Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 108
Filtrar
Mais filtros

País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Mol Ecol ; 31(15): 3979-3998, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-34516675

RESUMO

Secondary sympatry amongst sister lineages is strongly associated with genetic and ecological divergence. This pattern suggests that for closely related species to coexist in secondary sympatry, they must accumulate differences in traits that mediate ecological and/or reproductive isolation. Here, we characterized inter- and intraspecific divergence in three giant tree frog species whose distributions stretch across West and Central Africa. Using genome-wide single-nucleotide polymorphism data, we demonstrated that species-level divergence coincides temporally and geographically with a period of large-scale forest fragmentation during the late Pliocene. Our environmental niche models further supported a dynamic history of climatic suitability and stability, and indicated that all three species occupy distinct environmental niches. We found modest morphological differentiation amongst the species with significant divergence in tympanum diameter and male advertisement call. In addition, we confirmed that two species occur in secondary sympatry in Central Africa but found no evidence of hybridization. These patterns support the hypothesis that cycles of genetic exchange and isolation across West and Central Africa have contributed to globally significant biodiversity. Furthermore, divergence in both ecology and reproductive traits appear to have played important roles in maintaining distinct lineages. At the intraspecific level, we found that climatic refugia, precipitation gradients, marine incursions, and potentially riverine barriers generated phylogeographic structure throughout the Pleistocene and into the Holocene. Further studies examining phenotypic divergence and secondary contact amongst these geographically structured populations may demonstrate how smaller scale and more recent biogeographic barriers contribute to regional diversification.


La sympatrie secondaire parmi les espèces sœurs est fortement associée à la divergence génétique et écologique. Ce modèle suggère que pour que des espèces étroitement liées coexistent en sympatrie secondaire, elles doivent accumuler des différences dans les traits qui contribuent à l'isolement écologique ou reproductif. Ici, nous avons caractérisé la divergence inter- et intra-spécifique chez trois espèces de grenouilles arboricoles géantes dont les distributions s'étendent à travers l'Afrique de l'Ouest et Centrale. Avec des données génétiques, nous avons démontré que la divergence au niveau des espèces coïncide temporellement et géographiquement avec une période de fragmentation forestière à la fin du Pliocène. Nos modèles de niches environnementales ont soutenu une histoire dynamique de stabilité climatique, et ont indiqué que les trois espèces occupent des niches environnementales distinctes. Nous avons trouvé une différenciation morphologique modeste parmi les trois espèces mais une divergence significative dans le diamètre du tympan et les cris des mâles. De plus, nous avons confirmé que deux espèces sont présentes en sympatrie secondaire en Afrique Centrale mais n'avons trouvé aucune preuve d'hybridation. Ces résultats soutiennent l'hypothèse que les cycles d'échange génétique et d'isolement à travers l'Afrique de l'Ouest et Centrale ont contribué à une profonde concentration de biodiversité dans la région. De plus, la divergence des traits écologiques et reproducteurs semble avoir joué un rôle important dans le maintien de lignées distinctes. Au niveau intra-spécifique, nous avons constaté que les refuges climatiques, les gradients de précipitation, les incursions marines et potentiellement les barrières fluviales ont généré une structure phylogéographique pendant le Pléistocène et jusqu'à l'Holocène. Des études examinant la divergence phénotypique et le contact secondaire entre ces populations géographiquement structurées pourraient démontrer comment des barrières biogéographiques à échelle plus petite et plus récentes contribuent à la diversification régionale.


Assuntos
Anuros , Biodiversidade , África Central , Animais , Anuros/genética , DNA Mitocondrial/genética , Florestas , Variação Genética , Masculino , Filogenia , Filogeografia , Ranidae/genética
2.
Arch Orthop Trauma Surg ; 140(1): 139-144, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31691006

RESUMO

INTRODUCTION: Finger proximal interphalangeal joint (PIP) reconstruction after the destruction of parts of the joint remains challenging. Surgical techniques include implant arthroplasty, arthrodesis, free vascularized joint transfer, and non-vascularized bone and joint transfer. This study analyzes our experience after non-vascularized transfer in terms of range of motion, postoperative rehabilitation, and patient satisfaction. MATERIALS AND METHODS: Between 2009 and 2014, ten patients underwent non-vascularized partial joint transfer for PIP joint reconstruction. One of them was lost to follow-up. Included patients had osteochondral partial joint transplants of 25-50% of the toes (n = 4) and the hand (n = 5). Range of motion (ROM), grip-, and pinch-strength were measured at the last follow-up control and compared to the healthy side. Patients were asked to score the pain at rest/ on load on a visual scale (VAS: 0 = no pain; 10 = excruciating pain). Satisfaction self-assessment was evaluated by asking the patients to grade their postoperative result as excellent, very good, good or poor. RESULTS: Mean follow-up period was 4.0 years (range 1.2-7.9 years). Mean PIP joint flexion was 93 ± 26° at the last follow-up control. Mean grip- and pinch-strength of the operated side at the last control were, respectively, 43 ± 18 kg and 8 ± 5 kg, close to the healthy side values (45 ± 15 kg and 9 ± 4 kg). Mean pain at rest/on load measured on a visual scale was, respectively, 0.3 ± 1 and 1.8 ± 2. Eight patients (89%) rated their operation as excellent, and one as poor. CONCLUSION: In this study, non-vascularized partial joint transfer provides a mobile and stable PIP joint 4 years after reconstruction. The surgical technique presented herein is complex depending on additional injuries but results in great patient satisfaction.


Assuntos
Articulações dos Dedos/cirurgia , Articulações/transplante , Traumatismos dos Dedos/cirurgia , Humanos , Satisfação do Paciente , Força de Pinça , Amplitude de Movimento Articular , Articulação do Dedo do Pé/cirurgia
3.
Environ Res ; 162: 287-296, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29407760

RESUMO

Low doses of mercury (Hg) promote deleterious effects on cardiovascular system, but the mechanisms implicated remain unclear. This study analyzed whether angiotensin II AT-1 receptors are involved in the vascular dysfunction caused by chronic exposure to low HgCl2 doses. For this, rats were divided into four groups and untreated (saline by im injections and tap water by gavage) or treated for 30 days as follows: Mercury (HgCl2im, first dose of 4.6 µg kg-1 and subsequent doses of 0.07 µg kg-1 day-1, and tap water by gavage); Losartan (saline im and losartan, 15 mg kg-1 day-1, by gavage); Losartan-Mercury (HgCl2im and Losartan by gavage). Systolic blood pressure was measured by tail plethysmography, vascular reactivity in aorta by isolated organ bath, oxidative stress by measuring the levels of reactive oxygen species (ROS), malondialdehyde (MDA) and antioxidant capacity (FRAP) and protein expression of AT-1 receptors by Western Blot. As results, co-treatment with losartan prevented the increased aortic vasoconstrictor responses to phenylephrine (Phe), the involvement of ROS and prostanoids on the response to Phe and the reduced negative endothelial modulation by nitric oxide on these responses. Moreover, this co-treatment avoided the increase in plasmatic and vascular oxidative stress and AT-1 protein expression in aorta. In conclusion, these results suggest that AT-1 receptors upregulation might play a key role in the vascular damage induced by Hg exposure by increasing oxidative stress and probably by reducing NO bioavailability.


Assuntos
Angiotensina II , Mercúrio , Estresse Oxidativo , Receptor Tipo 1 de Angiotensina , Receptores de Angiotensina , Angiotensina II/efeitos dos fármacos , Angiotensina II/metabolismo , Animais , Pressão Sanguínea/efeitos dos fármacos , Endotélio Vascular , Mercúrio/toxicidade , Ratos , Ratos Wistar , Receptor Tipo 1 de Angiotensina/efeitos dos fármacos , Receptor Tipo 1 de Angiotensina/metabolismo , Receptores de Angiotensina/efeitos dos fármacos , Receptores de Angiotensina/metabolismo , Regulação para Cima , Vasoconstrição
4.
Arch Orthop Trauma Surg ; 138(11): 1623-1631, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30259125

RESUMO

INTRODUCTION: In Switzerland, collagenase Clostridium histolyticum therapy (CCH) for Dupuytren's disease was introduced in 2011. This study analyzes possible differences between CCH and limited fasciectomy (LF) in terms of range of motion, patient satisfaction and postoperative rehabilitation. MATERIALS AND METHODS: This retrospective study included 52 patients with Dupuytren's disease stage 1-3 according to Tubiana, treated with CCH or LF between January 2012 and December 2013. Complications were analyzed for each patient. The contracture of each treated joint measured on average at the 3 months and up to 2 years follow-up was compared with the preoperative values. The Michigan Hand score was evaluated at 2 years and the patients were asked to subjectively evaluate the outcome of the treatment and whether they would repeat it if necessary. Postoperative rehabilitation was also precisely quantified. RESULTS: 11 minor complications were reported for a complication rate of 29% in the CCH group. No major complications were reported in both groups. In the CCH group, mean MCP joint contracture was, respectively, 44° ± 20°, 9° ± 2° (gain of mobility compared to the preoperative situation 35°, P < 0.001), and 10° ± 3° (gain 34°, P < 0.001), respectively, before, at the 3 months' control and at the 2-year clinical control. In the LF group, mean MCP joint contracture was, respectively, 30° ± 21°, 2° ± 0.5° (gain 28°, P < 0.001), and 1° ± 0.5° (gain 29°, P < 0.001) for the same control periods. In the CCH group, mean PIP joint contracture was, respectively, 51° ± 21°, 18° ± 3° (gain of mobility compared to the preoperative situation 33°, P < 0.001), and 32° ± 4° (gain 19°, P < 0.001), respectively, before, at the 3 months' control and at the 2-year clinical control. In the LF group, mean PIP joint contracture was, respectively, 30° ± 20°, 2° ± 0.5° (gain of mobility compared to the preoperative situation 28°, P < 0.001), and 11° ± 4° (gain 19°, P < 0.001) for the same control periods. Outcomes were compared across the LF and CCH groups: surgery performed better than collagenase for PIP joint treatment at early (P < 0.001) and 2-year follow-up (P = 0.004) controls. However, patient satisfaction was higher in the CCH group: 92% were satisfied or very satisfied of the treatment compared to 71% in the LF group. All patients would reiterate the treatment in the CCH group if necessary compared to only 71% in the LF group. Rehabilitation was highly reduced in the CCH group compared to the LF group. CONCLUSION: In this study, surgery performed better than collagenase at early and 2-year follow-up in PIP joints and similar in MCP joints. While surgery seems to achieve better results, collagenase is considered in Switzerland as an off-the-shelf therapy that provides consistent results without scars, with shorter rehabilitation time, minor hand therapy, shorter splinting time, and applicability. LEVEL OF EVIDENCE AND STUDY TYPE: Level III.


Assuntos
Contratura de Dupuytren/terapia , Fasciotomia/métodos , Articulação da Mão/cirurgia , Colagenase Microbiana/uso terapêutico , Satisfação do Paciente/estatística & dados numéricos , Amplitude de Movimento Articular/fisiologia , Idoso , Contratura de Dupuytren/reabilitação , Fasciotomia/efeitos adversos , Feminino , Seguimentos , Articulação da Mão/patologia , Humanos , Luxações Articulares/cirurgia , Masculino , Colagenase Microbiana/efeitos adversos , Pessoa de Meia-Idade , Modalidades de Fisioterapia/estatística & dados numéricos , Estudos Retrospectivos , Suíça , Resultado do Tratamento
5.
J Surg Res ; 218: 49-57, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28985877

RESUMO

BACKGROUND: Immunosuppressive therapies derived from solid organ transplantation are effective in promoting survival of vascularized composite allotransplantation (VCA), but they cause serious side effects that are difficult to justify for this non-life-saving procedure. Unlike solid organ transplantation, hand and face transplants offer the possibility of site-specific immunosuppression for reducing systemic exposure while increasing intra-graft concentrations of the drug. Therefore, in this study, we tested whether a single intra-graft injection tacrolimus could promote VCA survival. METHODS: Brown Norway-to-Lewis hind limb transplantations were performed, and animals were left untreated (group I), treated with a daily injection of 1-mg/kg tacrolimus for 21 days (group 2) or injected with 7-mg tacrolimus directly into the transplanted limb on day 1 (group III). Graft rejection was monitored, and animals were sacrificed at grade 3 rejection or 200 days after transplantation. RESULTS: Intra-graft injection of tacrolimus significantly prolonged allograft survival as compared to untreated animals or animals treated with systemic tacrolimus. Half of the intra-graft-treated rats rejected their graft on average at day 70.5. Interestingly, the other half remained rejection-free for more than 200 days without signs of kidney or liver toxicity. In these animals, tacrolimus was detected in the VCA skin but not in the blood until day 200. Long-term survival was not linked to induction of donor-specific tolerance but to a higher level of lymphocyte chimerism. CONCLUSIONS: Intra-graft delivery of tacrolimus may promote VCA survival by increasing tissue drug availability and promoting the establishment of transient chimerism and thus long-term graft acceptance.


Assuntos
Rejeição de Enxerto/prevenção & controle , Membro Posterior/transplante , Imunossupressores/administração & dosagem , Tacrolimo/administração & dosagem , Alotransplante de Tecidos Compostos Vascularizados , Animais , Esquema de Medicação , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/patologia , Imunossupressores/uso terapêutico , Injeções Intralesionais , Injeções Subcutâneas , Estimativa de Kaplan-Meier , Masculino , Distribuição Aleatória , Ratos , Ratos Endogâmicos Lew , Tacrolimo/uso terapêutico , Resultado do Tratamento
6.
Reprod Fertil Dev ; 29(9): 1803-1812, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27755963

RESUMO

Mercury is a ubiquitous environmental pollutant and mercury contamination and toxicity are serious hazards to human health. Some studies have shown that mercury impairs male reproductive function, but less is known about its effects following exposure at low doses and the possible mechanisms underlying its toxicity. Herein we show that exposure of rats to mercury chloride for 30 days (first dose 4.6µgkg-1, subsequent doses 0.07µgkg-1day-1) resulted in mean (±s.e.m.) blood mercury concentrations of 6.8±0.3ngmL-1, similar to that found in human blood after occupational exposure or released from removal of amalgam fillings. Even at these low concentrations, mercury was deposited in reproductive organs (testis, epididymis and prostate), impaired sperm membrane integrity, reduced the number of mature spermatozoa and, in the testes, promoted disorganisation, empty spaces and loss of germinal epithelium. Mercury increased levels of reactive oxygen species and the expression of glutathione peroxidase (GPx) 1 and GPx4. These results suggest that the toxic effects of mercury on the male reproductive system are due to its accumulation in reproductive organs and that the glutathione system is its potential target. The data also suggest, for the first time, a possible role of the selenoproteins GPx1 and GPx4 in the reproductive toxicity of mercury chloride.


Assuntos
Glutationa Peroxidase/metabolismo , Mercúrio/farmacologia , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Testículo/efeitos dos fármacos , Animais , Epididimo/efeitos dos fármacos , Epididimo/metabolismo , Glutationa/metabolismo , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Espermatozoides/metabolismo , Testículo/metabolismo
7.
Rev Med Liege ; 72(6): 295-300, 2017 Jun.
Artigo em Francês | MEDLINE | ID: mdl-28628286

RESUMO

The prevalence of gestational diabetes increases as a result of universal screening, but also because of more stringent diagnostic criteria due to decreased set points. This diabetes can lead to severe complications for the offspring and / or for the mother. The management of a patient suffering from gestational diabetes is based on healthy diet and lifestyle advices. Iterative control of capillary glycemia is the usual way to monitor daily blood glucose. Continuous blood glucose measurement (CGM) provides reliable and comprehensive data over several days. Observing and interpreting the continuously recorded glucose concentration values should help to better understand the kinetics of glucose and to personalize the treatment. This preliminary study reports the results of 12 women with gestational diabetes and describes fluctuations of blood glucose levels all day long, particularly in the postprandial period. The CGM analysis shows that the maximum concentration of postprandial glucose is reached approximately 70 minutes after the morning and midday meals and 110 minutes after the evening meal.


La prévalence du diabète gestationnel augmente en raison d'un dépistage universel, mais aussi en raison de critères diagnostiques plus stricts, revus à la baisse. Ce diabète peut s'accompagner de complications pouvant être sévères pour l'enfant et/ou la mère. La prise en charge d'une patiente atteinte de diabète gestationnel repose sur les conseils hygiéno-diététiques adaptés et sur la surveillance des fluctuations glycémiques. En pratique habituelle, la surveillance glycémique quotidienne est réalisée via le contrôle itératif des glycémies capillaires. La mesure continue de la glycémie (MCG) offre l'avantage d'obtenir des données fiables et exhaustives sur plusieurs jours. Observer et interpréter les valeurs de concentration de glucose enregistrées de manière continue permettraient de mieux appréhender la cinétique du glucose et, idéalement, de personnaliser l'approche thérapeutique. Ce travail préliminaire rapporte les résultats observés chez 12 patientes présentant un diabète gestationnel et décrit les fluctuations du glucose au cours du nycthémère, particulièrement en période postprandiale. L'analyse de la MCG démontre que la concentration maximale de glucose postprandial est atteinte aux alentours de 70 minutes après le repas du matin et du midi et 110 minutes après le repas du soir.


Assuntos
Automonitorização da Glicemia , Diabetes Gestacional/sangue , Adulto , Automonitorização da Glicemia/instrumentação , Feminino , Humanos , Projetos Piloto , Período Pós-Prandial , Gravidez
8.
Acta Anaesthesiol Scand ; 60(10): 1404-1414, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27578364

RESUMO

BACKGROUND: Post-operative delirium and post-operative cognitive dysfunction (POCD) are both common but it has not been clarified how closely they are associated. We aimed to assess the possible relationship in a secondary analysis of data from the 'Surgery Depth of anaesthesia and Cognitive outcome'- study. METHODS: We included patients aged ≥ 60 years undergoing non-cardiac surgery planned for longer than 60 min. Delirium was assessed according to the Diagnostic and Statistical Manual of Mental Disorders IV criteria in the post-anaesthesia care unit (PACU) as well as within the first week after surgery. Cognitive function was assessed with a neuropsychological test battery. Multivariable analysis of POCD was performed with consideration of predisposing and precipitating factors. RESULTS: Of 1277 randomized patients, 850 (66.6%) had complete data. Delirium was found in 270 patients (32.9% of 850). We detected POCD in 162 (20.9% of 776) at 1 week and in 52 (9.4% of 553) at 3 months. In multivariable analysis (n = 808), delirium had no overall effect on POCD (P = 0.30). Patients with no delirium in PACU but with postoperative delirium within 7 days had an increased risk of POCD at 3 months (OR = 2.56 (95%-confidence interval: 1.07-6.16), P = 0.035). No significant association was found for the other subgroups. CONCLUSIONS: There is no clear evidence that postoperative delirium is independently associated with POCD up to 3 months.


Assuntos
Disfunção Cognitiva/etiologia , Delírio/etiologia , Complicações Pós-Operatórias/etiologia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada
9.
Rehabilitation (Stuttg) ; 54(2): 74-80, 2015 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-25719994

RESUMO

Consecutive admissions to the psychosomatic departments of 5 hospital units in southwest Germany registered between October 2012 and October 2013 were asked to participate in a study investigating the treatment selection process for psychosomatic rehabilitation. 527 patients were included in the study, 269 outpatients and 258 inpatients at the end of their inpatient treatment. 52 patients (10.1%) received the recommendation for rehabilitation. 47 (90.4%) could be followed up 3 months later. 22 patients had applied for a rehabilitation treatment, 11 (50%) had obtained an approval for their rehabilitation, 5 had still no answer and for 6 patients the request was refused. 4 of the latter had objected their refusal and were still waiting for an answer. Only one patient was already admitted to a rehabilitation center. Possible reasons for the low permeability at the interface between hospital care and rehabilitation are discussed.


Assuntos
Cuidados Críticos/estatística & dados numéricos , Transtornos Psicofisiológicos/epidemiologia , Transtornos Psicofisiológicos/reabilitação , Psicoterapia/estatística & dados numéricos , Centros de Reabilitação/estatística & dados numéricos , Doença Aguda , Adulto , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Prevalência , Revisão da Utilização de Recursos de Saúde
10.
Int Wound J ; 12(2): 173-8, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23786231

RESUMO

Abdominal wall defects continue to be a challenging problem for reconstructive surgeons. The aim of our study was to report a 3-year experience using a simple Two-step Technique (TST) to treat abdominal wall defects. Between January 2008 and December 2010, 20 patients with abdominal wall defects were treated by TST. Patients had a mean age of 37·5 ± 14·9 years (range: 22-85 years); 5 were women and 15 were men. The size of the defects was prospectively analysed. Early and late complications were recorded. Hospital stay, post-procedure downtime and patient overall satisfaction were systematically assessed. A secondary defect resulting from self-manipulation and an infection were responsible for a complication rate of 10%. Both underwent successful surgical revision which led to full resolution. The average hospital stay was 11·2 ± 4·9 weeks for the series. Long-term complications were scar hyperpigmentation in 11 cases, scar hypertrophy in 5 cases and scar widening in 3 cases. Mean patient satisfaction was 8·3 ± 0·5 [visual analogue scale (VAS) 0-10]. Average downtime post surgery was 4·1 ± 1·2 weeks. The mean follow-up was 24·6 ± 6·7 months. Reconstruction of abdominal wall defect with the TST is a reliable and reproducible technique. This technique provides excellent outcomes, and we anticipate that it will become widespread in the near future.


Assuntos
Parede Abdominal/patologia , Parede Abdominal/cirurgia , Técnicas de Fechamento de Ferimentos Abdominais , Tratamento de Ferimentos com Pressão Negativa , Deiscência da Ferida Operatória/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Estudos Prospectivos , Deiscência da Ferida Operatória/patologia , Resultado do Tratamento , Cicatrização , Adulto Jovem
11.
J Toxicol Environ Health A ; 77(1-3): 143-54, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24555655

RESUMO

Mercury (Hg) is a widespread environmental pollutant that adversely affects the male reproductive system. The precise mechanisms underlying mercuric chloride (HgCl2)-induced toxicity are not fully understood; however, evidence indicates that oxidative stress may be involved in this process. Although the adverse effects of high levels of inorganic Hg on the male reproductive system have been investigated, the effects of low levels of exposure are unknown. Therefore, the aim of this study was to investigate the effects of chronic exposure to low concentrations of HgCl2 on sperm parameters, lipid peroxidation, and antioxidant activity of male rats. Three-month-old male Wistar rats were treated for 30 d and divided into groups: control (saline, i.m.) and HgCl2 group (i.m., first dose 4.6 µg/kg, subsequent doses 0.07 µg/kg/d). Sperm parameters (count, motility and morphology) and biomarkers of oxidative stress in testis, epididymis, prostate, and vas deferens were analyzed. Mercury treatment produced a reduction in sperm quantity (testis and epididymis) and daily sperm production, following by decrease in sperm motility and increase on head and tail morphologic abnormalities. HgCl2 exposure was correlated with enhanced oxidative stress in reproductive organs, represented not only by augmented lipid peroxidation but also by changes in antioxidant enzymes activity superoxide dismutase (SOD) and catalase (CAT) and nonprotein thiol levels. In conclusion, chronic exposure to low doses of Hg impaired sperm quality and adversely affected male reproductive functions, which may be due, at least in part, to enhanced oxidative stress.


Assuntos
Poluentes Ambientais/toxicidade , Cloreto de Mercúrio/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Contagem de Espermatozoides , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/patologia , Espermatozoides/fisiologia , Testes de Toxicidade Crônica
12.
Ann Biomed Eng ; 52(1): 103-123, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37651029

RESUMO

Escherichia coli bacterium is a rod-shaped organism composed of a complex double membrane structure. Knowledge of electric field driven ion transport through both membranes and the evolution of their induced permeabilization has important applications in biomedical engineering, delivery of genes and antibacterial agents. However, few studies have been conducted on Gram-negative bacteria in this regard considering the contribution of all ion types. To address this gap in knowledge, we have developed a deterministic and stochastic Brownian dynamics model to simulate in 3D space the motion of ions through pores formed in the plasma membranes of E. coli cells during electroporation. The diffusion coefficient, mobility, and translation time of Ca2+, Mg2+, Na+, K+, and Cl- ions within the pore region are estimated from the numerical model. Calculations of pore's conductance have been validated with experiments conducted at Gustave Roussy. From the simulations, it was found that the main driving force of ionic uptake during the pulse is the one due to the externally applied electric field. The results from this work provide a better understanding of ion transport during electroporation, aiding in the design of electrical pulses for maximizing ion throughput, primarily for application in cancer treatment.


Assuntos
Eletroporação , Escherichia coli , Transporte de Íons , Transporte Biológico , Eletroporação/métodos , Íons
13.
Sci Rep ; 14(1): 4330, 2024 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-38383752

RESUMO

The therapeutic use of mesenchymal stem cells (MSCs) becomes more and more important due to their potential for cell replacement procedures as well as due to their immunomodulatory properties. However, protocols for MSCs differentiation can be lengthy and may result in incomplete or asynchronous differentiation. To ensure homogeneous populations for therapeutic purposes, it is crucial to develop protocols for separation of the different cell types after differentiation. In this article we show that, when MSCs start to differentiate towards adipogenic or osteogenic progenies, their dielectrophoretic behavior changes. The values of cell electric parameters which can be obtained by dielectrophoretic measurements (membrane permittivity, conductivity, and cytoplasm conductivity) change before the morphological features of differentiation become microscopically visible. We further demonstrate, by simulation, that these electric modifications make possible to separate cells in their early stages of differentiation by using the dielectrophoretic separation technique. A label free method which allows obtaining cultures of homogenously differentiated cells is thus offered.


Assuntos
Adipogenia , Células-Tronco Mesenquimais , Diferenciação Celular , Osteogênese , Células Cultivadas
14.
Br J Anaesth ; 110 Suppl 1: i98-105, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23539235

RESUMO

BACKGROUND: Postoperative delirium in elderly patients is a frequent complication and associated with poor outcome. The aim of this parallel group study was to determine whether monitoring depth of anaesthesia influences the incidence of postoperative delirium. METHODS: Patients who were planned for surgery in general anaesthesia expected to last at least 60 min and who were older than 60 yr were included between March 2009 and May 2010. A total of 1277 patients of a consecutive sample were randomized (n=638 open, n=639 blinded) and the data of 1155 patients were analysed (n=575 open, n=580 blinded). In one group, the anaesthesiologists were allowed to use the bispectral index (BIS) data to guide anaesthesia, while in the other group, BIS monitoring was blinded. Cognitive function was evaluated at baseline, 1 week, and 3 months after operation. RESULTS: Delirium incidence was lower in patients guided with BIS. Postoperative delirium was detected in 95 patients (16.7%) in the intervention group compared with 124 patients (21.4%) in the control group (P=0.036). In a multivariate analysis, the percentage of episodes of deep anaesthesia (BIS values <20) were independently predictive for postoperative delirium (P=0.006; odds ratio 1.027). BIS monitoring did not alter the incidence of postoperative cognitive dysfunction (7th day P=0.062; 90th day P=0.372). CONCLUSIONS: Intraoperative neuromonitoring is associated with a lower incidence of delirium, possibly by reducing extreme low BIS values. Therefore, in high-risk surgical patients, this may give the anaesthesiologist a possibility to influence one precipitating factor in the complex genesis of delirium. Clinical trial registration ISRCTN Register: 36437985. http://www.controlled-trials.com/ISRCTN36437985/.


Assuntos
Anestésicos Gerais/efeitos adversos , Transtornos Cognitivos/prevenção & controle , Delírio/prevenção & controle , Monitorização Intraoperatória/métodos , Complicações Pós-Operatórias/prevenção & controle , Idoso , Anestesia Geral/efeitos adversos , Anestesia Geral/métodos , Anestésicos Gerais/administração & dosagem , Transtornos Cognitivos/etiologia , Monitores de Consciência , Delírio/etiologia , Método Duplo-Cego , Esquema de Medicação , Eletroencefalografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Intraoperatória/instrumentação , Testes Neuropsicológicos , Estudos Prospectivos
15.
J Hand Surg Am ; 37(10): 2050-60, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22960029

RESUMO

PURPOSE: In clinical day-to-day life, grip strength, key pinch, and range of motion (ROM) serve to objectively evaluate treatment outcomes on wrist interventions. The goals of this study were to generate normative values of wrist function including the parameters of grip strength, key pinch, wrist ROM, and Disabilities of the Arm, Shoulder, and Hand (DASH) scores in a healthy, working population, and to investigate the influence of age, sex, body weight and height, handedness, and work strain. METHODS: We clinically examined 750 volunteer working subjects (363 women and 387 men, all white). We divided subjects into 2 groups depending on whether their labor involved high or low manual strain. We recorded participants' height, weight, grip strength, pinch strength, and wrist ROM. Each participant filled out a DASH questionnaire. RESULTS: Grip strength and pinch strength showed a maximum at between 30 and 49 years of age. In men, body mass index, body height, and weight all correlated with grip strength and pinch grip. Whereas women exhibited greater grip strength on the right side, men showed nonsignificant greater grip strength on the left side. Wrist ROM was greatest for ages ranging between 18 and 29 years. The average DASH value for all male subjects was significantly less than that of female subjects. In a healthy working population, the DASH score increased yearly by an average of 0.2 points in men and 0.3 points in women. CONCLUSIONS: This study showed that in a healthy working population, people 30 to 49 years of age had the highest grip strength and pinch strength. Age positively correlated with the DASH score and inversely related to wrist ROM. Persons employed in jobs with high manual strain presented with lower wrist ROM and higher DASH scores. CLINICAL RELEVANCE: These data help to objectively evaluate wrist function and the effectiveness of therapeutic interventions.


Assuntos
Avaliação da Deficiência , Força da Mão/fisiologia , Amplitude de Movimento Articular/fisiologia , Articulação do Punho/fisiologia , Adolescente , Adulto , Fatores Etários , Idoso , Estatura/fisiologia , Índice de Massa Corporal , Peso Corporal/fisiologia , Feminino , Lateralidade Funcional/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Ocupações , Estudos Prospectivos , Valores de Referência , Fatores Sexuais , Estresse Fisiológico , Adulto Jovem
16.
Arch Orthop Trauma Surg ; 132(12): 1807-11, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22983146

RESUMO

PURPOSE: The objective of this study was to examine the influence of anthropometric data, occupational manual strain, DASH (disability of arm, shoulder and hand) score and range of motion (ROM) on grip strength and key pinch. An additional goal was to develop models that enable the prediction of hand strength using the aforementioned parameters. METHODS: Normative data generated from a healthy working population (n = 750) served as basis for the statistical analysis. Prediction models for hand strength were developed using multivariate regression analysis. RESULTS: Gender, body weight and height, BMI and extension ROM correlate positively, age and DASH score, however, correlate negatively with grip strength and key pinch. Occupational manual strain has no influence on hand strength. The predictive power of the developed models was 68.4 % for grip strength and 57.1 % for key pinch. CONCLUSIONS: The developed models enable the prediction of hand strength using easily obtainable data points. The models will have application in clinical practice, physiological studies, medical evidence and rehab decisions.


Assuntos
Braço/fisiologia , Avaliação da Deficiência , Força da Mão/fisiologia , Mãos/fisiologia , Amplitude de Movimento Articular , Ombro/fisiologia , Inquéritos e Questionários , Articulação do Punho/fisiologia , Adulto , Estatura , Índice de Massa Corporal , Peso Corporal , Feminino , Humanos , Masculino , Valor Preditivo dos Testes
18.
Rev Med Liege ; 67(9): 461-7, 2012 Sep.
Artigo em Francês | MEDLINE | ID: mdl-23115847

RESUMO

Obesity, whose prevalence is increasing in industrialized countries, is recognized as a major risk factor for the development of type 2 diabetes. In contrast, the role of excess adiposity in the natural history of type 1 diabetes (T1DM) and its impact on therapeutic approaches are by far less known and most probably largely underestimated. The following items will be most particularly considered: 1) the accelerator role of obesity in the development of T1DM in young predisposed individuals; 2) the difficult diagnosis in presence of hybrid or double diabetes combining insulin secretory defect and insulin resistance; 3) the problem of managing both body weight and glucose control, especially in young females and adolescents; 4) the possible deleterious effects of intensive insulin therapy on body weight and some markers of the metabolic syndrome; 5) the worse cardiovascular prognosis of T1DM patients when obesity is present; 6) the possible role of other medications as adjunct therapy to insulin in insulin resistant obese T1DM patients; and finally 7) the expected benefit of bariatric surgery in some well selected T1DM patients with severe obesity.


Assuntos
Diabetes Mellitus Tipo 1/fisiopatologia , Obesidade/fisiopatologia , Adolescente , Cirurgia Bariátrica , Diabetes Mellitus Tipo 1/tratamento farmacológico , Humanos , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Síndrome Metabólica/tratamento farmacológico , Síndrome Metabólica/fisiopatologia , Obesidade/cirurgia , Fatores de Risco
19.
Rev Med Suisse ; 8(351): 1621-4, 1626-7, 2012 Aug 29.
Artigo em Francês | MEDLINE | ID: mdl-22988716

RESUMO

Bariatric surgery becomes more and more important in the management of the obese patient with type 2 diabetes, especially in case of failure of medical approaches. Metabolic improvement results not only from weight loss and the subsequent reduction in insulin resistance, but also from modifications of digestive hormones (especially incretins) that contribute to promote insulin secretion. This new paradigm, moving from bariatric surgery to metabolic surgery, opens new perspectives. The present article briefly describes innovative surgical techniques focusing on endocrine and metabolic improvement rather than on weight loss, the preliminary results of metabolic surgery in patients with type 2 diabetes and a body mass index <35 kg/m2 and, finally, some data regarding the surgical management of obese patients with type I diabetes not well treated with classical medical means.


Assuntos
Cirurgia Bariátrica , Diabetes Mellitus Tipo 2/cirurgia , Obesidade Mórbida/cirurgia , Índice de Massa Corporal , Diabetes Mellitus Tipo 2/etiologia , Humanos , Obesidade Mórbida/complicações
20.
Int J Radiat Biol ; 98(1): 109-121, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34714724

RESUMO

BACKGROUND: Despite the numerous literature results about biological effects of electromagnetic field (EMF) exposure, the interaction mechanisms of these fields with organisms are still a matter of debate. Extremely low frequency (ELF) MFs can modulate redox homeostasis and we showed that 24 h exposure to 50 Hz-1 mT has a pro-oxidant effect and effects on the epigenome of SH-SY5Y cells, decreasing miR-34b/c expression through the hypermethylation of their promoter. METHODS: Here, we investigated the role of the electromagnetic deposited energy density (ED) during exposures lasting 24 h to 1 mT amplitude MFs at a frequency of 50 Hz in inducing the above mentioned effects. To this end, we delivered ultrashort electric pulses, in the range of microsecond and nanosecond duration, with the same ED of the previously performed magnetic exposure to SH-SY5Y cells. Furthermore, we explored the effect of higher deposited energy densities. Analysis of i) gene and microRNA expression, ii) cell morphology, iii) reactive oxygen species (ROS) generation, and iv) apoptosis were carried out. RESULTS: We observed significant changes in egr-1 and c-fos expression at very low deposited ED levels, but no change of the ROS production, miR-34b/c expression, nor the appearance of indicators of apoptosis. We thus sought investigating changes in egr-1 and c-fos expression caused by ultrashort electric pulses at increasing deposited ED levels. The pulses with the higher deposited ED caused cell electroporation and even other morphological changes such as cell fusion. The changes in egr-1 and c-fos expression were more intense, but, again, no change of the ROS production, miR-34b/c expression, nor apoptosis induction was observed. CONCLUSIONS: These results, showing that extremely low levels of electric stimulation (never investigated until now) can cause transcriptional changes, also reveal the safety of the electroporating pulses used in biomedical applications and open up the possibility to further therapeutic applications of this technology.


Assuntos
MicroRNAs , Neuroblastoma , Linhagem Celular , Campos Eletromagnéticos/efeitos adversos , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Neuroblastoma/metabolismo , Espécies Reativas de Oxigênio/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA