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1.
J Med Internet Res ; 24(4): e28291, 2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-35436216

RESUMO

With the growing importance of communicating with the public via the web, many industries have used web analytics to provide information that organizations can use to better achieve their goals. Although the importance of health care websites has also grown, the health care industry has been slower to adopt the use of web analytics. Web analytics are the measurement, collection, analysis, and reporting of internet data used to measure direct user interaction. Our objective is to provide generalized methods for using web analytics as key performance metrics to evaluate websites and outline actionable recommendations for improvement. By deconstructing web analytic categories such as engagement, users, acquisition, content, and platform, we describe how web analytics are used to evaluate websites and how improvements can be made using this information. Engagement is how a user interacts with a website. It can be evaluated using the daily active users to monthly active users (DAU/MAU) ratio, bounce rate, pages viewed, and time on site. Poor engagement indicates potential problems with website usability. Users pertains to demographic information regarding the users interacting with a website. This data can help administrators understand who is engaging with their website. Acquisition refers to the overall website traffic and the method of traffic, which allows administrators to see how people are accessing their website. This information helps websites expand their methods of attracting users. Content refers to the overall relevancy, accuracy, and trustworthiness of a website's content. If a website has poor content, it will likely experience difficulty with user engagement. Finally, platform refers to the technical aspects of how people access a website. It includes both the internet browsers and devices used. By providing detailed descriptions of these categories, we have identified how web administrators can use web analytics to systematically assess their websites. We have also provided generalized recommendations for actionable improvements. By introducing the potential of web analytics to augment usability and the conversion rate, we hope to assist health care organizations in better communicating with the public and therefore accomplishing the goals of their websites.


Assuntos
Internet , Software , Atenção à Saúde , Humanos
2.
Antimicrob Agents Chemother ; 65(8): e0041221, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34060897

RESUMO

A total of 1,281 specimens from 1,024 patients were screened. Phylogenetic analysis classified 44 of these isolates as Klebsiella quasipneumoniae subsp. similipneumoniae (44/1,281 [3.4%]) and the remaining three as K. quasipneumoniae subsp. quasipneumoniae. The most common specimen source was urine (21/47 [44.7%]) followed by blood (14/47 [29.8%]). K. quasipneumoniae isolates were nonclonal. Carbapenemase-encoding genes (blaNDM and blaOXA-181) were detected in only two isolates (2/47 [4.3%]). K. quasipneumoniae appears to cause a spectrum of infections similar to those of K. pneumoniae, although higher rates of susceptibility to many commonly tested antimicrobials and low prevalence of virulence genes were demonstrated.


Assuntos
Farmacorresistência Bacteriana Múltipla , Infecções por Klebsiella , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Genômica , Humanos , Klebsiella/genética , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana , Filogenia , Singapura/epidemiologia , beta-Lactamases/genética
3.
Int J Syst Evol Microbiol ; 71(10)2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34698625

RESUMO

Staphylococcus argenteus and Staphylococcus schweitzeri are the newest members of the Staphylococcus aureus complex. The number of clinical reports attributed to these new S. aureus complex members is limited. In a retrospective clinical laboratory study conducted over a 4-month period investigating the prevalence of S. argenteus and S. schweitzeri, a total of 43 isolates were selected. Phylogeny based on core-gene multilocus sequence typing (MLST) analysis confirmed that 37 were S. argenteus but a genetically distinct clade of six isolates was identified. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) analyses further supported the classification of these six isolates as a separate species. When compared to S. aureus complex reference genomes, the ANI values were ≤94 % and the dDDH values were <53 %. Based on the seven-gene S. aureus MLST scheme, the six isolates belong to five novel allelic profiles (ST6105, ST6106, ST6107, ST6108 and ST109). Their clinical infection features were similar to S. aureus. Skin and soft tissue infections presented in four out of the six cases. Routine clinical diagnostic identification using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and biochemical profiling does not differentiate these new members from the rest of the complex. Genotypic analysis suggests that the six isolates belong to a novel species, Staphylococcus singaporensis sp. nov. with isolate SS21T (=DSM 111408T=NCTC14419T) designated as the type strain.


Assuntos
Filogenia , Staphylococcus/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Humanos , Tipagem de Sequências Multilocus , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Estudos Retrospectivos , Análise de Sequência de DNA , Staphylococcus/isolamento & purificação , Staphylococcus aureus/genética
4.
Infection ; 49(2): 305-311, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33315181

RESUMO

PURPOSE: One of the key approaches to minimize the risk of COVID-19 transmission would be to reduce the titres of SARS-CoV-2 in the saliva of infected COVID-19 patients. This is particularly important in high-risk procedures like dental treatment. The present randomized control trial evaluated the efficacy of three commercial mouth-rinse viz. povidone-iodine (PI), chlorhexidine gluconate (CHX) and cetylpyridinium chloride (CPC), in reducing the salivary SARS-CoV-2 viral load in COVID-19 patients compared with water. METHODS: A total of 36 SARS-CoV-2-positive patients were recruited, of which 16 patients were randomly assigned to four groups-PI group (n = 4), CHX group (n = 6), CPC group (n = 4) and water as control group (n = 2). Saliva samples were collected from all patients at baseline and at 5 min, 3 h and 6 h post-application of mouth-rinses/water. The samples were subjected to SARS-CoV-2 RT-PCR analysis. RESULTS: Comparison of salivary Ct values of patients within each group of PI, CHX, CPC and water at 5 min, 3 h and 6 h time points did not show any significant differences. However, when the Ct value fold change of each of the mouth-rinse group patients were compared with the fold change of water group patients at the respective time points, a significant increase was observed in the CPC group patients at 5 min and 6 h and in the PI group patients at 6 h. CONCLUSION: The effect of decreasing salivary load with CPC and PI mouth-rinsing was observed to be sustained at 6 h time point. Within the limitation of the current study, as number of the samples analyzed, the use of CPC and PI formulated that commercial mouth-rinses may be useful as a pre-procedural rinse to help reduce the transmission of COVID-19. ISRCTN (ISRCTN95933274), 09/09/20, retrospectively registered.


Assuntos
Anti-Infecciosos Locais/uso terapêutico , Tratamento Farmacológico da COVID-19 , Antissépticos Bucais/uso terapêutico , SARS-CoV-2/efeitos dos fármacos , Saliva/virologia , Carga Viral/efeitos dos fármacos , Adulto , COVID-19/prevenção & controle , COVID-19/transmissão , COVID-19/virologia , Cetilpiridínio/análise , Cetilpiridínio/uso terapêutico , Clorexidina/análogos & derivados , Clorexidina/análise , Clorexidina/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Antissépticos Bucais/química , Povidona-Iodo/análise , Povidona-Iodo/uso terapêutico , Singapura , Resultado do Tratamento , Adulto Jovem
5.
J Med Internet Res ; 23(12): e27750, 2021 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-34932015

RESUMO

BACKGROUND: Health care organizations are tasked with providing web-based health resources and information. Usability refers to the ease of user experience on a website. In this study, we conducted a usability analysis of academic medical centers in the United States, which, to the best of our knowledge, has not been previously carried out. OBJECTIVE: The primary aims of the study were to the following: (1) adapt a preexisting usability scoring methodology to academic medical centers; (2) apply and test this methodology on a sample set of academic medical center websites; and (3) make recommendations from these results on potential areas of improvements for our sample of academic medical center websites. METHODS: All website usability testing took place from June 1, 2020, to December 15, 2020. We replicated a methodology developed in previous literature and applied it to academic medical centers. Our sample included 73 US academic medical centers. Usability was split into four broad categories: accessibility (the ability of those with low levels of computer literacy to access and navigate the hospital's website); marketing (the ability of websites to be found through search engines and the relevance of descriptions to the links provided); content quality (grammar, frequency of information updates, material relevancy, and readability); and technology (download speed, quality of the programming code, and website infrastructure). Using these tools, we scored each website in each category. The composite of key factors in each category contributed to an overall "general usability" score for each website. An overall score was then calculated by applying a weighted percentage across all factors and was used for the final "overall usability" ranking. RESULTS: The category with the highest average score was technology, with a 0.82 (SD 0.068, SE 0.008). The lowest-performing category was content quality, with an average of 0.22 (SD 0.069, SE 0.008). As these numbers reflect weighted percentages as an integer, the higher the score, the greater the overall usability in that category. CONCLUSIONS: Our data suggest that technology, on average, was the highest-scored variable among academic medical center websites. Because website functionality is essential to a user's experience, it is justified that academic medical centers invest in optimal website performance. The overall lowest-scored variable was content quality. A potential reason for this may be that academic medical center websites are usually larger in size, making it difficult to monitor the increased quantity of content. An easy way to improve this variable is to conduct more frequent website audits to assess readability, grammar, and relevance. Marketing is another area in which these organizations have potential for improvement. Our recommendation is that organizations utilize search engine optimization techniques to improve their online visibility and discoverability.


Assuntos
Compreensão , Ferramenta de Busca , Centros Médicos Acadêmicos , Humanos , Internet , Estados Unidos
6.
Am J Infect Control ; 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38761850

RESUMO

BACKGROUND: We describe the investigations for control of two consecutive Serratia marcescens outbreaks in neonatology unit of Singapore General Hospital. METHODS: Epidemiological investigations, environmental sampling and risk-factors analysis were performed to guide infection control measures. Active surveillance sampling of nasopharyngeal aspirate and/or stool from neonates was conducted during both outbreaks. Whole-genome-sequencing was done to determine clonal links. Retrospective case-control study was conducted for second outbreak to identify risk factors for S marcescens acquisition. RESULTS: In 2022, two genetically unrelated S marcescens outbreaks were managed involving five neonates in March 2022 (outbreak 1) and eight neonates in November 2022 (outbreak 2). A link to positive isolates from sinks in intensive care units and milk preparation room was identified during outbreak 1. Neonatal jaundice (aOR, 16.46; p-value= 0.023) and non-formula milk feeding (aOR, 13.88; p-value= 0.02) were identified as risk factors during second outbreak. Multiple interventions adopted were cohorting of positive cases, carriage-screening, enhanced environmental cleaning, and emphasis on alcohol-based handrubs for hand-hygiene. CONCLUSION: The two outbreaks were likely due to infection prevention practices lapses and favourable environmental conditions. Nosocomial S marcescens outbreaks in neonatology units are difficult to control and require multidisciplinary approach with strict infection prevention measures to mitigate risk factors.

7.
J Immunother Cancer ; 11(12)2023 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-38164757

RESUMO

INTRODUCTION: The clinical benefit of the anti-CTLA-4 monoclonal antibody (mAb) ipilimumab has been well established but limited by immune-related adverse events, especially when ipilimumab is used in combination with anti-PD-(L)1 mAb therapy. To overcome these limitations, we have developed XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4 mAb. METHODS: XTX101 consists of an anti-human CTLA-4 mAb covalently linked to masking peptides that block the complementarity-determining regions, thereby minimizing the mAb binding to CTLA-4. The masking peptides are designed to be released by proteases that are typically dysregulated within the tumor microenvironment (TME), resulting in activation of XTX101 intratumorally. Mutations within the Fc region of XTX101 were included to enhance affinity for FcγRIII, which is expected to enhance potency through antibody-dependent cellular cytotoxicity. RESULTS: Biophysical, biochemical, and cell-based assays demonstrate that the function of XTX101 depends on proteolytic activation. In human CTLA-4 transgenic mice, XTX101 monotherapy demonstrated significant tumor growth inhibition (TGI) including complete responses, increased intratumoral CD8+T cells, and regulatory T cell depletion within the TME while maintaining minimal pharmacodynamic effects in the periphery. XTX101 in combination with anti-PD-1 mAb treatment resulted in significant TGI and was well tolerated in mice. XTX101 was activated in primary human tumors across a range of tumor types including melanoma, renal cell carcinoma, colon cancer and lung cancer in an ex vivo assay system. CONCLUSIONS: These data demonstrate that XTX101 retains the full potency of an Fc-enhanced CTLA-4 antagonist within the TME while minimizing the activity in non-tumor tissue, supporting the further evaluation of XTX101 in clinical studies.


Assuntos
Antineoplásicos , Melanoma , Humanos , Camundongos , Animais , Antígeno CTLA-4 , Ipilimumab/uso terapêutico , Antineoplásicos/uso terapêutico , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Melanoma/tratamento farmacológico , Modelos Animais de Doenças , Camundongos Transgênicos , Peptídeos/uso terapêutico , Microambiente Tumoral
8.
IDCases ; 30: e01611, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36032521

RESUMO

Background: Prolonged shedding/relapse of COVID-19 infection has been reported, particularly in patients who received anti-CD20 agents (eg. rituximab). However, cases of occult COVID-19, in which SARS-CoV-2 persistence in lung parenchyma is diagnosed despite clearance from nasopharyngeal (NP) specimens, are uncommon. Case summary: We describe two cases of occult COVID-19 in immunocompromised patients. Both patients had received rituximab previously. Both cases initially presented as ground-glass infiltrates on lung imaging; the diagnosis was originally not suspected due to repeated demonstration of negative SARS-CoV-2 from NP specimens, and alternative etiologies were originally considered. Persistence of SARS-CoV-2 in lung parenchyma, however, was demonstrated on bronchoalveolar lavage (BAL) specimens; additionally, isolation of viable SARS-CoV-2 virus and detection of SARS-CoV-2 nucleocapsid and spike-protein antigen in lung tissue on immunohistochemistry close to 3-months from primary infection strongly suggested ongoing viral persistence and replication as a driver of the lung parenchymal changes, which resolved after antiviral treatment. Discussion: Occult COVID-19 can be a cause of unexplained ground-glass infiltrates on lung imaging; negative NP samples do not rule out SARS-CoV-2 persistence and invasive sampling must be considered. The unsuspected presence of viable virus on BAL, however, highlights that procedurists perfoming aerosol-generating-procedures during an ongoing pandemic wave must also practise appropriate infection-prevention precautions to limit potential exposure.

9.
JMIR Hum Factors ; 8(1): e20721, 2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-33779564

RESUMO

BACKGROUND: As the public increasingly uses the internet to search for resources and information regarding health and medicine, it is important that health care organizations provide adequate web resources. Website usability refers to the ease of user experience on a website. In this study, we conducted usability analyses on digital health center websites. OBJECTIVE: The primary aims of this study were to (1) replicate a preexisting usability scoring methodology for digital health centers; (2) apply and test this replicated usability scoring methodology on a sample set of digital health center websites; and (3) derive recommendations from the results on potential areas of improvements for our sample of digital health center websites. METHODS: Website usability testing was conducted from March 1, 2020, to March 15, 2020. We replicated a methodology and scoring system from previous literature and applied them to digital health center websites. Our sample included 67 digital health centers that were affiliated with US universities or hospital systems. Usability was split into the following four broad categories: accessibility, marketing, content quality, and technology. Usability tools were used to score websites in each of the four categories. The composite of the key factors of each category was used to generate a general usability and overall usability score for each website. RESULTS: The category with the highest average score (6.3) was content quality. The content quality score also had the highest SD (2.18) and an SE of 0.27. The lowest performing category was technology, which had an average score of 0.9. The technology score also had the smallest SD (0.07) and an SE of 0.01. CONCLUSIONS: Our data suggest that content quality, on average, was the highest scoring variable among digital health center websites. As content is crucial to digital health knowledge, it is justified that digital health centers invest more resources into creating quality content. The overall lowest scoring variable was technology. Potential reasons for this finding include designated funding for servers, a lack of regulatory frameworks for social media presence and liability, and infrequent website audits. An easy approach for improving this variable is increasing website speed. Accessibility is another area that organizations can potentially improve. We recommend that these organizations perform periodic audits of their web presence with usability tools.

10.
Healthc (Amst) ; 9(4): 100570, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34343852

RESUMO

IMPORTANCE: The randomization process is considered among the most important components of a randomized control trial (RCTs) and a core advantage of RCTs. Proper randomization should eliminate most population biases, in which some populations, or members of a population are more likely to be selected or not selected than others, such that similar comparison groups are produced to evaluate treatments.4,5 OBJECTIVE: To assess the methodologic quality of the descriptions of randomization methods used to allocate participants to comparison groups in randomized controlled trials. EVIDENCE REVIEW: A cross-sectional review of phase 3 clinical trials reported in Clinicaltrials.gov. Beginning at all records available (n = 345,278) we included studies only listed for stage 3 RCTs in the U.S. National Library of Medicine database. A total of 1528 protocols were identified as of June 1, 2020. Exclusion criteria involved no protocol listed or non-randomized studies, of which 517 were excluded. There were 693 text articles excluded due to unclear methods of randomization. Inclusion criteria involved randomization methods based on "A review of randomization methods in clinical trials" by Berger and Antsygina.1 Each study protocol was extracted to identify the randomization methods described by three independent reviewers. Classification of randomization methods described in the study protocols for randomized clinical trials. FINDINGS: Only 20.8 % of the study protocols described a method for randomly assigning participants to groups. Of this subset that defined protocols, the Permuted-Block Design was used most often (85.9 %). More than three quarters of all study protocols (77.7 %) provided incomplete descriptions about the type of randomization method (i.e. no protocol, n/a, unclear). CONCLUSIONS: and Relevance:Proper randomization is required to generate unbiased comparison groups in controlled trials, yet the majority of study protocols for RCTs currently in Clinicaltrials.gov provide inadequate or unacceptable information regarding their randomization methods.


Assuntos
COVID-19 , Estudos Transversais , Humanos , Distribuição Aleatória , Ensaios Clínicos Controlados Aleatórios como Assunto , SARS-CoV-2 , Resultado do Tratamento
11.
Digit Health ; 7: 20552076211048985, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34691756

RESUMO

PROBLEM: As of 2020, less than 5% of physicians in the United States have a drug enforcement administration-X waiver to prescribe buprenorphine. The coronavirus-2019 pandemic restricted in-person gatherings, including traditional drug enforcement administration-X waiver courses. As a result, in-person conferences have needed to adopt remote formats. Many programs identified a gap between educational delivery and the faculty skills required to deliver content remotely. APPROACH: To address the need for high-quality remote learning, Get Waivered designed and implemented a novel experience for clinicians, called Get Waivered Remote. An educational session was live-streamed via Zoom™. To foster interactivity, like in-person didactic conferences, participants were polled to facilitate discussion among presenters, learners, and facilitators during the broadcast. OUTCOMES: The RE-AIM framework was used for evaluation. Our program had a Reach encompassing 814 users that participated during the live-streamed event; Effectiveness with 73.79% reporting being somewhat familiar or very familiar with the practice of opioid dependency treatment with approved buprenorphine medications; Adoption with 95.15% reporting a favorable experience and 92.23% reporting it was similar or more enjoyable than their usual teaching; Implementation with 450 messages sent by 281 users to engage with presenters and other learners via Zoom chat in real time. NEXT STEPS: Get Waivered Remote provides a proof-of-concept that a broadcast with a concurrent, interactive remote learning platform is feasible, low cost, and simple to execute. Further study is required to assess the ability of our group to maintain this innovation and also to measure its impact on the treatment of opioid use disorder.

12.
AEM Educ Train ; 5(3): e10604, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34124531

RESUMO

OBJECTIVES: The Council of Residency Directors (CORD) in Emergency Medicine (EM) has recommended that all residency programs should conduct virtual interviews for the 2020 to 2021 application cycle due to the COVID-19 pandemic. While factors such as geographical region, city, program size, or hospital affiliation are not modifiable, EM residencies can bridge the information gap created by a lack of face-to-face interaction by representing themselves digitally. Measuring usability provides an objective method for EM residencies to improve their Web presence and effectively represent themselves to applicants. METHODS: Our sample set included 55 U.S. EM residency program websites. Using methodology replicated from previous literature on health care website usability, we divided usability into four categories for quantifiable analysis: accessibility, marketing, content quality, and technology. Analysis was performed on each website and scored in all four categories. A "general usability" score was calculated for each website using a composite of the key factors within the four categories. Using a weighted percentage across all of the factors, an overall score was calculated. RESULTS: Content quality was the overall highest scoring category (mean ± SD = 5.4, SE = 0.33). The overall lowest performing category was technology (mean ± SD = 0.8 ± 0.09, SE = 0.01). CONCLUSIONS: Measuring usability can help EM residency programs identify ways to improve their Web presence. To effectively promote their programs, residencies need quality content that communicates their key features. Our recommendation is for all residency programs to periodically perform website audits and apply the usability measures outlined to improve their digital presence, especially during times when face-to-face interactions will be limited.

13.
PLoS One ; 15(10): e0240326, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33021985

RESUMO

COVID-19 has highlighted an opportunity for medical professionals to engage in online Public Engagement with Science (PES). Currently a popular platform for PES is Reddit. Reddit provides an Ask Me Anything (AMA) format for subject matter experts to answer questions asked by the public. On March 11, 2020, from 2:00 to 4:00pm EST, two Emergency Department physicians from Massachusetts General Hospital hosted an AMA session on coronavirus. We retroactively conducted an analysis of the questions and answers from this AMA session in order to better understand the public's concerns around coronavirus and identify future opportunities for medical experts to leverage the Reddit AMA format in communicating with the general public. Results suggested that participants sought not only to obtain information, but to engage in discussion, and did so with each other in the absence of expert responses. The majority of bi-directional discussion occurred between participants. Due to the volume of questions and ratio of experts to participants, not all questions were answered. More posts provided facts or opinions, than posts that providing resources or requesting resources.


Assuntos
Betacoronavirus , Infecções por Coronavirus/epidemiologia , Disseminação de Informação/métodos , Comportamento de Busca de Informação , Pneumonia Viral/epidemiologia , Mídias Sociais , COVID-19 , Compreensão , Infecções por Coronavirus/virologia , Serviço Hospitalar de Emergência , Hospitais Gerais , Humanos , Massachusetts , Pandemias , Médicos/psicologia , Pneumonia Viral/virologia , Profissionalismo , Opinião Pública , Estudos Retrospectivos , SARS-CoV-2
14.
J Parasitol ; 90(4): 893-5, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15357096

RESUMO

Parasites have been shown to up- and downregulate host apoptosis, most likely facilitating their ability to successfully establish an infection in the host. It has been demonstrated that pathogens modulate well-established pathways, leading to cell death, including induction of the Fas-FasL system to promote apoptosis. In contrast, it has also been shown that in other instances a decrease in host cell apoptosis results after the upregulation of genes in the Bcl-2 family. The present study examined the ability of Trypanosoma cruzi to modulate expression of host cell genes of the TNFR1 apoptotic pathway. Using microarray technology, gene expression was compared between uninfected BALB/c fibroblasts and T. cruzi-infected BALB/c fibroblasts. After comparing expression patterns between uninfected and T. cruzi-infected BALB/c fibroblasts, it was concluded that genetic expression of genes in the TNFR1 apoptotic pathway is downregulated in T. cruzi-infected cells, indicating that in BALB/c fibroblasts the parasite decreases the expression of genes, leading to host cell apoptosis.


Assuntos
Apoptose/genética , Regulação para Baixo , Fibroblastos/citologia , Análise de Sequência com Séries de Oligonucleotídeos , Trypanosoma cruzi/fisiologia , Animais , Camundongos , Camundongos Endogâmicos BALB C , Reação em Cadeia da Polimerase , Receptores do Fator de Necrose Tumoral/genética , Receptores do Fator de Necrose Tumoral/fisiologia , Trypanosoma cruzi/genética
15.
J Parasitol ; 90(3): 524-30, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15270096

RESUMO

Trypanosoma cruzi, a protozoan parasite, is the etiologic agent of Chagas disease. The disease is characterized by acute and chronic phases, with high and low parasitemia, respectively. A strong immune activation is necessary for the host to enter the chronic phase; however, immune mechanisms participating in the reduction of parasites between the acute and chronic phases of the disease have been very difficult to elucidate. We report here the discovery of anti-egressin, an antibody present in serum from chronically infected BALB/c mice that is able to inhibit parasite egress from infected BALB/c fibroblast cultures in vitro. The antibody is very concentrated in serum from these mice; chronic serum may be diluted 1:20 while still maintaining functional activity. Isotype analysis of anti-egressin has suggested it to be IgG2a. Further analysis revealed that anti-egressin was specific for a component expressed on the surface of infected host cells. The specificity of anti-egressin toward the extracellular portion of infected host cells was demonstrated both by using a quantitative assay measuring released trypomastigotes and through immunocytochemical staining. The novel role of anti-egressin in the inhibition of parasite egress from infected host cells has not been described in the literature to date. We believe that anti-egressin plays an important role in achieving the low parasitemia characteristic of chronic Chagas disease.


Assuntos
Fibroblastos/parasitologia , Imunoglobulina G/sangue , Trypanosoma cruzi/imunologia , Animais , Linhagem Celular , Fracionamento Químico , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Imunoglobulina G/química , Imunoglobulina G/imunologia , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos BALB C , Peso Molecular
16.
J Parasitol ; 90(1): 85-91, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15040671

RESUMO

Trypanosoma cruzi is the causative agent of Chagas disease, which is characterized by acute and chronic phases. During the former, parasitemia rises dramatically, then decreases significantly during the chronic phase. Immune mechanisms responsible for the parasitemia reduction have not been thoroughly elucidated. The goal of the present study was to further characterize the immune response during chronic infection. Previously, we described antiegressin, an antibody in sera from chronically infected mice. The in vitro presence of antiegressin inhibits parasite egress from infected host cells. Antiegressin appears by day 14 of an in vivo infection and is maintained through at least day 280 postinfection. The in vitro functional activity of antiegressin is initiated late in the 4-6 days intracellular growth cycle of T. cruzi; antiegressin may be added at day 4, inhibiting parasite release at day 5. Immunocytochemical staining using antineuraminidase demonstrates the presence of mature parasites inside host BALB/c fibroblasts grown in the presence of antiegressin. These results demonstrate the ability of antiegressin to inhibit emergence of developmentally mature trypomastigotes from infected host cells late in their intracellular growth cycle. We believe this antibody plays an important and novel role in achieving the low-parasitemia characteristic of chronic Chagas disease.


Assuntos
Doença de Chagas/imunologia , Fibroblastos/parasitologia , Imunoglobulina G/imunologia , Trypanosoma cruzi/imunologia , Animais , Linhagem Celular , Doença de Chagas/parasitologia , Feminino , Fibroblastos/imunologia , Imunoglobulina G/sangue , Imuno-Histoquímica , Camundongos , Neuraminidase/genética , Neuraminidase/imunologia , Neuraminidase/metabolismo , Trypanosoma cruzi/enzimologia , Trypanosoma cruzi/crescimento & desenvolvimento
17.
J Parasitol ; 89(5): 1078-80, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14627166

RESUMO

Dicationic compounds, which are derivatives of pentamidine, are being developed for use as antiprotozoal drugs. These compounds bind to the minor groove of DNA and are thought to inhibit DNA-dependent enzymes and thereby prevent cellular replication by protozoans. The objective of this study was to test the ability of a group of these compounds to inhibit the intracellular and extracellular reproduction of Trypanosoma cruzi in vitro. At present, there are few drugs in use capable of inhibiting the intracellular stages of this parasite, and therefore compounds with this ability would be of value. Cultures of mouse fibroblasts were infected and treated with doses of dicationic compounds, and the numbers of parasites released at the end of the 5- to 7-day growth cycle were determined. Five of the compounds tested were found to be effective at inhibiting T. cruzi growth at doses that were not toxic to the host cells. The compound found most effective (DB709) inhibited parasite release at the low concentration of 0.8 ng/ ml, justifying further study. These results suggest that dicationic compounds may have potential as chemotherapy against T. cruzi infection.


Assuntos
Pentamidina/análogos & derivados , Pentamidina/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Células Cultivadas , Fibroblastos/parasitologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Trypanosoma cruzi/crescimento & desenvolvimento
18.
Rand Health Q ; 4(1): 4, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-28083318

RESUMO

A focused review of recent RAND Health research identified small ideas that could save the U.S. health care system $13 to $22 billion per year, in the aggregate, if successfully implemented. In the substituting lower-cost treatments category, ideas are to reduce use of anesthesia providers in routine gastroenterology procedures for low-risk patients, change payment policy for emergency transport, increase use of lower-cost antibiotics for treatment of acute otitis media, shift care from emergency departments to retail clinics when appropriate, eliminate co-payments for higher-risk patients taking cholesterol-lowering drugs, increase use of $4 generic drugs, and reduce Medicare Part D use of brand-name prescription drugs by patients with diabetes. In the patient safety category, ideas are to prevent three types of health care-associated infections: (1) central line-associated bloodstream infections, (2) ventilator-associated pneumonia, and (3) catheter-associated urinary tract infections; use preoperative and anesthesia checklists to prevent operative and postoperative events; prevent in-facility pressure ulcers; use ultrasound guidance for central line placement; and prevent recurrent falls. Small ideas do not require systemic change; thus, they may be both more feasible to operationalize and less likely to encounter stiff political and organizational resistance.

19.
PLoS One ; 8(9): e75625, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24086592

RESUMO

Papillomavirus E2 proteins are predominantly retained in the nuclei of infected cells, but oncogenic (high-risk) HPV-18 and 16 E2 can shuttle between the host nucleus and cytoplasm. We show here that cytoplasmic HPV-18 E2 localizes to mitochondrial membranes, and independent mass spectrometry analyses of the E2 interactome revealed association to the inner mitochondrial membrane including components of the respiratory chain. Mitochondrial E2 association modifies the cristae morphology when analyzed by electron microscopy and increases production of mitochondrial ROS. This ROS release does not induce apoptosis, but instead correlates with stabilization of HIF-1α and increased glycolysis. These mitochondrial functions are not shared by the non-oncogenic (low-risk) HPV-6 E2 protein, suggesting that modification of cellular metabolism by high-risk HPV E2 proteins could play a role in carcinogenesis by inducing the Warburg effect.


Assuntos
Papillomavirus Humano 18/metabolismo , Membranas Mitocondriais/metabolismo , Proteínas Oncogênicas Virais/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Proteínas Virais/metabolismo , Apoptose/fisiologia , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Núcleo Celular/virologia , Citoplasma/metabolismo , Citoplasma/virologia , Glicólise/fisiologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/virologia , Membranas Mitocondriais/virologia
20.
Virology ; 429(1): 47-56, 2012 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-22541938

RESUMO

The Human Papillomavirus (HPV) E4 is known to be synthesized as an E1^E4 fusion resulting from splice donor and acceptor sites conserved across HPV types. Here we demonstrate the existence of 2 HPV-18 E2^E4 transcripts resulting from 2 splice donor sites in the 5' part of E2, while the splice acceptor site is the one used for E1^E4. Both E2^E4 transcripts are up-regulated by keratinocyte differentiation in vitro and can be detected in clinical samples containing low-grade HPV-18-positive cells from Pap smears. They give rise to two fusion proteins in vitro, E2^E4-S and E2^E4-L. Whereas we could not differentiate E2^E4-S from E1^E4 in vivo, E2^E4-L could be formally identified as a 23 kDa protein in raft cultures in which the corresponding transcript was also found, and in a biopsy from a patient with cervical intraepithelial neoplasia stage I-II (CINI-II) associated with HPV-18, demonstrating the physiological relevance of E2^E4 products.


Assuntos
Diferenciação Celular , Papillomavirus Humano 18/metabolismo , Queratinócitos/citologia , Proteínas Oncogênicas Virais/metabolismo , Infecções por Papillomavirus/virologia , Splicing de RNA , Sequência de Bases , Feminino , Papillomavirus Humano 18/genética , Humanos , Queratinócitos/virologia , Dados de Sequência Molecular , Proteínas Oncogênicas Virais/genética , Infecções por Papillomavirus/fisiopatologia , Sítios de Splice de RNA , RNA Viral/genética , RNA Viral/metabolismo
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