RESUMO
Between 2013 and 2018, the novel A/Anhui/1/2013 (AH/13)-lineage H7N9 virus caused at least five waves of outbreaks in humans, totaling 1,567 confirmed human cases in China. Surveillance data indicated a disproportionate distribution of poultry infected with this AH/13-lineage virus, and laboratory experiments demonstrated that this virus can efficiently spread among chickens but not among Pekin ducks. The underlying mechanism of this selective transmission remains unclear. In this study, we demonstrated the absence of Neu5Gc expression in chickens across all respiratory and gastrointestinal tissues. However, Neu5Gc expression varied among different duck species and even within the tissues of the same species. The AH/13-lineage viruses exclusively bind to acetylneuraminic acid (Neu5Ac), in contrast to wild waterbird H7 viruses that bind both Neu5Ac and N-glycolylneuraminic acid (Neu5Gc). The level of Neu5Gc expression influences H7 virus replication and facilitates adaptive mutations in these viruses. In summary, our findings highlight the critical role of Neu5Gc in affecting the host range and interspecies transmission dynamics of H7 viruses among avian species.IMPORTANCEMigratory waterfowl, gulls, and shorebirds are natural reservoirs for influenza A viruses (IAVs) that can occasionally spill over to domestic poultry, and ultimately humans. This study showed wild-type H7 IAVs from waterbirds initially bind to glycan receptors terminated with N-acetylneuraminic acid (Neu5Ac) or N-glycolylneuraminic acid (Neu5Gc). However, after enzootic transmission in chickens, the viruses exclusively bind to Neu5Ac. The absence of Neu5Gc expression in gallinaceous poultry, particularly chickens, exerts selective pressure, shaping IAV populations, and promoting the acquisition of adaptive amino acid substitutions in the hemagglutinin protein. This results in the loss of Neu5Gc binding and an increase in virus transmissibility in gallinaceous poultry, particularly chickens. Consequently, the transmission capability of these poultry-adapted H7 IAVs in wild water birds decreases. Timely intervention, such as stamping out, may help reduce virus adaptation to domestic chicken populations and lower the risk of enzootic outbreaks, including those caused by IAVs exhibiting high pathogenicity.
Assuntos
Galinhas , Patos , Influenza Aviária , Ácidos Neuramínicos , Replicação Viral , Animais , Influenza Aviária/virologia , Influenza Aviária/transmissão , Galinhas/virologia , Patos/virologia , Ácidos Neuramínicos/metabolismo , Ácido N-Acetilneuramínico/metabolismo , Subtipo H7N9 do Vírus da Influenza A/genética , Subtipo H7N9 do Vírus da Influenza A/patogenicidade , China , Humanos , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Doenças das Aves Domésticas/virologia , Doenças das Aves Domésticas/transmissão , Doenças das Aves Domésticas/metabolismo , Aves Domésticas/virologiaRESUMO
BACKGROUND: Common gastrointestinal disease irritable bowel syndrome (IBS) is marked by symptoms like changed bowel habits, bloating, and stomach ache. A low-FODMAP combined gluten-free diet (LF-GFD) has been suggested as a possible therapy for IBS symptoms management. OBJECTIVE: This study sought to investigate whether a LF-GFD would help patients with IBS. METHODS: Strict inclusion and exclusion criteria from internet databases helped to identify clinical studies evaluating the intervention of LF-GFD in the treatment of IBS patients. Using measurements including the visual analog scale (VAS) for bloating and pain, the IBS symptom severity scale (IBS-SSS), and IBS quality of life (IBS-QoL), the main results evaluated were the efficacy of LF-GFD in reducing IBS symptoms. Furthermore assessed were the psychological impacts of LF-GFD utilizing the self- rating depression scale (SDS) and self- rating anxiety scale (SAS). RESULTS: A total of 437 patients (221 on LF-GFD diet and 216 on GFD) were involved in 4 randomized controlled trials and 4 cohort studies. The combined results indicated that LF-GFD reduced the VAS bloating ratings (RR = - 0.58, 95%CI - 0.92-0.23, P = 0.0010, I2 = 83%) and the VAS pain scores (RR = - 0.42, 95%CI - 0.66-0.19, P = 0.005, I2 = 58%). In addition, LF-GFD indicated a substantial enhancement in IBS-SSS scores (MD = - 1.42, 95%CI - 2.74-0.10, P = 0.03, I2 = 24%) and IBS-QoL ratings (MD = 3.75, 95%CI 0.98-6.53, P = 0.008, I2 = 33%). Moreover, the LF-GFD group showed a substantial drop in SDS (MD = - 2.56, 95%CI - 3.38-1.74, P < 0.00001, I2 = 65%) and SAS (MD = - 4.30, 95%CI - 6.53-2.24, P < 0.0001, I2 = 0%) scores compared to the GFD group. CONCLUSION: LF-GFD therapy significantly enhances clinical symptoms and reduces anxiety and depression in individuals diagnosed with irritable bowel syndrome.
RESUMO
Human adenoviruses (HAdV) are genetically diverse and can infect a number of tissues with severities varied from mild to fatal. HAdV types 3, 4, 7, 11, 14, 21, and 55 were associated with acute respiratory illnesses outbreaks in the United States and in other countries. The risk of outbreaks can be effectively controlled by HAdV vaccination or mitigated by screening and preventive measures. During the influenza season 2018-2019, the DoD Global Respiratory Pathogen Surveillance Program (DoDGRS) received 24 300 respiratory specimens. HAdV samples that produced positive cytopathic effects in viral cultivation were subjected to next-generation sequencing for genome sequence assembly, genome typing, whole genome phylogeny, and sequence comparative analyses. A variety of HAdV types were identified in this study, including HAdV types 1-7, 14, 55, and 56. HAdV types 4, 7, and 14 were found in clustered cases in Colorado, Florida, New York, and South Carolina. Comparative sequence analyses of these isolates revealed the emergence of novel genetic mutations despite the stability of adenovirus genomes. Genomic surveillance of HAdV suggested possible undetected outbreaks and shed light on prevalence, genetic divergence, and viral evolution of HAdV. Continued surveillance will inform risk assessment and countermeasures.
Assuntos
Infecções por Adenovirus Humanos , Adenovírus Humanos , Infecções Respiratórias , Humanos , Estados Unidos , Estações do Ano , Genoma Viral , New York , FilogeniaRESUMO
BACKGROUND: In 2020, preventive measures were implemented to mitigate the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among 600-700 recruits arriving weekly at a basic combat training (BCT) facility in the southern United States. Trainees were sorted into companies and platoons (cocoons) at arrival, tested, quarantined for 14 days with daily temperature and respiratory-symptom monitoring and retested before release into larger groups for training where symptomatic testing was conducted. Nonpharmaceutical measures, such as masking, and social distancing, were maintained throughout quarantine and BCT. We assessed for SARS-CoV-2 transmission in the quarantine milieu. METHODS: Nasopharyngeal (NP) swabs were collected at arrival and at the end of quarantine and blood specimens at both timepoints and at the end of BCT. Epidemiological characteristics were analyzed for transmission clusters identified from whole-genome sequencing of NP samples. RESULTS: Among 1403 trainees enrolled from 25 August to 7 October 2020, epidemiological analysis identified three transmission clusters (n = 20 SARS-CoV-2 genomes) during quarantine, which spanned five different cocoons. However, SARS-CoV-2 incidence decreased from 2.7% during quarantine to 1.5% at the end of BCT; prevalence at arrival was 3.3%. CONCLUSIONS: These findings suggest layered SARS-CoV-2 mitigation measures implemented during quarantine minimized the risk of further transmission in BCT.
Assuntos
COVID-19 , Militares , Humanos , Estados Unidos/epidemiologia , SARS-CoV-2 , COVID-19/epidemiologia , COVID-19/prevenção & controle , Quarentena , Teste para COVID-19RESUMO
BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemiology implicates airborne transmission; aerosol infectiousness and impacts of masks and variants on aerosol shedding are not well understood. METHODS: We recruited coronavirus disease 2019 (COVID-19) cases to give blood, saliva, mid-turbinate and fomite (phone) swabs, and 30-minute breath samples while vocalizing into a Gesundheit-II, with and without masks at up to 2 visits 2 days apart. We quantified and sequenced viral RNA, cultured virus, and assayed serum samples for anti-spike and anti-receptor binding domain antibodies. RESULTS: We enrolled 49 seronegative cases (mean days post onset 3.8â ±â 2.1), May 2020 through April 2021. We detected SARS-CoV-2 RNA in 36% of fine (≤5 µm), 26% of coarse (>5 µm) aerosols, and 52% of fomite samples overall and in all samples from 4 alpha variant cases. Masks reduced viral RNA by 48% (95% confidence interval [CI], 3 to 72%) in fine and by 77% (95% CI, 51 to 89%) in coarse aerosols; cloth and surgical masks were not significantly different. The alpha variant was associated with a 43-fold (95% CI, 6.6- to 280-fold) increase in fine aerosol viral RNA, compared with earlier viruses, that remained a significant 18-fold (95% CI, 3.4- to 92-fold) increase adjusting for viral RNA in saliva, swabs, and other potential confounders. Two fine aerosol samples, collected while participants wore masks, were culture-positive. CONCLUSIONS: SARS-CoV-2 is evolving toward more efficient aerosol generation and loose-fitting masks provide significant but only modest source control. Therefore, until vaccination rates are very high, continued layered controls and tight-fitting masks and respirators will be necessary.
Assuntos
COVID-19 , SARS-CoV-2 , COVID-19/prevenção & controle , Humanos , Máscaras , RNA Viral , Aerossóis e Gotículas RespiratóriosRESUMO
BACKGROUND: With the emergence and spread of SARS-CoV-2 variants, genomic epidemiology and surveillance have proven invaluable tools for variant tracking. Here, we analyzed SARS-CoV-2 samples collected from personnel located at the US/NATO bases across Afghanistan. RESULTS: Sequencing and phylogenetic analyses revealed at least 16 independent introductions of SARS-CoV-2 into four of these relatively isolated compounds during April and May 2021, including multiple introductions of Alpha and Delta variants. Four of the introductions resulted in sustained spread of the virus within, and in two cases between, the compounds. Three of these outbreaks, one Delta and two Alpha, occurred simultaneously. CONCLUSIONS: Even in rigorously controlled and segregated environments, SARS-CoV-2 introduction and spread may occur frequently.
Assuntos
COVID-19 , Militares , Afeganistão/epidemiologia , COVID-19/epidemiologia , Surtos de Doenças , Genômica , Humanos , Filogenia , SARS-CoV-2/genéticaRESUMO
Intra-host single nucleotide variants (iSNVs) have been increasingly used in genomic epidemiology to increase phylogenetic resolution and reconstruct fine-scale outbreak dynamics. These analyses are preferably done on sequence data from direct clinical samples, but in many cases due to low viral loads, there might not be enough genetic material for deep sequencing and iSNV determination. Isolation of the virus from clinical samples with low-passage number increases viral load, but few studies have investigated how dengue virus (DENV) culture isolation from a clinical sample impacts the consensus sequence and the intra-host virus population frequencies. In this study, we investigate consensus and iSNV frequency differences between DENV sequenced directly from clinical samples and their corresponding low-passage isolates. Twenty five DENV1 and DENV2 positive sera and their corresponding viral isolates (T. splendens inoculation and C6/36 passage) were obtained from a prospective cohort study in the Philippines. These were sequenced on MiSeq with minimum nucleotide depth of coverage of 500×, and iSNVs were detected using LoFreq. For both DENV1 and DENV2, we found a maximum of one consensus nucleotide difference between clinical sample and isolate. Interestingly, we found that iSNVs with frequencies ≥5â% were often preserved between the samples, and that the number of iSNV positions, and sample diversity, at this frequency cutoff did not differ significantly between the sample pairs (clinical sample and isolate) in either DENV1 or DENV2 data. Our results show that low-passage DENV isolate consensus genomes are largely representative of their direct sample parental viruses, and that low-passage isolates often mirror high frequency within-host variants from direct samples.
Assuntos
Vírus da Dengue/classificação , Vírus da Dengue/genética , Dengue/virologia , Variação Genética , Sequência de Bases , Vírus da Dengue/isolamento & purificação , Genoma Viral , Humanos , Filipinas , Filogenia , Estudos Prospectivos , RNA Viral/genéticaRESUMO
The long-lasting global COVID-19 pandemic demands timely genomic investigation of SARS-CoV-2 viruses. Here, we report a simple and efficient workflow for whole-genome sequencing utilizing one-step reverse transcription-PCR (RT-PCR) amplification on a microfluidic platform, followed by MiSeq amplicon sequencing. The method uses Fluidigm integrated fluidic circuit (IFC) and instruments to amplify 48 samples with 39 pairs of primers, including 35 custom-designed primer pairs and four additional primer pairs from the ARTIC network protocol v3. Application of this method on RNA samples from both viral isolates and clinical specimens demonstrates robustness and efficiency in obtaining the full genome sequence of SARS-CoV-2.
Assuntos
Genoma Viral , Sequenciamento de Nucleotídeos em Larga Escala , Microfluídica , SARS-CoV-2/genética , Sequenciamento Completo do Genoma , COVID-19/virologia , Primers do DNA , Humanos , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Inpatient coronavirus disease 2019 (COVID-19) cases present enormous costs to patients and health systems in the United States. Many hospitalized patients may continue testing COVID-19 positive even after the resolution of symptoms. Thus, a pressing concern for clinicians is the safety of discharging these asymptomatic patients if they have any remaining infectivity. This case report explores the viral viability in a patient with persistent COVID-19 over the course of a 2-month hospitalization. Positive nasopharyngeal swab samples were collected and isolated in the laboratory and analyzed by quantitative reverse-transcription polymerase chain reactions (qRT-PCR), and serology was tested for neutralizing antibodies throughout the hospitalization period. The patient experienced waning symptoms by hospital day 40 and had no viable virus growth by hospital day 41, suggesting no risk of infectivity, despite positive RT-PCR results which prolonged his hospital stay. Notably, this case showed infectivity for at least 24 days after disease onset, which is longer than the discontinuation of transmission-based precautions recommended by the Center for Disease Control and Prevention. Thus, our findings suggest that the timeline for discontinuing transmission-based precautions may need to be extended for patients with severe and prolonged COVID-19 disease. Additional large-scale studies are needed to draw definitive conclusions on the appropriate clinical management for these patients. â.
Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Teste de Ácido Nucleico para COVID-19 , COVID-19/diagnóstico , Eliminação de Partículas Virais/fisiologia , Idoso , Infecções Assintomáticas , Humanos , Masculino , RNA Viral/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , SARS-CoV-2/genética , SARS-CoV-2/imunologiaRESUMO
Recent outbreaks of emerging and re-emerging viruses have shown that timely detection of novel arboviruses with epidemic potential is essential to mitigate human health risks. There are rising concerns that emergent JEV genotype V (GV) is circulating in Asia, against which current vaccines may not be efficacious. To ascertain if JEV GV and other arboviruses are circulating in East Asia, we conducted next-generation sequencing on 260 pools of Culex tritaeniorhynchus and Culex bitaeniorhynchus mosquitoes (6540 specimens) collected at Camp Humphreys, Republic of Korea (ROK) in 2018. Interrogation of our data revealed a highly abundant and diverse virosphere that contained sequences from 122 distinct virus species. Our statistical and hierarchical analysis uncovered correlates of potential health, virological, and ecological relevance. Furthermore, we obtained evidence that JEV GV was circulating in Pyeongtaek and, retrospectively, in Seoul in 2016 and placed these findings within the context of human and fowl reservoir activity. Sequence-based analysis of JEV GV showed a divergent genotype that is the most distant from the GIII-derived live attenuated SA14-14-2 vaccine strain and indicated regions probably responsible for reduced antibody affinity. These results emphasize recent concerns of shifting JEV genotype in East Asia and highlight the critical need for a vaccine proven efficacious against this re-emergent virus. Together, our one-health approach to Culex viral metagenomics uncovered novel insights into virus ecology and human health.
Assuntos
Culex , Culicidae , Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa , Animais , Vírus da Encefalite Japonesa (Espécie)/genética , Encefalite Japonesa/epidemiologia , Genótipo , Humanos , Metagenômica , Filogenia , Estudos Retrospectivos , ViromaRESUMO
During 2017-2018, Barmah Forest virus was recovered from mosquitoes trapped in military training areas in Australia and from a soldier infected at 1 of these areas. Phylogenies of the nucleotide sequences of the envelope glycoprotein gene E2 and the 3' untranslated region suggest that 2 lineages are circulating in eastern Australia.
Assuntos
Alphavirus , Arbovírus , Culicidae , Militares , Alphavirus/genética , Animais , Austrália/epidemiologia , HumanosRESUMO
Human adenovirus type 55 (HAdV-55) causes acute respiratory disease of variable severity and has become an emergent threat in both civilian and military populations. HAdV-55 infection is endemic to China and South Korea, but data from other regions and time periods are needed for comprehensive assessment of HAdV-55 prevalence from a global perspective. In this study, we subjected HAdV-55 isolates from various countries collected during 1969-2018 to whole-genome sequencing, genomic and proteomic comparison, and phylogenetic analyses. The results show worldwide distribution of HAdV-55; recent strains share a high degree of genomic homogeneity. Distinct strains circulated regionally for several years, suggesting persistent local transmission. Several cases of sporadic introduction of certain strains to other countries were documented. Among the identified amino acid mutations distinguishing HAdV-55 strains, some have potential impact on essential viral functions and may affect infectivity and transmission.
Assuntos
Infecções por Adenovirus Humanos , Adenovírus Humanos , Infecções Respiratórias , Infecções por Adenovirus Humanos/epidemiologia , Adenovírus Humanos/genética , China , DNA Viral , Humanos , Filogenia , Proteômica , República da Coreia/epidemiologiaRESUMO
BACKGROUND: Genetic polymorphisms of Toll-like receptors play important roles in gastric carcinogenesis. The aim of this study was to determine the role of TLR2-196 to -174 ins/del polymorphism in gastric cancer susceptibility and prognosis. METHODS: This study included 520 people from southern China. Samples were genotyped by the allele-specific polymerase chain reaction, among which 10% were randomly selected for sequencing. The serological method was used to determine Helicobacter pylori. RESULTS: The TLR2 genotype was not associated with the risk of H. pylori infection. The del/del genotype exhibited significantly higher gastric cancer risk (adjusted OR 2.59, 95% CI 1.33â5.07) than that of the ins/ins genotype. Further stratification analyses demonstrated that the del/del genotype was associated with a risk of intestinal gastric cancer (adjusted OR 2.62, 95% CI 1.34-5.14). In addition, the presence of the del/del genotype and the H. pylori infection conferred a synergistic effect (OR 3.04, 95% CI 1.33â6.98) for the development of gastric cancer. The del/del genotype was not associated with a poor prognosis in gastric cancer patients. CONCLUSION: The del/del genotype is associated with an increased gastric cancer risk in the southern Chinese population. However, TLR2 polymorphism is neither associated with H. pylori infection, nor with a poor prognosis.
Assuntos
Adenocarcinoma/genética , Infecções por Helicobacter/genética , Polimorfismo Genético , Neoplasias Gástricas/genética , Receptor 2 Toll-Like/genética , Adenocarcinoma/microbiologia , Adenocarcinoma/mortalidade , Idoso , Povo Asiático/genética , Estudos de Casos e Controles , Feminino , Frequência do Gene , Predisposição Genética para Doença , Infecções por Helicobacter/complicações , Helicobacter pylori/patogenicidade , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Prognóstico , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/mortalidadeRESUMO
The goal of this study is to evaluate PD-L1 prevalence and its association with major clinical characteristics in Chinese non-small cell lung cancer (NSCLC) patients to inform the clinical development of anti-PD1/PD-L1 agents in this population. We used phosphatase and tensin homolog (PTEN) expression through IHC as a surrogate tissue quality marker to screen surgical NSCLC samples in tissue microarray (TMA; 172 cases) or whole-section (268 cases) format. The samples were then analyzed with a clinically validated PD-L1 IHC assay. The results were correlated with baseline characteristics and clinical outcomes. PTEN IHC showed that 108 TMA samples and 105 whole-section samples qualified for PD-L1 IHC. With a clinically relevant cutoff, 41.7% of the TMA samples were PD-L1 positive. PD-L1 level was much lower in EGFR-mutant patients and seemed to be a favorable prognostic factor for both overall survival (OS) and recurrence-free survival (RFS). These findings were confirmed in the whole-section samples except that their survival data were not mature enough for correlation analysis. In summary, PD-L1 expression was detected in approximately 40% of PTEN-qualified Chinese NSCLC samples, negatively correlated with EGFR mutation and seemed to be a favorable prognostic factor for both OS and RFS. Notably, the different results from PTEN-qualified and PTEN-disqualified samples underscore the importance of tissue quality control prior to biomarker testing.
Assuntos
Antígeno B7-H1/metabolismo , Biomarcadores Tumorais/análise , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Neoplasias Pulmonares/diagnóstico , Mutação , PTEN Fosfo-Hidrolase/genética , Análise Serial de Tecidos/normas , Idoso , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Estudos de Coortes , Detecção Precoce de Câncer , Feminino , Seguimentos , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Masculino , Pessoa de Meia-Idade , Prognóstico , Taxa de SobrevidaRESUMO
BACKGROUND: Vesiviruses (family Caliciviridae) had been shown capable of invading a variety of host species, raising concern of their zoonotic potential. Since the 1980's, several canine caliciviruses (CaCV) isolates have been reported and are phylogenetically related to the vesiviruses with features distinct from both Vesicular exanthema of swine virus (VESV) and Feline calicivirus (FCV) species in phylogeny, serology and cell culture specificities. Etiological studies of canine diseases in dogs used for military services and laboratory studies were conducted in 1963-1978 at the Walter Reed Army Institute of Research. Multiple known and unknown viral pathogens including caliciviruses were recovered. METHODS: Four unidentified isolates were recovered in Walter Reed Canine Cells (WRCC) from respiratory, fecal and penile specimens. Physicochemical tests, electron microscopy, viral cultivation in human and animal cells, antibody neutralization assays, and recently the genome sequencing were used to characterize the isolates. Sera from these dogs and their cohorts were tested with the isolates to determine origin and prevalence of the infections. RESULTS: The viral isolates were small non-enveloped spherical RNA virions, 27 to 42 nm in diameter with cup-like structures, indicating they are caliciviruses. They propagated in WRCC and MDCK cells, not in either other canine cells or human and other animal cells. Each isolate is antigenically distinct and react with dog sera in respective cohorts. The genomes have nucleotide identities ranging from 70.3% to 90.7% and encode the non-structural polyprotein (1810 amino acids), major capsid protein (691 amino acids) and minor structural protein (134 amino acids). They belong to two different phylogenetic clades in Vesivirus genus with close relation with canine calicivirus (CaCV). CONCLUSIONS: These CaCV isolates have restricted cell tropism, antigenic diversity and genetic variation. Further investigation will shed light on antigenic relation to other vesiviruses, and its pathogenicity for dogs and potential infectivity to other animals. Together with the previously reported CaCV strains provides significant evidence to support the formation of a new CaCV species in the Vesivirus genus.
Assuntos
Infecções por Caliciviridae/veterinária , Doenças do Cão/virologia , Genótipo , Sorogrupo , Vesivirus/classificação , Vesivirus/genética , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Linhagem Celular , Doenças do Cão/história , Cães , História do Século XX , Células Madin Darby de Rim Canino , Testes de Neutralização , Filogenia , Prevalência , RNA Viral/genética , Análise de Sequência de DNA , Vesivirus/isolamento & purificaçãoRESUMO
BACKGROUND: Innovative technical approaches to controlling undesired sensory and motor activity, such as hyperalgesia or spasticity, may contribute to rehabilitation techniques for improving neural plasticity in patients with neurologic disorders. To date, transcutaneous electrical stimulation has used low frequency pulsed currents for sensory inhibition and muscle activation. Yet, few studies have attempted to achieve motor nerve inhibition using transcutaneous electrical stimulation. This study aimed to develop a technique for transcutaneous electrical nerve inhibition (TENI) using medium-frequency alternating current (MFAC) to suppress both sensory and motor nerve activity in humans. METHODS: Surface electrodes were affixed to the skin of eight young adults to stimulate the median nerve. Stimulation intensity was increased up to 50% and 100% of the pain threshold. To identify changes in sensory perception by transcutaneous MFAC (tMFAC) stimulation, we examined tactile and pressure pain thresholds in the index and middle fingers before and after stimulation at 10 kHz. To demonstrate the effect of tMFAC stimulation on motor inhibition, stimulation was applied while participants produced flexion forces with the index and middle fingers at target forces (50% and 90% of MVC, maximum voluntary contraction). RESULTS: tMFAC stimulation intensity significantly increased tactile and pressure pain thresholds, indicating decreased sensory perception. During the force production task, tMFAC stimulation with the maximum intensity immediately reduced finger forces by ~ 40%. Finger forces recovered immediately after stimulation cessation. The effect on motor inhibition was greater with the higher target force (90% MVC) than with the lower target (50% MVC). Also, higher tMFAC stimulation intensity provided a greater inhibition effect on both sensory and motor nerve activity. CONCLUSION: We found that tMFAC stimulation immediately inhibits sensory and motor activity. This pre-clinical study demonstrates a novel technique for TENI using MFAC stimulation and showed that it can effectively inhibit both sensory perception and motor activity. The proposed technique can be combined with existing rehabilitation devices (e.g., a robotic exoskeleton) to inhibit undesired sensorimotor activities and to accelerate recovery after neurologic injury.
Assuntos
Limiar Sensorial/fisiologia , Estimulação Elétrica Nervosa Transcutânea/métodos , Adulto , Feminino , Humanos , Masculino , Nervo Mediano/fisiologia , Atividade Motora/fisiologia , Estimulação Elétrica Nervosa Transcutânea/instrumentaçãoRESUMO
To study trafficking of bulk internalized vesicles such as macropinosome and lysosome in live cells, an efficient and convenient assay was established according to the axon turning assay. By injecting indicator or fluorescent dyes through a micropipette with air pressure into cell cultures to create a stable gradient around the micropipette tip, vesicles were indicated and labeled. With live cell imaging, the whole process was recorded. Without wash-out of fluorescent dyes and transferring, this assay is an effective, fast labeling system for bulk internalized vesicles, and can also be combined with imaging system.
Assuntos
Corantes Fluorescentes , Lisossomos , Vesículas Transportadoras , AnimaisRESUMO
The genus Bartonella contains >40 species, and an increasing number of these Bartonella species are being implicated in human disease. One such pathogen is Bartonella ancashensis, which was isolated in blood samples from 2 patients living in Caraz, Peru, during a clinical trial of treatment for bartonellosis. Three B. ancashensis strains were analyzed by using whole-genome restriction mapping and high-throughput pyrosequencing. Genome-wide comparative analysis of Bartonella species showed that B. ancashensis has features seen in modern and ancient lineages of Bartonella species and is more related to B. bacilliformis. The divergence between B. ancashensis and B. bacilliformis is much greater than what is seen between known Bartonella genetic lineages. In addition, B. ancashensis contains type IV secretion system proteins, which are not present in B. bacilliformis. Whole-genome analysis indicates that B. ancashensis might represent a distinct Bartonella lineage phylogenetically related to B. bacilliformis.
Assuntos
Infecções por Bartonella/microbiologia , Bartonella/genética , Genoma Bacteriano , Adolescente , Adulto , Bartonella/classificação , Infecções por Bartonella/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Peru/epidemiologia , Filogenia , Adulto JovemRESUMO
Flaviviruses comprise a large and diverse group of positive-stranded RNA viruses, including tick-, mosquito- and unknown-vector-borne flaviviruses. A novel flavivirus was detected in pools of Aedes vexans nipponii (n=1) and Aedes esoensis (n=3) collected in 2012 and 2013 near the demilitarized zone (DMZ), Republic of Korea (ROK). Phylogenetic analyses of the NS5, E gene and complete polyprotein coding sequence (CDS) showed that the novel virus fell within the Aedes-borne flaviviruses (ABFVs), with nucleotide identity ranging from 57.8-75.1â%, 46.1-74.2â% and 51.1-76.2â%, respectively. While the novel ABFV was distant from other flaviviruses within the group, it formed a clade with Ilomantsi virus (ILOV). Sequence alignments of the partial NS5 gene, full-length E gene and polyprotein CDS between the novel virus and ILOV showed approximately 76.2â% nucleotide identity and 90â% amino acid identity, respectively. The ABFV identified in Aedes mosquitoes from the ROK is a novel ABFV based on the sequence analyses and is designated as Panmunjeom flavivirus (PANFV).
Assuntos
Aedes/virologia , Flavivirus/classificação , Flavivirus/isolamento & purificação , Filogenia , Animais , República da Coreia , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico , Proteínas do Envelope Viral/genética , Proteínas não Estruturais Virais/genéticaRESUMO
Human adenoviruses (HAdV), in particular types 4 and 7, frequently cause acute respiratory disease (ARD) during basic military training. HAdV4 and HAdV7 vaccines reduced the ARD risk in U.S. military. It is important to identify other respiratory pathogens and assess their potential impact on military readiness. In 2002, during a period when the HAdV vaccines were not available, throat swabs were taken from trainees (n = 184) with respiratory infections at Fort Jackson, South Carolina. Viral etiology was investigated initially with viral culture and neutralization assay and recently in this study by sequencing the viral isolates. Viral culture and neutralization assays identified 90 HAdV4 isolates and 27 additional cultures that showed viral cytopathic effects (CPE), including some with picornavirus-like CPE. Next-generation sequencing confirmed these results and determined viral genotypes, including 77 HAdV4, 4 HAdV3, 1 HAdV2, 17 coxsackievirus A21 (CAV21), and 1 enterovirus D68. Two samples were positive for both HAdV4 and CAV21. The identified genotypes are phylogenetically close to but distinct from those found during other years or in other military/non-military sites. HAdV4 is the predominant respiratory pathogen in unvaccinated military trainee. HAdV4 has temporal and demographic variability. CAV21 is a significant respiratory pathogen and needs to be evaluated for its current significance in military basic trainees.