DNA SYNTHESIS IN CULTURED EPIDERMAL CELLS FROM PSORIATIC AND NORMAL SKIN

While it is generally accepted that psoriatic epidermis in vivo shows an increase in the number of DNA-synthesizing cells and mitoses, the published data from in vitro studies disagree as to whether or not psoriatic epidermal cells in vitro are more proliferative than normal epidermal cells. In this study, DNA synthesis was measured autoradiographically using cultured epidermal cells from both the involved and uninvolved skin of 8 psoriatic patients as well as from 8 normal individuals. Our results showed no statistically significant differences in DNA synthesis among the three groups.     

THE GROWTH OF ADULT HUMAN SKIN IN VITRO

Summary.— In this report we investigate the role of serum in organ culture of adult human skin. The migratory overgrowth of dermis by epidermal cells is shown to depend on the presence of high molecular weight (mol. wt.) components of serum. Regeneration of the epidermis after 19 days' incubation occurs in the presence of 10% whole serum in the growth medium. DNA synthesis is found to increase in long-term incubations in medium including serum components but not in the presence of Minimal Essential Medium (MEM) only.     

GLYCOPROTEIN IN CULTURED HUMAN SKIN FIBROBLASTS

A unique glycoprotein has been isolated from cultured human embryonic fibroblasts and their culture medium. Analysis showed a composition of 17.5 γ/mg uronic acid, 40 γ/mg hexosamine, and 93.5 γ/mg sialic acid. Gas chromatography revealed fucose, mannose, galactose, and glucose. Ten percent acrylamide 0.1% sodium sulfate acrylamide disc electrophorisis of the glycoprotein after treatment with 6 M urea showed a RF ratio of 0.3 and a molecular weight of about 95,000. The protein content was 454 γ/mg and amino acid analysis revealed high contents of aspartic acid, threonine, glutamic acid, alanine, and leucine. The existence of acidic glycoproteins in human fibroblasts suggests an association with collagen fibril maturation and may be of etiologic and diagnostic significance in connective tissue disease of the skin.     

ACTION OF STAPHYLOCOCCAL EPIDEMOLYTIC TOXIN ON MOUSE SKIN IN ORGAN CULTURE

Summary.— Changes similar to those of Toxic Epidermal Necrolysis (T.E.N.) have been produced in organ cultures of infant mouse skin maintained in a chemically defined medium with added staphylococcal epidermolytic toxin.     

MEASUREMENT OF BLOOD FLOW IN SKIN WITH AN INTACT VASCULAR PEDICLE

An experimental model was devised to confirm directly the validity of total skin blood flow measurement, as postulated by Sejrsen. A section of skin in the groin of the rat was prepared, which contained an intact artery and vein. Both of these were direct branches of the femoral vessels. When 133Xe was injected intradermally in saline solution, it was demonstrated that a sham isolated vascular pedicle cleared the isotope, and that the clearance was biexpoential, suggesting two compartments. When the vascualr pedicle was ligated, thereby removing direct blood flow to the piece of skin, the 133Xe clearance curve was monexponential. It is concluded that the rapid portion of the biexponential clearance curve, as analyzed by Sejrsen, does represent the dermal vascular components of isotope clearance, and that measurement of cutaneous blood flow by this method is a valid and useful technique. Results using this technique to follow rejection in a new skin transplant model are presented.     

EXPERIMENTAL ZOSTERIFORM HERPES SIMPLEX VIRUS INFECTION IN MOUSE SKIN

SUMMARY.— A highly reproducible model in which linear zosteriform lesions are produced in the skin of Webster Schneider mice, using an oral strain of herpes simplex virus, (HSV) is described. The incidence of infection is high, and a large proportion of infected animals develop a highly characteristic ascending paralysis which is invariably fatal.     

THE IN VITRO PENETRATION OF FLUOCINONIDE THROUGH HUMAN SKIN FROM DIFFERENT VOLUMES OF DMSO

Summary.— The penetration of fluocinonide from solution in DMSO across human abdominal skin in vitro has been examined. Different volumes of solution, ranging from 0.025 ml to 0.75 ml, were studied.
The results show that better penetration is achieved in this in vitro situation from smaller volumes than from larger volumes. Possible mechanisms that might account for this phenomenon are discussed. A possible explanation considers that the flux of water into the DMSO solution causes an increase in the thermodynamic activity of the drug and hence in the penetration rate of the drug into and through the skin.     

IMMUNOHISTOCHEMICAL DEMONSTRATION OF POLY(ADENOSINE DIPHOSPHATE-RIBOSE) SYNTHESIS IN HUMAN SKIN

The distribution of poly(adenosine diphosphate-ribose) [poly(ADP-ribose)] synthesis in human skin was investigated by an indirect immunofluorescence technique using a specific antibody against poly(ADP-ribose). In normal skin, the specific immunofluorescence of poly(ADP-ribose) was observed in nuclei of not only epidermal cells but also cells in the dermis, including the hair follicle and sweat gland. Preincubation of tissue sections with NAD, a substrate for poly(ADP-ribose) synthesis, intensified the immunofluorescence of poly(ADP-ribose). Nuclear immunofluorescence was prominent in the lower and middle layers of the epidermis and became weaker in the upper layers in parallel with the disappearance of the nuclei, especially in tissues untreated with NAD. The immunostaining pattern of poly(ADP-ribose) synthesis in psoriatic epidermis was similar to that of normal skin except that fluorescence was observed in nuclei of the parakeratotic horny layer. In affected cancerous skin, immunofluorescence of poly(ADP-ribose) was weak in nuclei of cells in the inner layers of horn pearl of well differentiated squamous cell carcinoma, although fluorescence was prominent in the outer layer cells of horn pearl. In contrast, tumor cells of both malignant melanoma and basal cell epithelioma exhibited the nuclear immunofluorescence of poly(ADP-ribose) synthesis. These results suggest that the capacity for synthesizing poly(ADP-ribose) may be related to the differentiation of epidermal cells.     

A COMPARISON OF IN VIVO AND IN VITRO METHODS OF IDENTIFYING HUMAN EPIDERMAL CELLS IN DNA SYNTHESIS

Summary.— For identifying epidermal cells in DNA synthesis there are 2 rather different methods in use: subcutaneous injection of ³H thymidine in vivo , and short term incubation of skin slices with ³H thymidine in vitro.
A direct comparison of these methods on the skin of the same individuals at the same times shows little difference in the results obtained. If anything, the in vivo method is slightly more sensitive.     

COMPARATIVE STUDY OF THE SENSITIVITY OF MOUSE DORSAL ROOT GANGLION AND CEREBELLUM TO HERPES SIMPLEX VIRUS IN VITRO

To study the effect of Herpes simplex virus (HSV) on nervous tissue, we examined (1) the possibility of establishment of latent infection in vitro, (2) the replication of HSV in mouse dorsal root ganglion and cerebellar cultures and (3) the effect of anti-HSV rabbit serum on the maintenance of both cultures. Although both cultures without antibody were finally destroyed after inoculation, replication of HSV in cerebellar cultures was much higher than in the ganglion in both medium and tissue (P<0.005). Infected cultures treated with anti-HSV antibody (CF: ×128) could survive longer in nerve cells of ganglion than in those of cerebellum. These results suggest that the ganglion can resist HSV infection and this makes latent infection possible.     

MORPHOLOGICAL AND BIOCHEMICAL STUDIES ON THE DEVELOPMENT OF FOETAL MOUSE SKIN

SUMMARY.— It has been noted that biochemical and morphological changes occurred simultaneously during the embryogenesis of mouse skin. The onset of histological maturation of collagen fibres coincided with a change in the pattern of the in vitro incorporation of both ³⁵SO₄ into the sulphated mucopoly-saccharide and ¹⁴C-proline into the collagen of whole skin. Simultaneously, an increase in thickness and differentiation of the epidermis and changes in the basement membrane were observed. Thus, by applying a variety of techniques it has been demonstrated that a critical period of skin maturation involving dermis and epidermis is reached on the eighteenth day of embryogenesis in the mouse.     

AGE AND SEX VARIATION IN SKIN SURFACE LIPID COMPOSITION AND SEBUM EXCRETION RATE

Summary.— The sebum excretion rate and skin surface lipid composition were determined in 193 male and female control subjects aged between 4 and 60 years. The sebum excretion rate, squalene and wax ester content of surface lipid were maximal in males aed 26–40. The percentages of surface lipid wax esters were greater in males than females at all ages, but the prepubertal peak of wax esters in males may be due to an epidermal contribution from sterol esters. There was no significant age or sex variation in the sum of the percentages of triglycerides and free fatty acids, but the degree of hydrolysis varied considerably with age. The free fatty acid content was greatest in the first decade in both sexes, when the sebum excretion rate is at the lowest levels. Cholesterol content of surface lipid rose to maximal levels at puberty in both sexes.     

THE ADENYL CYCLASE OF SKIN I. MEASUREMENT AND PROPERTIES

A method is described for the measurement of cutaneous adenyl cyclase. Certain properties of the adenyl cyclase of guinea-pig skin have been studied; this enzyme appears to be unusual in that no stimulation of its activity by adrenalin could be demonstrated.     

IMMUNO-HISTOPATHOLOGY OF THE SKIN IN PEMPHIGOID

SUMMARY.— The in vivo direct immunofluorescent (DIF) staining patterns of the skin surrounding the lesions of 5 patients suffering from pemphigoid are reported.
It appeared that fine granular IgG deposits occur in the dermis and more closely packed in the junctional zone of most of the biopsies examined. Only 1 case with a very high (anti-basement membrane) IgG antibody titre showed a conspicuous linear fluorescence of the basement membrane zone, while 2 other cases with a less high antibody litre showed both types of staining patterns. The impression was gained that there is some relation between the antibody litre and the DIF staining pattern in DH.
The findings of this study are also in favour of the concept that pemphigoid and dermatitis herpetiformis are 2 different disease entities; however the existence of intermediate cases cannot be ruled out.
The advantages of the DIF method are discussed. An improved filter combination for blue narrow-band excitation and a rigid control of the conjugates used for IF studies are recommended.     

大疱性疾病正常皮肤免疫荧光检测的临床意义

本文DIF检测天疱疮正常皮肤阳性率为93.2%,大疱性类天疱疮正常皮肤阳性率为100%,因此作者认为进行正常皮肤的DIF检测对无皮肤损害的天疱疮、大疱性类天疱疮的早期诊断、鉴别诊断、推测予后具有重要意义。     

VARIATIONS IN SKIN SURFACE LIPID COMPOSITION AND SEBUM EXCRETION RATE WITH DIFFERENT SAMPLING TECHNIQUES II

Summary.— The technique of Sellotape stripping was used to investigate the role of the stratum corneum in modifying sebum excretion rate and skin surface lipid composition.
All experiments were performed on the forehead. The stratum corneum influences the rate of sebum excretion as Sellotape stripping produced a significant increase in sebum excretion rate, but this effect was abolished by systemic antibiotics.
Skin surface lipid composition, when sampled by absorbent papers, was not influenced by Sellotape stripping, but when sampled by an ether-soaked sponge after Sellotape stripping, had a lessened epidermal lipid contribution. Thus the stratum corneum modifies skin surface lipid composition when sampled by an organic solvent.
Absorbent papers may be preferable to other sampling techniques on the forehead in the investigation of the role of sebaceous biochemical factors in the pathogenesis of acne vulgaris.