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1.
Br J Clin Pharmacol ; 90(1): 274-285, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37621050

RESUMO

AIMS: This phase I study investigated potential drug-drug interactions of the maturation inhibitor GSK3640254 (GSK'254) with darunavir/ritonavir (DRV/RTV) and/or etravirine (ETR). METHODS: In this randomized, open-label, single-sequence, multiple-dose study, healthy participants received GSK'254 200 mg once daily alone or coadministered with DRV/RTV 600/100 mg twice daily (BID; n = 19), ETR 200 mg BID (n = 19) or DRV/RTV 600/100 mg + ETR 200 mg BID (n = 16) under fed conditions. Primary endpoints were steady-state area under the plasma concentration-time curve from time 0 to the end of the dosing interval (AUC0-τ ) and maximum observed concentration (Cmax ). Secondary endpoints included trough concentration (Cτ ), safety and tolerability. Pharmacokinetic parameters were calculated using standard noncompartmental analysis, and geometric least-squares mean ratios were derived from linear mixed-effects models. RESULTS: GSK'254 AUC0-τ (geometric least-squares mean ratio [90% confidence interval], 1.14 [1.00-1.29]), Cmax (1.07 [0.92-1.24]) and Cτ (1.17 [1.01-1.35]) were similar when administered alone and with DRV/RTV. Etravirine coadministration decreased GSK'254 AUC0-τ (0.53 [0.48-0.59]), Cmax (0.60 [0.53-0.68]) and Cτ (0.51 [0.39-0.66]). Similar reductions were not observed with GSK'254 + DRV/RTV + ETR (AUC0-τ , 0.94 [0.82-1.09]; Cmax , 0.89 [0.75-1.07]; Cτ , 1.02 [0.89-1.18]). GSK'254 had no meaningful effect on DRV/RTV or ETR concentrations. All reported adverse events (AEs) were grade 1; 3 led to withdrawal and resolved (rash, asymptomatic electrocardiogram T-wave inversion, periorbital oedema). Most common AEs were diarrhoea (n = 9) and headache (n = 7). No deaths or serious AEs occurred. CONCLUSION: GSK'254 pharmacokinetics was not meaningfully affected by DRV/RTV or DRV/RTV + ETR, but were reduced with only ETR; no new tolerability concerns were observed.


Assuntos
Fármacos Anti-HIV , Ritonavir , Adulto , Humanos , Darunavir , Sulfonamidas , Interações Medicamentosas
2.
Angew Chem Int Ed Engl ; 62(27): e202304197, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37133456

RESUMO

Large graphene-like molecules with four zigzag edges are ideal gain medium materials for organic near-infrared (NIR) lasers. However, synthesizing them becomes increasingly challenging as the molecular size increases. In this study, we introduce a new intramolecular radical-radical coupling approach and successfully synthesize two fused triangulene dimers (1 a/1 b) efficiently. X-ray crystallographic analysis of 1 a indicates that there is no intermolecular π-π stacking in the solid state. When the more soluble derivative 1 b is dispersed in polystyrene thin films, amplified spontaneous emission in the NIR region is observed. Using 1 b as the active gain material, we fabricate solution-processed distributed feedback lasers that exhibit a narrow emission linewidth at around 790 nm. The laser devices also exhibit low thresholds with high photostability. Our study provides a new synthetic strategy for extended nanographenes, which have diverse applications in electronics and photonics.

3.
Eur J Pediatr ; 180(9): 2879-2888, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33791862

RESUMO

Latin America (LATAM) children offer special insight into Severe Acute Respiratory Syndrome Coronavirus 2 (SARS COV2) due to high-risk race/ethnicity, variability in medical resources, diverse socioeconomic background, and numerous involved organ systems. This multinational study of LATAM youth examined the distinguishing features of acute or late multisystem SARS COV2 with versus without cardiac involvement. A consecutive sample of youth 0-18 years old (N = 98;50% male) presenting with multisystem SARS COV2 to 32 centers in 10 Latin American countries participating in a pediatric cardiac multi-imaging society were grouped as with versus without cardiac involvement, defined as abnormal echocardiographic findings or arrhythmia. Collected clinical data were analyzed by Student's t-test or Fisher's exact test. Cardiac (N = 48, 50% male) versus no cardiac (N = 50, 50% male) were similar in age; weight; nonrespiratory symptoms; and medical history. The cardiac group had 1 death and symptoms including coronary artery dilation, ejection fraction <50%, pericardial effusion, peripheral edema, arrhythmia, and pulmonary artery thrombus. The cardiac group had higher risk of ICU admission (77% vs 54%, p = 0.02); invasive ventilation (23% vs 4%,p = 0.007); vasoactive infusions (27% vs 4%, p = 0.002); prominent respiratory symptoms (60% vs 36%, p < 0.03); abnormal chest imaging (69% vs 34%, p = 0.001); troponin (33% vs 12%, p = 0.01); alanine aminotransferase (33% vs 12%, p = 0.02); and thrombocytopenia (46% vs 22%, p = 0.02). Receiver operating curve analysis showed that abnormal laboratories had 94% sensitivity and 98% negative predictive value on the need for ICU interventions.Conclusion: In LATAM children with multisystem SARS COV2, cardiac involvement was prevalent. Cardiac involvement was more likely to require ICU interventions, certain abnormal labs, and respiratory involvement. What is Known: • SARS COV2 can be asymptomatic in children but in some cases can have serious multisystemic involvement. • Hispanic ethnicity is purportedly at high risk of SARS COV2 in nations where they are often disadvantaged minority populations. What is New: • Latin American children presenting with multisystem SARS COV2 frequently have cardiac involvement which was associated with ICU interventions; prominent respiratory symptoms; abnormal chest X-ray; elevated troponin, ALT, and thrombocytopenia. • Elevated troponin, ALT or thrombocytopenia had high sensitivity and negative predictive value on the need for intensive care interventions.


Assuntos
COVID-19 , SARS-CoV-2 , Adolescente , Arritmias Cardíacas , Criança , Pré-Escolar , Cuidados Críticos , Feminino , Humanos , Lactente , Recém-Nascido , América Latina/epidemiologia , Masculino
4.
Bioinformatics ; 33(19): 3145-3147, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28957496

RESUMO

SUMMARY: To expedite the review of semi-automated probability maps of organelles and other features from 3D electron microscopy data we have developed Probability Map Viewer, a Java-based web application that enables the computation and visualization of probability map generation results in near real-time as the data are being collected from the microscope. Probability Map Viewer allows the user to select one or more voxel classifiers, apply them on a sub-region of an active collection, and visualize the results as overlays on the raw data via any web browser using a personal computer or mobile device. Thus, Probability Map Viewer accelerates and informs the image analysis workflow by providing a tool for experimenting with and optimizing dataset-specific segmentation strategies during imaging. AVAILABILITY AND IMPLEMENTATION: https://github.com/crbs/probabilitymapviewer. CONTACT: mellisman@ucsd.edu. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Microscopia Eletrônica/métodos , Software , Organelas/ultraestrutura , Probabilidade , Fluxo de Trabalho
5.
Nanoscale ; 16(2): 664-677, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38100059

RESUMO

Graphene-based solution-gated field-effect transistors (gSGFETs) allow the quantification of the brain's full-band signal. Extracellular alternating current (AC) signals include local field potentials (LFP, population activity within a reach of hundreds of micrometers), multiunit activity (MUA), and ultimately single units. Direct current (DC) potentials are slow brain signals with a frequency under 0.1 Hz, and commonly filtered out by conventional AC amplifiers. This component conveys information about what has been referred to as "infraslow" activity. We used gSGFET arrays to record full-band patterns from both physiological and pathological activity generated by the cerebral cortex. To this end, we used an in vitro preparation of cerebral cortex that generates spontaneous rhythmic activity, such as that occurring in slow wave sleep. This examination extended to experimentally induced pathological activities, including epileptiform discharges and cortical spreading depression. Validation of recordings obtained via gSGFETs, including both AC and DC components, was accomplished by cross-referencing with well-established technologies, thereby quantifying these components across different activity patterns. We then explored an additional gSGFET potential application, which is the measure of externally induced electric fields such as those used in therapeutic neuromodulation in humans. Finally, we tested the gSGFETs in human cortical slices obtained intrasurgically. In conclusion, this study offers a comprehensive characterization of gSGFETs for brain recordings, with a focus on potential clinical applications of this emerging technology.


Assuntos
Grafite , Humanos , Córtex Cerebral , Encéfalo
6.
Proc Natl Acad Sci U S A ; 107(21): 9861-6, 2010 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-20457914

RESUMO

A striking but poorly understood feature of many diseases is the unique involvement of neural tissue. One example is the CNS-specific disorder DYT1 dystonia, caused by a 3-bp deletion ("DeltaE") in the widely expressed gene TOR1A. Disease mutant knockin mice (Tor1a(DeltaE/DeltaE)) exhibit disrupted nuclear membranes selectively in neurons, mimicking the tissue specificity of the human disease and providing a model system in which to dissect the mechanisms underlying neural selectivity. Our in vivo studies demonstrate that lamina-associated polypeptide 1 (LAP1) and torsinB function with torsinA to maintain normal nuclear membrane morphology. Moreover, we show that nonneuronal cells express dramatically higher levels of torsinB and that RNAi-mediated depletion of torsinB (but not other torsin family members) causes nuclear membrane abnormalities in Tor1a(DeltaE/DeltaE) nonneuronal cells. The Tor1a(DeltaE/DeltaE) neural selective phenotype therefore arises because high levels of torsinB protect nonneuronal cells from the consequences of torsinA dysfunction, demonstrating how tissue specificity may result from differential susceptibility of cell types to insults that disrupt ubiquitous biological pathways.


Assuntos
Chaperonas Moleculares/metabolismo , Mutação , Neurônios/metabolismo , Animais , Células Cultivadas , Feminino , Masculino , Camundongos , Microscopia Eletrônica , Chaperonas Moleculares/genética , Neurônios/ultraestrutura , Interferência de RNA
7.
Clin Pharmacol Drug Dev ; 12(6): 594-601, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36808268

RESUMO

Rimegepant is an oral small-molecule calcitonin gene-related peptide antagonist for acute migraine treatment with or without aura and prevention of episodic migraine in adults. This was a rimegepant single- and multiple-dose phase 1, randomized, placebo-controlled, double-blind study to evaluate the pharmacokinetics and confirm safety in healthy Chinese participants. Participants received a 75-mg rimegepant orally disintegrating tablet (ODT) (N = 12) or matching placebo (N = 4) ODT on days 1 and 3-7 after fasting for pharmacokinetic assessments. Safety assessments included 12-lead electrocardiograms, vital signs, clinical laboratory data, and adverse events (AEs). After a single dose (9 females, 7 males) median time to maximum plasma concentration was 1.5 hours; mean values were 937 ng/mL (maximum concentration), 4582 h*ng/mL (area under the concentration-time curve, 0 to infinity), 7.7 hours (terminal elimination half-life), and 19.9 L/h (apparent clearance). Similar results were seen after 5 daily doses, with minimal accumulation. Six (37.5%) participants experienced ≥1 treatment-emergent AE: 4 (33.3%) had received rimegepant and 2 (50.0%) had received placebo. All AEs were grade 1 and resolved by the end of the study with no deaths, serious/significant AEs, or AEs leading to discontinuation. Overall, single- and multiple-dose rimegepant ODT 75 mg was safe and well-tolerated in healthy Chinese adults with similar pharmacokinetics to non-Asian healthy participants. Trial registration: This trial is registered with the China Center for Drug Evaluation (CDE): CTR20210569.


Assuntos
Transtornos de Enxaqueca , Adulto , Feminino , Humanos , Masculino , Administração Oral , População do Leste Asiático , Transtornos de Enxaqueca/tratamento farmacológico , Comprimidos
8.
bioRxiv ; 2023 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-37066274

RESUMO

Perineuronal nets (PNN), a specialized form of ECM (?), surround numerous neurons in the CNS and allow synaptic connectivity through holes in its structure. We hypothesis that PNNs serve as gatekeepers that guard and protect synaptic territory, and thus may stabilize an engram circuit. We present high-resolution, and 3D EM images of PNN- engulfed neurons showing that synapses occupy the PNN holes, and that invasion of other cellular components are rare. PNN constituents are long-lived and can be eroded faster in an enriched environment, while synaptic proteins have high turnover rate. Preventing PNN erosion by using pharmacological inhibition of PNN-modifying proteases or MMP9 knockout mice allowed normal fear memory acquisition but diminished remote-memory stabilization, supporting the above hypothesis. Significance: In this multidisciplinary work, we challenge the hypothesis that the pattern of holes in the perineuronal nets (PNN) hold the code for very-long-term memories. The scope of this work might lead us closer to the understanding of how we can vividly remember events from childhood to death bed. We postulate that the PNN holes hold the code for the engram. To test this hypothesis, we used three independent experimental strategies; high-resolution 3D electron microscopy, Stable Isotop Labeling in Mammals (SILAM) for proteins longevity, and pharmacologically and genetically interruption of memory consolidation in fear conditioning experiments. All of these experimental results did not dispute the PNN hypothesis.

9.
Mol Vis ; 18: 3029-48, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23288995

RESUMO

PURPOSE: Postnatal lead exposure produces rod-selective and Bax-mediated apoptosis, decreased scotopic electroretinograms (ERGs), and scotopic and mesopic vision deficits in humans and/or experimental animals. Rod, but not cone, inner segment mitochondria were considered the primary site of action. However, photoreceptor synaptic mitochondria were not examined. Thus, our experiments investigated the structural and functional effects of environmentally relevant postnatal lead exposure on rod spherule and cone pedicle mitochondria and whether Bcl-xL overexpression provided neuroprotection. METHODS: C57BL/6N mice pups were exposed to lead only during lactation via dams drinking water containing lead acetate. The blood [Pb] at weaning was 20.6±4.7 µg/dl, which decreased to the control value by 2 months. To assess synaptic mitochondrial structural differences and vulnerability to lead exposure, wild-type and transgenic mice overexpressing Bcl-xL in photoreceptors were used. Electron microscopy, three-dimensional electron tomography, and retinal and photoreceptor synaptic terminal oxygen consumption (QO(2)) studies were conducted in adult control, Bcl-xL, lead, and Bcl-xL/lead mice. RESULTS: The spherule and pedicle mitochondria in lead-treated mice were swollen, and the cristae structure was markedly changed. In the lead-treated mice, the mitochondrial cristae surface area and volume (abundance: measure correlated with ATP (ATP) synthesis) were decreased in the spherules and increased in the pedicles. Pedicles also had an increased number of crista segments per volume. In the lead-treated mice, the number of segments/crista and fraction of cristae with multiple segments (branching) similarly increased in spherule and pedicle mitochondria. Lead-induced remodeling of spherule mitochondria produced smaller cristae with more branching, whereas pedicle mitochondria had larger cristae with more branching and increased crista junction (CJ) diameter. Lead decreased dark- and light-adapted photoreceptor and dark-adapted photoreceptor synaptic terminal QO(2). Bcl-xL partially blocked many of the lead-induced alterations relative to controls. However, spherules still had partially decreased abundance, whereas pedicles still had increased branching, increased crista segments per volume, and increased crista junction diameter. Moreover, photoreceptor and synaptic QO(2) were only partially recovered. CONCLUSIONS: These findings reveal cellular and compartmental specific differences in the structure and vulnerability of rod and cone inner segment and synaptic mitochondria to postnatal lead exposure. Spherule and pedicle mitochondria in lead-exposed mice displayed complex and distinguishing patterns of cristae and matrix damage and remodeling consistent with studies showing that synaptic mitochondria are more sensitive to Ca(2+) overload, oxidative stress, and ATP loss than non-synaptic mitochondria. The lead-induced decreases in QO(2) likely resulted from the decreased spherule cristae abundance and smaller cristae, perhaps due to Bax-mediated effects as they occurred in apoptotic rod inner segments. The increase in pedicle cristae abundance and CJ diameter could have resulted from increased Drp1-mediated fission, as small mitochondrial fragments were observed. The mechanisms of Bcl-xL-mediated remodeling might occur via interaction with formation of CJ protein 1 (Fcj1), whereas the partial protection of synaptic QO(2) might result from the enhanced efficiency of energy metabolism via Bcl-xL's direct interaction with the F1F0 ATP synthase and/or regulation of cellular redox status. These lead-induced alterations in photoreceptor synaptic terminal mitochondria likely underlie the persistent scotopic and mesopic deficits in lead-exposed children, workers, and experimental animals. Our findings stress the clinical and scientific importance of examining synaptic dysfunction following injury or disease during development, and developing therapeutic treatments that prevent synaptic degeneration in retinal and neurodegenerative disorders even when apoptosis is blocked.


Assuntos
Exposição Ambiental , Mitocôndrias/efeitos dos fármacos , Compostos Organometálicos/toxicidade , Células Fotorreceptoras Retinianas Cones/efeitos dos fármacos , Células Fotorreceptoras Retinianas Bastonetes/efeitos dos fármacos , Sinapses/efeitos dos fármacos , Proteína bcl-X/genética , Adaptação Ocular/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Cálcio/metabolismo , Adaptação à Escuridão/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Lactação , Camundongos , Camundongos Transgênicos , Microscopia Eletrônica , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , ATPases Mitocondriais Próton-Translocadoras/genética , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Estresse Oxidativo , Consumo de Oxigênio , Células Fotorreceptoras Retinianas Cones/metabolismo , Células Fotorreceptoras Retinianas Cones/ultraestrutura , Células Fotorreceptoras Retinianas Bastonetes/metabolismo , Células Fotorreceptoras Retinianas Bastonetes/ultraestrutura , Transdução de Sinais/efeitos dos fármacos , Sinapses/metabolismo , Sinapses/ultraestrutura , Tomografia Computadorizada por Raios X , Proteína bcl-X/metabolismo
10.
Microorganisms ; 10(11)2022 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-36363700

RESUMO

Cacao plant cadmium accumulation has become a major concern, especially for small Amazonian producers. A sustainable alternative to address its toxicity is the use of cadmium removal bacteria. In this regard, 138 rhizosphere isolates from cacao were examined. Supported by their phenotypic characterization and in vitro cadmium tolerance, three hypertolerant bacteria were selected and identified as members of the Bacillus (S1C2, R1C2) and Pseudomonas (V3C3) genera. They were able to grow normally and reduce the cadmium content under in vitro conditions. However, only S1C2 and R1C2 evidenced to employ intracellular Cd2+ accumulation, suggesting the variability of bacterial detoxification mechanisms. Their bioremediation capacity for Theobroma cacao CCN51 was also analyzed. Surprisingly, we found high detectable levels of Cd2+ in the non-cadmium supplemented control, suggesting an extra source of cadmium in the pot. Moreover, despite their cadmium reduction performance under in vitro conditions, they exerted highly variable outcomes on stem cadmium accumulation. While S1C2 and R1C2 showed a considerable reduction of Cd content in cacao stems, the strain V3C3 did not show any effect on Cd content. This highlights the complexity of the plant-bacteria interactions and the importance of the in vivo test for the selection of promising PGPR bacteria. Overall, our results suggest the cadmium alleviation potential and promising prospects of native Bacillus strains associated with Amazonian cacao.

11.
Front Psychiatry ; 11: 174, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32256404

RESUMO

Cerebellum plays a role in the regulation of cognitive processes. Cerebellar alterations could explain cognitive impairments in schizophrenia. We describe the case of a 50 years old patient with schizophrenia whom underwent cerebellar transcranial direct current stimulation (tDCS). In order to study the effect of cerebellar stimulation on cognitive functions, the patient underwent a neuropsychological assessment and an eyeblink conditioning (EBC) protocol. Although the effect of brain stimulation cannot be only assessed in a single-case study, our results suggest that cerebellar stimulation may have an effect on a broad range of cognitive functions typically impaired in patients with schizophrenia, including verbal episodic, short term, and working memory. In addition to neuropsychological tests, we evaluated the cerebellar function by performing EBC before and after tDCS. Our data suggest that tDCS can improve EBC. Further clinical trials are required for better understanding of how cerebellar stimulation can modulate cognitive processes in patients with schizophrenia and healthy controls.

12.
Cell Rep ; 29(3): 628-644.e6, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31618632

RESUMO

The form and synaptic fine structure of melanopsin-expressing retinal ganglion cells, also called intrinsically photosensitive retinal ganglion cells (ipRGCs), were determined using a new membrane-targeted version of a genetic probe for correlated light and electron microscopy (CLEM). ipRGCs project to multiple brain regions, and because the method labels the entire neuron, it was possible to analyze nerve terminals in multiple retinorecipient brain regions, including the suprachiasmatic nucleus (SCN), olivary pretectal nucleus (OPN), and subregions of the lateral geniculate. Although ipRGCs provide the only direct retinal input to the OPN and SCN, ipRGC terminal arbors and boutons were found to be remarkably different in each target region. A network of dendro-dendritic chemical synapses (DDCSs) was also revealed in the SCN, with ipRGC axon terminals preferentially synapsing on the DDCS-linked cells. The methods developed to enable this analysis should propel other CLEM studies of long-distance brain circuits at high resolution.


Assuntos
Encéfalo/metabolismo , Células Ganglionares da Retina/metabolismo , Opsinas de Bastonetes/metabolismo , Sinapses/metabolismo , Animais , Axônios/fisiologia , Encéfalo/patologia , Ritmo Circadiano/fisiologia , Feminino , Masculino , Camundongos , Camundongos Knockout , Microscopia Eletrônica , Área Pré-Tectal/metabolismo , Área Pré-Tectal/patologia , Células Ganglionares da Retina/patologia , Opsinas de Bastonetes/deficiência , Opsinas de Bastonetes/genética , Núcleo Supraquiasmático/metabolismo , Núcleo Supraquiasmático/patologia
13.
J Struct Biol ; 161(3): 469-80, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18096402

RESUMO

The node of Ranvier is a site for ionic conductances along myelinated nerves and governs the saltatory transmission of action potentials. Defects in the cross-bridging and spacing of the cytoskeleton are a prominent pathological feature in diseases of the peripheral nerve. Electron tomography was used to examine cytoskeletal-cytoskeletal, membrane-cytoskeletal, and heterologous cell connections in the paranodal region of the node of Ranvier in peripheral nerves. Focal attachment of cytoskeletal filaments to each other and to the axolemma and paranodal membranes of the Schwann cell via narrow cross-bridges was visualized in both neuronal and glial cytoplasm. A subset of intermediate filaments associates with the cytoplasmic surfaces of supramolecular complexes of transmembrane structures that are presumed to include known and unknown junctional proteins. Mitochondria were linked to both microtubules and neurofilaments in the axoplasm and to neighboring smooth endoplasmic reticulum by narrow cross-bridges. Tubular cisternae in the glial cytoplasm were also linked to the paranodal glial cytoplasmic loop juxtanodal membrane by short cross-bridges. In the extracellular matrix between axon and Schwann cell, junctional bridges formed long cylinders linking the two membranes. Interactions between cytoskeleton, membranes, and extracellular matrix associations in the paranodal region are likely critical not only for scaffolding, but also for intracellular and extracellular communication.


Assuntos
Citoesqueleto/ultraestrutura , Nervos Periféricos/ultraestrutura , Nós Neurofibrosos/diagnóstico por imagem , Animais , Membrana Celular/ultraestrutura , Matriz Extracelular/ultraestrutura , Microscopia Eletrônica , Mitocôndrias/ultraestrutura , Ratos , Tomografia , Ultrassonografia
14.
Small ; 4(2): 262-9, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18200644

RESUMO

Metallic nanoparticles (NPs) can be used for the diagnosis, imaging, and therapy of tumors and cardiovascular disease. However, targeted delivery of NPs to specific cells remains a major limitation for clinical realization of these potential treatment options. Herein, a novel strategy for the specific coupling of NPs to a targeted adenoviral (Ad) platform to deliver NPs to specific cells is defined. Genetic manipulation of the gene-therapy vector is combined with a specific chemical coupling strategy. In particular, a high-affinity interaction between a sequence of six-histidine amino acid residues genetically incorporated into Ad capsid proteins and nickel(II) nitrilotriacetic acid on the surface of gold NPs is employed. The selective self-assembly of gold NPs and Ad vectors into multifunctional platforms does not negatively affect the targeting of Ad to specific cells. This opens the possibility of using Ad vectors for targeted NP delivery, thereby providing a new type of combinatorial approach for the treatment of diseases that involves both nanotechnology and gene therapy.


Assuntos
Adenoviridae/genética , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/química , Proteínas do Capsídeo/genética , Antígeno Carcinoembrionário/genética , Linhagem Celular , Expressão Gênica , Terapia Genética , Vetores Genéticos , Ouro , Células HeLa , Humanos , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Transmissão , Nanotecnologia , Espectrofotometria Atômica
15.
Mol Cell Biol ; 38(19)2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30012865

RESUMO

The organization of the five ß-type globin genes on chromosome 11 reflects the timing of expression during erythroid cell development, with the embryonic ε-globin gene being located at the 5' end, followed by the two fetal γ-globin genes, and with the adult ß- and δ-globin genes being located at the 3' end. Here, we functionally characterized a DNase I-hypersensitive site (HS) located 4 kb upstream of the Gγ-globin gene (HBG-4kb HS). This site is occupied by transcription factors USF1, USF2, EGR1, MafK, and NF-E2 in the human erythroleukemia cell line K562 and exhibits histone modifications typical for enhancers. We generated a synthetic zinc finger (ZF) DNA-binding domain targeting the HBG-4kb HS (HBG-4kb ZF). The HBG-4kb ZF interacted with the target site in vitro and in the context of cells with a high affinity and specificity. Direct delivery of the HBG-4kb ZF to K562 and primary human erythroid cells caused a reduction in γ-globin gene expression which was associated with decreased binding of transcription factors and active histone marks at and downstream of the HS. The data demonstrate that the HBG-4kb HS is important for fetal globin production and suggest that it may act by opening chromatin in a directional manner.


Assuntos
Cromatina/genética , gama-Globinas/genética , Desoxirribonuclease I , Elementos Facilitadores Genéticos , Eritropoese/genética , Regulação da Expressão Gênica no Desenvolvimento , Genes de Troca , Código das Histonas/genética , Humanos , Células K562 , Modelos Genéticos , Polimorfismo de Nucleotídeo Único , RNA/genética , RNA/metabolismo , gama-Globinas/metabolismo
16.
Front Neurosci ; 12: 862, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30555290

RESUMO

Developing new standardized tools to characterize brain recording devices is critical to evaluate neural probes and for translation to clinical use. The signal-to-noise ratio (SNR) measurement is the gold standard for quantifying the performance of brain recording devices. Given the drawbacks with the SNR measure, our first objective was to devise a new method to calculate the SNR of neural signals to distinguish signal from noise. Our second objective was to apply this new SNR method to evaluate electrodes of three different materials (platinum black, Pt; carbon nanotubes, CNTs; and gold, Au) co-localized in tritrodes to record from the same cortical area using specifically designed multielectrode arrays. Hence, we devised an approach to calculate SNR at different frequencies based on the features of cortical slow oscillations (SO). Since SO consist in the alternation of silent periods (Down states) and active periods (Up states) of neuronal activity, we used these as noise and signal, respectively. The spectral SNR was computed as the power spectral density (PSD) of Up states (signal) divided by the PSD of Down states (noise). We found that Pt and CNTs electrodes have better recording performance than Au electrodes for the explored frequency range (5-1500 Hz). Together with two proposed SNR estimators for the lower and upper frequency limits, these results substantiate our SNR calculation at different frequency bands. Our results provide a new validated SNR measure that provides rich information of the performance of recording devices at different brain activity frequency bands (<1500 Hz).

17.
Rev Gastroenterol Mex ; 70(3): 284-90, 2005.
Artigo em Espanhol | MEDLINE | ID: mdl-17063784

RESUMO

UNLABELLED: Clinical manifestations of hemorrhoidal disease depend on its location (internal or external) and the presence or not of complications. PURPOSE: To describe the results of the three most common alternatives for non-surgical procedures treating internal hemorrhoids: rubber band ligation, esclerotherapy and infrared photocoagulation. MATERIALS AND METHODS: A retrospective, longitudinal and descriptive study from January 1998 to December 2002 was carried out, including variables like age, gender, clinical manifestations and date of initiation, type of non-surgical alternative treatment, complications, management and stage of the illness. RESULTS: In 9,103 charts reviewed this study included 2,701 patients with hemorrhoidal disease, with an annual incidence of 540.20 patients; 1,388 (51.39%) were male and 1,313 (48.62%) were female; ages between 17 and 78 years, 44.10 as a mean age. Rubber band ligation was used in 516 patients (67.45%), esclerotherapy in 177 (23.13%) and infrared photocoagulation in 72 cases (9.41%). CONCLUSIONS: Rubber band ligation is mainly indicated for internal hemorrhoids II degree, the esclerotherapy is indicated in the suppression of acute hemorrhage, but in the long term, this method has the poorest results. Infrared photocoagulation has its best results in internal hemorrhoids I degree because it causes less pain and complications and patients accept it better.


Assuntos
Hemorroidas/terapia , Fotocoagulação , Escleroterapia , Adolescente , Adulto , Idoso , Feminino , Humanos , Ligadura , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
18.
Nat Neurosci ; 18(8): 1077-80, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26120963

RESUMO

Astrocytes modulate neuronal activity and inhibit regeneration. We show that cleaved p75 neurotrophin receptor (p75(NTR)) is a component of the nuclear pore complex (NPC) required for glial scar formation and reduced gamma oscillations in mice via regulation of transforming growth factor (TGF)-ß signaling. Cleaved p75(NTR) interacts with nucleoporins to promote Smad2 nucleocytoplasmic shuttling. Thus, NPC remodeling by regulated intramembrane cleavage of p75(NTR) controls astrocyte-neuronal communication in response to profibrotic factors.


Assuntos
Astrócitos/metabolismo , Ritmo Gama/fisiologia , Atividade Motora/fisiologia , Poro Nuclear/metabolismo , Receptor de Fator de Crescimento Neural/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo , Animais , Comportamento Animal/fisiologia , Eletroencefalografia , Gliose/metabolismo , Células HEK293 , Humanos , Hidrocefalia/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células NIH 3T3 , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Receptor de Fator de Crescimento Neural/deficiência , Proteína Smad2/metabolismo
19.
Front Neuroanat ; 8: 126, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25426032

RESUMO

Electron microscopy (EM) facilitates analysis of the form, distribution, and functional status of key organelle systems in various pathological processes, including those associated with neurodegenerative disease. Such EM data often provide important new insights into the underlying disease mechanisms. The development of more accurate and efficient methods to quantify changes in subcellular microanatomy has already proven key to understanding the pathogenesis of Parkinson's and Alzheimer's diseases, as well as glaucoma. While our ability to acquire large volumes of 3D EM data is progressing rapidly, more advanced analysis tools are needed to assist in measuring precise three-dimensional morphologies of organelles within data sets that can include hundreds to thousands of whole cells. Although new imaging instrument throughputs can exceed teravoxels of data per day, image segmentation and analysis remain significant bottlenecks to achieving quantitative descriptions of whole cell structural organellomes. Here, we present a novel method for the automatic segmentation of organelles in 3D EM image stacks. Segmentations are generated using only 2D image information, making the method suitable for anisotropic imaging techniques such as serial block-face scanning electron microscopy (SBEM). Additionally, no assumptions about 3D organelle morphology are made, ensuring the method can be easily expanded to any number of structurally and functionally diverse organelles. Following the presentation of our algorithm, we validate its performance by assessing the segmentation accuracy of different organelle targets in an example SBEM dataset and demonstrate that it can be efficiently parallelized on supercomputing resources, resulting in a dramatic reduction in runtime.

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