SELECTIVE TOXICITY OF RHODAMINE 123 ON CARCINOMA CELL IN VITRO

The selective toxicity of the mitochondria-specific cationic fluorescent dye rhodamine 123 (Rh-123) on He La cells in culture was studied. In this report, we demonstrate that with continuous exposure, Rh-123 markedly inhibited the growth of HeLa cells but had little effect on normal human kidney fibroblasts. With continuous exposure to Rh-123, the growth rate, colony forming ability, anl mitotic index of HeLa cells were decreased. The mechanism of toxicity of Rh-123 on HeLa cells was investigated by EM and enzyme cytochemistry stain. The mitochondria of carcinoma cells were the main targets for the inhibitory action of Rh-123, since they selectively accumulated the dye. At the dosage of Rh-123 which was toxic to HeLa cells, the structure and function of mitochondria were disrupted, as the mitochondria-related enzymes, i.e., ATPase, LDH and SDH were inhibited. The possible mechanism of the action of Rh-123 on HeLa cells is briefly discussed.

SELECTIVE KILLING OF GASTRIC CANCER CELLS BY MONOCLONAL ANTIBODY CONJUGATED WITH A CHAIN OF RICIN

A specific cytotoxic agent against gastric cancer was constructed by covalently coupling the ricin A chain to monoclonal artibody, MGb2. MGb2 was modified by SPDP to introduce the 3-(2-pyridylthio) propionyl radical and then treated with a reduced A chain to give a disulfide linked conjugate that retained the original binding specificity of the antibody moiety. The conjugate obtained retained the activity of the antibody and the biological activity of the A chain well.

Oncological Hyperthermia: Where to Go from Here?

Oncological hyperthermia is one of the most versatile forms of oncotherapy. It can complement every conventional treatment method and be applied to any tumorous cancer, irrespective of its stages and localization. Numerous technical realizations are conventionally compared by their thermal effect, measured by temperature. However, nonthermal (mainly electric) excitation effects are more recognized nowadays. The technical variants alter the synergy between thermal and nonthermal energy components. Nonthermal energy absorption-induced molecular mechanisms include essential behaviors like selectivity and immunogenicity. The nonthermal electromagnetic effects excite molecular changes, intracellular signals, gene expressions, and many other chemical reactions. Their synergy with thermal conditions is based on the Arrhenius law, which describes the rapid growth of chemical reactions with temperature. A unique technical realization of hyperthermia, modulated electrohyperthermia (mEHT) tries to optimize the thermal and nonthermal effects. The results look very perspective, containing the high accuracy of targeting the tumor cells, the immunogenic cell death, and the activation of tumor-specific immune reactions restoring the healthy immune surveillance to destroy the cancer.

Combined use of Y-tube conduits with human umbilical cord stem cells for repairing nerve bifurcation defects

Given the anatomic complexity at the bifurcation point of a nerve trunk,enforced suturing between stumps can lead to misdirection of nerve axons,thereby resulting in adverse consequences.We assumed that Y-tube conduits injected with human umbilical cord stem cells could be an effective method to solve such problems,but studies focused on the best type of Y-tube conduit remain controversial.Therefore,the present study evaluated the applicability and efficacy of various types of Y-tube conduits containing human umbilical cord stem cells for treating rat femoral nerve defects on their bifurcation points.At 12 weeks after the bridging surgery that included treatment with different types of Y-tube conduits,there were no differences in quadriceps femoris muscle weight or femoral nerve ultrastructure.However,the Y-tube conduit group with longer branches and a short trunk resulted in a better outcome according to retrograde labeling and electrophysiological analysis.It can be concluded from the study that repairing a mixed nerve defect at its bifurcation point with Y-tube conduits,in particular those with long branches and a short trunk,is effective and results in good outcomes.

Recent Advances on Surface-modified Biomaterials Promoting Selective Adhesion and Directional Migration of Cells

The surfaces and interfaces of biomaterials interact with the biological systems in multi-scale levels,and thereby influence the biological functions and comprehensive performance in vitro and in vivo.In particular,a surface promoting the selective adhesion and directional migration of desired types of cells in complex environment is extremely important in the repair and regeneration of tissues such as peripheral nerve and blood vessel,and long-term application of intracorporal devices such as intravascular implants.Therefore,surface modification of biomaterials is a facile and effective method to achieve the desired cell-biomaterials interactions.In this short review,recent advances on the surface modification of biomaterials to regulate selective cell adhesion and migration are briefly summarized.In particular,the surface properties of biomaterials are manipulated via the convenient introduction of amino groups to the ester-based polymers,the formation of polyelectrolyte multilayers,and the fabrication of topology and gradient cues,etc.,followed by the association of chemical and biological signals such as collagen,heparin,hyaluronic acid,peptides and cell growth factors.The selective adhesion and directional migration of various types of cells such as endothelial cells(ECs),smooth muscle cells(SMCs),hepatocytes and Schwann cells(SCs)are achieved over the competitive counterpart cells by the use of cell-resisting substances and cell-selective motifs on gradient substrates in most cases.Recent advances on cell behaviors in three-dimensional(3D)ceH-extracellular matrix(ECM)-mimicking substrates are also reviewed.

Development of electron and hole selective contact materials for perovskite solar cells

Nowadays,both n-i-p and p-i-n perovskite solar cells（PSCs） device structures are reported to give high performance with photo conversion efficiencies（PCEs） above 20%.The efficiency of the PSCs is fundementally determined by the charge selective contact materials.Hence,by introducing proper contact materials with good charge selectivity,one could potentially reduce interfacial charge recombination as well as increase device performance.In the past few years,copious charge selective contact materials have been proposed.Significant improvements in the corresponding devices were observed and the reported PCEs were close to that of classic Spiro-OMeTAD.This mini-review summarizes the state-of-the-art progress of typical electron/hole selective contact materials for efficient perovskite solar cells and an outlook to their development is made.

Elite Opposition Based Metaheuristic Framework for Load Balancing in LTE Network

In present scenario of wireless communications,Long Term Evolution(LTE)based network technology is evolved and provides consistent data delivery with high speed andminimal delay through mobile devices.The traffic management and effective utilization of network resources are the key factors of LTE models.Moreover,there are some major issues in LTE that are to be considered are effective load scheduling and traffic management.Through LTE is a depraved technology,it is been suffering from these issues.On addressing that,this paper develops an Elite Opposition based Spider Monkey Optimization Framework for Efficient Load Balancing(SMO-ELB).In this model,load computation of each mobile node is done with Bounding Theory based Load derivations and optimal cell selection for seamless communication is processed with Spider Monkey Optimization Algorithm.The simulation results show that the proposed model provides better results than exiting works in terms of efficiency,packet delivery ratio,Call Dropping Ratio(CDR)and Call Blocking Ratio(CBR).

Nano-micrometer surface roughness gradients reveal topographical influences on differentiating responses of vascular cells on biodegradable magnesium

Distinctively directing endothelial cells(ECs)and smooth muscle cells(SMCs),potentially by surface topography cue,is of central importance for enhancing bioefficacy of vascular implants.For the first time,surface gradients with a broad range of nano-micrometer roughness are developed on Mg,a promising next-generation biodegradable metal,to carry out a systematic study on the response of ECs and SMCs.Cell adhesion,spreading,and proliferation are quantified along gradients by high-throughput imaging,illustrating drastic divergence between ECs and SMCs,especially in highly rough regions.The profound role of surface topography overcoming the biochemical cue of released Mg2+is unraveled at different roughness ranges for ECs and SMCs.Further insights into the underlying regulatory mechanism are gained at subcellular and gene levels.Our work enables highefficient exploration of optimized surface morphology for modulating favored cell selectivity of promoting ECs and suppressing SMCs,providing a potential strategy to achieve rapid endothelialization for Mg.

Zebl represses TCR signaling, promotes the proliferation of T cell progenitors and is essential for NK1.1^(+) T cell development

T cell development proceeds un der the in fluence of a n etwork of transcription factors(TFs).The precise role of Zeb1,a member of this network,remains unclear.Here,we report that Zeb1 expression is induced early during T cell development in CD4^(-)CD8^(-)double-negative(DN)stage 2(DN2).Zeb1 expression was further increased in the CD4^(+)CD8^(+)double-positive(DP)stage before decreasing in more mature T cell subsets.We performed an exhaustive characterization of T cells in Cellophane mice that bear Zeb 7 hypomorphic mutations.The Zebl mutation profoundly affected all thymic subsets,especially DN2 and DP cells.Zeb1 promoted the survival and proliferation of both cell populations in a cell-intrinsic manner.In the periphery of Cellophane mice,the number of conventional T cells was near normal,but invariant NKT cells,NK1.1^(+)γδ T cells and Ly49^(+)CD8 T cells were virtually absent.This suggested that Zebl regulates the development of unconventional T cell types from DP progenitors.A transcriptomic analysis of WT and Cellophane DP cells revealed that Zebl regulated the expression of multiple genes involved in the cell cycle and TCR sign aling,which possibly occurred in cooperation with Tcf1 and Heb.In deed,Cellophane DP cells displayed stron ger signaling than WT DP cells upon TCR engagement in terms of the calcium respons巳phosphorylation events,and expression of early genes.Thus,Zebl is a key regulator of the cell cycle and TCR signaling during thymic T cell development.We propose that thymocyte selection is perturbed in Zeb7-mutated mice in a way that does not allow the survival of unconventional T cell subsets.

A dual V_t disturb-free subthreshold SRAM with write-assist and read isolation

This paper presents a new dual V_t 8 T SRAM cell having single bit-line read and write, in addition to Write Assist and Read Isolation（WARI）. Also a faster write back scheme is proposed for the half selected cells. A high V_t device is used for interrupting the supply to one of the inverters for weakening the feedback loop for assisted write. The proposed cell provides an improved read static noise margin（RSNM） due to the bit-line isolation during the read. Static noise margins for data read（RSNM）, write（WSNM）, read delay, write delay, data retention voltage（DRV）, leakage and average powers have been calculated. The proposed cell was found to operate properly at a supply voltage as small as 0.41 V. A new write back scheme has been suggested for half-selected cells,which uses a single NMOS access device and provides reduced delay, pulse timing hardware requirements and power consumption. The proposed new WARI 8 T cell shows better performance in terms of easier write, improved read noise margin, reduced leakage power, and less delay as compared to the existing schemes that have been available so far. It was also observed that with proper adjustment of the cell ratio the supply voltage can further be reduced to 0.2 V.