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1.
Epilepsia ; 62(7): 1559-1568, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34060082

RESUMO

OBJECTIVE: Previous positron emission tomography (PET) studies using [11 C]ABP688 show reduced metabotropic glutamate receptor type 5 (mGluR5) allosteric binding site availability in the epileptogenic hippocampus of mesial temporal lobe epilepsy (MTLE) patients. However, the link between mGluR5 abnormalities and postsurgical outcomes remains unclear. Here, we test whether reduced PET [11 C]ABP688 binding in cornu ammonis (CA) sectors more vulnerable to glutamatergic excitotoxicity relates to surgical outcomes. METHODS: We obtained magnetic resonance imaging (MRI) and [11 C]ABP688-PET from 31 unilateral MTLE patients and 30 healthy controls. MRI hippocampal subfields were segmented using FreeSurfer. To respect the lower PET special resolution, MRI-derived anatomical subfields were combined into CA1-3, CA4/dentate gyrus, and Subiculum. Partial volume corrected [11 C]ABP688 nondisplaceable binding potential (BPND ) values were averaged across each subfield, and Z-scores were calculated. Subfield [11 C]ABP688-BPND was compared between seizure-free and non-seizure-free patients. In addition, we also assessed subfield volumes and [18 F]fluorodeoxyglucose (FDG) uptake in each clinical group. RESULTS: MTLE [11 C]ABP688-BPND was reduced in ipsilateral (epileptogenic) CA1-3 and CA4/dentate-gyrus (p < .001, 95% confidence interval [CI] = .29-.51) compared to controls, with no difference in Subiculum. [11 C]ABP688-BPND and subfield volumes were compared between seizure-free (Engel IA, n = 13) and non-seizure-free patients (Engel IC-III, n = 10). In ipsilateral CA1-3 only, [11 C]ABP688-BPND was lower in seizure-free patients than in non-seizure-free patients (p = .012, 95% CI = 1.46-11.0) independently of volume. A subset analysis of 12 patients with [11 C]ABP688-PET+[18 F]FDG-PET showed no between-group significant difference in [18 F]FDG uptake, whereas CA1-3 [11 C]ABP688-BPND remained significantly lower in the seven of 12 seizure-free patients (p = .03, 95% CI = -3.13 to -.21). SIGNIFICANCE: Reduced mGluR5 allosteric site availability in hippocampal CA1-3, measured in vivo by [11 C]ABP688-PET, is associated with postsurgery seizure freedom independent of atrophy or hypometabolism. Information derived from hippocampal CA1-3 [11 C]ABP688-PET is a promising imaging biomarker potentially impactful in surgical decisions for MRI-negative/PET-negative MTLE patients.


Assuntos
Epilepsia do Lobo Temporal/genética , Epilepsia do Lobo Temporal/cirurgia , Ácido Glutâmico/genética , Hipocampo/metabolismo , Procedimentos Neurocirúrgicos , Receptores de Ácido Caínico/genética , Adolescente , Adulto , Idoso , Região CA1 Hipocampal/metabolismo , Região CA3 Hipocampal , Epilepsia do Lobo Temporal/diagnóstico por imagem , Feminino , Fluordesoxiglucose F18 , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Oximas , Tomografia por Emissão de Pósitrons , Piridinas , Compostos Radiofarmacêuticos , Receptores de Ácido Caínico/metabolismo , Resultado do Tratamento , Adulto Jovem
2.
Educ Inf Technol (Dordr) ; 26(2): 2053-2089, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33013181

RESUMO

In everyday life, people seek, evaluate, and use online sources to underpin opinions and make decisions. While education must promote the skills people need to critically question the sourcing of online information, it is important, more generally, to understand how to successfully promote the acquisition of any skills related to seeking online information. This review outlines technologies that aim to support users when they collaboratively seek online information. Upon integrating psychological-pedagogical approaches on trust in and the sourcing of online information, argumentation, and computer-supported collaborative learning, we reviewed the literature (N = 95 journal articles) on technologies for collaborative online information seeking. The technologies we identified either addressed collaborative online information seeking as an exclusive process for searching for online information or, alternatively, addressed online information seeking within the context of a more complex learning process. Our review was driven by three main research questions: We aimed to understand whether and how the studies considered 1) the role of trust and critical questioning in the sourcing of online information, 2) the learning processes at play when information seekers engage in collaborative argumentation, and 3) what affordances are offered by technologies that support users' collaborative seeking of online information. The reviewed articles that focused exclusively on technologies for seeking online information primarily addressed aspects of cooperation (e.g., task management), whereas articles that focused on technologies for integrating the processes of information seeking into the entire learning processes instead highlighted aspects of collaborative argumentation (e.g., exchange of multiple perspectives and critical questioning in argumentation). Seven of the articles referred to trust as an aspect of seekers' sourcing strategies. We emphasize how researchers', users', and technology developers' consideration of collaborative argumentation could expand the benefits of technological support for seeking online information.

3.
Proc Natl Acad Sci U S A ; 114(4): E600-E609, 2017 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-28069964

RESUMO

The principles that guide large-scale cortical reorganization remain unclear. In the blind, several visual regions preserve their task specificity; ventral visual areas, for example, become engaged in auditory and tactile object-recognition tasks. It remains open whether task-specific reorganization is unique to the visual cortex or, alternatively, whether this kind of plasticity is a general principle applying to other cortical areas. Auditory areas can become recruited for visual and tactile input in the deaf. Although nonhuman data suggest that this reorganization might be task specific, human evidence has been lacking. Here we enrolled 15 deaf and 15 hearing adults into an functional MRI experiment during which they discriminated between temporally complex sequences of stimuli (rhythms). Both deaf and hearing subjects performed the task visually, in the central visual field. In addition, hearing subjects performed the same task in the auditory modality. We found that the visual task robustly activated the auditory cortex in deaf subjects, peaking in the posterior-lateral part of high-level auditory areas. This activation pattern was strikingly similar to the pattern found in hearing subjects performing the auditory version of the task. Although performing the visual task in deaf subjects induced an increase in functional connectivity between the auditory cortex and the dorsal visual cortex, no such effect was found in hearing subjects. We conclude that in deaf humans the high-level auditory cortex switches its input modality from sound to vision but preserves its task-specific activation pattern independent of input modality. Task-specific reorganization thus might be a general principle that guides cortical plasticity in the brain.


Assuntos
Córtex Auditivo/fisiologia , Surdez/fisiopatologia , Estimulação Acústica , Adulto , Córtex Auditivo/diagnóstico por imagem , Surdez/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Estimulação Luminosa , Adulto Jovem
4.
Proc Natl Acad Sci U S A ; 114(4): 734-739, 2017 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-28057865

RESUMO

Autoantibodies against myelin oligodendrocyte glycoprotein (MOG) are associated with autoimmune central nervous system diseases like acute disseminated encephalomyelitis (ADEM). For ADEM, it is speculated that a preceding infection is the trigger of the autoimmune response, but the mechanism connecting the infection to the production of MOG antibodies remains a mystery. We reasoned that the ability of B cells to capture cognate antigen from cell membranes, along with small quantities of coexpressed "bystander" antigens, might enable B-cell escape from tolerance. We tested this hypothesis using influenza hemagglutinin as a model viral antigen and transgenic, MOG-specific B cells. Using flow cytometry and live and fixed cell microscopy, we show that MOG-specific B cells take up large amounts of MOG from cell membranes. Uptake of the antigen from the membrane leads to a strong activation of the capturing B cell. When influenza hemagglutinin is also present in the membrane of the target cell, it can be cocaptured with MOG by MOG-specific B cells via the B-cell receptor. Hemagglutinin and MOG are both presented to T cells, which in turn are activated and proliferate. As a consequence, MOG-specific B cells get help from hemagglutinin-specific T cells to produce anti-MOG antibodies. In vivo, the transfer of MOG-specific B cells into recipient mice after the cocapture of MOG and hemagglutinin leads to the production of class-switched anti-MOG antibodies, dependent on the presence of hemagglutinin-specific T cells. This mechanism offers a link between infection and autoimmunity.


Assuntos
Antígenos Virais/imunologia , Autoantígenos/imunologia , Linfócitos B/imunologia , Animais , Autoanticorpos/imunologia , Autoimunidade/imunologia , Linhagem Celular , Membrana Celular/imunologia , Células HEK293 , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Glicoproteína Mielina-Oligodendrócito/imunologia , Receptores de Antígenos de Linfócitos B/imunologia , Linfócitos T/imunologia
5.
J Med Internet Res ; 20(1): e30, 2018 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-29362212

RESUMO

BACKGROUND: Online health forums are widely used, but the quality of advice differs as much as the knowledge backgrounds of the audience members who receive the advice. It is important to understand how people judge the information given online. In line with the communication accommodation theory (CAT), online forums represent specific social contexts of communication which can present either accommodative or nonaccommodative language to an audience. Accordingly, use of accommodative or nonaccommodative language might affect people's perceived trust in the communicator. OBJECTIVE: The objective of this study was to investigate how experts who use accommodative (vs nonaccommodative) language are evaluated by passive users of an online forum. METHODS: Participants (n=98) took part in an online experiment and read experts' posts about 10 nutrition myths. Following a 2 x 2 mixed design, experts' posts were written using either low or high amounts of medical technical jargon (MTJ) (within factor) and were directed at different audiences (mainly other medical experts [in a professional forum] vs a user group mainly comprising laypersons [in an advisory forum]) (between factor). Accommodation occurred where experts used high amounts of MTJ to address other medical experts in the professional forum; it also occurred when experts used low amounts of MTJ to address laypersons in the advisory forum. Conversely, nonaccommodation occurred when experts used high amounts of MTJ in the advisory forum and low amounts of MTJ in the professional forum. In each condition, participants evaluated the credibility of the information, the trustworthiness of the experts, and the accommodation by the experts. RESULTS: Overall, participants judged the credibility of information to be higher when experts used MTJ that was accommodative to the designated audience, F1,95=3.10, P=.04, ηp2=.031. In addition, participants judged the experts in professional forums to be more trustworthy than experts in advisory forums (all F1,96≥3.54, P ≤.03, ηp2≥.036). Moreover, participants rated experts who used high amounts of MTJ to have higher competence (F1,96=37.54, P<.001, ηp2=.28], lower integrity (F1,96=10.77, P=.001, ηp2=.101), and lower benevolence (F1,96=9.75, P=.002, ηp2=.092), as well as to have lower perceived accommodation to the audience (all F1,96≥72.17, P<.001, ηp2≥.43) compared with experts who used low MTJ. CONCLUSIONS: To provide health information online that is perceived as credible, experts should consider using similar language as the language used by the addressed audience. As it is often impossible to determine the exact makeup of an online audience, further research might investigate whether having experts explicitly declare which audience they intend to address can help people to more reliably assess an expert's trustworthiness. Furthermore, as people assess information differently depending on the context of online communication, it would be valuable for research to consider other aspects of the context beyond those of the audience.


Assuntos
Internet/normas , Telemedicina/normas , Adolescente , Adulto , Comunicação , Compreensão , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Percepção , Adulto Jovem
6.
J Neurosci ; 34(5): 1633-46, 2014 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-24478347

RESUMO

Primary sensory afferents of the dorsal root ganglion (DRG) that innervate the skin detect a wide range of stimuli, such as touch, temperature, pain, and itch. Different functional classes of nociceptors project their axons to distinct target zones within the developing skin, but the molecular mechanisms that regulate target innervation are less clear. Here we report that the Nogo66 receptor homolog NgR2 is essential for proper cutaneous innervation. NgR2(-/-) mice display increased density of nonpeptidergic nociceptors in the footpad and exhibit enhanced sensitivity to mechanical force and innocuous cold temperatures. These sensory deficits are not associated with any abnormality in morphology or density of DRG neurons. However, deletion of NgR2 renders nociceptive nonpeptidergic sensory neurons insensitive to the outgrowth repulsive activity of skin-derived Versican. Biochemical evidence shows that NgR2 specifically interacts with the G3 domain of Versican. The data suggest that Versican/NgR2 signaling at the dermo-epidermal junction acts in vivo as a local suppressor of axonal plasticity to control proper density of epidermal sensory fiber innervation. Our findings not only reveal the existence of a novel and unsuspected mechanism regulating epidermal target innervation, but also provide the first evidence for a physiological role of NgR2 in the peripheral nervous system.


Assuntos
Epiderme/inervação , Gânglios Espinais/citologia , Regulação da Expressão Gênica no Desenvolvimento/genética , Receptores de Superfície Celular/metabolismo , Células Receptoras Sensoriais/metabolismo , Versicanas/metabolismo , Animais , Animais Recém-Nascidos , Células CHO , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Cricetulus , Proteínas F-Box , Glicoproteínas/metabolismo , Hiperalgesia/fisiopatologia , Camundongos , Camundongos Knockout , Proteínas de Neurofilamentos/metabolismo , Nociceptores/metabolismo , Receptor Nogo 2 , Limiar da Dor/fisiologia , Estimulação Física/efeitos adversos , Ligação Proteica/genética , Receptores de Superfície Celular/genética , Receptores Purinérgicos P2X/genética , Receptores Purinérgicos P2X/metabolismo , Células Receptoras Sensoriais/classificação , Células Receptoras Sensoriais/citologia , Canais de Cátion TRPV/metabolismo , Tubulina (Proteína)/metabolismo , Versicanas/química , Versicanas/genética
7.
J Biol Chem ; 289(40): 27859-73, 2014 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-25122765

RESUMO

Proteolysis of the Glu(441)-Ala(442) bond in the glycosaminoglycan (GAG) ß domain of the versican-V1 variant by a disintegrin-like and metalloproteinase domain with thrombospondin type 1 motif (ADAMTS) proteases is required for proper embryo morphogenesis. However, the processing mechanism and the possibility of additional ADAMTS-cleaved processing sites are unknown. We demonstrate here that if Glu(441) is mutated, ADAMTS5 cleaves inefficiently at a proximate upstream site but normally does not cleave elsewhere within the GAGß domain. Chondroitin sulfate (CS) modification of versican is a prerequisite for cleavage at the Glu(441)-Ala(442) site, as demonstrated by reduced processing of CS-deficient or chondroitinase ABC-treated versican-V1. Site-directed mutagenesis identified the N-terminal CS attachment sites Ser(507) and Ser(525) as essential for processing of the Glu(441)-Ala(442) bond by ADAMTS5. A construct including only these two GAG chains, but not downstream GAG attachment sites, was cleaved efficiently. Therefore, CS chain attachment to Ser(507) and Ser(525) is necessary and sufficient for versican proteolysis by ADAMTS5. Mutagenesis of Glu(441) and an antibody to a peptide spanning Thr(432)-Gly(445) (i.e. containing the scissile bond) reduced versican-V1 processing. ADAMTS5 lacking the C-terminal ancillary domain did not cleave versican, and an ADAMTS5 ancillary domain construct bound versican-V1 via the CS chains. We conclude that docking of ADAMTS5 with two N-terminal GAG chains of versican-V1 via its ancillary domain is required for versican processing at Glu(441)-Ala(442). V1 proteolysis by ADAMTS1 demonstrated a similar requirement for the N-terminal GAG chains and Glu(441). Therefore, versican cleavage can be inhibited substantially by mutation of Glu(441), Ser(507), and Ser(525) or by an antibody to the region of the scissile bond.


Assuntos
Proteínas ADAM/metabolismo , Versicanas/metabolismo , Proteínas ADAM/química , Proteínas ADAM/genética , Proteína ADAMTS1 , Proteína ADAMTS5 , Motivos de Aminoácidos , Sulfatos de Condroitina/metabolismo , Humanos , Ligação Proteica , Estrutura Terciária de Proteína , Proteólise , Versicanas/química , Versicanas/genética
9.
iScience ; 27(1): 108671, 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38292167

RESUMO

Alzheimer's disease (AD) is a multifactorial pathology, with most cases having a sporadic origin. Recently, knock-in (KI) mouse models, such as the novel humanized amyloid-ß (hAß)-KI, have been developed to better resemble sporadic human AD. METHODS: Here, we compared hippocampal publicly available transcriptomic profiles of transgenic (5xFAD and APP/PS1) and KI (hAß-KI) mouse models with early- (EOAD) and late- (LOAD) onset AD patients. RESULTS: The three mouse models presented more Gene Ontology biological processes terms and enriched signaling pathways in common with LOAD than with EOAD individuals. Experimental validation of consistently dysregulated genes revealed five altered in mice (SLC11A1, S100A6, CD14, CD33, and C1QB) and three in humans (S100A6, SLC11A1, and KCNK). Finally, we identified 17 transcription factors potentially acting as master regulators of AD. CONCLUSION: Our cross-species analyses revealed that the three mouse models presented a remarkable similarity to LOAD, with the hAß-KI being the more specific one.

10.
Viruses ; 15(2)2023 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-36851525

RESUMO

The COVID-19 pandemic has lately been driven by Omicron. This work aimed to study the dynamics of SARS-CoV-2 Omicron lineages during the third and fourth waves of COVID-19 in Argentina. Molecular surveillance was performed on 3431 samples from Argentina, between EW44/2021 and EW31/2022. Sequencing, phylogenetic and phylodynamic analyses were performed. A differential dynamic between the Omicron waves was found. The third wave was associated with lineage BA.1, characterized by a high number of cases, very fast displacement of Delta, doubling times of 3.3 days and a low level of lineage diversity and clustering. In contrast, the fourth wave was longer but associated with a lower number of cases, initially caused by BA.2, and later by BA.4/BA.5, with doubling times of about 10 days. Several BA.2 and BA.4/BA.5 sublineages and introductions were detected, although very few clusters with a constrained geographical distribution were observed, suggesting limited transmission chains. The differential dynamic could be due to waning immunity and an increase in population gatherings in the BA.1 wave, and a boosted population (for vaccination or recent prior immunity for BA.1 infection) in the wave caused by BA2/BA.4/BA.5, which may have limited the establishment of the new lineages.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/epidemiologia , Argentina/epidemiologia , Pandemias , Filogenia
11.
J Neurosci ; 31(14): 5262-70, 2011 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-21471361

RESUMO

Peanut agglutinin-binding disaccharides and chondroitin sulfate mark transient mesenchymal barriers to advancing motor and sensory axons innervating the hindlimbs during chick development. Here we show that the vast majority of these carbohydrates are at the critical stage and location attached to the versican splice variants V0 and V1. We reveal that the isolated isoforms of this extracellular matrix proteoglycan suppress axon extension at low concentrations and induce growth cone collapse and rapid retraction at higher levels. Moreover, we demonstrate that versican V0 and/or V1, recombinantly expressed in collagen-I gels or ectopically deposited in the hindlimbs of chicken embryos in ovo, cause untimely defasciculation and axon stalling. Consequently, severe disturbances of nerve patterning are observed in the versican-treated embryos. Our experiments emphasize the inhibitory capacity of versicans V0 and V1 in axonal growth and evidence for their function as basic guidance cues during development of the peripheral nervous system.


Assuntos
Axônios/fisiologia , Membro Posterior/citologia , Membro Posterior/embriologia , Nervos Periféricos/citologia , Versicanas/metabolismo , Animais , Células COS , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Células Cultivadas , Embrião de Galinha , Chlorocebus aethiops , Técnicas de Cocultura/métodos , Fibronectinas/metabolismo , Gânglios Espinais/citologia , Humanos , Laminina/metabolismo , Lectinas/metabolismo , Camundongos , Camundongos Knockout , Proteínas de Neurofilamentos/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteoglicanas/metabolismo , Receptores Mitogênicos/metabolismo , Transfecção/métodos , Versicanas/genética
12.
Front Psychol ; 13: 1036669, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36337485

RESUMO

Training can influence behavioral performance and lead to brain reorganization. In particular, training in one modality, for example, auditory, can improve performance in another modality, for example, visual. Previous research suggests that one of the mechanisms behind this phenomenon could be the cross-modal recruitment of the sensory areas, for example, the auditory cortex. Studying expert musicians offers a chance to explore this process. Rhythm is an aspect of music that can be presented in various modalities. We designed an fMRI experiment in which professional pianists and non-musicians discriminated between two sequences of rhythms presented auditorily (series of sounds) or visually (series of flashes). Behavioral results showed that musicians performed in both visual and auditory rhythmic tasks better than non-musicians. We found no significant between-group differences in fMRI activations within the auditory cortex. However, we observed that musicians had increased activation in the right Inferior Parietal Lobe when compared to non-musicians. We conclude that the musicians' superior visual rhythm discrimination is not related to cross-modal recruitment of the auditory cortex; instead, it could be related to activation in higher-level, multimodal areas in the cortex.

13.
Front Neurol ; 13: 888479, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35937057

RESUMO

Abnormalities in the expression of metabotropic glutamate receptor type 5 (mGluR5) have been observed in the hippocampus of patients with drug-resistant mesial Temporal Lobe Epilepsy (mTLE). Ex-vivo studies in mTLE hippocampal surgical specimens have shown increased mGluR5 immunoreactivity, while in vivo whole brain imaging using positron emission tomography (PET) demonstrated reduced hippocampal mGluR5 availability. To further understand mGluR5 abnormalities in mTLE, we performed a saturation autoradiography study with [3H]ABP688 (a negative mGluR5 allosteric modulator). We aimed to evaluate receptor density (Bmax) and dissociation constants (KD) in hippocampal mTLE surgical specimens and in non-epilepsy hippocampi from necropsy controls. mTLE specimens showed a 43.4% reduction in receptor density compared to control hippocampi, which was independent of age, sex and KD (multiple linear regression analysis). There was no significant difference in KD between the groups, which suggests that the decreased mGluR5 availability found in vivo with PET cannot be attributed to reduced affinity between ligand and binding site. The present study supports that changes within the epileptogenic tissue include mGluR5 internalization or conformational changes that reduce [3H]ABP688 binding, as previously suggested in mTLE patients studied in vivo.

14.
Neurology ; 99(22): e2428-e2436, 2022 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-36266044

RESUMO

BACKGROUND AND OBJECTIVES: To assess the concordance and discordance between the core Alzheimer disease (AD) CSF biomarkers and [18F]fluorodeoxyglucose (FDG)-PET patterns evaluated clinically in memory clinic patients who meet appropriate use criteria for AD biomarker investigations. METHODS: We retrospectively assessed participants with atypical and/or early-onset dementia evaluated at a tertiary care memory clinic. All individuals underwent CSF evaluations for Aß42, phosphorylated tau (P-tau181) and total tau, and brain [18F]FDG-PET. [18F]FDG-PET data were visually interpreted by 2 nuclear medicine experts as being consistent with AD or non-AD. CSF biomarker results were similarly grouped into AD biomarker positive/negative. Contingency tables and Kappa coefficients were used to establish the level of agreement and disagreement between CSF and [18F]FDG-PET results in all individuals. RESULTS: One hundred thirty-six individuals had both [18F]FDG-PET and lumbar puncture performed as part of the early-onset and/or atypical dementia assessments. [18F]FDG-PET showed a pattern suggestive of AD in 43% of patients, while CSF biomarkers showed results consistent with AD in 57% of participants. In patients who met criteria for AD biomarker investigations, we found that [18F]FDG-PET was discordant with CSF AD biomarkers in nearly 20% of cases; 12% of individuals with [18F]FDG-PET scans consistent with AD had AD-negative CSF results; and 7% of individuals with [18F]FDG-PET scans not consistent with AD had AD-positive CSF results, potentially suggesting atypical AD variants or less advanced neurodegeneration. [18F]FDG-PET discriminated patients with an AD-positive CSF profile from patients with an AD-negative profile with a sensitivity and specificity higher than 80% (sensitivity: 81%, 95% CI = 71-88%, SP: 81%, 95% CI = 68-89%). Furthermore, [18F]FDG-PET had a positive predictive value of 87% (95% CI = 78-93%) and a negative predictive value of 72% (95% CI = 60-82%). DISCUSSION: CSF and [18F]FDG-PET disagreed in nearly 20% of the cases studied in this clinical series. While CSF Aß42 and P-tau181 biomarkers are specific for AD, the topographical information from [18F]FDG-PET may provide complementary information.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Doença de Alzheimer/diagnóstico por imagem , Fluordesoxiglucose F18 , Proteínas tau , Peptídeos beta-Amiloides , Estudos Retrospectivos , Tomografia por Emissão de Pósitrons , Biomarcadores , Fragmentos de Peptídeos
15.
J Neurosci ; 30(43): 14476-81, 2010 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-20980605

RESUMO

Oligodendrocyte myelin glycoprotein (OMgp) is expressed by both neurons and oligodendrocytes in the CNS. It has been implicated in growth cone collapse and neurite outgrowth inhibition by signaling through the Nogo receptor and paired Ig-like receptor B (PirB). OMgp was also reported to be an extracellular matrix (ECM) protein surrounding CNS nodes of Ranvier and proposed to function as (1) an inhibitor of nodal collateral sprouting and (2) an important contributor to proper nodal and paranodal architecture. However, we show here that the anti-OMgp antiserum used in previous studies to define the functions of OMgp at nodes is not specific. Among all reported nodal ECM components, the antiserum exhibited strong cross-reactivity against versican V2 isoform, a chondroitin sulfate proteoglycan. Furthermore, the OMgp antiserum labeled OMgp-null nodes, but not nodes from versican V2-deficient mice, and preadsorption of the OMgp antiserum with recombinant versican V2 blocked nodal labeling. Analysis of CNS nodes in OMgp-null mice failed to reveal any nodal or paranodal defects, or increased nodal collateral sprouting, indicating that OMgp does not participate in CNS node of Ranvier assembly or maintenance. We successfully identified a highly specific anti-OMgp antibody and observed OMgp staining in white matter only after initiation of myelination. OMgp immunoreactivity decorated the surface of mature myelinated axons, but was excluded from compact myelin and nodes. Together, our results strongly argue against the nodal localization of OMgp and its proposed functions at nodes, and reveal OMgp's authentic localization relative to nodes and myelin.


Assuntos
Glicoproteína Associada a Mielina/fisiologia , Nós Neurofibrosos/fisiologia , Animais , Anticorpos Bloqueadores/farmacologia , Especificidade de Anticorpos , Axônios/fisiologia , Axônios/ultraestrutura , Western Blotting , Reações Cruzadas , Matriz Extracelular/fisiologia , Proteínas Ligadas por GPI , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Camundongos Knockout , Microscopia Eletrônica , Proteínas da Mielina , Bainha de Mielina/fisiologia , Glicoproteína Associada a Mielina/genética , Glicoproteína Mielina-Oligodendrócito , Equilíbrio Postural/genética , Equilíbrio Postural/fisiologia , Nós Neurofibrosos/genética , Versicanas/genética , Versicanas/fisiologia
16.
Glycobiology ; 21(2): 257-68, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20947661

RESUMO

Previous work has shown that versican, decorin and a catabolic fragment of decorin, termed decorunt, are the most abundant proteoglycans in human skin. Further analysis of versican indicates that four major core protein species are present in human skin at all ages examined from fetal to adult. Two of these are identified as the V0 and V1 isoforms, with the latter predominating. The other two species are catabolic fragments of V0 and V1, which have the amino acid sequence DPEAAE as their carboxyl terminus. Although the core proteins of human skin versican show no major age-related differences, the glycosaminoglycans (GAGs) of adult skin versican are smaller in size and show differences in their sulfation pattern relative to those in fetal skin versican. In contrast to human skin versican, human skin decorin shows minimal age-related differences in its sulfation pattern, although, like versican, the GAGs of adult skin decorin are smaller than those of fetal skin decorin. Analysis of the catabolic fragments of decorin from adult skin reveals the presence of other fragments in addition to decorunt, although the core proteins of these additional decorin catabolic fragments have not been identified. Thus, versican and decorin of human skin show age-related differences, versican primarily in the size and the sulfation pattern of its GAGs and decorin in the size of its GAGs. The catabolic fragments of versican are detected at all ages examined, but appear to be in lower abundance in adult skin compared with fetal skin. In contrast, the catabolic fragments of decorin are present in adult skin, but are virtually absent from fetal skin. Taken together, these data suggest that there are age-related differences in the catabolism of proteoglycans in human skin. These age-related differences in proteoglycan patterns and catabolism may play a role in the age-related changes in the physical properties and injury response of human skin.


Assuntos
Envelhecimento , Decorina , Envelhecimento da Pele , Pele , Versicanas , Adulto , Envelhecimento/metabolismo , Sequência de Aminoácidos , Sítios de Ligação de Anticorpos/genética , Decorina/genética , Decorina/metabolismo , Combinação de Medicamentos , Eletroforese em Gel de Poliacrilamida , Feto/metabolismo , Humanos , Immunoblotting , Pessoa de Meia-Idade , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Pele/metabolismo , Sulfamonometoxina/metabolismo , Trimetoprima/metabolismo , Versicanas/genética , Versicanas/metabolismo , Adulto Jovem
17.
J Cell Biol ; 175(6): 1005-15, 2006 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-17158956

RESUMO

Given their accessibility, multipotent skin-derived cells might be useful for future cell replacement therapies. We describe the isolation of multipotent stem cell-like cells from the adult trunk skin of mice and humans that express the neural crest stem cell markers p75 and Sox10 and display extensive self-renewal capacity in sphere cultures. To determine the origin of these cells, we genetically mapped the fate of neural crest cells in face and trunk skin of mouse. In whisker follicles of the face, many mesenchymal structures are neural crest derived and appear to contain cells with sphere-forming potential. In the trunk skin, however, sphere-forming neural crest-derived cells are restricted to the glial and melanocyte lineages. Thus, self-renewing cells in the adult skin can be obtained from several neural crest derivatives, and these are of distinct nature in face and trunk skin. These findings are relevant for the design of therapeutic strategies because the potential of stem and progenitor cells in vivo likely depends on their nature and origin.


Assuntos
Linhagem da Célula , Células-Tronco Multipotentes/citologia , Crista Neural/citologia , Pele/citologia , Adipócitos/citologia , Adipócitos/metabolismo , Adulto , Animais , Diferenciação Celular , Células Cultivadas , Proteínas de Ligação a DNA/metabolismo , Face , Feminino , Imunofluorescência , Folículo Piloso/citologia , Folículo Piloso/fisiologia , Proteínas de Grupo de Alta Mobilidade/metabolismo , Humanos , Masculino , Melanócitos/citologia , Melanócitos/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Células-Tronco Multipotentes/fisiologia , Crista Neural/fisiologia , Neuroglia/citologia , Neuroglia/fisiologia , Fatores de Transcrição SOXE , Fatores de Transcrição/metabolismo
18.
Nat Med ; 9(5): 562-7, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12704383

RESUMO

Suppression of dendritic cell function in cancer patients is thought to contribute to the inhibition of immune responses and disease progression. Molecular mechanisms of this suppression remain elusive, however. Here, we show that a fraction of blood monocyte-derived myeloid dendritic cells (MDCs) express B7-H1, a member of the B7 family, on the cell surface. B7-H1 could be further upregulated by tumor environmental factors. Consistent with this finding, virtually all MDCs isolated from the tissues or draining lymph nodes of ovarian carcinomas express B7-H1. Blockade of B7-H1 enhanced MDC-mediated T-cell activation and was accompanied by downregulation of T-cell interleukin (IL)-10 and upregulation of IL-2 and interferon (IFN)-gamma. T cells conditioned with the B7-H1-blocked MDCs had a more potent ability to inhibit autologous human ovarian carcinoma growth in non-obese diabetic-severe combined immunodeficient (NOD-SCID) mice. Therefore, upregulation of B7-H1 on MDCs in the tumor microenvironment downregulates T-cell immunity. Blockade of B7-H1 represents one approach for cancer immunotherapy.


Assuntos
Antígeno B7-1/fisiologia , Proteínas Sanguíneas , Citotoxicidade Imunológica , Células Dendríticas/imunologia , Células Mieloides/imunologia , Neoplasias Ovarianas/terapia , Peptídeos , Animais , Antígenos CD , Antígeno B7-H1 , Feminino , Humanos , Interleucina-10/biossíntese , Interleucina-12/biossíntese , Ativação Linfocitária , Glicoproteínas de Membrana , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Neoplasias Ovarianas/imunologia , Linfócitos T/imunologia
19.
Ann Plast Surg ; 66(2): 154-63, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21042188

RESUMO

The goal of this prospective randomized clinical trial was to compare 2 cohorts of standardized cleft patients with regard to functional speech outcome and the presence or absence of palatal fistulae. The 2 cohorts are randomized to undergo either a conventional von Langenbeck repair with intravelar velarplasty or the double-opposing Z-plasty Furlow procedure. A prospective 2 × 2 × 2 factorial clinical trial was used in which each subject was randomly assigned to 1 of 8 different groups: 1 of 2 different lip repairs (Spina vs. Millard), 1 of 2 different palatal repair (von Langenbeck vs. Furlow), and 1 of 2 different ages at time of palatal surgery (9-12 months vs. 15-18 months). All surgeries were performed by the same 4 surgeons. A cul-de-sac test of hypernasality and a mirror test of nasal air emission were selected as primary outcome measures for velopharyngeal function. Both a surgeon and speech pathologist examined patients for the presence of palatal fistulae. In this study, the Furlow double-opposing Z-palatoplasty resulted in significantly better velopharyngeal function for speech than the von Langenbeck procedure as determined by the perceptual cul-de-sac test of hypernasality. Fistula occurrence was significantly higher for the Furlow procedure than for the von Langenbeck. Fistulas were more likely to occur in patients with wider clefts and when relaxing incisions were not used.


Assuntos
Fenda Labial/cirurgia , Fissura Palatina/cirurgia , Palato/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Humanos , Lactente , Estudos Prospectivos , Resultado do Tratamento
20.
Cleft Palate Craniofac J ; 48(4): 412-8, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20536371

RESUMO

OBJECTIVE: Cleft palate increases the risk of chronic middle ear disease and hearing loss. The goal of this report was to determine which of two palate surgeries and which timing of palate surgery were associated with better otologic and audiologic outcomes in children with unilateral cleft lip and palate at 5 to 6 years of age. DESIGN: Subjects were randomly assigned to the von Langenbeck with intravelar veloplasty or Furlow palate repair, to palate surgery at 9 to 12 months or 15 to 18 months of age, and to the Spina or Millard lip repair. SETTING: Centralized, tertiary care craniofacial treatment center. PATIENTS: A total of 673 infants with unilateral cleft lip and palate. INTERVENTIONS: Palate and lip were repaired using established techniques. Serial otoscopic and audiometric evaluations were performed. MAIN OUTCOME MEASURES: Hearing and otoscopic findings at 5 to 6 years old. RESULTS: There were 370 children available for analysis. Hearing and need for tympanostomy tube placement did not differ by palatoplasty, age at palatoplasty, cheiloplasty, or surgeon. Risk of developing cholesteatoma or perforation was higher with Millard cheiloplasty (odds ratio  =  5.1, 95% confidence interval  =  1.44 to 18.11, p  =  .012). Type and age at palatoplasty were not significantly associated with either the rate of developing these sequelae or the rate of achieving bilaterally normal hearing and ear examinations. CONCLUSIONS: Type of palatoplasty did not influence otologic and audiologic outcomes in 5- to 6-year-olds with unilateral cleft lip and palate. The potential influence of lip repair on otologic outcomes warrants further investigation.


Assuntos
Fenda Labial/cirurgia , Fissura Palatina/cirurgia , Otopatias/etiologia , Orelha Média/fisiologia , Perda Auditiva/etiologia , Procedimentos de Cirurgia Plástica/métodos , Testes de Impedância Acústica/métodos , Fatores Etários , Audiometria de Tons Puros/métodos , Colesteatoma da Orelha Média/etiologia , Método Duplo-Cego , Feminino , Seguimentos , Perda Auditiva Condutiva/etiologia , Humanos , Lactente , Masculino , Ventilação da Orelha Média , Otite Média com Derrame/etiologia , Otoscopia/métodos , Palato Mole/cirurgia , Estudos Prospectivos , Resultado do Tratamento , Perfuração da Membrana Timpânica/etiologia
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