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In this present study, the material science background of crosslinked gelatin (GEL) was investigated. The aim was to assess the optimal reaction parameters for the production of a water-insoluble crosslinked gelatin matrix suitable for heat sterilization. Matrices were subjected to enzymatic degradation assessments, and their ability to withstand heat sterilization was evaluated. The impact of different crosslinkers on matrix properties was analyzed. It was found that matrices crosslinked with butanediol diglycidyl ether (BDDE) and poly(ethylene glycol) diglycidyl ether (PEGDE) were resistant to enzymatic degradation and heat sterilization. Additionally, at 1 v/v % crosslinker concentration, the crosslinked weight was lower than the starting weight, suggesting simultaneous degradation and crosslinking. The crosslinked weight and swelling ratio were optimal in the case of the matrices that were crosslinked with 3% and 5% v/v BDDE and PEGDE. FTIR analysis confirmed crosslinking, and the reduction of free primary amino groups indicated effective crosslinking even at a 1% v/v crosslinker concentration. Moreover, stress-strain and compression characteristics of the 5% v/v BDDE crosslinked matrix were comparable to native gelatin. Based on material science measurements, the crosslinked matrices may be promising candidates for scaffold development, including properties such as resistance to enzymatic degradation and heat sterilization.
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Reagentes de Ligações Cruzadas , Resinas Epóxi , Gelatina , Água , Gelatina/química , Reagentes de Ligações Cruzadas/química , Água/química , Polietilenoglicóis/química , Temperatura Alta , Alicerces Teciduais/química , Materiais Biocompatíveis/química , Teste de Materiais , Espectroscopia de Infravermelho com Transformada de Fourier , Solubilidade , Esterilização/métodosRESUMO
The increasing knowledge of molecular alterations in malignancies, including mutations and regulatory failures in the mTOR (mechanistic target of rapamycin) signaling pathway, highlights the importance of mTOR hyperactivity as a validated target in common and rare malignancies. This review summarises recent findings on the characterization and prognostic role of mTOR kinase complexes (mTORC1 and mTORC2) activity regarding differences in their function, structure, regulatory mechanisms, and inhibitor sensitivity. We have recently identified new tumor types with RICTOR (rapamycin-insensitive companion of mTOR) amplification and associated mTORC2 hyperactivity as useful potential targets for developing targeted therapies in lung cancer and other newly described malignancies. The activity of mTOR complexes is recommended to be assessed and considered in cancers before mTOR inhibitor therapy, as current first-generation mTOR inhibitors (rapamycin and analogs) can be ineffective in the presence of mTORC2 hyperactivity. We have introduced and proposed a marker panel to determine tissue characteristics of mTOR activity in biopsy specimens, patient materials, and cell lines. Ongoing phase trials of new inhibitors and combination therapies are promising in advanced-stage patients selected by genetic alterations, molecular markers, and/or protein expression changes in the mTOR signaling pathway. Hopefully, the summarized results, our findings, and the suggested characterization of mTOR activity will support therapeutic decisions.
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Neoplasias Pulmonares , Serina-Treonina Quinases TOR , Humanos , Proteína Companheira de mTOR Insensível à Rapamicina/genética , Proteína Companheira de mTOR Insensível à Rapamicina/metabolismo , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Sirolimo/farmacologia , Fatores de Transcrição/metabolismoRESUMO
We aimed to investigate serum amino-terminal C-type natriuretic peptide (NT-proCNP) and its relationship with quantitative and qualitative HDL-parameters in patients with end-stage renal disease (ESRD) before, then 1 and 6 months after kidney transplantation (TX). Seventy patients (47 males, 23 females, mean age 51.7 ± 12.4 years) were enrolled in a prospective follow-up study. We examined serum creatinine, C-reactive protein, procalcitonin, fasting glucose and lipid parameters before, then 1 and 6 months after TX. High-density lipoprotein- (HDL)-associated paraoxonase-1 (PON1) paraoxonase and arylesterase activities were measured spectrophotometrically. Lipoprotein subfractions were determined by Lipoprint. NT-proCNP and oxidized low-density lipoprotein (oxLDL) levels were measured by ELISA. Mean NT-proCNP was 45.8 ± 21.9 pmol/L before renal transplantation and decreased markedly 1 month and 6 months after transplantation (5.3 ± 2.5 and 7.7 ± 4.9 pmol/L, respectively, P = 1 × 10-4). During the 6 months' follow-up, PON1 arylesterase, paraoxonase and salt-stimulated paraoxonase activities improved. NT-proCNP positively correlated with procalcitonin and creatinine and negatively with GFR, LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C). There was a negative correlation between serum NT-proCNP and PON1 arylesterase activity. According to the multiple regression analysis, the best predicting variables of NT-proCNP were serum procalcitonin, creatinine and PON1 arylesterase activity. NT-proCNP might be a novel link between HDL dysfunction and impaired vascular function in ESRD, but not after kidney transplantation. Further studies in larger populations are needed to clarify the exact role of NT-proCNP in the risk prediction for cardiovascular comorbidities and complications in ESRD.
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Falência Renal Crônica , Transplante de Rim , Masculino , Feminino , Humanos , Adulto , Pessoa de Meia-Idade , Peptídeo Natriurético Tipo C , Lipoproteínas HDL , Seguimentos , Estudos Prospectivos , Pró-Calcitonina , Arildialquilfosfatase/metabolismo , Creatinina , Falência Renal Crônica/cirurgia , Vasodilatadores , ColesterolRESUMO
Background: Insects have specialized cell types that participate in the elimination of parasites, for instance, the lamellocytes of the broadly studied species Drosophila melanogaster. Other drosophilids, such as Drosophila ananassae and the invasive Zaprionus indianus, have multinucleated giant hemocytes, a syncytium of blood cells that participate in the encapsulation of the eggs or larvae of parasitoid wasps. These cells can be formed by the fusion of hemocytes in circulation or originate from the lymph gland. Their ultrastructure highly resembles that of the mammalian megakaryocytes. Methods: Morphological, protein expressional, and functional features of blood cells were revealed using epifluorescence and confocal microscopy. The respective hemocyte subpopulations were identified using monoclonal antibodies in indirect immunofluorescence assays. Fluorescein isothiocyanate (FITC)-labeled Escherichia coli bacteria were used in phagocytosis tests. Gene expression analysis was performed following mRNA sequencing of blood cells. Results: D. ananassae and Z. indianus encapsulate foreign particles with the involvement of multinucleated giant hemocytes and mount a highly efficient immune response against parasitoid wasps. Morphological, protein expressional, and functional assays of Z. indianus blood cells suggested that these cells could be derived from large plasmatocytes, a unique cell type developing specifically after parasitoid wasp infection. Transcriptomic analysis of blood cells, isolated from naïve and wasp-infected Z. indianus larvae, revealed several differentially expressed genes involved in signal transduction, cell movements, encapsulation of foreign targets, energy production, and melanization, suggesting their role in the anti-parasitoid response. A large number of genes that encode proteins associated with coagulation and wound healing, such as phenoloxidase activity factor-like proteins, fibrinogen-related proteins, lectins, and proteins involved in the differentiation and function of platelets, were constitutively expressed. The remarkable ultrastructural similarities between giant hemocytes and mammalian megakaryocytes, and presence of platelets, and giant cell-derived anucleated fragments at wound sites hint at the involvement of this cell subpopulation in wound healing processes, in addition to participation in the encapsulation reaction. Conclusion: Our observations provide insights into the broad repertoire of blood cell functions required for efficient defense reactions to maintain the homeostasis of the organism. The analysis of the differentiation and function of multinucleated giant hemocytes gives an insight into the diversification of the immune mechanisms.
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Hemócitos , Vespas , Animais , Drosophila melanogaster , Diferenciação Celular , Drosophila , Plaquetas , MamíferosRESUMO
BACKGROUND: Pigment epithelium-derived factor (PEDF) is a serin protease inhibitor and a potent inhibitor of angiogenesis. Its serum level has significant associations with metabolic parameters. However, little is known about the association between PEDF levels and lipid parameters in renal transplanted (TX) patients. Therefore, our aim was to investigate the relationship between PEDF level and lipid parameters in TX patients. METHODS: Seventy TX patients (47 males, 23 females, mean age 51.7 ± 12.4 years) and 34 healthy controls were enrolled. We examined the serum creatinine, C-reactive protein, fasting glucose and lipid parameters right before, then 1 and 6 months after TX. High-density lipoprotein (HDL)-associated paraoxonase-1 (PON1) activities were measured spectrophotometrically. Lipoprotein subfractions were determined by Lipoprint. PEDF and oxidized low-density liporotein (oxLDL) levels were measured by ELISA. RESULTS: Before transplantation, patients had had a significantly higher PEDF level compared to control subjects (p < 0.001). One month after transplantation, their PEDF level decreased significantly reaching the healthy controls' level, and this lower level was maintained during the 6 months follow-up period as well. The initial oxLDL level was significantly higher, while PON1 activities were significantly lower in the patient group compared to the control group. We found a significant positive correlation between PEDF and total cholesterol, low-density lipoprotein (LDL)-cholesterol, triglyceride, oxLDL and small HDL subfraction; while negative correlations were found between PEDF and mean LDL size and large HDL subfraction during the entire follow-up period. CONCLUSION: PEDF may play an important role in the increased oxidative stress and enhanced atherogenesis in renal transplant patients.
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Falência Renal Crônica , Transplante de Rim , Serpinas , Adulto , Arildialquilfosfatase , Proteína C-Reativa , Colesterol , Creatinina , Proteínas do Olho , Feminino , Glucose , Humanos , Falência Renal Crônica/cirurgia , Lipoproteínas , Lipoproteínas HDL , Lipoproteínas LDL , Masculino , Pessoa de Meia-Idade , Fatores de Crescimento Neural , TriglicerídeosRESUMO
The present research aimed to characterize soft tissue implants that were prepared with the use of crosslinked hyaluronic acid (HA) using two different crosslinkers and multiple reagent concentrations, alone or in combination with fibrin. The effect of the implants was evaluated in an in vivo mouse model, after 4 weeks in one group and after 12 weeks in the other. The explants were compared using analytical methods, evaluating microscopic images, and a histology analysis. The kinetics of the degradation and remodeling of explants were found to be greatly dependent on the concentration and type of crosslinker; generally, divinyl sulfone (DVS) resists degradation more effectively compared to butanediol diglycidyl ether (BDDE). The presence of fibrin enhances the formation of blood vessels, and the infiltration of cells and extracellular matrix. In summary, if the aim is to create a soft tissue implant with easier degradation of the HA content, then the use of 2-5% BDDE is found to be optimal. For a longer degradation time, 5% DVS is the more suitable crosslinker. The use of fibrin was found to support the biological process of remodeling, while keeping the advances of HA in void filling, enabling the parallel degradation and remodeling processes.
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INTRODUCTION: Lung transplant recipients (LuTX) represent a vulnerable population for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Even though many vaccines are already developed, more clinical data need to support effective immunological response in immunocompromised patients. METHODS: Stable LuTX recipients with no medical history of coronavirus disease (COVID-19) were enrolled. Currently available messenger RNA (mRNA) (BNT162b2-mRNA, mRNA-1273) and non-mRNA (ChAdOx1, BBIBP-CorV) vaccines were given according to availability, boosters were all mRNA-based. SARS-CoV-2 Spike1 immunoglobulin G (IgG) antibody titer was evaluated before and 2 weeks after second and third dose. Difference between mRNA versus non-mRNA vaccines was assessed. RESULTS: Forty-one patients (49% men, age 48.4 ± 13.8 years) received two doses of SARS-CoV-2 vaccines: 23 of mRNA, 18 of non-mRNA, and 24/41 (58%) received a third dose. Median 92 months passed since transplantation, and serum level of tacrolimus was median 5.5 ng/ml. Positive serology was found in 37% of all patients after the second dose, 86% had mRNA vaccine. After the third dose, 29% became positive who had no antibody before. Significantly higher level of antibody was found after the second mRNA than non-mRNA vaccines (2.2 vs. 1568.8 U/ml, respectively, p = .002). 6/23 (26%) patients received two doses of mRNA vaccine developed COVID-19 after the second injection in an average of 178 days, half of them recovered, half of them died in intensive care unit (ICU). 3/6 (50%) patients with two doses mRNA and recovered from COVID-19 had significantly higher level of antibody (average 20847.3 U/ml) than without infection. After the booster vaccine, 1/24 (4%) developed infection. CONCLUSION: Immunosuppression therapy may induce a weaker SARS-CoV-2 response in LuTX recipients; therefore, third dose is a priority in transplanted patients. The highest antibody level was measured recovering from COVID after two doses. Our data confirm that booster mRNA vaccine could increase antibody levels, even if immunization was started with non-mRNA vaccine.
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Vacina BNT162 , Vacinas contra COVID-19 , COVID-19 , Transplantados , Adulto , Anticorpos Antivirais , Vacina BNT162/efeitos adversos , COVID-19/prevenção & controle , Vacinas contra COVID-19/efeitos adversos , Feminino , Humanos , Pulmão , Masculino , Pessoa de Meia-Idade , SARS-CoV-2 , Vacinas Virais/efeitos adversosRESUMO
Alzheimer's disease (AD) is the most common form of dementia characterized by cognitive dysfunctions. Pharmacological interventions to slow the progression of AD are intensively studied. A potential direction targets neuronal sigma-1 receptors (S1Rs). S1R ligands are recognized as promising therapeutic agents that may alleviate symptom severity of AD, possibly via preventing amyloid-ß-(Aß-) induced neurotoxicity on the endoplasmic reticulum stress-associated pathways. Furthermore, S1Rs may also modulate adult neurogenesis, and the impairment of this process is reported to be associated with AD. We aimed to investigate the effects of two S1R agonists, dimethyltryptamine (DMT) and PRE084, in an Aß-induced in vivo mouse model characterizing neurogenic and anti-neuroinflammatory symptoms of AD, and the modulatory effects of S1R agonists were analyzed by immunohistochemical methods and western blotting. DMT, binding moderately to S1R but with high affinity to 5-HT receptors, negatively influenced neurogenesis, possibly as a result of activating both receptors differently. In contrast, the highly selective S1R agonist PRE084 stimulated hippocampal cell proliferation and differentiation. Regarding neuroinflammation, DMT and PRE084 significantly reduced Aß1-42-induced astrogliosis, but neither had remarkable effects on microglial activation. In summary, the highly selective S1R agonist PRE084 may be a promising therapeutic agent for AD. Further studies are required to clarify the multifaceted neurogenic and anti-neuroinflammatory roles of these agonists.
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Doença de Alzheimer , Receptores sigma , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Modelos Animais de Doenças , Camundongos , N,N-Dimetiltriptamina , Neurogênese , Doenças Neuroinflamatórias , Fragmentos de Peptídeos , Receptores sigma/metabolismo , Receptor Sigma-1RESUMO
Background: Afamin is a liver-produced bioactive protein and features α- and γ-tocopherol binding sites. Afamin levels are elevated in metabolic syndrome and obesity and correlate well with components of metabolic syndrome. Afamin concentrations, correlations between afamin and vitamin E, afamin and lipoprotein subfractions in non-diabetic, obese patients have not been fully examined. Methods: Fifty non-diabetic, morbidly obese patients and thirty-two healthy, normal-weight individuals were involved in our study. The afamin concentrations were measured by ELISA. Lipoprotein subfractions were determined with gel electrophoresis. Gas chromatography-mass spectrometry was used to measure α- and γ tocopherol levels. Results: Afamin concentrations were significantly higher in the obese patients compared to the healthy control (70.4 ± 12.8 vs. 47.6 ± 8.5 µg/mL, p < 0.001). Positive correlations were found between afamin and fasting glucose, HbA1c, hsCRP, triglyceride, and oxidized LDL level, as well as the amount and ratio of small HDL subfractions. Negative correlations were observed between afamin and mean LDL size, as well as the amount and ratio of large HDL subfractions. After multiple regression analysis, HbA1c levels and small HDL turned out to be independent predictors of afamin. Conclusions: Afamin may be involved in the development of obesity-related oxidative stress via the development of insulin resistance and not by affecting α- and γ-tocopherol levels.
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Proteínas de Transporte , Glicoproteínas , Obesidade Mórbida , Albumina Sérica Humana , Proteínas de Transporte/metabolismo , Estudos de Casos e Controles , Glicoproteínas/metabolismo , Humanos , Resistência à Insulina , Lipoproteínas , Síndrome Metabólica/metabolismo , Obesidade Mórbida/metabolismo , Estresse Oxidativo , Albumina Sérica Humana/metabolismoRESUMO
Spreading depolarizations (SDs) indicate injury progression and predict worse clinical outcome in acute brain injury. We demonstrate in rodents that acute brain swelling upon cerebral ischemia impairs astroglial glutamate clearance and increases the tissue area invaded by SD. The cytotoxic extracellular glutamate accumulation (>15 µM) predisposes an extensive bulk of tissue (4-5 mm2) for a yet undescribed simultaneous depolarization (SiD). We confirm in rat brain slices exposed to osmotic stress that SiD is the pathological expansion of prior punctual SD foci (0.5-1 mm2), is associated with astrocyte swelling, and triggers oncotic neuron death. The blockade of astrocytic aquaporin-4 channels and Na+/K+/Cl- co-transporters, or volume-regulated anion channels mitigated slice edema, extracellular glutamate accumulation (<10 µM) and SiD occurrence. Reversal of slice swelling by hyperosmotic mannitol counteracted glutamate accumulation and prevented SiD. In contrast, inhibition of glial metabolism or inhibition of astrocyte glutamate transporters reproduced the SiD phenotype. Finally, we show in the rodent water intoxication model of cytotoxic edema that astrocyte swelling and altered astrocyte calcium waves are central in the evolution of SiD. We discuss our results in the light of evidence for SiD in the human cortex. Our results emphasize the need of preventive osmotherapy in acute brain injury.
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Edema Encefálico , Lesões Encefálicas , Animais , Ratos , Astrócitos/metabolismo , Edema Encefálico/patologia , Lesões Encefálicas/metabolismo , Edema/metabolismo , Ácido Glutâmico/metabolismo , Simportadores de Cloreto de Sódio-Potássio/metabolismoRESUMO
Dimethyltryptamine (DMT), an endogenous ligand of sigma-1 receptors (Sig-1Rs), acts against systemic hypoxia, but whether DMT may prevent cerebral ischemic injury is unexplored. Here global forebrain ischemia was created in anesthetized rats and aggravated with the induction of spreading depolarizations (SDs) and subsequent short hypoxia before reperfusion. Drugs (DMT, the selective Sig-1R agonist PRE-084, the Sig-1R antagonist NE-100, or the serotonin receptor antagonist asenapine) were administered intravenously alone or in combination while physiological variables and local field potential from the cerebral cortex was recorded. Neuroprotection and the cellular localization of Sig-1R were evaluated with immunocytochemistry. Plasma and brain DMT content was measured by 2D-LC-HRMS/MS. The affinity of drugs for cerebral Sig-1R was evaluated with a radioligand binding assay. Both DMT and PRE-084 mitigated SDs, counteracted with NE-100. Further, DMT attenuated SD when co-administered with asenapine, compared to asenapine alone. DMT reduced the number of apoptotic and ferroptotic cells and supported astrocyte survival. The binding affinity of DMT to Sig-1R matched previously reported values. Sig-1Rs were associated with the perinuclear cytoplasm of neurons, astrocytes and microglia, and with glial processes. According to these data, DMT may be considered as adjuvant pharmacological therapy in the management of acute cerebral ischemia.
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Isquemia Encefálica/metabolismo , Encéfalo/metabolismo , Depressão Alastrante da Atividade Elétrica Cortical/efeitos dos fármacos , N,N-Dimetiltriptamina/farmacologia , Doenças Neurodegenerativas/metabolismo , Receptores sigma/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Isquemia Encefálica/tratamento farmacológico , Depressão Alastrante da Atividade Elétrica Cortical/fisiologia , Relação Dose-Resposta a Droga , Masculino , N,N-Dimetiltriptamina/uso terapêutico , Doenças Neurodegenerativas/prevenção & controle , Ratos , Ratos Sprague-Dawley , Receptores sigma/agonistas , Receptor Sigma-1RESUMO
[This corrects the article DOI: 10.1371/journal.pone.0233851.].
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Hypoxic-ischemic encephalopathy (HIE) is still a major cause of neonatal death and disability as therapeutic hypothermia (TH) alone cannot afford sufficient neuroprotection. The present study investigated whether ventilation with molecular hydrogen (2.1% H2) or graded restoration of normocapnia with CO2 for 4 h after asphyxia would augment the neuroprotective effect of TH in a subacute (48 h) HIE piglet model. Piglets were randomized to untreated naïve, control-normothermia, asphyxia-normothermia (20-min 4%O2-20%CO2 ventilation; Tcore = 38.5 °C), asphyxia-hypothermia (A-HT, Tcore = 33.5 °C, 2-36 h post-asphyxia), A-HT + H2, or A-HT + CO2 treatment groups. Asphyxia elicited severe hypoxia (pO2 = 19 ± 5 mmHg) and mixed acidosis (pH = 6.79 ± 0.10). HIE development was confirmed by altered cerebral electrical activity and neuropathology. TH was significantly neuroprotective in the caudate nucleus but demonstrated virtually no such effect in the hippocampus. The mRNA levels of apoptosis-inducing factor and caspase-3 showed a ~10-fold increase in the A-HT group compared to naïve animals in the hippocampus but not in the caudate nucleus coinciding with the region-specific neuroprotective effect of TH. H2 or CO2 did not augment TH-induced neuroprotection in any brain areas; rather, CO2 even abolished the neuroprotective effect of TH in the caudate nucleus. In conclusion, the present findings do not support the use of these medical gases to supplement TH in HIE management.
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Asfixia Neonatal/terapia , Dano Encefálico Crônico/prevenção & controle , Dióxido de Carbono/uso terapêutico , Hidrogênio/uso terapêutico , Hipotermia Induzida , Hipóxia-Isquemia Encefálica/terapia , Neuroproteção/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Acidose/sangue , Acidose/etiologia , Acidose/prevenção & controle , Administração por Inalação , Animais , Animais Recém-Nascidos , Fator de Indução de Apoptose/biossíntese , Fator de Indução de Apoptose/genética , Asfixia Neonatal/complicações , Asfixia Neonatal/tratamento farmacológico , Dano Encefálico Crônico/etiologia , Fator Neurotrófico Derivado do Encéfalo/biossíntese , Fator Neurotrófico Derivado do Encéfalo/genética , Dióxido de Carbono/administração & dosagem , Dióxido de Carbono/toxicidade , Caspase 3/biossíntese , Caspase 3/genética , Núcleo Caudado/patologia , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Eletroencefalografia , Potenciais Evocados Visuais/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Hipocampo/patologia , Hidrogênio/administração & dosagem , Hidrogênio/análise , Hipóxia-Isquemia Encefálica/complicações , Hipóxia-Isquemia Encefálica/tratamento farmacológico , Hipóxia-Isquemia Encefálica/patologia , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/genética , Fármacos Neuroprotetores/administração & dosagem , Especificidade de Órgãos , Distribuição Aleatória , SuínosRESUMO
Odontarrhena lesbiaca is an endemic species to the serpentine soils of Lesbos Island (Greece). As a nickel (Ni) hyperaccumulator, it possesses an exceptional Ni tolerance; and it can accumulate up to 0.2-2.4% Ni of its leaves' dry weight. In our study, O. lesbiaca seeds from two geographically separated study sites (Ampeliko and Loutra) were germinated and grown on control and Ni-containing (3000 mg/kg) soil in a rhizotron system. Ni excess induced significant Ni uptake and translocation in both O. lesbiaca ecotypes and affected their root architecture differently: plants from the Ampeliko site proved to be more tolerant; since their root growth was less inhibited compared to plants originated from the Loutra site. In the roots of the Ampeliko ecotype nitric oxide (NO) was being accumulated, while the degree of protein tyrosine nitration decreased; suggesting that NO in this case acts as a signaling molecule. Moreover, the detected decrease in protein tyrosine nitration may serve as an indicator of this ecotype's better relative tolerance compared to the more sensitive plants originated from Loutra. Results suggest that Ni hypertolerance and the ability of hyperaccumulation might be connected to the plants' capability of maintaining their nitrosative balance; yet, relatively little is known about the relationship between excess Ni, tolerance mechanisms and the balance of reactive nitrogen species in plants so far.
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Brain interstitial pH (pHbrain) alterations play an important role in the mechanisms of neuronal injury in neonatal hypoxic-ischemic encephalopathy (HIE) induced by perinatal asphyxia. The newborn pig is an established large animal model to study HIE, however, only limited information on pHbrain alterations is available in this species and it is restricted to experimental perinatal asphyxia (PA) and the immediate reventilation. Therefore, we sought to determine pHbrain over the first 24h of HIE development in piglets. Anaesthetized, ventilated newborn pigs (n = 16) were instrumented to control major physiological parameters. pHbrain was determined in the parietal cortex using a pH-selective microelectrode. PA was induced by ventilation with a gas mixture containing 6%O2-20%CO2 for 20 min, followed by reventilation with air for 24h, then the brains were processed for histopathology assessment. The core temperature was maintained unchanged during PA (38.4±0.1 vs 38.3±0.1°C, at baseline versus the end of PA, respectively; mean±SEM). In the arterial blood, PA resulted in severe hypoxia (PaO2: 65±4 vs 23±1*mmHg, *p<0.05) as well as acidosis (pHa: 7.53±0.03 vs 6.79±0.02*) that is consistent with the observed hypercapnia (PaCO2: 37±3 vs 160±6*mmHg) and lactacidemia (1.6±0.3 vs 10.3±0.7*mmol/L). Meanwhile, pHbrain decreased progressively from 7.21±0.03 to 5.94±0.11*. Reventilation restored pHa, blood gases and metabolites within 4 hours except for PaCO2 that remained slightly elevated. pHbrain returned to 7.0 in 29.4±5.5 min and then recovered to its baseline level without showing secondary alterations during the 24 h observation period. Neuropathological assessment also confirmed neuronal injury. In conclusion, in spite of the severe acidosis and alterations in blood gases during experimental PA, pHbrain recovered rapidly and notably, there was no post-asphyxia hypocapnia that is commonly observed in many HIE babies. Thus, the neuronal injury in our piglet model is not associated with abnormal pHbrain or low PaCO2 over the first 24 h after PA.
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Encéfalo/metabolismo , Hipóxia-Isquemia Encefálica/metabolismo , Acidose/sangue , Acidose/complicações , Acidose/metabolismo , Acidose/fisiopatologia , Animais , Animais Recém-Nascidos , Asfixia Neonatal/sangue , Asfixia Neonatal/metabolismo , Asfixia Neonatal/fisiopatologia , Encéfalo/patologia , Encéfalo/fisiopatologia , Hemodinâmica , Concentração de Íons de Hidrogênio , Hipercapnia/sangue , Hipercapnia/complicações , Hipercapnia/metabolismo , Hipercapnia/fisiopatologia , Hipóxia-Isquemia Encefálica/sangue , Hipóxia-Isquemia Encefálica/complicações , Hipóxia-Isquemia Encefálica/fisiopatologia , Masculino , Neurônios/patologia , Oxigênio/metabolismo , SuínosRESUMO
Spontaneous, recurrent spreading depolarizations (SD) are increasingly more appreciated as a pathomechanism behind ischemic brain injuries. Although the prostaglandin F2α - FP receptor signaling pathway has been proposed to contribute to neurodegeneration, it has remained unexplored whether FP receptors are implicated in SD or the coupled cerebral blood flow (CBF) response. We set out here to test the hypothesis that FP receptor blockade may achieve neuroprotection by the inhibition of SD. Global forebrain ischemia/reperfusion was induced in anesthetized rats by the bilateral occlusion and later release of the common carotid arteries. An FP receptor antagonist (AL-8810; 1 mg/bwkg) or its vehicle were administered via the femoral vein 10 min later. Two open craniotomies on the right parietal bone served the elicitation of SD with 1 M KCl, and the acquisition of local field potential. CBF was monitored with laser speckle contrast imaging over the thinned parietal bone. Apoptosis and microglia activation, as well as FP receptor localization were evaluated with immunohistochemistry. The data demonstrate that the antagonism of FP receptors suppressed SD in the ischemic rat cerebral cortex and reduced the duration of recurrent SDs by facilitating repolarization. In parallel, FP receptor antagonism improved perfusion in the ischemic cerebral cortex, and attenuated hypoemic CBF responses associated with SD. Further, FP receptor antagonism appeared to restrain apoptotic cell death related to SD recurrence. In summary, the antagonism of FP receptors (located at the neuro-vascular unit, neurons, astrocytes and microglia) emerges as a promising approach to inhibit the evolution of SDs in cerebral ischemia.
Assuntos
Isquemia Encefálica/tratamento farmacológico , Circulação Cerebrovascular/efeitos dos fármacos , Depressão Alastrante da Atividade Elétrica Cortical/efeitos dos fármacos , Dinoprosta/análogos & derivados , Animais , Isquemia Encefálica/fisiopatologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/fisiopatologia , Infarto Cerebral/tratamento farmacológico , Circulação Cerebrovascular/fisiologia , Depressão Alastrante da Atividade Elétrica Cortical/fisiologia , Dinoprosta/farmacologia , Masculino , Prosencéfalo/efeitos dos fármacos , Prosencéfalo/fisiopatologia , Prostaglandinas/farmacologia , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacosRESUMO
Stroke is an important cause of mortality and disability. Treatment options are limited, therefore the progress in this regard is urgently needed. Nimodipine, an L-type voltage-gated calcium channel antagonist dilates cerebral arterioles, but its systemic administration may cause potential side effects. We have previously constructed chitosan nanoparticles as drug carriers, which release nimodipine in response to decreasing pH typical of cerebral ischemia. Here we have set out to evaluate this nanomedical approach to deliver nimodipine selectively to acidic ischemic brain tissue. After washing a nanoparticle suspension with or without nimodipine (100⯵M) on the exposed brain surface of anesthetized rats (nâ¯=â¯18), both common carotid arteries were occluded to create forebrain ischemia. Spreading depolarizations (SDs) were elicited by 1M KCl to deepen the ischemic insult. Local field potential, cerebral blood flow (CBF) and tissue pH were recorded from the cerebral cortex. Microglia activation and neuronal survival were evaluated in brain sections by immunocytochemistry. Ischemia-induced tissue acidosis initiated nimodipine release from nanoparticles, confirmed by the significant elevation of baseline CBF (47.8⯱â¯23.7 vs. 29.3⯱â¯6.96%). Nimodipine shortened the duration of both SD itself (48.07⯱â¯23.29 vs. 76.25⯱â¯17.2â¯s), and the associated tissue acidosis (65.46⯱â¯20.2 vs. 138.3⯱â¯66.07â¯s), moreover it enhanced the SD-related hyperemia (48.15⯱â¯42.04 vs. 17.29⯱â¯11.03%). Chitosan nanoparticles did not activate microglia. The data support the concept that tissue acidosis linked to cerebral ischemia can be employed as a trigger for targeted drug delivery. Nimodipine-mediated vasodilation and SD inhibition can be achieved by pH-responsive chitosan nanoparticles applied directly to the brain surface.
Assuntos
Acidose/metabolismo , Isquemia Encefálica/metabolismo , Bloqueadores dos Canais de Cálcio/administração & dosagem , Quitosana/metabolismo , Microglia/efeitos dos fármacos , Nanopartículas/metabolismo , Nimodipina/administração & dosagem , Prosencéfalo/efeitos dos fármacos , Acidose/etiologia , Animais , Materiais Biocompatíveis , Isquemia Encefálica/complicações , Isquemia Encefálica/patologia , Artéria Carótida Primitiva , Sobrevivência Celular , Circulação Cerebrovascular , Depressão Alastrante da Atividade Elétrica Cortical/efeitos dos fármacos , Portadores de Fármacos , Sistemas de Liberação de Medicamentos , Concentração de Íons de Hidrogênio , Neurônios/efeitos dos fármacos , Neurônios/patologia , Prosencéfalo/irrigação sanguínea , Prosencéfalo/patologia , RatosRESUMO
A fixed combination of Berberis aristata and Silybum marianum (Berberol) has been used by patients with dyslipidaemia. The aim of the present meta-analysis was to systematically evaluate the efficacy and safety of a fixed combination of B. aristata and S. marianum (Berberol) on serum lipid levels compared to placebo in a meta-analysis based on randomised, controlled trials. The meta-analysis was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, using the PICO (patients, intervention, comparison, outcome) format, and it was registered in the International Prospective Register of Systematic Reviews. The Cochrane Central Register of Controlled Trials, PubMed, Embase, and Web of Science databases were searched for relevant studies. Placebo-controlled clinical studies involving adult patients with a condition of dyslipidaemia and receiving a fixed combination of B. aristata and S. marianum were included. Four randomised trials, including a total of 491 patients, were pooled in statistical analysis. According to the present meta-analysis, Berberol significantly lowered the low-density lipoprotein level, total cholesterol, fasting plasma glucose levels, and the Homeostatic Model Assessment index compared to placebo; however, its effects on the high-density lipoprotein level, triglyceride level, and body mass index were not statistically significant by the end of a 3-month treatment period. Berberol appeared to be safe, and it did not increase the levels of alanine transaminase, aspartate transaminase, and creatine kinase enzymes. Berberol is an effective and presumably safe complementary therapy for the treatment of dyslipidaemia; however, the evidence supporting its use is very limited. The optimum dose and duration of treatment are unclear. A comprehensive evaluation of efficacy and safety is required in further high-quality clinical studies involving larger patient populations.
Assuntos
Berberis , Dislipidemias/tratamento farmacológico , Fitoterapia , Silybum marianum , Animais , Quimioterapia Combinada , HumanosRESUMO
Cortical spreading depolarization (SD) involves activation of NMDA receptors and elicit neurovascular unit dysfunction. NMDA cannot trigger SD in newborns, thus its effect on neurovascular function is not confounded by other aspects of SD. The present study investigated if NMDA affected hypercapnia-induced microvascular and electrophysiological responses in the cerebral cortex of newborn pigs. Anesthetized piglets were fitted with cranial windows over the parietal cortex to study hemodynamic and electrophysiological responses to graded hypercapnia before/after topically applied NMDA assessed with laser-speckle contrast imaging and recording of local field potentials (LFP)/neuronal firing, respectively. NMDA increased cortical blood flow (CoBF), suppressed LFP power in most frequency bands but evoked a 2.5 Hz δ oscillation. The CoBF response to hypercapnia was abolished after NMDA and the hypercapnia-induced biphasic changes in δ and θ LFP power were also altered. MK-801 prevented NMDA-induced increases in CoBF and the attenuation of microvascular reactivity to hypercapnia. The neuronal nitric oxide synthase (nNOS) inhibitor (N-(4 S)-4-amino-5-[aminoethyl]aminopentyl-N'-nitroguanidin) also significantly preserved the CoBF response to hypercapnia after NMDA, although it didn't reduce NMDA-induced increases in CoBF. In conclusion, excess activation of NMDA receptors alone can elicit SD-like neurovascular unit dysfunction involving nNOS activity.
Assuntos
Córtex Cerebral/efeitos dos fármacos , Circulação Cerebrovascular/efeitos dos fármacos , Hipercapnia/fisiopatologia , N-Metilaspartato/farmacologia , Neurônios/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Arteríolas/efeitos dos fármacos , Córtex Cerebral/fisiopatologia , Masculino , Suínos , Vasodilatação/efeitos dos fármacosRESUMO
BACKGROUND: Unilateral weakness of an upper extremity is most frequently caused by traumatic nerve injury or compression neuropathy. In rare cases, lesion of the central nervous system may result in syndromes suggesting peripheral nerve damage by the initial examination. Pseudoperipheral hand palsy is the best known of these, most frequently caused by a small lesion in the contralateral motor cortex of the brain. The 'hand knob' area refers to a circumscribed region in the precentral gyrus of the posterior frontal lobe, the lesion of which leads to isolated weakness of the upper extremity mimicking peripheral nerve damage. The etiology of this rare syndrome is almost exclusively related to an embolic infarction. CASE PRESENTATION: We present the case of a 70-year-old male patient with isolated left sided upper extremity weakness and clumsiness without sensory disturbance suggesting a lesion of the radial nerve. Nerve conduction studies had normal results excluding peripheral nerve damage. Neuroimaging (cranial CT and MRI) detected 3 space occupying lesions, one of them in the right precentral gyrus. An irregularly shaped tumor was found by CT in the left lung with multiple associated lymph node conglomerates. The metastasis from this mucinous tubular adenocarcinoma with solid anaplastic parts to the 'hand knob' area was responsible for the first clinical sign related to the pulmonary malignancy. CONCLUSIONS: Pseudoperipheral palsy of the upper extremity is not necessarily the consequence of an embolic stroke. If nerve conduction studies have normal results, neuroimaging - preferably MRI - should be performed, as lesion in the hand-knob area of the precentral gyrus can also be caused by a malignancy.