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1.
Bioconjug Chem ; 35(7): 1044-1052, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38875443

RESUMO

Subcutaneous (SC) injection of protein-based therapeutics is a convenient and clinically established drug delivery method. However, progress is needed to increase the bioavailability. Transport of low molecular weight (Mw) biotherapeutics such as insulin and small molecule contrast agents such as lipiodol has been studied using X-ray computed tomography (CT). This analysis, however, does not translate to the investigation of higher Mw therapeutics, such as monoclonal antibodies (mAbs), due to differences in molecular and formulation properties. In this study, an iodinated fluorescein analog rose bengal (RB) was used as a radiopaque and fluorescent label to track the distribution of bovine serum albumin (BSA) compared against unconjugated RB and sodium iodide (NaI) via CT and confocal microscopy following injection into ex vivo porcine SC tissue. Importantly, the high concentration BSA-RB exhibited viscosities more like that of viscous biologics than the small molecule contrast agents, suggesting that the labeled protein may serve as a more suitable formulation for the investigation of injection plumes. Three-dimensional (3D) renderings of the injection plumes showed that the BSA-RB distribution was markedly different from unconjugated RB and NaI, indicating the need for direct visualization of large protein therapeutics using conjugated tags rather than using small molecule tracers. Whereas this proof-of-concept study shows the novel use of RB as a label for tracking BSA distribution, our experimental approach may be applied to high Mw biologics, including mAbs. These studies could provide crucial information about diffusion in SC tissue and the influence of injection parameters on distribution, transport, and downstream bioavailability.


Assuntos
Rosa Bengala , Soroalbumina Bovina , Tomografia Computadorizada por Raios X , Soroalbumina Bovina/química , Soroalbumina Bovina/metabolismo , Animais , Rosa Bengala/química , Bovinos , Tomografia Computadorizada por Raios X/métodos , Microscopia de Fluorescência/métodos , Transporte Proteico , Tela Subcutânea/diagnóstico por imagem , Tela Subcutânea/metabolismo , Suínos , Corantes Fluorescentes/química
2.
Biotechnol Bioeng ; 120(8): 2326-2332, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37466320

RESUMO

Diffusion and movement of subcutaneously injected biologics and high-concentration immunoglobulin G (IgG) therapeutics away from the injection site and through the subcutaneous (SC) tissue may be concentration dependent. This possibility was confirmed by in situ measurement of diffusion coefficients of unlabeled bovine IgG in phosphate-buffered saline within an in vitro hyaluronic acid matrix that represents the SC electrostatic environment. Diffusion decreased from 2.67 to 0.05 × 10-7 cm2 /s when IgG concentration increased from 25 to 73 mg/mL. The results demonstrated that in situ detection of unlabeled proteins within an in vitro SC environment provides another useful tool for the preclinical characterization of injectable biologics.


Assuntos
Produtos Biológicos , Ácido Hialurônico , Animais , Bovinos , Difusão , Imunoglobulina G
3.
Biotechnol Bioeng ; 119(12): 3647-3656, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36131370

RESUMO

There are currently more than 560 therapeutic monoclonal antibodies (mAbs) at various stages of research and clinical testing, including candidates for administration by subcutaneous (SC) injection. Preclinical studies based on in vitro measurements of high molecular weight proteins within simulated SC matrices are assisting laboratory studies of interactions of injectable biotherapeutic proteins within the SC environment in relation to bioavailability. We report a new method for directly measuring diffusion of unlabeled, high molecular weight proteins injected into an in vitro matrix that simulates the negatively charged environment of the SC. The matrix consists of 10 mg/ml HA in a repurposed cell culture chamber. The measurement consists of pipetting triplicate 20 µl protein samples into the matrix, placing the chamber in a laboratory scanner, activating tryptophan residues in the protein at 280 nm, and imaging the resulting protein fluorescence at 384 nm over a 0.5-4 h time period thus tracking protein movement. This facile approach enables mapping of protein concentration as a function of time and distance within the matrix, and determination of diffusion coefficients, D, within ±10%. Bovine IgG and BSA gave D = 2.3 ± 0.2*10-7 and 4.6 ± 0.2*10-7 cm2 /s at 24°C, respectively, for initial protein concentrations of 21 mg/mL.


Assuntos
Anticorpos Monoclonais , Ácido Hialurônico , Animais , Bovinos , Injeções Subcutâneas , Disponibilidade Biológica , Difusão
4.
Phys Chem Chem Phys ; 23(48): 27484-27497, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34873605

RESUMO

We report on single- and double-charge photofragment formation by synchrotron radiation, following C 1s core excitation and ionization and Cl 2p inner excitation and ionization of chlorobenzene, C6H5Cl. From a comparison of experimental near-edge X-ray absorption fine structure spectra and theoretical ab initio calculations, the nature of various core and inner shell transitions of the molecule and pure atomic features were identified. To shed light on the normal Auger processes following excitation or ionization of the molecule at the Cl 2p or C 1s sites, we addressed the induced ionic species formation. With energy resolved electron spectra and ion time-of-flight spectra coincidence measurements, the ionic species were correlated with binding energy regions and initial states of vacancies. We explored the formation of the molecular dication C6H5Cl2+, the analogue benzene dication C6H42+, and the singly charged species produced by single loss of a carbon atom, C5HnCl+. The appearance and intensities of the spectral features associated with these ionic species are shown to be strongly site selective and dependent on the energy ranges of the Auger electron emission. Unexpected intensities for the analogue double charged benzene C6H42+ ion were observed with fast Auger electrons. The transitions leading to C6H5Cl2+ were identified from the binding energy representation of high resolution electron energy spectra. Most C6H5Cl2+ ions decay into two singly charged moieties, but intermediate channels are opened leading to other heavy dicationic species, C6H42+ and C6H4Cl2+, the channel leading to the first of these being much more favored than the other.

5.
BMC Neurol ; 15: 262, 2015 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-26689596

RESUMO

BACKGROUND: Epilepsy is one of the most prevalent neurological disorders. It remains medically intractable for about one-third of patients with focal epilepsy, for whom precise localization of the epileptogenic zone responsible for seizure initiation may be critical for successful surgery. Existing fMRI literature points to widespread network disturbances in functional connectivity. Per previous scalp and intracranial EEG studies and consistent with excessive local synchronization during interictal discharges, we hypothesized that, relative to same regions in healthy controls, epileptogenic foci would exhibit less chaotic dynamics, identifiable via entropic analyses of resting state fMRI time series. METHODS: In order to first validate this hypothesis on a cohort of patients with known ground truth, here we test individuals with well-defined epileptogenic foci (left mesial temporal lobe epilepsy). We analyzed voxel-wise resting-state fMRI time-series using the autocorrelation function (ACF), an entropic measure of regulation and feedback, and performed follow-up seed-to-voxel functional connectivity analysis. Disruptions in connectivity of the region exhibiting abnormal dynamics were examined in relation to duration of epilepsy and patients' cognitive performance using a delayed verbal memory recall task. RESULTS: ACF analysis revealed constrained (less chaotic) functional dynamics in left temporal lobe epilepsy patients, primarily localized to ipsilateral temporal pole, proximal to presumed focal points. Autocorrelation decay rates differentiated, with 100 % accuracy, between patients and healthy controls on a subject-by-subject basis within a leave-one-subject out classification framework. Regions identified via ACF analysis formed a less efficient network in patients, as compared to controls. Constrained dynamics were linked with locally increased and long-range decreased connectivity that, in turn, correlated significantly with impaired memory (local left temporal connectivity) and epilepsy duration (left temporal - posterior cingulate cortex connectivity). CONCLUSIONS: Our current results suggest that data driven functional MRI methods that target network dynamics hold promise in providing clinically valuable tools for identification of epileptic regions.


Assuntos
Encéfalo/patologia , Epilepsia do Lobo Temporal/patologia , Imageamento por Ressonância Magnética , Adulto , Mapeamento Encefálico , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
6.
J Neuroradiol ; 42(3): 169-75, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25841700

RESUMO

INTRODUCTION: Early carotid revascularization (≤ 14 days) is recommended for symptomatic carotid stenosis. Carotid artery stenting (CAS) has become an alternative to carotid endarterectomy (CEA); however, safety data on early CAS is controversial. The study aims to compare early versus late CAS, when CAS is performed as a first intention revascularization strategy. METHODS: A retrospective analysis of all symptomatic patients admitted to our stroke unit who underwent CAS was conducted. Patients were divided between two groups: patients who had undergone CAS within 14 days after symptoms and those who had undergone CAS later. Primary endpoints were ipsilateral ischemic stroke or ipsilateral parenchymal hemorrhage (iPH) at 30 days. The secondary endpoints were major adverse cardiac and cerebrovascular events (MACCE) at the 30-day and at the 12-month follow-up. RESULTS: One hundred twenty-seven consecutive patients were evaluated. Primary endpoints obtained in the early and late CAS groups were, respectively, ipsilateral stroke (2.0% vs. 2.6%, P = 1.00) and iPH (2.0% vs. 0.0%, P = 0.40). The rates of MACCE between the early and the late CAS groups were, respectively, (7.8% vs. 2.6%, P = 0.21) at the 30-day follow-up, and (12.2% vs. 10.5%, P = 0.77) at the 12-month follow-up. CONCLUSIONS: In this study, CAS seems to be safe when used as first intention revascularization treatment within 2 weeks of symptoms, if infarcted area is less than one third of the middle cerebral artery territory. Our results need to be confirmed by larger studies.


Assuntos
Angioplastia com Balão/métodos , Estenose das Carótidas/cirurgia , Endarterectomia das Carótidas , Stents , Adulto , Idoso , Idoso de 80 Anos ou mais , Isquemia Encefálica/etiologia , Isquemia Encefálica/cirurgia , Estenose das Carótidas/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Medição de Risco , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/cirurgia , Fatores de Tempo , Resultado do Tratamento
7.
Headache ; 53(1): 165-167, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22963467

RESUMO

Trigeminal neuralgia (TN) is a condition characterized by brief electric shock-like pains in the topography of the trigeminal nerve. The most common cause of this disorder is the compression of the trigeminal nerve root by tortuous or aberrant vessels. In this report, we describe a patient who presented due to paroxysmal and excruciating facial pain that was found to be secondary to pancreatic cancer.


Assuntos
Adenocarcinoma/complicações , Adenocarcinoma/secundário , Neoplasias Pancreáticas/complicações , Neuralgia do Trigêmeo/etiologia , Neoplasias Encefálicas/secundário , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Pancreáticas/patologia
8.
Bioresour Technol ; 384: 129338, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37343796

RESUMO

Pelleting of lignocellulosic biomass to improve its transportation, storage and handling impacts subsequent processing and conversion. This work reports the role of high moisture pelleting in the enzymatic digestibility of corn stover prior to pretreatment, together with associated substrate characteristics. Pelleting increases the digestibility of unpretreated corn stover, from 8.2 to 15.5% glucan conversion, at 5% solid loading using 1 FPU Cellic® CTec2 per g solids. Compositional analysis indicates that loose and pelleted corn stover have similar non-dissolvable compositions, although their extractives are different. Enzymatic hydrolysis of corn stover after size reduction to normalize particle sizes and removal of extractives confirms that pelleting improves corn stover digestibility. Such differences may be explained by the decreased particle size, improved substrate accessibility, and hydrolysis of cross-linking structures induced by pelleting. These findings are useful for the development of processing schemes for sustainable and efficient use of lignocellulose.


Assuntos
Celulase , Zea mays , Zea mays/química , Celulase/química , Hidrólise , Biomassa
9.
Int J Biol Macromol ; 185: 543-550, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34197857

RESUMO

Controlled or slow release fertilizers have been recommended to enhance crop yield, while minimizing environmental and economic issues related from current fertilizer applications. However, alternative biodegradable and non-toxic coating material should be suggested to produce biocoated fertilizers. Here we propose the use of lignin and poly(vinyl acetate) (PVAc) as biocoating materials for preparing slow release urea fertilizer. The blend of PVAc and lignin at a mass ratio of 75:25 improved the characteristics of the formed film and increased the nitrogen release time if compared to the pure polymers. The nitrogen release time from urea granules coated with a polymeric layer of 154.3 ±â€¯5.5 µm formed by lignin and PVAc was 36 times greater than from bare urea. The increase in the polymeric coating from 52.6 ±â€¯5.2 to 80.2 ±â€¯6.1 µm decreased the curvature of the nitrogen release data by a factor of at least 1.7, while the curvature was decreased in at least 1.3 with the increase in the polymeric coating from 80.2 ±â€¯6.1 to 158.9 ±â€¯10.6 µm. The adjustment of nitrogen release data to the Peppas-Sahlin model indicated the Fickian diffusion is more predominant than relaxation contributions, since the used polymers did not present considerable swelling. Thus, the blending of PVAc and lignin at 25 wt% of lignin and 75 wt% of PVAc is suggested as a biocoating material for producing slow release fertilizers.


Assuntos
Lignina/química , Nitrogênio/química , Polivinil/química , Composição de Medicamentos , Fertilizantes , Ureia/química
10.
Biotechnol Prog ; 37(6): e3216, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34590438

RESUMO

The measurement of yield stress and shear thinning flow behavior of slurries formed from unpretreated corn stover at solids loadings of 100-300 g/L provides a key metric for the ability to move, pump, and mix this lignocellulosic slurry, particularly since corn stover slurries represent a major potential feedstock for biorefineries. This study compared static yield stress values and flow hysteresis of corn stover slurries of 100, 150, 200, 250, and 300 g/L, after these slurries were formed by adding pellets to a cellulase enzyme solution (Celluclast 1.5 L) in a fed-batch manner. A rotational rheometer was used to quantitate relative yield stress and its dependence on processing history at insoluble solids concentrations of 4%-21% (wt/vol). Key findings confirmed previous observations that yield stress increases with solids loadings and reaches ~3000 Pa at 25% (wt/vol) solids concentration compared to ~200 Pa after enzyme liquefaction. While optimization of slurry forming (i.e., liquefaction) conditions remains to be done, metrics for quantifying liquefaction extent are needed. The method for obtaining comparative metrics is demonstrated here and shows that the yield stress, shear thinning and shear thickening flow behaviors of enzyme liquefied corn stover slurries can be analyzed using a wide-gap rheometry setup with relative measuring geometries to mimic the conditions that may exist in a mixing vessel of a bioreactor while applying controlled and precise levels of strain.


Assuntos
Biomassa , Reologia/métodos , Zea mays , Reatores Biológicos , Celulases/metabolismo , Zea mays/química , Zea mays/metabolismo
11.
Animals (Basel) ; 11(8)2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34438906

RESUMO

This study evaluated the effects of the duration of ZH supplementation and days on feed (DOF) on performance, carcass characteristics, and saleable meat yield of Nellore young bulls. The fixed effects included the duration (0, 20, 30, or 40 d before slaughter plus a 3 d ZH withdrawal period-8.33 mg of ZH/kg of DM) and DOF (90 and 117 d). Feed efficiency (G:F) linearly increased when the duration of ZH supplementation increased (p < 0.01). Nellore bulls fed ZH had greater HCW (p < 0.01), dressing percentage (p < 0.01) and Longissimus muscle area (LMA) (p < 0.01), but less 12th-rib fat (p = 0.04) than the control group. The hot carcass weight (HCW) (p < 0.01), and dressing percentage increased linearly (p < 0.01) with the increase of duration of ZH supplementation. The HCW, ossification, and 12th-rib fat increased with DOF (p < 0.01). The ZH supplemented group had most of the individual cuts of hindquarters and total saleable meat increased compared with the control. Zilpaterol hydrochloride was effective in improving hot carcass weight, hindquarter, and saleable meat yields of Nellore bulls when fed for at least 20 d before slaughter, independently of days on feed.

12.
Bioresour Technol ; 341: 125773, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34419879

RESUMO

The movement of solid material into and between unit operations within a biorefinery is a bottleneck in reaching design capacity, with formation of biomass slurries needed to introduce feedstock. Corn stover slurries have been achieved from dilute acid, pretreated materials resulting in slurry concentrations of up to about 150 g/L, above which flowability is compromised. We report a new strategy to liquefy corn stover at higher solids concentration (300 g/L) by initially cooking it with the enzyme mimetic maleic acid at 40 mM and 150 °C. This is followed by 6 h of enzymatic modification at 1 FPU (2.2 mg protein)/g solids, resulting in a yield stress of 171 Pa after 6 h and 58 Pa in 48 h compared to 6806 Pa for untreated stover. Mimetic treatment of corn stover pellets minimizes the inhibitory effect of xylo-oligomers on hydrolytic enzymes. This strategy allows for the delivery of solid lignocellulosic slurry into a pretreatment reactor by pumping, improving operability of a biorefinery.


Assuntos
Ácidos , Zea mays , Biomassa , Hidrólise
13.
Cerebrovasc Dis ; 29(1): 36-42, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-19893310

RESUMO

BACKGROUND: Obstructive sleep apnea (OSA) is related to increased systemic inflammation and arterial hypertension. We hypothesize that OSA is frequent in patients with acute hypertensive intracerebral hemorrhage (ICH) and is related to the perihematoma edema. METHODS: Thirty-two non-comatose patients with a hypertensive ICH underwent polysomnography in the acute phase. Perihematoma edema volume was measured on CT scans at admission, after 24 h (early control) and after 4-5 days (late control). The Spearman coefficient (r(s)) was used for correlations. RESULTS: OSA occurred in 19 (59.4%) patients. The apnea-hypopnea index was correlated with relative edema at admission CT (r(s) = 0.40; p = 0.031), early CT (r(s) = 0.46; p = 0.011) and at late CT (r(s) = 0.59; p = 0.006). CONCLUSIONS: OSA is highly frequent during the acute phase of hypertensive ICH and is related to perihematoma edema.


Assuntos
Edema Encefálico/etiologia , Hematoma/etiologia , Hemorragia Intracraniana Hipertensiva/complicações , Apneia Obstrutiva do Sono/etiologia , Doença Aguda , Idoso , Edema Encefálico/diagnóstico por imagem , Feminino , Hematoma/diagnóstico por imagem , Humanos , Hemorragia Intracraniana Hipertensiva/diagnóstico por imagem , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Polissonografia , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Índice de Gravidade de Doença , Apneia Obstrutiva do Sono/diagnóstico , Fatores de Tempo , Tomografia Computadorizada por Raios X
14.
Comput Biol Med ; 124: 103966, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32860977

RESUMO

Twelve to 66% of patients with clinically non-functioning pituitary adenoma (NFPA) experience tumor recurrence 1-5 years after the first surgery. Nevertheless, there is still no recurrence prediction factor concisely established and reproduced in the literature for NFPA management. The present study evaluates the prognostic value of MRI Radiomics features combined with machine learning models to assess recurrence after the first surgery in patients with clinically non-functioning pituitary adenomas (NFPA). We carried out a retrospective study on 27 patients with NFPA, 10 patients having experienced tumor recurrence after the first surgery and 17 who did not. Preoperative 3D T1 contrast-enhanced MR images of patients were used to extract up to 255 Radiomics features from two and three-dimensional segmented regions. Additionally, gender, age at first surgery, and the presence of remnant tumor tissue were investigated to find the correlation with NFPA recurrence. Conventional statistics tests were used to evaluate whether the outcome patient groups (stable and recurrent) were different considering each feature individually. Additionally, five well-known machine-learning algorithms were used in combination with Radiomic features to classify recurrent and stable lesions. We found statistical evidence (p < 0.02) for 6 two-dimensional and 13 three-dimensional radiomic features. We achieved accuracies of up to 96.3% for 3D-feature based models and up to 92.6% accuracies for 2D-feature based models. 3D-feature based models achieved better performances using considerably fewer features when compared to 2D-feature based models. We concluded that Radiomics have the potential of NFPA recurrence prediction after the first surgery. Three-dimensional Radiomics have superior discrimination power to predict NFPA recurrence than two-dimensional radiomic features. Finally, the combination of Radiomics with machine-learning algorithms can offer computational models capable of non-invasive, unbiased, and quick assessment that might improve the prediction of NFPA recurrence.


Assuntos
Aprendizado de Máquina , Imageamento por Ressonância Magnética , Neoplasias Hipofisárias , Algoritmos , Humanos , Neoplasias Hipofisárias/diagnóstico por imagem , Estudos Retrospectivos
15.
Artigo em Inglês | MEDLINE | ID: mdl-31142253

RESUMO

OBJECTIVE: Schistosomiasis is a debilitating disease that affects 200 million people worldwide. Schistosoma haematobium and Schistosoma mansoni are the major causative agents of this disease. Cancer-association and infertility-association in Schistosoma haematobium infection have already been described and it is known that the parasite produces a catechol-estrogen molecule that induces a hormonal imbalance in the host. METHODS: In order to better understand the relation of hormonal imbalance in experimental Schistosoma mansoni infection, we investigated a serum panel of steroid hormones in Schistosoma mansoni infected hamsters. RESULTS: We found a decrease in the serum levels of Estradiol (E2), Testosterone and Progesterone in infected females and an increase of Testosterone and a decrease in Progesterone in infected males in comparison with controls. CONCLUSION: These results indicate that S. mansoni alters the levels of steroid hormones in infected males and females and it will increase the repertoire of data about the host-parasite molecular interplay and its relation with the endocrine system.


Assuntos
Estradiol/sangue , Progesterona/sangue , Schistosoma mansoni/patogenicidade , Esquistossomose mansoni/sangue , Testosterona/sangue , Animais , Modelos Animais de Doenças , Regulação para Baixo , Feminino , Interações Hospedeiro-Parasita , Masculino , Mesocricetus , Esquistossomose mansoni/parasitologia , Fatores Sexuais
16.
Neuroimage Clin ; 20: 705-714, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30221622

RESUMO

Intravoxel Incoherent Motion (IVIM) is a recently rediscovered noninvasive magnetic resonance imaging (MRI) method based on diffusion-weighted imaging. It enables the separation of the intravoxel signal into diffusion due to Brownian motion and perfusion-related contributions and provides important information on microperfusion in the tissue and therefore it is a promising tool for applications in neurological and neurovascular diseases. This review focuses on the basic principles and outputs of IVIM and details it major applications in the brain, such as stroke, tumor, and cerebral small vessel disease. A bi-exponential model that considers two different compartments, namely capillaries, and medium-sized vessels, has been frequently used for the description of the IVIM signal and may be important in those clinical applications cited before. Moreover, the combination of IVIM and arterial spin labeling MRI enables the estimation of water permeability across the blood-brain barrier (BBB), suggesting a potential imaging biomarker for disrupted-BBB diseases.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Transtornos Cerebrovasculares/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Acidente Vascular Cerebral/diagnóstico por imagem , Encéfalo/irrigação sanguínea , Encéfalo/patologia , Neoplasias Encefálicas/irrigação sanguínea , Neoplasias Encefálicas/patologia , Transtornos Cerebrovasculares/patologia , Humanos , Processamento de Imagem Assistida por Computador , Acidente Vascular Cerebral/patologia
17.
Psychiatry Res Neuroimaging ; 272: 71-78, 2018 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-29229240

RESUMO

Schizophrenia is a severe mental disorder that affects the anatomy and function of the brain, with an impact on one's thoughts, feelings, and behavior. The purpose of the study was to investigate cerebral blood flow (CBF) and brain connectivity in a group of patients with schizophrenia. Pseudo-continuous arterial spin labeling (pCASL) images were acquired from 28 patients in treatment and 28 age-matched healthy controls. Mean CBF and connectivity patterns were assessed. Schizophrenia patients had decreased CBF in the bilateral frontal pole and superior frontal gyrus, right medial frontal gyrus, triangular and opercular parts of the inferior frontal gyrus, posterior division of the left supramarginal gyrus, superior and inferior divisions of the left lateral occipital cortex, and bilateral occipital pole. Moreover, through different methods to assess connectivity, our results showed abnormal connectivity patterns in regions involved in motor, sensorial, and cognitive functions. Using pCASL, a non-invasive technique, we found CBF deficits and altered functional organization of the brain in schizophrenia patients that are associated with the symptoms and characteristics of the disorder.


Assuntos
Circulação Cerebrovascular/fisiologia , Imageamento por Ressonância Magnética/métodos , Imagem de Perfusão/métodos , Esquizofrenia/fisiopatologia , Marcadores de Spin , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Mapeamento Encefálico , Estudos de Casos e Controles , Cognição , Feminino , Humanos , Masculino , Esquizofrenia/diagnóstico por imagem
18.
Toxicon ; 50(5): 724-30, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17669457

RESUMO

Monocrotaline is a pyrrolizidine alkaloid present in plants of the Crotalaria species, which causes cytotoxicity and genotoxicity, including hepatotoxicity in animals and humans. It is metabolized by cytochrome P-450 in the liver to the alkylating agent dehydromonocrotaline. We evaluated the effects of monocrotaline and its metabolite on respiration, membrane potential and ATP levels in isolated rat liver mitochondria, and on respiratory chain complex I NADH oxidase activity in submitochondrial particles. Dehydromonocrotaline, but not the parent compound, showed a concentration-dependent inhibition of glutamate/malate-supported state 3 respiration (respiratory chain complex I), but did not affect succinate-supported respiration (complex II). Only dehydromonocrotaline dissipated mitochondrial membrane potential, depleted ATP, and inhibited complex I NADH oxidase activity (IC50=62.06 microM) through a non-competitive type of inhibition (K(I)=8.1 microM). Therefore, dehydromonocrotaline is an inhibitor of the activity of respiratory chain complex I NADH oxidase, an action potentially accounting for the well-documented monocrotaline's hepatotoxicity to animals and humans. The mechanism probably involves change of the complex I conformation resulting from modification of cysteine thiol groups by the metabolite.


Assuntos
Alquilantes/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Complexo I de Transporte de Elétrons/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Mitocôndrias Hepáticas/efeitos dos fármacos , Monocrotalina/análogos & derivados , Trifosfato de Adenosina/metabolismo , Animais , Doença Hepática Induzida por Substâncias e Drogas/enzimologia , Relação Dose-Resposta a Droga , Complexo I de Transporte de Elétrons/antagonistas & inibidores , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias Hepáticas/enzimologia , Monocrotalina/farmacologia , Complexos Multienzimáticos/metabolismo , NADH NADPH Oxirredutases/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Ratos , Ratos Wistar , Partículas Submitocôndricas/efeitos dos fármacos , Partículas Submitocôndricas/enzimologia
19.
Mayo Clin Proc ; 92(3): 460-466, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28259231

RESUMO

The World Health Organization considers the Zika virus (ZIKV) outbreak in the Americas a global public health emergency. The neurologic complications due to ZIKV infection comprise microcephaly, meningoencephalitis, and Guillain-Barré syndrome. We describe a fatal case of an adult patient receiving an immunosuppressive regimen following heart transplant. The patient was admitted with acute neurologic impairment and experienced progressive hemodynamic instability and mental deterioration that finally culminated in death. At autopsy, a pseudotumoral form of ZIKV meningoencephalitis was confirmed. Zika virus infection was documented by reverse trancriptase-polymerase chain reaction, immunohistochemistry, and immunofluorescence and electron microscopy of the brain parenchyma and cerebral spinal fluid. The sequencing of the viral genome in this patient confirmed a Brazilian ZIKV strain. In this case, central nervous system involvement and ZIKV propagation to other organs in a disseminated pattern is quite similar to that observed in other fatal Flaviviridae viral infections.


Assuntos
Transplante de Coração/efeitos adversos , Hospedeiro Imunocomprometido , Imunossupressores/efeitos adversos , Meningoencefalite/virologia , Infecção por Zika virus/complicações , Zika virus/isolamento & purificação , Doença Aguda , Adulto , Líquido Cefalorraquidiano/virologia , Evolução Fatal , Imunofluorescência/métodos , Genoma Viral , Humanos , Imuno-Histoquímica , Imunossupressores/uso terapêutico , Imageamento por Ressonância Magnética , Masculino , Meningoencefalite/diagnóstico por imagem , Meningoencefalite/imunologia , Neuroimagem , Tecido Parenquimatoso/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Zika virus/genética , Infecção por Zika virus/diagnóstico , Infecção por Zika virus/imunologia
20.
J Photochem Photobiol B ; 84(1): 21-7, 2006 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-16495072

RESUMO

UV radiation-induced skin damages may result in pre-cancerous and cancerous skin lesions, and acceleration of skin aging. It involves an imbalance of the endogenous antioxidant system that leads to the increase of free radical levels and inflammation. Therefore, antioxidant supplementation might inhibit such imbalance. In this regard, quercetin is a promising drug, this plant derived lipophilic flavonoid presents the higher antioxidant activity among flavonoids and multiple antioxidant mechanisms. Thus, the present study investigated the possible beneficial effects of topical formulations containing quercetin to inhibit UVB irradiation-induced oxidative damages. Quercetin was administered on the dorsal skin of hairless mice using two formulations, formulation 1 (non-ionic emulsion with high lipid content) and formulation 2 (anionic emulsion with low lipid content). The UVB irradiation (0.31-3.69 J/cm(2)) induced a dose-dependent increase in the myeloperoxidase (MPO) activity (4-2708%) and depletion of reduced glutathione (GSH) (22-68%) in the skin of hairless mice after 6h. These results demonstrated that the UVB doses are not excessive, and additionally, they are lower than the doses used in other similar studies. Proteinases secretion/activity, detected by the qualitative sodium dodecyl sulphate polyacrylamide gel electrophoresis substrate-embedded enzymography (zymography), was also enhanced in the same manner as MPO activity using the UVB dose of 1.23J /cm(2). Formulations 1 and 2 inhibited the MPO activity increase (62% and 59%, respectively), GSH depletion (119% and 53%, respectively) and proteinases secretion/activity. To our knowledge, this is the first study to demonstrate the effectiveness of topical formulations containing quercetin to inhibit the UVB irradiation-induced skin damages. Thus, these data suggest the possible usefulness of topical formulations containing quercetin to prevent UVB radiation skin damages.


Assuntos
Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/efeitos da radiação , Quercetina/farmacologia , Pele/efeitos dos fármacos , Pele/efeitos da radiação , Raios Ultravioleta , Administração Tópica , Animais , Glutationa/efeitos dos fármacos , Glutationa/metabolismo , Camundongos , Camundongos Pelados , Peptídeo Hidrolases/efeitos dos fármacos , Peptídeo Hidrolases/metabolismo , Peroxidase/efeitos dos fármacos , Peroxidase/metabolismo , Quercetina/administração & dosagem , Protetores contra Radiação/administração & dosagem , Protetores contra Radiação/farmacologia , Pele/metabolismo , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/efeitos da radiação
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