Elution of amikacin and vancomycin from a calcium sulfate/chitosan bone scaffold

Doty, Heather A.,Courtney, Harry S.,Jennings, Jessica A.,Haggard, Warren O.,Bumgardner, Joel D. Techno-Press 2015 Biomaterials and Biomechanics in Bioengineering Vol.2 No.3

Treatment of polymicrobial infected musculoskeletal defects continues to be a challenge in orthopaedics. This research investigated single and dual-delivery of two antibiotics, vancomycin and amikacin, targeting different classes of microorganism from a biodegradable calcium sulfate-chitosan-nHA microsphere composite scaffold. The addition of chitosan-nHA was included to provide additional structure for cellular attachment and as a secondary drug-loading device. All scaffolds exhibited an initial burst of antibiotics, but groups containing chitosan reduced the burst for amikacin at 1hr by 50%, and vancomycin by 14-25% over the first 2 days. Extended elution was present in groups containing chitosan; amikacin was above MIC ($2-4{\mu}g/mL$, Pseudomonas aeruginosa) for 7-42 days and vancomycin was above MIC ($0.5-1{\mu}g/mL$ Staphylococcus aureus) for 42 days. The antibiotic activity of the eluates was tested against S. aureus and P. aeruginosa. The elution from the dual-loaded scaffold was most effective against S. aureus (bacteriostatic 34 days and bactericidal 27 days), compared to vancomycin-loaded scaffolds (bacteriostatic and bactericidal 14 days). The dual- and amikacin-loaded scaffolds were effective against P. aeruginosa, but eluates exhibited very short antibacterial properties; only 24 hours bacteriostatic and 1-5 hours bactericidal activity. For all groups, vancomycin recovery was near 100% whereas the amikacin recovery was 41%. In conclusion, in the presence of chitosan-nHA microspheres, the dual-antibiotic loaded scaffold was able to sustain an extended vancomycin elution longer than individually loaded scaffolds. The composite scaffold shows promise as a dual-drug delivery system for infected orthopaedic wounds and overcomes some deficits of other dual-delivery systems by extending the antibiotic release.

충치예방에 공헌하는 감미료

Doty Theodore E. 한국식품산업협회 1978 좋은식품 Vol.44 No.-

Elution of amikacin and vancomycin from a calcium sulfate/chitosan bone scaffold

Doty, Heather A.,Courtney, Harry S.,Jennings, Jessica A.,Haggard, Warren O.,Bumgardner, Joel D. Techno-Press 2015 Biomaterials and biomedical engineering Vol.2 No.3

Treatment of polymicrobial infected musculoskeletal defects continues to be a challenge in orthopaedics. This research investigated single and dual-delivery of two antibiotics, vancomycin and amikacin, targeting different classes of microorganism from a biodegradable calcium sulfate-chitosan-nHA microsphere composite scaffold. The addition of chitosan-nHA was included to provide additional structure for cellular attachment and as a secondary drug-loading device. All scaffolds exhibited an initial burst of antibiotics, but groups containing chitosan reduced the burst for amikacin at 1hr by 50%, and vancomycin by 14-25% over the first 2 days. Extended elution was present in groups containing chitosan; amikacin was above MIC ($2-4{\mu}g/mL$, Pseudomonas aeruginosa) for 7-42 days and vancomycin was above MIC ($0.5-1{\mu}g/mL$ Staphylococcus aureus) for 42 days. The antibiotic activity of the eluates was tested against S. aureus and P. aeruginosa. The elution from the dual-loaded scaffold was most effective against S. aureus (bacteriostatic 34 days and bactericidal 27 days), compared to vancomycin-loaded scaffolds (bacteriostatic and bactericidal 14 days). The dual- and amikacin-loaded scaffolds were effective against P. aeruginosa, but eluates exhibited very short antibacterial properties; only 24 hours bacteriostatic and 1-5 hours bactericidal activity. For all groups, vancomycin recovery was near 100% whereas the amikacin recovery was 41%. In conclusion, in the presence of chitosan-nHA microspheres, the dual-antibiotic loaded scaffold was able to sustain an extended vancomycin elution longer than individually loaded scaffolds. The composite scaffold shows promise as a dual-drug delivery system for infected orthopaedic wounds and overcomes some deficits of other dual-delivery systems by extending the antibiotic release.

Black walnut, Osage orange and eastern redcedar sawmill waste as natural dyes: effect of aluminum mordant on color parameters

Kelsie Doty,Sherry Haar,Jooyoun Kim 한국의류학회 2016 Fashion and Textiles Vol.3 No.1

The triple bottom line can be impacted in both positive and negative ways by the use of tree sawmill waste as a natural dye. Trees contain a biomordant in the form of tannin which may eliminate the need for metallic mordants, thus reducing water, thermal energy, residual waste, and exposure to a mordant chemical. Dyeing with mill waste provides an economic option for an existing timber manufacturing byproduct. This research analyzed the impact of potassium aluminum sulfate (PAS) on dye concentration, hue, and colorfastness to light and laundering for three regional dyewoods (black walnut, Osage orange, and eastern redcedar) on wool yarn. Dye concentrations were pre-tested to find a standard depth of shade between mordanted and nonmordanted yarns. Tests for colorfastness to light and laundering were performed according to AATCC methods. Resulting colors for exposed and unexposed specimens were rated using CIE L*a*b* values and descriptive statistics were used to examine directional relationship within independent variables mordant and exposure (light and laundering). Two-sample t test was performed to investigate the effect of a PAS mordant versus no mordant on overall color difference between specimens exposed to light and laundering. Findings indicated that dye absorption was improved with the use of a PAS mordant. For yarns premordanted with PAS the dyewood colors became warmer. A PAS mordant slightly improved colorfastness to light for black walnut and eastern redcedar, but did not influence Osage orange which had a color change from bright yellow to warm brown after exposure to light. Colorfastness to laundering improved only for Osage orange with a PAS mordant.

유아 시각 예술 교육과정 : 발달과 문화를 표현하기 위한 자유로운 공간인 마음의 팔렛트

Lois McFadyen Christensen & Lynn Doty Kirklnd,이정숙 역 대한어린이교육협회 2010 어린이교육 Vol.- No.12

지금 유아교육 현장은 아이들이 입을 손해는 생각하지 않고 읽기, 쓰기, 셈하기 그리고 평가에 크게 집중되어 있다. 정책 입안자들은 유아기 아이들이 의례적으로 형식적인 교육 을 받게 준비했고, 종종 운영자들과 교사들도 그런 방향으로 지도했다. 교사들은 낮은 단계 에서 암기를 강조하고 복습하는 인지 기능에 집중한 어린이들의 교육을 가속화하기 위해 비전문화가 되었다(Aldridge & Goldman, 2006: Katz, 1993; Kohn, 2001; Ohanian, 1999). 이 렇게 오로지 학업적인 성과를 보기 위해서 어린 아이들에게 압박을 가하는 것은 아이들에 게 자연스럽게 나타나는 창의성에 필수적인 경험과 중요한 언어적 반영을 억제 하게 된다. 이런 압박은 하나에 모든 것을 맞추는 형식의 교육과정을 만들게 된다(Association for Childhood Education International[ACEI], 2001; Novinger & O'Brien, 2003).

High - Temperature Materials : PROCESSING OF INTERMETALLIC MATRIX COMPISITES BY REACTIVE HOT COMPACTION AND " In - Situ " REINFORCEMENT COATING

Y . S . Kim,H . Doty,L . Shaw,R . Abbaschian 대한금속재료학회 ( 구 대한금속학회 ) 1995 Advanced Material and Processing Vol.3 No.-

Functional Gradient Materials : REACTIVE HOT COMPACTION OF FUNCTIONALLY GRADED COMPOSITES

A . Gomez,H . F . Wang,H . Doty,R . Abbaschian 대한금속재료학회 ( 구 대한금속학회 ) 1995 Advanced Material and Processing Vol.2 No.-

Investigation of White Matter and Grey Matter Alterations in the Monkey Brain Following Ischemic Stroke Using Diffusion Tensor Imaging

Chun-Xia Li,Yuguang Meng,Yumei Yan,Doty Kempf,Leonard Howell,Frank Tong,Xiaodong Zhang 대한자기공명의과학회 2022 Investigative Magnetic Resonance Imaging Vol.26 No.4

Purpose: Investigation of stroke lesions mostly focuses on the grey matter (GM). White matter (WM) degeneration during acute stroke has remained understudied. In the present study, monkeys were employed to investigate the alterations in GM and WM in the brain following ischemic occlusion using diffusion tensor imaging (DTI). Materials and Methods: Permanent middle cerebral artery occlusion was induced in rhesus monkeys (n = 6) using an interventional approach. Serial DTI was conducted on a clinical 3 T in the hyperacute phase (2–6 hours), 48, and 96 hours post-occlusion. Regions of interest in GM and WM of lesion areas were selected for data analysis. Results: Mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) in WM decreased substantially during hyperacute stroke, similar to those seen in GM. No obvious fractional anisotropy changes were seen in WM during the hyperacute phase until 48 hours poststroke when significant fiber loss was observed. Pseudo-normalization of MD, AD, and RD was seen at 96 hours. Pathological changes in WM and GM were observed in ischemic areas at 8, 48, and 96 hours poststroke. Relative changes in MD, AD, and RD of WM were correlated negatively with infarction volumes at 6 hours poststroke. Conclusion: The present study revealed the microstructural changes in GM and WM of monkey brains during acute stroke using DTI. The preliminary results suggest that AD and RD may be sensitive surrogate markers to assess specific microstructural changes in WM during the hyperacute stroke.

포플러와 버드나무에서 분리한 내생균의 잠재적 역할에 관한 연구

강준원 ( Jun Won Kang ),( Zareen Khan ),( Jenny Knoth ),( David Roman ),( Sharon Doty ) 한국임학회 2014 산림과학 공동학술대회 논문집 Vol.2014 No.-

식물체의 뿌리 주변이나 내부 조직에는 다양한 미생물들이 식물체와 상호작용을 하며 살고 있다. 내생균 (Endophyte)은 숙주식물의 내부 조직에 서식하며 병원성을 나타내지 않는 세균, 곰팡이를 의미한다. 이러한 내생균은 오염된 토양과 지하수를 정화할 수 있는 식물체의 정화능을 향상 시켜줄 뿐만 아니라, 질소고정, 식물 성장호르몬 분비, 환경 스트레스에 대한 식물의 저항성을 증가시키면서, 숙주식물을 보호하는 역할을 한다. 본 연구에서는 포플러와 버드나무 조직 내에 공생하는 다양한 내생균의 잠재적 기능에 대하여 알아보았으며. 이러한 내생균의 활용은 형질전환체 개발의 대안이 될 수 있을 것으로 기대된다. Most plants associate with various microbes that live around the plant`s root or intercellular space of the plant. The term endophyte refers to microorganisms, bacteria, or fungi, which live within plant tissues without causing any disease. Natural endophytes have a capacity for assisting the phytoremediation of contaminated soil and groundwater in addition to providing other benefits to the plants. We isolated a variety of microbial endosymbionts from poplar and willow trees with properties including plant growth promotion, pollutant degradation, and nitrogen fixation. With the range of beneficial traits provided, these natural endophytes provide an alternative to plant or microbial genetic engineering.

시멘트를 사용한 Failed Total Hip Replacements에서의 금속 파편(Metallic Debris) 및 롤리에틸렌 파련(Polyethylene Debris)의 크기에 관한 연구

이중명,Eduardo a. Salvati,Foster Betts,Edward F. DiCarlo,Stephen B. Doty,Peter G. Bullough (Joong Myung Lee) 대한고관절학회 1991 Hip and Pelvis Vol.3 No.2

Reports of different failure rates with total hip replacements depending on the metal from which the parts were manufactured have prompted us to measure the size of metallic and polyethylene particulate debris present in the periarticular tissues around failed cemented total hip prostheses. Two methods of specimen preparation were used: An isolations method, in which the tissue was remove leaving the metallic debris and a non-isolation method consisting of routine histologic preparation for light microscopy. For each methods, we used the femoral components from ten cases each of titanium alloy, cobalt-chrome alloy, stainless steel. Particles were measured on a computer-assisted image analyzer. In all cases the mean size of metallic particulate debris with the isolation method was 0.8-1.0microns in short dimension and 1.5-1.8microns in long dimension. From the nonisolation method, the mean size was significantly smaller at 0.3-0.4 microns in short dimension and 0.6-0.7 microns in long dimension. Howerver, when the same technique was used, the sizes of metallic particulate debris did not differ. The mean size of polyethylene debris was 2-4microns in short dimerision, 8-3microns in long dimension, and was larger in tissues retrieved from titanium alloy failures than in tissues from cobaltchrome and stainless steel implants. This study suggests that factors other than the size of metallic debris (e.g. constituents of the alloy, amount, and celerity of generation of ddbris) may be more important for the failure of total hip replacement.