摘要:

SUMMARYThe topical application to human skin of a 1:1 aqueous solution of ammonium hydroxide in a well drilled into a plastic block will provoke an infra‐epidermal blister in an average time of about 13 min.The blister roof can be used for physico‐chemical analyses of the horny layer while the base is suitable for studies of wound healing, bacterial infections, etc.The minimal blistering time (MBT) increases directly as the number of cell layers of the stratum corneum and ranges from 3 to 57 min in different regions and persons. The intensity of the dermatitis provoked by a 24 h exposure to sodium lauryl sulphate is strongly correlated with the MBT. The latter is therefore a reliable measure of cutaneous irritability.The blisters are virtually painless. The inflammatory reaction clinically and histologically is slight. Healing is rapid without scarr

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1977.tb07148.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYIt is important in the technique of photopatch testing, using oil of bergamot, to have determined the concentration of the active psoralen, bergapten, so as to avoid false negative responses in the assessment of phototoxic reactions. Techniques for assessing the phototoxic components of oil of bergamot are described and quantitative analyses of bergapten, the only significant photoactive compound in the samples examined, are reported. The phototoxicity of bergapten was found to be nearly the same as that of xanthotoxin (8‐MOP) in tests on human ski

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1977.tb07149.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYHistochemical and electron microscopic studies were carried out on the newborn mouse model of the staphylococcal scalded skin syndrome to investigate the mechanism of action of the staphylococcal epidermolytic toxin that causes it. Histochemical studies showed that an intra‐epidermal split develops below the subcorneal zone which is rich in catabolic enzymes (the so‐called esterase‐acid phosphatase‐rich band). However, histochemical alterations in the enzyme pattern could not be demonstrated. The earliest change revealed by electron microscopy was a widening of the intercellular space, with the formation of microvilli at the level between the stratum spinosum and stratum granulosum where the split later occurs. A clearing of the peripheral cytoplasm along the cell membranes was also revealed. In pre‐split areas, adhesion between cell membranes of adjacent cells seems to be lost; desmosomes continue to hold the cells together but the split develops when these are broken by mechanical pressure. Later, damaged cell membranes may be seen. Extracellular keratinosomes remain unchanged.Although these findings do not agree with the already divergent results of other studies, they help support the findings of all groups that cases of the Lyell syndrome produced by staphylococci do not occur through necrolysis; it is therefore inappropriate to continue applying the term ‘toxic epidermal necrolysis’

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1977.tb07150.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYIn squamous epithelia with a single layer of germinative cells, the age distribution of cells in the cell cycle is shown to depend on the direction of the mitotic axis (i.e. a line joining the nuclei of daughter cells) relative to the plane of the basal layer. When axes are in the plane of the basal layer the age distribution is exponential; when cells divide at right angles to the plane of the basal layer, the age distribution is rectangular. When there is a ratio of vertical to horizontal axes, the age distribution is intermediate but can be calculated from knowledge of the proportion of axes in the plane of the layer. Squamous epithelia can be classified according to this arrangement of axes.When there are multiple layers of germinative cells, as in psoriasis, the age distribution is shown to be exponential to a good approximation, whatever the direction of the mitotic axes in the several layers.The importance of these observations is demonstrated by analysing metaphase arrest experiments with vincristine in the single layer of germinative cells in the mouse oesophagus, and in the several layers found in psoriatic epidermis. Choice of the wrong age distribution leads to an error of 6 h in the oesophagus and 23 h in psoriatic epidermis, when the mean cell cycle time is calculated.It is concluded that, in squamous epithelium, it is most important to know the age distribution before calculating the cell cycle time by methods involving measurement of the rate of entry of cells into mitosis or DNA synthesis.

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1977.tb07151.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYA new model for assaying epidermal cell turnover times is presented. It is based on desquamation rates of the stratum corneum and the consequent obligatory turnover time of the keratinocyte layer. A total epidermal turnover time of 45 days is derived from the model for the human volar forearms.

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1977.tb07152.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYNail growth of all fingers was measured on 13 men wintering in Antarctica. A mean rate of 109–5 μm/ day was found with the longer digits having faster growth. No significant difference was demonstrated between the warmer and colder months of the study period. Monthly variations suggested that subjects had an individual rate irrespective of environmental influences.Comparison with previous studies both in polar and temperate conditions showed growth rates in Antarctica have increased progressively; present values being comparable with observations in temperate climat

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1977.tb07153.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYThirty‐nine clinically uninflamed cysts of the three most common varieties, epidermoid cysts, tri‐chilemmal cysts and steatocystoma multiplex were removed under sterile conditions and the contents cultured under aerobic and anaerobic conditions. Seventy‐three percent of epidermoid cysts grew significant numbers of organisms whereas none of the trichilemmal cysts did so. The organisms found were the common skin commensals,Staphylococcus epidermidisbiotype I, anaerobic Gram positive cocci of the Gaffya type andCorynebacterium acnesType I. This indicates that cysts which clinically have a punctum, namely epidermoid cysts, may become colonized with surface bacteria under normal circumstances. If they become colonized with pathogenic bacteria they become inflamed, a not uncommon clinical picture. The results from patients with steatocystoma multiplex were difficult to interpret because of the small numbers of patients involved and the unusual clinical appearance they pres

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1977.tb07154.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYCommercial solutions of clotrimazole, tolnaftate and tolcyclate were tested for 12 h in cultures ofMicrosporum canis. They induced modifications in particle distribution, a blebbing of particle‐free areas and the appearance of lamellar figures on the plasma membrane of fungus cells. The first two changes in the plasma membrane might be ascribed to a modification of the spectrin‐like meshwork, while the third could be the result of a crystalline organization of membrane lip

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1977.tb07155.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYFibroblasts of skin explants from three normal men and six patients with recessive epidermolysis bullosa dystrophica (EBD‐R) were cultured in Dulbecco's medium, grown to confluence, sectioned and studied with the electron microscope.The normal control fibroblasts from the 6th to 13th passage (secretory phase) showed irregular or lobed nuclei with centrally scattered chromatin. They also had prominent RER, Golgi complexes, variously shaped mitochondria and cytoskeletal microfibrils. Their peripheral cytoplasm exhibited many vacuoles and a small number of these were autophagic lysosomes.In addition to the ultrastructural features described in the control fibroblasts, the EBD‐R cells from the 6th passage contained remarkable numbers of strongly electron dense lysosomal bodies through their entire cytoplasm with very few empty vacuoles.It is speculated that the accumulation of these lysosomes may be connected with a primary metabolic cellular defect in the dermal fibroblasts of patients with EBD‐R akin to that described in mucopolysaccharide storage dis

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1977.tb07156.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYThis paper reports chemotactic studies on human polymorphonuclear leukocytes using prostaglandins, prostaglandin precursors and prostaglandin metabolites in vitro.Chemotaxis could not be demonstrated when arachidonic acid, prostaglandins D2, E, E2, F2α, and the prostaglandin metabolites 15 keto E2, 15 keto F2αwere incubated with polymorphonuclear leukocytes using the Boyden millipore techniqu

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1977.tb07157.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY