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Ophthalmic Plastic and Reconstructive... Jul 2001Lower eyelid retraction is common in patients with dysthyroid orbitopathy and is seen less commonly in other conditions. Treatment typically requires vertical...
PURPOSE
Lower eyelid retraction is common in patients with dysthyroid orbitopathy and is seen less commonly in other conditions. Treatment typically requires vertical augmentation of the posterior eyelid lamella with an interpositional graft. Several autologous, homologous, and alloplastic materials have been used. We investigated the gross and microscopic in vivo histology of acellular homologous dermis used as a structural interpositional graft in the lower eyelids of Yucatan minipigs.
METHODS
This prospective, experimental study was designed as follows: Surgery was performed on the left lower eyelid of 4 Yucatan minipigs in accordance with the Massachusetts General Hospital Subcommittee on Research Animal Care guidelines. A 4 x 20-mm strip of acellular porcine dermis was prepared and sutured into place between the tarsus and conjunctiva/lower lid retractors. Tissues were harvested at 6 and 12 weeks and were evaluated histologically.
RESULTS
Gross examination revealed vertical elongation of the palpebral conjunctival surface. Histologic evaluation was performed with hematoxylin and eosin and Verhoeff elastin stains. Serial sections demonstrated incorporation of grafted dermal matrix into native tissues without evidence of inflammation. Definitive differentiation between grafted dermis and native dermis was not possible with light microscopy. Portions of the graft appeared to be epithelialized, whereas other histologic regions showed poorly adhesive epithelium. Inflammatory infiltrates including lymphocytes and polymorphonuclear leukocytes were not seen. No epithelioid or giant cells were identified in the sections examined.
CONCLUSIONS
Acellular homologous dermis produced no measurable untoward effects when implanted as an interpositional graft in the lower eyelid of Yucatan minipigs. On the basis of its material characteristics, it appears to be suitable for this purpose: It is readily available, easily stored, easy to manipulate, and produces minimal inflammation. Long-term persistence, early postoperative histology, and clinical eyelid elevation in humans remain to be evaluated.
Topics: Animals; Dermis; Eyelid Diseases; Eyelids; Models, Animal; Ophthalmologic Surgical Procedures; Prospective Studies; Suture Techniques; Swine; Swine, Miniature
PubMed: 11476177
DOI: 10.1097/00002341-200107000-00006 -
Development, Growth & Differentiation Aug 2018Adult mammals do not regenerate the dermis of the skin but form a scar after a deep skin injury. Since a scar causes serious medical problems, skin regeneration, instead... (Review)
Review
Adult mammals do not regenerate the dermis of the skin but form a scar after a deep skin injury. Since a scar causes serious medical problems, skin regeneration, instead of formation of a scar, has been strongly desired from a clinical point of view. Recent studies have suggested multiple origins of myofibroblasts, which are scar-forming cells in skin wound healing of mammals. While amphibians have skin structures that are basically common to mammals as tetrapods, both urodele and anuran amphibians regenerate almost complete skin structures including the dermis and secretion glands without forming a remarkable scar after a deep skin injury. In skin regeneration of a metamorphosed Xenopus laevis, an amphibian, cells that resemble limb blastema cells accumulate under the epidermis after injury and cells from subcutaneous tissues (tissues underlying the skin) contribute to skin regeneration. The skin of urodele amphibians and that of anuran amphibians provide valuable models for studying skin regeneration as adults. Recent progress in transgenesis and genome editing techniques with whole genome sequencing in Xenopus and an axolotl have enabled comparative analyses by molecular genetics of mammal skin and amphibian skin. Such comparative analyses would enable direct comparison of scar-forming myofibroblasts in mammals and blastema-like cells that contribute to skin regeneration in amphibians, ultimately leading to realization of skin regeneration in adult mammals. Amphibian skin regeneration will also be useful for determining how to step up skin regeneration to a higher level of regeneration such as limb regeneration in the future.
Topics: Adult; Ambystoma mexicanum; Animals; Cicatrix; Dermis; Disease Models, Animal; Humans; Myofibroblasts; Regeneration; Xenopus laevis
PubMed: 29947057
DOI: 10.1111/dgd.12544 -
Journal of Cellular Biochemistry May 2006Skin is a representative self-renewing tissue containing stem cells. Although many attempts have been made to define and isolate skin-derived stem cells, establishment...
Skin is a representative self-renewing tissue containing stem cells. Although many attempts have been made to define and isolate skin-derived stem cells, establishment of a simple and reliable isolation procedure remains a goal to be achieved. Here, we report the isolation of cells having stem cell properties from mouse embryonic skin using a simple selection method based on an assumption that stem cells may grow in an anchorage-independent manner. We inoculated single cell suspensions prepared from mouse embryonic dermis into a temperature-sensitive gel and propagated the resulting colonies in a monolayer culture. The cells named dermis-derived epithelial progenitor-1 (DEEP) showed epithelial morphology and grew rapidly to a more than 200 population doubling level over a period of 250 days. When the cells were kept confluent, they spontaneously formed spheroids and continuously grew even in spheroids. Immunostaining revealed that all of the clones were positive for the expression of cytokeratin-8, -18, -19, and E-cadherin and negative for the expression of cytokeratin-1, -5, -6, -14, -20, vimentin, nestin, a ckit. Furthermore, they expressed epithelial stem cell markers such as p63, integrin beta1, and S100A6. On exposure to TGFbeta in culture, some of DEEP-1 cells expressed alpha-smooth muscle actin. When the cells were transplanted into various organs of adult SCID mice, a part of the inoculated cell population acquired neural, hepatic, and renal cell properties. These results indicate that the cells we isolated were of epithelial stem cell origin and that our new approach is useful for isolation of multipotent stem cells from skin tissues.
Topics: Animals; Animals, Newborn; Biomarkers; Cell Culture Techniques; Cell Differentiation; Cell Proliferation; Cell Separation; Clone Cells; Dermis; Epithelial Cells; Gels; Mice; Mice, Inbred C57BL; Mice, SCID; Multipotent Stem Cells
PubMed: 16408300
DOI: 10.1002/jcb.20757 -
Angewandte Chemie (International Ed. in... Aug 2015The computer-assisted design and optimization of peptides with selective cancer cell killing activity was achieved through merging the features of anticancer peptides,...
The computer-assisted design and optimization of peptides with selective cancer cell killing activity was achieved through merging the features of anticancer peptides, cell-penetrating peptides, and tumor-homing peptides. Machine-learning classifiers identified candidate peptides that possess the predicted properties. Starting from a template amino acid sequence, peptide cytotoxicity against a range of cancer cell lines was systematically optimized while minimizing the effects on primary human endothelial cells. The computer-generated sequences featured improved cancer-cell penetration, induced cancer-cell apoptosis, and were enabled a decrease in the cytotoxic concentration of co-administered chemotherapeutic agents in vitro. This study demonstrates the potential of multidimensional machine-learning methods for rapidly obtaining peptides with the desired cellular activities.
Topics: Antineoplastic Agents; Apoptosis; Breast Neoplasms; Cell Survival; Cell-Penetrating Peptides; Cells, Cultured; Computer-Aided Design; Dermis; Drug Therapy, Combination; Female; Humans
PubMed: 26119906
DOI: 10.1002/anie.201504018 -
Journal of Dermatological Science May 2013Hair follicle morphogenesis and regeneration depend on intensive but well-orchestrated interactions between epithelial and mesenchymal components. Accordingly, the... (Review)
Review
Hair follicle morphogenesis and regeneration depend on intensive but well-orchestrated interactions between epithelial and mesenchymal components. Accordingly, the enhancement of this crosstalk represents a promising approach to achieve successful bioengineering of human hair follicles. The present article summarizes the techniques, both currently available and potentially feasible, to promote epithelial-mesenchymal interactions (EMIs) necessary for human hair follicle regeneration. The strategies include the preparation of epithelial components with high receptivity to trichogenic dermal signals and/or mesenchymal cell populations with potent hair inductive capacity. In this regard, bulge epithelial stem cells, keratinocytes predisposed to hair follicle fate or keratinocyte precursor cells with plasticity may provide favorable epithelial cell populations. Dermal papilla cells sustaining intrinsic hair inductive capacity, putative dermal papilla precursor cells in the dermal sheath/neonatal dermis or trichogenic dermal cells derived from undifferentiated stem/progenitor cells are promising candidates as hair inductive dermal cells. The most established protocol for in vivo hair follicle reconstitution is co-grafting of epithelial and mesenchymal components into immunodeficient mice. In theory, combination of individually optimized cellular components of respective lineages should elicit most intensive EMIs to form hair follicles. Still, EMIs can be further ameliorated by the modulation of non-cell autonomous conditions, including cell compartmentalization to replicate the positional relationship in vivo and humanization of host environment by preparing human stromal bed. These approaches may not always synergistically intensify EMIs, however, step-by-step investigation probing optimal combinations should maximally enhance EMIs to achieve successful human hair follicle bioengineering.
Topics: Bioengineering; Cell Communication; Dermis; Epithelial-Mesenchymal Transition; Hair Follicle; Humans; In Vitro Techniques; Regeneration
PubMed: 23557720
DOI: 10.1016/j.jdermsci.2013.02.004 -
The Australasian Journal of Dermatology Nov 2015We compared the thickness of both dermis and subcutis (measured using ultrasound) in overweight and obese adults with type 1 (n = 10) or type 2 (n = 8) diabetes...
We compared the thickness of both dermis and subcutis (measured using ultrasound) in overweight and obese adults with type 1 (n = 10) or type 2 (n = 8) diabetes mellitus. When adjusted for confounding factors, patients with type 1 diabetes had thicker subcutis than those with type 2 diabetes, with this difference being particularly marked in the abdomen. There were no observed differences in dermal thickness between the groups.
Topics: Adult; Aged; Dermis; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Female; Humans; Male; Middle Aged; Obesity; Subcutaneous Tissue; Ultrasonography; Young Adult
PubMed: 25178391
DOI: 10.1111/ajd.12177 -
International Journal of Molecular... Dec 2012Human skin is exposed to solar ultraviolet radiation comprising UVB (280-315 nm) and UVA (315-400 nm) on a daily basis. Within the last two decades, the molecular and... (Review)
Review
Human skin is exposed to solar ultraviolet radiation comprising UVB (280-315 nm) and UVA (315-400 nm) on a daily basis. Within the last two decades, the molecular and cellular response to UVA/UVB and the possible effects on human health have been investigated extensively. It is generally accepted that the mutagenic and carcinogenic properties of UVB is due to the direct interaction with DNA. On the other hand, by interaction with non-DNA chromophores as endogenous photosensitizers, UVA induces formation of reactive oxygen species (ROS), which play a pivotal role as mediators of UVA-induced injuries in human skin. This review gives a short overview about relevant findings concerning the molecular mechanisms underlying UVA/UVB-induced cell death. Furthermore, we will highlight the potential role of cutaneous antioxidants and photolabile nitric oxide derivates (NODs) in skin physiology. UVA-induced decomposition of the NODs, like nitrite, leads not only to non-enzymatic formation of nitric oxide (NO), but also to toxic reactive nitrogen species (RNS), like peroxynitrite. Whereas under antioxidative conditions the generation of protective amounts of NO is favored, under oxidative conditions, less injurious reactive nitrogen species are generated, which may enhance UVA-induced cell death.
Topics: Animals; Cell Death; Dermis; Humans; Nitric Oxide; Nitrites; Protective Agents; Ultraviolet Rays
PubMed: 23344028
DOI: 10.3390/ijms14010191 -
Skin Pharmacology and Physiology 2020The dermal papilla comprises mesenchymal cells in hair follicles, which play the main role in regulating hair growth. Maintaining the potential hair inductivity of... (Review)
Review
The dermal papilla comprises mesenchymal cells in hair follicles, which play the main role in regulating hair growth. Maintaining the potential hair inductivity of dermal papilla cells (DPCs) and dermal sheath cells during cell culture is the main factor in in vitro morphogenesis and regeneration of hair follicles. Using common methods for the cultivation of human dermal papilla reduces the maintenance requirements of the inductive capacity of the dermal papilla and the expression of specific dermal papilla biomarkers. Optimizing culture conditions is therefore crucial for DPCs. Moreover, exosomes appear to play a key role in regulating the hair follicle growth through a paracrine mechanism and provide a functional method for treating hair loss. The present review investigated the biology of DPCs, the molecular and cell signaling mechanisms contributing to hair follicle growth in humans, the properties of the dermal papilla, and the effective techniques in maintaining hair inductivity in DPC cultures in humans as well as hair follicle bioengineering.
Topics: Cell Culture Techniques; Dermis; Hair; Hair Follicle; Humans; Intercellular Signaling Peptides and Proteins; Regeneration
PubMed: 33053562
DOI: 10.1159/000510152 -
The International Journal of... 2004The dorsal and the ventral trunk integuments of the chick differ in their dermal cell lineage (originating from the somatic and somatopleural mesoderm respectively) and... (Comparative Study)
Comparative Study Review
The dorsal and the ventral trunk integuments of the chick differ in their dermal cell lineage (originating from the somatic and somatopleural mesoderm respectively) and in the distribution of their feather fields. The dorsal macropattern has a large spinal pteryla surrounded by semi-apteria, whereas the ventral skin has a true medial apterium surrounded by the ventral pterylae. Comparison of the results of heterotopic transplantations of distal somatopleure in place of somatic mesoderm (Mauger 1972) or in place of proximal somatopleure (our data), leads to two conclusions. These are that the fate of the midventral apterium is not committed at day 2 of incubation and that the signals from the environment which specify the ventral and dorsal featherforming dermal progenitors are different. Effectively, Shh, but not Wnt -1 signalling can induce the formation of feather forming dermis from the embryonic somatopleure. Shh is not able, however, to trigger the formation of a feather forming dermis from the extra embryonic somatopleure. This brief report constitutes the first attempt, by comparing old and new preliminary results, to understand whether dermal progenitors at different sites are specified by different signalling pathways.
Topics: Animals; Cell Lineage; Chick Embryo; Dermis; Feathers; Hedgehog Proteins; Mesoderm; Signal Transduction; Skin; Stem Cells; Trans-Activators; Transplantation, Heterologous
PubMed: 15272375
DOI: 10.1387/ijdb.15272375 -
Gerontology 2005We had proposed the usefulness of cutaneous microdialysis for the study of antioxidants in the skin.
BACKGROUND
We had proposed the usefulness of cutaneous microdialysis for the study of antioxidants in the skin.
OBJECTIVE
We designed a study analyzing the level of uric acid in the skin, one of the major antioxidants, for an age-dependent change.
METHODS
16 healthy male volunteers were divided into two groups according to age. Eleven subjects were in their 3rd decade, under 30 years of age (young group) and the others were their 8th decade (old group), over 70 years of age. Dialysate samples were analyzed using high-performance liquid chromatography analysis.
RESULTS
In the young group the mean level of uric acid was 31.9+/-16.1 microg/ml, while in old group it was 13.4+/-5.2 microg/ml.
CONCLUSION
This result demonstrated an in vivo state of antioxidant level in the human skin and the age-dependent difference was concordant with other in vitro or ex vivo studies; therefore, cutaneous microdialysis could be used in analysis and monitoring studies including human antioxidants and anti-aging.
Topics: Adult; Aged; Aging; Antioxidants; Dermis; Humans; Male; Microdialysis; Uric Acid
PubMed: 15980651
DOI: 10.1159/000085119