Retinal ganglion cells of high cytochrome oxidase activity in the rat

Retinal ganglion cells in the rat were studied using the heavy metal intensified cytochrome oxidase and horseradish peroxidase histochemical methods.The results show that a population of large retinal ganglion cells was consistently observed with the cytochrome oxidase staining method in retinas of normal rats or rats which received unilateral thalamotomy at birth.These cytochrome oxidase rich ganglion cells appeared to have large somata,3-6 primary dendrites and extensive dendritic arbors,and are comparable to ganglion cells labeled by the wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP).However,the morphological details of some of the cells revealed by the cytochrome oxidase staining method are frequently better than those shown by the HRP histochemical method.These results suggest that the mitochondrial enzyme cytochrome oxidase can be used as a simple but reliable marker for identifying and studying a population of retinal genglion cells with high metabolic rate in the rat.     

IS THE ADOPTION OF MORE EFFICIENT STRATEGIES OF ORGAN PROCUREMENT THE ANSWER TO PERSISTENT ORGAN SHORTAGE IN TRANSPLANTATION?

[I]s persistent organ shortage the major obstacle to the performance of more procedures as often popularly portrayed? Does the answer therefore lie in the adoption of more efficient strategies of organ procurement? While the measures taken to improve the efficiency of organ procurement may be inspired by the laudable motive of saving lives, they may ultimately prove to be myopic if the larger ethical issues raised by organ transplant programs for the allocation of national and organ resources are not given their due consideration. For any society that desires to include organ transplantation in its health delivery system, it must consider the social and ethical issues that transplant programs raise for the macroallocation of available national resources and the manner by which organ resources are procured, and distributed. The failure to resolve these issues in an ethically acceptable manner at any of these levels would render any transplant program ethically indefensible. This essay therefore argues that before a society decides on its policy of organ procurement it ought to make prior assessments of: a) its social priorities; b) the policies for ensuring fair access to organ resources; and c) the extent to which it is willing to support transplants.     

Phosphorylation and biosynthesis of high molecular weight proteins of tumor nuclear matrix

INTRODUCTIONAsearlyasin1948wehavefr8CtionatedisolatednucleifromnormalandtumorcellsbyextractionwithiMNaCIanddilutealkali[1].Thenuclearresiduewasthenstudiedmorethoroughly[2,3].Lateron,sillillarproteinousnuclearresidueswereisolatedbyotherworkers[46]andasstud…     

Adversarial interspecies relationships facilitate population suppression by gene drive in spatially explicit models

Suppression gene drives bias their inheritance to spread through a population, potentially eliminating it when they reach high frequency. CRISPR homing suppression drives have already seen success in the laboratory, but several models predict that success may be elusive in population with realistic spatial structure due to extinction-recolonization cycles. Here, we extend our continuous space framework to include two competing species or predator–prey pairs. We find that in both general and mosquito-specific models, competing species or predators can facilitate drive-based suppression, albeit at the cost of an increased rate of drive loss outcomes. These results are robust in mosquito models with seasonal fluctuations. Our study illustrates the difficulty of predicting outcomes in complex ecosystems. However, our results are promising for the prospects of less powerful suppression gene drives to successfully eliminate target mosquito and other pest populations.     

An amino acidic adjuvant to augment cryoinjury of MCF-7 breast cancer cells

One of the major challenges in cryosurgery is to minimize incomplete cryodestruction near the edge of the iceball. In the present study, the feasibility and effectiveness of an amino acidic adjuvant, glycine was investigated to enhance the cryodestruction of MCF-7 human breast cancer cell at mild freezing/thawing conditions via eutectic solidification. The effects of glycine addition on the phase change characteristics of NaCl–water binary mixture were investigated with a differential scanning calorimeter and cryo-macro/microscope. The results confirmed that a NaCl–glycine–water mixture has two distinct eutectic phase change events – binary eutectic solidification of water–glycine, and ternary eutectic solidification of NaCl–glycine–water. In addition, its effects on the cryoinjury of MCF-7 cells were investigated by assessing the post-thaw cellular viability after a single freezing/thawing cycle with various eutectic solidification conditions due to different glycine concentrations, end temperatures and hold times. The viability of MCF-7 cells in isotonic saline supplemented with 10% or 20% glycine without freezing/thawing remained higher than 90% (n = 9), indicating no apparent toxicity was induced by the addition of glycine. With 10% glycine supplement, the viability of the cells frozen to −8.5 °C decreased from 85.9 ± 1.8% to 38.5 ± 1.0% on the occurrence of binary eutectic solidification of glycine–water (n = 3 for each group). With 20% glycine supplement, the viability of the cells frozen to −8.5 °C showed similar trends to those with 10% supplement. However, as the end temperature was lowered to −15 °C, the viability drastically decreased from 62.5 ± 2.0% to 3.6 ± 0.7% (n = 3 for each group). The influences of eutectic kinetics such as nucleation temperature, hold time and method were less significant. These results imply that the binary eutectic solidification of water–glycine can augment the cryoinjury of MCF-7 cells, and the extent of the eutectic solidification is significant.     

Design and performance study of a novel immobilized hollow fiber membrane bioreactor

A dual-layer coaxial hollow fiber (DLHF) bioreactor for cell immobilization developed to overcome nutrients transport limitation is presented. Cells were contained in the annular space between two coaxial hollow fibers, and nutrients were supplied by a forced convective transport from the shell side through the annular space to the lumen side. With judicious selection of the membrane materials, a low operating transmembrane pressure of 50 kPa, and using E. coli as the model organism, a high cell density of 10(11) cells/mL annular space volume and a high cell viability of (up to 80%) were obtained.     

Development of 3-D poly(trimethylenecarbonate-co-ε-caprolactone)-block-poly(p-dioxanone) scaffold for bone regeneration with high porosity using a wet electrospinning method

The three dimensional (3-D) poly(trimethylenecarbonate-co-ε-caprolactone)-block-poly(p-dioxanone) scaffold was made using a wet electrospinning method and its application as a tissue engineered matrix was evaluated for bone regeneration. The scaffold was highly porous (90%) and interconnected among pores. Under scanning electron microscopy, the cells of the center of the scaffold showed healthy well attached shape even at 4 days after seeding. The osteoblastic MC3T3-E1 cells proliferated 1.2 times faster at 4 day, 1.5 times faster at 7 days after seeding as compared with the control in the scaffold (P < 0.05). The activity of alkaline phosphatase, a bone formation marker, of cells seeded in the scaffold was nearly four times faster compared to control 28 days after seeding (P < 0.05). Taken together, newly developed 3-D poly(trimethylenecarbonate-co-ε-caprolactone)-block-poly(p-dioxanone) scaffold is a promising candidate for bone regeneration.     

Chemical engineering of mesenchymal stem cells to induce a cell rolling response

Covalently conjugated sialyl Lewis X (SLeX) on the mesenchymal stem cell (MSC) surface through a biotin-streptavidin bridge imparts leukocyte-like rolling characteristics without altering the cell phenotype and the multilineage differentiation potential. We demonstrate that the conjugation of SLeX on the MSC surface is stable, versatile, and induces a robust rolling response on P-selectin coated substrates. These results indicate the potential to increase the targeting efficiency of any cell type to specific tissue.     

GLAD: a system for developing and deploying large-scale bioinformatics grid

MOTIVATION: Grid computing is used to solve large-scale bioinformatics problems with gigabytes database by distributing the computation across multiple platforms. Until now in developing bioinformatics grid applications, it is extremely tedious to design and implement the component algorithms and parallelization techniques for different classes of problems, and to access remotely located sequence database files of varying formats across the grid. In this study, we propose a grid programming toolkit, GLAD (Grid Life sciences Applications Developer), which facilitates the development and deployment of bioinformatics applications on a grid. RESULTS: GLAD has been developed using ALiCE (Adaptive scaLable Internet-based Computing Engine), a Java-based grid middleware, which exploits the task-based parallelism. Two bioinformatics benchmark applications, such as distributed sequence comparison and distributed progressive multiple sequence alignment, have been developed using GLAD.