiation, with a more significant reduction in differentiation (2X) than proliferation (30%). Age matched CD51++ macrophages inhibited CD51+ SLC development, with a more significant reduction in old cells (60%) than young (40%). Crossed-age co-culture experiments indicated that the age of CD51+ SLCs plays a more significant role in determining age-related inhibitory effects. In LC lineage formation, CD51+ SLC had both reduced LC lineage markers and increased myoid cell lineage markers, suggesting an age-related lineage shift for SLCs.ConclusionThe results suggest that aging affected both SLC function and their regulatory niche cell, macrophages

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An Experimental assessment of the performance of Linear and Kernel-based Methods for Face Recognition

This paper presents the results of a comparative study of linear and kernel-based methods for face recognition. These experimental results include: (1) a comparative study of linear methods for feature extraction, such as Principal Component Analysis (PCA), Fisher’s Linear Discriminant Analysis (FDA), and kernel based methods for feature extraction, such as Kernel based Principal Component Analysis (KPCA), Kernel based Discriminant Analysis (KDA). (2) a comparative study of linear methods for recognition or classification, such as Nearest Neighbor (NN), Linear Support Vector Machine (LSVM), and kernel based methods for classification, such as Kernel based Nearest Neighbor (KNN), Nonlinear Support Vector Machine (NSVM). In addition, we also obtain some interesting conclusions after all of these methods are performed on several well-known face database, i.e. ORL, YALE and UMIST Face Database, respectively. Key words: Linear methods; kernel based methods; feature extraction; face recognition; data structure of face databas

Poly(carbazole-co-1,4-dimethoxybenzene): Synthesis, Electrochemiluminescence Performance, and Application in Detection of Fe³⁺

In this study, four polycarbazole derivatives (PCMB-Ds) with different alkyl side chains were designed and synthesized via Wittig–Horner reaction. A novel solid-phase electrochemiluminescence (ECL) system was prepared by immobilizing PCMB-D on an indium tin oxide (ITO) electrode with polyvinylidene fluoride (PVDF) in the presence of tripropylamine (TPrA). It could be found that the increase in alkyl side chain length had little effect on the ECL signal of PCMB-D, while the increase in the degree of polymerization (DP) greatly enhanced the ECL signal. Furthermore, the P-3/ITO ECL sensor based on the polyoctylcarbazole derivative (P-3) with the best ECL performance was successfully constructed and detected Fe3+ under the optimal experimental conditions. The ECL signal steadily diminished with the increased concentration of Fe3+ because of the competition and complexation between Fe3+ and P-3 under the condition of pH 7.4. This P-3/ITO platform could realize a highly sensitive and selective detection of Fe3+ with a wide detection range (from 6 × 10−8 mol/L to 1 × 10−5 mol/L) and low detection limit of 2 × 10−8 mol/L, which could allow the detection of Fe3+ in multiple scenarios, and would have a great application prospect

Iron Catalyzed Dual-Oxidative Dehydrogenative (DOD) Tandem Annulation of Glycine Derivatives with Tetrahydrofurans

A novel iron-catalyzed dual-oxidative dehydrogenative (DOD) tandem annulation of glycine derivatives with tetrahydrofurans (THFs) for the synthesis of high value quinoline fused lactones has been developed. The reactions were performed under mild reaction conditions. And the use of cheap substrates (glycine derivatives and THF) and an even cheaper simple inorganic iron salt as the catalyst makes this protocol very attractive for potential synthetic applications

Copper-Catalyzed Aerobic Oxidative Dehydrogenative Formal [2 + 3] Cyclization of Glycine Esters with α‑Angelicalactone: Approach To Construct Polysubstituted Pyrrolidones

A novel and efficient copper-catalyzed aerobic oxidative dehydrogenative formal [2 + 3] cyclization of glycine derivatives with α-angelicalactone is described. A series of complex pyrrolidones were produced under mild and simple reaction conditions