Optimization of Antibacterial Activity of Perilla frutescens var. acuta Leaf against Staphylococcus aureus Using Evolutionary Operation Factorial Design Technique

This study was undertaken to optimize extraction using evolutionary operation-factorial (EVOP) design technique to elicit the antibacterial activity of Perilla frutescens var. acuta leaf against Staphylococcus aureus ATCC6538. Higher antibacterial activity was achieved at higher extraction temperature and over a longer extraction time. Antibacterial activity was not affected by differentiation of the ethanol concentration in the extraction solvent. The maximum antibacterial activity of ethanolic extract of P. frutescens leaf against S. aureus was obtained at 75 °C (R = -0.7904(**)) extraction temperature, 24 h (R = -0.7273(**)) extraction time, and 45% (R = -0.0635) ethanol concentration. The population of S. aureus was decreased from 7.535 log CFU/mL in the initial set to 4.865 log CFU/mL in the third set by EVOP factorial design technique, as well as to 2.600 log CFU/mL by extraction with ethyl acetate. Further, the ethyl acetate extract revealed the highest phenolic contents (111.3 ± 8.6 mg% of dry sample) as compared to the other extracts. Also, the scanning electronic microscopic study of the ethanolic extract of P. frutescens revealed potential detrimental effect on the morphology of S. aureus.     

The usefulness of Tc-99m HMPAO labeled WBC SPECT in eosinophilic gastroenteritis

Tc-99m HMPAO labeled WBC SPECT was performed in 5 patients with eosinophilic gastroenteritis before and after successful medical therapy. The imaging findings were graded according to the following imaging scheme; grade 0, no uptake; grade 1, uptake < bone marrow; grade 2, uptake < liver; grade 3, uptake > liver. In no patient was the diagnosis made radiologically or with colonoscopy. The sites of involvement were identified with Tc-99m HMPAO WBC imaging in all patients before treatment and the radionuclide imaging studies were all negative after therapy.     

Overload vector quantisation by selective shell projection inlattice VQ

An efficient overload vector quantisation algorithm is proposed for lattice vector quantisation (LVQ). It selects a projection shell for each overload vector by changing its scaled position along the radial direction to the origin in the truncated lattice and obtains the adjusted overload scaling factor for dequantisation from the orthogonality principle. Experimental results show that this algorithm achieves a good performance in signal to quantisation noise ratio (SQNR) over the conventional algorithm using a single projection of the overload vector on the external shell     

Anti-inflammatory drug releasing absorbable surgical sutures using poly(lactic-co-glycolic acid) particle carriers

The goal of the current study was to develop an absorbable surgical suture incorporating poly(lactic-co-glycolic acid) (PLGA) particles loaded with dexamethasone (DEX) as an anti-inflammatory drug. DEX-loaded PLGA (DEX/PLGA) particles, prepared using a water-in-oil emulsion method, were electrostatically immobilized onto the surface of absorbable sutures. The surfaces of these DEX/PLGA particles were coated with positively charged polyethyleneimine (PEI) molecules, which imparted a net positive surface charge. These modified PEI-coated DEX/PLGA (PEI/DEX/PLGA) particles were then immobilized on negatively charged absorbable suture surfaces by electrostatic attraction. The results showed that DEX was efficiently loaded into PLGA particles and that the surfaces of DEX/PLGA particles were successfully coated with PEI. PEI/DEX/PLGA particles were well dispersed and immobilized onto suture surfaces. In addition, PEI/DEX/PLGA particles remained adherent to suture surfaces in vitro and demonstrated sustained DEX release in phosphate-buffered saline (pH 7.4) at 37 °C for up to 28 days under static conditions. The tensile strength and elongation at break of PEI/DEX/PLGA particle-treated sutures were almost the same as that of non-treated control sutures. Findings of this study show that various therapeutic drugs could be efficiently incorporated into absorbable sutures using biodegradable polymeric particles, and suggest that the devised absorbable, drug-eluting, sutures offer a promising basis for a novel absorbable surgical suture system.     

Protease Inhibitors from Plants with Antimicrobial Activity

Antimicrobial proteins (peptides) are known to play important roles in the innate host defense mechanisms of most living organisms, including plants, insects, amphibians and mammals. They are also known to possess potent antibiotic activity against bacteria, fungi, and even certain viruses. Recently, the rapid emergence of microbial pathogens that are resistant to currently available antibiotics has triggered considerable interest in the isolation and investigation of the mode of action of antimicrobial proteins (peptides). Plants produce a variety of proteins (peptides) that are involved in the defense against pathogens and invading organisms, including ribosome-inactivating proteins, lectins, protease inhibitors and antifungal peptides (proteins). Specially, the protease inhibitors can inhibit aspartic, serine and cysteine proteinases. Increased levels of trypsin and chymotrypsin inhibitors correlated with the plants resistance to the pathogen. Usually, the purification of antimicrobial proteins (peptides) with protease inhibitor activity was accomplished by salt-extraction, ultrafiltration and C₁₈ reverse phase chromatography, successfully. We discuss the relation between antimicrobial and anti-protease activity in this review. Protease inhibitors from plants potently inhibited the growth of a variety of pathogenic bacterial and fungal strains and are therefore excellent candidates for use as the lead compounds for the development of novel antimicrobial agents.     

UV photo-responsive characteristics of an n-channel GaN Schottky-barrier MISFET for UV image sensors

The ultraviolet (UV) responsive properties of the enhancement-mode n-channel Schottky-barrier MISFET (SB-MISFET), which was fabricated on a p-type GaN layer grown on silicon substrate, were investigated. The drain leakage current of the MISFET is less than 1 nA/mm/sup 2/, which is quite low compared to recently reported photodetectors. The MISFET exhibited a cutoff wavelength of 365 nm, and the UV/visible rejection ratio was about 120 near the threshold voltage. This is the first demonstration of the MISFET-type UV photodetector, which is highly applicable to the UV image sensors.     

Inhibitory effect of phosphatidylserine on atopy-like dermatitis in NC/Nga mice

In the present study, the anti-atopic effect of phosphatidylserine (PS) extracted from soybean was investigated in NC/Nga mice. The atopic symptoms were evaluated by scoring spontaneous scratching behavior and skin lesions, by measuring serum levels of immunoglobulin E (IgE) and interleukin-4 (IL-4), and by observing skin histology. After observing the maximum severity of atopic symptoms, PS was initiated. The PS treatment significantly alleviated apparent symptoms of atopic dermatitis and scratching behavior. The suppression of atopic dermatitis by PS was verified by decreases in the serum levels of IgE (p<0.05 after 8 weeks; p<0.001 after 9 weeks) and IL-4 (p<0.01 after 7 weeks; p<0.001 after 9 weeks). Histological observations also indicated that the thickening process of skin and the infiltration of inflammatory cells were significantly inhibited. Taken together, PS from soybean might be useful for alleviating atopic dermatitis symptoms and thus for developing a new medicine for treating human atopic disease.     

Characterization of traditionally fermented Korean soybean paste, eoyukjang, and isolation of its microorganisms

In this study, traditionally fermented Korean soybean paste, eoyukjang, was characterized and its microorganisms were isolated. The contents of amino-type and ammonia-type nitrogens in the pastes we examined were 89.60 to 98.93 mg/% and 0.32 to 0.30 mM, respectively. Antioxidant activity increased during ripening, with antioxidant activities in 1- and 4-year-old pastes measured at 9.80 and 13.84 μmol of Trolox equivalents/g, respectively. Twenty-two and 19 microorganisms were isolated from soybean pastes under aerobic and anaerobic conditions, respectively. After identification, Bacillus amyloliquefaciens, Bacillus subtilis, and Bacillus vallismortis were dominant. In the enzyme activities, protease and lipoxygenase activities were observed from 0.065 to 0.733 unit/mg protein and 0.016 to 0.19 unit/mg protein, respectively. Amylase activity was, however, broad between 43.1 to 571.8 unit/mg protein.