76 resultados para Well-behaved solutions


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Static incubation tests, where microcapsules and beads are contacted with polymer and protein solutions, have been developed for the characterization of permselective materials applied for bioartificial organs and drug delivery. A combination of polymer ingress, detected by size-exclusion chromatography, and protein ingress/ egress, assessed by gel electrophoresis, provides information regarding the diffusion kinetics, molar mass cutoff(MMCO) and permeability. This represents an improvement over existing permeability measurements that are based on the diffusion of a single type of solute. Specifically, the permeability of capsules based on alginate, cellulose sulfate, polymethylene-co-guanidine were characterized as a function of membrane thickness. Solid alginate beads were also evaluated. The MMCO of these capsules was estimated to be between 80 and 90 kDa using polymers, and between 116-150 kDa with proteins. Apparently, the globular shape of the proteins (radius of gyration (Rg) of 4.2-4.6 nm) facilitates their passage through the membrane, comparatively to the polysaccharide coil conformation (Rg of 6.5-8.3 nm). An increase of the capsule membrane thickness reduced these values. The MMCO of the beads, which do not have a membrane limiting their permselective properties, was higher, between 110 and 200 kDa with dextrans, and between 150 and 220 kDa with proteins. Therefore, although the permeability estimated with biologically relevant molecules is generally higher due to their lower radius of gyration, both the MMCO of synthetic and natural watersoluble polymers correlate well, and can be used as in vitro metrics for the immune protection ability of microcapsules and microbeads. This article shows, to the authors' knowledge, the first reported concordance between permeability measures based on model natural and biological macromolecules.

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Zebrafish is a good model for studying regeneration because of the rapidity with which it occurs. Better understanding of this process may lead in the future to improvement of the regenerating capacity of humans. Signaling factors are the second largest category of genes, regulated during regeneration after the regulators of wound healing. Major developmental signaling pathways play a role in this multistep process, such as Bmp, Fgf, Notch, retinoic acid, Shh, and Wnt. In the present study, we focus on TGF-β-induced genes, bigh3 and bambia. Bigh3 encodes keratoepithelin, a protein first identified as an extracellular matrix protein reported to play a role in cell adhesion, as well as in cornea formation and osteogenesis. The expression of bigh3 in zebrafish fins has previously been reported. Here we demonstrate that tgf-b1 and tgf-b3 mRNA reacted with delay, first showing no regulation at 3âeuro0/00dpa, followed by upregulation at 4 and 5âeuro0/00dpa. Tgf-b1, tgf-2, and tgf-brII mRNA were back to normal levels at 10âeuro0/00dpa. Only tgf-b3 mRNA was still upregulated at that time. Bigh3 mRNA followed the upregulation of tgf-b1, while bambia mRNA behaved similarly to tgf-b2 mRNA. We show that upregulation of bigh3 and bambia mRNA correlated with the process of fin regeneration and regulation of TGF-b signaling, suggesting a new role for these proteins.

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RésuméL'addiction aux drogues est une maladie multifactorieile affectant toutes les strates de notre société. Cependant, la vulnérabilité à développer une addiction dépend de facteurs environnementaux, génétiques et psychosociaux. L'addiction aux drogues est décrite comme étant une maladie chronique avec un taux élevé de rechutes. Elle se caractérise par un besoin irrépressible de consommer une drogue et une augmentation progressive de la consommation en dépit des conséquences néfastes. Les mécanismes cérébraux responsables des dépendances aux drogues ne sont que partiellement élucidés, malgré une accumulation croissante d'évidences démontrant des adaptations au niveau moléculaire et cellulaire au sein des systèmes dopaminergique et glutamatergique. L'identification de nouveaux facteurs neurobiologiques responsables de la vulnérabilité aux substances d'abus est cruciale pour le développement de nouveaux traitements thérapeutiques capables d'atténuer et de soulager les symptômes liés à la dépendance aux drogues.Au cours des dernières années, de nombreuses études ont démontré qu'un nouveau circuit cérébral, le système hypocrétinergique, était impliqué dans plusieurs fonctions physiologiques, tel que l'éveil, le métabolisme énergétique, la motivation, le stress et les comportements liés aux phénomènes de récompense. Le système hypocrétinergique est composé d'environ 3000-4000 neurones issus de l'hypothalamus latéral projetant dans tout ie cerveau. Des souris transgéniques pour le gène des hypocrétines ont été générées et leur phénotype correspond à celui des animaux sauvages, excepté le fait qu'elles soient atteintes d'attaques de sommeil similaires à celles observées chez les patients narcoleptiques. H semblerait que les hypocrétines soient requises pour l'acquisition et l'expression de la dépendance aux drogues. Cependant, le mécanisme précis reste encore à être élucidé. Dans ce rapport, nous rendons compte des comportements liés aux phénomènes de récompense liés à l'alcool et à la cocaine chez les souris knock-out (KO), hétérozygotes (HET) et sauvages (WT).Nous avons, dans un premier temps, évalué l'impact d'injections répétées de cocaïne (15 mg/kg, ip) sur la sensibilisation locomotrice et sur le conditionnement place préférence. Nous avons pu observer que les souris WT, HET et KO exprimaient une sensibilisation locomotrice induite par une administration chronique de cocaïne, cependant les souris déficientes en hypocrétines démontraient une sensibilisation retardée et atténuée. Π est intéressant de mentionner que les mâles HET exprimaient une sensibilisation comportementale intermédiaire. Après normalisation des données, toutes les souris exprimaient une amplitude de sensibilisation similaire, excepté les souris mâles KO qui affichaient, le premier jour de traitement, une sensibilisation locomotrice réduite et retardée, reflétant un phénotype hypoactif plutôt qu'une altération de la réponse aux traitements chroniques de cocaïne. Contre toute attente, toutes les souris femelles exprimaient un pattern similaire de sensibilisation locomotrice à la cocaïne. Nous avons ensuite évalué l'effet d'un conditionnement comportemental à un environnement associé à des injections répétées de cocaine (15 mg / kg ip). Toutes les souris, quelque soit leur sexe ou leur génotype, ont manifesté une préférence marquée pour l'environnement apparié à la cocaïne. Après deux semaines d'abstinence à la cocaïne, les mâles et les femelles déficientes en hypocrétines n'exprimaient plus aucune préférence pour le compartiment précédemment associé à la cocaïne. Alors que les souris WT et HET maintenaient leur préférence pour le compartiment associé à la cocaïne. Pour finir, à l'aide d'un nouveau paradigme appelé IntelliCage®, nous avons pu évaluer la consommation de liquide chez les femelles WT, HET et KO. Lorsqu'il n'y avait que de l'eau disponible, nous avons observé que les femelles KO avaient tendance à moins explorer les quatre coins de la cage. Lorsque les souris étaient exposées à quatre types de solutions différentes (eau, ImM quinine ou 0.2% saccharine, alcool 8% et alcool 16%), les souris KO avaient tendance à moins consommer l'eau sucrée et les solutions alcoolisées. Cependant, après normalisation des données, aucune différence significative n'a pu être observée entre les différents génotypes, suggérant que la consommation réduite d'eau sucrée ou d'alcool peut être incombée à l'hypoactivité des souris KO.Ces résultats confirment que le comportement observé chez les souris KO serait dû à des compensations développementales, puisque la sensibilisation locomotrice et le conditionnement comportemental à la cocaïne étaient similaires aux souris HET et WT. En ce qui concerne la consommation de liquide, les souris KO avaient tendance à consommer moins d'eau sucrée et de solutions alcoolisées. Le phénotype hypoactif des souris déficientes en hypocrétine est probablement responsable de leur tendance à moins explorer leur environnement. Il reste encore à déterminer si l'expression de ce phénotype est la conséquence d'un état de vigilance amoindri ou d'une motivation diminuée à la recherche de récompense. Nos résultats suggèrent que les souris déficientes en hypocrétine affichent une motivation certaine à la recherche de récompense lorsqu'elles sont exposées à des environnements où peu d'efforts sont à fournir afin d'obtenir une récompense.AbstractDrug addiction is a multifactorial disorder affecting human beings regardless their education level, their economic status, their origin or even their gender, but the vulnerability to develop addiction depends on environmental, genetic and psychosocial dispositions. Drug addiction is defined as a chronic relapsing disorder characterized by compulsive drug seeking, with loss of control over drug intake and persistent maladaptive decision making in spite of adverse consequences. The brain mechanisms responsible for drug abuse remain partially unknown despite accumulating evidence delineating molecular and cellular adaptations within the glutamatergic and the dopaminergic systems. However, these adaptations do not fully explain the complex brain disease of drug addiction. The identification of other neurobiological factors responsible for the vulnerability to substance abuse is crucial for the development of promising therapeutic treatments able to alleviate signs of drug dependence.For the past few years, growing evidence demonstrated that a recently discovered brain circuit, the hypocretinergic system, is implicated in many physiological functions, including arousal, energy metabolism, motivation, stress and reward-related behaviors. The hypocretin system is composed of a few thousands neurons arising from the lateral hypothalamus and projecting to the entire brain. Hypocretin- deficient mice have been generated, and unexpectedly, their phenotype resembles that of wild type mice excepting sleep attacks strikingly similar to those of human narcolepsy patients. Evidence suggesting that hypocretins are required for the acquisition and the expression of drug addiction has also been reported; however the precise mechanism by which hypocretins modulate drug seeking behaviors remains a matter of debate. Here, we report alcohol and cocaine reward-related behaviors in hypocretin-deficient mice (KO), as well as heterozygous (HET) and wild type (WT) littermates.We first evaluated the impact of repeated cocaine injections (15 mg/kg, ip) on locomotor sensitization and conditioned place preference. We observed that WT, HET and KO mice exhibited behavioral sensitization following repeated cocaine administrations, but hypocretin deficient males displayed a delayed and attenuated response to chronic cocaine administrations. Interestingly, HET males exhibited an intermediate pattern of behavioral sensitization. However, after standardization of the post-injection data versus the period of habituation prior to cocaine injections, all mice displayed similar amplitudes of behavioral sensitization, except a reduced response in KO males on the first day, suggesting that the delayed and reduced cocaine-induced locomotor sensitization may reflect a hypoactive phenotype and probably not an altered response to repeated cocaine administrations. Unexpectedly, all female mice exhibited similar patterns of cocaine-induced behavioral sensitization. We then assessed the behavioral conditioning for an environment repeatedly paired with cocaine injections (15 mg/kg ip). All mice, whatever their gender or genotype, exhibited a robust preference for the environment previously paired with cocaine administrations. Noteworthy, following two weeks of cocaine abstinence, hypocretin-deficient males and females no longer exhibited any preference for the compartment previously paired with cocaine rewards whereas both WT and HET mice continued manifesting a robust preference. We finally assessed drinking behaviors in WT, HET and KO female mice using a novel paradigm, the IntelliCages®. We report here that KO females tended to less explore the four cage comers where water was easily available. When exposed to four different kinds of liquid solutions (water, ImM quinine or saccharine 0.2%, alcohol 8% and alcohol 16%), KO mice tended to less consume the sweet and the alcoholic beverages. However, after data standardization, no significant differences were noticed between genotypes suggesting that the hypoactive phenotype is most likely accountable for the trend regarding the reduced sweet or alcohol intake in KO.Taken together, the present findings confirm that the behavior seen in Hcrt KO mice likely reflects developmental compensations since only a slightly altered cocaine-induced behavioral sensitization and a normal behavioral conditioning with cocaine were observed in these mice compared to HET and WT littermates. With regards to drinking behaviors, KO mice barely displayed any behavioral changes but a trend for reducing sweet and alcoholic beverages. Overall, the most striking observation is the constant hypoactive phenotype seen in the hypocretin-deficient mice that most likely is accountable for their reduced tendency to explore the environment. Whether this hypoactive phenotype is due to a reduced alertness or reduced motivation for reward seeking remains debatable, but our findings suggest that the hypocretin-deficient mice barely display any altered motivation for reward seeking in environments where low efforts are required to access to a reward.

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SUMMARY: In a randomly selected cohort of Swiss community-dwelling elderly women prospectively followed up for 2.8 +/- 0.6 years, clinical fractures were assessed twice yearly. Bone mineral density (BMD) measured at tibial diaphysis (T-DIA) and tibial epiphysis (T-EPI) using dual-energy X-ray absorptiometry (DXA) was shown to be a valid alternative to lumbar spine or hip BMD in predicting fractures. INTRODUCTION: A study was carried out to determine whether BMD measurement at the distal tibia sites of T-EPI and T-DIA is predictive of clinical fracture risk. METHODS: In a predefined representative cohort of Swiss community-dwelling elderly women aged 70-80 years included in the prospective, multi-centre Swiss Evaluation of the Methods of Measurement of Osteoporotic Fracture risk (SEMOF) study, fracture risk profile was assessed and BMD measured at the lumbar spine (LS), hip (HIP) and tibia (T-DIA and T-EPI) using DXA. Thereafter, clinical fractures were reported in a bi-yearly questionnaire. RESULTS: During 1,786 women-years of follow-up, 68 clinical fragility fractures occurred in 61 women. Older age and previous fracture were identified as risk factors for the present fractures. A decrease of 1 standard deviation in BMD values yielded a 1.5-fold (HIP) to 1.8-fold (T-EPI) significant increase in clinical fragility fracture hazard ratio (adjusted for age and previous fracture). All measured sites had comparable performance for fracture prediction (area under the curve range from 0.63 [LS] to 0.68 [T-EPI]). CONCLUSION: Fracture risk prediction with BMD measurements at T-DIA and T-EPI is a valid alternative to BMD measurements at LS or HIP for patients in whom these sites cannot be accessed for clinical, technical or practical reasons.

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Objective: Although initially developed to assess spiritual well-being,the FACIT-Sp is increasingly used to assess the other end of the spectrum,i.e. spiritual distress. This study intends to investigate whether theFACIT-Sp could really contribute to this aim in older patients. Method:Patients (N=135, 81.47.1 years, 68.3% women) aged 65 years and over,with MMSE score>19, admitted consecutively in post-acute rehabilitationwere enrolled. The FACIT-Sp (12 items, score 0 to 48, high spiritualwell-being defined as score_36) was administered and commentswere systematically retrieved. Results: Overall, 32(23.7%) patients hadhigh spiritual well-being. FACIT-Sp internal consistency was good(Cronbach's 0.85) and a confirmatory factorial analysis was consistentwith Meaning and Faith proposed subscales. Qualitative analysisshowed that negative answers (score=0) to "My illness has strengthenedmy faith or spiritual beliefs" (N=76/135) could equally reflect theabsence of impact (49/76, 64.5%) or a negative impact (religious struggle,27/76, 35.5%) of illness on faith. However, former patients had significantlyhigher FACIT-Sp scores than the latter (30.35.6 vs 20.97.9,P<.001). Similarly, among patients (N=73/135) with negative answers(score<3) to "I feel a sense of purpose in my life" those mentioning their"old age" to explain their answer (N=34/73, 46.6%) had higher FACITSpscores than those who did not (26.47.7 vs 22.58.1,P=.02). Conclusion:The FACIT-Sp identifies older people with high spiritual wellbeingbut could underestimate well-being in some older patients. Lowscores on some items could have very different meanings and interpretationof FACIT-Sp global scores below the usual cut-off should becautious.

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OBJECTIVE: Sport practice is widely encouraged, both in guidelines and in clinical practice, because of its broad range of positive effects on health. However, very limited evidence directly supports this statement among adolescents and the sport duration that we should recommend remains unknown. We aimed to determine sport durations that were associated with poor well-being. METHODS: We conducted a survey including 1245 adolescents (16-20 years) from the general Swiss population. Participants were recruited from various settings (sport centres, peers of sport practicing adolescents, websites) and asked to complete a web-based questionnaire. Weekly sport practice was categorised into four groups: low (0-3.5 h), average (≈ recommended 7 h (3.6-10.5)), high (≈14 h (10.6-17.5)) and very high (>17.5 h). We assessed well-being using the WHO-5 Well-Being Index. RESULTS: Compared with adolescents in the average group, those in the very high group had a higher risk of poor well-being (OR 2.29 (95% CI 1.11 to 4.72)), as did those in the low group (OR 2.33 (1.58 to 3.44)). In contrast, those in the high group had a lower risk of poor well-being than those in the average group (OR 0.46 (0.23 to 0.93)). CONCLUSIONS: We found an inverted, U-shaped relationship between weekly sport practice duration and well-being among adolescents. The peak scores of well-being were around 14 h per week of sport practice, corresponding to twice the recommended 7 h. Practicing higher sport durations was an independent risk factor of poor well-being.

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Serum-free aggregating cell cultures of fetal rat telencephalon treated with the potent tumor promoter phorbol 12-myristate 13-acetate (PMA) showed a dose-dependent, persistent stimulation of the enzymes choline acetyltransferase (ChAT), glutamic acid decarboxylase and glutamine synthetase. After elimination of the proliferating cells by treatment of the cultures with Ara-C (0.4 microM) only the cholinergic marker enzyme, ChAT, could be stimulated by tumor promoters. The non-promoting phorbol ester, 4 alpha-phorbol 12,13-didecanoate proved to be inactive in these cultures, whereas the potent non-phorbol tumor promoter, mezerein, produced an even greater stimulatory effect than PMA. Since PMA and mezerein are potent and specific activators of protein kinase C, the present results suggest a role for this second messenger in the development of cholinergic telencephalon neurons. Stimulation of ChAT required prolonged exposure (48 h) of the cultures to PMA and the responsiveness of the cholinergic neurons to the tumor promoters decreased with progressive cellular maturation. The cholinergic telencephalon neurons showed the same pattern of responsiveness for tumor promoters as for nerve growth factor (NGF). However, the combined treatment with NGF and either PMA or mezerein produced an additive stimulatory effect, suggesting somewhat different mechanisms of action.

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BACKGROUND/AIMS: Alveolar echinococcosis (AE) is a serious liver disease. The aim of this study was to explore the long-term prognosis of AE patients, the burden of this disease in Switzerland and the cost-effectiveness of treatment. METHODS: Relative survival analysis was undertaken using a national database with 329 patient records. 155 representative cases had sufficient details regarding treatment costs and patient outcome to estimate the financial implications and treatment costs of AE. RESULTS: For an average 54-year-old patient diagnosed with AE in 1970 the life expectancy was estimated to be reduced by 18.2 and 21.3 years for men and women, respectively. By 2005 this was reduced to approximately 3.5 and 2.6 years, respectively. Patients undergoing radical surgery had a better outcome, whereas the older patients had a poorer prognosis than the younger patients. Costs amount to approximately Euro108,762 per patient. Assuming the improved life expectancy of AE patients is due to modern treatment the cost per disability-adjusted life years (DALY) saved is approximately Euro6,032. CONCLUSIONS: Current treatments have substantially improved the prognosis of AE patients compared to the 1970s. The cost per DALY saved is low compared to the average national annual income. Hence, AE treatment is highly cost-effective in Switzerland.

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The UHPLC strategy which combines sub-2 microm porous particles and ultra-high pressure (>1000 bar) was investigated considering very high resolution criteria in both isocratic and gradient modes, with mobile phase temperatures between 30 and 90 degrees C. In isocratic mode, experimental conditions to reach the maximal efficiency were determined using the kinetic plot representation for DeltaP(max)=1000 bar. It has been first confirmed that the molecular weight of the compounds (MW) was a critical parameter which should be considered in the construction of such curves. With a MW around 1000 g mol(-1), efficiencies as high as 300,000 plates could be theoretically attained using UHPLC at 30 degrees C. By limiting the column length to 450 mm, the maximal plate count was around 100,000. In gradient mode, the longest column does not provide the maximal peak capacity for a given analysis time in UHPLC. This was attributed to the fact that peak capacity is not only related to the plate number but also to column dead time. Therefore, a compromise should be found and a 150 mm column should be preferentially selected for gradient lengths up to 60 min at 30 degrees C, while the columns coupled in series (3x 150 mm) were attractive only for t(grad)>250 min. Compared to 30 degrees C, peak capacities were increased by about 20-30% for a constant gradient length at 90 degrees C and gradient time decreased by 2-fold for an identical peak capacity.

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Mutations in the Bacillus subtilis gene that affect the activity of the uridine diphosphate (UDP)-N-acetylglucosamine (GlcNAc) 4-epimerase (EC 5.1.3.7) were shown to map to galE, the structural gene of the UDP-glucose (Glc) 4-epimerase (EC 5.1.3.2). This genetic evidence that the same enzyme can catalyse the epimerisation of hexoses as well as of their N-acetylated forms is confirmed by in vitro assays with purified enzyme. It appears that in B. subtilis, Gne (GneA, GalE) is involved in two distinct and essential functions, i.e., cell detoxification under certain growth conditions and the biosynthesis of anionic cell wall polymers. We discuss the evidence that such enzymes capable of utilizing both UDP-hexoses and UDP-N-acetylhexosamines are present in other organisms.