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1.
J Korean Med Sci ; 39(4): e38, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38288539

RESUMO

BACKGROUND: Human adenovirus (HAdV) is a common cause of acute respiratory disease (ARD) and has raised significant concerns within the Korean military. Here, we conducted a comprehensive epidemiological analysis of HAdV-associated ARD by evaluating its prevalence, clinical outcomes, and prognosis. METHODS: We reviewed data from multiple sources, including the New Defense Medical Information System, Defense Medical Statistical Information System, Ministry of National Defense, Army Headquarters, Navy Headquarters, Air Force Headquarters, and Armed Forces Medical Command. We analyzed data of patients who underwent polymerase chain reaction (PCR) testing for respiratory viruses between January 2013 and July 2022 in all 14 Korean military hospitals. The analysis included the PCR test results, demographic characteristics, health care utilization, and prognosis including types of treatments received, incidence of pneumonia, and mortality. RESULTS: Among the 23,830 individuals who underwent PCR testing at Korean military hospitals, 44.78% (10,670 cases) tested positive for respiratory viruses. Across all military types and ranks, HAdV was the most prevalent virus, with a total of 8,580 patients diagnosed, among HAdV, influenza virus, human metapneumovirus, human parainfluenza virus, and human respiratory syncytial virus. HAdV-infected patients exhibited higher rates of healthcare use compared to non-HAdV-infected patients, including a greater number of emergency visits (1.04 vs. 1.02) and outpatient visits (1.31 vs. 1.27), longer hospitalizations (8.14 days vs. 6.84 days), and extended stays in the intensive care unit (5.21 days vs. 3.38 days). Furthermore, HAdV-infected patients had a higher proportion of pneumonia cases (65.79% vs. 48.33%) and greater likelihood of receiving advanced treatments such as high flow nasal cannula or continuous renal replacement therapy. CONCLUSION: Our findings indicate that HAdV posed a significant public health concern within the Korean military prior to the coronavirus disease 2019 (COVID-19) pandemic. Given the potential for a resurgence of outbreaks in the post-COVID-19 era, proactive measures, such as education, environmental improvements, and the development of HAdV vaccines, are crucial for effectively preventing future outbreaks.


Assuntos
Infecções por Adenovirus Humanos , Adenovírus Humanos , COVID-19 , Militares , Pneumonia , Infecções Respiratórias , Humanos , Adenovírus Humanos/genética , Infecções Respiratórias/diagnóstico , Prevalência , Infecções por Adenovirus Humanos/epidemiologia , Infecções por Adenovirus Humanos/diagnóstico , República da Coreia/epidemiologia
2.
Sensors (Basel) ; 21(5)2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33807891

RESUMO

Because the oxides of nitrogen (NOx) cause detrimental effects on not only the environment but humans, developing a high-performance NO2 gas sensor is a crucial issue for real-time monitoring. To this end, metal oxide semiconductors have been employed for sensor materials. Because in general, semiconductor-type gas sensors require a high working temperature, photoactivation has emerged as an alternative method for realizing the sensor working at room temperature. In this regard, titanium dioxide (TiO2) is a promising material for its photocatalytic ability with ultraviolet (UV) photonic energy. However, TiO2-based sensors inevitably encounter a problem of recombination of photogenerated electron-hole pairs, which occurs in a short time. To address this challenge, in this study, TiO2 nanorods (NRs) and Pt nanoparticles (NPs) under a UV-LED were used as an NO2 gas sensor to utilize the Schottky barrier formed at the TiO2-Pt junction, thereby capturing the photoactivated electrons by Pt NPs. The separation between the electron-hole pairs might be further enhanced by plasmonic effects. In addition, it is reported that annealing TiO2 NRs can achieve noteworthy improvements in sensing performance. Elucidation of the performance enhancement is suggested with the investigation of the X-ray diffraction patterns, which implies that the crystallinity was improved by the annealing process.

3.
J Med Virol ; 90(6): 1019-1026, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29424457

RESUMO

In order to diagnose the infectious disease from clinical samples, the various protocols such as culturing microorganism, rapid diagnostic test using chromatographic method, ELISA, conventional PCR are developed. Since a novel strain of avian influenza can be cross-infected human as well as birds and livestock due to genetic reassortment, some strains of influenza such as H7N9 and H5N1 have emerged as a severe virus which can be threaten the health of poultry as well as human. Therefore, we explored the development of simultaneously and rapid diagnostic tool for seasonal influenza (A/H1N1, A/H3N2, B) and highly pathogenic avian influenza (A/H5N1, A/H7N9). We analyzed the unique nucleotide sequences of influenza types including three seasonal influenza, A/H7N9, and A/H5N1, and distinguished each type of influenza and diagnosed through One Step RT-PCR. In the results, Chip-based PCR technique can be diagnosed rapidly and directly from naked eye with EvaGreen the influenza also respiratory specimens within 23 min 15 s, including reverse transcription. The Chip-based PCR is a point-of-care system, and it is expected to reduce diagnosis time and to develop a diagnostic kit. Furthermore the Chip based PCR technique can be used for high risk pathogen in bioterror and/or biological warfare in the field.


Assuntos
Influenza Humana/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Orthomyxoviridae/isolamento & purificação , Sistemas Automatizados de Assistência Junto ao Leito , Reação em Cadeia da Polimerase/métodos , Humanos , Orthomyxoviridae/genética , Fatores de Tempo
4.
J Korean Med Sci ; 31(8): 1190-6, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27478327

RESUMO

Diagnosis of scrub typhus is challenging due to its more than twenty serotypes and the similar clinical symptoms with other acute febrile illnesses including leptospirosis, murine typhus and hemorrhagic fever with renal syndrome. Accuracy and rapidity of a diagnostic test to Orientia tsutsugamushi is an important step to diagnose this disease. To discriminate scrub typhus from other diseases, the improved ImmuneMed Scrub Typhus Rapid Diagnostic Test (RDT) was evaluated in Korea and Sri Lanka. The sensitivity at the base of each IgM and IgG indirect immunofluorescent assay (IFA) in Korean patients was 98.6% and 97.1%, and the specificity was 98.2% and 97.7% respectively. The sensitivity and specificity for retrospective diagnosis at the base of IFA in Sri Lanka was 92.1% and 96.1%. ImmuneMed RDT was not reactive to any serum from seventeen diseases including hemorrhagic fever with renal syndrome (n = 48), leptospirosis (n = 23), and murine typhus (n = 48). ImmuneMed RDT shows superior sensitivity (98.6% and 97.1%) compared with SD Bioline RDT (84.4% at IgM and 83.3% at IgG) in Korea. The retrospective diagnosis of ImmuneMed RDT exhibits 94.0% identity with enzyme-linked Immunosorbent assay (ELISA) using South India patient serum samples. These results suggest that this RDT can replace other diagnostic tests and is applicable for global diagnosis of scrub typhus. This rapid and accurate diagnosis will be beneficial for diagnosing and managing scrub typhus.


Assuntos
Tifo por Ácaros/diagnóstico , Anticorpos Antibacterianos/sangue , Ensaio de Imunoadsorção Enzimática , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Orientia tsutsugamushi/imunologia , Kit de Reagentes para Diagnóstico , Estudos Retrospectivos , Tifo por Ácaros/microbiologia , Sensibilidade e Especificidade
5.
Vaccine ; 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38806354

RESUMO

BACKGROUND: Human adenovirus (HAdV) is a prevalent causative agent of acute respiratory disease (ARD) and is frequently responsible for outbreaks, particularly in military environments. Current vaccines do not effectively cover HAdV subtypes commonly found among Korean military personnel, highlighting the need for a new targeted vaccine. This study presents a cost-benefit analysis to evaluate the economic viability of developing and implementing such a vaccine within a military context. METHODS: We adopted a societal perspective for this cost-benefit analysis, which included estimating costs associated with vaccine development, production, and distribution over a projected timeline. We assumed a development period of five years, after which vaccine production and administration were initiated in the sixth year. The cost associated with vaccine development, production, and dispensation was considered. The benefits were calculated based on both direct and indirect cost savings from preventing HAdV infections through vaccination. All financial figures were expressed in 2023 US dollars. A sensitivity analysis was conducted to explore the impact of varying factors such as vaccination rate, incidence of infection, vaccine efficacy, and discount rate. RESULTS: For the base case scenario, we assumed a vaccination rate of 100 %, an incidence rate of 0.02, and a vaccine efficacy of 95 %, applying a 3 % discount rate. Initially, in the sixth year, the benefit-cost ratio stood at 0.71, suggesting a cost disadvantage at the onset of vaccination. However, this ratio improved to 1.32 in the following years, indicating a cost benefit from the seventh year onward. The cumulative benefit-cost ratio over a decade reached 2.72. The outcomes from the sensitivity analysis were consistent with these findings. CONCLUSION: Our cost-benefit analysis demonstrates that the introduction of an HAdV vaccine for the Korean military is economically advantageous, with substantial cost benefits accruing from the seventh year after the commencement of vaccination.

6.
Carcinogenesis ; 34(7): 1680-8, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23536579

RESUMO

Hepatitis B virus (HBV) X protein (HBx), encoded by the HBV genome, is involved in the development of HBV-mediated liver cancer, whose frequency is highly correlated with chromosomal instability (CIN). We reported previously that HBx induces mitotic checkpoint dysfunction by targeting the human serine/threonine kinase BubR1 (hBubR1). However, the underlying mechanism remained unresolved. Here, we show that HBx protein-associated protein α (HBxAPα)/Rsf-1 associates with hBubR1 and HBx in the chromatin fraction during mitosis. Depletion of HBxAPα/Rsf-1 abolished the interaction between HBx and hBubR1, indicating that HBxAPα/Rsf-1 mediates these interactions. Knockdown of HBxAPα/Rsf-1 with small interfering RNA did not affect the recruitment of hBubR1 to kinetochores; however, it did significantly impair HBx targeting to kinetochores. A deletion mutant analysis revealed that two Kunitz domains of HBx, the Cdc20-binding domain of hBubR1 and full-length of HBxAPα/Rsf-1 were essential for these interactions. Thus, binding of HBx to hBubR1, stabilized by HBxAPα/Rsf-1, significantly attenuated hBubR1 binding to Cdc20 and consequently increased the rate of mitotic aberrations. Collectively, our data show that the HBx impairs hBubR1 function and induces CIN through HBxAPα/Rsf-1, providing a novel mechanism for induction of genomic instability by a viral pathogen in hepatocarcinogenesis.


Assuntos
Instabilidade Cromossômica , Neoplasias Hepáticas/patologia , Pontos de Checagem da Fase M do Ciclo Celular , Proteínas Nucleares/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transativadores/metabolismo , Proteínas Cdc20 , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Células HEK293 , Células HeLa , Humanos , Cinetocoros/metabolismo , Neoplasias Hepáticas/metabolismo , Proteínas Nucleares/genética , Ligação Proteica , Mapeamento de Interação de Proteínas , Proteínas Serina-Treonina Quinases/genética , Estrutura Terciária de Proteína , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Deleção de Sequência , Transativadores/genética , Transfecção , Proteínas Virais Reguladoras e Acessórias
7.
Cell Death Dis ; 14(12): 788, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-38040710

RESUMO

Mitochondrial dysfunction is important in various chronic degenerative disorders, and aberrant immune responses elicited by cytoplasmic mitochondrial DNA (mtDNA) may be related. Here, we developed mtDNA-targeted MTERF1-FokI and TFAM-FokI endonuclease systems to induce mitochondrial DNA double-strand breaks (mtDSBs). In these cells, the mtDNA copy number was significantly reduced upon mtDSB induction. Interestingly, in cGAS knockout cells, synthesis of interferon ß1 and interferon-stimulated gene was increased upon mtDSB induction. We found that mtDSBs activated DNA-PKcs and HSPA8 in a VDAC1-dependent manner. Importantly, the mitochondrial E3 ligase MARCH5 bound active DNA-PKcs in cells with mtDSBs and reduced the type І interferon response through the degradation of DNA-PKcs. Likewise, mitochondrial damage caused by LPS treatment in RAW264.7 macrophage cells increased phospho-HSPA8 levels and the synthesis of mIFNB1 mRNA in a DNA-PKcs-dependent manner. Accordingly, in March5 knockout macrophages, phospho-HSPA8 levels and the synthesis of mIFNB1 mRNA were prolonged after LPS stimulation. Together, cytoplasmic mtDNA elicits a cellular immune response through DNA-PKcs, and mitochondrial MARCH5 may be a safeguard to prevent persistent inflammatory reactions.


Assuntos
Lipopolissacarídeos , Ubiquitina-Proteína Ligases , Humanos , Ubiquitina-Proteína Ligases/metabolismo , Lipopolissacarídeos/metabolismo , Proteínas de Membrana/metabolismo , Mitocôndrias/metabolismo , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Interferons/metabolismo , RNA Mensageiro/metabolismo
8.
Nanoscale ; 13(28): 12177-12184, 2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34259295

RESUMO

Nanostructured semiconducting metal oxides such as SnO2, ZnO, TiO2, and CuO have been widely used to fabricate high performance gas sensors. To improve the sensitivity and stability of gas sensors, we developed NO2 gas sensors composed of ZnO/TiO2 core-shell nanorods (NRs) decorated with Au nanoparticles (NPs) synthesized via a simple low-temperature aqueous solution process, operated under ultraviolet irradiation to realize room temperature operation. The fabricated gas sensor with a 10 nm-thick TiO2 shell layer shows 9 times higher gas sensitivity and faster response and recovery times than ZnO NR-based gas sensors. This high performance of the fabricated gas sensor can be ascribed to band bending between the ZnO and TiO2 core-shell layers and the localized surface plasmon resonance effect of Au NPs with a sufficient Debye length of the TiO2 shell layer.

9.
Korean J Intern Med ; 36(1): 205-213, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-31480827

RESUMO

BACKGROUND/AIMS: Human adenovirus type 55 (HAdV-55), an emerging epidemic strain, has caused several large outbreaks in the Korean military since 2014, and HAdV-associated acute respiratory illness (HAdV-ARI) has been continuously reported thereafter. METHODS: To evaluate the epidemiologic characteristics of HAdV-ARI in the Korean military, we analyzed respiratory virus polymerase chain reaction (RV-PCR) results, pneumonia surveillance results, and severe HAdV cases from all 14 Korean military hospitals from January 2013 to May 2018 and compared these data with nationwide RV surveillance data for the civilian population. RESULTS: A total of 14,630 RV-PCRs was performed at military hospitals. HAdV (45.4%) was the most frequently detected RV, followed by human rhinovirus (12.3%) and influenza virus (6.3%). The percentage of the military positive for HAdV was significantly greater than the percentage of civilians positive for HAdV throughout the study period, with a large outbreak occurring during the winter to spring of 2014 to 2015. The outbreak continued until the end of the study, and non-seasonal detections increased over time. The reported number of pneumonia patients also increased during the outbreak. Case fatality rate was 0.075% overall but 15.6% in patients with respiratory failure. The proportion of severe patients did not change significantly during the study period. CONCLUSION: A large HAdV outbreak is currently ongoing in the Korean military, with a trend away from seasonality, and HAdV-55 is likely the predominant strain. Persistent efforts to control the outbreak, HAdV type-specific surveillance, and vaccine development are required.


Assuntos
Infecções por Adenovirus Humanos , Adenovírus Humanos , Militares , Infecções Respiratórias , Infecções por Adenovirus Humanos/diagnóstico , Infecções por Adenovirus Humanos/epidemiologia , Adenovírus Humanos/genética , Surtos de Doenças , Humanos , República da Coreia/epidemiologia , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/epidemiologia
10.
Biotechnol Lett ; 32(5): 681-8, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20364295

RESUMO

A rapid detection method for Enterohemorrhagic Escherichia coli (EHEC), which has the virulent stx2 gene, was developed using a two-step, ultra-rapid real-time (URRT) PCR. URRT PCR was designed to detect the stx2 gene using a microchip-based, real-time PCR system, GenSpector TMC-1000, which only has a 6 microl total reaction volume with an extremely short denaturation step and combined annealing/extension step (1 and 3 s, respectively) for each cycle. Specific primers for the stx2 gene were designed to amplify a 100 bp region known for genetic stability among the various EHEC strains. Using the URRT PCR method, stx2 gene could be detected in 7 min 8 s including melting point (Tm) analysis. The detection limit for the stx2 gene for URRT-PCR was estimated to be 3 c.f.u./PCR with the amplification product having a consistent Tm of 85.2 +/- 0.4 degrees C. This method was tested for the various applications relevant to the different EHEC strains and was useful for the rapid detection of stx2-carrying EHEC strains.


Assuntos
Técnicas Bacteriológicas/métodos , Escherichia coli Êntero-Hemorrágica/isolamento & purificação , Proteínas de Escherichia coli/biossíntese , Reação em Cadeia da Polimerase/métodos , Toxina Shiga II/biossíntese , Fatores de Virulência/biossíntese , Primers do DNA/genética , Escherichia coli Êntero-Hemorrágica/genética , Escherichia coli Êntero-Hemorrágica/patogenicidade , Proteínas de Escherichia coli/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Sensibilidade e Especificidade , Toxina Shiga II/genética , Fatores de Tempo , Temperatura de Transição , Fatores de Virulência/genética
11.
PLoS One ; 15(7): e0236040, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32673367

RESUMO

We conducted a seroprevalence study of a large ongoing outbreak of human adenovirus type 55 (HAdV-55) among the military in South Korea. Serum samples were collected between 2018 and 2019 from military-exposed (military group) and non-exposed (non-military group) populations. The plaque reduction neutralization test (PRNT) was used to assess neutralization activity against HAdV-55. A total of 100 sera was collected from the non-military group, of which 18.8% showed HAdV-55 neutralizing antibody activity. Ninety-six sera were tested from the military group, which had significantly higher prevalence of neutralizing antibodies (56.0%, P <0.001). A significantly higher proportion of the military group had PRNT titers ≥1:1,000 than the non-military group (85.7% vs. 50.0%, P = 0.004). Among the military group, 48.9% of active-duty soldiers had PRNT titers ≥1:5,000, while none of the discharged civilians did (P = 0.007). In conclusion, Koreans were exposed to HAdV-55 in their communities, but the exposure risk was higher among people in military service.


Assuntos
Adenovírus Humanos/imunologia , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Militares/estatística & dados numéricos , Adulto , Humanos , Masculino , República da Coreia , Estudos Soroepidemiológicos , Adulto Jovem
12.
Adv Healthc Mater ; 9(7): e1900790, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32134572

RESUMO

Rapid and simple detection of RNA targets is in high demand due to the growing threat of pandemic viruses. One-step real-time, reverse transcription-polymerase chain reaction (One-step RT-qPCR) using a controlled release system of thermo-responsive materials is developed in this paper to enable high-fidelity RNA analysis as suppressing by-products. The nanocapsules, consisting of upper critical solution temperature (UCST) material and PCR primers, carry or release the primers depending upon the temperature. The UCST nanocapsules are introduced into hydrogel microparticles incorporated with RT primers and then the target RNA is selectively amplified in the microparticle through one-step RT-qPCR. Severe side products are sharply subdued by separating the PCR primers from the RT process by means of the microparticles with nanocapsules. Because the one-step assay is now implemented in a single microparticle, multiple target RNAs can be analyzed in a simple RT-qPCR of multiple particles. Reliable 18-plex one-step RT-qPCR is successfully conducted within 30 min using single-color fluorescent optics. This work also explains the facile fabrication processes used for the thermo-responsive nanocapsules and hydrogel microparticles by the blending polymerization method. Extensible multiplex analysis of influenza virus demonstrates the versatile uses of this one-step RT-qPCR platform.


Assuntos
Polímeros , RNA , Cápsulas , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade
13.
Micromachines (Basel) ; 11(4)2020 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-32224995

RESUMO

Advancements in nanotechnology have facilitated the increased use of ZnO nanostructures. In particular, hierarchical and core-shell nanostructures, providing a graded refractive index change, have recently been applied to enhance the photon extraction efficiency of photonic emitters. In this study, we demonstrate self-aligned hierarchical ZnO nanorod (ZNR)/NiO nanosheet arrays on a conventional photonic emitter (C-emitter) with a wavelength of 430 nm. These hierarchical nanostructures were synthesized through a two-step hydrothermal process at low temperature, and their optical output power was approximately 17% higher than that of ZNR arrays on a C-emitter and two times higher than that of a C-emitter. These results are due to the graded index change in refractive index from the GaN layer inside the device toward the outside as well as decreases in the total internal reflection and Fresnel reflection of the photonic emitter.

14.
Nanomaterials (Basel) ; 10(3)2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32143528

RESUMO

Prolonged exposure to NO2 can cause lung tissue inflammation, bronchiolitis fibrosa obliterans, and silo filler's disease. In recent years, nanostructured semiconducting metal oxides have been widely used to fabricate gas sensors because of their unique structure and surface-to-volume ratio compared to layered materials. In particular, the different morphologies of ZnO-based nanostructures significantly affect the detection property of NO2 gas sensors. However, because of the large interaction energy of chemisorption (1-10 eV), metal oxide-based gas sensors are typically operated above 100 °C, overcoming the energy limits to attain high sensitivity and fast reaction. High operating temperature negatively affects the reliability and durability of semiconductor-based sensors; at high temperature, the diffusion and sintering effects at the metal oxide grain boundaries are major factors causing undesirable long-term drift problems and preventing stability improvements. Therefore, we demonstrate NO2 gas sensors consisting of ZnO hemitubes (HTs) and nanotubes (NTs) covered with TiO2 nanoparticles (NPs). To operate the gas sensor at room temperature (RT), we measured the gas-sensing properties with ultraviolet illumination onto the active region of the gas sensor for photoactivation instead of conventional thermal activation by heating. The performance of these gas sensors was enhanced by the change of barrier potential at the ZnO/TiO2 interfaces, and their depletion layer was expanded by the NPs formation. The gas sensor based on ZnO HTs showed 1.2 times higher detection property than those consisting of ZnO NTs at the 25 ppm NO2 gas.

15.
Micromachines (Basel) ; 10(8)2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31405059

RESUMO

We demonstrate the surface plasmon (SP)-enhanced ultraviolet (UV) emitter using Pt nanoparticles (NPs). The UV emitter is hole-patterned on the p-AlGaN layer to consider the penetration depth of Pt NPs. The Pt NPs with sizes under 50 nm are required to realize the plasmonic absorption in UV wavelength. In this study, we confirm the average Pt NP sizes of 10 nm, 20 nm, and 25 nm, respectively, at an annealing temperature of 600 °C. The absorption of annealed Pt NPs is covered with the 365-nm wavelength. The electroluminescence intensity of SP-UV is 70% higher than that of reference UV emitter without hole-patterns and Pt NPs. This improvement can be attributed to the increase of spontaneous emission rate through resonance coupling between the excitons in multiple quantum wells and Pt NPs deposited on the p-AlGaN layer.

16.
Mol Brain ; 9(1): 55, 2016 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-27192976

RESUMO

BACKGROUND: Appropriate vertical movement is critical for the survival of flying animals. Although negative geotaxis (moving away from Earth) driven by gravity has been extensively studied, much less is understood concerning a static regulatory mechanism for inducing positive geotaxis (moving toward Earth). RESULTS: Using Drosophila melanogaster as a model organism, we showed that geomagnetic field (GMF) induces positive geotaxis and antagonizes negative gravitaxis. Remarkably, GMF acts as a sensory cue for an appetite-driven associative learning behavior through the GMF-induced positive geotaxis. This GMF-induced positive geotaxis requires the three geotaxis genes, such as cry, pyx and pdf, and the corresponding neurons residing in Johnston's organ of the fly's antennae. CONCLUSIONS: These findings provide a novel concept with the neurogenetic basis on the regulation of vertical movement by GMF in the flying animals.


Assuntos
Comportamento Animal/fisiologia , Drosophila melanogaster/fisiologia , Gravitação , Locomoção/fisiologia , Campos Magnéticos , Animais , Neurônios/metabolismo , Especificidade de Órgãos , Transdução de Sinais
17.
Int J Radiat Biol ; 89(12): 1035-44, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23859432

RESUMO

PURPOSE: Professional and public concern about the potential adverse effects of man-made electromagnetic fields (EMF) on the human body has dramatically expanded in recent years. Despite numerous attempts to investigate this issue, the long-standing challenge of reproducibility surrounding alternating EMF effects on human health remains unresolved. Our chief aim was to investigate a plausible mechanism for this phenomenon. MATERIALS AND METHODS: Growth of cultured human cancer cells, DU145 and Jurkat, exposed to power frequency magnetic field (MF) (60 Hz, 1 mT) for 3 days, was determined using a 2-(4-Iodophenyl)- 3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium (WST-1) assay and a trypan blue exclusion assay. This experiment was repeated at incubators long-term monitoring period up to 5.3 years. A periodogram analysis was performed to investigate periodic patterns in the MF and sham effects on cell growth. RESULTS: Unlike conventional assumptions, the MF effect on growth in both cell types was promotive or suppressive in a period-dependent manner. The converse cell growth induced by the MF was consistent in incubators, with little variation. CONCLUSIONS: Spatiotemporal evidence suggests that the period-dependent converse cell growth by the MF may contribute to the poor reproducibility and explain the adverse effects observed in previous experimental and epidemiological investigations. Additionally, the novel approach of this study may be applied to design features required to experimentally determine the effects of EMF on living organisms in a convincing manner.


Assuntos
Linhagem Celular Tumoral/citologia , Proliferação de Células , Campos Eletromagnéticos , Humanos , Células Jurkat , Masculino , Neoplasias da Próstata , Reprodutibilidade dos Testes , Sais de Tetrazólio , Fatores de Tempo , Azul Tripano
18.
Osong Public Health Res Perspect ; 3(2): 79-84, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24159495

RESUMO

OBJECTIVES: Hepatitis B virus (HBV) is a member of the hepadnavirus family. The HBV genome contains four genes designated as S, C, P, and X. The HBV X (HBx) gene encodes for a 16.5-kDa regulatory protein that enhances HBV replication and exerts multifunctional activities. The aim of this study is to describe the rapid and easy purification of HBx using ELP (elastin-like polypeptide) fusion protein. METHODS: The ELP-HBx fusion protein was overexpressed in Escherichia coli. Environmental sensitivity was demonstrated via turbidity and dynamic light scattering as a function of temperature. HBx was purified as an ELP fusion protein. ELPs are biopolymers of the pentapeptide repeat Val-Pro-Gly-Xaa-Gly that undergo an inverse temperature phase transition. ELP follows in temperature and salt consistency, precipitation, and solution repetition (inverse transition cycling) with polypeptide, where it purifies the protein in a simple manner. RESULTS: Fusion proteins underwent supramolecular aggregation at 40 ℃ in 1 M NaCl and slowly resolubilized at subphysiologic temperatures. ELP domain proteolysis liberated a peptide of comparable size and immunoreactivity to the commercial HBx. CONCLUSION: This study suggests that HBx can be purified rapidly and easily using inverse transition cycling, and that this method can be applied in determination of HBx 3D structures and HBx stability study.

19.
Mol Cells ; 34(2): 165-9, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22820921

RESUMO

The hepatitis B virus x protein (HBX) is expressed in HBV-infected liver cells and can interact with a wide range of cellular proteins. In order to understand such promiscuous behavior of HBX we expressed a truncated mini-HBX protein (named Tr-HBX) (residues 18-142) with 5 Cys → Ser mutations and characterized its structural features using circular dichroism (CD) spectropolarimetry, NMR spectroscopy as well as bioinformatics tools for predicting disorder in intrinsically unstructured proteins (IUPs). The secondary structural content of Tr-HBX from CD data suggests that Tr-HBX is only partially folded. The protein disorder prediction by IUPred reveals that the unstructured region encompasses its N-terminal ~30 residues of Tr-HBX. A two-dimensional (1)H-(15)N HSQC NMR spectrum exhibits fewer number of resonances than expected, suggesting that Tr-HBX is a hybrid type IUP where its folded C-terminal half coexists with a disordered N-terminal region. Many IUPs are known to be capable of having promiscuous interactions with a multitude of target proteins. Therefore the intrinsically disordered nature of Tr-HBX revealed in this study provides a partial structural basis for the promiscuous structure-function behavior of HBX.


Assuntos
Vírus da Hepatite B/metabolismo , Transativadores/química , Transativadores/metabolismo , Sequência de Aminoácidos , Dicroísmo Circular/métodos , Vírus da Hepatite B/genética , Mutagênese Sítio-Dirigida , Ressonância Magnética Nuclear Biomolecular , Estrutura Secundária de Proteína , Desdobramento de Proteína , Transativadores/genética , Transativadores/isolamento & purificação , Proteínas Virais Reguladoras e Acessórias
20.
J Virol Methods ; 179(1): 195-200, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22079620

RESUMO

A real-time reverse transcription-polymerase chain reaction (qRT-PCR) assay was developed for the fast and highly sensitive detection of the sacbrood virus (SBV) genome and applied to honeybee samples. Using plasmid DNA containing a partial SBV genome and diluted serially, as few as 1×10(2)copies/µl (correlation co-efficiency >0.99) were detected by the qRT-PCR assay, whereas 1×10(3)copies/µl were detected by the conventional RT-PCR assay. As a rapid detection method, ultra-rapid real-time PCR (URRT-PCR) was carried out with a GenSpector TMC-1000 silicon-glass chip-based thermal cycler, which has a 6µl micro-chamber volume and a fast outstandingly heating/cooling rate. Using this method, 10(3)copies of pBX-SBV3.8 clone were detected within 17 min after 40 PCR cycles, including melting point analysis. To reduce the detection time for SBV, synthesis of the cDNA of the SBV genome from a honeybee sample was attempted for different reaction times and the cDNA was used as the template for URRT-PCR assays. The results indicated that a 5 min reaction time was sufficient to synthesize cDNA as the template for the SBV URRT-PCR assay. This study described a novel PCR-based method that is able to detect an RNA virus in environmental samples within 22 min, including reverse transcription, PCR detection and melting point analysis in real-time.


Assuntos
Abelhas/virologia , Vírus de RNA/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Virologia/métodos , Animais , Entomologia/métodos , Vírus de RNA/genética , Sensibilidade e Especificidade , Fatores de Tempo
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