Showing papers in "Experimental Cell Research in 1956"

TL;DR: It is shown that the contamination of the nuclei by cytoplasmic structures is one of the main difficulties encountered in the isolation of the nuclear fraction and an accurate count of contaminants is necessary, especially in the study of thenuclear composition.

TL;DR: The tubule-inducing effect of embryonic mouse spinal cord on metanephrogenic mesenchyme can be transmitted across membrane filters of 20–30 microns thickness, and speculation is advanced that intercellular matrix or ground substance may play a significant role.

TL;DR: It is concluded that furrowing results from the active function of the cell cortex which, in turn, is under the influence of the internal structures (nucleus, spindle or asters).

TL;DR: A technique is described which permits a time-lapse cinematographic analysis of morphogenetic processes of sea urchin larvae and other marine larvae, the rapid swimming movements of which normally prohibit the use of time- lapse recording.

TL;DR: The ultrastructure of the cortical granules, of the vitelline membrane and of their products in sea urchin eggs has been studied by means of electron microscopy in ultra-thin sections prepared according to the technique of Sjostrand.

TL;DR: All four in vitro methods of estimating the percentage viability of a cell suspension gave similar results with a recently harvested cell suspension but three of them grossly overestimated the proportion of viable cells in a suspension which had been stored at 4 °C for 11 days.

TL;DR: The preparation of thin sections of melanocytes from the human hair follicle and of pigment granules isolated by various methods from hair is described in this paper, where it is shown that some granules appear to consist of several parallel lamellae which may form a succession of cylindrical or ellipsoidal shells.

TL;DR: In this article, the presence of large numbers of granules at the surface of the vitellus in the hamster egg before spermatozoon penetration was found to be associated with a distinct decrease in the light-refracting power of the Vitelline cortex.

TL;DR: The decrease in nuclear volume, prevention of cell division, and the lower average growth rate are reflections of a period of readjustment following the loss of cytoplasm.

TL;DR: In this paper, the effect of unequal division of Amoeba proteus was investigated and growth curves by weight for a large and small post-telophase amoebae produced by unequal division were determined.

TL;DR: In order to determine whether this reaction releases an egg-membrane lysin, dense sperm suspensions were stimulated by excess Ca ++ , and the reacted spermatozoa were centrifuged out of suspension and extracted with sea water after being frozen and ground in a mortar.

TL;DR: Most morphological stages from the granular vacuoles to yolk granules can be found, which suggests that yolkgranules may originate in the dictyosomes, which is similar to the Golgi apparatus from a vertebrate cell.

TL;DR: The data support the conclusion that the release of the mitochondrial complement of DPN and the loss of the phosphorylative ability, following Ca++ treatment or preincubation with no or little Mg++, are both secondary consequences of a release of mitochondrial ATP.

TL;DR: The development of mitotic activity following the administration of a small dose of estradiol benzoate has been followed in the epithelia of ear, seminal vesicle, and coagulating gland of the castrate male mouse.

TL;DR: In this paper, the authors show that the mitochondria of gametes of Allomyces macrogynus exhibit a double structure and a regular alveolar structure on tangential and oblique sections.

TL;DR: In this paper, the numerical ratio "ghosts"/protoplasts and the average size of the ghosts together with the size distribution indicate that the ghost cells represent morphologically undamaged cytoplasmic membranes.

TL;DR: Results have been interpreted to indicate that DPN and DPNH are reversibly associated with the mitochondrial structure, but the association of DpnH is firmer than that of DPN.

TL;DR: Ch Chromosome analyses were made in one hyperdiploid and two hypotetraploid strains of the mammary adenocarcinoma ascites TA3 of the mouse, suggesting that structural rearrangements are accumulated more freely on the polyploidlevel than on the diploid level.

TL;DR: The mechanism of the outflow from cut nerve fibres is discussed, and when the outflowing drop reaches a definite magnitude, the flow is arrested and the volume of the drop becomes for a time stationary.

TL;DR: Measurements have been made of the sedimentation rates, diffusion, viscosity and electrophoretic mobilities of the fertilizins of the sea urchin Arbacia punctulata and the sand dollar Echinarachnius parma, showing these fertilizin to be highly acidic as had been found in other species.