Hypoglycemic effects of vanadium on alloxan monohydrate induced diabetic dogs

The hypoglycemic effects after oral administration of vanadium have been studied previously in many species such as rats, mice and even humans. However, there has been no prior report on the glucose lowering effect of vanadium on diabetic dogs. Therefore, the purpose of this study was to evaluate the hypoglycemic effects of oral vanadium on diabetic dogs. Diabetes mellitus in the dogs studied was induced by alloxan monohydrate intravenous injection. The dogs were divided into two groups, one was the diabetic control (DC) group (n = 4) and the other was the vanadium treated (DV) group (n = 6). Fresh water was supplied to the dogs in the DC group, but sodium metavanadate solution (0.1~0.2 mg/ml) was given to the dogs in DV group from one week after the alloxan injection. The fasting glucose levels, fructosamine and serum chemistry profiles were compared between the two groups weekly for three weeks. The fasting blood glucose levels in DV group were significantly lower than those in the DC group (p < 0.01). Fructosamine levels in the DV group were also lower than those in the DC group (p < 0.05). The serum chemistry profiles were not significantly different in comparisons between the two groups. However, the cholesterol levels were significantly lower in the DV group compared to the DC group (p < 0.05). Our findings showed that oral vanadium administration had a hypoglycemic effect on chemically induced diabetic dogs.     

Epidemiological characteristics and financial costs of the 1997 foot-and-mouth disease epidemic in Taiwan

Between March and July 1997, a devastating outbreak of foot-and-mouth disease (FMD), serotype O, occurred in pigs in Taiwan. A total of 6,147 pig farms with more than 4 million pigs were infected, and 37.7 per cent of the pigs in Taiwan either died (0.18 million pigs) or were killed (3.85 million pigs). The epidemic reached its peak during the fifth week after it was first recognised. During the eighth and ninth weeks, a two-dose blanket vaccination programme was instituted which led to a large reduction in new outbreaks. Except for two cities, the whole of Taiwan was declared an FMD-infected zone. During the four months in which new farm outbreaks occurred, 21.7 per cent of the pigs on infected farms showed clinical signs, and there was an overall mortality of 3.95 per cent. During the early stages of the epidemic, the incubation period was as short as 24 hours and the case fatality rates for suckling piglets reached 100 per cent. The financial cost of the epidemic was estimated at US$ 378.6 million, including indemnities, vaccines, carcase disposal plus environmental protection, miscellaneous expenses, and loss of market value. Owing to the ban on exports of pork to Japan, it is estimated that the total economic cost to Taiwan's pig industry will be about US$ 1.6 billion.     

From followers to market leaders: Asian electronics firms in the global economy

Abstract: This paper aims to explain how a number of leading electronics firms from Asian newly industrialised economies of Hong Kong, Singapore, South Korea and Taiwan are articulated into global production networks and become major players in their respective market niches. Developing a triangular theoretical framework, I seek to explain the complex relationships between the dynamic articulation of these leading Asian electronics firms into different global production networks and their simultaneous upgrading from typical followers to market leaders. As a critique of the dominant developmental state discourse, I argue that the interplay between corporate strategies and home base advantages within the context of changing global production networks can offer a better explanation of the differentiated competitive outcomes of these Asian firms. This paper draws upon original data collected through personal interviews with top executives from leading electronics firms in the four Asian newly industrialised economies. I conclude the paper with some implications for theory and policy in relation to corporate development in Asian economies.     

The preparation of polyurethane foam combined with pH-sensitive alginate/bentonite hydrogel for wound dressings

Polyurethane (PU) foam was combined with protein drug-loaded pH-sensitive alginate-bentonite hydrogel for wound dressings. Alginate is a linear copolymer composed of 1–4-linked β-D-mannuronic acid (M) and its c-5-epimer α-Lguluronic acid (G). The amount of (M) and (G) and their sequential distribution are varied depending on the alginate source. Soluble sodium alginate can become a hydrogel when cross-linked with divalent cations and has widespread applications in the food, drink, pharmaceutical and bioengineering industries. Recently, it has been also proposed as a biomaterial for drug delivery systems. Bentonites are the natural inorganic polymers consisting of a large proportion of expandable clay minerals with a three-layer structure such as montmorillonite, beidellite, nontronite, etc. They are important adjutants and supports for medical products, and they have many useful physicochemical, mechanical, and biological properties such as absence of toxicity, indifference to other raw materials, sorption, swelling, and complex formation properties. Alginate-bentonite hydrogels were prepared at concentration ratios of 10/0, 7/3, 5/5, 3/7. PU foams were prepared using hydrophilic polyols. We investigated the controlled release of a protein drug from PU foam combined with alginate-bentonite hydrogel at different pH values of 4.2, 5.2, 7.2, 8.2. The mechanical properties and cytotoxicity tests of this foam were also studied.     

Promising antidiabetic potential of fucoxanthin isolated from the edible brown algae Eisenia bicyclis and Undaria pinnatifida

In the present study, we investigated the antidiabetic potential of fucoxanthin via the inhibition of rat lens aldose reductase (RLAR), human recombinant aldose reductase (HRAR), advanced glycation end-product (AGE) formation, protein tyrosine phosphatase 1B (PTP1B), and α-glucosidase. Fucoxanthin displayed potent inhibitory activity against AGE formation and HRAR and RLAR activity. In addition, fucoxanthin showed potent inhibitory activity against PTP1B. However, it did not show α-glucosidase inhibitory activity below 200 μM. In addition, our kinetic study revealed that fucoxanthin competitively inhibited RLAR, while it showed mixed-type inhibition against PTP1B. In order to confirm enzyme inhibition, we predicted the 3D structure of PTP1B using Autodock 4.0 to simulate the binding of fucoxanthin. Docking simulation results demonstrated that three residues of PTP1B (Phe30, Phe52, and Gly183) interact with the two hydroxyl groups of fucoxanthin. In addition, the binding energy was negative (?7.66 kcal/mol), indicating that the three hydrogen bonds may stabilize the open form of the enzyme and potentiate tighter binding to the active site of PTP1B, resulting in more effective PTP1B inhibition. The results of the present study therefore clearly demonstrate the promising potential of fucoxanthin as a therapeutic intervention for the management of diabetes as well as diabetes-associated complications, which could be explored further.     

Endurance of linear and cross-linked shape memory polyurethane under rigorous hydrolysis conditions

Linear shape memory polyurethane (SMPU) copolymers synthesized from 4,4′-methylene bis(phenylisocyanate) (MDI), poly(tetramethyleneglycol) (PTMG), and 1,4-butanediol (BD), and cross-linked SMPU by glycerol were being tested under the severe hydrolysis conditions for the tensile mechanical properties and the shape memory effect for 6 months. Tensile mechanical properties and shape memory effect were not substantially decreased after 6 months of storage, and SMPU structure was not affected during the long-term hydrolysis test as evidenced by IR, DSC, contact angle, and viscosity. Hydrolysis test was important in proving the durability of SMPU before application of SMPU in aqueous surrounding.     

Characterisation of QoI‐resistant field isolates of Botrytis cinerea from citrus and strawberry

BACKGROUND: In 2004, field isolates of Botrytis cinerea Pers. ex Fr., resistant to strobilurin fungicides (QoIs), were first found in commercial citrus orchards in Wakayama Prefecture, Japan. Subsequently, QoI‐resistant isolates of this fungus were also detected in plastic strawberry greenhouses in Saga, Ibaraki and Chiba prefectures, Japan. Biological and molecular characterisation of resistant isolates was conducted in this study. RESULTS: QoI‐resistant isolates of B. cinerea grew well on PDA plates containing kresoxim‐methyl or azoxystrobin at 1 mg L^?1, supplemented with 1 mM of n‐propyl gallate, an inhibitor of alternative oxidase, whereas the growth of sensitive isolates was strongly suppressed. Results from this in vitro test were in good agreement with those of fungus inoculation tests in vivo. In resistant isolates, the mutation at amino acid position 143 of the cytochrome b gene, known to be the cause of high QoI resistance in various fungal pathogens, was found, but only occasionally. The heteroplasmy of cytochrome b gene was confirmed, and the wild‐type sequence often present in the majority of resistant isolates, indicating that the proportion of mutated cytochrome b gene was very low. CONCLUSION: The conventional RFLP and sequence analyses of PCR‐amplified cytochrome b gene are insufficient for molecular identification of QoI resistance in B. cinerea. Copyright © 2009 Society of Chemical Industry