摘要:

AbstractErythrocytes from different cattle were shown to fall into two distinct groups with respect to fructose transport. The rates of entrance of fructose into the two classes of cells differed by a factor of 5 to 10. It was also found that one pathway, the slower, was susceptible to inhibition by glucose while the other was not. The characteristics of the two fructose transport systems remained constant for as long as a week (longest time studied) upon storage at 2°C. The differences observed could not be attributed to handling of the blood, to the relative glucose permeability, or to the age or sex of the animal. This work indicates that two different fructose transport systems are operating in beef erythrocytes of different individuals

ISSN:0021-9541    

DOI:10.1002/jcp.1040700102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractThe contact interaction between cells and thewalls of microchambers through which the cells are passing are quantitated in terms of parameters which are estimated from macroscopic experimental data. For this purpose, an analysis is made of the internal geometry of glass bead‐columns. A mathematical model is presented which describes the passage of cells down the column. This model relates the temporal pattern of the number of cells entering and leaving the bead‐column to the “dynamic adhesive” properties of a cell as it passes through a microscopic section of the bead

ISSN:0021-9541    

DOI:10.1002/jcp.1040700103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractExperiments made on the passage of cells through untreated and siliconized glass beads, and on the adhesion and spread of cultured cells on glass and Teflon surfaces show that, in the absence of serum and in its presence in low concentrations, cell adhesion and spread is sensitive to substratum wettability. On the other hand, in the presence of 100% serum, no differences in adhesive parameters are detectable. It is concluded that arguments correlating cell adhesion to surface wettability, and, by inference, surface free energy, are unsubstantiated in 100% serum, which may well approximate to thein vivosituation.The results also show no correlation between parameters of cell adhesion and cell separation, and thereby support the hypothesis that these are different processes.

ISSN:0021-9541    

DOI:10.1002/jcp.1040700104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractThe oxygen consumption of various diapausing blastocysts from mammals having delayed implantation (mink, northern fur seal, black bear, armadillo and lactating rat) was studied with the Cartesian diver apparatus and compared with that of blastocysts from mammals where implantation is not delayed (rabbit, nonlactating rat). In general, there is a variation in the respiratory rate between species and within a species but the oxygen consumption of the delayed blastocysts was not different from the non‐delayed ones. It was concluded that the control of the delay in implantation in the animals studied, does not lie in the realm of respiratory change

ISSN:0021-9541    

DOI:10.1002/jcp.1040700105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractChromosome studies in irradiated mice have indicated that following high sublethal whole‐body exposure regeneration of the reticular tissues occurs in a clonal fashion. With increasing doses, from 100 to 700 rads, these organs appeared to be repopulated from fewer and fewer surviving stem cells. In a few instances at the highest dose, the progeny of the same cell apparently differentiated to marrow cells at one site and to lymphoid cells in others, suggestive evidence of a totipotent hematopoietic stem cell in the adult mouse.Chromosome studies in mice receiving 900 rads with one limb shielded have indicated repopulation of the thymus and other reticular tissues by undamaged cells from the shielded marrow. Such marrow‐derived cells, perhaps by restoring immunological competence or by non‐immunological contact inhibition, could account for the known effect or limb shielding in reducing the incidence of radiation‐induced thymic ly

ISSN:0021-9541    

DOI:10.1002/jcp.1040700106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractParachloromercuribenzenesulfonate (PCMBS) has two opposing effects on the influx of Rb+into red blood cells. The ouabain‐insensitive component, indicative of passive permeability of the membrane to cations, is increased whereas the ouabain‐sensitive or active transport component is inhibited. The increased passive permeability is paralleled by the action of PCMBS on net K+efflux into a K+‐free medium. Inhibibition of active transport of Rb+is paralleled by the inhibitory action of PCMBS on net Na+efilux from Na+‐rich cells. Both effects are reversed rapidly by the penetrating sulfhydryl compound, cysteine, and considerably more slowly by the non‐penetrating sulfhydryl compound, ovalbumin. Measurements of PCMBS binding and of elution in the presence of cysteine and albumin indicate that only a fraction of the total sulfhydryl groups of the membrane is involved in either the effect on permeability or transport, and that the affected groups are located within the interior of the

ISSN:0021-9541    

DOI:10.1002/jcp.1040700107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractUnagitated cultures ofAcanthamoebain the logarithmic growth phase have been observed to consist of over 99% mononucleates and less than 1% multinucleates. A small increase in the relative numbers of multinucleates occurs as the culture age and conditions for growth become limiting. A large increase in the proportion of multinucleates occurs during logarithmic growth, if the cultures are agitated by shaking or by the bubbling from a stream of air. After an initial increase and until the end of logarithmic growth, the numbers of multinucleates in the agitated cultures are maintained at a constant fraction of the total population. Proportions of multinucleates as high as 25% are observed during this period. A second increase in the relative numbers occurs as conditions for growth become limiting. Under these conditions, the multinucleates may exceed 50% of the total population. The factors inducing multinuclearity as well as the kinetics of the mononucleate and multinucleate accumulation curves are discussed.

ISSN:0021-9541    

DOI:10.1002/jcp.1040700108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractA technique has been developed for the selective detachment of mitotic cells from monolayer cultures of Chiness hamster cells with a simple reciprocating shaking machine. Cultures prepared by the shake treatment and placed in spinner flasks are routinely obtained, in which the mitotic fraction drops from 0.95–0.05 in 19 minutes. Some properties of mitotic cells prepared by this technique are described, along with a simple procedure for producing large quantities of mitotic cells. Cells chilled immediately after collection from a series of shake treatments complete mitosis synchronously upon subsequent resuspension in warm mediu

ISSN:0021-9541    

DOI:10.1002/jcp.1040700109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractGiant squid axons were microinjected with serine, valine and leucine‐C14under controlled electrophysiological conditions. These amino acids are incorporated into TCA insoluble fraction in the isolated axon.This incorporation is higher in the stimulated axons as compared to non‐stimulated ones. By processing separately the axoplasm and axon sheath, it was found that the last one is responsible almost entirely for the observed incorporation.Through differential centrifugation of homogenates of microinjected axons was shown that the highest incorporation occurred in the 1500 × g sediment, which probably corresponds to membranes.The incorporation of amino acids in stimulated axons, is strongly inhibited by chloramphenicol and actinomyc

ISSN:0021-9541    

DOI:10.1002/jcp.1040700110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractControl and γ‐irradiated sea urchin (Arbacia punctulata) eggs were incubated with H3‐leucine. No incorporation of the amino acid into the proteins of most unirradiated eggs was detectable by autoradiography. All irradiated eggs incorporated the amino acid and the amount of autoradiographic labelling varied greatly from cell to

ISSN:0021-9541    

DOI:10.1002/jcp.1040700111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY