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.     

Predictors of objectively measured snoring in a working population

Sleep and Biological Rhythms - Although there have been many epidemiological studies of snoring, most did not assess snoring objectively. The aim of this study was to identify predictive factors...     

Decoding Humor Experiences from Brain Activity of People Viewing Comedy Movies

Humans naturally have a sense of humor. Experiencing humor not only encourages social interactions, but also produces positive physiological effects on the human body, such as lowering blood pressure. Recent neuro-imaging studies have shown evidence for distinct mental state changes at work in people experiencing humor. However, the temporal characteristics of these changes remain elusive. In this paper, we objectively measured humor-related mental states from single-trial functional magnetic resonance imaging (fMRI) data obtained while subjects viewed comedy TV programs. Measured fMRI data were labeled on the basis of the lag before or after the viewer’s perception of humor (humor onset) determined by the viewer-reported humor experiences during the fMRI scans. We trained multiple binary classifiers, or decoders, to distinguish between fMRI data obtained at each lag from ones obtained during a neutral state in which subjects were not experiencing humor. As a result, in the right dorsolateral prefrontal cortex and the right temporal area, the decoders showed significant classification accuracies even at two seconds ahead of the humor onsets. Furthermore, given a time series of fMRI data obtained during movie viewing, we found that the decoders with significant performance were also able to predict the upcoming humor events on a volume-by-volume basis. Taking into account the hemodynamic delay, our results suggest that the upcoming humor events are encoded in specific brain areas up to about five seconds before the awareness of experiencing humor. Our results provide evidence that there exists a mental state lasting for a few seconds before actual humor perception, as if a viewer is expecting the future humorous events.