Current perspectives of viral hepatitis.

Viral hepatitis represents a major danger to public health, and is a globally leading cause of death. The five liver-specific viruses: Hepatitis A virus, hepatitis B virus, hepatitis C virus, hepatitis D virus, and hepatitis E virus, each have their own unique epidemiology, structural biology, transmission, endemic patterns, risk of liver complications, and response to antiviral therapies. There remain few options for treatment, in spite of the increasing prevalence of viral-hepatitis-caused liver disease. Furthermore, chronic viral hepatitis is a leading worldwide cause of both liver-related morbidity and mortality, even though effective treatments are available that could reduce or prevent most patients' complications. In 2016, the World Health Organization released its plan to eliminate viral hepatitis as a public health threat by the year 2030, along with a discussion of current gaps and prospects for both regional and global eradication of viral hepatitis. Today, treatment is sufficiently able to prevent the disease from reaching advanced phases. However, future therapies must be extremely safe, and should ideally limit the period of treatment necessary. A better understanding of pathogenesis will prove beneficial in the development of potential treatment strategies targeting infections by viral hepatitis. This review aims to summarize the current state of knowledge on each type of viral hepatitis, together with major innovations.

SARS-CoV-2 Contamination on Healthy Individuals' Hands in Community Settings During the COVID-19 Pandemic.

Introduction Hand hygiene is an infection control measure for COVID-19 in our daily lives; however, the contamination levels of SARS-CoV-2 in the hands of healthy individuals remain unclear. Thus, we aimed to evaluate SARS-CoV-2 contamination levels by detecting viral RNA and viable viruses in samples obtained from the hands of 925 healthy individuals. Methods Swab samples were collected from the palms and fingers of healthy participants, including office workers, public officers, university students, university faculty and staff, and hospital staff between December 2022 and March 2023. The collected swab samples were analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) for SARS-CoV-2 RNA detection. Viral RNA-positive samples were subjected to plaque assay to detect viable viruses. Results We collected 1,022 swab samples from the hands of healthy participants. According to the criteria for data collection, 97 samples were excluded, and 925 samples were analyzed using RT-qPCR. SARS-CoV-2 RNA was detected in three of the 925 samples. The viral RNA detection rate was 0.32% (3/925), and the viral RNA copy numbers ranged from 5.0×103 to 1.7×105 copies/mL. The RT-qPCR-positive samples did not contain viable viruses, as confirmed by the plaque assay results. Conclusions The detection rate of SARS-CoV-2 RNA from the hands of healthy individuals was extremely low, and no viable viruses were detected. These results suggest that the risk of contact transmission via hands in a community setting is extremely rare.

Fluctuation in SARS-CoV-2 Environmental Surface Contamination Levels in Homes Where Patients With COVID-19 Stayed for Recuperation.

Introduction Transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) often occurs among family members. Elucidating where viable SARS-CoV-2 virions, and not just residual viral RNA, are present in the house is necessary to prevent the further spread of the coronavirus disease 2019 (COVID-19). We aimed to evaluate the environmental surface contamination levels of both SARS-CoV-2 RNA and viable viruses in the homes of housebound patients with COVID-19. Methods Environmental samples were collected from the households of three patients in April and July 2022 when the number of new COVID-19 cases in Japan was reported to be approximately 50,000 and 200,000 cases per day, respectively. For each case, samples were obtained from 19-26 household sites for seven consecutive days. SARS-CoV-2 RNA was examined in 455 samples through reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and RT-qPCR-positive samples were subjected to plaque assay to detect viable viruses. Results Among the 455 samples, 63 (13.8%) that were collected from patients' pillows and comforters, doorknobs, chairs, and refrigerators tested positive by RT-qPCR. The maximum detection rate of SARS-CoV-2 RNA-positive samples in each case ranged from 20.0% to 57.7% on days 1 to 3. The detection rate gradually decreased to 0-5.3% as the days elapsed. Although all RT-qPCR-positive samples were examined, no viable viruses were detected in these samples. Conclusions Although environmental contamination of SARS-CoV-2 RNA was observed in the homes of housebound patients with COVID-19, no viable viruses were isolated. This suggests that the indirect transmission risk from fomites was low.

Levels of environmental contamination with SARS-CoV-2 in hospital rooms and salivary viral loads of patients with coronavirus disease 2019.

BACKGROUND: Clarifying the presence of viable severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rather than SARS-CoV-2 viral RNA in inpatient rooms is important for infection control of coronavirus disease 2019 (COVID-19). In this study, we investigated levels of viral RNA and viable virus on environmental surfaces and in patient saliva. METHODS: Environmental samples from 23 sites in hospital rooms were collected every other day until patient discharge. Saliva specimens and samples from the inner surface of patient masks were also collected. Additionally, environmental samples were collected from 46 sites in hospital rooms on discharge day. The samples were examined using quantitative reverse transcription polymerase chain reaction (RT-qPCR) and plaque assays. RESULTS: The 10 enrolled cases were classified as mild COVID-19, and patients were discharged after 6-9 days. The viral RNA was detected in 12.4% (105/849) of serially collected environmental samples during hospitalization, whereas viable virus was detected only in 0.47% (4/849), which were from sinks and tap levers. Although all patients recovered, three cases retained viable virus in the last saliva specimen collected. In the 15 discharged rooms, viral RNA was detected in 6.6% (45/682) of the samples, and viable virus was detected in only one sample from the sink. CONCLUSIONS: Although environmental surfaces surrounding patients with COVID-19 were frequently contaminated with viral RNA, the presence of viable virus was rare and limited only to areas around sinks. These results suggest that contact infection risk via fomites in hospital rooms is extremely rare.

Assessment of environmental surface contamination with SARS-CoV-2 in concert halls and banquet rooms in Japan.

BACKGROUND: Although crowds are considered to be a risk factor for SARS-CoV-2 transmission, little is known about the changes in environmental surface contamination with the virus when a large number of people attend an event. In this study, we evaluated the changes in environmental surface contamination with SARS-CoV-2. METHODS: Environmental samples were collected from concert halls and banquet rooms before and after events in February to April 2022 when the 7-day moving average of new COVID-19 cases in Tokyo was reported to be 5000-18000 cases per day. In total, 632 samples were examined for SARS-CoV-2 by quantitative reverse transcription polymerase chain reaction (RT-qPCR) tests, and RT-qPCR-positive samples were subjected to a plaque assay. RESULTS: The SARS-CoV-2 RNA detection rate before and after the events ranged from 0% to 2.6% versus 0%-5.0% in environmental surface samples, respectively. However, no viable viruses were isolated from all RT-qPCR-positive samples by the plaque assay. There was no significant increase in the environmental surface contamination with SARS-CoV-2 after these events. CONCLUSIONS: These findings revealed that indirect contact transmission from environmental fomite does not seem to be of great magnitude in a community setting.

Development of Direct Immobilization Technique of Ag Nanoparticles on Resin Substrates Imparting High Antibacterial and Antiviral Activities.

A new method has been developed to impart the antimicrobial activity of silver nanoparticles to resin substrates. A resin substrate immersed in an aqueous solution of silver nitrate was irradiated with gamma ray or high energy electron beams. Silver nanoparticles were successfully immobilized on the resin surface directly by chemical reactions induced by ionizing radiation. It was experimentally confirmed that various resin materials, such as acrylonitrile-butadiene-styrene, polyethylene, polypropylene, polyvinyl chloride, and polycarbonate, were applicable for this process. The effects of gamma ray or electron beam irradiation on resin substrates were almost negligible since the irradiation dose was equal or less than that used for sterilization. Despite the small amount of Ag loadings, the obtained samples showed high antibacterial and antiviral activities.

Effective induction of death in mesothelioma cells with magnetite nanoparticles under an alternating magnetic field.

With the objective of finding an avenue for development of magnetic hyperthermia as an effective mesothelioma treatment, the influence of heating by magnetite nanoparticles (MNPs) with a diameter of ~40nm, which were incorporated into cells and then subjected to AC magnetic field, on induction of cell death was investigated in all three histological subtypes of human mesothelioma cells (i.e., epithelioid NCI-H28, sarcomatoid NCI-H2052, and biphasic MSTO-211H cells). Cellular uptake of MNPs was observed in all cell types, but the amount of MNPs incorporated per cell into MSTO-211H cells was smaller than in NCI-H28 and NCI-H2052 cells. On the other hand, cell death induced by cellular uptake of MNPs was observed specifically in MSTO-211H cells. Hence, when cells are heated by intracellular MNPs under AC magnetic field, a high degree of cell mortality in NCI-H28 and NCI-H2052 cells is induced by the temperature increase derived from the high amount of intracellular MNPs, but the combination of intracellular heating and cell-type-specific toxicity of MNPs induced high rates of cell death in MSTO-211H cells even at a lower temperature. Almost all of the heated cells were dead after 24-h incubation at 37°C in all histological subtypes. Additionally, higher mortalities were observed in all three types of mesothelioma cells after MNPs-heating, as compared to the heating with a thermostatic bath. Herein, the significance of cellular uptake of MNPs for effectively inducing cell death in mesothelioma has been demonstrated in vitro.

Activation of NMDA receptors thickens the postsynaptic density via proteolysis.

The postsynaptic density (PSD) is a protein complex that is critical for synaptic transmission. Ultrastructural changes in the PSD are therefore likely to modify synaptic functions. In this study, we investigated the ultrastructural changes in the PSD in the hippocampal CA1 stratum radiatum following neuronal excitation. Oxygen-glucose deprivation-induced PSD thickening in hippocampal slice cultures was blocked by the N-methyl-d-aspartate (NMDA) receptor antagonist MK801. To gain more insight into the mechanisms underlying NMDA receptor-mediated PSD thickening, we assessed the area, length, and thickness of the PSD after NMDA treatment. The PSDs thickened with just 2 min of NMDA receptor stimulation, and this treatment was considered sublethal. When N-acetyl-leucyl-leucyl-norleucinal, an inhibitor of calpain, cathepsins, and the proteasome, was applied, NMDA-induced PSD thickening was abolished. Furthermore, the calcium-induced calcium release inhibitor, ryanodine, reduced NMDA receptor-mediated PSD thickening. These results suggest that NMDA receptor activation induces PSD thickening by proteolysis through intracellular calcium increase, including that induced by calcium.

High-throughput walkthrough detection portal for counter terrorism: detection of triacetone triperoxide (TATP) vapor by atmospheric-pressure chemical ionization ion trap mass spectrometry.

With the aim of improving security, a high-throughput portal system for detecting triacetone triperoxide (TATP) vapor emitted from passengers and luggage was developed. The portal system consists of a push-pull air sampler, an atmospheric-pressure chemical ionization (APCI) ion source, and an explosives detector based on mass spectrometry. To improve the sensitivity of the explosives detector, a novel linear ion trap mass spectrometer with wire electrodes (wire-LIT) is installed in the portal system. TATP signals were clearly obtained 2 s after the subject under detection passed through the portal system. Preliminary results on sensitivity and throughput show that the portal system is a useful tool for preventing the use of TATP-based improvised explosive devices by screening persons in places where many people are coming and going.

Quantification of cyanamide contents in herbaceous plants.

Cyanamide (NH2CN) is found in nature, although it has long been recognized as an industrial product. Distribution of cyanamide in the plant kingdom was investigated using a direct quantitative determination method to detect and measure cyanamide by stable isotope dilution gas chromatography-mass spectrometry (the SID-GC-MS method). The SID-GC-MS method proved to be a robust way to quantify cyanamide contents in the extracts of 101 species of herbaceous plants. The average recovery of cyanamide from all plants tested was 55.6+/-20.3%. Vicia villosa and V. cracca contained cyanamide at 369-498 microg/gFW and 3,460-3,579 microg/gFW respectively, while the other 99 species contained no detectable cyanamide (<1 microg/gFW). This result suggests that distribution of cyanamide in the plant kingdom is limited and uneven.

Evidence of cyanamide production in hairy vetch Vicia villosa.

Cyanamide (NH(2)CN) has recently been isolated as a plant growth inhibitor from Vicia villosa, which is the first discovery of cyanamide from natural sources. To reveal the presence of the biosynthesized cyanamide in plants, 3.4 mM potassium ((15)N)nitrate was administered to 15- to 35-day-old plants of V. villosa, from which the cyanamide was purified and subjected to GC/MS analysis. The isotopic ratio (15)N/((14)N + (15)N) of the cyanamide was calculated to be 0.143, while that of the cyanamide extracted from V. villosa grown in the presence of a natural N source was 0.0065. The (15)N-enrichment proved de novo biosynthesis of cyanamide.

Involvement of protein phosphatase 2A in the maintenance of E-cadherin-mediated cell-cell adhesion through recruitment of IQGAP1.

Serine/threonine protein phosphatase (PP) 2A regulates many biological processes, however it remains unclear whether PP2A participates in cadherin-mediated cell-cell adhesion. We show here that the core enzyme of PP2A (PP2A-AC) is localized in the cell-cell adhesion sites between adjacent cells and associated with the E-cadherin-catenins complex in non-malignant human mammary epithelial (HME) cells at confluence. Treatment of the cells with either okadaic acid (OA), an inhibitor of PP2A, or siRNA for the regulatory subunit A of PP2A (PP2A-A) caused disruption of cell-cell adhesion and F-actin assembly, without affecting the complex formation of E-cadherin with beta- and alpha-catenins. While a small GTPase Rac and its effector IQGAP1 were associated with the E-cadherin-catenins complex, either OA or PP2A-A siRNA concomitantly induced the dissociation of IQGAP1, but not Rac, from the complex and the internalization of E-cadherin from the cell surface. We therefore propose that PP2A plays a crucial role in the maintenance of cell-cell adhesion through recruitment of IQGAP1 to the Rac-bound E-cadherin-catenins complex.

Direct quantitative determination of cyanamide by stable isotope dilution gas chromatography-mass spectrometry.

Cyanamide is a multifunctional agrochemical used, for example, as a pesticide, herbicide, and fertilizer. Recent research has revealed that cyanamide is a natural product biosynthesized in a leguminous plant, hairy vetch (Vicia villosa). In the present study, gas chromatography-mass spectrometry (GC-MS) equipped with a capillary column for amines was used for direct quantitative determination of cyanamide. Quantitative signals for ((14)N(2))cyanamide, ((15)N(2))cyanamide (internal standard for stable isotope dilution method), and m-(trifluoromethyl)benzonitrile (internal standard for correcting errors in GC-MS analysis) were recorded as peak areas on mass chromatograms at m/z 42 (A(42)), 44 (A(44)), and 171 (A(IS)), respectively. Total cyanamide content, ((14)N(2))cyanamide plus ((15)N(2))cyanamide, was determined as a function of (A(42)+A(44))/A(IS). Contents of ((14)N(2))cyanamide and ((15)N(2))cyanamide were then calculated by multiplying the total cyanamide content by A(42)/(A(42)+A(44)) and A(44)/(A(42)+A(44)), respectively. The limit of detection for the total cyanamide content by the GC-MS analysis was around 1ng. The molar ratio of ((14)N(2))cyanamide to ((15)N(2))cyanamide in the injected sample was equal to the observed A(42)/A(44) value in the range from 0.1 to 5. It was, therefore, possible to use the stable isotope dilution method to quantify the natural cyanamide content in samples; i.e., the natural cyanamide content was derived by subtracting the A(42)/A(44) ratio of the internal standard from the A(42)/A(44) ratio of sample spiked with internal standard, and then multiplying the resulting difference by the amount of added ((15)N(2))cyanamide (SID-GC-MS method). This method successfully gave a reasonable value for the natural cyanamide content in hairy vetch, concurring with the value obtained by a conventional method in which cyanamide was derivatized to a photometrically active compound 4-cyanimido-1,2-naphthoquinone and analyzed with reversed-phase HPLC (CNQ-HPLC method). The determination range of cyanamide in the SID-GC-MS method was almost the same as that in the CNQ-HPLC method; however, the SID-GC-MS method was much simpler than the CNQ-HPLC method.

Mitotic dissociation of IQGAP1 from Rac-bound beta1-integrin is mediated by protein phosphatase 2A.

Assembly of F-actin that links with beta1-integrin during the G1 phase of cell cycle is released from beta1-integrin and disrupted at mitosis. However, it remains unclear how F-actin assembly to which beta1-integrin anchors is cell cycle-dependently regulated. We show that beta1-integrin was co-immunoprecipitated and co-localized with a small GTPase Rac and its effector IQGAP1, along with PP2A-AC, in HME cells during G1. When the cells were accumulated to G2/M, the co-immunoprecipitation or co-localization of IQGAP1 and PP2A-AC with beta1-integrin was lost, leaving Rac bound to beta1-integrin. The dissociated IQGAP1 was co-immunoprecipitated with the concomitantly dissociated PP2A-A and -C, indicating the complex formation among the proteins in G2/M cells. Falling ball viscometric assays revealed that only IQGAP1-bound beta1-integrin-Rac in G1 cells exhibited an enhanced F-actin cross-linking activity. The results suggest that the mitotic loss of F-actin assembly to which beta1-integrin anchors is due to PP2A-mediated dissociation of IQGAP1 from Rac-bound beta1-integrin.

Growth inhibitory alkaloids from mesquite (Prosopis juliflora (Sw.) DC.) leaves.

Plant growth inhibitory alkaloids were isolated from the extract of mesquite [Prosopis juliflora (Sw.) DC.] leaves. Their chemical structures were established by ESI-MS, 1H and 13C NMR spectra analysis. The I50 value (concentration required for 50% inhibition of control) for root growth of cress (Lepidium sativum L.) seedlings was 400 microM for 3''''-oxo-juliprosopine, 500 microM for secojuliprosopinal, and 100 microM for a (1:1) mixture of 3-oxo-juliprosine and 3'-oxo-juliprosine, respectively. On the other hand, the minimum concentration exhibiting inhibitory effect on shoot growth of cress seedlings was 10 microM for 3''''-oxo-juliprosopine, 100 microM for secojuliprosopinal, and 1 microM for a (1:1) mixture of 3-oxo-juliprosine and 3'-oxo-juliprosine, respectively. Among these compounds, a (1:1) mixture of 3-oxo-juliprosine and 3'-oxo-juliprosine exhibited the strongest inhibitory effect on the growth of cress seedlings.

Isolation and identification of lateral bud growth inhibitor, indole-3-aldehyde, involved in apical dominance of pea seedlings.

A lateral bud growth inhibitor was isolated from etiolated pea seedlings and identified as indole-3-aldehyde. The indole-3-aldehyde content was significantly higher in the diffusates from explants with apical bud and indole-3-acetic acid treated decapitated explants, in which apical dominance is maintained, than in those from decapitated ones releasing apical dominance. When the indole-3-aldehyde was applied to the cut surface of etiolated decapitated plants or directly to the lateral buds, it inhibited outgrowth of the latter. These results suggest that indole-3-aldehyde plays an important role as a lateral bud growth inhibitor in apical dominance of pea seedlings.