Development of a Bicelle Lotion Containing a High Concentration of Ceramide

2021 ◽  
Vol 55 (3) ◽  
pp. 249-254
Author(s):  
Daisuke Tsukamoto ◽  
Mika Yamashita ◽  
Junko Kamimoto-Kuroki ◽  
Mitsuhito Sudo ◽  
Haruna Hayase ◽  
...  
Keyword(s):  
Author(s):  
Daniel C. Pease

A previous study demonstrated that tissue could be successfully infiltrated with 50% glutaraldehyde, and then subsequently polymerized with urea to create an embedment which retained cytomembrane lipids in sectioned material. As a result, the 180-190 Å periodicity characteristic of fresh, mammalian myelin was preserved in sections, as was a brilliant birefringence, and the capacity to bind OsO4 vapor in the hydrophobic bilayers. An associated (unpublished) study, carried out in co-operation with Drs. C.K. Akers and D.F. Parsons, demonstrated that the high concentration of glutaraldehyde (and urea) did not significantly alter the X-ray diffraction pattern of aldehyde-fixed, myelin. Thus, by itself, 50% glutaraldehyde has little effect upon cytomembrane systems and can be used with confidence for the first stages of dehydration.


Author(s):  
Glenn M. Cohen ◽  
Radharaman Ray

Retinal,cell aggregates develop in culture in a pattern similar to the in ovo retina, forming neurites first and then synapses. In the present study, we continuously exposed chick retinal cell aggregates to a high concentration (1 mM) of carbamylcholine (carbachol), an acetylcholine (ACh) analog that resists hydrolysis by acetylcholinesterase (AChE). This situation is similar to organophosphorus anticholinesterase poisoning in which the ACh level is elevated at synaptic junctions due to inhibition of AChE, Our objective was to determine whether continuous carbachol exposure either damaged cholino- ceptive neurites, cell bodies, and synaptic elements of the aggregates or influenced (hastened or retarded) their development.The retinal tissue was isolated aseptically from 11 day embryonic White Leghorn chicks and then enzymatically (trypsin) and mechanically (trituration) dissociated into single cells. After washing the cells by repeated suspension and low (about 200 x G) centrifugation twice, aggregate cell cultures (about l0 cells/culture) were initiated in 1.5 ml medium (BME, GIBCO) in 35 mm sterile culture dishes and maintained as experimental (containing 10-3 M carbachol) and control specimens.


Author(s):  
James Cronshaw

Long distance transport in plants takes place in phloem tissue which has characteristic cells, the sieve elements. At maturity these cells have sieve areas in their end walls with specialized perforations. They are associated with companion cells, parenchyma cells, and in some species, with transfer cells. The protoplast of the functioning sieve element contains a high concentration of sugar, and consequently a high hydrostatic pressure, which makes it extremely difficult to fix mature sieve elements for electron microscopical observation without the formation of surge artifacts. Despite many structural studies which have attempted to prevent surge artifacts, several features of mature sieve elements, such as the distribution of P-protein and the nature of the contents of the sieve area pores, remain controversial.


Author(s):  
R.A. Herring

Rapid thermal annealing (RTA) of ion-implanted Si is important for device fabrication. The defect structures of 2.5, 4.0, and 6.0 MeV As-implanted silicon irradiated to fluences of 2E14, 4E14, and 6E14, respectively, have been analyzed by electron diffraction both before and after RTA at 1100°C for 10 seconds. At such high fluences and energies the implanted As ions change the Si from crystalline to amorphous. Three distinct amorphous regions emerge due to the three implantation energies used (Fig. 1). The amorphous regions are separated from each other by crystalline Si (marked L1, L2, and L3 in Fig. 1) which contains a high concentration of small defect clusters. The small defect clusters were similar to what had been determined earlier as being amorphous zones since their contrast was principally of the structure-factor type that arises due to the difference in extinction distance between the matrix and damage regions.


2020 ◽  
Vol 477 (15) ◽  
pp. 2921-2934
Author(s):  
Rodrigo D. Requião ◽  
Géssica C. Barros ◽  
Tatiana Domitrovic ◽  
Fernando L. Palhano

Protein segments with a high concentration of positively charged amino acid residues are often used in reporter constructs designed to activate ribosomal mRNA/protein decay pathways, such as those involving nonstop mRNA decay (NSD), no-go mRNA decay (NGD) and the ribosome quality control (RQC) complex. It has been proposed that the electrostatic interaction of the positively charged nascent peptide with the negatively charged ribosomal exit tunnel leads to translation arrest. When stalled long enough, the translation process is terminated with the degradation of the transcript and an incomplete protein. Although early experiments made a strong argument for this mechanism, other features associated with positively charged reporters, such as codon bias and mRNA and protein structure, have emerged as potent inducers of ribosome stalling. We carefully reviewed the published data on the protein and mRNA expression of artificial constructs with diverse compositions as assessed in different organisms. We concluded that, although polybasic sequences generally lead to lower translation efficiency, it appears that an aggravating factor, such as a nonoptimal codon composition, is necessary to cause translation termination events.


1974 ◽  
Vol 32 (02/03) ◽  
pp. 704-713 ◽  
Author(s):  
F. N McKenzie ◽  
K.-E Arfors ◽  
N. A Matheson

SummaryA study has been made of the biochemical factors underlying the platelet response to laser-induced microvascular injury. A platelet aggregating substance is produced at sites of laser-induced injury which markedly stimulates platelet activity at a site of injury inflicted a short distance downstream. Distal sites of injury are not similarly influenced if the distance between the injuries is increased or if the proximal site no longer shows platelet-stimulating activity. The stimulating effect of an adjacent proximal injury on platelet activity at a distal site is inhibited by local intra-arterial infusion of adenosine. Measurements of arterial blood pressure and microvascular blood flow velocity during adenosine infusion showed that its inhibitory effect on platelet activity is largely independent of its vasodilator properties. The effect of infusion of different adenosine phosphates (AMP, ADP, ATP) was also studied. Very small amounts of ADP markedly stimulated platelet activity and the emboli formed were similar to those normally produced at sites of laser injury. At high concentration AMP inhibited while ATP stimulated platelet activity in vivo. The results emphasise the fundamental role of ADP as a mediator of the platelet response at sites of laser- induced microvascular injury.


1960 ◽  
Vol 4 (01) ◽  
pp. 031-044
Author(s):  
George Y. Shinowara ◽  
E. Mary Ruth

SummaryFour primary fractions comprising at least 97 per cent of the plasma proteins have been critically appraised for evidence of denaturation arising from a low temperature—low ionic strength fractionation system. The results in addition to those referable to the recovery of mass and biological activity include the following: The high solubilities of these fractions at pH 7.3 and low ionic strengths; the compatibility of the electrophoretic and ultracentrifugal data of the individual fractions with those of the original plasma; and the recovery of hemoglobin, not hematin, in fraction III obtained from specimens contaminated with this pigment. However, the most significant evidence for minimum alterations of native proteins was that the S20, w and the electrophoretic mobility data on the physically recombined fractions were identical to those found on whole plasma.The fractionation procedure examined here quantitatively isolates fibrinogen, prothrombin and antithrombin in primary fractions. Results have been obtained demonstrating its significance in other biological systems. These include the following: The finding of 5 S20, w classes in the 4 primary fractions; the occurrence of more than 90 per cent of the plasma gamma globulins in fraction III; the 98 per cent pure albumin in fraction IV; and, finally, the high concentration of beta lipoproteins in fraction II.


1963 ◽  
Vol 09 (02) ◽  
pp. 446-458 ◽  
Author(s):  
Rudolf Holemans ◽  
Dionysios Adamis ◽  
James F Horace

SummaryHeparin in high concentration inhibits the fibrinolysis of human plasma clots or bovine fibrin by fibrinolytic agents which produce plasminogen activation. Heparin has no effect on the fibrinolytic activity of plasmin or Aspergillus protease.In order to produce inhibition of plasminogen activation heparin requires the presence of a co-factor which is present in citrated human plasma but absent from its euglobulin fraction.In none of the concentrations tested has heparin an enhancing effect on fibrinolysis.


1983 ◽  
Vol 49 (01) ◽  
pp. 005-007 ◽  
Author(s):  
B Østerud ◽  
T Flægstad

SummaryIn 16 patients, 13 with meningococcal infection and 3 suspected to have this infection, 8 patients were found to possess significant higher level of tissue thromboplastin activity of their monocytes isolated from the blood at the admission to the hospital than normal. Five of those 8 patients had an extremely high concentration, > 60-300 fold increase, and all these patients died. The exposed tissue thromboplastin activity on the surface of the endotoxin stimulated monocytes is probably the direct inducer of disseminated intravascular coagulation (DIC) in meningococcal infection.


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