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1.
Eur J Nutr ; 61(4): 2051-2066, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34999930

RESUMO

PURPOSE: Particular interest is now given to the potential of dietary supplements as alternative non-pharmacological approaches in intestinal inflammation handling. In this aim, this study evaluates the efficiency of fish collagen peptides, Naticol®Gut, on colonic inflammation. METHODS: Wild type and Mannose receptor-deficient in the myeloid lineage C57BL/6 mice were administered with Dextran Sodium Sulfate (DSS), Naticol®Gut, DSS, and Naticol®Gut or only water for 4 or 8 days. Inflammatory status was evaluated by establishing macroscopic and microscopic scores, by measuring cytokine and calprotectin production by ELISA and the myeloperoxidase activity by chemiluminescence. Colonic macrophages were phenotyped by measuring mRNA levels of specific markers of inflammation and oxidative status. Colonic immune populations and T-cell activation profiles were determined by flow cytometry. Mucosa-associated gut microbiota assessment was undertaken by qPCR. The phenotype of human blood monocytes from inflammatory bowel disease (IBD) subjects was characterized by RT-qPCR and flow cytometry and their oxidative activity by chemiluminescence. RESULTS: Naticol®Gut-treated DSS mice showed attenuated colonic inflammation compared to mice that were only exposed to DSS. Naticol®Gut activity was displayed through its ability to orient the polarization of colonic macrophage towards an anti-inflammatory and anti-oxidant phenotype after its recognition by the mannose receptor. Subsequently, Naticol®Gut delivery modulated CD4 T cells in favor of a Th2 response and dampened CD8 T-cell activation. This immunomodulation resulted in an intestinal eubiosis. In human monocytes from IBD subjects, the treatment with Naticol®Gut also restored an anti-inflammatory and anti-oxidant phenotype. CONCLUSION: Naticol®Gut acts as a protective agent against colitis appearing as a new functional food and an innovative and complementary approach in gut health.


Assuntos
Colite , Doenças Inflamatórias Intestinais , Animais , Anti-Inflamatórios/uso terapêutico , Antioxidantes/uso terapêutico , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colágeno , Colo , Sulfato de Dextrana , Modelos Animais de Doenças , Humanos , Inflamação/tratamento farmacológico , Macrófagos , Manose/uso terapêutico , Receptor de Manose , Camundongos , Camundongos Endogâmicos C57BL , Peptídeos , Fenótipo
2.
Cell Biol Toxicol ; 37(3): 379-400, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32712770

RESUMO

Ziram, a zinc dithiocarbamate is widely used worldwide as a fungicide in agriculture. In order to investigate ziram-induced changes in macrophage functions and polarization, human monocytes-derived macrophages in culture were treated with ziram at 0.01-10 µmol.L-1 for 4-24 h. To characterize zinc involvement in these changes, we also determined the effects of disulfiram alone (dithiocarbamate without zinc) or in co-incubation with ZnSO4. We have shown that ziram and disulfiram at 0.01 µmol.L-1 increased zymosan phagocytosis. In contrast, ziram at 10 µmol.L-1 completely inhibited this phagocytic process, the oxidative burst triggered by zymosan and the production of TNF-α, IL-1ß, IL-6, and CCL2 triggered by LPS. Disulfiram had the same effects on these macrophages functions only when combined with zinc (10 µmol.L-1). In contrast, at 10 µmol.L-1 ziram and zinc associated-disulfiram induced expression of several antioxidants genes HMOX1, SOD2, and catalase, which could suggest the induction of oxidative stress. This oxidative stress could be involved in the increase in late apoptosis induced by ziram (10 µmol.L-1) and zinc associated-disulfiram. Concerning gene expression profiles of membrane markers of macrophage polarization, ziram at 10 µmol.L-1 had two opposite effects. It inhibited the gene expression of M2 markers (CD36, CD163) in the same way as the disulfiram-zinc co-treatment. Conversely, ziram induced gene expression of other M2 markers CD209, CD11b, and CD16 in the same way as treatment with zinc alone. Disulfiram-zinc association had no significant effects on these markers. These results taken together show that ziram via zinc modulates macrophages to M2-like anti-inflammatory phenotype which is often associated with various diseases.


Assuntos
Dissulfiram/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Zinco/farmacologia , Ziram/farmacologia , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Polaridade Celular/efeitos dos fármacos , Quimiocina CCL2/genética , Fungicidas Industriais/efeitos adversos , Fungicidas Industriais/farmacologia , Humanos , Interleucina-1beta/genética , Interleucina-6/genética , Macrófagos/efeitos dos fármacos , Estresse Oxidativo/genética , Fator de Necrose Tumoral alfa/genética
3.
J Clin Psychopharmacol ; 40(3): 222-230, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32332458

RESUMO

PURPOSE/BACKGROUND: Alzheimer disease (AD) is a public health issue because of the low number of symptomatic drugs and the difficulty to diagnose it at the prodromal stage. The need to develop new treatments and to validate sensitive tests for early diagnosis could be met by developing a challenge model reproducing cognitive impairments of AD. Therefore, we implemented a 24-hour sleep deprivation (SD) design on healthy volunteers in a randomized, double-blind, placebo-controlled, crossover study on 36 healthy volunteers. METHODS/PROCEDURE: To validate the SD model, cognitive tests were chosen to assess a transient worsening of cognitive functions after SD and a restoration under modafinil as positive control (one dose of 200 mg). Then, the same evaluations were replicated after 15 days of donepezil (5 mg/d) or memantine (10 mg/d). The working memory (WM) function was assessed by the N-back task and the rapid visual processing (RVP) task. FINDINGS/RESULTS: The accuracy of the N-back task and the reaction time of the RVP revealed the alteration of the WM with SD and its restoration with modafinil (changes in score after SD compared with baseline before SD), respectively, in the placebo group and in the modafinil group (-0.2% and +1.0% of satisfactory answers, P = 0.022; +21.3 and +1.9 milliseconds of reaction time, P = 0.025). Alzheimer disease drugs also tended to reverse this deterioration: the accuracy of the N-back task was more stable through SD (compared with -3.0% in the placebo group, respectively, in the memantine group and in the donepezil group: -1.4% and -1.6%, P = 0.027 and P = 0.092) and RVP reaction time was less impacted (compared with +41.3 milliseconds in the placebo group, respectively, in the memantine group and in the donepezil group: +16.1 and +29.3 milliseconds, P = 0.034 and P = 0.459). IMPLICATIONS/CONCLUSIONS: Our SD challenge model actually led to a worsening of WM that was moderated by both modafinil and AD drugs. To use this approach, the cognitive battery, the vulnerability of the subjects to SD, and the expected drug effect should be carefully considered.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Disfunção Cognitiva/tratamento farmacológico , Voluntários Saudáveis/psicologia , Memantina/uso terapêutico , Memória de Curto Prazo/efeitos dos fármacos , Privação do Sono/psicologia , Adulto , Doença de Alzheimer/psicologia , Estudos Cross-Over , Donepezila/uso terapêutico , Método Duplo-Cego , Humanos , Masculino , Modafinila/uso terapêutico , Modelos Psicológicos , Testes Neuropsicológicos , Nootrópicos/uso terapêutico , Tempo de Reação/efeitos dos fármacos
4.
Molecules ; 25(14)2020 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-32674431

RESUMO

Lignin is an aromatic biopolymer derived from lignocellulosic biomass. Providing a comprehensive structural analysis of lignin is the primary motivation for the quantification of various functional groups, with a view to valorizing lignin in a wide range of applications. This study investigated the lignin fluorobenzylation reaction and performed a subsequent 19F-NMR analysis to quantify hydroxyl groups, based on a work developed two decades ago by Barrelle et al. The objectives were to check the assignments proposed in this previous study and to examine the reactivity of various types of lignin hydroxyls with the derivatization agent. Selected lignin model compounds containing phenolic and aliphatic hydroxyls were subjected to the fluorobenzylation reaction, and the obtained reaction medium was analyzed by 13C and 19F NMR spectroscopy. The model compound results showed that phenolic hydroxyls were totally derivatized, whereas aliphatic hydroxyls underwent minimal conversion. They also confirmed that 19F NMR chemical shifts from -115 ppm to -117.3 ppm corresponded to phenolic groups. Then, a 19F NMR analysis was successfully applied to Organosolv commercial lignin after fluorobenzylation in order to quantify its phenolic group content; the values were found to be in the range of the reported values using other analytical techniques after lignin acetylation.


Assuntos
Lignina/química , Espectroscopia de Ressonância Magnética , Fenóis/química , Acetilação , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Radioisótopos de Flúor , Espectroscopia de Ressonância Magnética/métodos , Estrutura Molecular
5.
J Immunother Cancer ; 11(8)2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37586764

RESUMO

BACKGROUND: Ovarian adenocarcinoma (OVAD) frequently metastasizes to the peritoneal cavity and manifests by the formation of ascites, which constitutes a tumor-promoting microenvironment. In the peritoneal cavity, two developmentally, phenotypically and functionally distinct macrophage subsets, immunocompetent large peritoneal macrophages (LPM) and immunosuppressive small peritoneal macrophages (SPM), coexist. Because peroxisome proliferator-activated receptor γ (PPARγ) is a critical factor participating in macrophage differentiation and cooperates with CCAAT/enhancer binding protein ß (C/EBPß), a transcription factor essential for SPM-to-LPM differentiation, PPARγ could be also involved in the regulation of SPM/LPM balance and could be a promising therapeutic target. METHODS: To evaluate the 15(S)-hydroxyeicosatetraenoic acid (HETE), a PPARγ endogenous ligand, impact on ovarian tumor growth, we intraperitoneally injected 15(S)-HETE into a murine ovarian cancer model. This experimental model consists in the intraperitoneally injection of ID8 cells expressing luciferase into syngeneic C57BL/6 female mice. This ID8 orthotopic mouse model is a well-established experimental model of end-stage epithelial OVAD. Tumor progression was monitored using an in vivo imaging system. Peritoneal immune cells in ascites were analyzed by flow cytometry and cell sorting. To determine whether the impact of 15(S)-HETE in tumor development is mediated through the macrophages, these cells were depleted by injection of liposomal clodronate. To further dissect how 15(S)-HETE mediated its antitumor effect, we assessed the tumor burden in tumor-bearing mice in which the PPARγ gene was selectively disrupted in myeloid-derived cells and in mice deficient of the recombination-activating gene Rag2. Finally, to validate our data in humans, we isolated and treated macrophages from ascites of individuals with OVAD. RESULTS: Here we show, in the murine experimental model of OVAD, that 15(S)-HETE treatment significantly suppresses the tumor growth, which is associated with the differentiation of SPM into LPM and the LPM residency in the peritoneal cavity. We demonstrate that C/EBPß and GATA6 play a central role in SPM-to-LPM differentiation and in LPM peritoneal residence through PPARγ activation during OVAD. Moreover, this SPM-to-LPM switch is associated with the increase of the effector/regulatory T-cell ratio. Finally, we report that 15(S)-HETE attenuates immunosuppressive properties of human ovarian tumor-associated macrophages from ascites. CONCLUSION: Altogether, these results promote PPARγ as a potential therapeutic target to restrain OVAD development and strengthen the use of PPARγ agonists in anticancer therapy.


Assuntos
Adenocarcinoma , Neoplasias Ovarianas , PPAR gama , Animais , Feminino , Humanos , Camundongos , Ascite , Carcinoma Epitelial do Ovário , Terapia de Imunossupressão , Imunossupressores , Macrófagos Peritoneais , Camundongos Endogâmicos C57BL , Neoplasias Ovarianas/tratamento farmacológico , Microambiente Tumoral
6.
Diabetes ; 71(10): 2181-2196, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-35796692

RESUMO

Patients with diabetes present a persistent inflammatory process, leading to impaired wound healing. Since nonhealing diabetic wound management shows limited results, the introduction of advanced therapies targeting and correcting the inflammatory status of macrophages in chronic wounds could be an effective therapeutic strategy to stop the sustained inflammation and to return to a healing state. In an excisional skin injury in a diet-induced diabetic murine model, we demonstrate that topical administration of low-dose aspirin (36 µg/wound/day) improves cutaneous wound healing by increasing wound closure through the promotion of the inflammation resolution program of macrophages. This treatment increased efferocytosis of wound macrophages from aspirin-treated diabetic mice compared with untreated diabetic mice. We also show that aspirin treatment of high-fat-fed mice oriented the phenotype of wound macrophages toward an anti-inflammatory and proresolutive profile characterized by a decrease of LTB4 production. The use of diabetic mice deficient for 5-LOX or 12/15-LOX demonstrated that these two enzymes of acid arachidonic metabolism are essential for the beneficial effect of aspirin on wound healing. Thus, aspirin treatment modified the balance between pro- and anti-inflammatory eicosanoids by promoting the synthesis of proresolving LXA4 through 5-LOX, LTA4, 12/15-LOX signaling. In conclusion, the restoration of an anti-inflammatory and proresolutive phenotype of wound macrophages by the topical administration of low-dose aspirin represents a promising therapeutic approach in chronic wounds.


Assuntos
Diabetes Mellitus Experimental , Administração Tópica , Animais , Anti-Inflamatórios/uso terapêutico , Aspirina/metabolismo , Aspirina/farmacologia , Aspirina/uso terapêutico , Diabetes Mellitus Experimental/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Leucotrieno A4/metabolismo , Leucotrieno A4/farmacologia , Leucotrieno B4/metabolismo , Lipoxinas , Macrófagos/metabolismo , Camundongos , Fenótipo , Pele/metabolismo , Cicatrização
7.
J Fungi (Basel) ; 7(1)2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33467443

RESUMO

Candida albicans is an opportunistic pathogen that causes mucosal gastrointestinal (GI) candidiasis tightly associated with gut inflammatory status. The emergence of drug resistance, the side effects of currently available antifungals and the high frequency of recurrent candidiasis indicate that new and improved therapeutics are needed. Probiotics have been suggested as a useful alternative for the management of candidiasis. We demonstrated that oral administration of Lactobacillus gasseri LA806 alone or combined with Lactobacillus helveticus LA401 in Candida albicans-infected mice decrease the Candida colonization of the oesophageal and GI tract, highlighting a protective role for these strains in C. albicans colonization. Interestingly, the probiotic combination significantly modulates the composition of gut microbiota towards a protective profile and consequently dampens inflammatory and oxidative status in the colon. Moreover, we showed that L. helveticus LA401 and/or L. gasseri LA806 orient macrophages towards a fungicidal phenotype characterized by a C-type lectin receptors signature composed of Dectin-1 and Mannose receptor. Our findings suggest that the use of the LA401 and LA806 combination might be a promising strategy to manage GI candidiasis and the inflammation it causes by inducing the intrinsic antifungal activities of macrophages. Thus, the probiotic combination is a good candidate for managing GI candidiasis by inducing fungicidal functions in macrophages while preserving the GI integrity by modulating the microbiota and inflammation.

8.
Cancers (Basel) ; 13(8)2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33924378

RESUMO

AMHRII, the anti-Müllerian hormone receptor, is selectively expressed in normal sexual organs but is also re-expressed in gynecologic cancers. Hence, we developed murlentamab, a humanized glyco-engineered anti-AMHRII monoclonal antibody currently in clinical trial. Low-fucosylated antibodies are known to increase the antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) potency of effector cells, but some preliminary results suggest a more global murlentamab-dependent activation of the immune system. In this context, we demonstrate here that the murlentamab opsonization of AMHRII-expressing ovarian tumor cells, in the presence of unstimulated- or tumor-associated macrophage (TAM)-like macrophages, significantly promotes macrophage-mediated ADCC and shifts the whole microenvironment towards a pro-inflammatory and anti-tumoral status, thus triggering anti-tumor activity. We also report that murlentamab orients both unstimulated- and TAM-like macrophages to an M1-like phenotype characterized by a strong expression of co-stimulation markers, pro-inflammatory cytokines and chemokines, favoring T cell recruitment and activation. Moreover, we show that murlentamab treatment shifts CD4+ Th1/Th2 balance towards a Th1 response and activates CD8+ T cells. Altogether, these results suggest that murlentamab, through naïve macrophage orientation and TAM reprogrammation, stimulates the anti-tumor adaptive immune response. Those mechanisms might contribute to the sustained clinical benefit observed in advanced cancer patients treated with murlentamab. Finally, the enhanced murlentamab activity in combination with pembrolizumab opens new therapeutic perspectives.

9.
BMC Complement Med Ther ; 21(1): 64, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33588819

RESUMO

BACKGROUND: The disparity of harvesting locations can influence the chemical composition of a plant species, which could affect its quality and bioactivity. Terminalia albida is widely used in traditional Guinean medicine whose activity against malaria has been validated in vitro and in murine models. The present work investigated the antimalarial properties and chemical composition of two samples of T. albida collected from different locations in Guinea. METHOD: T. albida samples were collected in different locations in Guinea, in Dubréka prefecture (West maritime Guinea) and in Kankan prefecture (eastern Guinea). The identity of the samples was confirmed by molecular analysis. In vitro antiplasmodial activity of the two extracts was determined against the chloroquine resistant strain PfK1. In vivo, extracts (100 mg/kg) were tested in two experimental murine models, respectively infected with P. chabaudi chabaudi and P. berghei ANKA. The chemical composition of the two samples was assessed by ultra-high-performance liquid chromatography coupled to high resolution mass spectrometry. RESULTS: In vitro, the Dubréka sample (TaD) was more active with an IC50 of 1.5 µg/mL versus 8.5 µg/mL for the extract from Kankan (TaK). In vivo, the antiparasitic effect of TaD was substantial with 56% of parasite inhibition at Day 10 post-infection in P. chabaudi infection and 61% at Day 8 in P. berghei model, compared to 14 and 19% inhibition respectively for the treatment with TaK. In addition, treatment with TaD further improved the survival of P. berghei infected-mice by 50% at Day 20, while the mortality rate of mice treated with Tak was similar to the untreated group. The LC/MS analysis of the two extracts identified 38 compounds, 15 of which were common to both samples while 9 and 14 other compounds were unique to TaD and TaK respectively. CONCLUSION: This study highlights the variability in the chemical composition of the species T. albida when collected in different geographical locations. These chemical disparities were associated with variable antimalarial effects. From a public health perspective, these results underline the importance of defining chemical fingerprints related to botanical species identification and to biological activity, for the plants most commonly used in traditional medicine.


Assuntos
Antimaláricos/química , Malária/tratamento farmacológico , Fitoterapia , Extratos Vegetais/química , Plasmodium/efeitos dos fármacos , Terminalia/química , Animais , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Feminino , Guiné , Malária/parasitologia , Masculino , Medicinas Tradicionais Africanas , Camundongos Endogâmicos C57BL , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Especificidade da Espécie , Terminalia/classificação
10.
NPJ Regen Med ; 6(1): 41, 2021 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-34344890

RESUMO

Tissue repair after lesion usually leads to scar healing and thus loss of function in adult mammals. In contrast, other adult vertebrates such as amphibians have the ability to regenerate and restore tissue homeostasis after lesion. Understanding the control of the repair outcome is thus a concerning challenge for regenerative medicine. We recently developed a model of induced tissue regeneration in adult mice allowing the comparison of the early steps of regenerative and scar healing processes. By using studies of gain and loss of function, specific cell depletion approaches, and hematopoietic chimeras we demonstrate here that tissue regeneration in adult mammals depends on an early and transient peak of granulocyte producing reactive oxygen species and an efficient efferocytosis specifically by tissue-resident macrophages. These findings highlight key and early cellular pathways able to drive tissue repair towards regeneration in adult mammals.

11.
Carbohydr Polym ; 163: 254-260, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28267504

RESUMO

The development of new derivatives based on renewable natural resources using green chemistry is a concept gaining recognition in several industries. This work focused on the preparation and characterization of cellulose carbonate using dimethyl carbonate as the green reagent in ethanoic KOH solution. The effect of several reaction parameters were evaluated, i.e., temperature (25°C, 50°C, 90°C, 120°C, 150°C, and 180°C), time (6, 24, 48, and 72h), KOH concentration (15% and 30%), and the use of a catalyst (DBU). The degree of substitution (DS) of the resulting materials was evaluated by 13C CP/MAS NMR. The spectra of the prepared cellulose carbonate exhibited the main peaks associated with cellulose macromolecules (C1-C6) and those corresponding to carbonate functions at approximately 162ppm. Moreover, XPS was performed and confirmed the reaction modifications. Nevertheless, it is worth noting that 13C NMR and XPS spectra showed a significant difference in DS value, due to the difference between both techniques. However, our results from NMR and XPS experiments confirm that the major modifications during all the reactions occurred mainly at the surface. This green process opens the way for the easy production of a new class of cellulose derivatives.

12.
PLoS One ; 12(8): e0182970, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28806419

RESUMO

BACKGROUND: Dry immersion (DI), a ground-based model of microgravity previously used in Russia, has been recently implemented in France. The aim of this study was to analyze early events in a short-term DI model in which all conditions are met to investigate who is first challenged from osteo- or adipo-kines and to what extent they are associated to insulin-regulating hormones. METHODS: Twelve healthy men were submitted to a 3-day DI. Fasting blood was collected during pre-immersion phase for the determination of the baseline data collection (BDC), daily during DI (DI24h, DI48H and DI72h), then after recovery (R+3h and R+24h). Markers of bone turnover, phosphocalcic metabolism, adipokines and associated factors were measured. RESULTS: Bone resorption as assessed by tartrate-resistant acid phosphatase isoform 5b and N-terminal crosslinked telopeptide of type I collagen levels increased as early as DI24h. At the same time, total procollagen type I N- and C-terminal propeptides and osteoprotegerin, representing bone formation markers, decreased. Total osteocalcin [OC] was unaffected, but its undercarboxylated form [Glu-OC] increased from DI24h to R+3h. The early and progressive increase in bone alkaline phosphatase activities suggested an increased mineralization. Dickkopf-1 and sclerostin, as negative regulators of the Wnt-ß catenin pathway, were unaltered. No change was observed either in phosphocalcic homeostasis (calcium and phosphate serum levels, 25-hydroxyvitamin D, fibroblast growth factor 23 [FGF23]) or in inflammatory response. Adiponectemia was unchanged, whereas circulating leptin concentrations increased. Neutrophil gelatinase-associated lipocalin [lipocalin-2], a potential regulator of bone homeostasis, was found elevated by 16% at R+3h compared to DI24h. The secretory form of nicotinamide phosphoribosyl-transferase [visfatin] concentrations almost doubled after one day of DI and remained elevated. Serum insulin-like growth factor 1 levels progressively increased. Fasting insulin concentrations increased during the entire DI, whereas fasting glucose levels tended to be higher only at DI24h and then returned to BDC values. Changes in bone resorption parameters negatively correlated with changes in bone formation parameters. Percent changes of ultra-sensitive C-reactive protein positively correlated with changes in osteopontin, lipocalin-2 and fasting glucose. Furthermore, a positive correlation was found between changes in FGF23 and Glu-OC, the two main osteoblast-/osteocyte-derived hormones. CONCLUSION: Our results demonstrated that DI induced an unbalanced remodeling activity and the onset of insulin resistance. This metabolic adaptation was concomitant with higher levels of Glu-OC. This finding confirms the role of bone as an endocrine organ in humans. Furthermore, visfatin for which a great responsiveness was observed could represent an early and sensitive marker of unloading in humans.


Assuntos
Adipocinas/sangue , Remodelação Óssea , Imersão , Insulina/sangue , Adulto , Biomarcadores/sangue , Peso Corporal , Reabsorção Óssea/sangue , Osso e Ossos/metabolismo , Metabolismo Energético , Fator de Crescimento de Fibroblastos 23 , Hormônios/sangue , Humanos , Masculino , Redes e Vias Metabólicas , Osteogênese
13.
J Colloid Interface Sci ; 289(1): 249-61, 2005 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-15907861

RESUMO

The hydrolysis of three alkoxysilane coupling agents, gamma-methacryloxypropyltrimethoxysilane (MPS), gamma-aminopropyltriethoxysilane (APS), and gamma-diethylenetriaminopropyltrimethoxysilane (TAS), was carried out in an ethanol/water (80/20) solution and followed by 1H, 13C, and 29Si NMR spectroscopy, which showed that its rate increased in the order MPS < APS < TAS. The formation of the silanol groups was followed by their self-condensation to generate oligomeric structure. APS and MPS only gave soluble products, whereas colloidal particles precipitated in the medium when TAS was hydrolyzed. Pristine and hydrolyzed MPS were then adsorbed onto a cellulose substrate and thereafter a thermal treatment at 110-120 degrees C under reduced pressure was applied to the modified fibers to create permanent bonding of the coupling agent at their surface.


Assuntos
Celulose/química , Metacrilatos/química , Silanos/química , Adsorção , Hidrólise , Espectroscopia de Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/normas , Estrutura Molecular , Propilaminas , Padrões de Referência , Propriedades de Superfície , Temperatura
14.
J Neurol Sci ; 195(2): 139-44, 2002 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-11897244

RESUMO

In hypertensive patients, the upper and lower limits of cerebral autoregulation are shifted to higher levels. However, the dynamics of cerebral autoregulation in hypertensive patients are less well known. We compared the dynamics of cerebral autoregulation in 21 treated hypertensive patients (13 men and 8 women; mean age: 48.9+/-13.6 years) and in 21 normotensive subjects (13 men and 8 women; mean age: 51+/-14.5 years) by transcranial Doppler (TCD) of the middle cerebral artery (MCA) during the acute decrease in blood pressure induced by standing up after 2 min in squatting position. MCA maximal outline blood flow velocity (FV), blood pressure (Finapres) and end-tidal PCO2 were continuously monitored and computerised. A cerebral vascular resistance index (CR) was calculated as follows: mean arterial BP/MCA mean FV with normalised changes in CR per second during the blood pressure decrease (CR slope). The CR slope reflecting the rate of cerebral autoregulation did not differ between the two groups and within the hypertensive patients [well controlled (8 patients) and not controlled (13 patients)]. The time to maximum decrease of CR (T1) and the time to full recovery of CR after the initial drop (T2) were also similar in the two groups (controls T1: 11.3+/-3.1 s, T2: 12+/-5.9 s; hypertensive T1: 11.7+/-2.5 s, T2: 10.7+/-4.5 s) and within hypertensive patients. These findings suggest that the dynamics of cerebral autoregulation are well preserved in hypertensive patients, with no difference according to the efficiency of treatment of hypertension.


Assuntos
Encéfalo/irrigação sanguínea , Encéfalo/fisiopatologia , Artérias Cerebrais/fisiopatologia , Circulação Cerebrovascular/fisiologia , Hemodinâmica/fisiologia , Homeostase/fisiologia , Hipertensão/fisiopatologia , Adulto , Pressão Sanguínea/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência
15.
Clin Physiol Funct Imaging ; 22(2): 108-14, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12005152

RESUMO

Thoraco-cephalic fluid shift induced by weightlessness may influence cerebral autoregulation. Our objective was to assess effects of simulated weightlessness by a 7-day head-down bed rest (HDBR) on the kinetics of cerebral blood flow (CBF) autoregulation in eight healthy women (27.9 +/- 0.9 years). This was studied by transcranial Doppler (TCD) of the middle cerebral artery (MCA) during the sudden decrease in blood pressure (BP) induced by quickly deflating thigh cuff aftera 4-min arterial occlusion before (D - 3), during (D2, D5) and after the HDBR (D + 1). BP (Finapres) and MCA maximal blood flow velocity were continuously recorded. Cerebrovascular resistance (CR) was expressed as the ratio of mean BP to mean MCA velocity. The CR slope was defined as changes in CR per second during the BP decrease. The magnitude of the relative decrease in mean BP and MCA velocity as well as the CR slope did not differ significantly before, during and after the HDBR, showing no major impairment of cerebral autoregulation during short-term HDBR. The time to maximum decrease in CR (T1 in s), corresponding to the maximum vasodilation was reduced on D2 (7-2 +/- 0.6) versus D - 3 (9.9 +/- 1-3), D5 (9-6 +/- 0.8) and R + 1 (11.7 +/- 11) probably as a result of the fluid shift. We also looked if the responses during the thigh cuff release differed in women according to their tolerance to the 10 min stand test performed after the HDBR: T1 was larger in the five women who presented orthostatic intolerance suggesting that some differences in cerebral autoregulatory responses may be related to orthostatic intolerance.


Assuntos
Circulação Cerebrovascular/fisiologia , Homeostase/fisiologia , Simulação de Ausência de Peso , Adulto , Repouso em Cama , Velocidade do Fluxo Sanguíneo/fisiologia , Pressão Sanguínea/fisiologia , Feminino , Decúbito Inclinado com Rebaixamento da Cabeça , Frequência Cardíaca/fisiologia , Humanos , Cinética , Perna (Membro)/irrigação sanguínea , Artéria Cerebral Média/fisiologia , Postura/fisiologia , Ultrassonografia Doppler Transcraniana
16.
Auton Neurosci ; 145(1-2): 76-80, 2009 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-19006684

RESUMO

BACKGROUND: Sleep disorders are associated to a number of cardiovascular disturbances that might increase cardiovascular risk. Sleep deprivation, in particular, might, by inducing autonomic dysregulation, raise arterial pressure and hypertensive risk. Available evidence however is contradictory. METHODS: We tested the main hypothesis that one night sleep deprivation in 24 volunteers might alter hemodynamics (heart rate and Arterial Pressure - AP), autonomic regulation (mono and bivariate spectral analysis of RR and non invasive AP variability) and baroreflex control (spectral index alpha and spontaneous baroreflex slope), performance indices (reaction time) and subjective stress (questionnaires and salivary cortisol). Volunteers were studied in normal living conditions and while kept in isolation and confinement, to test the presence of possible bias related to environmental stress. RESULTS: Results indicate that there were no differences between normal living conditions and isolation and confinement (Intraclass Correlation Coefficient >0.75 for most variables). Conversely, after one night sleep deprivation subjects felt tired (p<0.05), and performance deteriorated (p<0.05), while cortisol profile was substantially maintained, hemodynamic parameters did not change and HRV and index alpha increased slightly. CONCLUSIONS: Findings support the contention that one night sleep deprivation, in absence of significant additional stress or disturbances, does not lead to increased arterial pressure values or to changes in autonomic or baroreflex profiles that could conceivably favor hypertension development, but induces the expected increase in tiredness and reduction in performance.


Assuntos
Sistema Nervoso Autônomo/fisiologia , Barorreflexo/fisiologia , Pressão Sanguínea/fisiologia , Frequência Cardíaca/fisiologia , Privação do Sono/fisiopatologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polissonografia/métodos , Privação do Sono/psicologia , Estresse Psicológico/fisiopatologia , Estresse Psicológico/psicologia , Vigília/fisiologia
17.
Magn Reson Chem ; 45(6): 473-83, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17431857

RESUMO

The hydrolysis of three alkoxy-silane coupling agents, gamma-methacryloxypropyl trimethoxy silane (MPS), gamma-aminopropyl triethoxy silane (APS), and gamma-diethylenetriaminopropyl trimethoxy silane (TAS), was carried out in ethanol/water solutions (80/20 w/w) at different pH values and followed by 1H, 13C and 29Si NMR spectroscopy. Acidic media were found to stabilize the hydrolyzed forms. As expected, the formation of silanol groups was followed by their self-condensation to generate oligomeric structures, yielding, ultimately, solid homopolycondensated structures, as analyzed by 29Si and 13C high-resolution solid-state NMR. Hydrolyzed MPS in acidic media was then successfully adsorbed onto a cellulose surface and the ensuing substrates submitted to thermal treatment at 110-120 degrees C under reduced pressure, in order to create covalent bonds between cellulose and the coupling agent.

18.
J Strength Cond Res ; 19(3): 640-6, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16095419

RESUMO

Thirty-two women between 62 and 75 years old were randomized into 3 groups. Each group performed a program of 4 sessions a week over 6 weeks. Group SC (n = 11) climbed up and down stairs, group ES (n = 11) practiced electrostimulation, and group SC + ES (n = 10) superimposed the 2 activities simultaneously. Using a force platform and a seesaw platform, static and dynamic balance in eyes-open and eyes-closed conditions were analyzed before and after the programs for each group. After the programs, the results indicated that dynamic balance improved for the 3 groups, but the contribution of visual information in the control of oscillation amplitude was lower in the SC group than in the ES and SC + ES groups. In the SC + ES group, the electrical stimulation interferes with neurophysiologic afference integration in postural control in relation to voluntary movement. Voluntary exercise appears to be more efficient than electrical stimulation and the superimposed techniques to change balancing tactics in the elderly.


Assuntos
Contração Isométrica/fisiologia , Atividade Motora/fisiologia , Músculo Esquelético/fisiologia , Equilíbrio Postural/fisiologia , Adaptação Fisiológica , Idoso , Análise de Variância , Composição Corporal/fisiologia , Estimulação Elétrica , Feminino , Marcha/fisiologia , Humanos , Pessoa de Meia-Idade
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