scholarly journals The histochemical distribution of protein bound sulfhydryl groups in human epidermis by the new staining method.

1979 ◽  
Vol 27 (5) ◽  
pp. 942-946 ◽  
Author(s):  
H Ogawa ◽  
A Taneda ◽  
Y Kanaoka ◽  
T Sekine
Keyword(s):  
Cell Membrane ◽  
Stratum Corneum ◽  
Staining Method ◽  
Sulfhydryl Groups ◽  
The Other ◽  
Human Epidermis ◽  
Horny Layer ◽  
Intercellular Spaces ◽  
Sh Groups ◽  
Thiol Reagent

Recently, we synthesized a new fluorescent thiol reagent, N-(7-dimethylamino-4-methylcoumarinyl)-maleimide (DACM) which is nonfluorescent by itself but will react readily with -SH groups to form highly fluorescent addition products. By the use of this reagent, we studied the localization and concentration of -SH groups and S--S linkages in the human epidermis. The distribution of -SH groups in living layers was abundant in cytoplasm but not in nuclei. The fluorescence was concentrated on the cell membrane or intercellular spaces (MIC parts) and was increased at the spino-granular junction. In the horny layer, the fluorescence of the MIC parts appeared brilliantly in the lower layers and decreased gradually. On the other hand, the fluorescence of cytoplasm in keratinized cells in the stratum corneum was faint. The localization of S--S linkages was not a characteristic of the living layers, but appeared abruptly at the junction of living and horny layers. The fluorescence was localized to the MIC parts and disappeared gradually. The distribution of S--S linkages appeared to be very low in the cytoplasm of keratinized cells. No substantial fluorescence was localized on keratohyalin granules even after reduction.

Ultrastructure and Staining of Developing Elastic Tissue

1971 ◽  
Vol 29 ◽  
pp. 244-245
Author(s):  
E. N. Albert
Keyword(s):  
Fine Structure ◽  
Phosphotungstic Acid ◽  
Staining Method ◽  
Rat Aorta ◽  
Uranyl Acetate ◽  
The Other ◽  
Elastic Fibers ◽  
Elastic Tissue ◽  
Lead Citrate ◽  
New Born

Silver tetraphenylporphine sulfonate (Ag-TPPS) was synthesized in this laboratory and used as an electron dense stain for elastic tissue (Fig 1). The procedures for the synthesis of tetraphenylporphine sulfonate and the staining method for mature elastic tissue have been described previously.The fine structure of developing elastic tissue was observed in fetal and new born rat aorta using tetraphenylporphine sulfonate, phosphotungstic acid, uranyl acetate and lead citrate. The newly forming elastica consisted of two morphologically distinct components. These were a central amorphous and a peripheral fibrous. The ratio of the central amorphous and the peripheral fibrillar portion changed in favor of the former with increasing age.It was also observed that the staining properties of the two components were entirely different. The peripheral fibrous component stained with uranyl acetate and/or lead citrate while the central amorphous portion demonstrated no affinity for these stains. On the other hand, the central amorphous portion of developing elastic fibers stained vigorously with silver tetraphenylporphine sulfonate, while the fibrillar part did not (compare figs 2, 3, 4). Based upon the above observations it is proposed that developing elastica consists of two components that are morphologically and chemically different.

Paracrystalline Aggregates of Psoriatic Keratin and Their Relation to Normal Keratin Structure

1985 ◽  
Vol 43 ◽  
pp. 680-681
Author(s):  
S. Trachtenberg ◽  
P.M. Steinert ◽  
B.L. Trus ◽  
A.C. Steven
Keyword(s):  
Cell Death ◽  
Stratum Corneum ◽  
Intermediate Filament ◽  
Skin Disease ◽  
Amorphous Matrix ◽  
Terminal Differentiation ◽  
Proteolytic Degradation ◽  
Horny Layer ◽  
Chronic Skin ◽  
Chronic Skin Disease

During terminal differentiation of vertebrate epidermis, certain specific keratin intermediate filament (KIF) proteins are produced. Keratinization of the epidermis involves cell death and disruption of the cytoplasm, leaving a network of KIF embedded in an amorphous matrix which forms the outer horny layer known as the stratum corneum. Eventually these cells are shed (desquamation). Normally, the processes of differentiation, keratinization, and desquamation are regulated in an orderly manner. In psoriasis, a chronic skin disease, a hyperkeratotic stratum corneum is produced, resulting in abnormal desquamation of unusually large scales. In this disease, the normal KIF proteins are diminished in amount or absent, and other proteins more typical of proliferative epidermal cells are present. There is also evidence of proteolytic degradation of the KIF.

scholarly journals Thiol-sensitive sites in cell adhesion. Decreased entry of SH-binding reagents into attached BHK cells

1982 ◽  
Vol 208 (2) ◽  
pp. 473-478 ◽  
Author(s):  
D D McAbee ◽  
F Grinnell
Keyword(s):  
Cell Adhesion ◽  
Small Molecules ◽  
Cell Spreading ◽  
The Other ◽  
Bhk Cells ◽  
Sh Groups ◽  
Nitrobenzoic Acid ◽  
Cytoplasmic Proteins ◽  
Adhesion Process ◽  
Suspended Cells

Studies were carried out to learn more about the critical SH groups involved in cell spreading. Pretreatment of suspended baby hamster kidney (BHK) cells with 3 mM-iodoacetate or iodoacetamide for 10 min at 4 degrees C completely inhibited the ability of the cells to spread on fibronectin-coated substrata. If, however, BHK cells were permitted to attach and spread before being treated with the SH-binding reagents, and then harvested by trypsinization and assayed for spreading on fibronectin-coated substrata, there was no inhibition of cell spreading. The extent of prior attachment required before the cells became insensitive to the SH-binding reagents was tested and was found to occur early during the cell adhesion process, before any cell spreading was observed. In analytical experiments, there did not appear to be any difference in the total number of SH groups between suspended or spread cells as determined with 5,5′-dithiobis-(2-nitrobenzoic acid). The uptake of radiolabelled iodoacetate into intact spread cells, however, was found to be 3.5 times less than that found with suspended cells. On the other hand, the distribution of incorporated radioactivity into suspended and spread cells was similar. Most of the radioactivity (approximately 70%) was incorporated into small molecules (e.g. glutathione and cysteine), less (approximately 20%) was incorporated into cytoplasmic proteins, and the least incorporation (approximately 10%) was into the cell cytoskeleton. The data are interpreted to indicate there is a decreased permeability of spread cells to the SH-binding reagents.

scholarly journals The Relationships between Cholesterol and Suicide: An Update

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Domenico De Berardis ◽  
Stefano Marini ◽  
Monica Piersanti ◽  
Marilde Cavuto ◽  
Giampaolo Perna ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cell Membrane ◽  
The Other ◽  
Core Component ◽  
Cell Membrane Stability ◽  
Cholesterol Levels ◽  
The Central Nervous System ◽  
Larger Sample

Cholesterol is a core component of the central nervous system, essential for the cell membrane stability and the correct functioning of neurotransmission. It has been observed that cholesterol may be somewhat associated with suicidal behaviours. Therefore, the aim of this paper was to elucidate current facts and views about the role of cholesterol levels in mood disorders. The majority of the studies reviewed in the present paper suggest an interesting relationship between cholesterol (especially lower levels) and suicidality. On the other hand, particularly during the last years, relationships between serum cholesterol and suicidality were doubted on the basis of some recent studies that have not found any correlation. However, the debate on relationships between cholesterol and suicide is open and longitudinal studies on a larger sample of patients are needed to further clarify this important issue.

AN ABNORMALITY OF KERATIN IN THE HARLEQUIN FETUS

PEDIATRICS ◽  
1970 ◽  
Vol 46 (3) ◽  
pp. 437-440
Author(s):  
John M. Craig ◽  
Lowell A. Goldsmith ◽  
Howard P. Baden
Keyword(s):  
Family History ◽  
Stratum Corneum ◽  
Diffraction Analysis ◽  
Thymus Gland ◽  
Horny Layer ◽  
X Ray Diffraction ◽  
Epithelial Surface ◽  
Negative Family History ◽  
X Ray ◽  
Fibrous Protein

A harlequin fetus was born to unrelated parents with a negative family history for any form of ichthyosis. The child was grossly deformed, showing thick plaques on the cutaneous surface, and survived only 48 hours. Pathological studies of the skin showed marked thickening of the stratum corneum, but no other distinctive changes. X-ray diffraction analysis of the horny layer revealed the presence of a cross-β fibrous protein rather than the usual α-protein. The epithelial surface of other organs appeared normal. The thymus gland was involuted and showed changes in the corpuscles. Abnormalities were also observed in the conversion of cartilage to bone.

Rotary movements and fluid membranes in termite flagellates

1976 ◽  
Vol 20 (3) ◽  
pp. 619-638
Author(s):  
S.L. Tamm ◽  
S. Tamm
Keyword(s):  
Plasma Membrane ◽  
Comparative Analysis ◽  
Cell Membrane ◽  
Shear Zone ◽  
Surrounding Medium ◽  
The Other ◽  
Visual Evidence ◽  
Fluid Membranes ◽  
Internal Motor ◽  
Rotary Motor

We previously described a remarkable type of cell motility that provided direct, visual evidence for the fluid nature of cell membranes. The movement involved continual, unidirectional rotation of one part of a protozoan, including the plasma membrane and cytoplasmic organelles, in relation to a neighbouring part. The cell membrane in the ‘shear zone’ appeared continuous with that of the rest of the cell. The rotary motor consisted, at least in part, of a non-contractile, microtubular axostyle which extended centrally through the cell. The protozoan was a devescovinid flagellate found in the hindgut of a Florida termite. In this paper, we have confirmed earlier reports of this type of motility in other kinds of devescovinids from Australian termites. By demonstrating continuity of the plasma membrane in the shear zone of the Australian devescovinids as well, we have obtained additional examples that provide direct, visual evidence for fluid membranes. A comparative analysis of rotational motility in various devescovinids revealed 2 different kinds of rotary mechanisms. Hyperdevescovina probably have an internal motor, in which one part of the cell exerts forces against another part, as in the Florida termite devescovinid. Devescovina species, on the other hand, have an external motor, in which flagellar and/or papillar movements exert forces against the surrounding medium. The structure of the axostyle in different devescovinids was compared, and its role in rotational motility discussed with respect to the behavioural data.

Ketoconazole - an antifungal drug for oral use

1981 ◽  
Vol 19 (23) ◽  
pp. 91-92
Keyword(s):  
Antifungal Activity ◽  
Cell Membrane ◽  
Oral Administration ◽  
Antifungal Agent ◽  
Systemic Effect ◽  
Antifungal Drug ◽  
The Other ◽  
Membrane Synthesis ◽  
Fungal Cell

Ketoconazole (Nizoral - Janssen) is a new antifungal agent. Like the other imidazoles with antifungal activity such as miconazole,1 clotrimazole2 and econazole,3 it acts by inhibiting fungal cell-membrane synthesis.4 It is well absorbed and exerts a systemic effect; it is thus suitable for oral administration.

Steps in p-aminohippurate transport by kidney slices

1958 ◽  
Vol 196 (1) ◽  
pp. 86-92 ◽  
Author(s):  
Ernest C. Foulkes ◽  
Benjamin F. Miller
Keyword(s):  
Cell Membrane ◽  
Transport System ◽  
Rate Constants ◽  
Extracellular Space ◽  
Concentration Ratio ◽  
Tissue Concentration ◽  
The Other ◽  
Facilitated Diffusion ◽  
Tubular Lumen ◽  
Cortical Slices

The existence of two intracellular fractions of PAH was demonstrated in renal cortical slices of the rabbit on incubation with C14-labeled PAH. One of these fractions is rapidly diffusible and rapidly equilibrates with extracellular PAH. The other fraction, in contrast, diffuses and equilibrates slowly; it is responsible for the high slice to medium concentration ratio of PAH. On the basis of these results a model of the PAH transport system in slices is proposed. This consists of step I, the diffusion of PAH from the medium into the extracellular space in the tissue; there follows step II, a facilitated diffusion step at the peritubular cell membrane; within the cell step III builds up a high tissue concentration of PAH; finally step IV transfers PAH across the luminal border of the cell into the tubular lumen from which it may diffuse back into the medium. Experiments were designed in which each of these steps could be measured individually and their rate constants determined. Alteration of the value of these rate constants by specific drugs localizes the action of such compounds at the peritubular cell membrane (Benemid, 9-alphafluorohydrocortisone) or at the level of both steps II and III in the case of DNP, octanoate and Diodrast. An explanation is also offered for the effect of cold on PAH influx and efflux. It can be calculated that the contribution of step IV to the turnover of PAH in slices is not quantitatively significant.

The effect of changing interfacial tension on the shape of the red cell

1970 ◽  
Vol 48 (6) ◽  
pp. 359-368 ◽  
Author(s):  
B. B. Shrivastav ◽  
A. C. Burton
Keyword(s):  
Cell Membrane ◽  
Interfacial Tension ◽  
Internal Pressure ◽  
Tween 80 ◽  
The Other ◽  
Red Cell ◽  
Osmotic Swelling ◽  
Red Cell Membrane ◽  
Normal Cells ◽  
Area Increase

Previous biophysical research on the equilibrium of the red cell membrane in the normal biconcave, and the other shapes assumed in osmotic swelling, has led to a relation for the dimple region, between the tension in the membrane, its curvature, and an internal pressure. The relation is tested on a new shape produced by adding 0.004% by volume of Tween 80. The opposite membranes near the axis of revolution of the cell become parallel over a disc of diameter 2.6 μ, at a distance of 0.77 μ apart (30% less than the nearest distance in normal cells). The 'dimple' region becomes more like a 'moon crater'. The volume of the cell is not significantly altered, but the surface area increases by about 14%. The shape is consistent with a decrease in interfacial tension of the membrane, and the area increase is similar to that found by Seeman for agents which enter into the membrane. The hypothesis of internal structure across the central part of the cell, indicated by previous studies of birefringence, is supported by the observations on this new shape.

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