Improved methods for detection and serotyping of coagulase from Staphylococcus aureus

Improved methods for detection and serotyping of staphylocoagulase were concomitantly devised. We devised an improved method for detection of coagulase activity on agarose film in the same manner as single radial immunodiffusion. The amounts of reagents required for detection of coagulase on agarose film were successfully diminished by adding polyethylene glycol (PEG) to the original formula described by Boothby et al. Using microplates in another improved method for coagulase serotyping, the amount of reaction fluid required was considerably less compared with the conventional tube method. PEG was found to be also effective to increase the efficacy of coagulase serotyping. In the presence or absence of anti-coagulase antisera, culture supernatants of staphylococcal strain grown in brain heart infusion broth were incubated with the reaction fluid containing bovine fibrinogen, rabbit plasma, 6-amino caproic acid, polyethylene glycol 6,000. Coagulase activity was visualized as a turbid mass formed in the wells. Turbid mass formation due to coagulase activity was type-specifically inhibited in the presence of type-specific antisera. Detailed procedures of the methods are precisely described with some preliminary results obtained by the methods.     

A study of the fine structure of the accessory muscle of the horseshoe crab,Tachypleus gigas

The accessory muscle of the walking leg of the horseshoe crab, Tachypleus gigas, was examined electron microscopically. The muscle fibers vary in size but are small in diameter, when compared with other arthropod skeletal muscles. They are striated with A, I, Z and poorly defined H bands. The sarcomere length ranges from 3-10 μm with most sarcomeres in the range of about 6 μm. The myofilaments are arranged in lamellae in larger fibers and less well organized in the smaller ones. Each thick filament is surrounded by 9-12 thin filaments which overlap. The SR is sparse but well organized to form a fenestrated collar around the fibrils. Individual SR tubules are also seen among the myofibrils. Long transverse tubules extend inward from the sarcolemma to form dyads or triads with the SR at the A-I junction. Both dyads and triads coexist in a single muscle fiber, a feature believed to have evolutionary significance. The neuromuscular relationship is unique. In the region of synaptic contact, the sarcolemma is usually elevated to form a large club-shaped structure containing no myofilaments and few other organelles. The axons or axon terminals and glial elements penetrate deep into the club-shaped sarcoplasm and form synapses with the fiber. As many as 13 terminals have been observed within a single section. Synaptic vesicles of two types are found in the axon terminals.     

Multicellular complex of chloride cells in the gills of freshwater teleosts

Morphology of branchial chloride cells in the freshwater teleosts Plecoglossus altivelis, Cyprinus carpio, and Oreochromis mossambicus was studied by light and transmission electron microscopy. The chloride cell has an apical membrane directly in contact with the outer medium. Generally, two or more neighboring chloride cells share an apical pit, forming a multicellular complex. The chloride cells form a multicellular complex in which cells differ in cytoplasmic electron density, development of tubular system, and in cell size. Chloride cells are linked by junctions which are shallower than the tight junctions that occur between neighboring pavement cells or between pavement and chloride cells. Multicellular complexes of chloride cells create additional paracellular pathways marked apically by the shallower junctions. Since junctional structure affects transepithelial permeability, development of multicellular complexes of chloride cells in freshwater fishes may be related to the transport of some substances as in the gills of marine fishes.     

A simple method for observation of phagocytosis on bacterial thin-layer

A simple method was developed to visually present the phagocytic activity of leukocytes by using adherent Staphylococcus aureus cells and blood applied on a plastic dish. When heparinized blood was applied on thin-layer of heat-killed S. aureus cells on the plastic dish, plaques due to the phagocytic activity of leukocytes were observed with a microscope under a low magnification. Fewer and smaller plaques were observed when plasma-deprived rather than whole blood was used. Some analyses were made in respect to the fundamental conditions required for optimal results. This method was considered to be useful for conveniently evaluating the serum opsonin activities and phagocytic function of leukocytes in various kinds of diseases.     

Body Mass Index Cutoffs for Underweight,Overweight, and Obesity in South Korean Schoolgirls

Objectives: To establish BMI percentiles and cutoffs for underweight, overweight, and obesity in South Korean schoolgirls. Research Methods and Procedures: A total of 1229 South Korean schoolgirls aged 8 to 18 years were randomly selected to complete a self‐administered questionnaire. BMI charts and cutoffs were constructed after analyzing data from 1107 subjects. Percentile curves were established by the modified LMS method. Results: The percentiles for underweight, overweight, and obesity corresponding to BMI of 18.5, 23.0, and 25.0 kg/m² at age 18 were the 13.0th percentile, the 77.8th percentile, and the 91.2nd percentile, respectively. The corresponding prevalences of underweight, overweight, and obesity were 12.1, 12.5, and 9.8%, respectively. Discussion: We established for the first time, to our knowledge, new BMI cutoffs for ages 8 to 18 that corresponded to BMIs of 18.5, 23.0, and 25.0 kg/m² for Asian adults designated by the International Obesity Task Force. These newly established BMI cutoffs might help to estimate the prevalence of overweight and obesity in Asian children.     

Gene expression of the biosynthetic enzymes and biosynthesis of starch during Rice Grain development

Amylose and amylopectin are determinants of the physicochemical properties for starch and grain quality in rice. Their biosynthesis is catalyzed by the interplay of ADP-glucose pyrophosphorylase (AGPase), granule-bound starch synthase (GBSS), soluble starch synthase (SSS), a starch branching enzyme (SBE), and a starch debranching enzyme (SDE). In this study, the genes for these enzymes were highly expressed 7 to 28 days after flowering during grain development, and their expression closely matched increases in both starch content and grain weight Among all the tested cultivars, amylose contents in the rice grains remained essentially constant throughout their development The AGPase gene was highly expressed in the high-yield cultivars of both glutinous and non-glutinous rice. The SSS gene was actively expressed when mature GBSS mRNA decreased. Genes responsible for amylopectin biosynthesis were simultaneously expressed in the late stage of grain development. We have now demonstrated that the expression patterns of starch biosynthetic genes differ between glutinous and non-glutinous rice, and between Tongil (a Japonica/ Indica hybrid) and Japonica types.     

cDNA cloning and mRNA expression of LIM protein gene homologue from the silkworm, Bombyx mori

LIM protein cDNA, from Bombyx mori that contains an open reading frame of 622 bp encoding 94 amino acids, was identified and characterized. The B. mori LIM protein homologue is classified into group 2 LIM proteins that contain glycine-rich LIM domain. B. mori LIM protein mRNA is up-regulated at late embryogenesis and detected in the mid-gut of 5th instar larvae.     

Fabrication of disposable protein chip for simultaneous sample detection

In this study, we have described a method for the fabrication of a protein chip on silicon substrate using hydrophobic thin film and microfluidic channels, for the simultaneous detection of multiple targets in samples. The use of hydrophobic thin film provides for a physical, chemical, and biological barrier for protein patterning. The microfluidic channels create four protein patterned strips on the silicon surfaces with a high signal-to-noise ratio. The feasibility of the protein chips was determined in order to discriminate between each protein interaction in a mixture sample that included biotin, ovalbumin, hepatitis B antigen. In the fabrication of the multiplexed assay system, the utilization of the hydrophobic thin film and the microfluidic networks constitutes a more convenient method for the development of biosensors or biochips. This technique may be applicable to the simultaneous evaluation of multiple protein-protein interactions.