18 results on '"Foo CW"'
Search Results
2. Comparing the first-attempt tracheal intubation success of the hyperangulated McGrath® X-blade vs the Macintosh-type CMAC videolaryngoscope in patients with cervical immobilization: a two-centre randomized controlled trial.
- Author
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Zhang J, Tan LZ, Toh H, Foo CW, Wijeratne S, Hu H, and Seet E
- Subjects
- Adult, Aged, Aged, 80 and over, Australia, Glottis, Humans, Intubation, Intratracheal, Middle Aged, Video Recording, Young Adult, Laryngoscopes, Laryngoscopy
- Abstract
We compared the hyperangulated McGrath X-blade with the Macintosh-type CMAC videolaryngoscope through the use of manual in-line stabilization on patients. The primary hypothesis was that the McGrath X-blade has a similar first-attempt success rate as the CMAC videolaryngoscope. 210 patients of ASA physical status I to III, aged 21 to 80 years old, undergoing general anesthesia requiring tracheal intubation were prospectively recruited into this two-centre randomized controlled trial, from June 2016 to April 2019. Patients with history of or predicted difficult airway, pre-existing dental risks, BMI > 35 kg/m
2 , cervical spondylosis or myelopathy, aspiration risks, patients who declined to participate or lacked the mental capacity to give consent were excluded. Participants were intubated using either hyperangulated McGrath X-blade (MGX) or Macintosh-type CMAC (CM) videolaryngoscopy, with manual in-line stabilization. Primary outcome measured was first-attempt tracheal intubation success. Secondary outcomes included overall successful intubation within 2 attempts or 120 s, time to intubation, glottic view obtained and intubation-related complications. First-attempt success rates were 71.4% in the MGX group vs. 79.0% in the CM group (p = 0.26), with an absolute difference of -7.6% (95%CI -20%, 5.0%, p value = 0.26), but this trial was underpowered to detect a difference. Overall success was 91.4% (MGX) vs. 92.4% (CM) (p > 0.99). The Cormack & Lehane laryngeal grade was superior in the MGX group compared to CM group (Grade I: MGX 44%, CM 23%; Grade II: MGX 53%, CM 45%; Grade III: MGX 3%, CM 32%; p < 0.001). The median time to intubation using the MGX was longer than the CM [MGX 55.5 s (42.1-78.3), CM 43.8 s (38-55.3); p < 0.001]. Our study did not demonstrate a significant difference in efficacy between the McGrath X-blade and the CMAC videolaryngoscope. In patients with manual in-line stabilization, no anticipated airway difficulty and in the hands of experienced operators, the McGrath X-blade provided superior glottic views but conferred no advantage over the C-MAC, with a longer median time to intubation compared to the CMAC videolaryngoscope.Trial registration: Australian New Zealand Clinical Trial Registry (ACTRN12616000668404)., (© 2021. The Author(s), under exclusive licence to Springer Nature B.V.)- Published
- 2022
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3. Intraoperative Celiac Plexus Block With Preperitoneal Infusion Reduces Opioid Usage in Major Hepato-pancreato-biliary Surgery: A Pilot Study.
- Author
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Teo ZHT, Tey BLJ, Foo CW, Wong WY, and Low JK
- Subjects
- Adult, Aged, Early Ambulation, Female, Humans, Infusions, Parenteral, Male, Middle Aged, Pain Measurement, Pain, Postoperative drug therapy, Pilot Projects, Retrospective Studies, Treatment Outcome, Analgesics, Opioid therapeutic use, Celiac Plexus, Hepatectomy, Intraoperative Care methods, Nerve Block methods, Pain, Postoperative prevention & control, Pancreaticoduodenectomy
- Abstract
Objective: Given the role of celiac plexus block (CPB) in the management of chronic pain, we sought to investigate the utility of CPB in the control of postoperative pain in major hepato-pancreato-biliary surgeries., Summary Background Data: CPB has been in practice for decades for the management of upper abdominal visceral pain, especially in cancer patients. Typically, in this group of patients with chronic pain, a neurolytic agent is injected to cause irreversible neural damage to achieve pain control. We apply this concept to postoperative pain control by injecting bupivacaine to the celiac plexus instead of a neurolytic agent. We aim to investigate if this novel technique decreases postoperative opioid usage, offers better pain relief and leads to earlier ambulation., Methods: A retrospective, single institution study comparing consecutive patients who received intraoperative CPB and preperitoneal infusion with patients who received only preperitoneal infusion in open hepato-pancreato-biliary surgery between the years 2016 and 2019 by a single surgeon. Patients with incomplete data on patient-controlled analgesia usage and postoperative ambulation information were excluded., Results: Patients with CPB used 31% less morphine on postoperative day 1 compared to patient without CPB and 42% less morphine on postoperative day 2. Overall average morphine usage was significantly lower in patients with CPB. Duration of patient-controlled analgesia was shorter for patient with CPB compared with patient without CPB. The dynamic visual analogue score was marginally better in patients with CPB. Time to ambulation was similar in both groups., Conclusions: CPB can be considered as part of a multimodal approach for postoperative pain management in open hepato-pancreato-biliary surgeries., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)
- Published
- 2021
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4. Reply from the authors. Schneider regimen vs a volatile inhalation anaesthetic (desflurane) for laparoscopic adrenalectomy and additional considerations for delivery of anaesthesia.
- Author
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Kumar CM, Foo CW, and Chen XY
- Subjects
- Female, Humans, Adrenalectomy, Anesthesia methods, Laparoscopy, Multiple Endocrine Neoplasia Type 2a surgery, Neck Dissection, Thyroid Neoplasms surgery, Thyroidectomy
- Published
- 2016
- Full Text
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5. Immunobullous disease and ulcerative colitis: a case series of six patients.
- Author
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Sotiriou MC, Foo CW, Scholes CT, and Zone JJ
- Subjects
- Adult, Aged, Colitis, Ulcerative immunology, Female, Humans, Immunoglobulin A immunology, Male, Middle Aged, Skin Diseases, Vesiculobullous immunology, Colitis, Ulcerative complications, Skin Diseases, Vesiculobullous complications
- Abstract
Cases of immunobullous skin disease associated with ulcerative colitis (UC) have been previously reported in the literature. There is no clear explanation for this association. In this series, we report six cases of immunobullous disease in patients with UC and discuss potential mechanisms of pathogenesis proposed to explain these concomitant diseases. The clinical presentation, immunopathology and treatment of six new cases are described and analysed. We report six patients, two with linear IgA bullous dermatosis (LABD), one with bullous pemphigoid (BP), one with mucous membrane pemphigoid (MMP) and two with IgA pemphigus. The patients' ages ranged from 33 to 66 years at the onset of their skin disease, and all but one case had a documented age of UC onset, confirmed with colonoscopy, prior to the development of skin disease. Direct immunofluorescence results in these patients demonstrated IgA basement membrane zone (BMZ) antibodies in the LABD cases, IgG antibodies at the BMZ in the BP and MMP cases, and IgA cell surface antibodies in the patients with IgA pemphigus. Additionally, indirect immunofluorescence was positive in one of the patients with LABD, the patient with BP and both of the patients with IgA pemphigus. The temporal association of UC and skin disease, in addition to the resolution of skin disease with total colectomy in one case, suggests colonic mucosal antigenic stimulation driving immune activation and leading to immunobullous skin disease., (© 2015 British Association of Dermatologists.)
- Published
- 2015
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6. Manganese-Enhanced Magnetic Resonance Imaging Enables In Vivo Confirmation of Peri-Infarct Restoration Following Stem Cell Therapy in a Porcine Ischemia-Reperfusion Model.
- Author
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Dash R, Kim PJ, Matsuura Y, Ikeno F, Metzler S, Huang NF, Lyons JK, Nguyen PK, Ge X, Foo CW, McConnell MV, Wu JC, Yeung AC, Harnish P, and Yang PC
- Subjects
- Animals, Cell Survival physiology, Disease Models, Animal, Gadolinium, Humans, Immunohistochemistry, Manganese, Mice, Myocardium pathology, Positron-Emission Tomography, Stem Cells physiology, Swine, Tissue Survival, Tomography, X-Ray Computed, Ventricular Function, Left physiology, Ventricular Remodeling physiology, Magnetic Resonance Imaging methods, Mesenchymal Stem Cell Transplantation, Reperfusion Injury therapy
- Abstract
Background: The exact mechanism of stem cell therapy in augmenting the function of ischemic cardiomyopathy is unclear. In this study, we hypothesized that increased viability of the peri-infarct region (PIR) produces restorative benefits after stem cell engraftment. A novel multimodality imaging approach simultaneously assessed myocardial viability (manganese-enhanced magnetic resonance imaging [MEMRI]), myocardial scar (delayed gadolinium enhancement MRI), and transplanted stem cell engraftment (positron emission tomography reporter gene) in the injured porcine hearts., Methods and Results: Twelve adult swine underwent ischemia-reperfusion injury. Digital subtraction of MEMRI-negative myocardium (intrainfarct region) from delayed gadolinium enhancement MRI-positive myocardium (PIR and intrainfarct region) clearly delineated the PIR in which the MEMRI-positive signal reflected PIR viability. Human amniotic mesenchymal stem cells (hAMSCs) represent a unique population of immunomodulatory mesodermal stem cells that restored the murine PIR. Immediately following hAMSC delivery, MEMRI demonstrated an increased PIR viability signal compared with control. Direct PIR viability remained higher in hAMSC-treated hearts for >6 weeks. Increased PIR viability correlated with improved regional contractility, left ventricular ejection fraction, infarct size, and hAMSC engraftment, as confirmed by immunocytochemistry. Increased MEMRI and positron emission tomography reporter gene signal in the intrainfarct region and the PIR correlated with sustained functional augmentation (global and regional) within the hAMSC group (mean change, left ventricular ejection fraction: hAMSC 85±60%, control 8±10%; P<0.05) and reduced chamber dilatation (left ventricular end-diastole volume increase: hAMSC 24±8%, control 110±30%; P<0.05)., Conclusions: The positron emission tomography reporter gene signal of hAMSC engraftment correlates with the improved MEMRI signal in the PIR. The increased MEMRI signal represents PIR viability and the restorative potential of the injured heart. This in vivo multimodality imaging platform represents a novel, real-time method of tracking PIR viability and stem cell engraftment while providing a mechanistic explanation of the therapeutic efficacy of cardiovascular stem cells., (© 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)
- Published
- 2015
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7. Anaesthetic management for laparoscopic bilateral adrenalectomy in MEN2A (Multiple endocrine neoplasia) followed by subsequent total thyroidectomy and radical neck dissection.
- Author
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Foo CW, Chen XY, and Kumar CM
- Subjects
- Adult, Female, Humans, Adrenalectomy, Anesthesia methods, Laparoscopy, Multiple Endocrine Neoplasia Type 2a surgery, Neck Dissection, Thyroid Neoplasms surgery, Thyroidectomy
- Published
- 2015
- Full Text
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8. Transendocardial mesenchymal stem cells and mononuclear bone marrow cells for ischemic cardiomyopathy: the TAC-HFT randomized trial.
- Author
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Heldman AW, DiFede DL, Fishman JE, Zambrano JP, Trachtenberg BH, Karantalis V, Mushtaq M, Williams AR, Suncion VY, McNiece IK, Ghersin E, Soto V, Lopera G, Miki R, Willens H, Hendel R, Mitrani R, Pattany P, Feigenbaum G, Oskouei B, Byrnes J, Lowery MH, Sierra J, Pujol MV, Delgado C, Gonzalez PJ, Rodriguez JE, Bagno LL, Rouy D, Altman P, Foo CW, da Silva J, Anderson E, Schwarz R, Mendizabal A, and Hare JM
- Subjects
- Aged, Bone Marrow Transplantation adverse effects, Cardiomyopathies, Disease Progression, Double-Blind Method, Female, Hospitalization, Humans, Male, Mesenchymal Stem Cell Transplantation adverse effects, Middle Aged, Myocardial Infarction, Stroke, Survival Analysis, Transplantation, Autologous, Treatment Outcome, Ventricular Dysfunction, Left therapy, Bone Marrow Transplantation methods, Mesenchymal Stem Cell Transplantation methods, Myocardial Ischemia therapy
- Abstract
Importance: Whether culture-expanded mesenchymal stem cells or whole bone marrow mononuclear cells are safe and effective in chronic ischemic cardiomyopathy is controversial., Objective: To demonstrate the safety of transendocardial stem cell injection with autologous mesenchymal stem cells (MSCs) and bone marrow mononuclear cells (BMCs) in patients with ischemic cardiomyopathy., Design, Setting, and Patients: A phase 1 and 2 randomized, blinded, placebo-controlled study involving 65 patients with ischemic cardiomyopathy and left ventricular (LV) ejection fraction less than 50% (September 1, 2009-July 12, 2013). The study compared injection of MSCs (n=19) with placebo (n = 11) and BMCs (n = 19) with placebo (n = 10), with 1 year of follow-up., Interventions: Injections in 10 LV sites with an infusion catheter., Main Outcomes and Measures: Treatment-emergent 30-day serious adverse event rate defined as a composite of death, myocardial infarction, stroke, hospitalization for worsening heart failure, perforation, tamponade, or sustained ventricular arrhythmias., Results: No patient had a treatment-emergent serious adverse events at day 30. The 1-year incidence of serious adverse events was 31.6% (95% CI, 12.6% to 56.6%) for MSCs, 31.6% (95% CI, 12.6%-56.6%) for BMCs, and 38.1% (95% CI, 18.1%-61.6%) for placebo. Over 1 year, the Minnesota Living With Heart Failure score improved with MSCs (-6.3; 95% CI, -15.0 to 2.4; repeated measures of variance, P=.02) and with BMCs (-8.2; 95% CI, -17.4 to 0.97; P=.005) but not with placebo (0.4; 95% CI, -9.45 to 10.25; P=.38). The 6-minute walk distance increased with MSCs only (repeated measures model, P = .03). Infarct size as a percentage of LV mass was reduced by MSCs (-18.9%; 95% CI, -30.4 to -7.4; within-group, P = .004) but not by BMCs (-7.0%; 95% CI, -15.7% to 1.7%; within-group, P = .11) or placebo (-5.2%; 95% CI, -16.8% to 6.5%; within-group, P = .36). Regional myocardial function as peak Eulerian circumferential strain at the site of injection improved with MSCs (-4.9; 95% CI, -13.3 to 3.5; within-group repeated measures, P = .03) but not BMCs (-2.1; 95% CI, -5.5 to 1.3; P = .21) or placebo (-0.03; 95% CI, -1.9 to 1.9; P = .14). Left ventricular chamber volume and ejection fraction did not change., Conclusions and Relevance: Transendocardial stem cell injection with MSCs or BMCs appeared to be safe for patients with chronic ischemic cardiomyopathy and LV dysfunction. Although the sample size and multiple comparisons preclude a definitive statement about safety and clinical effect, these results provide the basis for larger studies to provide definitive evidence about safety and to assess efficacy of this new therapeutic approach., Trial Registration: clinicaltrials.gov Identifier: NCT00768066.
- Published
- 2014
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9. A variant of AESOP syndrome (adenopathy and extensive skin patch overlying a plasmacytoma)--reply.
- Author
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Foo CW, Florell SR, and Petersen MJ
- Subjects
- Humans, Mucins metabolism, Plasmacytoma pathology, Skin pathology
- Published
- 2013
- Full Text
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10. Polarizable elements in scabies infestation: a clue to diagnosis.
- Author
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Foo CW, Florell SR, and Bowen AR
- Subjects
- Animals, Birefringence, Feces, Female, Hair Follicle parasitology, Hair Follicle pathology, Humans, Male, Mites growth & development, Mites ultrastructure, Retrospective Studies, Dermoscopy methods, Microscopy, Polarization methods, Pruritus parasitology, Pruritus pathology, Scabies diagnosis
- Abstract
The diagnosis of scabies infestation is straightforward in cases where mite parts are largely visible; however, mites are often not captured in a specimen's planes of section. Polariscopic examination is a fast and simple adjunctive diagnostic tool to light microscopy. We describe the unique polariscopic findings in scabies infestation. Two cases of crusted scabies and eight cases of typical scabies were subjected to polariscopic examination. Diagnostic mite parts were visualized in at least one section in all cases. Attached and detached spines as well as scybala (fecal material) are polarizable. Specifically, spines show a polarizable outer sheath with dark central core while scybala show peripherally concentrated, stippled birefringence. Similar stippled birefringence is visible within the gut of some mites whereas significant birefringence is not appreciated in other mite parts. These results suggest that polariscopic examination is a helpful clue in the diagnosis of scabies infestation, especially in cases where the body of the mite is not visualized., (Copyright © 2012 John Wiley & Sons A/S.)
- Published
- 2013
- Full Text
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11. A variant of AESOP syndrome (adenopathy and extensive skin patch overlying a plasmacytoma) in a malignant blue-cell tumor.
- Author
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Foo CW, Florell SR, and Petersen MJ
- Subjects
- Antineoplastic Combined Chemotherapy Protocols therapeutic use, Chemoradiotherapy, Erythema complications, Humans, Hyperplasia complications, Hyperplasia pathology, Magnetic Resonance Imaging, Male, Middle Aged, Sarcoma, Small Cell secondary, Sarcoma, Small Cell therapy, Soft Tissue Neoplasms therapy, Erythema pathology, Lymph Nodes pathology, Sarcoma, Small Cell complications, Soft Tissue Neoplasms complications, Soft Tissue Neoplasms pathology
- Published
- 2012
- Full Text
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12. Topical modalities for treatment and prevention of postsurgical hypertrophic scars.
- Author
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Foo CW and Tristani-Firouzi P
- Subjects
- Adjuvants, Immunologic therapeutic use, Administration, Cutaneous, Aminoquinolines therapeutic use, Cicatrix, Hypertrophic prevention & control, Compression Bandages, Dermatologic Agents therapeutic use, Humans, Imiquimod, Massage, Onions, Phytotherapy, Plant Extracts therapeutic use, Postoperative Complications prevention & control, Silicone Gels therapeutic use, Vitamin E therapeutic use, Vitamins therapeutic use, Cicatrix, Hypertrophic therapy, Postoperative Complications therapy
- Abstract
There is no universally accepted treatment regimen and no evidence-based literature to guide management of hypertrophic scars. This article summarizes the existing literature regarding topical treatments such as silicone gel sheeting and ointment, onion extract, vitamin E, pressure garment therapy, massage therapy, and topical imiquimod 5% cream in the management of hypertrophic scars., (2011 Elsevier Inc. All rights reserved.)
- Published
- 2011
- Full Text
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13. Multiple primary melanoma: the impact of atypical naevi and follow up.
- Author
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de Giorgi V, Rossari S, Papi F, Gori A, Alfaioli B, Grazzini M, Crocetti E, Verdelli A, Foo CW, and Lotti T
- Subjects
- Adult, Age Factors, Aged, Aged, 80 and over, Female, Humans, Italy epidemiology, Long-Term Care methods, Male, Middle Aged, Odds Ratio, Patient Compliance, Retrospective Studies, Risk Factors, Sex Factors, Young Adult, Melanoma pathology, Neoplasms, Multiple Primary pathology, Nevus pathology, Skin Neoplasms pathology
- Abstract
Background: Patients with melanoma are especially encouraged to have regular follow- up visits with their dermatologist and to perform total-body skin examination on a routine basis to identify new pigmented lesions or detect significant changes in existing naevi., Objectives: To identify main risk factors (sex, age, number of common and atypical naevi, family history, phototype) associated with multiple primary melanomas (MPM) and to investigate the association between regular follow up and tumour thickness of a second primary melanoma., Methods: We performed a retrospective analysis of patients with MPM in order to evaluate risk factors for developing a second primary melanoma. Medical records of patients with melanoma who developed a second primary melanoma were selected from a database of all patients with histopathologically confirmed melanoma treated at the dermatology clinic of the University of Florence, Italy, from 2000 to 2004. Medical data culled from the patient records were as follows: medical history, number of typical naevi, presence of atypical naevi, Breslow thickness, Clark level and histotype of the melanomas, site of the melanomas and patient adherence to 6-month follow-up examinations., Results: The presence of atypical naevi was associated with a higher risk of developing MPM (adjusted odds ratio 3·28, 95% confidence interval 1·35–7·44). Moreover, in the subjects who did not attend follow up, we noted that the thickness of the second melanoma was significantly higher, with a mean thickness of 1·22 mm, in comparison with patients with a careful adherence to follow up in whom the mean thickness was 0·36 mm (P = 0·0189)., Conclusions: For the first time, the validity of this clinical approach has been supported by real comparison of thickness levels of second melanoma in patients with or without periodical follow up. Results obtained from this analysis show that follow up is an effective method for early detection of melanoma.
- Published
- 2010
- Full Text
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14. Biomaterial design strategies for the treatment of spinal cord injuries.
- Author
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Straley KS, Foo CW, and Heilshorn SC
- Subjects
- Animals, Cell- and Tissue-Based Therapy methods, Cell- and Tissue-Based Therapy trends, Drug Delivery Systems methods, Drug Delivery Systems trends, Growth Cones drug effects, Growth Cones metabolism, Humans, Nerve Regeneration physiology, Tissue Transplantation methods, Tissue Transplantation trends, Biocompatible Materials therapeutic use, Drug Design, Nerve Regeneration drug effects, Spinal Cord Injuries physiopathology, Tissue Scaffolds trends
- Abstract
The highly debilitating nature of spinal cord injuries has provided much inspiration for the design of novel biomaterials that can stimulate cellular regeneration and functional recovery. Many experts agree that the greatest hope for treatment of spinal cord injuries will involve a combinatorial approach that integrates biomaterial scaffolds, cell transplantation, and molecule delivery. This manuscript presents a comprehensive review of biomaterial-scaffold design strategies currently being applied to the development of nerve guidance channels and hydrogels that more effectively stimulate spinal cord tissue regeneration. To enhance the regenerative capacity of these two scaffold types, researchers are focusing on optimizing the mechanical properties, cell-adhesivity, biodegradability, electrical activity, and topography of synthetic and natural materials, and are developing mechanisms to use these scaffolds to deliver cells and biomolecules. Developing scaffolds that address several of these key design parameters will lead to more successful therapies for the regeneration of spinal cord tissue.
- Published
- 2010
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15. Iatrogenic osteoporosis in dermatology.
- Author
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Foo CW, Yukumoto E, DeJournett R, and Johnson DW
- Subjects
- Dermatology, Glucocorticoids therapeutic use, Humans, Iatrogenic Disease, Osteoporosis diagnosis, Osteoporosis drug therapy, Practice Guidelines as Topic, Skin Diseases drug therapy, Glucocorticoids adverse effects, Osteoporosis chemically induced
- Published
- 2009
- Full Text
- View/download PDF
16. Non-invasive characterization of structure and morphology of silk fibroin biomaterials using non-linear microscopy.
- Author
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Rice WL, Firdous S, Gupta S, Hunter M, Foo CW, Wang Y, Kim HJ, Kaplan DL, and Georgakoudi I
- Subjects
- Animals, Microscopy, Fluorescence, Nonlinear Dynamics, Photons, Protein Structure, Secondary, Spectroscopy, Fourier Transform Infrared, Spectrum Analysis, Raman, Biocompatible Materials chemistry, Bombyx chemistry, Fibroins chemistry
- Abstract
Designing biomaterial scaffolds remains a major challenge in tissue engineering. Key to this challenge is improved understanding of the relationships between the scaffold properties and its degradation kinetics, as well as the cell interactions and the promotion of new matrix deposition. Here we present the use of non-linear spectroscopic imaging as a non-invasive method to characterize not only morphological, but also structural aspects of silkworm silk fibroin-based biomaterials, relying entirely on endogenous optical contrast. We demonstrate that two photon excited fluorescence and second harmonic generation are sensitive to the hydration, overall beta sheet content and molecular orientation of the sample. Thus, the functional content and high resolution afforded by these non-invasive approaches offer promise for identifying important connections between biomaterial design and functional engineered tissue development. The strategies described also have broader implications for understanding and tracking the remodeling of degradable biomaterials under dynamic conditions both in vitro and in vivo.
- Published
- 2008
- Full Text
- View/download PDF
17. RGD-functionalized bioengineered spider dragline silk biomaterial.
- Author
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Bini E, Foo CW, Huang J, Karageorgiou V, Kitchel B, and Kaplan DL
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Cells, Cultured, Circular Dichroism, Cloning, Molecular, DNA Primers, Insect Proteins genetics, Molecular Sequence Data, Recombinant Proteins chemistry, Recombinant Proteins genetics, Spectroscopy, Fourier Transform Infrared, Spiders, Insect Proteins chemistry, Oligopeptides chemistry, Protein Engineering, Silk chemistry
- Abstract
Spider silk fibers have remarkable mechanical properties that suggest the component proteins could be useful biopolymers for fabricating biomaterial scaffolds for tissue formation. Two bioengineered protein variants from the consensus sequence of the major component of dragline silk from Nephila clavipes were cloned and expressed to include RGD cell-binding domains. The engineered silks were characterized by CD and FTIR and showed structural transitions from random coil to insoluble beta-sheet upon treatment with methanol. The recombinant proteins were processed into films and fibers and successfully used as biomaterial matrixes to culture human bone marrow stromal cells induced to differentiate into bone-like tissue upon addition of osteogenic stimulants. The recombinant spider silk and the recombinant spider silk with RGD encoded into the protein both supported enhanced the differentiation of human bone marrow derived mesenchymal stem cells (hMSCs) to osteogenic outcomes when compared to tissue culture plastic. The recombinant spider silk protein without the RGD displayed enhanced bone related outcomes, measured by calcium deposition, when compared to the same protein with RGD. Based on comparisons to our prior studies with silkworm silks and RGD modifications, the current results illustrate the potential to bioengineer spider silk proteins into new biomaterial matrixes, while also highlighting the importance of subtle differences in silk sources and modes of presentation of RGD to cells in terms of tissue-specific outcomes.
- Published
- 2006
- Full Text
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18. Lessons from seashells: silica mineralization via protein templating.
- Author
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Foo CW, Huang J, and Kaplan DL
- Subjects
- Animals, Biomimetic Materials chemistry, Diatoms ultrastructure, Macromolecular Substances chemistry, Macromolecular Substances metabolism, Minerals chemistry, Minerals metabolism, Molecular Conformation, Peptides, Porifera ultrastructure, Proteins metabolism, Proteins ultrastructure, Diatoms chemistry, Diatoms metabolism, Porifera chemistry, Porifera metabolism, Proteins chemistry, Silicon Dioxide chemistry, Silicon Dioxide metabolism
- Abstract
Silica, the most abundant compound in the earth's crust, is also widespread in biological systems. Silica has many functions, including support and protection in single-celled organisms and in higher plants and animals alike. Despite this widespread occurrence and importance of function, little is known about biosilica and the mechanisms that produce controlled microscopic and macroscopic silica structures with nanoscale precision, exceeding present synthetic technological approaches. Here we highlight recent progress in identifying proteins, genes and the various environmental factors responsible for the controlled synthesis of silica by marine organisms. Examples of biomimetic approaches to biosilica formation using model peptides to control the formation of structures through manipulation of the processing environment are discussed.
- Published
- 2004
- Full Text
- View/download PDF
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