无血清人头皮体外组织培养的研究

目的 探讨用无血清培养基进行人头皮体外组织培养的可行性及培养头皮的结构和功能变化。方法 用无血清William E培养基进行人头皮气/液界面培养,用解剖显微镜检测毛发生长情况,HE染色法观察头皮组织结构变化,细胞毒性试剂盒检测培养上清液中的乳酸脱氢酶活性。结果 头部皮肤经过22天的无血清William E培养基体外器官型培养,仍保持结构的完整性。毛干生长的长度在无血清William E培养基显著高于含血清MEM培养基（P < 0.05）。无血清William E培养基组分别在培养第2天和第16天LDH活性出现两个峰,而含血清MEM培养基在第12天出现峰值。随着培养时间延长,毛囊渐由生长期转变为退行期和休止期。结论 这一器官型头皮培养模型可用于头部皮肤及毛囊的研究。     

Staphylococci of the normal human skin flora

Summary 352 strains of Staphylococci of the normal human skin flora were sampled from one volunteer by single scrabbing in a ca. 3 cm² measuring area. They were biotyped by the scheme of Pelzer et al. (1973)—a modified Baird-Parker-Scheme (1963)— and the resistance to antibiotics was investigated by the method of Bauer et al. (1966).All the nine biotypes of Staphylococci were found in variable quantities. It seems problematic to call one biotype as the main type. Morphologically identical colonies of Staphylococci from the indigenous flora of the human skin were not identical in their biotypes as previously described by Pelzer (1976).Only the investigation of all Staphylococci colonies from the culture plate can evaluate all biotypes of Staphylococci of the normal human skin flora, and can give the right quantitative correlation. Staphylococci were found to be sensitive and resistant up to four antibiotics, and one biotype did not show one type of antibiogram.     

Development of a short-term human full-thickness skin organ culture model in vitro under serum-free conditions

Skin exerts a variety of important functions to maintain its integrity and viability. It can be used as an experimental ex vivo model to study wound healing, oxidative stress, skin aging, carcinogenesis as well as topical or "systemic" therapeutic intervention in vitro. This report aims to validate a serum-free human full-thickness skin organ culture model with regard to dependency of skin viability on culture duration and location of skin cross-section (1-5) from the outer (section?1) to the inner side (section?5) of a skin specimen (5?×?10?mm). Cultured skin was analyzed in time-dependent manner for structural damage (H&E staining) and 'balance' between proliferation (Ki67) and apoptosis [cleavage of caspase-3, lactate dehydrogenase (LDH), TUNEL]. First structural disturbances were observed at 48?h (section?3; middle part), increasing with prolonged culture time. Cleavage of caspase-3 and appearance of apoptotic [TUNEL(+)] cells showed significant increase at 72?h in sections?4 and 5, respectively. This correlated to increasing LDH release. Parallel analysis of proliferating [Ki67(+)] cells revealed simultaneous down-regulation within the first 48?h reaching complete absence of Ki67(+) cells at 72?h. These data define an accurate, standardized and robust serum-free short-term ex vivo human full-thickness skin model which is suitable for experimental studies of up to 48 or 72?h in vitro. This model therefore might be used for research related to, e.g., short-term experimentally induced inflammation, UV-induced structural and functional damage, wound healing and substance penetration.     

Revascularization of free full thickness skin autografts

Summary The vascular system in experimental, free, full thickness skin autografts in guinea pigs was visualized by injecting Indian ink in the period between the 6th postoperative day and and eight weeks after the operation. Ideally, revascularization occurs by reactivation ofexisting vessels in the graft. Even reactivation of perifollicular vascular networks and the subepidermal vascular plexus is possible. If revascularization occurs through the growth ofnew vessels, for a long time the vascular arrangement is not the same as that in normal guinea pig skin. The epidermis usually shows acanthosis-like changes. Fast and effective revascularization minimizes the extent and duration of this change.

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Zusammenfassung Beim Meerschweinchen wurde das Gefäßsystem innerhalb experimentell gesetzter autologer freier Vollhauttransplantate durch Tuscheinjektion in einem Zeitraum zwischen dem 6. postoperativen Tag und 8 Wochen nach der Operation dargestellt. Die Revascularisation erfolgt im Idealfall durch Reaktivierung deralten Transplantatgefäße. Selbst eine Reaktivierung der perifollikulären Gefäßnetze und des subepidermalen Gefäßplexus ist möglich. Wenn es zu einer Revaskularisation durch Einwachsenneuer Gefäße kommt, so weicht die Gefäßanordnung über längere Zeiträume erheblich von der normaler Meerschweinchenhaut ab. Die Epidermis ist meist acanthoseähnlich verdickt. Dauer und Ausmaß dieser Veränderung sind um so geringer, je besser und schneller die Revascularisation erfolgt.

     

Investigation of pajama properties on skin under mild cold conditions: the interaction between skin and clothing

Background Clothing is considered the second skin of the human body. The aim of this study was to determine clothing–wearer interaction on skin physiology under mild cold conditions. Methods Skin physiological parameters, subjective sensory response, stress level, and physical properties of clothing fabric from two longitude parallel‐designed wear trials were studied. The wear trials involved four kinds of pajamas made from cotton or polyester material that had hydrophilic or hydrophobic treatment, conducted for three weeks under mild cold conditions. Statistical tools, factor analysis, hierarchical linear regression, and logistic regression were applied to analyze the strong predictors of skin physiological parameters, stress level, and sensory response. Results A framework was established to illustrate clothing–wearer interactions with clothing fabric properties, skin physiology, stress level, and sensory response under mild cold conditions. Discussion Fabric has various effects on the human body under mild cold conditions. A fabric’s properties influence skin physiology, sensation, and psychological response.     

Microbial flora and odor of the healthy human skin

The microflora resident on human skin shows great interindividual and intraindividual differences. It is essentially composed of micrococci, staphylococci, aerobic and anaerobic coryneforms as well as pityrosporum species which, in accordance with the different environment in the different regions of the body, are in a steady state. With increasing age, human skin microflora undergoes qualitative changes: the streptococci, which are found in infants, disappear and coryneform bacteria occur, which are mainly responsible for odor production. Anaerobic propionibacteria are more numerous in juveniles and young adults, a fact that may be explained by increased sebum production. Only the coryneform bacteria are able to produce the typical axillary odor by decomposition of apocrine sweat. Cocci, however, obviously do not have this capacity. It remains to be established which substances participate in odor production. With sensitive chromatographic methods amino acids, steroids and free fatty acids were detected, which could be related to body odor. There are possibly only a few commonly occurring odorous substances. The necessity of analyzing these substances is stressed.     

Improved barrier function observed in cultured skin substitutes developed under anchored conditions

Background/purpose: The current method of producing cultured skin substitutes (CSS) is focused on providing treatments for severe skin wounds/burns. We have developed a modified growth method to make them more suitable for in vitro product‐testing/toxicity‐testing purposes. Method: CSS grown in Petri dishes were either transferred to Franz diffusion cells on day 5 (modified method) or left in the Petri dish (standard method) and maintained in these environments for the remainder of the growth phase. Mitochondrial metabolism (MTT assay) was measured on days 5, 10 and 14 and histology was studied on days 5, 10 and 14. Barrier function for all tissues was evaluated by transferring them to Franz cells (standard method) and measuring transepidermal water loss (TEWL), ³H₂O penetration and ¹⁴C‐niacinamide permeability on days 7, 14 and 21. Results: CSS grown by the standard and modified methods showed comparable cell viability and tissue morphology. Barrier function, however, was markedly improved in CSS grown by the modified method. The average improvement at days 7 and 14 was 1.3‐fold for TEWL, 2.1‐fold for ³H₂O penetration and 6.4‐fold for ¹⁴C‐niacinamide permeability. The barrier function of CSS grown by the modified method was still significantly lower than that of human cadaver skin tested by the same methods. Conclusions: CSS developed using the anchored multi‐cell system showed similar cell viability and morphology and improved barrier function compared with CSS produced by the standard Petri dish method, thereby improving its potential as an in vitro skin permeability and toxicity model.     

EIectrical impedance and transepidermal water loss of healthy human skin under different conditions

Background/aims: The skin barrier function is a multidimensional quality, which can be defined by a combination of noninvasive measurements, including EIectrical impedance (EI) and transepidermal water loss (TEWL). Methods: TEWL and EI were determined on in five different areas of the body in 25 healthy volunteers. The effects of hydration (a 15 min water bath, a 1 h occlusion and application of an oil-in-water emulsion combined with occlusion) were measured on the volar forearm. Results: EI was highest in the axillary region, followed by the cheek, spinal region, presternal area and upper arm. TEWL was highest in the axillary region, followed by the cheek. Lowest levels were detected in the spinal region, the presternal region and the upper arm. The water bath increased EI but not TEWL. After 1 h occlusion TEWL was not increased and EI decreased, which corresponds to stratum corneum hydration. After a single application of an oil-in-water emulsion, we observed a reduction of EI and an increase of TEWL. The simultaneous use of occlusion and application of an emulsion led to the most significant reduction of EI. TEWL was increased during the following 30 min. Conclusions: EI and TEWL show a topological variability. Acute hydration increased EI but occlusion and/or moisturizing decreased EI. Acute hydration and occlusion alone did not significantly affect TEWL, but moisturizing in combination caused a longer lasting TEWL increase. To examine the stratum corneum function, the use of different noninvasive techniques seem to provide more complex information.