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1.
J Colloid Interface Sci ; 581(Pt A): 226-237, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32771734

RESUMO

HYPOTHESIS: Pickering emulsions can be produced using raw particles obtained from uncracked vegetal food byproducts as sole stabilizers. The complexity brought by these non-purified ingredients will be their strength since insoluble particles and soluble compounds shall display good complementary properties, at the interface and the continuous phase. EXPERIMENTS: Emulsions were monitored over a one-month storage as regards to oil droplet diameter as main indicator of stability. Then, two main studies were carried out: 1) on the whole powders (water binding capacity, dry matter and insoluble content, size and morphology); 2) on the soluble content (size, charge, pH, Brix degree, surface tension measurements). FINDINGS: All byproducts stabilized-emulsions were stable during storage. They display various oil droplet sizes with sugar beet < apple < oat. Direct observation of the oil-water interfaces showed adsorption of the solid particles, and some voids corresponding to soluble elements from the byproducts' powders. The latter displayed surface-active properties. The insoluble particles are driving the oil droplet size and protecting against coalescence while soluble compounds can also adsorb at the interface, lowering droplet size, and also act as thickening agents from the continuous phase (pectins). Vegetal byproducts are thus meta ingredients, able to stabilize clean-label emulsions.

2.
Food Res Int ; 132: 109087, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32331655

RESUMO

This study presents a novel strategy for the dynamic analysis of volatile compounds extracted from baking vapors using a fit-for-purpose model cake. This model imitates a real sponge cake in terms of structure and processing but it is not reactive towards Maillard and caramelization reactions. When implemented with precursors (glucose (G) or glucose + leucine (G + L)), the reactions are activated and volatile markers can be monitored dynamically during baking. A method for the on-line sampling of vapors during baking using sorbent tubes coupled to thermal desorption (TD-GC-MS) has been developed and proven to be an appropriate and rapid technique to analyze a large number of volatile compounds within a broad range of physical and chemical characteristics. Volatile markers such as acetic acid, furfural, furfuryl alcohol and 5-hydroxymethylfurfual were identified using both models: glucose (G) and glucose + leucine (G + L) because they arise from both caramelization and the Maillard reaction. On the other hand, 3-methylbutanal and 2,5-dimethylpyrazine were only identified in the (G + L) model cake as they arise from the Strecker degradation pathway induced by the presence of leucine. Moreover, the relative abundance of all markers of reactions covers a broad range. On-line sampling coupled to TD-GC-MS enabled the collection of kinetic data on these markers throughout the baking operation and discrimination of the two formulas (G vs G + L) and two baking temperatures (170 °C and 200 °C) used. These results offer promise for the further use of this approach to study reaction kinetics in model cakes.

3.
Food Chem ; 311: 125946, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31864183

RESUMO

This study describes an experimental design, based on pH-stat, to rapidly screen and assess food formulation effects on the degrees of hydrolysis (DH) of both proteins and lipids throughout in vitro gastro-intestinal digestions. This approach was used to quantitatively compare and hierarchize key structure parameters of protein emulsions. Six matrices (15 wt% whey proteins, 0 or 10 wt% oil), each differing by at least one structure characteristic, were studied. The physical state of the bulk and the oil droplet size were the major structural levers to modulate the hydrolysis of proteins (final DH between 51.7 and 58.3%) and lipids (final DH between 46.9 and 72.7%), with non-trivial interplays between proteolysis and lipolysis. Additionally, pH-stat measurements in presence of a pancreatic lipase inhibitor proved to be an efficient way to widen the scope of the proposed experimental approach to foods that are intrinsically made of both proteins and lipids.


Assuntos
Trato Gastrointestinal/metabolismo , Proteínas do Soro do Leite/química , Proteínas do Soro do Leite/metabolismo , Digestão , Emulsões/química , Emulsões/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Hidrólise , Lipase/metabolismo , Metabolismo dos Lipídeos , Lipídeos/química , Lipólise , Modelos Biológicos , Proteólise
4.
Eur J Med Genet ; 62(10): 103711, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31265899

RESUMO

Access to active search for actionable secondary findings (SF) in diagnostic practice is a major psychological and ethical issue for genomic medicine. In this study, we analyzed the preferences of patients and their families regarding SF and identified the reporting procedures necessary for informed consent. We interviewed parents of patients with undiagnosed rare diseases potentially eligible for exome sequencing and patients affected by the diseases listed in the ACMG recommendations. Four focus groups (FG) were formed: parents of patients with undiagnosed rare diseases (FG1, n = 5); patients with hereditary cancers (FG2, n = 10); patients with hereditary cardiac conditions (FG3, n = 3); and patients with metabolic diseases (FG4, n = 3). Psychologists presented three broad topics for discussion: 1. Favorable or not to SF access, 2. Reporting procedures, 3. Equity of access. Discussions were recorded and analyzed using simplified Grounded Theory. Overall, 8 participants declared being favorable to SF because of the medical benefit (mainly FG1); 11 were unfavorable because of the psychological consequences (mainly FG2, FG3, FG4); 2 were ambivalent. The possibility of looking for SF in minors was debated. The 4 key information-based issues for participants ranked as follows: explanation of SF issues, autonomy of choice, importance of a reflection period, and quality of interactions between patients and professionals. Examining equity of access to SF led to philosophical discussions on quality of life. In conclusion, individual experience and life context (circumstances) were decisive in participants' expectations and fears regarding access to SF. Additional longitudinal studies based on actual SF disclosure announcements are needed to establish future guidelines.


Assuntos
Ética Médica , Genômica/ética , Sequenciamento de Nucleotídeos em Larga Escala/ética , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Genéticas Inatas/diagnóstico , Doenças Genéticas Inatas/genética , Doenças Genéticas Inatas/psicologia , Testes Genéticos , Genoma Humano , Humanos , Achados Incidentais , Pessoa de Meia-Idade , Sequenciamento Completo do Exoma
5.
Microb Cell Fact ; 15: 70, 2016 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-27142045

RESUMO

Lactic acid bacteria (LAB) are promising vectors of choice to deliver active molecules to mucosal tissues. They are recognized as safe by the World Health Organization and some strains have probiotic properties. The wide range of potential applications of LAB-driven mucosal delivery includes control of inflammatory bowel disease, vaccine delivery, and management of auto-immune diseases. Because of this potential, strategies for the display of proteins at the surface of LAB are gaining interest. To display a protein at the surface of LAB, a signal peptide and an anchor domain are necessary. The recombinant protein can be attached to the membrane layer, using a transmembrane anchor or a lipoprotein-anchor, or to the cell wall, by a covalent link using sortase mediated anchoring via the LPXTG motif, or by non-covalent liaisons employing binding domains such as LysM or WxL. Both the stability and functionality of the displayed proteins will be affected by the kind of anchor used. The most commonly surfaced exposed recombinant proteins produced in LAB are antigens and antibodies and the most commonly used LAB are lactococci and lactobacilli. Although it is not necessarily so that surface-display is the preferred localization in all cases, it has been shown that for certain applications, such as delivery of the human papillomavirus E7 antigen, surface-display elicits better biological responses, compared to cytosolic expression or secretion. Recent developments include the display of peptides and proteins targeting host cell receptors, for the purpose of enhancing the interactions between LAB and host. Surface-display technologies have other potential applications, such as degradation of biomass, which is of importance for some potential industrial applications of LAB.


Assuntos
Antígenos de Superfície/metabolismo , Biotecnologia/métodos , Biotecnologia/tendências , Lactobacillus/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Proteínas de Transporte/metabolismo , Humanos , Ácido Láctico/metabolismo
6.
Gut ; 65(3): 415-425, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26045134

RESUMO

BACKGROUND: Crohn's disease (CD)-associated dysbiosis is characterised by a loss of Faecalibacterium prausnitzii, whose culture supernatant exerts an anti-inflammatory effect both in vitro and in vivo. However, the chemical nature of the anti-inflammatory compounds has not yet been determined. METHODS: Peptidomic analysis using mass spectrometry was applied to F. prausnitzii supernatant. Anti-inflammatory effects of identified peptides were tested in vitro directly on intestinal epithelial cell lines and on cell lines transfected with a plasmid construction coding for the candidate protein encompassing these peptides. In vivo, the cDNA of the candidate protein was delivered to the gut by recombinant lactic acid bacteria to prevent dinitrobenzene sulfonic acid (DNBS)-colitis in mice. RESULTS: The seven peptides, identified in the F. prausnitzii culture supernatants, derived from a single microbial anti-inflammatory molecule (MAM), a protein of 15 kDa, and comprising 53% of non-polar residues. This last feature prevented the direct characterisation of the putative anti-inflammatory activity of MAM-derived peptides. Transfection of MAM cDNA in epithelial cells led to a significant decrease in the activation of the nuclear factor (NF)-κB pathway with a dose-dependent effect. Finally, the use of a food-grade bacterium, Lactococcus lactis, delivering a plasmid encoding MAM was able to alleviate DNBS-induced colitis in mice. CONCLUSIONS: A 15 kDa protein with anti-inflammatory properties is produced by F. prausnitzii, a commensal bacterium involved in CD pathogenesis. This protein is able to inhibit the NF-κB pathway in intestinal epithelial cells and to prevent colitis in an animal model.


Assuntos
Proteínas de Bactérias/metabolismo , Clostridiales/metabolismo , Doença de Crohn/microbiologia , Disbiose/microbiologia , Mucosa Intestinal/microbiologia , Sequência de Aminoácidos , Animais , Anti-Inflamatórios/uso terapêutico , Proteínas de Bactérias/química , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/uso terapêutico , Biomarcadores/metabolismo , Linhagem Celular , Colite/induzido quimicamente , Colite/metabolismo , Colite/prevenção & controle , Doença de Crohn/metabolismo , Doença de Crohn/patologia , Disbiose/metabolismo , Disbiose/patologia , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , NF-kappa B/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
7.
Food Chem ; 190: 164-172, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26212956

RESUMO

The influence of protein and/or fibre enrichment on the nutritional properties of biscuits was studied in terms of proteolysis and amylolysis. Biscuits were digested using a multi-compartmental and dynamic system that simulates the main physiological digestive functions of the upper tract of healthy adult humans: the TIM-1. A control biscuit and three biscuits enriched in proteins and/or fibres were digested under the same conditions. Samples were collected in each compartment of the TIM-1 (stomach, duodenum, jejunum and ileum) at different times of digestion and analysed in terms of proteolysis and amylolysis. Results indicate that both formulation and processing impacted the digestive fate of the biscuits. Incorporating proteins or fibres in biscuits lowered or delayed proteolysis. Moreover a protein-plus-fibre additional or synergic effect was observed. Biscuits enriched in proteins and/or fibres displayed a higher amylolysis degree than the control biscuit, probably due to lower starch amounts and higher gelatinization degrees.


Assuntos
Fibras na Dieta/análise , Amido/química , Digestão , Técnicas In Vitro , Amido/metabolismo
8.
Food Chem ; 182: 55-63, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-25842308

RESUMO

The effects of biscuit composition on the viscosity generated during digestion were investigated. A control biscuit, one with proteins, one with fibres, and one with both proteins and fibres were digested under the same conditions, using the TNO intestinal model (TIM-1). The TIM-1 is a multi-compartmental and dynamic in vitro system, simulating digestion in the upper tract (stomach and small intestine) of healthy adult humans. Digesta were collected at different times, in the different compartments of the TIM-1 (stomach, duodenum, jejunum and ileum) and viscosity was measured with a dynamic rheometer. Results showed a marked effect of biscuit composition on chyme viscosity. Highest viscosity was obtained with biscuits containing viscous soluble fibres, followed by those enriched in both proteins and fibres, then by protein-enriched and control biscuits. The viscosity was maintained throughout the gut up to the ileal compartment. A prediction of the evolution of the chyme viscosity in each compartment of the TIM-1 was built, based on model curves describing the evolution of the viscosity as a function of biscuit concentration, and on dilution factors measured by spectrophotometry on a blank digestion.


Assuntos
Pão/análise , Fibras na Dieta/análise , Digestão/fisiologia , Humanos , Técnicas In Vitro , Viscosidade
10.
Carbohydr Polym ; 99: 345-55, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24274517

RESUMO

This study focused on the effects of the interactions between modified waxy maize starch, kappa carrageenan and skim milk on the microstructure of their mixed systems using Confocal Laser Scanning Microscopy (CLSM). A multiple staining of the components was set up with a view to improving starch covalent staining. In starch/carrageenan pasted mixtures, carrageenan was found to adsorb on and penetrate slightly into the starch granules, whereas no interactions were observed between starch and milk proteins. In ternary mixtures, interactions between starch granules and carrageenan were no longer observed, even when milk proteins were added after starch swelling in the carrageenan solution, thus showing preferential interactions between carrageenan/milk proteins in comparison to carrageenan/starch granules. Modifying the blending order of the components led to microstructure differences depending on several parameters such as starch/carrageenan interactions, carrageenan/milk proteins network structure, level of starch granules disruption and amylopectin contribution to the microstructure.


Assuntos
Carragenina/química , Proteínas do Leite/química , Amido/química , Animais , Bovinos , Corantes Fluorescentes/química , Tecnologia de Alimentos , Microscopia Confocal , Soluções , Coloração e Rotulagem , Zea mays
11.
Rev Neurol (Paris) ; 169(8-9): 670-6, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23972818

RESUMO

AIM: This study aimed to gain a better understanding of the psychological impact of participating in a clinical trial for patients with Pompe disease (Acid Maltase Deficiency). Attitudes and expectations of adult patients with neuromuscular diseases regarding medical trials are as yet unreported. In order to learn about the psychological consequences of participating in a clinical trial, we conducted a prospective assessment of patients with late-onset Pompe Disease, a rare genetic condition, for which no treatment had been available before. This psychological study was carried out as an ancillary study to the randomized double-blind placebo-controlled trial described elsewhere (van der Ploeg et al., 2010). SUBJECTS AND METHODS: We assessed patients (n=8) at inclusion, and at 12 and 18 months for six psychological dimensions: depression (Beck Depression Inventory, BDI), hopelessness (Beck Hopelessness Scale, BHS), anxiety (STAI A-B), quality of life (Whoqol-26), social adjustment (S.A.S-self-report) and locus of control (IPC Levenson). We produced a self-administered questionnaire in order to assess the attitudes, motivations and expectations of patients during the trial. RESULTS: At 12 months, mean social adjustment (SAS-SR, P=0.02) had improved, and at 18 months mean depression score had improved as well (BDI, P=0.03). The quality of life of patients (Whoqol-26) remained unchanged. Throughout the study, patients were more likely to have an internal locus of control than an external one (IPC Levenson). The self-administered questionnaire showed that patients' expectations were disproportionate compared to the medical information they had received starting the trial. For all patients, the first motivation for being enrolled in a clinical trial was "to help research", for half of them the motivation was to "improve their health". Whether patients believed to be part of one group or another (placebo or treatment) depended on their subjective perception of improvement during the trial. CONCLUSION: Given the small sample size, the conclusions of this study are preliminary. However, findings do suggest that there is a positive psychological impact of participating in a treatment trial. Moreover, the patients' reactions upon unblinding have led us to recommend that patients be asked whether they would like their group assignation disclosed to them or not.


Assuntos
Atitude , Ensaios Clínicos como Assunto/psicologia , Doenças Neuromusculares/psicologia , Participação do Paciente/psicologia , Percepção , Adulto , Idoso , Ensaios Clínicos como Assunto/estatística & dados numéricos , Terapia de Reposição de Enzimas/psicologia , Feminino , Seguimentos , Doença de Depósito de Glicogênio Tipo II/tratamento farmacológico , Doença de Depósito de Glicogênio Tipo II/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Neuromusculares/epidemiologia , Doenças Neuromusculares/terapia , Participação do Paciente/estatística & dados numéricos , Inquéritos e Questionários
12.
Ultrason Sonochem ; 20(3): 881-91, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23266492

RESUMO

Ultrasonication may be a cost-effective emulsion formation technique, but its impact on emulsion final structure and droplet size needs to be further investigated. Olive oil emulsions (20wt%) were formulated (pH∼7) using whey protein (3wt%), three kinds of hydrocolloids (0.1-0.5wt%) and two different emulsification energy inputs (single- and two-stage, methods A and B, respectively). Formula and energy input effects on emulsion performance are discussed. Emulsions stability was evaluated over a 10-day storage period at 5°C recording the turbidity profiles of the emulsions. Optical micrographs, droplet size and viscosity values were also obtained. A differential scanning calorimetric (DSC) multiple cool-heat cyclic method (40 to -40°C) was performed to examine stability via crystallization phenomena of the dispersed phase. Ultrasonication energy input duplication from 11kJ to 25kJ (method B) resulted in stable emulsions production (reduction of back scattering values, dBS∼1% after 10days of storage) at 0.5wt% concentration of any of the stabilizers used. At lower gum amount samples became unstable due to depletion flocculation phenomena, regardless of emulsification energy input used. High energy input during ultrasonic emulsification also resulted in sub-micron oil-droplets emulsions (D(50)=0.615µm compared to D(50)=1.3µm using method A) with narrower particle size distribution and in viscosity reduction. DSC experiments revealed no presence of bulk oil formation, suggesting stability for XG 0.5wt% emulsions prepared by both methods. Reduced enthalpy values found when method B was applied suggesting structural modifications produced by extensive ultrasonication. Change of ultrasonication conditions results in significant changes of oil droplet size and stability of the produced emulsions.


Assuntos
Emulsificantes/química , Emulsões/química , Proteínas do Leite/química , Óleos Vegetais/química , Sonicação/métodos , Água/química , Indústria Alimentícia/métodos , Armazenamento de Alimentos , Azeite de Oliva , Tamanho da Partícula , Viscosidade , Proteínas do Soro do Leite
13.
Eur J Neurol ; 18(12): 1397-401, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21554494

RESUMO

BACKGROUND: While border-zone infarcts (BZI) account for about 10% of strokes, studies on related aphasia are infrequent. The aim of this work was to redefine specifically their early clinical pattern and evolution. METHODS: We prospectively studied consecutive patients referred to our stroke unit within a 2-year period. Cases of aphasia in right-handed patients associated with a MRI confirmed left-sided hemispheric BZI were included. These patients had a standardized language examination in the first 48 h, at discharge from stroke unit and between 6 and 18 months later. RESULTS: Eight patients were included. Three had anterior (MCA/ACA), two posterior (MCA/PCA), two both anterior and posterior, and one bilateral BZI. All our patients initially presented transcortical mixed aphasia, characterized by comprehension and naming difficulties associated with preserved repetition. In all patients, aphasia rapidly improved. It fully recovered within a few days in three patients. Initial improvement was marked, although incomplete in the five remaining patients: their aphasias specifically evolved according to the stroke location toward transcortical motor aphasia for the three patients with anterior BZI and transcortical sensory aphasia for the two patients with posterior BZI. All patients made a full language recovery within 18 months after stroke. CONCLUSIONS: We report a specific aphasic pattern associated with hemispheric BZI, including an excellent long-term outcome. These findings appear relevant to (i) clinically suspect BZI and (ii) plan rehabilitation and inform the patient and his family of likelihood of full language recovery.


Assuntos
Afasia de Broca/etiologia , Afasia de Wernicke/etiologia , Infarto Cerebral/complicações , Idoso , Afasia de Broca/fisiopatologia , Afasia de Broca/reabilitação , Afasia de Wernicke/fisiopatologia , Afasia de Wernicke/reabilitação , Infarto Cerebral/classificação , Infarto Cerebral/patologia , Compreensão , Transtornos de Deglutição/etiologia , Imagem de Difusão por Ressonância Magnética , Dominância Cerebral , Paralisia Facial/etiologia , Feminino , Hemianopsia/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Paresia/etiologia , Prognóstico , Estudos Prospectivos , Recuperação de Função Fisiológica
14.
Water Sci Technol ; 63(7): 1349-56, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21508536

RESUMO

Rivers used for drinking water production might be subject to anthropogenic pollution discharge upstream of the intake point. This problem was investigated in the case of the Moselle River, used for water production in Nancy (350,000 inhabitants) and which might be impacted by industrial activities 60 km upstream. The arsenic flux of a pulp and paper mill discharging in the Moselle River at this location has been more specifically investigated. The main sources of arsenic in that mill seemed to be the recovered papers and the gravel pit water used as feed water. The arsenic input related to wood and bark was limited. The main arsenic outputs from the plant were the paper produced on site and the deinking sludge. The arsenic concentration in the effluent of the wastewater treatment plant (WWTP) was not correlated to the one in the gravel pit water, but may depend on the operating conditions of the WWTP or the changes in processes of the mill. The impact of this anthropogenic source of arsenic on the Moselle River was slightly larger in summer, when the flowrate was lower. Globally the impact of the paper mill on the Moselle River water quality was limited in terms of arsenic.


Assuntos
Arsênico/análise , Rios/química , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/análise , Abastecimento de Água/análise , Monitoramento Ambiental , França , Papel , Estações do Ano
15.
J Dairy Sci ; 91(4): 1325-33, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18349225

RESUMO

The naked eye observation of cream cheese confocal scanning laser microscopy images only provides qualitative information about its microstructure. Because those products are dense dairy gels, confocal scanning laser microscopy images of 2 different cream cheeses may appear close. Quantitative image analysis is then necessary to compensate for human eye deficiency (e.g., lack of precision, subjectivity). Two kinds of quantitative image analysis were performed in this study: high-order statistical methods and grayscale mathematical morphology. They were applied to study the microstructure of 3 different cream cheeses (same manufacturing process, same dry matter content, but different fat and protein contents). Advantages and drawbacks of both methods are reviewed. The way they may be used to describe cream cheese microstructure is also presented.


Assuntos
Queijo/análise , Tecnologia de Alimentos/métodos , Microscopia Confocal/métodos , Algoritmos , Análise de Componente Principal
17.
Chemistry ; 6(6): 1064-77, 2000 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-10785827

RESUMO

The synthesis of a series of chiral cyclomanganated 2-[(eta 6-phenyl)-Cr(CO)3]pyridine complexes derived from (-)-beta-pinene enables, by a "spirogenic transformation", the preparation of four different chiral helical heterobimetallic syn-facial complexes or Cr0/Mn1-spiralenes, among which two possess a right-handed P molecular helicity and two other a left-handed M one. These organometallic helical molecules are synthesised by applying two different methods to the chiral cyclomanganated (eta 6-arene)tricarbonylchromium substrates. The first method is the so-called "Fischer route" which involves a sequential addition of PhLi and MeOTf. The second method based on reaction of the cyclomanganated complex with diphenyldiazomethane which has been tested on achiral bimetallic substrates is a reasonable neutral alternative to the "Fischer methodology" for the synthesis of Cr0/Mn1-spiralenes. The crystal structure of one of these heterobimetallic chiral helical compounds serves as a starting point in the configurational and structural assessment of the synthesised chiral (eta 6-arene)tricarbonylchromium complexes. Application of the "Fischer route" to a cyclomanganated chiral 2-phenylpyridine generates a single chiral eta 3-benzylic complex--or Mn1-spiralene--bearing a left-handed M helicity which has been characterized by X-ray diffraction analysis. Circular dichroic spectroscopic measurements underline the predominant contribution of the chiral and chirally induced aromatic chromophores to the sign of the Cotton effects and confirm the helical configurations of the considered heterobimetallic species.

18.
Rev Epidemiol Sante Publique ; 48(1): 7-15, 2000 Jan.
Artigo em Francês | MEDLINE | ID: mdl-10740081

RESUMO

BACKGROUND: The regularity of medical followup of HIVinfected patients greatly influences the effectiveness of antiretroviral treatments and of prophylaxis of opportunistic infections. METHODS: To identify potential barriers to a regular followup, a retrospective study was conducted among the adult AIDS patients diagnosed between July 1993 and May 1995 in two French districts (Gironde and HautsdeSeine). Medical followup was described based on the frequency of CD4 counts in the medical file and on a confidential interview among patients whose HIV infection had been diagnosed at least 6 months before AIDS. Irregular followup (less than one CD4 count per year when CD4> 500/ mm(3), and per 6months when CD4< 500/ mm(3)) within the two years preceding AIDS diagnosis was analysed according to socioeconomic status and to social and behavioral factors. RESULTS: Among 290 patients, followup was irregular in 51% of the patients (injecting drug users: 66%, homo/bisexual men: 41%, patients infected through heterosexual contact: 49%, p<0.01). Factors independently associated with irregular followup were low income level (adjusted odds ratio (aOR)= 2.4; 95% confidence interval (CI), 1.44.1); absence of regular practitioner at HIV diagnosis (aOR= 1.9; 95% CI 1.13.3); imprisonment between HIV diagnosis and AIDS (aOR= 3.8; 95% CI 1.310. 9), and being non homo/bisexual male (aOR= 2.4; 95% CI 1.15.1) versus homo/bisexual male (aOR= 1.3; 95% CI 0.72.7) and female (reference). CONCLUSIONS: Results of this study show that several socioeconomic, psychological and cultural barriers to a regular preAIDS medical followup still exist. Impact of new antiretroviral therapy may only be optimal if these barriers are overcome.


Assuntos
Infecções Oportunistas Relacionadas com a AIDS/prevenção & controle , Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , Pneumonia por Pneumocystis/prevenção & controle , Síndrome de Imunodeficiência Adquirida/tratamento farmacológico , Adulto , Feminino , Seguimentos , França , Serviços de Saúde/estatística & dados numéricos , Humanos , Modelos Logísticos , Masculino , Fatores Socioeconômicos , Fatores de Tempo
19.
AIDS ; 12(7): 795-800, 1998 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-9619812

RESUMO

OBJECTIVE: To describe the circumstances of the first HIV-positive test and to study the determinants of a delayed diagnosis of HIV infection. METHODS: In a retrospective study among adult AIDS patients diagnosed between July 1993 and May 1995 in two French districts, data on socioeconomic characteristics, circumstances of first HIV-positive test and attitudes and behaviours regarding medical care were collected in a confidential interview and analysed for potential association with a late test, defined as a first HIV-positive test within 6 months of AIDS diagnosis. RESULTS: Of the 359 AIDS patients studied, 69 (19.2%) had a late test. Late testers were more likely than other patients to have had an HIV-positive test because of clinical symptoms (89.7 versus 38.9%, P < 0.001) and not to perceive themselves as being at risk of infection with HIV (53.6 versus 39.3%, P < 0.05). The proportion of late testers was 34.6% among heterosexually infected patients, 12.7% among homo-/ bisexual men and 9.6% among injecting drug users. Factors independently associated with a late test were male gender [adjusted odds ratio (aOR), 5.6; 95% confidence interval (CI), 1.7-18.9] and absence of earned income (aOR, 5.2; 95% CI, 1.4-19) among heterosexually infected patients; high education (aOR, 3.1; 95% CI, 1.0-9.6) and having consulted a person practising alternative medicine (aOR, 3.4; 95% CI, 1.2-10) in homo-/bisexual men. CONCLUSIONS: Despite incentives to be tested for HIV, many individuals in France are still tested too late, even if they are in known high-risk groups. Efforts to test HIV-infected people as early as possible should be made by increasing the perception of HIV risk and decreasing the level of missed opportunities for testing. Current case management approaches make this recommendation critically important from both public health and an individual perspective.


Assuntos
Infecções por HIV/diagnóstico , Adulto , Feminino , França/epidemiologia , Infecções por HIV/epidemiologia , Infecções por HIV/psicologia , Humanos , Entrevistas como Assunto , Masculino , Estudos Retrospectivos , Fatores de Risco
20.
Int J Biol Macromol ; 20(4): 259-64, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9253646

RESUMO

Gelatin gel properties have been studied using three techniques. Optical rotation measurements have shown that the lower the ageing temperature, the faster the helix content increases but the lower the helix stability. Rheological measurements show that a small increase in temperature leads to a melting of some junction zones followed by a build up of new ones. By ageing the gel at two successive temperatures one can show the existence of two populations of junction zones with different thermal stabilities. The same result is shown on melting thermograms obtained by differential scanning calorimetry. All these results are consistent with the hypothesis of the presence of junction zones of various lengths, the thermostability of which being proportional to their lengths.


Assuntos
Gelatina/química , Temperatura , Varredura Diferencial de Calorimetria , Géis , Temperatura Alta , Rotação Ocular , Conformação Proteica , Reologia/métodos , Fatores de Tempo
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