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Sample records for acellular dermal matrices

  1. [Penile augmentation using acellular dermal matrix].

    Science.gov (United States)

    Zhang, Jin-ming; Cui, Yong-yan; Pan, Shu-juan; Liang, Wei-qiang; Chen, Xiao-xuan

    2004-11-01

    Penile enhancement was performed using acellular dermal matrix. Multiple layers of acellular dermal matrix were placed underneath the penile skin to enlarge its girth. Since March 2002, penile augmentation has been performed on 12 cases using acellular dermal matrix. Postoperatively all the patients had a 1.3-3.1 cm (2.6 cm in average) increase in penile girth in a flaccid state. The penis had normal appearance and feeling without contour deformities. All patients gained sexual ability 3 months after the operation. One had a delayed wound healing due to tight dressing, which was repaired with a scrotal skin flap. Penile enlargement by implantation of multiple layers of acellular dermal matrix was a safe and effective operation. This method can be performed in an outpatient ambulatory setting. The advantages of the acellular dermal matrix over the autogenous dermal fat grafts are elimination of donor site injury and scar and significant shortening of operation time.

  2. Acellular Dermal Matrix: Treating Periocular Melanoma in a Patient with Xeroderma Pigmentosa

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    Kamlen Pillay, MBChB

    2017-08-01

    Full Text Available We report a 7-year-old girl with xeroderma pigmentosum (XP, who presented in our clinic with a large melanoma (35 × 50 × 20 mm, Breslow depth 18 mm in the zygomatic-malar area. Palliative surgery was performed to maintain her residual vision and to reduce the pain caused by the compression of local structures. Because of the limited access of autologous skin grafts in pediatric patients with XP who are severely affected, we opted to use an acellular dermal matrix. There was 100% graft uptake, and the pain due to compression by the tumor was alleviated. This case demonstrates that acellular dermal matrices can be safely and effectively used in oncological facial reconstruction, especially in patients with progressive conditions such as XP.

  3. A systematic review of acelluar dermal matrices in head and neck reconstruction.

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    Shridharani, Sachin M; Tufaro, Anthony P

    2012-11-01

    The use of acellular dermal matrices has been well described in the scientific literature since the early 1990 s and has been utilized for multiple applications in the head and neck for both aesthetic and reconstructive efforts. After systematically searching the PubMed database and following further refinement (based on the authors' inclusion and exclusion criteria), the authors identified 30 studies that provided information about patients who had undergone head and neck reconstruction with the use of acellular dermal matrix. Studies had to report quantifiable objective results in patients who were older than 1 year and younger than 90 years. The authors excluded single case reports, studies with fewer than 10 patients, and studies not published in English. The optimal material used as an implant for reconstruction possesses the following properties: facilitation of vascular ingrowth, decreased propensity to incite inflammation, biologic inertness, resistance to infection, and ease of handling. Acellular dermal matrix possesses many of these properties and is utilized in reconstructing nasal soft tissue and skeletal support, tympanic membrane, periorbital soft tissue, extraoral and intraoral defects, oropharyngeal defects, dura mater, and soft-tissue deficits from parotidectomy. Furthermore, it is used to assist in preventing Frey syndrome following parotidectomy and surgical treatment of facial paralysis. Use of acellular dermal matrix for head and neck reconstruction has expanded exponentially and is validated in many studies. Further prospective randomized control trials are warranted to further investigate the efficacy of acellular dermal matrix in head and neck reconstruction.

  4. Sterile Acellular Dermal Collagen as a Treatment for Rippling Deformity of Breast

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    Brittany Busse

    2014-01-01

    Full Text Available Prosthetic implants are frequently used for breast augmentation and breast reconstruction following mastectomy. Unfortunately, long-term aesthetic results of prosthetic breast restoration may be hindered by complications such as rippling, capsular contracture, and implant malposition. The advent of use of acellular dermal matrices has greatly improved the outcomes of prosthetic breast reconstruction. We describe a case of rippling deformity of breast that was treated using an acellular dermal matrix product, AlloMax. The patient presented with visible rippling of bilateral prosthetic breast implants as well as significant asymmetry of the breasts after multiple excisional biopsies for right breast ductal carcinoma in situ. A 6×10 cm piece of AlloMax was placed on the medial aspect of each breast between the implant and the skin flap. Follow-up was performed at 1 week, 3 months, and 1 year following the procedure. The patient recovered well from the surgery and there were no complications. At her first postoperative follow-up the patient was extremely satisfied with the result. At her 3-month and 1-year follow-up she had no recurrence of her previous deformity and no new deformity.

  5. Cleft Palate Fistula Closure Utilizing Acellular Dermal Matrix

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    Omri Emodi, DMD

    2018-03-01

    Full Text Available Summary:. Fistulas represent failure of cleft palate repair. Secondary and tertiary fistula repair is challenging, with high recurrence rates. In the present retrospective study, we review the efficacy of using acellular dermal matrix as an interposition layer for cleft palate fistula closure in 20 consecutive patients between 2013 and 2016. Complete fistula closure was obtained in 16 patients; 1 patient had asymptomatic recurrent fistula; 2 patients had partial closure with reduction of fistula size and minimal nasal regurgitation; 1 patient developed a recurrent fistula without changes in symptoms (success rate of 85%. We conclude that utilizing acellular dermal matrix for cleft palate fistula repair is safe and simple with a high success rate.

  6. Cleft Palate Fistula Closure Utilizing Acellular Dermal Matrix.

    Science.gov (United States)

    Emodi, Omri; Ginini, Jiriys George; van Aalst, John A; Shilo, Dekel; Naddaf, Raja; Aizenbud, Dror; Rachmiel, Adi

    2018-03-01

    Fistulas represent failure of cleft palate repair. Secondary and tertiary fistula repair is challenging, with high recurrence rates. In the present retrospective study, we review the efficacy of using acellular dermal matrix as an interposition layer for cleft palate fistula closure in 20 consecutive patients between 2013 and 2016. Complete fistula closure was obtained in 16 patients; 1 patient had asymptomatic recurrent fistula; 2 patients had partial closure with reduction of fistula size and minimal nasal regurgitation; 1 patient developed a recurrent fistula without changes in symptoms (success rate of 85%). We conclude that utilizing acellular dermal matrix for cleft palate fistula repair is safe and simple with a high success rate.

  7. Evaluation of human acellular dermis versus porcine acellular dermis in an in vivo model for incisional hernia repair.

    Science.gov (United States)

    Ngo, Manh-Dan; Aberman, Harold M; Hawes, Michael L; Choi, Bryan; Gertzman, Arthur A

    2011-05-01

    Incisional hernias commonly occur following abdominal wall surgery. Human acellular dermal matrices (HADM) are widely used in abdominal wall defect repair. Xenograft acellular dermal matrices, particularly those made from porcine tissues (PADM), have recently experienced increased usage. The purpose of this study was to compare the effectiveness of HADM and PADM in the repair of incisional abdominal wall hernias in a rabbit model. A review from earlier work of differences between human allograft acellular dermal matrices (HADM) and porcine xenograft acellular dermal matrices (PADM) demonstrated significant differences (P strength 15.7 MPa vs. 7.7 MPa for HADM and PADM, respectively. Cellular (fibroblast) infiltration was significantly greater for HADM vs. PADM (Armour). The HADM exhibited a more natural, less degraded collagen by electrophoresis as compared to PADM. The rabbit model surgically established an incisional hernia, which was repaired with one of the two acellular dermal matrices 3 weeks after the creation of the abdominal hernia. The animals were euthanized at 4 and 20 weeks and the wounds evaluated. Tissue ingrowth into the implant was significantly faster for the HADM as compared to PADM, 54 vs. 16% at 4 weeks, and 58 vs. 20% for HADM and PADM, respectively at 20 weeks. The original, induced hernia defect (6 cm(2)) was healed to a greater extent for HADM vs. PADM: 2.7 cm(2) unremodeled area for PADM vs. 1.0 cm² for HADM at 20 weeks. The inherent uniformity of tissue ingrowth and remodeling over time was very different for the HADM relative to the PADM. No differences were observed at the 4-week end point. However, the 20-week data exhibited a statistically different level of variability in the remodeling rate with the mean standard deviation of 0.96 for HADM as contrasted to a mean standard deviation of 2.69 for PADM. This was significant with P < 0.05 using a one tail F test for the inherent variability of the standard deviation. No

  8. Chest wall reconstruction with acellular dermal matrix (Strattice™) and a TRAM flap

    DEFF Research Database (Denmark)

    Brunbjerg, Mette Eline; Juhl, Alexander Andersen; Damsgaard, Tine Engberg

    2014-01-01

    Mette Eline Brunbjerg, Alexander Andersen Juhl, Tine E. Damsgaard. "Chest wall reconstruction with acellular dermal matrix (Strattice™) and a TRAM flap.” Acta Oncol. 2013 Jun;52(5):1052-4. Epub 2012 Oct 24. PMID: 23095144......Mette Eline Brunbjerg, Alexander Andersen Juhl, Tine E. Damsgaard. "Chest wall reconstruction with acellular dermal matrix (Strattice™) and a TRAM flap.” Acta Oncol. 2013 Jun;52(5):1052-4. Epub 2012 Oct 24. PMID: 23095144...

  9. Use of Porcine Acellular Dermal Matrix as a Dermal Substitute in Rats

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    Srivastava, Anil; DeSagun, Evangeline Z.; Jennings, Lawrence J.; Sethi, Stephen; Phuangsab, Anan; Hanumadass, Marella; Reyes, Hernan M.; Walter, Robert J.

    2001-01-01

    Objective To examine porcine acellular dermal matrix (ADM) as a xenogenic dermal substitute in a rat model. Summary Background Data Acellular dermal matrix has been used in the treatment of full-thickness skin injuries as an allogenic dermal substitute providing a stable wound base in human and animal studies. Methods Xenogenic and allogenic ADMs were produced by treating porcine or rat skin with Dispase and Triton X-100. Full-thickness skin defects (225 mm2) were created on the dorsum of rats (n = 29), porcine or rat ADMs were implanted in them, and these were overlain with ultrathin split-thickness skin grafts (STSGs). In two adjacent wounds, 0.005- or 0.017-inch-thick autografts were implanted. In other experiments, the antimicrobial agent used during ADM processing (azide or a mixture of antibiotics) and the orientation of the implanted ADM (papillary or reticular side of ADM facing the STSG) were studied. Grafts were evaluated grossly and histologically for 30 days after surgery. Results Significant wound contraction was seen at 14, 20, and 30 days after surgery in wounds receiving xenogenic ADM, allogenic ADM, and thin STSGs. Contraction of wounds containing xenogenic ADM was significantly greater than that of wounds containing allogenic ADM at 30 days after surgery. Graft take was poor in wounds containing xenogenic ADM and moderately good in those containing allogenic ADM. Wound healing was not significantly affected by the antimicrobial agent used during ADM preparation or by the ADM orientation. Conclusion Dispase–Triton-treated allogenic ADM was useful as a dermal substitute in full-thickness skin defects, but healing with xenogenic ADM was poor. PMID:11224629

  10. Acellular dermal matrix based nipple reconstruction: A modified technique

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    Raghavan Vidya

    2017-09-01

    Full Text Available Nipple areolar reconstruction (NAR has evolved with the advancement in breast reconstruction and can improve self-esteem and, consequently, patient satisfaction. Although a variety of reconstruction techniques have been described in the literature varying from nipple sharing, local flaps to alloplastic and allograft augmentation, over time, loss of nipple projection remains a major problem. Acellular dermal matrices (ADM have revolutionised breast reconstruction more recently. We discuss the use of ADM to act as a base plate and strut to give support to the base and offer nipple bulk and projection in a primary procedure of NAR with a local clover shaped dermal flap in 5 breasts (4 patients. We used 5-point Likert scales (1 = highly unsatisfied, 5 = highly satisfied to assess patient satisfaction. Median age was 46 years (range: 38–55 years. Nipple projection of 8 mm, 7 mm, and 7 mms were achieved in the unilateral cases and 6 mm in the bilateral case over a median 18 month period. All patients reported at least a 4 on the Likert scale. We had no post-operative complications. It seems that nipple areolar reconstruction [NAR] using ADM can achieve nipple projection which is considered aesthetically pleasing for patients.

  11. Usefulness of Cross-Linked Human Acellular Dermal Matrix as an Implant for Dorsal Augmentation in Rhinoplasty.

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    Yang, Chae Eun; Kim, Soo Jung; Kim, Ji Hee; Lee, Ju Hee; Roh, Tai Suk; Lee, Won Jai

    2018-02-01

    Asian noses are relatively small and flat compared to Caucasians; therefore, rhinoplasty procedures often focus on dorsal augmentation and tip projection rather than reduction in the nasal framework. Various autologous and alloplastic implant materials have been used for dorsal augmentation. Recently, human acellular dermal matrices have been introduced as an implant material for dorsal augmentation, camouflaging autologous implants without an additional donor site. Here, we introduce a cross-linked human acellular dermal matrix as an implant material in augmentation rhinoplasty and share the clinical experiences. Eighteen patients who underwent augmentation rhinoplasty using acellular dermal matrix from April 2014 to November 2015 were reviewed retrospectively. Clinical outcomes and complications were assessed at the outpatient clinic during the follow-up period ranging from 8 to 38 months. Contour changes were assessed through comparison of preoperative and postoperative photographs by two independent plastic surgeons. Patient satisfaction was assessed at the outpatient clinic by six questions regarding aesthetic and functional aspects. Postoperative photographs demonstrated the height of the nasal dorsum did not decrease over time except two patients whose ADM was grafted into a subperiosteal pocket. Others who underwent supraperiosteal implantation showed acceptable maintenance of dorsal height. No major complication was reported. Overall, patient satisfaction scored 81.02 out of 100. Cross-linked human ADM has advantages of both autogenous and alloplastic materials. The surgical results remain stable without complications. Therefore, it is a suitable alternative implant material for dorsal augmentation in rhinoplasty. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  12. Expanding the applications of Cadaveric skin - the properties and uses of an acellular dermal matrix

    International Nuclear Information System (INIS)

    Greenleaf, G.; Livesey, S.

    1999-01-01

    The ability to transplant organs and tissues has been one of the most significant advances of modern medicine. The availability of cadaveric allograft skin has greatly facilitated the practice of aggressive, early excision of massive burn injuries. Due to its ultimate rejection however, the role of allograft skin has historically been limited to that of a temporary wound dressing. Development of an acellular dermal allograft has greatly expanded the applications for donated human skin. AlloDerm(r) preserved dermal graft (LifeCell, The Woodlands, TX) is prepared via ionic separation of allograft skin followed by detergent removal of antigenic cells. Acellular dermal grafts are then cryoprotected and freeze-dried. The process maintains the structural integrity of the extracellular matrix and preserves the biochemical composition of the basement membrane. The resultant immunologically inert allograft can be used in a variety of applications. In burn injuries, lack of an adequate dermal component at either the donor or wound site may result in complications including contraction, delayed healing, hypertrophic scarring and keloid formation. Utilizing allogenic dermis eliminates the need for autologous dermis at the wound site and minimizes donor site trauma by allowing procurement of ultra-thin (0.006 ) autografts. Expanding the scope of traditional uses for allograft skin, acellular dermal grafts have been successfully utilized in a variety of procedures including duraplasty, orbital reconstruction, and hemia repar. In periodontal surgery, allograft tissue eliminates the need for painful palatal autografts and has been used to increase attached gingiva and reduce gingival recession. Resorption of autologous grafts or extrusion of synthetic material often hampers repair or reconstruction of soft tissue deficits. Transplantation of acellular allograft dermis provides a biochemically and structurally intact matrix, which persists and is ultimately repopulated with

  13. Coverage of Megaprosthesis with Human Acellular Dermal Matrix after Ewing's Sarcoma Resection: A Case Report

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    Robert M. Whitfield

    2011-01-01

    Full Text Available A 23-year-old female with Ewing's Sarcoma underwent tibial resection and skeletal reconstruction using proximal tibial allograft prosthetic reconstruction with distal femur endoprosthetic reconstruction and rotating hinge. Human acellular dermal matrix, (Alloderm, LifeCell, Branchburg, NJ, USA, was used to wrap the skeletal reconstruction. Soft tissue reconstruction was completed with a rotational gastrocnemius muscle flap and skin graft. Despite prolonged immobilization, the patient quickly regained full range of motion of her skeletal reconstruction. Synthetic mesh, tapes and tubes are used to perform capsule reconstruction of megaprosthesis. This paper describes the role of human acellular dermal matrix in capsule reconstruction around a megaprosthesis.

  14. [Autogenous platelet-rich plasma gel with acellular xenogeneic dermal matrix for treatment of deep II degree burns].

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    Hao, Tianzhi; Zhu, Jingmin; Hu, Wenbo; Zhang, Hua; Gao, Zhenhui; Wen, Xuehui; Zhou, Zhi; Lu, Gang; Liu, Jingjie; Li, Wen

    2010-06-01

    To investigate the effectiveness of autogenous platelet-rich plasma (PRP) gel with acellular xenogeneic dermal matrix in the treatment of deep II degree burns. From January 2007 to December 2009, 30 cases of deep II degree burns were treated. There were 19 males and 11 females with an average age of 42.5 years (range, 32-57 years). The burn area was 10% to 48% of total body surface area. The time from burn to hospitalization was 30 minutes to 8 hours. All patients were treated with tangential excision surgery, one side of the wounds were covered with autogenous PRP gel and acellular xenogeneic dermal matrix (PRP group), the other side of the wounds were covered with acellular xenogeneic dermal matrix only (control group). The healing rate, healing time, infection condition, and scar formation were observed. At 7 days after operation, the infection rate in PRP group (6.7%, 2/30) was significantly lower than that in control group (16.7%, 5/30, P deep II degree burns as well as alleviate the scar proliferation.

  15. The use of dermal autograft as an adjunct to breast reconstruction with tissue expanders.

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    Rinker, Brian

    2012-12-01

    Acellular dermal matrices are commonly used in breast reconstruction but add cost to the procedure and have been associated with complications. Dermal autograft may represent a useful alternative to matrices. Sixteen patients (26 breasts) underwent breast reconstruction using tissue expanders and dermal autograft. Their ages ranged from 41 to 66 years (median, 51 years). Autografts were harvested by wide excision of preexisting abdominal scars. Demographic data, clinical history, and harvest and preparation time were recorded. The initial fill volume, number of expansions, and complications were recorded and compared with published data for acellular dermal matrix-assisted reconstruction. Patients rated their satisfaction with scar appearance on a seven-point scale. Follow-up ranged from 6 to 16 months (mean, 10 months). Three patients were smokers. Mean body mass index was 30.5 (range, 19.1 to 48.8). Three patients received chemotherapy between reconstructive stages, and none required irradiation. The mean time of autograft harvest was 38 minutes, the mean initial fill was 190 cc, and the average number of expansions was 3.5. There were no implant losses. There were three minor complications (19 percent). Initial expander fill, number of expansions, and complication rate were equivalent to historical values for matrix-assisted breast reconstruction. Fourteen of 16 patients (88 percent) were "very satisfied" with their scars. The use of dermal autograft in tissue expander breast reconstruction offers the advantages of acellular dermal matrix, without the associated expense. The technique adds minimally to the operative time and morbidity and is associated with a low complication rate. Therapeutic, IV.

  16. Does Acellular Dermal Matrix Thickness Affect Complication Rate in Tissue Expander Based Breast Reconstruction?

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    Jessica F. Rose

    2016-01-01

    Full Text Available Background. While the benefits of using acellular dermal matrices (ADMs in breast reconstruction are well described, their use has been associated with additional complications. The purpose of this study was to determine if ADM thickness affects complications in breast reconstruction. Methods. A retrospective chart review was performed including all tissue expander based breast reconstructions with AlloDerm (LifeCell, Branchburg, NJ over 4 years. We evaluated preoperative characteristics and assessed postoperative complications including seroma, hematoma, infection, skin necrosis, and need for reintervention. We reviewed ADM thickness and time to Jackson-Pratt (JP drain removal. Results. Fifty-five patients underwent 77 ADM-associated tissue expander based breast reconstructions, with average age of 48.1 years and average BMI of 25.9. Average ADM thickness was 1.21 mm. We found higher complication rates in the thick ADM group. Significant associations were found between smokers and skin necrosis (p<0.0001 and seroma and prolonged JP drainage (p=0.0004; radiated reconstructed breasts were more likely to suffer infections (p=0.0085, and elevated BMI is a significant predictor for increased infection rate (p=0.0037. Conclusion. We found a trend toward increased complication rates with thicker ADMs. In the future, larger prospective studies evaluating thickness may provide more information.

  17. [Application of the xenogenic acellular dermal matrix membrane application used in the postoperative tissue shortage repair].

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    Bai, Yanxia; Yan, Liying; Zhang, Shaoqiang; Shao, Yuan; Yao, Xiaobao; Li, Honghui; Zhao, Ruimin; Zhao, Qian; Zhang, Pengfei; Yang, Qi

    2014-09-01

    To observe the short-term and long-term curative effect of the xenogenic acellular dermal matrix membrane (or joint muscle flap transfer) application used in the 82 cases postoperative tissue shortage repair that after the head neck carcinoma resection. To held the 82 cases head neck carcinoma postoperative mucosa shortage repaired after resection by the xenogenic acellular dermal matrix membrane (or joint muscle flap transfer), 65 cases mucosa shortage wound be directly covered by the repair membrane and the other 17 cases mucosa shortage wound be repaired by the tranfered muscle tissue flap with the repair membrane covered; 53 cases underwent additional postoperative radiotherapy between 2-4 weeks and follow-up in 1, 3, 6, 12, 18, 24, 30, 36, 48, 60 months and observed the operation site repair process through the electronic laryngoscope, observed the patients respiration, swallow, phonation function. Seventy-seven cases patients operation incision reached I phase healing standard, another 5 cases patients operation incision reached II phase healing standard because of the wound infection and fully-recovered through the local wound drainage,dressing process. All the patients tracheal cannula,the stomach tube be extubated successfully and without the local cicatricial constriction occurred. Seventy-eight cases follow up period reached 1 year including 53 cases who underwent postoperative radiotherapy, 49 cases follow up period reached 3 years including 32 cases who underwent postoperative radiotherapy, 14 cases follow up period reached 5 years including 12 cases who underwent postoperative radiotherapy. The patients with static local lesions discovered no reaction such as exclusion, allergy. The application of xenogenic acellular dermal matrix membrane (or joint muscle flap transfer used in in the postoperative tissue shortage repair that after the head neck carcinoma resection have several advantage such as comparatively easily implementation, operation safety

  18. Evaluation of lymphangiogenesis in acellular dermal matrix

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    Mario Cherubino

    2014-01-01

    Full Text Available Introduction: Much attention has been directed towards understanding the phenomena of angiogenesis and lymphangiogenesis in wound healing. Thanks to the manifold dermal substitute available nowadays, wound treatment has improved greatly. Many studies have been published about angiogenesis and cell invasion in INTEGRA® . On the other hand, the development of the lymphatic network in acellular dermal matrix (ADM is a more obscure matter. In this article, we aim to characterize the different phases of host cell invasion in ADM. Special attention was given to lymphangiogenic aspects. Materials and Methods: Among 57 rats selected to analyse the role of ADM in lymphangiogenesis, we created four groups. We performed an excision procedure on both thighs of these rats: On the left one we did not perform any action except repairing the borders of the wound; while on the right one we used INTEGRA® implant. The excision biopsy was performed at four different times: First group after 7 days, second after 14 days, third after 21 days and fourth after 28 days. For our microscopic evaluation, we used the classical staining technique of haematoxylin and eosin and a semi-quantitative method in order to evaluate cellularity counts. To assess angiogenesis and lymphangiogenesis development we employed PROX-1 Ab and CD31/PECAM for immunohistochemical analysis. Results: We found remarkable wound contraction in defects that healed by secondary intention while minor wound contraction was observed in defects treated with ADM. At day 7, optical microscopy revealed a more plentiful cellularity in the granulation tissue compared with the dermal regeneration matrix. The immunohistochemical process highlighted vascular and lymphatic cells in both groups. After 14 days a high grade of fibrosis was noticeable in the non-treated group. At day 21, both lymphatic and vascular endothelial cells were better developed in the group with a dermal matrix application. At day 28

  19. Yeasts from skin colonization are able to cross the acellular dermal matrix.

    Science.gov (United States)

    Jarros, Isabele Carrilho; Okuno, Érika; Costa, Maiara Ignacio; Veiga, Flávia Franco; de Souza Bonfim-Mendonça, Patricia; Negri, Melyssa Fernanda Norman; Svidzinski, Terezinha Inez Estivalet

    2018-04-01

    In recent decades, the prognosis for burn patients has improved considerably with the development of specialized care. The acellular dermal matrix (ADM) is a totally artificial acellular device that functions to control water loss, prevent penetration by bacteria and allow migration of endothelial cells and fibroblasts from patient tissues. However, little is known about its effectiveness against yeasts. The present study evaluated the capacity of colonization and migration of some human commensal yeasts. Three clinical isolates from skin scales, identified as Candida parapsilosis, Candida glabrata and Rhodotorula mucilaginosa, were used. Their ability to cross the ADM was evaluated. After three days, all isolates had crossed the ADM. C. parapsilosis showed the lowest growth, while R. mucilaginosa showed intermediate and C. glabrata the highest growth. In the plates incubated for seven days, the growth of C. parapsilosis and C. glabrata increased by 1 log over the third day. All isolates have the capacity to colonize and migrate through the matrix, increasing the potential risk to burn patients, who can develop severe and even fatal infections by invasive fungi. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Original technique for penile girth augmentation through porcine dermal acellular grafts: results in a 69-patient series.

    Science.gov (United States)

    Alei, Giovanni; Letizia, Piero; Ricottilli, Francesco; Simone, Pierfranco; Alei, Lavinia; Massoni, Francesco; Ricci, Serafino

    2012-07-01

    Although different techniques for augmentation phalloplasty have been reported in the medical literature, this issue is still highly controversial, and none of the proposed procedures has been unanimously approved. The aim of this study is to describe an innovative surgical technique for penile girth augmentation with porcine dermal acellular grafts, through a small transverse incision at the penile base, along the penopubic junction. Between 2000 and 2009, 104 patients were referred to our institution for penile enhancement. After a preoperative psychosexual consultation and a general medical assessment, 69 patients were deemed suitable good candidates for surgery. The average penis circumference was measured at the mid-length of the penis and was 8.1 cm (5.4-10.7 cm) and 10.8 cm (6.5-15.8 cm) during flaccidity and erection, respectively. All patients received penile augmentation with porcine dermal acellular grafts. Results evaluation of an innovative technique for penile girth augmentation through exogenous porcine grafts and small penobubic incision. Postoperative measurements were performed at 6 and 12 months. At the 1-year follow-up, the average penis circumference was 11.3 cm (8.2-13.2 cm, 3.1 cm mean increase) during flaccidity and 13.2 cm (8.8-14.5 cm, 2.4 cm mean increase) during erection. No major complications occurred in the series. Minor complications were resolved with conservative treatment within 3 weeks. Sexual activity was resumed from 1 to 2 months after surgery. The psychosexual impact of the operation was beneficial in the majority of cases. Penile girth enlargement with acellular dermal matrix grafts has several advantages over augmentation with autogenous dermis-fat grafts: the elimination of donor site morbidity and a significantly shorter operation time. With this approach, through a short dorsal incision at the base of the penis, the scar is concealed in a crease covered by pubic hair and thus hardly visible. © 2012

  1. Development of a tissue-engineered human oral mucosa equivalent based on an acellular allogeneic dermal matrix: a preliminary report of clinical application to burn wounds.

    Science.gov (United States)

    Iida, Takuya; Takami, Yoshihiro; Yamaguchi, Ryo; Shimazaki, Shuji; Harii, Kiyonori

    2005-01-01

    Tissue-engineered skin equivalents composed of epidermal and dermal components have been widely investigated for coverage of full-thickness skin defects. We developed a tissue-engineered oral mucosa equivalent based on an acellular allogeneic dermal matrix and investigated its characteristics. We also tried and assessed its preliminary clinical application. Human oral mucosal keratinocytes were separated from a piece of oral mucosa and cultured in a chemically-defined medium. The keratinocytes were seeded on to the acellular allogeneic dermal matrix and cultured. Histologically, the mucosa equivalent had a well-stratified epithelial layer. Immunohistochemical study showed that it was similar to normal oral mucosa. We applied this equivalent in one case with an extensive burn wound. The equivalent was transplanted three weeks after the harvest of the patient's oral mucosa and about 30% of the graft finally survived. We conclude that this new oral mucosa equivalent could become a therapeutic option for the treatment of extensive burns.

  2. A New Human-Derived Acellular Dermal Matrix for Breast Reconstruction Available for the European Market: Preliminary Results.

    Science.gov (United States)

    Folli, Secondo; Curcio, Annalisa; Melandri, Davide; Bondioli, Elena; Rocco, Nicola; Catanuto, Giuseppe; Falcini, Fabio; Purpura, Valeria; Mingozzi, Matteo; Buggi, Federico; Marongiu, Francesco

    2018-04-01

    The introduction of acellular dermal matrices (ADMs) contributed to the growing diffusion of direct-to-implant breast reconstruction (DTI-BR) following mastectomy for breast cancer. According to specific legislations, European specialists could not benefit from the use of human-derived ADMs, even though most evidence in the literature are available for this kind of device, showed optimal outcomes in breast reconstruction. The Skin Bank of the Bufalini Hospital (Cesena, Italy) obtained in 2009 the approval for the production and distribution of a new human cadaver-donor-derived ADM (named with the Italian acronym, MODA, for matrice omologa dermica acellulata) from the Italian National Transplant Center and National Health Institute. We report preliminary results of MODA application in direct-to-implant breast reconstruction following nipple-areola complex (NAC)-sparing mastectomy for breast cancer treatment. We prospectively enrolled all women undergoing NAC-sparing mastectomy for breast cancer and DTI-BR in our breast surgical unit from June 2015 to January 2017. We enrolled a selected population without previous chest wall irradiation, not being heavy tobacco smokers or diabetic, with a BMI MODA in direct-to-implant breast reconstruction following NAC-sparing mastectomy for breast cancer treatment. This is particularly relevant for the European market, where no other human-derived devices are available for breast reconstruction due to regulatory restrictions. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  3. Placement of a Non–Cross-Linked Porcine-Derived Acellular Dermal Matrix During Preperitoneal Laparoscopic Inguinal Hernia Repair

    OpenAIRE

    Alshkaki, Giath

    2013-01-01

    This retrospective chart review evaluated outcomes following laparoscopic inguinal herniorrhaphies with non–cross-linked intact porcine-derived acellular dermal matrix (PADM) by one surgeon in a community teaching facility hospital. Mesh was sutured and/or tacked in the preperitoneal space. Postoperative visits were scheduled at 2 weeks, 3 months, and 6 months, and then at 6-month intervals up to 2 years. PADM was placed in 14 male patients (mean age, 41.1 years). Seven patients had bilateral...

  4. Cost minimisation analysis of using acellular dermal matrix (Strattice™) for breast reconstruction compared with standard techniques.

    Science.gov (United States)

    Johnson, R K; Wright, C K; Gandhi, A; Charny, M C; Barr, L

    2013-03-01

    We performed a cost analysis (using UK 2011/12 NHS tariffs as a proxy for cost) comparing immediate breast reconstruction using the new one-stage technique of acellular dermal matrix (Strattice™) with implant versus the standard alternative techniques of tissue expander (TE)/implant as a two-stage procedure and latissimus dorsi (LD) flap reconstruction. Clinical report data were collected for operative time, length of stay, outpatient procedures, and number of elective and emergency admissions in our first consecutive 24 patients undergoing one-stage Strattice reconstruction. Total cost to the NHS based on tariff, assuming top-up payments to cover Strattice acquisition costs, was assessed and compared to the two historical control groups matched on key variables. Eleven patients having unilateral Strattice reconstruction were compared to 10 having TE/implant reconstruction and 10 having LD flap and implant reconstruction. Thirteen patients having bilateral Strattice reconstruction were compared to 12 having bilateral TE/implant reconstruction. Total costs were: unilateral Strattice, £3685; unilateral TE, £4985; unilateral LD and implant, £6321; bilateral TE, £5478; and bilateral Strattice, £6771. The cost analysis shows a financial advantage of using acellular dermal matrix (Strattice) in unilateral breast reconstruction versus alternative procedures. The reimbursement system in England (Payment by Results) is based on disease-related groups similar to that of many countries across Europe and tariffs are based on reported hospital costs, making this analysis of relevance in other countries. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Complications following Nipple-Sparing Mastectomy and Immediate Acellular Dermal Matrix Implant-based Breast Reconstruction—A Systematic Review and Meta-analysis

    Directory of Open Access Journals (Sweden)

    Lene Nyhøj Heidemann, MD

    2018-01-01

    Conclusion:. The use of acellular dermal matrix in nipple-sparing mastectomy and implant-based breast reconstruction can be done with acceptable complication rates in selected patients. We recommend future studies to include specific definitions when reporting complication rates. Furthermore, future studies should elaborate on demographic characteristics of the included study samples and include predictor analysis to enhance knowledge of high risk patients.

  6. Repair of Primary Cleft Palate and Oronasal Fistula With Acellular Dermal Matrix: A Systematic Review and Surgeon Survey.

    Science.gov (United States)

    Simpson, Andrew; Samargandi, Osama A; Wong, Alison; Graham, M Elise; Bezuhly, Michael

    2018-01-01

    The current review and survey aim to assess the effectiveness of acellular dermal matrix (ADM) in the repair of cleft palate and oronasal fistula and to evaluate the current trends of ADM use in palate surgery. A systematic review of English articles was conducted using MEDLINE (1960 to July 1, 2016), the Cochrane Controlled Trials Register (1960 to July 1, 2016), and EMBASE (1991 to July 1, 2016). Additional studies were identified through a review of references cited in initially identified articles. Search terms included "cleft palate," "palatal," "oronasal fistula," "acellular dermal matrix," and "Alloderm®." An online survey was disseminated to members of the American Cleft Palate-Craniofacial Association to assess current trends in ADM use in palate surgery. All studies evaluating the outcome of primary palate repair or repair of oronasal fistula with the use of aceullar dermal matrix products were included in the review. Twelve studies met inclusion criteria for review. Studies were generally of low quality, as indicated by methodological index for non-randomized studies (MINORS) scores ranging from 7 to 14. The pooled estimate for fistula formation after primary palatoplasty following ADM use was 7.1%. The pooled estimate for recurrence of fistula after attempted repair using ADM was 11%. Thirty-six cleft surgeons responded to the online survey study. Of these, 45% used ADM in primary cleft palate repair, while 67% used ADM for repair of oronasal fistulae. Use of ADM products is commonplace in palate surgery. Despite this, there is a paucity of high-quality data demonstrating benefit. Further randomized controlled trials examining ADM in palate surgery are required to help develop structured guidelines and improve care.

  7. Nerve Wrapping of the Sciatic Nerve With Acellular Dermal Matrix in Chronic Complete Proximal Hamstring Ruptures and Ischial Apophyseal Avulsion Fractures

    Science.gov (United States)

    Haus, Brian M.; Arora, Danny; Upton, Joseph; Micheli, Lyle J.

    2016-01-01

    Background: Patients with chronic injuries of the proximal hamstring can develop significant impairment because of weakness of the hamstring muscles, sciatic nerve compression from scar formation, or myositis ossificans. Purpose: To describe the surgical outcomes of patients with chronic injury of the proximal hamstrings who were treated with hamstring repair and sciatic neurolysis supplemented with nerve wrapping with acellular dermal matrix. Study Design: Retrospective case series; Level of evidence, 4. Methods: Fifteen consecutive patients with a diagnosis of chronic complete proximal hamstring rupture or chronic ischial tuberosity apophyseal avulsion fracture (mean age, 39.67 years; range, 14-69 years) were treated with proximal hamstring repair and sciatic neurolysis supplemented with nerve wrapping with acellular dermal matrix. Nine patients had preoperative sciatica, and 6 did not. Retrospective chart review recorded clinical outcomes measured by the degree of pain relief, the rate of return to activities, and associated postoperative complications. Results: All 15 patients were followed in the postoperative period for an average of 16.6 months. Postoperatively, there were 4 cases of transient sciatic nerve neurapraxia. Four patients (26%) required postoperative betamethasone sodium phosphate (Celestone Soluspan) injectable suspension USP 6 mg/mL. Among the 9 patients with preoperative sciatica, 6 (66%) had a good or excellent outcome and were able to return to their respective activities/sports; 3 (33%) had persistent chronic pain. One of these had persistent sciatic neuropathy that required 2 surgical reexplorations and scar excision after development of recurrent extraneural scar formation. Among the 6 without preoperative sciatica, 100% had a good or excellent outcomes and 83% returned to their respective activities/sports. Better outcomes were observed in younger patients, as the 3 cases of persistent chronic sciatic pain were in patients older than 45

  8. Evaluation of Sidestream Darkfield Microscopy for Real-Time Imaging Acellular Dermal Matrix Revascularization.

    Science.gov (United States)

    DeGeorge, Brent R; Olenczak, J Bryce; Cottler, Patrick S; Drake, David B; Lin, Kant Y; Morgan, Raymond F; Campbell, Christopher A

    2016-06-01

    Acellular dermal matrices (ADMs) serve as a regenerative framework for host cell integration and collagen deposition to augment the soft tissue envelope in ADM-assisted breast reconstruction-a process dependent on vascular ingrowth. To date noninvasive intra-operative imaging techniques have been inadequate to evaluate the revascularization of ADM. We investigated the safety, feasibility, and efficacy of sidestream darkfield (SDF) microscopy to assess the status of ADM microvascular architecture in 8 patients at the time of tissue expander to permanent implant exchange during 2-stage ADM-assisted breast reconstruction. The SDF microscopy is a handheld device, which can be used intraoperatively for the real-time assessment of ADM blood flow, vessel density, vessel size, and branching pattern. The SDF microscopy was used to assess the microvascular architecture in the center and border zone of the ADM and to compare the native, non-ADM-associated capsule in each patient as a within-subject control. No incidences of periprosthetic infection, explantation, or adverse events were reported after SDF image acquisition. Native capsules demonstrate a complex, layered architecture with an average vessel area density of 14.9 mm/mm and total vessel length density of 12.3 mm/mm. In contrast to native periprosthetic capsules, ADM-associated capsules are not uniformly vascularized structures and demonstrate 2 zones of microvascular architecture. The ADM and native capsule border zone demonstrates palisading peripheral vascular arcades with continuous antegrade flow. The central zone of the ADM demonstrates punctate perforating vascular plexi with intermittent, sluggish flow, and intervening 2- to 3-cm watershed zones. Sidestream darkfield microscopy allows for real-time intraoperative assessment of ADM revascularization and serves as a potential methodology to compare revascularization parameters among commercially available ADMs. Thr SDF microscopy demonstrates that the

  9. Surgical Outcomes of Deep Superior Sulcus Augmentation Using Acellular Human Dermal Matrix in Anophthalmic or Phthisis Socket.

    Science.gov (United States)

    Cho, Won-Kyung; Jung, Su-Kyung; Paik, Ji-Sun; Yang, Suk-Woo

    2016-07-01

    Patients with anophthalmic or phthisis socket suffer from cosmetic problems. To resolve those problems, the authors present the surgical outcomes of deep superior sulcus (DSS) augmentation using acellular dermal matrix in patients with anophthalmic or phthisis socket. The authors retrospectively reviewed anophthalmic or phthisis patients who underwent surgery for DSS augmentation using acellular dermal matrix. To evaluate surgical outcomes, the authors focused on 3 aspects: the possibility of wearing contact prosthesis, the degree of correction of the DSS, and any surgical complications. The degree of correction of DSS was classified as excellent: restoration of superior sulcus enough to remove sunken sulcus shadow; fair: gain of correction effect but sunken shadow remained; or fail: no effect of correction at all. Ten eyes of 10 patients were included. There was a mean 21.3 ± 37.1-month period from evisceration or enucleation to the operation for DSS augmentation. All patients could wear contact prosthesis after the operation (100%). The degree of correction was excellent in 8 patients (80%) and fair in 2. Three of 10 (30%) showed complications: eyelid entropion, upper eyelid multiple creases, and spontaneous wound dehiscence followed by inflammation after stitch removal. Uneven skin surface and paresthesia in the forehead area of the affected eye may be observed after surgery. The overall surgical outcomes were favorable, showing an excellent degree of correction of DSS and low surgical complication rates. This procedure is effective for patients who have DSS in the absence or atrophy of the eyeball.

  10. Radiologic-Pathologic Correlation: Acellular Dermal Matrix (Alloderm®) Used in Breast Reconstructive Surgery.

    Science.gov (United States)

    Lee, Christine U; Bobr, Aleh; Torres-Mora, Jorge

    2017-01-01

    Acellular dermal matrix (ADM) such as Alloderm ® is sometimes used in tissue reconstruction in primary and reconstructive breast surgeries. As ADM is incorporated into the native tissues, the evolving imaging findings that would correlate with varying degrees of host migration and neoangiogenesis into the matrix can be challenging to recognize. In the setting of a palpable or clinical area of concern after breast reconstructive surgery following breast cancer, confident diagnosis of a mass representing ADM rather than recurring or developing disease can be challenging. Such diagnostic imaging uncertainties generally result in short-term imaging and clinical follow-up, but occasionally, biopsy is performed for histopathological confirmation of benignity. A case of biopsy-proven Alloderm ® is described. To the best of our knowledge, this is the first radiologic-pathologic correlation of ADM in the literature.

  11. Acellular matrix of bovine pericardium bound with L-arginine

    International Nuclear Information System (INIS)

    Kim, Hyo Joo; Bae, Jin Woo; Kim, Chun Ho; Lee, Jin Woo; Shin, Jung Woog; Park, Ki Dong

    2007-01-01

    Surface immobilization of bioactive molecules onto natural tissues has been interestingly studied for the development of new functional matrices for the replacement of lost or malfunctioning tissues. In this study, an acellular matrix of bovine pericardium (ABP) was chemically modified by the direct coupling of L-arginine after glutaraldehyde (GA) cross-linking. The effects of L-arginine coupling on durability and calcification were investigated and the biocompatibility was evaluated in vitro and in vivo. A four-step detergent and enzymatic extraction process has been utilized to remove cellular components from fresh bovine pericardium (BP). Microscopic observation confirmed that nearly all cellular constituents are removed. Thermal and mechanical properties showed that the durability of L-arginine-treated matrices increased as compared with control ABP and GA-treated ABP. Resistance to collagenase digestion revealed that modified matrices have greater resistance to enzyme digestion than control ABP and GA-treated ABP. The in vivo calcification study demonstrated much less calcium deposition on L-arginine-treated ABP than GA-treated one. In vitro cell viability results showed that ABP modified with L-arginine leads to a significant increase in attachment of human dermal fibroblasts. The obtained results attest to the usefulness of L-arginine-treated ABP matrices for cardiovascular bioprostheses

  12. Acellular matrix of bovine pericardium bound with L-arginine

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo Joo [Department of Molecular Science and Technology, Ajou University, Suwon 443-749 (Korea, Republic of); Bae, Jin Woo [Department of Molecular Science and Technology, Ajou University, Suwon 443-749 (Korea, Republic of); Kim, Chun Ho [Laboratory of Tissue Engineering, Korea Cancer Center Hospital, Seoul 139-240 (Korea, Republic of); Lee, Jin Woo [Department of Orthopaedic Surgery, College of Medicine, Yonsei University, Seoul 120-749 (Korea, Republic of); Shin, Jung Woog [Department of Biomedical Engineering, Inje University, Gimhae 621-749 (Korea, Republic of); Park, Ki Dong [Department of Molecular Science and Technology, Ajou University, Suwon 443-749 (Korea, Republic of)

    2007-09-15

    Surface immobilization of bioactive molecules onto natural tissues has been interestingly studied for the development of new functional matrices for the replacement of lost or malfunctioning tissues. In this study, an acellular matrix of bovine pericardium (ABP) was chemically modified by the direct coupling of L-arginine after glutaraldehyde (GA) cross-linking. The effects of L-arginine coupling on durability and calcification were investigated and the biocompatibility was evaluated in vitro and in vivo. A four-step detergent and enzymatic extraction process has been utilized to remove cellular components from fresh bovine pericardium (BP). Microscopic observation confirmed that nearly all cellular constituents are removed. Thermal and mechanical properties showed that the durability of L-arginine-treated matrices increased as compared with control ABP and GA-treated ABP. Resistance to collagenase digestion revealed that modified matrices have greater resistance to enzyme digestion than control ABP and GA-treated ABP. The in vivo calcification study demonstrated much less calcium deposition on L-arginine-treated ABP than GA-treated one. In vitro cell viability results showed that ABP modified with L-arginine leads to a significant increase in attachment of human dermal fibroblasts. The obtained results attest to the usefulness of L-arginine-treated ABP matrices for cardiovascular bioprostheses.

  13. Prospective randomized comparison of scar appearances between cograft of acellular dermal matrix with autologous split-thickness skin and autologous split-thickness skin graft alone for full-thickness skin defects of the extremities.

    Science.gov (United States)

    Yi, Ju Won; Kim, Jae Kwang

    2015-03-01

    The purpose of this study was to evaluate the clinical outcomes of cografting of acellular dermal matrix with autologous split-thickness skin and autologous split-thickness skin graft alone for full-thickness skin defects on the extremities. In this prospective randomized study, 19 consecutive patients with full-thickness skin defects on the extremities following trauma underwent grafting using either cograft of acellular dermal matrix with autologous split-thickness skin graft (nine patients, group A) or autologous split-thickness skin graft alone (10 patients, group B) from June of 2011 to December of 2012. The postoperative evaluations included observation of complications (including graft necrosis, graft detachment, or seroma formation) and Vancouver Scar Scale score. No statistically significant difference was found regarding complications, including graft necrosis, graft detachment, or seroma formation. At week 8, significantly lower Vancouver Scar Scale scores for vascularity, pliability, height, and total score were found in group A compared with group B. At week 12, lower scores for pliability and height and total scores were identified in group A compared with group B. For cases with traumatic full-thickness skin defects on the extremities, a statistically significant better result was achieved with cograft of acellular dermal matrix with autologous split-thickness skin graft than with autologous split-thickness skin graft alone in terms of Vancouver Scar Scale score. Therapeutic, II.

  14. Biological function evaluation and effects of laser micro-pore burn-denatured acellular dermal matrix.

    Science.gov (United States)

    Zhang, Youlai; Zeng, Yuanlin; Xin, Guohua; Zou, Lijin; Ding, Yuewei; Duyin, Jiang

    2018-03-01

    In the field of burns repairs, many problems exist in the shortage of donor skin, the expense of allograft or xenograft skin, temporary substitution and unsatisfactory extremity function after wound healing. Previous studies showed that burn-denatured skin could return to normal dermis formation and function. This study investigates the application of laser micro-pore burn-denatured acellular dermis matrix (DADM) from an escharotomy in the repair of burn wounds and evaluates the biological properties and wound repair effects of DADM in implantation experiments in Kunming mice. Specific-pathogen-free (SPF) Kunming mice were used in this study. A deep II° burn wound was created on the dorsum of the mice by an electric heated water bath. The full-thickness wound tissue was harvested. The necrotic tissue and subcutaneous tissue were removed. The denatured dermis was preserved and treated with 0.25% trypsin, 0.5% Triton X-100. The DADM was drilled by laser micro-pore. The biological properties and grafting effects of laser micro-pore burn-DADM were evaluated by morphology, cytokine expression levels and subcutaneous implantation experiments in Kunming mice. We found statistical significance (Ppore burn-DADM (experimental group) compared to the control group (no laser micro-pore burn-DADM). Cytokine expression level was different in the dermal matrixes harvested at various time points after burn (24h, 48h, 72h and infected wound group). Comparing the dermal matrix from 24h burn tissue to infected wound tissue, the expression level of IL-6, MMP-24, VE-cadherin and VEGF were decreased. We found no inflammatory cells infiltration in the dermal matrix were observed in both experimental and control groups (24h burn group), while the obviously vascular infiltration and fiber fusion were observed in the experimental group after subcutaneous implantation experiments. There was better bio-performance, low immunogenicity and better dermal incorporation after treated by laser

  15. Healing rates for challenging rotator cuff tears utilizing an acellular human dermal reinforcement graft

    Science.gov (United States)

    Agrawal, Vivek

    2012-01-01

    Purpose: This study presents a retrospective case series of the clinical and structural outcomes (1.5 T MRI) of arthroscopic rotator cuff repair with acellular human dermal graft reinforcement performed by a single surgeon in patients with large, massive, and previously repaired rotator cuff tears. Materials and Methods: Fourteen patients with mean anterior to posterior tear size 3.87 ± 0.99 cm (median 4 cm, range 2.5–6 cm) were enrolled in the study and were evaluated for structural integrity using a high-field (1.5 T) MRI at an average of 16.8 months after surgery. The Constant-Murley scores, the Flexilevel Scale of Shoulder Function (Flex SF), scapular plane abduction, and strength were analyzed. Results: MRI results showed that the rotator cuff repair was intact in 85.7% (12/14) of the patients studied. Two patients had a Sugaya Type IV recurrent tear (2 of 14; 14.3%), which were both less than 1 cm. The Constant score increased from a preoperative mean of 49.72 (range 13–74) to a postoperative mean of 81.07 (range 45–92) (P value = 0.009). Flexilevel Scale of Shoulder Function (Flex SF) Score normalized to a 100-point scale improved from a preoperative mean of 53.69 to a postoperative mean of 79.71 (P value = 0.003). The Pain Score improved from a preoperative mean of 7.73 to a postoperative mean of 13.57 (P value = 0.008). Scapular plane abduction improved from a preoperative mean of 113.64° to a postoperative mean of 166.43° (P value = 0.010). The strength subset score improved from a preoperative mean of 1.73 kg to a postoperative mean of 7.52 kg (P value = 0.006). Conclusions: This study presents a safe and effective technique that may help improve the healing rates of large, massive, and revision rotator cuff tears with the use of an acellular human dermal allograft. This technique demonstrated favorable structural healing rates and statistically improved functional outcomes in the near term. Level of Evidence: 4. Retrospective case series. PMID

  16. Biologic meshes and synthetic meshes in cancer patients: a double-edged sword: differences in production of IL-6 and IL-12 caused by acellular dermal matrices in human immune cells.

    Science.gov (United States)

    Karsten, Maria Margarete; Enders, Sabine; Knabl, Julia; Kirn, Verena; Düwell, Peter; Rack, Brigitte; Blohmer, Jens-Uwe; Mayr, Doris; Dian, Darius

    2018-05-01

    In 2005, Breuing et al. first described the use of acellular dermal matrices (ADMs) in breast cancer patients. ADMs are assumed to be safe to use in an oncologic setting, but data from controlled studies are still needed. Here, we investigate the effects of ADMs on the production of interleukin (IL)-6 and IL-12, key regulators of immune suppression and activation. Strattice (ST), CollaMend (CM), and Biodesign (BD) biologic meshes and TiLoop, a synthetic mesh (TL), were used in this study. We isolated myeloid dendritic cells (MDCs), untouched plasmacytoid dendritic cells (pDCs), naïve B cells, and CD8+ T cells and co-cultured these cells with either the biologic meshes or TL. As positive controls, we used CpG ODN 2216 or lipopolysaccharide (LPS). The cytokine concentrations of IL-12p70 and IL-6 were determined after 7 days using sandwich ELISA sets. There were highly significant differences between the ADMs and TL in terms of their ability to stimulate immunologic responses. IL-6 expression was significantly increased in B cells (p = 0.0006131) and T cells (p = 0.00418) when comparing TL and ADMs. We also identified significant differences in IL-12 production by B cells (p = 0.0166) and T cells (p = 0.003636) when comparing TL and ADMs. Despite the assumed lack of an immunological response to ADMs, in our experimental study, human immune cells reacted with significantly different cytokine profiles. These findings may have implications for the potential activation or suppression of effector cells in cancer patients and could explain some of the post clinical post surgical signs of ADMS like skin rush and seroma.

  17. Acellular dermal matrix slings in tissue expander breast reconstruction: are there substantial benefits?

    Science.gov (United States)

    Collis, George N; TerKonda, Sarvam P; Waldorf, James C; Perdikis, Galen

    2012-05-01

    Acellular dermal matrix (ADM) slings in breast reconstruction are increasingly used but are not yet validated. This study compares immediate, expander-based breast reconstruction with and without the use of inferolateral ADM slings. There were 63 patients (106 breasts) in the ADM group and 42 patients (68 breasts) in the control group. Initial intraoperative fill volumes were significantly greater in the ADM group, median 69% full (250 mL) versus 50% full (180 mL; P < 0.001). However, the number of days to complete expansion between the 2 groups was similar. One less office visit was required to complete the fills in the ADM group (P < 0.01). Drains were removed 3 days later in the ADM group (P < 0.01). Overall complication rate was greater in the ADM group (18.9% vs. 7.4%, P < 0.05), with a slightly higher percentage of expanders requiring removal due to infection in the ADM group (5.7% vs. 4.4%, P = NS). This study suggests inferolateral ADM slings in expander-based breast reconstruction allow for significantly increased initial fill volumes and may offer an aesthetic advantage; however, its use is costly and increases complications.

  18. Daily Serum Collection after Acellular Dermal Matrix-Assisted Breast Reconstruction

    Directory of Open Access Journals (Sweden)

    Glenda Giorgia Caputo

    2015-05-01

    Full Text Available BackgroundThe acellular dermal matrix (ADM-assisted breast reconstruction technique is widely known, but discouraging results due to early postoperative complications have been reported. As the literature identifies seroma as the most common issue after breast surgery without identifying its pathogenesis, we aimed to report the trend of postoperative daily serum collection after ADM-assisted breast reconstruction and compare it with data in the literature in order to discover more about this little-known topic.MethodsA retrospective study on 28 consecutive patients who received ADM-assisted breast reconstruction between February 2013 and February 2014 was performed. In order to reduce the number of variables that could affect serum production, only one brand of ADM was used and all tissues were handled gently and precisely. The daily drainage volume was recorded per patient during the first four days of hospitalization. Likewise, postoperative complications were noted during routine follow-up.ResultsIn total, five (17.9% bilateral and 23 (82.1% unilateral ADM-assisted breast reconstructions (33 implants were performed. The mean age, body mass index, and length of hospital stay were 53.6 years, 21.3 kg/m2, and 4.5 days, respectively. One major complication led to implant loss (3.0%, and nine minor complications were successfully treated with ambulatory surgery (27.3%. Serum collection linearly decreased after 24 hours postoperatively.ConclusionsDaily drainage decreased following the theoretical decline of acute inflammation. In concordance with the literature, daily serum production may not be related to the use of ADM.

  19. [Study on preparation of laser micropore porcine acellular dermal matrix combined with split-thickness autograft and its application in wound transplantation].

    Science.gov (United States)

    Liang, Li-Ming; Chai, Ji-Ke; Yang, Hong-Ming; Feng, Rui; Yin, Hui-Nan; Li, Feng-Yu; Sun, Qiang

    2007-04-01

    To prepare a porcine acellular dermal matrix (PADM), and to optimize the interpore distance between PADM and co-grafted split-thickness autologous skin. Porcine skin was treated with trypsin/Triton X-100 to prepare an acellular dermal matrix. Micropores were produced on the PADM with a laser punch. The distance between micropores varied as 0.8 mm, 1.0 mm, 1.2 mm and 1.5 mm. Full-thickness defect wounds were created on the back of 144 SD rats. The rats were randomly divided into 6 groups as follows, with 24 rats in each group. Micropore groups I -IV: the wounds were grafted with PADM with micropores in four different intervals respectively, and covered with split-thickness autologous skin graft. Mesh group: the wounds were grafted with meshed PADM and split-thickness autograft. with simple split-thickness autografting. The gross observation of wound healing and histological observation were performed at 2, 4, 6 weeks after surgery. The wound healing rate and contraction rate were calculated. Two and four weeks after surgery, the wound healing rate in micropore groups I and II was lower than that in control group (P micropore groups I , II and mesh group (P > 0.05) until 6 weeks after grafting( P micropore groups I and II ([(16.0 +/- 2.6)%, (15.1 +/- 2.4)%] was remarkably lower than that in control group 4 and 6 weeks after grafting (P micropore PADM (0.8 mm or 1.0 mm in distance) grafting in combination with split-thickness autografting can improve the quality of wound healing. PADM with laser micropores in 1.0 mm distance is the best choice among them.

  20. Evaluating the Effectiveness of Cryopreserved Acellular Dermal Matrix in Immediate Expander-Based Breast Reconstruction: A Comparison Study

    Directory of Open Access Journals (Sweden)

    So-Young Kim

    2015-05-01

    Full Text Available BackgroundCGCryoDerm was first introduced in 2010 and offers a different matrix preservation processes for freezing without drying preparation. From a theoretical perspective, CGCryoDerm has a more preserved dermal structure and more abundant growth factors for angiogenesis and recellularization. In the current study, the authors performed a retrospective study to evaluate freezing- and freeze-drying-processed acellular dermal matrix (ADM to determine whether any differences were present in an early complication profile.MethodsPatients who underwent ADM-assisted tissue expander placement for two stage breast reconstruction between January of 2013 and March of 2014 were retrospectively reviewed and divided into two groups based on the types of ADM-assisted expander reconstruction (CGDerm vs. CGCryoDerm. Complications were divided into four main categories and recorded as follows: seroma, hematoma, infection, and mastectomy skin flap necrosis.ResultsIn a total of 82 consecutive patients, the CGCryoDerm group had lower rates of seroma when compared to the CGDerm group without statistical significance (3.0% vs. 10.2%, P=0.221, respectively. Other complications were similar in both groups. Reconstructions with CGCryoDerm were found to have a significantly longer period of drainage when compared to reconstructions with CGDerm (11.91 days vs. 10.41 days, P=0.043.ConclusionsPreliminary findings indicate no significant differences in early complications between implant/expander-based reconstructions using CGCryoderm and those using CGDerm.

  1. Augmentation of Distal Biceps Repair With an Acellular Dermal Graft Restores Native Biomechanical Properties in a Tendon-Deficient Model.

    Science.gov (United States)

    Conroy, Christine; Sethi, Paul; Macken, Craig; Wei, David; Kowalsky, Marc; Mirzayan, Raffy; Pauzenberger, Leo; Dyrna, Felix; Obopilwe, Elifho; Mazzocca, Augustus D

    2017-07-01

    -deficient, complete distal biceps rupture model, acellular dermal allograft augmentation restored the native tendon's biomechanical properties at time zero. The grafted tissue-deficient model demonstrated no significant differences in the load to failure and gap formation compared with the native tendon. As expected, dermal augmentation of attritional tendon repair increased the load to failure and stiffness as well as decreased displacement compared with the ungrafted tissue-deficient model. Tendons with their native width showed no statistical difference or negative biomechanical consequences of dermal augmentation. Dermal augmentation of the distal biceps is a biomechanically feasible option for patients with an attritionally thinned-out tendon.

  2. Chondrogenesis of human infrapatellar fat pad stem cells on acellular dermal matrix

    Directory of Open Access Journals (Sweden)

    Ken eYe

    2016-01-01

    Full Text Available Acellular dermal matrix (ADM has been in clinical use for decades in numerous surgical applications. The ability for ADM to promote cellular repopulation and revascularisation, and tissue regeneration is well documented. Adipose stem cells have the ability to differentiate into mesenchymal tissue types, including bone and cartilage. The aim of this study was to investigate the potential interaction between ADM and adipose stem cells in vitro using TGFβ3 and BMP6.Human infrapatellar fat pad derived adipose stem cells (IPFP-ASC were cultured with ADM derived from rat dermis under chondrogenic (TGFβ3 and BMP6 in vitro for 2 and 4 weeks. Histology, qPCR and immunohistochemistry were performed to assess for markers of chondrogenesis (collagen Type II, SOX9 and proteoglycans. At 4 weeks, cell-scaffold constructs displayed cellular changes consistent with chondrogenesis, with evidence of stratification of cell layers and development of a hyaline-like cartilage layer superficially which stained positively for collagen Type II and proteoglycans. Significant cell-matrix interaction was seen between the cartilage layer and the ADM itself with seamless integration between each layer. Real time qPCR showed significantly increases of COL2A1, SOX9, and ACAN gene expression over 4 weeks when compared to control. COL1A2 gene expression remained unchanged over 4 weeks.We believe the principles which make ADM versatile and successful for tissue regeneration are application to cartilage regeneration. This study demonstrates in vitro the ability for IPFP-ASCs to undergo chondrogenesis, infiltrate and interact with ADM. These outcomes serve as a platform for in vivo modelling of ADM for cartilage repair.

  3. Preparation of laser micropore porcine acellular dermal matrix for skin graft: an experimental study.

    Science.gov (United States)

    Chai, Jia-Ke; Liang, Li-Ming; Yang, Hong-Ming; Feng, Rui; Yin, Hui-Nan; Li, Feng-Yu; Sheng, Zhi-Yong

    2007-09-01

    In our previous study, we used composite grafts consisting of meshed porcine acellular dermal matrix (PADM) and thin split-thickness autologous epidermis to cover full thickness burn wounds in clinical practice. However, a certain degree of contraction might occur because the distribution of dermal matrix was not uniform in burn wound. In this study, we prepare a composite skin graft consisting of PADM with the aid of laser to improve the quality of healing of burn wound. PADM was prepared by the trypsin/Triton X-100 method. Micropores were produced on the PADM with a laser punch. The distance between micropores varied from 0.8, 1.0, 1.2 to 1.5mm. Full thickness defect wounds were created on the back of 144 SD rats. The rats were randomly divided into six groups: micropore groups I-IV in which the wound were grafted with PADM with micropores, in four different distances, respectively and split-thickness autograft; mesh group rats received meshed PADM graft and split-thickness autograft; control group received simple split-thickness autografting. The status of wound healing was histologically observed at regular time points after surgery. The wound healing rate and contraction rate were calculated. The wound healing rate in micropore groups I and II was not statistically different from that in control group, but was significantly higher than that in mesh group 6 weeks after grafting. The wound healing rate in micropore groups III and IV was lower than that in mesh and control groups 4 and 6 weeks after grafting. The wound contraction rate in micropore groups I and II was remarkably lower than that in control group 4 and 6 weeks after surgery and it was significantly much lower than that in mesh group 6 weeks after surgery. Histological examination revealed good epithelization, regularly arranged collagenous fibers and integral structure of basement membrane. Laser micropore PADM (0.8 or 1.0mm in distance) grafting in combination with split-thickness autografting can

  4. [EFFECTIVENESS OF VAGINOPLASTY WITH ACELLULAR DERMAL MATRIX AND MIXED PARTICLES GRAFT].

    Science.gov (United States)

    Zhou, Yu; Li, Qiang; Ll, Senkai; Zhou, Chuande; Li, Fengyong; Cao, Yujiao; Zhang, Siya; Wei, Shuyi; Zhao, Yang

    2015-06-01

    To evaluate the effectiveness or acellular dermal matrix (ADM) with autologous buccal micro mucosa and micro skin graft in vaginoplasty. A retrospective analysis was made on the clinical data of 67 patients with vaginal agenesis treated between July 2006 and June 2013. ADM and mixed particles were used in 20 cases (ADM group) and mixed particles graft in 47 cases (control group) in vaginoplasty. There was no significant difference in age between 2 groups (t=0.233, P=0.816). The depth, diameter, and volume of neovagina, epithelization time, stent needing time, and female sexual function index (FSFI) score were compared between 2 groups. There was no significant difference in operation time and amount of bleeding between 2 groups (t = -1.922, P = 0.059; t = 0.398, P = 0.692). The patients were followed up 11-38 months (mean, 16.08 months). Fifteen cases in ADM group and 29 cases in control group had sexual life after operation. Bleeding after operation occurred in 6 cases (2 in ADM group and 4 in control group). No stenosis was observed. Difference in epithelization time was not statistically significant (t = -1.938, P = 0.057). However, the stent needing time of ADM group was significantly shorter than that of control group (t = 7.020, P = 0.000). The neovagina was ideal in wetness degree, smoothness, flexibility, and hairlessness during follow-up. The depth, diameter, and volume of vagina had no significant difference between 2 groups (P > 0.05) at last follow-up, which were close to normal vagina. The other patients had normal sexual function except 1 patient whose FSFI score was less than 23; no statistically significant difference was found in FSFI score between 2 groups (P > 0.05). On the basis of mixed particles grafting, the ADM could improve trestle structure for resisting contracture. The effectiveness is better than merely mixed particles graft. The procedure has satisfactory anatomical and functional results.

  5. Repair of Postoperative Abdominal Hernia in a Child with Congenital Omphalocele Using Porcine Dermal Matrix

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    V. Lambropoulos

    2016-01-01

    Full Text Available Introduction. Incisional hernias are a common complication appearing after abdominal wall defects reconstruction, with omphalocele and gastroschisis being the most common etiologies in children. Abdominal closure of these defects represents a real challenge for pediatric surgeons with many surgical techniques and various prosthetic materials being used for this purpose. Case Report. We present a case of repair of a postoperative ventral hernia occurring after congenital omphalocele reconstruction in a three-and-a-half-year-old child using an acellular, sterile, porcine dermal mesh. Conclusion. Non-cross-linked acellular porcine dermal matrix is an appropriate mesh used for the reconstruction of abdominal wall defects and their postoperative complications like large ventral hernias with success and preventing their recurrence.

  6. Healing rate and autoimmune safety of full-thickness wounds treated with fish skin acellular dermal matrix versus porcine small-intestine submucosa: a noninferiority study.

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    Baldursson, Baldur Tumi; Kjartansson, Hilmar; Konrádsdóttir, Fífa; Gudnason, Palmar; Sigurjonsson, Gudmundur F; Lund, Sigrún Helga

    2015-03-01

    A novel product, the fish skin acellular dermal matrix (ADM) has recently been introduced into the family of biological materials for the treatment of wounds. Hitherto, these products have been produced from the organs of livestock. A noninferiority test was used to compare the effect of fish skin ADM against porcine small-intestine submucosa extracellular matrix in the healing of 162 full-thickness 4-mm wounds on the forearm of 81 volunteers. The fish skin product was noninferior at the primary end point, healing at 28 days. Furthermore, the wounds treated with fish skin acellular matrix healed significantly faster. These results might give the fish skin ADM an advantage because of its environmental neutrality when compared with livestock-derived products. The study results on these acute full-thickness wounds might apply for diabetic foot ulcers and other chronic full-thickness wounds, and the shorter healing time for the fish skin-treated group could influence treatment decisions. To test the autoimmune reactivity of the fish skin, the participants were tested with the following ELISA (enzyme-linked immunosorbent assay) tests: RF, ANA, ENA, anti ds-DNA, ANCA, anti-CCP, and anticollagen I and II. These showed no reactivity. The results demonstrate the claims of safety and efficacy of fish skin ADM for wound care. © The Author(s) 2015.

  7. Histology of the heterostracan dermal skeleton: Insight into the origin of the vertebrate mineralised skeleton.

    Science.gov (United States)

    Keating, Joseph N; Marquart, Chloe L; Donoghue, Philip C J

    2015-06-01

    Living vertebrates are divided into those that possess a fully formed and fully mineralised skeleton (gnathostomes) versus those that possess only unmineralised cartilaginous rudiments (cyclostomes). As such, extinct phylogenetic intermediates of these living lineages afford unique insights into the evolutionary assembly of the vertebrate mineralised skeleton and its canonical tissue types. Extinct jawless and jawed fishes assigned to the gnathostome stem evidence the piecemeal assembly of skeletal systems, revealing that the dermal skeleton is the earliest manifestation of a homologous mineralised skeleton. Yet the nature of the primitive dermal skeleton, itself, is poorly understood. This is principally because previous histological studies of early vertebrates lacked a phylogenetic framework required to derive evolutionary hypotheses. Nowhere is this more apparent than within Heterostraci, a diverse clade of primitive jawless vertebrates. To this end, we surveyed the dermal skeletal histology of heterostracans, inferred the plesiomorphic heterostracan skeleton and, through histological comparison to other skeletonising vertebrate clades, deduced the ancestral nature of the vertebrate dermal skeleton. Heterostracans primitively possess a four-layered skeleton, comprising a superficial layer of odontodes composed of dentine and enameloid; a compact layer of acellular parallel-fibred bone containing a network of vascular canals that supply the pulp canals (L1); a trabecular layer consisting of intersecting radial walls composed of acellular parallel-fibred bone, showing osteon-like development (L2); and a basal layer of isopedin (L3). A three layered skeleton, equivalent to the superficial layer L2 and L3 and composed of enameloid, dentine and acellular bone, is possessed by the ancestor of heterostracans + jawed vertebrates. We conclude that an osteogenic component is plesiomorphic with respect to the vertebrate dermal skeleton. Consequently, we interpret the

  8. The Effect of Sterile Acellular Dermal Matrix Use on Complication Rates in Implant-Based Immediate Breast Reconstructions

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    Jun Ho Lee

    2016-11-01

    Full Text Available BackgroundThe use of acellular dermal matrix (ADM in implant-based immediate breast reconstruction has been increasing. The current ADMs available for breast reconstruction are offered as aseptic or sterile. No published studies have compared aseptic and sterile ADM in implant-based immediate breast reconstruction. The authors performed a retrospective study to evaluate the outcomes of aseptic versus sterile ADM in implant-based immediate breast reconstruction.MethodsImplant-based immediate breast reconstructions with ADM conducted between April 2013 and January 2016 were included. The patients were divided into 2 groups: the aseptic ADM (AlloDerm group and the sterile ADM (MegaDerm group. Archived records were reviewed for demographic data and postoperative complication types and frequencies. The complications included were infection, flap necrosis, capsular contracture, seroma, hematoma, and explantation for any cause.ResultsTwenty patients were reconstructed with aseptic ADM, and 68 patients with sterile ADM. Rates of infection (15.0% vs. 10.3%, flap necrosis (5.0% vs. 7.4%, capsular contracture (20.0% vs. 14.7%, seroma (10.0% vs. 14.7%, hematoma (0% vs. 1.5%, and explantation (10.0% vs. 8.8% were not significantly different in the 2 groups.ConclusionsSterile ADM did not provide better results regarding infectious complications than aseptic ADM in implant-based immediate breast reconstruction.

  9. Xenogenic (porcine) acellular dermal matrix promotes growth of granulation tissues in the wound healing of Fournier gangrene.

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    Zhang, Zhaoxin; Lv, Lei; Mamat, Masut; Chen, Zhao; Zhou, Zhitao; Liu, Lihua; Wang, Zhizhong

    2015-01-01

    This article investigates the application values of Xenogenic (porcine) acellular dermal matrix (XADM) in preparation of a Fournier gangrene wound bed. Thirty-six consecutive cases of patients with Fournier gangrene between 2002 and 2012 were enrolled in our department of our hospital. The patients were divided into two groups according to different methods of wound bed preparation after surgical débridement, including the experimental group (17 cases) and the control group (19 cases). The wounds in the experimental group were covered with XADM after surgical wound débridement, whereas the wounds were cleaned with hydrogen peroxide and sodium hypochlorite solution (one time/day) in the control group. The wound bed preparation time and hospital stay were then compared in the two groups. The wound preparation time was 13.64 ± 1.46 days and hospitalization period was 26.06 ± 0.83 days in the experimental XADM group. In the control group, the wound bed preparation time and hospitalization period were 22.37 ± 1.38 and 38.11 ± 5.60 days, respectively. The results showed statistical differences between these two groups. When used in wound débridement after Fournier gangrene, XADM protects interecological organizations, promotes the growth of granulation tissues, and maximally retains function and morphology of the perineum and penis.

  10. Outcomes of Acellular Dermal Matrix for Immediate Tissue Expander Reconstruction with Radiotherapy: A Retrospective Cohort Study.

    Science.gov (United States)

    Craig, Elizabeth S; Clemens, Mark W; Koshy, John C; Wren, James; Hong, Zhang; Butler, Charles; Garvey, Patrick; Selber, Jesse; Kronowitz, Steven

    2018-05-24

    Despite increasing literature support for the use of acellular dermal matrix (ADM) in expander-based breast reconstruction, the effect of ADM on clinical outcomes in the presence of post-mastectomy radiation therapy (PMRT) has not been well described. To analyze the impact ADM plays on clinical outcomes on immediate tissue expander (ITE) reconstruction undergoing PMRT. We retrospectively reviewed patients who underwent ITE breast reconstruction from 2004 to 2014 at MD Anderson Cancer Center. Patients were categorized into four cohorts: ADM, ADM with PMRT, non-ADM, and non-ADM with PMRT. Outcomes and complications were compared between cohorts. Over ten years, 957 patients underwent ITE reconstruction (683 non-ADM, 113 non-ADM with PMRT, 486 ADM, and 88 ADM with PMRT) with 1,370 reconstructions. Overall complication rates for the ADM and non-ADM cohorts were 39.0 and 16.7%, respectively (p <0.001). Within both cohorts, mastectomy skin flap necrosis (MSFN) was the most common complication, followed by infection. ADM use was associated with a significantly higher rate of infections and seromas in both radiated and non-radiated groups; however, when comparing radiated cohorts, the incidence of explantation was significantly lower with the use of ADM. The decision to use ADM for expander-based breast reconstruction should be performed with caution, given higher overall rates of complications, including infections and seromas. There may, however, be a role for ADM in cases requiring PMRT, as the overall incidence of implant failure is lower than non-ADM cases.

  11. Outcomes of arthroscopic revision rotator cuff repair with acellular human dermal matrix allograft augmentation.

    Science.gov (United States)

    Hohn, Eric A; Gillette, Blake P; Burns, Joseph P

    2018-05-01

    The purpose was to assess the minimum 2-year patient-reported outcomes and failure rate of patients who underwent revision arthroscopic rotator cuff repair augmented with acellular human dermal matrix (AHDM) allograft for repairable retears. From 2008-2014, patients who underwent revision rotator cuff repair augmented with AHDM with greater than 2 years' follow-up by a single surgeon were retrospectively reviewed. Data regarding surgical history, demographic characteristics, and medical comorbidities were collected. Outcome data included American Shoulder and Elbow Surgeons (ASES) and Single Assessment Numeric Evaluation (SANE) scores, as well as rotator cuff healing on magnetic resonance imaging or ultrasound. Retears and subsequent surgical procedures were characterized. A total of 28 patients met our inclusion criteria, and 23 (82%) were available for follow-up at 2 years. The mean age was 60.1 ± 9.3 years (range, 43-79 years), with a mean follow-up period of 48 ± 23 months. All patients had at least 1 prior rotator cuff repair. Of the 23 patients, 13 (56%) underwent postoperative imaging, and 4 of these 13 (31%) had a retear. A reoperation was performed in 3 of 23 patients (13%). Among the 6 patients with both preoperative and postoperative outcome scores, we saw improvement in the ASES score from 56 to 85 (P = .03) and in the SANE score from 42 to 76 (P = .03). The full cohort's mean postoperative ASES and SANE scores were 77 and 69, respectively. AHDM allograft augmentation is a safe and effective treatment method for patients with full-thickness rotator cuff retears. Further research is needed with larger studies to confirm these findings from our small cohort of patients. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  12. Dynamic multiphoton imaging of acellular dermal matrix scaffolds seeded with mesenchymal stem cells in diabetic wound healing.

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    Chu, Jing; Shi, Panpan; Deng, Xiaoyuan; Jin, Ying; Liu, Hao; Chen, Maosheng; Han, Xue; Liu, Hanping

    2018-03-25

    Significantly effective therapies need to be developed for chronic nonhealing diabetic wounds. In this work, the topical transplantation of mesenchymal stem cell (MSC) seeded on an acellular dermal matrix (ADM) scaffold is proposed as a novel therapeutic strategy for diabetic cutaneous wound healing. GFP-labeled MSCs were cocultured with an ADM scaffold that was decellularized from normal mouse skin. These cultures were subsequently transplanted as a whole into the full-thickness cutaneous wound site in streptozotocin-induced diabetic mice. Wounds treated with MSC-ADM demonstrated an increased percentage of wound closure. The treatment of MSC-ADM also greatly increased angiogenesis and rapidly completed the reepithelialization of newly formed skin on diabetic mice. More importantly, multiphoton microscopy was used for the intravital and dynamic monitoring of collagen type I (Col-I) fibers synthesis via second harmonic generation imaging. The synthesis of Col-I fibers during diabetic wound healing is of great significance for revealing wound repair mechanisms. In addition, the activity of GFP-labeled MSCs during wound healing was simultaneously traced via two-photon excitation fluorescence imaging. Our research offers a novel advanced nonlinear optical imaging method for monitoring the diabetic wound healing process while the ADM and MSCs interact in situ. Schematic of dynamic imaging of ADM scaffolds seeded with mesenchymal stem cells in diabetic wound healing using multiphoton microscopy. PMT, photo-multiplier tube. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Acellular dermal matrix loading with bFGF achieves similar acceleration of bone regeneration to BMP-2 via differential effects on recruitment, proliferation and sustained osteodifferentiation of mesenchymal stem cells

    International Nuclear Information System (INIS)

    Du, Mi; Zhu, Ting; Duan, Xiaoqi; Ge, Shaohua; Li, Ning; Sun, Qinfeng; Yang, Pishan

    2017-01-01

    New generation of barrier membranes has been developed, which not only act as barriers but also as delivery devices to release specific growth factors. This study observed biological behaviors of bone morrow mesenchymal stem cells (BMMSCs) pretreated by bFGF or BMP-2 in vitro and evaluated differential bone regeneration process induced by bFGF and BMP-2 loaded acellular dermal matrix (ADM) membrane using critical-size rat calvarial defect model in vivo. The results showed that the proliferation capability of BMMSCs pretreated by bFGF was stronger than that by BMP-2, while there was temporally differential effect of bFGF and BMP-2 pretreatment on MSC osteogenic differentiation potentials. During healing process of rat calvarial defects, 2-fold more CD34 −/CD90 + MSCs in group of bFGF-ADM was observed than in any other treatment group at 2 weeks. However, there were similar amount of new bone formation and expression of osteopotin in newly-formed bone tissue in groups of bFGF- and BMP-2-ADM at 8 weeks, which were more than those in ADM alone and blank control. Taken together, bFGF-ADM guided similar bone regeneration to BMP-2 through more efficient recruitment of MSCs, and moreover, BMMSCs pretreated by bFGF showed stronger proliferation at 1–5 days and osteogenic differentiation potentials at 14 days compared with BMP-2 pretreatment. - Highlights: • An improved barrier membrane used in the field of bone tissue engineering was proposed, which is acellular dermal matrix (ADM) loaded with growth factors. • It is generally agreed that BMP-2 and -7 provide the greatest bone regeneration potentials, however, we found that ADM loading with bFGF could guide similar bone regeneration to BMP-2. • Compared with BMP-2, bFGF could more effectively recruit MSCs and moreover, BMMSCs pretreated by bFGF showed out stronger proliferation at 1-5 days and osteogenic differentiation potentials at 14 days.

  14. Does acellular dermal matrix really improve aesthetic outcome in tissue expander/implant-based breast reconstruction?

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    Ibrahim, Ahmed M S; Koolen, Pieter G L; Ganor, Oren; Markarian, Mark K; Tobias, Adam M; Lee, Bernard T; Lin, Samuel J; Mureau, Marc A M

    2015-06-01

    The expectation for improved results by women undergoing postmastectomy reconstruction has steadily risen. A majority of these operations are tissue expander/implant-based breast reconstructions. Acellular dermal matrix (ADM) offers numerous advantages in these procedures. Thus far, the evidence to justify improved aesthetic outcome has solely been based on surgeon opinion. The purpose of this study was to assess aesthetic outcome following ADM use in tissue expander/implant-based breast reconstruction by a panel of blinded plastic surgeons. Mean aesthetic results of patients who underwent tissue expander/implant-based breast reconstruction with (n = 18) or without ADM (n = 20) were assessed with objective grading of preoperative and postoperative photographs by five independent blinded plastic surgeons. Absolute observed agreement as well as weighted Fleiss Kappa (κ) test statistics were calculated to assess inter-rater variability. When ADM was incorporated, the overall aesthetic score was improved by an average of 12.1 %. In addition, subscale analyses revealed improvements in breast contour (35.2 %), implant placement (20.7 %), lower pole projection (16.7 %), and inframammary fold definition (13.8 %). Contour (p = 0.039), implant placement (p = 0.021), and overall aesthetic score (p = 0.022) reached statistical significance. Inter-rater reliability showed mostly moderate agreement. Mean aesthetic scores were higher in the ADM-assisted breast reconstruction cohort including the total aesthetic score which was statistically significant. Aesthetic outcome alone may justify the added expense of incorporating biologic mesh. Moreover, ADM has other benefits which may render it cost-effective. Larger prospective studies are needed to provide plastic surgeons with more definitive guidelines for ADM use. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the

  15. Acellular organ scaffolds for tumor tissue engineering

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    Guller, Anna; Trusova, Inna; Petersen, Elena; Shekhter, Anatoly; Kurkov, Alexander; Qian, Yi; Zvyagin, Andrei

    2015-12-01

    Rationale: Tissue engineering (TE) is an emerging alternative approach to create models of human malignant tumors for experimental oncology, personalized medicine and drug discovery studies. Being the bottom-up strategy, TE provides an opportunity to control and explore the role of every component of the model system, including cellular populations, supportive scaffolds and signalling molecules. Objectives: As an initial step to create a new ex vivo TE model of cancer, we optimized protocols to obtain organ-specific acellular matrices and evaluated their potential as TE scaffolds for culture of normal and tumor cells. Methods and results: Effective decellularization of animals' kidneys, ureter, lungs, heart, and liver has been achieved by detergent-based processing. The obtained scaffolds demonstrated biocompatibility and growthsupporting potential in combination with normal (Vero, MDCK) and tumor cell lines (C26, B16). Acellular scaffolds and TE constructs have been characterized and compared with morphological methods. Conclusions: The proposed methodology allows creation of sustainable 3D tumor TE constructs to explore the role of organ-specific cell-matrix interaction in tumorigenesis.

  16. Evaluation of the effectiveness of the prepectoral breast reconstruction with Braxon dermal matrix: First multicenter European report on 100 cases.

    Science.gov (United States)

    Vidya, Raghavan; Masià, Jaume; Cawthorn, Simon; Berna, Giorgio; Bozza, Fernando; Gardetto, Alexander; Kołacińska, Agnieszka; Dell'Antonia, Francesco; Tiengo, Cesare; Bassetto, Franco; Caputo, Glenda G; Governa, Maurizio

    2017-11-01

    We report the outcomes of the European prospective study on prepectoral breast reconstruction using preshaped acellular dermal matrix for complete breast implant coverage. Seventy-nine patients were enrolled between April 2014 and August 2015 all over Europe using a single protocol for patient selection and surgical procedure, according to the Association of Breast Surgery and British Association of Plastic Reconstructive and Aesthetic Surgeons joint guidelines for the use of acellular dermal matrix in breast surgery. The preshaped matrix completely wraps the breast implant, which is placed above the pectoralis major, without detaching the muscle. A total of 100 prepectoral breast reconstructions with complete implant coverage were performed. This series, with mean follow-up of 17.9 months, had two cases of implant loss (2.0%) including one necrosis of the nipple and one wound breakdown (1.0% respectively). No implant rotations were observed. Good cosmetic outcomes were obtained with natural movement of the breasts and softness to the touch; none of the patients reported experiencing pain or reduction in the movements of the pectoralis major muscle postoperatively. The use of preshaped acellular dermal matrix for a complete breast implant coverage in selected patients is safe and gives satisfactory results, both from the aesthetic view point and the low postoperative complication rates. Further studies reporting long-term outcomes are planned. © 2017 Crown copyright. The Breast Journal © 2017 Wiley Periodicals, Inc. This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland.

  17. Evaluation of a novel breast reconstruction technique using the Braxon® acellular dermal matrix: a new muscle-sparing breast reconstruction.

    Science.gov (United States)

    Berna, Giorgio; Cawthorn, Simon J; Papaccio, Guido; Balestrieri, Nicola

    2017-06-01

    Implant-based breast reconstruction is becoming increasingly popular because of the widespread adoption of acellular dermal matrix (ADM), which allows surgeons to obtain good aesthetic results with fewer operations. To develop more conservative surgical techniques, a retrospective, three-centre, proof-of-concept study was performed to study the effectiveness of a new, immediate, muscle-sparing breast reconstruction technique using the patented Braxon ® ADM, which enables subcutaneous positioning of the breast implant without detaching the pectoralis major. Ethics committee of the study coordinating centre approved medical record review on 19 women who underwent muscle-sparing breast reconstruction between November 2012 and January 2014. The first 10 implants were performed using 0.9-mm-thick porcine ADM, with preservatives. In the subsequent 15 implants, the product was changed to 0.6-mm-thick porcine dry ADM, without preservatives. Nineteen patients (25 implants) received six bilateral and 13 unilateral muscle-sparing breast reconstructions. For the first type of ADM used (0.9-mm-thick with preservatives), the rate of implant loss was 12% (n = 3) because of seroma (8%, n = 2) and infection (4%, n = 1). Minor complications, such as seroma (8%, n = 2), occurred when using the 0.6-mm-thick Braxon ® ADM and were treated by aspiration. Symmetrical and natural breasts with good shape, ptosis and softness to the touch were obtained. None of the patients reported experiencing pain. The preliminary results are encouraging from aesthetic and clinical viewpoints. Further studies are planned to evaluate long-term results. © 2014 Royal Australasian College of Surgeons.

  18. Effects of hydroxyapatite nanostructure on channel surface of porcine acellular dermal matrix scaffold on cell viability and osteogenic differentiation of human periodontal ligament stem cells

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    Ge S

    2013-05-01

    Full Text Available Shaohua Ge,1 Ning Zhao,1 Lu Wang,1 Hong Liu,2 Pishan Yang11Shandong Provincial Key Laboratory of Oral Biomedicine, Department of Periodontology, Shandong University; 2State Key Laboratory of Crystal Materials, Center of Bio and Micro/Nano Functional Materials, Shandong University, Jinan, People's Republic of ChinaAbstract: A new nanostructured hydroxyapatite-coated porcine acellular dermal matrix (HAp-PADM was fabricated by a biomimetic mineralization method. Human periodontal ligament stem cells were seeded on HAp-PADM and the effects of this scaffold on cell shape, cytoskeleton organization, cell viability, and osteogenic differentiation were examined. Periodontal ligament stem cells cultured on HAp-PADM exhibited different cell shape when compared with those on pure PADM. Moreover, HAp-PADM promoted cell viability and alkaline phosphatase activity significantly. Based on quantitative real-time polymerase chain reaction, the expression of bone-related markers runt-related transcription factor 2 (Runx2, osteopontin (OPN, and osteocalcin (OCN upregulated in the HAp-PADM scaffold. The enhancement of osteogenic differentiation of periodontal ligament stem cells on the HAp-PADM scaffold was proposed based on the research results. The results of this study highlight the micro-nano, two-level, three-dimensional HAp-PADM composite as a promising scaffold for periodontal tissue engineering.Keywords: hydroxyapatite, scaffold, nanostructure, proliferation, differentiation, tissue engineering

  19. Microporous dermal-mimetic electrospun scaffolds pre-seeded with fibroblasts promote tissue regeneration in full-thickness skin wounds.

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    Paul P Bonvallet

    Full Text Available Electrospun scaffolds serve as promising substrates for tissue repair due to their nanofibrous architecture and amenability to tailoring of chemical composition. In this study, the regenerative potential of a microporous electrospun scaffold pre-seeded with dermal fibroblasts was evaluated. Previously we reported that a 70% collagen I and 30% poly(Ɛ-caprolactone electrospun scaffold (70:30 col/PCL containing 160 μm diameter pores had favorable mechanical properties, supported fibroblast infiltration and subsequent cell-mediated deposition of extracellular matrix (ECM, and promoted more rapid and effective in vivo skin regeneration when compared to scaffolds lacking micropores. In the current study we tested the hypothesis that the efficacy of the 70:30 col/PCL microporous scaffolds could be further enhanced by seeding scaffolds with dermal fibroblasts prior to implantation into skin wounds. To address this hypothesis, a Fischer 344 (F344 rat syngeneic model was employed. In vitro studies showed that dermal fibroblasts isolated from F344 rat skin were able to adhere and proliferate on 70:30 col/PCL microporous scaffolds, and the cells also filled the 160 μm pores with native ECM proteins such as collagen I and fibronectin. Additionally, scaffolds seeded with F344 fibroblasts exhibited a low rate of contraction (~14% over a 21 day time frame. To assess regenerative potential, scaffolds with or without seeded F344 dermal fibroblasts were implanted into full thickness, critical size defects created in F344 hosts. Specifically, we compared: microporous scaffolds containing fibroblasts seeded for 4 days; scaffolds containing fibroblasts seeded for only 1 day; acellular microporous scaffolds; and a sham wound (no scaffold. Scaffolds containing fibroblasts seeded for 4 days had the best response of all treatment groups with respect to accelerated wound healing, a more normal-appearing dermal matrix structure, and hair follicle regeneration

  20. A Comparative 6-Month Clinical Study of Acellular Dermal Matrix Allograft and Subepithelial Connective Tissue Graft for Root Coverage

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    S. Sadat Mansouri

    2010-09-01

    Full Text Available Objective: Different surgical procedures have been proposed for the treatment of gingival recessions. The goal of this study was to compare the clinical results of gingival recession treatment using Subepithelial Connective Tissue Graft and an Acellular Dermal MatrixAllograft.Materials and Methods: The present study was performed on 5 patients with 9 bilateral Miller`s class I or II gingival recessions. This included 15 premolars and 3 canines. In each patient the teeth were randomly divided in two groups of test (ADMA and control (SCTG.Clinical parameters including recession height (RH, recession width (RW, keratinized gingiva (KG, clinical attachment level (CAL and probing depth (PD were measured at baseline, 2, 4 and 6 months after surgery and data analysis was performed using the Wilcoxon signed rank test.Results: The mean changes (mm from baseline to 6 months in SCTG and ADMA were 2.22±0.83 and 1.77±0.66 decrease in RH, 2.55±0.88 and 2.33±0.86 decrease in RW,1.44±0.88 and 2.0±1.11 increase in KG, 2.33±1.22 and 2.11±0.6 decrease in CAL and finally 0.22±0.66 and 0.33±0.7 decrease in PD, respectively. The differences in meanchanges were not significant between the two groups in any of the parameters. The percentage of root coverage was 85.7% and 71.1% for the control and test group,respectively. The changes from baseline to the 6 month visit were significant for both groups in all parameters but PD.Conclusion: Alloderm may be suggested as an acceptable substitute for connective tissue graft considering the root coverage effect and KG width increase.

  1. Coronally positioned flap with or without acellular dermal matrix graft in the treatment of class II gingival recession defects: A randomized controlled clinical study

    Directory of Open Access Journals (Sweden)

    Sunitha Jagannathachary

    2010-01-01

    Full Text Available The aim of the randomized controlled single blind study is to evaluate the treatment of Miller′s class II gingival recessions by coronally positioned flap (CPF with or without acellular dermal matrix allograft (ADMA. Ten patients with 20 sites with maxillary bilateral Miller′s class II facial recession defects were selected randomly into two groups of test (ADMA+CPF and control (CPF alone group with each group having 10 recession defects to be treated. The clinical parameters included plaque index (PI, gingival index (GI, probing pocket depth (PPD, clinical attachment level (CAL, recession height (RH, recession width (RW, height of the keratinized tissue (HKT, and thickness of the keratinized tissue (TKT. These measurements were recorded at baseline and after 6 months post-surgery. Statistical analysis was made by the paired "t" test for intragroup and intergroup comparison was done by the unpaired "t" test. The percentage of root coverage for both the experimental and control groups were 82.2% and 50%, respectively. The changes from baseline to 6 months were significant in both the groups for PD, CAL, and RH; however, for parameters such as RW, HKT, and TKT significance was seen only in the experimental group. On comparison between two groups, only TKT showed statistically significance. It can be concluded that the amount of root coverage obtained with ADMA + CPF was superior compared to CPF alone.

  2. Dextran derivatives modulate collagen matrix organization in dermal equivalent.

    Science.gov (United States)

    Frank, Laetitia; Lebreton-Decoster, Corinne; Godeau, Gaston; Coulomb, Bernard; Jozefonvicz, Jacqueline

    2006-01-01

    Dextran derivatives can protect heparin binding growth factor implied in wound healing, such as transforming growth factor-beta1 (TGF-beta1) and fibroblast growth factor-2 (FGF-2). The first aim of this study was to investigate the effect of these compounds on human dermal fibroblasts in culture with or without TGF-beta1. Several dextran derivatives obtained by substitution of methylcarboxylate (MC), benzylamide (B) and sulphate (Su) groups were used to determine the effects of each compound on fibroblast growth in vitro. The data indicate that sulphate groups are essential to act on the fibroblast proliferation. The dextran derivative LS21 DMCBSu has been chosen to investigate its effect on dermal wound healing process. Fibroblasts cultured in collagenous matrices named dermal equivalent were treated with the bioactive polymer alone or associated to TGF-beta1 or FGF-2. Cross-sections of dermal equivalent observed by histology or immunohistochemistry, demonstrated that the bioactive polymer accelerates the collagen matrices organization and stimulates the human type-III collagen expression. This bioactive polymer induces apoptosis of myofibroblast, property which may be beneficial in treatment of hypertrophic scar. Culture media analyzed by zymography and Western blot showed that this polymer significantly increases the secretion of zymogen and active form of matrix metalloproteinase-2 (MMP-2), involved in granulation tissue formation. These data suggest that this bioactive polymer has properties which may be beneficial in the treatment of wound healing.

  3. Cost analysis of postmastectomy reconstruction: A comparison of two staged implant reconstruction using tissue expander and acellular dermal matrix with abdominal-based perforator free flaps.

    Science.gov (United States)

    Tran, Bao Ngoc N; Fadayomi, Ayotunde; Lin, Samuel J; Singhal, Dhruv; Lee, Bernard T

    2017-09-01

    Two staged tissue expander-implant with acellular dermal matrix (TE/I + ADM) and deep inferior epigastric perforator (DIEP) flap are the most common implant and autologous methods of reconstruction in the U.S. Implant-based techniques are disproportionally more popular, partially due to its presumed cost effectiveness. We performed a comprehensive cost analysis to compare TE/I + ADM and DIEP flap. A comparative cost analysis of TE/I + ADM and DIEP flap was performed. Medicare reimbursement costs for each procedure and their associated complications were calculated. Pooled probabilities of complications including cellulitis, seroma, skin necrosis, implant removal, flap loss, partial flap loss, and fat necrosis, were calculated using published studies from 2010 to 2016. Average actual cost for successful TE/I + ADM and DIEP flap were $13 304.55 and $10 237.13, respectively. Incorporating pooled complication data from published literature resulted in an increase in cost to $13 963.46 for TE/I + ADM and $12 624.29 for DIEP flap. The expected costs for successful TE/I + ADM and DIEP flap were $9700.35 and $8644.23, which are lower than the actual costs. DIEP flap breast reconstruction incurs lower costs compared to TE/I + ADM. These costs are lower at baseline and when additional costs from pooled complications are incorporated. © 2017 Wiley Periodicals, Inc.

  4. Early Surgical Site Infection Following Tissue Expander Breast Reconstruction with or without Acellular Dermal Matrix: National Benchmarking Using National Surgical Quality Improvement Program

    Directory of Open Access Journals (Sweden)

    Sebastian Winocour

    2015-03-01

    Full Text Available BackgroundSurgical site infections (SSIs result in significant patient morbidity following immediate tissue expander breast reconstruction (ITEBR. This study determined a single institution's 30-day SSI rate and benchmarked it against that among national institutions participating in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP.MethodsWomen who underwent ITEBR with/without acellular dermal matrix (ADM were identified using the ACS-NSQIP database between 2005 and 2011. Patient characteristics associated with the 30-day SSI rate were determined, and differences in rates between our institution and the national database were assessed.Results12,163 patients underwent ITEBR, including 263 at our institution. SSIs occurred in 416 (3.4% patients nationwide excluding our institution, with lower rates observed at our institution (1.9%. Nationwide, SSIs were significantly more common in ITEBR patients with ADM (4.5% compared to non-ADM patients (3.2%, P=0.005, and this trend was observed at our institution (2.1% vs. 1.6%, P=1.00. A multivariable analysis of all institutions identified age ≥50 years (odds ratio [OR], 1.4; confidence interval [CI], 1.1-1.7, body mass index ≥30 kg/m2 vs. 4.25 hours (OR, 1.9; CI, 1.5-2.4 as risk factors for SSIs. Our institutional SSI rate was lower than the nationwide rate (OR, 0.4; CI, 0.2-1.1, although this difference was not statistically significant (P=0.07.ConclusionsThe 30-day SSI rate at our institution in patients who underwent ITEBR was lower than the nation. SSIs occurred more frequently in procedures involving ADM both nationally and at our institution.

  5. Cartilage oligomeric matrix protein enhances the vascularization of acellular nerves

    Directory of Open Access Journals (Sweden)

    Wei-ling Cui

    2016-01-01

    Full Text Available Vascularization of acellular nerves has been shown to contribute to nerve bridging. In this study, we used a 10-mm sciatic nerve defect model in rats to determine whether cartilage oligomeric matrix protein enhances the vascularization of injured acellular nerves. The rat nerve defects were treated with acellular nerve grafting (control group alone or acellular nerve grafting combined with intraperitoneal injection of cartilage oligomeric matrix protein (experimental group. As shown through two-dimensional imaging, the vessels began to invade into the acellular nerve graft from both anastomotic ends at day 7 post-operation, and gradually covered the entire graft at day 21. The vascular density, vascular area, and the velocity of revascularization in the experimental group were all higher than those in the control group. These results indicate that cartilage oligomeric matrix protein enhances the vascularization of acellular nerves.

  6. [Preparation of acellular matrix from antler cartilage and its biological compatibility].

    Science.gov (United States)

    Fu, Jing; Zhang, Wei; Zhang, Aiwu; Ma, Lijuan; Chu, Wenhui; Li, Chunyi

    2017-06-01

    To study the feasibility of acellular matrix materials prepared from deer antler cartilage and its biological compatibility so as to search for a new member of the extracellular matrix family for cartilage regeneration. The deer antler mesenchymal (M) layer tissue was harvested and treated through decellular process to prepare M layer acellular matrix; histologic observation and detection of M layer acellular matrix DNA content were carried out. The antler stem cells [antlerogenic periosteum (AP) cells] at 2nd passage were labelled by fluorescent stains and by PKH26. Subsequently, the M layer acellular matrix and the AP cells at 2nd passage were co-cultured for 7 days; then the samples were transplanted into nude mice to study the tissue compatibility of M layer acellular matrix in the living animals. HE and DAPI staining confirmed that the M layer acellular matrix did not contain nucleus; the DNA content of the M layer acellular matrix was (19.367±5.254) ng/mg, which was significantly lower than that of the normal M layer tissue [(3 805.500±519.119) ng/mg]( t =12.630, P =0.000). In vitro co-culture experiments showed that AP cells could adhere to or even embedded in the M layer acellular matrix. Nude mice transplantation experiments showed that the introduced AP cells could proliferate and induce angiogenesis in the M layer acellular matrix. The deer antler cartilage acellular matrix is successfully prepared. The M layer acellular matrix is suitable for adhesion and proliferation of AP cells in vitro and in vivo , and it has the function of stimulating angiogenesis. This model for deer antler cartilage acellular matrix can be applied in cartilage tissue engineering in the future.

  7. Glucose oxidase incorporated collagen matrices for dermal wound repair in diabetic rat models: a biochemical study.

    Science.gov (United States)

    Arul, V; Masilamoni, J G; Jesudason, E P; Jaji, P J; Inayathullah, M; Dicky John, D G; Vignesh, S; Jayakumar, R

    2012-05-01

    Impaired wound healing in diabetes is a well-documented phenomenon. Emerging data favor the involvement of free radicals in the pathogenesis of diabetic wound healing. We investigated the beneficial role of the sustained release of reactive oxygen species (ROS) in diabetic dermal wound healing. In order to achieve the sustained delivery of ROS in the wound bed, we have incorporated glucose oxidase in the collagen matrix (GOIC), which is applied to the healing diabetic wound. Our in vitro proteolysis studies on incorporated GOIC show increased stability against the proteases in the collagen matrix. In this study, GOIC film and collagen film (CF) are used as dressing material on the wound of streptozotocin-induced diabetic rats. A significant increase in ROS (p < 0.05) was observed in the fibroblast of GOIC group during the inflammation period compared to the CF and control groups. This elevated level up regulated the antioxidant status in the granulation tissue and improved cellular proliferation in the GOIC group. Interestingly, our biochemical parameters nitric oxide, hydroxyproline, uronic acid, protein, and DNA content in the healing wound showed that there is an increase in proliferation of cells in GOIC when compared to the control and CF groups. In addition, evidence from wound contraction and histology reveals faster healing in the GOIC group. Our observations document that GOIC matrices could be effectively used for diabetic wound healing therapy.

  8. [NEW PROGRESS OF ACELLULAR FISH SKIN AS NOVEL TISSUE ENGINEERED SCAFFOLD].

    Science.gov (United States)

    Wei, Xiaojuan; Wang, Nanping; He, Lan; Guo, Xiuyu; Gu, Qisheng

    2016-11-08

    To review the recent research progress of acellular fish skin as a tissue engineered scaffold, and to analyze the feasibility and risk management in clinical application. The research and development, application status of acellular fish skin as a tissue engineered scaffold were comprehensively analyzed, and then several key points were put forward. Acellular fish skin has a huge potential in clinical practice as novel acellular extracellular matrix, but there have been no related research reports up to now in China. As an emerging point of translational medicine, investigation of acellular fish skin is mainly focused on artificial skin, surgical patch, and wound dressings. Development of acellular fish skin-based new products is concerned to be clinical feasible and necessary, but a lot of applied basic researches should be carried out.

  9. The acellular matrix (ACM) for bladder tissue engineering: A quantitative magnetic resonance imaging study.

    Science.gov (United States)

    Cheng, Hai-Ling Margaret; Loai, Yasir; Beaumont, Marine; Farhat, Walid A

    2010-08-01

    Bladder acellular matrices (ACMs) derived from natural tissue are gaining increasing attention for their role in tissue engineering and regeneration. Unlike conventional scaffolds based on biodegradable polymers or gels, ACMs possess native biomechanical and many acquired biologic properties. Efforts to optimize ACM-based scaffolds are ongoing and would be greatly assisted by a noninvasive means to characterize scaffold properties and monitor interaction with cells. MRI is well suited to this role, but research with MRI for scaffold characterization has been limited. This study presents initial results from quantitative MRI measurements for bladder ACM characterization and investigates the effects of incorporating hyaluronic acid, a natural biomaterial useful in tissue-engineering and regeneration. Measured MR relaxation times (T(1), T(2)) and diffusion coefficient were consistent with increased water uptake and glycosaminoglycan content observed on biochemistry in hyaluronic acid ACMs. Multicomponent MRI provided greater specificity, with diffusion data showing an acellular environment and T(2) components distinguishing the separate effects of increased glycosaminoglycans and hydration. These results suggest that quantitative MRI may provide useful information on matrix composition and structure, which is valuable in guiding further development using bladder ACMs for organ regeneration and in strategies involving the use of hyaluronic acid.

  10. Effectiveness of Acellular Dermal Matrix on Autologous Split-Thickness Skin Graft in Treatment of Deep Tissue Defect: Esthetic Subjective and Objective Evaluation.

    Science.gov (United States)

    Lee, Yoo Jung; Park, Myong Chul; Park, Dong Ha; Hahn, Hyung Min; Kim, Sue Min; Lee, Il Jae

    2017-10-01

    A split-thickness skin graft (STSG) is performed to cover a large full-thickness skin defect. Esthetic and functional deficits can result, and many studies have sought to overcome them. This study compared the effectiveness of the acellular dermal matrix (ADM) graft and STSG concerning esthetic and functional effectiveness of ADM on scar quality. Of the patients who underwent anterolateral thigh free flap from 2011 to 2015, patients who received skin graft only (n = 10) or skin graft with ADM (n = 20) for coverage of the donor site were enrolled. In all cases, autologous STSG was performed with 1:1.5 meshed 0.008-0.010-inch-thick skin. In the skin graft with ADM group, 0.008-0.013-inch-thick meshed ADM (CGderm ® ; CGBio, Inc., Seungnam, Korea) was co-grafted. Negative-pressure wound therapy (CuraVAC ® ; CGBio, Inc., Seungnam, Korea) was applied to both groups in continuous mode at -120 mmHg. We investigate early outcomes (skin loss rate, duration of negative-pressure wound therapy, days to removal of stitches, days to achieve complete healing, and complications) and late outcomes in terms of scar quality (vascularity, pigmentation, pliability and height) and graft-related symptoms (itching sensation and pain). Assessments used the Vancouver Scar Scale and the Patient and Observer Scar Assessment Scale. Skin fold was measured to evaluate the elasticity of scar tissue. In the Vancouver Scar Scale, vascularity subscore (p = 0.003) and total score (p = 0.016) were significantly lower in the skin graft with ADM group. In Patient and Observer Scar Assessment Scale, the pain (p = 0.037) and stiffness subscores (p = 0.002), and total score (p = 0.017) were significantly lower in the skin graft with ADM group. Skin graft with ADM results in better scar quality in objective and subjective aspects. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to

  11. Acellular Nerve Allografts in Peripheral Nerve Regeneration: A Comparative Study

    Science.gov (United States)

    Moore, Amy M.; MacEwan, Matthew; Santosa, Katherine B.; Chenard, Kristofer E.; Ray, Wilson Z.; Hunter, Daniel A.; Mackinnon, Susan E.; Johnson, Philip J.

    2011-01-01

    Background Processed nerve allografts offer a promising alternative to nerve autografts in the surgical management of peripheral nerve injuries where short deficits exist. Methods Three established models of acellular nerve allograft (cold-preserved, detergent-processed, and AxoGen® -processed nerve allografts) were compared to nerve isografts and silicone nerve guidance conduits in a 14 mm rat sciatic nerve defect. Results All acellular nerve grafts were superior to silicone nerve conduits in support of nerve regeneration. Detergent-processed allografts were similar to isografts at 6 weeks post-operatively, while AxoGen®-processed and cold-preserved allografts supported significantly fewer regenerating nerve fibers. Measurement of muscle force confirmed that detergent-processed allografts promoted isograft-equivalent levels of motor recovery 16 weeks post-operatively. All acellular allografts promoted greater amounts of motor recovery compared to silicone conduits. Conclusions These findings provide evidence that differential processing for removal of cellular constituents in preparing acellular nerve allografts affects recovery in vivo. PMID:21660979

  12. Association of versican with dermal matrices and its potential role in hair follicle development and cycling

    DEFF Research Database (Denmark)

    du Cros, D L; LeBaron, R G; Couchman, J R

    1995-01-01

    Versican is a member of the group of aggregating proteoglycans involved in matrix assembly and structure and in cell adhesion. We examined changes in the distribution of versican in mammalian skin, with emphasis on hair follicle development and cycling. In adult human skin, immunostaining...... for versican appeared predominantly in the dermis, with intense staining of the reticular dermis. Weak staining was observed at the dermoepidermal junction and the connective tissue sheath of hair follicles. Versican expression was also noted in the reticular dermis of rat skin, within dermal papillae......, and possibly associated with follicle basement membranes. During mouse hair follicle development, versican was not expressed until the hair follicles were beginning to produce fibers. With follicle maturation, versican expression intensified in the dermal papillae, reaching a maximum at the height...

  13. Chemical stabilization of polymers: Implications for dermal exposure to additives.

    Science.gov (United States)

    Bartsch, N; Girard, M; Schneider, L; Weijgert, V Van De; Wilde, A; Kappenstein, O; Vieth, B; Hutzler, C; Luch, A

    2018-04-16

    Technical benefits of additives in polymers stand in marked contrast to their associated health risks. Here, a multi-analyte method based on gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) was developed to quantify polymer additives in complex matrices such as low-density polyethylene (LDPE) and isolated human skin layers after dermal exposure ex vivo. That way both technical aspects and dermal exposure were investigated. The effects of polymer additivation on the material were studied using the example of LDPE. To this end, a tailor-made polymer was applied in aging studies that had been furnished with two different mixtures of phenol- and diarylamine-based antioxidants, plasticizers and processing aids. Upon accelerated thermo-oxidative aging of the material, the formation of LDPE degradation products was monitored with attenuated total reflectance-Fourier transformed infrared (ATR-FTIR) spectroscopy. Compared to pure LDPE, a protective effect of added antioxidants could be observed on the integrity of the polymer. Further, thermo-oxidative degradation of the additives and its kinetics were investigated using LDPE or squalane as matrix. The half-lives of additives in both matrices revealed significant differences between the tested additives as well as between LDPE and squalane. For instance, 2-tert-butyl-6-[(3-tert-butyl-2-hydroxy-5-methylphenyl)methyl]-4-methylphenol (Antioxidant 2246) showed a half-life 12 times lower when incorporated in LDPE as compared to squalane. As a model for dermal exposure of consumers, human skin was brought into contact with the tailor-made LDPE containing additives ex vivo in static Franz diffusion cells. The skin was then analyzed for additives and decomposition products. This study proved 10 polymer additives of diverse pysicochemical properties and functionalities to migrate out of the polymer and eventually overcome the intact human skin barrier during contact. Moreover, their individual distribution within

  14. One-stage human acellular nerve allograft reconstruction for digital nerve defects

    Directory of Open Access Journals (Sweden)

    Xue-yuan Li

    2015-01-01

    Full Text Available Human acellular nerve allografts have a wide range of donor origin and can effectively avoid nerve injury in the donor area. Very little is known about one-stage reconstruction of digital nerve defects. The present study observed the feasibility and effectiveness of human acellular nerve allograft in the reconstruction of < 5-cm digital nerve defects within 6 hours after injury. A total of 15 cases of nerve injury, combined with nerve defects in 18 digits from the Department of Emergency were enrolled in this study. After debridement, digital nerves were reconstructed using human acellular nerve allografts. The patients were followed up for 6-24 months after reconstruction. Mackinnon-Dellon static two-point discrimination results showed excellent and good rates of 89%. Semmes-Weinstein monofilament test demonstrated that light touch was normal, with an obvious improvement rate of 78%. These findings confirmed that human acellular nerve allograft for one-stage reconstruction of digital nerve defect after hand injury is feasible, which provides a novel trend for peripheral nerve reconstruction.

  15. Pulmonary heart valve replacement using stabilized acellular xenogeneic scaffolds; effects of seeding with autologous stem cells

    Directory of Open Access Journals (Sweden)

    Harpa Marius Mihai

    2015-12-01

    Full Text Available Background: We hypothesized that an ideal heart valve replacement would be acellular valve root scaffolds seeded with autologous stem cells. To test this hypothesis, we prepared porcine acellular pulmonary valves, seeded them with autologous adipose derived stem cells (ADSCs and implanted them in sheep and compared them to acellular valves.

  16. Chondrogenic potential of physically treated bovine cartilage matrix derived porous scaffolds on human dermal fibroblast cells.

    Science.gov (United States)

    Moradi, Ali; Ataollahi, Forough; Sayar, Katayoun; Pramanik, Sumit; Chong, Pan-Pan; Khalil, Alizan Abdul; Kamarul, Tunku; Pingguan-Murphy, Belinda

    2016-01-01

    Extracellular matrices have drawn attention in tissue engineering as potential biomaterials for scaffold fabrication because of their bioactive components. Noninvasive techniques of scaffold fabrication and cross-linking treatments are believed to maintain the integrity of bioactive molecules while providing proper architectural and mechanical properties. Cartilage matrix derived scaffolds are designed to support the maintenance of chondrocytes and provide proper signals for differentiation of chondroinducible cells. Chondroinductive potential of bovine articular cartilage matrix derived porous scaffolds on human dermal fibroblasts and the effect of scaffold shrinkage on chondrogenesis were investigated. An increase in sulfated glycosaminoglycans production along with upregulation of chondrogenic genes confirmed that physically treated cartilage matrix derived scaffolds have chondrogenic potential on human dermal fibroblasts. © 2015 Wiley Periodicals, Inc.

  17. The effect of keratinocytes on the biomechanical characteristics and pore microstructure of tissue engineered skin using deep dermal fibroblasts.

    Science.gov (United States)

    Varkey, Mathew; Ding, Jie; Tredget, Edward E

    2014-12-01

    Fibrosis affects most organs, it results in replacement of normal parenchymal tissue with collagen-rich extracellular matrix, which compromises tissue architecture and ultimately causes loss of function of the affected organ. Biochemical pathways that contribute to fibrosis have been extensively studied, but the role of biomechanical signaling in fibrosis is not clearly understood. In this study, we assessed the effect keratinocytes have on the biomechanical characteristics and pore microstructure of tissue engineered skin made with superficial or deep dermal fibroblasts in order to determine any biomaterial-mediated anti-fibrotic influences on tissue engineered skin. Tissue engineered skin with deep dermal fibroblasts and keratinocytes were found to be less stiff and contracted and had reduced number of myofibroblasts and lower expression of matrix crosslinking factors compared to matrices with deep fibroblasts alone. However, there were no such differences between tissue engineered skin with superficial fibroblasts and keratinocytes and matrices with superficial fibroblasts alone. Also, tissue engineered skin with deep fibroblasts and keratinocytes had smaller pores compared to those with superficial fibroblasts and keratinocytes; pore size of tissue engineered skin with deep fibroblasts and keratinocytes were not different from those matrices with deep fibroblasts alone. A better understanding of biomechanical characteristics and pore microstructure of tissue engineered skin may prove beneficial in promoting normal wound healing over pathologic healing. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Integrin-linked kinase is required for TGF-β1 induction of dermal myofibroblast differentiation.

    Science.gov (United States)

    Vi, Linda; de Lasa, Cristina; DiGuglielmo, Gianni M; Dagnino, Lina

    2011-03-01

    Cutaneous repair after injury requires activation of resident dermal fibroblasts and their transition to myofibroblasts. The key stimuli for myofibroblast formation are activation of transforming growth factor-β (TGF-β) receptors and mechanotransduction mediated by integrins and associated proteins. We investigated the role of integrin-linked kinase (ILK) in TGF-β1 induction of dermal fibroblast transition to myofibroblasts. ILK-deficient fibroblasts treated with TGF-β1 exhibited attenuation of Smad 2 and 3 phosphorylation, accompanied by impaired transcriptional activation of Smad targets, such as α-smooth muscle actin. These alterations were not limited to Smad-associated TGF-β1 responses, as stimulation of noncanonical mitogen-activated protein kinase pathways by this growth factor was also diminished in the absence of ILK. ILK-deficient fibroblasts exhibited abnormalities in the actin cytoskeleton, and did not form supermature focal adhesions or contractile F-actin stress fibers, indicating a severe impairment in their capacity to differentiate into myofibroblasts. These defects extended to the inability of cells to contract extracellular matrices when embedded in collagen lattices. We conclude that ILK is necessary to transduce signals implicated in the transition of dermal fibroblasts to myofibroblasts originating from matrix substrates and TGF-β1.

  19. Nonexpansive immediate breast reconstruction using human acellular tissue matrix graft (AlloDerm).

    Science.gov (United States)

    Salzberg, C Andrew

    2006-07-01

    Immediate breast reconstruction has become a standard of care following mastectomy for cancer, largely due to improved esthetic and psychologic outcomes achieved with this technique. However, the current historical standards--transverse rectus abdominis myocutaneous flap reconstruction and expander--implant surgery-still have limitations as regards patient morbidity, short-term body-image improvements, and even cost. To address these shortcomings, we employ a novel concept of human tissue replacement to enhance breast shape and provide total coverage, enabling immediate mound reconstruction without the need for breast expansion prior to permanent implant placement. AlloDerm (human acellular tissue matrix) is a human-derived graft tissue with extensive experience in various settings of skin and soft tissue replacement surgery. This report describes the success using acellular tissue matrix to provide total coverage over the prosthesis in immediate reconstruction, with limited muscle dissection. In this population, 49 patients (76 breasts) successfully underwent the acellular tissue matrix-based immediate reconstruction, resulting in durable breast reconstruction with good symmetry. These findings may predict that acellular tissue matrix-supplemented immediate breast reconstruction will become a new technique for the immediate reconstruction of the postmastectomy breast.

  20. Naturally Occurring Extracellular Matrix Scaffolds for Dermal Regeneration: Do They Really Need Cells?

    Directory of Open Access Journals (Sweden)

    A. M. Eweida

    2015-01-01

    Full Text Available The pronounced effect of extracellular matrix (ECM scaffolds in supporting tissue regeneration is related mainly to their maintained 3D structure and their bioactive components. These decellularized matrix scaffolds could be revitalized before grafting via adding stem cells, fibroblasts, or keratinocytes to promote wound healing. We reviewed the online published literature in the last five years for the studies that performed ECM revitalization and discussed the results of these studies and the related literature. Eighteen articles met the search criteria. Twelve studies included adding cells to acellular dermal matrix (ADM, 3 studies were on small intestinal mucosa (SIS, one study was on urinary bladder matrix (UBM, one study was on amniotic membrane, and one study included both SIS and ADM loaded constructs. We believe that, in chronic and difficult-to-heal wounds, revitalizing the ECM scaffolds would be beneficial to overcome the defective host tissue interaction. This belief still has to be verified by high quality randomised clinical trials, which are still lacking in literature.

  1. Endothelial network formed with human dermal microvascular endothelial cells in autologous multicellular skin substitutes.

    Science.gov (United States)

    Ponec, Maria; El Ghalbzouri, Abdoelwaheb; Dijkman, Remco; Kempenaar, Johanna; van der Pluijm, Gabri; Koolwijk, Pieter

    2004-01-01

    A human skin equivalent from a single skin biopsy harboring keratinocytes and melanocytes in the epidermal compartment, and fibroblasts and microvascular dermal endothelial cells in the dermal compartment was developed. The results of the study revealed that the nature of the extracellular matrix of the dermal compartments plays an important role in establishment of endothelial network in vitro. With rat-tail type I collagen matrices only lateral but not vertical expansion of endothelial networks was observed. In contrast, the presence of extracellular matrix of entirely human origin facilitated proper spatial organization of the endothelial network. Namely, when human dermal fibroblasts and microvascular endothelial cells were seeded on the bottom of an inert filter and subsequently epidermal cells were seeded on top of it, fibroblasts produced extracellular matrix throughout which numerous branched tubes were spreading three-dimensionally. Fibroblasts also facilitated the formation of basement membrane at the epidermal/matrix interface. Under all culture conditions, fully differentiated epidermis was formed with numerous melanocytes present in the basal epidermal cell layer. The results of the competitive RT-PCR revealed that both keratinocytes and fibroblasts expressed VEGF-A, -B, -C, aFGF and bFGF mRNA, whereas fibroblasts also expressed VEGF-D mRNA. At protein level, keratinocytes produced 10 times higher amounts of VEGF-A than fibroblasts did. The generation of multicellular skin equivalent from a single human skin biopsy will stimulate further developments for its application in the treatment of full-thickness skin defects. The potential development of biodegradable, biocompatible material suitable for these purposes is a great challenge for future research.

  2. New Insights on the Composition and the Structure of the Acellular Extrinsic Fiber Cementum by Raman Analysis

    Science.gov (United States)

    Colard, Thomas; Falgayrac, Guillaume; Bertrand, Benoit; Naji, Stephan; Devos, Olivier; Balsack, Clara; Delannoy, Yann; Penel, Guillaume

    2016-01-01

    Acellular extrinsic fiber cementum is a mineralized tissue that covers the cervical half of the tooth root surface. It contains mainly extrinsic or Sharpey’s fibers that run perpendicular to the root surface to anchor the tooth via the periodontal ligament. Acellular cementum is continuously and slowly produced throughout life and exhibits an alternating bright and dark pattern under light microscopy. However, although a better understanding of the structural background of acellular cementum is relevant to many fields, such as cementochronology, periodontology and tissue engineering, acellular cementum remains rarely studied and poorly understood. In this work, we studied the acellular cementum at the incremental line scale of five human mandibular canines using polarized Raman spectroscopy. We provided Raman imaging analysis and polarized acquisitions as a function of the angular orientation of the sample. The results showed that mineral crystals were always parallel to collagen fibrils, and at a larger scale, we proposed an organizational model in which we found radial collagen fibers, “orthogonal” to the cementum surface, and “non-orthogonal” fibers, which consist of branching and bending radial fibers. Concerning the alternating pattern, we observed that the dark lines corresponded to smaller, more mineralized and probably more organized bands, which is consistent with the zoological assumption that incremental lines are produced during a winter rest period of acellular cementum growth. PMID:27936010

  3. Tetanus–diphtheria–acellular pertussis vaccination for adults: an update

    Science.gov (United States)

    2017-01-01

    Although tetanus and diphtheria have become rare in developed countries, pertussis is still endemic in some developed countries. These are vaccine-preventable diseases and vaccination for adults is important to prevent the outbreak of disease. Strategies for tetanus, diphtheria, and pertussis vaccines vary from country to country. Each country needs to monitor consistently epidemiology of the diseases and changes vaccination policies accordingly. Recent studies showed that tetanus–diphtheria–acellular pertussis vaccine for adults is effective and safe to prevent pertussis disease in infants. However, vaccine coverage still remains low than expected and seroprevalence of protective antibodies levels for tetanus, diphtheria, and pertussis decline with aging. The importance of tetanus–diphtheria–acellular pertussis vaccine administration should be emphasized for the protection of young adult and elderly people also, not limited to children. PMID:28168170

  4. Cytocompatibility and biologic characteristics of synthetic scaffold materials of rabbit acellular vascular matrix combining with human-like collagen I.

    Science.gov (United States)

    Liu, Xuqian; Wang, Jie; Dong, Fusheng; Song, Peng; Tian, Songbo; Li, Hexiang; Hou, Yali

    2017-10-01

    Scaffold material provides a three-dimensional growing environment for seed cells in the research field of tissue engineering. In the present study, rabbit arterial blood vessel cells were chemically removed with trypsin and Triton X-100 to prepare rabbit acellular vascular matrix scaffold material. Observation by He&Masson staining revealed that no cellular components or nuclei existed in the vascular intima and media after decellularization. Human-like collagen I was combined with acellular vascular matrix by freeze-drying to prepare an acellular vascular matrix-0.25% human-like collagen I scaffold to compensate for the extracellular matrix loss during the decellularization process. We next performed a series of experiments to test the water absorbing quality, biomechanics, pressure resistance, cytotoxicity, and ultra-micro structure of the acellular vascular matrix composite material and natural rabbit artery and found that the acellular vascular matrix-0.25% human-like collagen I material behaved similarly to natural rabbit artery. In conclusion, the acellular vascular matrix-0.25% human-like collagen I composite material provides a new approach and lays the foundation for novel scaffold material research into tissue engineering of blood vessels.

  5. Nanopatterned acellular valve conduits drive the commitment of blood-derived multipotent cells

    Directory of Open Access Journals (Sweden)

    Di Liddo R

    2016-10-01

    Full Text Available Rosa Di Liddo,1,2 Paola Aguiari,3 Silvia Barbon,1,2 Thomas Bertalot,1 Amit Mandoli,1 Alessia Tasso,1 Sandra Schrenk,1 Laura Iop,3 Alessandro Gandaglia,3 Pier Paolo Parnigotto,2 Maria Teresa Conconi,1,2 Gino Gerosa31Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 2Foundation for Biology and Regenerative Medicine, Tissue Engineering and Signaling ONLUS, 3Department of Cardiac, Thoracic and Vascular Sciences, University of Padova, Padova, Italy Abstract: Considerable progress has been made in recent years toward elucidating the correlation among nanoscale topography, mechanical properties, and biological behavior of cardiac valve substitutes. Porcine TriCol scaffolds are promising valve tissue engineering matrices with demonstrated self-repopulation potentiality. In order to define an in vitro model for investigating the influence of extracellular matrix signaling on the growth pattern of colonizing blood-derived cells, we cultured circulating multipotent cells (CMC on acellular aortic (AVL and pulmonary (PVL valve conduits prepared with TriCol method and under no-flow condition. Isolated by our group from Vietnamese pigs before heart valve prosthetic implantation, porcine CMC revealed high proliferative abilities, three-lineage differentiative potential, and distinct hematopoietic/endothelial and mesenchymal properties. Their interaction with valve extracellular matrix nanostructures boosted differential messenger RNA expression pattern and morphologic features on AVL compared to PVL, while promoting on both matrices the commitment to valvular and endothelial cell-like phenotypes. Based on their origin from peripheral blood, porcine CMC are hypothesized in vivo to exert a pivotal role to homeostatically replenish valve cells and contribute to hetero- or allograft colonization. Furthermore, due to their high responsivity to extracellular matrix nanostructure signaling, porcine CMC could be useful for a preliminary

  6. Immunogenicity and safety of an acellular pertussis, diphtheria ...

    African Journals Online (AJOL)

    Objective. To assess the immunogenicity and safety data for a pentavalent combination vaccine containing acellular pertussis, inactivated poliovirus, and Haemophilus influenzae (Hib) polysaccharide-conjugate antigens. Methods. A DTaP-IPV//PRP~T vaccine (Pentaxim™) was given at 6, 10 and 14 weeks of age to 212 ...

  7. Role of Demyelination Efficiency within Acellular Nerve Scaffolds during Nerve Regeneration across Peripheral Defects

    Directory of Open Access Journals (Sweden)

    Meiqin Cai

    2017-01-01

    Full Text Available Hudson’s optimized chemical processing method is the most commonly used chemical method to prepare acellular nerve scaffolds for the reconstruction of large peripheral nerve defects. However, residual myelin attached to the basal laminar tube has been observed in acellular nerve scaffolds prepared using Hudson’s method. Here, we describe a novel method of producing acellular nerve scaffolds that eliminates residual myelin more effectively than Hudson’s method through the use of various detergent combinations of sulfobetaine-10, sulfobetaine-16, Triton X-200, sodium deoxycholate, and peracetic acid. In addition, the efficacy of this new scaffold in repairing a 1.5 cm defect in the sciatic nerve of rats was examined. The modified method produced a higher degree of demyelination than Hudson’s method, resulting in a minor host immune response in vivo and providing an improved environment for nerve regeneration and, consequently, better functional recovery. A morphological study showed that the number of regenerated axons in the modified group and Hudson group did not differ. However, the autograft and modified groups were more similar in myelin sheath regeneration than the autograft and Hudson groups. These results suggest that the modified method for producing a demyelinated acellular scaffold may aid functional recovery in general after nerve defects.

  8. Biomimetic acellular detoxified glutaraldehyde cross-linked bovine pericardium for tissue engineering

    International Nuclear Information System (INIS)

    Mathapati, Santosh; Bishi, Dillip Kumar; Guhathakurta, Soma; Cherian, Kotturathu Mammen; Venugopal, Jayarama Reddy; Ramakrishna, Seeram; Verma, Rama Shanker

    2013-01-01

    Glutaraldehyde (GLUT) processing, cellular antigens, calcium ions in circulation, and phospholipids present in the native tissue are predominantly responsible for calcification, degeneration, and lack of natural microenvironment for host progenitor cell migration in tissue implants. The study presents an improved methodology for adhesion and proliferation of endothelial progenitor cells (EPCs) without significant changes in biomechanical and biodegradation properties of the processed acellular bovine pericardium. The anti-calcification potential of the processed tissue was enhanced by detoxification of GLUT-cross-linked bovine pericardium by decellularization, pretreating it with ethanol or removing the free aldehydes by citric acid treatment and lyophilization. The treated tissues were assessed for biomechanical properties, GLUT ligand quantification, adhesion, proliferation of EPCs, and biodegradability. The results indicate that there was no significant change in biomechanical properties and biodegradability when enzymatic hydrolysis (p > 0.05) is employed in detoxified acellular GLUT cross-linked tissue (DBP–G–CA–ET), compared with the native detoxified GLUT cross-linked bovine pericardium (NBP–G–CA–ET). DBP–G–CA–ET exhibited a significant (p > 0.05) increase in the viability of EPCs and cell adhesion as compared to acellular GLUT cross-linked bovine pericardium (p < 0.05). Lyophilized acellular detoxified GLUT cross-linked bovine pericardium, employed in our study as an alternative to conventional GLUT cross-linked bovine pericardium, might provide longer durability and better biocompatibility, and reduce calcification. The developed bovine pericardium patches could be used in cardiac reconstruction and repair, arteriotomy, soft tissue repair, and general surgical procedures with tissue regeneration dimensions. - Highlights: ► We improved the quality of patch biomaterial for cardiovascular surgical procedures. ► Bovine pericardium was

  9. Biomimetic acellular detoxified glutaraldehyde cross-linked bovine pericardium for tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Mathapati, Santosh; Bishi, Dillip Kumar [Stem Cell and Molecular Biology Laboratory, Department of Biotechnology, Indian Institute of Technology Madras, Chennai (India); Frontier Lifeline Pvt Ltd. and Dr. K. M. Cherian Heart Foundation, Mogappair, Chennai (India); Healthcare and Energy Materials Laboratory, NUSNNI, Faculty of Engineering, National University of Singapore (Singapore); Guhathakurta, Soma [Departmet of Engineering Design, Indian Institute of Technology Madras, Chennai (India); Cherian, Kotturathu Mammen [Frontier Lifeline Pvt Ltd. and Dr. K. M. Cherian Heart Foundation, Mogappair, Chennai (India); Venugopal, Jayarama Reddy; Ramakrishna, Seeram [Healthcare and Energy Materials Laboratory, NUSNNI, Faculty of Engineering, National University of Singapore (Singapore); Verma, Rama Shanker, E-mail: vermars@iitm.ac.in [Stem Cell and Molecular Biology Laboratory, Department of Biotechnology, Indian Institute of Technology Madras, Chennai (India)

    2013-04-01

    Glutaraldehyde (GLUT) processing, cellular antigens, calcium ions in circulation, and phospholipids present in the native tissue are predominantly responsible for calcification, degeneration, and lack of natural microenvironment for host progenitor cell migration in tissue implants. The study presents an improved methodology for adhesion and proliferation of endothelial progenitor cells (EPCs) without significant changes in biomechanical and biodegradation properties of the processed acellular bovine pericardium. The anti-calcification potential of the processed tissue was enhanced by detoxification of GLUT-cross-linked bovine pericardium by decellularization, pretreating it with ethanol or removing the free aldehydes by citric acid treatment and lyophilization. The treated tissues were assessed for biomechanical properties, GLUT ligand quantification, adhesion, proliferation of EPCs, and biodegradability. The results indicate that there was no significant change in biomechanical properties and biodegradability when enzymatic hydrolysis (p > 0.05) is employed in detoxified acellular GLUT cross-linked tissue (DBP–G–CA–ET), compared with the native detoxified GLUT cross-linked bovine pericardium (NBP–G–CA–ET). DBP–G–CA–ET exhibited a significant (p > 0.05) increase in the viability of EPCs and cell adhesion as compared to acellular GLUT cross-linked bovine pericardium (p < 0.05). Lyophilized acellular detoxified GLUT cross-linked bovine pericardium, employed in our study as an alternative to conventional GLUT cross-linked bovine pericardium, might provide longer durability and better biocompatibility, and reduce calcification. The developed bovine pericardium patches could be used in cardiac reconstruction and repair, arteriotomy, soft tissue repair, and general surgical procedures with tissue regeneration dimensions. - Highlights: ► We improved the quality of patch biomaterial for cardiovascular surgical procedures. ► Bovine pericardium was

  10. Inverse m-matrices and ultrametric matrices

    CERN Document Server

    Dellacherie, Claude; San Martin, Jaime

    2014-01-01

    The study of M-matrices, their inverses and discrete potential theory is now a well-established part of linear algebra and the theory of Markov chains. The main focus of this monograph is the so-called inverse M-matrix problem, which asks for a characterization of nonnegative matrices whose inverses are M-matrices. We present an answer in terms of discrete potential theory based on the Choquet-Deny Theorem. A distinguished subclass of inverse M-matrices is ultrametric matrices, which are important in applications such as taxonomy. Ultrametricity is revealed to be a relevant concept in linear algebra and discrete potential theory because of its relation with trees in graph theory and mean expected value matrices in probability theory. Remarkable properties of Hadamard functions and products for the class of inverse M-matrices are developed and probabilistic insights are provided throughout the monograph.

  11. Natural flexible dermal armor.

    Science.gov (United States)

    Yang, Wen; Chen, Irene H; Gludovatz, Bernd; Zimmermann, Elizabeth A; Ritchie, Robert O; Meyers, Marc A

    2013-01-04

    Fish, reptiles, and mammals can possess flexible dermal armor for protection. Here we seek to find the means by which Nature derives its protection by examining the scales from several fish (Atractosteus spatula, Arapaima gigas, Polypterus senegalus, Morone saxatilis, Cyprinius carpio), and osteoderms from armadillos, alligators, and leatherback turtles. Dermal armor has clearly been developed by convergent evolution in these different species. In general, it has a hierarchical structure with collagen fibers joining more rigid units (scales or osteoderms), thereby increasing flexibility without significantly sacrificing strength, in contrast to rigid monolithic mineral composites. These dermal structures are also multifunctional, with hydrodynamic drag (in fish), coloration for camouflage or intraspecies recognition, temperature and fluid regulation being other important functions. The understanding of such flexible dermal armor is important as it may provide a basis for new synthetic, yet bioinspired, armor materials. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Potential Dermal Exposure to Flonicamid and Risk Assessment of Applicators During Treatment in Apple Orchards.

    Science.gov (United States)

    Zhao, Mei-Ai; Yu, Aili; Zhu, Yong-Zhe; Kim, Jeong-Han

    2015-01-01

    Exposure and risk assessments of flonicamid for applicators were performed in apple orchards in Korea. Fifteen experiments were done with two experienced applicators under typical field conditions using a speed sprayer. In this study, cotton gloves, socks, masks, and dermal patches were used to monitor potential dermal exposure to flonicamid, and personal air samplers with XAD-2 resin and glass fiber filter were used to monitor potential inhalation exposure. The analytical methods were validated for the limit of detection, limit of quantitation, reproducibility, linearity of the calibration curve, and recovery of flonicamid from various exposure matrices. The results were encouraging and acceptable for an exposure study. The applicability of XAD-2 resin was evaluated via a trapping efficiency and breakthrough test. During the mixing/loading, the average total dermal exposure was 22.6 μg of flonicamid, corresponding to 4.5×10(-5)% of the prepared amount. For the spraying, the potential dermal exposure was 9.32 mg, and the ratio to applied amount was 1.9 × 10(-2%). The primary exposed body parts were the thigh (2.90 mg), upper arm (1.75 mg), and lower leg (1.66 mg). By comparison, absorbable quantity of exposure was small, only 1.62 μg (3.2×10(-6)%). The margin of safety (MOS) were calculated for risk assessment, in all sets of trials, MOS > 1, indicating the exposure level of flonicamid was considered to be safe in apple orchards. Although this was a limited study, it provided a good estimate of flonicamid exposure for orchard applicators.

  13. Method for detection of a suspect viral deoxyribonucleic acid in an acellular biological fluid

    Energy Technology Data Exchange (ETDEWEB)

    Berninger, M S

    1982-10-06

    A method for evaluating an acellular biological fluid for the presence of a suspect viral DNA, such as DNA of the Hepatitis-B virus, is described. The acellular biological fluid is treated to immobilize in denatured form the DNAs including the suspect viral DNA on a solid substrate. This substrate is contacted with a solution including radioisotopically-labelled suspect viral denatured DNA to renature the immobilized suspect viral native DNA. The solid substrate is then evaluated for radioisotopically-labelled suspect viral renatured DNA.

  14. Method for detection of a suspect viral deoxyribonucleic acid in an acellular biological fluid

    International Nuclear Information System (INIS)

    Berninger, M.S.

    1982-01-01

    A method for evaluating an acellular biological fluid for the presence of a suspect viral DNA, such as DNA of the Hepatitis-B virus, is described. The acellular biological fluid is treated to immobilize in denatured form the DNAs including the suspect viral DNA on a solid substrate. This substrate is contacted with a solution including radioisotopically-labelled suspect viral denatured DNA to renature the immobilized suspect viral native DNA. The solid substrate is then evaluated for radioisotopically-labelled suspect viral renatured DNA. (author)

  15. Focal dermal hypoplasia without focal dermal hypoplasia

    NARCIS (Netherlands)

    Contreras-Capetillo, Silvina N.; Lombardi, Maria Paola; Pinto-Escalante, Doris; Hennekam, Raoul C.

    2014-01-01

    Focal dermal hypoplasia (FDH; Goltz-Gorlin syndrome) is an X-linked dominant disorder affecting mainly tissues of ectodermal and mesodermal origin. The phenotype is characterized by hypoplastic linear skin lesions, eye malformations, hair and teeth anomalies, and multiple limbs malformations. The

  16. Biological background of dermal substitutes

    NARCIS (Netherlands)

    van der Veen, V. C.; van der Wal, M.B.; van Leeuwen, M.C.; Ulrich, M.; Middelkoop, E.

    2010-01-01

    Dermal substitutes are of major importance in treating full thickness skin defects, both in acute and chronic wounds. In this review we will outline specific requirements of three classes of dermal substitutes:-natural biological materials, with a more or less intact extracellular matrix

  17. Development of a pericardial acellular matrix biomaterial: biochemical and mechanical effects of cell extraction.

    Science.gov (United States)

    Courtman, D W; Pereira, C A; Kashef, V; McComb, D; Lee, J M; Wilson, G J

    1994-06-01

    There is evidence to suggest that the cellular components of homografts and bioprosthetic xenografts may contribute to calcification or immunogenic reactions. A four-step detergent and enzymatic extraction process has been developed to remove cellular components from bovine pericardial tissue. The process results in an acellular matrix material consisting primarily of elastin, insoluble collagen, and tightly bound glycosaminoglycans. Light and electron microscopy confirmed that nearly all cellular constituents are removed without ultrastructural evidence of damage to fibrous components. Collagen denaturation temperatures remained unaltered. Biochemical analysis confirmed the retention of collagen and elastin and some differential extraction of glycosaminoglycans. Low strain rate fracture testing and high strain rate viscoelastic characterization showed that, with the exception of slightly increased stress relaxation, the mechanical properties of the fresh tissue were preserved in the pericardial acellular matrix. Crosslinking of the material in glutaraldehyde or poly(glycidyl ether) produced mechanical changes consistent with the same treatments of fresh tissue. The pericardial acellular matrix is a promising approach to the production of biomaterials for heart valve or cardiovascular patching applications.

  18. Repair of articular cartilage defects by tissue-engineered cartilage constructed with adipose-derived stem cells and acellular cartilaginous matrix in rabbits.

    Science.gov (United States)

    Wang, Z J; An, R Z; Zhao, J Y; Zhang, Q; Yang, J; Wang, J B; Wen, G Y; Yuan, X H; Qi, X W; Li, S J; Ye, X C

    2014-06-18

    After injury, inflammation, or degeneration, articular cartilage has limited self-repair ability. We aimed to explore the feasibility of repair of articular cartilage defects with tissue-engineered cartilage constructed by acellular cartilage matrices (ACMs) seeded with adipose-derived stem cells (ADSCs). The ADSCs were isolated from 3-month-old New Zealand albino rabbit by using collagenase and cultured and amplified in vitro. Fresh cartilage isolated from adult New Zealand albino rabbit were freeze-dried for 12 h and treated with Triton X-100, DNase, and RNase to obtain ACMs. ADSCs were seeded in the acellular cartilaginous matrix at 2x10(7)/mL, and cultured in chondrogenic differentiation medium for 2 weeks to construct tissue-engineered cartilage. Twenty-four New Zealand white rabbits were randomly divided into A, B, and C groups. Engineered cartilage was transplanted into cartilage defect position of rabbits in group A, group B obtained ACMs, and group C did not receive any transplants. The rabbits were sacrificed in week 12. The restored tissue was evaluated using macroscopy, histology, immunohistochemistry, and transmission electron microscopy (TEM). In the tissue-engineered cartilage group (group A), articular cartilage defects of the rabbits were filled with chondrocyte-like tissue with smooth surface. Immunohistochemistry showed type II-collagen expression and Alcian blue staining was positive. TEM showed chondrocytes in the recesses, with plenty of secretary matrix particles. In the scaffold group (group B), the defect was filled with fibrous tissue. No repaired tissue was found in the blank group (group C). Tissue-engineered cartilage using ACM seeded with ADSCs can help repair articular cartilage defects in rabbits.

  19. Inductive capacity of irradiated dermal papillae

    International Nuclear Information System (INIS)

    Ibrahim, L.; Wright, E.A.

    1977-01-01

    It is stated that the importance of the dermal papilla for the maintenance and control of hair cycles in mammals has long been recognised, but there has been little direct evidence of its mode of functioning. Permanent removal of rat body hair has resulted from large doses of X-radiation and it was believed that this caused destruction of the dermal papilla, which in turn resulted in permanent epilation. A study is here reported on the effect of heavy doses of irradiation on the dermal papilla and epithelial elements of the hair follicles of mice and rats. It was found that the high doses that caused permanent epilation destroyed the epithelium but left the dermal papilla anatomically and functionally intact, so that even on transplantation it could induce a series of new hairs. The dose employed was 2500 R of X-radiation for mice or 5000 R for rats. Hairs after transplantation were shorter than normal and had a slower rate of growth; depending on the size of the transplanted dermal papilla. The hairs become shorter with successive cycles of irradiation. (U.K.)

  20. Skin equivalent tissue-engineered construct: co-cultured fibroblasts/ keratinocytes on 3D matrices of sericin hope cocoons.

    Directory of Open Access Journals (Sweden)

    Sunita Nayak

    Full Text Available The development of effective and alternative tissue-engineered skin replacements to autografts, allografts and xenografts has became a clinical requirement due to the problems related to source of donor tissue and the perceived risk of disease transmission. In the present study 3D tissue engineered construct of sericin is developed using co-culture of keratinocytes on the upper surface of the fabricated matrices and with fibroblasts on lower surface. Sericin is obtained from "Sericin Hope" silkworm of Bombyx mori mutant and is extracted from cocoons by autoclave. Porous sericin matrices are prepared by freeze dried method using genipin as crosslinker. The matrices are characterized biochemically and biophysically. The cell proliferation and viability of co-cultured fibroblasts and keratinocytes on matrices for at least 28 days are observed by live/dead assay, Alamar blue assay, and by dual fluorescent staining. The growth of the fibroblasts and keratinocytes in co-culture is correlated with the expression level of TGF-β, b-FGF and IL-8 in the cultured supernatants by enzyme-linked immunosorbent assay. The histological analysis further demonstrates a multi-layered stratified epidermal layer of uninhibited keratinocytes in co-cultured constructs. Presence of involucrin, collagen IV and the fibroblast surface protein in immuno-histochemical stained sections of co-cultured matrices indicates the significance of paracrine signaling between keratinocytes and fibroblasts in the expression of extracellular matrix protein for dermal repair. No significant amount of pro inflammatory cytokines (TNF-α, IL-1β and nitric oxide production are evidenced when macrophages grown on the sericin matrices. The results all together depict the potentiality of sericin 3D matrices as skin equivalent tissue engineered construct in wound repair.

  1. Porosity of porcine bladder acellular matrix: impact of ACM thickness.

    Science.gov (United States)

    Farhat, Walid; Chen, Jun; Erdeljan, Petar; Shemtov, Oren; Courtman, David; Khoury, Antoine; Yeger, Herman

    2003-12-01

    The objectives of this study are to examine the porosity of bladder acellular matrix (ACM) using deionized (DI) water as the model fluid and dextran as the indicator macromolecule, and to correlate the porosity to the ACM thickness. Porcine urinary bladders from pigs weighing 20-50 kg were sequentially extracted in detergent containing solutions, and to modify the ACM thickness, stretched bladders were acellularized in the same manner. Luminal and abluminal ACM specimens were subjected to fixed static DI water pressure (10 cm); and water passing through the specimens was collected at specific time interval. While for the macromolecule porosity testing, the diffusion rate and direction of 10,000 MW fluoroescein-labeled dextrans across the ACM specimens mounted in Ussing's chambers were measured. Both experiments were repeated on the thin stretched ACM. In both ACM types, the fluid porosity in both directions did not decrease with increased test duration (3 h); in addition, the abluminal surface was more porous to fluid than the luminal surface. On the other hand, when comparing thin to thick ACM, the porosity in either direction was higher in the thick ACM. Macromolecule porosity, as measured by absorbance, was higher for the abluminal thick ACM than the luminal side, but this characteristic was reversed in the thin ACM. Comparing thin to thick ACM, the luminal side in the thin ACM was more porous to dextran than in the thick ACM, but this characteristic was reversed for the abluminal side. The porcine bladder ACM possesses directional porosity and acellularizing stretched urinary bladders may increase structural density and alter fluid and macromolecule porosity. Copyright 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 970-974, 2003

  2. Genetics Home Reference: focal dermal hypoplasia

    Science.gov (United States)

    ... in people with focal dermal hypoplasia is an omphalocele , which is an opening in the wall of ... Dermal Hypoplasia MedlinePlus Encyclopedia: Ectodermal dysplasia MedlinePlus Encyclopedia: Omphalocele General Information from MedlinePlus (5 links) Diagnostic Tests ...

  3. From dermal exposure to internal dose

    NARCIS (Netherlands)

    Sandt, J.J.M. van de; Dellarco, M.; Hemmen, J.J. van

    2007-01-01

    Exposure scenarios form an essential basis for chemical risk assessment reports under the new EU chemicals regulation REACH (Registration, Evaluation, Authorisation and restriction of Chemicals). In case the dermal route of exposure is predominant, information on both exposure and dermal

  4. Risk of Brain Damage Following Pertussis Immunization with Whole-Cell cf Acellular Vaccines

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-06-01

    Full Text Available Serious neurological disorders reported following whole-cell (WC in comparison to acellular (AC pertussis vaccines (PV were evaluated by the Genetic Centers of America, Silver Spring, MD.

  5. Dermal uptake of petroleum substances.

    Science.gov (United States)

    Jakasa, Ivone; Kezic, Sanja; Boogaard, Peter J

    2015-06-01

    Petroleum products are complex substances comprising varying amounts of linear and branched alkanes, alkenes, cycloalkanes, and aromatics which may penetrate the skin at different rates. For proper interpretation of toxic hazard data, understanding their percutaneous absorption is of paramount importance. The extent and significance of dermal absorption of eight petroleum substances, representing different classes of hydrocarbons, was evaluated. Literature data on the steady-state flux and permeability coefficient of these substances were evaluated and compared to those predicted by mathematical models. Reported results spanned over 5-6 orders of magnitude and were largely dependent on experimental conditions in particular on the type of the vehicle used. In general, aromatic hydrocarbons showed higher dermal absorption than more lipophilic aliphatics with similar molecular weight. The results showed high variation and were largely influenced by experimental conditions emphasizing the need of performing the experiments under "in use" scenario. The predictive models overestimated experimental absorption. The overall conclusion is that, based on the observed percutaneous penetration data, dermal exposure to petroleum hydrocarbons, even of aromatics with highest dermal absorption is limited and highly unlikely to be associated with health risks under real use scenarios. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. Primary cell culture and morphological characterization of canine dermal papilla cells and dermal fibroblasts.

    Science.gov (United States)

    Bratka-Robia, Christine B; Mitteregger, Gerda; Aichinger, Amanda; Egerbacher, Monika; Helmreich, Magdalena; Bamberg, Elmar

    2002-02-01

    Skin biopsies were taken from female dogs, the primary hair follicles isolated and the dermal papilla dissected. After incubation in supplemented Amniomax complete C100 medium in 24-well culture plates, the dermal papilla cells (DPC) grew to confluence within 3 weeks. Thereafter, they were subcultivated every 7 days. Dermal fibroblast (DFB) cultures were established by explant culture of interfollicular dermis in serum-free medium, where they reached confluence in 10 days. They were subcultivated every 5 days. For immunohistochemistry, cells were grown on cover slips for 24 h, fixed and stained with antibodies against collagen IV and laminin. DPC showed an aggregative growth pattern and formation of pseudopapillae. Intensive staining for collagen IV and laminin could be observed until the sixth passage. DFB grew as branching, parallel lines and showed only weak staining for collagen IV and laminin.

  7. Dermal extracellular lipid in birds.

    Science.gov (United States)

    Stromberg, M W; Hinsman, E J; Hullinger, R L

    1990-01-01

    A light and electron microscopic study of the skin of domestic chickens, seagulls, and antarctic penguins revealed abundant extracellular dermal lipid and intracellular epidermal lipid. Dermal lipid appeared ultrastructurally as extracellular droplets varying from less than 1 micron to more than 25 microns in diameter. The droplets were often irregularly contoured, sometimes round, and of relatively low electron density. Processes of fibrocytes were often seen in contact with extracellular lipid droplets. Sometimes a portion of such a droplet was missing, and this missing part appeared to have been "digested away" by the cell process. In places where cells or cell processes are in contact with fact droplets, there are sometimes extracellular membranous whorls or fragments which have been associated with the presence of fatty acids. Occasionally (in the comb) free fat particles were seen in intimate contact with extravasated erythrocytes. Fat droplets were seen in the lumen of small dermal blood and lymph vessels. We suggest that the dermal extracellular lipid originates in the adipocyte layer and following hydrolysis the free fatty acids diffuse into the epidermis. Here they become the raw material for forming the abundant neutral lipid contained in many of the epidermal cells of both birds and dolphins. The heretofore unreported presence and apparently normal utilization of abundant extracellular lipid in birds, as well as the presence of relatively large droplets of neutral lipid in dermal vessels, pose questions which require a thorough reappraisal of present concepts of the ways in which fat is distributed and utilized in the body.

  8. Mesenchymal stem cells induce dermal fibroblast responses to injury

    International Nuclear Information System (INIS)

    Smith, Andria N.; Willis, Elise; Chan, Vincent T.; Muffley, Lara A.; Isik, F. Frank; Gibran, Nicole S.; Hocking, Anne M.

    2010-01-01

    Although bone marrow-derived mesenchymal stem cells have been shown to promote repair when applied to cutaneous wounds, the mechanism for this response remains to be determined. The aim of this study was to determine the effects of paracrine signaling from mesenchymal stem cells on dermal fibroblast responses to injury including proliferation, migration and expression of genes important in wound repair. Dermal fibroblasts were co-cultured with bone marrow-derived mesenchymal stem cells grown in inserts, which allowed for paracrine interactions without direct cell contact. In this co-culture model, bone marrow-derived mesenchymal stem cells regulate dermal fibroblast proliferation, migration and gene expression. When co-cultured with mesenchymal stem cells, dermal fibroblasts show increased proliferation and accelerated migration in a scratch assay. A chemotaxis assay also demonstrated that dermal fibroblasts migrate towards bone marrow-derived mesenchymal stem cells. A PCR array was used to analyze the effect of mesenchymal stem cells on dermal fibroblast gene expression. In response to mesenchymal stem cells, dermal fibroblasts up-regulate integrin alpha 7 expression and down-regulate expression of ICAM1, VCAM1 and MMP11. These observations suggest that mesenchymal stem cells may provide an important early signal for dermal fibroblast responses to cutaneous injury.

  9. Acellular pertussis vaccines--a question of efficacy.

    Science.gov (United States)

    Olin, P

    1995-06-01

    Whole cell pertussis vaccine is considered to offer at least 80% protection against typical whooping cough. The quest for an equally effective but less reactogenic vaccine is now drawing to a close. During the forthcoming year a number of efficacy trials of acellular pertussis vaccines will be terminated. A variety of vaccines containing one, two, three or five purified pertussis antigens are being tested in Germany, Italy, Senegal and Sweden. About 30,000 infants have been enrolled in placebo-controlled studies and more than 100,000 in whole cell vaccine-controlled trials. The final plans for analysis of a Swedish placebo-controlled trial of whole cell and acellular vaccines is presented. Due to the unexpected high incidence of pertussis in Sweden during 1993-1994, relative risk comparisons between vaccines will be attempted in that trial, in addition to estimating absolute efficacy. A crucial issue is to what extent data may be compared between trials, given differences in design, vaccination schedules, and chosen endpoints. A primary case definition of laboratory-confirmed pertussis with at least 21 days of paroxysmal cough have been adopted in most trials. Pre-planned meta-analysis using this single endpoint will facilitate comparisons between vaccines. Serological correlates to protection in individuals will be sought in the ongoing placebo-controlled trials. The concept of a serological correlate valid for a vaccinated population but not necessarily for the vaccinated individual, as is the case with Hib vaccines, may turn out to be the only alternative to performing large efficacy trials in the future.

  10. Optimization of human tendon tissue engineering: peracetic acid oxidation for enhanced reseeding of acellularized intrasynovial tendon.

    Science.gov (United States)

    Woon, Colin Y L; Pridgen, Brian C; Kraus, Armin; Bari, Sina; Pham, Hung; Chang, James

    2011-03-01

    Tissue engineering of human flexor tendons combines tendon scaffolds with recipient cells to create complete cell-tendon constructs. Allogenic acellularized human flexor tendon has been shown to be a useful natural scaffold. However, there is difficulty repopulating acellularized tendon with recipient cells, as cell penetration is restricted by a tightly woven tendon matrix. The authors evaluated peracetic acid treatment in optimizing intratendinous cell penetration. Cadaveric human flexor tendons were harvested, acellularized, and divided into experimental groups. These groups were treated with peracetic acid in varying concentrations (2%, 5%, and 10%) and for varying time periods (4 and 20 hours) to determine the optimal treatment protocol. Experimental tendons were analyzed for differences in tendon microarchitecture. Additional specimens were reseeded by incubation in a fibroblast cell suspension at 1 × 10(6) cells/ml. This group was then analyzed for reseeding efficacy. A final group underwent biomechanical studies for strength. The optimal treatment protocol comprising peracetic acid at 5% concentration for 4 hours produced increased scaffold porosity, improving cell penetration and migration. Treated scaffolds did not show reduced collagen or glycosaminoglycan content compared with controls (p = 0.37 and p = 0.65, respectively). Treated scaffolds were cytotoxic to neither attached cells nor the surrounding cell suspension. Treated scaffolds also did not show inferior ultimate tensile stress or elastic modulus compared with controls (p = 0.26 and p = 0.28, respectively). Peracetic acid treatment of acellularized tendon scaffolds increases matrix porosity, leading to greater reseeding. It may prove to be an important step in tissue engineering of human flexor tendon using natural scaffolds.

  11. Task-based dermal exposure models for regulatory risk assessment.

    Science.gov (United States)

    Warren, Nicholas D; Marquart, Hans; Christopher, Yvette; Laitinen, Juha; VAN Hemmen, Joop J

    2006-07-01

    The regulatory risk assessment of chemicals requires the estimation of occupational dermal exposure. Until recently, the models used were either based on limited data or were specific to a particular class of chemical or application. The EU project RISKOFDERM has gathered a considerable number of new measurements of dermal exposure together with detailed contextual information. This article describes the development of a set of generic task-based models capable of predicting potential dermal exposure to both solids and liquids in a wide range of situations. To facilitate modelling of the wide variety of dermal exposure situations six separate models were made for groupings of exposure scenarios called Dermal Exposure Operation units (DEO units). These task-based groupings cluster exposure scenarios with regard to the expected routes of dermal exposure and the expected influence of exposure determinants. Within these groupings linear mixed effect models were used to estimate the influence of various exposure determinants and to estimate components of variance. The models predict median potential dermal exposure rates for the hands and the rest of the body from the values of relevant exposure determinants. These rates are expressed as mg or microl product per minute. Using these median potential dermal exposure rates and an accompanying geometric standard deviation allows a range of exposure percentiles to be calculated.

  12. Adaptive bone formation in acellular vertebrae of sea bass (Dicentrarchus labrax L.)

    NARCIS (Netherlands)

    Kranenbarg, S.; Cleynenbreugel, van T.; Schipper, H.; Leeuwen, van J.L.

    2005-01-01

    Mammalian bone is an active tissue in which osteoblasts and osteoclasts balance bone mass. This process of adaptive modelling and remodelling is probably regulated by strain-sensing osteocytes. Bone of advanced teleosts is acellular yet, despite the lack of osteocytes, it is capable of an adaptive

  13. Dermal Contributions to Human Interfollicular Epidermal Architecture and Self-Renewal

    Directory of Open Access Journals (Sweden)

    Kynan T. Lawlor

    2015-11-01

    Full Text Available The human interfollicular epidermis is renewed throughout life by populations of proliferating basal keratinocytes. Though interfollicular keratinocyte stem cells have been identified, it is not known how self-renewal in this compartment is spatially organized. At the epidermal-dermal junction, keratinocytes sit atop a heterogeneous mix of dermal cells that may regulate keratinocyte self-renewal by influencing local tissue architecture and signalling microenvironments. Focusing on the rete ridges and complementary dermal papillae in human skin, we review the identity and organisation of abundant dermal cells types and present evidence for interactions between the dermal microenvironment and the interfollicular keratinocytes.

  14. Age-related disruption of autophagy in dermal fibroblasts modulates extracellular matrix components

    Energy Technology Data Exchange (ETDEWEB)

    Tashiro, Kanae [Skin Research Department, POLA Chemical Industries, Inc., Yokohama (Japan); Division of Pharmaceutical Cell Biology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka (Japan); Shishido, Mayumi [Skin Research Department, POLA Chemical Industries, Inc., Yokohama (Japan); Fujimoto, Keiko [Division of Pharmaceutical Cell Biology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka (Japan); Organelle Homeostasis Research Center, Kyushu University, Fukuoka (Japan); Hirota, Yuko [Division of Pharmaceutical Cell Biology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka (Japan); Yo, Kazuyuki; Gomi, Takamasa [Skin Research Department, POLA Chemical Industries, Inc., Yokohama (Japan); Tanaka, Yoshitaka, E-mail: tanakay@bioc.phar.kyushu-u.ac.jp [Division of Pharmaceutical Cell Biology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka (Japan); Organelle Homeostasis Research Center, Kyushu University, Fukuoka (Japan)

    2014-01-03

    Highlights: •Autophagosomes accumulate in aged dermal fibroblasts. •Autophagic degradation is impaired in aged dermal fibroblasts. •Autophagy disruption affects extracellular matrix components in dermal fibroblasts. -- Abstract: Autophagy is an intracellular degradative system that is believed to be involved in the aging process. The contribution of autophagy to age-related changes in the human skin is unclear. In this study, we examined the relationship between autophagy and skin aging. Transmission electron microscopy and immunofluorescence microscopy analyses of skin tissue and cultured dermal fibroblasts derived from women of different ages revealed an increase in the number of nascent double-membrane autophagosomes with age. Western blot analysis showed that the amount of LC3-II, a form associated with autophagic vacuolar membranes, was significantly increased in aged dermal fibroblasts compared with that in young dermal fibroblasts. Aged dermal fibroblasts were minimally affected by inhibition of autophagic activity. Although lipofuscin autofluorescence was elevated in aged dermal fibroblasts, the expression of Beclin-1 and Atg5—genes essential for autophagosome formation—was similar between young and aged dermal fibroblasts, suggesting that the increase of autophagosomes in aged dermal fibroblasts was due to impaired autophagic flux rather than an increase in autophagosome formation. Treatment of young dermal fibroblasts with lysosomal protease inhibitors, which mimic the condition of aged dermal fibroblasts with reduced autophagic activity, altered the fibroblast content of type I procollagen, hyaluronan and elastin, and caused a breakdown of collagen fibrils. Collectively, these findings suggest that the autophagy pathway is impaired in aged dermal fibroblasts, which leads to deterioration of dermal integrity and skin fragility.

  15. Age-related disruption of autophagy in dermal fibroblasts modulates extracellular matrix components

    International Nuclear Information System (INIS)

    Tashiro, Kanae; Shishido, Mayumi; Fujimoto, Keiko; Hirota, Yuko; Yo, Kazuyuki; Gomi, Takamasa; Tanaka, Yoshitaka

    2014-01-01

    Highlights: •Autophagosomes accumulate in aged dermal fibroblasts. •Autophagic degradation is impaired in aged dermal fibroblasts. •Autophagy disruption affects extracellular matrix components in dermal fibroblasts. -- Abstract: Autophagy is an intracellular degradative system that is believed to be involved in the aging process. The contribution of autophagy to age-related changes in the human skin is unclear. In this study, we examined the relationship between autophagy and skin aging. Transmission electron microscopy and immunofluorescence microscopy analyses of skin tissue and cultured dermal fibroblasts derived from women of different ages revealed an increase in the number of nascent double-membrane autophagosomes with age. Western blot analysis showed that the amount of LC3-II, a form associated with autophagic vacuolar membranes, was significantly increased in aged dermal fibroblasts compared with that in young dermal fibroblasts. Aged dermal fibroblasts were minimally affected by inhibition of autophagic activity. Although lipofuscin autofluorescence was elevated in aged dermal fibroblasts, the expression of Beclin-1 and Atg5—genes essential for autophagosome formation—was similar between young and aged dermal fibroblasts, suggesting that the increase of autophagosomes in aged dermal fibroblasts was due to impaired autophagic flux rather than an increase in autophagosome formation. Treatment of young dermal fibroblasts with lysosomal protease inhibitors, which mimic the condition of aged dermal fibroblasts with reduced autophagic activity, altered the fibroblast content of type I procollagen, hyaluronan and elastin, and caused a breakdown of collagen fibrils. Collectively, these findings suggest that the autophagy pathway is impaired in aged dermal fibroblasts, which leads to deterioration of dermal integrity and skin fragility

  16. Averaging operations on matrices

    Indian Academy of Sciences (India)

    2014-07-03

    Jul 3, 2014 ... Role of Positive Definite Matrices. • Diffusion Tensor Imaging: 3 × 3 pd matrices model water flow at each voxel of brain scan. • Elasticity: 6 × 6 pd matrices model stress tensors. • Machine Learning: n × n pd matrices occur as kernel matrices. Tanvi Jain. Averaging operations on matrices ...

  17. Midface swelling reveals nasofrontal dermal sinus

    International Nuclear Information System (INIS)

    Houneida, Zaghouani Ben Alaya; Manel, Limeme; Latifa, Harzallah; Habib, Amara; Dejla, Bakir; Chekib, Kraiem

    2012-01-01

    Nasofrontal dermal sinuses are very rare and generally occur in children. This congenital malformation can be revealed by midface swelling, which can be complicated by local infection or neuromeningitis. Such complications make the dermal sinus a life-threatening disease. Two cases of nasofrontal dermal sinuses are reported in this work. The first case is an 11-month-old girl who presented with left orbitonasal soft tissue swelling accompanied by inflammation. Physical examination found fever, left orbitonasal thickening, and a puncture hole letting out pus. Computed tomography revealed microabscesses located at the left orbitonasal soft tissues, a frontal bone defect, and an intracranial cyst. Magnetic resonance imaging showed the transosseous tract between the glabella and the brain and affirmed the epidermoid nature of the intracranial cyst. The second case is a 7-year-old girl who presented with a nasofrontal non-progressive mass that intermittently secreted a yellow liquid through an external orifice located at the glabella. MRI revealed a cystic mass located in the deep layer of the glabellar skin related to an epidermoid cyst with a nasofrontal dermal sinus tract. In both cases, surgical excision was performed, and pathological confirmation was made for the diagnoses of dermal sinuses. The postoperative course was favorable. Through these cases, the authors stress the role of imaging methods in confirming the diagnosis and looking for associated cysts (dermoid and epidermoid) to improve recognition of this rare disease. Knowledge of the typical clinical presentations, imaging manifestations, and most common sites of occurrence of this malformation are needed to formulate a differential diagnosis.

  18. VanderLaan Circulant Type Matrices

    Directory of Open Access Journals (Sweden)

    Hongyan Pan

    2015-01-01

    Full Text Available Circulant matrices have become a satisfactory tools in control methods for modern complex systems. In the paper, VanderLaan circulant type matrices are presented, which include VanderLaan circulant, left circulant, and g-circulant matrices. The nonsingularity of these special matrices is discussed by the surprising properties of VanderLaan numbers. The exact determinants of VanderLaan circulant type matrices are given by structuring transformation matrices, determinants of well-known tridiagonal matrices, and tridiagonal-like matrices. The explicit inverse matrices of these special matrices are obtained by structuring transformation matrices, inverses of known tridiagonal matrices, and quasi-tridiagonal matrices. Three kinds of norms and lower bound for the spread of VanderLaan circulant and left circulant matrix are given separately. And we gain the spectral norm of VanderLaan g-circulant matrix.

  19. Gene Expression Profiling of the Intact Dermal Sheath Cup of Human Hair Follicles.

    Science.gov (United States)

    Niiyama, Shiro; Ishimatsu-Tsuji, Yumiko; Nakazawa, Yosuke; Yoshida, Yuzo; Soma, Tsutomu; Ideta, Ritsuro; Mukai, Hideki; Kishimoto, Jiro

    2018-04-24

    Cells that constitute the dermal papillae of hair follicles might be derived from the dermal sheath, the peribulbar component of which is the dermal sheath cup. The dermal sheath cup is thought to include the progenitor cells of the dermal papillae and possesses hair inductive potential; however, it has not yet been well characterized. This study investigated the gene expression profile of the intact dermal sheath cup, and identified dermal sheath cup signature genes, including extracellular matrix components and BMP-binding molecules, as well as TGF-b1 as an upstream regulator. Among these, GREM2, a member of the BMP antagonists, was found by in situ hybridization to be highly specific to the dermal sheath cup, implying that GREM2 is a key molecule contributing to maintenance of the properties of the dermal sheath cup.

  20. DermAll nanomedicine for allergen-specific immunotherapy.

    Science.gov (United States)

    Garaczi, Edina; Szabó, Kornélia; Francziszti, László; Csiszovszki, Zsolt; Lőrincz, Orsolya; Tőke, Enikő R; Molnár, Levente; Bitai, Tamás; Jánossy, Tamás; Bata-Csörgő, Zsuzsanna; Kemény, Lajos; Lisziewicz, Julianna

    2013-11-01

    Allergen-specific immunotherapy (ASIT) the only disease-modifying treatment for IgE-mediated allergies is characterized with long treatment duration and high risk of side effects. We investigated the safety, immunogenicity and efficacy of a novel ASIT, called DermAll, in an experimental allergic rhinitis model. We designed and characterized DermAll-OVA, a synthetic plasmid pDNA/PEIm nanomedicine expressing ovalbumin (OVA) as model allergen. DermAll-OVA was administered topically with DermaPrep device to target Langerhans cells. To detect the clinical efficacy of DermAll ASIT we quantified the nasal symptoms and characterized the immunomodulatory activity of DermAll ASIT by measuring cytokine secretion after OVA-stimulation of splenocytes and antibodies from the sera. In allergic mice DermAll ASIT was as safe as Placebo, balanced the allergen-induced pathogenic TH2-polarized immune responses, and decreased the clinical symptoms by 52% [32%, 70%] compared to Placebo. These studies suggest that DermAll ASIT is safe and should significantly improve the immunopathology and symptoms of allergic diseases. A novel allergen-specific immunotherapy for IgE-mediated allergies is presented in this paper, using an experimental allergic rhinitis model and a synthetic plasmid pDNA/PEIm nanomedicine expressing ovalbumin as model allergen. Over 50% reduction of symptoms was found as the immune system's balance was favorably altered toward more TH2-polarized immune responses. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Brain abscess as a manifestation of spinal dermal sinus

    Directory of Open Access Journals (Sweden)

    Parisa Emami-Naeini

    2008-09-01

    Full Text Available Parisa Emami-Naeini, Ali Mahdavi, Hamed Ahmadi, Nima Baradaran, Farideh NejatDepartment of Neurosurgery, Children’s Hospital Medical Center, Medical Sciences/University of Tehran, Tehran, IranAbstract: Dermal sinuses have been associated with a wide spectrum of clinical manifestations ranging from asymptomatic to drainage of purulent material from the sinus tract, inclusion tumors, meningitis, and spinal abscess. To date, there has been no documented report of brain abscess as a complication of spinal dermal sinus. Here, we report an 8-month-old girl who was presented initially with a brain abscess at early infancy but lumbar dermal sinus and associated spinal abscess were discovered afterwards. The probable mechanisms of this rare association have been discussed.Keywords: brain abscess, spinal dermal sinus, spinal abscess

  2. Melanogenesis in dermal melanocytes of Japanese Silky chicken embryos.

    Science.gov (United States)

    Ortolani-Machado, C F; Freitas, P F; Faraco, C D

    2009-08-01

    The Japanese Silky chicken (SK) shows dermal and visceral hyperpigmentation. This study characterizes ultrastructurally the melanin granules developing in dermal melanocytes of the dorsal skin of SK, in an attempt to better understand the processes of melanogenesis in these permanently ectopic cells. The steps of melanogenesis are similar to those described for epidermal melanocytes, with melanosomes going from stage I to IV but, in SK, the maturation occurs in the cell body, as well as in the cytoplasmic processes. At stage III, the deposition of melanin is cumulative and can aggregate in rounded structures, which combine to turn into the mature granule. The final destiny of mature melanosomes is still unclear, although it was observed that dermal macrophages can accumulate melanin granules in their phagosomes. Even with the close proximity between melanocytes and other dermal cells, the transference of melanosomes was not observed. Our findings indicate that melanogenesis in dermal melanocytes in SK has the same morphological characteristics found in epidermal melanocytes, but the functional aspect still remains to be elucidated.

  3. Keratinocytes express fibrillin and assemble microfibrils: implications for dermal matrix organization.

    Science.gov (United States)

    Haynes, S L; Shuttleworth, C A; Kielty, C M

    1997-07-01

    Fibrillin-containing microfibrils are key architectural structures of the upper dermis and integral components of the dermal elastic fibre network. Microfibril bundles intercalate into the dermal-epithelial junction and provide an elastic connection between the dermal elastic fibre network and the epidermis. Immunohistochemical studies have suggested that they are laid down both at the dermal-epithelial junction and in the deep dermis. While dermal fibroblasts are responsible for deposition of the elastin and microfibrillar components that comprise the elastic fibres of the deep dermis, the cellular origin of the microfibril bundles that extrude from the dermal-epithelial junction is not well defined. We have used fresh tissues, freshly isolated epidermis and primary human and porcine keratinocyte cultures to investigate the possibility that keratinocytes are responsible for deposition of these microfibrils. We have shown that keratinocytes in vivo and in vitro synthesize both fibrillin-1 and fibrillin-2, and assemble beaded microfibrils concurrently with expression of basement membrane collagen. These observations suggest that keratinocytes co-ordinate the secretion, deposition and assembly of these distinct structural elements of the dermal matrix, and have important implications for skin remodelling.

  4. Anti-endotoxic and antibacterial effects of a dermal substitute coated with host defense peptides.

    Science.gov (United States)

    Kasetty, Gopinath; Kalle, Martina; Mörgelin, Matthias; Brune, Jan C; Schmidtchen, Artur

    2015-01-01

    Biomaterials used during surgery and wound treatment are of increasing importance in modern medical care. In the present study we set out to evaluate the addition of thrombin-derived host defense peptides to human acellular dermis (hAD, i.e. epiflex(®)). Antimicrobial activity of the functionalized hAD was demonstrated using radial diffusion and viable count assays against Gram-negative Escherichia coli, Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus bacteria. Electron microscopy analyses showed that peptide-mediated bacterial killing led to reduced hAD degradation. Furthermore, peptide-functionalized hAD displayed endotoxin-binding activity in vitro, as evidenced by inhibition of NF-κB activation in human monocytic cells (THP-1 cells) and a reduction of pro-inflammatory cytokine production in whole blood in response to lipopolysaccharide stimulation. The dermal substitute retained its anti-endotoxic activity after washing, compatible with results showing that the hAD bound a significant amount of peptide. Furthermore, bacteria-induced contact activation was inhibited by peptide addition to the hAD. E. coli infected hAD, alone, or after treatment with the antiseptic substance polyhexamethylenebiguanide (PHMB), yielded NF-κB activation in THP-1 cells. The activation was abrogated by peptide addition. Thus, thrombin-derived HDPs should be of interest in the further development of new biomaterials with combined antimicrobial and anti-endotoxic functions for use in surgery and wound treatment. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Risk of Children’s Dermal Exposure to Galaxolide through Personal Care Products

    Directory of Open Access Journals (Sweden)

    Patrícia Correia

    2015-04-01

    Full Text Available Galaxolide is the most used fragrance since the early 1990s, and it has been largely detected in environmental and biological matrices. This polycyclic musk is present in almost all of our daily products, so the risk of human exposure is substantial, as it had been proved by its detection in human tissues and fluids. Due to the lack of information about the concentrations found in consumer products, monitoring data is needed for exposure assessment purposes. Dermal contact, mostly by personal care products, seems to be the major route of human exposure to galaxolide, and, due to the immaturity of young children’s skin, exposure consequences can be worse in this population. The main objective of this study was to evaluate galaxolide levels in personal care products used by children of Oporto (Portugal, aged 0–5 years, and relate it with consumer habits. Consumer patterns were obtained through 250 questionnaires to caregivers of Oporto children. The 79 most used products were extracted by a dispersive solid phase extraction methodology known as QuEChERS and galaxolide was determined by High Performance Liquid Chromatography (HPLC with fluorescence detection. The concentrations ranged between 0.001 ± 0.001 mg·kg−1, on a baby wipe, and 300.480 ± 8.819 mg·kg−1, on glycerin soap, which may correspond to an estimated daily dermal exposure of 277.10 ± 0.02 µg·day−1 on the population of Oporto children. This value is in the range of the results observed for adults, although no information of toxicological risk for children is available.

  6. Lichen planus following tetanus-diphtheria-acellular pertussis vaccination: A case report and review of the literature.

    Science.gov (United States)

    Rosengard, Heather C; Wheat, Chikoti M; Tilson, Matthew P; Cuda, Jonathan D

    2018-01-01

    Lichen planus is an inflammatory dermatosis with a prevalence of approximately 1%. Recent meta-analyses show that patients with hepatitis C virus have a 2.5- to 4.5-fold increased risk of developing lichen planus. Lichen planus has also followed vaccinations and has specifically been attributed to the hepatitis B vaccine, the influenza vaccine, and the tetanus-diphtheria-acellular pertussis vaccine. We describe a case of lichen planus in a hepatitis C virus-infected African American male occurring in temporal association with the administration of the tetanus-diphtheria-acellular pertussis vaccine. The patient's presentation was clinically consistent with lichen planus and confirmed by biopsy. It is likely that many cases of vaccine-induced lichen planus have gone unpublished or unrecognized. In areas with high prevalence of hepatitis C virus infection, we may expect to see more cases of vaccine-induced lichen planus especially in light of the updated Centers for Disease Control and Prevention tetanus-diphtheria-acellular pertussis vaccination recommendations. This case serves to educate healthcare providers about vaccine-induced lichen planus and, in particular, the need to counsel hepatitis C virus-infected patients about a potential risk of developing lichen planus following vaccination. We also reflect on current theories suggesting the T-cell-mediated pathogenesis of lichen planus and the role that hepatitis C virus and toxoid or protein vaccines may play in initiating the disease.

  7. Update on botulinum toxin and dermal fillers.

    Science.gov (United States)

    Berbos, Zachary J; Lipham, William J

    2010-09-01

    The art and science of facial rejuvenation is an ever-evolving field of medicine, as evidenced by the continual development of new surgical and nonsurgical treatment modalities. Over the past 10 years, the use of botulinum toxin and dermal fillers for aesthetic purposes has risen sharply. Herein, we discuss properties of several commonly used injectable products and provide basic instruction for their use toward the goal of achieving facial rejuvenation. The demand for nonsurgical injection-based facial rejuvenation products has risen enormously in recent years. Used independently or concurrently, botulinum toxin and dermal filler agents offer an affordable, minimally invasive approach to facial rejuvenation. Botulinum toxin and dermal fillers can be used to diminish facial rhytides, restore facial volume, and sculpt facial contours, thereby achieving an aesthetically pleasing, youthful facial appearance.

  8. Assessment of predictive dermal exposure to chemicals in the work environment

    Directory of Open Access Journals (Sweden)

    Agnieszka Jankowska

    2017-08-01

    Full Text Available Assessment of dermal exposure to chemicals in the work environment is problematic, mainly as a result of the lack of measurement data on occupational exposure to chemicals. Due to common prevalence of occupational skin exposure and its health consequences it is necessary to look for efficient solutions allowing for reliable exposure assessment. The aim of the study is to present predictive models used to assess non-measured dermal exposure, as well as to acquaint Polish users with the principles of the selected model functioning. This paper presents examples of models to assist the employer in the the assessment of occupational exposure associated with the skin contact with chemicals, developed in European Union (EU countries, as well as in countries outside the EU. Based on the literature data dermal exposure models EASE (Estimation and Assessment of Substance Exposure, COSHH Essentials (Control of Substances Hazardous to Health Regulations, DREAM (Dermal Exposure Assessment Method, Stoffenmanager , ECETOC TRA (European Centre for Ecotoxicology and Toxicology of Chemicals Targeted Risk Assessment, MEASE (Metal’s EASE, PHED (Pesticide Handlers Exposure Database, DERM (Dermal Exposure Ranking Method and RISKOFDERM (Risk Assessment of Occupational Dermal Exposure to Chemicals were briefly described. Moreover the characteristics of RISKOFDERM, guidelines for its use, information on input and output data were further detailed. Problem of full work shift dermal exposure assessment is described. An example of exposure assessment using RISKOFDERM and effectiveness evaluation to date were also presented. When no measurements are available, RISKOFDERM allows dermal exposure assessment and thus can improve the risk assessment quality and effectiveness of dermal risk management. Med Pr 2017;68(4:557–569

  9. The radiological features of Goltz syndrome: Focal dermal hypoplasia

    International Nuclear Information System (INIS)

    Boothyrod, A.E.; Hall, C.M.

    1988-01-01

    Two female infants with Goltz syndrome (focal dermal hypoplasia) were recently investigated for severe feeding problems and failure to thrive. Both demonstrated severe skeletal malformations and marked gastrooesophageal reflux with laxity of the hiatus. One child (case 1) exhibited nasal regurgitation during feeding. Interestingly, both children had undergone surgery; Case 1 or a right parasagittal abdominal hernia associated with focal dermal hypoplasia of the abdominal wall and Case 2 for an exomphalos also associated with dermal hypoplasia. This observation suggests more widespread mesodermal abnormality. (orig./GDG)

  10. Merkel Cell Polyomavirus Infection of Animal Dermal Fibroblasts.

    Science.gov (United States)

    Liu, Wei; Krump, Nathan A; MacDonald, Margo; You, Jianxin

    2018-02-15

    Merkel cell polyomavirus (MCPyV) is the first polyomavirus to be associated with human cancer. Mechanistic studies attempting to fully elucidate MCPyV's oncogenic mechanisms have been hampered by the lack of animal models for MCPyV infection. In this study, we examined the ability of MCPyV-GFP pseudovirus (containing a green fluorescent protein [GFP] reporter construct), MCPyV recombinant virions, and several MCPyV chimeric viruses to infect dermal fibroblasts isolated from various model animals, including mouse ( Mus musculus ), rabbit ( Oryctolagus cuniculus ), rat ( Rattus norvegicus ), chimpanzee ( Pan troglodytes ), rhesus macaque ( Macaca mulatta ), patas monkey ( Erythrocebus patas ), common woolly monkey ( Lagothrix lagotricha ), red-chested mustached tamarin ( Saguinus labiatus ), and tree shrew ( Tupaia belangeri ). We found that MCPyV-GFP pseudovirus was able to enter the dermal fibroblasts of all species tested. Chimpanzee dermal fibroblasts were the only type that supported vigorous MCPyV gene expression and viral replication, and they did so to a level beyond that of human dermal fibroblasts. We further demonstrated that both human and chimpanzee dermal fibroblasts produce infectious MCPyV virions that can successfully infect new cells. In addition, rat dermal fibroblasts supported robust MCPyV large T antigen expression after infection with an MCPyV chimeric virus in which the entire enhancer region of the MCPyV early promoter has been replaced with the simian virus 40 (SV40) analog. Our results suggest that viral transcription and/or replication events represent the major hurdle for MCPyV cross-species transmission. The capacity of rat dermal fibroblasts to support MCPyV early gene expression suggests that the rat is a candidate model organism for studying viral oncogene function during Merkel cell carcinoma (MCC) oncogenic progression. IMPORTANCE MCPyV plays an important role in the development of a highly aggressive form of skin cancer, Merkel

  11. Flexible Dermal Armor : Designs Learned from Nature

    OpenAIRE

    Chen, Irene Hsu

    2015-01-01

    Designs derived from nature have become a perfect blueprint for today's engineers and scientists to follow and implement. One particularly noted area is the defense industry, wherein flexible dermal armor inspired by nature has been pioneering many sophisticated technologies and designs in recent years. Designers today are considering borrowing aspects of flexibility and mobility of natural dermal armors to enhance the maneuverability of man-made armor by imitating the following mechanisms : ...

  12. A Dermal Piercing Complicated by Mycobacterium fortuitum

    Science.gov (United States)

    Scroggins-Markle, Leslie; Kelly, Brent

    2013-01-01

    Background. Dermal piercings have recently become a fashion symbol. Common complications include hypertrophic scarring, rejection, local infection, contact allergy, and traumatic tearing. We report a rare case of Mycobacterium fortuitum following a dermal piercing and discuss its medical implications and treatments. Case. A previously healthy 19-year-old woman presented complaining of erythema and edema at the site of a dermal piercing on the right fourth dorsal finger. She was treated with a 10-day course of trimethoprim-sulfamethoxazole and one course of cephalexin by her primary care physician with incomplete resolution. The patient stated that she had been swimming at a local water park daily. A punch biopsy around the dermal stud was performed, and cultures with sensitivities revealed Mycobacterium fortuitum. The patient was treated with clarithromycin and ciprofloxacin for two months receiving full resolution. Discussion. Mycobacterium fortuitum is an infrequent human pathogen. This organism is a Runyon group IV, rapidly growing nontuberculous mycobacteria, often found in water,soil, and dust. Treatment options vary due to the size of the lesion. Small lesions are typically excised, while larger lesions require treatment for 2–6 months with antibiotics. We recommend a high level of suspicion for atypical mycobacterial infections in a piercing resistant to other therapies. PMID:24073343

  13. A Dermal Piercing Complicated by Mycobacterium fortuitum

    Directory of Open Access Journals (Sweden)

    Trisha Patel

    2013-01-01

    Full Text Available Background. Dermal piercings have recently become a fashion symbol. Common complications include hypertrophic scarring, rejection, local infection, contact allergy, and traumatic tearing. We report a rare case of Mycobacterium fortuitum following a dermal piercing and discuss its medical implications and treatments. Case. A previously healthy 19-year-old woman presented complaining of erythema and edema at the site of a dermal piercing on the right fourth dorsal finger. She was treated with a 10-day course of trimethoprim-sulfamethoxazole and one course of cephalexin by her primary care physician with incomplete resolution. The patient stated that she had been swimming at a local water park daily. A punch biopsy around the dermal stud was performed, and cultures with sensitivities revealed Mycobacterium fortuitum. The patient was treated with clarithromycin and ciprofloxacin for two months receiving full resolution. Discussion. Mycobacterium fortuitum is an infrequent human pathogen. This organism is a Runyon group IV, rapidly growing nontuberculous mycobacteria, often found in water,soil, and dust. Treatment options vary due to the size of the lesion. Small lesions are typically excised, while larger lesions require treatment for 2–6 months with antibiotics. We recommend a high level of suspicion for atypical mycobacterial infections in a piercing resistant to other therapies.

  14. Central role of pyrophosphate in acellular cementum formation.

    Directory of Open Access Journals (Sweden)

    Brian L Foster

    Full Text Available Inorganic pyrophosphate (PP(i is a physiologic inhibitor of hydroxyapatite mineral precipitation involved in regulating mineralized tissue development and pathologic calcification. Local levels of PP(i are controlled by antagonistic functions of factors that decrease PP(i and promote mineralization (tissue-nonspecific alkaline phosphatase, Alpl/TNAP, and those that increase local PP(i and restrict mineralization (progressive ankylosis protein, ANK; ectonucleotide pyrophosphatase phosphodiesterase-1, NPP1. The cementum enveloping the tooth root is essential for tooth function by providing attachment to the surrounding bone via the nonmineralized periodontal ligament. At present, the developmental regulation of cementum remains poorly understood, hampering efforts for regeneration. To elucidate the role of PP(i in cementum formation, we analyzed root development in knock-out ((-/- mice featuring PP(i dysregulation.Excess PP(i in the Alpl(-/- mouse inhibited cementum formation, causing root detachment consistent with premature tooth loss in the human condition hypophosphatasia, though cementoblast phenotype was unperturbed. Deficient PP(i in both Ank and Enpp1(-/- mice significantly increased cementum apposition and overall thickness more than 12-fold vs. controls, while dentin and cellular cementum were unaltered. Though PP(i regulators are widely expressed, cementoblasts selectively expressed greater ANK and NPP1 along the root surface, and dramatically increased ANK or NPP1 in models of reduced PP(i output, in compensatory fashion. In vitro mechanistic studies confirmed that under low PP(i mineralizing conditions, cementoblasts increased Ank (5-fold and Enpp1 (20-fold, while increasing PP(i inhibited mineralization and associated increases in Ank and Enpp1 mRNA.Results from these studies demonstrate a novel developmental regulation of acellular cementum, wherein cementoblasts tune cementogenesis by modulating local levels of PP(i, directing and

  15. Dermal fillers for facial soft tissue augmentation.

    Science.gov (United States)

    Dastoor, Sarosh F; Misch, Carl E; Wang, Hom-Lay

    2007-01-01

    Nowadays, patients are demanding not only enhancement to their dental (micro) esthetics, but also their overall facial (macro) esthetics. Soft tissue augmentation via dermal filling agents may be used to correct facial defects such as wrinkles caused by age, gravity, and trauma; thin lips; asymmetrical facial appearances; buccal fold depressions; and others. This article will review the pathogenesis of facial wrinkles, history, techniques, materials, complications, and clinical controversies regarding dermal fillers for soft tissue augmentation.

  16. Post Kala-azar Dermal Leishmaniasis (PKDL) In vivo veritas

    Indian Academy of Sciences (India)

    Immunology LAB-1

    2016-08-26

    Aug 26, 2016 ... 50. 100. 150. 200. 250. 300. 0. 200. 400. 600. 800. 1000. 1200. 1400. 1600 ... Rapid diagnostic tests exist (PKDL?) • Effective ... ld (C t). No: of parasites/ 200 µl of blood. Post Kala Azar Dermal Leishmaniasis (PKDL); dermal ...

  17. Infinite matrices and sequence spaces

    CERN Document Server

    Cooke, Richard G

    2014-01-01

    This clear and correct summation of basic results from a specialized field focuses on the behavior of infinite matrices in general, rather than on properties of special matrices. Three introductory chapters guide students to the manipulation of infinite matrices, covering definitions and preliminary ideas, reciprocals of infinite matrices, and linear equations involving infinite matrices.From the fourth chapter onward, the author treats the application of infinite matrices to the summability of divergent sequences and series from various points of view. Topics include consistency, mutual consi

  18. Relative absorption and dermal loading of chemical substances: Consequences for risk assessment

    NARCIS (Netherlands)

    Buist, H.E.; Schaafsma, G.; Sandt, J.J.M. van de

    2009-01-01

    Quantification of skin absorption is an essential step in reducing the uncertainty of dermal risk assessment. Data from literature indicate that the relative dermal absorption of substances is dependent on dermal loading. Therefore, an internal exposure calculated with absorption data determined at

  19. Complex Wedge-Shaped Matrices: A Generalization of Jacobi Matrices

    Czech Academy of Sciences Publication Activity Database

    Hnětynková, Iveta; Plešinger, M.

    2015-01-01

    Roč. 487, 15 December (2015), s. 203-219 ISSN 0024-3795 R&D Projects: GA ČR GA13-06684S Keywords : eigenvalues * eigenvector * wedge-shaped matrices * generalized Jacobi matrices * band (or block) Krylov subspace methods Subject RIV: BA - General Mathematics Impact factor: 0.965, year: 2015

  20. Regenerative and Antibacterial Properties of Acellular Fish Skin Grafts and Human Amnion/Chorion Membrane: Implications for Tissue Preservation in Combat Casualty Care.

    Science.gov (United States)

    Magnusson, Skuli; Baldursson, Baldur Tumi; Kjartansson, Hilmar; Rolfsson, Ottar; Sigurjonsson, Gudmundur Fertram

    2017-03-01

    Improvised explosive devices and new directed energy weapons are changing warfare injuries from penetrating wounds to large surface area thermal and blast injuries. Acellular fish skin is used for tissue repair and during manufacturing subjected to gentle processing compared to biologic materials derived from mammals. This is due to the absence of viral and prion disease transmission risk, preserving natural structure and composition of the fish skin graft. The aim of this study was to assess properties of acellular fish skin relevant for severe battlefield injuries and to compare those properties with those of dehydrated human amnion/chorion membrane. We evaluated cell ingrowth capabilities of the biological materials with microscopy techniques. Bacterial barrier properties were tested with a 2-chamber model. The microstructure of the acellular fish skin is highly porous, whereas the microstructure of dehydrated human amnion/chorion membrane is mostly nonporous. The fish skin grafts show superior ability to support 3-dimensional ingrowth of cells compared to dehydrated human amnion/chorion membrane (p fish skin is a bacterial barrier for 24 to 48 hours. The unique biomechanical properties of the acellular fish skin graft make it ideal to be used as a conformal cover for severe trauma and burn wounds in the battlefield. Reprint & Copyright © 2017 Association of Military Surgeons of the U.S.

  1. CTRP6 inhibits fibrogenesis in TGF-β1-stimulated human dermal fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Rong-hui, E-mail: fan_ronghuixa@163.com [Department of Burn and Plastic Surgery, Shaanxi Provincial People’s Hospital, Xi’an 710068 (China); Zhu, Xiu-mei; Sun, Yao-wen [Department of Burn and Plastic Surgery, Shaanxi Provincial People’s Hospital, Xi’an 710068 (China); Peng, Hui-zi [Department of Cosmetology Plastic Surgery, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi 710061 (China); Wu, Hang-li; Gao, Wen-jie [Department of Burn and Plastic Surgery, Shaanxi Provincial People’s Hospital, Xi’an 710068 (China)

    2016-07-08

    Skin fibrosis is characterized by excessive proliferation of fibroblasts and overproduction of extracellular matrix (ECM). C1q/tumor necrosis factor-related protein 6 (CTRP6), a member of CTRPs, has been involved in the development of cardiac fibrosis. However, the function and detailed regulatory mechanism of CTRP6 in skin fibrosis remain unclear. The aim of this study was to investigate the effect of CTRP6 on the activation of human dermal fibroblasts. Our results showed that CTRP6 was lowly expressed in scar tissues and transforming growth factor-β1 (TGF-β1)-treated dermal fibroblasts. CTRP6 overexpression significantly inhibited the proliferation of dermal fibroblasts, as well as suppressed the expression of ECM in TGF-β1-treated dermal fibroblasts. Furthermore, CTRP6 overexpression markedly inhibited TGF-β1-induced phosphorylation of Smad3 in dermal fibroblasts. In conclusion, the data reported here demonstrate that CTRP6 is able to inhibit the proliferation and ECM expression in human dermal fibroblasts through suppressing the TGF-β1/Smad3 signaling pathway. These findings suggest that CTRP6 may be a potential therapeutic target for the prevention of skin fibrosis. -- Highlights: •CTRP6 expression was decreased in scar tissues and TGF-β1-treated dermal fibroblasts. •CTRP6 inhibits TGF-β1-induced the proliferation of dermal fibroblasts. •CTRP6 inhibits expression of collagen type I and α-SMA. •CTRP6 inhibits the activation of TGF-β1/Smad3 signaling pathway in dermal fibroblasts.

  2. CTRP6 inhibits fibrogenesis in TGF-β1-stimulated human dermal fibroblasts

    International Nuclear Information System (INIS)

    Fan, Rong-hui; Zhu, Xiu-mei; Sun, Yao-wen; Peng, Hui-zi; Wu, Hang-li; Gao, Wen-jie

    2016-01-01

    Skin fibrosis is characterized by excessive proliferation of fibroblasts and overproduction of extracellular matrix (ECM). C1q/tumor necrosis factor-related protein 6 (CTRP6), a member of CTRPs, has been involved in the development of cardiac fibrosis. However, the function and detailed regulatory mechanism of CTRP6 in skin fibrosis remain unclear. The aim of this study was to investigate the effect of CTRP6 on the activation of human dermal fibroblasts. Our results showed that CTRP6 was lowly expressed in scar tissues and transforming growth factor-β1 (TGF-β1)-treated dermal fibroblasts. CTRP6 overexpression significantly inhibited the proliferation of dermal fibroblasts, as well as suppressed the expression of ECM in TGF-β1-treated dermal fibroblasts. Furthermore, CTRP6 overexpression markedly inhibited TGF-β1-induced phosphorylation of Smad3 in dermal fibroblasts. In conclusion, the data reported here demonstrate that CTRP6 is able to inhibit the proliferation and ECM expression in human dermal fibroblasts through suppressing the TGF-β1/Smad3 signaling pathway. These findings suggest that CTRP6 may be a potential therapeutic target for the prevention of skin fibrosis. -- Highlights: •CTRP6 expression was decreased in scar tissues and TGF-β1-treated dermal fibroblasts. •CTRP6 inhibits TGF-β1-induced the proliferation of dermal fibroblasts. •CTRP6 inhibits expression of collagen type I and α-SMA. •CTRP6 inhibits the activation of TGF-β1/Smad3 signaling pathway in dermal fibroblasts.

  3. Ultrastructural changes following electron irradiation in three-dimensional culture of normal human dermal fibroblasts

    International Nuclear Information System (INIS)

    Han, Chunmao; Ishikura, Naotaka; Tsukada, Sadao

    1994-01-01

    The present study was designed to examine the effect of electron irradiation on fibroblasts and extracellular matrices electron-microscopically. The three-dimensional dermal fibroblast culture was exposed to one, 4 or 10 Gy of electron beams. One day after irradiation, fibroblasts were vacuolated in all irradiated groups and intercellular spaces were increased in a dose-dependent manner. Seven days later, intercellular spaces became dense in both one and 4 Gy groups, although they were still extremely increased in the 10 Gy group. The remaining fibroblasts were still activated in all groups. Thirty days after irradiation, myofibroblastic cells were scarcely observed, but extracellular fine fibrils and collagen fibrils were observed in all irradiated groups. The other ultrastructural findings were similar to those in the control group. In conclusion, electron beams damaged not only cells but also extracellular matrix. The extracellular matrix may be repaired by activated residual fibroblasts, resulting in the mixture of new and old collagen fibrils having different diamters. (N.K.)

  4. DREAM: a method for semi-quantitative dermal exposure assessment

    NARCIS (Netherlands)

    Wendel de Joode, B. van; Brouwer, D.H.; Kromhout, H.; Hemmen, J.J. van

    2003-01-01

    This paper describes a new method (DREAM) for structured, semi-quantitative dermal exposure assessment for chemical or biological agents that can be used in occupational hygiene or epidemiology. It is anticipated that DREAM could serve as an initial assessment of dermal exposure, amongst others,

  5. Dermal reflectivity determined by optical coherence tomography is an indicator of epidermal hyperplasia and dermal edema within inflamed skin

    Science.gov (United States)

    Phillips, Kevin G.; Wang, Yun; Levitz, David; Choudhury, Niloy; Swanzey, Emily; Lagowski, James; Kulesz-Martin, Molly; Jacques, Steven L.

    2011-04-01

    Psoriasis is a common inflammatory skin disease resulting from genetic and environmental alterations of cutaneous immune responses. While numerous therapeutic targets involved in the immunopathogenesis of psoriasis have been identified, the in vivo dynamics of inflammation in psoriasis remain unclear. We undertook in vivo time course focus-tracked optical coherence tomography (OCT) imaging to noninvasively document cutaneous alterations in mouse skin treated topically with Imiquimod (IMQ), an established model of a psoriasis-like disease. Quantitative appraisal of dermal architectural changes was achieved through a two parameter fit of OCT axial scans in the dermis of the form A(x, y, z) = ρ(x, y)exp [ - μ(x, y)z]. Ensemble averaging over 2000 axial scans per mouse in each treatment arm revealed no significant changes in the average dermal attenuation rate, , however the average local dermal reflectivity , decreased significantly following 1, 3, and 6 days of IMQ treatment (p humans.

  6. Comparative developmental dermal toxicity and mutagenicity of carbazole and benzo[a]carbazole

    International Nuclear Information System (INIS)

    Dutson, S.M.; Booth, G.M.; Seegmiller, R.E.; Schaalje, G.B.; Castle, R.N.

    1997-01-01

    The objectives of this study were (1) to determine the developmental toxicity of carbazole and benzo[a]carbazole following daily dermal administration to female Sprague-Dawley rats on days 0 through 20 of gestation and (2) to determine the mutagenicity of these two compounds using a modified version of the Ames assay. These chemicals are of concern because they are found in a variety of environmental matrices including crude oil mixtures. No signs of maternal or developmental toxicity were considered to be related to dermal administration of carbazole at does of 2.5, 25.0, and 250.0 mg/kg. Signs of maternal toxicity considered to be related to administration of benzo[a]carbazole included significantly decreased body-weight gain and decreased absolute-food consumption at a dose of 250.0 mg/kg. Signs of developmental toxicity considered to be related to administration of benzo[a]carbazole included significantly decreased number of total (live and dead combined) and live pups on lactation day 0 as well as significantly decreased average pup weight on lactation days 0 and 4 at a dose of 250.0 mg/kg. Because developmental toxicity following benzo[a]carbazole treatment was observed only at a dose at which maternal toxicity was observed, it is likely that the effects on the offspring are secondary to the treatment effects on the dam. Evidence of toxic effects with benzo[a]carbazole in the absence of effects with carbazole suggests that the substituted benzene ring enhances the biological activity of this compound. Carbazole was nonmutagenic with or without S-9 activation, whereas benzo[a]carbazole showed a clear dose-response with S-9 activation. Without S-9 activation, benzo[a]carbazole was nonmutagenic. Apparently benzo[a]carbazole must be enzymatically activated in order to be mutagenic

  7. Validation of the dermal exposure model in ECETOC TRA.

    Science.gov (United States)

    Marquart, Hans; Franken, Remy; Goede, Henk; Fransman, Wouter; Schinkel, Jody

    2017-08-01

    The ECETOC TRA model (presently version 3.1) is often used to estimate worker inhalation and dermal exposure in regulatory risk assessment. The dermal model in ECETOC TRA has not yet been validated by comparison with independent measured exposure levels. This was the goal of the present study. Measured exposure levels and relevant contextual information were gathered via literature search, websites of relevant occupational health institutes and direct requests for data to industry. Exposure data were clustered in so-called exposure cases, which are sets of data from one data source that are expected to have the same values for input parameters in the ECETOC TRA dermal exposure model. For each exposure case, the 75th percentile of measured values was calculated, because the model intends to estimate these values. The input values for the parameters in ECETOC TRA were assigned by an expert elicitation and consensus building process, based on descriptions of relevant contextual information.From more than 35 data sources, 106 useful exposure cases were derived, that were used for direct comparison with the model estimates. The exposure cases covered a large part of the ECETOC TRA dermal exposure model. The model explained 37% of the variance in the 75th percentiles of measured values. In around 80% of the exposure cases, the model estimate was higher than the 75th percentile of measured values. In the remaining exposure cases, the model estimate may not be sufficiently conservative.The model was shown to have a clear bias towards (severe) overestimation of dermal exposure at low measured exposure values, while all cases of apparent underestimation by the ECETOC TRA dermal exposure model occurred at high measured exposure values. This can be partly explained by a built-in bias in the effect of concentration of substance in product used, duration of exposure and the use of protective gloves in the model. The effect of protective gloves was calculated to be on average a

  8. Analysis of human acellular nerve allograft reconstruction of 64 injured nerves in the hand and upper extremity: a 3 year follow-up study.

    Science.gov (United States)

    Zhu, Shuang; Liu, Jianghui; Zheng, Canbin; Gu, Liqiang; Zhu, Qingtang; Xiang, Jianping; He, Bo; Zhou, Xiang; Liu, Xiaolin

    2017-08-01

    Human acellular nerve allografts have been increasingly applied in clinical practice. This study was undertaken to investigate the functional outcomes of nerve allograft reconstruction for nerve defects in the upper extremity. A total of 64 patients from 13 hospitals were available for this follow-up study after nerve repair using human acellular nerve allografts. Sensory and motor recovery was examined according to the international standards for motor and sensory nerve recovery. Subgroup analysis and logistic regression analysis were conducted to identify the relationship between the known factors and the outcomes of nerve repair. Mean follow-up time was 355 ± 158 (35-819) days; mean age was 35 ± 11 (14-68) years; average nerve gap length was 27 ± 13 (10-60) mm; no signs of infection, tissue rejection or extrusion were observed among the patients; 48/64 (75%) repaired nerves experienced meaningful recovery. Univariate analysis showed that site and gap length significantly influenced prognosis after nerve repair using nerve grafts. Delay had a marginally significant relationship with the outcome. A multivariate logistic regression model revealed that gap length was an independent predictor of nerve repair using human acellular nerve allografts. The results indicated that the human acellular nerve allograft facilitated safe and effective nerve reconstruction for nerve gaps 10-60 mm in length in the hand and upper extremity. Factors such as site and gap length had a statistically significant influence on the outcomes of nerve allograft reconstruction. Gap length was an independent predictor of nerve repair using human acellular nerve allografts. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  9. On reflectionless equi-transmitting matrices

    Directory of Open Access Journals (Sweden)

    Pavel Kurasov

    2014-01-01

    Full Text Available Reflectionless equi-transmitting unitary matrices are studied in connection to matching conditions in quantum graphs. All possible such matrices of size 6 are described explicitly. It is shown that such matrices form 30 six-parameter families intersected along 12 five-parameter families closely connected to conference matrices.

  10. Proof-of-Principle Dermal Decontamination Experiments: Swine Skin

    Science.gov (United States)

    2007-04-01

    cycles and the measurements taken after each cycle were recorded. All water rinses were performed using tap water and applied using a gentle stream...uniform and highly reproducible. EpiDermFT ( EFT ) consists of organized basal, spinous, granular, and cornified epidermal layers analogous to those found...in vivo. The dermal compartment is composed of a collagen matrix containing viable normal human dermal fibroblasts (NHDF). EFT is mitotically and

  11. Changes in dermal papilla structures due to aging in the facial cheek region.

    Science.gov (United States)

    Mizukoshi, K; Yonekura, K; Futagawa, M; Nakamura, T; Hirayama, K; Takahashi, K

    2015-05-01

    In the past, it has been possible to measure the dermal papilla structures which are undulations between the epidermis and dermis by noninvasive method. However, almost all of previous studies were not intended to measure facial skin but another site of body. Here, we investigated age-dependent alterations for dermal papilla structures in the facial cheek region after elucidating the difference of characteristics between the body site. The surface of the dermis was observed under scanning electron microscope (SEM) using face and abdominal skin biopsy samples. A total of 90 Japanese women were investigated by in vivo confocal laser microscope (CLSM). The number and the shape in the horizontal cross-sectional images of the dermal papilla were analyzed. The facial skin had different characteristics in comparison to the abdominal skin by SEM observation. Under CLSM observation, we found abnormal dermal papilla structures which were accompanied by spots or enlarged pore areas and eliminated these structures from our analysis. We revealed a decrease in the number of normal dermal papilla structures with age and large individual differences at younger ages. We found abnormal dermal papilla structures and differences in the dermal papilla structures between face and other body site. With these taken into consideration, we could precisely investigate the aging alteration of normal dermal papilla structures in the face. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Measurements of Dermal and Oral Emissions from Humans

    DEFF Research Database (Denmark)

    Tsushima, Sayana; Bekö, Gabriel; Bossi, Rossana

    2016-01-01

    Human related pollutants (bioeffluents) emitted through skin and via exhaled breath were measured. Two climate chambers were connected via flexible ducts. The ducts were in one chamber attached to a breathing mask, through which five subjects exhaled on one occasion the air into the other chamber......: Human bioeffluents emitted orally were in this way isolated from those that were emitted dermally. On another occasion, the subjects exhaled the air into the chamber where they were sitting, thus exposure contained oral and dermal bioeffluents. Another twenty subjects assessed the air quality...... in the chambers. They judged the air quality in the chamber with dermal bioeffluents to be lower than in the one containing orally exhaled bioeffluents, and similar to the air quality in the chamber with all bioeffluents. The chemical compounds with slightly elevated concentrations differed between the two...

  13. Increased acellular and cellular surface mineralization induced by nanogrooves in combination with a calcium-phosphate coating.

    NARCIS (Netherlands)

    Klymov, A.; Song, J.; Cai, X; Riet, J. te; Leeuwenburgh, S.C.; Jansen, J.A.; Walboomers, X.F.

    2016-01-01

    The current work evaluated the influence of nanoscale surface-topographies in combination with a calcium phosphate (CaP) coating on acellular and cellular surface mineralization. Four groups of substrates were produced, including smooth, grooved (940nm pitch, 430nm groove width, 185nm depth), smooth

  14. Fungible Correlation Matrices: A Method for Generating Nonsingular, Singular, and Improper Correlation Matrices for Monte Carlo Research.

    Science.gov (United States)

    Waller, Niels G

    2016-01-01

    For a fixed set of standardized regression coefficients and a fixed coefficient of determination (R-squared), an infinite number of predictor correlation matrices will satisfy the implied quadratic form. I call such matrices fungible correlation matrices. In this article, I describe an algorithm for generating positive definite (PD), positive semidefinite (PSD), or indefinite (ID) fungible correlation matrices that have a random or fixed smallest eigenvalue. The underlying equations of this algorithm are reviewed from both algebraic and geometric perspectives. Two simulation studies illustrate that fungible correlation matrices can be profitably used in Monte Carlo research. The first study uses PD fungible correlation matrices to compare penalized regression algorithms. The second study uses ID fungible correlation matrices to compare matrix-smoothing algorithms. R code for generating fungible correlation matrices is presented in the supplemental materials.

  15. Differential Apoptosis in Mucosal and Dermal Wound Healing

    Science.gov (United States)

    Johnson, Ariel; Francis, Marybeth; DiPietro, Luisa Ann

    2014-01-01

    Objectives: Dermal and mucosal healing are mechanistically similar. However, scarring and closure rates are dramatically improved in mucosal healing, possibly due to differences in apoptosis. Apoptosis, nature's preprogrammed form of cell death, occurs via two major pathways, extrinsic and intrinsic, which intersect at caspase3 (Casp3) cleavage and activation. The purpose of this experiment was to identify the predominant pathways of apoptosis in mucosal and dermal wound healing. Approach: Wounds (1 mm biopsy punch) were made in the dorsal skin (n=3) or tongue (n=3) of female Balb/C mice aged 6 weeks. Wounds were harvested at 6 h, 24 h, day 3 (D3), D5, D7, and D10. RNA was isolated and analyzed using real time reverse transcriptase–polymerase chain reaction. Expression levels for genes in the intrinsic and extrinsic apoptotic pathways were compared in dermal and mucosal wounds. Results: Compared to mucosal healing, dermal wounds exhibited significantly higher expression of Casp3 (at D5; phealing compared to skin. Conclusion: Expression patterns of key regulators of apoptosis in wound healing indicate that apoptosis occurs predominantly through the intrinsic pathway in the healing mucosa, but predominantly through the extrinsic pathway in the healing skin. The identification of differences in the apoptotic pathways in skin and mucosal wounds may allow the development of therapeutics to improve skin healing. PMID:25493209

  16. Volume correction in the aging hand: role of dermal fillers

    Directory of Open Access Journals (Sweden)

    Rivkin AZ

    2016-08-01

    Full Text Available Alexander Z Rivkin David Geffen/UCLA School of Medicine Los Angeles, CA, USA Abstract: The hands, just like the face, are highly visible parts of the body. They age at a similar rate and demonstrate comparable changes with time, sun damage, and smoking. Loss of volume in the hands exposes underlying tendons, veins, and bony prominences. Rejuvenation of the hands with dermal fillers is a procedure with high patient satisfaction and relatively low risk for complications. This study will review relevant anatomy, injection technique, clinical safety, and efficacy of dermal filler volumization of the aging hand. Keywords: dermal fillers, hands, volumization, hyaluronic acid, calcium hydroxylapatite

  17. Double stochastic matrices in quantum mechanics

    International Nuclear Information System (INIS)

    Louck, J.D.

    1997-01-01

    The general set of doubly stochastic matrices of order n corresponding to ordinary nonrelativistic quantum mechanical transition probability matrices is given. Lande's discussion of the nonquantal origin of such matrices is noted. Several concrete examples are presented for elementary and composite angular momentum systems with the focus on the unitary symmetry associated with such systems in the spirit of the recent work of Bohr and Ulfbeck. Birkhoff's theorem on doubly stochastic matrices of order n is reformulated in a geometrical language suitable for application to the subset of quantum mechanical doubly stochastic matrices. Specifically, it is shown that the set of points on the unit sphere in cartesian n'-space is subjective with the set of doubly stochastic matrices of order n. The question is raised, but not answered, as to what is the subset of points of this unit sphere that correspond to the quantum mechanical transition probability matrices, and what is the symmetry group of this subset of matrices

  18. Deterministic matrices matching the compressed sensing phase transitions of Gaussian random matrices

    Science.gov (United States)

    Monajemi, Hatef; Jafarpour, Sina; Gavish, Matan; Donoho, David L.; Ambikasaran, Sivaram; Bacallado, Sergio; Bharadia, Dinesh; Chen, Yuxin; Choi, Young; Chowdhury, Mainak; Chowdhury, Soham; Damle, Anil; Fithian, Will; Goetz, Georges; Grosenick, Logan; Gross, Sam; Hills, Gage; Hornstein, Michael; Lakkam, Milinda; Lee, Jason; Li, Jian; Liu, Linxi; Sing-Long, Carlos; Marx, Mike; Mittal, Akshay; Monajemi, Hatef; No, Albert; Omrani, Reza; Pekelis, Leonid; Qin, Junjie; Raines, Kevin; Ryu, Ernest; Saxe, Andrew; Shi, Dai; Siilats, Keith; Strauss, David; Tang, Gary; Wang, Chaojun; Zhou, Zoey; Zhu, Zhen

    2013-01-01

    In compressed sensing, one takes samples of an N-dimensional vector using an matrix A, obtaining undersampled measurements . For random matrices with independent standard Gaussian entries, it is known that, when is k-sparse, there is a precisely determined phase transition: for a certain region in the (,)-phase diagram, convex optimization typically finds the sparsest solution, whereas outside that region, it typically fails. It has been shown empirically that the same property—with the same phase transition location—holds for a wide range of non-Gaussian random matrix ensembles. We report extensive experiments showing that the Gaussian phase transition also describes numerous deterministic matrices, including Spikes and Sines, Spikes and Noiselets, Paley Frames, Delsarte-Goethals Frames, Chirp Sensing Matrices, and Grassmannian Frames. Namely, for each of these deterministic matrices in turn, for a typical k-sparse object, we observe that convex optimization is successful over a region of the phase diagram that coincides with the region known for Gaussian random matrices. Our experiments considered coefficients constrained to for four different sets , and the results establish our finding for each of the four associated phase transitions. PMID:23277588

  19. Dermal bioavailability of benzo[a]pyrene on lampblack: implications for risk assessment.

    Science.gov (United States)

    Stroo, Hans F; Roy, Timothy A; Liban, Cris B; Kreitinger, Joseph P

    2005-06-01

    Lampblack is the principal source of contamination in soils at manufactured gas plant (MGP) sites where oil was used as the feedstock. Risks and cleanup criteria at these sites are determined primarily by the total carcinogenic polynuclear aromatic hydrocarbon (PAH) content, particularly the concentration of benzo[a]pyrene (BaP). Dermal contact with soils at oil-gas MGP sites is a significant component of the overall risks. Seven samples were collected from oil-gas MGP sites and the steady-state dermal fluxes were measured over 96 h in vitro. The standard dermal bioassay technique (in which 3H-BaP is added to the soil matrix) was modified to allow direct measurement of the dermal absorption of the native BaP in the samples. The experimentally derived dermal absorption factors for BaP were 14 to 107 times lower than the default assumption of 15% over 24 h (55-fold lower on average). The dermal fluxes were correlated positively to the total BaP and total carbon concentrations. The measured dermal absorption factors were compared to the default risk-assessment calculations for all seven samples. The calculated excess cancer risk was reduced as a result of using the measured absorption factors by 97% on average (with reductions ranging from 93 to 99%). This work indicates the risks at oil-gas MGP sites currently are overestimated by one to two orders of magnitude, and provides a protocol for the testing and data analysis needed to generate site-specific cleanup levels.

  20. Matrices and linear transformations

    CERN Document Server

    Cullen, Charles G

    1990-01-01

    ""Comprehensive . . . an excellent introduction to the subject."" - Electronic Engineer's Design Magazine.This introductory textbook, aimed at sophomore- and junior-level undergraduates in mathematics, engineering, and the physical sciences, offers a smooth, in-depth treatment of linear algebra and matrix theory. The major objects of study are matrices over an arbitrary field. Contents include Matrices and Linear Systems; Vector Spaces; Determinants; Linear Transformations; Similarity: Part I and Part II; Polynomials and Polynomial Matrices; Matrix Analysis; and Numerical Methods. The first

  1. Toxicity of middle distillates from dermal exposure.

    Science.gov (United States)

    Koschier, F J

    1999-02-01

    This report focuses on recent studies that investigated the effects of kerosine dermal exposure on neurotoxicity and reproductive/developmental toxicity. Background toxicity information will also be reviewed for kerosine range mid distillates. The kerosine range mid distillates have a carbon range of C9-C16 and have a boiling range of 302-554 degrees F (150-290 degrees C). This category includes kerosine, aviation fuels (e.g., Jet A, JP-5 and JP-8), no. 1 fuel oil and diesel fuel oil. In general, the kerosine range mid distillates demonstrate relatively low acute toxicity by any route of exposure. High inhalation exposures can induce central nervous system depression characterized by ataxia, hypoactivity and prostration. Kerosines are known to cause skin irritation and inflammation under conditions of acute and repeated exposure in animals and humans, but are only slightly irritating to the eye and are not skin sensitizers. In addition, the absorption of kerosine range mid distillates through the skin has been demonstrated to be fairly rapid, but limited to approximately 10-15% of the applied dose after 24 hours. The kerosine range mid distillates are generally inactive in genetic toxicity tests although positive studies have been reported. Positive results, while at times equivocal, have been reported for straight run kerosine and jet fuel A in the mouse lymphoma assay with metabolic activation, and hydrodesulfurized kerosine (mouse) and jet fuel A (rat) in the bone marrow cytogenetic assay. Effects on the nervous and reproductive systems have been reported in humans and experimental animals under conditions where inhalation and dermal exposure to specific kerosine type fuels are sometimes difficult to separate. Recent laboratory studies have addressed this point and examined the effects of dermal exposure. In these studies, rats were exposed to hydrodesulfurized kerosine by skin application to determine the potential of dermal contact to cause reproductive

  2. Dermal pocketing following distal finger replantation.

    Science.gov (United States)

    Puhaindran, Mark E; Paavilainen, Pasi; Tan, David M K; Peng, Yeong Pin; Lim, Aymeric Y T

    2010-08-01

    Replantation is an ideal technique for reconstruction following fingertip amputation as it provides 'like for like' total reconstruction of the nail complex, bone pulp tissue and skin with no donor-site morbidity. However, fingertips are often not replanted because veins cannot be found or are thought to be too small to repair. Attempts at 'cap-plasty' or pocketing of replanted tips with and without microvascular anastomosis have been done in the past with varying degrees of success. We prospectively followed up a group of patients who underwent digital replantation and dermal pocketing in the palm to evaluate the outcome of this procedure. There were 10 patients with 14 amputated digits (two thumbs, five index, four middle, two ring and one little) who underwent dermal pocketing of the amputated digit following replantation. Among the 14 digits that were treated with dermal pocketing, 11 survived completely, one had partial atrophy and two were completely lost. Complications encountered included finger stiffness (two patients) and infection of the replanted fingertip with osteomyelitis of the distal phalanx (one patient). We believe that this technique can help increase the chance of survival for distal replantation with an acceptable salvage rate of 85% in our series. Copyright 2009 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  3. Augmented cartilage regeneration by implantation of cellular versus acellular implants after bone marrow stimulation: a systematic review and meta-analysis of animal studies

    Directory of Open Access Journals (Sweden)

    Michiel W. Pot

    2017-10-01

    Full Text Available Bone marrow stimulation may be applied to regenerate focal cartilage defects, but generally results in transient clinical improvement and formation of fibrocartilage rather than hyaline cartilage. Tissue engineering and regenerative medicine strive to develop new solutions to regenerate hyaline cartilage tissue. This systematic review and meta-analysis provides a comprehensive overview of current literature and assesses the efficacy of articular cartilage regeneration by implantation of cell-laden versus cell-free biomaterials in the knee and ankle joint in animals after bone marrow stimulation. PubMed and EMBASE (via OvidSP were systematically searched using tissue engineering, cartilage and animals search strategies. Included were primary studies in which cellular and acellular biomaterials were implanted after applying bone marrow stimulation in the knee or ankle joint in healthy animals. Study characteristics were tabulated and outcome data were collected for meta-analysis for studies applying semi-quantitative histology as outcome measure (117 studies. Cartilage regeneration was expressed on an absolute 0–100% scale and random effects meta-analyses were performed. Implantation of cellular biomaterials significantly improved cartilage regeneration by 18.6% compared to acellular biomaterials. No significant differences were found between biomaterials loaded with stem cells and those loaded with somatic cells. Culture conditions of cells did not affect cartilage regeneration. Cartilage formation was reduced with adipose-derived stem cells compared to other cell types, but still improved compared to acellular scaffolds. Assessment of the risk of bias was impaired due to incomplete reporting for most studies. Implantation of cellular biomaterials improves cartilage regeneration compared to acellular biomaterials.

  4. Augmented cartilage regeneration by implantation of cellular versus acellular implants after bone marrow stimulation: a systematic review and meta-analysis of animal studies.

    Science.gov (United States)

    Pot, Michiel W; van Kuppevelt, Toin H; Gonzales, Veronica K; Buma, Pieter; IntHout, Joanna; de Vries, Rob B M; Daamen, Willeke F

    2017-01-01

    Bone marrow stimulation may be applied to regenerate focal cartilage defects, but generally results in transient clinical improvement and formation of fibrocartilage rather than hyaline cartilage. Tissue engineering and regenerative medicine strive to develop new solutions to regenerate hyaline cartilage tissue. This systematic review and meta-analysis provides a comprehensive overview of current literature and assesses the efficacy of articular cartilage regeneration by implantation of cell-laden versus cell-free biomaterials in the knee and ankle joint in animals after bone marrow stimulation. PubMed and EMBASE (via OvidSP) were systematically searched using tissue engineering, cartilage and animals search strategies. Included were primary studies in which cellular and acellular biomaterials were implanted after applying bone marrow stimulation in the knee or ankle joint in healthy animals. Study characteristics were tabulated and outcome data were collected for meta-analysis for studies applying semi-quantitative histology as outcome measure (117 studies). Cartilage regeneration was expressed on an absolute 0-100% scale and random effects meta-analyses were performed. Implantation of cellular biomaterials significantly improved cartilage regeneration by 18.6% compared to acellular biomaterials. No significant differences were found between biomaterials loaded with stem cells and those loaded with somatic cells. Culture conditions of cells did not affect cartilage regeneration. Cartilage formation was reduced with adipose-derived stem cells compared to other cell types, but still improved compared to acellular scaffolds. Assessment of the risk of bias was impaired due to incomplete reporting for most studies. Implantation of cellular biomaterials improves cartilage regeneration compared to acellular biomaterials.

  5. Lambda-matrices and vibrating systems

    CERN Document Server

    Lancaster, Peter; Stark, M; Kahane, J P

    1966-01-01

    Lambda-Matrices and Vibrating Systems presents aspects and solutions to problems concerned with linear vibrating systems with a finite degrees of freedom and the theory of matrices. The book discusses some parts of the theory of matrices that will account for the solutions of the problems. The text starts with an outline of matrix theory, and some theorems are proved. The Jordan canonical form is also applied to understand the structure of square matrices. Classical theorems are discussed further by applying the Jordan canonical form, the Rayleigh quotient, and simple matrix pencils with late

  6. Manin matrices and Talalaev's formula

    International Nuclear Information System (INIS)

    Chervov, A; Falqui, G

    2008-01-01

    In this paper we study properties of Lax and transfer matrices associated with quantum integrable systems. Our point of view stems from the fact that their elements satisfy special commutation properties, considered by Yu I Manin some 20 years ago at the beginning of quantum group theory. These are the commutation properties of matrix elements of linear homomorphisms between polynomial rings; more explicitly these read: (1) elements of the same column commute; (2) commutators of the cross terms are equal: [M ij , M kl ] [M kj , M il ] (e.g. [M 11 , M 22 ] = [M 21 , M 12 ]). The main aim of this paper is twofold: on the one hand we observe and prove that such matrices (which we call Manin matrices in short) behave almost as well as matrices with commutative elements. Namely, the theorems of linear algebra (e.g., a natural definition of the determinant, the Cayley-Hamilton theorem, the Newton identities and so on and so forth) have a straightforward counterpart in the case of Manin matrices. On the other hand, we remark that such matrices are somewhat ubiquitous in the theory of quantum integrability. For instance, Manin matrices (and their q-analogs) include matrices satisfying the Yang-Baxter relation 'RTT=TTR' and the so-called Cartier-Foata matrices. Also, they enter Talalaev's remarkable formulae: det(∂ z -L gaudin (z)), det(1-e -∂z T Yangian (z)) for the 'quantum spectral curve', and appear in the separation of variables problem and Capelli identities. We show that theorems of linear algebra, after being established for such matrices, have various applications to quantum integrable systems and Lie algebras, e.g. in the construction of new generators in Z(U crit (gl-hat n )) (and, in general, in the construction of quantum conservation laws), in the Knizhnik-Zamolodchikov equation, and in the problem of Wick ordering. We propose, in the appendix, a construction of quantum separated variables for the XXX-Heisenberg system

  7. Estimating dermal transfer from PCB-contaminated porous surfaces.

    Science.gov (United States)

    Slayton, T M; Valberg, P A; Wait, A D

    1998-06-01

    Health risks posed by dermal contact with PCB-contaminated porous surfaces have not been directly demonstrated and are difficult to estimate indirectly. Surface contamination by organic compounds is commonly assessed by collecting wipe samples with hexane as the solvent. However, for porous surfaces, hexane wipe characterization is of limited direct use when estimating potential human exposure. Particularly for porous surfaces, the relationship between the amount of organic material collected by hexane and the amount actually picked up by, for example, a person's hand touch is unknown. To better mimic PCB pickup by casual hand contact with contaminated concrete surfaces, we used alternate solvents and wipe application methods that more closely mimic casual dermal contact. Our sampling results were compared to PCB pickup using hexane-wetted wipes and the standard rubbing protocol. Dry and oil-wetted samples, applied without rubbing, picked up less than 1% of the PCBs picked up by the standard hexane procedure; with rubbing, they picked up about 2%. Without rubbing, saline-wetted wipes picked up 2.5%; with rubbing, they picked up about 12%. While the nature of dermal contact with a contaminated surface cannot be perfectly reproduced with a wipe sample, our results with alternate wiping solvents and rubbing methods more closely mimic hand contact than the standard hexane wipe protocol. The relative pickup estimates presented in this paper can be used in conjunction with site-specific PCB hexane wipe results to estimate dermal pickup rates at sites with PCB-contaminated concrete.

  8. Introduction into Hierarchical Matrices

    KAUST Repository

    Litvinenko, Alexander

    2013-01-01

    Hierarchical matrices allow us to reduce computational storage and cost from cubic to almost linear. This technique can be applied for solving PDEs, integral equations, matrix equations and approximation of large covariance and precision matrices.

  9. Introduction into Hierarchical Matrices

    KAUST Repository

    Litvinenko, Alexander

    2013-12-05

    Hierarchical matrices allow us to reduce computational storage and cost from cubic to almost linear. This technique can be applied for solving PDEs, integral equations, matrix equations and approximation of large covariance and precision matrices.

  10. Measurements of Dermal Uptake of Nicotine Directly from Air and Clothing

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Morrison, Glenn; Weschler, Charles J.

    2016-01-01

    Dermal uptake directly from air is a significant contributor to total exposure for certain organic compounds, and has been recently experimentally verified for two phthalates. The objective of the current study was to investigate whether airborne nicotine can be dermally absorbed. Two bare-skinne...

  11. Human dermal absorption of chlorinated organophosphate flame retardants; implications for human exposure

    Energy Technology Data Exchange (ETDEWEB)

    Abou-Elwafa Abdallah, Mohamed, E-mail: mae_abdallah@yahoo.co.uk [Division of Environmental Health and Risk Management, School of Geography, Earth, and Environmental Sciences, University of Birmingham, Birmingham B15 2TT (United Kingdom); Department of Analytical Chemistry, Faculty of Pharmacy, Assiut University, 71526 Assiut (Egypt); Pawar, Gopal; Harrad, Stuart [Division of Environmental Health and Risk Management, School of Geography, Earth, and Environmental Sciences, University of Birmingham, Birmingham B15 2TT (United Kingdom)

    2016-01-15

    Tris-2-chloroethyl phosphate (TCEP), tris (1-chloro-2-propyl) phosphate (TCIPP) and tris-1,3-dichloropropyl phosphate (TDCIPP) are organophosphate flame retardants (PFRs) widely applied in a plethora of consumer products despite their carcinogenic potential. Human dermal absorption of these PFRs is investigated for the first time using human ex vivo skin and EPISKIN™ models. Results of human ex vivo skin experiments revealed 28%, 25% and 13% absorption of the applied dose (500 ng/cm{sup 2}, finite dose) of TCEP, TCIPP and TDCIPP, respectively after 24 h exposure. The EPISKIN™ model showed enhanced permeability values (i.e. weaker barrier), that were respectively 16%, 11% and 9% for TCEP, TCIPP and TDCIPP compared to human ex vivo skin. However, this difference was not significant (P > 0.05). Estimated permeability constants (K{sub p}, cm/h) showed a significant negative correlation with log K{sub ow} for the studied contaminants. The effect of hand-washing on dermal absorption of PFRs was investigated. Washing reduced overall dermal absorption, albeit to varying degrees depending on the physicochemical properties of the target PFRs. Moreover, slight variations of the absorbed dose were observed upon changing the dosing solution from acetone to 20% Tween 80 in water, indicating the potential influence of the dose vehicle on the dermal absorption of PFRs. Finally, estimated dermal uptake of the studied PFRs via contact with indoor dust was higher in UK toddlers (median ΣPFRs = 36 ng/kg bw day) than adults (median ΣPFRs = 4 ng/kg bw day). More research is required to fully elucidate the toxicological implications of such exposure. - Highlights: • Human dermal absorption of PFRs was studied using human ex vivo skin and EPISKIN™. • Absorbed fractions of TCEP, TCIPP and TDCIPP were 28%, 25% and 13% of applied dose. • Permeability constants showed significant negative correlation to log K{sub ow} of PFRs. • Skin washing reduced the overall dermal

  12. Human dermal absorption of chlorinated organophosphate flame retardants; implications for human exposure

    International Nuclear Information System (INIS)

    Abou-Elwafa Abdallah, Mohamed; Pawar, Gopal; Harrad, Stuart

    2016-01-01

    Tris-2-chloroethyl phosphate (TCEP), tris (1-chloro-2-propyl) phosphate (TCIPP) and tris-1,3-dichloropropyl phosphate (TDCIPP) are organophosphate flame retardants (PFRs) widely applied in a plethora of consumer products despite their carcinogenic potential. Human dermal absorption of these PFRs is investigated for the first time using human ex vivo skin and EPISKIN™ models. Results of human ex vivo skin experiments revealed 28%, 25% and 13% absorption of the applied dose (500 ng/cm 2 , finite dose) of TCEP, TCIPP and TDCIPP, respectively after 24 h exposure. The EPISKIN™ model showed enhanced permeability values (i.e. weaker barrier), that were respectively 16%, 11% and 9% for TCEP, TCIPP and TDCIPP compared to human ex vivo skin. However, this difference was not significant (P > 0.05). Estimated permeability constants (K p , cm/h) showed a significant negative correlation with log K ow for the studied contaminants. The effect of hand-washing on dermal absorption of PFRs was investigated. Washing reduced overall dermal absorption, albeit to varying degrees depending on the physicochemical properties of the target PFRs. Moreover, slight variations of the absorbed dose were observed upon changing the dosing solution from acetone to 20% Tween 80 in water, indicating the potential influence of the dose vehicle on the dermal absorption of PFRs. Finally, estimated dermal uptake of the studied PFRs via contact with indoor dust was higher in UK toddlers (median ΣPFRs = 36 ng/kg bw day) than adults (median ΣPFRs = 4 ng/kg bw day). More research is required to fully elucidate the toxicological implications of such exposure. - Highlights: • Human dermal absorption of PFRs was studied using human ex vivo skin and EPISKIN™. • Absorbed fractions of TCEP, TCIPP and TDCIPP were 28%, 25% and 13% of applied dose. • Permeability constants showed significant negative correlation to log K ow of PFRs. • Skin washing reduced the overall dermal absorption of target PFRs

  13. MERSENNE AND HADAMARD MATRICES CALCULATION BY SCARPIS METHOD

    Directory of Open Access Journals (Sweden)

    N. A. Balonin

    2014-05-01

    Full Text Available Purpose. The paper deals with the problem of basic generalizations of Hadamard matrices associated with maximum determinant matrices or not optimal by determinant matrices with orthogonal columns (weighing matrices, Mersenne and Euler matrices, ets.; calculation methods for the quasi-orthogonal local maximum determinant Mersenne matrices are not studied enough sufficiently. The goal of this paper is to develop the theory of Mersenne and Hadamard matrices on the base of generalized Scarpis method research. Methods. Extreme solutions are found in general by minimization of maximum for absolute values of the elements of studied matrices followed by their subsequent classification according to the quantity of levels and their values depending on orders. Less universal but more effective methods are based on structural invariants of quasi-orthogonal matrices (Silvester, Paley, Scarpis methods, ets.. Results. Generalizations of Hadamard and Belevitch matrices as a family of quasi-orthogonal matrices of odd orders are observed; they include, in particular, two-level Mersenne matrices. Definitions of section and layer on the set of generalized matrices are proposed. Calculation algorithms for matrices of adjacent layers and sections by matrices of lower orders are described. Approximation examples of the Belevitch matrix structures up to 22-nd critical order by Mersenne matrix of the third order are given. New formulation of the modified Scarpis method to approximate Hadamard matrices of high orders by lower order Mersenne matrices is proposed. Williamson method is described by example of one modular level matrices approximation by matrices with a small number of levels. Practical relevance. The efficiency of developing direction for the band-pass filters creation is justified. Algorithms for Mersenne matrices design by Scarpis method are used in developing software of the research program complex. Mersenne filters are based on the suboptimal by

  14. Advantages of implantation of acellular porcine-derived mesh in the treatment of human rectocele – Case report

    Directory of Open Access Journals (Sweden)

    Tomasz Kościński

    2016-09-01

    The clinical experience and review of the literature by the authors suggest that a porcine-derived acellular mesh is non-cytotoxic, pyrogenic or allergenic, and the application of a biomesh in the management of rectocele is effective and safe, and the risk of mesh erosion is very low.

  15. Dermal pharmacokinetics of microemulsion formulations determined by in vivo microdialysis

    DEFF Research Database (Denmark)

    Kreilgaard, Mads

    2001-01-01

    To investigate the potential of improving dermal drug delivery of hydrophilic and lipophilic substances by formulation in microemulsion vehicles and to establish a reliable pharmacokinetic model to analyze cutaneous microdialysis data.......To investigate the potential of improving dermal drug delivery of hydrophilic and lipophilic substances by formulation in microemulsion vehicles and to establish a reliable pharmacokinetic model to analyze cutaneous microdialysis data....

  16. The basic science of dermal fillers: past and present Part II: adverse effects.

    Science.gov (United States)

    Gilbert, Erin; Hui, Andrea; Meehan, Shane; Waldorf, Heidi A

    2012-09-01

    The ideal dermal filler should offer long-lasting aesthetic improvement with a minimal side-effect profile. It should be biocompatible and stable within the injection site, with the risk of only transient undesirable effects from injection alone. However, all dermal fillers can induce serious and potentially long-lasting adverse effects. In Part II of this paper, we review the most common adverse effects related to dermal filler use.

  17. Dermal exposure assessment to benzene and toluene using charcoal cloth pads

    NARCIS (Netherlands)

    Wendel de Joode, B. van; Tielemans, E.; Vermeulen, R.; Wegh, H.; Kromhout, H.

    2005-01-01

    Charcoal cloth pads have been used to assess volatile chemicals on the skin in a laboratory setting; however, they have not yet been applied to measure dermal exposure in occupational settings. This study aimed at evaluating whether charcoal pads can be used to assess dermal exposure to benzene and

  18. Dermal insecticide residues from birds inhabiting an orchard

    Science.gov (United States)

    Vyas, N.B.; Spann, J.W.; Hulse, C.S.; Gentry, S.; Borges, S.L.

    2007-01-01

    The US Environmental Protection Agency conducts risk assessments of insecticide applications to wild birds using a model that is limited to the dietary route of exposure. However, free-flying birds are also exposed to insecticides via the inhalation and dermal routes. We measured azinphos-methyl residues on the skin plus feathers and the feet of brown-headed cowbirds (Molothrus ater) in order to quantify dermal exposure to songbirds that entered and inhabited an apple (Malus x domestica) orchard following an insecticide application. Exposure to azinphos-methyl was measured by sampling birds from an aviary that was built around an apple tree. Birds sampled at 36 h and 7-day post-application were placed in the aviary within 1 h after the application whereas birds exposed for 3 days were released into the aviary 4-day post-application. Residues on vegetation and soil were also measured. Azinphos-methyl residues were detected from the skin plus feathers and the feet from all exposure periods. Our results underscore the importance of incorporating dermal exposure into avian pesticide risk assessments.

  19. [Penile augmentation and elongation using autologous dermal-fat strip grafting].

    Science.gov (United States)

    Yang, Zhe; Li, Yang-qun; Tang, Yong; Chen, Wen; Li, Qiang; Zhou, Chuan-de; Zhao, Mu-xin; Hu, Chun-mei

    2012-05-01

    To investigate the effect of autologous dermal-fat strip grafting in penile augmentation and elongation. From May 2004 to December 2010, 24 patients underwent penile enhancement with free dermal-fat strip grafting. Through suprapubic incision, the superior suspensory ligament and part deep suspensory ligament are cutted off to lengthen the penis. The resulted dead space is filled with the autologous dermal-fat strip (6.0-9.5 cm in length, 1.2-1.5 cm in width and 0.6-0.8 cm in depth) to enhance the penis. Primary healing was achieved in 23 cases. Incisional fat liquefaction happened in one case which healed after dressing change. The penile appearance was satisfactory both at rest or erection. The penile length and circumference increased by 2.5-4.8 cm (average, 3.2 cm) and 1.8-3.0 cm (average, 2.4 cm), respectively. 18 patients were followed up for 3 months to 5 years. All the patients were satisfactory on the cosmetic and functional results. No complication happened. It is safe and effective for penile augmention and elongation with autologous dermal-fat strip grafting and disconnection of penile suspensory ligament.

  20. INVIVO DEGRADATION OF PROCESSED DERMAL SHEEP COLLAGEN EVALUATED WITH TRANSMISSION ELECTRON-MICROSCOPY

    NARCIS (Netherlands)

    VANWACHEM, PB; VANLUYN, MJA; NIEUWENHUIS, P; KOERTEN, HK; DAMINK, LO; TENHOOPEN, H; FEIJEN, J

    The in vivo degradation of hexamethylenediisocyanate-tanned dermal sheep collagen was studied with transmission electron microscopy. Discs of hexamethylenediisocyanate-tanned dermal sheep collagen were subcutaneously implanted in rats. Both an intra- and an extracellular route of degradation could

  1. Dermal fillers in aesthetics: an overview of adverse events and treatment approaches.

    Science.gov (United States)

    Funt, David; Pavicic, Tatjana

    2015-01-01

    The ever-expanding range of dermal filler products for aesthetic soft tissue augmentation is of benefit for patients and physicians, but as indications and the number of procedures performed increase, the number of complications will likely also increase. To describe potential adverse events associated with dermal fillers and to provide structured and clear guidance on their treatment and avoidance. Reports of dermal filler complications in the medical literature were reviewed and, based on the publications retrieved and the authors' extensive experience, recommendations for avoiding and managing complications are provided. Different dermal fillers have widely varying properties, associated risks, and injection requirements. All dermal fillers have the potential to cause complications. Most are related to volume and technique, though some are associated with the material itself. The majority of adverse reactions are mild and transient, such as bruising and trauma-related edema. Serious adverse events are rare, and most are avoidable with proper planning and technique. For optimum outcomes, aesthetic physicians should have a detailed understanding of facial anatomy; the individual characteristics of available fillers; their indications, contraindications, benefits, and drawbacks; and ways to prevent and avoid potential complications.

  2. Whole-cell or acellular pertussis vaccination in infancy determines IgG subclass profiles to DTaP booster vaccination

    NARCIS (Netherlands)

    van der Lee, Saskia; Sanders, Elisabeth A.M.; Berbers, Guy A M; Buisman, Anne-Marie

    2018-01-01

    Introduction Duration of protection against pertussis is shorter in adolescents who have been immunized with acellular pertussis (aP) in infancy compared with adolescents who received whole-cell pertussis (wP) vaccines in infancy, which is related to immune responses elicited by these priming

  3. Intrinsic character of Stokes matrices

    Science.gov (United States)

    Gagnon, Jean-François; Rousseau, Christiane

    2017-02-01

    Two germs of linear analytic differential systems x k + 1Y‧ = A (x) Y with a non-resonant irregular singularity are analytically equivalent if and only if they have the same eigenvalues and equivalent collections of Stokes matrices. The Stokes matrices are the transition matrices between sectors on which the system is analytically equivalent to its formal normal form. Each sector contains exactly one separating ray for each pair of eigenvalues. A rotation in S allows supposing that R+ lies in the intersection of two sectors. Reordering of the coordinates of Y allows ordering the real parts of the eigenvalues, thus yielding triangular Stokes matrices. However, the choice of the rotation in x is not canonical. In this paper we establish how the collection of Stokes matrices depends on this rotation, and hence on a chosen order of the projection of the eigenvalues on a line through the origin.

  4. Hierarchical matrices algorithms and analysis

    CERN Document Server

    Hackbusch, Wolfgang

    2015-01-01

    This self-contained monograph presents matrix algorithms and their analysis. The new technique enables not only the solution of linear systems but also the approximation of matrix functions, e.g., the matrix exponential. Other applications include the solution of matrix equations, e.g., the Lyapunov or Riccati equation. The required mathematical background can be found in the appendix. The numerical treatment of fully populated large-scale matrices is usually rather costly. However, the technique of hierarchical matrices makes it possible to store matrices and to perform matrix operations approximately with almost linear cost and a controllable degree of approximation error. For important classes of matrices, the computational cost increases only logarithmically with the approximation error. The operations provided include the matrix inversion and LU decomposition. Since large-scale linear algebra problems are standard in scientific computing, the subject of hierarchical matrices is of interest to scientists ...

  5. Development of an acellular tumor extracellular matrix as a three-dimensional scaffold for tumor engineering.

    Directory of Open Access Journals (Sweden)

    Wei-Dong Lü

    Full Text Available Tumor engineering is defined as the construction of three-dimensional (3D tumors in vitro with tissue engineering approaches. The present 3D scaffolds for tumor engineering have several limitations in terms of structure and function. To get an ideal 3D scaffold for tumor culture, A549 human pulmonary adenocarcinoma cells were implanted into immunodeficient mice to establish xenotransplatation models. Tumors were retrieved at 30-day implantation and sliced into sheets. They were subsequently decellularized by four procedures. Two decellularization methods, Tris-Trypsin-Triton multi-step treatment and sodium dodecyl sulfate (SDS treatment, achieved complete cellular removal and thus were chosen for evaluation of histological and biochemical properties. Native tumor tissues were used as controls. Human breast cancer MCF-7 cells were cultured onto the two 3D scaffolds for further cell growth and growth factor secretion investigations, with the two-dimensional (2D culture and cells cultured onto the Matrigel scaffolds used as controls. Results showed that Tris-Trypsin-Triton multi-step treated tumor sheets had well-preserved extracellular matrix structures and components. Their porosity was increased but elastic modulus was decreased compared with the native tumor samples. They supported MCF-7 cell repopulation and proliferation, as well as expression of growth factors. When cultured within the Tris-Trypsin-Triton treated scaffold, A549 cells and human colorectal adenocarcinoma cells (SW-480 had similar behaviors to MCF-7 cells, but human esophageal squamous cell carcinoma cells (KYSE-510 had a relatively slow cell repopulation rate. This study provides evidence that Tris-Trypsin-Triton treated acellular tumor extracellular matrices are promising 3D scaffolds with ideal spatial arrangement, biomechanical properties and biocompatibility for improved modeling of 3D tumor microenvironments.

  6. Hydroquinone PBPK model refinement and application to dermal exposure.

    Science.gov (United States)

    Poet, Torka S; Carlton, Betsy D; Deyo, James A; Hinderliter, Paul M

    2010-11-01

    A physiologically based pharmacokinetic (PBPK) model for hydroquinone (HQ) was refined to include an expanded description of HQ-glucuronide metabolites and a description of dermal exposures to support route-to-route and cross-species extrapolation. Total urinary excretion of metabolites from in vivo rat dermal exposures was used to estimate a percutaneous permeability coefficient (K(p); 3.6×10(-5) cm/h). The human in vivo K(p) was estimated to be 1.62×10(-4) cm/h, based on in vitro skin permeability data in rats and humans and rat in vivo values. The projected total multi-substituted glutathione (which was used as an internal dose surrogate for the toxic glutathione metabolites) was modeled following an exposure scenario based on submersion of both hands in a 5% aqueous solution of HQ (similar to black and white photographic developing solution) for 2 h, a worst-case exposure scenario. Total multi-substituted glutathione following this human dermal exposure scenario was several orders of magnitude lower than the internal total glutathione conjugates in rats following an oral exposure to the rat NOEL of 20 mg/kg. Thus, under more realistic human dermal exposure conditions, it is unlikely that toxic glutathione conjugates (primarily the di- and, to a lesser degree, the tri-glutathione conjugate) will reach significant levels in target tissues. Copyright © 2010. Published by Elsevier Ltd.

  7. A Novel Biodegradable Polyurethane Matrix for Auricular Cartilage Repair: An In Vitro and In Vivo Study.

    Science.gov (United States)

    Iyer, Kartik; Dearman, Bronwyn L; Wagstaff, Marcus J D; Greenwood, John E

    2016-01-01

    Auricular reconstruction poses a challenge for reconstructive and burns surgeons. Techniques involving cartilage tissue engineering have shown potential in recent years. A biodegradable polyurethane matrix developed for dermal reconstruction offers an alternative to autologous, allogeneic, or xenogeneic biologicals for cartilage reconstruction. This study assesses such a polyurethane matrix for this indication in vivo and in vitro. To evaluate intrinsic cartilage repair, three pigs underwent auricular surgery to create excisional cartilage ± perichondrial defects, measuring 2 × 3 cm in each ear, into which acellular polyurethane matrices were implanted. Biopsies were taken at day 28 for histological assessment. Porcine chondrocytes ± perichondrocytes were cultured and seeded in vitro onto 1 × 1 cm polyurethane scaffolds. The total culture period was 42 days; confocal, histological, and immunohistochemical analyses of scaffold cultures were performed on days 14, 28, and 42. In vivo, the polyurethane matrices integrated with granulation tissue filling all biopsy samples. Minimal neocartilage invasion was observed marginally on some samples. Tissue composition was identical between ears whether perichondrium was left intact, or not. In vitro, the polyurethane matrix was biocompatible with chondrocytes ± perichondrocytes and supported production of extracellular matrix and Type II collagen. No difference was observed between chondrocyte culture alone and chondrocyte/perichondrocyte scaffold coculture. The polyurethane matrix successfully integrated into the auricular defect and was a suitable scaffold in vitro for cartilage tissue engineering, demonstrating its potential application in auricular reconstruction.

  8. Dermal Sensitization Potential of Triethyleneglycol Dinitrate (TEGDN) in Guinea Pigs

    Science.gov (United States)

    1989-01-01

    mutagenicity assay, acute oral toxicity tests in rats and mice, acute dermal toxicity in rabbits, dermal and ocular irritation studies in rabbits, and...conditions: 85E0102 had diffuse tracheitis, mild endocarditis , mild hepatitis, and diffuse pigment granules in the small intestine; 85E0103 had mild...severe ulceration progressing to necrosis. Sensitization is manifested as indirect inflammation mediated by components of the immune system in

  9. Special matrices of mathematical physics stochastic, circulant and Bell matrices

    CERN Document Server

    Aldrovandi, R

    2001-01-01

    This book expounds three special kinds of matrices that are of physical interest, centering on physical examples. Stochastic matrices describe dynamical systems of many different types, involving (or not) phenomena like transience, dissipation, ergodicity, nonequilibrium, and hypersensitivity to initial conditions. The main characteristic is growth by agglomeration, as in glass formation. Circulants are the building blocks of elementary Fourier analysis and provide a natural gateway to quantum mechanics and noncommutative geometry. Bell polynomials offer closed expressions for many formulas co

  10. Whole-cell or acellular pertussis vaccination in infancy determines IgG subclass profiles to DTaP booster vaccination.

    NARCIS (Netherlands)

    van der Lee, Saskia; Sanders, Elisabeth A M; Berbers, Guy A M; Buisman, Anne-Marie

    2018-01-01

    Duration of protection against pertussis is shorter in adolescents who have been immunized with acellular pertussis (aP) in infancy compared with adolescents who received whole-cell pertussis (wP) vaccines in infancy, which is related to immune responses elicited by these priming vaccines. To better

  11. Characterization of dermal plates from armored catfish Pterygoplichthys pardalis reveals sandwich-like nanocomposite structure.

    Science.gov (United States)

    Ebenstein, Donna; Calderon, Carlos; Troncoso, Omar P; Torres, Fernando G

    2015-05-01

    Dermal plates from armored catfish are bony structures that cover their body. In this paper we characterized structural, chemical, and nanomechanical properties of the dermal plates from the Amazonian fish Pterygoplichthys pardalis. Analysis of the morphology of the plates using scanning electron microscopy (SEM) revealed that the dermal plates have a sandwich-like structure composed of an inner porous matrix surrounded by two external dense layers. This is different from the plywood-like laminated structure of elasmoid fish scales but similar to the structure of osteoderms found in the dermal armour of some reptiles and mammals. Chemical analysis performed using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) results revealed similarities between the composition of P. pardalis plates and the elasmoid fish scales of Arapaima gigas. Reduced moduli of P. pardalis plates measured using nanoindentation were also consistent with reported values for A. gigas scales, but further revealed that the dermal plate is an anisotropic and heterogeneous material, similar to many other fish scales and osteoderms. It is postulated that the sandwich-like structure of the dermal plates provides a lightweight and tough protective layer. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Skin derived precursor Schwann cell-generated acellular matrix modified chitosan/silk scaffolds for bridging rat sciatic nerve gap.

    Science.gov (United States)

    Zhu, Changlai; Huang, Jing; Xue, Chengbin; Wang, Yaxian; Wang, Shengran; Bao, Shuangxi; Chen, Ruyue; Li, Yuan; Gu, Yun

    2017-12-27

    Extracellular/acellular matrix has been attracted much research interests for its unique biological characteristics, and ACM modified neural scaffolds shows the remarkable role of promoting peripheral nerve regeneration. In this study, skin-derived precursors pre-differentiated into Schwann cells (SKP-SCs) were used as parent cells to generate acellular(ACM) for constructing a ACM-modified neural scaffold. SKP-SCs were co-cultured with chitosan nerve guidance conduits (NGC) and silk fibroin filamentous fillers, followed by decellularization to stimulate ACM deposition. This NGC-based, SKP-SC-derived ACM-modified neural scaffold was used for bridging a 10 mm long rat sciatic nerve gap. Histological and functional evaluation after grafting demonstrated that regenerative outcomes achieved by this engineered neural scaffold were better than those achieved by a plain chitosan-silk fibroin scaffold, and suggested the benefits of SKP-SC-derived ACM for peripheral nerve repair. Copyright © 2017 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

  13. Chitosan solutions as injectable systems for dermal filler applications: Rheological characterization and biological evidence.

    Science.gov (United States)

    Halimi, C; Montembault, A; Guerry, A; Delair, T; Viguier, E; Fulchiron, R; David, L

    2015-01-01

    A new generation of dermal filler for wrinkle filler based on chitosan was compared to current hyaluronic acid-based dermal fillers by using a new rheological performance criterion based on viscosity during injection related to Newtonian viscosity. In addition an in vivo evaluation was performed for preclinical evidence of chitosan use as dermal filler. In this way, biocompatibility and dermis reconstruction was evaluated on a pig model.

  14. Characterization and evolution of dermal filaments from patients with Morgellons disease.

    Science.gov (United States)

    Middelveen, Marianne J; Mayne, Peter J; Kahn, Douglas G; Stricker, Raphael B

    2013-01-01

    Morgellons disease is an emerging skin disease characterized by formation of dermal filaments associated with multisystemic symptoms and tick-borne illness. Some clinicians hypothesize that these often colorful dermal filaments are textile fibers, either self-implanted by patients or accidentally adhering to lesions, and conclude that patients with this disease have delusions of infestation. We present histological observations and electron microscopic imaging from representative Morgellons disease samples revealing that dermal filaments in these cases are keratin and collagen in composition and result from proliferation and activation of keratinocytes and fibroblasts in the epidermis. Spirochetes were detected in the dermatological specimens from our study patients, providing evidence that Morgellons disease is associated with an infectious process.

  15. The Economics of Prepectoral Breast Reconstruction.

    Science.gov (United States)

    Glasberg, Scot Bradley

    2017-12-01

    The world of breast reconstruction over the last several years has seen a dramatic shift in focus to discussion and the application of placing tissue expanders and implants back into the prepectoral space. Although this technique failed during the early advent of breast reconstruction, newer technologies such as advances in fat grafting, improved acellular dermal matrices, better methods of assessing breast flap viability, and enhanced implants appear to have set the stage for the resurgence and positive early results seen with this technique. The main benefits of a switch to prepectoral breast reconstruction clinically appears to be less associated pain, lower incidence of animation deformities, and its associated symptoms as well as presumably better aesthetics. Early data suggest that the results are extremely promising and early adopters have attempted to define the ideal patients for prepectoral breast reconstruction. As with any new operative procedure, an assessment of finances and costs are crucial to its successful implementation. Although current data are minimal, this article attempts to build the fundamentals of an economic model that exhibits and displays potential savings through the use of prepectoral breast reconstruction.

  16. Tetrabromobisphenol A In vitro Dermal Absopriton Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — In vitro dermal absorption data of tetrabromobisphenol A using human cadaver and rat skin. This dataset is associated with the following publication: Knudsen, G., M....

  17. Dynamic interactions between dermal macrophages and Staphylococcus aureus.

    Science.gov (United States)

    Feuerstein, Reinhild; Kolter, Julia; Henneke, Philipp

    2017-01-01

    The dermis, a major reservoir of immune cells in immediate vicinity to the colonizing skin microflora, serves as an important site of host-pathogen interactions. Macrophages (Mϕ) are the most frequent resident immune cell type in the dermis. They protect the host from invasive infections by highly adapted bacteria, such as staphylococci via pattern recognition of bacterial effectors, phagocytosis, and recruitment of other myeloid cells from the blood. Already under homeostatic conditions, the dermal Mϕ population receives a dynamic input of monocytes invading from the bloodstream. This quantitative renewal is promoted further at the beginning of life, when prenatally seeded cells are rapidly replaced and in healing phases after injuries or infections. Here, we discuss the potential implications of the dynamic dermal Mϕ biology on the establishment and maintenance of immunity against Staphylococcus aureus, which can either be a harmless colonizer or an invasive pathogen. The understanding of the heterogeneity of the "mature" dermal Mϕ compartment driven both by the influx of differentiating monocytes and by a bone marrow-independent Mϕ persistence and expansion may help to explain failing immunity and immunopathology originating from the skin, the important interface between host and environment. © Society for Leukocyte Biology.

  18. Inhalational and dermal exposures during spray application of biocides.

    Science.gov (United States)

    Berger-Preiss, Edith; Boehncke, Andrea; Könnecker, Gustav; Mangelsdorf, Inge; Holthenrich, Dagmar; Koch, Wolfgang

    2005-01-01

    Data on inhalational and potential dermal exposures during spray application of liquid biocidal products were generated. On the one hand, model experiments with different spraying devices using fluorescent tracers were carried out to investigate the influence of parameters relevant to the exposure (e.g. spraying equipment, nozzle size, direction of application). On the other hand, measurements were performed at selected workplaces (during disinfection operations in food and feed areas; pest control operations for private, public and veterinary hygiene; wood protection and antifouling applications) after application of biocidal products such as Empire 20, Responsar SC, Omexan-forte, Actellic, Perma-forte; Fendona SC, Pyrethrum mist; CBM 8, Aldekol Des 03, TAD CID, Basileum, Basilit. The measurements taken in the model rooms demonstrated dependence of the inhalation exposure on the type of spraying device used, in the following order: "spraying with low pressure" < "airless spraying" < "fogging" indicating that the particle diameter of the released spray droplets is the most important parameter. In addition inhalation exposure was lowest when the spraying direction was downward. Also for the potential dermal exposure, the spraying direction was of particular importance: overhead spraying caused the highest contamination of body surfaces. The data of inhalational and potential dermal exposures gained through workplace measurements showed considerable variation. During spraying procedures with low-pressure equipments, dose rates of active substances inhaled by the operators ranged from 7 to 230 microg active substance (a.s.)/h. An increase in inhaled dose rates (6-33 mg a.s./h) was observed after use of high application volumes/time unit during wood protection applications indoors. Spraying in the veterinary sector using medium-pressure sprayers led to inhaled dose rates between 2 and 24mga.s./h. The highest inhaled dose rates were measured during fogging (114 mg a

  19. Frequency filtering decompositions for unsymmetric matrices and matrices with strongly varying coefficients

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, C.

    1996-12-31

    In 1992, Wittum introduced the frequency filtering decompositions (FFD), which yield a fast method for the iterative solution of large systems of linear equations. Based on this method, the tangential frequency filtering decompositions (TFFD) have been developed. The TFFD allow the robust and efficient treatment of matrices with strongly varying coefficients. The existence and the convergence of the TFFD can be shown for symmetric and positive definite matrices. For a large class of matrices, it is possible to prove that the convergence rate of the TFFD and of the FFD is independent of the number of unknowns. For both methods, schemes for the construction of frequency filtering decompositions for unsymmetric matrices have been developed. Since, in contrast to Wittums`s FFD, the TFFD needs only one test vector, an adaptive test vector can be used. The TFFD with respect to the adaptive test vector can be combined with other iterative methods, e.g. multi-grid methods, in order to improve the robustness of these methods. The frequency filtering decompositions have been successfully applied to the problem of the decontamination of a heterogeneous porous medium by flushing.

  20. Use of dermal fat graft for augmentation of the labia majora.

    Science.gov (United States)

    Salgado, Christopher J; Tang, Jennifer C; Desrosiers, Arthur E

    2012-02-01

    Dermal fat grafts have been utilized in plastic surgery for both reconstructive and aesthetic purposes of the face, breast, and body. There are multiple reports in the literature on the male phallus augmentation with the use of dermal fat grafts. Few reports describe female genitalia aesthetic surgery, in particular rejuvenation of the labia majora. In this report we describe an indication and use of autologous dermal fat graft for labia majora augmentation in a patient with loss of tone and volume in the labia majora. We found that this procedure is an option for labia majora augmentation and provides a stable result in volume-restoration. Copyright © 2011 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  1. Collagen/chitosan based two-compartment and bi-functional dermal scaffolds for skin regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Feng [Department of Plastic Surgery and Burns, Shenzhen Second People' s Hospital, Shenzhen 518035 (China); Wang, Mingbo [Key Laboratory of Biomedical Materials and Implants, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); She, Zhending [Key Laboratory of Biomedical Materials and Implants, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); Shenzhen Lando Biomaterials Co., Ltd., Shenzhen 518057 (China); Fan, Kunwu; Xu, Cheng [Department of Plastic Surgery and Burns, Shenzhen Second People' s Hospital, Shenzhen 518035 (China); Chu, Bin; Chen, Changsheng [Key Laboratory of Biomedical Materials and Implants, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); Shi, Shengjun, E-mail: shengjunshi@yahoo.com [The Burns Department of Zhujiang Hospital, Southern Medical University, Guangzhou 510280 (China); Tan, Rongwei, E-mail: tanrw@landobiom.com [Key Laboratory of Biomedical Materials and Implants, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); Shenzhen Lando Biomaterials Co., Ltd., Shenzhen 518057 (China)

    2015-07-01

    Inspired from the sophisticated bilayer structures of natural dermis, here, we reported collagen/chitosan based two-compartment and bi-functional dermal scaffolds. Two functions refer to mediating rapid angiogenesis based on recombinant human vascular endothelial growth factor (rhVEGF) and antibacterial from gentamicin, which were encapsulated in PLGA microspheres. The gentamicin and rhVEGF encapsulated PLGA microspheres were further combined with collagen/chitosan mixtures in low (lower layer) and high (upper layer) concentrations, and molded to generate the two-compartment and bi-functional scaffolds. Based on morphology and pore structure analyses, it was found that the scaffold has a distinct double layered porous and connective structure with PLGA microspheres encapsulated. Statistical analysis indicated that the pores in the upper layer and in the lower layer have great variations in diameter, indicative of a two-compartment structure. The release profiles of gentamicin and rhVEGF exceeded 28 and 49 days, respectively. In vitro culture of mouse fibroblasts showed that the scaffold can facilitate cell adhesion and proliferation. Moreover, the scaffold can obviously inhibit proliferation of Staphylococcus aureus and Serratia marcescens, exhibiting its unique antibacterial effect. The two-compartment and bi-functional dermal scaffolds can be a promising candidate for skin regeneration. - Highlights: • The dermal scaffold is inspired from the bilayer structures of natural dermis. • The dermal scaffold has two-compartment structures. • The dermal scaffold containing VEGF and gentamicin encapsulated PLGA microspheres • The dermal scaffold can facilitate cell adhesion and proliferation.

  2. Collagen/chitosan based two-compartment and bi-functional dermal scaffolds for skin regeneration

    International Nuclear Information System (INIS)

    Wang, Feng; Wang, Mingbo; She, Zhending; Fan, Kunwu; Xu, Cheng; Chu, Bin; Chen, Changsheng; Shi, Shengjun; Tan, Rongwei

    2015-01-01

    Inspired from the sophisticated bilayer structures of natural dermis, here, we reported collagen/chitosan based two-compartment and bi-functional dermal scaffolds. Two functions refer to mediating rapid angiogenesis based on recombinant human vascular endothelial growth factor (rhVEGF) and antibacterial from gentamicin, which were encapsulated in PLGA microspheres. The gentamicin and rhVEGF encapsulated PLGA microspheres were further combined with collagen/chitosan mixtures in low (lower layer) and high (upper layer) concentrations, and molded to generate the two-compartment and bi-functional scaffolds. Based on morphology and pore structure analyses, it was found that the scaffold has a distinct double layered porous and connective structure with PLGA microspheres encapsulated. Statistical analysis indicated that the pores in the upper layer and in the lower layer have great variations in diameter, indicative of a two-compartment structure. The release profiles of gentamicin and rhVEGF exceeded 28 and 49 days, respectively. In vitro culture of mouse fibroblasts showed that the scaffold can facilitate cell adhesion and proliferation. Moreover, the scaffold can obviously inhibit proliferation of Staphylococcus aureus and Serratia marcescens, exhibiting its unique antibacterial effect. The two-compartment and bi-functional dermal scaffolds can be a promising candidate for skin regeneration. - Highlights: • The dermal scaffold is inspired from the bilayer structures of natural dermis. • The dermal scaffold has two-compartment structures. • The dermal scaffold containing VEGF and gentamicin encapsulated PLGA microspheres • The dermal scaffold can facilitate cell adhesion and proliferation

  3. In vivo degradation of processed dermal sheep collagen evaluated with transmission electron microscopy

    NARCIS (Netherlands)

    van Wachem, P.B.; van Luyn, M.J.A.; Nieuwenhuis, P.; Koerten, H.K.; Olde damink, L.H.H.; Olde-Damink, L.; ten Hoopen, Hermina W.M.; Feijen, Jan

    1991-01-01

    The in vivo degradation of hexamethylenediisocyanate-tanned dermal sheep collagen was studied with transmission electron microscopy. Discs of hexamethylenediisocyanate-tanned dermal sheep collagen were subcutaneously implanted in rats. Both an intra- and an extracellular route of degradation could

  4. Introduction to matrices and vectors

    CERN Document Server

    Schwartz, Jacob T

    2001-01-01

    In this concise undergraduate text, the first three chapters present the basics of matrices - in later chapters the author shows how to use vectors and matrices to solve systems of linear equations. 1961 edition.

  5. Age-related changes in dermal fiber-like structures in facial cheeks.

    Science.gov (United States)

    Mizukoshi, K; Hirayama, K

    2017-08-01

    Despite recent progress in non-invasive measurement methods, such as in vivo laser confocal microscopy (CLSM), it is difficult to quantitatively measure age-related changes in dermal fibrous structures in the face using these methods and qualitative characteristics. We used characteristics extracted from the analysis of CLSM images to quantitatively investigate the effects of aging on dermal fibrous structures in the face. CLSM images of dermal fibrous structures were obtained from 90 Japanese females, ranging in age from 20 to 60 years. The feature values of CLSM images were extracted using image analysis methods, such as short-line segment-matching processing and spatial frequency analysis. The qualitative characteristics of the dermal fibrous structures in the CLSM images were obtained by principal component analysis (PCA) of these feature values. The fibrous structures were scored on the basis of qualitative characteristics and then age-related changes in the scores among the subjects were quantitatively evaluated. The PCA results showed that there were two characteristics in the images of fibrous structures: clearness and directionality. The clearness of fibrous structures decreased and directionality isotropy increased with age. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Pathological rate matrices: from primates to pathogens

    Directory of Open Access Journals (Sweden)

    Knight Rob

    2008-12-01

    Full Text Available Abstract Background Continuous-time Markov models allow flexible, parametrically succinct descriptions of sequence divergence. Non-reversible forms of these models are more biologically realistic but are challenging to develop. The instantaneous rate matrices defined for these models are typically transformed into substitution probability matrices using a matrix exponentiation algorithm that employs eigendecomposition, but this algorithm has characteristic vulnerabilities that lead to significant errors when a rate matrix possesses certain 'pathological' properties. Here we tested whether pathological rate matrices exist in nature, and consider the suitability of different algorithms to their computation. Results We used concatenated protein coding gene alignments from microbial genomes, primate genomes and independent intron alignments from primate genomes. The Taylor series expansion and eigendecomposition matrix exponentiation algorithms were compared to the less widely employed, but more robust, Padé with scaling and squaring algorithm for nucleotide, dinucleotide, codon and trinucleotide rate matrices. Pathological dinucleotide and trinucleotide matrices were evident in the microbial data set, affecting the eigendecomposition and Taylor algorithms respectively. Even using a conservative estimate of matrix error (occurrence of an invalid probability, both Taylor and eigendecomposition algorithms exhibited substantial error rates: ~100% of all exonic trinucleotide matrices were pathological to the Taylor algorithm while ~10% of codon positions 1 and 2 dinucleotide matrices and intronic trinucleotide matrices, and ~30% of codon matrices were pathological to eigendecomposition. The majority of Taylor algorithm errors derived from occurrence of multiple unobserved states. A small number of negative probabilities were detected from the Pad�� algorithm on trinucleotide matrices that were attributable to machine precision. Although the Pad

  7. Assessment of dermal exposure to chemicals

    NARCIS (Netherlands)

    Hemmen, J.J. van; Brouwer, D.H.

    1995-01-01

    The methods for the dermal exposure assessment vary in their complexity and are in some sense complementary to each other. The most easy-to-use methods involve a pseudo-skin-approach, such as gloves and removal by washing. In some cases generic modelling appears to be possible. The experimental

  8. Spectra of sparse random matrices

    International Nuclear Information System (INIS)

    Kuehn, Reimer

    2008-01-01

    We compute the spectral density for ensembles of sparse symmetric random matrices using replica. Our formulation of the replica-symmetric ansatz shares the symmetries of that suggested in a seminal paper by Rodgers and Bray (symmetry with respect to permutation of replica and rotation symmetry in the space of replica), but uses a different representation in terms of superpositions of Gaussians. It gives rise to a pair of integral equations which can be solved by a stochastic population-dynamics algorithm. Remarkably our representation allows us to identify pure-point contributions to the spectral density related to the existence of normalizable eigenstates. Our approach is not restricted to matrices defined on graphs with Poissonian degree distribution. Matrices defined on regular random graphs or on scale-free graphs, are easily handled. We also look at matrices with row constraints such as discrete graph Laplacians. Our approach naturally allows us to unfold the total density of states into contributions coming from vertices of different local coordinations and an example of such an unfolding is presented. Our results are well corroborated by numerical diagonalization studies of large finite random matrices

  9. Assessment of dermal exposure to bitumen condensate among road paving and mastic crews with an observational method

    NARCIS (Netherlands)

    Agostini, M.; Fransman, W.; Vocht, F.D.; Joode, B.V.W.D.; Kromhout, H.

    2011-01-01

    Objective: To assess dermal exposure to bitumen condensate among road pavers and indoor mastic workers in multiple crews using a semi-quantitative observational method [DeRmal Exposure Assessment Method (DREAM)].Methods: Two skilled observers assessed dermal exposure to bitumen condensate among 85

  10. SVOC exposure indoors: fresh look at dermal pathways.

    Science.gov (United States)

    Weschler, C J; Nazaroff, W W

    2012-10-01

    This paper critically examines indoor exposure to semivolatile organic compounds (SVOCs) via dermal pathways. First, it demonstrates that--in central tendency--an SVOC's abundance on indoor surfaces and in handwipes can be predicted reasonably well from gas-phase concentrations, assuming that thermodynamic equilibrium prevails. Then, equations are developed, based upon idealized mass-transport considerations, to estimate transdermal penetration of an SVOC either from its concentration in skin-surface lipids or its concentration in air. Kinetic constraints limit air-to-skin transport in the case of SVOCs that strongly sorb to skin-surface lipids. Air-to-skin transdermal uptake is estimated to be comparable to or larger than inhalation intake for many SVOCs of current or potential interest indoors, including butylated hydroxytoluene, chlordane, chlorpyrifos, diethyl phthalate, Galaxolide, geranyl acetone, nicotine (in free-base form), PCB28, PCB52, Phantolide, Texanol and Tonalide. Although air-to-skin transdermal uptake is anticipated to be slow for bisphenol A, we find that transdermal permeation may nevertheless be substantial following its transfer to skin via contact with contaminated surfaces. The paper concludes with explorations of the influence of particles and dust on dermal exposure, the role of clothing and bedding as transport vectors, and the potential significance of hair follicles as transport shunts through the epidermis. Human exposure to indoor pollutants can occur through dietary and nondietary ingestion, inhalation, and dermal absorption. Many factors influence the relative importance of these pathways, including physical and chemical properties of the pollutants. This paper argues that exposure to indoor semivolatile organic compounds (SVOCs) through the dermal pathway has often been underestimated. Transdermal permeation of SVOCs can be substantially greater than is commonly assumed. Transport of SVOCs from the air to and through the skin is

  11. A single-arm trial indirect comparison investigation: a proof-of-concept method to predict venous leg ulcer healing time for a new acellular synthetic matrix matched to standard care control

    OpenAIRE

    Shannon, R; Nelson, A

    2017-01-01

    To compare data on time to healing from two separate cohorts: one treated with a new acellular synthetic matrix plus standard care (SC) and one matched from four large UK pragmatic, randomised controlled trials [venous leg ulcer (VLU) evidence network]. We introduce a new proof-of-concept strategy to a VLU clinical evidence network, propensity score matching and sensitivity analysis to predict the feasibility of the new acellular synthetic matrix plus SC for success in future randomised, cont...

  12. Different IgG-subclass distributions after whole-cell and acellular pertussis infant primary vaccinations in healthy and pertussis infected children

    NARCIS (Netherlands)

    Hendrikx, Lotte H.; Schure, Rose-Minke; Ozturk, Kemal; de Rond, Lia G. H.; de Greeff, S. C.; Sanders, Elisabeth A. M.; Berbers, Guy A. M.; Buisman, Anne-Marie

    2011-01-01

    The distribution of IgG-subclasses provides insight in the immunological mechanisms of protection against whooping cough. We investigated the effect of Dutch whole-cell pertussis and acellular pertussis vaccines administered in infancy on the IgG-subclass distributions in healthy children aged 12

  13. Liposome-containing Hibiscus sabdariffa calyx extract formulations with increased antioxidant activity, improved dermal penetration and reduced dermal toxicity.

    Science.gov (United States)

    Pinsuwan, Sirirat; Amnuaikit, Thanaporn; Ungphaiboon, Suwipa; Itharat, Arunporn

    2010-12-01

    Hibiscus sabdariffa Linn, or Roselle, is a medicinal plant used extensively in traditional Thai medicine since ancient times. The extracts of Roselle calyces possess antioxidant activity and have potential for development as active ingredients in cosmetic products. However the limitations of using Roselle extracts in cosmetics are its low skin permeation and dermal irritation. Liposome technology is an obvious approach that might overcome these problems. Liposome formulations of standardized Roselle extracts were developed with various lipid components. The formulation showing the highest entrapment efficiency was selected for stability, skin permeation and dermal irritability studies. The liposome formulation with the highest entrapment efficiency (83%) and smalôlest particle size (332 mm) was formulated with phosphatidylcholine from soybean (SPC): Tween 80: deoxycholic acid (DA); 84:16:2.5 weight ratio, total lipid of 200 g/mL and 10% w/v Roselle extract in final liposomal preparation. This liposome formulation was found to be stable after storage at 4 degrees C, protected from light, for 2 months. The in vitro skin permeation studies, using freshly excised pig skin and modified Franz-diffusion cells, showed that the liposome formulation was able to considerably increased the rate of permeation of active compounds in Roselle extracts compared to the Roselle extract solution. The in vivo dermal irritability testing on rabbit skin showed that the liposome formulation dramatically decreased skin irritability compared to the unformulated extract. These results showed that the liposomes containing Roselle extracts had good stability, high entrapment efficacy, increased skin permeation and low skin irritation.

  14. Acellular Mouse Kidney ECM can be Used as a Three-Dimensional Substrate to Test the Differentiation Potential of Embryonic Stem Cell Derived Renal Progenitors.

    Science.gov (United States)

    Sambi, Manpreet; Chow, Theresa; Whiteley, Jennifer; Li, Mira; Chua, Shawn; Raileanu, Vanessa; Rogers, Ian M

    2017-08-01

    The development of strategies for tissue regeneration and bio-artificial organ development is based on our understanding of embryogenesis. Differentiation protocols attempt to recapitulate the signaling modalities of gastrulation and organogenesis, coupled with cell selection regimens to isolate the cells of choice. This strategy is impeded by the lack of optimal in vitro culture systems since traditional culture systems do not allow for the three-dimensional interaction between cells and the extracellular matrix. While artificial three-dimensional scaffolds are available, using the natural extracellular matrix scaffold is advantageous because it has a distinct architecture that is difficult to replicate. The adult extracellular matrix is predicted to mediate signaling related to tissue repair not embryogenesis but existing similarities between the two argues that the extracellular matrix will influence the differentiation of stem and progenitor cells. Previous studies using undifferentiated embryonic stem cells grown directly on acellular kidney ECM demonstrated that the acellular kidney supported cell growth but limited differentiation occurred. Using mouse kidney extracellular matrix and mouse embryonic stem cells we report that the extracellular matrix can support the development of kidney structures if the stem cells are first differentiated to kidney progenitor cells before being applied to the acellular organ.

  15. Chemiluminescence in cryogenic matrices

    Science.gov (United States)

    Lotnik, S. V.; Kazakov, Valeri P.

    1989-04-01

    The literature data on chemiluminescence (CL) in cryogenic matrices have been classified and correlated for the first time. The role of studies on phosphorescence and CL at low temperatures in the development of cryochemistry is shown. The features of low-temperature CL in matrices of nitrogen and inert gases (fine structure of spectra, matrix effects) and the data on the mobility and reactivity of atoms and radicals at very low temperatures are examined. The trends in the development of studies on CL in cryogenic matrices, such as the search for systems involving polyatomic molecules and extending the forms of CL reactions, are followed. The reactions of active nitrogen with hydrocarbons that are accompanied by light emission and CL in the oxidation of carbenes at T >= 77 K are examined. The bibliography includes 112 references.

  16. Labeled chloroquine analog in diagnosis of ocular and dermal melanomas

    International Nuclear Information System (INIS)

    Beierwaltes, W.H.

    1974-01-01

    On the basis of the melanin-specific properties of chloroquine, an 125 I-labeled chloroquine analog (NM-113) was synthesized for use in the diagnosis of ocular and dermal melanomas. The limitations and indications for the use of NM-113 in the diagnosis of dermal melanomas are summarized, and its efficiency in the diagnosis of ocular melanomas is discussed. The low probability of side effects (radiation effects) on the retina from a diagnostic dose of 2 m Ci (46 rads) is mentioned. (U.S.)

  17. A Fibrocontractive Mechanochemical Model of Dermal Wound Closure Incorporating Realistic Growth Factor Kinetics

    KAUST Repository

    Murphy, Kelly E.

    2012-01-13

    Fibroblasts and their activated phenotype, myofibroblasts, are the primary cell types involved in the contraction associated with dermal wound healing. Recent experimental evidence indicates that the transformation from fibroblasts to myofibroblasts involves two distinct processes: The cells are stimulated to change phenotype by the combined actions of transforming growth factor β (TGFβ) and mechanical tension. This observation indicates a need for a detailed exploration of the effect of the strong interactions between the mechanical changes and growth factors in dermal wound healing. We review the experimental findings in detail and develop a model of dermal wound healing that incorporates these phenomena. Our model includes the interactions between TGFβ and collagenase, providing a more biologically realistic form for the growth factor kinetics than those included in previous mechanochemical descriptions. A comparison is made between the model predictions and experimental data on human dermal wound healing and all the essential features are well matched. © 2012 Society for Mathematical Biology.

  18. A Fibrocontractive Mechanochemical Model of Dermal Wound Closure Incorporating Realistic Growth Factor Kinetics

    KAUST Repository

    Murphy, Kelly E.; Hall, Cameron L.; Maini, Philip K.; McCue, Scott W.; McElwain, D. L. Sean

    2012-01-01

    Fibroblasts and their activated phenotype, myofibroblasts, are the primary cell types involved in the contraction associated with dermal wound healing. Recent experimental evidence indicates that the transformation from fibroblasts to myofibroblasts involves two distinct processes: The cells are stimulated to change phenotype by the combined actions of transforming growth factor β (TGFβ) and mechanical tension. This observation indicates a need for a detailed exploration of the effect of the strong interactions between the mechanical changes and growth factors in dermal wound healing. We review the experimental findings in detail and develop a model of dermal wound healing that incorporates these phenomena. Our model includes the interactions between TGFβ and collagenase, providing a more biologically realistic form for the growth factor kinetics than those included in previous mechanochemical descriptions. A comparison is made between the model predictions and experimental data on human dermal wound healing and all the essential features are well matched. © 2012 Society for Mathematical Biology.

  19. Extracellular matrices for gastrointestinal surgery: Ex vivo testing and current applications

    Science.gov (United States)

    Hoeppner, Jens; Marjanovic, Goran; Helwig, Peter; Hopt, Ulrich Theodor; Keck, Tobias

    2010-01-01

    AIM: To assess the effects of bile and pancreatic juice on structural and mechanical resistance of extracellular matrices (ECMs) in vitro. METHODS: Small-intestinal submucosa (SIS), porcine dermal matrix (PDM), porcine pericardial matrix (PPM) and bovine pericardial matrix (BPM) were incubated in human bile and pancreatic juice in vitro. ECMs were examined by macroscopic observation, scanning electron microscopy (SEM) and testing of mechanical resistance. RESULTS: PDM dissolved within 4 d after exposure to bile or pancreatic juice. SIS, PPM and PDM retained their integrity for > 60 d when incubated in either digestive juice. The effect of bile was found to be far more detrimental to mechanical stability than pancreatic juice in all tested materials. In SIS, the loss of mechanical stability after incubation in either of the digestive secretions was less distinct than in PPM and BPM [mFmax 4.01/14.27 N (SIS) vs 2.08/5.23 N (PPM) vs 1.48/7.89 N (BPM)]. In SIS, the extent of structural damage revealed by SEM was more evident in bile than in pancreatic juice. In PPM and BPM, structural damage was comparable in both media. CONCLUSION: PDM is less suitable for support of gastrointestinal healing. Besides SIS, PPM and BPM should also be evaluated experimentally for gastrointestinal indications. PMID:20731016

  20. Creation of an acellular vaginal matrix for potential vaginal augmentation and cloacal repair.

    Science.gov (United States)

    Greco, K V; Jones, L G; Obiri-Yeboa, I; Ansari, T

    2018-05-21

    our aim was to use porcine vagina to create a vaginal matrix and test its cellular biocompatibility. vagina was harvested from pigs and de-cellularised (DC) using a combination of detergents (Triton x-100 and sodium deoxycholate) and enzymes (DNAse/RNAse). the presence of cellular material, collagen structural integrity and basement membrane proteins were assessed histologically. To address cytocompatibility, porcine adipose derived-mesenchymal stem cells (AD-MSC) were harvested from abdominal fat together with vaginal epithelial cells (VEC) and seeded onto the mucosal aspect of the vaginal scaffold. Both cells populations were seeded individually and assessed histologically at days 3 and 10. MAIN OUTCOMES/RESULTS: the combination of enzymes and detergents resulted in a totally acellular matrix with very low DNA amount (control= 97.5ng/μl ± 10.8 vs DC= 40.1 ng/μl ±0.33 p=0.02). The extra cellular matrix (ECM) showed retention of collagen fibres and elastin and a 50% retention in glycosaminoglycan content; (control= 1.18μg/mg ± 0.28 DC = 1.35μg/mg ± 0.1 p=0.03) and an intact basement membrane (positive for both laminin and collagen IV). Seeded scaffolds showed cell attachment with both AD-MSC and VEC at days 3 and 10. it is possible to generate an acellular porcine vaginal matrix capable of supporting cells to reconstruct the vagina for future pre-clinical testing, and holds promise for creating clinically relevant sized tissue for human application. Copyright © 2018. Published by Elsevier Inc.

  1. Efek Pemberian Suntikan Subkutan Vitamin C Terhadap Luka Insisi Dermal

    Directory of Open Access Journals (Sweden)

    Surya Darma

    2014-09-01

    Full Text Available Abstrak Vitamin C berfungsi sebagai kofaktor enzyme prolil dan lysil hydroxilase. Enzym tersebut berfungsi dalam proses hidroksilasi yang membentuk ikatan hidroksiprolin dan hidroksilisin pada fibroblast dalam membentuk kolagen. Selain itu Vitaimin C juga berfungsi meregulasi dan menstabilkan trankripsi gen mRNA prokolagen pada proses pembentukan kolagen di dermis. Berdasarkan hal tersebut diatas, peneliti tertarik untuk membuktikan apakah pemberian vitamin C subkutan disekitar luka insisi dermal berefek pada pembentukan kolagen yang lebih padat dalam proses penyembuhan luka. Metode: Penelitian eksperimental ini menggunakan tikus Wistar sebanyak 32 ekor, yang dibagi menjadi 2 kelompok yaitu 16 ekor sebagai kontrol dan 16 ekor lagi sebagai perlakuan. Pada kedua kelompok dilakukan insisi di punggung sepanjang 2 cm. Kelompok perlakuan diberi suntikan vitamin C subkutan disekitar luka insisi dermal sebanyak 9 mg (0,09ml, sedangkan kelompokkontrol tidak diberikan.Pada hari kelima dilakukan pengambilan jaringan luka pada kedua sampel untuk pemeriksaan kepadatan kolagen secara mikroskopik. Hasil:Kepadatan kolagen pada hari kelimamenunjukkan perbedaan yang bermakna dari efek penyuntikan vitamin C subkutan terhadap kepadatan kolagen (χ2 = 5,833; P<0,05. Kesimpulan: Penyuntikan vitamin C subkutan disekitar luka insisi dermal efektif dalam meeningkatan kepadatan kolagen. Kata kunci: suntikan vitamin C subkutan, kepadatan kolagen.Abstract Vitamin C functions as enzyme co-factor for prolyl and hidroxylase lysil. The enzyme functions in hydroxylase process that builds hydroxyproline and hydroxylysine bondsin fibroblast in the synthesis of collagen. Besides that, vitamin C also functions in regulating and stabilizing procollagen mRNA gen transcription in dermal collagen synthesis. Based on the facts above, researchers are interested to prove whether subcutaneous injection of vitamin C around dermal insisional wound would result in more compact collagen

  2. Efek Pemberian Suntikan Subkutan Vitamin C Terhadap Luka Insisi Dermal

    Directory of Open Access Journals (Sweden)

    Surya Darma

    2013-09-01

    Full Text Available Abstrak Vitamin C berfungsi sebagai kofaktor enzyme prolil dan lysil hydroxilase. Enzym tersebut berfungsi dalam proses hidroksilasi yang membentuk ikatan hidroksiprolin dan hidroksilisin pada fibroblast dalam membentuk kolagen. Selain itu Vitaimin C juga berfungsi meregulasi dan menstabilkan trankripsi gen mRNA prokolagen pada proses pembentukan kolagen di dermis. Berdasarkan hal tersebut diatas, peneliti tertarik untuk membuktikan apakah pemberian vitamin C subkutan disekitar luka insisi dermal berefek pada pembentukan kolagen yang lebih padat dalam proses penyembuhan luka. Metode: Penelitian eksperimental ini menggunakan tikus Wistar sebanyak 32 ekor, yang dibagi menjadi 2 kelompok yaitu 16 ekor sebagai kontrol dan 16 ekor lagi sebagai perlakuan. Pada kedua kelompok dilakukan insisi di punggung sepanjang 2 cm. Kelompok perlakuan diberi suntikan vitamin C subkutan disekitar luka insisi dermal sebanyak 9 mg (0,09ml, sedangkan kelompokkontrol tidak diberikan.Pada hari kelima dilakukan pengambilan jaringan luka pada kedua sampel untuk pemeriksaan kepadatan kolagen secara mikroskopik. Hasil:Kepadatan kolagen pada hari kelimamenunjukkan perbedaan yang bermakna dari efek penyuntikan vitamin C subkutan terhadap kepadatan kolagen (χ2 = 5,833; P<0,05. Kesimpulan: Penyuntikan vitamin C subkutan disekitar luka insisi dermal efektif dalam meeningkatan kepadatan kolagen. Kata kunci: suntikan vitamin C subkutan, kepadatan kolagen. Abstract Vitamin C functions as enzyme co-factor for prolyl and hidroxylase lysil. The enzyme functions in hydroxylase process that builds hydroxyproline and hydroxylysine bondsin fibroblast in the synthesis of collagen. Besides that, vitamin C also functions in regulating and stabilizing procollagen mRNA gen transcription in dermal collagen synthesis. Based on the facts above, researchers are interested to prove whether subcutaneous injection of vitamin C around dermal insisional wound would result in more compact collagen

  3. Harmonization of future needs for dermal exposure assessment and modeling : a workshop report

    NARCIS (Netherlands)

    Marquart, H.; Maidment, S.; Mcclaflin, J.L.; Fehrenbacher, M.C.

    2001-01-01

    Dermal exposure assessment and modeling is still in early phases of development. This article presents the results of a workshop organized to harmonize the future needs in this field. Methods for dermal exposure assessment either assess the mass of contaminant that is transferred to the skin, or the

  4. SIRT-1 regulates TGF-β-induced dermal fibroblast migration via modulation of Cyr61 expression.

    Science.gov (United States)

    Kwon, Eun-Jeong; Park, Eun-Jung; Yu, Hyeran; Huh, Jung-Sik; Kim, Jinseok; Cho, Moonjae

    2018-05-01

    SIRT1 is a NAD-dependent protein deacetylase that participates in cellular regulation. The increased migration of fibroblasts is an important phenotype in fibroblast activation. The role of SIRT1 in cell migration remains controversial as to whether SIRT1 acts as an activator or suppressor of cell migration. Therefore, we have established the role of SIRT1 in the migration of human dermal fibroblasts and explored targets of SIRT1 during dermal fibroblast migration. SIRT1 and Cyr61 were expressed in human dermal fibroblasts and the stimulation with TGF-β further induced their expression. Treatment with resveratrol (RSV), a SIRT1 agonist, or overexpression of SIRT1 also promoted the expression Cyr61 in human dermal fibroblasts, whereas the inhibition of SIRT1 activity by nicotinamide or knockdown of SIRT1 decreased the level of Cyr61, as well as TGF-β or RSV-induced Cyr61 expression. Blocking of ERK signaling by PD98509 reduced the expression of Cyr61 induced by TGF-β or RSV. TGF-β, RSV, or SIRT1 overexpression enhanced β-catenin as well as Cyr61 expression. This stimulation was reduced by the Wnt inhibitor XAV939. RSV increased migration and nicotinamide attenuated RSV-induced migration of human dermal fibroblasts. Furthermore, SIRT1 overexpression promoted cell migration, whereas blocking Cyr61 attenuated SIRT1-stimulated migration of human dermal fibroblasts. SIRT1 increased cell migration by stimulating Cyr61 expression and the ERK and Wnt/β-catenin signaling. SIRT1-induced Cyr61 activity is very important for human dermal fibroblasts migration.

  5. Characterization and evolution of dermal filaments from patients with Morgellons disease

    OpenAIRE

    Middelveen, Marianne J; Mayne, Peter J; Kahn, Douglas G; Stricker, Raphael B

    2013-01-01

    Marianne J Middelveen,1 Peter J Mayne,1 Douglas G Kahn,2 Raphael B Stricker11International Lyme and Associated Diseases Society, Bethesda, MD, USA; 2Department of Pathology, Olive View–UCLA Medical Center, Sylmar, CA, USAAbstract: Morgellons disease is an emerging skin disease characterized by formation of dermal filaments associated with multisystemic symptoms and tick-borne illness. Some clinicians hypothesize that these often colorful dermal filaments are textile fibers, either s...

  6. Influence of extracellular matrix proteins on human keratinocyte attachment, proliferation and transfer to a dermal wound model.

    Science.gov (United States)

    Dawson, R A; Goberdhan, N J; Freedlander, E; MacNeil, S

    1996-03-01

    The aim of this study was to investigate whether prior culture of cells on ECM proteins might positively influence the performance of keratinocytes when cells are transferred to a dermal in vitro wound bed model. Keratinocytes were cultured using a method for producing cultured epithelial autografts for severely burned patients (essentially using Green's medium, a mitogen-rich medium containing fetal calf serum, cholera toxin, EGF, insulin, transferrin and triiodothyronine). Cells were cultured either on irradiated 3T3 fibroblasts (as in the standard Rheinwald and Green technique) or, alternatively, on collagen I, collagen IV, matrigel, RGD, vitronectin or fibronectin. Under these conditions matrigel, collagen I and IV enhanced initial attachment, RGD, vitronectin, fibronectin and irradiated 3T3 fibroblasts did not. Proliferation of cells was positively influenced by matrigel, collagen I and IV and irradiated 3T3 fibroblasts; of these, however, only matrigel and 3T3 fibroblasts had sustained significant effects on keratinocyte proliferation over 4 days. Cells on fibronectin showed significantly reduced proliferation. An acellular non-viable dermis was then used to mimic the homograft allodermis onto which cultured epithelial autograft sheets are grafted clinically and cells cultured on the various ECM proteins for 96 h were transferred to this in vitro wound model. None of the substrates enhanced keratinocyte performance on this model. It was concluded that under these conditions some ECM proteins can significantly affect keratinocyte attachment and, to a lesser extent, proliferation but that the culture of keratinocytes on these ECM proteins does not appear to confer any lasting benefit to the attachment of these keratinocytes to an in vitro wound-bed model.

  7. Respiratory and dermal symptoms in Thai nurses using latex products.

    Science.gov (United States)

    Supapvanich, C; Povey, A C; de Vocht, F

    2013-09-01

    Despite known health risks related to the use of powdered latex gloves (PLGs), they are still widely used in hospitals in developing countries due to the high cost of alternatives. To determine the prevalence of dermal and respiratory symptoms associated with latex glove use in nurses in Thailand and evaluate the influence of previously reported occupational risk factors in this population. A cross-sectional study in female nurses working in three Thai hospitals. Participants completed a questionnaire on demographics, occupational and personal history, use of latex products at work and dermal and respiratory symptoms attributed to occupational use of latex gloves. Of 899 nurses, 18% reported health effects attributed to the use of latex products. After adjustment for confounding, occupational risk factors associated with increased reporting of dermal symptoms included wearing more than 15 pairs of PLG per day (odds ratio (OR): 2.10, 95% confidence interval (CI): [1.32-3.34]), using chlorhexidine (OR: 2.07, 95% CI: [1.22-3.52]) and being an operating theatre nurse (OR: 2.46, 95% CI: [1.47-4.12]). Being a labour ward nurse (OR: 3.52, 95% CI: [1.26-9.85]) was the only factor associated with increased reporting of respiratory symptoms. Continuing use of PLGs in Thai nurses is associated with increased prevalence of dermal symptoms compared with data from developed countries. Measures to reduce such health effects are well established and should be considered. Additionally, replacement of chlorhexidine with an alternative detergent seems advisable.

  8. Skew-adjacency matrices of graphs

    NARCIS (Netherlands)

    Cavers, M.; Cioaba, S.M.; Fallat, S.; Gregory, D.A.; Haemers, W.H.; Kirkland, S.J.; McDonald, J.J.; Tsatsomeros, M.

    2012-01-01

    The spectra of the skew-adjacency matrices of a graph are considered as a possible way to distinguish adjacency cospectral graphs. This leads to the following topics: graphs whose skew-adjacency matrices are all cospectral; relations between the matchings polynomial of a graph and the characteristic

  9. The invariant theory of matrices

    CERN Document Server

    Concini, Corrado De

    2017-01-01

    This book gives a unified, complete, and self-contained exposition of the main algebraic theorems of invariant theory for matrices in a characteristic free approach. More precisely, it contains the description of polynomial functions in several variables on the set of m\\times m matrices with coefficients in an infinite field or even the ring of integers, invariant under simultaneous conjugation. Following Hermann Weyl's classical approach, the ring of invariants is described by formulating and proving the first fundamental theorem that describes a set of generators in the ring of invariants, and the second fundamental theorem that describes relations between these generators. The authors study both the case of matrices over a field of characteristic 0 and the case of matrices over a field of positive characteristic. While the case of characteristic 0 can be treated following a classical approach, the case of positive characteristic (developed by Donkin and Zubkov) is much harder. A presentation of this case...

  10. Cross-finger dermal pocketing to augment venous outflow for distal fingertip replantation.

    Science.gov (United States)

    Tan, Valerie H; Murugan, Arul; Foo, Tun-Lin; Puhaindran, Mark E

    2014-09-01

    Venous anastomosis in distal fingertip replantations is not always possible, and venous congestion is recognized as a potential cause of failure. Methods previously described to address this problem include amputate deepithelization and dermal pocketing postarterial anastomosis to augment venous outflow. However, attachment of the digit to the palm or abdomen resulted in finger stiffness. We describe a modification of the previous methods by utilizing dermal flaps raised from the adjacent digit in the form of a cross-finger flap. The key differences are the partial deepithelization of the replanted fingertip and subsequent replacement of the dermal flap to the donor digit to minimize donor site morbidity. During the period where the 2 digits are attached, interphalangeal joint mobilization is permitted to maintain joint mobility.

  11. Exact Inverse Matrices of Fermat and Mersenne Circulant Matrix

    Directory of Open Access Journals (Sweden)

    Yanpeng Zheng

    2015-01-01

    Full Text Available The well known circulant matrices are applied to solve networked systems. In this paper, circulant and left circulant matrices with the Fermat and Mersenne numbers are considered. The nonsingularity of these special matrices is discussed. Meanwhile, the exact determinants and inverse matrices of these special matrices are presented.

  12. Complications caused by injection of dermal filler in Danish patients

    DEFF Research Database (Denmark)

    Uth, Charlotte Caspara; Elberg, Jens Jørgen; Zachariae, Claus

    2016-01-01

    Background: The usage of dermal fillers has increased significantly in recent years. Soft tissue augmentation with fillers helps to diminish the facial lines and to restore volume and fullness in the face at a relatively low cost. With the increasing number of treatments, the number of complicati......Background: The usage of dermal fillers has increased significantly in recent years. Soft tissue augmentation with fillers helps to diminish the facial lines and to restore volume and fullness in the face at a relatively low cost. With the increasing number of treatments, the number...

  13. Enhancing Understanding of Transformation Matrices

    Science.gov (United States)

    Dick, Jonathan; Childrey, Maria

    2012-01-01

    With the Common Core State Standards' emphasis on transformations, teachers need a variety of approaches to increase student understanding. Teaching matrix transformations by focusing on row vectors gives students tools to create matrices to perform transformations. This empowerment opens many doors: Students are able to create the matrices for…

  14. DERMAL, ORAL, AND INHALATION PHARMACOKINETICS OF METHYL TERTIARY BUTYL ETHER (MTBE) IN HUMAN VOLUNTEERS

    Science.gov (United States)

    Methyl tertiary butyl ether (MTBE), a gasoline additive, used to increase octane and reduce carbon monoxide emissions and ozone precursors has contaminated drinking water leading to exposure by oral, inhalation, and dermal routes. To determine its dermal, oral, and inhalation ki...

  15. The Dermal Apron Technique for Immediate Implant Socket Management: A Novel Technique.

    Science.gov (United States)

    Levin, Barry P

    2016-01-01

    With immediate implant placement and provisionalization (IIP) in the esthetic zone, measures to counter hard and soft tissue loss are frequently necessary. To reduce the morbidity associated with bone and connective tissue procurement, various exogenous materials are utilized. The "Dermal Apron Technique" presented in this article demonstrates the use of a composite bone particulate (allograft/xenograft) plus a dermal allograft, adapted around screw-retained temporary crowns and secured within a subperiosteal pouch. The purpose is to augment the thickness of peri-implant mucosa for the purpose of preserving ridge dimensions and preventing mucosal recession. Controlled studies are required to further support its use. Clinical significance: Soft tissue health and harmony are critical for successful implant therapy in the esthetic regions of the dentition. Often, autogenous soft tissue grafts are used to augment peri-implant soft tissues. The Dermal Apron Technique is a method, that in specific situations, obviates the need for autogenous grafting. This reduces treatment time and morbidity associated with procurement of these grafts. The Dermal Apron Technique is used simultaneous with immediate placement and provisionalization and can improve long-term esthetic outcomes for patients. © 2016 Wiley Periodicals, Inc.

  16. Dermal exposure to monoterpenes during wood work.

    Science.gov (United States)

    Eriksson, Kare; Wiklund, Leif

    2004-06-01

    The dermal exposure to the suspected allergenic monoterpenes [small alpha]-pinene, [small beta]-pinene and [capital Delta](3)-carene was assessed with a patch sampling technique. The patch used was made of activated charcoal sandwiched between two layers of cotton cloth. Patches were fastened at 12 different spots on a sampling overall and at the front of a cap to estimate the potential exposure of the body. Fastening two patches on a cotton glove, one patch representing the dorsal side and one patch representing the palm of the hand respectively, assessed the exposure on the hands. Sampling was carried out during collecting of pine and spruce boards in sawmills and during sawing of pine wood pieces in joinery shops respectively. The potential dermal exposure of the total body was 29.0-1 890 mg h(-1) with a geometric mean (GM) of 238 mg h(-1) during sawing. During collecting the GM was estimated to 100 mg h(-1) with a range of 12.2-959 mg h(-1). The hands had a mean exposure of 9.24 mg h(-1) during sawing and 3.25 mg h(-1) during collecting respectively. The good correlation between the mass of contamination on the individual body parts and the potential body exposure indicates that sampling can be performed on one body part to give a good estimation of the potential body exposure. Monoterpenes were detected at patches fastened underneath the protective clothing indicating a contamination of the skin of the worker. The patch used may overestimate the dermal exposure.

  17. Group inverses of M-matrices and their applications

    CERN Document Server

    Kirkland, Stephen J

    2013-01-01

    Group inverses for singular M-matrices are useful tools not only in matrix analysis, but also in the analysis of stochastic processes, graph theory, electrical networks, and demographic models. Group Inverses of M-Matrices and Their Applications highlights the importance and utility of the group inverses of M-matrices in several application areas. After introducing sample problems associated with Leslie matrices and stochastic matrices, the authors develop the basic algebraic and spectral properties of the group inverse of a general matrix. They then derive formulas for derivatives of matrix f

  18. DERMAL, ORAL AND INHALATION PHARMACOKINETICS OF METHYL TERTIARY-BUTYL ETHER (MTBE) IN HUMAN VOLUNTEERS

    Science.gov (United States)

    Methyl tertiary butyl ether (MTBE), a gasoline additive used to increase octane and reduce carbon monoxide emissions and ozone precursors, has contaminated drinking water and can lead to exposure by oral, inhalation, and dermal routes. To determine its dermal, oral, and inhal...

  19. Inference for High-dimensional Differential Correlation Matrices.

    Science.gov (United States)

    Cai, T Tony; Zhang, Anru

    2016-01-01

    Motivated by differential co-expression analysis in genomics, we consider in this paper estimation and testing of high-dimensional differential correlation matrices. An adaptive thresholding procedure is introduced and theoretical guarantees are given. Minimax rate of convergence is established and the proposed estimator is shown to be adaptively rate-optimal over collections of paired correlation matrices with approximately sparse differences. Simulation results show that the procedure significantly outperforms two other natural methods that are based on separate estimation of the individual correlation matrices. The procedure is also illustrated through an analysis of a breast cancer dataset, which provides evidence at the gene co-expression level that several genes, of which a subset has been previously verified, are associated with the breast cancer. Hypothesis testing on the differential correlation matrices is also considered. A test, which is particularly well suited for testing against sparse alternatives, is introduced. In addition, other related problems, including estimation of a single sparse correlation matrix, estimation of the differential covariance matrices, and estimation of the differential cross-correlation matrices, are also discussed.

  20. Pigmentation and dermal conservative effects of the astonishing ...

    African Journals Online (AJOL)

    Background: The preference for a fairer skin-tone has become a common trend ... to evaluate the potent dermal protective effect of the two seaweeds Sargassum ... Extracts with potent melanocytotoxicity were formulated into cosmetic cream ...

  1. Phenomenological mass matrices with a democratic warp

    International Nuclear Information System (INIS)

    Kleppe, A.

    2018-01-01

    Taking into account all available data on the mass sector, we obtain unitary rotation matrices that diagonalize the quark matrices by using a specific parametrization of the Cabibbo-Kobayashi-Maskawa mixing matrix. In this way, we find mass matrices for the up- and down-quark sectors of a specific, symmetric form, with traces of a democratic texture.

  2. Risk of Febrile Seizures and Epilepsy After Vaccination With Diphtheria, Tetanus, Acellular Pertussis, Inactivated Poliovirus, and Haemophilus Influenzae Type b

    DEFF Research Database (Denmark)

    Sun, Yuelian; Christensen, Jakob Christensen; Hviid, Anders

    2012-01-01

    -acellular pertussis–inactivated poliovirus– Haemophilus influenzae type b (DTaP-IPV-Hib) vaccine since September 2002. Objective To estimate the risk of febrile seizures and epilepsy after DTaP-IPV-Hib vaccination given at 3, 5, and 12 months. Design, Setting, and Participants A population-based cohort study of 378...

  3. Diagonalization of the mass matrices

    International Nuclear Information System (INIS)

    Rhee, S.S.

    1984-01-01

    It is possible to make 20 types of 3x3 mass matrices which are hermitian. We have obtained unitary matrices which could diagonalize each mass matrix. Since the three elements of mass matrix can be expressed in terms of the three eigenvalues, msub(i), we can also express the unitary matrix in terms of msub(i). (Author)

  4. Disposition of 2,4-dichlorophenoxyacetic acid dimethylamine by Fischer 344 rats dosed orally and dermally

    International Nuclear Information System (INIS)

    Pelletier, O.; Ritter, L.; Caron, J.; Somers, D.

    1989-01-01

    The dimethylamine salt of 14C-ring-labeled 2,4-D was administered to Fischer 344 rats orally (1 and 0.4 mg/kg body weight) and dermally (10 mg/kg body weight). Absorption, distribution, and elimination were determined from 14C-labeled 2,4-D in blood, tissues, and excreta. Quantitatively, most of the orally administered dose (94-96%) became systemically available within 6 h. Following dermal administration 10% of the dose became systemically available over 72 h. However, peak concentrations in blood and kidneys were achieved within 30 min of dosing by either route. By 1.5 h after dosing, 2,4-D concentrations in blood, muscle, liver, and kidneys had decreased in both the orally dosed and dermally dosed animals. Between 2 and 8 h, the blood, muscle, liver and kidney concentrations in dermally dosed animals maintained a plateau while urinary excretion increased, presumably due to continued absorption of 2,4-D from the skin. The concentrations in orally dosed animals continued to decrease. Following 7 h of dermal exposure, skin cleansing removed about 63% of the applied dose; about 17% of the applied dose remained at the site of dermal dosing. At 8 h, 2,4-D concentrations in blood, muscle, liver, and kidneys of dermally dosed animals began to decrease, most likely a result of the removal of the reservoir on the skin. However, 2,4-D continued to be absorbed from skin site, resulting in a slower decline of the 2,4-D concentrations in these tissues over remainder of the 72-h study period. By comparison, in animals that had been orally dosed, the absorbed dose was almost completely excreted within 24 h

  5. Elevated Immune Response Among Children 4 Years of Age With Pronounced Local Adverse Events After the Fifth Diphtheria, Tetanus, Acellular Pertussis Vaccination.

    NARCIS (Netherlands)

    van der Lee, Saskia; Kemmeren, Jeanet M; de Rond, Lia G H; Öztürk, Kemal; Westerhof, Anneke; de Melker, Hester E; Sanders, Elisabeth A M; Berbers, Guy A M; van der Maas, Nicoline A T; Rümke, Hans C; Buisman, Anne-Marie

    In the Netherlands, acellular pertussis vaccines replaced the more reactogenic whole-cell pertussis vaccines. This replacement in the primary immunization schedule of infants coincided with a significant increase in pronounced local adverse events (AEs) in 4 years old children shortly after the

  6. The construction of factorized S-matrices

    International Nuclear Information System (INIS)

    Chudnovsky, D.V.

    1981-01-01

    We study the relationships between factorized S-matrices given as representations of the Zamolodchikov algebra and exactly solvable models constructed using the Baxter method. Several new examples of symmetric and non-symmetric factorized S-matrices are proposed. (orig.)

  7. Increased dermal mast cell prevalence and susceptibility to development of basal cell carcinoma in humans

    DEFF Research Database (Denmark)

    Grimbaldeston, Michele A; Skov, Lone; Finlay-Jones, John J

    2002-01-01

    eliminate them. Studies in a range of inbred mouse strains as well as mast cell-depleted mice reconstituted with mast cell precursors support a functional link between histamine-staining dermal mast cells and the extent of susceptibility to UVB-induced systemic immunomodulation. Humans, like mouse strains......, display variations in dermal mast cell prevalence. In a study of Danish and South Australian BCC patients and control subjects, one 4-mm punch biopsy of non-sun-exposed buttock skin was sampled from each participant. This skin site was investigated to avoid any changes in mast cell prevalence caused...... by sun exposure. Two sections (4 microm) per biopsy were immunohistochemically stained for detection of histamine-containing dermal mast cells. Computer-generated image analysis evaluated dermal mast cell prevalence in both sections by quantifying the total number of mast cells according to the total...

  8. Quantification of dermal exposure to nanoparticles from solid nanocomposites by using single particle ICP-MS

    DEFF Research Database (Denmark)

    Mackevica, Aiga; Olsson, Mikael Emil; Hansen, Steffen Foss

    2016-01-01

    , optical or photocatalytical properties. There is a lot of research focusing on effects exerted by nanoparticles, but the knowledge concerning release and subsequential exposure to nanoparticles is very limited, and information regarding potential dermal exposure from nanomaterial containing solid articles...... and characterization. In this study, we have investigated the potential dermal exposure to three different types of nano-enabled consumer products: Ag-containing keyboard covers, TiO2 coated ceramic tiles, and wood painted with CuO containing paint. The potential for dermal transfer from the aforementioned surfaces...

  9. Matrices in Engineering Problems

    CERN Document Server

    Tobias, Marvin

    2011-01-01

    This book is intended as an undergraduate text introducing matrix methods as they relate to engineering problems. It begins with the fundamentals of mathematics of matrices and determinants. Matrix inversion is discussed, with an introduction of the well known reduction methods. Equation sets are viewed as vector transformations, and the conditions of their solvability are explored. Orthogonal matrices are introduced with examples showing application to many problems requiring three dimensional thinking. The angular velocity matrix is shown to emerge from the differentiation of the 3-D orthogo

  10. A Brief Historical Introduction to Matrices and Their Applications

    Science.gov (United States)

    Debnath, L.

    2014-01-01

    This paper deals with the ancient origin of matrices, and the system of linear equations. Included are algebraic properties of matrices, determinants, linear transformations, and Cramer's Rule for solving the system of algebraic equations. Special attention is given to some special matrices, including matrices in graph theory and electrical…

  11. Dermal changes in superficial basal cell carcinoma, melanoma in situ and actinic keratosis and their implications

    Science.gov (United States)

    Kazlouskaya, Viktoryia; Malhotra, Saurabh; Navarro, Raquel; Wu, Karen Nguyen; Shvartsbeyn, Marianna; Shengli, Chen; Gui, Jiang; Elston, Dirk M.

    2018-01-01

    Background Basal cell carcinoma (BCC) has a characteristic stroma, but less is known about the dermal characteristics associated with melanoma in situ (MIS) and actinic keratosis (AK). Materials and methods Dermal changes were studied in 301 specimens of AK, BCC and MIS. Subsequently, blinded images of dermal changes from 90 randomly selected cases of those entities were used to assess the predictive value of the dermal changes. Agreement with the final diagnosis was calculated using kappa coefficient (κ). Results Fibromyxoid stroma was present in 82% of BCC cases; fibrous stroma was seen in 25% of BCC, 58% of MIS and 35.6% of AK specimens (p <0.05). A lichenoid inflammatory infiltrate was frequently associated with AK and a perifollicular infiltrate with periadnexal fibrosis with MIS. Blinded evaluation of images of the dermal changes associated with the tumors yielded the correct diagnosis in (54.4, 41.1 and 27.8%; average 41.2%) by the three appraisers. Coefficient of agreement in blinded imaged evaluation with the actual diagnosis was higher in the BCC and MIS compared with AK (κ = 0.37, p = 0.0001; κ = 0.2, p = 0.0005 and κ = −0.06, p = 0.84, respectively). Conclusion Dermal features may be helpful in predicting the correct diagnosis when tumor is not visible. PMID:24117926

  12. Dermal absorption and urinary elimination of N-methyl-2-pyrrolidone.

    Science.gov (United States)

    Bader, Michael; Keener, Stephen A; Wrbitzky, Renate

    2005-09-01

    The dermal absorption of the solvent N-methyl-2-pyrrolidone (NMP) and its elimination in urine was investigated in an experimental study. Seven volunteers were exposed to 1045 mg of liquid NMP under occlusive conditions for 2 h. Urine was collected before, during and up to 72 h after the exposure and analysed for NMP by GC/MS after liquid-liquid extraction. Additionally, the remaining NMP in the pads was determined to estimate the total dermal uptake. The concentration of NMP in urine increased rapidly after beginning of the exposure up to 1 h after the exposure was completed. A peak concentration of 1,836+/-863 microg/l was observed, the half-life in urine was 3.2 h. About 0.5% of the absorbed dose was excreted metabolically unchanged. An average dermal absorption of 5.5 mg cm(-2) h(-1) was calculated. The results of this study show that the percutaneous absorption of NMP may contribute significantly to the overall uptake of the solvent, e.g. in the workplace. Therefore, a biological monitoring of NMP exposed workers is essential for occupational-medical surveillance.

  13. Tricho-odonto-onycho-dermal dysplasia and WNT10A mutations.

    Science.gov (United States)

    Kantaputra, P; Kaewgahya, M; Jotikasthira, D; Kantaputra, W

    2014-04-01

    We report on three novel (IVS2+1G>A splice site, c.1066G>T, and c.1039G>T, and one previously reported (c.637G>A) WNT10A mutations in three patients affected with odonto-onycho-dermal dysplasia (OODD; OMIM 275980). OODD is a rare form of autosomal recessive ectodermal dysplasia involving hair, teeth, nails, and skin, characterized by hypodontia (tooth agenesis), smooth tongue with marked reduction of filiform and fungiform papillae, nail dysplasia, dry skin, palmoplantar keratoderma, and hyperhidrosis of palms and soles. The novel IVS+1G>A splice site mutation is predicted to cause significant protein alteration. The other novel mutations we found including c.1066G>T and c.1039G>T are predicted to cause p.Gly356Cys and p.Glu347X, respectively. Barrel-shaped mandibular incisors and severe hypodontia appear to be associated with homozygous or compound heterozygous mutations of WNT10A. The name "tricho-odonto-onycho-dermal dysplasia" is suggested to replace "odonto-onycho-dermal dysplasia" because hair anomalies including hypotrichosis and slow-growing hair have been reported in numerous reported patients with this syndrome. © 2014 Wiley Periodicals, Inc.

  14. Hydrocortisone and triiodothyronine regulate hyaluronate synthesis in a tissue-engineered human dermal equivalent through independent pathways.

    Science.gov (United States)

    Deshpande, Madhura; Papp, Suzanne; Schaffer, Lana; Pouyani, Tara

    2015-02-01

    Hydrocortisone (HC) and triiodothyronine (T3) have both been shown to be capable of independently inhibiting hyaluronate (HA, hyaluronic acid) synthesis in a self-assembled human dermal equivalent (human dermal matrix). We sought to investigate the action of these two hormones in concert on extracellular matrix formation and HA inhibition in the tissue engineered human dermal matrix. To this end, neonatal human dermal fibroblasts were cultured in defined serum-free medium for 21 days in the presence of each hormone alone, or in combination, in varying concentrations. Through a process of self-assembly, a substantial dermal extracellular matrix formed that was characterized. The results of these studies demonstrate that combinations of the hormones T3 and hydrocortisone showed significantly higher levels of hyaluronate inhibition as compared to each hormone alone in the human dermal matrix. In order to gain preliminary insight into the genes regulating HA synthesis in this system, a differential gene array analysis was conducted in which the construct prepared in the presence of 200 μg/mL HC and 0.2 nM T3 was compared to the normal construct (0.4 μg/mL HC and 20 pM T3). Using a GLYCOv4 gene chip containing approximately 1260 human genes, we observed differential expression of 131 genes. These data suggest that when these two hormones are used in concert a different mechanism of inhibition prevails and a combination of degradation and inhibition of HA synthesis may be responsible for HA regulation in the human dermal matrix. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  15. Hypercyclic Abelian Semigroups of Matrices on Cn

    International Nuclear Information System (INIS)

    Ayadi, Adlene; Marzougui, Habib

    2010-07-01

    We give a complete characterization of existence of dense orbit for any abelian semigroup of matrices on C n . For finitely generated semigroups, this characterization is explicit and is used to determine the minimal number of matrices in normal form over C which forms a hypercyclic abelian semigroup on C n . In particular, we show that no abelian semigroup generated by n matrices on C n can be hypercyclic. (author)

  16. Generalized Perron--Frobenius Theorem for Nonsquare Matrices

    OpenAIRE

    Avin, Chen; Borokhovich, Michael; Haddad, Yoram; Kantor, Erez; Lotker, Zvi; Parter, Merav; Peleg, David

    2013-01-01

    The celebrated Perron--Frobenius (PF) theorem is stated for irreducible nonnegative square matrices, and provides a simple characterization of their eigenvectors and eigenvalues. The importance of this theorem stems from the fact that eigenvalue problems on such matrices arise in many fields of science and engineering, including dynamical systems theory, economics, statistics and optimization. However, many real-life scenarios give rise to nonsquare matrices. A natural question is whether the...

  17. Functional trade-off between strength and thermal capacity of dermal armor: Insights from girdled lizards.

    Science.gov (United States)

    Broeckhoven, Chris; du Plessis, Anton; Hui, Cang

    2017-10-01

    The presence of dermal armor is often unambiguously considered the result of an evolutionary predator-prey arms-race. Recent studies focusing predominantly on osteoderms - mineralized elements embedded in the dermis layer of various extant and extinct vertebrates - have instead proposed that dermal armor might exhibit additional functionalities besides protection. Multiple divergent functionalities could impose conflicting demands on a phenotype, yet, functional trade-offs in dermal armor have rarely been investigated. Here, we use high-resolution micro-computed tomography and voxel-based simulations to test for a trade-off between the strength and thermal capacity of osteoderms using two armored cordylid lizards as model organisms. We demonstrate that high vascularization, associated with improved thermal capacity might limit the strength of osteoderms. These results call for a holistic, cautionary future approach to studies investigating dermal armor, especially those aiming to inspire artificial protective materials. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. A randomised, double-blind, non-inferiority clinical trial on the safety and immunogenicity of a tetanus, diphtheria and monocomponent acellular pertussis (TdaP) vaccine in comparison to a tetanus and diphtheria (Td) vaccine when given as booster vaccinations to healthy adults

    DEFF Research Database (Denmark)

    Thierry-Carstensen, Birgit; Jordan, Karina; Uhlving, Hilde Hylland

    2012-01-01

    Increasing incidence of pertussis in adolescents and adults has stimulated the development of safe and immunogenic acellular pertussis vaccines for booster vaccination of adolescents and adults.......Increasing incidence of pertussis in adolescents and adults has stimulated the development of safe and immunogenic acellular pertussis vaccines for booster vaccination of adolescents and adults....

  19. Formal matrices

    CERN Document Server

    Krylov, Piotr

    2017-01-01

    This monograph is a comprehensive account of formal matrices, examining homological properties of modules over formal matrix rings and summarising the interplay between Morita contexts and K theory. While various special types of formal matrix rings have been studied for a long time from several points of view and appear in various textbooks, for instance to examine equivalences of module categories and to illustrate rings with one-sided non-symmetric properties, this particular class of rings has, so far, not been treated systematically. Exploring formal matrix rings of order 2 and introducing the notion of the determinant of a formal matrix over a commutative ring, this monograph further covers the Grothendieck and Whitehead groups of rings. Graduate students and researchers interested in ring theory, module theory and operator algebras will find this book particularly valuable. Containing numerous examples, Formal Matrices is a largely self-contained and accessible introduction to the topic, assuming a sol...

  20. ESTIMATION OF FUNCTIONALS OF SPARSE COVARIANCE MATRICES.

    Science.gov (United States)

    Fan, Jianqing; Rigollet, Philippe; Wang, Weichen

    High-dimensional statistical tests often ignore correlations to gain simplicity and stability leading to null distributions that depend on functionals of correlation matrices such as their Frobenius norm and other ℓ r norms. Motivated by the computation of critical values of such tests, we investigate the difficulty of estimation the functionals of sparse correlation matrices. Specifically, we show that simple plug-in procedures based on thresholded estimators of correlation matrices are sparsity-adaptive and minimax optimal over a large class of correlation matrices. Akin to previous results on functional estimation, the minimax rates exhibit an elbow phenomenon. Our results are further illustrated in simulated data as well as an empirical study of data arising in financial econometrics.

  1. Sexual dimorphisms in the dermal denticles of the lesser-spotted catshark, Scyliorhinus canicula (Linnaeus, 1758.

    Directory of Open Access Journals (Sweden)

    Neil Crooks

    Full Text Available The dermal layers of several elasmobranch species have been shown to be sexually dimorphic. Generally, when this occurs the females have thicker dermal layers compared to those of males. This sexual dimorphism has been suggested to occur as a response to male biting during mating. Although male biting as a copulatory behaviour in Scyliorhinus canicula has been widely speculated to occur, only relatively recently has this behaviour been observed. Male S. canicula use their mouths to bite the female's pectoral and caudal fins as part of their pre-copulatory behaviour and to grasp females during copulation. Previous work has shown that female S. canicula have a thicker epidermis compared to that of males. The structure of the dermal denticles in females may also differ from that of males in order to protect against male biting or to provide a greater degree of friction in order to allow the male more purchase. This study reveals that the length, width and density of the dermal denticles of mature male and female S. canicula are sexually dimorphic across the integument in areas where males have been observed to bite and wrap themselves around females (pectoral fin, area posterior to the pectoral fin, caudal fin, and pelvic girdle. No significant differences in the dermal denticle dimensions were found in other body areas examined (head, dorsal skin and caudal peduncle. Sexually dimorphic dermal denticles in mature S. canicula could be a response to male biting/wrapping as part of the copulatory process.

  2. Determinants of dermal exposure relevant for exposure modelling in regulatory risk assessment.

    Science.gov (United States)

    Marquart, J; Brouwer, D H; Gijsbers, J H J; Links, I H M; Warren, N; van Hemmen, J J

    2003-11-01

    Risk assessment of chemicals requires assessment of the exposure levels of workers. In the absence of adequate specific measured data, models are often used to estimate exposure levels. For dermal exposure only a few models exist, which are not validated externally. In the scope of a large European research programme, an analysis of potential dermal exposure determinants was made based on the available studies and models and on the expert judgement of the authors of this publication. Only a few potential determinants appear to have been studied in depth. Several studies have included clusters of determinants into vaguely defined parameters, such as 'task' or 'cleaning and maintenance of clothing'. Other studies include several highly correlated parameters, such as 'amount of product handled', 'duration of task' and 'area treated', and separation of these parameters to study their individual influence is not possible. However, based on the available information, a number of determinants could clearly be defined as proven or highly plausible determinants of dermal exposure in one or more exposure situation. This information was combined with expert judgement on the scientific plausibility of the influence of parameters that have not been extensively studied and on the possibilities to gather relevant information during a risk assessment process. The result of this effort is a list of determinants relevant for dermal exposure models in the scope of regulatory risk assessment. The determinants have been divided into the major categories 'substance and product characteristics', 'task done by the worker', 'process technique and equipment', 'exposure control measures', 'worker characteristics and habits' and 'area and situation'. To account for the complex nature of the dermal exposure processes, a further subdivision was made into the three major processes 'direct contact', 'surface contact' and 'deposition'.

  3. A dermal model for spray painters, part I : subjective exposure modelling of spray paint deposition

    NARCIS (Netherlands)

    Brouwer, D.H.; Semple, S.; Marquart, J.; Cherrie, J.W.

    2001-01-01

    The discriminative power of existing dermal exposure models is limited. Most models only allow occupational hygienists to rank workers between and within workplaces according to broad bands of dermal exposure. No allowance is made for the work practices of different individuals. In this study a

  4. THE ALGORITHM AND PROGRAM OF M-MATRICES SEARCH AND STUDY

    Directory of Open Access Journals (Sweden)

    Y. N. Balonin

    2013-05-01

    Full Text Available The algorithm and software for search and study of orthogonal bases matrices – minimax matrices (M-matrix are considered. The algorithm scheme is shown, comments on calculation blocks are given, and interface of the MMatrix software system developed with participation of the authors is explained. The results of the universal algorithm work are presented as Hadamard matrices, Belevitch matrices (C-matrices, conference matrices and matrices of even and odd orders complementary and closely related to those ones by their properties, in particular, the matrix of the 22-th order for which there is no C-matrix. Examples of portraits for alternative matrices of the 255-th and the 257-th orders are given corresponding to the sequences of Mersenne and Fermat numbers. A new way to get Hadamard matrices is explained, different from the previously known procedures based on iterative processes and calculations of Lagrange symbols, with theoretical and practical meaning.

  5. Acellular bi-layer silk fibroin scaffolds support tissue regeneration in a rabbit model of onlay urethroplasty.

    Science.gov (United States)

    Chung, Yeun Goo; Tu, Duong; Franck, Debra; Gil, Eun Seok; Algarrahi, Khalid; Adam, Rosalyn M; Kaplan, David L; Estrada, Carlos R; Mauney, Joshua R

    2014-01-01

    Acellular scaffolds derived from Bombyx mori silk fibroin were investigated for their ability to support functional tissue regeneration in a rabbit model of urethra repair. A bi-layer silk fibroin matrix was fabricated by a solvent-casting/salt leaching process in combination with silk fibroin film casting to generate porous foams buttressed by homogeneous silk fibroin films. Ventral onlay urethroplasty was performed with silk fibroin grafts (Group 1, N = 4) (Width × Length, 1 × 2 cm(2)) in adult male rabbits for 3 m of implantation. Parallel control groups consisted of animals receiving small intestinal submucosa (SIS) implants (Group 2, N = 4) or urethrotomy alone (Group 3, N = 3). Animals in all groups exhibited 100% survival prior to scheduled euthanasia and achieved voluntary voiding following 7 d of initial catheterization. Retrograde urethrography of each implant group at 3 m post-op revealed wide urethral calibers and preservation of organ continuity similar to pre-operative and urethrotomy controls with no evidence of contrast extravasation, strictures, fistulas, or stone formation. Histological (hematoxylin and eosin and Masson's trichrome), immunohistochemical, and histomorphometric analyses demonstrated that both silk fibroin and SIS scaffolds promoted similar extents of smooth muscle and epithelial tissue regeneration throughout the original defect sites with prominent contractile protein (α-smooth muscle actin and SM22α) and cytokeratin expression, respectively. De novo innervation and vascularization were also evident in all regenerated tissues indicated by synaptophysin-positive neuronal cells and vessels lined with CD31 expressing endothelial cells. Following 3 m post-op, minimal acute inflammatory reactions were elicited by silk fibroin scaffolds characterized by the presence of eosinophil granulocytes while SIS matrices promoted chronic inflammatory responses indicated by mobilization of mononuclear cell infiltrates. The results of this study

  6. Acellular bi-layer silk fibroin scaffolds support tissue regeneration in a rabbit model of onlay urethroplasty.

    Directory of Open Access Journals (Sweden)

    Yeun Goo Chung

    Full Text Available Acellular scaffolds derived from Bombyx mori silk fibroin were investigated for their ability to support functional tissue regeneration in a rabbit model of urethra repair. A bi-layer silk fibroin matrix was fabricated by a solvent-casting/salt leaching process in combination with silk fibroin film casting to generate porous foams buttressed by homogeneous silk fibroin films. Ventral onlay urethroplasty was performed with silk fibroin grafts (Group 1, N = 4 (Width × Length, 1 × 2 cm(2 in adult male rabbits for 3 m of implantation. Parallel control groups consisted of animals receiving small intestinal submucosa (SIS implants (Group 2, N = 4 or urethrotomy alone (Group 3, N = 3. Animals in all groups exhibited 100% survival prior to scheduled euthanasia and achieved voluntary voiding following 7 d of initial catheterization. Retrograde urethrography of each implant group at 3 m post-op revealed wide urethral calibers and preservation of organ continuity similar to pre-operative and urethrotomy controls with no evidence of contrast extravasation, strictures, fistulas, or stone formation. Histological (hematoxylin and eosin and Masson's trichrome, immunohistochemical, and histomorphometric analyses demonstrated that both silk fibroin and SIS scaffolds promoted similar extents of smooth muscle and epithelial tissue regeneration throughout the original defect sites with prominent contractile protein (α-smooth muscle actin and SM22α and cytokeratin expression, respectively. De novo innervation and vascularization were also evident in all regenerated tissues indicated by synaptophysin-positive neuronal cells and vessels lined with CD31 expressing endothelial cells. Following 3 m post-op, minimal acute inflammatory reactions were elicited by silk fibroin scaffolds characterized by the presence of eosinophil granulocytes while SIS matrices promoted chronic inflammatory responses indicated by mobilization of mononuclear cell infiltrates. The results

  7. Characterization and evolution of dermal filaments from patients with Morgellons disease

    Directory of Open Access Journals (Sweden)

    Middelveen MJ

    2013-01-01

    Full Text Available Marianne J Middelveen,1 Peter J Mayne,1 Douglas G Kahn,2 Raphael B Stricker11International Lyme and Associated Diseases Society, Bethesda, MD, USA; 2Department of Pathology, Olive View–UCLA Medical Center, Sylmar, CA, USAAbstract: Morgellons disease is an emerging skin disease characterized by formation of dermal filaments associated with multisystemic symptoms and tick-borne illness. Some clinicians hypothesize that these often colorful dermal filaments are textile fibers, either self-implanted by patients or accidentally adhering to lesions, and conclude that patients with this disease have delusions of infestation. We present histological observations and electron microscopic imaging from representative Morgellons disease samples revealing that dermal filaments in these cases are keratin and collagen in composition and result from proliferation and activation of keratinocytes and fibroblasts in the epidermis. Spirochetes were detected in the dermatological specimens from our study patients, providing evidence that Morgellons disease is associated with an infectious process.Keywords: Morgellons disease, digital dermatitis, Lyme disease, Borrelia burgdorferi, spirochetes, keratin, keratinocytes, collagen, fibroblasts

  8. The modified Gauss diagonalization of polynomial matrices

    International Nuclear Information System (INIS)

    Saeed, K.

    1982-10-01

    The Gauss algorithm for diagonalization of constant matrices is modified for application to polynomial matrices. Due to this modification the diagonal elements become pure polynomials rather than rational functions. (author)

  9. Quantum Hilbert matrices and orthogonal polynomials

    DEFF Research Database (Denmark)

    Andersen, Jørgen Ellegaard; Berg, Christian

    2009-01-01

    Using the notion of quantum integers associated with a complex number q≠0 , we define the quantum Hilbert matrix and various extensions. They are Hankel matrices corresponding to certain little q -Jacobi polynomials when |q|<1 , and for the special value they are closely related to Hankel matrice...

  10. Editorial Commentary: The Acellular Osteochondral Allograft, the Emperor Has New Clothes.

    Science.gov (United States)

    Mandelbaum, Bert R; Chahla, Jorge

    2017-12-01

    For larger lesions (>2.5-cm 2 ), clinical evidence and practice have shown that fresh osteochondral allograft have good durability, with 88% return to sport and greater than 75% 10-year survival rates for treatment of large femoral condyle lesions. That said, the use of fresh osteochondral allografts in clinical practice is limited by the availability of acceptable donor tissues for eligible patients in a timely fashion. Significant diminution of chondrocyte viability and density occurs during the preservation and storage period. All osteochondral allografts are not equal in performance and outcome. Chondrocyte density and viability are critical for successful transplantation and outcome in the short and long term. This commentary highlights the high failure rates of tissue when it is acellular. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  11. Discrete canonical transforms that are Hadamard matrices

    International Nuclear Information System (INIS)

    Healy, John J; Wolf, Kurt Bernardo

    2011-01-01

    The group Sp(2,R) of symplectic linear canonical transformations has an integral kernel which has quadratic and linear phases, and which is realized by the geometric paraxial optical model. The discrete counterpart of this model is a finite Hamiltonian system that acts on N-point signals through N x N matrices whose elements also have a constant absolute value, although they do not form a representation of that group. Those matrices that are also unitary are Hadamard matrices. We investigate the manifolds of these N x N matrices under the Sp(2,R) equivalence imposed by the model, and find them to be on two-sided cosets. By means of an algorithm we determine representatives that lead to collections of mutually unbiased bases.

  12. Abel-grassmann's groupoids of modulo matrices

    International Nuclear Information System (INIS)

    Javaid, Q.; Awan, M.D.; Naqvi, S.H.A.

    2016-01-01

    The binary operation of usual addition is associative in all matrices over R. However, a binary operation of addition in matrices over Z/sub n/ of a nonassociative structures of AG-groupoids and AG-groups are defined and investigated here. It is shown that both these structures exist for every integer n >≥ 3. Various properties of these structures are explored like: (i) Every AG-groupoid of matrices over Z/sub n/ is transitively commutative AG-groupoid and is a cancellative AG-groupoid if n is prime. (ii) Every AG-groupoid of matrices over Z/sub n/ of Type-II is a T/sup 3/-AG-groupoid. (iii) An AG-groupoid of matrices over Z/sub n/ ; G /sub nAG/(t,u), is an AG-band, if t+u=1(mod n). (author)

  13. 14C-Methylenebisphenylisocyanate (14C-MDI). Study of absorption after single dermal and intradermal administration in rats

    International Nuclear Information System (INIS)

    Leibold, E.; Hoffmann, H.D.; Hildebrand, B.

    1999-01-01

    The absorption, distribution and excretion of radioactivity was studied in groups of four male Wistar rats following a single dermal and intradermal administration of 14 C- Methylenebisphenylisocyanate ( 14 C-MDI) at nominal dose levels of 4.0 and 0.4 mg/cm 2 for dermal administration and 0.4 mg/animal for intradermal administration. These dose levels nominally corresponded to 40 and 4.0 mg/animal for dermal administration. Considering the animal weights, dose levels corresponded to about 140 and 14 mg/kg body weight (dermal administration) and 1.4 mg/kg body weight (intradermal administration). In the experiments with dermal administration, animals were exposed for 8 hours and sacrificed 8, 24 or 120 h after beginning of exposure. In the experiment with intradermal administration, animals were sacrificed 120 h after treatment. After dermal administration of 14 C-MDI, mean recoveries of radioactivity from all dose groups were in the range from 97.86 to 108.07% of the total radioactivity administered. Generally, the largest proportion of radioactivity was found at the application site and dressing. The total amount of radioactivity absorbed (including excreta, cage wash, tissues/organs and carcass) increased with increasing sacrifice time. Dermal absorption was very low and quantitatively similar at both dose levels; maximally ca. 0.9 % of the applied radioactivity was absorbed. After intradermal administration of 14 C-MDI, the mean recovery of radioactivity was 100.90 % of the radioactivity administered. The largest proportion of radioactivity was found at the application site. The total amount of radioactivity absorbed (including excreta, cage wash, tissues/organs and carcass) amounted to about 26 % of the radioactivity applied. Irrespective of the mode of administration of 1 4C -MDI, concentrations of radioactivity in tissues and organs generally were below 1 μg Eq/g at 120 h after administration. In summary, the results of this study comparing systemic

  14. Bio-artificial pleura using an autologous dermal fibroblast sheet

    Science.gov (United States)

    Kanzaki, Masato; Takagi, Ryo; Washio, Kaoru; Kokubo, Mami; Yamato, Masayuki

    2017-10-01

    Air leaks (ALs) are observed after pulmonary resections, and without proper treatment, can produce severe complications. AL prevention is a critical objective for managing patients after pulmonary resection. This study applied autologous dermal fibroblast sheets (DFS) to close ALs. For sealing ALs in a 44-year-old male human patient with multiple bullae, a 5 × 15-mm section of skin was surgically excised. From this skin specimen, primary dermal fibroblasts were isolated and cultured for 4 weeks to produce DFSs that were harvested after a 10-day culture. ALs were completely sealed using surgical placement of these autologous DFSs. DFS were found to be a durable long-term AL sealant, exhibiting requisite flexibility, elasticity, durability, biocompatibility, and usability, resulting reliable AL closure. DFS should prove to be an extremely useful tissue-engineered pleura substitute.

  15. Free probability and random matrices

    CERN Document Server

    Mingo, James A

    2017-01-01

    This volume opens the world of free probability to a wide variety of readers. From its roots in the theory of operator algebras, free probability has intertwined with non-crossing partitions, random matrices, applications in wireless communications, representation theory of large groups, quantum groups, the invariant subspace problem, large deviations, subfactors, and beyond. This book puts a special emphasis on the relation of free probability to random matrices, but also touches upon the operator algebraic, combinatorial, and analytic aspects of the theory. The book serves as a combination textbook/research monograph, with self-contained chapters, exercises scattered throughout the text, and coverage of important ongoing progress of the theory. It will appeal to graduate students and all mathematicians interested in random matrices and free probability from the point of view of operator algebras, combinatorics, analytic functions, or applications in engineering and statistical physics.

  16. Quantum matrices in two dimensions

    International Nuclear Information System (INIS)

    Ewen, H.; Ogievetsky, O.; Wess, J.

    1991-01-01

    Quantum matrices in two-dimensions, admitting left and right quantum spaces, are classified: they fall into two families, the 2-parametric family GL p,q (2) and a 1-parametric family GL α J (2). Phenomena previously found for GL p,q (2) hold in this general situation: (a) powers of quantum matrices are again quantum and (b) entries of the logarithm of a two-dimensional quantum matrix form a Lie algebra. (orig.)

  17. Rat hair follicle dermal papillae have an extracellular matrix containing basement membrane components

    DEFF Research Database (Denmark)

    Couchman, J R

    1986-01-01

    , to be replaced by synthesis of other components including type I and III collagens. It seems likely therefore that the dermal papilla cells in vivo synthesize a basement membrane type of extracellular matrix, although a contribution from epithelial, and in some cases capillary endothelial, cells cannot be ruled......Dermal papillae are small mesenchymally derived zones at the bases of hair follicles which have an important role in hair morphogenesis in the embryo and control of the hair growth cycle in postnatal mammals. The cells of the papilla are enmeshed in a dense extracellular matrix which undergoes...... extensive changes in concert with the hair cycle. Here it is shown that this matrix in anagen pelage follicles of postnatal rats contains an abundance of basement membrane components rather than dermal components such as interstitial collagens. In particular, type IV collagen, laminin, and basement membrane...

  18. Full incorporation of Strattice™ Reconstructive Tissue Matrix in a reinforced hiatal hernia repair: a case report

    Directory of Open Access Journals (Sweden)

    Freedman Bruce E

    2012-08-01

    Full Text Available Abstract Introduction A non-cross-linked porcine acellular dermal matrix was used to reinforce an esophageal hiatal hernia repair. A second surgery was required 11 months later to repair a slipped Nissen; this allowed for examination of the hiatal hernia repair and showed the graft to be well vascularized and fully incorporated. Case presentation A 71-year-old Caucasian woman presented with substernal burning and significant dysphagia. An upper gastrointestinal series revealed a type III complex paraesophageal hiatal hernia. She underwent laparoscopic surgery to repair a hiatal hernia that was reinforced with a xenograft (Strattice™ Reconstructive Tissue Matrix, LifeCell, Branchburg, NJ, USA along with a Nissen fundoplication. A second surgery was required to repair a slipped Nissen; this allowed for examination of the hiatal repair and graft incorporation 11 months after the initial surgery. Conclusion In this case, a porcine acellular dermal matrix was an effective tool to reinforce the crural hiatal hernia repair. The placement of the mesh and method of fixation are believed to be crucial to the success of the graft. It was found to be well vascularized 11 months after the original placement with no signs of erosion, stricture, or infection. Further studies and long-term follow-up are required to support the findings of this case report.

  19. Synchronous correlation matrices and Connes’ embedding conjecture

    Energy Technology Data Exchange (ETDEWEB)

    Dykema, Kenneth J., E-mail: kdykema@math.tamu.edu [Department of Mathematics, Texas A& M University, College Station, Texas 77843-3368 (United States); Paulsen, Vern, E-mail: vern@math.uh.edu [Department of Mathematics, University of Houston, Houston, Texas 77204 (United States)

    2016-01-15

    In the work of Paulsen et al. [J. Funct. Anal. (in press); preprint arXiv:1407.6918], the concept of synchronous quantum correlation matrices was introduced and these were shown to correspond to traces on certain C*-algebras. In particular, synchronous correlation matrices arose in their study of various versions of quantum chromatic numbers of graphs and other quantum versions of graph theoretic parameters. In this paper, we develop these ideas further, focusing on the relations between synchronous correlation matrices and microstates. We prove that Connes’ embedding conjecture is equivalent to the equality of two families of synchronous quantum correlation matrices. We prove that if Connes’ embedding conjecture has a positive answer, then the tracial rank and projective rank are equal for every graph. We then apply these results to more general non-local games.

  20. Realm of Matrices

    Indian Academy of Sciences (India)

    IAS Admin

    harmonic analysis and complex analysis, in ... gebra describes not only the study of linear transforma- tions and .... special case of the Jordan canonical form of matrices. ..... Richard Bronson, Schaum's Outline Series Theory And Problems Of.

  1. Virial expansion for almost diagonal random matrices

    Science.gov (United States)

    Yevtushenko, Oleg; Kravtsov, Vladimir E.

    2003-08-01

    Energy level statistics of Hermitian random matrices hat H with Gaussian independent random entries Higeqj is studied for a generic ensemble of almost diagonal random matrices with langle|Hii|2rangle ~ 1 and langle|Hi\

  2. Chequered surfaces and complex matrices

    International Nuclear Information System (INIS)

    Morris, T.R.; Southampton Univ.

    1991-01-01

    We investigate a large-N matrix model involving general complex matrices. It can be reinterpreted as a model of two hermitian matrices with specific couplings, and as a model of positive definite hermitian matrices. Large-N perturbation theory generates dynamical triangulations in which the triangles can be chequered (i.e. coloured so that neighbours are opposite colours). On a sphere there is a simple relation between such triangulations and those generated by the single hermitian matrix model. For the torus (and a quartic potential) we solve the counting problem for the number of triangulations that cannot be quechered. The critical physics of chequered triangulations is the same as that of the hermitian matrix model. We show this explicitly by solving non-perturbatively pure two-dimensional ''chequered'' gravity. The interpretative framework given here applies to a number of other generalisations of the hermitian matrix model. (orig.)

  3. Development and characterization of hyaluronic acid-lysine nanoparticles with potential as innovative dermal filling

    Directory of Open Access Journals (Sweden)

    Jaqueline Carneiro

    Full Text Available ABSTRACT Skin aging causes changes such as wrinkles and flaccidity leading to a large demand for aesthetic procedures, including dermal filling. A key agent in dermal filling is hyaluronic acid (HA, which is a naturally occurring glycosaminoglycan. However, it is a hydrophilic macromolecule that experiences great difficulty in crossing the skin barrier causing most commercial formulations containing it to be injectable, which in turn brings risks since they involve an invasive technique. In that sense, the aim of this study was to develop and characterize nanoparticles obtained from ionic interaction between HA and lysine (Lys for use as a potential agent of dermal filling for topical application, increasing and improving its applicability and safety. To this end, nanoparticles were obtained by dripping of Lys over HA under magnetic stirring. A nanometric size was confirmed and a suitable surface charge was obtained by zeta potential. Nanoparticles were almost spherical in shape with a smooth surface. Interaction between raw materials for preparing nanoparticles was studied by FTIR and NMR spectroscopy and an ionic interaction was confirmed. These physicochemical features suggest that obtained nanoparticles can be further used as a topical dermal filling.

  4. Review of data on the dermal penetration of mineral oils and waxes used in cosmetic applications.

    Science.gov (United States)

    Petry, T; Bury, D; Fautz, R; Hauser, M; Huber, B; Markowetz, A; Mishra, S; Rettinger, K; Schuh, W; Teichert, T

    2017-10-05

    Mineral oils and waxes used in cosmetic products, also referred to as "personal care products" outside the European Union, are mixtures of predominantly saturated hydrocarbons consisting of straight-chain, branched and ring structures with carbon chain lengths greater than C16. They are used in skin and lip care cosmetic products due to their excellent skin tolerance as well as their high protecting and cleansing performance and broad viscosity options. Recently, concerns have been raised regarding potential adverse health effects of mineral oils and waxes from dermal application of cosmetics. In order to be able to assess the risk for the consumer the dermal penetration potential of these ingredients has to be evaluated. The scope and objective of this review are to identify and summarize publicly available literature on the dermal penetration of mineral oils and waxes as used in cosmetic products. For this purpose, a comprehensive literature search was conducted. A total of 13 in vivo (human, animal) and in vitro studies investigating the dermal penetration of mineral oils and waxes has been identified and analysed. The majority of the substances were dermally adsorbed to the stratum corneum and only a minor fraction reached deeper skin layers. Overall, there is no evidence from the various studies that mineral oils and waxes are percutaneously absorbed and become systemically available. Thus, given the absence of dermal uptake, mineral oils and waxes as used in cosmetic products do not present a risk to the health of the consumer. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Sterilization of Lung Matrices by Supercritical Carbon Dioxide.

    Science.gov (United States)

    Balestrini, Jenna L; Liu, Angela; Gard, Ashley L; Huie, Janet; Blatt, Kelly M S; Schwan, Jonas; Zhao, Liping; Broekelmann, Tom J; Mecham, Robert P; Wilcox, Elise C; Niklason, Laura E

    2016-03-01

    Lung engineering is a potential alternative to transplantation for patients with end-stage pulmonary failure. Two challenges critical to the successful development of an engineered lung developed from a decellularized scaffold include (i) the suppression of resident infectious bioburden in the lung matrix, and (ii) the ability to sterilize decellularized tissues while preserving the essential biological and mechanical features intact. To date, the majority of lungs are sterilized using high concentrations of peracetic acid (PAA) resulting in extracellular matrix (ECM) depletion. These mechanically altered tissues have little to no storage potential. In this study, we report a sterilizing technique using supercritical carbon dioxide (ScCO2) that can achieve a sterility assurance level 10(-6) in decellularized lung matrix. The effects of ScCO2 treatment on the histological, mechanical, and biochemical properties of the sterile decellularized lung were evaluated and compared with those of freshly decellularized lung matrix and with PAA-treated acellular lung. Exposure of the decellularized tissue to ScCO2 did not significantly alter tissue architecture, ECM content or organization (glycosaminoglycans, elastin, collagen, and laminin), observations of cell engraftment, or mechanical integrity of the tissue. Furthermore, these attributes of lung matrix did not change after 6 months in sterile buffer following sterilization with ScCO2, indicating that ScCO2 produces a matrix that is stable during storage. The current study's results indicate that ScCO2 can be used to sterilize acellular lung tissue while simultaneously preserving key biological components required for the function of the scaffold for regenerative medicine purposes.

  6. Primary vaccination of adults with reduced antigen-content diphtheria-tetanus-acellular pertussis or dTpa-inactivated poliovirus vaccines compared to diphtheria-tetanus-toxoid vaccines.

    NARCIS (Netherlands)

    Theeten, H.; Rumke, H.C.; Hoppener, F.J.; Vilatimo, R.; Narejos, S.; Damme, P. van; Hoet, B.

    2007-01-01

    OBJECTIVE: To evaluate immunogenicity and reactogenicity of primary vaccination with reduced-antigen-content diphtheria-tetanus-acellular pertussis (dTpa) or dTpa-inactivated poliovirus (dTpa-IPV) vaccine compared to diphtheria-tetanus-toxoid vaccines (Td) in adults > or = 40 years of age without

  7. Dermal morphological changes following salicylic acid peeling and microdermabrasion.

    Science.gov (United States)

    Abdel-Motaleb, Amira A; Abu-Dief, Eman E; Hussein, Mahmoud Ra

    2017-12-01

    Microdermabrasion and chemical peeling are popular, inexpensive, and safe methods for treatment of some skin disorders and to rejuvenate skin. To study the alterations of the dermal connective tissue following salicylic acid peeling and microdermabrasion. Twenty patients were participated in our study. All participants underwent facial salicylic acid 30% peel or microdermabrasion (10 cases in each group) weekly for 6 weeks. Punch biopsies were obtained from the clinically normal skin of the right postauricular region 1 week before treatment (control group). Other punch skin biopsies were obtained 1 week after the end of the treatments from the left postauricular area. This region was treated in a similar way to the adjacent lesional skin (treated group). We used routine histological techniques (H&E stain), special stains (Masson trichrome and orcein stains), and image analyzer to study the alterations of the dermal connective tissues. Our study demonstrates variations in the morphological changes between the control and the treated groups, and between chemical peels and microdermabrasion. Both salicylic acid 30% and microdermabrasion were associated with thickened epidermal layer, shallow dermal papillae, dense collagen, and elastic fibers. There was a significant increase among those treated sites vs control regarding epidermal thickness and collagen thickness. Also, there was a highly statistically significant increase among those treated with salicylic acid vs microdermabrasion regarding the epidermal, collagen, and elastin thickness. Both methods stimulate the repair process. The mechanisms underlying these variations are open for further investigations. © 2017 Wiley Periodicals, Inc.

  8. Focal dermal hypoplasia: A rare case report

    Directory of Open Access Journals (Sweden)

    Sahana M Srinivas

    2015-01-01

    Full Text Available Focal dermal hypoplasia (Goltz syndrome is a rare genetic multisystem disorder primarily involving the skin, skeletal system, eyes, and face. We report the case of an eight-month-old female child who presented with multiple hypopigmented atrophic macules along the lines of blaschko, skeletal anomalies, umbilical hernia, developmental delay, hypoplastic nails, syndactyly, and lobster claw deformity characteristic of Goltz syndrome.

  9. Intrinsic Density Matrices of the Nuclear Shell Model

    International Nuclear Information System (INIS)

    Deveikis, A.; Kamuntavichius, G.

    1996-01-01

    A new method for calculation of shell model intrinsic density matrices, defined as two-particle density matrices integrated over the centre-of-mass position vector of two last particles and complemented with isospin variables, has been developed. The intrinsic density matrices obtained are completely antisymmetric, translation-invariant, and do not employ a group-theoretical classification of antisymmetric states. They are used for exact realistic density matrix expansion within the framework of the reduced Hamiltonian method. The procedures based on precise arithmetic for calculation of the intrinsic density matrices that involve no numerical diagonalization or orthogonalization have been developed and implemented in the computer code. (author). 11 refs., 2 tabs

  10. Assessment of dermal exposure and histopathologic changes of different sized nano-silver in healthy adult rabbits

    Science.gov (United States)

    kazem Koohi, Mohammad; Hejazy, Marzie; Asadi, Farzad; Asadian, Peyman

    2011-07-01

    The purpose of this study is to evaluate the dermal toxicity (Irritation/Corrosion) of three sizes of nanosilver particles (10, 20 and 30 nm) during 3 min, 1 and 4 hours according to the OECD/OCDE guideline Histopathological effects in secondary organs from liver, kidney, heart, spleen and brain 14 day post dermal administration are also reported. 10 and 20 nm Ag nanoparticles treated group showed well defined dermal erythema and oedema. Histopathological findings of 10 and 20 nm (4 hours exposure) on 14-day post dermal administration showed hyperkeratosis, acanthosis, hair-filled follicles and papillomatosis in an irregular epidermis, fibrosis, hyperemia, erythema, intracellular oedema and hyalinisation of collagen in dermis of skin. Liver revealed midzonal and periacinar necrosis, portal mononuclear infiltration, liver fatty change, liver congestion and hyperemic central vein. Splenic red pulp congestion and white pulp hyperreactivity, splenic trabeculae and sinusoidal congestion and hyaline change were found in spleen. Fatty degeneration in some cardiovascular cells and subendocardial hemorrhage without inflammation was perceived. Picnotic appearance of pyramidal neurons in the brain cortex, gliosis and mild perineuronal oedema ischemic cell change and hyperemic meninges was observed in brain. Our research concluded that dermal exposure to lesser sizes of silver nanoparticles is more disastrous than greater ones.

  11. Assessment of dermal exposure and histopathologic changes of different sized nano-silver in healthy adult rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Koohi, Mohammad kazem; Hejazy, Marzie [Toxicology division, Basic science department, Faculty of Veterinary Medicine, University of Tehran, Qareeb Street, Azadi Av. PO Box: 14155-6453, Tehran (Iran, Islamic Republic of); Asadi, Farzad [Biochemistry division, Basic science department, Faculty of Veterinary Medicine, University of Tehran, Qareeb Street, Azadi Av. PO Box: 14155-6453, Tehran (Iran, Islamic Republic of); Asadian, Peyman, E-mail: mkkoohi@ut.ac.ir [Clinical pathology department, Faculty of Veterinary Medicine, University of Khorramabad (Iran, Islamic Republic of)

    2011-07-06

    The purpose of this study is to evaluate the dermal toxicity (Irritation/Corrosion) of three sizes of nanosilver particles (10, 20 and 30 nm) during 3 min, 1 and 4 hours according to the OECD/OCDE guideline Histopathological effects in secondary organs from liver, kidney, heart, spleen and brain 14 day post dermal administration are also reported. 10 and 20 nm Ag nanoparticles treated group showed well defined dermal erythema and oedema. Histopathological findings of 10 and 20 nm (4 hours exposure) on 14-day post dermal administration showed hyperkeratosis, acanthosis, hair-filled follicles and papillomatosis in an irregular epidermis, fibrosis, hyperemia, erythema, intracellular oedema and hyalinisation of collagen in dermis of skin. Liver revealed midzonal and periacinar necrosis, portal mononuclear infiltration, liver fatty change, liver congestion and hyperemic central vein. Splenic red pulp congestion and white pulp hyperreactivity, splenic trabeculae and sinusoidal congestion and hyaline change were found in spleen. Fatty degeneration in some cardiovascular cells and subendocardial hemorrhage without inflammation was perceived. Picnotic appearance of pyramidal neurons in the brain cortex, gliosis and mild perineuronal oedema ischemic cell change and hyperemic meninges was observed in brain. Our research concluded that dermal exposure to lesser sizes of silver nanoparticles is more disastrous than greater ones.

  12. Design of an elastin-layered dermal regeneration template.

    Science.gov (United States)

    Mithieux, Suzanne M; Weiss, Anthony S

    2017-04-01

    We demonstrate a novel approach for the production of tunable quantities of elastic fibers. We also show that exogenous tropoelastin is rate-limiting for elastin synthesis regardless of the age of the dermal fibroblast donor. Additionally, we provide a strategy to further enhance synthesis by older cells through the application of conditioned media. We show that this approach delivers an elastin layer on one side of the leading dermal repair template for contact with the deep dermis in order to deliver prefabricated elastic fibers to a physiologically appropriate site during subsequent surgery. This system is attractive because it provides for the first time a viable path for sufficient, histologically detectable levels of patient elastin into full-thickness wound sites that have until now lacked this elastic underlayer. The scars of full thickness wounds typically lack elasticity. Elastin is essential for skin elasticity and is enriched in the deep dermis. This paper is significant because it shows that: (1) we can generate elastic fibers in tunable quantities, (2) tropoelastin is the rate-limiting component in elastin synthesis in vitro, (3) we can generate elastin fibers regardless of donor age, (4) we describe a novel approach to further increase the numbers and thickness of elastic fibers for older donors, (5) we improve on Integra Dermal Regeneration Template and generate a new hybrid biomaterial intended to subsequently surgically deliver these elastic fibers, (6) the elastic fiber layer is presented on the side of Integra that is intended for delivery into its physiologically appropriate site i.e. the deep dermis. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  13. Pengujian Toksisitas Akut Oral Dan Dermal pada Biolarvasida Metarhizium anisopliae terhadap Tikus Putih Spraque Dawley

    Directory of Open Access Journals (Sweden)

    Deni Zulfiana

    2016-03-01

    Full Text Available Acute oral and dermal toxicity test against white rats was conducted to determine the toxicity and side effects of bio-larvacide (Metarhizium anisopliae crude extract on humans. In the oral test used a maximum dose 5000 mg/kg and dermal testing used a maximum dose of 2000 mg/kg. Dose treatment and control tested to 5 Spraque Dawley male rats. The results showed that oral treatment with a dose of 5000 mg/kg did not cause mortality and did not cause changes in anatomic pathology of viceral organs. In the dermal treatment with a dose of 2000 mg/kg did not cause mortality and did not cause changes in anatomic pathology of viceral organs. Based on these results LD50 acute oral M. anisopliae biolarvacide above 5000 mg/kg and the acute dermal is above 2000 mg/kg. It was therefore concluded that the formulation of Metarhizium anisopliae biolarvasida classified as not hazardous when used in accordance with the recommendation of the class I (WHO, 2003.

  14. Management of acute complex traumatic wound with a dermal ...

    African Journals Online (AJOL)

    Background: Acute complex traumatic wounds of the lower limbs are usually ... The recovery is lengthy, and the outcome dependent on the initial injury, the surgical ... of fracture and use of a dermal regeneration template over the fracture site, ...

  15. Skin permeability and pharmacokinetics of diclofenac epolamine administered by dermal patch in Yorkshire-Landrace pigs

    Directory of Open Access Journals (Sweden)

    Tse S

    2012-10-01

    Full Text Available Susanna Tse,1 Kendall D Powell,2 Stephen MacLennan,3 Allan R Moorman,4 Craig Paterson,5 Rosonald R Bell11Pfizer Inc, Groton, CT, USA; 2Tandem Labs, Durham, NC, USA; 3BioCryst Pharmaceuticals Inc, Durham, NC, USA; 4Alta Vetta Pharmaceutical Consulting LLC, Durham, NC, USA; 5Salix Pharmaceuticals Inc, Raleigh, NC, USAPurpose: This study compared the pharmacokinetic profile, and systemic and local absorption of diclofenac, following dermal patch application and oral administration in Yorkshire- Landrace pigs.Patients and methods: Twelve anesthetized, female, Yorkshire-Landrace pigs were randomized to receive either the dermal patch (FLECTOR® patch, 10 × 14 cm; Alpharma Pharmaceuticals, a subsidiary of Pfizer Inc, New York, NY or 50 mg oral diclofenac (Voltaren®; Novartis, East Hanover, NJ. Tissue (skin area of 2 × 2 cm and underlying muscles approximately 2–3 cm in depth and blood (10 mL samples were collected at timed intervals up to 11.5 hours after initial patch application or oral administration. The concentrations of diclofenac in plasma, skin, and muscle samples were analyzed using validated ultra performance liquid chromatography tandem mass spectrometric methods.Results: Peak systemic exposure of diclofenac was very low by dermal application compared with oral administration (maximum concentration [Cmax] values of 3.5 vs 9640 ng/mL, respectively. Absorption of diclofenac into underlying muscles beneath the dermal patch was sustained, and followed apparently zero-order kinetics, with the skin serving as a depot with elevated concentrations of diclofenac. Concentrations of diclofenac in muscles beneath the patch application site were similar to corresponding tissues after oral administration (Cmax values of 879 and 1160 ng/mL, respectively. In contrast to the wide tissue distribution of diclofenac after oral administration, dermal patch application resulted in high concentrations of diclofenac only on the treated skin and immediate

  16. Dissolving microneedle patches for dermal vaccination

    OpenAIRE

    Leone, M.; Monkare, J.T.; Bouwstra, J.A.; Kersten, G.F.A.

    2017-01-01

    The dermal route is an attractive route for vaccine delivery due to the easy skin accessibility and a dense network of immune cells in the skin. The development of microneedles is crucial to take advantage of the skin immunization and simultaneously to overcome problems related to vaccination by conventional needles (e.g. pain, needle-stick injuries or needle re-use). This review focuses on dissolving microneedles that after penetration into the skin dissolve releasing the encapsulated antige...

  17. Random matrices and random difference equations

    International Nuclear Information System (INIS)

    Uppuluri, V.R.R.

    1975-01-01

    Mathematical models leading to products of random matrices and random difference equations are discussed. A one-compartment model with random behavior is introduced, and it is shown how the average concentration in the discrete time model converges to the exponential function. This is of relevance to understanding how radioactivity gets trapped in bone structure in blood--bone systems. The ideas are then generalized to two-compartment models and mammillary systems, where products of random matrices appear in a natural way. The appearance of products of random matrices in applications in demography and control theory is considered. Then random sequences motivated from the following problems are studied: constant pulsing and random decay models, random pulsing and constant decay models, and random pulsing and random decay models

  18. Quantum Entanglement and Reduced Density Matrices

    Science.gov (United States)

    Purwanto, Agus; Sukamto, Heru; Yuwana, Lila

    2018-05-01

    We investigate entanglement and separability criteria of multipartite (n-partite) state by examining ranks of its reduced density matrices. Firstly, we construct the general formula to determine the criterion. A rank of origin density matrix always equals one, meanwhile ranks of reduced matrices have various ranks. Next, separability and entanglement criterion of multipartite is determined by calculating ranks of reduced density matrices. In this article we diversify multipartite state criteria into completely entangled state, completely separable state, and compound state, i.e. sub-entangled state and sub-entangledseparable state. Furthermore, we also shorten the calculation proposed by the previous research to determine separability of multipartite state and expand the methods to be able to differ multipartite state based on criteria above.

  19. Augmentation Phalloplasty With Autologous Dermal Fat Graft in the Treatment of "Small Penis".

    Science.gov (United States)

    Xu, Lisi; Zhao, Muxin; Chen, Wen; Li, Yangqun; Yang, Zhe; Ma, Ning; Wang, Weixin; Feng, Jun; Liu, Qiyu; Ma, Tong

    2016-02-01

    Our objective is to report on the efficacy and safety of dermal fat graft in augmentation phalloplasty performed on patients who presented complaining of "small penis," and evaluate the cosmetic and psychological outcomes of it. From April 2010 and January 2015, 23 Chinese adult patients aged 18 to 33 years (average, 23 years) with subjective perception of small penis were included; all who requested an increase in the penile dimension underwent penile elongation (suprapubic skin advancement-ligamentolysis) and girth enhancement by dermal fat graft. Besides objective measurement, Male Genital Image Scale was used to facilitate selection of patients and evaluate the outcome, respectively. The change and shrinkage of the dermal fat strips was evaluated by ultrasound examination and computed tomography. No major complications or erection deficiencies occurred during the postoperative follow-up period. After 6 months, the mean flaccid length was increased by 2.27 ± 0.54 cm, whereas the mean flaccid circumference gain was 1.67 ± 0.46 cm. Significant improvement of genital satisfaction was reported during the follow-up. The shrinkage of dermal fat strips was inconspicuous, and no curvature was observed due to fibrosis. With strict patient selection, this procedure is proved to be a plausible and reasonable option for patients with penile dysmorphophobia. Also, it provides a potential alternative procedure to current dominant methods and promotes the aesthetic results with penile lengthening.

  20. Dual-dermal-barrier fashion flaps for the treatment of sacral pressure sores.

    Science.gov (United States)

    Hsiao, Yen-Chang; Chuang, Shiow-Shuh

    2015-02-01

    The sacral region is one of the most vulnerable sites for the development of pressure sores. Even when surgical reconstruction is performed, there is a high chance of recurrence. Therefore, the concept of dual-dermal-barrier fashion flaps for sacral pressure sore reconstruction was proposed. From September 2007 to June 2010, nine patients with grade IV sacral pressures were enrolled. Four patients received bilateral myocutaneous V-Y flaps, four patients received bilateral fasciocutaneous V-Y flaps, and one patient received bilateral rotation-advanced flaps for sacral pressure reconstruction. The flaps were designed based on the perforators of the superior gluteal artery in one patient's reconstructive procedure. All flaps' designs were based on dual-dermal-barrier fashion. The mean follow-up time was 16 months (range = 12-25). No recurrence was noted. Only one patient had a complication of mild dehiscence at the middle suture line, occurring 2 weeks after the reconstructive surgery. The dual-dermal fashion flaps are easily duplicated and versatile. The study has shown minimal morbidity and a reasonable outcome.

  1. Central Role for Dermal Fibroblasts in Skin Model Protection against Candida albicans.

    Science.gov (United States)

    Kühbacher, Andreas; Henkel, Helena; Stevens, Philip; Grumaz, Christian; Finkelmeier, Doris; Burger-Kentischer, Anke; Sohn, Kai; Rupp, Steffen

    2017-06-01

    The fungal pathogen Candida albicans colonizes basically all human epithelial surfaces, including the skin. Under certain conditions, such as immunosuppression, invasion of the epithelia occurs. Not much is known about defense mechanisms against C. albicans in subepithelial layers such as the dermis. Using immune cell-supplemented 3D skin models we defined a new role for fibroblasts in the dermis and identified a minimal set of cell types for skin protection against C. albicans invasion. Dual RNA sequencing of individual host cell populations and C. albicans revealed that dermal invasion is directly impeded by dermal fibroblasts. They are able to integrate signals from the pathogen and CD4+ T cells and shift toward an antimicrobial phenotype with broad specificity that is dependent on Toll-like receptor 2 and interleukin 1β. These results highlight a central function of dermal fibroblasts for skin protection, opening new possibilities for treatment of infectious diseases. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  2. Coverage of Deep Cutaneous Wounds Using Dermal Template in Combination with Negative-pressure Therapy and Subsequent Skin Graft

    Science.gov (United States)

    Chang, Alexandre A.; Lobato, Rodolfo C.; Nakamoto, Hugo A.; Tuma, Paulo; Ferreira, Marcus C.

    2014-01-01

    Background: We consider the use of dermal matrix associated with a skin graft to cover deep wounds in the extremities when tendon and bone are exposed. The objective of this article was to evaluate the efficacy of covering acute deep wounds through the use of a dermal regeneration template (Integra) associated with vacuum therapy and subsequent skin grafting. Methods: Twenty patients were evaluated prospectively. All of them had acute (up to 3 weeks) deep wounds in the limbs. We consider a deep wound to be that with exposure of bone, tendon, or joint. Results: The average area of integration of the dermal regeneration template was 86.5%. There was complete integration of the skin graft over the dermal matrix in 14 patients (70%), partial integration in 5 patients (25%), and total loss in 1 case (5%). The wound has completely closed in 95% of patients. Conclusions: The use of Integra dermal template associated with negative-pressure therapy and skin grafting showed an adequate rate of resolution of deep wounds with low morbidity. PMID:25289363

  3. Preparation of acellular scaffold for corneal tissue engineering by supercritical carbon dioxide extraction technology.

    Science.gov (United States)

    Huang, Yi-Hsun; Tseng, Fan-Wei; Chang, Wen-Hsin; Peng, I-Chen; Hsieh, Dar-Jen; Wu, Shu-Wei; Yeh, Ming-Long

    2017-08-01

    In this study, we developed a novel method using supercritical carbon dioxide (SCCO 2 ) to prepare acellular porcine cornea (APC). Under gentle extraction conditions using SCCO 2 technology, hematoxylin and eosin staining showed that cells were completely lysed, and cell debris, including nuclei, was efficiently removed from the porcine cornea. The SCCO 2 -treated corneas exhibited intact stromal structures and appropriate mechanical properties. Moreover, no immunological reactions and neovascularization were observed after lamellar keratoplasty in rabbits. All transplanted grafts and animals survived without complications. The transplanted APCs were opaque after the operation but became transparent within 2weeks. Complete re-epithelialization of the transplanted APCs was observed within 4weeks. In conclusion, APCs produced by SCCO 2 extraction technology could be an ideal and useful scaffold for corneal tissue engineering. We decellularized the porcine cornea using SCCO 2 extraction technology and investigated the characteristics, mechanical properties, and biocompatibility of the decellularized porcine cornea by lamellar keratoplasty in rabbits. To the best of our knowledge, this is the first report describing the use of SCCO 2 extraction technology for preparation of acellular corneal scaffold. We proved that the cellular components of porcine corneas had been efficiently removed, and the biomechanical properties of the scaffold were well preserved by SCCO 2 extraction technology. SCCO 2 -treated corneas maintained optical transparency and exhibited appropriate strength to withstand surgical procedures. In vivo, the transplanted corneas showed no evidence of immunological reactions and exhibited good biocompatibility and long-term stability. Our results suggested that the APCs developed by SCCO 2 extraction technology could be an ideal and useful scaffold for corneal replacement and corneal tissue engineering. Copyright © 2017 Acta Materialia Inc. Published by

  4. A structured observational method to assess dermal exposure to manufactured nanoparticles: DREAM as an initial assessment tool

    NARCIS (Netherlands)

    Duuren-Stuurman, B. van; Pelzer, J.; Moehlmann, C.; Berges, M.; Bard, D.; Wake, D.; Mark, D.; Jankowska, E.; Brouwer, D.

    2010-01-01

    Preliminary results of inventories of exposure scenarios for nanomaterials have indicated possible dermal exposure. Within the NANOSH project focused on occupational safety and health aspects of nanotechnology a shortened version of the observational DeRmal Exposure AssessMent (DREAM) method was

  5. Malware analysis using visualized image matrices.

    Science.gov (United States)

    Han, KyoungSoo; Kang, BooJoong; Im, Eul Gyu

    2014-01-01

    This paper proposes a novel malware visual analysis method that contains not only a visualization method to convert binary files into images, but also a similarity calculation method between these images. The proposed method generates RGB-colored pixels on image matrices using the opcode sequences extracted from malware samples and calculates the similarities for the image matrices. Particularly, our proposed methods are available for packed malware samples by applying them to the execution traces extracted through dynamic analysis. When the images are generated, we can reduce the overheads by extracting the opcode sequences only from the blocks that include the instructions related to staple behaviors such as functions and application programming interface (API) calls. In addition, we propose a technique that generates a representative image for each malware family in order to reduce the number of comparisons for the classification of unknown samples and the colored pixel information in the image matrices is used to calculate the similarities between the images. Our experimental results show that the image matrices of malware can effectively be used to classify malware families both statically and dynamically with accuracy of 0.9896 and 0.9732, respectively.

  6. Malware Analysis Using Visualized Image Matrices

    Directory of Open Access Journals (Sweden)

    KyoungSoo Han

    2014-01-01

    Full Text Available This paper proposes a novel malware visual analysis method that contains not only a visualization method to convert binary files into images, but also a similarity calculation method between these images. The proposed method generates RGB-colored pixels on image matrices using the opcode sequences extracted from malware samples and calculates the similarities for the image matrices. Particularly, our proposed methods are available for packed malware samples by applying them to the execution traces extracted through dynamic analysis. When the images are generated, we can reduce the overheads by extracting the opcode sequences only from the blocks that include the instructions related to staple behaviors such as functions and application programming interface (API calls. In addition, we propose a technique that generates a representative image for each malware family in order to reduce the number of comparisons for the classification of unknown samples and the colored pixel information in the image matrices is used to calculate the similarities between the images. Our experimental results show that the image matrices of malware can effectively be used to classify malware families both statically and dynamically with accuracy of 0.9896 and 0.9732, respectively.

  7. Production and characterization of cornstarch/cellulose acetate/silver sulfadiazine extrudate matrices

    Energy Technology Data Exchange (ETDEWEB)

    Zepon, Karine Modolon [CIMJECT, Departamento de Engenharia Mecânica, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); TECFARMA, Universidade do Sul de Santa Catarina, 88704-900 Tubarão, SC (Brazil); Petronilho, Fabricia [FICEXP, Universidade do Sul de Santa Catarina, 88704-900 Tubarão, SC (Brazil); Soldi, Valdir [POLIMAT, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Salmoria, Gean Vitor [CIMJECT, Departamento de Engenharia Mecânica, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Kanis, Luiz Alberto, E-mail: luiz.kanis@unisul.br [TECFARMA, Universidade do Sul de Santa Catarina, 88704-900 Tubarão, SC (Brazil)

    2014-11-01

    The production and evaluation of cornstarch/cellulose acetate/silver sulfadiazine extrudate matrices are reported herein. The matrices were melt extruded under nine different conditions, altering the temperature and the screw speed values. The surface morphology of the matrices was examined by scanning electron microscopy. The micrographs revealed the presence of non-melted silver sulfadiazine microparticles in the matrices extruded at lower temperature and screw speed values. The thermal properties were evaluated and the results for both the biopolymer and the drug indicated no thermal degradation during the melt extrusion process. The differential scanning analysis of the extrudate matrices showed a shift to lower temperatures for the silver sulfadiazine melting point compared with the non-extruded drug. The starch/cellulose acetate matrices containing silver sulfadiazine demonstrated significant inhibition of the growth of Pseudomonas aeruginosa and Staphylococcus aureus. In vivo inflammatory response tests showed that the extrudate matrices, with or without silver sulfadiazine, did not trigger chronic inflammatory processes. - Highlights: • Melt extruded bio-based matrices containing silver sulfadiazine was produced. • The silver sulfadiazine is stable during melt-extrusion. • The extrudate matrices shown bacterial growth inhibition. • The matrices obtained have potential to development wound healing membranes.

  8. Potential health effects associated with dermal exposure to occupational chemicals.

    Science.gov (United States)

    Anderson, Stacey E; Meade, B Jean

    2014-01-01

    There are a large number of workers in the United States, spanning a variety of occupational industries and sectors, who are potentially exposed to chemicals that can be absorbed through the skin. Occupational skin exposures can result in numerous diseases that can adversely affect an individual's health and capacity to perform at work. In general, there are three types of chemical-skin interactions of concern: direct skin effects, immune-mediated skin effects, and systemic effects. While hundreds of chemicals (metals, epoxy and acrylic resins, rubber additives, and chemical intermediates) present in virtually every industry have been identified to cause direct and immune-mediated effects such as contact dermatitis or urticaria, less is known about the number and types of chemicals contributing to systemic effects. In an attempt to raise awareness, skin notation assignments communicate the potential for dermal absorption; however, there is a need for standardization among agencies to communicate an accurate description of occupational hazards. Studies have suggested that exposure to complex mixtures, excessive hand washing, use of hand sanitizers, high frequency of wet work, and environmental or other factors may enhance penetration and stimulate other biological responses altering the outcomes of dermal chemical exposure. Understanding the hazards of dermal exposure is essential for the proper implementation of protective measures to ensure worker safety and health.

  9. Polynomial sequences generated by infinite Hessenberg matrices

    Directory of Open Access Journals (Sweden)

    Verde-Star Luis

    2017-01-01

    Full Text Available We show that an infinite lower Hessenberg matrix generates polynomial sequences that correspond to the rows of infinite lower triangular invertible matrices. Orthogonal polynomial sequences are obtained when the Hessenberg matrix is tridiagonal. We study properties of the polynomial sequences and their corresponding matrices which are related to recurrence relations, companion matrices, matrix similarity, construction algorithms, and generating functions. When the Hessenberg matrix is also Toeplitz the polynomial sequences turn out to be of interpolatory type and we obtain additional results. For example, we show that every nonderogative finite square matrix is similar to a unique Toeplitz-Hessenberg matrix.

  10. The basic science of dermal fillers: past and present Part I: background and mechanisms of action.

    Science.gov (United States)

    Gilbert, Erin; Hui, Andrea; Waldorf, Heidi A

    2012-09-01

    Dermal fillers have provided a safe and effective means for aesthetic soft tissue augmentation, and have experienced a dramatic increase in popularity during the past 10 years. Much focus has been placed upon filler technique and patient outcomes. However, there is a relative lack of literature reviewing the basic science of dermal fillers, which is vital to a physician's understanding of how each product behaves in vivo. Part I of this article reviews the basic science and evolution of both historical and contemporary dermal fillers; Part II examines their adverse effects. We endeavor to provide the physician with a practical approach to choosing products that maximize both aesthetic outcome and safety.

  11. Abdominal wall reconstruction using De-epithelialized dermal flap: A ...

    African Journals Online (AJOL)

    Abdominal wall reconstruction using De-epithelialized dermal flap: A new technique. ... Journal of Surgical Technique and Case Report ... Background: Although autogenous materials have been used in abdominal wall hernioplasty for a long time, the introduction of prosthetic materials diminished their popularity. However ...

  12. S-matrices and integrability

    International Nuclear Information System (INIS)

    Bombardelli, Diego

    2016-01-01

    In these notes we review the S-matrix theory in (1+1)-dimensional integrable models, focusing mainly on the relativistic case. Once the main definitions and physical properties are introduced, we discuss the factorization of scattering processes due to integrability. We then focus on the analytic properties of the two-particle scattering amplitude and illustrate the derivation of the S-matrices for all the possible bound states using the so-called bootstrap principle. General algebraic structures underlying the S-matrix theory and its relation with the form factors axioms are briefly mentioned. Finally, we discuss the S-matrices of sine-Gordon and SU (2), SU (3) chiral Gross–Neveu models. (topical review)

  13. Role of clothing in both accelerating and impeding dermal absorption of airborne SVOCs

    DEFF Research Database (Denmark)

    Morrison, Glenn C.; Weschler, Charles J.; Bekö, Gabriel

    2016-01-01

    To assess the influence of clothing on dermal uptake of semi-volatile organic compounds (SVOCs), we measured uptake of selected airborne phthalates for an individual wearing clean clothes or air-exposed clothes and compared these results with dermal uptake for bare-skinned individuals under....... The individual wore either clean (fresh) cotton clothes or cotton clothes that had been exposed to the same chamber air concentrations for 9 days. For a 6-h exposure, the net amounts of DEP and DnBP absorbed when wearing fresh clothes were, respectively, 0.017 and 0.007 μg/kg/(μg/m3); for exposed clothes...... the results were 0.178 and 0.261 μg/kg/(μg/m3), respectively (values normalized by air concentration and body mass). When compared against the average results for bare-skinned participants, clean clothes were protective, whereas exposed clothes increased dermal uptake for DEP and DnBP by factors of 3.3 and 6...

  14. Matrices Aléatoires Tri-diagonales et Par Blocs.

    OpenAIRE

    MEKKI, Slimane

    2014-01-01

    Dans ce mémoire l'étude porte sur la densité de matrice aléatoire, les densités des valeurs propres d'une matrice pour les trois ensembles G.O.E, G.U.E, G.S.E. Après nous avons explicité les formules des densités de valeurs propres des matrices tri-diagonales dans les cas HERMITE et LAGUERRE Des simulations sur les constantes de normalisations pour les densités des matrices aléatoires ou des valeurs propres sont présentées.

  15. Hierarchical quark mass matrices

    International Nuclear Information System (INIS)

    Rasin, A.

    1998-02-01

    I define a set of conditions that the most general hierarchical Yukawa mass matrices have to satisfy so that the leading rotations in the diagonalization matrix are a pair of (2,3) and (1,2) rotations. In addition to Fritzsch structures, examples of such hierarchical structures include also matrices with (1,3) elements of the same order or even much larger than the (1,2) elements. Such matrices can be obtained in the framework of a flavor theory. To leading order, the values of the angle in the (2,3) plane (s 23 ) and the angle in the (1,2) plane (s 12 ) do not depend on the order in which they are taken when diagonalizing. We find that any of the Cabbibo-Kobayashi-Maskawa matrix parametrizations that consist of at least one (1,2) and one (2,3) rotation may be suitable. In the particular case when the s 13 diagonalization angles are sufficiently small compared to the product s 12 s 23 , two special CKM parametrizations emerge: the R 12 R 23 R 12 parametrization follows with s 23 taken before the s 12 rotation, and vice versa for the R 23 R 12 R 23 parametrization. (author)

  16. Laminin active peptide/agarose matrices as multifunctional biomaterials for tissue engineering.

    Science.gov (United States)

    Yamada, Yuji; Hozumi, Kentaro; Aso, Akihiro; Hotta, Atsushi; Toma, Kazunori; Katagiri, Fumihiko; Kikkawa, Yamato; Nomizu, Motoyoshi

    2012-06-01

    Cell adhesive peptides derived from extracellular matrix components are potential candidates to afford bio-adhesiveness to cell culture scaffolds for tissue engineering. Previously, we covalently conjugated bioactive laminin peptides to polysaccharides, such as chitosan and alginate, and demonstrated their advantages as biomaterials. Here, we prepared functional polysaccharide matrices by mixing laminin active peptides and agarose gel. Several laminin peptide/agarose matrices showed cell attachment activity. In particular, peptide AG73 (RKRLQVQLSIRT)/agarose matrices promoted strong cell attachment and the cell behavior depended on the stiffness of agarose matrices. Fibroblasts formed spheroid structures on the soft AG73/agarose matrices while the cells formed a monolayer with elongated morphologies on the stiff matrices. On the stiff AG73/agarose matrices, neuronal cells extended neuritic processes and endothelial cells formed capillary-like networks. In addition, salivary gland cells formed acini-like structures on the soft matrices. These results suggest that the peptide/agarose matrices are useful for both two- and three-dimensional cell culture systems as a multifunctional biomaterial for tissue engineering. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Influence of surfaces modified with biomimetic extracellular matrices on adhesion and proliferation of mesenchymal stem cells and osteosarcoma cells.

    Science.gov (United States)

    Cai, Rong; Kawazoe, Naoki; Chen, Guoping

    2015-02-01

    Preparation of surfaces modified with biomimetic extracellular matrices (ECMs) is important for investigation of the interaction between ECMs and cells. In the present study, surfaces modified with ECMs from normal somatic cells, stem cells and tumor cells were prepared by cell culture method. The ECMs derived from bone marrow-derived mesenchymal stem cells (MSCs), dermal fibroblasts (FBs), osteoblasts (OBs) and MG63 osteosarcoma cells were deposited on the surfaces of cell-culture polystyrene plates (TCPS). The ECMs from different cell types had different compositions. The effects of the ECM-deposited surfaces on the adhesion, spreading and proliferation of MSCs and MG63 human osteosarcoma cells were dependent on the type of both ECMs and cells. The surfaces deposited with ECMs from MSCs, FBs and OBs promoted cell adhesion more strongly than surfaces deposited with ECMs from MG63 cells and TCPS. Compared to TCPS, the ECM-deposited surfaces promoted proliferation of MSCs while they inhibited the proliferation of MG63 cells. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Characterization and assessment of dermal and inhalable nickel exposures in nickel production and primary user industries.

    Science.gov (United States)

    Hughson, G W; Galea, K S; Heim, K E

    2010-01-01

    The aim of this study was to measure the levels of nickel in the skin contaminant layer of workers involved in specific processes and tasks within the primary nickel production and primary nickel user industries. Dermal exposure samples were collected using moist wipes to recover surface contamination from defined areas of skin. These were analysed for soluble and insoluble nickel species. Personal samples of inhalable dust were also collected to determine the corresponding inhalable nickel exposures. The air samples were analysed for total inhalable dust and then for soluble, sulfidic, metallic, and oxidic nickel species. The workplace surveys were carried out in five different workplaces, including three nickel refineries, a stainless steel plant, and a powder metallurgy plant, all of which were located in Europe. Nickel refinery workers involved with electrolytic nickel recovery processes had soluble dermal nickel exposure of 0.34 microg cm(-2) [geometric mean (GM)] to the hands and forearms. The GM of soluble dermal nickel exposure for workers involved in packing nickel salts (nickel chloride hexahydrate, nickel sulphate hexahydrate, and nickel hydroxycarbonate) was 0.61 microg cm(-2). Refinery workers involved in packing nickel metal powders and end-user powder operatives in magnet production had the highest dermal exposure (GM = 2.59 microg cm(-2) soluble nickel). The hands, forearms, face, and neck of these workers all received greater dermal nickel exposure compared with the other jobs included in this study. The soluble nickel dermal exposures for stainless steel production workers were at or slightly above the limit of detection (0.02 microg cm(-2) soluble nickel). The highest inhalable nickel concentrations were observed for the workers involved in nickel powder packing (GM = 0.77 mg m(-3)), although the soluble component comprised only 2% of the total nickel content. The highest airborne soluble nickel exposures were associated with refineries using

  19. Accelerating Matrix-Vector Multiplication on Hierarchical Matrices Using Graphical Processing Units

    KAUST Repository

    Boukaram, W.

    2015-03-25

    Large dense matrices arise from the discretization of many physical phenomena in computational sciences. In statistics very large dense covariance matrices are used for describing random fields and processes. One can, for instance, describe distribution of dust particles in the atmosphere, concentration of mineral resources in the earth\\'s crust or uncertain permeability coefficient in reservoir modeling. When the problem size grows, storing and computing with the full dense matrix becomes prohibitively expensive both in terms of computational complexity and physical memory requirements. Fortunately, these matrices can often be approximated by a class of data sparse matrices called hierarchical matrices (H-matrices) where various sub-blocks of the matrix are approximated by low rank matrices. These matrices can be stored in memory that grows linearly with the problem size. In addition, arithmetic operations on these H-matrices, such as matrix-vector multiplication, can be completed in almost linear time. Originally the H-matrix technique was developed for the approximation of stiffness matrices coming from partial differential and integral equations. Parallelizing these arithmetic operations on the GPU has been the focus of this work and we will present work done on the matrix vector operation on the GPU using the KSPARSE library.

  20. Task-based dermal exposure models for regulatory risk assessment

    NARCIS (Netherlands)

    Warren, N.D.; Marquart, H.; Christopher, Y.; Laitinen, J.; Hemmen, J.J. van

    2006-01-01

    The regulatory risk assessment of chemicals requires the estimation of occupational dermal exposure. Until recently, the models used were either based on limited data or were specific to a particular class of chemical or application. The EU project RISKOFDERM has gathered a considerable number of

  1. Effect of pore size and cross-linking of a novel collagen-elastin dermal substitute on wound healing

    NARCIS (Netherlands)

    Boekema, B.K.H.L.; Vlig, M.; Damink, L.O.; Middelkoop, E.; Eummelen, L.; Buhren, A.V.; Ulrich, M.M.W.

    2014-01-01

    Collagen-elastin (CE) scaffolds are frequently used for dermal replacement in the treatment of full-thickness skin defects such as burn wounds. But little is known about the optimal pore size and level of cross-linking. Different formulations of dermal substitutes with unidirectional pores were

  2. Wound healing effects of collagen-laminin dermal matrix impregnated with resveratrol loaded hyaluronic acid-DPPC microparticles in diabetic rats.

    Science.gov (United States)

    Gokce, Evren H; Tuncay Tanrıverdi, Sakine; Eroglu, Ipek; Tsapis, Nicolas; Gokce, Goksel; Tekmen, Isıl; Fattal, Elias; Ozer, Ozgen

    2017-10-01

    An alternative formulation for the treatment of diabetic foot wounds that heal slowly is a requirement in pharmaceutical field. The aim of this study was to develop a dermal matrix consisting of skin proteins and lipids with an antioxidant that will enhance healing and balance the oxidative stress in the diabetic wound area due to the high levels of glucose. Thus a novel three dimensional collagen-laminin porous dermal matrix was developed by lyophilization. Resveratrol-loaded hyaluronic acid and dipalmitoylphosphatidylcholine microparticles were combined with this dermal matrix. Characterization, in vitro release, microbiological and in vivo studies were performed. Spherical microparticles were obtained with a high RSV encapsulation efficacy. The microparticles were well dispersed in the dermal matrix from the surface to deeper layers. Collagenase degraded dermal matrix, however the addition of RSV loaded microparticles delayed the degradation time. The release of RSV was sustained and reached 70% after 6h. Histological changes and antioxidant parameters in different treatment groups were investigated in full-thickness excision diabetic rat model. Collagen fibers were intense and improved by the presence of formulation without any signs of inflammation. The highest healing score was obtained with the dermal matrix impregnated with RSV-microparticles with an increased antioxidant activity. Collagen-laminin dermal matrix with RSV microparticles was synergistically effective due to presence of skin components in the formulation and controlled release achieved. This combination is a safe and promising option for the treatment of diabetic wounds requiring long recovery. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Acceleration of Regeneration of Large Gap Peripheral Nerve Injuries Using Acellular Nerve Allografts plus amniotic Fluid Derived Stem Cells (AFS)

    Science.gov (United States)

    2016-09-01

    AWARD NUMBER: W811XWH-13-1-0310 TITLE: Acceleration of Regeneration of Large-Gap Peripheral Nerve Injuries Using Acellular Nerve Allografts...plus amniotic Fluid Derived Stem Cells (AFS). PRINCIPAL INVESTIGATOR: Zhongyu Li, MD, PhD RECIPIENT: Wake Forest University Health Sciences...REPORT DATE September 2016 2. REPORT TYPE Annual 3. DATES COVERED 1Sep2015 - 31Aug2016 4. TITLE AND SUBTITLE Acceleration of Regeneration of Large

  4. The Antitriangular Factorization of Saddle Point Matrices

    KAUST Repository

    Pestana, J.

    2014-01-01

    Mastronardi and Van Dooren [SIAM J. Matrix Anal. Appl., 34 (2013), pp. 173-196] recently introduced the block antitriangular ("Batman") decomposition for symmetric indefinite matrices. Here we show the simplification of this factorization for saddle point matrices and demonstrate how it represents the common nullspace method. We show that rank-1 updates to the saddle point matrix can be easily incorporated into the factorization and give bounds on the eigenvalues of matrices important in saddle point theory. We show the relation of this factorization to constraint preconditioning and how it transforms but preserves the structure of block diagonal and block triangular preconditioners. © 2014 Society for Industrial and Applied Mathematics.

  5. Differentiation within autologous fibrin scaffolds of porcine dermal cells with the mesenchymal stem cell phenotype

    International Nuclear Information System (INIS)

    Puente, Pilar de la; Ludeña, Dolores; López, Marta; Ramos, Jennifer; Iglesias, Javier

    2013-01-01

    Porcine mesenchymal stem cells (pMSCs) are an attractive source of cells for tissue engineering because their properties are similar to those of human stem cells. pMSCs can be found in different tissues but their dermal origin has not been studied in depth. Additionally, MSCs differentiation in monolayer cultures requires subcultured cells, and these cells are at risk of dedifferentiation when implanting them into living tissue. Following this, we attempted to characterize the MSCs phenotype of porcine dermal cells and to evaluate their cellular proliferation and differentiation in autologous fibrin scaffolds (AFSs). Dermal biopsies and blood samples were obtained from 12 pigs. Dermal cells were characterized by flow cytometry. Frozen autologous plasma was used to prepare AFSs. pMSC differentiation was studied in standard structures (monolayers and pellets) and in AFSs. The pMSCs expressed the CD90 and CD29 markers of the mesenchymal lineage. AFSs afforded adipogenic, osteogenic and chondrogenic differentiation. The porcine dermis can be proposed to be a good source of MSCs with adequate proliferative capacity and a suitable expression of markers. The pMSCs also showed optimal proliferation and differentiation in AFSs, such that these might serve as a promising autologous and implantable material for use in tissue engineering. -- Highlights: ► Low fibrinogen concentration provides a suitable matrix for cell migration and differentiation. ► Autologous fibrin scaffolds is a promising technique in tissue engineering. ► Dermal cells are an easily accessible mesenchymal stem cell source. ► Fibrin scaffolds afforded adipogenic, osteogenic and chondrogenic differentiation.

  6. {sup 14}C-Methylenebisphenylisocyanate ({sup 14}C-MDI). Study of absorption after single dermal and intradermal administration in rats

    Energy Technology Data Exchange (ETDEWEB)

    Leibold, E.; Hoffmann, H.D.; Hildebrand, B

    1999-07-01

    The absorption, distribution and excretion of radioactivity was studied in groups of four male Wistar rats following a single dermal and intradermal administration of {sup 14}C- Methylenebisphenylisocyanate ({sup 14}C-MDI) at nominal dose levels of 4.0 and 0.4 mg/cm{sup 2} for dermal administration and 0.4 mg/animal for intradermal administration. These dose levels nominally corresponded to 40 and 4.0 mg/animal for dermal administration. Considering the animal weights, dose levels corresponded to about 140 and 14 mg/kg body weight (dermal administration) and 1.4 mg/kg body weight (intradermal administration). In the experiments with dermal administration, animals were exposed for 8 hours and sacrificed 8, 24 or 120 h after beginning of exposure. In the experiment with intradermal administration, animals were sacrificed 120 h after treatment. After dermal administration of {sup 14}C-MDI, mean recoveries of radioactivity from all dose groups were in the range from 97.86 to 108.07% of the total radioactivity administered. Generally, the largest proportion of radioactivity was found at the application site and dressing. The total amount of radioactivity absorbed (including excreta, cage wash, tissues/organs and carcass) increased with increasing sacrifice time. Dermal absorption was very low and quantitatively similar at both dose levels; maximally ca. 0.9 % of the applied radioactivity was absorbed. After intradermal administration of {sup 14}C-MDI, the mean recovery of radioactivity was 100.90 % of the radioactivity administered. The largest proportion of radioactivity was found at the application site. The total amount of radioactivity absorbed (including excreta, cage wash, tissues/organs and carcass) amounted to about 26 % of the radioactivity applied. Irrespective of the mode of administration of 1{sup 4C}-MDI, concentrations of radioactivity in tissues and organs generally were below 1 {mu}g Eq/g at 120 h after administration. In summary, the results of this

  7. Graphs and matrices

    CERN Document Server

    Bapat, Ravindra B

    2014-01-01

    This new edition illustrates the power of linear algebra in the study of graphs. The emphasis on matrix techniques is greater than in other texts on algebraic graph theory. Important matrices associated with graphs (for example, incidence, adjacency and Laplacian matrices) are treated in detail. Presenting a useful overview of selected topics in algebraic graph theory, early chapters of the text focus on regular graphs, algebraic connectivity, the distance matrix of a tree, and its generalized version for arbitrary graphs, known as the resistance matrix. Coverage of later topics include Laplacian eigenvalues of threshold graphs, the positive definite completion problem and matrix games based on a graph. Such an extensive coverage of the subject area provides a welcome prompt for further exploration. The inclusion of exercises enables practical learning throughout the book. In the new edition, a new chapter is added on the line graph of a tree, while some results in Chapter 6 on Perron-Frobenius theory are reo...

  8. Bayesian Nonparametric Clustering for Positive Definite Matrices.

    Science.gov (United States)

    Cherian, Anoop; Morellas, Vassilios; Papanikolopoulos, Nikolaos

    2016-05-01

    Symmetric Positive Definite (SPD) matrices emerge as data descriptors in several applications of computer vision such as object tracking, texture recognition, and diffusion tensor imaging. Clustering these data matrices forms an integral part of these applications, for which soft-clustering algorithms (K-Means, expectation maximization, etc.) are generally used. As is well-known, these algorithms need the number of clusters to be specified, which is difficult when the dataset scales. To address this issue, we resort to the classical nonparametric Bayesian framework by modeling the data as a mixture model using the Dirichlet process (DP) prior. Since these matrices do not conform to the Euclidean geometry, rather belongs to a curved Riemannian manifold,existing DP models cannot be directly applied. Thus, in this paper, we propose a novel DP mixture model framework for SPD matrices. Using the log-determinant divergence as the underlying dissimilarity measure to compare these matrices, and further using the connection between this measure and the Wishart distribution, we derive a novel DPM model based on the Wishart-Inverse-Wishart conjugate pair. We apply this model to several applications in computer vision. Our experiments demonstrate that our model is scalable to the dataset size and at the same time achieves superior accuracy compared to several state-of-the-art parametric and nonparametric clustering algorithms.

  9. Efficient dermal delivery of retinyl palmitate: Progressive polarimetry and Raman spectroscopy to evaluate the structure and efficacy.

    Science.gov (United States)

    Lee, Jun Bae; Lee, Dong Ryeol; Choi, Nak Cho; Jang, Jihui; Park, Chun Ho; Yoon, Moung Seok; Lee, Miyoung; Won, Kyoungae; Hwang, Jae Sung; Kim, B Moon

    2015-10-12

    Over the past decades, there has been a growing interest in dermal drug delivery. Although various novel delivery devices and methods have been developed, dermal delivery is still challenging because of problems such as poor drug permeation, instability of vesicles and drug leakage from vesicles induced by fusion of vesicles. To solve the vesicle instability problems in current dermal delivery systems, we developed materials comprised of liquid crystals as a new delivery vehicle of retinyl palmitate and report the characterization of the liquid crystals using a Mueller matrix polarimetry. The stability of the liquid-crystal materials was evaluated using the polarimeter as a novel evaluation tool along with other conventional methods. The dermal delivery of retinyl palmitate was investigated through the use of confocal Raman spectroscopy. The results indicate that the permeation of retinyl palmitate was enhanced by up to 106% compared to that using an ordinary emulsion with retinyl palmitate. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Abdominal wall reconstruction using De-epithelialized dermal flap: A ...

    African Journals Online (AJOL)

    Background: Although autogenous materials have been used in abdominal wall hernioplasty for a long time, the introduction of prosthetic materials diminished their popularity. However, these materials may be expensive, inappropriate or unavailable. The aim of this study is to determine the place of de-epithelialized dermal ...

  11. Implanon sub-dermal implant: an emerging method of contraception ...

    African Journals Online (AJOL)

    Implanon, a single rod sub-dermal implant is a relatively new contraceptive which offers long term reversible contraception for women. This study seeks to determine the safety, efficacy and acceptor characteristics of Implanon at the family planning clinic of University of Ilorin Teaching Hospital (UITH), Ilorin, Nigeria.

  12. Dermal exposure to jet fuel JP-8 significantly contributes to the production of urinary naphthols in fuel-cell maintenance workers.

    Science.gov (United States)

    Chao, Yi-Chun E; Kupper, Lawrence L; Serdar, Berrin; Egeghy, Peter P; Rappaport, Stephen M; Nylander-French, Leena A

    2006-02-01

    Jet propulsion fuel 8 (JP-8) is the major jet fuel used worldwide and has been recognized as a major source of chemical exposure, both inhalation and dermal, for fuel-cell maintenance workers. We investigated the contributions of dermal and inhalation exposure to JP-8 to the total body dose of U.S. Air Force fuel-cell maintenance workers using naphthalene as a surrogate for JP-8 exposure. Dermal, breathing zone, and exhaled breath measurements of naphthalene were obtained using tape-strip sampling, passive monitoring, and glass bulbs, respectively. Levels of urinary 1- and 2-naphthols were determined in urine samples and used as biomarkers of JP-8 exposure. Multiple linear regression analyses were conducted to investigate the relative contributions of dermal and inhalation exposure to JP-8, and demographic and work-related covariates, to the levels of urinary naphthols. Our results show that both inhalation exposure and smoking significantly contributed to urinary 1-naphthol levels. The contribution of dermal exposure was significantly associated with levels of urinary 2-naphthol but not with urinary 1-naphthol among fuel-cell maintenance workers who wore supplied-air respirators. We conclude that dermal exposure to JP-8 significantly contributes to the systemic dose and affects the levels of urinary naphthalene metabolites. Future work on dermal xenobiotic metabolism and toxicokinetic studies are warranted in order to gain additional knowledge on naphthalene metabolism in the skin and the contribution to systemic exposure.

  13. Dermal transfer quantification of nanoparticles from nano-enabled surfaces

    DEFF Research Database (Denmark)

    Mackevica, Aiga; Olsson, Mikael Emil; Mines, Paul D.

    2018-01-01

    ). The dermal transfer testing by wipe sampling and analytical approach used in this study demonstrates that wipe testing in combination with spICP-MS analysis can provide both qualitative data in terms of mass and number-based NP release, as well as particle characterization in terms of NP size distribution...... and characterize NP release from keyboard covers and freshly painted surfaces, in terms of mass and number concentration, as well as released particle size distribution through the use of spICP-MS. Three types of NPs were selected for method validation testing, Ag, TiO2, and CuO; and, the particle extraction from...... wipes was found to be efficient for Ag and CuO, but not for TiO2 particles. Thereafter, potential dermal transfer was tested by wipe sampling for two nanoAg-containing silicon keyboard covers, and wood painted with nanoCuO-containing paint. AgNP release was observed for one of the keyboard cover types...

  14. Allogeneic human dermal fibroblasts are viable in peripheral blood mononuclear co-culture

    Directory of Open Access Journals (Sweden)

    Restu Syamsul Hadi

    2014-08-01

    Full Text Available Background Transplanted allogeneic dermal fibroblasts retain stem cell subpopulations, and are easily isolated, expanded and stored using standard techniques. Their potential for regenerative therapy of chronic wounds should be evaluated. The aim of this study was to determine allogeneic fibroblast viability in the presence of peripheral blood mononuclear cells (PBMC. Methods In this experimental study, fibroblasts were isolated from foreskin explants, expanded in the presence of serum, and stored using slow-freezing. We used one intervention group of allogeneic fibroblasts co-cultured with PBMC and 2 control groups of separate fibroblast and PBMC cultures.Fibroblasts were characterized by their collagen secretion and octamer-binding transcription factor 4 (OCT4 expression. Viability was evaluated using water soluble tetrazolium-1 (WST-1 proliferation assay. Absorbances were measured at 450 nm. Data analysis was performed by student’s paired t-test. Results Dermal fibroblasts were shown to secrete collagen, express OCT4, be recoverable after cryopreservation, and become attached to the culture dish in a co-culture with PBMC. Co-cultured and control fibroblasts had no significantly different cell viabilities (p>0.05. Calculated viable cell numbers increased 1.8 and 5.1-fold, respectively, at days 2 and 4 in vitro. Both groups showed comparable doubling times at days 2 and 4 in vitro. PBMC did not interfere with allogeneic fibroblast viability and proliferative capacity Conclusions Allogeneic fibroblasts remain viable and proliferate in the presence of host PBMC. Future research should evaluate allogeneic human dermal fibroblast competency in clinical settings. Dermal fibroblasts are a potential source for cell therapy in chronic wound management.

  15. On Skew Circulant Type Matrices Involving Any Continuous Fibonacci Numbers

    Directory of Open Access Journals (Sweden)

    Zhaolin Jiang

    2014-01-01

    inverse matrices of them by constructing the transformation matrices. Furthermore, the maximum column sum matrix norm, the spectral norm, the Euclidean (or Frobenius norm, and the maximum row sum matrix norm and bounds for the spread of these matrices are given, respectively.

  16. Immanant Conversion on Symmetric Matrices

    Directory of Open Access Journals (Sweden)

    Purificação Coelho M.

    2014-01-01

    Full Text Available Letr Σn(C denote the space of all n χ n symmetric matrices over the complex field C. The main objective of this paper is to prove that the maps Φ : Σn(C -> Σn (C satisfying for any fixed irre- ducible characters X, X' -SC the condition dx(A +aB = dχ·(Φ(Α + αΦ(Β for all matrices A,В ε Σ„(С and all scalars a ε C are automatically linear and bijective. As a corollary of the above result we characterize all such maps Φ acting on ΣИ(С.

  17. A Bayesian statistical analysis of mouse dermal tumor promotion assay data for evaluating cigarette smoke condensate.

    Science.gov (United States)

    Kathman, Steven J; Potts, Ryan J; Ayres, Paul H; Harp, Paul R; Wilson, Cody L; Garner, Charles D

    2010-10-01

    The mouse dermal assay has long been used to assess the dermal tumorigenicity of cigarette smoke condensate (CSC). This mouse skin model has been developed for use in carcinogenicity testing utilizing the SENCAR mouse as the standard strain. Though the model has limitations, it remains as the most relevant method available to study the dermal tumor promoting potential of mainstream cigarette smoke. In the typical SENCAR mouse CSC bioassay, CSC is applied for 29 weeks following the application of a tumor initiator such as 7,12-dimethylbenz[a]anthracene (DMBA). Several endpoints are considered for analysis including: the percentage of animals with at least one mass, latency, and number of masses per animal. In this paper, a relatively straightforward analytic model and procedure is presented for analyzing the time course of the incidence of masses. The procedure considered here takes advantage of Bayesian statistical techniques, which provide powerful methods for model fitting and simulation. Two datasets are analyzed to illustrate how the model fits the data, how well the model may perform in predicting data from such trials, and how the model may be used as a decision tool when comparing the dermal tumorigenicity of cigarette smoke condensate from multiple cigarette types. The analysis presented here was developed as a statistical decision tool for differentiating between two or more prototype products based on the dermal tumorigenicity. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  18. Effects of solid acellular type-I/III collagen biomaterials on in vitro and in vivo chondrogenesis of mesenchymal stem cells.

    Science.gov (United States)

    Gao, Liang; Orth, Patrick; Cucchiarini, Magali; Madry, Henning

    2017-09-01

    Type-I/III collagen membranes are advocated for clinical use in articular cartilage repair as being able of inducing chondrogenesis, a technique termed autologous matrix-induced chondrogenesis (AMIC). Area covered: The current in vitro and translational in vivo evidence for chondrogenic effects of solid acellular type-I/III collagen biomaterials. Expert commentary: In vitro, mesenchymal stem cells (MSCs) adhere to the fibers of the type-I/III collagen membrane. No in vitro study provides evidence that a type-I/III collagen matrix alone may induce chondrogenesis. Few in vitro studies compare the effects of type-I and type-II collagen scaffolds on chondrogenesis. Recent investigations suggest better chondrogenesis with type-II collagen scaffolds. A systematic review of the translational in vivo data identified one long-term study showing that covering of cartilage defects treated by microfracture with a type-I/III collagen membrane significantly enhanced the repair tissue volume compared with microfracture alone. Other in vivo evidence is lacking to suggest either improved histological structure or biomechanical function of the repair tissue. Taken together, there is a paucity of in vitro and preclinical in vivo evidence supporting the concept that solid acellular type-I/III collagen scaffolds may be superior to classical approaches to induce in vitro or in vivo chondrogenesis of MSCs.

  19. The 'golden' matrices and a new kind of cryptography

    International Nuclear Information System (INIS)

    Stakhov, A.P.

    2007-01-01

    We consider a new class of square matrices called the 'golden' matrices. They are a generalization of the classical Fibonacci Q-matrix for continuous domain. The 'golden' matrices can be used for creation of a new kind of cryptography called the 'golden' cryptography. The method is very fast and simple for technical realization and can be used for cryptographic protection of digital signals (telecommunication and measurement systems)

  20. Laboratory Validation and Field Assessment of Petroleum Laboratory Technicians' Dermal Exposure to Crude Oil Using a Wipe Sampling Method.

    Science.gov (United States)

    Galea, Karen S; Mueller, Will; Arfaj, Ayman M; Llamas, Jose L; Buick, Jennifer; Todd, David; McGonagle, Carolyn

    2018-05-21

    Crude oil may cause adverse dermal effects therefore dermal exposure is an exposure route of concern. Galea et al. (2014b) reported on a study comparing recovery (wipe) and interception (cotton glove) dermal sampling methods. The authors concluded that both methods were suitable for assessing dermal exposure to oil-based drilling fluids and crude oil but that glove samplers may overestimate the amount of fluid transferred to the skin. We describe a study which aimed to further evaluate the wipe sampling method to assess dermal exposure to crude oil, with this assessment including extended sample storage periods and sampling efficiency tests being undertaken at environmental conditions to mimic those typical of outdoor conditions in Saudi Arabia. The wipe sampling method was then used to assess the laboratory technicians' actual exposure to crude oil during typical petroleum laboratory tasks. Overall, acceptable storage efficiencies up to 54 days were reported with results suggesting storage stability over time. Sampling efficiencies were also reported to be satisfactory at both ambient and elevated temperature and relative humidity environmental conditions for surrogate skin spiked with known masses of crude oil and left up to 4 h prior to wiping, though there was an indication of reduced sampling efficiency over time. Nineteen petroleum laboratory technicians provided a total of 35 pre- and 35 post-activity paired hand wipe samples. Ninety-three percent of the pre-exposure paired hand wipes were less than the analytical limit of detection (LOD), whereas 46% of the post-activity paired hand wipes were less than the LOD. The geometric mean paired post-activity wipe sample measurement was 3.09 µg cm-2 (range 1.76-35.4 µg cm-2). It was considered that dermal exposure most frequently occurred through direct contact with the crude oil (emission) or via deposition. The findings of this study suggest that the wipe sampling method is satisfactory in quantifying

  1. Advanced incomplete factorization algorithms for Stiltijes matrices

    Energy Technology Data Exchange (ETDEWEB)

    Il`in, V.P. [Siberian Division RAS, Novosibirsk (Russian Federation)

    1996-12-31

    The modern numerical methods for solving the linear algebraic systems Au = f with high order sparse matrices A, which arise in grid approximations of multidimensional boundary value problems, are based mainly on accelerated iterative processes with easily invertible preconditioning matrices presented in the form of approximate (incomplete) factorization of the original matrix A. We consider some recent algorithmic approaches, theoretical foundations, experimental data and open questions for incomplete factorization of Stiltijes matrices which are {open_quotes}the best{close_quotes} ones in the sense that they have the most advanced results. Special attention is given to solving the elliptic differential equations with strongly variable coefficients, singular perturbated diffusion-convection and parabolic equations.

  2. On the Eigenvalues and Eigenvectors of Block Triangular Preconditioned Block Matrices

    KAUST Repository

    Pestana, Jennifer

    2014-01-01

    Block lower triangular matrices and block upper triangular matrices are popular preconditioners for 2×2 block matrices. In this note we show that a block lower triangular preconditioner gives the same spectrum as a block upper triangular preconditioner and that the eigenvectors of the two preconditioned matrices are related. © 2014 Society for Industrial and Applied Mathematics.

  3. Isolation of intact sub-dermal secretory cavities from Eucalyptus

    Directory of Open Access Journals (Sweden)

    Goodger Jason QD

    2010-09-01

    Full Text Available Abstract Background The biosynthesis of plant natural products in sub-dermal secretory cavities is poorly understood at the molecular level, largely due to the difficulty of physically isolating these structures for study. Our aim was to develop a protocol for isolating live and intact sub-dermal secretory cavities, and to do this, we used leaves from three species of Eucalyptus with cavities that are relatively large and rich in essential oils. Results Leaves were digested using a variety of commercially available enzymes. A pectinase from Aspergillus niger was found to allow isolation of intact cavities after a relatively short incubation (12 h, with no visible artifacts from digestion and no loss of cellular integrity or cavity contents. Several measurements indicated the potential of the isolated cavities for further functional studies. First, the cavities were found to consume oxygen at a rate that is comparable to that estimated from leaf respiratory rates. Second, mRNA was extracted from cavities, and it was used to amplify a cDNA fragment with high similarity to that of a monoterpene synthase. Third, the contents of the cavity lumen were extracted, showing an unexpectedly low abundance of volatile essential oils and a sizeable amount of non-volatile material, which is contrary to the widely accepted role of secretory cavities as predominantly essential oil repositories. Conclusions The protocol described herein is likely to be adaptable to a range of Eucalyptus species with sub-dermal secretory cavities, and should find wide application in studies of the developmental and functional biology of these structures, and the biosynthesis of the plant natural products they contain.

  4. Biocompatibility and tissue regenerating capacity of crosslinked dermal sheep collagen

    NARCIS (Netherlands)

    van Wachem, P.B.; van Luyn, M.J.A.; Olde Damink, L.H.H.; Olde damink, L.H.H.; Dijkstra, Pieter J.; Feijen, Jan; Nieuwenhuis, P.

    1994-01-01

    The biocompatibility and tissue regenerating capacity of four crosslinked dermal sheep collagens (DSC) was studied. In vitro, the four DSC versions were found to be noncytotoxic or very low in cytoxicity. After subcutaneous implantation in rats, hexamethylenediisocyanatecrcrosslinked DSC (HDSC)

  5. On Investigating GMRES Convergence using Unitary Matrices

    Czech Academy of Sciences Publication Activity Database

    Duintjer Tebbens, Jurjen; Meurant, G.; Sadok, H.; Strakoš, Z.

    2014-01-01

    Roč. 450, 1 June (2014), s. 83-107 ISSN 0024-3795 Grant - others:GA AV ČR(CZ) M100301201; GA MŠk(CZ) LL1202 Institutional support: RVO:67985807 Keywords : GMRES convergence * unitary matrices * unitary spectra * normal matrices * Krylov residual subspace * Schur parameters Subject RIV: BA - General Mathematics Impact factor: 0.939, year: 2014

  6. "G.P.S Matrices" programme: A method to improve the mastery level of social science students in matrices operations

    Science.gov (United States)

    Lee, Ken Voon

    2013-04-01

    The purpose of this action research was to increase the mastery level of Form Five Social Science students in Tawau II National Secondary School in the operations of addition, subtraction and multiplication of matrices in Mathematics. A total of 30 students were involved. Preliminary findings through the analysis of pre-test results and questionnaire had identified the main problem faced in which the students felt confused with the application of principles of the operations of matrices when performing these operations. Therefore, an action research was conducted using an intervention programme called "G.P.S Matrices" to overcome the problem. This programme was divided into three phases. 'Gift of Matrices' phase aimed at forming matrix teaching aids. The second and third phases were 'Positioning the Elements of Matrices' and 'Strenghtening the Concept of Matrices'. These two phases were aimed at increasing the level of understanding and memory of the students towards the principles of matrix operations. Besides, this third phase was also aimed at creating an interesting learning environment. A comparison between the results of pre-test and post-test had shown a remarkable improvement in students' performances after implementing the programme. In addition, the analysis of interview findings also indicated a positive feedback on the changes in students' attitude, particularly in the aspect of students' understanding level. Moreover, the level of students' memory also increased following the use of the concrete matrix teaching aids created in phase one. Besides, teachers felt encouraging when conducive learning environment was created through students' presentation activity held in third phase. Furthermore, students were voluntarily involved in these student-centred activities. In conclusion, this research findings showed an increase in the mastery level of students in these three matrix operations and thus the objective of the research had been achieved.

  7. Nerve stepping stone has minimal impact in aiding regeneration across long acellular nerve allografts.

    Science.gov (United States)

    Yan, Ying; Hunter, Daniel A; Schellhardt, Lauren; Ee, Xueping; Snyder-Warwick, Alison K; Moore, Amy M; Mackinnon, Susan E; Wood, Matthew D

    2018-02-01

    Acellular nerve allografts (ANAs) yield less consistent favorable outcomes compared with autografts for long gap reconstructions. We evaluated whether a hybrid ANA can improve 6-cm gap reconstruction. Rat sciatic nerve was transected and repaired with either 6-cm hybrid or control ANAs. Hybrid ANAs were generated using a 1-cm cellular isograft between 2.5-cm ANAs, whereas control ANAs had no isograft. Outcomes were assessed by graft gene and marker expression (n = 4; at 4 weeks) and motor recovery and nerve histology (n = 10; at 20 weeks). Hybrid ANAs modified graft gene and marker expression and promoted modest axon regeneration across the 6-cm defect compared with control ANA (P nerve gaps with autografts. Muscle Nerve 57: 260-267, 2018. © 2017 Wiley Periodicals, Inc.

  8. Comparison of Calcium and Barium Microcapsules as Scaffolds in the Development of Artificial Dermal Papillae.

    Science.gov (United States)

    Liu, Yang; Lin, Changmin; Zeng, Yang; Li, Haihong; Cai, Bozhi; Huang, Keng; Yuan, Yanping; Li, Yu

    2016-01-01

    This study aimed to develop and evaluate barium and calcium microcapsules as candidates for scaffolding in artificial dermal papilla. Dermal papilla cells (DPCs) were isolated and cultured by one-step collagenase treatment. The DPC-Ba and DPC-Ca microcapsules were prepared by using a specially designed, high-voltage, electric-field droplet generator. Selected microcapsules were assessed for long-term inductive properties with xenotransplantation into Sprague-Dawley rat ears. Both barium and calcium microcapsules maintained xenogenic dermal papilla cells in an immunoisolated environment and induced the formation of hair follicle structures. Calcium microcapsules showed better biocompatibility, permeability, and cell viability in comparison with barium microcapsules. Before 18 weeks, calcium microcapsules gathered together, with no substantial immune response. After 32 weeks, some microcapsules were near inflammatory cells and wrapped with fiber. A few large hair follicles were found. Control samples showed no marked changes at the implantation site. Barium microcapsules were superior to calcium microcapsules in structural and mechanical stability. The cells encapsulated in hydrogel barium microcapsules exhibited higher short-term viability. This study established a model to culture DPCs in 3D culture conditions. Barium microcapsules may be useful in short-term transplantation study. Calcium microcapsules may provide an effective scaffold for the development of artificial dermal papilla.

  9. RELATIONS BETWEEN INVITRO CYTOTOXICITY AND CROSS-LINKED DERMAL SHEEP COLLAGENS

    NARCIS (Netherlands)

    VANLUYN, MJA; VANWACHEM, PB; DAMINK, LO; DIJKSTRA, PJ; FEIJEN, J; NIEUWENHUIS, P

    Collagen-based biomaterials have found various applications in the biomedical field. However, collagen-based biomaterials may induce cytotoxic effects. This study evaluated possible cytotoxic effects of (crosslinked) dermal sheep collagen (DSC) using a 7-d-methylcellulose cell culture with human

  10. In vivo and in vitro dermal penetration of 2,4,5,2',4', 5'-hexachlorobiphenyl in young and adult rats

    International Nuclear Information System (INIS)

    Shah, P.V.; Sumler, M.R.; Fisher, H.L.; Hall, L.L.

    1989-01-01

    Penetration of 2,4,5,2',4',5'-[ 14 C]hexachlorobiphenyl (HCB) through skin of young (33 days) and adult (82 days) female Fischer 344 rats was determined in vivo and by two in vitro methods. In vivo dermal penetration at 120 hr was 45% in young and 43% in adults. At 72 hr in vivo dermal penetration was 35% in young and 26% in adults compared to 1.5% for young and 1.0% for adult as measured with a continuous flow in vitro system and 2.9% for young and 1.9% for adults as measured with a static in vitro system. Most of the dermally absorbed HCB remained in the body as only 4.9 and 2.6% of that absorbed was excreted by young and adult rats, respectively, at the end of 120 hr. Significant differences in dermal penetration and kinetics of HCB between young and adult female rats were observed. The elimination of ECB-derived material was approximately six times higher in feces than in urine. A physiological pharmacokinetic model was fitted to the organ and tissue radioactivity distribution data. Parameters in the model determined from dermal dosing of female Fischer 344 rats were in reasonable agreement with those reported in the literature for adult male Sprague-Dawley rats (iv dose). The rate constant for dermal penetration was 0.83 x 10 -4 min -1 for adults and 0.96 x 10 -4 min -1 for young. The delay or lag time parameter for dermal penetration was 4.4 hr in adults and 1.1 hr in young

  11. Genomic regions associated with the sex-linked inhibitor of dermal melanin in Silkie chicken

    Directory of Open Access Journals (Sweden)

    Ming TIAN,Rui HAO,Suyun FANG,Yanqiang WANG,Xiaorong GU,Chungang FENG,Xiaoxiang HU,Ning LI

    2014-09-01

    Full Text Available A unique characteristic of the Silkie chicken is its fibromelanosis phenotype. The dermal layer of its skin, its connective tissue and shank dermis are hyperpigmented. This dermal hyperpigmentation phenotype is controlled by the sex-linked inhibitor of dermal melanin gene (ID and the dominant fibromelanosis allele. This study attempted to confirm the genomic region associated with ID. By genotyping, ID was found to be closely linked to the region between GGA_rs16127903 and GGA_rs14685542 (8406919 bp on chromosome Z, which contains ten functional genes. The expression of these genes was characterized in the embryo and 4 days after hatching and it was concluded that MTAP, encoding methylthioadenosinephosphorylase, would be the most likely candidate gene. Finally, target DNA capture and sequence analysis was performed, but no specific SNP(s was found in the targeted region of the Silkie genome. Further work is necessary to identify the causal ID mutation located on chromosome Z.

  12. One-stage reconstruction of soft tissue defects with the sandwich technique: Collagen-elastin dermal template and skin grafts

    Directory of Open Access Journals (Sweden)

    Uwe Wollina

    2011-01-01

    Full Text Available Background : A full-thickness soft tissue defect closure often needs complex procedures. The use of dermal templates can be helpful in improving the outcome. Objective : The objective was to evaluate a sandwich technique combining the dermal collagen-elastin matrix with skin grafts in a one-stage procedure. Materials and Methods : Twenty-three patients with 27 wounds were enrolled in this prospective single-centre observational study. The mean age was 74.8 ± 17.2 years. Included were full-thickness defects with exposed bone, cartilage and/ or tendons. The dermal collagen-elastin matrix was applied onto the wound bed accomplished by skin transplants, i.e. ′sandwich′ transplantation. In six wounds, the transplants were treated with intermittent negative pressure therapy. Results : The size of defects was ≤875 cm 2 . The use of the dermal template resulted in a complete and stable granulation in 100% of wounds. Seventeen defects showed a complete closure and 19 achieved a complete granulation with an incomplete closure. There was a marked pain relief. No adverse events were noted due to the dermal template usage. Conclusions : Sandwich transplantation with the collagen-elastin matrix is a useful tool when dealing with full-thickness soft tissue defects with exposed bone, cartilage or tendons.

  13. CONVERGENCE OF POWERS OF CONTROLLABLE INTUITIONISTIC FUZZY MATRICES

    OpenAIRE

    Riyaz Ahmad Padder; P. Murugadas

    2016-01-01

    Convergences of powers of controllable intuitionistic fuzzy matrices have been stud¬ied. It is shown that they oscillate with period equal to 2, in general. Some equalities and sequences of inequalities about powers of controllable intuitionistic fuzzy matrices have been obtained.

  14. Dermal absorption and distribution of 14 C carbaryl in wistar rats

    International Nuclear Information System (INIS)

    Tos-Luty, S.; Tokarska-Rodak, M.; Latuszynska, J.; Przebirowska, D.

    2001-01-01

    The level of 14 C carbaryl was determined in blood (leukocytes, erythrocytes, all blood cells, plasma) and organs (brain, heart, lungs, liver, spleen, skin at the site of exposure) of male Wistar rats after dermal administration. The application liquid was 14 C carbaryl solution in 96% ethyl alcohol. This preparation, possessing an activity of 670 kBq/ml, containing 1.67 mg of carbaryl, was applied to the skin of the tail according to Massmann's method in own modification. The amount of the preparation per 1 cm 2 of the tail skin was 0.19 mg of carbaryl (74.4 kBq). The tails of experimental rats were exposed to 14 C carbaryl by soaking for 4 h daily: once, twice or three times. Beta radiation from 14 C was measured in homogenized organs (brain, heart, lungs, liver, skin) and in blood by computer controlled Wallac scintillation counter Model 1409, using Multi Calc software. The dermal absorption of carbaryl at the site of exposure and in the surrounding area of about 2 cm was observed already during 4 hour exposure. Carbaryl reached plasma within 4 h of a single dermal exposure and penetrated into leukocytes, erythrocytes, heart, liver, lung, kidney and brain. The largest amount of 14 C carbaryl, about 2% of absorbed dose, was detected in liver. (author)

  15. Securing the Airway in Pretracheal Dermal Metastases From Oropharyngeal Carcinoma: A Case Report.

    Science.gov (United States)

    Truong, Angela T; Truong, Dam-Thuy; Gillenwater, Ann M; Soliz, Jose M; Rahlfs, Thomas F

    2018-04-23

    Dermal metastases reflect the ominous and aggressive spread of oropharyngeal squamous cell carcinomas. The rampant proliferation of these metastatic tumors to the neck results in respiratory distress and impending airway obstruction. We report a case of a patient with massive neck dermal metastases requiring urgent airway control for intermittent stridor. Awake tracheostomy is generally regarded as the gold standard to manage the compromised airway. However, in this unusual case, after discussion between surgeon and anesthesiologist, because of the anticipated formidable difficulties in performing awake tracheostomy, it was decided that awake fiberoptic intubation would provide the best chance of success.

  16. Blood Vessel-Derived Acellular Matrix for Vascular Graft Application

    Directory of Open Access Journals (Sweden)

    Luigi Dall’Olmo

    2014-01-01

    Full Text Available To overcome the issues connected to the use of autologous vascular grafts and artificial materials for reconstruction of small diameter (<6 mm blood vessels, this study aimed to develop acellular matrix- (AM- based vascular grafts. Rat iliac arteries were decellularized by a detergent-enzymatic treatment, whereas endothelial cells (ECs were obtained through enzymatic digestion of rat skin followed by immunomagnetic separation of CD31-positive cells. Sixteen female Lewis rats (8 weeks old received only AM or previously in vitro reendothelialized AM as abdominal aorta interposition grafts (about 1 cm. The detergent-enzymatic treatment completely removed the cellular part of vessels and both MHC class I and class II antigens. One month after surgery, the luminal surface of implanted AMs was partially covered by ECs and several platelets adhered in the areas lacking cell coverage. Intimal hyperplasia, already detected after 1 month, increased at 3 months. On the contrary, all grafts composed by AM and ECs were completely covered at 1 month and their structure was similar to that of native vessels at 3 months. Taken together, our findings show that prostheses composed of AM preseeded with ECs could be a promising approach for the replacement of blood vessels.

  17. Loop diagrams without γ matrices

    International Nuclear Information System (INIS)

    McKeon, D.G.C.; Rebhan, A.

    1993-01-01

    By using a quantum-mechanical path integral to compute matrix elements of the form left-angle x|exp(-iHt)|y right-angle, radiative corrections in quantum-field theory can be evaluated without encountering loop-momentum integrals. In this paper we demonstrate how Dirac γ matrices that occur in the proper-time ''Hamiltonian'' H lead to the introduction of a quantum-mechanical path integral corresponding to a superparticle analogous to one proposed recently by Fradkin and Gitman. Direct evaluation of this path integral circumvents many of the usual algebraic manipulations of γ matrices in the computation of quantum-field-theoretical Green's functions involving fermions

  18. Zinc oxide nanoparticles: a 90-day repeated-dose dermal toxicity study in rats

    Directory of Open Access Journals (Sweden)

    Ryu HJ

    2014-12-01

    Full Text Available Hwa Jung Ryu,1,* Mu Yeb Seo,2,* Sung Kyu Jung,1 Eun Ho Maeng,2 Seung-Young Lee,2 Dong-Hyouk Jang,2 Taek-Jin Lee,2 Ki-Yeon Jo,2 Yu-Ri Kim,3 Kyu-Bong Cho,4 Meyoung-Kon Kim,3 Beom Jun Lee,5 Sang Wook Son1 1Department of Dermatology, Korea University College of Medicine, Seoul, 2Korea Testing and Research Institute, Gyunggido, 3Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul, 4Department of Clinical Laboratory Science, Shinheung College, Uijeongbu, 5College of Veterinary Medicine, Chungbuk National University, Cheongju, Republic of Korea *These authors contributed equally to this work and both should be considered first authors Abstract: Zinc oxide (ZnO works as a long-lasting, broad-spectrum physical sunblock, and can prevent skin cancer, sunburn, and photoaging. Nanosized ZnO particles are used often in sunscreens due to consumer preference over larger sizes, which appear opaque when dermally applied. Although the US Food and Drug Administration approved the use of nanoparticles (NPs in sunscreens in 1999, there are ongoing safety concerns. The aim of this study was to evaluate the subchronic toxicity of ZnO NPs after dermal application according to the Organization for Economic Cooperation and Development Test Guidelines 411 using Good Laboratory Practice. Sprague Dawley rats were randomly divided into eight (one control, one vehicle control, three experimental, and three recovery groups. Different concentrations of ZnO NPs were dermally applied to the rats in the experimental groups for 90 days. Clinical observations as well as weight and food consumption were measured and recorded daily. Hematology and biochemistry parameters were determined. Gross pathologic and histopathologic examinations were performed on selected tissues from all animals. Analyses of tissue were undertaken to determine target organ tissue distribution. There was no increased mortality in the experimental group. Although there

  19. Laminin peptide YIGSR induces collagen synthesis in Hs27 human dermal fibroblasts

    International Nuclear Information System (INIS)

    Yoon, Jong Hyuk; Kim, Jaeyoon; Lee, Hyeongjoo; Kim, So Young; Jang, Hwan-Hee; Ryu, Sung Ho; Kim, Beom Joon; Lee, Taehoon G.

    2012-01-01

    Highlights: ► We identify a function of the YIGSR peptide to enhance collagen synthesis in Hs27. ► YIGSR peptide enhanced collagen type 1 synthesis both of gene and protein levels. ► There were no changes in cell proliferation and MMP-1 level in YIGSR treatment. ► The YIGSR effect on collagen synthesis mediated activation of FAK, pyk2 and ERK. ► The YIGSR-induced FAK and ERK activation was modulated by FAK and MEK inhibitors. -- Abstract: The dermal ECM is synthesized from fibroblasts and is primarily compromised of fibrillar collagen and elastic fibers, which support the mechanical strength and resiliency of skin, respectively. Laminin, a major glycoprotein located in the basement membrane, promotes cell adhesion, cell growth, differentiation, and migration. The laminin tyrosine-isoleucine-glycine-serine-arginine (YIGSR) peptide, corresponding to the 929–933 sequence of the β1 chain, is known to be a functional motif with effects on the inhibition of tumor metastasis, the regulation of sensory axonal response and the inhibition of angiogenesis through high affinity to the 67 kDa laminin receptor. In this study, we identified a novel function of the YIGSR peptide to enhance collagen synthesis in human dermal fibroblasts. To elucidate this novel function regarding collagen synthesis, we treated human dermal fibroblasts with YIGSR peptide in both a time- and dose-dependent manner. According to subsequent experiments, we found that the YIGSR peptide strongly enhanced collagen type 1 synthesis without changing cell proliferation or cellular MMP-1 level. This YIGSR peptide-mediated collagen type 1 synthesis was modulated by FAK inhibitor and MEK inhibitor. This study clearly reveals that YIGSR peptide plays a novel function on the collagen type 1 synthesis of dermal fibroblasts and also suggests that YIGSR is a strong candidate peptide for the treatment of skin aging and wrinkles.

  20. Classification en référence à une matrice stochastique

    OpenAIRE

    Verdun , Stéphane; Cariou , Véronique; Qannari , El Mostafa

    2009-01-01

    International audience; Etant donné un tableau de données X portant sur un ensemble de n objets, et une matrice stochastique S qui peut être assimilée à une matrice de transition d'une chaîne de Markov, nous proposons une méthode de partitionnement consistant à appliquer la matrice S sur X de manière itérative jusqu'à convergence. Les classes formant la partition sont déterminées à partir des états stationnaires de la matrice stochastique. Cette matrice stochastique peut être issue d'une matr...

  1. Capture Matrices Handbook

    Science.gov (United States)

    2014-04-01

    materials, the affinity ligand would need identification , as well as chemistries that graft the affinity ligand onto the surface of magnetic...ACTIVE CAPTURE MATRICES FOR THE DETECTION/ IDENTIFICATION OF PHARMACEUTICALS...6 As shown in Figure 2.3-1a, the spectra exhibit similar baselines and the spectral peaks lineup . Under these circumstances, the spectral

  2. Binary Positive Semidefinite Matrices and Associated Integer Polytopes

    DEFF Research Database (Denmark)

    Letchford, Adam N.; Sørensen, Michael Malmros

    2012-01-01

    We consider the positive semidefinite (psd) matrices with binary entries, along with the corresponding integer polytopes. We begin by establishing some basic properties of these matrices and polytopes. Then, we show that several families of integer polytopes in the literature-the cut, boolean qua...

  3. Chain of matrices, loop equations and topological recursion

    CERN Document Server

    Orantin, Nicolas

    2009-01-01

    Random matrices are used in fields as different as the study of multi-orthogonal polynomials or the enumeration of discrete surfaces. Both of them are based on the study of a matrix integral. However, this term can be confusing since the definition of a matrix integral in these two applications is not the same. These two definitions, perturbative and non-perturbative, are discussed in this chapter as well as their relation. The so-called loop equations satisfied by integrals over random matrices coupled in chain is discussed as well as their recursive solution in the perturbative case when the matrices are Hermitean.

  4. Theoretical Properties for Neural Networks with Weight Matrices of Low Displacement Rank

    OpenAIRE

    Zhao, Liang; Liao, Siyu; Wang, Yanzhi; Li, Zhe; Tang, Jian; Pan, Victor; Yuan, Bo

    2017-01-01

    Recently low displacement rank (LDR) matrices, or so-called structured matrices, have been proposed to compress large-scale neural networks. Empirical results have shown that neural networks with weight matrices of LDR matrices, referred as LDR neural networks, can achieve significant reduction in space and computational complexity while retaining high accuracy. We formally study LDR matrices in deep learning. First, we prove the universal approximation property of LDR neural networks with a ...

  5. Esophageal tissue engineering: Current status and perspectives.

    Science.gov (United States)

    Poghosyan, T; Catry, J; Luong-Nguyen, M; Bruneval, P; Domet, T; Arakelian, L; Sfeir, R; Michaud, L; Vanneaux, V; Gottrand, F; Larghero, J; Cattan, P

    2016-02-01

    Tissue engineering, which consists of the combination and in vivo implantation of elements required for tissue remodeling toward a specific organ phenotype, could be an alternative for classical techniques of esophageal replacement. The current hybrid approach entails creation of an esophageal substitute composed of an acellular matrix and autologous epithelial and muscle cells provides the most successful results. Current research is based on the use of mesenchymal stem cells, whose potential for differentiation and proangioogenic, immune-modulator and anti-inflammatory properties are important assets. In the near future, esophageal substitutes could be constructed from acellular "intelligent matrices" that contain the molecules necessary for tissue regeneration; this should allow circumvention of the implantation step and still obtain standardized in vivo biological responses. At present, tissue engineering applications to esophageal replacement are limited to enlargement plasties with absorbable, non-cellular matrices. Nevertheless, the application of existing clinical techniques for replacement of other organs by tissue engineering in combination with a multiplication of translational research protocols for esophageal replacement in large animals should soon pave the way for health agencies to authorize clinical trials. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  6. Handling of thermal paper: Implications for dermal exposure to bisphenol A and its alternatives.

    Directory of Open Access Journals (Sweden)

    Meghan R Bernier

    Full Text Available Bisphenol A (BPA is an endocrine disrupting chemical used in a wide range of consumer products including photoactive dyes used in thermal paper. Recent studies have shown that dermal absorption of BPA can occur when handling these papers. Yet, regulatory agencies have largely dismissed thermal paper as a major source of BPA exposure. Exposure estimates provided by agencies such as the European Food Safety Authority (EFSA are based on assumptions about how humans interact with this material, stating that 'typical' exposures for adults involve only one handling per day for short periods of time (30% of individuals hold thermal paper with more than three fingertips, and >60% allow the paper to touch their palm. Only 11% of the participants we observed were consistent with the EFSA model for time of contact and dermal surface area. Mathematical modeling based on handling times we measured and previously published transfer coefficients, concentrations of BPA in paper, and absorption factors indicate the most conservative estimated intake from handling thermal paper in this population is 51.1 ng/kg/day, similar to EFSA's estimates of 59 ng/kg/day from dermal exposures. Less conservative estimates, using published data on concentrations in thermal paper and transfer rates to skin, indicate that exposures are likely significantly higher. Based on our observational data, we propose that the current models for estimating dermal BPA exposures are not consistent with normal human behavior and should be reevaluated.

  7. A multicenter randomized controlled trial comparing absorbable barbed sutures versus conventional absorbable sutures for dermal closure in open surgical procedures.

    Science.gov (United States)

    Rubin, J Peter; Hunstad, Joseph P; Polynice, Alain; Gusenoff, Jeffrey A; Schoeller, Thomas; Dunn, Raymond; Walgenbach, Klaus J; Hansen, Juliana E

    2014-02-01

    Barbed sutures were developed to reduce operative time and improve security of wound closure. The authors compare absorbable barbed sutures (V-Loc, Covidien, Mansfield, Massachusetts) with conventional (smooth) absorbable sutures for soft tissue approximation. A prospective multicenter randomized study comparing barbed sutures with smooth sutures was undertaken between August 13, 2009, and January 31, 2010, in 241 patients undergoing abdominoplasty, mastopexy, and reduction mammaplasty. Each patient received barbed sutures on 1 side of the body, with deep dermal sutures eliminated or reduced. Smooth sutures with deep dermal and subcuticular closure were used on the other side as a control. The primary endpoint was dermal closure time. Safety was assessed through adverse event reporting through a 12-week follow-up. A total of 229 patients were ultimately treated (115 with slow-absorbing polymer and 114 with rapid-absorbing polymer). Mean dermal closure time was significantly quicker with the barbed suture compared with the smooth suture (12.0 vs 19.2 minutes; P<.001), primarily due to the need for fewer deep dermal sutures. The rapid-absorbing barbed suture showed a complication profile equivalent to the smooth suture, while the slow-absorbing barbed suture had a higher incidence of minor suture extrusion. Barbed sutures enabled faster dermal closure quicker than smooth sutures, with a comparable complication profile. 1.

  8. 77 FR 43089 - Evaluation of an Up-and-Down Procedure for Acute Dermal Systemic Toxicity Testing: Request for...

    Science.gov (United States)

    2012-07-23

    ... vivo acute dermal systemic toxicity tests. Corresponding acute oral LD 50 data for the same compounds....), estimated LD 50 , and incidence of death and other adverse effects. Background Information on ICCVAM and... tests. DATES: Nominations and test method data for the acute dermal and oral tests should be submitted...

  9. The Modern Origin of Matrices and Their Applications

    Science.gov (United States)

    Debnath, L.

    2014-01-01

    This paper deals with the modern development of matrices, linear transformations, quadratic forms and their applications to geometry and mechanics, eigenvalues, eigenvectors and characteristic equations with applications. Included are the representations of real and complex numbers, and quaternions by matrices, and isomorphism in order to show…

  10. Flux Jacobian Matrices For Equilibrium Real Gases

    Science.gov (United States)

    Vinokur, Marcel

    1990-01-01

    Improved formulation includes generalized Roe average and extension to three dimensions. Flux Jacobian matrices derived for use in numerical solutions of conservation-law differential equations of inviscid flows of ideal gases extended to real gases. Real-gas formulation of these matrices retains simplifying assumptions of thermodynamic and chemical equilibrium, but adds effects of vibrational excitation, dissociation, and ionization of gas molecules via general equation of state.

  11. Differential activation behavior of dermal dendritic cells underlies the strain-specific Th1 responses to single epicutaneous immunization.

    Science.gov (United States)

    Lee, Chih-Hung; Chen, Jau-Shiuh; Chiu, Hsien-Ching; Hong, Chien-Hui; Liu, Ching-Yi; Ta, Yng-Cun; Wang, Li-Fang

    2016-12-01

    Epicutaneous immunization with allergens is an important sensitization route for atopic dermatitis. We recently showed in addition to the Th2 response following single epicutaneous immunization, a remarkable Th1 response is induced in B6 mice, but not in BALB/c mice, mimicking the immune response to allergens in human non-atopics and atopics. We investigated the underlying mechanisms driving this differential Th1 response between BALB/c and B6 mice. We characterized dermal dendritic cells by flow cytometric analysis. We measured the induced Th1/Th2 responses by measuring the IFN-γ/IL-13 contents of supernatants of antigen reactivation cultures of lymph node cells. We demonstrate that more dermal dendritic cells with higher activation status migrate into draining lymph nodes of B6 mice compared to BALB/c mice. Dermal dendritic cells of B6 mice have a greater ability to capture protein antigen than those of BALB/c mice. Moreover, increasing the activation status or amount of captured antigen in dermal dendritic cells induced a Th1 response in BALB/c mice. Further, differential activation behavior, but not antigen-capturing ability of dermal dendritic cells between BALB/c and B6 mice is dendritic cell-intrinsic. These results show that the differential activation behavior of dermal dendritic cells underlies the strain-specific Th1 responses following single epicutaneous immunization. Furthermore, our findings highlight the potential differences between human atopics and non-atopics and provide useful information for the prediction and prevention of atopic diseases. Copyright © 2016 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  12. Dermal Exposure to Jet Fuel JP-8 Significantly Contributes to the Production of Urinary Naphthols in Fuel-Cell Maintenance Workers

    OpenAIRE

    Chao, Yi-Chun E.; Kupper, Lawrence L.; Serdar, Berrin; Egeghy, Peter P.; Rappaport, Stephen M.; Nylander-French, Leena A.

    2005-01-01

    Jet propulsion fuel 8 (JP-8) is the major jet fuel used worldwide and has been recognized as a major source of chemical exposure, both inhalation and dermal, for fuel-cell maintenance workers. We investigated the contributions of dermal and inhalation exposure to JP-8 to the total body dose of U.S. Air Force fuel-cell maintenance workers using naphthalene as a surrogate for JP-8 exposure. Dermal, breathing zone, and exhaled breath measurements of naphthalene were obtained using tape-strip sam...

  13. Data depth and rank-based tests for covariance and spectral density matrices

    KAUST Repository

    Chau, Joris

    2017-06-26

    In multivariate time series analysis, objects of primary interest to study cross-dependences in the time series are the autocovariance or spectral density matrices. Non-degenerate covariance and spectral density matrices are necessarily Hermitian and positive definite, and our primary goal is to develop new methods to analyze samples of such matrices. The main contribution of this paper is the generalization of the concept of statistical data depth for collections of covariance or spectral density matrices by exploiting the geometric properties of the space of Hermitian positive definite matrices as a Riemannian manifold. This allows one to naturally characterize most central or outlying matrices, but also provides a practical framework for rank-based hypothesis testing in the context of samples of covariance or spectral density matrices. First, the desired properties of a data depth function acting on the space of Hermitian positive definite matrices are presented. Second, we propose two computationally efficient pointwise and integrated data depth functions that satisfy each of these requirements. Several applications of the developed methodology are illustrated by the analysis of collections of spectral matrices in multivariate brain signal time series datasets.

  14. Data depth and rank-based tests for covariance and spectral density matrices

    KAUST Repository

    Chau, Joris; Ombao, Hernando; Sachs, Rainer von

    2017-01-01

    In multivariate time series analysis, objects of primary interest to study cross-dependences in the time series are the autocovariance or spectral density matrices. Non-degenerate covariance and spectral density matrices are necessarily Hermitian and positive definite, and our primary goal is to develop new methods to analyze samples of such matrices. The main contribution of this paper is the generalization of the concept of statistical data depth for collections of covariance or spectral density matrices by exploiting the geometric properties of the space of Hermitian positive definite matrices as a Riemannian manifold. This allows one to naturally characterize most central or outlying matrices, but also provides a practical framework for rank-based hypothesis testing in the context of samples of covariance or spectral density matrices. First, the desired properties of a data depth function acting on the space of Hermitian positive definite matrices are presented. Second, we propose two computationally efficient pointwise and integrated data depth functions that satisfy each of these requirements. Several applications of the developed methodology are illustrated by the analysis of collections of spectral matrices in multivariate brain signal time series datasets.

  15. A decision support framework for characterizing and managing dermal exposures to chemicals during Emergency Management and Operations.

    Science.gov (United States)

    Dotson, G Scott; Hudson, Naomi L; Maier, Andrew

    2015-01-01

    Emergency Management and Operations (EMO) personnel are in need of resources and tools to assist in understanding the health risks associated with dermal exposures during chemical incidents. This article reviews available resources and presents a conceptual framework for a decision support system (DSS) that assists in characterizing and managing risk during chemical emergencies involving dermal exposures. The framework merges principles of three decision-making techniques: 1) scenario planning, 2) risk analysis, and 3) multicriteria decision analysis (MCDA). This DSS facilitates dynamic decision making during each of the distinct life cycle phases of an emergency incident (ie, preparedness, response, or recovery) and identifies EMO needs. A checklist tool provides key questions intended to guide users through the complexities of conducting a dermal risk assessment. The questions define the scope of the framework for resource identification and application to support decision-making needs. The framework consists of three primary modules: 1) resource compilation, 2) prioritization, and 3) decision. The modules systematically identify, organize, and rank relevant information resources relating to the hazards of dermal exposures to chemicals and risk management strategies. Each module is subdivided into critical elements designed to further delineate the resources based on relevant incident phase and type of information. The DSS framework provides a much needed structure based on contemporary decision analysis principles for 1) documenting key questions for EMO problem formulation and 2) a method for systematically organizing, screening, and prioritizing information resources on dermal hazards, exposures, risk characterization, and management.

  16. Species Typing in Dermal Leishmaniasis

    Science.gov (United States)

    Dujardin, Jean-Claude

    2015-01-01

    SUMMARY Leishmania is an infectious protozoan parasite related to African and American trypanosomes. All Leishmania species that are pathogenic to humans can cause dermal disease. When one is confronted with cutaneous leishmaniasis, identification of the causative species is relevant in both clinical and epidemiological studies, case management, and control. This review gives an overview of the currently existing and most used assays for species discrimination, with a critical appraisal of the limitations of each technique. The consensus taxonomy for the genus is outlined, including debatable species designations. Finally, a numerical literature analysis is presented that describes which methods are most used in various countries and regions in the world, and for which purposes. PMID:25672782

  17. In vivo dermal absorption of pyrethroid pesticides in the rat.

    Science.gov (United States)

    The potential for exposure to pyrethroid pesticides has risen recently because of their increased use. The objective of this study was to examine the in vivo dermal absorption of bifenthrin, deltamethrin and permethrin in the rat. Hair on the dorsal side of anesthetized adult m...

  18. Dermal uptake of nicotine from air and clothing: Experimental verification

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Morrison, Glenn; Weschler, Charles J.

    2017-01-01

    Studies suggest that dermal uptake of certain semivolatile organic compounds (SVOC) directly from air can be a significant exposure pathway. This has been experimentally confirmed for two phthalates (Weschler et al., 2015). Morrison et al. (2016) showed that clean clothing can impede, while cloth...

  19. Almost commuting self-adjoint matrices: The real and self-dual cases

    Science.gov (United States)

    Loring, Terry A.; Sørensen, Adam P. W.

    2016-08-01

    We show that a pair of almost commuting self-adjoint, symmetric matrices is close to a pair of commuting self-adjoint, symmetric matrices (in a uniform way). Moreover, we prove that the same holds with self-dual in place of symmetric and also for paths of self-adjoint matrices. Since a symmetric, self-adjoint matrix is real, we get a real version of Huaxin Lin’s famous theorem on almost commuting matrices. Similarly, the self-dual case gives a version for matrices over the quaternions. To prove these results, we develop a theory of semiprojectivity for real C*-algebras and also examine various definitions of low-rank for real C*-algebras.

  20. Forecasting Covariance Matrices: A Mixed Frequency Approach

    DEFF Research Database (Denmark)

    Halbleib, Roxana; Voev, Valeri

    This paper proposes a new method for forecasting covariance matrices of financial returns. The model mixes volatility forecasts from a dynamic model of daily realized volatilities estimated with high-frequency data with correlation forecasts based on daily data. This new approach allows for flexi......This paper proposes a new method for forecasting covariance matrices of financial returns. The model mixes volatility forecasts from a dynamic model of daily realized volatilities estimated with high-frequency data with correlation forecasts based on daily data. This new approach allows...... for flexible dependence patterns for volatilities and correlations, and can be applied to covariance matrices of large dimensions. The separate modeling of volatility and correlation forecasts considerably reduces the estimation and measurement error implied by the joint estimation and modeling of covariance...

  1. Propositional matrices as alternative representation of truth values ...

    African Journals Online (AJOL)

    The paper considered the subject of representation of truth values in symbolic logic. An alternative representation was given based on the rows and columns properties of matrices, with the operations involving the logical connectives subjected to the laws of algebra of propositions. Matrices of various propositions detailing ...

  2. Dermal toxicity of Colloidal Nanosilver in Albino Rabbit: A New Approach to Physicochemical Properties

    Directory of Open Access Journals (Sweden)

    Anoushe Raesian

    2017-09-01

    Full Text Available Objective(s: Silver nanoparticles have been widely used as new potent antimicrobial agents in cosmetic and hygienic products, as well as in new medical devices. Serious concerns have been expressed on the potential health risks of dermal applications of nanosilver containing consumer products (AgNPs, therefore regulatory health risk assessment has become necessary for the safe usage of AgNPs in biomedical products with special emphasis to their dermal toxicity potentials. We aimed in the present study to compare the dermal toxicity of three different AgNP containing disinfectantsin an albino rabbit model and tried to determine the role of size and other physicochemical properties on their possible dermal toxicity. Methods: After the characterization of all three samples by transmission electron microscopy (TEM, X-Ray Diffraction (XRD and Dynamic Light Scattering (DLS , corrosive and irritant potentials  of AgNPs in three different sizes of three colloidal AgNPs were scored by the OECD 404 guideline with necessary modifications and were applied under the specified concentrations via nanosilver skin patches on the shaved skin of young female albino rabbits. All skin reactions were recorded in 3 min as well as in 1, 4, 24, 48 and 72 hours from the application and compared with the control group and followed up for 14 days. Results: Although short-term observations didn’t show any significant changes in the weight of animals and macroscopic  variables, long-term histopathological abnormalities were seen in the skin of all test groups, which was not associated with the size and other physicochemical properties of AgNP samples. The toxicity manifestations were dry skin, scaling in doses lower than 100 ppm and erythema in higher doses up to 4000 ppm which was reversed. Conclusions: This finding creates a new issue in the possible dermal effects of all colloidal AgNPs, containing nano health products, which should be considered in future studies by

  3. Advective and diffusive dermal processes for estimating terrestrial amphibian pesticide exposure

    Science.gov (United States)

    Background/Question/Methods Dermal exposure presents a potentially significant but understudied route for pesticide uptake in terrestrial amphibians. Historically, evaluation of pesticide risk to both amphibians and reptiles has been achieved by comparing ingestion and inhalat...

  4. Real-time three-dimensional imaging of epidermal splitting and removal by high-definition optical coherence tomography.

    Science.gov (United States)

    Boone, Marc; Draye, Jean Pierre; Verween, Gunther; Pirnay, Jean-Paul; Verbeken, Gilbert; De Vos, Daniel; Rose, Thomas; Jennes, Serge; Jemec, Gregor B E; Del Marmol, Véronique

    2014-10-01

    While real-time 3-D evaluation of human skin constructs is needed, only 2-D non-invasive imaging techniques are available. The aim of this paper is to evaluate the potential of high-definition optical coherence tomography (HD-OCT) for real-time 3-D assessment of the epidermal splitting and decellularization. Human skin samples were incubated with four different agents: Dispase II, NaCl 1 M, sodium dodecyl sulphate (SDS) and Triton X-100. Epidermal splitting, dermo-epidermal junction, acellularity and 3-D architecture of dermal matrices were evaluated by High-definition optical coherence tomography before and after incubation. Real-time 3-D HD-OCT assessment was compared with 2-D en face assessment by reflectance confocal microscopy (RCM). (Immuno) histopathology was used as control. HD-OCT imaging allowed real-time 3-D visualization of the impact of selected agents on epidermal splitting, dermo-epidermal junction, dermal architecture, vascular spaces and cellularity. RCM has a better resolution (1 μm) than HD-OCT (3 μm), permitting differentiation of different collagen fibres, but HD-OCT imaging has deeper penetration (570 μm) than RCM imaging (200 μm). Dispase II and NaCl treatments were found to be equally efficient in the removal of the epidermis from human split-thickness skin allografts. However, a different epidermal splitting level at the dermo-epidermal junction could be observed and confirmed by immunolabelling of collagen type IV and type VII. Epidermal splitting occurred at the level of the lamina densa with dispase II and above the lamina densa (in the lamina lucida) with NaCl. The 3-D architecture of dermal papillae and dermis was more affected by Dispase II on HD-OCT which corresponded with histopathologic (orcein staining) fragmentation of elastic fibres. With SDS treatment, the epidermal removal was incomplete as remnants of the epidermal basal cell layer remained attached to the basement membrane on the dermis. With Triton X-100 treatment

  5. Wishart and anti-Wishart random matrices

    International Nuclear Information System (INIS)

    Janik, Romuald A; Nowak, Maciej A

    2003-01-01

    We provide a compact exact representation for the distribution of the matrix elements of the Wishart-type random matrices A † A, for any finite number of rows and columns of A, without any large N approximations. In particular, we treat the case when the Wishart-type random matrix contains redundant, non-random information, which is a new result. This representation is of interest for a procedure for reconstructing the redundant information hidden in Wishart matrices, with potential applications to numerous models based on biological, social and artificial intelligence networks

  6. Information geometry of density matrices and state estimation

    International Nuclear Information System (INIS)

    Brody, Dorje C

    2011-01-01

    Given a pure state vector |x) and a density matrix ρ-hat, the function p(x|ρ-hat)= defines a probability density on the space of pure states parameterised by density matrices. The associated Fisher-Rao information measure is used to define a unitary invariant Riemannian metric on the space of density matrices. An alternative derivation of the metric, based on square-root density matrices and trace norms, is provided. This is applied to the problem of quantum-state estimation. In the simplest case of unitary parameter estimation, new higher-order corrections to the uncertainty relations, applicable to general mixed states, are derived. (fast track communication)

  7. Supercritical fluid extraction behaviour of polymer matrices

    International Nuclear Information System (INIS)

    Sujatha, K.; Kumar, R.; Sivaraman, N.; Srinivasan, T.G.; Vasudeva Rao, P.R.

    2007-01-01

    Organic compounds present in polymeric matrices such as neoprene, surgical gloves and PVC were co-extracted during the removal of uranium using supercritical fluid extraction (SFE) technique. Hence SFE studies of these matrices were carried out to establish the extracted species using HPLC, IR and mass spectrometry techniques. The initial study indicated that uranium present in the extract could be purified from the co-extracted organic species. (author)

  8. Dissecting antigen processing and presentation routes in dermal vaccination strategies

    NARCIS (Netherlands)

    Platteel, Anouk C M; Henri, Sandrine; Zaiss, Dietmar M; Sijts, Alice J A M

    2017-01-01

    The skin is an attractive site for vaccination due to its accessibility and presence of immune cells surveilling this barrier. However, knowledge of antigen processing and presentation upon dermal vaccination is sparse. In this study we determined antigen processing routes that lead to CD8(+) T cell

  9. Radiological impact of the use of calcium hydroxylapatite dermal fillers

    International Nuclear Information System (INIS)

    Feeney, J.N.; Fox, J.J.; Akhurst, T.

    2009-01-01

    Aim: To report a case series in which the radiological features of the subcutaneous use of calcium hydroxylapatite (CaHa) dermal fillers are described for the first time. Materials and methods: Five patients with facial hyperattenuating hypermetabolic subcutaneous lesions were identified on 2- [ 18 F]-fluoro-2-deoxy-D-glucose (FDG) positron-emission tomography/computed tomography (PET/CT), who gave a history of facial injections to augment physical appearance. Correlation with additional imaging studies was performed. Results: All cases had subcutaneous high attenuation material on CT (range 280-700 HU), which was FDG avid on PET, with a standardized uptake value (SUV) range of 2.9-13.4. Magnetic resonance imaging (MRI) demonstrated a heterogeneous intermediate signal intensity subcutaneous lesion with enhancement post-gadolinium in one case. Conclusions: CaHa dermal filler is hyperattenuating on CT, hypermetabolic on FDG-PET imaging, of intermediate signal intensity on MRI, and is a potential cause of a false-positive imaging study.

  10. Dermal Exposure Assessment to Pesticides in Farming Systems in Developing Countries: Comparison of Models

    Directory of Open Access Journals (Sweden)

    Camilo Lesmes Fabian

    2015-04-01

    Full Text Available In the field of occupational hygiene, researchers have been working on developing appropriate methods to estimate human exposure to pesticides in order to assess the risk and therefore to take the due decisions to improve the pesticide management process and reduce the health risks. This paper evaluates dermal exposure models to find the most appropriate. Eight models (i.e., COSHH, DERM, DREAM, EASE, PHED, RISKOFDERM, STOFFENMANAGER and PFAM were evaluated according to a multi-criteria analysis and from these results five models (i.e., DERM, DREAM, PHED, RISKOFDERM and PFAM were selected for the assessment of dermal exposure in the case study of the potato farming system in the Andean highlands of Vereda La Hoya, Colombia. The results show that the models provide different dermal exposure estimations which are not comparable. However, because of the simplicity of the algorithm and the specificity of the determinants, the DERM, DREAM and PFAM models were found to be the most appropriate although their estimations might be more accurate if specific determinants are included for the case studies in developing countries.

  11. Quantitative and qualitative evaluation of dermal elastin of draught horses with chronic progressive lymphoedema.

    Science.gov (United States)

    De Cock, H E V; Van Brantegem, L; Affolter, V K; Oosterlinck, M; Ferraro, G L; Ducatelle, R

    2009-01-01

    Chronic progressive lymphoedema (CPL) in horses, a disease of certain draught breeds, is associated with altered elastin metabolism. The characteristic lesions are seen in the skin of the lower (distal) limbs. This study was based on horses of susceptible breeds, with and without CPL, and on horses of a non-susceptible breed. Skin samples were obtained for examination from the neck (considered a non-affected region) and from the distal limb. The skin lesions were characterized histologically and the dermal elastic fibres were evaluated morphologically and quantitatively. In all horses the mean elastin concentrations were highest in the superficial dermis, gradually decreasing in the mid-dermis and deep dermis. As compared with horses of a non-susceptible breed, affected horses had increased amounts of dermal elastin in both the distal limb and neck, while non-affected horses of a susceptible breed had decreased amounts. The findings support an earlier hypothesis that CPL of horses is a generalized disease. Reduced efficiency of the elastic network in supporting the dermal lymphatics may explain the development of CPL.

  12. Fabrication of Aligned Carbon Nanotube/Polycaprolactone/Gelatin Nanofibrous Matrices for Schwann Cell Immobilization

    Directory of Open Access Journals (Sweden)

    Shiao-Wen Tsai

    2014-01-01

    Full Text Available In this study, we utilized a mandrel rotating collector consisting of two parallel, electrically conductive pieces of tape to fabricate aligned electrospun polycaprolactone/gelatin (PG and carbon nanotube/polycaprolactone/gelatin (PGC nanofibrous matrices. Furthermore, we examined the biological performance of the PGC nanofibrous and film matrices using an in vitro culture of RT4-D6P2T rat Schwann cells. Using cell adhesion tests, we found that carbon nanotube inhibited Schwann cell attachment on PGC nanofibrous and film matrices. However, the proliferation rates of Schwann cells were higher when they were immobilized on PGC nanofibrous matrices compared to PGC film matrices. Using western blot analysis, we found that NRG1 and P0 protein expression levels were higher for cells immobilized on PGC nanofibrous matrices compared to PG nanofibrous matrices. However, the carbon nanotube inhibited NRG1 and P0 protein expression in cells immobilized on PGC film matrices. Moreover, the NRG1 and P0 protein expression levels were higher for cells immobilized on PGC nanofibrous matrices compared to PGC film matrices. We found that the matrix topography and composition influenced Schwann cell behavior.

  13. Sensory evaluation and chemical analysis of exhaled and dermally emitted bioeffluents

    DEFF Research Database (Denmark)

    Tsushima, S.; Wargocki, Pawel; Tanabe, S.

    2018-01-01

    Conditions in which exhaled and dermally emitted bioeffluents could be sampled separately or together (whole-body emission) were created. Five lightly dressed males exhaled the air through a mask to another, identical chamber or without a mask to the chamber in which they were sitting; the outdoor......) was less acceptable, and the odor intensity was higher than when only exhaled bioeffluents were present. The presence or absence of exhaled bioeffluents in the unoccupied chamber made no significant difference to sensory assessments. At 28°C and with ozone present, the odor intensity increased and the PAQ...... was less acceptable in the chambers with whole-body bioeffluents. The concentrations of nonanal, decanal, geranylacetone, and 6-MHO were higher when dermally emitted bioeffluents were present; they increased further when ozone was present. The concentration of squalene then decreased and increased again...

  14. Silencing p75NTR prevents proNGF-induced endothelial cell death and development of acellular capillaries in rat retina

    Directory of Open Access Journals (Sweden)

    Ahmed Y Shanab

    Full Text Available Accumulation of the nerve growth factor precursor (proNGF and its receptor p75NTR have been associated with several neurodegenerative diseases in both brain and retina. However, whether proNGF contributes to microvascular degeneration remain unexplored. This study seeks to investigate the mechanism by which proNGF/p75NTR induce endothelial cell (EC death and development of acellular capillaries, a surrogate marker of retinal ischemia. Stable overexpression of the cleavage-resistant proNGF and molecular silencing of p75NTR were utilized in human retinal EC and rat retinas in vivo. Stable overexpression of proNGF decreased NGF levels and induced retinal vascular cell death evident by 1.9-fold increase in acellular capillaries and activation of JNK and cleaved-PARP that were mitigated by p75NTRshRNA. In vitro, overexpression of proNGF did not alter TNF-α level, reduced NGF, however induced EC apoptosis evident by activation of JNK and p38 MAPK, cleaved-PARP. Silencing p75NTR using siRNA restored expression of NGF and TrkA activation and prevented EC apoptosis. Treatment of EC with human-mutant proNGF induced apoptosis that coincided with marked protein interaction and nuclear translocation of p75NTR and the neurotrophin receptor interacting factor. These effects were abolished by a selective p75NTR antagonist. Therefore, targeting p75NTR represents a potential therapeutic strategy for diseases associated with aberrant expression of proNGF.

  15. In vitro dermal absorption of decabromodiphenyl ethane in rat and human skin

    Data.gov (United States)

    U.S. Environmental Protection Agency — In vitro dermal absorption of decabromodiphenyl ethane in rat and human skin. This dataset is associated with the following publication: Knudsen, G., J.M. Sanders,...

  16. Reliability of a semi-quantitative method for dermal exposure assessment (DREAM)

    NARCIS (Netherlands)

    Wendel de Joode, B. van; Hemmen, J.J. van; Meijster, T.; Major, V.; London, L.; Kromhout, H.

    2005-01-01

    Valid and reliable semi-quantitative dermal exposure assessment methods for epidemiological research and for occupational hygiene practice, applicable for different chemical agents, are practically nonexistent. The aim of this study was to assess the reliability of a recently developed

  17. Validation and comparison of two sampling methods to assess dermal exposure to drilling fluids and crude oil.

    Science.gov (United States)

    Galea, Karen S; McGonagle, Carolyn; Sleeuwenhoek, Anne; Todd, David; Jiménez, Araceli Sánchez

    2014-06-01

    Dermal exposure to drilling fluids and crude oil is an exposure route of concern. However, there have been no published studies describing sampling methods or reporting dermal exposure measurements. We describe a study that aimed to evaluate a wipe sampling method to assess dermal exposure to an oil-based drilling fluid and crude oil, as well as to investigate the feasibility of using an interception cotton glove sampler for exposure on the hands/wrists. A direct comparison of the wipe and interception methods was also completed using pigs' trotters as a surrogate for human skin and a direct surface contact exposure scenario. Overall, acceptable recovery and sampling efficiencies were reported for both methods, and both methods had satisfactory storage stability at 1 and 7 days, although there appeared to be some loss over 14 days. The methods' comparison study revealed significantly higher removal of both fluids from the metal surface with the glove samples compared with the wipe samples (on average 2.5 times higher). Both evaluated sampling methods were found to be suitable for assessing dermal exposure to oil-based drilling fluids and crude oil; however, the comparison study clearly illustrates that glove samplers may overestimate the amount of fluid transferred to the skin. Further comparison of the two dermal sampling methods using additional exposure situations such as immersion or deposition, as well as a field evaluation, is warranted to confirm their appropriateness and suitability in the working environment. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  18. Dermal exposure assessment of pesticide use: The case of sprayers in potato farms in the Colombian highlands

    International Nuclear Information System (INIS)

    Lesmes-Fabian, Camilo; García-Santos, Glenda; Leuenberger, Fanny; Nuyttens, David; Binder, Claudia R.

    2012-01-01

    Quantifying dermal exposure to pesticides in farming systems in developing countries is of special interest for the estimation of potential health risks, especially when there is a lack of occupational hygiene regulations. In this paper we present the results of a dermal exposure assessment for the potato farming system in the highlands of Colombia, where farmers apply pesticides with hand pressure sprayers without any personal protective equipment. The fractioning of the pesticide, in terms of potential and actual dermal exposure, was determined via the whole-body dosimetry methodology, using the tracer uranine as pesticide surrogate, and luminescence spectrometry as analytical method. We assessed the three activities involved in pesticide management: preparation, application, and cleaning; analyzed three types of nozzles: one with a standard discharge and two modified by farmers to increase the discharge; and derived the protection factor given by work clothing. Our results suggest that to reduce the health risk, three aspects have to be considered: (i) avoiding the modification of nozzles, which affects the droplet size spectrum and increases the level of dermal exposure; (ii) using adequate work clothing made of thick fabrics, especially on the upper body parts; and (iii) cleaning properly the tank sprayer before the application activity. - Highlights: ► We assessed dermal exposure to pesticides in the potato farming system in Colombia. ► High potential exposure was found in lower body parts during the application. ► High actual exposure was found in arms and back due to inadequate protection. ► There is a high health risk of using Metamidophos under current working conditions.

  19. Fabrication and In Vitro Characterization of Electrochemically Compacted Collagen/Sulfated Xylorhamnoglycuronan Matrix for Wound Healing Applications

    Directory of Open Access Journals (Sweden)

    Lingzhi Kang

    2018-04-01

    Full Text Available Skin autografts are in great demand due to injuries and disease, but there are challenges using live tissue sources, and synthetic tissue is still in its infancy. In this study, an electrocompaction method was applied to fabricate the densely packed and highly ordered collagen/sulfated xylorhamnoglycuronan (SXRGlu scaffold which closely mimicked the major structure and components in natural skin tissue. The fabricated electrocompacted collagen/SXRGlu matrices (ECLCU were characterized in terms of micromorphology, mechanical property, water uptake ability and degradability. The viability, proliferation and morphology of human dermal fibroblasts (HDFs cells on the fabricated matrices were also evaluated. The results indicated that the electrocompaction process could promote HDFs proliferation and SXRGlu could improve the water uptake ability and matrices’ stability against collagenase degradation, and support fibroblast spreading on the ECLCU matrices. Therefore, all these results suggest that the electrocompacted collagen/SXRGlu scaffold is a potential candidate as a dermal substitute with enhanced biostability and biocompatibility.

  20. Dermal absorption and disposition of 1,3-diphenylguanidine in rats

    International Nuclear Information System (INIS)

    Shah, P.V.; Sumler, M.R.; Ioannou, Y.M.; Fisher, H.L.; Hall, L.L.

    1985-01-01

    Dermal absorption, distribution, and metabolism of 1,3-diphenylguanidine (CAS 102-06-7) (DPG), widely used as an accelerator in processing rubber and in food packaging, was studied in adult female Sprague-Dawley rats. DPG shows 10% penetration through clipped back skin of the rats in 5 d. The first-order dermal absorption rate constant as determined by least square method was 0.021 +/- 0.002 d -1 (T/sub 1/2/ = 33.6 d). Approximately 13% of the absorbed dose remained in the body in 5 d. Retention in skin, muscle, liver, intestine and fat contributed most to the body burden of DPG-derived radioactivity in 5 d. All tissues showed tissue to blood ratios greater than 1, with liver and intestine ratios of 26 at 5 d. Approximately 61% of the absorbed dose was eliminated into urine and 27% into feces in 5 d showing rapid clearance of absorbed DPG from the body. High-pressure liquid chromatography (HPLC) analysis of urine revealed two major peaks [parent compound metabolite(s)]. Within 72 h, approximately 50% of the DPG-derived radioactivity excreted in the urine was parent compound. After 72 h, the DPG-derived radioactivity in the urine was present in the form of a single metabolite, and no parent compound was detected. No parent compound was detected in feces. Two metabolites, neither of which occurred in urine, were detected in feces. The HPLC analysis of the radioactivity at the application site showed only parent compound. Even though DPG shows slow dermal penetration, this route of exposure needs to be considered in the risk assessments because of the suspected chronic toxicity of DPG

  1. Evaluation of dermal wound healing activity of synthetic peptide SVVYGLR.

    Science.gov (United States)

    Uchinaka, Ayako; Kawaguchi, Naomasa; Ban, Tsuyoshi; Hamada, Yoshinosuke; Mori, Seiji; Maeno, Yoshitaka; Sawa, Yoshiki; Nagata, Kohzo; Yamamoto, Hirofumi

    2017-09-23

    SVVYGLR peptide (SV peptide) is a 7-amino-acid sequence with angiogenic properties that is derived from osteopontin in the extracellular matrix and promotes differentiation of fibroblasts to myofibroblast-like cells and the production of collagen type Ⅲ by cardiac fibroblasts. However, the effects of SV peptide on dermal cells and tissue are unknown. In this study, we evaluated the effects of this peptide in a rat model of dermal wound healing. The synthetic SV peptide was added to dermal fibroblasts or keratinocytes, and their cellular motility was evaluated. In an in vivo wound healing exeriment, male rats aged 8 weeks were randomly assigned to the SV peptide treatment, non-treated control, or phosphate-buffered saline (PBS) groups. Wound healing was assessed by its repair rate and histological features. Scratch assay and cell migration assays using the Chemotaxicell method showed that SV peptide significantly promoted the cell migration in both fibroblasts and keratinocytes. In contrast the proliferation potency of these cells was not affected by SV peptide. In the rat model, wound healing progressed faster in the SV peptide-treated group than in the control and PBS groups. The histopathological analyses showed that the SV peptide treatment stimulated the migration of fibroblasts to the wound area and increased the number of myofibroblasts. Immunohistochemical staining showed a marked increase of von Willebland factor-positive neomicrovessels in the SV peptide-treated group. In conclusion, SV peptide has a beneficial function to promote wound healing by stimulating granulation via stimulating angiogenesis, cell migration, and the myofibroblastic differentiation of fibroblasts. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Nano-Fiber Reinforced Enhancements in Composite Polymer Matrices

    Science.gov (United States)

    Chamis, Christos C.

    2009-01-01

    Nano-fibers are used to reinforce polymer matrices to enhance the matrix dependent properties that are subsequently used in conventional structural composites. A quasi isotropic configuration is used in arranging like nano-fibers through the thickness to ascertain equiaxial enhanced matrix behavior. The nano-fiber volume ratios are used to obtain the enhanced matrix strength properties for 0.01,0.03, and 0.05 nano-fiber volume rates. These enhanced nano-fiber matrices are used with conventional fiber volume ratios of 0.3 and 0.5 to obtain the composite properties. Results show that nano-fiber enhanced matrices of higher than 0.3 nano-fiber volume ratio are degrading the composite properties.

  3. BIOCOMPATIBILITY AND TISSUE REGENERATING CAPACITY OF CROSS-LINKED DERMAL SHEEP COLLAGEN

    NARCIS (Netherlands)

    VANWACHEM, PB; VANLUYN, MJA; DAMINK, LHHO; DIJKSTRA, PJ; FEIJEN, J; NIEUWENHUIS, P

    The biocompatibility and tissue regenerating capacity of four crosslinked dermal sheep collagens (DSC) was studied. In vitro, the four DSC versions were found to be noncytotoxic or very low in cytoxicity. After subcutaneous implantation in rats, hexamethylenediisocyanate-crosslinked DSC (HDSC)

  4. DERMAL AND MOUTHING TRANSFERS OF SURFACE RESIDUES MEASURED USING FLUORESCENCE IMAGING

    Science.gov (United States)

    To reduce the uncertainty associated with current estimates of children's exposure to pesticides by dermal contact and non-dietary ingestion, residue transfer data are required. Prior to conducting exhaustive studies, a screening study to develop and test methods for measuring...

  5. Meet and Join Matrices in the Poset of Exponential Divisors

    Indian Academy of Sciences (India)

    ... exponential divisor ( G C E D ) and the least common exponential multiple ( L C E M ) do not always exist. In this paper we embed this poset in a lattice. As an application we study the G C E D and L C E M matrices, analogues of G C D and L C M matrices, which are both special cases of meet and join matrices on lattices.

  6. Dermatopharmacokinetic and pharmacodynamic evaluation of ethosomes of griseofulvin designed for dermal delivery

    Energy Technology Data Exchange (ETDEWEB)

    Aggarwal, Nidhi; Goindi, Shishu, E-mail: shishugoindi@yahoo.co.in [Panjab University, University Institute of Pharmaceutical Sciences (India)

    2013-10-15

    The present study is aimed at evaluation of the dermal delivery potential of griseofulvin-loaded ethosomes. Griseofulvin-loaded ethosomes were prepared using 'Cold technique' (Indian Patent Application 208/DEL/2009). The optimized formulation was characterized for vesicular shape and size, drug entrapment efficiency, drug content, pH, stability, and spreadability. Ex vivo skin permeation, dermatopharmacokinetics, and skin sensitivity studies were carried out using male Laca mice. In vivo antifungal activity was assessed against Microsporum canis using guinea pig model for dermatophytosis. The optimized formulation E7 possessing 2 % phospholipid (PL) and 30 % ethanol exhibited the highest drug entrapment (72.94 {+-} 0.80 %) and optimum vesicle size (148.5 {+-} 0.48 nm). E7 illustrated remarkably higher drug permeation and skin retention when compared with liposomes. Pharmacodynamic studies in guinea pigs induced with M. canis revealed that the dermal fungal infection was completely cured in 8 days upon twice daily topical application of griseofulvin-loaded ethosomes whereas liposomes led to complete cure in 14 days. The formulation was observed to be non-sensitizing, histopathologically safe, and stable at 5 {+-} 3, 25 {+-} 2, and 40 {+-} 2 Degree-Sign C for a period of 1 year. Results indicated that dermal delivery of griseofulvin employing ethosomes could be a commendable alternative to reduce the bio-burden associated with conventional oral formulations.

  7. Dermal-epidermal membrane systems by using human keratinocytes and mesenchymal stem cells isolated from dermis

    Energy Technology Data Exchange (ETDEWEB)

    Salerno, Simona, E-mail: s.salerno@itm.cnr.it [Institute on Membrane Technology, National Research Council of Italy, ITM-CNR, c/o University of Calabria, via P. Bucci cubo 17/C, I-87036, Rende (CS) (Italy); Messina, Antonietta [Institute on Membrane Technology, National Research Council of Italy, ITM-CNR, c/o University of Calabria, via P. Bucci cubo 17/C, I-87036, Rende (CS) (Italy); Giordano, Francesca [Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, I-87036 Rende, (CS) (Italy); Bader, Augustinus [Biomedical-Biotechnological Center, BBZ, University of Leipzig, D-04103 Leipzig (Germany); Drioli, Enrico [Institute on Membrane Technology, National Research Council of Italy, ITM-CNR, c/o University of Calabria, via P. Bucci cubo 17/C, I-87036, Rende (CS) (Italy); WCU Energy Engineering Department, Hanyang University, Seoul (Korea, Republic of); De Bartolo, Loredana, E-mail: l.debartolo@itm.cnr.it [Institute on Membrane Technology, National Research Council of Italy, ITM-CNR, c/o University of Calabria, via P. Bucci cubo 17/C, I-87036, Rende (CS) (Italy)

    2017-02-01

    Dermal-epidermal membrane systems were developed by co-culturing human keratinocytes with Skin derived Stem Cells (SSCs), which are Mesenchymal Stem Cells (MSCs) isolated from dermis, on biodegradable membranes of chitosan (CHT), polycaprolactone (PCL) and a polymeric blend of CHT and PCL. The membranes display physico-chemical, morphological, mechanical and biodegradation properties that could satisfy and fulfil specific requirements in skin tissue engineering. CHT membrane exhibits an optimal biodegradation rate for acute wounds; CHT-PCL for the chronic ones. On the other hand, PCL membrane in spite of its very slow biodegradation rate exhibits mechanical properties similar to in vivo dermis, a lower hydrophilic character, and a surface roughness, all properties that make it able to sustain cell adhesion and proliferation for in vitro skin models. Both CHT–PCL and PCL membranes guided epidermal and dermal differentiation of SSCs as pointed out by the expression of cytokeratins and the deposition of the ECM protein fibronectin, respectively. In the dermal-epidermal membrane systems, a more suitable microenvironment for the SSCs differentiation was promoted by the interactions and the mutual interplay with keratinocytes. Being skin tissue-biased stem cells committed to their specific final dermal and/or epidermal cell differentiation, SSCs are more suitable for skin tissue engineering than other adult MSCs with different origin. For this reason, they represent a useful autologous cell source for engineering skin substitutes for both in vivo and in vitro applications.

  8. Laminin peptide YIGSR induces collagen synthesis in Hs27 human dermal fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jong Hyuk; Kim, Jaeyoon; Lee, Hyeongjoo [NovaCell Technology Inc., Pohang, Kyungbuk 790-784 (Korea, Republic of); Kim, So Young [Department of Dermatology, Chung-Ang University College of Medicine, Seoul 156-756 (Korea, Republic of); Department of Convergence Medicine and Pharmaceutical Biosciences, Graduate School, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Jang, Hwan-Hee [Functional Food and Nutrition Division, Department of Agrofood Resources, Rural Development Administration, Suwon 441-853 (Korea, Republic of); Ryu, Sung Ho [Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang, Kyungbuk 790-784 (Korea, Republic of); Kim, Beom Joon [Department of Dermatology, Chung-Ang University College of Medicine, Seoul 156-756 (Korea, Republic of); Department of Convergence Medicine and Pharmaceutical Biosciences, Graduate School, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Lee, Taehoon G., E-mail: taehoon@novacelltech.com [NovaCell Technology Inc., Pohang, Kyungbuk 790-784 (Korea, Republic of)

    2012-11-23

    Highlights: Black-Right-Pointing-Pointer We identify a function of the YIGSR peptide to enhance collagen synthesis in Hs27. Black-Right-Pointing-Pointer YIGSR peptide enhanced collagen type 1 synthesis both of gene and protein levels. Black-Right-Pointing-Pointer There were no changes in cell proliferation and MMP-1 level in YIGSR treatment. Black-Right-Pointing-Pointer The YIGSR effect on collagen synthesis mediated activation of FAK, pyk2 and ERK. Black-Right-Pointing-Pointer The YIGSR-induced FAK and ERK activation was modulated by FAK and MEK inhibitors. -- Abstract: The dermal ECM is synthesized from fibroblasts and is primarily compromised of fibrillar collagen and elastic fibers, which support the mechanical strength and resiliency of skin, respectively. Laminin, a major glycoprotein located in the basement membrane, promotes cell adhesion, cell growth, differentiation, and migration. The laminin tyrosine-isoleucine-glycine-serine-arginine (YIGSR) peptide, corresponding to the 929-933 sequence of the {beta}1 chain, is known to be a functional motif with effects on the inhibition of tumor metastasis, the regulation of sensory axonal response and the inhibition of angiogenesis through high affinity to the 67 kDa laminin receptor. In this study, we identified a novel function of the YIGSR peptide to enhance collagen synthesis in human dermal fibroblasts. To elucidate this novel function regarding collagen synthesis, we treated human dermal fibroblasts with YIGSR peptide in both a time- and dose-dependent manner. According to subsequent experiments, we found that the YIGSR peptide strongly enhanced collagen type 1 synthesis without changing cell proliferation or cellular MMP-1 level. This YIGSR peptide-mediated collagen type 1 synthesis was modulated by FAK inhibitor and MEK inhibitor. This study clearly reveals that YIGSR peptide plays a novel function on the collagen type 1 synthesis of dermal fibroblasts and also suggests that YIGSR is a strong candidate

  9. Dermal uptake of phthalates from clothing: comparison of model to human participant results

    DEFF Research Database (Denmark)

    Morrison, Glenn; Weschler, Charles J.; Bekö, Gabriel

    2016-01-01

    In this research, we extend a model of transdermal uptake of phthalates to include a layer of clothing. When compared with experimental results, this model better estimates dermal uptake of diethylphthalate (DEP) and di-n-butylphthalate (DnBP) than a previous model. It also demonstrates that uptake...... is sensitive to both the gap between skin and clothing and the time clothing is allowed to adsorb phthalates. The model predictions are consistent with the observation that exposed clothing increases dermal uptake when compared with uptake observed in bare-skin participants. Extension of this model beyond...... the cotton-phthalate system will be challenging until data on partition coefficients are quantified for other combinations of SVOCs, fabric materials and environmental conditions....

  10. Joint Estimation of Multiple Precision Matrices with Common Structures.

    Science.gov (United States)

    Lee, Wonyul; Liu, Yufeng

    Estimation of inverse covariance matrices, known as precision matrices, is important in various areas of statistical analysis. In this article, we consider estimation of multiple precision matrices sharing some common structures. In this setting, estimating each precision matrix separately can be suboptimal as it ignores potential common structures. This article proposes a new approach to parameterize each precision matrix as a sum of common and unique components and estimate multiple precision matrices in a constrained l 1 minimization framework. We establish both estimation and selection consistency of the proposed estimator in the high dimensional setting. The proposed estimator achieves a faster convergence rate for the common structure in certain cases. Our numerical examples demonstrate that our new estimator can perform better than several existing methods in terms of the entropy loss and Frobenius loss. An application to a glioblastoma cancer data set reveals some interesting gene networks across multiple cancer subtypes.

  11. Burn injury suppresses human dermal dendritic cell and Langerhans cell function

    NARCIS (Netherlands)

    van den Berg, Linda M.; de Jong, Marein A. W. P.; Witte, Lot de; Ulrich, Magda M. W.; Geijtenbeek, Teunis B. H.

    2011-01-01

    Human skin contains epidermal Langerhans cells (LCs) and dermal dendritic cells (DCs) that are key players in induction of adaptive immunity upon infection. After major burn injury, suppressed adaptive immunity has been observed in patients. Here we demonstrate that burn injury affects adaptive

  12. New experimental data on the human dermal absorption of Simazine and Carbendazim help to refine the assessment of human exposure.

    Science.gov (United States)

    Bányiová, Katarína; Nečasová, Anežka; Kohoutek, Jiří; Justan, Ivan; Čupr, Pavel

    2016-02-01

    Due to their widespread usage, people are exposed to pesticides on a daily basis. Although these compounds may have adverse effects on their health, there is a gap in the data and the methodology needed to reliably quantify the risks of non-occupational human dermal exposure to pesticides. We used Franz cells and human skin in order to measure the dermal absorption kinetics (steady-state flux, lag time and permeability coefficient) of Carbendazim and Simazine. These parameters were then used to refine the dermal exposure model and a probabilistic simulation was used to quantify risks resulting from exposure to pesticide-polluted waters. The experimentally derived permeability coefficient was 0.0034 cm h(-1) for Carbendazim and 0.0047 cm h(-1) for Simazine. Two scenarios (varying exposure duration and concentration, i.e. environmentally relevant and maximum solubility) were used to quantify the human health risks (hazard quotients) for Carbendazim and Simazine. While no risks were determined in the case of either scenario, the permeability coefficient, which is concentration independent and donor, formulation, compound and membrane specific, may be used in other scenarios and exposure models to quantify more precisely the dermally absorbed dose during exposure to polluted water. To the best of our knowledge, the dermal absorption kinetics parameters defined here are being published for the first time. The usage of experimental permeability parameters in combination with probabilistic risk assessment thus provides a new tool for quantifying the risks of human dermal exposure to pesticides. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Reepithelialization from stem cells of hair follicles of dermal graft of the scalp in acute treatment of third-degree burns: first clinical and histologic study.

    Science.gov (United States)

    Zakine, Gilbert; Mimoun, Maurice; Pham, Julien; Chaouat, Marc

    2012-07-01

    The scalp, an excellent donor site for thin skin grafts, presents a limited surface but is rich in keratinocyte stem cells. The purpose of this study was to double scalp harvesting in one procedure and to evaluate the capacity of the dermal layer to spontaneously reepithelialize from hair follicle stem cells. Two layers of 0.2-mm split-thickness skin graft, a dermoepidermal graft and a dermal graft, were harvested from scalp during the same procedure. Fifteen burn patients were included in this study. Healing of the scalp donor site and percentage of graft taken were evaluated. The Vancouver Scar Scale was used at 3 months and 1 year. Histologic studies were performed at day 0 and 3 months on grafts, and on the scalp at day 28. Nine patients were treated on the limbs with meshed dermal graft. Six were treated on the hands with unmeshed dermal graft. Graft take was good for both types of grafts. The mean time for scalp healing was 9.3 days. Histologic study confirmed that the second layer was a dermal graft with numerous annexes and that, at 3 months, the dermis had normal thickness but with rarer and smaller epidermal crests than dermal graft. The difference between the mean Vancouver Scar Scale score of dermal graft and dermoepidermal graft was not significant. The authors' study shows the efficacy of dermal graft from the scalp and good scalp healing. Therapeutic, II.

  14. Asymptotics of eigenvalues and eigenvectors of Toeplitz matrices

    Science.gov (United States)

    Böttcher, A.; Bogoya, J. M.; Grudsky, S. M.; Maximenko, E. A.

    2017-11-01

    Analysis of the asymptotic behaviour of the spectral characteristics of Toeplitz matrices as the dimension of the matrix tends to infinity has a history of over 100 years. For instance, quite a number of versions of Szegő's theorem on the asymptotic behaviour of eigenvalues and of the so-called strong Szegő theorem on the asymptotic behaviour of the determinants of Toeplitz matrices are known. Starting in the 1950s, the asymptotics of the maximum and minimum eigenvalues were actively investigated. However, investigation of the individual asymptotics of all the eigenvalues and eigenvectors of Toeplitz matrices started only quite recently: the first papers on this subject were published in 2009-2010. A survey of this new field is presented here. Bibliography: 55 titles.

  15. Asiaticoside induces cell proliferation and collagen synthesis in human dermal fibroblasts

    Directory of Open Access Journals (Sweden)

    Linda Yulianti

    2015-08-01

    Full Text Available Asiatiocoside, a saponin component isolated from Centella asiatica can improve wound healing by promoting the proliferation of human dermal fibroblasts (HDF and synthesis of collagen. The skin-renewing cells and type I and III collagen synthesis decrease with aging, resulting in the reduction of skin elasticity and delayed wound healing. Usage of natural active compounds from plants in wound healing should be evaluated and compared to retinoic acid as an active agent that regulates wound healing. The aim of this study was to compare and evaluate the effect of asiaticoside and retinoic acid to induce greater cell proliferation and type I and III collagen synthesis in human dermal fibroblast. Methods Laboratory experiments were conducted using human dermal fibroblasts (HDF isolated from human foreskin explants. Seven passages of HDF were treated with asiaticoside and retinoic acid at several doses and incubated for 24 and 48 hours. Cell viability in all groups was tested with the MTT assay to assess HDF proliferation. Type I and III collagen synthesis was examined using the respective ELISA kits. Analysis of variance was performed to compare the treatment groups. Results Asiaticoside had significantly stronger effects on HDF proliferation than retinoic acid (p<0.05. The type III collagen production was significantly greater induction with asiaticoside compared to retinoic acid (p<0.05. Conclusion Asiaticoside induces HDF proliferation and type I and III collagen synthesis in a time- and dose-dependent pattern. Asiaticoside has a similar effect as retinoic acid on type I and type III collagen synthesis.

  16. On the norms of r-circulant matrices with generalized Fibonacci numbers

    Directory of Open Access Journals (Sweden)

    Amara Chandoul

    2017-01-01

    Full Text Available In this paper, we obtain a generalization of [6, 8]. Firstly, we consider the so-called r-circulant matrices with generalized Fibonacci numbers and then found lower and upper bounds for the Euclidean and spectral norms of these matrices. Afterwards, we present some bounds for the spectral norms of Hadamard and Kronecker product of these matrices.

  17. Dermal exposure assessment of pesticide use: The case of sprayers in potato farms in the Colombian highlands

    Energy Technology Data Exchange (ETDEWEB)

    Lesmes-Fabian, Camilo, E-mail: camilo.lesmes@geographie.uni-muenchen.de [Department of Geography, University of Munich, Luisenstrasse 37, D-80333 Munich (Germany); Institute for Systems Science, Innovation and Sustainability Research, Karl-Franzens University of Graz, Merangase 18/I, A-8010 Graz (Austria); Garcia-Santos, Glenda [Department of Geography, University of Zurich, Winterthurerstrasse 190, 8057 Zurich (Switzerland); Leuenberger, Fanny [Institute of Geology, Swiss Federal Institute of Technology (ETH), Sonneggstrasse 5, 8092 Zurich (Switzerland); Nuyttens, David [Institute for Agricultural and Fisheries Research, Technology and Food Science Unit, Agricultural Engineering, Burg. van Gansberghelaan 115 bus 1, 9820 Merelbeke (Belgium); Binder, Claudia R. [Department of Geography, University of Munich, Luisenstrasse 37, D-80333 Munich (Germany); Institute for Systems Science, Innovation and Sustainability Research, Karl-Franzens University of Graz, Merangase 18/I, A-8010 Graz (Austria)

    2012-07-15

    Quantifying dermal exposure to pesticides in farming systems in developing countries is of special interest for the estimation of potential health risks, especially when there is a lack of occupational hygiene regulations. In this paper we present the results of a dermal exposure assessment for the potato farming system in the highlands of Colombia, where farmers apply pesticides with hand pressure sprayers without any personal protective equipment. The fractioning of the pesticide, in terms of potential and actual dermal exposure, was determined via the whole-body dosimetry methodology, using the tracer uranine as pesticide surrogate, and luminescence spectrometry as analytical method. We assessed the three activities involved in pesticide management: preparation, application, and cleaning; analyzed three types of nozzles: one with a standard discharge and two modified by farmers to increase the discharge; and derived the protection factor given by work clothing. Our results suggest that to reduce the health risk, three aspects have to be considered: (i) avoiding the modification of nozzles, which affects the droplet size spectrum and increases the level of dermal exposure; (ii) using adequate work clothing made of thick fabrics, especially on the upper body parts; and (iii) cleaning properly the tank sprayer before the application activity. - Highlights: Black-Right-Pointing-Pointer We assessed dermal exposure to pesticides in the potato farming system in Colombia. Black-Right-Pointing-Pointer High potential exposure was found in lower body parts during the application. Black-Right-Pointing-Pointer High actual exposure was found in arms and back due to inadequate protection. Black-Right-Pointing-Pointer There is a high health risk of using Metamidophos under current working conditions.

  18. In vitro acellular dissolution of mineral fibres: A comparative study.

    Science.gov (United States)

    Gualtieri, Alessandro F; Pollastri, Simone; Bursi Gandolfi, Nicola; Gualtieri, Magdalena Lassinantti

    2018-05-04

    The study of the mechanisms by which mineral fibres promote adverse effects in both animals and humans is a hot topic of multidisciplinary research with many aspects that still need to be elucidated. Besides length and diameter, a key parameter that determines the toxicity/pathogenicity of a fibre is biopersistence, one component of which is biodurability. In this paper, biodurability of mineral fibres of social and economic importance (chrysotile, amphibole asbestos and fibrous erionite) has been determined for the first time in a systematic comparative way from in vitro acellular dissolution experiments. Dissolution was possible using the Gamble solution as simulated lung fluid (pH = 4 and at body temperature) so to reproduce the macrophage phagolysosome environment. The investigated mineral fibres display very different dissolution rates. For a 0.25 μm thick fibre, the calculated dissolution time of chrysotile is in the range 94-177 days, very short if compared to that of amphibole fibres (49-245 years), and fibrous erionite (181 years). Diffraction and SEM data on the dissolution products evidence that chrysotile rapidly undergoes amorphization with the formation of a nanophasic silica-rich fibrous metastable pseudomorph as first dissolution step whereas amphibole asbestos and fibrous erionite show minor signs of dissolution even after 9-12 months.

  19. Regeneration of dermal patterns from the remaining pigments after surgery in Eublepharis macularius (a case report)

    OpenAIRE

    Nakashima, Noriyuki

    2016-01-01

    Background: Dermal injury of the Eublepharis macularius (leopard gecko) often results in a loss of the spotted patterns. The scar is usually well recovered, but the spots and the tubercles may be lost depending on the size and part of the lesion. This report presents a surgical attempting, in which the pigments in the edge of the remaining skin flap are partially preserved to maximally restore the natural pigmentation patterns during the course of dermal regeneration. Case presentation: A fou...

  20. Dermal exposure assessment of pesticide use: the case of sprayers in potato farms in the Colombian highlands.

    Science.gov (United States)

    Lesmes-Fabian, Camilo; García-Santos, Glenda; Leuenberger, Fanny; Nuyttens, David; Binder, Claudia R

    2012-07-15

    Quantifying dermal exposure to pesticides in farming systems in developing countries is of special interest for the estimation of potential health risks, especially when there is a lack of occupational hygiene regulations. In this paper we present the results of a dermal exposure assessment for the potato farming system in the highlands of Colombia, where farmers apply pesticides with hand pressure sprayers without any personal protective equipment. The fractioning of the pesticide, in terms of potential and actual dermal exposure, was determined via the whole-body dosimetry methodology, using the tracer uranine as pesticide surrogate, and luminescence spectrometry as analytical method. We assessed the three activities involved in pesticide management: preparation, application, and cleaning; analyzed three types of nozzles: one with a standard discharge and two modified by farmers to increase the discharge; and derived the protection factor given by work clothing. Our results suggest that to reduce the health risk, three aspects have to be considered: (i) avoiding the modification of nozzles, which affects the droplet size spectrum and increases the level of dermal exposure; (ii) using adequate work clothing made of thick fabrics, especially on the upper body parts; and (iii) cleaning properly the tank sprayer before the application activity. Copyright © 2012. Published by Elsevier B.V.

  1. Measurements of dermal uptake of nicotine directly from air and clothing

    DEFF Research Database (Denmark)

    Beko, G.; Morrison, G.; Weschler, Charles J.

    2017-01-01

    In this preliminary study, we have investigated whether dermal uptake of nicotine directly from air or indirectly from clothing can be a meaningful exposure pathway. Two participants wearing only shorts and a third participant wearing clean cotton clothes were exposed to environmental tobacco smo...

  2. Hypersymmetric functions and Pochhammers of 2×2 nonautonomous matrices

    Directory of Open Access Journals (Sweden)

    A. F. Antippa

    2004-01-01

    Full Text Available We introduce the hypersymmetric functions of 2×2 nonautonomous matrices and show that they are related, by simple expressions, to the Pochhammers (factorial polynomials of these matrices. The hypersymmetric functions are generalizations of the associated elementary symmetric functions, and for a specific class of 2×2 matrices, having a high degree of symmetry, they reduce to these latter functions. This class of matrices includes rotations, Lorentz boosts, and discrete time generators for the harmonic oscillators. The hypersymmetric functions are defined over four sets of independent indeterminates using a triplet of interrelated binary partitions. We work out the algebra of this triplet of partitions and then make use of the results in order to simplify the expressions for the hypersymmetric functions for a special class of matrices. In addition to their obvious applications in matrix theory, in coupled difference equations, and in the theory of symmetric functions, the results obtained here also have useful applications in problems involving successive rotations, successive Lorentz transformations, discrete harmonic oscillators, and linear two-state systems.

  3. Prospective study of single-stage repair of contaminated hernias using a biologic porcine tissue matrix: the RICH Study.

    Science.gov (United States)

    Itani, Kamal M F; Rosen, Michael; Vargo, Daniel; Awad, Samir S; Denoto, George; Butler, Charles E

    2012-09-01

    In the presence of contamination, the repair of a ventral incisional hernia (VIH) is challenging. The presence of comorbidities poses an additional risk for postoperative wound events and hernia recurrence. To date, very few studies describe the outcomes of VIH repair in this high-risk population. A prospective, multicenter, single-arm, the Repair of Infected or Contaminated Hernias study was performed to study the clinical outcomes of open VIH repair of contaminated abdominal defects with a non-cross-linked, porcine, acellular dermal matrix, Strattice. Of 85 patients who consented to participate, 80 underwent open VIH repair with Strattice. Hernia defects were 'clean-contaminated' (n = 39), 'contaminated' (n = 39), or 'dirty' (n = 2), and the defects were classified as grade 3 (n = 60) or grade 4 (n = 20). The midline was restored, and primary closure was achieved in 64 patients; the defect was bridged in 16 patients. At 24 months, 53 patients (66%) experienced 95 wound events. There were 28 unique, infection-related events in 24 patients. Twenty-two patients experienced seromas, all but 5 of which were transient and required no intervention. No unanticipated adverse events occurred, and no tissue matrix required complete excision. There were 22 hernia (28%) recurrences by month 24. There was no correlation between infection-related events and hernia recurrence. The use of the intact, non-cross-linked, porcine, acellular dermal matrix, Strattice, in the repair of contaminated VIH in high-risk patients allowed for successful, single-stage reconstruction in >70% of patients followed for 24 months after repair. Published by Mosby, Inc.

  4. An algorithmic characterization of P-matricity

    OpenAIRE

    Ben Gharbia , Ibtihel; Gilbert , Jean Charles

    2013-01-01

    International audience; It is shown that a matrix M is a P-matrix if and only if, whatever is the vector q, the Newton-min algorithm does not cycle between two points when it is used to solve the linear complementarity problem 0 ≤ x ⊥ (Mx+q) ≥ 0.; Nous montrons dans cet article qu'une matrice M est une P-matrice si, et seulement si, quel que soit le vecteur q, l'algorithme de Newton-min ne fait pas de cycle de deux points lorsqu'il est utilisé pour résoudre le problème de compl\\émentarité lin...

  5. Biocompatible polymer microneedle for topical/dermal delivery of tranexamic acid.

    Science.gov (United States)

    A Machekposhti, S; Soltani, M; Najafizadeh, P; Ebrahimi, S A; Chen, P

    2017-09-10

    Recently-introduced biocompatible polymeric microneedles offer an efficient method for drug delivery. Tranexamic acid is a novel drug for treating melasma that is administered both locally and orally and inhibits excessive melanin via melanocyte. The tranexamic acid biocompatible polymer microneedle used in this study was fabricated from PVP and methacrylic acid, using the lithography method. The required mechanical strength to pierce skin was attained by optimizing the ratio of PVP to methacrylic acid. Acute dermal toxicity was done, and drug diffusion in skin layers was simulated by calculating the diffusion coefficient of tranexamic acid in interstitial fluid (plasma). The biocompatible polymer microneedle was fabricated at 60°C. Needles could sustain 0.6N that is enough to pierce stratum corneum. 34% of the released drug was locally effective and the rest permeated through the skin. The pyramidal polymer microneedle in this study was fully released in skin in approx. 7h. This polymer microneedle has no dermal toxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Partitioning sparse rectangular matrices for parallel processing

    Energy Technology Data Exchange (ETDEWEB)

    Kolda, T.G.

    1998-05-01

    The authors are interested in partitioning sparse rectangular matrices for parallel processing. The partitioning problem has been well-studied in the square symmetric case, but the rectangular problem has received very little attention. They will formalize the rectangular matrix partitioning problem and discuss several methods for solving it. They will extend the spectral partitioning method for symmetric matrices to the rectangular case and compare this method to three new methods -- the alternating partitioning method and two hybrid methods. The hybrid methods will be shown to be best.

  7. Complete horizontal skin cell resurfacing and delayed vertical cell infiltration into porcine reconstructive tissue matrix compared to bovine collagen matrix and human dermis.

    Science.gov (United States)

    Mirastschijski, Ursula; Kerzel, Corinna; Schnabel, Reinhild; Strauss, Sarah; Breuing, Karl-Heinz

    2013-10-01

    Xenogenous dermal matrices are used for hernia repair and breast reconstruction. Full-thickness skin replacement is needed after burn or degloving injuries with exposure of tendons or bones. The authors used a human skin organ culture model to study whether porcine reconstructive tissue matrix (Strattice) is effective as a dermal tissue replacement. Skin cells or split-thickness skin grafts were seeded onto human deepidermized dermis, Strattice, and Matriderm. Cellular resurfacing and matrix infiltration were monitored by live fluorescence imaging, histology, and electron microscopy. Proliferation, apoptosis, cell differentiation, and adhesion were analyzed by immunohistochemistry. Epithelial resurfacing and vertical proliferation were reduced and delayed with both bioartificial matrices compared with deepidermized dermis; however, no differences in apoptosis, cell differentiation, or basement membrane formation were found. Vertical penetration was greatest on Matriderm, whereas no matrix infiltration was found on Strattice in the first 12 days. Uncompromised horizontal resurfacing was greatest with Strattice but was absent with Matriderm. Strattice showed no stimulatory effect on cellular inflammation. Matrix texture and surface properties governed cellular performance on tissues. Although dense dermal compaction delayed vertical cellular ingrowth for Strattice, it allowed uncompromised horizontal resurfacing. Dense dermal compaction may slow matrix decomposition and result in prolonged biomechanical stability of the graft. Reconstructive surgeons should choose the adequate matrix substitute depending on biomechanical requirements at the recipient site. Strattice may be suitable as a dermal replacement at recipient sites with high mechanical load requirements.

  8. A physiological toxicokinetic model for dermal absorption of waterborne pyrene by trout

    Energy Technology Data Exchange (ETDEWEB)

    Namdari, R.; Law, F.C.P. [Simon Fraser Univ., Burnaby, British Columbia (Canada)

    1995-12-31

    A physiologically-based toxicokinetic (PB-TK) model was developed to describe the disposition of pyrene in trout following a bolus injection into the dorsal aorta. In the present study, the PB-TK model was adapted for dermal absorption of waterborne pyrene by trout. A skin compartment with transdermal flux described mathematically by the permeability-area-concentration product was added to the PB-TK model to allow prediction of pyrene concentrations in target organs and blood on the basis of exposure concentration at the skin surface. Physiologically relevant parameters e.g., organ volume, blood flow rate, and tissue/blood partitioning coefficient which were derived from the model were similar to those reported in the previous publication. The dermal PB-TK model was validated by exposing the trunk of trout (400--500 g) to stagnant water containing 24 ppm pyrene in a specially designed chamber for 4 hr, 24 hr or 48 hr. The trout were sacrificed at the conclusion of pyrene exposure and the tissues analyzed for unchanged pyrene by HPLC. In separate experiments, trout were implanted with dorsal aorta cannuli before the trunks were exposed to stagnant water containing 24 ppm pyrene in the chamber for 4 hr. At specific time intervals during and after pyrene exposure, blood samples were withdrawn through the cannula and analyzed for pyrene by HPLC. The agreement between simulated and experimentally obtained values shows that this model is an appropriate tool to predict dermal absorption of waterborne pyrene by trout.

  9. Differentiation of human multipotent dermal fibroblasts into islet-like cell clusters

    Directory of Open Access Journals (Sweden)

    Liu Wei

    2010-06-01

    Full Text Available Abstract Background We have previously obtained a clonal population of cells from human foreskin that is able to differentiate into mesodermal, ectodermal and endodermal progenies. It is of great interest to know whether these cells could be further differentiated into functional insulin-producing cells. Results Sixty-one single-cell-derived dermal fibroblast clones were established from human foreskin by limiting dilution culture. Of these, two clones could be differentiated into neuron-, adipocyte- or hepatocyte-like cells under certain culture conditions. In addition, those two clones were able to differentiate into islet-like clusters under pancreatic induction. Insulin, glucagon and somatostatin were detectable at the mRNA and protein levels after induction. Moreover, the islet-like clusters could release insulin in response to glucose in vitro. Conclusions This is the first study to demonstrate that dermal fibroblasts can differentiate into insulin-producing cells without genetic manipulation. This may offer a safer cell source for future stem cell-based therapies.

  10. Biomaterials as novel penetration enhancers for transdermal and dermal drug delivery systems.

    Science.gov (United States)

    Chen, Yang; Wang, Manli; Fang, Liang

    2013-01-01

    The highly organized structure of the stratum corneum provides an effective barrier to the drug delivery into or across the skin. To overcome this barrier function, penetration enhancers are always used in the transdermal and dermal drug delivery systems. However, the conventional chemical enhancers are often limited by their inability to delivery large and hydrophilic molecules, and few to date have been routinely incorporated into the transdermal formulations due to their incompatibility and local irritation issues. Therefore, there has been a search for the compounds that exhibit broad enhancing activity for more drugs without producing much irritation. More recently, the use of biomaterials has emerged as a novel method to increase the skin permeability. In this paper, we present an overview of the investigations on the feasibility and application of biomaterials as penetration enhancers for transdermal or dermal drug delivery systems.

  11. Application of Bladder Acellular Matrix in Urinary Bladder Regeneration: The State of the Art and Future Directions

    Directory of Open Access Journals (Sweden)

    Marta Pokrywczynska

    2015-01-01

    Full Text Available Construction of the urinary bladder de novo using tissue engineering technologies is the “holy grail” of reconstructive urology. The search for the ideal biomaterial for urinary bladder reconstruction has been ongoing for decades. One of the most promising biomaterials for this purpose seems to be bladder acellular matrix (BAM. In this review we determine the most important factors, which may affect biological and physical properties of BAM and its regeneration potential in tissue engineered urinary bladder. We also point out the directions in modification of BAM, which include incorporation of exogenous growth factors into the BAM structure. Finally, we discuss the results of the urinary bladder regeneration with cell seeded BAM.

  12. Topological expansion of the chain of matrices

    International Nuclear Information System (INIS)

    Eynard, B.; Ferrer, A. Prats

    2009-01-01

    We solve the loop equations to all orders in 1/N 2 , for the Chain of Matrices matrix model (with possibly an external field coupled to the last matrix of the chain). We show that the topological expansion of the free energy, is, like for the 1 and 2-matrix model, given by the symplectic invariants of [19]. As a consequence, we find the double scaling limit explicitly, and we discuss modular properties, large N asymptotics. We also briefly discuss the limit of an infinite chain of matrices (matrix quantum mechanics).

  13. Pesticide risk assessment: A study on inhalation and dermal exposure to 2,4-D and paraquat among Malaysian paddy farmers.

    Science.gov (United States)

    Baharuddin, Mohd Rafee B; Sahid, Ismail B; Noor, Mohamad Azhar B Mohd; Sulaiman, Norela; Othman, Fadzil

    2011-01-01

    A cross-section analytical study was conducted to evaluate the risk of pesticide exposure to those applying the Class II pesticides 2,4-D and paraquat in the paddy-growing areas of Kerian, Perak, Malaysia. It investigated the influence of weather on exposure as well as documented health problems commonly related to pesticide exposure. Potential inhalation and dermal exposure for 140 paddy farmers (handlers of pesticides) were assessed. Results showed that while temperature and humidity affected exposure, windspeed had the strongest impact on pesticide exposure via inhalation. However, the degree of exposure to both herbicides via inhalation was below the permissible exposure limits set by United States National Institute of Occupational Safety and Health (NIOSH). Dermal Exposure Assessment Method (DREAM) readings showed that dermal exposure with manual spraying ranged from moderate to high. With motorized sprayers, however, the level of dermal exposure ranged from low to moderate. Dermal exposure was significantly negatively correlated with the usage of protective clothing. Various types of deleterious health effects were detected among users of manual knapsack sprayers. Long-term spraying activities were positively correlated with increasing levels of the gamma-glutamyl transpeptidase (GGT) liver enzyme. The type of spraying equipment, usage of proper protective clothing and adherence to correct spraying practices were found to be the most important factors influencing the degree of pesticide exposure among those applying pesticides.

  14. Newton`s iteration for inversion of Cauchy-like and other structured matrices

    Energy Technology Data Exchange (ETDEWEB)

    Pan, V.Y. [Lehman College, Bronx, NY (United States); Zheng, Ailong; Huang, Xiaohan; Dias, O. [CUNY, New York, NY (United States)

    1996-12-31

    We specify some initial assumptions that guarantee rapid refinement of a rough initial approximation to the inverse of a Cauchy-like matrix, by mean of our new modification of Newton`s iteration, where the input, output, and all the auxiliary matrices are represented with their short generators defined by the associated scaling operators. The computations are performed fast since they are confined to operations with short generators of the given and computed matrices. Because of the known correlations among various structured matrices, the algorithm is immediately extended to rapid refinement of rough initial approximations to the inverses of Vandermonde-like, Chebyshev-Vandermonde-like and Toeplitz-like matrices, where again, the computations are confined to operations with short generators of the involved matrices.

  15. Dissolving Microneedle Patches for Dermal Vaccination.

    Science.gov (United States)

    Leone, M; Mönkäre, J; Bouwstra, J A; Kersten, G

    2017-11-01

    The dermal route is an attractive route for vaccine delivery due to the easy skin accessibility and a dense network of immune cells in the skin. The development of microneedles is crucial to take advantage of the skin immunization and simultaneously to overcome problems related to vaccination by conventional needles (e.g. pain, needle-stick injuries or needle re-use). This review focuses on dissolving microneedles that after penetration into the skin dissolve releasing the encapsulated antigen. The microneedle patch fabrication techniques and their challenges are discussed as well as the microneedle characterization methods and antigen stability aspects. The immunogenicity of antigens formulated in dissolving microneedles are addressed. Finally, the early clinical development is discussed.

  16. Agricultural matrices affect ground ant assemblage composition inside forest fragments.

    Directory of Open Access Journals (Sweden)

    Diego Santana Assis

    Full Text Available The establishment of agricultural matrices generally involves deforestation, which leads to fragmentation of the remaining forest. This fragmentation can affect forest dynamics both positively and negatively. Since most animal species are affected, certain groups can be used to measure the impact of such fragmentation. This study aimed to measure the impacts of agricultural crops (matrices on ant communities of adjacent lower montane Atlantic rainforest fragments. We sampled nine forest fragments at locations surrounded by different agricultural matrices, namely: coffee (3 replicates; sugarcane (3; and pasture (3. At each site we installed pitfall traps along a 500 m transect from the interior of the matrix to the interior of the fragment (20 pitfall traps ~25 m apart. Each transect was partitioned into four categories: interior of the matrix; edge of the matrix; edge of the fragment; and interior of the fragment. For each sample site, we measured ant species richness and ant community composition within each transect category. Ant richness and composition differed between fragments and matrices. Each sample location had a specific composition of ants, probably because of the influence of the nature and management of the agricultural matrices. Species composition in the coffee matrix had the highest similarity to its corresponding fragment. The variability in species composition within forest fragments surrounded by pasture was greatest when compared with forest fragments surrounded by sugarcane or, to a lesser extent, coffee. Functional guild composition differed between locations, but the most representative guild was 'generalist' both in the agricultural matrices and forest fragments. Our results are important for understanding how agricultural matrices act on ant communities, and also, how these isolated forest fragments could act as an island of biodiversity in an 'ocean of crops'.

  17. Agricultural matrices affect ground ant assemblage composition inside forest fragments.

    Science.gov (United States)

    Assis, Diego Santana; Dos Santos, Iracenir Andrade; Ramos, Flavio Nunes; Barrios-Rojas, Katty Elena; Majer, Jonathan David; Vilela, Evaldo Ferreira

    2018-01-01

    The establishment of agricultural matrices generally involves deforestation, which leads to fragmentation of the remaining forest. This fragmentation can affect forest dynamics both positively and negatively. Since most animal species are affected, certain groups can be used to measure the impact of such fragmentation. This study aimed to measure the impacts of agricultural crops (matrices) on ant communities of adjacent lower montane Atlantic rainforest fragments. We sampled nine forest fragments at locations surrounded by different agricultural matrices, namely: coffee (3 replicates); sugarcane (3); and pasture (3). At each site we installed pitfall traps along a 500 m transect from the interior of the matrix to the interior of the fragment (20 pitfall traps ~25 m apart). Each transect was partitioned into four categories: interior of the matrix; edge of the matrix; edge of the fragment; and interior of the fragment. For each sample site, we measured ant species richness and ant community composition within each transect category. Ant richness and composition differed between fragments and matrices. Each sample location had a specific composition of ants, probably because of the influence of the nature and management of the agricultural matrices. Species composition in the coffee matrix had the highest similarity to its corresponding fragment. The variability in species composition within forest fragments surrounded by pasture was greatest when compared with forest fragments surrounded by sugarcane or, to a lesser extent, coffee. Functional guild composition differed between locations, but the most representative guild was 'generalist' both in the agricultural matrices and forest fragments. Our results are important for understanding how agricultural matrices act on ant communities, and also, how these isolated forest fragments could act as an island of biodiversity in an 'ocean of crops'.

  18. MALDI matrices for low molecular weight compounds: an endless story?

    Science.gov (United States)

    Calvano, Cosima Damiana; Monopoli, Antonio; Cataldi, Tommaso R I; Palmisano, Francesco

    2018-04-23

    Since its introduction in the 1980s, matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) has gained a prominent role in the analysis of high molecular weight biomolecules such as proteins, peptides, oligonucleotides, and polysaccharides. Its application to low molecular weight compounds has remained for long time challenging due to the spectral interferences produced by conventional organic matrices in the low m/z window. To overcome this problem, specific sample preparation such as analyte/matrix derivatization, addition of dopants, or sophisticated deposition technique especially useful for imaging experiments, have been proposed. Alternative approaches based on second generation (rationally designed) organic matrices, ionic liquids, and inorganic matrices, including metallic nanoparticles, have been the object of intense and continuous research efforts. Definite evidences are now provided that MALDI MS represents a powerful and invaluable analytical tool also for small molecules, including their quantification, thus opening new, exciting applications in metabolomics and imaging mass spectrometry. This review is intended to offer a concise critical overview of the most recent achievements about MALDI matrices capable of specifically address the challenging issue of small molecules analysis. Graphical abstract An ideal Book of matrices for MALDI MS of small molecules.

  19. Hierarchical Matrices Method and Its Application in Electromagnetic Integral Equations

    Directory of Open Access Journals (Sweden)

    Han Guo

    2012-01-01

    Full Text Available Hierarchical (H- matrices method is a general mathematical framework providing a highly compact representation and efficient numerical arithmetic. When applied in integral-equation- (IE- based computational electromagnetics, H-matrices can be regarded as a fast algorithm; therefore, both the CPU time and memory requirement are reduced significantly. Its kernel independent feature also makes it suitable for any kind of integral equation. To solve H-matrices system, Krylov iteration methods can be employed with appropriate preconditioners, and direct solvers based on the hierarchical structure of H-matrices are also available along with high efficiency and accuracy, which is a unique advantage compared to other fast algorithms. In this paper, a novel sparse approximate inverse (SAI preconditioner in multilevel fashion is proposed to accelerate the convergence rate of Krylov iterations for solving H-matrices system in electromagnetic applications, and a group of parallel fast direct solvers are developed for dealing with multiple right-hand-side cases. Finally, numerical experiments are given to demonstrate the advantages of the proposed multilevel preconditioner compared to conventional “single level” preconditioners and the practicability of the fast direct solvers for arbitrary complex structures.

  20. The recurrence sequences via Sylvester matrices

    Science.gov (United States)

    Karaduman, Erdal; Deveci, Ömür

    2017-07-01

    In this work, we define the Pell-Jacobsthal-Slyvester sequence and the Jacobsthal-Pell-Slyvester sequence by using the Slyvester matrices which are obtained from the characteristic polynomials of the Pell and Jacobsthal sequences and then, we study the sequences defined modulo m. Also, we obtain the cyclic groups and the semigroups from the generating matrices of these sequences when read modulo m and then, we derive the relationships among the orders of the cyclic groups and the periods of the sequences. Furthermore, we redefine Pell-Jacobsthal-Slyvester sequence and the Jacobsthal-Pell-Slyvester sequence by means of the elements of the groups and then, we examine them in the finite groups.

  1. Porcine bladder acellular matrix (ACM): protein expression, mechanical properties

    International Nuclear Information System (INIS)

    Farhat, Walid A; Chen Jun; Haig, Jennifer; Antoon, Roula; Litman, Jessica; Yeger, Herman; Sherman, Christopher; Derwin, Kathleen

    2008-01-01

    Experimentally, porcine bladder acellular matrix (ACM) that mimics extracellular matrix has excellent potential as a bladder substitute. Herein we investigated the spatial localization and expression of different key cellular and extracellular proteins in the ACM; furthermore, we evaluated the inherent mechanical properties of the resultant ACM prior to implantation. Using a proprietary decellularization method, the DNA contents in both ACM and normal bladder were measured; in addition we used immunohistochemistry and western blots to quantify and localize the different cellular and extracellular components, and finally the mechanical testing was performed using a uniaxial mechanical testing machine. The mean DNA content in the ACM was significantly lower in the ACM compared to the bladder. Furthermore, the immunohistochemical and western blot analyses showed that collagen I and IV were preserved in the ACM, but possibly denatured collagen III in the ACM. Furthermore, elastin, laminin and fibronectin were mildly reduced in the ACM. Although the ACM did not exhibit nucleated cells, residual cellular components (actin, myosin, vimentin and others) were still present. There was, on the other hand, no significant difference in the mean stiffness between the ACM and the bladder. Although our decellularization method is effective in removing nuclear material from the bladder while maintaining its inherent mechanical properties, further work is mandatory to determine whether these residual DNA and cellular remnants would lead to any immune reaction, or if the mechanical properties of the ACM are preserved upon implantation and cellularization

  2. Porcine bladder acellular matrix (ACM): protein expression, mechanical properties.

    Science.gov (United States)

    Farhat, Walid A; Chen, Jun; Haig, Jennifer; Antoon, Roula; Litman, Jessica; Sherman, Christopher; Derwin, Kathleen; Yeger, Herman

    2008-06-01

    Experimentally, porcine bladder acellular matrix (ACM) that mimics extracellular matrix has excellent potential as a bladder substitute. Herein we investigated the spatial localization and expression of different key cellular and extracellular proteins in the ACM; furthermore, we evaluated the inherent mechanical properties of the resultant ACM prior to implantation. Using a proprietary decellularization method, the DNA contents in both ACM and normal bladder were measured; in addition we used immunohistochemistry and western blots to quantify and localize the different cellular and extracellular components, and finally the mechanical testing was performed using a uniaxial mechanical testing machine. The mean DNA content in the ACM was significantly lower in the ACM compared to the bladder. Furthermore, the immunohistochemical and western blot analyses showed that collagen I and IV were preserved in the ACM, but possibly denatured collagen III in the ACM. Furthermore, elastin, laminin and fibronectin were mildly reduced in the ACM. Although the ACM did not exhibit nucleated cells, residual cellular components (actin, myosin, vimentin and others) were still present. There was, on the other hand, no significant difference in the mean stiffness between the ACM and the bladder. Although our decellularization method is effective in removing nuclear material from the bladder while maintaining its inherent mechanical properties, further work is mandatory to determine whether these residual DNA and cellular remnants would lead to any immune reaction, or if the mechanical properties of the ACM are preserved upon implantation and cellularization.

  3. Porcine bladder acellular matrix (ACM): protein expression, mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Farhat, Walid A [Department of Surgery, Division of Urology, University of Toronto and Hospital for Sick Children, Toronto, ON M5G 1X8 (Canada); Chen Jun; Haig, Jennifer; Antoon, Roula; Litman, Jessica; Yeger, Herman [Department of Developmental and Stem Cell Biology, Research Institute, Hospital for Sick Children, Toronto, ON M5G 1X8 (Canada); Sherman, Christopher [Department of Anatomic Pathology, Sunnybrook and Women' s College Health Sciences Centre, Toronto, ON (Canada); Derwin, Kathleen [Department of Biomedical Engineering, Lerner Research Institute and Orthopaedic Research Center, Cleveland Clinic Foundation, Cleveland, OH (United States)], E-mail: walid.farhat@sickkids.ca

    2008-06-01

    Experimentally, porcine bladder acellular matrix (ACM) that mimics extracellular matrix has excellent potential as a bladder substitute. Herein we investigated the spatial localization and expression of different key cellular and extracellular proteins in the ACM; furthermore, we evaluated the inherent mechanical properties of the resultant ACM prior to implantation. Using a proprietary decellularization method, the DNA contents in both ACM and normal bladder were measured; in addition we used immunohistochemistry and western blots to quantify and localize the different cellular and extracellular components, and finally the mechanical testing was performed using a uniaxial mechanical testing machine. The mean DNA content in the ACM was significantly lower in the ACM compared to the bladder. Furthermore, the immunohistochemical and western blot analyses showed that collagen I and IV were preserved in the ACM, but possibly denatured collagen III in the ACM. Furthermore, elastin, laminin and fibronectin were mildly reduced in the ACM. Although the ACM did not exhibit nucleated cells, residual cellular components (actin, myosin, vimentin and others) were still present. There was, on the other hand, no significant difference in the mean stiffness between the ACM and the bladder. Although our decellularization method is effective in removing nuclear material from the bladder while maintaining its inherent mechanical properties, further work is mandatory to determine whether these residual DNA and cellular remnants would lead to any immune reaction, or if the mechanical properties of the ACM are preserved upon implantation and cellularization.

  4. Quantitative mass spectrometry of unconventional human biological matrices

    Science.gov (United States)

    Dutkiewicz, Ewelina P.; Urban, Pawel L.

    2016-10-01

    The development of sensitive and versatile mass spectrometric methodology has fuelled interest in the analysis of metabolites and drugs in unconventional biological specimens. Here, we discuss the analysis of eight human matrices-hair, nail, breath, saliva, tears, meibum, nasal mucus and skin excretions (including sweat)-by mass spectrometry (MS). The use of such specimens brings a number of advantages, the most important being non-invasive sampling, the limited risk of adulteration and the ability to obtain information that complements blood and urine tests. The most often studied matrices are hair, breath and saliva. This review primarily focuses on endogenous (e.g. potential biomarkers, hormones) and exogenous (e.g. drugs, environmental contaminants) small molecules. The majority of analytical methods used chromatographic separation prior to MS; however, such a hyphenated methodology greatly limits analytical throughput. On the other hand, the mass spectrometric methods that exclude chromatographic separation are fast but suffer from matrix interferences. To enable development of quantitative assays for unconventional matrices, it is desirable to standardize the protocols for the analysis of each specimen and create appropriate certified reference materials. Overcoming these challenges will make analysis of unconventional human biological matrices more common in a clinical setting. This article is part of the themed issue 'Quantitative mass spectrometry'.

  5. Synthesis and characterization of injectable, thermosensitive, and biocompatible acellular bone matrix/poly(ethylene glycol)-poly (ε-caprolactone)-poly(ethylene glycol) hydrogel composite.

    Science.gov (United States)

    Ni, Pei-Yan; Fan, Min; Qian, Zhi-Yong; Luo, Jing-Cong; Gong, Chang-Yang; Fu, Shao-Zhi; Shi, Shuai; Luo, Feng; Yang, Zhi-Ming

    2012-01-01

    In orthopedic tissue engineering, the extensively applied acellular bone matrix (ABM) can seldom be prefabricated just right to mold the cavity of the diverse defects, might induce severe inflammation on account of the migration of small granules and usually bring the patients great pain in the treatment. In this study, a new injectable thermosensitive ABM/PECE composite with good biocompatibility was designed and prepared by adding the ABM granules into the triblock copolymer poly(ethylene eglycol)-poly(ε-caprolactone)-poly(ethylene eglycol) (PEG-PCL-PEG, PECE). The PECE was synthesized by ring-opening copolymerization and characterized by ¹H NMR. The ABM was prepared by acellular treatment of natural bone and ground to fine granules. The obtained ABM/PECE composite showed the most important absorption bands of ABM and PECE copolymer in FT-IR spectroscopy and underwent sol-gel phage transition from solution to nonflowing hydrogel at 37°C. SEM results indicated that the ABM/PECE composite with different ABM contents all presented similar porous 3D structure. ABM/PECE composite presented mild cytotoxicity to rat MSCs in vitro and good biocompatibility in the BALB/c mice subcutis up to 4 weeks. In conclusion, all the results confirmed that the injectable thermosensitive ABM/PECE composite was a promising candidate for orthopedic tissue engineering in a minimally-invasive way. Copyright © 2011 Wiley Periodicals, Inc.

  6. A Prospective, Postmarket, Compassionate Clinical Evaluation of a Novel Acellular Fish-skin Graft Which Contains Omega-3 Fatty Acids for the Closure of Hard-to-heal Lower Extremity Chronic Ulcers.

    Science.gov (United States)

    Yang, Chun K; Polanco, Thais O; Lantis, John C

    2016-04-01

    A novel piscine acellular fish-skin graft product has 510k clearance on the US market. This product (Omega3, Kerecis, Isafjordur, Iceland) is to be used similarly to extracellular matrices (ECMs) on the market (eg, bovine and porcine) except that it contains fats, including omega-3 polyunsaturated fatty acids that have been associated with anti-inflammatory properties in many studies. While many current ECMs are effective on open wounds, studies have largely excluded application to hard-to-heal ulcers. To test this product in a real-world environment, the authors chose to look specifically at hard-to-heal ulcers based on previously defined wound and patient factors. The primary objective was to assess the percentage of wound closure area from baseline after 5 weekly fish-skin graft applications in 18 patients with at least 1 "hard-to-heal" criteria. Patients underwent application of the fish skin for 5 sequential weeks, followed by 3 weeks of standard of care. Wound area, skin assessments, and pain were assessed weekly. A 40% decrease in wound surface area (P skin graft and secondary dressing (P < 0.05). Complete closure was seen in 3 of 18 patients by the end of the study phase. This fish-skin product appears to provide promise as an effective wound closing adjunctive ECM. This is true when used in this compassionate setting, where many other products fail. This study lacks a control arm and an aggressive application schedule, but the investigators believe it represents real-world practice.

  7. A Conceptual Cost Benefit Analysis of Tailings Matrices Use in Construction Applications

    Directory of Open Access Journals (Sweden)

    Mahmood Ali A.

    2016-01-01

    Full Text Available As part of a comprehensive research program, new tailings matrices are formulated of combinations of tailings and binder materials. The research program encompasses experimental and numerical analysis of the tailings matrices to investigate the feasibility of using them as construction materials in cold climates. This paper discusses a conceptual cost benefit analysis for the use of these new materials. It is shown here that the financial benefits of using the proposed new tailings matrices in terms of environmental sustainability are much higher when compared to normal sand matrices.

  8. Flexible Bayesian Dynamic Modeling of Covariance and Correlation Matrices

    KAUST Repository

    Lan, Shiwei

    2017-11-08

    Modeling covariance (and correlation) matrices is a challenging problem due to the large dimensionality and positive-definiteness constraint. In this paper, we propose a novel Bayesian framework based on decomposing the covariance matrix into variance and correlation matrices. The highlight is that the correlations are represented as products of vectors on unit spheres. We propose a variety of distributions on spheres (e.g. the squared-Dirichlet distribution) to induce flexible prior distributions for covariance matrices that go beyond the commonly used inverse-Wishart prior. To handle the intractability of the resulting posterior, we introduce the adaptive $\\\\Delta$-Spherical Hamiltonian Monte Carlo. We also extend our structured framework to dynamic cases and introduce unit-vector Gaussian process priors for modeling the evolution of correlation among multiple time series. Using an example of Normal-Inverse-Wishart problem, a simulated periodic process, and an analysis of local field potential data (collected from the hippocampus of rats performing a complex sequence memory task), we demonstrated the validity and effectiveness of our proposed framework for (dynamic) modeling covariance and correlation matrices.

  9. A case of cellulitis-like foreign body reaction after hyaluronic acid dermal filler injection

    Directory of Open Access Journals (Sweden)

    Yo Sup Shin

    2018-03-01

    Full Text Available A 58-year-old female presented with 3 weeks history of painful skin lesion on the right cheek. Diagnosis was cellulitis based on the clinical manifestation and laboratory test. However, skin lesion did not improve with antibiotics, and as a consequence, biopsy was performed. Based on histopathological findings and additional information of her previous history of intradermal filler injection, the lesion was diagnosed to be foreign body reaction. Previous reported cases of foreign body reaction induced by hyaluronic acid dermal filler typically manifested as nodular lesions, but cellulitis-like cutaneous manifestation has not been reported. Therefore, we report this interesting case of foreign body reaction after hyaluronic acid dermal filler injection.

  10. Default values for assessment of potential dermal exposure of the hands to industrial chemicals in the scope of regulatory risk assessments

    NARCIS (Netherlands)

    Marquart, H.; Warren, N.D.; Laitinen, J.; Hemmen, J.J. van

    2006-01-01

    Dermal exposure needs to be addressed in regulatory risk assessment of chemicals. The models used so far are based on very limited data. The EU project RISKOFDERM has gathered a large number of new measurements on dermal exposure to industrial chemicals in various work situations, together with

  11. An introduction to the theory of canonical matrices

    CERN Document Server

    Turnbull, H W

    2004-01-01

    Thorough and self-contained, this penetrating study of the theory of canonical matrices presents a detailed consideration of all the theory's principal features. Topics include elementary transformations and bilinear and quadratic forms; canonical reduction of equivalent matrices; subgroups of the group of equivalent transformations; and rational and classical canonical forms. The final chapters explore several methods of canonical reduction, including those of unitary and orthogonal transformations. 1952 edition. Index. Appendix. Historical notes. Bibliographies. 275 problems.

  12. Complementary Set Matrices Satisfying a Column Correlation Constraint

    OpenAIRE

    Wu, Di; Spasojevic, Predrag

    2006-01-01

    Motivated by the problem of reducing the peak to average power ratio (PAPR) of transmitted signals, we consider a design of complementary set matrices whose column sequences satisfy a correlation constraint. The design algorithm recursively builds a collection of $2^{t+1}$ mutually orthogonal (MO) complementary set matrices starting from a companion pair of sequences. We relate correlation properties of column sequences to that of the companion pair and illustrate how to select an appropriate...

  13. Improving reptile ecological risk assessment: oral and dermal toxicity of pesticides to a common lizard species (Sceloporus occidentalis).

    Science.gov (United States)

    Weir, Scott M; Yu, Shuangying; Talent, Larry G; Maul, Jonathan D; Anderson, Todd A; Salice, Christopher J

    2015-08-01

    Reptiles have been understudied in ecotoxicology, which limits consideration in ecological risk assessments. The goals of the present study were 3-fold: to improve oral and dermal dosing methodologies for reptiles, to generate reptile toxicity data for pesticides, and to correlate reptile and avian toxicity. The authors first assessed the toxicity of different dosing vehicles: 100 μL of water, propylene glycol, and acetone were not toxic. The authors then assessed the oral and dermal toxicity of 4 pesticides following the up-and-down procedure. Neither brodifacoum nor chlorothalonil caused mortality at doses ≤ 1750 μg/g. Under the "neat pesticide" oral exposure, endosulfan (median lethal dose [LD50] = 9.8 μg/g) was more toxic than λ-cyhalothrin (LD50 = 916.5 μg/g). Neither chemical was toxic via dermal exposure. An acetone dosing vehicle increased λ-cyhalothrin toxicity (oral LD50 = 9.8 μg/g; dermal LD50 = 17.5 μg/g), but not endosulfan. Finally, changes in dosing method and husbandry significantly increased dermal λ-cyhalothrin LD50s, which highlights the importance of standardized methods. The authors combined data from the present study with other reptile LD50s to correlate with available avian data. When only definitive LD50s were used in the analysis, a strong correlation was found between avian and reptile toxicity. The results suggest it is possible to build predictive relationships between avian and reptile LD50s. More research is needed, however, to understand trends associated with chemical classes and modes of action. © 2015 SETAC.

  14. Hamiltonian structure of isospectral deformation equation and semi-classical approximation to factorized S-matrices

    International Nuclear Information System (INIS)

    Chudnovsky, D.V.; Chudnovsky, G.V.

    1980-01-01

    We consider semi-classical approximation to factorized S-matrices. We show that this new class of matrices, called s-matrices, defines Hamiltonian structures for isospectral deformation equations. Concrete examples of factorized s-matrices are constructed and they are used to define Hamiltonian structure for general two-dimensional isospectral deformation systems. (orig.)

  15. Evaluation of 3D-human skin equivalents for assessment of human dermal absorption of some brominated flame retardants.

    Science.gov (United States)

    Abdallah, Mohamed Abou-Elwafa; Pawar, Gopal; Harrad, Stuart

    2015-11-01

    Ethical and technical difficulties inherent to studies in human tissues are impeding assessment of the dermal bioavailability of brominated flame retardants (BFRs). This is further complicated by increasing restrictions on the use of animals in toxicity testing, and the uncertainties associated with extrapolating data from animal studies to humans due to inter-species variations. To overcome these difficulties, we evaluate 3D-human skin equivalents (3D-HSE) as a novel in vitro alternative to human and animal testing for assessment of dermal absorption of BFRs. The percutaneous penetration of hexabromocyclododecanes (HBCD) and tetrabromobisphenol-A (TBBP-A) through two commercially available 3D-HSE models was studied and compared to data obtained for human ex vivo skin according to a standard protocol. No statistically significant differences were observed between the results obtained using 3D-HSE and human ex vivo skin at two exposure levels. The absorbed dose was low (less than 7%) and was significantly correlated with log Kow of the tested BFR. Permeability coefficient values showed increasing dermal resistance to the penetration of γ-HBCD>β-HBCD>α-HBCD>TBBPA. The estimated long lag times (>30 min) suggests that frequent hand washing may reduce human exposure to HBCDs and TBBPA via dermal contact. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Self-orthogonal codes from some bush-type Hadamard matrices ...

    African Journals Online (AJOL)

    By means of a construction method outlined by Harada and Tonchev, we determine some non-binary self-orthogonal codes obtained from the row span of orbit matrices of Bush-type Hadamard matrices that admit a xed-point-free and xed-block-free automorphism of prime order. We show that the code [20; 15; 4]5 obtained ...

  17. In vitro dermal absorption of pyrethroid pesticides in human and rat skin

    International Nuclear Information System (INIS)

    Hughes, Michael F.; Edwards, Brenda C.

    2010-01-01

    Dermal exposure to pyrethroid pesticides can occur during manufacture and application. This study examined the in vitro dermal absorption of pyrethroids using rat and human skin. Dermatomed skin from adult male Long Evans rats or human cadavers was mounted in flow-through diffusion cells, and radiolabeled bifenthrin, deltamethrin or cis-permethrin was applied in acetone to the skin. Fractions of receptor fluid were collected every 4 h. At 24 h, the skins were washed with soap and water to remove unabsorbed chemical. The skin was then solubilized. Two additional experiments were performed after washing the skin; the first was tape-stripping the skin and the second was the collection of receptor fluid for an additional 24 h. Receptor fluid, skin washes, tape strips and skin were analyzed for radioactivity. For rat skin, the wash removed 53-71% of the dose and 26-43% remained in the skin. The cumulative percentage of the dose at 24 h in the receptor fluid ranged from 1 to 5%. For human skin, the wash removed 71-83% of the dose and 14-25% remained in the skin. The cumulative percentage of the dose at 24 h in the receptor fluid was 1-2%. Tape-stripping removed 50-56% and 79-95% of the dose in rat and human skin, respectively, after the wash. From 24-48 h, 1-3% and about 1% of the dose diffused into the receptor fluid of rat and human skin, respectively. The pyrethroids bifenthrin, deltamethrin and cis-permethrin penetrated rat and human skin following dermal application in vitro. However, a skin wash removed 50% or more of the dose from rat and human skin. Rat skin was more permeable to the pyrethroids than human skin. Of the dose in skin, 50% or more was removed by tape-stripping, suggesting that permeation of pyrethroids into viable tissue could be impeded. The percentage of the dose absorbed into the receptor fluid was considerably less than the dose in rat and human skin. Therefore, consideration of the skin type used and fractions analyzed are important when using

  18. A hyaluronic acid membrane delivery system for cultured keratinocytes: clinical "take" rates in the porcine kerato-dermal model.

    Science.gov (United States)

    Myers, S R; Grady, J; Soranzo, C; Sanders, R; Green, C; Leigh, I M; Navsaria, H A

    1997-01-01

    The clinical take rates of cultured keratinocyte autografts are poor on a full-thickness wound unless a dermal bed is provided. Even under these circumstances two important problems are the time delay in growing autografts and the fragility of the grafts. A laser-perforated hyaluronic acid membrane delivery system allows grafting at early confluence without requiring dispase digestion to release grafts from their culture dishes. We designed this study to investigate the influence of this membrane on clinical take rates in an established porcine kerato-dermal grafting model. The study demonstrated a significant reduction in take as a result of halving the keratinocyte seeding density onto the membrane. The take rates, however, of grafts grown on the membrane at half or full conventional seeding density and transplanted to a dermal wound bed were comparable, if not better, than those of keratinocyte sheet grafts.

  19. Improved cartilage regeneration by implantation of acellular biomaterials after bone marrow stimulation: a systematic review and meta-analysis of animal studies

    Directory of Open Access Journals (Sweden)

    Michiel W. Pot

    2016-09-01

    Full Text Available Microfracture surgery may be applied to treat cartilage defects. During the procedure the subchondral bone is penetrated, allowing bone marrow-derived mesenchymal stem cells to migrate towards the defect site and form new cartilage tissue. Microfracture surgery generally results in the formation of mechanically inferior fibrocartilage. As a result, this technique offers only temporary clinical improvement. Tissue engineering and regenerative medicine may improve the outcome of microfracture surgery. Filling the subchondral defect with a biomaterial may provide a template for the formation of new hyaline cartilage tissue. In this study, a systematic review and meta-analysis were performed to assess the current evidence for the efficacy of cartilage regeneration in preclinical models using acellular biomaterials implanted after marrow stimulating techniques (microfracturing and subchondral drilling compared to the natural healing response of defects. The review aims to provide new insights into the most effective biomaterials, to provide an overview of currently existing knowledge, and to identify potential lacunae in current studies to direct future research. A comprehensive search was systematically performed in PubMed and EMBASE (via OvidSP using search terms related to tissue engineering, cartilage and animals. Primary studies in which acellular biomaterials were implanted in osteochondral defects in the knee or ankle joint in healthy animals were included and study characteristics tabulated (283 studies out of 6,688 studies found. For studies comparing non-treated empty defects to defects containing implanted biomaterials and using semi-quantitative histology as outcome measure, the risk of bias (135 studies was assessed and outcome data were collected for meta-analysis (151 studies. Random-effects meta-analyses were performed, using cartilage regeneration as outcome measure on an absolute 0–100% scale. Implantation of acellular

  20. Improved cartilage regeneration by implantation of acellular biomaterials after bone marrow stimulation: a systematic review and meta-analysis of animal studies.

    Science.gov (United States)

    Pot, Michiel W; Gonzales, Veronica K; Buma, Pieter; IntHout, Joanna; van Kuppevelt, Toin H; de Vries, Rob B M; Daamen, Willeke F

    2016-01-01

    Microfracture surgery may be applied to treat cartilage defects. During the procedure the subchondral bone is penetrated, allowing bone marrow-derived mesenchymal stem cells to migrate towards the defect site and form new cartilage tissue. Microfracture surgery generally results in the formation of mechanically inferior fibrocartilage. As a result, this technique offers only temporary clinical improvement. Tissue engineering and regenerative medicine may improve the outcome of microfracture surgery. Filling the subchondral defect with a biomaterial may provide a template for the formation of new hyaline cartilage tissue. In this study, a systematic review and meta-analysis were performed to assess the current evidence for the efficacy of cartilage regeneration in preclinical models using acellular biomaterials implanted after marrow stimulating techniques (microfracturing and subchondral drilling) compared to the natural healing response of defects. The review aims to provide new insights into the most effective biomaterials, to provide an overview of currently existing knowledge, and to identify potential lacunae in current studies to direct future research. A comprehensive search was systematically performed in PubMed and EMBASE (via OvidSP) using search terms related to tissue engineering, cartilage and animals. Primary studies in which acellular biomaterials were implanted in osteochondral defects in the knee or ankle joint in healthy animals were included and study characteristics tabulated (283 studies out of 6,688 studies found). For studies comparing non-treated empty defects to defects containing implanted biomaterials and using semi-quantitative histology as outcome measure, the risk of bias (135 studies) was assessed and outcome data were collected for meta-analysis (151 studies). Random-effects meta-analyses were performed, using cartilage regeneration as outcome measure on an absolute 0-100% scale. Implantation of acellular biomaterials significantly

  1. Defense against dermal exposures is only skin deep

    DEFF Research Database (Denmark)

    Nielsen, Jesper Bo; Nielsen, Flemming; Sørensen, Jens Ahm

    2007-01-01

    study demonstrates that a limited damage to the skin significantly increases the permeability coefficient (K (p)) as well as total percutaneous penetration of chemicals, and most significantly for those compounds that due to their physicochemical characteristics (the most hydrophilic as well as the most...... compartments is affected by the physicochemical characteristics of the chemicals as well as by the integrity of the skin. This observation may have implications when evaluating the possibility of removing chemicals from the skin through different cleansing procedures following unintended dermal exposures....

  2. Some thoughts on positive definiteness in the consideration of nuclear data covariance matrices

    Energy Technology Data Exchange (ETDEWEB)

    Geraldo, L.P.; Smith, D.L.

    1988-01-01

    Some basic mathematical features of covariance matrices are reviewed, particularly as they relate to the property of positive difiniteness. Physical implications of positive definiteness are also discussed. Consideration is given to an examination of the origins of non-positive definite matrices, to procedures which encourage the generation of positive definite matrices and to the testing of covariance matrices for positive definiteness. Attention is also given to certain problems associated with the construction of covariance matrices using information which is obtained from evaluated data files recorded in the ENDF format. Examples are provided to illustrate key points pertaining to each of the topic areas covered.

  3. Some thoughts on positive definiteness in the consideration of nuclear data covariance matrices

    International Nuclear Information System (INIS)

    Geraldo, L.P.; Smith, D.L.

    1988-01-01

    Some basic mathematical features of covariance matrices are reviewed, particularly as they relate to the property of positive difiniteness. Physical implications of positive definiteness are also discussed. Consideration is given to an examination of the origins of non-positive definite matrices, to procedures which encourage the generation of positive definite matrices and to the testing of covariance matrices for positive definiteness. Attention is also given to certain problems associated with the construction of covariance matrices using information which is obtained from evaluated data files recorded in the ENDF format. Examples are provided to illustrate key points pertaining to each of the topic areas covered

  4. OPTIMIZATION OF RESULTS AND TREATMENT TIMING OF DEEP DERMAL BURNS IN CHILDREN

    Directory of Open Access Journals (Sweden)

    Konstantin Aleksandrovich Afonichev

    2014-06-01

    Full Text Available Untreated deep dermal burns in children are the cause of long-term treatment and severe cicatricial deformities, resulting in poor cosmetic results and greatly impairing functional outcome. The problem of optimizing the results and timing of treatment of deep burns in children in recent years has become particularly urgent. We observed 1853 children with III-A degree burns. Some of the children's burns healed spontaneously, which led to the development of scar deformities during the first six months after injury. Risk factors for their development, depending on the patient's age and location of the lesion, are pointed out. Other children underwent early tangential excision of eschar. The analysis of the treatment results showed that the use of early surgery in children with deep dermal burns can reduce treatment time, as well as significantly to improve the cosmetic and functional outcomes of trauma.

  5. In vitro bioaccessibility of copper azole following simulated dermal transfer from pressure-treated wood

    Data.gov (United States)

    U.S. Environmental Protection Agency — In vitro bioaccessibility of copper azole following simulated dermal transfer from pressure-treated wood. This dataset is associated with the following publication:...

  6. Studies estimating the dermal bioavailability of polynuclear aromatic hydrocarbons from manufactured plant tar-contaminated soils

    International Nuclear Information System (INIS)

    Roy, T.A.; Krueger, A.J.; Taylor, B.B.; Mauro, D.M.; Goldstein, L.S.

    1998-01-01

    In vitro percutaneous absorption studies were performed with contaminated soils or organic extracts of contaminated soils collected at manufactured gas plant (MGP) sites. The MGP tar contaminated soils were found to contain a group of targeted polynuclear aromatic hydrocarbons (PAH) at levels ranging from 10 to 2400 mg/kg. The soil extracts contained target PAH at levels ranging from 12 000 - 34 000 mg/kg. Dermal penetration rates of target PAH from the MGP tar-contaminated soils/soil extracts were determined experimentally through human skin using 3 H-benzo(a)pyrene (BaP) as a surrogate. Results from three MGP sites showed reductions of 2-3 orders of magnitude in PAH absorption through human skin from the most contaminated soils in comparison to the soil extracts. Reduction in PAH penetration can be attributed to PAH concentration and (soil) matrix properties. PAH dermal flux values are used to determine site-specific dermally absorbed dose (DAD) and chronic daily intake (CDI) which are essential terms required to estimate risk associated with human exposure to MGP tar and MGP tar-contaminated soils. 21 refs., 4 figs., 3 tabs

  7. Progranulin Overproduction Due to Fli-1 Deficiency Contributes to the Resistance of Dermal Fibroblasts to Tumor Necrosis Factor in Systemic Sclerosis.

    Science.gov (United States)

    Ichimura, Yohei; Asano, Yoshihide; Akamata, Kaname; Noda, Shinji; Taniguchi, Takashi; Takahashi, Takehiro; Toyama, Tetsuo; Tada, Yayoi; Sugaya, Makoto; Sato, Shinichi; Kadono, Takafumi

    2015-12-01

    Progranulin is a growth factor that is active in wound repair and is an antagonist of tumor necrosis factor (TNF) receptors, regulating fibroblast activation, angiogenesis, and inflammation. Because long-standing activation of gene programs related to wound healing is a hallmark of systemic sclerosis (SSc), we sought to investigate the role of progranulin in SSc. Progranulin expression levels in human and murine skin samples were determined by immunohistochemical analysis and quantitative reverse transcription-polymerase chain reaction. The role of progranulin in fibroblast activation was examined using a gene-silencing technique. Progranulin levels in serum obtained from 60 patients with SSc and 16 healthy control subjects were determined by enzyme-linked immunosorbent assay. Progranulin expression was increased in SSc dermal fibroblasts compared with normal dermal fibroblasts, both in vivo and in vitro. Transcription factor Fli-1, a deficiency of which is involved in the activation of SSc dermal fibroblasts, served as a potent repressor of the progranulin gene, and Fli-1(+/-) mice and bleomycin-treated wild-type mice exhibited up-regulated expression of progranulin in dermal fibroblasts. SSc dermal fibroblasts were resistant to the antifibrotic effect of TNF, but this resistance was reversed by gene silencing of progranulin. Serum progranulin levels were elevated in patients with early diffuse cutaneous SSc (dcSSc), especially in those with inflammatory skin symptoms, and were positively correlated with the C-reactive protein level. Progranulin overproduction due to Fli-1 deficiency may contribute to the constitutive activation of SSc dermal fibroblasts by antagonizing the antifibrotic effect of TNF. Progranulin may also be involved in the inflammatory process associated with progressive skin sclerosis in early dcSSc. © 2015, American College of Rheumatology.

  8. Phacomatosis pigmento-pigmentaria: aberrant dermal melanocytosis and nevus spilus.

    Science.gov (United States)

    Wolf, Ronni; Ruocco, Eleonora; Baroni, Adone

    2011-08-15

    We present a dermal melanocytosis with superimposed nevus spilus on the arm of a 5-year-old boy. We recently introduced a new type of phacomatosis, which we termed "phacomatosis pigmentopigmentalis," that is analogous to phacomatosis pigmentokeratotica or pigmentovascularis, for describing the association of two pigmented nevi. The present case is an example of this type of phacomatosis, which now we prefer to define phacomatosis pigmento-pigmentaria according to the correct Latin terminology.

  9. Associative Yang-Baxter equation for quantum (semi-)dynamical R-matrices

    International Nuclear Information System (INIS)

    Sechin, Ivan; Zotov, Andrei

    2016-01-01

    In this paper we propose versions of the associative Yang-Baxter equation and higher order R-matrix identities which can be applied to quantum dynamical R-matrices. As is known quantum non-dynamical R-matrices of Baxter-Belavin type satisfy this equation. Together with unitarity condition and skew-symmetry it provides the quantum Yang-Baxter equation and a set of identities useful for different applications in integrable systems. The dynamical R-matrices satisfy the Gervais-Neveu-Felder (or dynamical Yang-Baxter) equation. Relation between the dynamical and non-dynamical cases is described by the IRF (interaction-round-a-face)-Vertex transformation. An alternative approach to quantum (semi-)dynamical R-matrices and related quantum algebras was suggested by Arutyunov, Chekhov, and Frolov (ACF) in their study of the quantum Ruijsenaars-Schneider model. The purpose of this paper is twofold. First, we prove that the ACF elliptic R-matrix satisfies the associative Yang-Baxter equation with shifted spectral parameters. Second, we directly prove a simple relation of the IRF-Vertex type between the Baxter-Belavin and the ACF elliptic R-matrices predicted previously by Avan and Rollet. It provides the higher order R-matrix identities and an explanation of the obtained equations through those for non-dynamical R-matrices. As a by-product we also get an interpretation of the intertwining transformation as matrix extension of scalar theta function likewise R-matrix is interpreted as matrix extension of the Kronecker function. Relations to the Gervais-Neveu-Felder equation and identities for the Felder’s elliptic R-matrix are also discussed.

  10. Effect of radiation on reconstitution of skin equivalent (dermal alterations); Effet de l`irradiation sur la reconstruction d`une peau equivalente (alterations dermiques)

    Energy Technology Data Exchange (ETDEWEB)

    Gentilhomme, E.; Bergier, J.; Richard, M.; Neveux, Y.

    1994-12-31

    Dermal equivalents have been treated by single doses of gamma irradiation of 10, 20, 30 and 50 Gray. Numerations at different times show a dose and time dependant diminution of cellular population. This diminution is histologically observed in dermal part of reconstituted skin, in association with cellular and functional alterations of fibroblast cells. Modifications of epidermal epithelia are also noted in some reconstituted skin. This model would be useful to apprehend the effect of a dermal irradiation lesion on the later epidermization. (author). 4 refs.

  11. The influence of water mixtures on the dermal absorption of glycol ethers

    International Nuclear Information System (INIS)

    Traynor, Matthew J.; Wilkinson, Simon C.; Williams, Faith M.

    2007-01-01

    Glycol ethers are solvents widely used alone and as mixtures in industrial and household products. Some glycol ethers have been shown to have a range of toxic effects in humans following absorption and metabolism to their aldehyde and acid metabolites. This study assessed the influence of water mixtures on the dermal absorption of butoxyethanol and ethoxyethanol in vitro through human skin. Butoxyethanol penetrated human skin up to sixfold more rapidly from aqueous solution (50%, 450 mg/ml) than from the neat solvent. Similarly penetration of ethoxyethanol was increased threefold in the presence of water (50%, 697 mg/ml). There was a corresponding increase in apparent permeability coefficient as the glycol ether concentration in water decreased. The maximum penetration rate of water also increased in the presence of both glycol ethers. Absorption through a synthetic membrane obeyed Fick's Law and absorption through rat skin showed a similar profile to human skin but with a lesser effect. The mechanisms for this phenomenon involves disruption of the stratum corneum lipid bilayer by desiccation by neat glycol ether micelles, hydration with water mixtures and the physicochemical properties of the glycol ether-water mixtures. Full elucidation of the profile of absorption of glycol ethers from mixtures is required for risk assessment of dermal exposure. This work supports the view that risk assessments for dermal contact scenarios should ideally be based on absorption data obtained for the relevant formulation or mixture and exposure scenario and that absorption derived from permeability coefficients may be inappropriate for water-miscible solvents

  12. Determination of radiation exposure of humans due to dermal contact with radionuclides

    International Nuclear Information System (INIS)

    Pratzel, H.G.

    1992-01-01

    It is the aim of this research project to determine the distribution of radioactive substances in the skin and organism, in order to be able to predict from these data the radiation exposure to be expected following contamination of the skin with radionuclides. Further investigations are to be carried out into the suitability of measures of prevention and decontamination. In view of the fact that only small amounts of those compounds are absorbed by the skin, the determination of the parameters chosen was carried out in radionuclide studies in young pigs. With the exception of the skin of the palms and soles, the radiation effects in man could easily be extrapolated from the results of these experiments. The findings revealed permit the following conclusions to be drawn: The incorporation of radioactive substances after dermal contamination is quite unavoidable, even if this is immediately followed by decontamination measures. The degree of incorporation and resulting radiation dose are only minor and remain several orders of magnitude below the dermal radiation dose. If the skin is contaminated with radioactive liquids, the extent of incorporation and accumulation is proportionate to the activity concentration of those liquids. The incorporated radiation dose is in direct proportion to the contaminated skin area and also shows a relationship to the duration of contamination, if the skin is wet. The uptake by the organism may be somewhat reduced, if decontamination is initiated immediately. Dermal protectives may help to reduce skin permeability and, thus, the uptake of radioactivity into the corneal layer and follicles. (orig./MG) [de

  13. Asymmetric correlation matrices: an analysis of financial data

    Science.gov (United States)

    Livan, G.; Rebecchi, L.

    2012-06-01

    We analyse the spectral properties of correlation matrices between distinct statistical systems. Such matrices are intrinsically non-symmetric, and lend themselves to extend the spectral analyses usually performed on standard Pearson correlation matrices to the realm of complex eigenvalues. We employ some recent random matrix theory results on the average eigenvalue density of this type of matrix to distinguish between noise and non-trivial correlation structures, and we focus on financial data as a case study. Namely, we employ daily prices of stocks belonging to the American and British stock exchanges, and look for the emergence of correlations between two such markets in the eigenvalue spectrum of their non-symmetric correlation matrix. We find several non trivial results when considering time-lagged correlations over short lags, and we corroborate our findings by additionally studying the asymmetric correlation matrix of the principal components of our datasets.

  14. No Eigenvalues Outside the Limiting Support of Generally Correlated Gaussian Matrices

    KAUST Repository

    Kammoun, Abla; Alouini, Mohamed-Slim

    2016-01-01

    This paper investigates the behaviour of the spectrum of generally correlated Gaussian random matrices whose columns are zero-mean independent vectors but have different correlations, under the specific regime where the number of their columns and that of their rows grow at infinity with the same pace. Following the approach proposed in [1], we prove that under some mild conditions, there is no eigenvalue outside the limiting support of generally correlated Gaussian matrices. As an outcome of this result, we establish that the smallest singular value of these matrices is almost surely greater than zero. From a practical perspective, this control of the smallest singular value is paramount to applications from statistical signal processing and wireless communication, in which this kind of matrices naturally arise.

  15. No Eigenvalues Outside the Limiting Support of Generally Correlated Gaussian Matrices

    KAUST Repository

    Kammoun, Abla

    2016-05-04

    This paper investigates the behaviour of the spectrum of generally correlated Gaussian random matrices whose columns are zero-mean independent vectors but have different correlations, under the specific regime where the number of their columns and that of their rows grow at infinity with the same pace. Following the approach proposed in [1], we prove that under some mild conditions, there is no eigenvalue outside the limiting support of generally correlated Gaussian matrices. As an outcome of this result, we establish that the smallest singular value of these matrices is almost surely greater than zero. From a practical perspective, this control of the smallest singular value is paramount to applications from statistical signal processing and wireless communication, in which this kind of matrices naturally arise.

  16. 40 CFR 795.232 - Inhalation and dermal pharmacokinetics of commercial hexane.

    Science.gov (United States)

    2010-07-01

    ... studies of volatile solvents in hairless mice. I. Description of a skin depot”, In: Journal of Applied... concentration. (C) Dermal studies. The test substance shall be applied and kept on the skin for a minimum of 6... data shall be evaluated by appropriate statistical methods. (3) Reporting results. In addition to the...

  17. The Use of Poly-4-Hydroxybutyrate (P4HB) Scaffold in the Ptotic Breast: A Multicenter Clinical Study.

    Science.gov (United States)

    Adams, William P; Baxter, Richard; Glicksman, Caroline; Mast, Bruce A; Tantillo, Michael; Van Natta, Bruce W

    2018-04-06

    Mastopexy and reduction mammaplasty are often limited by the patient's poor native soft tissue quality, resulting in ptosis recurrence and loss of rejuvenated surgical results. Surgical scaffolds and acellular dermal matrices are used in these procedures to provide physical and mechanical stabilization of weakened or compromised tissue. GalaFLEX scaffold, made from poly-4-hydroxybutyrate (P4HB), is a next-generation product for soft tissue reinforcement that resorbs gradually while aiding tissue regeneration to achieve excellent outcomes. To assess the clinical performance of GalaFLEX scaffold in soft tissue reinforcement during elective mastopexy and reduction mammaplasty. This multicenter, single-arm, observational study assessed product performance and outcomes of GalaFLEX scaffold when used in breast surgery. Outcomes included ptosis correction and maintenance, associated adverse events, patient and surgeon satisfaction, and mammographic and ultrasound imaging evaluation. At 6 centers in the US, 62 of 69 enrolled patients were treated. Of this population, 89.7% had successful ptosis correction and maintenance at 1 year, with high patient and surgeon satisfaction for breast shape, droop/sag of the breast, and maintenance of results at 1 year. There were 5 adverse events deemed related to the device (8.0%), including nerve pain, breast swelling, ptosis, and 2 instances of asymmetry. GalaFLEX scaffold safely and successfully supports and elevates breast tissue in mastopexy and reduction mammaplasty, with maintained support at 1 year. Surgeon and patient satisfaction were high. No mammogram or ultrasound interference was detected.

  18. Adhesion and metabolic activity of human corneal cells on PCL based nanofiber matrices

    Energy Technology Data Exchange (ETDEWEB)

    Stafiej, Piotr; Küng, Florian [Department of Ophthalmology, Universität Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen (Germany); Institute of Polymer Materials, Universität Erlangen-Nürnberg, Martensstraße 7, 91054 Erlangen (Germany); Thieme, Daniel; Czugala, Marta; Kruse, Friedrich E. [Department of Ophthalmology, Universität Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen (Germany); Schubert, Dirk W. [Institute of Polymer Materials, Universität Erlangen-Nürnberg, Martensstraße 7, 91054 Erlangen (Germany); Fuchsluger, Thomas A., E-mail: thomas.fuchsluger@uk-erlangen.de [Department of Ophthalmology, Universität Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen (Germany)

    2017-02-01

    In this work, polycaprolactone (PCL) was used as a basic polymer for electrospinning of random and aligned nanofiber matrices. Our aim was to develop a biocompatible substrate for ophthalmological application to improve wound closure in defects of the cornea as replacement for human amniotic membrane. We investigated whether blending the hydrophobic PCL with poly (glycerol sebacate) (PGS) or chitosan (CHI) improves the biocompatibility of the matrices for cell expansion. Human corneal epithelial cells (HCEp) and human corneal keratocytes (HCK) were used for in vitro biocompatibility studies. After optimization of the electrospinning parameters for all blends, scanning electron microscopy (SEM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), and water contact angle were used to characterize the different matrices. Fluorescence staining of the F-actin cytoskeleton of the cells was performed to analyze the adherence of the cells to the different matrices. Metabolic activity of the cells was measured by cell counting kit-8 (CCK-8) for 20 days to compare the biocompatibility of the materials. Our results show the feasibility of producing uniform nanofiber matrices with and without orientation for the used blends. All materials support adherence and proliferation of human corneal cell lines with oriented growth on aligned matrices. Although hydrophobicity of the materials was lowered by blending PCL, no increase in biocompatibility or proliferation, as was expected, could be measured. All tested matrices supported the expansion of human corneal cells, confirming their potential as substrates for biomedical applications. - Highlights: • PCL was blended with chitosan and poly(glycerol sebacate) for electrospinning. • Biocompatibility was proven with two human corneal cell lines. • Both cell lines adhered and proliferated on random and aligned nanofiber matrices. • Cytoskeletal orientation is shown on aligned nanofiber matrices.

  19. Dermal application of nitric oxide releasing acidified nitrite-containing liniments significantly reduces blood pressure in humans.

    Science.gov (United States)

    Opländer, Christian; Volkmar, Christine M; Paunel-Görgülü, Adnana; Fritsch, Thomas; van Faassen, Ernst E; Mürtz, Manfred; Grieb, Gerrit; Bozkurt, Ahmet; Hemmrich, Karsten; Windolf, Joachim; Suschek, Christoph V

    2012-02-15

    Vascular ischemic diseases, hypertension, and other systemic hemodynamic and vascular disorders may be the result of impaired bioavailability of nitric oxide (NO). NO but also its active derivates like nitrite or nitroso compounds are important effector and signal molecules with vasodilating properties. Our previous findings point to a therapeutical potential of cutaneous administration of NO in the treatment of systemic hemodynamic disorders. Unfortunately, no reliable data are available on the mechanisms, kinetics and biological responses of dermal application of nitric oxide in humans in vivo. The aim of the study was to close this gap and to explore the therapeutical potential of dermal nitric oxide application. We characterized with human skin in vitro and in vivo the capacity of NO, applied in a NO-releasing acidified form of nitrite-containing liniments, to penetrate the epidermis and to influence local as well as systemic hemodynamic parameters. We found that dermal application of NO led to a very rapid and significant transepidermal translocation of NO into the underlying tissue. Depending on the size of treated skin area, this translocation manifests itself through a significant systemic increase of the NO derivates nitrite and nitroso compounds, respectively. In parallel, this translocation was accompanied by an increased systemic vasodilatation and blood flow as well as reduced blood pressure. We here give evidence that in humans dermal application of NO has a therapeutic potential for systemic hemodynamic disorders that might arise from local or systemic insufficient availability of NO or its bio-active NO derivates, respectively. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. RISKOFDERM: Risk Assessment of Occupational Dermal Exposure to Chemicals. An Introduction to a Series of Papers on the Development of a Toolkit

    NARCIS (Netherlands)

    Hemmen, J.J. van; Auffarth, J.; Evans, P.G.; Rajan-Sithamparanadarajah, B.; Marquart, H.; Oppl, R.

    2003-01-01

    Dermal exposure to industrial chemicals during work is of major concern in the risk assessment of chemicals. Current approaches in procedures for European legislation are not based on experimental data on dermal exposures in workplaces because these are lacking. A large project, with four

  1. Correlation of Hypoxia and Pro-senescence Protein Expression in Green Sea Turtle (Chelonia mydas Lung Epithelial and Dermal Fibroblast Cell Culture

    Directory of Open Access Journals (Sweden)

    Anggraini Barlian

    2018-03-01

    Full Text Available Recent studies have shown hypoxia-induced gene expression correlated with cellular senescence. HIF-1α (hypoxia-inducible factor 1-alpha, p53, and pRB were induced under hypoxia and correlated with cellular senescence. The localization and expression of HIF-1α, p53, and pRB in Chelonia mydas lung epithelial and dermal fibroblast cell cultures were analyzed under normoxic and hypoxic conditions (at 4 and 24 hours. Human dermal fibroblast was used for comparison purposes. Protein localization was analyzed with immunocytochemistry, while protein expression was analyzed with the Western blot and enhanced chemiluminescence (ECL method. HIF-1α, p53, and pRB were localized in the nuclei of the C. mydas cell cultures treated with hypoxia. The C. mydas lung epithelial cell cultures had a higher increase of HIF-1α expression than the human dermal fibroblast cell culture. The hypoxic conditions did not affect p53 expression significantly in C. mydas lung epithelial and dermal fibroblast cell cultures. Meanwhile, pRB expression changed significantly under hypoxia in the C. mydas dermal fibroblast cells. Expression of p53 and pRB in the human cell cultures was higher than in the C. mydas cell cultures. This research suggests that C. mydas and human cell cultures have different pro-senescence protein expression responses under hypoxic conditions.

  2. First results in the application of silicon photomultiplier matrices to small animal PET

    Energy Technology Data Exchange (ETDEWEB)

    Llosa, G. [University of Pisa, Department of Physics, Pisa (Italy)], E-mail: gabriela.llosa@pi.infn.it; Belcari, N.; Bisogni, M.G. [University of Pisa, Department of Physics, Pisa (Italy); INFN Pisa (Italy); Collazuol, G. [University of Pisa, Department of Physics, Pisa (Italy); Scuola Normale Superiore, Pisa (Italy); Marcatili, S. [University of Pisa, Department of Physics, Pisa (Italy); INFN Pisa (Italy); Boscardin, M.; Melchiorri, M.; Tarolli, A.; Piemonte, C.; Zorzi, N. [FBK irst, Trento (Italy); Barrillon, P.; Bondil-Blin, S.; Chaumat, V.; La Taille, C. de; Dinu, N.; Puill, V.; Vagnucci, J-F. [Laboratoire de l' Accelerateur Lineaire, IN2P3-CNRS, Orsay (France); Del Guerra, A. [University of Pisa, Department of Physics, Pisa (Italy); INFN Pisa (Italy)

    2009-10-21

    A very high resolution small animal PET scanner that employs matrices of silicon photomultipliers as photodetectors is under development at the University of Pisa and INFN Pisa. The first SiPM matrices composed of 16 (4x4)1mmx1mm pixel elements on a common substrate have been produced at FBK-irst, and are being evaluated for this application. The MAROC2 ASIC developed at LAL-Orsay has been employed for the readout of the SiPM matrices. The devices have been tested with pixelated and continuous LYSO crystals. The results show the good performance of the matrices and lead to the fabrication of matrices with 64 SiPM elements.

  3. First results in the application of silicon photomultiplier matrices to small animal PET

    International Nuclear Information System (INIS)

    Llosa, G.; Belcari, N.; Bisogni, M.G.; Collazuol, G.; Marcatili, S.; Boscardin, M.; Melchiorri, M.; Tarolli, A.; Piemonte, C.; Zorzi, N.; Barrillon, P.; Bondil-Blin, S.; Chaumat, V.; La Taille, C. de; Dinu, N.; Puill, V.; Vagnucci, J-F.; Del Guerra, A.

    2009-01-01

    A very high resolution small animal PET scanner that employs matrices of silicon photomultipliers as photodetectors is under development at the University of Pisa and INFN Pisa. The first SiPM matrices composed of 16 (4x4)1mmx1mm pixel elements on a common substrate have been produced at FBK-irst, and are being evaluated for this application. The MAROC2 ASIC developed at LAL-Orsay has been employed for the readout of the SiPM matrices. The devices have been tested with pixelated and continuous LYSO crystals. The results show the good performance of the matrices and lead to the fabrication of matrices with 64 SiPM elements.

  4. More about unphysical zeroes in quark mass matrices

    Energy Technology Data Exchange (ETDEWEB)

    Emmanuel-Costa, David, E-mail: david.costa@tecnico.ulisboa.pt [Departamento de Física and Centro de Física Teórica de Partículas - CFTP, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, 1049-001 Lisboa (Portugal); González Felipe, Ricardo, E-mail: ricardo.felipe@tecnico.ulisboa.pt [Departamento de Física and Centro de Física Teórica de Partículas - CFTP, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, 1049-001 Lisboa (Portugal); ISEL - Instituto Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa, Rua Conselheiro Emídio Navarro, 1959-007 Lisboa (Portugal)

    2017-01-10

    We look for all weak bases that lead to texture zeroes in the quark mass matrices and contain a minimal number of parameters in the framework of the standard model. Since there are ten physical observables, namely, six nonvanishing quark masses, three mixing angles and one CP phase, the maximum number of texture zeroes in both quark sectors is altogether nine. The nine zero entries can only be distributed between the up- and down-quark sectors in matrix pairs with six and three texture zeroes or five and four texture zeroes. In the weak basis where a quark mass matrix is nonsingular and has six zeroes in one sector, we find that there are 54 matrices with three zeroes in the other sector, obtainable through right-handed weak basis transformations. It is also found that all pairs composed of a nonsingular matrix with five zeroes and a nonsingular and nondecoupled matrix with four zeroes simply correspond to a weak basis choice. Without any further assumptions, none of these pairs of up- and down-quark mass matrices has physical content. It is shown that all non-weak-basis pairs of quark mass matrices that contain nine zeroes are not compatible with current experimental data. The particular case of the so-called nearest-neighbour-interaction pattern is also discussed.

  5. Basal Cell Carcinoma With Matrical Differentiation: Clinicopathologic, Immunohistochemical, and Molecular Biological Study of 22 Cases.

    Science.gov (United States)

    Kyrpychova, Liubov; Carr, Richard A; Martinek, Petr; Vanecek, Tomas; Perret, Raul; Chottová-Dvořáková, Magdalena; Zamecnik, Michal; Hadravsky, Ladislav; Michal, Michal; Kazakov, Dmitry V

    2017-06-01

    Basal cell carcinoma (BCC) with matrical differentiation is a fairly rare neoplasm, with about 30 cases documented mainly as isolated case reports. We studied a series of this neoplasm, including cases with an atypical matrical component, a hitherto unreported feature. Lesions coded as BCC with matrical differentiation were reviewed; 22 cases were included. Immunohistochemical studies were performed using antibodies against BerEp4, β-catenin, and epithelial membrane antigen (EMA). Molecular genetic studies using Ion AmpliSeq Cancer Hotspot Panel v2 by massively parallel sequencing on Ion Torrent PGM were performed in 2 cases with an atypical matrical component (1 was previously subjected to microdissection to sample the matrical and BCC areas separately). There were 13 male and 9 female patients, ranging in age from 41 to 89 years. Microscopically, all lesions manifested at least 2 components, a BCC area (follicular germinative differentiation) and areas with matrical differentiation. A BCC component dominated in 14 cases, whereas a matrical component dominated in 4 cases. Matrical differentiation was recognized as matrical/supramatrical cells (n=21), shadow cells (n=21), bright red trichohyaline granules (n=18), and blue-gray corneocytes (n=18). In 2 cases, matrical areas manifested cytologic atypia, and a third case exhibited an infiltrative growth pattern, with the tumor metastasizing to a lymph node. BerEP4 labeled the follicular germinative cells, whereas it was markedly reduced or negative in matrical areas. The reverse pattern was seen with β-catenin. EMA was negative in BCC areas but stained a proportion of matrical/supramatrical cells. Genetic studies revealed mutations of the following genes: CTNNB1, KIT, CDKN2A, TP53, SMAD4, ERBB4, and PTCH1, with some differences between the matrical and BCC components. It is concluded that matrical differentiation in BCC in most cases occurs as multiple foci. Rare neoplasms manifest atypia in the matrical areas

  6. Linking existing in vitro dermal absorption data to physicochemical properties: Contribution to the design of a weight-of-evidence approach for the safety evaluation of cosmetic ingredients with low dermal bioavailability.

    Science.gov (United States)

    Ates, Gamze; Steinmetz, Fabian P; Doktorova, Tatyana Yordanova; Madden, Judith C; Rogiers, Vera

    2016-04-01

    To characterize the risk of cosmetic ingredients when threshold toxicity is assumed, often the "margin of safety" (MoS) is calculated. This uncertainty factor is based on the systemic no observable (adverse) effect level (NO(A)EL) which can be derived from in vivo repeated dose toxicity studies. As in vivo studies for the purpose of the cosmetic legislation are no longer allowed in Europe and a validated in vitro alternative is not yet available, it is no longer possible to derive a NO(A)EL value for a new cosmetic ingredient. Alternatively, cosmetic ingredients with a low dermal bioavailability might not need repeated dose data, as internal exposure will be minimal and systemic toxicity might not be an issue. This study shows the possibility of identifying compounds suspected to have a low dermal bioavailability based on their physicochemical properties (molecular weight, melting point, topological polar surface area and log P) and their in vitro dermal absorption data. Although performed on a limited number of compounds, the study suggests a strategic opportunity to support the safety assessor's reasoning to omit a MoS calculation and to focus more on local toxicity and mutagenicity/genotoxicity for ingredients for which limited systemic exposure is to be expected. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Mixture component effects on the in vitro dermal absorption of pentachlorophenol

    Energy Technology Data Exchange (ETDEWEB)

    Riviere, J.E.; Qiao, G.; Baynes, R.E.; Brooks, J.D. [Coll. of Veterinary Medicine, North Carolina State Univ., Raleigh, NC (United States); Mumtaz, M. [Agency for Toxic Substances and Disease Registry (ATSDR), Atlanta, GA (United States)

    2001-08-01

    Interactions between chemicals in a mixture and interactions of mixture components with the skin can significantly alter the rate and extent of percutaneous absorption, as well as the cutaneous disposition of a topically applied chemical. The predictive ability of dermal absorption models, and consequently the dermal risk assessment process, would be greatly improved by the elucidation and characterization of these interactions. Pentachlorophenol (PCP), a compound known to penetrate the skin readily, was used as a marker compound to examine mixture component effects using in vitro porcine skin models. PCP was administered in ethanol or in a 40% ethanol/60% water mixture or a 40% ethanol/60% water mixture containing either the rubefacient methyl nicotinate (MNA) or the surfactant sodium lauryl sulfate (SLS), or both MNA and SLS. Experiments were also conducted with {sup 14}C-labelled 3,3',4,4'-tetrachlorobiphenyl (TCB) and 3,3',4,4',5-pentachlorobiphenyl (PCB). Maximal PCP absorption was 14.12% of the applied dose from the mixture containing SLS, MNA, ethanol and water. However, when PCP was administered in ethanol only, absorption was only 1.12% of the applied dose. There were also qualitative differences among the absorption profiles for the different PCP mixtures. In contrast with the PCP results, absorption of TCB or PCB was negligible in perfused porcine skin, with only 0.14% of the applied TCB dose and 0.05% of the applied PCB dose being maximally absorbed. The low absorption levels for the PCB congeners precluded the identification of mixture component effects. These results suggest that dermal absorption estimates from a single chemical exposure may not reflect absorption seen after exposure as a chemical mixture and that absorption of both TCB and PCB are minimal in this model system. (orig.)

  8. In vivo and in vitro dermal penetration of lipophilic and hydrophilic pesticides in mice

    International Nuclear Information System (INIS)

    Grissom, R.E. Jr.; Brownie, C.; Guthrie, F.E.

    1987-01-01

    Dermal absorption is a major portal of entry for a wide variety of potentially toxic substances. In vivo and in vitro investigations assessing penetration of topically applied xenobiotics using both human and other animals have been conducted. Current ethical considerations have drastically curtailed the testing of xenobiotics in human volunteers; consequently, dermal penetration in humans is usually estimated from in vivo tests in animals and in vitro tests using either human or animal skin. In order for in vitro penetration results to be meaningful, there needs to be close relationship with in vivo data. The objective of the present study was to investigate the relationship between in vivo and in vitro penetration of both hydrophilic and lipophilic 14 C-labelled compounds in mice

  9. Dirac Matrices and Feynman’s Rest of the Universe

    Directory of Open Access Journals (Sweden)

    Young S. Kim

    2012-10-01

    Full Text Available There are two sets of four-by-four matrices introduced by Dirac. The first set consists of fifteen Majorana matrices derivable from his four γ matrices. These fifteen matrices can also serve as the generators of the group SL(4, r. The second set consists of ten generators of the Sp(4 group which Dirac derived from two coupled harmonic oscillators. It is shown possible to extend the symmetry of Sp(4 to that of SL(4, r if the area of the phase space of one of the oscillators is allowed to become smaller without a lower limit. While there are no restrictions on the size of phase space in classical mechanics, Feynman’s rest of the universe makes this Sp(4-to-SL(4, r transition possible. The ten generators are for the world where quantum mechanics is valid. The remaining five generators belong to the rest of the universe. It is noted that the groups SL(4, r and Sp(4 are locally isomorphic to the Lorentz groups O(3, 3 and O(3, 2 respectively. This allows us to interpret Feynman’s rest of the universe in terms of space-time symmetry.

  10. A case of congenital dermal sinus of the occipital region detected by CT at the onset of meningitis

    International Nuclear Information System (INIS)

    Fujiwara, Katsuhiko; Esumi, Noriko; Nishimura, Osamu

    1985-01-01

    A 4-year-old girl who was found to have congenital dermal sinus of the occipital region by CT at the second onset of meningitis is reported. CT at the first onset of meningitis (at the age of 3 years and 9 months) revealed only small, oval low density areas in the posterior fossa of the occipital region. CT at the second onset showed an abscess in the posterior fossa and dissociation in the posterior part of the cranium. Skin examination in the occipital region disclosed induration of the median area. Thus, congenital dermal sinus was suspected. Further CT disclosed that the patient subsequently developed hydrocephalus despite the intravenous and intrameningeal administration of antibiotics. Therefore, she underwent excision of a cyst and was pathologically diagnosed as having dermoid associated with abscess in the tip of the dermal sinus, which was followed by induration of the occipital skin. (Namekawa, K.)

  11. Dynamical correlations for circular ensembles of random matrices

    International Nuclear Information System (INIS)

    Nagao, Taro; Forrester, Peter

    2003-01-01

    Circular Brownian motion models of random matrices were introduced by Dyson and describe the parametric eigenparameter correlations of unitary random matrices. For symmetric unitary, self-dual quaternion unitary and an analogue of antisymmetric Hermitian matrix initial conditions, Brownian dynamics toward the unitary symmetry is analyzed. The dynamical correlation functions of arbitrary number of Brownian particles at arbitrary number of times are shown to be written in the forms of quaternion determinants, similarly as in the case of Hermitian random matrix models

  12. Quantum Algorithms for Weighing Matrices and Quadratic Residues

    OpenAIRE

    van Dam, Wim

    2000-01-01

    In this article we investigate how we can employ the structure of combinatorial objects like Hadamard matrices and weighing matrices to device new quantum algorithms. We show how the properties of a weighing matrix can be used to construct a problem for which the quantum query complexity is ignificantly lower than the classical one. It is pointed out that this scheme captures both Bernstein & Vazirani's inner-product protocol, as well as Grover's search algorithm. In the second part of the ar...

  13. Regulation of gene expression by tobacco product preparations in cultured human dermal fibroblasts

    International Nuclear Information System (INIS)

    Malpass, Gloria E.; Arimilli, Subhashini; Prasad, G.L.; Howlett, Allyn C.

    2014-01-01

    Skin fibroblasts comprise the first barrier of defense against wounds, and tobacco products directly contact the oral cavity. Cultured human dermal fibroblasts were exposed to smokeless tobacco extract (STE), total particulate matter (TPM) from tobacco smoke, or nicotine at concentrations comparable to those found in these extracts for 1 h or 5 h. Differences were identified in pathway-specific genes between treatments and vehicle using qRT-PCR. At 1 h, IL1α was suppressed significantly by TPM and less significantly by STE. Neither FOS nor JUN was suppressed at 1 h by tobacco products. IL8, TNFα, VCAM1, and NFκB1 were suppressed after 5 h with STE, whereas only TNFα and NFκB1 were suppressed by TPM. At 1 h with TPM, secreted levels of IL10 and TNFα were increased. Potentially confounding effects of nicotine were exemplified by genes such as ATF3 (5 h), which was increased by nicotine but suppressed by other components of STE. Within 2 h, TPM stimulated nitric oxide production, and both STE and TPM increased reactive oxygen species. The biological significance of these findings and utilization of the gene expression changes reported herein regarding effects of the tobacco product preparations on dermal fibroblasts will require additional research. - Highlights: • Tobacco product preparations (TPPs) alter gene expression in dermal fibroblasts. • Some immediate early genes critical to the inflammatory process are affected. • Different TPPs produce differential responses in certain pro-inflammatory genes

  14. Regulation of gene expression by tobacco product preparations in cultured human dermal fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Malpass, Gloria E., E-mail: gloria.malpass@gmail.com [Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, NC 27157 (United States); Arimilli, Subhashini, E-mail: sarimill@wakehealth.edu [Department of Microbiology and Immunology, Wake Forest University Health Sciences, Winston-Salem, NC 27157 (United States); Prasad, G.L., E-mail: prasadg@rjrt.com [R and D Department, R.J. Reynolds Tobacco Company, Winston-Salem, NC 27102 (United States); Howlett, Allyn C., E-mail: ahowlett@wakehealth.edu [Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, NC 27157 (United States)

    2014-09-01

    Skin fibroblasts comprise the first barrier of defense against wounds, and tobacco products directly contact the oral cavity. Cultured human dermal fibroblasts were exposed to smokeless tobacco extract (STE), total particulate matter (TPM) from tobacco smoke, or nicotine at concentrations comparable to those found in these extracts for 1 h or 5 h. Differences were identified in pathway-specific genes between treatments and vehicle using qRT-PCR. At 1 h, IL1α was suppressed significantly by TPM and less significantly by STE. Neither FOS nor JUN was suppressed at 1 h by tobacco products. IL8, TNFα, VCAM1, and NFκB1 were suppressed after 5 h with STE, whereas only TNFα and NFκB1 were suppressed by TPM. At 1 h with TPM, secreted levels of IL10 and TNFα were increased. Potentially confounding effects of nicotine were exemplified by genes such as ATF3 (5 h), which was increased by nicotine but suppressed by other components of STE. Within 2 h, TPM stimulated nitric oxide production, and both STE and TPM increased reactive oxygen species. The biological significance of these findings and utilization of the gene expression changes reported herein regarding effects of the tobacco product preparations on dermal fibroblasts will require additional research. - Highlights: • Tobacco product preparations (TPPs) alter gene expression in dermal fibroblasts. • Some immediate early genes critical to the inflammatory process are affected. • Different TPPs produce differential responses in certain pro-inflammatory genes.

  15. Empowering first year (post-matric) students in basic research skills ...

    African Journals Online (AJOL)

    Post-matric students from under-resourced (historically disadvantaged) black high schools generally encounter difficulties in their academic work at university. The study reported here was intended to empower first year (post-matric) students from these schools with basic research skills in a bid to counteract the effects of ...

  16. Applicability of non-invasively collected matrices for human biomonitoring

    Directory of Open Access Journals (Sweden)

    Nickmilder Marc

    2009-03-01

    Full Text Available Abstract With its inclusion under Action 3 in the Environment and Health Action Plan 2004–2010 of the European Commission, human biomonitoring is currently receiving an increasing amount of attention from the scientific community as a tool to better quantify human exposure to, and health effects of, environmental stressors. Despite the policy support, however, there are still several issues that restrict the routine application of human biomonitoring data in environmental health impact assessment. One of the main issues is the obvious need to routinely collect human samples for large-scale surveys. Particularly the collection of invasive samples from susceptible populations may suffer from ethical and practical limitations. Children, pregnant women, elderly, or chronically-ill people are among those that would benefit the most from non-invasive, repeated or routine sampling. Therefore, the use of non-invasively collected matrices for human biomonitoring should be promoted as an ethically appropriate, cost-efficient and toxicologically relevant alternative for many biomarkers that are currently determined in invasively collected matrices. This review illustrates that several non-invasively collected matrices are widely used that can be an valuable addition to, or alternative for, invasively collected matrices such as peripheral blood sampling. Moreover, a well-informed choice of matrix can provide an added value for human biomonitoring, as different non-invasively collected matrices can offer opportunities to study additional aspects of exposure to and effects from environmental contaminants, such as repeated sampling, historical overview of exposure, mother-child transfer of substances, or monitoring of substances with short biological half-lives.

  17. Polymer Percolation Threshold in Multi-Component HPMC Matrices Tablets

    Directory of Open Access Journals (Sweden)

    Maryam Maghsoodi

    2011-06-01

    Full Text Available Introduction: The percolation theory studies the critical points or percolation thresholds of the system, where onecomponent of the system undergoes a geometrical phase transition, starting to connect the whole system. The application of this theory to study the release rate of hydrophilic matrices allows toexplain the changes in release kinetics of swellable matrix type system and results in a clear improvement of the design of controlled release dosage forms. Methods: In this study, the percolation theory has been applied to multi-component hydroxypropylmethylcellulose (HPMC hydrophilic matrices. Matrix tablets have been prepared using phenobarbital as drug,magnesium stearate as a lubricant employing different amount of lactose and HPMC K4M as a fillerandmatrix forming material, respectively. Ethylcelullose (EC as a polymeric excipient was also examined. Dissolution studies were carried out using the paddle method. In order to estimate the percolation threshold, the behaviour of the kinetic parameters with respect to the volumetric fraction of HPMC at time zero, was studied. Results: In both HPMC/lactose and HPMC/EC/lactose matrices, from the point of view of the percolation theory, the optimum concentration for HPMC, to obtain a hydrophilic matrix system for the controlled release of phenobarbital is higher than 18.1% (v/v HPMC. Above 18.1% (v/v HPMC, an infinite cluster of HPMC would be formed maintaining integrity of the system and controlling the drug release from the matrices. According to results, EC had no significant influence on the HPMC percolation threshold. Conclusion: This may be related to broad functionality of the swelling hydrophilic matrices.

  18. Inverted duplication including Endothelin 3 closely related to dermal hyperpigmentation in Silkie chickens

    Directory of Open Access Journals (Sweden)

    Ming TIAN,Suyun FANG,Yanqiang WANG,Xiaorong GU,Chungang FENG,Rui HAO,Xiaoxiang HU,Ning LI

    2014-06-01

    Full Text Available The dermal hyperpigmentation phenotype in chickens is controlled by the dominant fibromelanosis allele. One of the ten unique characteristics of Silkie chickens is the fibromelanosis phenotype, which is pigmentation in the dermal layer of the skin and connective tissue. In this study, we found a mutation of fibromelanosis, a genomic rearrangement that included an inverted duplication of endothelin3 (EDN3, is responsible. We show that, as a stimulator of melanoblast proliferation, EDN3 expression was increased in silkie embryos and in both skin and muscle throughout adulthood. EDN3 expression led to an increase in expression of the downstream genes EDNRB2 and TYRP2, and was closely relate with the hyperpigmentation phenotype. We examined eight different Chinese chicken breeds showing hyperpigmentation and conclude that this structural genetic variant exists in all fibromelanosis chicken breeds.

  19. Efficient linear algebra routines for symmetric matrices stored in packed form.

    Science.gov (United States)

    Ahlrichs, Reinhart; Tsereteli, Kakha

    2002-01-30

    Quantum chemistry methods require various linear algebra routines for symmetric matrices, for example, diagonalization or Cholesky decomposition for positive matrices. We present a small set of these basic routines that are efficient and minimize memory requirements.

  20. Secondary cytotoxicity of (crosslinked) dermal sheep collagen during repeated exposure to human fibroblasts

    NARCIS (Netherlands)

    van Luyn, M.J.A.; van Wachem, P.B.; Olde damink, L.H.H.; Olde Damink, L.H.H.; Dijkstra, Pieter J.; Feijen, Jan; Nieuwenhuis, P.

    1992-01-01

    We investigated commercially available dermal sheep collagen either cross-linked with hexamethylenediisocyanate, or cross-linked with glutaraldehyde. In previous in vitro studies we could discriminate primary, i.e. extractable, and secondary cytotoxicity, due to cell-biomaterial interactions, i.e.