摘要:

Summary.—1Epidermal mass (thickness) is controlled by a complex mechanism in which the epidermal chalone plays a central role. The chalone inhibits epidermal mitotic activity by reducing the proportion of the basal cells that are in the mitotic cycle and the speed at which this cycle is completed. It also acts to reduce the speed at which the distal post‐mitotic cells age and die.2The response of the epidermal mass (thickness) to a rising mitotic rate (falling chalone concentration) is divisible into 3 separate phases.3In Phase 1 (e.g. normal mouse epidermis) the mitotic rate is low. Mitosis occurs in the basal layer in such a way that the 2 daughter cells remain basal; the pressure so generated is relieved by the extrusion of a neighbouring basal post‐mitotic cell. Any change in the mitotic rate is matched by an equivalent change in the rate of ageing of the extruded cells; thus no change in epidermal thickness occurs.4In Phase 2 (e.g. normal human epidermis, hyperplastic mouse epidermis) the mitotic rate has increased beyond the point at which all the basal cells have entered the mitotic cycle; there are therefore no post‐mitotic basal cells available to be extruded. From this point onwards the greater the mitotic rate (the lower the chalone content), the higher the lateral pressure within the basal layer, the greater the folding (or doubling) of this layer, the higher the numbers of basal mitotic cells per unit area of skin, the higher in consequence the number of distal post‐mitotic cells (which are also ageing more quickly) per unit area of skin, and the thicker the epidermis. Thus epidermal mass (thickness) is a function of the degree of folding (or doubling) of the basal layer and of the increased rate of post‐mitotic ageing. Towards the top of Phase 2 (e.g. psoriasis, papillomata) the chalone content of the whole epidermis has fallen to a low level, but the rate of cell gain still equals the rate of cell loss.5In Phase 3 (e.g. epidermal carcinomata) the average chalone content is very low, and the rate of cell gain exceeds the rate of cell loss. The normal balance can be restored by raising the chalone concentration artificially.6The manner in which this mechanism operates during normal healing and tissue regeneration is examined, and reasons are given for considering that these epidermal reactions are typical of mitotic tissues and of tumours

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1972.tb00307.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Summary.—The electronmicroscopic appearance of the epidermis in 2 cases of indeterminate leprosy was studied. There was a significant decrease in the number of melanocytes and several of those present showed signs of depressed activity and atrophy. Langerhans cells were increased in number and seemed to replace the melanocytes. Further study is indicated to elucidate the pathogenesis of melanocyte inactivity and reduction in numbe

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1972.tb00308.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Summary.—Measurements of skin conductivity using silver disc and multiplint electrodes have been described. Comparisons with skin temperature measurements using thermistor probes have been made, and a parallel between the two parameters demonstrated. A connection between skin conductivity and blood flow was suggested, and confirmed by the effects on conductivity of exercise and the intradermal injection of adrenaline and histamine under the electrode site. The implications of this are discussed and a possible role of such measurements in the clinic is mentione

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1972.tb00309.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Summary.—Lipids were extracted from slices taken horizontally through the epidermis of the cow snout. The fatty acid compositions of the phospholipids, triglycerides and free fatty acids of each slice were determined. There was a decrease in the proportion of octadecenoic acid in the phospholipids and triglycerides, and marked increases in the proportions of octadecenoic and octadecadienoic acids in the triglycerides towards the skin surface. There was little consistent change in the composition of the free fatty acids through the epidermis. Possible explanations for these findings are discusse

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1972.tb00310.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Summary.—By patch testing cross‐sensitivity was not observed between the sesquiterpene lactone, alantolactone (fromInula) and ilicic acid, which is an unsaturated sesquiterpenoid lacking a lactone ring (fromAmbrosia) and α‐methylene‐γ‐butyrolactone (fromTulipa) which is the simplest structure containing the grouping that is characteristic of the active compounds; and protolichesterinic acid (from the lichenCetraria) which is an unsaturated lactonic acid.Some 50 additional potentially allergenic sesquiterpene lactones derived from plants are listed from the families, Compositae, Lauraceae, and Magnoliaceae; some lactones from the family Umbelliferae are

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1972.tb00311.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Summary.—Seborrhoeic dermatitis of the face is common in those males who grow moustaches or beards. Although the pathophysiology of the process remains hypothetical, the prevention and therapy are clear cut. They involve the use of shampoos containing tar, salicylic acid and sulphur and, in extensive cases, the use of topical corticosteroids. There is no indication for radical surgical procedures such as shavin

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1972.tb00312.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Summary.—The authors have observed an itching dermatitis of 9 months duration in the 3 members of a family in the Netherlands. The source of the itch appeared to be a mangy dog that lived in contact with the family and was heavily infested by the miteCheyletiella yasguriSmiley. All the symptoms disappeared quickly in both the family and the dog after treatment with an acaricid

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1972.tb00313.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Summary.—Deficient folate activity was diagnosed in all of 7 patients treated for psoriasis with methotrexate (Mtx) by applying a new method (Ellegaard and Esmann, 1972a) of assaying folate activity which utilizes the folate‐dependent incorporation of14C‐formate into serine of lymphocytes during incubation under standardized conditions. The arithmetical mean of this folate activity was 4–8%± 0.6 (SEM) of added14C‐activity per 109lymphocytes per 4 hours, as compared to 9.2%± 0.4 in 24 normals. The14C‐formate incorporation into RNA was severely depressed in each case. Mtx added to lymphocytesin vitrohad no effect on the folate activity.In addition, the new observation was made that patients under treatment with Mtx develop decreasing serum concentrations of B12, possibly due to an impaired B

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1972.tb00314.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Summary.—Clinical and histological features and mitotic counts have been studied in the lesions of 11 patients with psoriasis who were treated with topically applied retinoic acid ointment for a period of 3 months.Serial biopsies were taken at monthly intervals from treated lesions in all 11 patients and from lesions treated with the unmedicated ointment base in 9.There was no significant difference between treated and placebo groups regarding any of the parameters studied. Irritant effects of the retinoic acid were prominent in 7 patients.The significance of these results is discussed in the light of the known mechanism of action of retinoic aci

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1972.tb00315.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Summary.—Eight patients with symptomatic porphyria (porphyria cutanea tarda symptomatica, PCT) were treated with small doses of chloroquin sulphate over periods ranging from 2 to 16 weeks. A good clinical and biochemical response was obtained in all but one patient, who relapsed after initial improvement. Manifestations of acute untoward reaction were seen in one patient only. It is concluded that low dose chloroquine therapy is both safe and effective in PCT.Studies in porphyric rats indicate that the mechanism of action of chloroquine in PCT is probably not related, as has been suggested, to the formation of a chloroquine‐porphyrin complex which damages liver cells and thereby leads to a reduction in hepatic porphyrin stores.Chloroquine therapy led to increased urinary iron excretion and an increase in the desferrioxamine‐chelatable iron in patients with PCT. It is suggested that the prolonged beneficial effects of chloroquine treatment may be related to reduction in a specific pool of liver

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1972.tb00316.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY