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1.
J Texture Stud ; 54(6): 913-925, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37646203

RESUMO

Sodium caseinates-kefiran systems were studied to explore whether any potential interactions between them might exist. The study was performed using low-deformation rheological techniques, which were dynamic and creep tests. The systems were prepared under various experimental conditions such as heating and acidification. Besides, the structure development of the systems in relation to time was also monitored using oscillatory shear rheometry. The results indicated that the structural characteristics of the systems were mainly affected by the state of the caseinates such as the formation of aggregates and to a lesser degree by the interactions of kefiran molecules with the caseinates. Freeze-thaw treatment produced cryogels with good thermal stability and fairly satisfactory mechanical properties. The morphology of the caseinate-kefiran systems was also investigated by means of confocal laser scanning microscopy.


Assuntos
Polissacarídeos , Cloreto de Sódio , Polissacarídeos/química , Fenômenos Químicos
2.
Adv Exp Med Biol ; 1359: 201-234, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35471541

RESUMO

For constructing neuronal network models computational neuroscientists have access to wide-ranging anatomical data that nevertheless tend to cover only a fraction of the parameters to be determined. Finding and interpreting the most relevant data, estimating missing values, and combining the data and estimates from various sources into a coherent whole is a daunting task. With this chapter we aim to provide guidance to modelers by describing the main types of anatomical data that may be useful for informing neuronal network models. We further discuss aspects of the underlying experimental techniques relevant to the interpretation of the data, list particularly comprehensive data sets, and describe methods for filling in the gaps in the experimental data. Such methods of "predictive connectomics" estimate connectivity where the data are lacking based on statistical relationships with known quantities. Exploiting organizational principles that link the plethora of data in a unifying framework can be useful for informing computational models. Besides overarching principles, we touch upon the most prominent features of brain organization that are likely to influence predicted neuronal network dynamics, with a focus on the mammalian cerebral cortex. Given the still existing need for modelers to navigate a complex data landscape full of holes and stumbling blocks, it is vital that the field of neuroanatomy is moving toward increasingly systematic data collection, representation, and publication.


Assuntos
Conectoma , Rede Nervosa , Animais , Encéfalo/fisiologia , Córtex Cerebral , Conectoma/métodos , Mamíferos , Rede Nervosa/fisiologia , Neurônios
3.
Sci Adv ; 5(6): eaav9694, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31206020

RESUMO

The wiring of vertebrate and invertebrate brains provides the anatomical skeleton for cognition and behavior. Connections among brain regions are characterized by heterogeneous strength that is parsimoniously described by the wiring cost and homophily principles. Moreover, brains exhibit a characteristic global network topology, including modules and hubs. However, the mechanisms resulting in the observed interregional wiring principles and network topology of brains are unknown. Here, with the aid of computational modeling, we demonstrate that a mechanism based on heterochronous and spatially ordered neurodevelopmental gradients, without the involvement of activity-dependent plasticity or axonal guidance cues, can reconstruct a large part of the wiring principles (on average, 83%) and global network topology (on average, 80%) of diverse adult brain connectomes, including fly and human connectomes. In sum, space and time are key components of a parsimonious, plausible neurodevelopmental mechanism of brain wiring with a potential universal scope, encompassing vertebrate and invertebrate brains.


Assuntos
Encéfalo/fisiologia , Drosophila melanogaster/fisiologia , Macaca/fisiologia , Modelos Neurológicos , Rede Nervosa/fisiologia , Vias Neurais/fisiologia , Animais , Encéfalo/anatomia & histologia , Cognição/fisiologia , Conectoma/estatística & dados numéricos , Drosophila melanogaster/anatomia & histologia , Humanos , Macaca/anatomia & histologia , Camundongos , Vias Neurais/anatomia & histologia , Análise Espaço-Temporal , Especificidade da Espécie
4.
Hippokratia ; 19(1): 25-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26435642

RESUMO

BACKGROUND: A Vitamin D Receptor gene (VDR) polymorphism, rs10735810 (Fok1), has been associated in the past with idiopathic short stature (ISS) in a linkage study. We have investigated the association of the same, as well as a different polymorphism in the same gene [rs731236 (Taq1)] with ISS, in an independent study in Greek children. METHODS: The VDR rs10735810 (Fok1) and rs731236 (Taq1) polymorphisms were genotyped in a group of ISS children (n= 47) and an age and sex-matched group of normal height children (n= 60) from northern Greece. Genotyping was accomplished through established PCR-RFLP methods. RESULTS: An association trend of rs10735810 with ISS was observed, with the TT (ff) genotype being apparently underrepresented among ISS children compared to controls (p= 0.076; OR= 0.165, 95% CI= 0.025-1.094). CONCLUSIONS: The above results, together with recent evidence related to the functionality of the rs10735810 polymorphism, cannot exclude an involvement of VDR in the pathogenesis of ISS. Hippokratia 2015, 19 (1): 25-29.

5.
Hippokratia ; 17(2): 120-5, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24376315

RESUMO

AIM: To study possible ocular surface and lacrimal drainage changes in women being on adjuvant chemotherapy with 5-Fluorouracil 600 mg/m2, Epirubicin 60-90 mg/m(2), Cyclophosphamide 600 mg/m(2) (FEC) regimen for breast cancer. METHODS: Sixty one consecutive women with early stage breast cancer (median age 58 years - interquartile range 22) were included in this study. They all underwent mastectomy followed by 6 cycles of tri-weekly administration of FEC regimen and were free of ocular surface, eyelid and tear film symptomatic disease at baseline. None of them had pre- or coexisting treatment with other chemotherapeutic agent or radiotherapy. Slit lamp examination of the ocular surface, Schirmer test I (without topical anesthesia) and tears Break up Time test (BUT) were performed before the initiation of treatment and immediately after the third therapeutic cycle. RESULTS: From 61 women 39.34% had significant conjunctival hyperemia, 41.0% lid margin abnormalities, 4.92% blepharitis, 6.56% madarosis, 3.28% punctate epithelial keratopathy and 4.92% oedema of the lower punctum mucosal opening after three chemotherapeutic cycles. Mean BUT measures were found lower after the third chemotherapeutic cycle (p=0.001) but mean Schirmer test I values were higher after the third chemotherapeutic cycle (p=0.001). CONCLUSION: Women on chemotherapy with FEC regimen are more susceptible to develop ocular surface and tear film alterations, within the first three cycles of chemotherapy for breast cancer, and thus, prompt ophthalmological evaluation may be proven beneficial for early diagnosis and management of the induced ocular disease.

6.
Psychopharmacology (Berl) ; 229(2): 219-26, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23604336

RESUMO

Release of dopamine in the nucleus accumbens (NAcc) is essential for acute drug reward. The present study was designed to trace the reinforcing effect of dopamine release by measuring the functional connectivity (FC) between the NAcc and brain regions involved in a limbic cortical-subcortical circuit during a dopaminergic challenge. Twenty healthy volunteers received single doses of methylphenidate (40 mg) and placebo on separate test days according to a double-blind, cross-over study design. Resting state functional magnetic resonance imaging (fMRI) was measured between 1.5 and 2 h postdosing. FC between regions of interest (ROI) in the NAcc, the medial dorsal nucleus (MDN) of the thalamus and remote areas within the limbic circuit was explored. Methylphenidate significantly reduced FC between the NAcc and the basal ganglia (i.e., subthalamic nucleus and ventral pallidum (VP)), relative to placebo. Methylphenidate also decreased FC between the NAcc and the medial prefrontal cortex (mPFC) as well as the temporal cortex. Methylphenidate did not affect FC between MDN and the limbic circuit. It is concluded that methylphenidate directly affects the limbic reward circuit. Drug-induced changes in FC of the NAcc may serve as a useful marker of drug activity in in the brain reward circuit.


Assuntos
Estimulantes do Sistema Nervoso Central/farmacologia , Metilfenidato/farmacologia , Núcleo Accumbens/efeitos dos fármacos , Recompensa , Adulto , Mapeamento Encefálico , Cromatografia Líquida , Método Duplo-Cego , Feminino , Lateralidade Funcional , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Espectrometria de Massas , Metilfenidato/sangue , Núcleo Accumbens/irrigação sanguínea , Oxigênio/sangue , Adulto Jovem
7.
J Biol Regul Homeost Agents ; 25(3): 303-11, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22023754

RESUMO

Pulpitis is a typical inflammatory disease of dental pulp, characterized by the local accumulation of inflammatory mediators, including cytokines and chemokines. In addition to serving as intercellular messengers mediating the inflammatory response, cytokines and chemokines induce the expression and stimulate the activity of molecular and cellular agents which participate actively in destructive and reparative processes in the pulp. It is the balance between these processes which eventually determines the extent of pulp inflammation and the viability of the affected tooth. Over the last decade, a number of studies have attempted to correlate cytokine gene expression in the pulp with various stages of inflammation, with possible diagnostic applications in mind. A small survey of relevant information is presented in this paper.


Assuntos
Citocinas/imunologia , Polpa Dentária/imunologia , Regulação da Expressão Gênica/imunologia , Pulpite/imunologia , Animais , Polpa Dentária/patologia , Humanos , Inflamação/diagnóstico , Inflamação/imunologia , Inflamação/patologia , Pulpite/diagnóstico , Pulpite/patologia
8.
Curr Pharm Des ; 15(30): 3464-75, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19860692

RESUMO

PDE5 inhibitors have been clearly established as first-line therapy for the treatment of erectile dysfunction (ED). Three PDE5 inhibitors--sildenafil (Viagra), vardenafil (Levitra) and tadalafil (Cialis)--are currently approved by the FDA and the EMEA for use in ED, whereas sildenafil is also marketed under a different proprietary name (Revatio) for the treatment of pulmonary arterial hypertension (PAH). A forth PDE5 inhibitor, udenafil (Zydena), is currently marketed. In the present review the molecular basis and the mechanism of action of PDE5 inhibitors is discussed. In addition experimental and clinical data concerning their effects on different tissues, organs and systems is systematically reviewed and their possible beneficial action in numerous disorders is presented.


Assuntos
Inibidores da Fosfodiesterase 5 , Inibidores de Fosfodiesterase/farmacologia , Animais , Plaquetas/efeitos dos fármacos , Plaquetas/enzimologia , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/fisiologia , Trato Gastrointestinal/efeitos dos fármacos , Coração/efeitos dos fármacos , Humanos , Imunidade/efeitos dos fármacos , Sistema Respiratório/efeitos dos fármacos , Doenças Respiratórias/tratamento farmacológico , Fenômenos Fisiológicos do Sistema Urinário/efeitos dos fármacos , Sistema Urogenital/efeitos dos fármacos , Doenças Urológicas/tratamento farmacológico , Visão Ocular/efeitos dos fármacos
9.
Inflamm Res ; 58(8): 437-40, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19434479

RESUMO

There is mounting evidence that tumour necrosis factor (TNF) is involved in the early phase of inflammatory response, but its relation to histamine action is unclear. In this study we examined the effect of drugs interfering with TNF expression (thalidomide) and activity (infliximab) and compared it to that of a H(1)R histamine receptor antagonist (loratadine) in a model of histamine-induced rat hind-paw oedema formation. Systemic administration of all three drugs effectively reduced the oedema formed by the subsequent transplantar administration of histamine into the rat paw, in a dose-dependent manner. The time-dependence of the effect exerted by thalidomide and infliximab was very similar to that of loratadine. Moreover, there appears no significant synergistic effect between infliximab and loratadine, suggesting that TNF is either a major modulator or a direct mediator of oedema formation induced by histamine, in the rat paw.


Assuntos
Edema/induzido quimicamente , Edema/patologia , Histamina , Inibidores do Fator de Necrose Tumoral , Fatores de Necrose Tumoral/fisiologia , Animais , Anti-Inflamatórios/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Relação Dose-Resposta a Droga , Edema/tratamento farmacológico , Pé/patologia , Antagonistas dos Receptores Histamínicos H1/uso terapêutico , Infliximab , Loratadina/uso terapêutico , Masculino , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Talidomida/uso terapêutico
10.
Eur J Neurol ; 14(7): 745-9, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17594329

RESUMO

We have examined the association of phosphodiesterase 4D (PDE4D) single nucleotide polymorphism (SNP45) and microsatellite marker AC008818-1 with ischaemic stroke, in an independent cohort of Greek patients and control individuals with no clinical manifestations of vascular disease. Significantly different distributions were observed with respect to the AC008818-1 alleles, with allele 148 associating with an increased risk of stroke incidence, and allele 144 with a protective effect. In addition, the haplotype defined by allele 148 and G allele of SNP45 was found to be significantly increased in patients even though no statistically significant differences emerged with respect to SNP45 alone. The previously established association of a PDE4D gene haplotype with ischaemic stroke in a population from Iceland was independently confirmed in our Greek population, suggesting that PDE4D may be involved in the aetiology and pathogenesis of stroke.


Assuntos
3',5'-AMP Cíclico Fosfodiesterases/genética , Isquemia Encefálica/genética , 3',5'-AMP Cíclico Fosfodiesterases/fisiologia , Idoso , Idoso de 80 Anos ou mais , Alelos , Isquemia Encefálica/epidemiologia , Estudos de Coortes , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3 , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4 , Feminino , Predisposição Genética para Doença , Genótipo , Grécia/epidemiologia , Haplótipos/genética , Humanos , Islândia/epidemiologia , Masculino , Polimorfismo de Nucleotídeo Único
11.
Int Endod J ; 40(3): 198-203, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17305696

RESUMO

AIM: To analyse the gene expression of tumour necrosis factor-alpha (TNF-alpha) in human dental pulps, under normal and inflammatory conditions and to examine the association between any observed alterations in the expression of this cytokine with the severity of the clinical symptoms. METHODOLOGY: Eighteen pulpal samples were obtained from single-rooted human teeth. Six of the teeth were normal (group A), six had been diagnosed with reversible pulpitis (group B), and the remaining six were from teeth diagnosed with irreversible pulpitis (group C). TNF-alpha gene expression was semi-quantitatively analysed in each sample with RT-PCR, and the results from each group of teeth were compared with the Kruskal-Wallis and Mann-Whitney tests. RESULTS: Tumour necrosis factor-alpha was detected in all three groups of dental pulp. Statistical analysis provided evidence of a significant increase of TNF-alpha gene expression associated with irreversible inflammation compared with healthy controls (P = 0.002). No such difference was detected in reversibly inflamed pulp in comparison to healthy teeth (P = 0.699). CONCLUSION: Tumour necrosis factor-alpha gene expression in inflamed human dental pulp tissue is positively associated with the severity of clinical symptoms.


Assuntos
Pulpite/genética , Fator de Necrose Tumoral alfa/genética , Adolescente , Adulto , Estudos de Casos e Controles , Polpa Dentária/química , Humanos , Pulpite/patologia , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estatísticas não Paramétricas , Fator de Necrose Tumoral alfa/análise , Fator de Necrose Tumoral alfa/biossíntese , Regulação para Cima
12.
Food Addit Contam ; 23(6): 634-41, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16766462

RESUMO

Overall migration from a wide range of commercial plastics-based netting materials destined to be used as either meat or vegetable packaging materials into the fatty food simulant isooctane or the aqueous simulant distilled water, respectively, was studied. In addition, sensory tests of representative netting materials were carried out in bottled water in order to investigate possible development of off-odour/taste and discoloration in this food simulant as a result of migration from the netting material. Sensory tests were supplemented by determination of the volatile compounds' profile in table water exposed to the netting materials using SPME-GC/MS. Test conditions for packaging material/food simulant contact and method of overall migration analysis were according to European Union Directives 90/128 (EEC, 1990) and 2002/72 (EEC, 2002). The results showed that for both PET and polyethylene-based netting materials, overall migration values into distilled water ranged between 11.5 and 48.5 mg l(-1), well below the upper limit (60 mg l(-1)) for overall migration values from plastics-packaging materials set by the European Union. The overall migration values from netting materials into isooctane ranged between 38.0 and 624.0 mg l(-1), both below and above the European Union upper limit for migration. Sensory tests involving contact of representative samples with table water under refluxing (100 degrees C/4 h) conditions showed a number of the netting materials produced both off-odour and/or taste as well as discoloration of the food simulant rendering such materials unfit for the packaging of foodstuffs in applications involving heating at elevated temperatures. GC/MS analysis showed the presence of numerous volatile compounds being produced after netting materials/water contact under refluxing conditions. Although it is extremely difficult to establish a clear correlation between sensory off-odour development and GC/MS volatile compounds' profile, it may be postulated that plastics oxidation products such as hexanal, heptanal, octanal and 2,6 di-tert-butylquinone may contribute to off-odour development using commercially bottled table water as a food simulant. Likewise, compounds such as carbon disulfide, [1,1'-biphenyl]-2-ol and propanoic acid, 2 methyl 1-(1,1-dimethyl)-2-methyl-1,3-propanediyl ester probably originating from cotton and rubber components of netting materials may also contribute to off-odour/taste development.


Assuntos
Embalagem de Alimentos , Temperatura Alta , Plásticos/química , Sensação , Cor , Contaminação de Alimentos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Carne , Octanos , Polietileno , Polietilenotereftalatos , Olfato , Paladar , Verduras , Água
13.
Methods Find Exp Clin Pharmacol ; 28(9): 605-8, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17200726

RESUMO

Blood transfusions have been shown in the past to compromise wound healing in experimental models of colonic anastomosis. Transforming growth factor beta (TGFbeta) has been proposed to play a major role in the process of colonic wound healing, and its expression is believed to be modulated by interleukin-2 (IL2). According to an earlier report, the postoperative administration of the histamine receptor-2 antagonist ranitidine increases the blood levels of soluble IL2 receptor in humans undergoing abdominal surgery and could thus affect molecular determinants of colonic anastomosis. In this study we examined the effect of blood transfusions, with and without ranitidine administration, on the gene expression of TGFbeta(1) and the specificity-conveying alpha subunit of the receptor for IL2, in rat perianastomotic tissue. Analysis of gene expression by semiquantitative RT-PCR revealed a tendency for downregulation of both genes, albeit in a statistically nonsignificant manner. This effect was not prevented by the postoperative administration of ranitidine. On the other hand, there appears to be a significant correlation between expression of TGFbeta(1) and that of IL2 receptor alpha subunit, irrespective of treatment.


Assuntos
Transfusão de Sangue , Colo/patologia , Expressão Gênica , Subunidade alfa de Receptor de Interleucina-2/genética , Modelos Animais , Fator de Crescimento Transformador beta/genética , Cicatrização , Animais , Sequência de Bases , Primers do DNA , Masculino , Ratos , Ratos Wistar
14.
Food Addit Contam ; 22(12): 1264-73, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16356891

RESUMO

The effects of gamma-irradiation (5-60 kGy) on radiolysis products and sensory changes of experimental five-layer food-packaging films were determined. Films contained a middle buried layer of recycled low-density polyethylene (LDPE) comprising 25-50% by weight (bw) of the multilayer structure. Respective films containing 100% virgin LDPE as the buried layer were used as controls. Under realistic polymer/food simulant contact conditions during irradiation, a large number of primary and secondary radiolysis products (hydrocarbons, aldehydes, ketones, alcohols, carboxylic acids) were produced. These compounds were detected in the food simulant after contact with all films tested, even at the lower absorbed doses of 5 and 10 kGy (approved doses for food preservation). The type and concentration of radiolysis products increased progressively with increasing dose. Generally, there were no significant differences in radiolysis products between samples containing a buried layer of recycled LDPE and those containing virgin LDPE (all absorbed doses), indicating the good barrier properties of external virgin polymer layers. Volatile and non-volatile compounds produced during irradiation affected the sensory properties of potable water after contact with packaging films. Taste transfer to water was observed mainly at higher doses and was more noticeable for multilayer structures containing recycled LDPE, even though differences were slight.


Assuntos
Embalagem de Alimentos/métodos , Raios gama , Polietileno/química , Sensação , Cor , Conservação dos Recursos Naturais , Desenho de Equipamento , Contaminação de Alimentos/prevenção & controle , Irradiação de Alimentos/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Isomerismo , Polietileno/efeitos da radiação , Doses de Radiação , Olfato , Paladar
15.
J Appl Microbiol ; 98(3): 752-60, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15715879

RESUMO

AIMS: To determine the microbiological, biochemical and sensory changes of mussels during storage under aerobic, vacuum packaging (VP) and modified atmosphere packaging (MAP) conditions at 4 degrees C, and to determine shelf-life of mussels under the same packaging conditions using the above assessment parameters. METHODS AND RESULTS: Aqua-cultured mussels (Mytilus galloprovincialis) were obtained from a local culture farm, packaged aerobically under VP and MAP (50%/50% CO2/N2: M1, 80%/20% CO2/N2: M2, 40%/30%/30% CO2/N2/O2: M3), and stored at 4 degrees C. Quality evaluation was carried out using microbiological, chemical and sensory analyses. Microbiological results revealed that the M2 and VP delayed microbial growth compared with that of air-packaged samples. The effect was more pronounced for total viable count (TVC), Pseudomonas spp., lactic acid bacteria (LAB) and H2S-producing bacteria. TVC was reduced by 0.9-1.0, Pseudomonas spp. by 0.7-0.8, LAB by 1.0-2.2, H2S-producing bacteria by 0.7-1.2. Enterobacteriaceae were not significantly affected by MAP conditions. Of the chemical indices determined, the total volatile basic nitrogen and trimethylamine nitrogen values remained lower than the proposed acceptability limits of 35 mg N 100 g(-1) and 12 mg N 100 g(-1), respectively, after 15 days of storage. Both the VP and air-packaged mussel samples exceeded these limits. The thiobarbituric acid value of all MAP and VP mussels remained lower than the proposed acceptability limit of 1 mg malondialdehyde kg(-1). The air-packaged samples exceeded this limit. All samples retained desirable sensory characteristics during the first 8 days of storage. CONCLUSIONS: Based on odour and taste evaluation, the M1 and M3 samples remained acceptable until ca day 11-12, the M2 samples remained acceptable until ca day 14-15 days while the VP and air-packaged mussel samples remained acceptable until ca days 10-11 and 8-9 of storage respectively. Based primarily on sensory, but also on biochemical and microbiological parameters determined, M2 gas mixture was the most effective for mussel preservation achieving a shelf-life of ca 14-15 days. SIGNIFICANCE AND IMPACT OF THE STUDY: MAP (M2) can be used to increase the shelf-life of refrigerated mussels. A shelf-life extension of refrigerated mussels by ca 5-6 days under MAP may be obtained.


Assuntos
Bivalves , Inspeção de Alimentos/métodos , Microbiologia de Alimentos , Conservação de Alimentos , Animais , Técnicas Bacteriológicas , Bivalves/química , Bivalves/microbiologia , Contagem de Colônia Microbiana , Embalagem de Alimentos , Nitrogênio/análise , Tiobarbitúricos/análise , Vácuo
16.
Appl Microbiol Biotechnol ; 64(1): 106-11, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-13680200

RESUMO

Stirred, pH-controlled anaerobic batch cultures were used to evaluate the in vitro utilisation by canine gut microflora of novel alpha-galactooligosaccharides synthesised with an enzyme extract from a canine Lactobacillus reuteri strain. Fructooligosaccharides (FOS), melibiose and raffinose were used as reference carbohydrates for the prebiotic properties of the synthesised oligosaccharide (galactosyl melibiose mixture-GMM). Addition of Lactobacillus acidophilus was used as control for the evaluation of the synbiotic properties of the oligosaccharide with L. reuteri. Populations of predominant gut bacterial groups were monitored over 48 h of batch culture by fluorescent in situ hybridisation, and short-chain fatty acid (SCFA) production was measured. GMM showed a higher increase in bifidobacteria and lactobacilli population number and size as well as a higher decrease in clostridia population number and size compared to the commercial prebiotics (FOS, melibiose, raffinose). This prebiotic effect was further increased by the addition of L. reuteri followed by a change in the SCFA production pattern compared to GMM alone or GMM with L. acidophilus. The observed change in SCFA production was in accordance with the fermentation properties of L. reuteri, suggesting that the novel synbiotic had a significant effect on the canine gut microflora fermentation.


Assuntos
Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Fezes/microbiologia , Lactobacillus/enzimologia , Oligossacarídeos/metabolismo , alfa-Galactosidase/metabolismo , Ácido Acético/análise , Anaerobiose , Animais , Ácido Butírico/análise , Contagem de Colônia Microbiana , Cães , Ácidos Graxos/análise , Fermentação , Ácido Láctico/análise , Lactobacillus/crescimento & desenvolvimento , Lactobacillus/metabolismo , Melibiose/metabolismo , Propionatos/análise , Rafinose/metabolismo , alfa-Galactosidase/isolamento & purificação
17.
Food Addit Contam ; 19(12): 1190-9, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12623680

RESUMO

The effect of gamma-radiation doses (5, 10, 30 kGy) on the mechanical properties, gas and water vapour permeability, infrared (IR) spectra, and overall migration into aqueous and alternative fatty food simulants of commercial monolayer flexible packaging films ethylene vinyl acetate (EVA), high-density polyethylene (HDPE), polystyrene (PS), bi-axially oriented polypropylene (BOPP), low-density polyethylene (LDPE) and Ionomer was studied. For comparison purposes, respective non-irradiated (control) films were also studied. The results showed that radiation doses of 5, 10 and 30 kGy did not induce any statistically significant changes in the permeability of all studied films to gases (oxygen and carbon dioxide) and water vapour. Likewise, IR spectra of all studied films showed no significant differences after all absorbed doses. The mechanical properties (tensile strength, percentage elongation at break and Young's modulus) of all studied films remained unaffected after absorbed doses of 5 and 10 kGy. In contrast, the tensile strength of HDPE, BOPP and Ionomer films irradiated at a dose of 30kGy decreased. In addition, the percentage elongation at break of LDPE and Ionomer films irradiated at a dose of 30 kGy decreased while Young's modulus of all samples remained unaffected. All mechanical properties of PS and EVA films remained unaffected after radiation at 30 kGy. Radiation (all absorbed doses) resulted in no statistically significant differences in overall migration values into distilled water for all studied films. For 3% aqueous acetic acid, absorbed doses of 5 and 10 kGy did not affect overall migration values of all investigated samples with the exception of the Ionomer film, for which the overall migration value decreased at 10 kGy. An absorbed dose of 30 kGy caused an increase in BOPP overall migration values and a decrease in Ionomer overall migration values. In contrast, a dose of 30 kGy induced no changes in overall migration values of EVA, HDPE, LDPE and PS films into the same simulant. There were no statistically significant differences in overall migration values of EVA, PS and LDPE films into iso-octane for all absorbed doses. In contrast, a dose of 30 kGy resulted in an increase in overall migration values of BOPP and a respective decrease in HDPE and Ionomer films.


Assuntos
Contaminação de Alimentos/análise , Irradiação de Alimentos , Embalagem de Alimentos , Raios gama , Plásticos/efeitos da radiação , Relação Dose-Resposta à Radiação , Humanos , Permeabilidade/efeitos da radiação , Doses de Radiação , Espectrofotometria Infravermelho , Resistência à Tração/efeitos da radiação , Água/química
18.
Int J Biochem Cell Biol ; 32(9): 975-82, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11084377

RESUMO

The aim of this work was to isolate and characterise the glycosaminoglycans present in the different tissue structures of the human penis in view of their potentially significant role in the physiology of erection. Penile tissue samples were obtained from patients who underwent penectomy and were subsequently dissected into individual tissue structures. Total glycosaminoglycans were isolated and purified from tunica albuginea, corpora cavernosa and corpus spongiosum, following tissue mincing, ultrasonication, lipid extraction, extensive digestion with pronase and DNase, treatment with alkali-borohydride and ethanol precipitation. Isolated glycosaminoglycans were separated by cellulose acetate electrophoresis and fractionated by anion exchange chromatography on DEAE Sephacel columns. Different glycosaminoglycan fractions were identified using glycosaminoglycan-degrading enzymes of known specificity. Gradient polyacrylamide gel electrophoresis was used to determine the average molecular mass of the glycosaminoglycans. The corpus cavernosum and the corpus spongiosum extracts contained almost twice the amount of glycosaminoglycan-associated uronic acids as compared to the tunical extracts (1.47+/-0.09, and 1.49+/-0.15 as opposed to 0.75+/-0.15 microg/mg dry defatted tissue, respectively; S.E.M., n=5). With the exception of hyaluronic acid, the relative amount of individual glycosaminoglycan types varied significantly among extracts of different origin. Heparan sulphate was more abundant in cavernosal, dermatan sulphate in tunical, and chondroitin-6-sulphate in corpus spongiosum extracts. No structure-specific differences were detected with respect to the molecular mass distribution of each glycosaminoglycan type. Our study shows that the different structures of the human penis produce distinct profiles of glycosaminoglycans, which are well suited to the individual functional characteristics of these structures.


Assuntos
Glicosaminoglicanos/metabolismo , Pênis/anatomia & histologia , Pênis/química , Fracionamento Químico , Glicosaminoglicanos/classificação , Glicosaminoglicanos/isolamento & purificação , Humanos , Masculino , Pessoa de Meia-Idade , Especificidade de Órgãos , Pênis/metabolismo
19.
Clin Physiol ; 20(5): 336-47, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10971544

RESUMO

The aim of the current study was the introduction and standardization of two experimental conditions for dynamic pupillometry. Pupillometry is a method that can provide valuable data concerning the functioning of the autonomous nervous system. The system for recording the pupil reaction was developed in the Laboratory of Clinical Neurophysiology of the 1st Department of Neurology of Aristotle University of Thessaloniki, in co-operation with the Laboratory of Fluid Mechanics of the Aristotle University of Thessaloniki. This system is fully automated. It includes an infra-red video camera, which has the capacity to record in complete darkness, and an SLE (clinical photic stimulator) lamp. A software application automatically performed all the procedures. During the first experiment, one flash was administered. During the second experiment, a series of 25 flashes (1 Hz frequency) was administered. Fifty physically and mentally healthy subjects aged 23-48 years took part in the study. Means, standard deviations and ranges for all variables characterizing normal subjects during both experimental conditions are reported. Test/re-test results and comparisons of the two eyes are also reported. The combined use of these two experimental conditions in dynamic pupillometry may be a very useful tool in medical research. There are already reports on the usefulness of pupillometry in the research of various diseases, including depression and Alzheimer's disease. It is expected that it will also be a valuable research tool in the study of diabetes, alcoholism, myasthenia gravis, cancer, multiple sclerosis, etc.


Assuntos
Automação/normas , Equipamentos para Diagnóstico/normas , Óptica e Fotônica/instrumentação , Reflexo Pupilar/fisiologia , Adulto , Interpretação Estatística de Dados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa/instrumentação , Estimulação Luminosa/métodos , Tempo de Reação/fisiologia , Reprodutibilidade dos Testes
20.
J Dairy Sci ; 83(8): 1712-8, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10984146

RESUMO

Food-grade polyvinyl chloride (PVC) film containing 28.3% di-(2-ethylhexylexyl)adipate (DEHA) plasticizer was used to wrap three different types of cheese (Kefalotyri, Edam, and Feta). Samples were split into two groups and stored at 5+/-0.5 degrees C. One group was analyzed for DEHA content at intervals between 1 and 240 h of contact (kinetic study), and a second group was cut into slices (1.2 mm thick) after 240 h of cheese/PVC contact and was analyzed for DEHA content (penetration study). The DEHA was determined by indirect gas chromatography. Statistically significant differences in migration of DEHA were observed between the cheese types. Migration of DEHA depended on contact time, fat, and moisture contents, and consistency of cheese samples. Equilibrium conditions were approached after approximately 100 h of contact for Edam and 150 h for Kefalotyri cheese. Equilibrium conditions were not reached for Feta cheese, even after 240 h of contact. After 240 h of contact under refrigeration, the migration of DEHA was approximately 345.4 mg/kg (18.9 mg/dm2) for Kefalotyri, 222.5 mg/kg (12.2 mg/dm2) for Edam, and 133.9 mg/kg (7.3 mg/dm2) for Feta. The loss of DEHA from the PVC film into the three cheese types was 37.8, 24.3, and 14.6%, respectively. These values, with the exception of Feta, were higher than the upper limit for global migration from plastic packaging materials into food and food stimulants set by the European Union (EU) (10 mg/dm2 or 60 mg/kg). After 240 h of cheese/film contact, DEHA was detected in the first three slices beneath the cheese surface (3.6 mm total depth) of Edam cheese and in the first two slices (2.4 mm total depth) of Kefalotryi and Feta cheeses. DEHA was not detected in subsequent layers. The effect of cheese rind on migration of DEHA was studied in Edam and Kefalotyri cheeses. The DEHA migration after 240 h into the first 1 mm beneath the surface of Kefalotyri cheese was 22.4 mg/kg, while DEHA was not detected in Edam cheese.


Assuntos
Adipatos/metabolismo , Queijo/análise , Manipulação de Alimentos , Plastificantes/metabolismo , Cloreto de Polivinila/metabolismo , Cromatografia Gasosa , Europa (Continente) , Gorduras/química , Manipulação de Alimentos/legislação & jurisprudência , Cinética , Fatores de Tempo
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