Biomedical subjects

Jui-Yang Lai

Publications and source records attributed to Jui-Yang Lai.

10 recordsLinked to original sources

PubMed2006

A novel strategy for corneal endothelial reconstruction with a bioengineered cell sheet.

Cellular organization of foreign grafts constructed from cultivated cells is critical to successful graft-host integration and tissue repair. This study described a novel human corneal endothelial cell (HCEC) therapeutic method, where cultivated adult HCEC sheet with uniform orientation was prepared and transplanted to a rabbit cornea. Having a correct morphology and intact barriers, the HCEC sheet was made by the temperature-modulated detachment of monolayered HCECs from thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm)-grafted surfaces and was delivered with proper polarity to the corneal posterior surface by a bioadhesive gelatin disc. Results of the in vivo studies, including the follow-up clinical observations and histological examinations, showed the laminated HCEC sheet was successfully integrated into rabbit cornea denuded with endothelial layer after the biodegradation of gelatin carrier. These data indicate the feasibility of the proposed procedure in cell therapy for corneal endothelial cell loss.

Acrylamides↗

PubMed2006

Bioengineered human corneal endothelium for transplantation.

OBJECTIVE: To investigate whether the bioengineered human corneal endothelial cell (HCEC) monolayers harvested from thermoresponsive culture supports could be used as biological tissue equivalents. METHODS: Untransformed adult HCECs derived from eye bank corneas were cultivated on a thermoresponsive poly-N-isopropylacrylamide-grafted surface for 3 weeks at 37 degrees C. Confluent cell cultures with a phenotype and cell density similar to HCECs in vivo were detached as a laminated sheet by lowering the culture temperature to 20 degrees C. In vitro characteristics of the HCEC sheets were determined evaluating their viability and by scanning electron microscopy, immunohistochemistry, and histological studies. RESULTS: After separation from culture surfaces via a thermal stimulus, the HCEC sheets remained viable. Polygonal cell morphology and multiple cellular interconnections were observed throughout the HCEC sheets. Immunolocalization of zonula occludens-1 and Na+,K+-adenosine triphosphatase (ATPase) indicated the formation of tight junctions and the distribution of ionic pumps at the cell boundary. In addition, we ascertained that cultured HCECs have a monolayered architecture that mimics native corneal endothelium. CONCLUSION: These data suggest that a well-organized and functional HCEC monolayer can feasibly be used as tissue equivalents for replacing compromised endothelium.Clinical Relevance Bioengineered human corneal endothelium fabricated from thermoresponsive supports can potentially offer a new therapeutic strategy for corneal endothelial cell loss.

Aged↗

PubMed2006

Propionibacterium acnes DNA from an explanted intraocular lens detected by polymerase chain reaction in a case of chronic pseudophakic endophthalmitis.

We report a case of Propionibacterium acnes DNA from the explanted intraocular lens (IOL) a 76-year-old man with delayed-onset chronic endophthalmitis. The detection was by polymerase chain reaction (PCR). Slitlamp microscopic examination showed cells and flare in the anterior chamber, keratic precipitates on the endothelium, and multiple white plaques on both surfaces of the IOL. Propionibacterium acnes DNA was found in both the aqueous humor and the explanted IOL by PCR. Scanning electron microscopy showed diphtheroid particles, a coating of biofilm-like deposits, as well as scattered crystals on the surface of the explanted IOL and supported the possibility of P acne colonies on the IOL.

Aged↗

PubMed2006

Effect of charge and molecular weight on the functionality of gelatin carriers for corneal endothelial cell therapy.

Cell transplantation strategies usually involve the use of supporting carrier materials because of the soft and fragile nature of these grafts. In this work, a cell-adhesive gelatin hydrogel carrier was fabricated to deliver cultivated human corneal endothelial cell (HCEC) sheets, which were harvested from thermo-responsive poly(N-isopropylacrylamide) (PNIPAAm)-grafted culture surfaces. The carrier disks, consisting of gelatins with a different isoelectric point (IEP = 5.0 and 9.0) and a molecular weight (MW) ranging from 3 to 100 kDa, were subjected to 16.6 kGy gamma irradiation for sterilization. The effect of IEP and MW of the raw gelatins (i.e., before irradiation) on the functionality of sterilized disks was studied by determinations of mechanical property, water content, dissolution degree, and cytocompatibility. Irrespective of the IEP of raw gelatin, hydrogel disks prepared with high MW (100 kDa) exhibited a greater tensile strength, lower water content, and slower dissolution rate than those made of low MW gelatin (8 and 3 kDa). From the investigation of cellular responses to the disks, the negatively charged gelatin (IEP = 5.0) groups were more cytocompatible when compared with their positively charged counterparts (IEP = 9.0) at the same MW (100 kDa). Additionally, in the negatively charged gelatin groups, only a slight increase in pro-inflammatory cytokine expression was observed with increasing MW of gelatin from 3 to 100 kDa. It is concluded that the gamma-sterilized hydrogel disks made from raw gelatins (IEP = 5.0, MW = 100 kDa) with appropriate dissolution degree and acceptable cytocompatibility are capable of providing stable mechanical support, making these carriers promising candidates for intraocular delivery of cultivated HCEC sheets.

Animals↗

PubMed2006

Corneal injury by anti-misting agent in swim goggles: a case report.

PURPOSE: To report a case of corneal injury by swim goggle anti-misting agent. METHODS: Case report. RESULTS: A 47-year-old man presented with ocular injury caused by swim goggle anti-misting agent. Two weeks previously, the patient felt sudden ocular pain and grit after pool water flooded his goggles while swimming. Before the patient's swim, a copious amount of anti-misting agent was sprayed inside his goggles. On examination, severe corneal epithelial defect and stroma edema of the right eye were noted. Best-corrected visual acuity (BCVA) was 20/40. Right eye corneal thickness was 625 microm. Topical corticosteroids, antibiotic eye drops, and oral tetracycline were started. After 1 week of treatment, the epithelial defect of his right cornea improved slightly. Stromal edema decreased mildly. Epithelial defect persisted at 1 month follow-up. Right eye BCVA remained 20/40. Three months after treatment, the right eye epithelial defect healed completely. Mild diffuse superficial stromal opacity was noted. BCVA improved to 20/20. At 1-year follow-up, right eye corneal thickness was 547 microm, which was thinner than the left eye. Right eye corneal endothelial cell density measured approximately 1500 cells/mm2, which was less than the left eye at 2300 cells/mm2. The faint, diffuse stromal opacity disappeared; however, white subepithelial plaques were noted in the cornea centers. After 1 month of treatment with topical corticosteroids, the plaques subsided completely. The corneas remained clear at 2-year follow-up. CONCLUSION: Anti-misting agent can cause severe corneal injuries, including persistent epithelial defects, stromal edema and opacity, endothelial cell loss, and subepithelial plaque.

Anti-Bacterial Agents↗

PubMed2006

Herpes simplex keratitis following excimer laser application.

PURPOSE: To report two cases of herpes simplex keratitis following excimer laser application. METHODS: Two immunocompetent patients with no history of ocular viral infection developed ulcers after LASIK and phototherapeutic keratectomy (PTK), respectively. RESULTS: Antiviral treatment was administered, and the lesions healed within 14 days. CONCLUSIONS: These two cases suggest that herpes simplex virus was associated with the use of the excimer laser.

Adult↗

PubMed2005

Multiple elements in the deposits of opacified Hydroview intraocular lens.

PURPOSE: To report the ultrastructural and elemental features of two opacified intraocular lenses (IOLs). DESIGN: Histopathologic case series. METHODS: Two opaque hydrophilic acrylic IOLs (Hydroview H60M, Bausch & Lomb Surgical Clearwater, Florida, USA) explanted from two Chinese patients in Taiwan. The explanted IOLs were evaluated by light microscopy, scanning electron microscopy, and energy-dispersive x-ray spectroscopy. RESULTS: Brownish granular and scattered crystal-like deposits were found in case 2, whereas only fine white granular deposits were found in case 1. Using EDX spectroscopy, the elements of deposits on IOL optics were calcium and phosphorus in case 1, but in case 2, fluorine, magnesium, and sodium were demonstrated in addition to calcium and phosphorus. CONCLUSIONS: Our study indicated a difference in morphology and elements of deposits on opaque IOL optics between these two cases. It was suggested that multiple elements may contribute to the formation of deposits.

Acrylic Resins↗

PubMed2005

Laser-assisted subepithelial keratectomy for dry eye associated with soft contact lenses.

PURPOSE: To evaluate the efficacy and safety of laser-assisted subepithelial keratectomy (LASEK) in myopic patients with preoperative dry eye associated with extended soft contact lens use. SETTING: Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan. METHODS: This nonrandomized prospective interventional case series study comprised 9 patients (18 eyes) with dry eye and keratoconjunctivitis associated with long-term complicated soft contact lens use. Prior to LASEK surgery and for 1 year following surgery, measurements and comparisons were made of uncorrected visual acuity, best corrected visual acuity (BCVA), manifest refraction, symptoms, tear function, ocular surface abnormality, and corneal sensitivity. RESULTS: No significant differences (P > .05) in the mean results of the Schirmer test with anesthesia and tear breakup times before and after LASEK were evident. Corneal sensitivity recovered within 1 month after LASEK. No complications occurred during or after LASEK. Subepithelial haze and superficial punctate epithelial defects occurred in 1 eye, representing a loss of 1 Snellen line of BCVA. CONCLUSION: Laser-assisted subepithelial keratomileusis in dry eyes and keratoconjunctivitis associated with complicated soft contact lens wearing was safe and efficacious.

Adult↗

PubMed2005

Ocular hypersensitivitiy to topical vancomycin in a case of chronic endophthalmitis.

PURPOSE: To report a case of ocular allergy to topical vancomycin eye drops. METHODS: Interventional case report. RESULTS: A 76-year-old man presented with progressive itching, soreness, and burning sensations, photophobia, and tearing in his left eye 3 days after completing 2 weeks of treatment with 5% vancomycin eye drops. He had been suffering for the previous 2 years from chronic recurrent endophthalmitis and secondary glaucoma associated with cataract surgery in his left eye. He denied any history of drug or food allergy. Examination by slit-lamp microscope showed left periorbital skin erosive rash, marked hyperemia of conjunctiva, central epithelial defect, corneal stromal edema, and Descemet membrane striae. Vancomycin skin tests were positive. The patient's symptoms resolved after discontinuing vancomycin eye drops and responded well to systemic corticosteroids, antihistamines, and topical corticosteroid treatments. Teicoplanin treated his endophthalmitis successfully. CONCLUSION: A case of hypersensitivity to topical vancamycin was reported. Patients who receive topical vancomycin should be informed of this possible adverse effect and instructed to contact their ophthalmologists if allergic reactions occur.

Administration, Topical↗

PubMed2002

Absorbable sandwich-like membrane for retinal-sheet transplantation.

Neural retinal transplantation has great potential for the alleviation of different degenerative and hereditary retinal disorders. However, because of the fragile and soft nature of retina, retinal-sheet transplantation is relatively difficult to achieve. To overcome this difficulty, we developed a technique for lamellar tissue transplantation. Biodegradable gelatin membranes were fabricated into a sandwich and encapsulated retinal grafts for transplantation. Before transplantation, we characterized the in vivo and in vitro properties of such membranes to determine the optimal sterilization procedure, that is, a sterile membrane with suitable degradability and good mechanical properties and without cytotoxicity. Three sterilization methods were conducted, with hydrogen peroxide gas plasma (HPGP), ethylene oxide (EO), and gamma-ray irradiation (gamma). The results were compared with those of a control (no disinfection). Initial studies revealed that the gelatin membranes sterilized with HPGP or EO exhibited retinal pigment epithelium (RPE) cytotoxicity, whereas the membrane sterilized by 16.6-kGy gamma ray irradiation had no RPE cytotoxicity and had enhanced mechanical properties. In the in vivo rabbit study, implanted gelatin membranes demonstrated satisfactory biocompatibility without any inflammation. Transplanted retinal sheets survived well and developed laminar structures. Such a method using gelatin membranes for tissue transportation has great potential for future routine retinal-sheet transplantation.

Absorption↗