An improved method for the serotyping of free coagulase from Staphylococcus aureus.

The serotyping of free coagulase, one of the most reliable ways to identify strains of Staphylococcus aureus, and widely employed in Japan, has been improved by adding magnetite sand to the reaction mixture. Culture medium supernatant and a type-specific antibody are mixed in a well of a microtiter plate, and plasma-enriched bovine fibrinogen is treated with magnetite sand. The use of tranexamic acid and gum arabic in the reaction mixture also increases the sensitivity of the reaction. Finally, the plate is placed on a magnetic stirrer. If the type of the coagulase corresponds to that of the antibody, no clot formation will occur, and this is easily confirmed by the movement of the sand. Although the amount of reaction mixture required is much less than that for the conventional tube method, our new method is able to detect slight increases in viscosity of the reaction mixture due to fibrin formation even before complete clotting occurs, thus providing very high sensitivity. Clot formation can also be judged by observing a turbid mass of fibrin in the well (Hwang's method), but this approach is a little slower than our method involving immobilization of magnetite sand.     

Multiple DNA and protein sequence alignment on a workstation and a supercomputer

This paper describes a multiple alignment method using a workstationand supercomputer. The method is based on the alignment of aset of aligned sequences with the new sequence, and uses a recursiveprocedure of such alignment. The alignment is executed in areasonable computation time on diverse levels from a workstationto a supercomputer, from the viewpoint of alignment resultsand computational speed by parallel processing. The applicationof the algorithm is illustrated by several examples of multiplealignment of 12 amino acid and DNA sequences of HIV (human immunodeficiencyvirus) env genes. Colour graphic programs on a workstation andparallel processing on a supercomputer are discussed. Received on April 26, 1988; accepted on July 7, 1988     

Antiviral activities of mycophenolic acid and IMD-0354 against SARS-CoV-2

In this study, the anti–severe acute respiratory syndrome coronavirus-2 (anti-SARS-CoV-2) activity of mycophenolic acid (MPA) and IMD-0354 was analyzed. These compounds were chosen based on their antiviral activities against other coronaviruses. Because they also inhibit dengue virus (DENV) infection, other anti-DENV compounds/drugs were also assessed. On SARS-CoV-2-infected VeroE6/TMPRSS2 monolayers, both MPA and IMD-0354, but not other anti-DENV compounds/drugs, showed significant anti-SARS-CoV-2 activity. Although MPA reduced the viral RNA level by only approximately 100-fold, its half maximal effective concentration was as low as 0.87 µ m , which is easily achievable at therapeutic doses of mycophenolate mofetil. MPA targets the coronaviral papain-like protease and an in-depth study on its mechanism of action would be useful in the development of novel anti-SARS-CoV-2 drugs.     

Sonication-assisted efficient Agrobacterium-mediated genetic transformation of the multipurpose woody desert shrub Leptadenia pyrotechnica

The desert shrub Leptadenia pyrotechnica (Forssk.) Decne (Asclepiadaceae) is an important multipurpose woody species of tropical and sub-tropical arid regions. The shrub’s excellent pharmacological properties, importance in desert afforestation and role in sand dune fixation has been elaborately studied in recent years which make it a potential candidate for genetic manipulation in the global warming scenario. We have developed an Agrobacterium-mediated transformation protocol for L. pyrotechnica using hypocotyl explants from 5 days old seedlings. The reliability of the protocol has been tested by transforming the species with gus and gfp reporter genes separately. Hypocotyl explants were sonicated for 40 s, infected with Agrobacterium suspension of OD₆₀₀ 0.5, co-cultivated in the dark for 2 days at 26 °C in presence of 200 μM acetosyringone. Transgenic plants were obtained after 20–22 weeks at a frequency of 14 and 11 % for gus and gfp reporter genes respectively. Transgenic plants were confirmed by PCR and Southern blots. Expression of the two reporter genes has been tested in different stages of transgenic plant development. No phenotypic differences between the wild-type and transgenic plants were noted. This method will be very helpful to introduce alien genes-of-interest for various biotechnological applications.     

A Novel Monoclonal Antibody disrupting Cell Type Specific Substratum Adhesion of Frog (Xenopus laevis) Epithelial Cells and Endothelial Cells

We isolated a mouse monoclonal antibody (FAD-II) that disrupts cell-substratum adhesion of amphibian ( Xenopus laevis ) epithelial cells and endothelial cells. The effect of the antibody was cell-type specific, and the antibody had no effect on fibroblastic cells while fibronectin peptide blocked cell-substratum adhesion of all the cell types examined. In developing frog embryos, the epitopes recognized by the antibody were detected in pronephrotic ducts and in other tissue cells of embryos (from stage 33/34 afterwards). In adult tissues, the antibody mainly recognized antigens in extracelluar matrices. The antigens recognized by the antibody seems to be novel glycoepitopes in frog cells.     

A 38 base pair insertion in the pro alpha 2(I) collagen gene of a patient with Marfan syndrome

Abnormalities in type I collagen have been recognized in a number of connective tissue disorders. In the Marfan syndrome, an autosomal dominant condition producing a generalized abnormality in connective tissue, no consistent abnormality has been identified, although one individual has been found to have an elongated pro alpha 2(I) collagen chain [Byers et al, Proc Natl Acad Sci USA 78:7745, 1981]. To determine the nature of the alteration in the gene that produced this abnormality, we studied the pro alpha 2(I) gene from this individual by genomic blotting and gene cloning. Genomic mapping studies detected no abnormalities. However, analysis of the cloned segment of the pro alpha 2(I) collagen gene from the Marfan individual indicates that the gene contains a 38 base pair insertion in an intron near the collagenase cleavage site. Although the relationship of this insertion to the protein abnormality is unclear, it may be a useful marker for the diagnosis of the Marfan syndrome.