Therapeutic potential of abalone and status of bioactive molecules: A comprehensive review.

Marine organisms are increasingly being investigated as sources of bioactive molecules with therapeutic applications as nutraceuticals and pharmaceuticals. In particular, nutraceuticals are gaining popularity worldwide owing to their therapeutic potential and incorporation in functional foods and dietary supplements. Abalone, a marine gastropod, contains a variety of bioactive compounds with anti-oxidant, anti-thrombotic, anti-inflammatory, anti-microbial, and anti-cancer activities. For thousands of years different cultures have used abalone as a traditional functional food believing consumption provides health benefits. Abalone meat is one of the most precious commodities in Asian markets where it is considered a culinary delicacy. Recent research has revealed that abalone is composed of many vital moieties like polysaccharides, proteins, and fatty acids that provide health benefits beyond basic nutrition. A review of past and present research is presented with relevance to the therapeutic potential of bioactive molecules from abalone.

Validation of two scoring systems for the prediction of posterior capsule rupture during phacoemulsification surgery.

AIM: To attempt to validate two scoring systems for the prediction of intraoperative complication during phacoemulsification surgery. METHODS: The study population was patients attending Sunderland Eye Infirmary who underwent phacoemulsification surgery between 1 January 2001 and 31 December 2003. The authors applied each scoring system to a control group of 300 patients from this study population and extrapolated the results to give an estimate of the spread of scores for the entire population. They then applied the same scoring systems to all complicated cases from the same study population. Using these results they were able to calculate the risk of a complication for a particular score on each scoring system. CONCLUSION: The application of these systems in clinical practice would allow appropriate selection of phacoemulsification cases for trainee surgeons, more accurate consent from patients for their phacoemulsification surgery, and the unbiased comparison of surgical outcomes from surgeons with differing case mix difficulties.

Alphagan allergy may increase the propensity for multiple eye-drop allergy.

AIMS: Since its introduction in 1996, brimonidine tartrate 0.2% ophthalmic solution (Alphagan, Allergan) twice daily has become established as an effective intra ocular pressure-lowering treatment. While the efficacy of Alphagan cannot be questioned, we gained the clinical impression that the drug has an unacceptably high rate of allergy. Of greater concern, we suspected that patients suffering from local Alphagan allergy had a higher rate of allergy to subsequently used topical preparations. We analysed data from a large scale study of glaucoma patients to establish whether our suspicions were correct. SUBJECTS AND METHODS: We have created a database of the entire glaucoma treatment histories for consecutive patients attending a single consultant's clinics (DMIM) at Glasgow Royal Infirmary between May 1999 and September 2001. All have undergone medical treatment for primary open angle glaucoma, ocular hypertension, or normal tension glaucoma. Patients with any other form of glaucoma, and patients in whom a full record of treatment was not available were excluded from the study. RESULTS: Alphagan was discontinued due to allergy on 73 per 100,000 patient treatment days. This was a far higher frequency than for other preparations. In patients allergic to both Alphagan and another preparation (Timoptol, Trusopt and Xalatan), the mean interval between the first and second allergy was shorter when Alphagan allergy occurred first. This was statistically significant in Timoptol and Trusopt cross-reactivity. CONCLUSIONS: Alphagan has high allergenicity, and may increase the likelihood of allergy to subsequently used preparations.

Genomic organisation and alternative splicing of mouse and human thioredoxin reductase 1 genes.

BACKGROUND: Thioredoxin reductase (TR) is a redox active protein involved in many cellular processes as part of the thioredoxin system. Presently there are three recognised forms of mammalian thioredoxin reductase designated as TR1, TR3 and TGR, that represent the cytosolic, mitochondrial and novel forms respectively. In this study we elucidated the genomic organisation of the mouse (Txnrd1) and human thioredoxin reductase 1 genes (TXNRD1) through library screening, restriction mapping and database mining. RESULTS: The human TXNRD1 gene spans 100 kb of genomic DNA organised into 16 exons and the mouse Txnrd1 gene has a similar exon/intron arrangement. We also analysed the alternative splicing patterns displayed by the mouse and human thioredoxin reductase 1 genes and mapped the different mRNA isoforms with respect to genomic organisation. These isoforms differ at the 5' end and encode putative proteins of different molecular mass. Genomic DNA sequences upstream of mouse exon 1 were compared to the human promoter to identify conserved elements. CONCLUSIONS: The human and mouse thioredoxin reductase 1 gene organisation is highly conserved and both genes exhibit alternative splicing at the 5' end. The mouse and human promoters share some conserved sequences.

[3H]L-694,247 labels the 5-HT1D beta receptor in pig caudate membranes.

This study, carried out in pig caudate membranes, characterises the radioligand binding site labelled with [3H]L-694,247 (2-[5-[3-(4-methylsulphonylamino)benzyl-1,2,4-oxadiazol-5-yl ]-1H-indole-3 - yl]ethylamine). The affinities of 27 standard compounds are consistent with binding to a 5-HT1D recognition site. In addition the results indicate that, under the assay conditions described, [3H]L-694,247 specifically labels the 5-HT1D beta recognition site since ketanserin and ritanserin display a low affinity consistent with their activities at this subtype of the 5-HT1D receptor.

Structural analysis of inositol monophosphatase complexes with substrates.

The structures of ternary complexes of human inositol monophosphatase with inhibitory Gd3+ and either D- or L-myo-inositol 1-phosphate have been determined to 2.2-2.3 A resolution using X-ray crystallography. Substrate and metal are bound identically in each active site of the phosphatase dimer. The substrate is present at full occupancy, while the metal is present at only 35% occupancy, suggesting that Li+ from the crystallization solvent partially replaces Gd3+ upon substrate binding. The phosphate groups of both substrates interact with the phosphatase in the same manner with one phosphate oxygen bound to the octahedrally coordinated active site metal and another oxygen forming hydrogen bonds with the amide groups of residues 94 and 95. The active site orientations of the inositol rings of D- and L-myo-inositol 1-phosphate differ by rotation of nearly 60 degrees about the phosphate ester bond. Each substrate utilizes the same key residues (Asp 93, Ala 196, Glu 213, and Asp 220) to form the same number of hydrogen bonds with the enzyme. Mutagenesis experiments confirm the interaction of Glu 213 with the inositol ring and suggest that interactions with Ser 165 may develop during the transition state. The structural data suggest that the active site nucleophile is a metal-bound water that is activated by interaction with Glu 70 and Thr 95. Expulsion of the ester oxygen appears to be promoted by three aspartate residues acting together (90, 93, and 220), either to donate a proton to the leaving group or to form another metal binding site from which a second Mg2+ coordinates the leaving group during the transition state.