Introduction: Traumatic brain injury (TBI) is a leading cause of death and disability worldwide and is associated with mortality rates as high as 30%. Patients with TBI are at high risk for secondary injury and need to be transported to definitive care expeditiously. However, the physiologic effects of aeromedical evacuation are not well understood and may compound these risks.
View Article and Find Full Text PDFWe examined whether effects of prior experience are mediated by distinct brain processes from those processing current stimulus features. We recorded event-related potentials (ERPs) during an auditory stream segregation task that presented an adaptation sequence with a small, intermediate, or large frequency separation between low and high tones (Deltaf), followed by a test sequence with intermediate Deltaf. Perception of two streams during the test was facilitated by small prior Deltaf and by prior perception of two streams and was accompanied by more positive ERPs.
View Article and Find Full Text PDFThe thiocarbamate alcoholism drug disulfiram blocks the P-glycoprotein extrusion pump, inhibits the transcription factor nuclear factor-kappaB, sensitizes tumors to chemotherapy, reduces angiogenesis, and inhibits tumor growth in mice. Thiocarbamates react with critical thiols and also complex metal ions. Using melanoma as the paradigm, we tested whether disulfiram might inhibit growth by forming mixed disulfides with critical thiols in a mechanism facilitated by metal ions.
View Article and Find Full Text PDFThe goal of tissue engineering is to create bioartificial tissues for the replacement of failed or nonfunctional tissue. Porous tissue-engineered scaffolds may be created through a solvent-casting/porogen-leaching technique. Almost exclusively, sodium chloride (NaCl) is the porogen of choice.
View Article and Find Full Text PDFPancreatic islet-cell tumors (ICTs) are rare malignancies usually recognized by specific clinical endocrinopathies. The purpose of this study is to evaluate our surgical experience with functioning pancreatic ICT in an academic referral center. Twenty patients (male:female 12:8) with a mean age of 53 years (range 26-82) underwent surgery for a functioning pancreatic ICT [gastrinoma (eight), multiple endocrine neoplasia (three), insulinoma (seven), glucagonoma (four), and VI-Poma (vasoactive intestinal peptide; one)] between June 1975 and March 2001.
View Article and Find Full Text PDFJ Biomed Mater Res
September 2002
Absorbable polymers are unique materials that find application as temporary scaffolds in tissue engineering. They are often extremely sensitive to histological processing and, for this reason, studying fragile, tissue-engineered constructs before implantation can be quite difficult. This research investigates the use of noninvasive imaging using magnetic resonance microscopy (MRM) as a tool to enhance the assessment of these cellular constructs.
View Article and Find Full Text PDFSoft tissue reconstruction using tissue-engineered constructs requires the development of materials that are biocompatible and support cell adhesion and growth. The objective of this study was to evaluate the use of macroporous hydrogel fragments that were formed using either unmodified alginate or alginate covalently linked with the fibronectin cell adhesion peptide RGD (alginate-RGD). These materials were injected into the subcutaneous space of adult, domesticated female sheep and harvested for histological comparisons at 1 and 3 months.
View Article and Find Full Text PDFJ Biomed Mater Res
December 2001
Tissue engineered biomaterial constructs are needed for plastic and reconstructive applications. To successfully form a space-filling tissue, the construct should induce a minimal inflammatory response, create minimal or no fibrotic capsule, and establish a vascular bed within the first few days after implantation to ensure survival of the implanted cells. In addition, the biomaterial should support cellular adhesion and induce tissue ingrowth.
View Article and Find Full Text PDFAs an adjuvant therapy for patients with high risk of recurrent melanoma, high-dose interferon (IFN)-alpha2b therapy has been shown to have some efficacy. We examined 22 patients with resected melanoma who were treated with repeated injections of recombinant IFN-alpha2b during the treatment. Both angiogenic and immune parameters were measured.
View Article and Find Full Text PDFCrit Rev Biomed Eng
April 2001
Absorbable mesh was investigated as a potential containment material in which to house discrete, small, tissue-engineered constructs. The mesh was fashioned into bags of varying shapes and consistent volumes. Cells were cultivated on porous, collagen beads, and the tissue constructs were placed into the bags.
View Article and Find Full Text PDFRecent Results Cancer Res
March 2001
Melanoma inhibitory activity (MIA) was originally identified as an 11 kDa protein secreted from malignant melanoma cells. We have shown that MIA is strongly expressed in melanoma and melanoma cell lines but not in melanocytes and normal skin. We also observed that MIA mRNA expression correlates with progressive malignancy of melanocytic tumors.
View Article and Find Full Text PDFJ Biomed Mater Res
September 2000
Development of tissue-engineered devices may be enhanced by combining cells with porous absorbable polymeric scaffolds before implantation. The cells are seeded throughout the scaffolds and allowed to proliferate in vitro for a predetermined amount of time. The distribution of cells throughout the porous material is one critical component determining success or failure of the tissue-engineered device.
View Article and Find Full Text PDFObjectives: To evaluate melanoma biopsy specimens for human papilloma virus (HPV) and determine the relation between the presence of HPV, in vitro growth, and clinical progression of melanoma in the patients from whom the biopsy specimens were derived.
Summary Background Data: Ultraviolet radiation from sun exposure appears to be the primary causal agent in the development of cutaneous melanoma. However, other agents, including HPV, as observed in different epithelial carcinomas, may also play a role in melanoma development and progression.
Melanoma inhibitory activity protein (MIA) has been detected in patients with advanced melanoma. The present study measured the variations in blood concentrations of MIA in 84 patients with AJCC stage II to IV melanoma by ELISA. Patients treated with repeated injections of a polyvalent melanoma vaccine (PMV), interferon-alpha-2b (IFN-alpha2b), or interleukin-2 (IL-2) were followed during treatment duration.
View Article and Find Full Text PDFThe use of absorbable polymeric biomaterials is increasing in the field of tissue engineering. These polymeric scaffolds provide mechanical strength and shape as the engineered tissue forms. Histological analysis is an important part of the development of an appropriate polymeric construct, because it allows the analysis of the cell/material interaction.
View Article and Find Full Text PDFAbsorbable biomaterials have been recently incorporated into the field of tissue engineering. Little work has been performed, even with the clinically acceptable absorbables, concerning their tissue promoting capability or lack, thereof. Furthermore, the relative attractions of cells to these implants may be largely disguised by the presence of serum.
View Article and Find Full Text PDFHighly porous matrices of poly-L-lactide (PL) and polyglycolide (PG), 24, 50, or 95 mg/cc in the form of 10 x 10 x 3 mm wafers, were implanted subcutaneously (two per rat) in the flanks of 8-12-week-old female Lewis rats (n = 120). Matrices were harvested, two rats per week, for 15 weeks and examined histologically. At weeks 1 and 2, a thin fibrous capsule was present and matrices showed capillary beds and host-cell infiltration along the implant margins.
View Article and Find Full Text PDFObjective: The purpose of this study was to determine the sensitivity, specificity, and clinical utility of 18F 2-fluoro-2-deoxy-D-glucose (FDG) total-body positron emission tomography (PET) scanning for the detection of metastases in patients with malignant melanoma.
Summary Background Data: Recent preliminary reports suggest that PET using FDG may be more sensitive and specific for detection of metastatic melanoma than standard radiologic imaging studies using computed tomography (CT). PET technology is showing utility in the detection of metastatic tumors from multiple primary sites including breast, lung, lymphoma, and melanoma.
There are many clinical situations in which a large tissue mass is required to replace tissue lost to surgical resection (e.g., mastectomy).
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