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John L Semple

Publications and source records attributed to John L Semple.

9 recordsLinked to original sources
PubMed2006

Decellularized placental matrices for adipose tissue engineering.

A tissue-engineered adipose substitute would be invaluable to plastic surgeons for reconstructive, corrective, and cosmetic procedures. This work involves the design of a scaffold for soft tissue augmentation incorporating the decellularized extracellular matrix (ECM) of human placenta. We have developed a protocol to decellularize an intact, large segment (8 cm by 8 cm) of the human placenta. To facilitate the complete decellularization of the dense matrix, a system was designed to perfuse the required chemicals into the placenta via the existing vasculature. Following processing, the original architecture of the placental ECM was preserved, including an intact vascular network. Histological, immunohistochemical, and scanning electron microscopic analyses confirmed the removal of the cells and cellular debris and characterized the composition and structure of the matrix. In vitro cell culture experimentation showed that the placental decellular matrix (PDM) could facilitate the adhesion of primary human adipose precursor cells at early time points. The PDM has great potential for use as a scaffold for adipose tissue engineering, as the placenta is a rich source of human ECM components that can be readily harvested without harm to the donor.

Adipose Tissue↗
PubMed2006

Patient self-assessment of the cosmetic results of breast reconstruction.

BACKGROUND: In a previous study, the authors evaluated factors that contribute to patient satisfaction with breast reconstruction, using a comprehensive chart review and questionnaire. The results of part of this questionnaire, regarding patients' rating of the cosmetic result of their breast reconstruction, are presented in this article. METHODS: The questionnaire was mailed to 267 patients, 214 questionnaires (80.1 percent) were returned, and 200 contained a response to the question rating the overall cosmetic outcome of breast reconstruction (Fig. 1). To conduct a statistical analysis, the data were collapsed into two smaller groups. An "excellent" or "good" result was considered a "favorable" outcome, while lower responses were "unfavorable" outcomes. RESULTS: The outcome was rated as excellent by 82 patients, good by 76 patients, fair by 31 patients, and poor by 11 patients. A significant association was found between overall cosmesis and breast size, shape, or scars. CONCLUSION: It should not be assumed that patients' responses regarding satisfaction with reconstruction will reflect their specific feelings regarding cosmetic results.

Breast Neoplasms↗
PubMed2006

A comparison of human and porcine acellularized dermis: interactions with human fibroblasts in vitro.

BACKGROUND: Dermal substitutes derived from xenograft materials require elaborate processing at a considerable cost. Acellularized porcine dermis is a readily available material associated with minimal immunogenicity. The objective of this study was to evaluate acellularized pig dermis as a scaffold for human fibroblasts. METHODS: In vitro methods were used to evaluate fibroblast adherence, proliferation, and migration on pig acellularized dermal matrix. Acellular human dermis was used as a control. RESULTS: Pig acellularized dermal matrix was found to be inferior to human acellularized dermal matrix as a scaffold for human fibroblasts. Significantly more samples of human acellularized dermal matrix (83 percent, n = 24; p < 0.05) demonstrated fibroblast infiltration below the cell-seeded surface than pig acellularized dermal matrix (31 percent, n = 49). Significantly more (p < 0.05) fibroblasts infiltrated below the surface of human acellularized dermal matrix (mean, 1072 +/- 80 cells per section; n = 16 samples) than pig acellularized dermal matrix (mean, 301 +/- 48 cells per section; n = 16 samples). Fibroblasts migrated significantly less (p < 0.05) distance from the cell-seeded pig acellularized dermal matrix surface than in the human acellularized dermal matrix (78.8 percent versus 38.3 percent cells within 150 mum from the surface, respectively; n = 5). Fibroblasts proliferated more rapidly (p < 0.05) on pig acellularized dermal matrix (n = 9) than on the human acellularized dermal matrix (7.4-fold increase in cell number versus 1.8-fold increase, respectively; n = 9 for human acellularized dermal matrix). There was no difference between the two materials with respect to fibroblast adherence (8120 versus 7436 average adherent cells per section, for pig and human acellularized dermal matrix, respectively; n = 20 in each group; p > 0.05). CONCLUSION: Preliminary findings suggest that substantial differences may exist between human fibroblast behavior in cell-matrix interactions of porcine and human acellularized dermis.

Adolescent↗
PubMed2005

Time to reconsider subcutaneous mastectomy for breast-cancer prevention?

Genetic testing for women at increased risk of developing breast cancer has moved from the research setting to become part of established clinical practice. By testing for inherited mutations in BRCA1 and BRCA2, we are identifying more and more women who have an 80% or more lifetime risk of developing breast cancer. Since the discovery of BRCA1 in 1994, several clinical studies have led to strategies for reducing the risk of developing breast cancer, including prophylactic mastectomy, prophylactic oophorectomy, and preventive tamoxifen. We believe that in 2005, all prophylactic options, including subcutaneous and total mastectomy should be discussed and made available to women who find themselves unfortunate enough to have inherited a BRCA mutation.

Breast Neoplasms↗
PubMed2004

Satisfaction with breast reconstruction in women with bilateral prophylactic mastectomy: a descriptive study.

Prophylactic bilateral mastectomy is an option for women who are at an increased risk of developing breast cancer. Prophylactic mastectomy is often performed with immediate reconstruction (i.e., at the same time and under the same anesthetic as the mastectomy). Satisfaction with reconstruction has been described previously for women with mastectomy for breast cancer. However, the authors know of no previous research that has reported on satisfaction with reconstruction in patients who have electively sought mastectomy for the prevention of breast cancer. Women in the province of Ontario who had undergone prophylactic bilateral mastectomy plus breast reconstruction between 1991 and 2000 were asked to rate their level of satisfaction with the cosmetic results of their mastectomy and reconstruction and their overall satisfaction with their decision to have prophylactic mastectomy. Women were also asked whether they experienced complications associated with their surgery and what types of complications they experienced. Thirty-seven women completed questionnaires for this study, and all of them had immediate breast reconstruction after prophylactic mastectomy. The majority of women (70.3 percent) reported being satisfied or extremely satisfied with the cosmetic results of their breast reconstruction. Women with self-reported postsurgical complications (16.2 percent) were significantly less satisfied with reconstruction than those who did not report complications (p = 0.009). Personal subjective risk of breast cancer before prophylactic mastectomy was negatively correlated with satisfaction with reconstruction (r = -0.38, p = 0.024) and with subjective risk estimation after prophylactic surgery (r = -0.54, p = 0.001). Women who did not worry about developing breast cancer after prophylactic mastectomy had significantly higher levels of satisfaction with breast reconstruction than those who continued to worry (p < 0.001). Women who reported an improved body image after reconstruction were significantly more likely to report higher levels of satisfaction than those who reported a diminished body image (p = 0.007). The majority of women were satisfied with the cosmetic results of breast reconstruction after prophylactic mastectomy. Women who overestimated their breast cancer risk had lower satisfaction levels. Correcting overestimation of breast cancer risk in women who have prophylactic mastectomy may improve satisfaction with reconstruction following prophylactic mastectomy.

Adult↗
PubMed2003

Acellularization of human placenta with preservation of the basement membrane: a potential matrix for tissue engineering.

Basement membrane directs cell migration, cell adherence, and tissue organization in vivo. These qualities would be advantageous in tissue engineering, during which repopulation of scaffolds by functional cells is a common problem. The purpose of this study was to expose human term placenta to a chemical acellularization protocol using the isolated cotyledon perfusion technique to develop an acellular scaffold rich in extracellular matrix components for tissue engineering applications. The processed blocks of tissue demonstrated no cellular material on histologic examination. Periodic acid-Schiff staining, type IV collagen labeling, and transmission electron microscopy demonstrated preservation of the extracellular matrix and basement membrane. Maintenance of the extracellular matrix architecture was seen on scanning electron microscopy. Placenta-derived acellular matrix is a potential volume scaffold for tissue engineering. It is rich in extracellular matrix, has a complex architecture of vascular channels, and has unique donor opportunities.

Basement Membrane↗
PubMed2002

Microbial growth in saline breast implants and saline tissue expanders.

The subject of microbial growth within the saline medium of prosthetic breast implants has been one of great controversy in recent years. Although several articles have described microbial growth within the tissue surrounding implanted breast prostheses, few have attempted to determine the possibility of such contamination of the luminal saline. The authors studied the intraluminal saline medium of a series of explanted breast prostheses with the objective of identifying any microbial contamination. Over a 6-month period, a consecutive series of saline-filled breast implants and tissue expanders were removed from 37 patients. Under the supervision of a microbiologist, saline extracted from each implant was subjected to bacterial and fungal cultures, Gram staining, and acid-fast staining. A total of 24 saline-filled breast implants were removed from 15 patients, and 32 saline-filled tissue expanders were removed from 22 patients. The average length of implantation was 28.1 months for the implants and 7.1 months for the expanders. None of the saline within the implants or expanders within our series displayed any evidence of microbial contamination. These results suggest that microbial contamination of the luminal saline of prosthetic breast implants is an extremely unlikely event.

Adult↗
PubMedDate not supplied

In vitro, in vivo, in silico: computational systems in tissue engineering and regenerative medicine.

The emergence of computational systems in tissue engineering and regenerative medicine is paralleling the rapid rise of new technology. Developments in software and hardware have allowed access to the huge data streams that are now available. The Human Genome Project led the way and opened many avenues for other branches of science and biology with extensive but contained databanks. The availability of vast amounts of data means nothing without the ability to integrate the information into a useful form. Tissue engineering has always been a practical science in which function and utility are key objectives. This review delineates key areas of this rapidly ascending branch of science and illustrates examples central to the successful integration of computational methods.

Animals↗