Sequence rearrangement in JC virus DNAs molecularly cloned from immunosuppressed renal transplant patients.

From nonimmunocompromised individuals, we have recently identified a possible archetypal JC virus DNA sequence from which various regulatory sequences of JC virus isolates derived from patients with progressive multifocal leukoencephalopathy (PML) could have evolved. In this study, we analyzed the regulatory sequences of JCV DNAs cloned from urine samples of a PML risk group (renal transplant patients on immunosuppressive therapy). A number of JC virus DNAs were molecularly cloned from virions excreted in the urine of eight patients. Furthermore, fragments containing the regulatory region were amplified by the polymerase chain reaction and subsequently molecularly cloned from cell-associated JC virus excreted in the urine of two patients. The regulatory regions in all clones were analyzed with restriction enzymes, and those in representative clones were sequenced. We found that clones with the archetypal regulatory sequence were predominant in all urine samples, but a few clones carried regulatory sequences that diverged from the archetypal sequence by deletion or duplication. The finding that sequence rearrangement in the archetypal regulatory region occurs in the course of infection in immunosuppressed hosts is consistent with the adaptation hypothesis which has been put forward to explain the divergence of the regulatory regions in PML-derived JC virus isolates.     

Occurrence of differentiated keratin peptide(K1) in cultured human squamous cell carcinomas.

To date, the largest keratin peptide(K1, 68 KD) has been absent in cultured human squamous cell carcinomas. Using a low salt aqueous solution, not containing high salt and Triton X-100, as a washing buffer for keratin extraction, followed by two dimensional polyacrylamide gel electrophoresis, immunological techniques and Northern blot analysis, we demonstrated K1 peptide in two kinds of cultured human squamous cell carcinomas. Until now keratin extraction has been done using high salt/Triton X-100 solution during which K1 peptide may be removed together developed an affinity with the buffer. Many investigators may have therefore overlooked K1.     

Microwave treatment of cellulosic materials for their enzymatic hydrolysis

Summary Rice straw and bagasse with water content 84 or 94% were irradiated with microwave (2450MHz) in sealed glass vessels. This treatment enhanced markedly the accessibility of the cellulosic materials for the enzymatic hydrolysis: for example, 1.6 times in the rice straw by the microwave treatment at 170 °C for 5 min and 3.2 times in the bagasse by the treatment at 200 °C for 5 min, compared with the untreated.     

Missing piece of top predator-based conservation: Demographic analysis of an owl population on a remote subtropical island

Top predators are frequently the target of conservation programs. Owls are such predators. However, previous studies of owls are biased to species occurring in temperate regions, whereas most owl species occur in tropical or subtropical regions and are understudied. Furthermore, owls are often endemic to islands and of unknown conservation status. Demographic data for such species are especially scarce although they are essential for initiating and promoting their conservation. As a case study of demographic analysis of owls in a tropical or subtropical area and on islands, we applied an integrated population model to 7-year monitoring data (2012–2018) of the Ryukyu Scops Owl population on Minami-daito Island, Japan. We used survival history data from 903 individuals, reproduction and sex ratio data from 213 broods, and count data of 2,526 individuals in total. Long-term averages of annual survival rates were 0.73 for adult females and 0.74 for adult males, although the sexual difference was not significant. Sex ratio estimates fluctuated annually and long-term averages were slightly skewed to males: 0.51 among fledglings, 0.54 among yearlings, and 0.52 among adults. Long-term averages of population size were estimated to be 273.4 females and 296.8 males. The long-term average of population growth rate was 0.98, suggesting a slightly declining trend. It was fortunate to recognize the declining trend during the early phase. Considering the general lack of fundamental ecological data on owls of tropical or subtropical areas and on islands, it seems likely that many endangered owl populations await conservation efforts.     

Polyethylene Glycol–Modified Papain Catalyzed Oligopeptide Synthesis from the Esters of l-Aspartic and l-Glutamic Acids in Benzene

Comparative studies were made of the polymerization of l-aspartic and l-glutamic acid dialkyl esters using polyethylene glycol–modified papain as a catalyst in phosphate buffer (pH 7.5) and in benzene. Changes in the substrate specificity of papain and in the composition of oligomerized products were observed. In the buffer, the diethyl and di-n-propyl esters of l-glutamic acid were sufficiently converted to high molecular weight oligomers with the accumulation of dimer and trimer, but l-aspartic acid esters were very poor substrates. In benzene, l-aspartic acid esters became more reactive than L-glutamic acid esters. In particular, from l-aspartic acid dimethyl ester the product, which was mainly composed of heptamer to decamer, was obtained in a 90% yield. The reaction in benzene required desalted substrates and a small amount of water to proceed extensively.     

Enhanced Stability and Thickness‐Independent Oxygen Evolution Electrocatalysis of Heterostructured Anodes with Buried Epitaxial Bilayers

Achieving high oxygen evolution reaction (OER) activity while maintaining performance stability is a key challenge for designing perovskite structure oxide OER catalysts, which are often unstable in alkaline environments transforming into an amorphous phase. While the chemical and structural transformation occurring during electrolysis at the electrolyte–catalyst interface is now regarded as a crucial factor influencing OER activity, here, using La_0.7Sr_0.3CoO_3?δ (LSCO) as an active OER catalyst, the critical influence of buried layers on the oxidation current stability in nanoscopically thin, chemically and structurally evolving, catalyst layers is revealed. The use of epitaxial thin films is demonstrated to engineer both depletion layer widths and chemical stability of the catalyst support structure resulting in heterostructured anodes that maintain facile transport kinetics across the electrolyte–anode interface for atomically thin (2–3 unit cells) LSCO catalyst layers and greatly enhanced oxidation current stability as the perovskite structure OER catalysts chemically and structurally transform. This work opens up an approach to design robust and active heterostructured anodes with dynamically evolving ultrathin OER electrocatalyst layers for future green fuel technologies such as conformal coatings of high‐density 3D anode topologies for water splitting.     

Molecular cloning, functional expression, and mutagenesis of cDNA encoding class I chitinase from rye (Secale cereale) seeds

A cDNA encoding rye seed chitinase-a (RSC-a) was cloned by rapid amplification of cDNA ends and PCR procedures. It consists of 1,191 nucleotides and encodes an open reading frame of 321 amino acid residues. Recombinant RSC-a (rRSC-a) was produced in the oxidative cytoplasm of Escherichia coli Origami(DE3) in a soluble form by inducing bacteria at a low temperature (20 degrees C). Purified rRSC-a showed properties similar to the original enzyme from rye seeds in terms of chitinase activity toward a soluble substrate, glycolchitin, and an insoluble substrate, chitin beads, in chitin-binding ability to chitin, and in antifungal activity against Trichoderma sp. in vitro. rRSC-a mutants were subsequently produced and purified by the same procedures as those for rRSC-a. Mutation of Trp23 to Ala decreased the chitinase activity toward both substrates and impaired the chitin-binding ability. Furthermore, the antifungal activity of this mutant was weakened with increasing of the NaCl concentration in the culture medium. Complete abolishment of both activities was observed upon the mutation of Glu126 to Gln. The roles of these residues in both activities are discussed.     

Role of caveolin-1 and cytoskeletal proteins, actin and vimentin, in adipogenesis of bovine intramuscular preadipocyte cells

We investigated the involvement of caveolin-1 and the cytoskeletal proteins, actin and vimentin, in the adipogenesis of bovine intramuscular preadipocyte (BIP) cells. Immunoblot analysis demonstrated that levels of caveolin-1 and actin gradually increased during adipose conversion in BIP cells, whereas a slight decrease was observed for vimentin. We found that part of the vimentin was clearly distributed to caveolin-1-enriched membrane fractions in BIP cells, but actin was not. During adipogenesis of BIP cells, treatment with the tubulin depolymerizer, nocodazole, significantly increased intracellular triglyceride accumulation compared to non-treated cells. Immunocytochemical analysis showed that actin microfilaments were significantly disrupted in nocodazole-treated cells. Also, a decrease in the localization of vimentin in caveolin-1-enriched fractions and a failure of vimentin to co-immunoisolate with caveolin-1 were observed in nocodazole-treated cells. These results suggest that a rearrangement of cytoskeletal proteins has a role in the intracellular accumulation of lipid droplets during adipogenesis of BIP cells.