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1.
EBioMedicine ; : 105157, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38821778

RESUMO

BACKGROUND: Tight-fitting masks and respirators, in manikin studies, improved aerosol source control compared to loose-fitting masks. Whether this translates to humans is not known. METHODS: We compared efficacy of masks (cloth and surgical) and respirators (KN95 and N95) as source control for SARS-CoV-2 viral load in exhaled breath of volunteers with COVID-19 using a controlled human experimental study. Volunteers (N = 44, 43% female) provided paired unmasked and masked breath samples allowing computation of source-control factors. FINDINGS: All masks and respirators significantly reduced exhaled viral load, without fit tests or training. A duckbill N95 reduced exhaled viral load by 98% (95% CI: 97%-99%), and significantly outperformed a KN95 (p < 0.001) as well as cloth and surgical masks. Cloth masks outperformed a surgical mask (p = 0.027) and the tested KN95 (p = 0.014). INTERPRETATION: These results suggest that N95 respirators could be the standard of care in nursing homes and healthcare settings when respiratory viral infections are prevalent in the community and healthcare-associated transmission risk is elevated. FUNDING: Defense Advanced Research Projects Agency, National Institute of Allergy and Infectious Diseases, Centers for Disease Control and Prevention, the Bill & Melinda Gates Foundation, and The Flu Lab.

2.
Workplace Health Saf ; 71(3): 137-143, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36476243

RESUMO

BACKGROUND: With the emergence of SARS-CoV-2, healthcare workers (HCW) have relied on reusable personal protective equipment (PPE), including respirators and face shields (FSs). The effectiveness of decontamination procedures outside experimental settings is unclear. We examined the prevalence of surface contamination on reusable PPE used by HCWs at a hospital incorporating daily centralized decontamination and post-use wiping by sampling for common pathogens. METHOD: Samples were collected from HCWs' CleanSpace Halo respirator face masks (FMs) and FSs at the start of shift, immediately after use, and after cleaning with disinfecting wipes. Samples were analyzed for pathogens using the Applied Biosystems™ TaqPath™ COVID-19 Combo Kit and ThermoFisher TaqMan Array Card. Patient charts were reviewed for clinical correlation. FINDINGS: Of the 89 samples, 51 from FMs and 38 from FSs, none tested positive for SARS-CoV-2, despite 58 being obtained from PPE used in the care of patients with COVID-19, many with recent aerosol-generating procedures. Four samples tested positive (4.5%) for Staphylococcus aureus, two each from FMs and FSs. FMs that tested positive were not worn concurrently with FSs that tested positive. The FM and FS samples testing positive were worn in the care of patients without diagnosed S. aureus infection. No FMs tested positive following wipe-based disinfection, but both positive FS samples were found after disinfection wiping. CONCLUSION/APPLICATION TO PRACTICE: Contamination of reusable PPE appears uncommon, especially with SARS-CoV-2, when regular decontamination programs are in place. The rare presence of S. aureus highlights the importance of doffing procedures and hand hygiene by HCW to prevent surface contamination.


Assuntos
COVID-19 , Humanos , SARS-CoV-2 , Estado Terminal , Staphylococcus aureus , Transmissão de Doença Infecciosa do Paciente para o Profissional/prevenção & controle , Equipamento de Proteção Individual , Pessoal de Saúde , Ventiladores Mecânicos
3.
Nat Nanotechnol ; 18(2): 168-176, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36585515

RESUMO

Cotton textiles are ubiquitous in daily life and are also one of the primary mediums for transmitting viruses and bacteria. Conventional approaches to fabricating antiviral and antibacterial textiles generally load functional additives onto the surface of the fabric and/or their microfibres. However, such modifications are susceptible to deterioration after long-term use due to leaching of the additives. Here we show a different method to impregnate copper ions into the cellulose matrix to form a copper ion-textile (Cu-IT), in which the copper ions strongly coordinate with the oxygen-containing polar functional groups (for example, hydroxyl) of the cellulose chains. The Cu-IT displays high antiviral and antibacterial performance against tobacco mosaic virus and influenza A virus, and Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa and Bacillus subtilis bacteria due to the antimicrobial properties of copper. Furthermore, the strong coordination bonding of copper ions with the hydroxyl functionalities endows the Cu-IT with excellent air/water retainability and superior mechanical stability, which can meet daily use and resist repeated washing. This method to fabricate Cu-IT is cost-effective, ecofriendly and highly scalable, and this textile appears very promising for use in household products, public facilities and medical settings.


Assuntos
Antivirais , Cobre , Têxteis/microbiologia , Antibacterianos , Celulose
4.
Clin Infect Dis ; 76(5): 786-794, 2023 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-36285523

RESUMO

BACKGROUND: Aerosol inhalation is recognized as the dominant mode of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission. Three highly transmissible lineages evolved during the pandemic. One hypothesis to explain increased transmissibility is that natural selection favors variants with higher rates of viral aerosol shedding. However, the extent of aerosol shedding of successive SARS-CoV-2 variants is unknown. We aimed to measure the infectivity and rate of SARS-CoV-2 shedding into exhaled breath aerosol (EBA) by individuals during the Delta and Omicron waves and compared those rates with those of prior SARS-CoV-2 variants from our previously published work. METHODS: Individuals with coronavirus disease 2019 (COVID-19) (n = 93; 32 vaccinated and 20 boosted) were recruited to give samples, including 30-minute breath samples into a Gesundheit-II EBA sampler. Samples were quantified for viral RNA using reverse-transcription polymerase chain reaction and cultured for virus. RESULTS: Alpha (n = 4), Delta (n = 3), and Omicron (n = 29) cases shed significantly more viral RNA copies into EBAs than cases infected with ancestral strains and variants not associated with increased transmissibility (n = 57). All Delta and Omicron cases were fully vaccinated and most Omicron cases were boosted. We cultured virus from the EBA of 1 boosted and 3 fully vaccinated cases. CONCLUSIONS: Alpha, Delta, and Omicron independently evolved high viral aerosol shedding phenotypes, demonstrating convergent evolution. Vaccinated and boosted cases can shed infectious SARS-CoV-2 via EBA. These findings support a dominant role of infectious aerosols in transmission of SARS-CoV-2. Monitoring aerosol shedding from new variants and emerging pathogens can be an important component of future threat assessments and guide interventions to prevent transmission.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Aerossóis e Gotículas Respiratórios , RNA Viral
5.
Microbiol Spectr ; 10(2): e0012822, 2022 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-35311575

RESUMO

Saliva is an attractive sample for detecting SARS-CoV-2. However, contradictory reports exist concerning the sensitivity of saliva versus nasal swabs. We followed close contacts of COVID-19 cases for up to 14 days from the last exposure and collected self-reported symptoms, midturbinate swabs (MTS), and saliva every 2 or 3 days. Ct values, viral load, and frequency of viral detection by MTS and saliva were compared. Fifty-eight contacts provided 200 saliva-MTS pairs, and 14 contacts (13 with symptoms) had one or more positive samples. Saliva and MTS had similar rates of viral detection (P = 0.78) and substantial agreement (κ = 0.83). However, sensitivity varied significantly with time since symptom onset. Early on (days -3 to 2), saliva had 12 times (95% CI: 1.2, 130) greater likelihood of viral detection and 3.2 times (95% CI: 2.8, 3.8) higher RNA copy numbers compared to MTS. After day 2 of symptoms, there was a nonsignificant trend toward greater sensitivity using MTS. Saliva and MTS demonstrated high agreement making saliva a suitable alternative to MTS for SARS-CoV-2 detection. Saliva was more sensitive early in the infection when the transmission was most likely to occur, suggesting that it may be a superior and cost-effective screening tool for COVID-19. IMPORTANCE The findings of this manuscript are increasingly important with new variants that appear to have shorter incubation periods emerging, which may be more prone to detection in saliva before detection in nasal swabs. Therefore, there is an urgent need to provide the science to support the use of a detection method that is highly sensitive and widely acceptable to the public to improve screening rates and early detection. The manuscript presents the first evidence that saliva-based RT-PCR is more sensitive than MTS-based RT-PCR in detecting SARS-CoV-2 during the presymptomatic period - the critical period for unwitting onward transmission. Considering other advantages of saliva samples, including the lower cost, greater acceptability within the general population, and less risk to health care workers, our findings further supported the use of saliva to identify presymptomatic infection and prevent transmission of the virus.


Assuntos
COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , Humanos , Nasofaringe , SARS-CoV-2/genética , Saliva , Manejo de Espécimes/métodos
6.
Clin Infect Dis ; 75(1): e241-e248, 2022 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34519774

RESUMO

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 3.8 ±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 Respiratórios
7.
Environ Int ; 137: 105537, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32028176

RESUMO

Strategies to protect building occupants from the risk of acute respiratory infection (ARI) need to consider ventilation for its ability to dilute and remove indoor bioaerosols. Prior studies have described an association of increased self-reported colds and influenza-like symptoms with low ventilation but have not combined rigorous characterization of ventilation with assessment of laboratory confirmed infections. We report a study designed to fill this gap. We followed laboratory confirmed ARI rates and measured CO2 concentrations for four months during the winter-spring of 2018 in two campus residence halls: (1) a high ventilation building (HVB) with a dedicated outdoor air system that supplies 100% of outside air to each dormitory room, and (2) a low ventilation building (LVB) that relies on infiltration as ventilation. We enrolled 11 volunteers for a total of 522 person-days in the HVB and 109 volunteers for 6069 person-days in the LVB, and tested upper-respiratory swabs from symptomatic cases and their close contacts for the presence of 44 pathogens using a molecular assay. We observed one ARI case in the HVB (0.70/person-year) and 47 in the LVB (2.83/person-year). Simultaneously, 154 CO2 sensors distributed primarily in the dormitory rooms collected 668,390 useful data points from over 1 million recorded data points. Average and standard deviation of CO2 concentrations were 1230 ppm and 408 ppm in the HVB, and 1492 ppm and 837 ppm in the LVB, respectively. Importantly, this study developed and calibrated multi-zone models for the HVB with 229 zones and 983 airflow paths, and for the LVB with 529 zones and 1836 airflow paths by using a subset of CO2 data for model calibration. The models were used to calculate ventilation rates in the two buildings and potential for viral aerosol migration between rooms in the LVB. With doors and windows closed, the average ventilation rate was 12 L/s in the HVB dormitory rooms and 4 L/s in the LVB dormitory rooms. As a result, residents had on average 6.6 L/(s person) of outside air in the HVB and 2.3 L/(s person) in the LVB. LVB rooms located at the leeward side of the building had smaller average ventilation rates, as well as a somewhat higher ARI incidence rate and average CO2 concentrations when compared to those values in the rooms located at the windward side of the building. Average ventilation rates in twenty LVB dormitory rooms increased from 2.3 L/s to 7.5 L/s by opening windows, 3.6 L/s by opening doors, and 8.8 L/s by opening both windows and doors. Therefore, opening both windows and doors in the LVB dormitory rooms can increase ventilation rates to the levels comparable to those in the HVB. But it can also have a negative effect on thermal comfort due to low outdoor temperatures. Simulation results identified an aerobiologic pathway from a room occupied by an index case of influenza A to a room occupied by a possible secondary case.


Assuntos
Poluição do Ar em Ambientes Fechados , Infecções Respiratórias , Poluição do Ar em Ambientes Fechados/análise , Feminino , Habitação , Humanos , Masculino , Maryland , Infecções Respiratórias/epidemiologia , Estudantes , Temperatura , Universidades , Ventilação , Adulto Jovem
8.
Proc Natl Acad Sci U S A ; 109(21): 7974-81, 2012 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-22566635

RESUMO

We recently reported a deletion of exon 2 of the trimethyllysine hydroxylase epsilon (TMLHE) gene in a proband with autism. TMLHE maps to the X chromosome and encodes the first enzyme in carnitine biosynthesis, 6-N-trimethyllysine dioxygenase. Deletion of exon 2 of TMLHE causes enzyme deficiency, resulting in increased substrate concentration (6-N-trimethyllysine) and decreased product levels (3-hydroxy-6-N-trimethyllysine and γ-butyrobetaine) in plasma and urine. TMLHE deficiency is common in control males (24 in 8,787 or 1 in 366) and was not significantly increased in frequency in probands from simplex autism families (9 in 2,904 or 1 in 323). However, it was 2.82-fold more frequent in probands from male-male multiplex autism families compared with controls (7 in 909 or 1 in 130; P = 0.023). Additionally, six of seven autistic male siblings of probands in male-male multiplex families had the deletion, suggesting that TMLHE deficiency is a risk factor for autism (metaanalysis Z-score = 2.90 and P = 0.0037), although with low penetrance (2-4%). These data suggest that dysregulation of carnitine metabolism may be important in nondysmorphic autism; that abnormalities of carnitine intake, loss, transport, or synthesis may be important in a larger fraction of nondysmorphic autism cases; and that the carnitine pathway may provide a novel target for therapy or prevention of autism.


Assuntos
Transtorno Autístico , Carnitina/deficiência , Cromossomos Humanos X/genética , Genes Ligados ao Cromossomo X/genética , Erros Inatos do Metabolismo , Oxigenases de Função Mista/genética , Transtorno Autístico/epidemiologia , Transtorno Autístico/genética , Transtorno Autístico/metabolismo , Carnitina/biossíntese , Cognição/fisiologia , Éxons/genética , Deleção de Genes , Humanos , Masculino , Erros Inatos do Metabolismo/epidemiologia , Erros Inatos do Metabolismo/genética , Erros Inatos do Metabolismo/metabolismo , Oxigenases de Função Mista/sangue , Oxigenases de Função Mista/urina , Penetrância , Fatores de Risco , Irmãos
9.
Eur J Hum Genet ; 20(3): 283-90, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22045295

RESUMO

Prader-Willi syndrome (PWS) is a multisystem, contiguous gene disorder caused by an absence of paternally expressed genes within the 15q11.2-q13 region via one of the three main genetic mechanisms: deletion of the paternally inherited 15q11.2-q13 region, maternal uniparental disomy and imprinting defect. The deletion class is typically subdivided into Type 1 and Type 2 based on their proximal breakpoints (BP1-BP3 and BP2-BP3, respectively). Despite PWS being a well-characterized genetic disorder the role of the specific genes contributing to various aspects of the phenotype are not well understood. Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) is a recently developed technique that detects copy number changes and aberrant DNA methylation. In this study, we initially applied MS-MLPA to elucidate the deletion subtypes of 88 subjects. In our cohort, 32 had a Type 1 and 49 had a Type 2 deletion. The remaining seven subjects had unique or atypical deletions that were either smaller (n=5) or larger (n=2) than typically described and were further characterized by array-based comparative genome hybridization. In two subjects both the PWS region (15q11.2) and the newly described 15q13.3 microdeletion syndrome region were deleted. The subjects with a unique or an atypical deletion revealed distinct phenotypic features. In conclusion, unique or atypical deletions were found in ∼8% of the deletion subjects with PWS in our cohort. These novel deletions provide further insight into the potential role of several of the genes within the 15q11.2 and the 15q13.3 regions.


Assuntos
Deleção Cromossômica , Fenótipo , Síndrome de Prader-Willi/genética , Adolescente , Adulto , Criança , Pré-Escolar , Cromossomos Humanos Par 15 , Estudos de Coortes , Variações do Número de Cópias de DNA , Metilação de DNA , Feminino , Ordem dos Genes , Humanos , Lactente , Masculino , Síndrome de Prader-Willi/diagnóstico , Reprodutibilidade dos Testes , Adulto Jovem
10.
Hum Mol Genet ; 20(22): 4360-70, 2011 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-21865298

RESUMO

Autism is a neurodevelopmental disorder with increasing evidence of heterogeneous genetic etiology including de novo and inherited copy number variants (CNVs). We performed array comparative genomic hybridization using a custom Agilent 1 M oligonucleotide array intended to cover 197 332 unique exons in RefSeq genes; 98% were covered by at least one probe and 95% were covered by three or more probes with the focus on detecting relatively small CNVs that would implicate a single protein-coding gene. The study group included 99 trios from the Simons Simplex Collection. The analysis identified and validated 55 potentially pathogenic CNVs, categorized as de novo autosomal heterozygous, inherited homozygous autosomal, complex autosomal and hemizygous deletions on the X chromosome of probands. Twenty percent (11 of 55) of these CNV calls were rare when compared with the Database of Genomic Variants. Thirty-six percent (20 of 55) of the CNVs were also detected in the same samples in an independent analysis using the 1 M Illumina single-nucleotide polymorphism array. Findings of note included a common and sometimes homozygous 61 bp exonic deletion in SLC38A10, three CNVs found in lymphoblast-derived DNA but not present in whole-blood derived DNA and, most importantly, in a male proband, an exonic deletion of the TMLHE (trimethyllysine hydroxylase epsilon) that encodes the first enzyme in the biosynthesis of carnitine. Data for CNVs present in lymphoblasts but absent in fresh blood DNA suggest that these represent clonal outgrowth of individual B cells with pre-existing somatic mutations rather than artifacts arising in cell culture. GEO accession number GSE23765 (http://www.ncbi.nlm.nih.gov/geo/, date last accessed on 30 August 2011). Genboree accession: http://genboree.org/java-bin/gbrowser.jsp?refSeqId=1868&entryPointId=chr17&from=53496072&to=53694382&isPublic=yes, date last accessed on 30 August 2011.


Assuntos
Transtorno Autístico/genética , Hibridização Genômica Comparativa/métodos , Variações do Número de Cópias de DNA/genética , Éxons/genética , Oxigenases de Função Mista/genética , Feminino , Humanos , Masculino
11.
Healthc Q ; 14 Spec No 2: 72-9, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-24956429

RESUMO

In this article, the authors review research to identify bullying as a critical public health issue for Canada. Drawing from recent World Health Organization surveys, they examine the prevalence of Canadian children and youth involved in bullying others or being victimized. There is a strong association between involvement in bullying and health problems for children who bully, those who are victimized and those involved in both bullying and being victimized. Health problems can manifest as physical complaints (e.g., headaches), mental health concerns (e.g., depression, anxiety) and psychosocial problems (e.g., substance use, crime). In Canada, there has recently been a disturbing incidence of Canadian children who have committed suicide as a result of prolonged victimization by peers. Healthcare professionals play a major role in protecting and promoting the health and well-being of Canadian children and youth. Given the significant mental and physical health problems associated with involvement in bullying, it is important that clinicians, especially primary care healthcare professionals, be able to identify signs and symptoms of such involvement. Healthcare professionals can play an essential role supporting children and their parents and advocating for the safety and protection for those at risk. By understanding bullying as a destructive relationship problem that significantly impacts physical and mental health, healthcare professionals can play a major role in promoting healthy relationships and healthy development for all Canadian children and youth. This review provides an overview of the nature of bullying and the physical and psychological health problems associated with involvement in bullying. The review is followed by a discussion of the implications for health professionals and a protocol for assessing the potential link between bullying and a child's physical and psychological symptoms.


Assuntos
Bullying , Adolescente , Bullying/estatística & dados numéricos , Canadá/epidemiologia , Criança , Vítimas de Crime/psicologia , Humanos , Prevalência , Saúde Pública , Fatores de Risco
12.
Nat Genet ; 41(12): 1269-71, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19898479

RESUMO

We report a recurrent 680-kb deletion within chromosome 15q13.3 in ten individuals, from four unrelated families, with neurodevelopmental phenotypes including developmental delay, mental retardation and seizures. This deletion likely resulted from nonallelic homologous recombination between low-copy repeats on the normal and inverted region of chromosome 15q13.3. Although this deletion also affects OTUD7A, accumulated data suggest that haploinsufficiency of CHRNA7 is causative for the majority of neurodevelopmental phenotypes in the 15q13.3 microdeletion syndrome.


Assuntos
Deleção Cromossômica , Deficiência Intelectual/genética , Malformações do Sistema Nervoso/genética , Fenótipo , Anormalidades Múltiplas/genética , Adulto , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Receptores Nicotínicos/genética , Recombinação Genética , Convulsões/genética , Receptor Nicotínico de Acetilcolina alfa7
13.
Nat Genet ; 40(6): 719-21, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18500341

RESUMO

Prader-Willi syndrome (PWS) is caused by deficiency for one or more paternally expressed imprinted transcripts within chromosome 15q11-q13, including SNURF-SNRPN and multiple small nucleolar RNAs (snoRNAs). Balanced chromosomal translocations that preserve expression of SNURF-SNRPN and centromeric genes but separate the snoRNA HBII-85 cluster from its promoter cause PWS. A microdeletion of the HBII-85 snoRNAs in a child with PWS provides, in combination with previous data, effectively conclusive evidence that deficiency of HBII-85 snoRNAs causes the key characteristics of the PWS phenotype, although some atypical features suggest that other genes in the region may make more subtle phenotypic contributions.


Assuntos
Deleção Cromossômica , Cromossomos Humanos Par 15/genética , Impressão Genômica , Síndrome de Prader-Willi/genética , RNA Nucleolar Pequeno/genética , Autoantígenos/genética , Pré-Escolar , Quebra Cromossômica , Feminino , Humanos , Masculino , Proteínas Nucleares/genética , Linhagem , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ribonucleoproteínas Nucleares Pequenas/genética , Transcrição Gênica , Proteínas Centrais de snRNP
14.
J Virol ; 82(4): 1870-83, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18077723

RESUMO

The mechanism of CD4(+) T-cell depletion during chronic human immunodeficiency virus type 1 (HIV-1) infection remains unknown. Many studies suggest a significant role for chronic CD4(+) T-cell activation. We assumed that the pathogenic process of excessive CD4(+) T-cell activation would be reflected in the transcriptional profiles of activated CD4(+) T cells. Here we demonstrate that the transcriptional programs of in vivo-activated CD4(+) T cells from untreated HIV-positive (HIV(+)) individuals are clearly different from those of activated CD4(+) T cells from HIV-negative (HIV(-)) individuals. We observed a dramatic up-regulation of cell cycle-associated and interferon-stimulated transcripts in activated CD4(+) T cells of untreated HIV(+) individuals. Furthermore, we find an enrichment of proliferative and type I interferon-responsive transcription factor binding sites in the promoters of genes that are differentially expressed in activated CD4(+) T cells of untreated HIV(+) individuals compared to those of HIV(-) individuals. We confirm these findings by examination of in vivo-activated CD4(+) T cells. Taken together, these results suggest that activated CD4(+) T cells from untreated HIV(+) individuals are in a hyperproliferative state that is modulated by type I interferons. From these results, we propose a new model for CD4(+) T-cell depletion during chronic HIV-1 infection.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Infecções por HIV/imunologia , HIV-1 , Interferon Tipo I/metabolismo , Ativação Linfocitária/genética , Proteínas Reguladoras de Apoptose/genética , Linfócitos T CD4-Positivos/efeitos dos fármacos , Ciclo Celular/genética , Feminino , Perfilação da Expressão Gênica , Humanos , Interferon Tipo I/farmacologia , Depleção Linfocítica , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Regiões Promotoras Genéticas , Regulação para Cima
15.
J Virol ; 81(23): 12748-57, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17855517

RESUMO

CD4+ CD25+ regulatory T cells (Tregs) suppress the activation and proliferation of effector lymphocytes. In human immunodeficiency virus type 1 (HIV-1) infection, Tregs play a significant role in controlling the apoptotic loss of uninfected CD4+ T cells resulting from high levels of generalized immune activation. During acute HIV-1 infection, more than 50% of CD4+ T cells are depleted from the gastrointestinal lamina propria. To elucidate the role of Tregs in HIV-1-induced depletion of CD4+ T cells in the gut-associated lymphoid tissue (GALT), we first determine the distribution of Tregs in a setting of acute infection using the simian immunodeficiency virus (SIV)/pigtailed macaque model of HIV-1 disease. CD4+ T cells from the GALT, lymph nodes, and peripheral blood were isolated from SIV-infected pigtailed macaques on days 4, 14, and 114 postinoculation. Quantitative real-time reverse transcription-PCR was used to quantitate FOXP3 copy numbers in SIV-infected and uninfected control macaques. Expression of FOXP3 in the ileal lamina propria was significantly decreased at all stages of infection compared to levels in uninfected control macaques. In addition, functional analysis of ileal CD4+ T cells from SIV-infected macaques revealed a lack of suppressive activity suggestive of the absence of Tregs in that compartment. These results indicate that Tregs are rapidly depleted in the GALT of SIV-infected macaques, defining a role for the loss of Treg-mediated suppression in early events in the pathogenesis of the disease.


Assuntos
Sangue/imunologia , Mucosa Intestinal/imunologia , Linfonodos/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Subpopulações de Linfócitos T/imunologia , Linfócitos T Reguladores/imunologia , Animais , Fatores de Transcrição Forkhead/biossíntese , Fatores de Transcrição Forkhead/genética , Expressão Gênica , Subunidade alfa de Receptor de Interleucina-2/análise , Macaca nemestrina , Masculino , RNA/biossíntese , RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Vírus da Imunodeficiência Símia/imunologia , Subpopulações de Linfócitos T/química , Linfócitos T Reguladores/química
16.
Eur J Hum Genet ; 15(9): 943-9, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17522620

RESUMO

Angelman syndrome (AS) is a neurodevelopmental disorder characterized by mental retardation, absent speech, ataxia, and a happy disposition. Deletions of the 15q11q13 region are found in approximately 70% of AS patients. The deletions are sub-classified into class I and class II based on their sizes of approximately 6.8 and approximately 6.0, respectively, with two different proximal breakpoints and a common distal breakpoint. Utilizing a chromosome 15-specific comparative genomic hybridization genomic microarray (array-CGH), we have identified, determined the deletion sizes, and mapped the breakpoints in a cohort of 44 cases, to relate those breakpoints to the genomic architecture and derive more precise genotype-phenotype correlations. Interestingly four patients of the 44 studied (9.1%) had novel and unusually large deletions, and are reported here. This is the first report of very large deletions of 15q11q13 resulting in AS; the largest deletion being >10.6 Mb. These novel deletions involve three different distal breakpoints, two of which have been earlier shown to be involved in the generation of isodicentric 15q chromosomes (idic15). Additionally, precise determination of the deletion breakpoints reveals the presence of directly oriented low-copy repeats (LCRs) flanking the recurrent and novel breakpoints. The LCRs are adequate in size, orientation, and homology to enable abnormal recombination events leading to deletions and duplications. This genomic organization provides evidence for a common mechanism for the generation of both common and rare deletion types. Larger deletions result in a loss of several genes outside the common Angelman syndrome-Prader-Willi syndrome (AS-PWS) critical interval, and a more severe phenotype.


Assuntos
Síndrome de Angelman/genética , Deleção Cromossômica , Cromossomos Humanos Par 15 , Síndrome de Angelman/psicologia , Pré-Escolar , Quebra Cromossômica , Feminino , Genótipo , Humanos , Lactente , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Fenótipo , Testes Psicológicos
17.
J Am Chem Soc ; 124(1): 18-9, 2002 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-11772052

RESUMO

This communication describes the fabrication of three-dimensional structures of organic polymers using principles of design inspired by protein folding. The structures consist of rigid polyhedral components with dimensions of a few millimeters ("microdomains"), representing alpha-helical and beta-sheet secondary structures, connected with flexible linkers representing loops or turns. These structures were fabricated from polyurethane using photolithographic and soft lithographic techniques. The surfaces of the microdomains were patterned into hydrophobic and hydrophilic regions, and a hydrophobic photocurable liquid (serving both as lubricant and adhesive) was selectively precipitated onto the hydrophobic areas. The unfolded structures were suspended in water and agitated by tumbling. Self-assembly occurred through coalescence of the thin films of hydrophobic liquid, and was caused by minimization of the free energy of the interface between the liquid adhesive and the water. The self-assembled structures were locked in place by curing the adhesive with UV light. These results demonstrate the use of concepts abstracted from the study of proteins-including attractive hydrophobic interactions, shape complementarity, and conformational constraint-in the self-assembly of complex, three-dimensional structures on the millimeter scale.


Assuntos
Modelos Moleculares , Dobramento de Proteína , Estrutura Secundária de Proteína
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