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1.
Nat Immunol ; 22(6): 781-793, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34031617

RESUMO

Multimodal T cell profiling can enable more precise characterization of elusive cell states underlying disease. Here, we integrated single-cell RNA and surface protein data from 500,089 memory T cells to define 31 cell states from 259 individuals in a Peruvian tuberculosis (TB) progression cohort. At immune steady state >4 years after infection and disease resolution, we found that, after accounting for significant effects of age, sex, season and genetic ancestry on T cell composition, a polyfunctional type 17 helper T (TH17) cell-like effector state was reduced in abundance and function in individuals who previously progressed from Mycobacterium tuberculosis (M.tb) infection to active TB disease. These cells are capable of responding to M.tb peptides. Deconvoluting this state-uniquely identifiable with multimodal analysis-from public data demonstrated that its depletion may precede and persist beyond active disease. Our study demonstrates the power of integrative multimodal single-cell profiling to define cell states relevant to disease and other traits.


Assuntos
Memória Imunológica , Mycobacterium tuberculosis/imunologia , Células Th17/imunologia , Tuberculose Pulmonar/imunologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Criança , Progressão da Doença , Feminino , Seguimentos , Predisposição Genética para Doença , Técnicas de Genotipagem , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/isolamento & purificação , Peru , RNA-Seq , Fatores Sexuais , Análise de Célula Única , Fatores Socioeconômicos , Tuberculose Pulmonar/sangue , Tuberculose Pulmonar/genética , Tuberculose Pulmonar/microbiologia , Adulto Jovem
2.
Nat Immunol ; 19(4): 397-406, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29531339

RESUMO

The hallmark function of αß T cell antigen receptors (TCRs) involves the highly specific co-recognition of a major histocompatibility complex molecule and its carried peptide. However, the molecular basis of the interactions of TCRs with the lipid antigen-presenting molecule CD1c is unknown. We identified frequent staining of human T cells with CD1c tetramers across numerous subjects. Whereas TCRs typically show high specificity for antigen, both tetramer binding and autoreactivity occurred with CD1c in complex with numerous, chemically diverse self lipids. Such extreme polyspecificity was attributable to binding of the TCR over the closed surface of CD1c, with the TCR covering the portal where lipids normally protrude. The TCR essentially failed to contact lipids because they were fully seated within CD1c. These data demonstrate the sequestration of lipids within CD1c as a mechanism of autoreactivity and point to small lipid size as a determinant of autoreactive T cell responses.


Assuntos
Antígenos CD1/imunologia , Autoantígenos/imunologia , Autoimunidade/imunologia , Glicoproteínas/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T/imunologia , Apresentação de Antígeno/imunologia , Humanos , Lipídeos/imunologia , Ativação Linfocitária/imunologia
3.
Nature ; 582(7811): 234-239, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32499652

RESUMO

On average, Peruvian individuals are among the shortest in the world1. Here we show that Native American ancestry is associated with reduced height in an ethnically diverse group of Peruvian individuals, and identify a population-specific, missense variant in the FBN1 gene (E1297G) that is significantly associated with lower height. Each copy of the minor allele (frequency of 4.7%) reduces height by 2.2 cm (4.4 cm in homozygous individuals). To our knowledge, this is the largest effect size known for a common height-associated variant. FBN1 encodes the extracellular matrix protein fibrillin 1, which is a major structural component of microfibrils. We observed less densely packed fibrillin-1-rich microfibrils with irregular edges in the skin of individuals who were homozygous for G1297 compared with individuals who were homozygous for E1297. Moreover, we show that the E1297G locus is under positive selection in non-African populations, and that the E1297 variant shows subtle evidence of positive selection specifically within the Peruvian population. This variant is also significantly more frequent in coastal Peruvian populations than in populations from the Andes or the Amazon, which suggests that short stature might be the result of adaptation to factors that are associated with the coastal environment in Peru.


Assuntos
Estatura/genética , Fibrilina-1/genética , Mutação de Sentido Incorreto , Seleção Genética , Feminino , Frequência do Gene , Estudo de Associação Genômica Ampla , Hereditariedade , Humanos , Indígenas Sul-Americanos/genética , Masculino , Microfibrilas/química , Microfibrilas/genética , Peru
4.
Artigo em Inglês | MEDLINE | ID: mdl-38416532

RESUMO

RATIONALE: The persistent burden of TB disease emphasizes the need to identify individuals with TB for treatment and those at a high risk of incident TB for prevention. Targeting interventions towards those at high risk of developing and transmitting tuberculosis is a public health priority. OBJECTIVES: We aimed to identify characteristics of individuals involved in tuberculosis transmission in a community setting, which may guide the prioritization of targeted interventions. METHODS: We collected clinical and socio-demographic data from a cohort of tuberculosis patients in Lima, Peru. We used whole-genome sequencing data to assess the genetic distance between all possible pairs of patients; we considered pairs to be the result of a direct transmission event if they differed by three or fewer SNPs and we assumed that the first diagnosed patient in a pair was the transmitter and the second to be the recipient. We used logistic regression to examine the association between host factors and the likelihood of direct tuberculosis transmission. MAIN RESULTS: Analyzing data from 2,518 tuberculosis index patients, we identified 1,447 direct transmission pairs. Regardless of recipient attributes, individuals less than 34 years old, males, and those with a history of incarceration had a higher likelihood of being transmitters in direct transmission pairs. Direct transmission was more likely when both patients were drinkers or smokers. CONCLUSIONS: This study identifies men, young adults, former prisoners, alcohol consumers, and smokers as priority groups for targeted interventions. Innovative strategies are needed to extend tuberculosis screening to social groups like young adults and prisoners with limited access to routine preventive care. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

5.
Proc Natl Acad Sci U S A ; 119(45): e2207022119, 2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36322726

RESUMO

Spatially targeted interventions may be effective alternatives to individual or population-based prevention strategies against tuberculosis (TB). However, their efficacy may depend on the mechanisms that lead to geographically constrained hotspots. Local TB incidence may reflect high levels of local transmission; conversely, they may point to frequent travel of community members to high-risk areas. We used whole-genome sequencing to explore patterns of TB incidence and transmission in Lima, Peru. Between 2009 and 2012, we recruited incident pulmonary TB patients and their household contacts, whom we followed for the occurrence of TB disease. We used whole-genome sequences of 2,712 Mycobacterial tuberculosis isolates from 2,440 patients to estimate pariwise genomic distances and compared these to the spatial distance between patients' residences. Genomic distances increased rapidly as spatial distances increased and remained high beyond 2 km of separation. Next, we divided the study catchment area into 1 × 1 km grid-cell surface units and used household spatial coordinates to locate each TB patient to a specific cell. We estimated cell-specific transmission by calculating the proportion of patients in each cell with a pairwise genomic distance of 10 or fewer single-nucleotide polymorphisms. We found that cell-specific TB incidence and local transmission varied widely but that cell-specific TB incidence did not correlate closely with our estimates of local transmission (Cohen's k = 0.27). These findings indicate that an understanding of the spatial heterogeneity in the relative proportion of TB due to local transmission may help guide the implementation of spatially targeted interventions.


Assuntos
Mycobacterium tuberculosis , Tuberculose Pulmonar , Tuberculose , Humanos , Peru/epidemiologia , Tuberculose/epidemiologia , Mycobacterium tuberculosis/genética , Tuberculose Pulmonar/epidemiologia , Sequenciamento Completo do Genoma
6.
Emerg Infect Dis ; 30(6): 1115-1124, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38781680

RESUMO

The World Health Organization's end TB strategy promotes the use of symptom and chest radiograph screening for tuberculosis (TB) disease. However, asymptomatic early states of TB beyond latent TB infection and active disease can go unrecognized using current screening criteria. We conducted a longitudinal cohort study enrolling household contacts initially free of TB disease and followed them for the occurrence of incident TB over 1 year. Among 1,747 screened contacts, 27 (52%) of the 52 persons in whom TB subsequently developed during follow-up had a baseline abnormal radiograph. Of contacts without TB symptoms, persons with an abnormal radiograph were at higher risk for subsequent TB than persons with an unremarkable radiograph (adjusted hazard ratio 15.62 [95% CI 7.74-31.54]). In young adults, we found a strong linear relationship between radiograph severity and time to TB diagnosis. Our findings suggest chest radiograph screening can extend to detecting early TB states, thereby enabling timely intervention.


Assuntos
Características da Família , Programas de Rastreamento , Radiografia Torácica , Humanos , Peru/epidemiologia , Masculino , Feminino , Adulto , Adolescente , Adulto Jovem , Programas de Rastreamento/métodos , Estudos Longitudinais , Pessoa de Meia-Idade , Criança , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/diagnóstico por imagem , Busca de Comunicante/métodos , Pré-Escolar , Tuberculose Latente/diagnóstico , Tuberculose Latente/epidemiologia , Tuberculose Latente/diagnóstico por imagem , Lactente , Tuberculose/epidemiologia , Tuberculose/diagnóstico , Tuberculose/diagnóstico por imagem
7.
J Infect Dis ; 2023 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-37995298

RESUMO

We explored the utility of brief Mycobacterium tuberculosis whole-genome sequencing (WGS) "snapshots" at a sentinel site within Lima, Peru for evaluating local transmission dynamics over time. Within a 17 km2 area, 15/70 (21%) isolates with WGS collected during 2011-2012 and 22/81 (27%) collected during 2020-2021 were clustered (p = 0.414), and additional isolates clustered with those from outside the area. Isolates from the later period were disproportionately related to large historic clusters in Lima from the earlier period. WGS snapshots at a sentinel site may not be useful for monitoring transmission, but monitoring the persistence of large transmission clusters might be.

8.
Clin Infect Dis ; 76(3): e987-e989, 2023 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35723266

RESUMO

Using data from 388 people diagnosed with tuberculosis through a community-based screening program in Lima, Peru, we estimated that cough screening followed by sputum smear microscopy would have detected only 23% of cases found using an algorithm of radiographic screening followed by rapid nucleic acid amplification testing and clinical evaluation.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Humanos , Tuberculose/diagnóstico , Programas de Rastreamento , Técnicas de Amplificação de Ácido Nucleico , Algoritmos , Peru/epidemiologia , Escarro , Mycobacterium tuberculosis/genética , Sensibilidade e Especificidade
9.
Am J Respir Crit Care Med ; 206(7): 892-900, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-35608549

RESUMO

Rationale: Although World Health Organization guidelines emphasize contact investigation for tuberculosis (TB)-exposed children, data that support chest radiography as a useful tool are lacking. Objectives: We evaluated the diagnostic and prognostic information of chest radiography in children exposed to TB and measured the efficacy of isoniazid preventive therapy (IPT) in those with relevant radiographic abnormalities. Methods: Between September 2009 and August 2012, we enrolled 4,468 TB-exposed children who were screened by tuberculin skin testing, symptom assessment, and chest radiography. Those negative for TB disease were followed for 1 year for the occurrence of new TB diagnoses. We assessed the protective efficacy of IPT in children with and without abnormal chest radiographs. Measurements and Main Results: Compared with asymptomatic children with normal chest films, asymptomatic children with abnormal radiographs were 25.1-fold more likely to have coprevalent TB (95% confidence interval [CI], 1.02-613.76) and 26.7-fold more likely to be diagnosed with incident TB disease during follow-up (95% CI, 10.44-68.30). Among the 29 symptom-negative and CXR-abnormal child contacts, 20% (3/15) of the isoniazid recipients developed incident TB, compared with 57% (8/14) of those who did not receive IPT (82% IPT efficacy). Conclusions: Our results strongly support the use of chest radiography as a routine screening tool for the evaluation of child TB contacts, which is readily available. Radiographic abnormalities not usually considered suggestive of TB may indicate incipient or subclinical disease, although TB preventive treatment is adequate in most cases.


Assuntos
Isoniazida , Tuberculose , Antituberculosos/uso terapêutico , Criança , Humanos , Isoniazida/uso terapêutico , Radiografia , Tuberculina , Tuberculose/diagnóstico por imagem , Tuberculose/tratamento farmacológico
10.
BMC Infect Dis ; 22(1): 829, 2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36352374

RESUMO

BACKGROUND: The COVID-19 pandemic disrupted TB services worldwide, leading to diagnostic delays. There have been few published reports describing how the pandemic affected people's pathway to diagnosis from their own perspectives. We sought to evaluate the impact on the pandemic on people's experiences obtaining a TB diagnosis. METHODS: We performed a mixed-methods study, enrolling newly diagnosed TB patients from 12 health centers in Lima, Peru. We used structured surveys to quantify diagnostic delay, defined as the time between symptom onset and diagnosis, and in-depth interviews to understand the ways in which the pandemic affected the pathway to care. We compared diagnostic delay between patients enrolled during the first year of the pandemic to those diagnosed after using a Wilcoxon rank-sum test. We used an inductive content analysis approach to analyze interview content related to the pandemic. RESULTS: We enrolled 51 patients during November 2020-April 2021 (during the first year of the pandemic) and 49 patients during October 2021-February 2022. Median diagnostic delay was longer for patients diagnosed during the first year of the pandemic (median 15 [IQR 5-26] weeks compared to 6 [IQR 3-18] weeks, p = 0.027). Qualitative analysis of 26 interviews revealed that the pandemic affected participants' care-seeking behavior and their ability to access to TB diagnostic services, particularly for those diagnosed in the first year of the pandemic. Many participants initially had their symptoms attributed to COVID-19, resulting in delayed TB evaluation and additional costs for COVID-19 treatment. CONCLUSIONS: The COVID-19 pandemic impacted multiple steps in the pathway to care for TB patients in Lima, causing delays in TB diagnosis. These findings demonstrate how the shifting of health care resources to prioritize COVID-19 can lead to collateral damage for people with TB and other conditions.


Assuntos
COVID-19 , Tuberculose , Humanos , COVID-19/diagnóstico , Diagnóstico Tardio , Pandemias , Peru/epidemiologia , Estudos Transversais , Tuberculose/diagnóstico , Tuberculose/epidemiologia , Tuberculose/terapia , Tratamento Farmacológico da COVID-19
11.
Arch Virol ; 166(1): 167-178, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33130911

RESUMO

HIV infects its target cell and integrates into its genome as an essential step in its replication cycle. Proviral DNA is also subjected to the same transcriptional regulation as the host cell genome by its own transcriptional factors, with activating or repressive activity. There is a clear interaction between the presence of transcriptional repressors and a decrease in the rate of HIV replication, promoting gene silencing in infected cells, which serve as viral reservoirs. This represents a major obstacle for HIV eradication. The ZBTB gene family comprises 49 genes that encode transcription factors that have a repressor function in differentiation and development of cells of the lymphopoietic lineage, including the main target cells of HIV, CD4+ T cells. In this cross-sectional study, we evaluated the expression profile of ZBTB genes in CD4+ T cells of HIV-positive individuals with different levels of infection control. We found upregulation of gene expression of ZBTB4 (p < 0.01), ZBTB7B (p < 0.001), and ZBTB38 (p < 0.05) and downregulation of ZBTB16 (p < 0.01) in HIV-positive patients compared to HIV-negative individuals. Interestingly, in a deeper analysis, we observed that elite controllers had the highest levels of expression of the ZBTB38, ZBTB2, HIC1, ZBTB7A, ZBTB7B (ThPOK) and ZBTB4 genes, showing 2.56- to 7.60-fold upregulation compare to the ART-naïve group. These results suggest a possible contribution of these ZBTB transcriptional repressors in HIV-positive patients and a possible new molecular mechanism of viral control.


Assuntos
Proteínas de Ligação a DNA/genética , Infecções por HIV/genética , Infecções por HIV/virologia , Fatores de Transcrição/genética , Adulto , Linfócitos T CD4-Positivos/virologia , Linhagem Celular , Feminino , Expressão Gênica/genética , Regulação da Expressão Gênica/genética , HIV-1/patogenicidade , Humanos , Leucócitos Mononucleares/virologia , Masculino , Latência Viral/genética , Replicação Viral/genética
12.
J Immunol ; 203(12): 3395-3406, 2019 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-31694911

RESUMO

High-throughput TCR sequencing allows interrogation of the human TCR repertoire, potentially connecting TCR sequences to antigenic targets. Unlike the highly polymorphic MHC proteins, monomorphic Ag-presenting molecules such as MR1, CD1d, and CD1b present Ags to T cells with species-wide TCR motifs. CD1b tetramer studies and a survey of the 27 published CD1b-restricted TCRs demonstrated a TCR motif in humans defined by the TCR ß-chain variable gene 4-1 (TRBV4-1) region. Unexpectedly, TRBV4-1 was involved in recognition of CD1b regardless of the chemical class of the carried lipid. Crystal structures of two CD1b-specific TRBV4-1+ TCRs show that germline-encoded residues in CDR1 and CDR3 regions of TRBV4-1-encoded sequences interact with each other and consolidate the surface of the TCR. Mutational studies identified a key positively charged residue in TRBV4-1 and a key negatively charged residue in CD1b that is shared with CD1c, which is also recognized by TRBV4-1 TCRs. These data show that one TCR V region can mediate a mechanism of recognition of two related monomorphic Ag-presenting molecules that does not rely on a defined lipid Ag.


Assuntos
Motivos de Aminoácidos , Antígenos CD1d/química , Antígenos CD1d/metabolismo , Sítios de Ligação , Receptores de Antígenos de Linfócitos T alfa-beta/química , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Apresentação de Antígeno , Sequência Conservada , Epitopos de Linfócito T/química , Epitopos de Linfócito T/imunologia , Epitopos de Linfócito T/metabolismo , Rearranjo Gênico , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Imunofenotipagem , Lipídeos/química , Modelos Moleculares , Mutação , Ligação Proteica , Conformação Proteica , Multimerização Proteica , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Relação Estrutura-Atividade , Linfócitos T/imunologia , Linfócitos T/metabolismo
13.
BMC Public Health ; 21(1): 121, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33430823

RESUMO

BACKGROUND: To ensure patient-centered tuberculosis preventive treatment, it is important to consider factors that make it easier for patients to complete treatment. However, there is little published literature about patient preferences for different preventive treatment regimen options, particularly from countries with high tuberculosis burdens. METHODS: We conducted a qualitative research study using a framework analysis approach to understand tuberculosis preventive treatment preferences among household contacts. We conducted three focus group discussions with 16 members of families affected by tuberculosis in Lima, Peru. Participants were asked to vote for preferred preventive treatment regimens and discuss the reasons behind their choices. Coding followed a deductive approach based on prior research, with data-driven codes added. RESULTS: In total, 7 (44%) participants voted for 3 months isoniazid and rifapentine, 4 (25%) chose 3 months isoniazid and rifampicin, 3 (19%) chose 4 months rifampicin, and 2 (13%) chose 6 months isoniazid. Preferences for shorter regimens over 6 months of isoniazid were driven by concerns over "getting tired" or "getting bored" of taking medications, the difficulty of remembering to take medications, side effects, and interference with daily life. For some, weekly dosing was perceived as being easier to remember and less disruptive, leading to a preference for 3 months isoniazid and rifapentine, which is dosed weekly. However, among caregivers, having a child-friendly formulation was more important than regimen duration. Caregivers reported difficulty in administering pills to children, and preferred treatments available as syrup or dispersible formulations. CONCLUSIONS: There is demand for shorter regimens and child-friendly formulations for tuberculosis preventive treatment in high-burden settings. Individual preferences differ, suggesting that patient-centered care would best be supported by having multiple shorter regimens available.


Assuntos
Isoniazida , Tuberculose , Antituberculosos/uso terapêutico , Criança , Protocolos Clínicos , Quimioterapia Combinada , Humanos , Isoniazida/uso terapêutico , Assistência Centrada no Paciente , Peru , Tuberculose/tratamento farmacológico , Tuberculose/prevenção & controle
14.
Sensors (Basel) ; 21(6)2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33804127

RESUMO

This paper presents a novel mechanism for fingerprint dynamic presentation attack detection. We utilize five spatio-temporal feature extractors to efficiently eliminate and mitigate different presentation attack species. The feature extractors are selected such that the fingerprint ridge/valley pattern is consolidated with the temporal variations within the pattern in fingerprint videos. An SVM classification scheme, with a second degree polynomial kernel, is used in our presentation attack detection subsystem to classify bona fide and attack presentations. The experiment protocol and evaluation are conducted following the ISO/IEC 30107-3:2017 standard. Our proposed approach demonstrates efficient capability of detecting presentation attacks with significantly low BPCER where BPCER is 1.11% for an optical sensor and 3.89% for a thermal sensor at 5% APCER for both.

15.
Am J Respir Crit Care Med ; 198(5): 657-666, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29954183

RESUMO

RATIONALE: We examined whether increased rifampin doses could shorten standard therapy for tuberculosis without increased toxicity. OBJECTIVES: To assess the differences across three daily oral doses of rifampin in change in elimination rate of Mycobacterium tuberculosis in sputum and frequency of rifampin-related adverse events. METHODS: We conducted a blinded, randomized, controlled phase 2 clinical trial of 180 adults with new smear-positive pulmonary tuberculosis, susceptible to isoniazid and rifampin. We randomized 1:1:1 to rifampin at 10, 15, and 20 mg/kg/d during the intensive phase. We report the primary efficacy and safety endpoints: change in elimination rate of M. tuberculosis log10 colony-forming units and frequency of grade 2 or higher rifampin-related adverse events. We report efficacy by treatment arm and by primary (area under the plasma concentration-time curve [AUC]/minimum inhibitory concentration [MIC]) and secondary (AUC) pharmacokinetic exposure. MEASUREMENTS AND MAIN RESULTS: Each 5-mg/kg/d increase in rifampin dose resulted in differences of -0.011 (95% confidence interval, -0.025 to +0.002; P = 0.230) and -0.022 (95% confidence interval, -0.046 to -0.002; P = 0.022) log10 cfu/ml/d in the modified intention-to-treat and per-protocol analyses, respectively. The elimination rate in the per-protocol population increased significantly with rifampin AUC0-6 (P = 0.011) but not with AUC0-6/MIC99.9 (P = 0.053). Grade 2 or higher rifampin-related adverse events occurred with similar frequency across the three treatment arms: 26, 31, and 23 participants (43.3%, 51.7%, and 38.3%, respectively) had at least one event (P = 0.7092) up to 4 weeks after the intensive phase. Treatment failed or disease recurred in 11 participants (6.1%). CONCLUSIONS: Our findings of more rapid sputum sterilization and similar toxicity with higher rifampin doses support investigation of increased rifampin doses to shorten tuberculosis treatment. Clinical trial registered with www.clinicaltrials.gov (NCT 01408914) .


Assuntos
Antibióticos Antituberculose/uso terapêutico , Rifampina/uso terapêutico , Tuberculose Pulmonar/tratamento farmacológico , Adulto , Feminino , Humanos , Masculino , Mycobacterium tuberculosis/efeitos dos fármacos , Escarro , Resultado do Tratamento , Adulto Jovem
16.
Sensors (Basel) ; 19(18)2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31546976

RESUMO

In this article, a gait recognition algorithm is presented based on the information obtained from inertial sensors embedded in a smartphone, in particular, the accelerometers and gyroscopes typically embedded on them. The algorithm processes the signal by extracting gait cycles, which are then fed into a Recurrent Neural Network (RNN) to generate feature vectors. To optimize the accuracy of this algorithm, we apply a random grid hyperparameter selection process followed by a hand-tuning method to reach the final hyperparameter configuration. The different configurations are tested on a public database with 744 users and compared with other algorithms that were previously tested on the same database. After reaching the best-performing configuration for our algorithm, we obtain an equal error rate (EER) of 11.48% when training with only 20% of the users. Even better, when using 70% of the users for training, that value drops to 7.55%. The system manages to improve on state-of-the-art methods, but we believe the algorithm could reach a significantly better performance if it was trained with more visits per user. With a large enough database with several visits per user, the algorithm could improve substantially.

18.
J Neuroinflammation ; 11: 209, 2014 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-25511018

RESUMO

BACKGROUND: The anti-inflammatory effect of the cerebral dopamine neurotrophic factor (CDNF) was shown recently in primary glial cell cultures, yet such effect remains unknown both in vivo and in 6-hydroxydopamine (6-OHDA) models of Parkinson's disease (PD). We addressed this issue by performing an intranigral transfection of the human CDNF (hCDNF) gene in the critical period of inflammation after a single intrastriatal 6-OHDA injection in the rat. METHODS: At day 15 after lesion, the plasmids p3xNBRE-hCDNF or p3xNBRE-EGFP, coding for enhanced green florescent protein (EGFP), were transfected into the rat substantia nigra (SN) using neurotensin (NTS)-polyplex. At day 15 post-transfection, we measured nitrite and lipoperoxide levels in the SN. We used ELISA to quantify the levels of TNF-α, IL-1ß, IL-6, endogenous rat CDNF (rCDNF) and hCDNF. We also used qRT-PCR to measure rCDNF and hCDNF transcripts, and immunofluorescence assays to evaluate iNOS, CDNF and glial cells (microglia, astrocytes and Neuron/Glial type 2 (NG2) cells). Intact SNs were additional controls. RESULTS: In the SN, 6-OHDA triggered nitrosative stress, increased inflammatory cytokines levels, and activated the multipotent progenitor NG2 cells, which convert into astrocytes to produce rCDNF. In comparison with the hemiparkinsonian rats that were transfected with the EGFP gene or without transfection, 6-OHDA treatment and p3xNBRE-hCDNF transfection increased the conversion of NG2 cells into astrocytes resulting in 4-fold increase in the rCDNF protein levels. The overexpressed CDNF reduced nitrosative stress, glial markers and IL-6 levels in the SN, but not TNF-α and IL-1ß levels. CONCLUSION: Our results show the anti-inflammatory effect of CDNF in a 6-OHDA rat of Parkinson's disease. Our results also suggest the possible participation of TNF-α, IL-1ß and IL-6 in rCDNF production by astrocytes, supporting their anti-inflammatory role.


Assuntos
Fatores de Crescimento Neural/biossíntese , Fatores de Crescimento Neural/genética , Oxidopamina/toxicidade , Substância Negra/efeitos dos fármacos , Substância Negra/metabolismo , Transfecção , Animais , Humanos , Inflamação/induzido quimicamente , Inflamação/genética , Inflamação/metabolismo , Injeções Intraventriculares , Masculino , Oxidopamina/administração & dosagem , Ratos , Ratos Wistar
19.
Am J Trop Med Hyg ; 111(1): 168-175, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38744270

RESUMO

In Latin America, little is known about the involvement of private health-care providers in tuberculosis (TB) detection and management. We sought to gain a better understanding of current and potential roles of the private sector in delivering TB services in Peru. We conducted a mixed-methods study in North Lima, Peru. The quantitative component comprised a patient pathway analysis assessing the alignment of TB services with patient care-seeking behavior. The qualitative component comprised in-depth interviews with 18 private health-care providers and 5 key informants. We estimated that 77% of patients sought care initially at a facility with TB diagnostic capacity and 59% at a facility with TB treatment capacity. Among private facilities, 43% offered smear microscopy, 13% offered radiography, and none provided TB treatment. Among public-sector facilities, 100% offered smear microscopy, 26% offered radiography, and 99% provided TB treatment. Private providers believed they offered shorter wait times and a faster diagnosis, but they struggled with a lack of referral systems and communication with the public sector. Nonrecognition of private-sector tests by the public sector led to duplicate testing of referred patients. Although expressing willingness to collaborate with public-sector programs for diagnosis and referral, private providers had limited interest in treating TB. This study highlights the role of private providers in Peru as an entry point for TB care. Public-private collaboration is necessary to harness the potential of the private sector as an ally for early diagnosis.


Assuntos
Setor Privado , Tuberculose , Humanos , Peru/epidemiologia , Tuberculose/diagnóstico , Tuberculose/tratamento farmacológico , Tuberculose/terapia , Setor Público , Pessoal de Saúde , Aceitação pelo Paciente de Cuidados de Saúde
20.
Stem Cells ; 30(6): 1277-85, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22415951

RESUMO

The objective of this article is to assess the safety of intraspinal infusion of autologous bone marrow mononuclear cells (BMNCs) and, ultimately, to look for histopathological signs of cellular neurotrophism in amyotrophic lateral sclerosis (ALS) patients. We conducted an open single arm phase I trial. After 6 months observation, autologous BMNCs were infused into the posterior spinal cord funiculus. Safety was the primary endpoint and was defined as the absence of serious transplant-related adverse events. In addition, forced vital capacity (FVC), ALS-functional rating scale (ALS-FRS), Medical Research Council scale for assessment of muscle power (MRC), and Norris scales were assessed 6 and 3 months prior to the transplant and quarterly afterward for 1 year. Pathological studies were performed in case of death. Eleven patients were included. We did not observe any severe transplant-related adverse event, but there were 43 nonsevere events. Twenty-two (51%) resolved in ≤2 weeks and only four were still present at the end of follow-up. All were common terminology criteria for adverse events grade ≤2. No acceleration in the rate of decline of FVC, ALS-FRS, Norris, or MRC scales was observed. Four patients died on days 359, 378, 808, and 1,058 post-transplant for reasons unrelated to the procedure. Spinal cord pathological analysis showed a greater number of motoneurons in the treated segments compared with the untreated segments (4.2 ± 0.8 motoneurons per section [mns per sect] and 0.9 ± 0.3 mns per sect, respectively). In the treated segments, motoneurons were surrounded by CD90+ cells and did not show degenerative ubiquitin deposits. This clinical trial confirms not only the safety of intraspinal infusion of autologous BMNC in ALS patients but also provides evidence strongly suggesting their neurotrophic activity.


Assuntos
Esclerose Lateral Amiotrófica/patologia , Esclerose Lateral Amiotrófica/cirurgia , Células da Medula Óssea/patologia , Transplante de Medula Óssea/métodos , Degeneração Neural/patologia , Medula Espinal/patologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neurônios Motores/patologia , Projetos Piloto , Medula Espinal/cirurgia
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