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1.
Int Urogynecol J ; 34(9): 2197-2206, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37042972

RESUMO

INTRODUCTION AND HYPOTHESIS: The purpose was to investigate the safety and feasibility of transurethral injections of autologous muscle precursor cells (MPCs) into the external urinary sphincter (EUS) to treat stress urinary incontinence (SUI) in female patients. METHODS: Prospective and randomised phase I clinical trial. Standardised 1-h pad test, International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI-SF), urodynamic study, and MRI of the pelvis were performed at baseline and 6 months after treatment. MPCs gained through open muscle biopsy were transported to a GMP facility for processing and cell expansion. The final product was injected into the EUS via a transurethral ultrasound-guided route. Primary outcomes were defined as any adverse events (AEs) during follow-up. Secondary outcomes were functional, questionnaire, and radiological results. RESULTS: Ten female patients with SUI grades I-II were included in the study and 9 received treatment. Out of 8 AEs, 3 (37.5%) were potentially related to treatment and treated conservatively: 1 urinary tract infection healed with antibiotics treatment, 1 dysuria and 1 discomfort at biopsy site. Functional urethral length under stress was 25 mm at baseline compared with 30 mm at 6 months' follow-up (p=0.009). ICIQ-UI-SF scores improved from 7 points at baseline to 4 points at follow-up (p=0.035). MRI of the pelvis revealed no evidence of tumour or necrosis, whereas the diameter of the EUS muscle increased from 1.8 mm at baseline to 1.9 mm at follow-up (p=0.009). CONCLUSION: Transurethral injections of autologous MPCs into the EUS for treatment of SUI in female patients can be regarded as safe and feasible. Only a minimal number of expected and easily treatable AEs were documented.


Assuntos
Incontinência Urinária por Estresse , Incontinência Urinária , Humanos , Feminino , Incontinência Urinária por Estresse/terapia , Estudos Prospectivos , Uretra/diagnóstico por imagem , Músculos , Resultado do Tratamento
2.
Proc Natl Acad Sci U S A ; 114(46): 12285-12290, 2017 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-29087337

RESUMO

Neuroscientists have long debated whether some regions of the human brain are exclusively engaged in a single specific mental process. Consistent with this view, fMRI has revealed cortical regions that respond selectively to certain stimulus classes such as faces. However, results from multivoxel pattern analyses (MVPA) challenge this view by demonstrating that category-selective regions often contain information about "nonpreferred" stimulus dimensions. But is this nonpreferred information causally relevant to behavior? Here we report a rare opportunity to test this question in a neurosurgical patient implanted for clinical reasons with strips of electrodes along his fusiform gyri. Broadband gamma electrocorticographic responses in multiple adjacent electrodes showed strong selectivity for faces in a region corresponding to the fusiform face area (FFA), and preferential responses to color in a nearby site, replicating earlier reports. To test the causal role of these regions in the perception of nonpreferred dimensions, we then electrically stimulated individual sites while the patient viewed various objects. When stimulated in the FFA, the patient reported seeing an illusory face (or "facephene"), independent of the object viewed. Similarly, stimulation of color-preferring sites produced illusory "rainbows." Crucially, the patient reported no change in the object viewed, apart from the facephenes and rainbows apparently superimposed on them. The functional and anatomical specificity of these effects indicate that some cortical regions are exclusively causally engaged in a single specific mental process, and prompt caution about the widespread assumption that any information scientists can decode from the brain is causally relevant to behavior.


Assuntos
Epilepsia Resistente a Medicamentos/diagnóstico por imagem , Reconhecimento Visual de Modelos , Lobo Temporal/diagnóstico por imagem , Adulto , Mapeamento Encefálico , Cor , Epilepsia Resistente a Medicamentos/patologia , Epilepsia Resistente a Medicamentos/fisiopatologia , Estimulação Elétrica , Eletrodos Implantados , Face/anatomia & histologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Estimulação Luminosa , Lobo Temporal/patologia , Lobo Temporal/fisiopatologia
3.
J Neurosci ; 36(5): 1682-97, 2016 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-26843649

RESUMO

The existence of color-processing regions in the human ventral visual pathway (VVP) has long been known from patient and imaging studies, but their location in the cortex relative to other regions, their selectivity for color compared with other properties (shape and object category), and their relationship to color-processing regions found in nonhuman primates remain unclear. We addressed these questions by scanning 13 subjects with fMRI while they viewed two versions of movie clips (colored, achromatic) of five different object classes (faces, scenes, bodies, objects, scrambled objects). We identified regions in each subject that were selective for color, faces, places, and object shape, and measured responses within these regions to the 10 conditions in independently acquired data. We report two key findings. First, the three previously reported color-biased regions (located within a band running posterior-anterior along the VVP, present in most of our subjects) were sandwiched between face-selective cortex and place-selective cortex, forming parallel bands of face, color, and place selectivity that tracked the fusiform gyrus/collateral sulcus. Second, the posterior color-biased regions showed little or no selectivity for object shape or for particular stimulus categories and showed no interaction of color preference with stimulus category, suggesting that they code color independently of shape or stimulus category; moreover, the shape-biased lateral occipital region showed no significant color bias. These observations mirror results in macaque inferior temporal cortex (Lafer-Sousa and Conway, 2013), and taken together, these results suggest a homology in which the entire tripartite face/color/place system of primates migrated onto the ventral surface in humans over the course of evolution. SIGNIFICANCE STATEMENT: Here we report that color-biased cortex is sandwiched between face-selective and place-selective cortex on the bottom surface of the brain in humans. This face/color/place organization mirrors that seen on the lateral surface of the temporal lobe in macaques, suggesting that the entire tripartite system is homologous between species. This result validates the use of macaques as a model for human vision, making possible more powerful investigations into the connectivity, precise neural codes, and development of this part of the brain. In addition, we find substantial segregation of color from shape selectivity in posterior regions, as observed in macaques, indicating a considerable dissociation of the processing of shape and color in both species.


Assuntos
Mapeamento Encefálico/métodos , Percepção de Forma/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Estimulação Luminosa/métodos , Córtex Visual/fisiologia , Vias Visuais/fisiologia , Adulto , Animais , Reconhecimento Facial/fisiologia , Feminino , Humanos , Macaca , Masculino , Especificidade da Espécie , Adulto Jovem
4.
J Vis ; 17(12): 25, 2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-29090319

RESUMO

We present a full analysis of data from our preliminary report (Lafer-Sousa, Hermann, & Conway, 2015) and test whether #TheDress image is multistable. A multistable image must give rise to more than one mutually exclusive percept, typically within single individuals. Clustering algorithms of color-matching data showed that the dress was seen categorically, as white/gold (W/G) or blue/black (B/K), with a blue/brown transition state. Multinomial regression predicted categorical labels. Consistent with our prior hypothesis, W/G observers inferred a cool illuminant, whereas B/K observers inferred a warm illuminant; moreover, subjects could use skin color alone to infer the illuminant. The data provide some, albeit weak, support for our hypothesis that day larks see the dress as W/G and night owls see it as B/K. About half of observers who were previously familiar with the image reported switching categories at least once. Switching probability increased with professional art experience. Priming with an image that disambiguated the dress as B/K biased reports toward B/K (priming with W/G had negligible impact); furthermore, knowledge of the dress's true colors and any prior exposure to the image shifted the population toward B/K. These results show that some people have switched their perception of the dress. Finally, consistent with a role of attention and local image statistics in determining how multistable images are seen, we found that observers tended to discount as achromatic the dress component that they did not attend to: B/K reporters focused on a blue region, whereas W/G reporters focused on a golden region.


Assuntos
Percepção de Cores/fisiologia , Sinais (Psicologia) , Reconhecimento Psicológico/fisiologia , Adulto , Idoso , Algoritmos , Vestuário , Humanos , Iluminação/normas , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Análise de Regressão , Adulto Jovem
5.
Cereb Cortex ; 25(4): 959-71, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24122139

RESUMO

Over 40 years ago, Hubel and Wiesel gave a preliminary report of the first account of cells in monkey cerebral cortex selective for binocular disparity. The cells were located outside of V-1 within a region referred to then as "area 18." A full-length manuscript never followed, because the demarcation of the visual areas within this region had not been fully worked out. Here, we provide a full description of the physiological experiments and identify the locations of the recorded neurons using a contemporary atlas generated by functional magnetic resonance imaging; we also perform an independent analysis of the location of the neurons relative to an anatomical landmark (the base of the lunate sulcus) that is often coincident with the border between V-2 and V-3. Disparity-tuned cells resided not only in V-2, the area now synonymous with area 18, but also in V-3 and probably within V-3A. The recordings showed that the disparity-tuned cells were biased for near disparities, tended to prefer vertical orientations, clustered by disparity preference, and often required stimulation of both eyes to elicit responses, features strongly suggesting a role in stereoscopic depth perception.


Assuntos
Neurônios/fisiologia , Disparidade Visual/fisiologia , Córtex Visual/fisiologia , Potenciais de Ação , Animais , Atlas como Assunto , Macaca , Masculino , Microeletrodos , Estimulação Luminosa , Visão Binocular/fisiologia
6.
J Vis ; 14(8): 12, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-25027164

RESUMO

Macaque monkeys are a model of human color vision. To facilitate linking physiology in monkeys with psychophysics in humans, we directly compared color-detection thresholds in humans and rhesus monkeys. Colors were defined by an equiluminant plane of cone-opponent color space. All subjects were tested on an identical apparatus with a four-alternative forced-choice task. Targets were 2° square, centered 2° from fixation, embedded in luminance noise. Across all subjects, the change in detection thresholds from initial testing to plateau performance ("learning") was similar for +L − M (red) colors and +M − L (bluish-green) colors. But the extent of learning was higher for +S (lavender) than for −S (yellow-lime); moreover, at plateau performance, the cone contrast at the detection threshold was higher for +S than for −S. These asymmetries may reflect differences in retinal circuitry for S-ON and S-OFF. At plateau performance, the two species also had similar detection thresholds for all colors, although monkeys had shorter reaction times than humans and slightly lower thresholds for colors that modulated L/M cones. We discuss whether these observations, together with previous work showing that monkeys have lower spatial acuity than humans, could be accounted for by selective pressures driving higher chromatic sensitivity at the cost of spatial acuity amongst monkeys, specifically for the more recently evolved L − M mechanism.


Assuntos
Percepção de Cores/fisiologia , Limiar Sensorial/fisiologia , Animais , Sensibilidades de Contraste/fisiologia , Feminino , Humanos , Macaca mulatta , Masculino , Psicofísica , Células Fotorreceptoras Retinianas Cones/fisiologia
7.
ACS Omega ; 9(21): 22777-22793, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38826533

RESUMO

Malaria, caused by Plasmodium protozoa with Plasmodium falciparum as the most virulent species, continues to pose significant health challenges. Despite the availability of effective antimalarial drugs, the emergence of resistance has heightened the urgency for developing novel therapeutic compounds. In this study, we investigated the enoyl-ACP reductase enzyme of P. falciparum (PfENR) as a promising target for antimalarial drug discovery. Through a comprehensive analysis, we conducted a comparative evaluation of two lead compounds, LD1 (CID: 44405336, lead compounds 1) and LD2 (CID: 72703246, lead compounds 2), obtained from the PubChem/NCBI ligand database, to serve as reference molecules in the identification of potential derivatives using virtual screening assays. Among the newly identified candidates, Ligand 1 (LG1) and Ligand 2 (LG2) exhibited intriguing characteristics and underwent further investigation through docking and molecular dynamics simulations. Ligand 1 (LG1) demonstrated interactions similar to LD1, including hydrogen bonding with Asp218, while Ligand 2 (LG2) displayed superior binding energy comparable to LD1 and LD2, despite lacking hydrogen bonding interactions observed in the control compounds triclosan and its derivative 7-(4-chloro-2-hydroxyphenoxy)-4-methyl-2H-chromen-2-one (CHJ). Following computational validation using the MM/GBSA method to estimate binding free energy, commercially acquired LG1 and LG2 ligands were subjected to in vitro testing. Inhibition assays were performed to evaluate their potential as PfENR inhibitors alongside triclosan as a control compound. LG1 exhibited no inhibitory effects, while LG2 demonstrated inhibitory effects like triclosan. In conclusion, this study contributes valuable insights into developing novel antimalarial drugs by identifying LG2 as a potential ligand and employing a comprehensive approach integrating computational and experimental methodologies.

8.
Sci Rep ; 14(1): 9655, 2024 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-38671016

RESUMO

The manufacturing of mRNA vaccines relies on cell-free based systems that are easily scalable and flexible compared with the traditional vaccine manufacturing processes. Typically, standard processes yield 2 to 5 g L-1 of mRNA, with recent process optimisations increasing yields to 12 g L-1. However, increasing yields can lead to an increase in the production of unwanted by-products, namely dsRNA. It is therefore imperative to reduce dsRNA to residual levels in order to avoid intensive purification steps, enabling cost-effective manufacturing processes. In this work, we exploit sequence modifications downstream of the T7 RNA polymerase promoter to increase mRNA yields whilst simultaneously minimising dsRNA. In particular, transcription performance was optimised by modifying the sequence downstream of the T7 promoter with additional AT-rich sequences. We have identified variants that were able to produce higher amounts of mRNA (up to 14 g L-1) in 45 min of reaction. These variants exhibited up to a 30% reduction in dsRNA byproduct levels compared to a wildtype T7 promoter, and have similar EGFP protein expression. The results show that optimising the non-coding regions can have an impact on mRNA production yields and quality, reducing overall manufacturing costs.


Assuntos
RNA Polimerases Dirigidas por DNA , Regiões Promotoras Genéticas , RNA Mensageiro , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Polimerases Dirigidas por DNA/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Proteínas Virais/genética , Proteínas Virais/metabolismo , Bacteriófago T7/genética , RNA de Cadeia Dupla/genética , RNA de Cadeia Dupla/metabolismo , Vacinas de mRNA
9.
ACS Omega ; 9(21): 22619-22624, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38826531

RESUMO

DNA origami is an emerging technology that can be used as a nanoscale platform in numerous applications ranging from drug delivery systems to biosensors. The DNA nanostructures are assembled from large single-stranded DNA (ssDNA) scaffolds, ranging from hundreds to thousands of nucleotides and from short staple strands. Scaffolds are usually obtained by asymmetric PCR (aPCR) or Escherichia coli infection/transformation with phages or phagemids. Scaffold quantification is typically based on agarose gel electrophoresis densitometry for molecules obtained by aPCR, or by UV absorbance, in the case of scaffolds obtained by infection or transformation. Although these methods are well-established and easy-to-apply, the results obtained are often inaccurate due to the lack of selectivity and sensitivity in the presence of impurities. Herein, we present an HPLC method based on ion-pair reversed-phase (IP-RP) chromatography to quantify DNA scaffolds. Using IP-RP chromatography, ssDNA products (449 and 1000 nt) prepared by aPCR were separated from impurities and from the double stranded (ds) DNA byproduct. Additionally, both ss and dsDNA were quantified with high accuracy. The method was used to guide the optimization of the production of ssDNA by aPCR, which targeted the maximization of the ratio of ssDNA to dsDNA obtained. Moreover, ssDNA produced from phage infection of E. coli cells was also quantified by IP-RP using commercial ssDNA from the M13mp18 phage as a standard.

10.
Mol Diagn Ther ; 28(4): 479-494, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38796660

RESUMO

INTRODUCTION: Hantavirus, a zoonotic pathogen, causes severe syndromes like hemorrhagic fever with renal syndrome (HFRS), sometimes fatal in humans. Considering the importance of detecting the hantavirus antigen, the construction of an immunosensor is essential. The structural and functional characteristics of camelid nanobodies (VHHs) encourage their application in the areas of nanobiotechnology, therapeutics, diagnostics, and basic research. Therefore, this study aimed to standardize stable bioconjugates using gold nanoparticles (AuNPs) and VHHs, in order to develop immunobiosensors for the diagnosis of hantavirus infection. METHODS: Immobilized metal affinity chromatography (IMAC) was performed to obtain purified recombinant anti-hantavirus nucleocapsid nanobodies (anti-prNΔ85 VHH), while AuNPs were synthesized for bioconjugation. UV-visible spectrophotometry and transmission electron microscopy (TEM) analysis were employed to characterize AuNPs. RESULTS: The bioconjugation stability parameters (VHH-AuNPs), analyzed by spectrophotometry, showed that the ideal pH value and VHH concentration were obtained at 7.4 and 50 µg/mL, respectively, after addition of 1 M NaCl, which induces AuNP aggregation. TEM performed before and after bioconjugation showed uniform, homogeneous, well-dispersed, and spherical AuNPs with an average diameter of ~ 14 ± 0.57 nm. Furthermore, high-resolution images revealed a thin white halo on the surface of the AuNPs, indicating the coating of the AuNPs with protein. A biosensor simulation test (dot blot-like [DB-like]) was performed in stationary phase to verify the binding and detection limits of the recombinant nucleocapsid protein from the Araucária hantavirus strain (prN∆85). DISCUSSION: Using AuNPs/VHH bioconjugates, a specific interaction was detected between 5 and 10 min of reaction in a dose-dependent manner. It was observed that this test was sensitive enough to detect prNΔ85 at concentrations up to 25 ng/µL. Considering that nanostructured biological systems such as antibodies conjugated with AuNPs are useful tools for the development of chemical and biological sensors, the stability of the bioconjugate indicates proficiency in detecting antigens. The experimental results obtained will be used in a future immunospot assay or lateral flow immunochromatography analysis for hantavirus detection.


Assuntos
Técnicas Biossensoriais , Ouro , Nanopartículas Metálicas , Orthohantavírus , Anticorpos de Domínio Único , Ouro/química , Nanopartículas Metálicas/química , Anticorpos de Domínio Único/imunologia , Anticorpos de Domínio Único/química , Orthohantavírus/imunologia , Humanos , Técnicas Biossensoriais/métodos , Anticorpos Antivirais/imunologia , Animais , Infecções por Hantavirus/diagnóstico
11.
J Neurosci ; 32(43): 15216-26, 2012 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-23100442

RESUMO

Chromatic mechanisms have been studied extensively with psychophysical techniques in humans, but the number and nature of the mechanisms are still controversial. Appeals to monkey neurophysiology are often used to sort out the competing claims and to test hypotheses arising from the experiments in humans, but psychophysical chromatic mechanisms have never been assessed in monkeys. Here we address this issue by measuring color-detection thresholds in monkeys before and after chromatic adaptation, employing a standard approach used to determine chromatic mechanisms in humans. We conducted separate experiments using adaptation configured as either flickering full-field colors or heterochromatic gratings. Full-field colors would favor activity within the visual system at or before the arrival of retinal signals to V1, before the spatial transformation of color signals by the cortex. Conversely, gratings would favor activity within the cortex where neurons are often sensitive to spatial chromatic structure. Detection thresholds were selectively elevated for the colors of full-field adaptation when it modulated along either of the two cardinal chromatic axes that define cone-opponent color space [L vs M or S vs (L + M)], providing evidence for two privileged cardinal chromatic mechanisms implemented early in the visual-processing hierarchy. Adaptation with gratings produced elevated thresholds for colors of the adaptation regardless of its chromatic makeup, suggesting a cortical representation comprised of multiple higher-order mechanisms each selective for a different direction in color space. The results suggest that color is represented by two cardinal channels early in the processing hierarchy and many chromatic channels in brain regions closer to perceptual readout.


Assuntos
Percepção de Cores/fisiologia , Cor , Macaca mulatta/fisiologia , Psicofísica , Limiar Sensorial/fisiologia , Adaptação Fisiológica , Animais , Sensibilidades de Contraste , Análise de Fourier , Masculino , Estimulação Luminosa , Células Fotorreceptoras Retinianas Cones/fisiologia , Detecção de Sinal Psicológico
12.
Mutat Res ; 754(1-2): 58-62, 2013 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-23624100

RESUMO

Fanconi Anemia (FA) is a chromosome instability (CI) syndrome, clinically characterized by progressive bone marrow failure and increased cancer predisposition. Lymphocytes from FA patients have hypersensitivity to alkylating agents, particularly to diepoxybutane (DEB). The antibiotic fosfomycin (FOM) is an alkylating agent. FOM is used as a large spectrum antibiotic and also as a prophylactic pre-surgery agent. FOM has been considered non-genotoxic. However, no specific genotoxic evaluation directed to patients with hypersensitivity to alkylating agents was performed. As FA patients are very susceptible to infections and may be submitted to several surgeries, FOM can eventually be prescribed to them during their lifetime. In the present study we evaluated the putative genotoxic effect of FOM in cultured lymphocytes from FA patients, compared to cultured lymphocytes from healthy donors (HD). Cultures from FA patients and HD were treated with 0.5mM FOM or with 0.6mM DEB and CI was evaluated. Results showed that FOM significantly increases CI in cultured lymphocytes from FA patients, compared to lymphocytes from HD, in which no effect was found. Additionally, a direct correlation between DEB and FOM toxicity was observed in lymphocytes from FA patients, indicating similar susceptibility to both agents.


Assuntos
Instabilidade Cromossômica/efeitos dos fármacos , Anemia de Fanconi/sangue , Fosfomicina/farmacologia , Linfócitos/efeitos dos fármacos , Estudos de Casos e Controles , Anemia de Fanconi/genética , Humanos , Linfócitos/ultraestrutura
13.
Curr Res Neurobiol ; 4: 100063, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36578652

RESUMO

We have previously demonstrated that macaque monkeys can behaviorally detect a subtle optogenetic impulse delivered to their inferior temporal (IT) cortex. We have also shown that the ability to detect the cortical stimulation impulse varies depending on some characteristics of the visual images viewed at the time of brain stimulation, revealing the visual nature of the perceptual events induced by stimulation of the IT cortex. Here we systematically studied the effect of the size of viewed objects on behavioral detectability of optogenetic stimulation of the central IT cortex. Surprisingly, we found that behavioral detection of the same optogenetic impulse highly varies with the size of the viewed object images. Reduction of the object size in four steps from 8 to 1 degree of visual angle significantly decreased detection performance. These results show that identical stimulation impulses delivered to the same neural population induce variable perceptual events depending on the mere size of the objects viewed at the time of brain stimulation.

14.
J Pediatr (Rio J) ; 99(6): 568-573, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37356812

RESUMO

OBJECTIVE: The authors investigated the functional status at ICU admission and at hospital discharge, and the impact of dysfunctions on survivors' lifespan. METHOD: Single-center retrospective cohort. The FSS (Functional Status Scale) was calculated at ICU admission and at hospital discharge. A new morbidity was defined as an increase in FSS ≥ 3. RESULTS: Among 1002 patients, there were 855 survivors. Of these, 194 (22.6%) had died by the end of the study; 45 (5.3%) had a new morbidity. Means in the motor domain at admission and discharge were 1.37 (SD: 0.82) and 1.53 (SD 0.95, p = 0.002). In the feeding domain, the means were 1.19 (SD 0.63) and 1.30 (SD 0.76), p = 0.002; global means were 6.93 (SD 2.45) and 7.2 (SD 2.94), p = 0.007.  Acute respiratory failure requiring mechanical ventilation, the score PRISM IV, age < 5 years, and central nervous system tumors were independent predictors of new morbidity. New morbidity correlated with lower odds of survival after hospital discharge, considering all causes of death (p = 0.014), and was independently predictive of death (Cox hazard ratio = 1.98). In Weibull models, shortening in the life span of 14.2% (p = 0.014) was estimated as a new morbidity. CONCLUSIONS: New morbidities are related to age, disease severity at admission, and SNC tumors. New morbidities, in turn, correlate with lower probabilities of survival and shortening of the remaining life span. Physical rehabilitation interventions in this population of children may have the potential to provide an increase in lifespan.


Assuntos
Cuidados Críticos , Hospitalização , Criança , Humanos , Pré-Escolar , Estudos Retrospectivos , Morbidade , Alta do Paciente
15.
Curr Biol ; 33(3): 581-588.e4, 2023 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-36610394

RESUMO

Artificial activation of neurons in early visual areas induces perception of simple visual flashes.1,2 Accordingly, stimulation in high-level visual cortices is expected to induce perception of complex features.3,4 However, results from studies in human patients challenge this expectation. Stimulation rarely induces any detectable visual event, and never a complex one, in human subjects with closed eyes.2 Stimulation of the face-selective cortex in a human patient led to remarkable hallucinations only while the subject was looking at faces.5 In contrast, stimulations of color- and face-selective sites evoke notable hallucinations independent of the object being viewed.6 These anecdotal observations suggest that stimulation of high-level visual cortex can evoke perception of complex visual features, but these effects depend on the availability and content of visual input. In this study, we introduce a novel psychophysical task to systematically investigate characteristics of the perceptual events evoked by optogenetic stimulation of macaque inferior temporal (IT) cortex. We trained macaque monkeys to detect and report optogenetic impulses delivered to their IT cortices7,8,9 while holding fixation on object images. In a series of experiments, we show that detection of cortical stimulation is highly dependent on the choice of images presented to the eyes and it is most difficult when fixating on a blank screen. These findings suggest that optogenetic stimulation of high-level visual cortex results in easily detectable distortions of the concurrent contents of vision.


Assuntos
Optogenética , Córtex Visual , Animais , Humanos , Macaca mulatta/fisiologia , Lobo Temporal/fisiologia , Neurônios/fisiologia , Córtex Visual/fisiologia , Estimulação Luminosa/métodos
16.
J Virol Methods ; 320: 114787, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37516366

RESUMO

Viral infections have been the cause of high mortality rates throughout different periods in history. Over the last two decades, outbreaks caused by zoonotic diseases and transmitted by arboviruses have had a significant impact on human health. The emergence of viral infections in different parts of the world encourages the search for new inputs to fight pathologies of viral origin. Antibodies represent the predominant class of new drugs developed in recent years and approved for the treatment of various human diseases, including cancer, autoimmune and infectious diseases. A promising group of antibodies are single-domain antibodies derived from camelid heavy chain immunoglobulins, or VHHs, are biomolecules with nanometric dimensions and unique pharmaceutical and biophysical properties that can be used in the diagnosis and immunotherapy of viral infections. For viral neutralization to occur, VHHs can act in different stages of the viral cycle, including the actual inhibition of infection, to hindering viral replication or assembly. This review article addresses advances involving the use of VHHs in therapeutic propositions aimed to battle different viruses that affect human health.


Assuntos
Antivirais , Anticorpos de Domínio Único , Viroses , Anticorpos de Domínio Único/uso terapêutico , Animais , Camelidae/metabolismo , Antivirais/uso terapêutico , Terapia de Alvo Molecular , Viroses/tratamento farmacológico , Viroses/virologia , Humanos , Vírus/classificação
17.
Mutat Res ; 747(1): 77-81, 2012 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-22565221

RESUMO

Ptaquiloside, a norsesquiterpene glycoside from bracken (Pteridium aquilinum), is a known carcinogen towards animals. Its genotoxicity is mainly attributed to its DNA-alkylating and clastogenic properties. This study analyses various modes of genotoxic action of ptaquiloside in human mononuclear blood cells. The alkaline comet assay was performed on cells exposed to 5µg/ml ptaquiloside for 5, 10, 20, 30, 40 or 50min. Tail length was used as a DNA-damage parameter. Assays to determine structural and numerical chromosomal aberrations and sister-chromatid exchange were conducted on cells exposed to 5, 10 or 20µg/ml ptaquiloside for 48h. The tail length showed maximum DNA damage at 20-30min, diminishing onwards. Highly significant (p<0.001) dose-dependent increases in structural and numerical chromosomal aberrations and SCE were observed in response to ptaquiloside. These results indicate that ptaquiloside is not only a DNA-alkylating agent, but expresses its genotoxicity through multiple mechanisms including clastogenesis, aneugenesis and the mechanism underlying SCE induction, which is not entirely understood. Recent studies support the role played by aneuploidy in oncogenesis, highlighting the importance of this endpoint for mutagenicity screening. SCE are thought to represent the long-term effects of mutagens and are an important genotoxicity biomarker. The present results also agree with data from epidemiological studies and from animal in vivo studies, further supporting the hypothesis that ptaquiloside may represent a significant threat to human health.


Assuntos
Indanos/toxicidade , Linfócitos/efeitos dos fármacos , Mutagênicos/toxicidade , Sesquiterpenos/toxicidade , Troca de Cromátide Irmã/efeitos dos fármacos , Alquilantes/toxicidade , Aneugênicos/toxicidade , Ensaio Cometa , Dano ao DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Fatores de Tempo
18.
J Opt Soc Am A Opt Image Sci Vis ; 29(5): 657-70, 2012 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-22561924

RESUMO

Colors defined by the two intermediate directions in color space, "orange-cyan" and "lime-magenta," elicit the same spatiotemporal average response from the two cardinal chromatic channels in the lateral geniculate nucleus (LGN). While we found LGN functional magnetic resonance imaging (fMRI) responses to these pairs of colors were statistically indistinguishable, primary visual cortex (V1) fMRI responses were stronger to orange-cyan. Moreover, linear combinations of single-cell responses to cone-isolating stimuli of V1 cone-opponent cells also yielded stronger predicted responses to orange-cyan over lime-magenta, suggesting these neurons underlie the fMRI result. These observations are consistent with the hypothesis that V1 recombines LGN signals into "higher-order" mechanisms tuned to noncardinal color directions. In light of work showing that natural images and daylight samples are biased toward orange-cyan, our findings further suggest that V1 is adapted to daylight. V1, especially double-opponent cells, may function to extract spatial information from color boundaries correlated with scene-structure cues, such as shadows lit by ambient blue sky juxtaposed with surfaces reflecting sunshine.


Assuntos
Percepção de Cores/fisiologia , Luz , Imageamento por Ressonância Magnética/métodos , Córtex Visual/fisiologia , Animais , Cor , Discriminação Psicológica/fisiologia , Macaca mulatta , Masculino , Neurônios/citologia , Estimulação Luminosa , Células Fotorreceptoras Retinianas Cones/fisiologia , Córtex Visual/citologia , Campos Visuais/fisiologia , Vigília/fisiologia
19.
J Cancer Res Clin Oncol ; 148(12): 3351-3360, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35751683

RESUMO

BACKGROUND: Apalutamide (APA) is a next-generation androgen receptor antagonist for the treatment of advanced prostate cancer. We have previously shown that upregulation of autophagy is one of the mechanisms by which prostate cancer (PC) cells survive APA anti-tumor treatment in vitro. Therefore, we investigated the characteristics of the autophagic response to APA treatment, alone and in combination with autophagy inhibition, in an in vivo model. METHODS: Tumor cells were injected into previously castrated nude mice. Four groups of mice bearing LNCaP xenografts were treated with daily intraperitoneal (i.p.) injections of vehicle (control), APA (10 mg/kg), APA (10 mg/kg) + Chl (Chloroquine, 10 mg/kg) or Chl (10 mg/kg). The animals of each treatment group (3/treatment) were kept for the duration of 2 and 3 weeks. At the end of the experiments, the animals were sacrificed and all samples assessed for tumor weight and size, histological analysis, immunoblotting (WES) and immunofluorescence. RESULTS: The tumor weight was significantly reduced in mice treated with APA + Chl (203.2 ± 5.0, SEM, P = 0.0066) compared to vehicle control (380.4 ± 37.0). Importantly, the combined treatment showed a higher impact on tumor weight than APA (320.4 ± 45.5) or Chl (337.9 ± 35) alone. The mice treated with the combination of APA + Chl exhibited a reduced expression of ATG5 (autophagy-related five protein), Beclin 1 and LC3 punctuations and an increase in P62 as visualized by immunofluorescence and WES. In addition, Ki-67 nuclear staining was detected in all samples however reduced in APA + Chl (58%) compared to vehicle control (100%). The reduction in Ki-67 protein was associated with an increase in caspase 3 and endothelial CD31 protein expression. CONCLUSION: These data demonstrate that a treatment with APA + Chl leads to reduced autophagy levels and to tumor suppression compared to the APA monotherapy. Hence, the increased antitumor effect of APA in combination with autophagy inhibitors might provide a new therapeutic approach potentially translatable to patients.


Assuntos
Antagonistas de Receptores de Andrógenos , Neoplasias da Próstata , Animais , Humanos , Masculino , Camundongos , Antagonistas de Receptores de Andrógenos/farmacologia , Apoptose , Autofagia , Proteína Beclina-1 , Caspase 3 , Linhagem Celular Tumoral , Cloroquina/farmacologia , Cloroquina/uso terapêutico , Modelos Animais de Doenças , Xenoenxertos , Antígeno Ki-67 , Camundongos Nus , Neoplasias da Próstata/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
20.
Biomed Res Int ; 2022: 2748962, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35909472

RESUMO

In order to address the global antivenom crisis, novel antivenoms need to present high therapeutic efficacy, broad neutralization ability against systemic and local damage, sufficient safety, and cost-effectiveness. Due to biological characteristics of camelid single-domain antibodies (VHH) such as high affinity, their ability to penetrate dense tissues, and facility for genetic manipulation, their application in antivenoms has expanded considerably. VHHs that are active against the metalloprotease BjussuMP-II from the snake Bothrops jararacussu were selected. After isolation of BjussuMP-II, a camelid was immunized with the purified toxin in order to construct the recombinant phage library. Following a round of biopanning, 52% of the selected clones were able to recognize BjussuMP-II in an ELISA assay. After sequencing, seven sequence profiles were identified. One selected clone (VHH61) showed cross-reactivity to B. brazili venom, but did not recognize the Crotalus and Lachesis genera, indicating specificity for the Bothrops genus. Through in vitro tests, the capacity to neutralize the toxicity triggered by BjussuMP-II was observed. Circular dichroism spectroscopy indicated a robust secondary structure for VHH61, and the calculated melting temperature (T M) for the clone was 56.4°C. In silico analysis, through molecular docking of anti-BjussuMP-II VHHs with metalloprotease, revealed their potential interaction with amino acids present in regions critical for the toxin's conformation and stability. The findings suggest that anti-BjussuMP-II VHHs may be beneficial in the development of next-generation antivenoms.


Assuntos
Bothrops , Venenos de Crotalídeos , Anticorpos de Domínio Único , Mordeduras de Serpentes , Animais , Antivenenos/uso terapêutico , Bothrops/metabolismo , Metaloproteases/metabolismo , Simulação de Acoplamento Molecular , Testes de Neutralização , Anticorpos de Domínio Único/farmacologia , Mordeduras de Serpentes/tratamento farmacológico
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