PubMed · 5970181
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
H F Mengoli, A L Watne. 1966-10-29. Immunological and polyionic interaction in polyacrylamide gel.. https://doi.org/10.1038/212481a0
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
A novel approach to immobilize nonuniform initial drug concentration profiles in multilaminated matrix devices utilizing photopolymerization techniques is presented. Solution polymerization of 2-hydroxyethyl methacrylate (HEMA) and diethylene glycol dimethacrylate (DEGDMA) in the presence of a model compound, acid orange 8 (AO8), was conducted using UV light and photoinitiators to construct a laminated matrix device. In this process, each layer was polymerized with a different AO8 concentration to form a nonuniform initial concentration profile in the matrix devices. The AO8 diffusion coefficients measured in this work were used in a concurrently developed model to predict the effects of nonuniform AO8 concentration profiles on AO8 release patterns. The release data predicted by the model agreed well with the experimentally determined data. The results indicate that a zero-order release pattern can be approximated by employing a suitable nonuniform initial drug concentration profile.
OBJECTIVE: To compare the visual outcome, neodymium:YAG (Nd:YAG) capsulotomy rates, and percentage of posterior capsular opacification (PCO) seen with polymethylmethacrylate (PMMA), silicone, and polyacrylic intraocular lens implants 3 years after surgery. DESIGN: Randomized, prospective trial. PARTICIPANTS: Ninety eyes of 81 patients were examined at a British teaching hospital. INTERVENTION: Ninety eyes were prospectively randomized to receive a PMMA, silicone, or polyacrylic (AcrySof, Alcon, Fort Worth, TX) implant. All lenses had 6-mm disc optics with PMMA haptics. A standardized surgical protocol was performed by a single surgeon using an extracapsular technique with capsulorhexis; any surgical complications were excluded and all patients had standardized postoperative medication and follow-up. MAIN OUTCOME MEASURES: Patients were seen at 6 months and 1, 2, and 3 years after surgery. At 3 years, logarithm of the minimum angle of resolution (LogMAR) visual acuity and Pelli-Robson contrast sensitivity were measured and YAG capsulotomy rates determined. Posterior capsular opacification was assessed objectively by digital retroillumination imaging using dedicated software and calculated as the percentage area of opacified capsule. RESULTS: At 3 years, the overall follow-up rate was 71%: 19 patients were available for examination with polyacrylic lens implants, 22 with silicone, and 23 with PMMA. There was a significant difference in percentage PCO at 3 years among the lens types (P = 0.0001). Polyacrylic lenses were associated with less PCO (10%) than silicone (40%) and PMMA lenses (56%). The YAG capsulotomy rate was 0% for polyacrylic, 14% for silicone, and 26% for PMMA (P = 0.05). The visual acuity and contrast sensitivity were not significantly different among the three groups if patients with age-related macular degeneration and those requiring YAG capsulotomies are excluded. CONCLUSIONS: Intraocular lenses made from polyacrylic are associated with a significantly reduced degree of PCO and lower YAG rates.
A systematic structure-activity relationship study of plicatin B (1), an antimutagenic constituent of Psoralea juncea, was undertaken with a view toward elucidating its chemical mode of action and possibly optimizing its antimutagenic activity during the process. Compound 1 and its related analogues were examined for their antimutagenic activity against mutations induced by ethyl methanesulfonate, a direct acting mutagen and alkylating agent, in Salmonella typhimurium strain TA100, utilizing the modified Ames test protocol. The dihydro analogue 3 resulting from saturation of the conjugated alkene double bond of 1 was found to exhibit reduced cytotoxicity and enhanced efficacy relative to the parent compound. This result serves preliminarily to exclude a Michael acceptor role of the alpha,beta-unsaturated carbonyl moiety in connection with its antimutagenic activity.