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1.
J Infect Dis ; 227(8): 981-992, 2023 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-36468309

RESUMO

BACKGROUND: Control of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission requires understanding SARS-CoV-2 replication dynamics. METHODS: We developed a multiplexed droplet digital polymerase chain reaction (ddPCR) assay to quantify SARS-CoV-2 subgenomic RNAs (sgRNAs), which are only produced during active viral replication, and discriminate them from genomic RNAs (gRNAs). We applied the assay to specimens from 144 people with single nasopharyngeal samples and 27 people with >1 sample. Results were compared to quantitative PCR (qPCR) and viral culture. RESULTS: sgRNAs were quantifiable across a range of qPCR cycle threshold (Ct) values and correlated with Ct values. The ratio sgRNA:gRNA was stable across a wide range of Ct values, whereas adjusted amounts of N sgRNA to a human housekeeping gene declined with higher Ct values. Adjusted sgRNA and gRNA amounts were quantifiable in culture-negative samples, although levels were significantly lower than in culture-positive samples. Daily testing of 6 persons revealed that sgRNA is concordant with culture results during the first week of infection but may be discordant with culture later in infection. sgRNA:gRNA is constant during infection despite changes in viral culture. CONCLUSIONS: Ct values from qPCR correlate with active viral replication. More work is needed to understand why some cultures are negative despite presence of sgRNA.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , COVID-19/diagnóstico , Teste para COVID-19 , Genômica , Reação em Cadeia da Polimerase , Reação em Cadeia da Polimerase em Tempo Real/métodos , RNA Viral/genética , RNA Viral/análise , SARS-CoV-2/genética , RNA Subgenômico/genética
2.
BMC Infect Dis ; 23(1): 570, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37658305

RESUMO

BACKGROUND: Integration of a sensitive point-of-care (POC) HIV viral load (VL) test into screening algorithms may help detect acute HIV infection earlier, identify people with HIV (PWH) who are not virally suppressed, and facilitate earlier referral to antiretroviral therapy (ART), or evaluation for pre-exposure prophylaxis (PrEP). This report describes a randomized clinical trial sponsored by the Centers for Disease Control and Prevention (CDC): "Ending the HIV Epidemic Through Point-of-Care Technologies" (EHPOC). The study's primary aim is to evaluate the use of a POC HIV VL test as part of a testing approach and assess the impact on time to linkage to ART or PrEP. The study will recruit people in Baltimore, Maryland, including patients attending a hospital emergency department, patients attending an infectious disease clinic, and people recruited via community outreach. The secondary aim is to evaluate the performance characteristics of two rapid HIV antibody tests approved by the United States Food and Drug Administration (FDA). METHODS: The study will recruit people 18 years or older who have risk factors for HIV acquisition and are not on PrEP, or PWH who are not taking ART. Participants will be randomly assigned to either the control arm or the intervention arm. Participants randomized to the control arm will only receive the standard-of-care (SOC) HIV screening tests. Intervention arm participants will receive a POC HIV VL test in addition to the SOC HIV diagnostic screening tests. Follow up will consist of an interim phone survey conducted at week-4 and an in-person week-12 visit. Demographic and behavioral information, and oral fluid and blood specimens will be collected at enrollment and at week-12. Survey data will be captured in a Research Electronic Data Capture (REDCap) database. Participants in both arms will be referred for either ART or PrEP based on their HIV test results. DISCUSSION: The EHPOC trial will explore a novel HIV diagnostic technology that can be performed at the POC and provide viral assessment. The study may help inform HIV testing algorithms and contribute to the evidence to support same day ART and PrEP recommendations. TRIAL REGISTRATION: NIH ClinicalTrials.gov NCT04793750. Date: 11 March 2021.


Assuntos
Infecções por HIV , Sistemas Automatizados de Assistência Junto ao Leito , Estados Unidos , Humanos , Baltimore , Infecções por HIV/diagnóstico , Infecções por HIV/tratamento farmacológico , Infecções por HIV/prevenção & controle , Carga Viral , Teste de HIV
3.
J Clin Microbiol ; 60(7): e0018722, 2022 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-35730949

RESUMO

COVID-19 has brought unprecedented attention to the crucial role of diagnostics in pandemic control. We compared severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test performance by sample type and modality in close contacts of SARS-CoV-2 cases. Close contacts of SARS-CoV-2-positive individuals were enrolled after informed consent. Clinician-collected nasopharyngeal (NP) swabs in viral transport media (VTM) were tested with a routine clinical reference nucleic acid test (NAT) and PerkinElmer real-time reverse transcription-PCR (RT-PCR) assay; positive samples were tested for infectivity using a VeroE6TMPRSS2 cell culture model. Self-collected passive drool was also tested using the PerkinElmer RT-PCR assay. For the first 4 months of study, midturbinate swabs were tested using the BD Veritor rapid antigen test. Between 17 November 2020 and 1 October 2021, 235 close contacts of SARS-CoV-2 cases were recruited, including 95 with symptoms (82% symptomatic for ≤5 days) and 140 asymptomatic individuals. Reference NATs were positive for 53 (22.6%) participants; 24/50 (48%) were culture positive. PerkinElmer testing of NP and saliva samples identified an additional 28 (11.9%) SARS-CoV-2 cases who tested negative by reference NAT. Antigen tests performed for 99 close contacts showed 83% positive percent agreement (PPA) with reference NAT among early symptomatic persons, but 18% PPA in others; antigen tests in 8 of 11 (72.7%) culture-positive participants were positive. Contacts of SARS-CoV-2 cases may be falsely negative early after contact, but more sensitive platforms may identify these cases. Repeat or serial SARS-CoV-2 testing with both antigen and molecular assays may be warranted for individuals with high pretest probability for infection.


Assuntos
COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , Teste para COVID-19 , Humanos , Pandemias , Sensibilidade e Especificidade
4.
PLoS Biol ; 17(11): e3000516, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31751328

RESUMO

Behavior provides important insights into neuronal processes. For example, analysis of reaching movements can give a reliable indication of the degree of impairment in neurological disorders such as stroke, Parkinson disease, or Huntington disease. The analysis of such movement abnormalities is notoriously difficult and requires a trained evaluator. Here, we show that a deep neural network is able to score behavioral impairments with expert accuracy in rodent models of stroke. The same network was also trained to successfully score movements in a variety of other behavioral tasks. The neural network also uncovered novel movement alterations related to stroke, which had higher predictive power of stroke volume than the movement components defined by human experts. Moreover, when the regression network was trained only on categorical information (control = 0; stroke = 1), it generated predictions with intermediate values between 0 and 1 that matched the human expert scores of stroke severity. The network thus offers a new data-driven approach to automatically derive ratings of motor impairments. Altogether, this network can provide a reliable neurological assessment and can assist the design of behavioral indices to diagnose and monitor neurological disorders.


Assuntos
Processamento de Imagem Assistida por Computador , Doenças do Sistema Nervoso/fisiopatologia , Redes Neurais de Computação , Animais , Modelos Animais de Doenças , Membro Anterior , Masculino , Atividade Motora , Transtornos Motores/fisiopatologia , Destreza Motora , Movimento , Ratos , Acidente Vascular Cerebral/fisiopatologia
5.
Mol Biol Rep ; 49(7): 6659-6691, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35253073

RESUMO

Parasitic diseases have a serious impact on the world in terms of health and economics and are responsible for worldwide mortality and morbidity. The present review features the hybrid targeting involving three main enzymes for the treatment of different parasitic diseases. The enzymes Dihydrofolate reductase, thymidylate synthase, and Serine hydroxy methyltransferase play an essential role in the folate pathway. The present review focuses on these enzymes, which can be targeted against several diseases. It shed light on the past, present, and future of these targets, and it can be assessed that these targets can play a significant role against several infectious diseases. For combating viral and protozoal infectious diseases, these targets in combination should be addressed.


Assuntos
Doenças Transmissíveis , Tetra-Hidrofolato Desidrogenase , Humanos , Metiltransferases , Serina , Tetra-Hidrofolato Desidrogenase/genética , Tetra-Hidrofolato Desidrogenase/metabolismo , Timidilato Sintase/genética , Timidilato Sintase/metabolismo
6.
J Infect Dis ; 224(6): 976-982, 2021 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-34191025

RESUMO

BACKGROUND: Serial screening is critical for restricting spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by facilitating timely identification of infected individuals to interrupt transmission. Variation in sensitivity of different diagnostic tests at different stages of infection has not been well documented. METHODS: In a longitudinal study of 43 adults newly infected with SARS-CoV-2, all provided daily saliva and nasal swabs for quantitative reverse transcription polymerase chain reaction (RT-qPCR), Quidel SARS Sofia antigen fluorescent immunoassay (FIA), and live virus culture. RESULTS: Both RT-qPCR and Quidel SARS Sofia antigen FIA peaked in sensitivity during the period in which live virus was detected in nasal swabs, but sensitivity of RT-qPCR tests rose more rapidly prior to this period. We also found that serial testing multiple times per week increases the sensitivity of antigen tests. CONCLUSIONS: RT-qPCR tests are more effective than antigen tests at identifying infected individuals prior to or early during the infectious period and thus for minimizing forward transmission (given timely results reporting). All tests showed >98% sensitivity for identifying infected individuals if used at least every 3 days. Daily screening using antigen tests can achieve approximately 90% sensitivity for identifying infected individuals while they are viral culture positive.


Assuntos
Teste para COVID-19 , COVID-19/diagnóstico , Testes Diagnósticos de Rotina , SARS-CoV-2/isolamento & purificação , Adulto , Idoso , Animais , Antígenos Virais/análise , Chlorocebus aethiops , Feminino , Humanos , Estudos Longitudinais , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real , Saliva , Sensibilidade e Especificidade , Células Vero , Adulto Jovem
7.
Bioorg Chem ; 115: 105209, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34364054

RESUMO

A series of semicarbazone, thiosemicarbazone, thiazole, and oxazole derivatives were designed, synthesized, and examined for monoamine oxidase inhibition using two isoforms, i.e., MAO-A and MAO-B. Among all the analogues, 3c and 3j possessed substantial activity against MAO-A with IC50 values of 5.619 ± 1.04 µM and 0.5781 ± 0.1674 µM, respectively. Whereas 3d and 3j were active against monoamine oxidase B with the IC50 values of 9.952 ± 1.831 µM and 3.5 ± 0.7 µM, respectively. Other derivatives active against MAO-B were 3c and 3g with the IC50 values of 17.67 ± 5.6 µM and 37.18 ± 2.485 µM. Moreover, molecular docking studies were achieved for the most potent compound (3j) contrary to human MAO-A and MAO-B. Kinetic studies were also performed for the most potent analogue to evaluate its mode of interaction with MAO-A and MAO-B.


Assuntos
Simulação de Acoplamento Molecular , Inibidores da Monoaminoxidase/farmacologia , Monoaminoxidase/metabolismo , Oxazóis/farmacologia , Semicarbazonas/farmacologia , Tiazóis/farmacologia , Tiossemicarbazonas/farmacologia , Relação Dose-Resposta a Droga , Humanos , Cinética , Estrutura Molecular , Inibidores da Monoaminoxidase/síntese química , Inibidores da Monoaminoxidase/química , Oxazóis/química , Semicarbazonas/química , Relação Estrutura-Atividade , Tiazóis/química , Tiossemicarbazonas/química
8.
Drug Dev Ind Pharm ; 47(8): 1193-1199, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34647512

RESUMO

BACKGROUND: Emulgels are the emerging drug delivery system nowadays that has become popular for the delivery of hydrophobic drugs. This formulation is considered a novel type of drug delivery system and a mixture of emulsion and gel. OBJECTIVE: The objective of this review is to throw light on the preparation of emulgels and their evaluation which will conclude how important these dosage forms are. In the coming years, it will be most commonly used because it is easy to use and enhances patient compliance. CONCLUSION: Emulgels are easily removable, spreadable, thixotropic, greaseless, have a pleasing appearance, emollient, long shelf life, and transparent. In the present era, the emulgels are being used for the delivery of many drugs like analgesics, anti-inflammatory, anti-acne and anti-fungal. Hence, it is of great pharmacological importance and is relatively free of side effects.


Assuntos
Sistemas de Liberação de Medicamentos , Excipientes , Emulsões , Excipientes/química , Géis/química , Humanos
9.
Exp Brain Res ; 235(6): 1919-1932, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28315945

RESUMO

Multiple motor channel (MMC) theory of neocortical organization proposes that complex movements, such as reaching for a food item to eat, are produced by the coordinated action of separate neural channels. For example, the human reach-to-grasp act is mediated by two visuo-parieto-motor cortex channels, one for the reach and one for the grasp. The present analysis asked whether there is a similar organization of reach-and-grasp movements in the mouse. The reach-to-eat movements of the same mice were examined from high-shutter speed, frame-by-frame video analysis in three tasks in which the mice obtained equivalent success scores: when freely-moving reaching for food pellets, when head-fixed reaching for food pellets, and when head-fixed reaching for pieces of pasta. To reach, the mice used egocentric cues to vary upper arm movements in a task-appropriate manner to place an open hand on the food or to locate the food using a "touch-release-grasp" strategy. Although mice could not hand-shape offline when reaching, they could hand-shape using online touch-related cues from the mouth to manipulate the food at the mouth. That the reach can be performed offline in relation to egocentric cues whereas hand shaping for the grasp requires online cues supports the idea that for the mouse, as for primates, the reach and grasp are separate acts. The results are further discussed in relation to the use of the head-fixed behavioral procedure to identify the independent neural substrates of the reach and the grasp using mesoscale stimulation/imaging methods.


Assuntos
Comportamento Animal/fisiologia , Atividade Motora/fisiologia , Neocórtex/fisiologia , Desempenho Psicomotor/fisiologia , Animais , Cabeça , Masculino , Camundongos , Camundongos Endogâmicos C57BL
10.
Prog Mol Biol Transl Sci ; 206: 389-434, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38811086

RESUMO

While amyloid has traditionally been viewed as a harmful formation, emerging evidence suggests that amyloids may also play a functional role in cell biology, contributing to normal physiological processes that have been conserved throughout evolution. Functional amyloids have been discovered in several creatures, spanning from bacteria to mammals. These amyloids serve a multitude of purposes, including but not limited to, forming biofilms, melanin synthesis, storage, information transfer, and memory. The functional role of amyloids has been consistently validated by the discovery of more functional amyloids, indicating a conceptual convergence. The biology of amyloids is well-represented by non-pathogenic amyloids, given the numerous ones already identified and the ongoing rate of new discoveries. In this chapter, functional amyloids in microorganisms, animals, and plants are described.


Assuntos
Amiloide , Amiloide/metabolismo , Animais , Humanos
11.
J AOAC Int ; 96(1): 56-9, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23513958

RESUMO

The objective of this research was to develop and validate a rapid, economical, and sensitive HPLC method for quantitative determination of gliquidone, pioglitazone hydrochloride, and atorvastatin in tablets and serum. Due to drug combination of these formulations, there has been a need for a reliable quantitative method to determine these drugs in commercial samples and human serum. The chromatographic separation was carried out at ambient temperature with a mobile phase consisting of methanol-water (90 + 10, v/v), with pH adjusted to 3.50 with phosphoric acid. The pump was operated at a flow rate of 1 mL/min, and all analytes were detected at 235 nm. The method was linear over the concentration range of 5-50 microg/mL for all the drugs. The LOD of gliquidone, pioglitazone hydrochloride, and atorvastatin was 0.30, 1.30, and 0.57 microg/mL and LOQ was 0.98, 4.28, and 1.90 microg/mL, respectively. The proposed method was successfully applied to the determination of these drugs in commercial tablets and human serum. The established method was validated with respect to specificity, linearity, precision, accuracy, and ruggedness.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Ácidos Heptanoicos/análise , Pirróis/análise , Compostos de Sulfonilureia/análise , Tiazolidinedionas/análise , Atorvastatina , Humanos , Pioglitazona , Comprimidos
12.
Cureus ; 15(10): e47282, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38021644

RESUMO

The association between Insulin resistance, a global health issue, and endocrine disruptors (EDCs), chemicals interfering with the endocrine system, has sparked concern in the scientific community. This article provides a comprehensive review of the existing literature regarding the intricate relationship between EDCs and insulin resistance. Phthalates, commonly found in consumer products, are well-established EDCs with documented effects on insulin-signaling pathways and metabolic processes. Epidemiological studies have connected phthalate exposure to an increased risk of type 2 diabetes mellitus (T2DM). Perfluoroalkyl substances (PFAS), persistent synthetic compounds, have shown inconsistent associations with T2DM in epidemiological research. However, studies suggest that PFAS may influence insulin resistance and overall metabolic health, with varying effects depending on specific PFAS molecules and study populations. Bisphenol A (BPA), found in plastics and resins, has emerged as a concern for glucose regulation and insulin resistance. Research has linked BPA exposure to T2DM, altered insulin release, obesity, and changes in the mass and function of insulin-secreting ß-cells. Triclosan, an antibacterial agent in personal care products, exhibits gender-specific associations with T2DM risk. It may impact gut microbiota, thyroid hormones, obesity, and inflammation, raising concerns about its effects on metabolic health. Furthermore, environmental EDCs like polycyclic aromatic hydrocarbons, pesticides, and heavy metals have demonstrated associations with T2DM, insulin resistance, hypertension, and obesity. Occupational exposure to specific pesticides and heavy metals has been linked to metabolic abnormalities.

13.
Cureus ; 15(10): e47207, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38021880

RESUMO

Acute coronary syndrome (ACS) stands as a leading global cause of mortality, underscoring the importance of effective prevention, early diagnosis, and timely intervention. While medications offer benefits to many patients, revascularization procedures such as coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), and emerging hybrid approaches remain pivotal for ACS management. This review delves into the 2018 ESC/EACTS guidelines alongside an analysis of existing literature to shed light on the spectrum of revascularization methods. While both CABG and PCI demonstrate promising outcomes, the optimal choice between the two hinges on a comprehensive assessment of individual patient factors, anatomical complexity guided by advanced imaging, comorbidities, and age. The determination of whether to pursue culprit or total revascularization, as well as immediate or staged revascularization, is contingent upon various factors, including age, disease complexity, and clinical outcomes. This evidence-based decision-making process is orchestrated by a multidisciplinary heart team grounded in ongoing clinical evaluation. The primary objective of this review is to provide valuable insights into revascularization strategies and scrutinize the congruence of current guidelines with recent advancements in the field.

14.
Adv Pharm Bull ; 12(3): 419-422, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35935058

RESUMO

Cytokines, as protein biomarkers, have essential functions in the diagnosis, identification, and healing of a broad range of syndromes. For the specific and accurate monitoring of immune conditions, which change rapidly throughout the duration of disease, sophisticated sensors for detecting cytokines are essential and will assist in clinical testing and studies of various diseases. The present manuscript briefly discusses fundamental principles applied to the development of tools for cytokine detection and new biomarker development. The latest developments in the technologies for highly sensitive and multiplexed cytokine quantification, with current detection capabilities across a broad, vibrant array, are also discussed. Finally, nanomaterial-based cytokine sensors, currently considered new approaches, are presented from the perspective of optimizing the sensitivity and multiplexity of cytokine detection.

15.
J Biomol Struct Dyn ; 40(17): 7680-7692, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-33779506

RESUMO

Reverse transcriptase is the most therapeutic target for the discovery of novel, potent, and non-toxic new anti-retroviral drugs. In the present work, various docking software such as Sybyl Surflex-Dock, OpenEye FRED, and Hermes GOLD were evaluated for their efficiency to reproduce known cognate inhibitors' conformations. Three metrics were used and compared to assess the performance of the applied scoring functions, i.e. enrichment factor, receiver operating characteristic (ROC) curves, and Bedroc analysis. Twelve different scoring functions of three softwares were used to assess their ability to rank the cognate ligand within the active site of its proteins. The extensive virtual screening task was performed on eight crystal structures, and the performance of docking and scoring was assessed by their ability to efficiently detect known active compounds enriched in the top-ranked of the list among a randomly selected dataset of the ten thousand compounds of the NCI database. The effectiveness of post-docking relaxation in Surflex was also evaluated. The top 20, 50, and 100 compounds were selected based on consensus scoring functions from all 48 proteins with different ligand complexes. Further, the shortlisted leads were subjected to ADMET via using Discovery Studio. The results further implicate the importance of various statistical tools that should be followed before large-scale virtual screening for the drug discovery process. In silico results demonstrating the experiment was successful. The study of the research covers the combinatorial in silico techniques such as benchmarking of the softwares and scoring functions, statistical tools applied for screening and different conformations of HIV-RT crystal structures for virtual screening with rigid and flexible molecular docking and molecular dynamics simulation approach. This study reveals a clear roadmap to identify novel scaffolds against HIV-RT for antiretroviral therapy, thus providing the remedial solutions of HIV related infections and other diseases caused by malfunctioning of the target protein.Communicated by Ramaswamy H. Sarma.


Assuntos
Simulação de Dinâmica Molecular , Software , Ligantes , Simulação de Acoplamento Molecular , Proteínas/química , DNA Polimerase Dirigida por RNA
16.
Heliyon ; 8(1): e08809, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35111986

RESUMO

The vehicular industry is looking for continuous challenges to develop the sustainability of its manufacturing, maintenance processes, and vehicle emissions due to marketability, environmental, economic, and policy concerns. The present study focuses on the impact of these processes on the environment. In Pakistan, most of the auto-body refinishing processes are carried out in an open atmosphere. The shades of Azadirachta indica (Neem Tree) are generally used for the outdoor practice of scrapping, grinding, and painting in auto-body refinishing shops of Pakistan. Azadirachta indica leaves were selected as bio-indicator. For the present work, 26 affected sites and 10 control sites were selected from Karachi city, which is the financial hub and biggest city of Pakistan. Concentrations of different metals (Fe, Co, Cd, Cr, Cu, Mn, Mo, Ni, Pb, and Zn) were determined by atomic absorption spectrophotometer. A geographic information system (GIS) is used to present the variation in concentrations within Karachi city. The only positive correlation was observed in Pb and Mn (0.750). Principal component analysis (PCA) is applied to identify the anthropogenic effect between auto-body refinishing areas and control areas. Almost all analyzed metals show higher concentration at affected sites but Pb (87.14 mg/kg), Mn (46.47 mg/kg) and Fe (146.95 mg/kg) were leading the values, as compared to their concentration at control sites, Pb (48.83 mg/kg), Mn (15.23 mg/kg) and Fe (43.07 mg/kg). All analyzed metals are frequently present in different color pigments, whereas Pb, Mn, and Fe may also come from other sources, like the anti-knocking agent, vehicular exhaust, and scraping of car surface.

17.
medRxiv ; 2022 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-35169814

RESUMO

OBJECTIVES: COVID-19 has brought unprecedented attention to the crucial role of diagnostics in pandemic control. We compared SARS-CoV-2 test performance by sample type and modality in close contacts of SARS-CoV-2 cases. METHODS: Close contacts of SARS-CoV-2 positive individuals were enrolled after informed consent. Clinician-collected nasopharyngeal (NP) swabs in viral transport media (VTM) were tested with a nucleic acid test (NAT). NP VTM and self-collected passive drool were tested using the PerkinElmer real-time reverse transcription PCR (RT-PCR) assay. For the first 4 months of study, mid-turbinate swabs were tested using the BD Veritor rapid antigen test. NAT positive NP samples were tested for infectivity using a VeroE6TMPRSS2 cell culture model. RESULTS: Between November 17, 2020, and October 1, 2021, 235 close contacts of SARS-CoV-2 cases were recruited, including 95 with symptoms (82% symptomatic for < 5 days) and 140 asymptomatic individuals. NP swab reference tests were positive for 53 (22.6%) participants; 24/50 (48%) were culture positive. PerkinElmer testing of NP and saliva samples identified an additional 28 (11.9%) SARS-CoV-2 cases who tested negative by clinical NAT. Antigen tests performed for 99 close contacts showed 83% positive percent agreement (PPA) with reference NAT among early symptomatic persons, but 18% PPA in others; antigen tests in 8 of 11 (72.7%) culture-positive participants were positive. CONCLUSIONS: Contacts of SARS-CoV-2 cases may be falsely negative early after contact, which more sensitive platforms may identify. Repeat or serial SARS-CoV-2 testing with both antigen and molecular assays may be warranted for individuals with high pretest probability for infection.

18.
Nat Microbiol ; 7(5): 640-652, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35484231

RESUMO

The dynamics of SARS-CoV-2 replication and shedding in humans remain poorly understood. We captured the dynamics of infectious virus and viral RNA shedding during acute infection through daily longitudinal sampling of 60 individuals for up to 14 days. By fitting mechanistic models, we directly estimated viral expansion and clearance rates and overall infectiousness for each individual. Significant person-to-person variation in infectious virus shedding suggests that individual-level heterogeneity in viral dynamics contributes to 'superspreading'. Viral genome loads often peaked days earlier in saliva than in nasal swabs, indicating strong tissue compartmentalization and suggesting that saliva may serve as a superior sampling site for early detection of infection. Viral loads and clearance kinetics of Alpha (B.1.1.7) and previously circulating non-variant-of-concern viruses were mostly indistinguishable, indicating that the enhanced transmissibility of this variant cannot be explained simply by higher viral loads or delayed clearance. These results provide a high-resolution portrait of SARS-CoV-2 infection dynamics and implicate individual-level heterogeneity in infectiousness in superspreading.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Carga Viral , Eliminação de Partículas Virais
19.
Open Forum Infect Dis ; 9(7): ofac192, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35791353

RESUMO

Background: The global effort to vaccinate people against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during an ongoing pandemic has raised questions about how vaccine breakthrough infections compare with infections in immunologically naive individuals and the potential for vaccinated individuals to transmit the virus. Methods: We examined viral dynamics and infectious virus shedding through daily longitudinal sampling in 23 adults infected with SARS-CoV-2 at varying stages of vaccination, including 6 fully vaccinated individuals. Results: The durations of both infectious virus shedding and symptoms were significantly reduced in vaccinated individuals compared with unvaccinated individuals. We also observed that breakthrough infections are associated with strong tissue compartmentalization and are only detectable in saliva in some cases. Conclusions: Vaccination shortens the duration of time of high transmission potential, minimizes symptom duration, and may restrict tissue dissemination.

20.
J Chromatogr Sci ; 59(10): 923-927, 2021 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-33621328

RESUMO

A simple, accurate and precise RP-HPLC method was developed for the simultaneous determination of chloroquine, pyrimethamine and cetirizine hydrochloride concentrations in bulk drug and human serum. The assay was performed using a mobile phase of methanol: water (70:30) at pH of 2.8 ± 0.05 on the Purospher C-18 column with UV detection at 230 nm and rosuvastatin used as an internal standard. The retention times observed for chloroquine, pyrimethamine and cetirizine hydrochloride were 3.5, 2.5 and 5.5 minutes, respectively. The method was found to be specific for the assayed drugs showing a linear response in the concentration range of 1-100 µg mL-1 with coefficients of determination values of (r = 0.999). The method was developed and validated according to ICH guidelines. The method was used to monitor the serum samples and was found to be sensitive for therapeutic purposes, showing the potential to be a useful tool for routine analysis in laboratories.


Assuntos
Cetirizina , Pirimetamina , Cloroquina , Cromatografia Líquida de Alta Pressão , Humanos , Reprodutibilidade dos Testes
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