5-Aminolevulinic acid (ALA) is the universal precursor of tetrapyrroles, such as chlorophyll and heme. The major control of chlorophyll biosynthesis is at the step of ALA formation. In the chloroplasts of plants, as in Escherichia coli, ALA is derived from the glutamate of GIu-tRNA via the two-step C5 pathway. The first enzyme, GIu-tRNA reductase, catalyzes the reduction of GIu-tRNA to glutamat...

Two methacrylic derivatives of ibuprofen (N-h4-[2-(4-isobutylphenyl)propionyloxy]phenylj methacrylamide (MAI) and 2-[(4-isobutylphenyl)propionyloxy]ethyl methacrylate (MEI)) were used together with 2-hydroxyethyl methacrylate (HEMA) to synthesize four polymeric materials: two hydrophobic homopolymers, PMAI and PMEI, and two hydrophilic copolymers containing 70% (w/w) HEMA, MAI–HEMA 30 and MEI–H...

The first committed step of porphyrin synthesis in higher plants is the reduction of glutamyl-tRNA to glutamate 1-semialdehyde. This reaction is catalyzed by glutamyl-tRNA reductase, which is encoded by hemA genes. Two hemA cDNA clones (hemA1 and hemA2) were obtained from cucumber (Cucumis sativus) cotyledons by the PCR and cDNA library screening. They showed significant homology with published...

Basic fibroblast growth factor (bFGF), a known angiogenic factor, may provide a potential strategy for the treatment of myocardial infarction (MI), but it is limited by a relatively short half-life. Dex-PCL-HEMA/PNIPAAm hydrogel provides a reservoir for the controlled release of growth factors. The aim of the current study was to evaluate the effects of bFGF incorporated into a Dex-PCL-HEMA/PNI...

Purpose: To fabricate and evaluate oral 2-hydroxyethyl methacrylate-co-acrylic acid hydrogels as a drug delivery system for sustained release of nicorandil. Methods: HEMA-co-AA hydrogels using different monomer concentrations were prepared by free radical polymerization. N, N-methylene bis acrylamide (MBA) was used as crosslinker and potassium persulphate (KPS) as initiator. Nicorandil (20 mg) ...

Two revisited mathematical kinetic relationships were derived, evaluated and applied on linear polymers such as polystyrene and copolymers such as (NIPAAm-alt-HEMA) and (MAAm-alt-HEMA) copolymers respectively. The validity of these equations was successfully verified. The first relationship, equation 12, interrelates exponentially kinetic chain length, average molecular weight and degree of pol...

PURPOSE A four-month extended wear clinical trial was conducted to compare the ocular effects of a high Dk Balafilcon A silicone hydrogel lens and a low Dk HEMA 38.6 per cent H20 soft lens. METHOD Twenty-four subjects who were adapted to daily wear of soft lenses wore a high Dk lens in one eye and a low Dk HEMA lens in the other eye for four months on an extended wear basis after one week of ...

Thermoresponsive polymeric platforms are used to optimise drug delivery in pharmaceutical systems and bioactive medical devices. However, the practical application of these systems is compromised by their poor mechanical properties. This study describes the design of thermoresponsive semi-interpenetrating polymer networks (s-IPNs) based on cross-linked p(NIPAA) or p(NIPAA-co-HEMA) hydrogels con...

Relationships between corneal endothelial cell adhesion and intraocular lens (IOL) surface properties were studied to develop a lens surface with a lower potential to damage the corneal endothelium. The surfaces examined were poly(methyl methacrylate) (PMMA) and four types of plasma-deposited coatings on PMMA. These four films were prepared from perfluoropropane, ethylene oxide, 2-hydroxyethyl ...