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Quan T. Molecular insights of human skin epidermal and dermal aging. J Dermatol Sci 2023; 112:48-53. [PMID: 37661473 DOI: 10.1016/j.jdermsci.2023.08.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/03/2023] [Accepted: 08/15/2023] [Indexed: 09/05/2023]
Abstract
Human skin is the most widespread and abundant type of tissue in the human body. With the passage of time, most of our organs, including a substantial part of the skin, tend to undergo a gradual thinning or decrease in size. As we age, there is a gradual and progressive reduction in the thickness of both the epidermis and dermis layers of our skin. This is primarily attributed to the decline of epidermal stem cells and the loss of dermal collagen, which is the most abundant protein in the human body. Age-related alterations of the epidermis and dermis impair skin structure/function and create a tissue microenvironment that promotes age-related skin diseases, such as impaired skin barrier, delayed wound healing, and skin cancer development. This review will examine the current body of literature pertaining to our knowledge of skin epidermal and dermal aging.
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Affiliation(s)
- Taihao Quan
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, MI, USA.
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2
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Qin Z, He T, Guo C, Kim JY, Quan T. CCN1 is predominantly elevated in human skin dermis by solar-simulated ultraviolet irradiation and accumulated in dermal extracellular matrix. J Cell Commun Signal 2023:10.1007/s12079-023-00767-6. [PMID: 37245186 DOI: 10.1007/s12079-023-00767-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 05/03/2023] [Indexed: 05/29/2023] Open
Abstract
Skin primarily comprises a collagen-rich extracellular matrix (ECM) that provides structural and functional support to the skin. Aging causes progressive loss and fragmentation of dermal collagen fibrils, leading to thin and weakened skin (Dermal aging). We previously reported that CCN1 is elevated in naturally aged human skin, photoaged human skin, and acute UV-irradiated human skin dermal fibroblasts in vivo. Elevated CCN1 alters the expression of numerous secreted proteins that have deleterious effects on the dermal microenvironment, impairing the structural integrity and function of the skin. Here we show that CCN1 is predominantly elevated in the human skin dermis by UV irradiation and accumulated in the dermal extracellular matrix. Laser capture microdissection indicated that CCN1 is predominantly induced in the dermis, not in the epidermis, by acute UV irradiation in human skin in vivo. Interestingly, while UV-induced CCN1 in the dermal fibroblasts and in the medium is transient, secreted CCN1 accumulates in the ECM. We explored the functionality of the matrix-bound CCN1 by culturing dermal fibroblasts on an acellular matrix plate that was enriched with a high concentration of CCN1. We observed that matrix-bound CCN1 activates integrin outside-in signaling resulting in the activation of FAK and its downstream target paxillin and ERK, as well as elevated MMP-1 and inhibition of collagen, in human dermal fibroblasts. These data suggest that accumulation of CCN1 in the dermal ECM is expected to progressively promote the aging of the dermis and thereby negatively impact the function of the dermis.
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Affiliation(s)
- Zhaoping Qin
- Department of Dermatology, University of Michigan Medical School, 1301 Catherine, Medical Science I, Room 6447, Ann Arbor, MI, 48109-0609, USA
| | - Tianyuan He
- Department of Dermatology, University of Michigan Medical School, 1301 Catherine, Medical Science I, Room 6447, Ann Arbor, MI, 48109-0609, USA
| | - Chunfang Guo
- Department of Dermatology, University of Michigan Medical School, 1301 Catherine, Medical Science I, Room 6447, Ann Arbor, MI, 48109-0609, USA
| | - Jun Young Kim
- Department of Dermatology, University of Michigan Medical School, 1301 Catherine, Medical Science I, Room 6447, Ann Arbor, MI, 48109-0609, USA
- Department of Dermatology, School of Medicine, Kyungpook National University, Daegu, South Korea
| | - Taihao Quan
- Department of Dermatology, University of Michigan Medical School, 1301 Catherine, Medical Science I, Room 6447, Ann Arbor, MI, 48109-0609, USA.
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3
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Potkrajcic V, Kolbenschlag J, Sachsenmaier S, Daigeler A, Ladurner R, Golf A, Gani C, Zips D, Paulsen F, Eckert F. Postoperative complications and oncologic outcomes after multimodal therapy of localized high risk soft tissue sarcoma. Radiat Oncol 2022; 17:210. [PMID: 36544149 PMCID: PMC9768905 DOI: 10.1186/s13014-022-02166-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 11/21/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Standard therapy for localized high-risk soft tissue sarcoma includes surgical resection and neoadjuvant or adjuvant radiation therapy (± chemotherapy and locoregional hyperthermia). No difference in oncologic outcomes for patients treated with neoadjuvant and adjuvant radiation therapy was reported, whereas side effect profiles differ. The aim of this analysis was to analyse oncologic outcomes and postoperative complications in patients treated with multimodal treatment. METHODS Oncologic outcomes and major wound complications (MWC, subclassified as wound healing disorder, infection, abscess, fistula, seroma and hematoma) were evaluated in 74 patients with localized high-risk soft tissue sarcoma of extremities and trunk undergoing multimodal treatment, and also separately for the subgroup of lower extremity tumors. Clinical factors and treatment modalities (especially neoadjuvant vs. adjuvant radiotherapy) were evaluated regarding their prognostic value and impact on postoperative wound complications. RESULTS Oncologic outcomes were dependent on number of high risk features (tumor size, depth to superficial fascia and grading), but not on therapy sequencing (however with higher risk patients in the neoadjuvant group). Different risk factors influenced different subclasses of wound healing complications. Slightly higher MWC-rates were observed in patients treated with neoadjuvant therapy, compared to adjuvant radiotherapy, although only with a trend to statistical significance (31.8% vs. 13.3%, p = 0.059). However, except for wound infections, no significant difference for other subclasses of postoperative complications was observed between neoadjuvant and adjuvant therapy. Diabetes was confirmed as a major risk factor for immune-related wound complications. CONCLUSION Rates of major wound complications in this cohort are comparable to published data, higher rates of wound infections were observed after neoadjuvant radiotherapy. Tumor localization, patient age and diabetes seem to be major risk factors. The number of risk factors for high risk soft tissue sarcoma seem to influence DMFS. Neoadjuvant treatment increases the risk only for wound infection treated with oral or intravenous antibiotic therapy and appears to be a safe option at an experienced tertiary center in absence of other risk factors.
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Affiliation(s)
- Vlatko Potkrajcic
- grid.10392.390000 0001 2190 1447Department of Radiation Oncology, Eberhard-Karls-University Tuebingen, Hoppe-Seyler-Str. 3, 72076 Tübingen, Germany
| | - Jonas Kolbenschlag
- grid.10392.390000 0001 2190 1447Department of Hand, Plastic, Reconstructive and Burn Surgery, BG Unfallklinik, Eberhard-Karls-University Tuebingen, Schnarrenbergstraße 95, 72076 Tübingen, Germany
| | - Saskia Sachsenmaier
- grid.10392.390000 0001 2190 1447Department of Orthopaedic Surgery, Eberhard-Karls-University Tuebingen, Hoppe-Seyler-Str. 3, 72076 Tübingen, Germany
| | - Adrien Daigeler
- grid.10392.390000 0001 2190 1447Department of Hand, Plastic, Reconstructive and Burn Surgery, BG Unfallklinik, Eberhard-Karls-University Tuebingen, Schnarrenbergstraße 95, 72076 Tübingen, Germany
| | - Ruth Ladurner
- grid.10392.390000 0001 2190 1447Department of General, Visceral and Transplant Surgery, Eberhard-Karls-University Tuebingen, Hoppe Seyler-Str. 3, 72076 Tübingen, Germany
| | - Alexander Golf
- grid.10392.390000 0001 2190 1447Department of Internal Medicine, Medical Oncology and Pulmonology, Eberhard-Karls-University Tuebingen, Otfried-Müller-Straße 14, 72076 Tuebingen, Germany
| | - Cihan Gani
- grid.10392.390000 0001 2190 1447Department of Radiation Oncology, Eberhard-Karls-University Tuebingen, Hoppe-Seyler-Str. 3, 72076 Tübingen, Germany
| | - Daniel Zips
- grid.10392.390000 0001 2190 1447Department of Radiation Oncology, Eberhard-Karls-University Tuebingen, Hoppe-Seyler-Str. 3, 72076 Tübingen, Germany ,grid.7497.d0000 0004 0492 0584German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK) Partnersite Tuebingen, Heidelberg, Germany ,grid.6363.00000 0001 2218 4662Department of Radiation Oncology and Radiotherapy, Charité University Hospital, Charitépl. 1, 10117 Berlin, Germany
| | - Frank Paulsen
- grid.10392.390000 0001 2190 1447Department of Radiation Oncology, Eberhard-Karls-University Tuebingen, Hoppe-Seyler-Str. 3, 72076 Tübingen, Germany
| | - Franziska Eckert
- grid.10392.390000 0001 2190 1447Department of Radiation Oncology, Eberhard-Karls-University Tuebingen, Hoppe-Seyler-Str. 3, 72076 Tübingen, Germany ,grid.22937.3d0000 0000 9259 8492Department of Radiation Oncology, Comprehensive Cancer Center, Medical University Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
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Paw E, Vangaveti V, Zonta M, Heal C. Protocol for an open randomised controlled trial investigating Fibrin Glue in Skin grafts for Skin cancer (FiGSS). BMJ Open 2022; 12:e064431. [PMID: 36351733 PMCID: PMC9644346 DOI: 10.1136/bmjopen-2022-064431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION Skin cancer is a common disease in the tropics, and oncological resection typically requires reconstruction with skin grafts. Fibrin glue, initially established as a haemostatic agent, has been studied extensively as an adhesive for skin grafts in burns. This study aims to investigate the use of fibrin as an adhesive for split skin grafts in skin cancers. METHODS AND ANALYSIS The study design is a prospective randomised controlled trial with the aim of investigating the impact of two different methods of split skin graft fixation. The intervention of fibrin glue will be compared with the control of staples or sutures. The trial will be conducted at two sites, a public hospital and a private hospital in Townsville, Australia, over a 24-month period with 334 participants to be recruited. Consecutive patients presenting for skin excisions and grafting will be eligible to participate in this study. Randomisation will be on the level of the patient. The primary outcome is graft take based on wound healing at 1 month. Secondary outcomes will be pain on dressing changes and operative time. ETHICS AND DISSEMINATION The study has been approved by The Townsville University Hospital Human Research Ethics Committee. Findings will be disseminated in conference presentations and journals and through online electronic media. TRIAL REGISTRATION NUMBER ACTRN12618000484246.
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Affiliation(s)
- Ekta Paw
- College of Medicine and Dentistry, James Cook University, Townsville, Queensland, Australia
| | - Venkat Vangaveti
- College of Medicine and Dentistry, James Cook University, Townsville, Queensland, Australia
| | - Mark Zonta
- Department of Surgery, Townsville University Hospital, Townsville, Queensland, Australia
| | - Clare Heal
- College of Medicine and Dentistry, James Cook University, Townsville, Queensland, Australia
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Lim J, Cho CH, Lee SB. Microbiological Profile and Clinical Characteristics of Bacterial Keratitis with Poor Visual Outcome. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2022. [DOI: 10.3341/jkos.2022.63.7.602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Purpose: To compare clinical characteristics between the poor visual outcome (PVO) and good visual outcome (GVO) groups in culture-proven bacterial keratitis.Methods: A total of 230 cases (44 and 186 eyes in the PVO and GVO groups, respectively) of culture-proven bacterial keratitis, treated between January 2007 and December 2020, were reviewed retrospectively. The PVO group included cases with the final best-corrected visual acuity (BCVA) of less than 0.1 and no improvement compared to the initial BCVA. The remaining cases were included in the GVO group. The microbiological profiles, epidemiology, predisposing factors, and clinical characteristics were compared between the PVO and GVO groups, and the risk factors for PVO were analyzed.Results: Staphylococcus spp. and Pseudomonas spp. were common isolates in both the PVO and GVO groups, with no significant differences in the distribution of isolates. There were no significant differences between the groups in terms of sex, seasonal distribution, corneal trauma, and prior topical steroid use, but contact lens wear was significantly less in the PVO group. Significant risk factors for PVO were age ≥60 years (Z = 4.22, two-proportion Z-test), central corneal lesions (Z = 3.80), epithelial defect size ≥5 mm<sup>2</sup> (Z = 3.74), prior ocular surgery (Z = 3.63), hypopyon (Z = 3.42), previous ocular surface disease (Z = 3.32), and diabetes (Z = 3.12).Conclusions: In patients with bacterial keratitis, PVO was associated with older age, severe initial corneal findings, previous ocular disease history, and diabetes, but not with the causative pathogen itself.
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6
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Peng Q, Gorter WS, Vermolen FJ. Comparison between a phenomenological approach and a morphoelasticity approach regarding the displacement of extracellular matrix. Biomech Model Mechanobiol 2022; 21:919-935. [PMID: 35403944 PMCID: PMC9132877 DOI: 10.1007/s10237-022-01568-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 02/25/2022] [Indexed: 11/30/2022]
Abstract
Plastic (permanent) deformations were earlier, modeled by a phenomenological model in Peng and Vermolen (Biomech Model Mechanobiol 19(6):2525–2551, 2020). In this manusctipt, we consider a more physics-based formulation that is based on morphoelasticity. We firstly introduce the morphoelasticity approach and investigate the impact of various input variables on the output parameters by sensitivity analysis. A comparison of both model formulations shows that both models give similar computational results. Furthermore, we carry out Monte Carlo simulations of the skin contraction model containing the morphoelasticity approach. Most statistical correlations from the two models are similar, however, the impact of the collagen density on the severeness of contraction is larger for the morphoelasticity model than for the phenomenological model.
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Affiliation(s)
- Q Peng
- Mathematical Institute, Leiden University, 2333 CA, Niels Bohrweg, The Netherlands. .,Delft Institute of Applied Mathematics, Delft University of Technology, Mekelweg 4, 2628 CD, Delft, The Netherlands. .,Computational Mathematics Group, Discipline group Mathematics and statistics, Faculty of Science, Hasselt University, Campus Diepenbeek, Agoralaan Gebouw D, BE 3590, Diepenbeek, Belgium.
| | - W S Gorter
- Delft Institute of Applied Mathematics, Delft University of Technology, Mekelweg 4, 2628 CD, Delft, The Netherlands
| | - F J Vermolen
- Delft Institute of Applied Mathematics, Delft University of Technology, Mekelweg 4, 2628 CD, Delft, The Netherlands.,Computational Mathematics Group, Discipline group Mathematics and statistics, Faculty of Science, Hasselt University, Campus Diepenbeek, Agoralaan Gebouw D, BE 3590, Diepenbeek, Belgium
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Bozkaya O, Arat E, Gün Gök Z, Yiğitoğlu M, Vargel İ. Production and characterization of hybrid nanofiber wound dressing containing Centella asiatica coated silver nanoparticles by mutual electrospinning method. Eur Polym J 2022. [DOI: 10.1016/j.eurpolymj.2022.111023] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Qin Z, He T, Guo C, Quan T. Age-related downregulation of CCN2 is regulated by cell size in a YAP/TAZ-dependent manner in human dermal fibroblasts: impact on dermal aging. JID INNOVATIONS 2022; 2:100111. [PMID: 35480397 PMCID: PMC9035808 DOI: 10.1016/j.xjidi.2022.100111] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 12/22/2021] [Accepted: 12/28/2021] [Indexed: 12/17/2022] Open
Abstract
CCN2, a member of the CCN family of matricellular proteins, is a key mediator and biomarker of tissue fibrosis. We previously reported that CCN2 is significantly reduced in aged human dermis, which contributes to dermal aging through the downregulation of collagen production, the major structural protein in the skin. In this study, we investigated the underlying mechanisms of the age-related downregulation of CCN2 in human skin dermal fibroblasts. Dermal fibroblasts isolation and laser-capture microdissection‒coupled RT-PCR from human skin confirmed that age-related reduction of CCN2 expression is regulated by epigenetics. Mechanistic investigation revealed that age-related reduction of CCN2 is regulated by impaired dermal fibroblast spreading/cell size, which is a prominent feature of aged dermal fibroblasts in vivo. Gain-of-function and loss-of-function analysis confirmed that age-related downregulation of CCN2 is regulated by YAP/TAZ in response to reduced cell size. We further confirmed that restoration of dermal fibroblast size rapidly reversed the downregulation of CCN2 in a YAP/TAZ-dependent manner. Finally, we confirmed that reduced YAP/TAZ nuclear staining is accompanied by loss of CCN2 in aged human skin in vivo. Our data reveal a mechanism by which age-related reduction in fibroblast spreading/size drives YAP/TAZ-dependent downregulation of CCN2 expression, which in turn contributes to loss of collagen in aged human skin.
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Affiliation(s)
- Zhaoping Qin
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Tianyuan He
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Chunfang Guo
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Taihao Quan
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Correspondence: Taihao Quan, Department of Dermatology, University of Michigan Medical School, 1301 Catherine, Medical Science I, Room 6447, Ann Arbor, Michigan 48109-0609, USA.
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Does Probiotic Consumption Enhance Wound Healing? A Systematic Review. Nutrients 2021; 14:nu14010111. [PMID: 35010987 PMCID: PMC8746682 DOI: 10.3390/nu14010111] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/21/2021] [Accepted: 12/23/2021] [Indexed: 01/04/2023] Open
Abstract
The use of probiotics is one of the emerging lines of treatment for wound healing. This systematic review aimed to summarize currently available evidence on the effect of oral or enteral probiotic therapy on skin or oral mucosal wound healing in humans. To verify the developments in this field and the level of available scientific evidence, we applied a broad search strategy with no restrictions on wound type, target population, probiotic strain, or intervention protocol used. This review included seven studies involving 348 individuals. Four studies reported positive outcomes for healing improvement after probiotic therapy, and none of the studies reported adverse effects or a marked increase in wound healing time. The positive or neutral results observed do not generate strong evidence regarding the effectiveness of probiotics for wound healing. However, they suggest a promising field for future clinical research where the probiotic strains used, type of wounds, and target population are controlled for.
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Wen S, Ye L, Wang X, Liu D, Yang B, Man MQ. Aged and young mice differentially respond to tape-stripping in epidermal gene expression. Exp Dermatol 2021; 31:312-319. [PMID: 34585796 DOI: 10.1111/exd.14463] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/19/2021] [Accepted: 09/27/2021] [Indexed: 11/30/2022]
Abstract
Disruption of epidermal permeability barrier induces an increase in proinflammatory cytokine expression and release, stimulation of epidermal lipid and DNA synthesis, and expression of antimicrobial peptides. Although alterations in epidermal function in the aged skin are known, whether the epidermal transcriptomic responses to barrier disruption differ between aged and young mice remains unknown. Here, we performed RNA sequencing of the epidermis in 2-month- vs. 20-month-old mice following barrier disruption with repeated tape-stripping. At baseline condition, the epidermis of 20-month-old mice displayed an upregulation of inflammation-associated genes and down-regulation of epidermal structure- and development-related genes in comparison to 2-month-old mice. Barrier disruption upregulated expression levels of 327 genes and downregulated 209 genes in 2-month-old mice. In 20-month-old mice, the numbers of upregulated and down-regulated genes were 537 and 299, respectively. In comparison to young mice, the prominently upregulated genes in the 20-month-old mice were associated with the IL-17 signalling pathway, while downregulated genes were mainly involved in the cytokine-cytokine receptor interaction pathway. These results indicate that inflammation-associated signalling pathways are upregulated, while epidermal structure- and development-related genes are downregulated in the epidermis of aged mice, with further aggravation following barrier disruption, suggesting the importance of improving epidermal function in the elderly.
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Affiliation(s)
- Si Wen
- Dermatology Hospital, Southern Medical University, Guangdong, China
| | - Li Ye
- Dermatology Hospital, Southern Medical University, Guangdong, China
| | - Xiaohua Wang
- Dermatology Hospital, Southern Medical University, Guangdong, China
| | - Dan Liu
- Dermatology Hospital, Southern Medical University, Guangdong, China
| | - Bin Yang
- Dermatology Hospital, Southern Medical University, Guangdong, China
| | - Mao-Qiang Man
- Dermatology Hospital, Southern Medical University, Guangdong, China
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Cheungpasitporn W, Lentine KL, Tan JC, Kaufmann M, Caliskan Y, Bunnapradist S, Lam NN, Schnitzler M, Axelrod DA. Immunosuppression Considerations for Older Kidney Transplant Recipients. CURRENT TRANSPLANTATION REPORTS 2021; 8:100-110. [PMID: 34211822 PMCID: PMC8244945 DOI: 10.1007/s40472-021-00321-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2021] [Indexed: 02/06/2023]
Abstract
PURPOSE OF REVIEW While kidney transplantation improves the long-term survival of the majority of patients with end-stage kidney disease (ESKD), age-related immune dysfunction and associated comorbidities make older transplant recipients more susceptible to complications related to immunosuppression. In this review, we discuss appropriate management of immunosuppressive agents in older adults to minimize adverse events, avoid acute rejection, and maximize patient and graft survival. RECENT FINDINGS Physiological changes associated with senescence can impact drug metabolism and increase the risk of posttransplant infection and malignancy. Clinical trials assessing the safety and efficacy of immunosuppressive agents in older adults are lacking. Recent findings from U.S. transplant registry-based studies suggest that risk-adjusted death-censored graft failure is higher among older patients who received antimetabolite avoidance, mammalian target of rapamycin inhibitor (mTORi)-based, and cyclosporine-based regimens. Observational data suggest that risk-adjusted mortality may be increased in older patients who receive mTORi-based and cyclosporine-based regimens but lower in those managed with T-cell induction and maintenance steroid avoidance/withdrawal. SUMMARY Tailored immunosuppression management to improve patient and graft survival in older transplant recipients is an important goal of personalized medicine. Lower intensity immunosuppression, such as steroid-sparing regimens, appear beneficial whereas mTORi- and cyclosporine-based maintenance are associated with greater potential for adverse effects. Prospective clinical trials to assess the safety and efficacy of immunosuppression agents in older recipients are urgently needed.
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Harn HIC, Chen CC, Wang SP, Lei M, Chuong CM. Tissue Mechanics in Haired Murine Skin: Potential Implications for Skin Aging. Front Cell Dev Biol 2021; 9:635340. [PMID: 33681217 PMCID: PMC7933214 DOI: 10.3389/fcell.2021.635340] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/01/2021] [Indexed: 12/19/2022] Open
Abstract
During aging, the skin undergoes changes in architecture and composition. Skin aging phenotypes occur due to accumulated changes in the genome/epigenome, cytokine/cell adhesion, cell distribution/extracellular matrix (ECM), etc. Here we review data suggesting that tissue mechanics also plays a role in skin aging. While mouse and human skin share some similarities, their skin architectures differ in some respects. However, we use recent research in haired murine skin because of the available experimental data. Skin suffers from changes in both its appendages and inter-appendage regions. The elderly exhibit wrinkles and loose dermis and are more likely to suffer from wounds and superficial abrasions with poor healing. They also have a reduction in the number of skin appendages. While telogen is prolonged in aging murine skin, hair follicle stem cells can be rejuvenated to enter anagen if transplanted to a young skin environment. We highlight recent single-cell analyses performed on epidermis and aging human skin which identified new basal cell subpopulations that shift in response to wounding. This may be due to alterations of basement membrane stiffness which would change tissue mechanics in aging skin, leading to altered homeostatic dynamics. We propose that the extracellular matrix (ECM) may play a key role as a chemo-mechanical integrator of the multi-layered senescence-associated signaling pathways, dictating the tissue mechanical landscape of niche microenvironments in aging phenotypes. We show examples where failed chemo-mechanical signaling leads to deteriorating homeostasis during skin aging and suggest potential therapeutic strategies to guide future research to delay the aging processes.
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Affiliation(s)
- Hans I-Chen Harn
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States.,International Research Center of Wound Repair and Regeneration (iWRR), National Cheng Kung University, Tainan, Taiwan
| | - Chih-Chiang Chen
- Department of Dermatology, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.,Department of Dermatology, National Yang-Ming University, Taipei, Taiwan
| | - Sheng-Pei Wang
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States.,International Research Center of Wound Repair and Regeneration (iWRR), National Cheng Kung University, Tainan, Taiwan
| | - Mingxing Lei
- 111 Project Laboratory of Biomechanics and Tissue Repair, College of Bioengineering, Chongqing University, Chongqing, China.,Key Laboratory of Biorheological Science and Technology of the Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, China
| | - Cheng-Ming Chuong
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
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13
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Xiang Y, Qin Z, Yang Y, Fisher GJ, Quan T. Age-related elevation of HGF is driven by the reduction of fibroblast size in a YAP/TAZ/CCN2 axis-dependent manner. J Dermatol Sci 2021; 102:36-46. [PMID: 33648801 DOI: 10.1016/j.jdermsci.2021.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 02/03/2021] [Accepted: 02/12/2021] [Indexed: 12/12/2022]
Abstract
BACKGROUND Aged human skin is primarily attributable to the loss of collagen. Hepatocyte growth factor (HGF) acts as an anti-fibrotic factor by suppression of collagen production. In aged human skin, HGF is elevated in dermal fibroblasts and thus contributes to dermal aging (thin dermis) by suppression of collagen production. OBJECTIVE We aimed to investigate the underlying mechanisms of age-related elevation of HGF expression. METHODS Collagen fibrils in the aged skin dermis are fragmented and disorganized, which impairs collagen-fibroblast interaction, resulting in reduced fibroblast spreading and size. To explore the connection between reduced dermal fibroblast size and age-related elevation of HGF expression, we manipulate dermal fibroblast size, and cell-size dependent regulation of HGF was investigated by laser capture microdissection, immunostaining, capillary electrophoresis immunoassay, and quantitative RT-PCR. RESULTS We found that reduced fibroblast size is responsible for age-related elevation of HGF expression. Further investigation indicated that cell size-dependent upregulation of HGF expression was mediated by impeded YAP/TAZ nuclear translocation and their target gene, CCN2. Conversely, restoration of dermal fibroblast size rapidly reversed cell-size-dependent upregulation of HGF in a YAP/TAZ-dependent manner. Finally, we confirmed that elevated HGF expression is accompanied by the reduced expression of YAP/TAZ and CCN2 in the aged human skin in vivo. CONCLUSION Age-related elevation of HGF is driven by the reduction of fibroblast size in a YAP/TAZ/CCN2 axis-dependent manner. These data reveal a novel mechanism by which reduction of fibroblast size upregulates HGF expression, which in turn contributes to loss of collagen, a prominent feature of aged human skin.
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Affiliation(s)
- Yaping Xiang
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Zhaoping Qin
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Yan Yang
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Gary J Fisher
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Taihao Quan
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, MI, USA.
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14
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El Mohtadi M, Whitehead K, Dempsey-Hibbert N, Belboul A, Ashworth J. Estrogen deficiency - a central paradigm in age-related impaired healing? EXCLI JOURNAL 2021; 20:99-116. [PMID: 33510594 PMCID: PMC7838826 DOI: 10.17179/excli2020-3210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 01/04/2021] [Indexed: 11/10/2022]
Abstract
Wound healing is a dynamic biological process achieved through four sequential, overlapping phases; hemostasis, inflammation, tissue proliferation and remodeling. For effective wound healing, all four phases must occur in the appropriate order and time frame. It is well accepted that the wound healing process becomes disrupted in the elderly, increasing the propensity of non-healing wound states that can lead to substantial patient morbidity and an enormous financial burden on healthcare systems. Estrogen deprivation in the elderly has been identified as the key driver of age-related delayed wound healing in both genders, with topical and systemic estrogen replacement reversing the detrimental effects of aging on wound repair. Evidence suggests estrogen deprivation may contribute to the development of chronic wound healing states in the elderly but research in this area is somewhat limited, warranting further investigations. Moreover, although the beneficial effects of estrogen on cutaneous healing have been widely explored, the development of estrogen-based treatments to enhance wound repair in the elderly have yet to be widely exploited. This review explores the critical role of estrogen in reversing age-related impaired healing and evaluates the prospect of developing more focused novel therapeutic strategies that enhance wound repair in the elderly via activation of specific estrogen signaling pathways in regenerating tissues, whilst leaving non-target tissues largely unaffected.
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Affiliation(s)
- Mohamed El Mohtadi
- Department of Biology, Edge Hill University, Ormskirk, Lancashire, L39 4QP, UK
| | - Kathryn Whitehead
- Centre for Bioscience, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK
| | - Nina Dempsey-Hibbert
- Centre for Bioscience, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK
| | - Amina Belboul
- Centre for Bioscience, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK
| | - Jason Ashworth
- Centre for Bioscience, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK
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15
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Agent-based modelling and parameter sensitivity analysis with a finite-element method for skin contraction. Biomech Model Mechanobiol 2020; 19:2525-2551. [PMID: 32623543 PMCID: PMC7603478 DOI: 10.1007/s10237-020-01354-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 05/30/2020] [Indexed: 11/30/2022]
Abstract
In this paper, we extend the model of wound healing by Boon et al. (J Biomech 49(8):1388–1401, 2016). In addition to explaining the model explicitly regarding every component, namely cells, signalling molecules and tissue bundles, we categorized fibroblasts as regular fibroblasts and myofibroblasts. We do so since it is widely documented that myofibroblasts play a significant role during wound healing and skin contraction and that they are the main phenotype of cells that is responsible for the permanent deformations. Furthermore, we carried out some sensitivity tests of the model by modifying certain parameter values, and we observe that the model shows some consistency with several biological phenomena. Using Monte Carlo simulations, we found that there is a significant strong positive correlation between the final wound area and the minimal wound area. The high correlation between the wound area after 4 days and the final/minimal wound area makes it possible for physicians to predict the most probable time evolution of the wound of the patient. However, the collagen density ratio at the time when the wound area reaches its equilibrium and minimum, cannot indicate the degree of wound contractions, whereas at the 4th day post-wounding, when the collagen is accumulating from null, there is a strong negative correlation between the area and the collagen density ratio. Further, under the circumstances that we modelled, the probability that patients will end up with 5% contraction is about 0.627.
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16
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Suh DH, Ahn HJ, Seo JK, Lee SJ, Shin MK, Song KY. Monopolar radiofrequency treatment for facial laxity: Histometric analysis. J Cosmet Dermatol 2020; 19:2317-2324. [PMID: 32319176 DOI: 10.1111/jocd.13449] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 03/26/2020] [Accepted: 04/16/2020] [Indexed: 02/02/2023]
Abstract
BACKGROUND A monopolar radiofrequency device can be used in facial tightening. The device targets the dermis and fibrous septae, and the treatment results in immediate collagen contraction and the induction of subsequent collagen remodeling. AIMS We aimed to evaluate the histometric change of the subjects treated with a monopolar radiofrequency device using a novel tip. MATERIALS AND METHODS Eleven subjects with skin types III and IV participated in the study. They received a single session of a monopolar radiofrequency on the face, and biopsies were performed before treatment, and 2 and 6 months after the treatment. Hematoxylin and eosin, Masson trichome, and Victoria blue stains were used. An image analysis was performed using the Image J software. The dermal density of collagen and elastic fiber, and the coherency of collagen fibers were assessed in the papillary, upper reticular, and lower reticular dermises, respectively. RESULTS The monopolar radiofrequency treatments led to improvements in collagen fiber density and coherency. In the Masson trichome staining, the collagen fiber densities were 0.736 ± 0.06 and 0.652 ± 0.063 before treatment and increased to 0.773 ± 0.044 (P = .018) and 0.686 ± 0.05 (P = .045) in the papillary and lower reticular dermises, respectively. The density of the elastic fibers in all parts of the dermis showed a tendency to increase after treatment, though not statistically significantly. The mean coherency was higher after than before treatment. CONCLUSIONS In this in vivo study, we found that the collagen and elastic fiber densities and architectural structures were improved after treatment.
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Affiliation(s)
| | - Hye-Jin Ahn
- Department of Dermatology, College of Medicine, Kyung Hee University, Seoul, Korea
| | - Jong-Kil Seo
- Department of Dermatology, College of Medicine, Kyung Hee University, Seoul, Korea
| | | | - Min Kyung Shin
- Department of Dermatology, College of Medicine, Kyung Hee University, Seoul, Korea
| | - Kye Young Song
- Department of Pathology, Kuro Sungsim Medical Center, Seoul, Korea
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17
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Pratsinis H, Mavrogonatou E, Kletsas D. Scarless wound healing: From development to senescence. Adv Drug Deliv Rev 2019; 146:325-343. [PMID: 29654790 DOI: 10.1016/j.addr.2018.04.011] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 03/29/2018] [Accepted: 04/09/2018] [Indexed: 12/21/2022]
Abstract
An essential element of tissue homeostasis is the response to injuries, cutaneous wound healing being the most studied example. In the adults, wound healing aims at quickly restoring the barrier function of the skin, leading however to scar, a dysfunctional fibrotic tissue. On the other hand, in fetuses a scarless tissue regeneration takes place. During ageing, the wound healing capacity declines; however, in the absence of comorbidities a higher quality in tissue repair is observed. Senescent cells have been found to accumulate in chronic unhealed wounds, but more recent reports indicate that their transient presence may be beneficial for tissue repair. In this review data on skin wound healing and scarring are presented, covering the whole spectrum from early embryonic development to adulthood, and furthermore until ageing of the organism.
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18
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Abstract
It is well known that advancing age is a factor that affects the normal course of wound healing. The population over the age of 65 years is increasing globally, and this may be accompanied by an increase in the number of individuals experiencing delayed wound healing. There is a breadth of research to show that age-related changes in the epidermis and dermis change the skin's ability to resist damage and injury. In particular, the dermoepidermal junction becomes flattened, which predisposes the tissue to shear and friction forces. Within the dermis, alterations in the amount and structure of collagen also mean that the tissue is much more rigid. Prompt assessment of the skin to identify existing conditions as well as preventive measures is therefore essential. This article discusses the anatomy of the skin and the effects of ageing on the tissues. It also offers some guidance on skin assessment and the basics of skin care.
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Affiliation(s)
- Hilary Bonifant
- Senior Diabetes Podiatrist, Tū Ora Compass Health, Wellington, New Zealand, Year 2 Student, Masters in Wound Healing and Tissue Repair, Cardiff University School of Medicine, College of Biomedical and Life Sciences
| | - Samantha Holloway
- Reader, Centre for Medical Education Programme Director, MSc in Wound Healing and Tissue Repair, Cardiff University School of Medicine, College of Biomedical and Life Sciences
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19
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Qin Z, Fisher GJ, Voorhees JJ, Quan T. Actin cytoskeleton assembly regulates collagen production via TGF-β type II receptor in human skin fibroblasts. J Cell Mol Med 2018; 22:4085-4096. [PMID: 29888864 PMCID: PMC6111811 DOI: 10.1111/jcmm.13685] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 04/23/2018] [Indexed: 12/01/2022] Open
Abstract
The dermal compartment of skin is primarily composed of collagen-rich extracellular matrix (ECM), which is produced by dermal fibroblasts. In Young skin, fibroblasts attach to the ECM through integrins. During ageing, fragmentation of the dermal ECM limits fibroblast attachment. This reduced attachment is associated with decreased collagen production, a major cause of skin thinning and fragility, in the elderly. Fibroblast attachment promotes assembly of the cellular actin cytoskeleton, which generates mechanical forces needed for structural support. The mechanism(s) linking reduced assembly of the actin cytoskeleton to decreased collagen production remains unclear. Here, we report that disassembly of the actin cytoskeleton results in impairment of TGF-β pathway, which controls collagen production, in dermal fibroblasts. Cytoskeleton disassembly rapidly down-regulates TGF-β type II receptor (TβRII) levels. This down-regulation leads to reduced activation of downstream effectors Smad2/Smad3 and CCN2, resulting in decreased collagen production. These responses are fully reversible; restoration of actin cytoskeleton assembly up-regulates TβRII, Smad2/Smad3, CCN2 and collagen expression. Finally, actin cytoskeleton-dependent reduction of TβRII is mediated by induction of microRNA 21, a potent inhibitor of TβRII protein expression. Our findings reveal a novel mechanism that links actin cytoskeleton assembly and collagen expression in dermal fibroblasts. This mechanism likely contributes to loss of TβRII and collagen production, which are observed in aged human skin.
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Affiliation(s)
- Zhaoping Qin
- Department of DermatologyUniversity of Michigan Medical SchoolAnn ArborMIUSA
| | - Gary J. Fisher
- Department of DermatologyUniversity of Michigan Medical SchoolAnn ArborMIUSA
| | - John J. Voorhees
- Department of DermatologyUniversity of Michigan Medical SchoolAnn ArborMIUSA
| | - Taihao Quan
- Department of DermatologyUniversity of Michigan Medical SchoolAnn ArborMIUSA
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20
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Bellare A, Epperly MW, Greenberger JS, Fisher R, Glowacki J. Development of tensile strength methodology for murine skin wound healing. MethodsX 2018; 5:337-344. [PMID: 30050753 PMCID: PMC6058076 DOI: 10.1016/j.mex.2018.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 04/05/2018] [Indexed: 12/18/2022] Open
Abstract
In this study, a methodology was evaluated and improved to quickly measure the tensile strength of murine skin in a biomechanical assay for an incisional wound healing model. The aim was to streamline and enhance the wound model, skin specimen preparation, and tensile test so that large numbers of fresh tissue could be tested reliably and rapidly. Linear incisions of 25-mm length were made in the dorsal skin of mice along the spine and metallic staples were used to close the wound. After 20 days, the mice were sacrificed, and a square-shaped section of skin containing the linear incision was excised. Two metallic punches were fabricated and used to punch 15-mm long strips of skin of 2 mm width whose length was orthogonal to the direction of incision. The tensiometer configuration was modified to expedite tensile measurements on fresh skin, and load-to-failure was measured for each strip of skin from the cephalad to the caudal region. We evaluated sources of error in the animal model and the testing protocol and developed procedures to maximize speed and reproducibility in tensile strength measurements. This report provides guidance for efficient and reproducible tensile strength measurement of large numbers of skin specimens from freshly sacrificed animals. Tattoo placement to identify the two ends of the healing incisional wound assisted in decreasing error in the position and orientation of tensile strips. Custom-made punches to prepare skin strips for tensile testing helped conduct tensile tests of fresh tissue rapidly. Alteration of the manual grips of the tensile tester enabled specimens to be gripped rapidly to significantly accelerate testing for each skin strip.
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Affiliation(s)
- Anuj Bellare
- Department of Orthopedic Surgery, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Michael W Epperly
- Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA
| | - Joel S Greenberger
- Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA
| | - Renee Fisher
- Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA
| | - Julie Glowacki
- Department of Orthopedic Surgery, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA
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21
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Klugarova J, Klugar M, Mareckova J, Gallo J, Kelnarova Z. The effectiveness of inpatient physical therapy compared to outpatient physical therapy in older adults after total hip replacement in the post-discharge period: a systematic review. ACTA ACUST UNITED AC 2018; 14:174-209. [PMID: 26878927 DOI: 10.11124/jbisrir-2016-2392] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
BACKGROUND Total hip replacement is the most effective and safest method for treating severe degenerative, traumatic and other diseases of the hip joint. Total hip replacement can reliably relieve pain and improve function in the majority of patients for a period of 15 to 20 years or more postoperatively. Physical therapy follows each total hip replacement surgery. Physical therapy protocols after total hip replacement in the post-discharge period vary widely in terms of setting (inpatient, outpatient), content (the particular set of exercises used), and frequency (e.g. daily versus twice a week). In current literature, there is no systematic review which has compared the effectiveness of inpatient and outpatient physical therapy in patients after total hip replacement in the post-discharge period. OBJECTIVES The objective of this systematic review was to compare the effectiveness of inpatient physical therapy with outpatient physical therapy on the quality of life and gait measures in older adults after total hip replacement in the post-discharge period. INCLUSION CRITERIA This review considered studies that include older adults (over 65 years) who have had total hip replacement and are in the post-discharge period. Adults with bilateral or multiple simultaneous surgeries and also patients who have had hemiarthroplasty of the hip joint were excluded.This review considered studies that included any type of physical therapy delivered in inpatient settings provided by professionals with education in physical therapy. Inpatient physical therapy delivered at any frequency and over any duration was included.This review considered studies that included as a comparator any type of physical therapy delivered in outpatient settings provided by professionals with education in physical therapy or no physical therapy.This review considered studies that included the following primary and secondary outcomes. The primary outcome was quality of life, assessed by any validated assessment tool. The secondary outcome was measures of gait assessed by any valid methods.This review considered both experimental and observational study designs including randomized controlled trials, non-randomized controlled trials, quasi-experimental, before and after studies, prospective and retrospective cohort studies, case control studies and analytical cross sectional studies for inclusion. SEARCH STRATEGY The search strategy aimed to find both published and unpublished studies. A three-step search strategy was utilized in 12 databases. Studies published in all languages and any date were considered for inclusion in this review. METHODOLOGICAL QUALITY Assessment of methodological quality was not conducted as no studies were identified that met the inclusion criteria. DATA EXTRACTION AND SYNTHESIS Data extraction and synthesis was not performed because no studies were included in this systematic review. RESULTS During to the three-step search strategy 4330 papers were identified. The primary and secondary reviewer independently retrieved 42 potentially relevant papers according to the inclusion criteria by title and abstract screening. Following assessment of full text all of the retrieved papers were excluded based on the inclusion criteria. CONCLUSIONS There is no scientific evidence comparing the effectiveness of inpatient physical therapy with outpatient physical therapy in older patients after total hip replacement in the post-discharge period. IMPLICATIONS FOR RESEARCH This systematic review has identified gaps in the literature for comparing the effectiveness of inpatient physical therapy with and outpatient physical therapy on the quality of life and gait measures in older adults after total hip replacement in the post-discharge period. Prospective randomized double blind multicenter controlled trials are needed to answer this important clinical question.
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Affiliation(s)
- Jitka Klugarova
- 1. The Czech Republic (Middle European) Centre for Evidence-Based Health Care: an Affiliate Center of the Joanna Briggs Institute; Department of Social Medicine and Public Health, Faculty of Medicine and Dentistry, Palacký University, Olomouc, Czech Republic
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22
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Qin Z, Worthen CA, Quan T. Cell-size-dependent upregulation of HGF expression in dermal fibroblasts: Impact on human skin connective tissue aging. J Dermatol Sci 2017; 88:289-297. [PMID: 28826691 DOI: 10.1016/j.jdermsci.2017.08.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 07/05/2017] [Accepted: 08/02/2017] [Indexed: 11/29/2022]
Abstract
BACKGROUND Aged human skin is primarily attributable to loss of collagen, the main structural component of skin. Hepatocyte growth factor (HGF) acts as an anti-fibrotic factor by suppression of collagen production. It is not known whether HGF is involved in age-related collagen deficit in human skin. OBJECTIVE The objective of this study was to investigate the expression of HGF in human skin, and the underlying mechanisms of age-related elevation of HGF expression. METHODS The expression of HGF in young (25±5years, six subjects) and aged (75±6years, six subjects) human skin was determined by laser capture microdissection (LCM) coupled real-time PCR and immunohistology. The underlying mechanisms of age-related elevation of HGF were investigated by reducing dermal fibroblast size, which is a prominent feature of aged skin fibroblast in vivo. RESULTS HGF is predominantly expressed in human skin dermal fibroblasts, the major cells responsible for collagen production, and is significantly elevated in aged human skin in vivo. Mechanistically, reduced fibroblast size, which is a prominent feature of aged skin fibroblasts in vivo, is responsible for age-related elevation of HGF expression. Cell-size-dependent upregulation of HGF expression is driven by increased c-Jun and impaired TGF-β signaling. Restoration of fibroblast size normalizes increased c-Jun expression and impaired TGF-β signaling, and thus reversed the elevated HGF expression. Finally, we confirmed that application of retinoid (ROL), which has been shown to improve aged human skin, significantly reduced elevated HGF mRNA expression in aged human skin in vivo (78±4years, six subjects). CONCLUSION These data reveal a novel mechanism by which reduction of fibroblast size upregulates HGF expression, which in turn contributes to loss of collagen, a prominent feature of aged skin.
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Affiliation(s)
- Zhaoping Qin
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Christal A Worthen
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Taihao Quan
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, MI, USA.
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23
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Ambrozova N, Ulrichova J, Galandakova A. Models for the study of skin wound healing. The role of Nrf2 and NF-κB. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2017; 161:1-13. [PMID: 28115750 DOI: 10.5507/bp.2016.063] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 12/13/2016] [Indexed: 02/03/2023] Open
Abstract
Nrf2 and NF-κB transcription factors act in wound healing via their anti-inflammatory and anti-oxidant effects or through the immune response. Studying this process is a matter of some importance given the high cost of wound treatment. A major contribution in this regard is being made by models that enable investigation of the involvement of multiple factors in wound healing and testing new curative substances. This literature review was carried out via searches in the PubMed and Web of Science databases up to 2016. It covers skin wound healing, available models for its study (part I), the role of Nrf2 and NF-κB, substances that influence them and whether they can be used as markers (part II). Was found that in vitro assays are used for their availability but a holistic view must be established in vivo. In silico approaches are facilitating assessment of a vast amount of research data. Nfr2 and NF-κB play a crucial and reciprocal role in wound healing. Nrf2 controls repair-associated inflammation and protects against excessive accumulation of ROS while Nf-κB activates the innate immune reaction, proliferation and migration of cells, modulates expression of matrix metalloproteinases, secretion and stability of cytokines and growth factors for wound healing.
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Affiliation(s)
- Nikola Ambrozova
- Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic.,Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic
| | - Jitka Ulrichova
- Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic.,Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic
| | - Adela Galandakova
- Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic.,Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic
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24
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Rittié L, Farr EA, Orringer JS, Voorhees JJ, Fisher GJ. Reduced cell cohesiveness of outgrowths from eccrine sweat glands delays wound closure in elderly skin. Aging Cell 2016; 15:842-52. [PMID: 27184009 PMCID: PMC5013029 DOI: 10.1111/acel.12493] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2016] [Indexed: 01/03/2023] Open
Abstract
Human skin heals more slowly in aged vs. young adults, but the mechanism for this delay is unclear. In humans, eccrine sweat glands (ESGs) and hair follicles underlying wounds generate cohesive keratinocyte outgrowths that expand to form the new epidermis. Here, we compared the re‐epithelialization of partial‐thickness wounds created on the forearm of healthy young (< 40 yo) and aged (> 70 yo) adults. Our results confirm that the outgrowth of cells from ESGs is a major feature of repair in young skin. Strikingly, in aged skin, although ESG density is unaltered, less than 50% of the ESGs generate epithelial outgrowths during repair (vs. 100% in young). Surprisingly, aging does not alter the wound‐induced proliferation response in hair follicles or ESGs. Instead, there is an overall reduced cohesiveness of keratinocytes in aged skin. Reduced cell–cell cohesiveness was most obvious in ESG‐derived outgrowths that, when present, were surrounded by unconnected cells in the scab overlaying aged wounds. Reduced cell–cell contact persisted during the repair process, with increased intercellular spacing and reduced number of desmosomes. Together, reduced outgrowths of ESG (i) reduce the initial number of cells participating in epidermal repair, (ii) delay wound closure, and (iii) lead to a thinner repaired epidermis in aged vs. young skin. Failure to form cohesive ESG outgrowths may reflect impaired interactions of keratinocytes with the damaged ECM in aged skin. Our findings provide a framework to better understand the mediators of delayed re‐epithelialization in aging and further support the importance of ESGs for the repair of human wounds.
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Affiliation(s)
- Laure Rittié
- Department of Dermatology University of Michigan Medical School Ann Arbor MI USA
| | - Elyssa A. Farr
- Department of Dermatology University of Michigan Medical School Ann Arbor MI USA
| | - Jeffrey S. Orringer
- Department of Dermatology University of Michigan Medical School Ann Arbor MI USA
| | - John J. Voorhees
- Department of Dermatology University of Michigan Medical School Ann Arbor MI USA
| | - Gary J. Fisher
- Department of Dermatology University of Michigan Medical School Ann Arbor MI USA
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25
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Abstract
Pressure ulcers are a serious health concern for elders in acute care, long-term care, and home care settings. The occurrence of a pressure ulcer is considered a sentinel event in terms of quality of care. Pressure ulcers may result in significant morbidity and mortality and are associated with high cost in terms of human suffering, cost of treatment, and possible litigation. Several risk factors have been identified for the development of pressure ulcers. Identification of elderly patients at risk of pressure and implementation of preventative measures are essential. Management of a pressure ulcer involves debridement, cleansing, selection of an appropriate dressing, and prevention of infection. This article reviews suggested guidelines for the prevention and management of pressure ulcers.
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Affiliation(s)
- Christine K. O’Neil
- Division of Social, Clinical, and Administrative Science, Mylan School of Pharmacy, Duquesne University, Pittsburgh, Pennsylvania,
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26
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Leifert WR, Nguyen T, Rembach A, Martins R, Rainey-Smith S, Masters CL, Ames D, Rowe CC, Macaulay SL, François M, Fenech MF. Buccal Cell Cytokeratin 14 Correlates with Multiple Blood Biomarkers of Alzheimer's Disease Risk. J Alzheimers Dis 2016; 48:443-52. [PMID: 26402008 DOI: 10.3233/jad-150330] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Mild cognitive impairment (MCI) may reflect early stages of neurodegenerative disorders such as Alzheimer's disease (AD). Our hypothesis was that cytokeratin 14 (CK14) expression could be used with blood-based biomarkers such as homocysteine, vitamin B12, and folate to identify individuals with MCI or AD from the Australian Imaging, Biomarkers and Lifestyle (AIBL) flagship study of aging. Buccal cells from 54 individuals were analyzed by a newly developed method that is rapid, automated, and quantitative for buccal cell CK14 expression levels. CK14 was negatively correlated with plasma Mg²⁺ and LDL, while positively correlated with vitamin B12, red cell hematocrit/volume, and basophils in the MCI group and positively correlated with insulin and vitamin B12 in the AD group. The combined biomarker panel (CK14 expression, plasma vitamin B12, and homocysteine) was significantly lower in the MCI (p = 0.003) and AD (p = 0.0001) groups compared with controls. Receiver-operating characteristic curves yielded area under the curve (AUC) values of 0.829 for the MCI (p = 0.002) group and 0.856 for the AD (p = 0.0003) group. These complex associations of multiple related parameters highlight the differences between the MCI and AD cohorts and possibly an underlying metabolic pathology associated with the development of early memory impairment. The changes in buccal cell CK14 expression observed in this pilot study supports previous results suggesting the peripheral biomarkers and metabolic changes are not restricted to brain pathology alone in MCI and AD and could prove useful as a potential biomarker in identifying individuals with an increased risk of developing MCI and eventually AD.
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Affiliation(s)
- Wayne R Leifert
- CSIRO Food and Nutrition Flagship, Genome Health and Healthy Ageing, Adelaide, South Australia, Australia
| | - Tori Nguyen
- CSIRO Food and Nutrition Flagship, Genome Health and Healthy Ageing, Adelaide, South Australia, Australia
| | - Alan Rembach
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Ralph Martins
- Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical Sciences, Edith Cowan University, Joondalup, Western Australia, Australia.,Sir James McCusker Alzheimer's Disease Research Unit (Hollywood Private Hospital), Perth, Western Australia
| | - Stephanie Rainey-Smith
- Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
| | - Colin L Masters
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - David Ames
- National Ageing Research Institute, Parkville, Victoria, Australia
| | - Christopher C Rowe
- Department of Nuclear Medicine & Centre for PET, Austin Health, Heidelberg, Victoria, Australia
| | - S Lance Macaulay
- CSIRO Food and Nutrition Flagship, Genome Health and Healthy Ageing, Adelaide, South Australia, Australia
| | - Maxime François
- CSIRO Food and Nutrition Flagship, Genome Health and Healthy Ageing, Adelaide, South Australia, Australia
| | - Michael F Fenech
- CSIRO Food and Nutrition Flagship, Genome Health and Healthy Ageing, Adelaide, South Australia, Australia
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27
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Kim DJ, Mustoe T, Clark RAF. Cutaneous wound healing in aging small mammals: a systematic review. Wound Repair Regen 2016; 23:318-39. [PMID: 25817246 DOI: 10.1111/wrr.12290] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 03/27/2015] [Accepted: 03/27/2015] [Indexed: 12/31/2022]
Abstract
As the elderly population grows, so do the clinical and socioeconomic burdens of nonhealing cutaneous wounds, the majority of which are seen among persons over 60 years of age. Human studies on how aging effects wound healing will always be the gold standard, but studies have ethical and practical hurdles. Choosing an animal model is dictated by costs and animal lifespan that preclude large animal use. Here, we review the current literature on how aging effects cutaneous wound healing in small animal models and, when possible, compare healing across studies. Using a literature search of MEDLINE/PubMed databases, studies were limited to those that utilized full-thickness wounds and compared the wound-healing parameters of wound closure, reepithelialization, granulation tissue fill, and tensile strength between young and aged cohorts. Overall, wound closure, reepithelialization, and granulation tissue fill were delayed or decreased with aging across different strains of mice and rats. Aging in mice was associated with lower tensile strength early in the wound healing process, but greater tensile strength later in the wound healing process. Similarly, aging in rats was associated with lower tensile strength early in the wound healing process, but no significant tensile strength difference between young and old rats later in healing wounds. From studies in New Zealand White rabbits, we found that reepithelialization and granulation tissue fill were delayed or decreased overall with aging. While similarities and differences in key wound healing parameters were noted between different strains and species, the comparability across the studies was highly questionable, highlighted by wide variability in experimental design and reporting. In future studies, standardized experimental design and reporting would help to establish comparable study groups, and advance the overall knowledge base, facilitating the translatability of animal data to the human clinical condition.
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Affiliation(s)
- Dong Joo Kim
- School of Medicine, Department of Dermatology, Stony Brook University, Stony Brook, New York
| | - Thomas Mustoe
- Division of Plastic and Reconstructive Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Richard A F Clark
- Department of Dermatology, Stony Brook University, Stony Brook, New York, and.,Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
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Taneja S, Mitnitski AB, Rockwood K, Rutenberg AD. Dynamical network model for age-related health deficits and mortality. Phys Rev E 2016; 93:022309. [PMID: 26986354 DOI: 10.1103/physreve.93.022309] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Indexed: 01/03/2023]
Abstract
How long people live depends on their health, and how it changes with age. Individual health can be tracked by the accumulation of age-related health deficits. The fraction of age-related deficits is a simple quantitative measure of human aging. This quantitative frailty index (F) is as good as chronological age in predicting mortality. In this paper, we use a dynamical network model of deficits to explore the effects of interactions between deficits, deficit damage and repair processes, and the connection between the F and mortality. With our model, we qualitatively reproduce Gompertz's law of increasing human mortality with age, the broadening of the F distribution with age, the characteristic nonlinear increase of the F with age, and the increased mortality of high-frailty individuals. No explicit time-dependence in damage or repair rates is needed in our model. Instead, implicit time-dependence arises through deficit interactions-so that the average deficit damage rates increase, and deficit repair rates decrease, with age. We use a simple mortality criterion, where mortality occurs when the most connected node is damaged.
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Affiliation(s)
- Swadhin Taneja
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2.,Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada B3H 2Y9.,Division of Geriatric Medicine, Dalhousie University, Halifax, Nova Scotia, Canada B3H 2E1
| | - Arnold B Mitnitski
- Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada B3H 2Y9
| | - Kenneth Rockwood
- Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada B3H 2Y9.,Division of Geriatric Medicine, Dalhousie University, Halifax, Nova Scotia, Canada B3H 2E1
| | - Andrew D Rutenberg
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
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The effect of patient education with telephone follow-up on wound healing in adult patients with clean wounds: a randomized controlled trial. J Wound Ostomy Continence Nurs 2015; 41:345-55. [PMID: 24988513 DOI: 10.1097/won.0000000000000047] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE The purpose of this study was to determine the influence of clean dressing technique in a home-care setting following a patient education program and telephone follow-up in a group of adult patients to wound healing in patients managed by sterile dressing changes by professional nurses in a general care outpatient clinic. DESIGN Randomized controlled trial. SUBJECTS AND SETTING The sample comprised adult patients with clean wounds who attended a general outpatient clinic in the Kowloon East district, a densely populated urban area in Hong Kong. Sixty-five subjects were randomly allocated to the intervention group and 61 were allocated to the control group. INSTRUMENT The Bates-Jensen Wound Assessment Tool (BWAT) was used to measure progress toward wound healing. METHODS We compared a control group of patients who received normal wound care (sterile dressing changes by professional nurses in a nonspecialized outpatient clinic) to a group of adult patients who managed their wounds using clean technique for dressing changes in their home following education on wound care. The intervention group also received follow-up telephone calls on days 1 and 3. The BWAT was completed to assess the wounds of both groups on the patients' first attendance and once a week until their wounds had healed. RESULTS Analysis revealed no significant differences between groups based on demographic or pertinent clinical characteristics. The mean BWAT score decreased in 2 weeks, from 27.26 to 15.15 (Freidman test, χ= 26.00, P < .000) for the intervention group and from 27.11 to 17.15 (Freidman test, χ= 24.15, P < .000) for the control group. A Mann-Whitney U test was used to compare the differences between the 2 groups based on total BWAT score. No statistically significant differences were found when groups were compared at baseline (Z =-0.416, P = .678), week 1 (Z =-1.313, P = .189), or week 2 (Z =-0.905, P = .418). CONCLUSION No differences in wound healing were found when patients who dressed their wounds at home using clean techniques versus patients who had their wounds dressed with sterile technique by professional nurses in a general outpatient clinic.
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Kapetanovic R, Bokil NJ, Sweet MJ. Innate immune perturbations, accumulating DAMPs and inflammasome dysregulation: A ticking time bomb in ageing. Ageing Res Rev 2015; 24:40-53. [PMID: 25725308 DOI: 10.1016/j.arr.2015.02.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 01/29/2015] [Accepted: 02/16/2015] [Indexed: 01/11/2023]
Abstract
Ageing has pronounced effects on the immune system, including on innate immune cells. Whilst most studies suggest that total numbers of different innate immune cell populations do not change dramatically during ageing, many of their functions such as phagocytosis, antigen presentation and inflammatory molecule secretion decline. In contrast, many endogenous damage-associated molecular patterns (DAMPs) accumulate during ageing. These include reactive oxygen species (ROS) released from damaged mitochondria, extracellular nucleotides like ATP, high mobility group box (HMGB) 1 protein, oxidized low density lipoprotein, amyloid-beta (Aβ), islet amyloid polypeptide and particulates like monosodium urate (MSU) crystals and cholesterol crystals. Some of these DAMPs trigger the activation of inflammasomes, cytosolic danger sensing signalling platforms that drive both the maturation of specific pro-inflammatory mediators such as IL-1β, as well as the initiation of pro-inflammatory pyroptotic cell death. Herein, we review the evidence that dysregulated inflammasome activation, via altered innate immune cell functions and elevated levels of DAMPs, contributes to the establishment of chronic, low-grade inflammation (characterized by elevated levels of IL-6 and C-reactive protein) and the development of age-related pathological processes.
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Affiliation(s)
- Ronan Kapetanovic
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Qld, Australia
| | - Nilesh J Bokil
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Qld, Australia
| | - Matthew J Sweet
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Qld, Australia.
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Optimal Timing of Whole-Brain Radiation Therapy Following Craniotomy for Cerebral Malignancies. World Neurosurg 2015; 84:412-9. [PMID: 25839399 DOI: 10.1016/j.wneu.2015.03.052] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2014] [Revised: 03/22/2015] [Accepted: 03/23/2015] [Indexed: 11/21/2022]
Abstract
BACKGROUND For patients with cerebral metastases that are limited in number, surgical resection followed by whole-brain radiation therapy is the standard of care. In addition, for high-grade gliomas, maximal surgical resection followed by local radiotherapy is considered the optimal treatment. Radiation is known to impair wound healing, including healing of surgical incisions. Radiotherapy shortly after surgical resection would be expected to minimize the opportunity for tumor regrowth or progression. Owing to these competing interests, the purpose of this study was to shed light on the optimal timing of radiotherapy after surgical resection of brain metastasis or high-grade gliomas. METHODS A review of the literature was conducted on the following topics: radiation and wound healing, corticosteroid use and wound healing, radiotherapy for tumor control for cerebral metastases and high-grade gliomas, and whole-brain radiation therapy or focal radiotherapy after craniotomy with focus on the timing of radiotherapy after surgery. RESULTS In animal models, wound integrity and healing was less impaired by radiotherapy administered 1 week after surgery. In humans, this timing would be expected to be significantly longer, on the order of several weeks. CONCLUSIONS Given the limited literature, insufficient conclusions can be drawn. However, animal data suggest a period of at least 1 week (but it is likely several weeks in humans) is necessary for reconstitution of wound strength before initiation of radiation therapy. A randomized prospective study is recommended to understand better the effect of the timing of radiation therapy following surgical intervention for brain metastasis or high-grade gliomas.
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François M, Leifert W, Martins R, Thomas P, Fenech M. Biomarkers of Alzheimer's disease risk in peripheral tissues; focus on buccal cells. Curr Alzheimer Res 2015; 11:519-31. [PMID: 24938500 PMCID: PMC4166904 DOI: 10.2174/1567205011666140618103827] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 05/26/2014] [Accepted: 06/16/2014] [Indexed: 12/29/2022]
Abstract
Alzheimer's disease (AD) is a progressive degenerative disorder of the brain and is the most common form of dementia. To-date no simple, inexpensive and minimally invasive procedure is available to confirm with certainty the early diagnosis of AD prior to the manifestations of symptoms characteristic of the disease. Therefore, if population screening of individuals is to be performed, more suitable, easily accessible tissues would need to be used for a diagnostic test that would identify those who exhibit cellular pathology indicative of mild cognitive impairment (MCI) and AD risk so that they can be prioritized for primary prevention. This need for minimally invasive tests could be achieved by targeting surrogate tissues, since it is now well recognized that AD is not only a disorder restricted to pathology and biomarkers within the brain. Human buccal cells for instance are accessible in a minimally invasive manner, and exhibit cytological and nuclear morphologies that may be indicative of accelerated ageing or neurodegenerative disorders such as AD. However, to our knowledge there is no review available in the literature covering the biology of buccal cells and their applications in AD biomarker research. Therefore, the aim of this review is to summarize some of the main findings of biomarkers reported for AD in peripheral tissues, with a further focus on the rationale for the use of the buccal mucosa (BM) for biomarkers of AD and the evidence to date of changes exhibited in buccal cells with AD.
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Affiliation(s)
| | | | | | | | - Michael Fenech
- CSIRO Animal, Food and Health Sciences, Gate 13, Kintore Ave, Adelaide, South Australia, 5000, Australia.
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Yamaoka H, Sumiyoshi H, Higashi K, Nakao S, Minakawa K, Sumida K, Saito K, Ikoma N, Mabuchi T, Ozawa A, Inagaki Y. A novel small compound accelerates dermal wound healing by modifying infiltration, proliferation and migration of distinct cellular components in mice. J Dermatol Sci 2014; 74:204-13. [DOI: 10.1016/j.jdermsci.2014.03.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 03/06/2014] [Accepted: 03/07/2014] [Indexed: 01/20/2023]
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da Silva EA, de Marins RL, Rondon A, Damião R. Age-related structural changes of the urethral plate in hypospadias. J Pediatr Urol 2013; 9:1155-60. [PMID: 23706383 DOI: 10.1016/j.jpurol.2013.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Accepted: 04/19/2013] [Indexed: 12/31/2022]
Abstract
PURPOSE To describe age-related changes in the extracellular matrix (ECM) of the human urethral plate in patients operated on for hypospadias, specifically describing histological features and determining the differences in the major components of the ECM, and thus providing an evaluation of the quality and wound healing potential of the urethral tissue. PATIENTS AND METHODS Urethral plate samples were obtained from 16 patients who underwent hypospadias repair (6 months-53 years of age), not previously submitted to any surgery. As a control group, male urethras were obtained from five fetuses. ECM structural characterization was performed by Hematoxylin and Eosin, Masson's trichrome, Weigert's resorcin-fuchsin, and Sirius red. The concentration of total collagen was determined by a hydroxyproline assay. RESULTS Urethral plates were lined with squamous epithelium. Most urethral plate samples showed well-vascularized connective tissue and typical vascular sinusoids surrounded by an ECM with smooth muscle cells, collagen, elastic fibers and fibroblasts. ECM of the older urethral plates was characterized by abundant collagen content (types I and III), scarce elastic fibers, low cellular density, and no vascular sinusoids. Total collagen concentration increased significantly with aging (r = 0.798; p = 0.006). CONCLUSIONS Urethral plates of hypospadias present important age-related structural changes. These changes may play a role in urethral healing following hypospadias repair, although this subject deserves more investigation.
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Affiliation(s)
- Eloísio Alexsandro da Silva
- Laboratory for Translational Research in Urology - UroLab, Service of Urology, Pedro Ernesto Memorial Hospital, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil.
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Heinbokel T, Elkhal A, Liu G, Edtinger K, Tullius SG. Immunosenescence and organ transplantation. Transplant Rev (Orlando) 2013; 27:65-75. [PMID: 23639337 PMCID: PMC3718545 DOI: 10.1016/j.trre.2013.03.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Revised: 12/17/2012] [Accepted: 03/19/2013] [Indexed: 12/22/2022]
Abstract
Increasing numbers of elderly transplant recipients and a growing demand for organs from older donors impose pressing challenges on transplantation medicine. Continuous and complex modifications of the immune system in parallel to aging have a major impact on transplant outcome and organ quality. Both, altered alloimmune responses and increased immunogenicity of organs present risk factors for inferior patient and graft survival. Moreover, a growing body of knowledge on age-dependent modifications of allorecognition and alloimmune responses may require age-adapted immunosuppression and organ allocation. Here, we summarize relevant aspects of immunosenescence and their possible clinical impact on organ transplantation.
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Affiliation(s)
- Timm Heinbokel
- Division of Transplant Surgery and Transplant Surgery Research Laboratory, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
- Institute of Medical Immunology, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Abdallah Elkhal
- Division of Transplant Surgery and Transplant Surgery Research Laboratory, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
| | - Guangxiang Liu
- Division of Transplant Surgery and Transplant Surgery Research Laboratory, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
| | - Karoline Edtinger
- Division of Transplant Surgery and Transplant Surgery Research Laboratory, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
| | - Stefan G. Tullius
- Division of Transplant Surgery and Transplant Surgery Research Laboratory, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
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Iaizzo PA, Laske TG, Harlow HJ, McClay CB, Garshelis DL. Wound healing during hibernation by black bears (Ursus americanus) in the wild: elicitation of reduced scar formation. Integr Zool 2012; 7:48-60. [PMID: 22405448 DOI: 10.1111/j.1749-4877.2011.00280.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Even mildly hypothermic body or limb temperatures can retard healing processes in mammals. Despite this, we observed that hibernating American black bears (Ursus americanus Pallas, 1780) elicit profound abilities in mounting inflammatory responses to infection and/or foreign bodies. In addition, they resolve injuries during hibernation while maintaining mildly hypothermic states (30-35 °C) and without eating, drinking, urinating or defecating. We describe experimental studies on free-ranging bears that document their abilities to completely resolve cutaneous cuts and punctures incurred during or prior to hibernation. We induced small, full-thickness cutaneous wounds (biopsies or incisions) during early denning, and re-biopsied sites 2-3 months later (near the end of denning). Routine histological methods were used to characterize these skin samples. All biopsied sites with respect to secondary intention (open circular biopsies) and primary intention (sutured sites) healed, with evidence of initial eschar (scab) formation, completeness of healed epidermis and dermal layers, dyskeratosis (inclusion cysts), and abilities to produce hair follicles. These healing abilities of hibernating black bears are a clear survival advantage to animals injured before or during denning. Bears are known to have elevated levels of hibernation induction trigger (delta-opioid receptor agonist) and ursodeoxycholic acid (major bile acid within plasma, mostly conjugated with taurine) during hibernation, which may relate to these wound-healing abilities. Further research as to the underlying mechanisms of wound healing during hibernation could have applications in human medicine. Unique approaches may be found to improve healing for malnourished, hypothermic, diabetic and elderly patients or to reduce scarring associated with burns and traumatic injuries.
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Affiliation(s)
- Paul A Iaizzo
- Department of Surgery, University of Minnesota, Minneapolis, MN 55455, USA.
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Carlson ME, Suetta C, Conboy MJ, Aagaard P, Mackey A, Kjaer M, Conboy I. Molecular aging and rejuvenation of human muscle stem cells. EMBO Mol Med 2010; 1:381-91. [PMID: 20049743 PMCID: PMC2875071 DOI: 10.1002/emmm.200900045] [Citation(s) in RCA: 184] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Very little remains known about the regulation of human organ stem cells (in general, and during the aging process), and most previous data were collected in short-lived rodents. We examined whether stem cell aging in rodents could be extrapolated to genetically and environmentally variable humans. Our findings establish key evolutionarily conserved mechanisms of human stem cell aging. We find that satellite cells are maintained in aged human skeletal muscle, but fail to activate in response to muscle attrition, due to diminished activation of Notch compounded by elevated transforming growth factor beta (TGF-β)/phospho Smad3 (pSmad3). Furthermore, this work reveals that mitogen-activated protein kinase (MAPK)/phosphate extracellular signal-regulated kinase (pERK) signalling declines in human muscle with age, and is important for activating Notch in human muscle stem cells. This molecular understanding, combined with data that human satellite cells remain intrinsically young, introduced novel therapeutic targets. Indeed, activation of MAPK/Notch restored ‘youthful’ myogenic responses to satellite cells from 70-year-old humans, rendering them similar to cells from 20-year-old humans. These findings strongly suggest that aging of human muscle maintenance and repair can be reversed by ‘youthful’ calibration of specific molecular pathways.
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Affiliation(s)
- Morgan E Carlson
- Department of Bioengineering, University of California, Berkeley, Berkeley CA, USA
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Abstract
Chronic wounds affect a substantial number of individuals throughout the world, and impose a significant psychological, physical and economic burden. As the population ages, the incidence of chronic wounds is also expected to rise. Clinicians struggle to find the optimal approaches to prevention and treatment of these nonhealing or slow-healing wounds. This review discusses current best practices and evidence-based recommendations for preventing and managing chronic wounds in general, as well as pressure ulcers, diabetic foot ulcers and venous leg ulcers specifically. This review highlights the significant gaps and inconsistencies in the current evidence base for chronic wound care, which have hindered making substantial progress in improving wound healing rates. It concludes with recommendations for improving the research and clinical knowledge base related to optimal wound-care practices.
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Affiliation(s)
- Katherine R Jones
- Frances Payne Bolton School of Nursing, Case Western Reserve University, Cleveland, OH 48106-4904, USA
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Abstract
A number of protective immune functions decline with age along with physiological and anatomical changes, contributing to the increased susceptibility of older adults to infectious diseases and suboptimal protective immune responses to vaccination. Influenza vaccination is the most cost-effective strategy to prevent complications from influenza viral infections; however, the immunogenicity and effectiveness of currently licensed vaccines in the United States is about 30-50% in preventing complications arising from influenza and preventing death from all causes during winter months in older adults. Hence, it is crucial to understand the molecular mechanisms that lead to immune dysfunction as a function of age so that appropriate strategies can be developed to enhance the disease resistance and immunogenicity of preventive vaccines, including influenza vaccines, for the older adult population.
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Aging and diabetes impair the neovascular potential of adipose-derived stromal cells. Plast Reconstr Surg 2009; 123:475-485. [PMID: 19182604 DOI: 10.1097/prs.0b013e3181954d08] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Aging and diabetes are major risk factors for poor wound healing and tissue regeneration that reflect an impaired ability to respond to ischemic insults. The authors explored the intrinsic neovascular potential of adipose-derived stromal cells in the setting of advanced age and in type 1 and type 2 diabetes. METHODS Adipose-derived stromal cells isolated from young, aged, streptozotocin-induced, and db/db diabetic mice were exposed to normoxia and hypoxia in vitro. Vascular endothelial growth factor (VEGF) expression, proliferation, and tubulization were measured. Conditioned media harvested from adipose-derived stromal cell cultures were assessed for their ability to stimulate human umbilical vein endothelial cell proliferation (n = 3 and n = 3). RESULTS Young adipose-derived stromal cells demonstrated significantly higher levels of VEGF production, proliferation, and tubulogenesis than those derived from aged, streptozotocin-induced, and db/db mice in both normoxia and hypoxia. Although aged and diabetic adipose-derived stromal cells retained the ability to up-regulate VEGF secretion, proliferation, and tubulogenesis in response to hypoxia, the response was blunted compared with young controls. Conditioned media derived from these cells cultured in normoxia in vitro also had a significantly greater ability to increase human umbilical vein endothelial cell proliferation compared with media harvested from aged, streptozotocin-induced, and db/db adipose-derived stromal cells. This effect was magnified in conditioned media harvested from hypoxic adipose-derived stromal cell cultures. CONCLUSIONS This study demonstrates that aging and type 1 and type 2 diabetes impair intrinsic adipose-derived stromal cell function; however, these cells may still be a suitable source of angiogenic cells that can potentially improve neovascularization of ischemic tissues.
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Thomas P, Wang YJ, Zhong JH, Kosaraju S, O'Callaghan NJ, Zhou XF, Fenech M. Grape seed polyphenols and curcumin reduce genomic instability events in a transgenic mouse model for Alzheimer's disease. Mutat Res 2008; 661:25-34. [PMID: 19027755 DOI: 10.1016/j.mrfmmm.2008.10.016] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2008] [Revised: 10/22/2008] [Accepted: 10/24/2008] [Indexed: 11/28/2022]
Abstract
The study set out to determine (a) whether DNA damage is elevated in mice that carry mutations in the amyloid precursor protein (APP695swe) and presenilin 1 (PSEN1-dE9) that predispose to Alzheimer's disease (AD) relative to non-transgenic control mice, and (b) whether increasing the intake of dietary polyphenols from curcumin or grape seed extract could reduce genomic instability events in a transgenic mouse model for AD. DNA damage was measured using the micronucleus (MN) assay in both buccal mucosa and erythrocytes and an absolute telomere length assay for both buccal mucosa and olfactory bulb tissue. MN frequency tended to be higher in AD mice in both buccal mucosa (1.7-fold) and polychromatic erythrocytes (1.3-fold) relative to controls. Telomere length was significantly reduced by 91% (p=0.04) and non-significantly reduced by 50% in buccal mucosa and olfactory bulbs respectively in AD mice relative to controls. A significant 10-fold decrease in buccal MN frequency (p=0.01) was found for AD mice fed diets containing curcumin (CUR) or micro-encapsulated grape seed extract (MGSE) and a 7-fold decrease (p=0.02) for AD mice fed unencapsulated grape seed extract (GSE) compared to the AD group on control diet. Similarly, in polychromatic erythrocytes a significant reduction in MN frequency was found for the MGSE cohort (65.3%) (p<0.05), whereas the AD CUR and AD GSE groups were non-significantly reduced by 39.2 and 34.8% respectively compared to the AD Control. A non-significant 2-fold increase in buccal cell telomere length was evident for the CUR, GSE and MGSE groups compared to the AD control group. Olfactory bulb telomere length was found to be non-significantly 2-fold longer in mice fed on the CUR diet compared to controls. These results suggest potential protective effects of polyphenols against genomic instability events in different somatic tissues of a transgenic mouse model for AD.
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Affiliation(s)
- Philip Thomas
- CSIRO Human Nutrition, PO Box 10041, Adelaide BC, Adelaide, SA 5000, Australia
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Khanal S, Tomlinson A, Esakowitz L, Bhatt P, Jones D, Nabili S, Mukerji S. Changes in corneal sensitivity and tear physiology after phacoemulsification. Ophthalmic Physiol Opt 2008; 28:127-34. [DOI: 10.1111/j.1475-1313.2008.00539.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Radek KA, Baer LA, Eckhardt J, DiPietro LA, Wade CE. Mechanical unloading impairs keratinocyte migration and angiogenesis during cutaneous wound healing. J Appl Physiol (1985) 2008; 104:1295-303. [PMID: 18292299 DOI: 10.1152/japplphysiol.00977.2007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Although initially thought to improve an individual's ability to heal, mechanical unloading promoted by extended periods of bed rest has emerged as a contributing factor to delayed or aberrant tissue repair. Using a rat hindlimb unloading (HLU) model of hypogravity, we mimicked some aspects of physical inactivity by removing weight-bearing loads from the hindlimbs and producing a systemic cephalic fluid shift. This model simulates bed rest in that the animal undergoes physiological adaptations, resulting in a reduction in exercise capability, increased frequency of orthostatic intolerance, and a reduction in plasma volume. To investigate whether changes associated with prior prolonged bed rest correlate with impaired cutaneous wound healing, we examined wound closure, angiogenesis, and collagen content in day 2 to day 21 wounds from rats exposed to HLU 2 wk before excisional wounding. Wound closure was delayed in day 2 wounds from HLU rats compared with ambulatory controls. Although the levels of proangiogenic growth factors, fibroblast growth factor-2 (FGF-2), and vascular endothelial growth factor (VEGF) were similar between the two groups, wound vascularity was significantly reduced in day 7 wounds from HLU animals. To further examine this disparity, total collagen content was assessed but found to be similar between the two groups. Taken together, these results suggest that keratinocyte and endothelial cell function may be impaired during the wound healing process under periods of prolonged inactivity or bed rest.
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Affiliation(s)
- Katherine A Radek
- Department of Medicine, University of California-San Diego, San Diego, CA, USA
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Kaestli LZ, Wasilewski-Rasca AF, Bonnabry P, Vogt-Ferrier N. Use of Transdermal Drug Formulations in the Elderly. Drugs Aging 2008; 25:269-80. [DOI: 10.2165/00002512-200825040-00001] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Thomas P, Harvey S, Gruner T, Fenech M. The buccal cytome and micronucleus frequency is substantially altered in Down's syndrome and normal ageing compared to young healthy controls. Mutat Res 2007; 638:37-47. [PMID: 17920640 DOI: 10.1016/j.mrfmmm.2007.08.012] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2007] [Revised: 08/20/2007] [Accepted: 08/21/2007] [Indexed: 11/30/2022]
Abstract
The buccal micronucleus cytome assay was used to investigate biomarkers for DNA damage, cell death and basal cell frequency in buccal cells of healthy young, healthy old and young Down's syndrome cohorts. With normal ageing a significant increase in cells with micronuclei (P<0.05, average increase +366%), karyorrhectic cells (P<0.001, average increase +439%), condensed chromatin cells (P<0.01, average increase +45.8%) and basal cells (P<0.001, average increase +233%) is reported relative to young controls. In Down's syndrome we report a significant increase in cells with micronuclei (P<0.001, average increase +733%) and binucleated cells (P<0.001, average increase +84.5%) and a significant decrease in condensed chromatin cells (P<0.01, average decrease -52%), karyolytic cells (P<0.001, average decrease -51.8%) and pyknotic cells (P<0.001, average decrease -75.0%) relative to young controls. These changes show distinct differences between the cytome profile of normal ageing relative to that for a premature ageing syndrome, and highlight the diagnostic value of the cytome approach for measuring the profile of cells with DNA damage, cell death and proportion of cells with proliferative potential (i.e., basal cells). Significant correlations amongst cell death biomarkers observed in this study were used to propose a new model of the inter-relationship of cell types scored within the buccal micronucleus cytome assay. This study validates the use of a cytome approach to investigate DNA damage, cell death and cell proliferation in buccal cells with ageing.
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Affiliation(s)
- Philip Thomas
- CSIRO Human Nutrition, PO Box 10041, Adelaide BC, Adelaide, SA 5000, Australia.
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Abstract
Pressure ulcers remain a complex and costly problem to the health care system. As the population ages, a greater number of individuals will be at high risk for developing pressure ulcers. An understanding of the physiologic changes that occur with aging skin is important in preventing and treating chronic wounds. Risk factor assessment and modification, when possible, can help to reduce the development of pressure ulcerations. Although the goal continues to be prevention, once a pressure ulcer does occur, a systematic and comprehensive approach to assessment and treatment is necessary to reduce healing times.
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Affiliation(s)
- Aimée Dinorah Garcia
- Michael E. DeBakey VA Medical Center, Baylor College of Medicine, 2002 Holcombe ECL 110, Houston, TX 77030, USA.
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Benatti BB, Neto JBC, Casati MZ, Sallum EA, Sallum AW, Nociti FH. Periodontal healing may be affected by aging: a histologic study in rats. J Periodontal Res 2006; 41:329-33. [PMID: 16827728 DOI: 10.1111/j.1600-0765.2006.00872.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND OBJECTIVE Although wound healing has been reported to be impaired with aging, very little is known about its effect on periodontal tissues. Therefore, the aim of this study was to evaluate, histologically in rats, the influence of aging on a spontaneous periodontal healing model. MATERIAL AND METHODS Twenty-four male Wistar rats were used and assigned to the following groups: control (n = 12; 2 mo old) and aged (n = 12; 18 mo old). Fenestration defects (4 x 3 x 1 mm) were created bilaterally at the buccal aspect of the distal root of the first mandibular molars, and the mandibulae were retrieved 3 and 6 wk postoperatively. The percentage of bone fill and density of newly formed bone, new cementum formation (NC), and the extension of the remaining defect (ERD) were histometrically obtained. RESULTS Intragroup analysis demonstrated that, except for cementum, all histological parameters significantly improved over time (p < 0.05). Intergroup analysis additionally showed that the defects were initially similar in size, and that at 3 wk aging negatively influenced newly formed bone (86.38 +/- 2.99% and 73.06 +/- 3.21%, p < 0.001, for groups control and aged, respectively), BF (75.84 +/- 16.53% and 57.70 +/- 22.28%, p = 0.014) and ERD (0.41 +/- 0.20 mm and 1.17 +/- 0.37 mm, p < 0.001). At 6 wk, aging negatively influenced newly formed bone (88.12 +/- 2.90% and 78.19 +/- 5.35%, p < 0.001, for groups control and aged, respectively) and ERD (0.01 +/- 0.006 mm and 0.34 +/- 0.18 mm, p = 0.003), but not BF (98.15 +/- 2.43% and 87.87 +/- 11.63%, p > 0.05). No new cementum was formed along the root surface in the above groups. CONCLUSION Within the limits of the present study, data analysis suggests that aging may impair, but not prevent, periodontal healing.
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Affiliation(s)
- B B Benatti
- Department of Prosthodontics and Periodontics, Division of Periodontics, Faculty of Dentistry, Campinas State University, Piracicaba, São Paulo, Brazil
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