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1.
J Infect ; 88(2): 123-131, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38104727

RESUMO

BACKGROUND: Subclinical pulmonary tuberculosis (PTB) is an asymptomatic disease state between established TB infection and symptomatic (clinical) TB disease. It is present in 20-25% of PTB patients in high-income countries. Mycobacterium tuberculosis complex (MTBC) genetic heterogeneity, and differential host immunological responses, have been implicated in its pathogenesis. METHODS: To determine the association between MTBC lineage and PTB disease phenotype, we used two retrospective cohorts of PTB patients in Canada and two independent lineage attribution methods (DNA fingerprinting and genome sequencing). The first cohort, Cohort 1, consisted of consecutively diagnosed PTB patients between 2014 and 2020. The second, Cohort 2, consisted of newly-arrived foreign-born PTB patients who either were or were not referred for post-landing medical surveillance between 2004 and 2017. Univariable and multivariable logistic regression models were sequentially fitted to both cohorts, adjusting for age, sex, disease type, drug resistance and HIV. Evolution of radiographic features was correlated to lineage in Cohort 2. FINDINGS: Cohort 1 and 2 included 874 (209 subclinical) and 111 (44 subclinical) patients, respectively. In both cohorts, subclinical patients were more likely than clinical patients to have relapse/retreatment disease, be smear-negative, have longer times-to-culture positivity and to harbor an ancestral MTBC lineage (Indo-Oceanic or Mycobacterium africanum). Relapse/retreatment disease and ancestral MTBC lineage were independent predictors of subclinical disease (ORs and 95% CIs in Cohort 1, 1.85 [1.07,3.28], p < 0.029 and 2.30 [1.66,3.18], p < 0.001, respectively, and Cohort 2, 5.74 [1.37-24.06], p < 0.017 and 3.21 (1.29,7.97], p < 0.012, respectively). The geographic distribution of Indo-Oceanic strains causing subclinical disease was uneven. Non-progressive lung disease was more common in patients infected with ancestral than modern lineages in Cohort 2, 56.0% vs 25.4%, p < 0.005. INTERPRETATION: MTBC lineage is a strong predictor of PTB disease phenotype. The genetic drivers of this association, and the relative contribution of other explanatory variables, are unknown.


Assuntos
Mycobacterium tuberculosis , Tuberculose Pulmonar , Humanos , Mycobacterium tuberculosis/genética , Filogenia , Estudos de Coortes , Estudos Retrospectivos , Tuberculose Pulmonar/tratamento farmacológico , Fenótipo , Recidiva
2.
Sci Rep ; 13(1): 15992, 2023 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-37749142

RESUMO

Nanoparticle (NP) skin exposure is linked to an increased prevalence of allergic contact dermatitis. In our prior studies using the mouse contact hypersensitivity (CHS) model, we reported that silica 20 nm (SiO2) NPs suppressed the allergic response and titanium dioxide NPs doped with manganese (mTiO2) exacerbated it. In this work, we conducted in vitro experiments using bone marrow-derived dendritic cells (BMDCs) to study the combinatorial effect of the potent 2,4-dinitrofluorobenzene (DNFB) hapten sensitizer with SiO2 and mTiO2 NPs on BMDC cytotoxicity, cytokine secretion and phenotype using the B7 family ligands. Results show that DNFB and mTiO2 behave similarly and exhibit proinflammatory characteristics while SiO2 promotes a naive phenotype. We observe that the B7-H3 (CD276) ligand is only expressed on CD80 + (B7-1) BMDCs. Results from adoptive transfer CHS studies, combined with BMDC phenotype analysis, point to the importance of PD-L2 expression in modulating the adaptive immune response. This work identifies metrics that can be used to predict the effects of NPs on contact allergy and to guide efforts to engineer cell-based therapies to induce hapten specific immune tolerance.


Assuntos
Dermatite Alérgica de Contato , Dióxido de Silício , Animais , Camundongos , Dinitrofluorbenzeno/toxicidade , Imunomodulação , Antígeno B7-1 , Modelos Animais de Doenças , Células Dendríticas
3.
Res Sq ; 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37503107

RESUMO

Nanoparticle (NP) skin exposure is linked to the increased prevalence of allergic contact dermatitis. In prior studies using the mouse contact hypersensitivity (CHS) model, we reported that silica 20 nm (Si20nm) suppressed the allergic response and TiO2 doped with manganese (mTiO2) exacerbated it. In this work, we conducted in vitro experiments using bone marrow-derived dendritic cells (BMDCs) to study the combinatorial effect of the potent 2, 4-dinitrofluorobenzene (DNFB) hapten sensitizer with Si20nm and mTiO2 NPs on BMDC cytotoxicity, cytokine secretion and phenotype using the B7 family ligands. Results show that DNFB and mTiO2 behave similarly and exhibit proinflammatory characteristics while Si20nm promotes a naive phenotype. We observe that the B7-H3 (CD276) ligand is only expressed on CD80+ (B7-1) BMDC. Results from adoptive transfer CHS studies, combined with BMDC phenotype analysis, point to the importance of PD-L2 expression in modulating the adaptive immune response. This work identifies metrics that can be used to predict the effects of NPs on contact allergy and to guide efforts to engineer cell-based therapies to induce antigen specific immune tolerance.

4.
Mayo Clin Proc Innov Qual Outcomes ; 7(3): 165-170, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37168770

RESUMO

Subclinical pulmonary tuberculosis (PTB) is defined as "…a state of disease due to viable Mycobacterium tuberculosis that does not cause TB-related symptoms but does cause other abnormalities that can be detected using existing radiologic and mycobacteriologic assays." In high-income countries, subclinical PTB is usually diagnosed during active case finding, is acid-fast bacilli smear negative, and associated with minimal or no lung parenchymal abnormality on chest radiograph. In the absence of symptoms, the epidemiologic risk of TB and chest radiograph are critical to making the diagnosis. In a cohort of 327 patients with subclinical PTB, we address the question-how well field radiologists perform at identifying features important to the diagnosis of PTB, the presence or absence of which have been established by a panel of expert radiologists? Although not performing badly compared with this "gold standard," field readers were nevertheless susceptible to overread or underread films and miss key diagnostic features, such as the presence of a lung parenchymal abnormality, typical pattern, or cavitation. In the context of active case finding during which most patients with subclinical PTB are discovered, limitations of the chest radiograph need to be recognized, and sputum, ideally induced, should be submitted regardless of the radiographic findings.

6.
Int J Infect Dis ; 129: 165-174, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36736990

RESUMO

OBJECTIVES: Relatively little is known about the prevalence, risk factors, and public health consequences of peripheral lymph node (PLN)-associated pulmonary tuberculosis (PTB). METHODS: We developed a 10-year (2010-2019) population-based cohort of PLNTB patients in Canada. We used systematically collected primary source data and expert reader chest radiograph interpretations in a multivariable logistic regression to determine associations between sputum culture positivity and demographic, clinical, and radiographic features. Public health risks were estimated among contacts of PLNTB patients. RESULTS: There were 306 patients with PLNTB, among whom 283 (92.5%) were 15-64 years of age, 159 (52.0%) were female, and 293 (95.8%) were foreign-born. Respiratory symptoms were present in 21.6%, and abnormal chest radiograph in 23.2%. Sputum culture positivity ranged from 12.9% in patients with no symptoms and normal lung parenchyma to 66.7% in patients with both. Respiratory symptoms, abnormal lung parenchyma, and HIV-coinfection (borderline) were independent predictors of sputum culture positivity (odds ratio [OR] 2.24 [95% confidence interval [CI] 1.15-4.39], P = 0.01, OR 4.78 [95% CI 2.41-9.48], P < 0.001, and OR 2.54 [95% CI 0.99-6.52], P = 0.05), respectively. Among contacts of sputum culture-positive PLNTB patients, one secondary case and 16 new infections were identified. CONCLUSION: Isochronous PTB is common in PLNTB patients. Routine screening of PLNTB patients for PTB is strongly recommended.


Assuntos
Mycobacterium tuberculosis , Tuberculose dos Linfonodos , Tuberculose Pulmonar , Humanos , Feminino , Masculino , Prevalência , Saúde Pública , Tuberculose Pulmonar/diagnóstico , Fatores de Risco , Linfonodos , Escarro
7.
EClinicalMedicine ; 55: 101755, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36447641

RESUMO

Background: Many of the 10-20% percent of COVID-19 survivors who develop Post COVID-19 Condition (PCC, or Long COVID) describe experiences suggestive of stigmatization, a known social determinant of health. Our objective was to develop an instrument, the Post COVID-19 Condition Stigma Questionnaire (PCCSQ), with which to quantify and characterise PCC-related stigma. Methods: We conducted a prospective cohort study to assess the reliability and validity of the PCCSQ. Patients referred to our Post COVID-19 Clinic in the Canadian City of Edmonton, Alberta between May 29, 2021 and May 24, 2022 who met inclusion criteria (attending an academic post COVID-19 clinic; age ≥18 years; persistent symptoms and impairment at ≥ 12 weeks since PCR positive acute COVID-19 infection; English-speaking; internet access; consenting) were invited to complete online questionnaires, including the PCCSQ. Analyses were conducted to estimate the instrument's reliability, construct validity, and association with relevant instruments and defined health outcomes. Findings: Of the 198 patients invited, 145 (73%) met inclusion criteria and completed usable questionnaires. Total Stigma Score (TSS) on the PCCSQ ranged from 40 to 174/200. The mean (SD) was 103.9 (31.3). Cronbach's alpha was 0.97. Test-retest reliability was 0.92. Factor analysis supported a 6-factor latent construct. Subtest reliabilities were >0.75. Individuals reporting increased TSS occurred across all demographic groups. Increased risk categories included women, white ethnicity, and limited educational opportunities. TSS was positively correlated with symptoms, depression, anxiety, loneliness, reduced self-esteem, thoughts of self-harm, post-COVID functional status, frailty, EQ5D5L score, and number of ED visits. It was negatively correlated with perceived social support, 6-min walk distance, and EQ5D5L global rating. Stigma scores were significantly increased among participants reporting employment status as disabled. Interpretation: Our findings suggested that the PCCSQ is a valid, reliable tool with which to estimate PCC-related stigma. It allows for the identification of patients reporting increased stigma and offers insights into their experiences. Funding: The Edmonton Post COVID-19 Clinic is supported by the University of Alberta and Alberta Health Services. No additional sources of funding were involved in the execution of this research study.

8.
Sci Rep ; 12(1): 16567, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-36195738

RESUMO

Subclinical pulmonary tuberculosis (PTB) is a recently described intermediate state of great interest, but about which little is known. This study sought to describe and compare the frequency of key radiologic features of subclinical PTB on chest radiograph (CXR) versus computed tomographic scan (CT), and to interpret the clinical and public health relevance of the differences. Diagnostic CXRs and CT scans of the thorax and neck in a 16-year cohort of subclinical PTB patients in Canada were re-acquired and read by two independent readers and arbitrated by a third reader. Logistic regression models were fit to determine how likely CXR features can be detected by CT scan versus CXR after adjustment for age and sex. Among 296 subclinical patients, CXRs were available in 286 (96.6%) and CT scans in 94 (32.9%). CXR features in patients with and without CT scans were comparable. Lung cavitation was 4.77 times (95% CI 1.95-11.66), endobronchial spread 19.36 times (95% CI 8.05-46.52), and moderate/far-advanced parenchymal disease 3.23 times (95% CI 1.66-6.30), more common on CT scan than CXR. We conclude that the extent to which CXRs under-detect key radiologic features in subclinical PTB is substantial. This may have public health and treatment implications.


Assuntos
Tuberculose Pulmonar , Estudos de Coortes , Humanos , Radiografia , Radiografia Torácica , Tórax/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Tuberculose Pulmonar/diagnóstico
9.
Chest ; 162(2): 309-320, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35122750

RESUMO

BACKGROUND: Very little is known about subclinical pulmonary TB (PTB), a recently described intermediate state, in high-income countries. RESEARCH QUESTION: What is the prevalence of subclinical PTB in Canada? What are its diagnostic chest radiography features? What is the relationship between those features and time to culture positivity, and what is the association between DNA fingerprint clustering, a measure of local transmission, and radiographic or other features in the foreign-born? STUDY DESIGN AND METHODS: We used primary source data to identify a 16-year retrospective cohort of patients with PTB. Demographic and mycobacteriologic features in patients with subclinical and clinical disease were compared, and the reason for assessment of patients with subclinical disease was described. Diagnostic chest radiographs in patients with subclinical disease were read by two independent readers and were arbitrated by a third reader. Linear regression was used to compute time to culture positivity (in days) in relationship to the change in chest radiograph findings from normal or minimally abnormal to moderately or far advanced, adjusted for age and sex and stratified by reason for assessment. Multivariate logistic regression was used in foreign-born patients with subclinical disease to determine associations between DNA fingerprint clustering of Mycobacterium TB isolates and age, sex, chest radiograph features, and time since arrival. RESULTS: We identified 1,656 patients with PTB, 347 of whom (21%) were subclinical. Compared with patients with clinical disease, patients with subclinical disease were more likely to be foreign-born (90.2% vs 79.6%) and to demonstrate negative smear results (88.2% vs 43.5%). The median time to culture-positivity was 18 days (interquartile range [IQR], 14-25 days) vs 12 days (IQR, 7-17 days). Most patients with PTB (75.2%) were identified during active case finding. Parenchymal disease was absent or minimal on chest radiography in 86.4% of patients. More advanced disease on chest radiography was associated with shorter times to culture positivity in nonstratified (by 3.3 days) and stratified (by 4.5-5.8 days) analysis (active case-finding groups). DNA fingerprint clustering was associated with male sex and a longer time between arrival and diagnosis. INTERPRETATION: Subclinical patients with PTB constitute a substantial and heterogeneous minority of patients with PTB in high-income countries. DNA fingerprint clustering is consistent with some, albeit limited, local transmission.


Assuntos
Mycobacterium tuberculosis , Tuberculose Pulmonar , Estudos de Coortes , Humanos , Modelos Logísticos , Masculino , Mycobacterium tuberculosis/genética , Radiografia , Estudos Retrospectivos , Escarro/microbiologia , Tuberculose Pulmonar/complicações , Tuberculose Pulmonar/diagnóstico por imagem , Tuberculose Pulmonar/epidemiologia
10.
J Intern Med ; 291(5): 694-697, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34875129

RESUMO

Coronavirus disease-19 (COVID-19) has resulted in much acute morbidity and mortality worldwide. There is now a growing recognition of the post-acute sequela of COVID-19, termed long COVID. However, the risk factors contributing to this condition remain unclear. Here, we address the growing controversy in the literature of whether hospitalization is a risk factor for long COVID. We found that hospitalization is associated with worse pulmonary restriction and reduction in diffusion capacity at 3 months post-infection. However, the impact on mental health, functional and quality of life is equally severe in those who have and have not been hospitalized during the acute infection. These findings suggest that hospitalization is a risk factor for pulmonary complications of long COVID but not the overall severity of long COVID.


Assuntos
COVID-19 , COVID-19/complicações , Progressão da Doença , Hospitalização , Humanos , Qualidade de Vida , SARS-CoV-2 , Síndrome de COVID-19 Pós-Aguda
11.
J Med Virol ; 93(9): 5644-5647, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33951208

RESUMO

In 2020, numerous fast-spreading severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants have been reported. These variants had unusually high genetic changes in the spike (S) protein. In an attempt to understand the genetic background of SARS-CoV-2 viruses in Hong Kong, especially before vaccination, the purpose of this study is to summarize the S protein mutations detected among coronavirus disease 2019 (COVID-19) patients in Hong Kong in 2020. COVID-19 cases were selected every month in 2020. One virus from each case was analyzed. The full encoding region of the S proteins was sequenced. From January 2020 to December 2020, a total of 340 COVID-19 viruses were sequenced. The amino acids of the S protein for 44 (12.9%) were identical to the reference sequence, WIV04 (GenBank accession MN996528). For the remaining 296 sequences (87.1%), a total of 43 nonsynonymous substitution patterns were found. Of the nonsynonymous substitutions found, some of them were only detected at specific time intervals and then they disappeared. The ongoing genetic surveillance system is important. It would facilitate early detection of mutations that can increase infectivity as well as mutations that are selected for the virus to escape immunological restraint.


Assuntos
COVID-19/virologia , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/genética , Sequência de Bases , COVID-19/epidemiologia , Genoma Viral/genética , Hong Kong/epidemiologia , Humanos , Mutação
12.
J Infect Dis ; 224(6): 1029-1038, 2021 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-33502538

RESUMO

BACKGROUND: Multidrug-resistant (MDR) tuberculosis has increased among migrants in Canada. The cause(s) of this increase is unknown. METHODS: We performed a retrospective cohort study in a Canadian province with substantially increased immigration between 1982-2001 and 2002-2019. The proportion of MDR tuberculosis among migrants arriving from high MDR (HMDR) tuberculosis burden countries during these 2 periods was used to estimate the proportion of cases due to immigration versus change in proportion in the country of birth. Epidemiologic, spatiotemporal, and drug resistance pattern data were used to confirm local transmission. RESULTS: Fifty-two of 3514 (1.48%) foreign-born culture-positive tuberculosis patients had MDR tuberculosis: 8 (0.6%) in 1982-2001 and 44 (2.0%) in 2002-2019. Between time periods, the proportion of MDR tuberculosis among migrants with tuberculosis from HMDR tuberculosis countries increased from 1.11% to 3.62%, P = .003; 31.6% attributable to recent immigration and 68.4% to a higher proportion of MDR tuberculosis in cases arrived from HMDR tuberculosis countries. No cases of MDR tuberculosis were attributable to local transmission. CONCLUSIONS: In stark contrast to HMDR tuberculosis countries, local transmission plays no important role in the occurrence of MDR tuberculosis in Canada. Improved tuberculosis programming in HMDR tuberculosis countries is urgently needed.


Assuntos
Emigrantes e Imigrantes/estatística & dados numéricos , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/transmissão , Adolescente , Adulto , Idoso , Antituberculosos/uso terapêutico , Canadá/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/isolamento & purificação , Estudos Retrospectivos , Tuberculose/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Adulto Jovem
15.
Neoplasia ; 20(7): 697-709, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29852322

RESUMO

Germline BRCA1 or BRCA2 mutations (mtBRCA1 and mtBRCA2) increase risk for high-grade serous ovarian cancer (HGSOC), the most commonly diagnosed epithelial ovarian cancer histotype. Other identified risk factors for this cancer, which originates primarily in the distal fallopian tube epithelium (FTE), implicate ovulation, during which the FTE cells become transiently exposed to follicular fluid (FF). To test whether mtBRCA1 or mtBRCA2 nonmalignant FTE cells respond differently to periovulatory FF exposure than control patient FTE cells, gene expression profiles from primary FTE cultures derived from BRCA1 or BRCA2 mutation carriers or control patients were compared at baseline, 24 hours after FF exposure, and 24 hours after FF replacement with culture medium. Hierarchical clustering revealed both FF exposure and BRCA mutation status affect gene expression, with BRCA1 mutation having the greatest impact. Gene set enrichment analysis revealed increased NFκB and EGFR signaling at baseline in mtBRCA1 samples, with increased interferon target gene expression, including members of the ISGylation pathway, observed after recovery from FF exposure. Gene set enrichment analysis did not identify altered pathway signaling in mtBRCA2 samples. An inverse relationship between EGFR signaling and ISGylation with BRCA1 protein levels was verified in an immortalized FTE cell line, OE-E6/E7, stably transfected with BRCA1 cDNA. Suppression of ISG15 and ISGylated protein levels by increased BRCA1 expression was found to be mediated by decreased NFκB signaling. These studies indicate that increased NFκB signaling associated with decreased BRCA1 expression results in increased ISG15 and protein ISGylation following FF exposure, which may be involved in predisposition to HGSOC.


Assuntos
Células Epiteliais/metabolismo , Tubas Uterinas/citologia , Tubas Uterinas/metabolismo , Líquido Folicular/metabolismo , Genes BRCA1 , Mutação , NF-kappa B/metabolismo , Transdução de Sinais , Adulto , Biomarcadores , Células Cultivadas , Receptores ErbB/metabolismo , Feminino , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Genes BRCA2 , Humanos , Pessoa de Meia-Idade , Filogenia , Transcriptoma
16.
ERJ Open Res ; 4(2)2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29750144

RESUMO

The epidemiology of tuberculosis (TB) in high-income countries is increasingly dictated by immigration. The influence of this trend on paediatric TB and TB elimination are not well defined. We undertook a 25-year conventional and molecular epidemiologic study of paediatric TB in Alberta, one of four major immigrant-receiving provinces in Canada. All isolates of Mycobacterium tuberculosis were DNA fingerprinted using standard methodology. Between 1990 and 2014, 176 children aged 0-14 years were diagnosed with TB. Foreign-born children or Canadian-born children of foreign-born parents accounted for an increasingly large proportion of total cases during the study period (from 32.1% to 89.5%). Of the 78 culture-positive cases, 35 (44.9%) had a putative source case identified by conventional epidemiology, with 34 (97.1%) having a concordant molecular profile. Of the remaining 43 culture-positive cases, molecular profiling identified spatially and temporally related sources in six cases (14.0%). These six children, along with four other children whose source cases were discovered through reverse-contact tracing, had a high morbidity and mortality. The increasing burden of paediatric TB in both foreign-born children and Canadian-born children of foreign-born parents calls for more timely diagnosis of source cases and more targeted screening for latent TB infection.

17.
PLoS One ; 11(4): e0154032, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27105337

RESUMO

BACKGROUND: Computer-aided detection to identify and diagnose pulmonary tuberculosis is being explored. While both cavitation on chest radiograph and smear-positivity on microscopy are independent risk factors for the infectiousness of pulmonary tuberculosis it is unknown which radiographic pattern, were it detectable, would provide the greatest public health benefit; i.e. reduced transmission. Herein we provide that evidence. OBJECTIVES: 1) to determine whether pulmonary tuberculosis in a high income, low incidence country is more likely to present with "typical" adult-type pulmonary tuberculosis radiographic features and 2) to determine whether those with "typical" radiographic features are more likely than those without such features to transmit the organism and/or cause secondary cases. METHODS: Over a three-year period beginning January 1, 2006 consecutive adults with smear-positive pulmonary tuberculosis in the Province of Alberta, Canada, were identified and their pre-treatment radiographs scored by three independent readers as "typical" (having an upper lung zone predominant infiltrate, with or without cavitation but no discernable adenopathy) or "atypical" (all others). Each patient's pre-treatment bacillary burden was carefully documented and, during a 30-month transmission window, each patient's transmission events were recorded. Mycobacteriology, radiology and transmission were compared in those with "typical" versus "atypical" radiographs. FINDINGS: A total of 97 smear-positive pulmonary tuberculosis cases were identified, 69 (71.1%) with and 28 (28.9%) without "typical" chest radiographs. "Typical" cases were more likely to have high bacillary burdens and cavitation (Odds Ratios and 95% Confidence Intervals: 2.75 [1.04-7.31] and 9.10 [2.51-32.94], respectively). Typical cases were also responsible for most transmission events-78% of tuberculin skin test conversions (p<0.002) and 95% of secondary cases in reported close contacts (p<0.01); 94% of secondary cases in "unreported" contacts (p<0.02). CONCLUSION: As a group, smear-positive pulmonary tuberculosis patients with typical radiographic features constitute the greatest public health risk. This may have implications for automated detection systems.


Assuntos
Automação , Radiografia Torácica , Tuberculose Pulmonar/transmissão , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tuberculose Pulmonar/diagnóstico por imagem , Adulto Jovem
18.
PLoS One ; 9(2): e88684, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24533136

RESUMO

Previously we reported studies of XMetA, an agonist antibody to the insulin receptor (INSR). We have now utilized phage display to identify XMetS, a novel monoclonal antibody to the INSR. Biophysical studies demonstrated that XMetS bound to the human and mouse INSR with picomolar affinity. Unlike monoclonal antibody XMetA, XMetS alone had little or no agonist effect on the INSR. However, XMetS was a strong positive allosteric modulator of the INSR that increased the binding affinity for insulin nearly 20-fold. XMetS potentiated insulin-stimulated INSR signaling ∼15-fold or greater including; autophosphorylation of the INSR, phosphorylation of Akt, a major enzyme in the metabolic pathway, and phosphorylation of Erk, a major enzyme in the growth pathway. The enhanced signaling effects of XMetS were more pronounced with Akt than with Erk. In cultured cells, XMetS also enhanced insulin-stimulated glucose transport. In contrast to its effects on the INSR, XMetS did not potentiate IGF-1 activation of the IGF-1 receptor. We studied the effect of XMetS treatment in two mouse models of insulin resistance and diabetes. The first was the diet induced obesity mouse, a hyperinsulinemic, insulin resistant animal, and the second was the multi-low dose streptozotocin/high-fat diet mouse, an insulinopenic, insulin resistant animal. In both models, XMetS normalized fasting blood glucose levels and glucose tolerance. In concert with its ability to potentiate insulin action at the INSR, XMetS reduced insulin and C-peptide levels in both mouse models. XMetS improved the response to exogenous insulin without causing hypoglycemia. These data indicate that an allosteric monoclonal antibody can be generated that markedly enhances the binding affinity of insulin to the INSR. These data also suggest that an INSR monoclonal antibody with these characteristics may have the potential to both improve glucose metabolism in insulinopenic type 2 diabetes mellitus and correct compensatory hyperinsulinism in insulin resistant conditions.


Assuntos
Anticorpos Monoclonais/química , Antígenos CD/metabolismo , Glucose/metabolismo , Receptor de Insulina/metabolismo , Sítio Alostérico , Animais , Peptídeo C/química , Células CHO , Separação Celular , Cricetinae , Cricetulus , Diabetes Mellitus Tipo 2/metabolismo , Citometria de Fluxo , Humanos , Hiperglicemia/metabolismo , Hiperinsulinismo/metabolismo , Insulina/química , Resistência à Insulina , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , Biblioteca de Peptídeos , Fosforilação , Estrutura Terciária de Proteína , Transdução de Sinais
19.
MAbs ; 6(1): 262-72, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24423625

RESUMO

Novel therapies are needed for the treatment of hypoglycemia resulting from both endogenous and exogenous hyperinsulinema. To provide a potential new treatment option, we identified XMetD, an allosteric monoclonal antibody to the insulin receptor (INSR) that was isolated from a human antibody phage display library. To selectively obtain antibodies directed at allosteric sites, panning of the phage display library was conducted using the insulin-INSR complex. Studies indicated that XMetD bound to the INSR with nanomolar affinity. Addition of insulin reduced the affinity of XMetD to the INSR by 3-fold, and XMetD reduced the affinity of the INSR for insulin 3-fold. In addition to inhibiting INSR binding, XMetD also inhibited insulin-induced INSR signaling by 20- to 100-fold. These signaling functions included INSR autophosphorylation, Akt activation and glucose transport. These data indicated that XMetD was an allosteric antagonist of the INSR because, in addition to inhibiting the INSR via modulation of binding affinity, it also inhibited the INSR via modulation of signaling efficacy. Intraperitoneal injection of XMetD at 10 mg/kg twice weekly into normal mice induced insulin resistance. When sustained-release insulin implants were placed into normal mice, they developed fasting hypoglycemia in the range of 50 mg/dl. This hypoglycemia was reversed by XMetD treatment. These studies demonstrate that allosteric monoclonal antibodies, such as XMetD, can antagonize INSR signaling both in vitro and in vivo. They also suggest that this class of allosteric monoclonal antibodies has the potential to treat hyperinsulinemic hypoglycemia resulting from conditions such as insulinoma, congenital hyperinsulinism and insulin overdose.


Assuntos
Anticorpos Monoclonais/imunologia , Hiperinsulinismo Congênito/imunologia , Receptor de Insulina/antagonistas & inibidores , Anticorpos de Cadeia Única/imunologia , Animais , Anticorpos Monoclonais/farmacologia , Transporte Biológico Ativo/efeitos dos fármacos , Transporte Biológico Ativo/imunologia , Células CHO , Hiperinsulinismo Congênito/tratamento farmacológico , Hiperinsulinismo Congênito/patologia , Cricetinae , Cricetulus , Glucose/imunologia , Resistência à Insulina/imunologia , Camundongos , Ratos , Receptor de Insulina/imunologia , Anticorpos de Cadeia Única/farmacologia
20.
Exp Biol Med (Maywood) ; 239(1): 24-32, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24186266

RESUMO

Evidence indicates that high-grade serous ovarian carcinoma (HGSOC) may originate from lesions within the distal fallopian tube epithelium (FTE). Our previous studies indicate that fallopian tube epithelial cells from carriers of germline mutations in breast cancer susceptibility genes exhibit a pro-inflammatory gene expression signature during the luteal phase, suggesting that delayed resolution of postovulatory inflammatory signaling may contribute to predisposition to this ovarian cancer histotype. To determine whether exposure of tubal epithelial cells to periovulatory follicular fluid alters expression of inflammation-associated genes, we used an ex vivo culture system of bovine oviductal epithelial cells. Oviductal cells grown on collagen IV-coated transwell membranes assumed a cobblestone appearance and immunocytochemistry for FoxJ1 and Pax8 indicated that both ciliated and secretory epithelial cells were maintained in the cultures. Oviductal cells were exposed to human follicular fluid or culture medium for 24 h following which total cellular RNA was extracted at various time points. Expression of genes associated with inflammation was determined by quantitative real-time RT-PCR. Exposure to follicular fluid transiently increased the transcript levels of interleukin 8 (IL8) and cyclooxygenase 2 (PTGS2), and decreased the expression of mitochondrial superoxide dismutase (SOD2), glutathione peroxidase 3 (GPX3), disabled homolog 2 (DAB2), and glucocorticoid receptor (NR3C1). Tumor necrosis factor (TNF) and IL6 levels were also decreased while those of nicotinomide phosphoribosyltransferase (NAMPT) were unaffected. This study demonstrates that periovulatory follicular fluid can act directly upon oviductal epithelial cells to alter gene expression that might contribute to early carcinogenic events. Furthermore, these findings illustrate the potential use of bovine oviductal cells to study signaling events implicated in ovarian carcinogenesis.


Assuntos
Líquido Folicular/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteínas de Neoplasias/biossíntese , Neoplasias Ovarianas/metabolismo , Oviductos/metabolismo , Transcrição Gênica , Animais , Bovinos , Células Cultivadas , Feminino , Humanos , Inflamação/metabolismo , Inflamação/patologia , Neoplasias Ovarianas/patologia , Oviductos/patologia
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