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1.
Diagnostics (Basel) ; 13(2)2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36673033

RESUMO

The monospecific dense fine speckled (DFS) immunofluorescence assay (IFA) pattern is considered a potential marker to aid in exclusion of antinuclear antibody (ANA)-associated rheumatic diseases (AARD). This pattern is typically produced by autoantibodies against transcription co-activator DFS70/LEDGFp75, which are frequently found in healthy individuals and patients with miscellaneous inflammatory conditions. In AARD patients, these antibodies usually co-exist with disease-associated ANAs. Previous studies reported the occurrence of monospecific autoantibodies that generate a DFS-like or pseudo-DFS IFA pattern but do not react with DFS70/LEDGFp75. We characterized this pattern using confocal microscopy and immunoblotting. The target antigen associated with this pattern partially co-localized with DFS70/LEDGFp75 and its interacting partners H3K36me2, an active chromatin marker, and MLL, a transcription factor, in HEp-2 cells, suggesting a role in transcription. Immunoblotting did not reveal a common protein band immunoreactive with antibodies producing the pseudo-DFS pattern, suggesting they may recognize diverse proteins or conformational epitopes. Given the subjectivity of the HEp-2 IFA test, the awareness of pseudo-DFS autoantibodies reinforces recommendations for confirmatory testing when reporting patient antibodies producing a putative DFS pattern in a clinical setting. Future studies should focus on defining the potential diagnostic utility of the pseudo-DFS pattern and its associated antigen(s).

2.
Sci Transl Med ; 15(703): eadh0004, 2023 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-37406137

RESUMO

Broadly neutralizing antibodies (bNAbs) may provide an alternative to standard antiretroviral treatment (ART) for controlling HIV-1 replication and may have immunotherapeutic effects against HIV-1 reservoirs. We conducted a prospective clinical trial with two HIV-1 bNAbs (VRC01LS and 10-1074) in children (n = 25) who had previously initiated small-molecule ART treatment before 7 days of age and who continued treatment for at least 96 weeks. Both bNAbs were dosed intravenously every 4 weeks, overlapping with ART for at least 8 weeks and then continued for up to 24 weeks or until detectable viremia of HIV-1 RNA rose above 400 copies per milliliter in the absence of ART. Eleven (44%) children maintained HIV-1 RNA below 400 copies per milliliter through 24 weeks of bNAb-only treatment; 14 (56%) had detectable viremia above 400 copies per milliliter at a median of 4 weeks. Archived HIV-1 provirus susceptible to 10-1074, lower birth HIV-1 DNA reservoir in peripheral blood mononuclear cells, sustained viral suppression throughout early life, and combined negative qualitative HIV-1 DNA polymerase chain reaction and negative HIV-1 serology at entry were associated with maintaining suppression on bNAbs alone. This proof-of-concept study suggests that bNAbs may represent a promising treatment modality for infants and children living with HIV-1. Future studies using newer bNAb combinations with greater breadth and potency are warranted.


Assuntos
Infecções por HIV , HIV-1 , Criança , Humanos , Antirretrovirais/uso terapêutico , Anticorpos Neutralizantes , Botsuana , Anticorpos Amplamente Neutralizantes/uso terapêutico , Anticorpos Anti-HIV , Leucócitos Mononucleares , Estudos Prospectivos , Viremia/tratamento farmacológico
3.
Soc Work ; 66(3): 206-216, 2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34179993

RESUMO

The experience of adolescent homelessness is best understood from the perspective of those experiencing it. Although there is existing literature on the experiences of street youths and on the risk factors of youth homelessness, little of it has explored the experience of adolescents in homeless families as well as their strengths and their resources. Through discourse and photography, the research described in this article explored the lived experience of a particular group of adolescents who were living with their homeless families. Through a lens of critical phenomenology using in-depth interviews and photographs, the overarching theme that emerged was how resources, including family, friends, and safety, helped youths stay positive in a challenging situation. The results of this study articulate the self-identified strengths, assets, and coping skills of the cohort, and the perspectives of these adolescents will help professionals identify strategies that may benefit other adolescents in homeless families. This research provides a voice to this vulnerable population, promotes social justice, and informs practice.


Assuntos
Jovens em Situação de Rua , Pessoas Mal Alojadas , Adaptação Psicológica , Adolescente , Humanos , Problemas Sociais , Serviço Social
4.
Radiology ; 257(3): 802-9, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20876389

RESUMO

PURPOSE: To establish whether fetal exposure to the operating noise of 1.5-T magnetic resonance (MR) imaging is associated with cochlear injury and subsequent hearing loss in neonates. MATERIALS AND METHODS: The study was performed with local research ethics committee approval and written informed parental consent. Neonatal hearing test results, including otoacoustic emission (OAE) data, were sought for all neonates delivered in Sheffield who had previously undergone in utero MR imaging between August 1999 and September 2007. The prevalence of hearing impairment in these neonates was determined, with corresponding 95% confidence intervals calculated by using the binomial exact method, and mean OAE measurements were compared with anonymized local audiometric reference data by using the t test. RESULTS: One hundred three neonates who had undergone in utero MR imaging were identified; 96 of them had completed hearing screening assessment. Thirty-four of these babies were admitted to the neonatal intensive care unit (NICU), and one of them had bilateral hearing impairment. The prevalence of hearing impairment was 1% (one of 96; 95% confidence interval: 0.03%, 5.67%), which is in accordance with the prevalence expected, given the high proportion of babies in this study who had been in the NICU (ie, NICU graduates). In addition, for the well babies, there was no significant difference in mean OAE cochlear response compared with that for a reference data set of more than 16,000 OAE results. When NICU graduates were included in the comparison, a significant difference (P = .002) was found in one of four frequency bands used to analyze the cochlear response; however, this difference was small compared with the normal variation in OAE measurements. CONCLUSION: The findings in this study provide some evidence that exposure of the fetus to 1.5-T MR imaging during the second and third trimesters of pregnancy is not associated with an increased risk of substantial neonatal hearing impairment.


Assuntos
Estimulação Acústica , Cóclea/fisiologia , Transtornos da Audição/diagnóstico , Imageamento por Ressonância Magnética/efeitos adversos , Triagem Neonatal/métodos , Ruído , Feminino , Idade Gestacional , Transtornos da Audição/epidemiologia , Transtornos da Audição/fisiopatologia , Humanos , Recém-Nascido , Masculino , Emissões Otoacústicas Espontâneas , Gravidez , Prevalência , Fatores de Risco
5.
Microbiol Resour Announc ; 9(46)2020 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-33184160

RESUMO

Cluster EC ClearAsMud and cluster EA4 Kauala are lytic Siphoviridae bacteriophages that were isolated from soil in southern California using Microbacterium foliorum NRRL B-24224 as the host. The ClearAsMud and Kauala genomes are 52,987 bp and 39,378 bp, respectively, and contain 92 and 56 predicted protein-coding genes, respectively.

6.
Neuroradiology ; 51(5): 347-56, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19277622

RESUMO

In the previous article, we considered the normal appearances of the midline stuctures of the brain as they appear on high-resolution magnetic resonance imaging. In this article, we discuss the effects of failed commissuration on the midline structures. We highlight some of the misconceptions of this process that may lead to misdiagnosis of agenesis of the corpus callosum in utero.


Assuntos
Agenesia do Corpo Caloso , Corpo Caloso/patologia , Fórnice/anormalidades , Fórnice/patologia , Imageamento por Ressonância Magnética/métodos , Septo Pelúcido/anormalidades , Septo Pelúcido/patologia , Criança , Humanos , Valores de Referência
7.
Neuroradiology ; 51(5): 337-45, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19271214

RESUMO

The midline structures of the supra-tentorial brain are important landmarks for judging if the brain has formed correctly. In this article, we consider the normal appearances of the corpus callosum, septum pellucidum and fornix as shown on MR imaging in normal and near-normal states.


Assuntos
Agenesia do Corpo Caloso , Corpo Caloso/patologia , Fórnice/anormalidades , Fórnice/patologia , Imageamento por Ressonância Magnética/métodos , Septo Pelúcido/anormalidades , Septo Pelúcido/patologia , Criança , Humanos , Valores de Referência
8.
N Z Med J ; 132(1506): 60-65, 2019 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-31778373

RESUMO

AIM: Surgeon-performed ultrasound-guided fine needle aspiration cytology (US-FNAC) and radiologist-performed US-FNAC are both accepted forms of thyroid nodule assessment. To date there have been no studies comparing cost of evaluation between these two models. The aim of this study is to compare surgeon-performed thyroid US-FNAC to radiologist-performed US-FNAC. The primary outcome of interest was cost of surgeon-performed US-FNAC compared to cost of radiologist-performed US-FNAC. Secondary outcome of interest was time to treatment decision. METHODS: A retrospective analysis of all thyroid biopsies performed in 2016 and 2017 in a single centre were included. Costs were calculated using labour costs for SMO and allied technical personnel. RESULTS: There were 92 patients included in the analysis. Forty-two underwent surgeon-performed US-FNAC and 50 underwent radiologist-performed US-FNAC. Mean cost in surgeon-performed US-FNAC was $653 compared to $1017 in radiologist-performed US-FNA. Time from first appointment to definitive management plan was 47 days in surgeon-performed USFNAC and 116 days in radiologist-performed US-FNAC. CONCLUSIONS: This study demonstrates surgeon-performed US-FNAC for evaluation of thyroid nodules results in significantly lower costs and improved timeliness of care when compared to radiologist-performed US-FNAC.


Assuntos
Biópsia por Agulha Fina/métodos , Biópsia Guiada por Imagem/métodos , Radiologistas , Cirurgiões , Nódulo da Glândula Tireoide/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise Custo-Benefício , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nova Zelândia , Estudos Retrospectivos , Ultrassonografia
9.
Bull Am Meteorol Soc ; 100(1): 93-121, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32042201

RESUMO

The Cloud System Evolution in the Trades (CSET) study was designed to describe and explain the evolution of the boundary layer aerosol, cloud, and thermodynamic structures along trajectories within the north-Pacific trade-winds. The study centered on 7 round-trips of the NSF NCAR Gulfstream V (GV) between Sacramento, CA and Kona, Hawaii between 1 July and 15 August 2015. The CSET observing strategy was to sample aerosol, cloud, and boundary layer properties upwind from the transition zone over the North Pacific and to resample these areas two days later. GFS forecast trajectories were used to plan the outbound flight to Hawaii with updated forecast trajectories setting the return flight plan two days later. Two key elements of the CSET observing system were the newly developed HIAPER Cloud Radar (HCR) and the High Spectral Resolution Lidar (HSRL). Together they provided unprecedented characterizations of aerosol, cloud and precipitation structures that were combined with in situ measurements of aerosol, cloud, precipitation, and turbulence properties. The cloud systems sampled included solid stratocumulus infused with smoke from Canadian wildfires, mesoscale cloud-precipitation complexes, and patches of shallow cumuli in very clean environments. Ultra-clean layers observed frequently near the top of the boundary layer were often associated with shallow, optically thin, layered veil clouds. The extensive aerosol, cloud, drizzle and boundary layer sampling made over open areas of the Northeast Pacific along 2-day trajectories during CSET is unprecedented and will enable modeling studies of boundary layer cloud system evolution and the role of different processes in that evolution.

10.
Diabetes Care ; 40(7): 951-957, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28483786

RESUMO

OBJECTIVE: This multicenter, double-blind, treat-to-target, phase 3 trial evaluated the efficacy and safety of fast-acting insulin aspart (faster aspart) versus insulin aspart (IAsp) in adults with type 2 diabetes receiving basal insulin and oral antidiabetic agents. RESEARCH DESIGN AND METHODS: The primary end point was HbA1c change from baseline after 26 weeks' treatment. After an 8-week run-in to optimize basal insulin, subjects were randomized (1:1) to mealtime faster aspart (n = 345) or IAsp (n = 344), titrated using a simple daily patient-driven algorithm, plus insulin glargine U100 and metformin. RESULTS: HbA1c change was -1.38% (faster aspart) and -1.36% (IAsp); mean HbA1c was 6.6% for both groups. Faster aspart demonstrated noninferiority versus IAsp in reducing HbA1c (estimated treatment difference [ETD] [95% CI] -0.02% [-0.15; 0.10]). Both treatments improved postprandial plasma glucose (PPG) control; the PPG increment (liquid meal test) was statistically significant in favor of faster aspart after 1 h (ETD [95% CI] -0.59 mmol/L [-1.09; -0.09]; -10.63 mg/dL [-19.56; -1.69]; P = 0.0198), but not after 2-4 h. Change from baseline in fasting plasma glucose, body weight, and overall severe/blood glucose-confirmed hypoglycemia rates (rate ratio [RR] [95% CI] 1.09 [0.88; 1.36]) were similar between treatments. Postmeal hypoglycemia (0-2 h) rates were 2.27 (faster aspart) and 1.49 (IAsp) per patient-year of exposure (RR [95% CI] 1.60 [1.13; 2.27]). CONCLUSIONS: Faster aspart and IAsp were confirmed noninferior in a basal-bolus regimen regarding change from baseline in HbA1c. Faster aspart improved 1-h PPG with no differences in 2-4-h PPG versus IAsp. Overall hypoglycemia rates were similar except for an increase in 0-2-h postmeal hypoglycemia with faster aspart.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Insulina Aspart/uso terapêutico , Insulina/uso terapêutico , Idoso , Glicemia/metabolismo , Método Duplo-Cego , Determinação de Ponto Final , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemia/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Insulina Glargina/uso terapêutico , Masculino , Refeições , Metformina/uso terapêutico , Pessoa de Meia-Idade , Período Pós-Prandial
11.
Sci Rep ; 6: 27068, 2016 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-27279482

RESUMO

An external guide sequence (EGS) is a RNA sequence which can interact with a target mRNA to form a tertiary structure like a pre-tRNA and recruit intracellular ribonuclease P (RNase P), a tRNA processing enzyme, to degrade target mRNA. Previously, an in vitro selection procedure has been used by us to engineer new EGSs that are more robust in inducing human RNase P to cleave their targeted mRNAs. In this study, we constructed EGSs from a variant to target the mRNA encoding herpes simplex virus 1 (HSV-1) major transcription regulator ICP4, which is essential for the expression of viral early and late genes and viral growth. The EGS variant induced human RNase P cleavage of ICP4 mRNA sequence 60 times better than the EGS generated from a natural pre-tRNA. A decrease of about 97% and 75% in the level of ICP4 gene expression and an inhibition of about 7,000- and 500-fold in viral growth were observed in HSV infected cells expressing the variant and the pre-tRNA-derived EGS, respectively. This study shows that engineered EGSs can inhibit HSV-1 gene expression and viral growth. Furthermore, these results demonstrate the potential for engineered EGS RNAs to be developed and used as anti-HSV therapeutics.


Assuntos
Herpesvirus Humano 1/genética , Ribonuclease P/fisiologia , Replicação Viral , Expressão Gênica , Regulação Viral da Expressão Gênica , Células HeLa , Herpesvirus Humano 1/metabolismo , Humanos , Proteínas Imediatamente Precoces/genética , Proteínas Imediatamente Precoces/metabolismo , Sequências Repetidas Invertidas , Cinética , Estabilidade de RNA , RNA Guia de Cinetoplastídeos/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Viral/genética , RNA Viral/metabolismo , Carga Viral
12.
ANZ J Surg ; 85(10): 728-33, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26044983

RESUMO

BACKGROUND: Acute colonic pseudo-obstruction is an uncommon but potentially morbid complication of pregnancy. The aim of the study was to review a single institution's experience with acute colonic pseudo-obstruction in post-partum patients and develop an algorithm for management based on a literature review. METHODS: This is a retrospective study where patients were identified over a 2-year period (1 December 2012 to 31 November 2014) by checking all deliveries in Christchurch Women's Hospital against diagnosis codes for bowel obstruction and ileus. Clinical records and radiology were then reviewed to identify those with acute colonic pseudo-obstruction and the management of these patients was reviewed. RESULTS: Over the study period, seven patients were identified from 10,240 deliveries. Two patients required laparotomy and the rest resolved without surgical intervention. One patient was treated with neostigmine and three with erythromycin. One patient had an unsuccessful attempt at endoscopic decompression, however, symptoms resolved without further intervention following this. A management algorithm was developed based on the literature review. CONCLUSIONS: Acute colonic pseudo-obstruction occurs in post-partum patients more frequently than suspected (one in 1500 deliveries). The management needs to be active with early correction of electrolyte abnormalities, avoidance of narcotic pain relief and early mobilization. Timely administration of neostigmine or endoscopic decompression can reduce the incidence of colonic ischaemia and perforation and the need for surgical intervention.


Assuntos
Pseudo-Obstrução do Colo/diagnóstico , Pseudo-Obstrução do Colo/cirurgia , Obstrução Intestinal/cirurgia , Complicações na Gravidez/diagnóstico , Complicações na Gravidez/cirurgia , Dor Abdominal/diagnóstico , Dor Abdominal/diagnóstico por imagem , Doença Aguda , Adulto , Antibacterianos/uso terapêutico , Cesárea/métodos , Pseudo-Obstrução do Colo/fisiopatologia , Descompressão Cirúrgica/métodos , Eritromicina/uso terapêutico , Feminino , Humanos , Obstrução Intestinal/diagnóstico , Obstrução Intestinal/fisiopatologia , Laparotomia/métodos , Neostigmina/uso terapêutico , Parassimpatomiméticos/uso terapêutico , Gravidez , Complicações na Gravidez/fisiopatologia , Radiografia , Estudos Retrospectivos , Tomógrafos Computadorizados , Resultado do Tratamento
13.
Viruses ; 7(7): 3345-60, 2015 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-26114473

RESUMO

An engineered RNase P-based ribozyme variant, which was generated using the in vitro selection procedure, was used to target the overlapping mRNA region of two proteins essential for human cytomegalovirus (HCMV) replication: capsid assembly protein (AP) and protease (PR). In vitro studies showed that the generated variant, V718-A, cleaved the target AP mRNA sequence efficiently and its activity was about 60-fold higher than that of wild type ribozyme M1-A. Furthermore, we observed a reduction of 98%-99% in AP/PR expression and an inhibition of 50,000 fold in viral growth in cells with V718-A, while a 75% reduction in AP/PR expression and a 500-fold inhibition in viral growth was found in cells with M1-A. Examination of the antiviral effects of the generated ribozyme on the HCMV replication cycle suggested that viral DNA encapsidation was inhibited and as a consequence, viral capsid assembly was blocked when the expression of AP and PR was inhibited by the ribozyme. Thus, our study indicates that the generated ribozyme variant is highly effective in inhibiting HCMV gene expression and blocking viral replication, and suggests that engineered RNase P ribozyme can be potentially developed as a promising gene-targeting agent for anti-HCMV therapy.


Assuntos
Proteínas do Capsídeo/metabolismo , Infecções por Citomegalovirus/virologia , Citomegalovirus/fisiologia , RNA Catalítico/metabolismo , Ribonuclease P/metabolismo , Replicação Viral , Proteínas do Capsídeo/antagonistas & inibidores , Proteínas do Capsídeo/genética , Citomegalovirus/genética , Infecções por Citomegalovirus/genética , Infecções por Citomegalovirus/terapia , Regulação Viral da Expressão Gênica , Humanos , RNA Catalítico/genética , Ribonuclease P/genética
14.
PLoS One ; 10(6): e0129276, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26083421

RESUMO

Attenuated strains of invasive enteric bacteria, such as Salmonella, represent promising gene delivery agents for nucleic acid-based vaccines as they can be administrated orally. In this study, we constructed a novel attenuated strain of Salmonella for the delivery and expression of the hemagglutinin (HA) and neuraminidase (NA) of a highly pathogenic H5N1 influenza virus. We showed that the constructed Salmonella strain exhibited efficient gene transfer activity for HA and NA expression and little cytotoxicity and pathogenicity in mice. Using BALB/c mice as the model, we evaluated the immune responses and protection induced by the constructed Salmonella-based vaccine. Our study showed that the Salmonella-based vaccine induced significant production of anti-HA serum IgG and mucosal IgA, and of anti-HA interferon-γ producing T cells in orally vaccinated mice. Furthermore, mice orally vaccinated with the Salmonella vaccine expressing viral HA and NA proteins were completely protected from lethal challenge of highly pathogenic H5N1 as well as H1N1 influenza viruses while none of the animals treated with the Salmonella vaccine carrying the empty expression vector with no viral antigen expression was protected. These results suggest that the Salmonella-based vaccine elicits strong antigen-specific humoral and cellular immune responses and provides effective immune protection against multiple strains of influenza viruses. Furthermore, our study demonstrates the feasibility of developing novel attenuated Salmonella strains as new oral vaccine vectors against influenza viruses.


Assuntos
Vírus da Influenza A Subtipo H1N1/imunologia , Virus da Influenza A Subtipo H5N1/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Vacinas contra Salmonella/uso terapêutico , Proteínas Virais/imunologia , Administração Oral , Animais , Feminino , Técnicas de Transferência de Genes , Hemaglutininas/genética , Hemaglutininas/imunologia , Imunidade Celular , Imunidade Humoral , Vírus da Influenza A Subtipo H1N1/genética , Virus da Influenza A Subtipo H5N1/genética , Camundongos , Camundongos Endogâmicos BALB C , Neuraminidase/genética , Neuraminidase/imunologia , Infecções por Orthomyxoviridae/imunologia , Vacinas contra Salmonella/administração & dosagem , Vacinas contra Salmonella/genética , Vacinas contra Salmonella/imunologia , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/genética , Vacinas Atenuadas/imunologia , Vacinas Atenuadas/uso terapêutico , Proteínas Virais/genética
15.
Viruses ; 6(6): 2376-91, 2014 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-24932966

RESUMO

RNase P ribozyme can be engineered to be a sequence-specific gene-targeting agent with promising application in both basic research and clinical settings. By using an in vitro selection system, we have previously generated RNase P ribozyme variants that have better catalytic activity in cleaving an mRNA sequence than the wild type ribozyme. In this study, one of the variants was used to target the mRNA encoding human cytomegalovirus (HCMV) essential transcription factor immediate-early protein 2 (IE2). The variant was able to cleave IE2 mRNA in vitro 50-fold better than the wild type ribozyme. A reduction of about 98% in IE2 expression and a reduction of 3500-fold in viral production was observed in HCMV-infected cells expressing the variant compared to a 75% reduction in IE2 expression and a 100-fold reduction in viral production in cells expressing the ribozyme derived from the wild type sequence. These results suggest that ribozyme variants that are selected to be highly active in vitro are also more effective in inhibiting the expression of their targets in cultured cells. Our study demonstrates that RNase P ribozyme variants are efficient in reducing HCMV gene expression and growth and are potentially useful for anti-viral therapeutic application.


Assuntos
Infecções por Citomegalovirus/virologia , Citomegalovirus/fisiologia , Regulação Viral da Expressão Gênica , Ribonuclease P/genética , Replicação Viral , Linhagem Celular , Expressão Gênica , Humanos , Conformação de Ácido Nucleico , RNA Mensageiro/química , RNA Mensageiro/genética , Ribonuclease P/química , Especificidade por Substrato
16.
J Clin Microbiol ; 40(12): 4520-7, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12454145

RESUMO

We investigated the diversity of the primary sequences of 16S rRNA genes among Neisseria meningitidis strains (Men) and evaluated the use of this approach as a molecular subtyping tool. We aligned and compared a 1,417-bp fragment of the 16S rRNA gene from 264 Men strains of serogroups A, B, C, and Y (MenA, MenB, MenC, and MenY, respectively) isolated throughout the world over a 30-year period. Thirty-one positions of difference were found among 49 16S types: differences between types ranged from 1 to 14 positions (0.07 to 0.95%). 16S types and serogroups were highly associated; only 3 out 49 16S types were shared by two or more serogroups. We have identified 16S types that are exclusively associated with strains of certain hypervirulent clones: 16S type 5 with MenA subgroup III, 16S type 4 with the MenB electrophoretic type 5 (ET-5) complex, and 16S types 12 and 13 with MenC of the ET-37 complex. For MenC strains, 16S sequencing provided the highest sensitivity and specificity and the best overall association with the outbreak-related versus sporadic isolates when compared with pulsed-field gel electrophoresis, multilocus enzyme electrophoresis, and multilocus sequence typing. We demonstrated for the first time an unexpected diversity among 16S rRNA genes of Men strains, identified 16S types associated with well-defined hypervirulent clones, and showed the potential of this approach to rapidly identify virulent strains associated with outbreaks and/or an increased incidence of sporadic disease.


Assuntos
Técnicas de Tipagem Bacteriana , Genes de RNAr/genética , Variação Genética , Neisseria meningitidis/classificação , Análise de Sequência de DNA , DNA Ribossômico/análise , Surtos de Doenças , Eletroforese/métodos , Humanos , Infecções Meningocócicas/epidemiologia , Infecções Meningocócicas/microbiologia , Dados de Sequência Molecular , Neisseria meningitidis/genética , RNA Ribossômico 16S/genética , Sorotipagem
17.
J Infect Dis ; 186(7): 958-65, 2002 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-12232836

RESUMO

Haemophilus influenzae type b (Hib) invasive disease and oropharyngeal carriage continue in rural Alaska despite widespread vaccination. This study investigated whether invasive-disease reemergence during 1996-1997 could be attributed to strains distinguishable from strains carried by vaccinated children. Twenty-four invasive and 42 carriage Hib isolates, collected during 1992-1997, were characterized by pulsed-field gel electrophoresis (PFGE), multilocus enzyme electrophoresis, and biotyping. This Hib population was highly clonal, since only 2 strains, electrophoretic type (ET) 55/PFGE 1 and ET 56/PFGE 3, accounted for 62% of all isolates. The ET 55/PFGE 1 and ET 56/PFGE 3 strains were found in 74% of the carriers and caused 80% of the invasive Hib disease that occurred during April 1996-March 1997. Strains causing invasive disease could not be distinguished from strains carried by vaccinated children. Continued monitoring of Hib carriage may provide insights into the epidemiology of continued transmission in an era of widespread vaccination.


Assuntos
Portador Sadio/epidemiologia , Infecções por Haemophilus/epidemiologia , Haemophilus influenzae tipo b/genética , Alaska/epidemiologia , Pré-Escolar , Eletroforese em Gel de Campo Pulsado , Genótipo , Infecções por Haemophilus/prevenção & controle , Vacinas Anti-Haemophilus/administração & dosagem , Haemophilus influenzae tipo b/isolamento & purificação , Humanos , Lactente , Epidemiologia Molecular , Vacinação
18.
J Infect Dis ; 186(1): 40-8, 2002 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-12089660

RESUMO

Carriage of Neisseria meningitidis in a Georgia county with hypersporadic incidence of meningococcal disease ("hypersporadic county") and in a county with no cases of meningococcal disease was determined by a cross-sectional pharyngeal culture study of high school students. Among 2730 students from whom culture samples were obtained, meningococcal carriage was 7.7% (140/1818) in the hypersporadic county and 6.1% (56/912) in the comparison county. Carriage rates by serogroup and genetic type (i.e., electrophoretic type [ET]) did not differ significantly between counties, but apartment or mobile home residency was a risk factor for carriage in the hypersporadic county. Although most cases of meningococcal disease in the hypersporadic county were caused by members of the serogroup C ET-37 clonal group, no ET-37 meningococcal isolates were recovered from carriers in this county. However, 38% of all meningococcal isolates recovered from carriers in both counties were members of the serogroup Y ET-508 clonal group, an emerging cause of meningococcal disease in Georgia and throughout the United States during 1996-2001. Shifts in carriage and transmission of meningococcal strains with different pathogenic potential are important determinants of meningococcal disease incidence.


Assuntos
Portador Sadio/microbiologia , Meningite Meningocócica/microbiologia , Neisseria meningitidis/isolamento & purificação , Adolescente , Adulto , Idoso , Portador Sadio/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , Feminino , Genótipo , Georgia/epidemiologia , Humanos , Incidência , Lactente , Masculino , Meningite Meningocócica/epidemiologia , Pessoa de Meia-Idade , Neisseria meningitidis/genética , Faringe/microbiologia , Características de Residência , Fatores de Risco , Sorotipagem , Estudantes
19.
Emerg Infect Dis ; 8(5): 516-8, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-11996689

RESUMO

In the 1990s, the Newly Independent and Baltic States of the former Soviet Union experienced the largest diphtheria outbreak since the 1960s; it was caused by Corynebacterium diphtheriae strains of a unique clonal group. To address its origin, we studied 47 clinical isolates from Russia and demonstrated that this clonal group was an integral part of the endemic reservoir that existed in Russia at least 5 years before the epidemic began.


Assuntos
Corynebacterium diphtheriae/genética , Corynebacterium diphtheriae/isolamento & purificação , Difteria/epidemiologia , Difteria/microbiologia , Difteria/história , Surtos de Doenças/história , Genótipo , História do Século XX , Humanos , Filogenia , Ribotipagem , Federação Russa/epidemiologia
20.
J Infect Dis ; 185(11): 1596-605, 2002 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-12023765

RESUMO

In 2000, >400 cases of disease caused by Neisseria meningitidis serogroup W135 (MenW135), the largest MenW135 outbreak reported to date, occurred worldwide among Hajj pilgrims and their contacts. To elucidate the origin of the outbreak strains and to investigate their relatedness to major clonal groups, genotypic and phenotypic subtyping was performed on 26 MenW135 outbreak-associated isolates and 50 MenW135 isolates collected worldwide from 1970 through 2000. All outbreak-associated isolates were members of a single clone of the hypervirulent electrophoretic type (ET)-37 complex, designated the "(W)ET-37 clone"; 19 additional MenW135 strains were also members of this clone, and the remaining 31 MenW135 strains were clearly distinct. The 2000 MenW135 outbreak was not caused by emergence of a new MenW135 strain but rather by expansion of the (W)ET-37 clone that has been in circulation at least since 1970; the strains most closely related to those causing the 2000 outbreak have been isolated in Algeria, Mali, and The Gambia in the 1990s.


Assuntos
Surtos de Doenças , Infecções Meningocócicas/epidemiologia , Neisseria meningitidis/classificação , Neisseria meningitidis/genética , Técnicas de Tipagem Bacteriana , DNA Bacteriano/análise , DNA Bacteriano/genética , Eletroforese/métodos , Genótipo , Saúde Global , Humanos , Islamismo , Infecções Meningocócicas/microbiologia , Neisseria meningitidis/fisiologia , Fenótipo , RNA Ribossômico 16S/genética , Análise de Sequência de DNA/métodos , Viagem , Virulência/genética
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