Aggressive encounters between males inChrysolina aurichalcea (Coleoptera: Chrysomelidae)

During the breeding season ofC. aurichalcea, an unpaired male is occasionally seen attacking a mating male on the host plant,Artemisia princeps. To clarify the significance of this behaviour, aggressive encounters between an unpaired male and a mating male were observed 269 times in experimental conditions. Intruders resulted in take-over (10.4%), loss (36.5%), draw (39.0%), or non-interference (14.1%). Frontal attack had 5 times higher probability of take-over than back one. A larger unpaired male had a slightly greater chance of take-over (P<0.02). The importance of aggressive encounters was discussed in view of sperm competition and of cost and benefit.     

A new model for the bending of DNAs containing the oligo(dA) tracts based on NMR observations.

The conformations of double-stranded d(GGAAATTTCC) x 2, d(GGTTTAAACC) x 2, d(CGCAAAAAAGCG)d(CGCTTTTTTGCG) and d(GCATTTTGAAACG)d(CGTTTCAAAATGC) have been studied by NMR spectroscopy. Analyses of cross peaks in NOESY spectra between the H2 of an adenine and the H1' of a deoxyribose in the 3'-neighbouring residue on the complementary strand revealed that the minor groove of the oligo(dA) tract is compressed gradually from 5' to 3' in each duplex. In view of this gradual compression of the minor groove along the oligo(dA) tract, it can be understood clearly why d(GGAAATTTCC)n x 2 and d(GAAAATTTTC)n x 2 are bent, and d(GGTTTAAACC)n x 2 and d(GTTTTAAAAC)n x 2 are not bent. The relative extents of bending of a series of d(AjN10-j)nd(N10-jTj)n sequences can also be understood systematically. Additionally, it was found that the TA step disturbed the compression of the minor groove of the oligo(dA) tract to some extent.     

Observation by SEM of the attachment ofAgrobacterium tumefaciens to the surface of vinca,asparagus and rice cells

Transformation of vinca cells was performed by the co-cultivation of cell-wall regenerated vinca protoplasts withAgrobacterium tumefaciens. Using thisin vitro and single cell system, attachment of the bacteria to the surface of vinca cells was observed by scanning electron microscopy (SEM). Figures of the bacteria polarly binding to the plant cell wall were often observed. AsEscherichia coli does not attach to the plant cells at all, the observed attachment ofA. tumefaciens is suggested as a characteristic feature in crown gall induction. Even though no evidence of transformation was obtained by the co-cultivation methods, a similar attachment was observed in the cell-wall regenerated protoplasts of rice. The bacteria also attached to the surface of isolated mesophyll cells of asparagus and root hairs of rice. From these observation, we concluded that the attachment is not the limiting step of crown gall induction byA. tumefaciens in monocotyledonous plants. Extracellular fibrils like pili were observed with a few strains of A.tumefaciens for the first time. These fibrils were observed regardless of their ability of attachment and infectivity.     

Chinese medicine,Coix seeds increase peripheral cytotoxic T and NK cells

Coix seeds, a Chinese medicine have been used in Japan and reported to be effective in patients with verruca vulgaris and verrucae planae juveniles. We investigated thein vivo effects on lymphocyte subsets in seven healthy volunteers who took six tablets of Coix seeds three times a day (a typical dose) for four weeks. Leukocyte counts and the percentage of total lymphocytes did not change but the percentages of CD3^–CD56⁺ cells and CD16⁺CD57^– cells increased significantly. These results indicate that Coix seeds increase peripheral cytotoxic lymphocytes and may be effective to viral infection through the enhancement of cytotoxic activity.     

Morphological changes in a human scirrhous gastric carcinoma cell line (KATO-III) when cultured in collagen-coated dishes

The morphological differences between cells of a human scirrhous gastric carcinoma cell line (KATO-III) cultured in plastic dishes and in collagen-coated dishes were examined by phase-contrast and electron microscopy. When KATO-III cells were inoculated into plastic dishes, a few cells became attached to the surface of the dishes and the rest remained in suspension. However, when they were inoculated into collagen-coated dishes, they all remained in suspension. In both types of dish, most of the cells in suspension were single although a few were in clusters. The cells in suspension in collagen-coated dishes differed in morphology from those in the plastic dishes. They had abundant cytoplasm, well-developed Golgi complexes, and many microvillus-like cell protrusions. Moreover, they had hemidesmosome-like and desmosome-like structures on their surface and an increased amount of intracytoplasmic desmosome-like structures. The cells in clusters in the collagen-coated dishes were closely connected by junctional complexes, such as tight junctions, desmosomes and interdigitations, whereas those in plastic dishes were linked only by desmosomes. These results suggest that collagen affects the morphology of human scirrhous carcinoma cells.     

Interleukin 2 enhances natural killing of normal lymphocytes

Purified Interleukin 2 (IL-2), free of interferon (IFN), significantly enhanced NK activity of normal human peripheral blood mononuclear cells (PBMC). This enhancing activity was absorbed by IL-2 receptor-bearing cells but was not blocked by antibody to α-IFN. IFN in the culture supernatants was greatly increased after stimulation with poly(I:C) plus IL-2. There was less IFN produced by either modulator acting alone. Stimulation of PBMC with IL-2 and/or poly(I:C) increased the proportion of OKM1⁺ cells and anti-Leu-7⁺ cells. When cells expressing either surface antigen were specifically lysed to deplete NK, cytotoxic activity could be restored by overnight incubation in IL-2. This result suggests that IL-2 stimulates the development of NK cells from precursors that lack cell surface OKM1 or Leu-7. IL-2 acted directly on large granular lymphocytes and did not require the presence of adherent cells. These results suggest that IL-2 may act synergistically with other IFN inducers and may play an important role in the regulation of NK cells.     

Hemoglobin Decrease with Iron Deficiency Induced by Daclatasvir plus Asunaprevir Combination Therapy for Chronic Hepatitis C Virus Genotype 1b

Background

Decreased hemoglobin (Hb) level has been supposed to be a relatively rare side effect of a combination therapy against hepatitis C virus that consists of the NS5A inhibitor daclatasvir (DCV) and the NS3/4A protease inhibitor asunaprevir (ASV).

Methods

The study was conducted in 75 patients with genotype 1b chronic hepatitis C virus infection who had started combination therapy with DCV and ASV at St. Marianna University School of Medicine Hospital between September 2014 and December 2014.

Results

Among the patients examined, decreased Hb level by ≥1.5 g/dL from the values at treatment initiation was observed in 11 individuals. This was accompanied by decreased mean corpuscular volume, and iron and ferritin levels.

Conclusions

These findings suggest that the mechanism of the phenomenon is caused by iron deficiency. The underlying mechanism and clinical impacts will need to be further examined.     

Severe Fever with Thrombocytopenia Syndrome Virus Antigen Detection Using Monoclonal Antibodies to the Nucleocapsid Protein

Background

Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne infectious disease with a high case fatality rate, and is caused by the SFTS virus (SFTSV). SFTS is endemic to China, South Korea, and Japan. The viral RNA level in sera of patients with SFTS is known to be strongly associated with outcomes. Virological SFTS diagnosis with high sensitivity and specificity are required in disease endemic areas.

Methodology/Principal Findings

We generated novel monoclonal antibodies (MAbs) against the SFTSV nucleocapsid (N) protein and developed a sandwich antigen (Ag)-capture enzyme-linked immunosorbent assay (ELISA) for the detection of N protein of SFTSV using MAb and polyclonal antibody as capture and detection antibodies, respectively. The Ag-capture system was capable of detecting at least 350–1220 TCID₅₀/100 μl/well from the culture supernatants of various SFTSV strains. The efficacy of the Ag-capture ELISA in SFTS diagnosis was evaluated using serum samples collected from patients suspected of having SFTS in Japan. All 24 serum samples (100%) containing high copy numbers of viral RNA (>10⁵ copies/ml) showed a positive reaction in the Ag-capture ELISA, whereas 12 out of 15 serum samples (80%) containing low copy numbers of viral RNA (<10⁵ copies/ml) showed a negative reaction in the Ag-capture ELISA. Among these Ag-capture ELISA-negative 12 samples, 9 (75%) were positive for IgG antibodies against SFTSV.

Conclusions

The newly developed Ag-capture ELISA is useful for SFTS diagnosis in acute phase patients with high levels of viremia.     

Muramidase Catalyzed Hydrolysis of p-Nitrophenylacetate

It was found that muramidase can catalyze the hydrolysis of p-nitrophenylacetate (NPA) producing p-nitrophenol and acetic acid. The activity of muramidase for NPA, however, simply increased on raising a temperature and with an increase in alkalinity of reaction mixture. The mechanism of muramidase catalyzed hydrolysis of NPA differs from that of chymotrypsin which can catalyze burstly the hydrolysis of NPA by its histsdine residue.

The amount of reducing power produced owing to the hydrolysis of glycol chitin by muramidase was not affected by the presence of NPA, and inversely, the hydrolysis of NPA was not affected by glycol chitin. Obviously, there was no competitive inhibition between NPA and glycol chitin. The responses of modified muramidase to glycol chitin and to NPA did not correspond at all. The catalytic site of muramidase for glycol chitin may be different from that of muramidase for NPA. The hydrolysis of NPA is catalyzed by some free amino groups in the muramidase molecule, while the catalytic site for glycol chitin is not known.     

Coronary Vasoactivity of Novel N6-Substituted Adenosines

Abstract

Previous studies of the structure-coronary vasoactivity relationships of adenosines substituted at N-6 identified certain simple alkyl and aralkyl groups that can promote activity and others that reduce activity. The present study shows that such alkyl and aryl moieties, when combined in an N-6 substituent, can contribute additively to coronary vasoactivity.