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1.
Nutrients ; 12(5)2020 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-32380648

RESUMO

Chorioamnionitis can lead to inflammation and injury of the liver and gut, thereby predisposing patients to adverse outcomes such as necrotizing enterocolitis (NEC). In addition, intestinal bile acids (BAs) accumulation is causally linked to NEC development. Plant sterols are a promising intervention to prevent NEC development, considering their anti-inflammatory properties in the liver. Therefore, we investigated whether an intra-amniotic (IA) Ureaplasma parvum (UP) infection affected the liver and enterohepatic circulation (EHC) and evaluated whether an IA administered plant sterol mixture dissolved in ß-cyclodextrin exerted prophylactic effects. An ovine chorioamnionitis model was used in which liver inflammation and the EHC were assessed following IA UP exposure in the presence or absence of IA prophylactic plant sterols (a mixture of ß-sitosterol and campesterol dissolved in ß-cyclodextrin (carrier)) or carrier alone. IA UP exposure caused an inflammatory reaction in the liver, histologically seen as clustered and conflated hepatic erythropoiesis in the parenchyma, which was partially prevented by IA administration of sterol + ß-cyclodextrin, or ß-cyclodextrin alone. In addition, IA administration of ß-cyclodextrin prior to UP caused changes in the expression of several hepatic BAs transporters, without causing alterations in other aspects of the EHC. Thereby, the addition of plant sterols to the carrier ß-cyclodextrin did not have additional effects.


Assuntos
Colesterol/análogos & derivados , Corioamnionite/tratamento farmacológico , Corioamnionite/microbiologia , Portadores de Fármacos , Enterocolite Necrosante/microbiologia , Enterocolite Necrosante/prevenção & controle , Circulação Êntero-Hepática/efeitos dos fármacos , Feto/irrigação sanguínea , Fígado/irrigação sanguínea , Fitosteróis/administração & dosagem , Fitoterapia , Profilaxia Pós-Exposição/métodos , Sitosteroides/administração & dosagem , Infecções por Ureaplasma , Ureaplasma , beta-Ciclodextrinas , Animais , Colesterol/administração & dosagem , Colesterol/farmacologia , Modelos Animais de Doenças , Feminino , Inflamação , Injeções Intralesionais , Fitosteróis/farmacologia , Gravidez , Ovinos , Sitosteroides/farmacologia
2.
Sci Rep ; 10(1): 3898, 2020 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-32127612

RESUMO

With the current practice of therapeutic hypothermia for neonatal encephalopathy, disability rates and the severity spectrum of cerebral palsy are reduced. Nevertheless, safe and effective adjunct therapies are needed to optimize outcomes. This study's objective was to assess if 18 mg/kg melatonin given rapidly over 2 h at 1 h after hypoxia-ischemia with cooling from 1-13 h was safe, achieved therapeutic levels within 3 h and augmented hypothermic neuroprotection. Following hypoxia-ischemia, 20 newborn piglets were randomized to: (i) Cooling 1-13 h (HT; n = 6); (ii) HT+ 2.5% ethanol vehicle (HT+V; n = 7); (iii) HT + Melatonin (HT+M; n = 7). Intensive care was maintained for 48 h; aEEG was acquired throughout, brain MRS acquired at 24 and 48 h and cell death (TUNEL) evaluated at 48 h. There were no differences for insult severity. Core temperature was higher in HT group for first hour after HI. Comparing HT+M to HT, aEEG scores recovered more quickly by 19 h (p < 0.05); comparing HT+V to HT, aEEG recovered from 31 h (p < 0.05). Brain phosphocreatine/inorganic phosphate and NTP/exchangeable phosphate were higher at 48 h in HT+M versus HT (p = 0.036, p = 0.049 respectively). Including both 24 h and 48 h measurements, the rise in Lactate/N-acetyl aspartate was reduced in white (p = 0.030) and grey matter (p = 0.038) after HI. Reduced overall TUNEL positive cells were observed in HT+M (47.1 cells/mm2) compared to HT (123.8 cells/mm2) (p = 0.0003) and HT+V (97.5 cells/mm2) compared to HT (p = 0.012). Localized protection was seen in white matter for HT+M versus HT (p = 0.036) and internal capsule for HT+M compared to HT (p = 0.001) and HT+V versus HT (p = 0.006). Therapeutic melatonin levels (15-30mg/l) were achieved at 2 h and were neuroprotective following HI, but ethanol vehicle was partially protective.


Assuntos
Asfixia/terapia , Etanol/farmacologia , Hipotermia Induzida , Melatonina/farmacologia , Animais , Animais Recém-Nascidos , Asfixia/tratamento farmacológico , Asfixia/metabolismo , Asfixia/fisiopatologia , Relação Dose-Resposta a Droga , Interações Medicamentosas , Eletroencefalografia/efeitos dos fármacos , Melatonina/farmacocinética , Melatonina/uso terapêutico , Suínos , Distribuição Tecidual
3.
J Aerosol Med Pulm Drug Deliv ; 31(6): 323-330, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29583110

RESUMO

BACKGROUND: Vitamin A (VA) is crucial for lung growth and development. In premature infants, inadequate VA levels are associated with an increased risk of bronchopulmonary dysplasia (BPD). Intramuscular VA supplementation has been shown to decrease the incidence of BPD, but is not widely used in the clinical setting due to concerns about feasibility and pain. We studied VA kinetics, distribution, and the induction of early genetic expression of retinoid homeostatic genes in the lung after endotracheal and intravenous application in a preterm lamb model. METHODS: Lambs were delivered prematurely after 85% of gestation, intubated, and ventilated for 3 hours. The animals were randomized to receive no VA ("control"), a bolus of VA intravenously ("i.v."), or VA endotracheally directly after administration of surfactant ("e.t."). RESULTS: Animals treated with VA endotracheally directly after administration of surfactant showed significant increases of VA in serum and lung compared to controls. Animals treated with a bolus of VA intravenously showed significant increases of VA in serum, lung, and liver; however, peak serum concentrations and mRNA levels of homeostatic genes raised concerns about toxicity in this group. CONCLUSIONS: Endotracheal VA supplementation in preterm lambs is feasible and might offer advantages in comparison to i.v. Further studies are warranted to explore biological effects in the context of BPD.


Assuntos
Displasia Broncopulmonar/prevenção & controle , Pulmão/efeitos dos fármacos , Surfactantes Pulmonares/administração & dosagem , Vitamina A/administração & dosagem , Vitamina A/farmacocinética , Administração por Inalação , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Infusões Intravenosas , Intubação Intratraqueal , Pulmão/crescimento & desenvolvimento , Gravidez , Distribuição Aleatória , Sensibilidade e Especificidade , Ovinos
4.
Neurodegener Dis ; 17(1): 44-58, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27617773

RESUMO

BACKGROUND: The survival of motor neurons is dependent upon neurotrophic factors both during childhood and adolescence and during adult life. In disease conditions, such as in patients with amyotrophic lateral sclerosis (ALS), the mRNA levels of trophic factors like brain-derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1), fibroblast growth factor-2 (FGF-2), and vascular endothelial growth factor are downregulated. This was replicated in our in vivo experimental system following the injection of cerebral spinal fluid (CSF) of sporadic ALS (ALS-CSF) patients. OBJECTIVE: To evaluate the protective role of BDNF in a model of sporadic ALS patients. METHODS: The expressions of endogenous BDNF, its receptor TrkB, the enzyme choline acetyl transferase (ChAT), and phosphorylated neurofilaments were studied in NSC-34 cells. The calcium-buffering and proapoptotic effects were assessed by calbindin-D28K and caspase-3 expression, respectively. RESULTS: ALS-CSF considerably depleted the endogenous BDNF protein, while its effect on IGF-1 and FGF-2 was inconsequential; this indirectly indicates a key role for BDNF in supporting motor neuronal survival. The exogenous supplementation of BDNF reversed autocrine expression; however, it may not be completely receptor mediated, as the TrkB levels were not restored. BDNF completely revived ChAT expression. It may inhibit apoptosis by restoring Ca2+ homeostasis, since caspase-3 and calbindin-D28K expression was back to normal. The organellar ultrastructural changes were only partially reversed. CONCLUSION: Our study provides evidence that BDNF supplementation ameliorates most but not all degenerative changes. The incomplete revival at the ultrastructural level signifies the requirement of factors other than BDNF for near-total protection of motor neurons, and, to an extent, it explains why only a partial success is achieved in clinical trials with BDNF in ALS patients.


Assuntos
Esclerose Lateral Amiotrófica/líquido cefalorraquidiano , Fator Neurotrófico Derivado do Encéfalo/farmacologia , Neurônios Motores/efeitos dos fármacos , Degeneração Neural/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Recuperação de Função Fisiológica/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Cálcio/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Humanos , Filamentos Intermediários/efeitos dos fármacos , Filamentos Intermediários/metabolismo , Filamentos Intermediários/patologia , Camundongos , Neurônios Motores/fisiologia , Neurônios Motores/ultraestrutura , Degeneração Neural/patologia , Degeneração Neural/fisiopatologia , Ratos Wistar , Receptor trkB/metabolismo , Recuperação de Função Fisiológica/fisiologia , Medula Espinal/efeitos dos fármacos , Medula Espinal/patologia , Medula Espinal/fisiopatologia
5.
Mol Cell Pediatr ; 3(1): 15, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27075524

RESUMO

After birth, adequate lung function is necessary for the successful adaptation of a preterm baby. Both prenatal and postnatal insults and therapeutic interventions have an immediate effect on lung function and gas exchange but also interfere with fetal and neonatal lung development. Prenatal insults like chorioamnionitis and prenatal interventions like maternal glucocorticosteroids interact but might also determine the preterm baby's lung response to postnatal interventions ("second hit") like supplementation of oxygen and drug therapy. We review current experimental and clinical findings on the influence of different perinatal factors on preterm lung development and discuss how well-established interventions in neonatal care might be adapted to attenuate postnatal lung injury.

6.
BMC Cancer ; 4: 24, 2004 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-15171791

RESUMO

BACKGROUND: Signaling networks promoting cell growth and proliferation are frequently deregulated in cancer. Tumors often are highly dependent on such signaling pathways and may become hypersensitive to downregulation of key components within these signaling cascades. The classical mitogenic cascade transmits stimuli from growth factor receptors via Ras, Raf, MEK and ERK to the cell nucleus and provides attractive molecular targets for cancer treatment. For example, Ras and Raf kinase inhibitors are already in a number of ongoing phase II and phase III clinical trials. In this study the effect of the Raf kinase inhibitor BAY 43-9006 and of the MEK inhibitor CI-1040 (PD184352) on a Raf dependent lung tumor mouse model was analyzed in detail. METHODS: We have generated a lung cancer mouse model by targeting constitutively active C-Raf kinase to the lung. These mice develop adenomas within 4 months of life. At this time-point they received daily intraperitoneal injections of either 100 mg/kg BAY 43-9006 or CI-1040 for additional 21 days. Thereafter, lungs were isolated and the following parameters were analyzed using histology and immunohistochemistry: overall lung structure, frequency of adenoma foci, proliferation rate, ERK activity, caspase-3 activation, and lung differentiation. RESULTS: Both inhibitors were equally effective in vitro using a sensitive Raf/MEK/ERK ELISA. In vivo, the systemic administration of the MEK inhibitor CI-1040 reduced adenoma formation to a third and significantly restored lung structure. The proliferation rate of lung cells of mice treated with CL-1040 was decreased without any obvious effects on differentiation of pneumocytes. In contrast, the Raf inhibitor BAY 43-9006 did not influence adenoma formation in vivo. CONCLUSION: The MEK inhibitor CI-1040 may be used for the treatment of Ras and/or Raf-dependent human malignancies.


Assuntos
Adenoma/tratamento farmacológico , Benzamidas/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Proteínas Proto-Oncogênicas c-raf/antagonistas & inibidores , Adenoma/enzimologia , Adenoma/patologia , Animais , Apoptose/efeitos dos fármacos , Benzenossulfonatos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/patologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Camundongos Transgênicos , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Niacinamida/análogos & derivados , Compostos de Fenilureia , Proteínas Proto-Oncogênicas c-raf/fisiologia , Piridinas/farmacologia , Sorafenibe
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