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1.
Int J Biol Macromol ; 149: 262-270, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-31987939

RESUMO

The aim of this study was to analyzing the impact of germination time on the morphology, crystallinity, gelatinization and viscosity properties on the starch of Esmeralda and Perla barley variety. The two barley were germinated for 1 to 8 days, at 26 °C and 65% relative humidity. Micrographs showed the presence of pinholes and eroded surfaces. Starch in Esmeralda was hydrolyzed completely at 8 days of germination. Birefringence was reduced from day 4, losing molecular structuring of the crystalline area. Morphometric data: fractal dimension, area, perimeter, circularity, and roundness decreased significantly along germination time in both varieties. The entropy increased significantly, from 0.79 to 10.09 in Esmeralda and from 0.46 to 7.57 in Perla. Relative crystallinity decreased significantly in the Perla from 24.7% to 23.6%. Viscosity peaks were also significantly reduced, pasting temperature was constant in Esmeralda but in Perla was significantly reduced from 95.43 to 95.19 °C with germination, the gelatinization temperature increased significantly in the Esmeralda while in Perla it remained constant. Enthalpy decreased significantly to 75.8% and 37% in Esmeralda and Perla respectively. The study of germination impact on structural and physicochemical properties is important to identify the use of hydrolyzed starches in the food industry or others.


Assuntos
Amilose/química , Hordeum/química , Amido/química , Termodinâmica , Amilose/ultraestrutura , Germinação/fisiologia , Hidrólise , Estrutura Molecular , Oryza/química , Oryza/ultraestrutura , Amido/ultraestrutura , Temperatura , Viscosidade
2.
J Hazard Mater ; 356: 91-97, 2018 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-29857226

RESUMO

Advanced oxidation processes are useful methodologies to accomplish abatement of contaminants; however, elucidation of the reaction mechanisms is hampered by the difficult detection of the short-lived primary key species involved in the photocatalytic processes. Nevertheless, herein the combined use of an organic photocatalyst such as triphenylpyrylium (TPP+) and photophysical techniques based on emission and absorption spectroscopy allowed monitoring the photocatalyst-derived short-lived intermediates. This methodology has been applied to the photocatalyzed degradation of different pollutants, such as acetaminophen, acetamiprid, caffeine and carbamazepine. First, photocatalytic degradation of a mixture of the pollutants showed that acetaminophen was the most easily photodegraded, followed by carbamazepine and caffeine, being the abatement of acetamiprid almost negligible. This process was accompanied by mineralization, as demonstrated by trapping of carbon dioxide using barium hydroxide. Then, emission spectroscopy measurements (steady-state and time-resolved fluorescence) allowed demonstrating quenching of the singlet excited state of TPP+. Laser flash photolysis experiments with absorption detection showed that oxidation of contaminants is accompanied by TPP+ reduction, with formation of a pyranyl radical (TPP), that constituted a fingerprint of the redox nature of the occurring process. The relative amounts of TPP detected was also correlated with the efficiency of the photodegradation process.


Assuntos
Acetaminofen/química , Derivados de Benzeno/química , Cafeína/química , Carbamazepina/química , Neonicotinoides/química , Derivados de Benzeno/efeitos da radiação , Luz , Oxirredução , Fotólise
3.
J Hazard Mater ; 342: 633, 2018 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-28898860

RESUMO

Advanced oxidation processes are useful methodologies to accomplish abatement of contaminants; however, elucidation of the reaction mechanisms is hampered by the difficult detection of the short-lived primary key species involved in the photocatalytic processes. Nevertheless, herein the combined use of an organic photocatalyst such as triphenylpyrylium (TPP+) and photophysical techniques based on emission and absorption spectroscopy allowed monitoring the photocatalyst-derived short-lived intermediates. This methodology has been applied to the photocatalyzed degradation of different pollutants, such as acetaminophen, acetamiprid, caffeine and carbamazepine. First, photocatalytic degradation of a mixture of the pollutants showed that acetaminophen was the most easily photodegraded, followed by carbamazepine and caffeine, being the abatement of acetamiprid almost negligible. This process was accompanied by mineralization, as demonstrated by trapping of carbon dioxide using barium hydroxide. Then, emission spectroscopy measurements (steady-state and time-resolved fluorescence) allowed demonstrating quenching of the singlet excited state of TPP+. Laser flash photolysis experiments with absorption detection showed that oxidation of contaminants is accompanied by TPP+ reduction, with formation of a pyranyl radical (TPP), that constituted a fingerprint of the redox nature of the occurring process. The relative amounts of TPP detected was also correlated with the efficiency of the photodegradation process.

4.
Phys Chem Chem Phys ; 18(18): 12733-41, 2016 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-27098151

RESUMO

The model reaction of photoinduced donor-acceptor interaction in linked systems (dyads) has been used to study the comparative reactivity of a well-known anti-inflammatory drug, (S)-naproxen (NPX) and its (R)-isomer. (R)- or (S)-NPX in these dyads is linked to (S)-N-methylpyrrolidine (Pyr) using a linear or cyclic amino acid bridge (AA or CyAA), to give (R)-/(S)-NPX-AA-(S)-Pyr flexible and (R)-/(S)-NPX-CyAA-(S)-Pyr rigid dyads. The donor-acceptor interaction is reminiscent of the binding (partial charge transfer, CT) and electron transfer (ET) processes involved in the extensively studied inhibition of the cyclooxygenase enzymes (COXs) by the NPX enantiomers. Besides that, both optical isomers undergo oxidative metabolism by enzymes from the P450 family, which also includes ET. The scheme proposed for the excitation quenching of the (R)- and (S)-NPX excited state in these dyads is based on the joint analysis of the chemically induced dynamic nuclear polarization (CIDNP) and fluorescence data. The (1)H CIDNP effects in this system appear in the back electron transfer in the biradical-zwitterion (BZ), which is formed via dyad photoirradiation. The rate constants of individual steps in the proposed scheme and the fluorescence quantum yields of the local excited (LE) states and exciplexes show stereoselectivity. It depends on the bridge's length, structure and solvent polarity. The CIDNP effects (experimental and calculated) also demonstrate stereodifferentiation. The exciplex quantum yields and the rates of formation are larger for the dyads containing (R)-NPX, which let us suggest a higher contribution from the CT processes with the (R)-optical isomer.


Assuntos
Anti-Inflamatórios não Esteroides/química , Naproxeno/química , Aminoácidos/química , Transporte de Elétrons , Luz , Modelos Moleculares , Processos Fotoquímicos , Pirrolidinas/química , Espectrometria de Fluorescência , Estereoisomerismo
5.
Org Biomol Chem ; 14(9): 2679-83, 2016 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-26833240

RESUMO

The aim of the present paper is to explore the potential of radical-mediated dehydrogenation of bile salts (BSs), which is reminiscent of the enzymatic action of hydroxysteroid dehydrogenase enzymes (HSDH). The concept has been demonstrated using triplet carbonyls that can be efficiently generated upon selective UVA-excitation. Hydrogen atom transfer (HAT) from BSs to triplet benzophenone (BP) derivatives gave rise to radicals, ultimately leading to reduction of the BP chromophore with concomitant formation of the oxo-analogs of the corresponding BSs. The direct reactivity of triplet BP with BSs in the initial step was evaluated by determining the kinetic rate constants using laser flash photolysis (LFP). The BP triplet decay was monitored (λmax = 520 nm) upon addition of increasing BS concentrations, and the obtained rate constant values indicated a reactivity of the methine hydrogen atoms in the order of C-3 < C-12 < C-7. The steady-state kinetics of the overall process, monitored through the disappearance of the typical BP absorption band at 260 nm, was much faster under N2 than under O2, also supporting the role of the oxygen-quenchable triplet in the dehydrogenation process. Furthermore, irradiation of deaerated aqueous solutions of sodium cholate in the presence of KPMe provided the oxo-analogs, 3[O],7[O]-CA, 3[O]-CA and 7[O]-CA, arising from the HAT process.


Assuntos
Benzofenonas/química , Ácidos e Sais Biliares/química , Hidrogênio/química , Radicais Livres/química , Hidrogenação , Cinética , Estrutura Molecular , Raios Ultravioleta
6.
Lett Appl Microbiol ; 62(2): 177-84, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26612600

RESUMO

UNLABELLED: Antibiotic-resistant Salmonella strains were isolated from saladette and red round type tomatoes, and an analysis done of the antibacterial activity of roselle calyx extracts against any of the identified strains. One hundred saladette tomato samples and 100 red round tomato samples were collected from public markets. Each sample consisted of four whole tomatoes. Salmonella was isolated from the samples by conventional culture procedure. Susceptibility to 16 antibiotics was tested for the isolated Salmonella strains by standard test. The antibacterial effect of four roselle calyx extracts (water, methanol, acetone and ethyl acetate), sodium hypochlorite and acetic acid against antibiotic-resistant Salmonella isolates was evaluated on contaminated tomatoes. Twenty-four Salmonella strains were isolated from 12% of each tomato type. Identified Salmonella serotypes were Typhimurium and Typhi. All isolated strains exhibited resistance to at least three antibiotics and some to as many as 12. Over contaminated tomatoes, the roselle calyx extracts produced a greater reduction (2-2·6 log) in antibiotic-resistant Salmonella strain concentration than sodium hypochlorite and acetic acid. SIGNIFICANCE AND IMPACT OF THE STUDY: The presence of multidrug-resistant Salmonella in vegetables is a significant public health concern. Multidrug-resistant Salmonella strains were isolated from raw tomatoes purchased in public markets in Mexico and challenged with roselle Hibiscus sabdariffa calyx extracts, sodium hypochlorite and acetic acid. On tomatoes, the extracts caused a greater reduction in the concentration of antibiotic-resistant Salmonella strains than sodium hypochlorite and acetic acid. Roselle calyx extracts are a potentially useful addition to disinfection procedures of raw tomatoes in the field, processing plants, restaurants and homes.


Assuntos
Ácido Acético/farmacologia , Desinfetantes/farmacologia , Hibiscus/metabolismo , Extratos Vegetais/farmacologia , Salmonella typhi/efeitos dos fármacos , Salmonella typhimurium/efeitos dos fármacos , Hipoclorito de Sódio/farmacologia , Solanum lycopersicum/microbiologia , Antibacterianos/farmacologia , Desinfecção/métodos , Farmacorresistência Bacteriana Múltipla , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/prevenção & controle , México , Testes de Sensibilidade Microbiana , Salmonella typhi/isolamento & purificação , Salmonella typhimurium/isolamento & purificação
7.
EJVES Short Rep ; 33: 32-33, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28856322

RESUMO

INTRODUCTION: Transobturator bypass is an older and less frequently performed revascularization of the lower extremity that is useful in the setting of multiple failed lower extremity bypasses usually due to groin sepsis and infection(s). It can be a technically challenging operation due to anatomic constraints. REPORT: We describe a successful transobturator bypass utilizing fluoroscopy for passage of bypass tunneler and graft through the obturator foramen. DISCUSSION: Live fluoroscopy is a versatile technique and in conjunction with our described surgical technique of lower extremity bypass should help increase the technical success rates of this procedure.

8.
Phys Chem Chem Phys ; 18(2): 901-7, 2016 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-26648262

RESUMO

Photoinduced processes with partial (exciplex) and full charge transfer in donor-acceptor systems are of interest because they are frequently used for modeling drug-protein binding. Low field photo-CIDNP (chemically induced dynamic nuclear polarization) for these processes in dyads, including the drug, (S)- and (R)-naproxen and (S)-N-methyl pyrrolidine in solutions with strong and weak permittivity have been measured. The dramatic influence of solvent permittivity on the field dependence of the N-methyl pyrrolidine (1)H CIDNP effects has been found. The field dependences of both (R,S)- and (S,S)-dyads in a polar medium are the curves with a single extremum in the area of the S-T+ terms intersection. Moreover, the CIDNP field dependences of the same protons measured in a low polar medium present curves with several extrema. The shapes of the experimental CIDNP field dependence with two extrema have been described using the Green function approach for the calculation of the CIDNP effects in the system without electron exchange interactions. The article discusses the possible causes of the differences between the CIDNP field dependence detected in a low-permittivity solvent with the strong Coulomb interactions and in a polar solvent.


Assuntos
Naproxeno/química , Processos Fotoquímicos , Pirrolidinas/química , Transporte de Elétrons , Espectroscopia de Ressonância Magnética , Conformação Molecular , Simulação de Dinâmica Molecular
10.
Eur Rev Med Pharmacol Sci ; 17(24): 3285-90, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24379057

RESUMO

BACKGROUND: Short bowel syndrome is a disabling disease requiring long-term nutritional support and ancillary drugs. Aiming to analyze the most commonly prescribed drugs, a retrospective analysis was conducted is an outpatient cohort. PATIENTS AND METHODS: Stable patients (N= 37, 59.5% males, age 51.1 ± 20.1 years, body mass index 20.1 ± 7.9 kg/m2) with three or more appointments in the Outpatient Service during the last 18 months were retrospectively analyzed. regarding oral pharmacologic prescriptions. Medications were classified as on label or off label. RESULTS: A total of 257 oral prescriptions were retrieved from computer files, encompassing 17 different preparations. The majority was employed on label however 28.8% (74/257) were classified as off label and scrutinized with regard to indications. The main categories were pharmacologic modulators of gastrointestinal secretions and motility, along with antibiotics. Virtually all patients required one or more of such drugs, without differences regarding demographic or clinical variables. Adverse effects or premature drug discontinuation were not observed. CONCLUSIONS: This is the first study to our knowledge highlighting the importance of adjuvant drugs, particularly with unconventional indications, in the management of short bowel syndrome. Antidiarrheic agents, pancrelipase micropellets, antacids and antibiotics represented the most relevant off label prescriptions for this population.


Assuntos
Fármacos Gastrointestinais/uso terapêutico , Uso Off-Label , Síndrome do Intestino Curto/tratamento farmacológico , Administração Oral , Adulto , Idoso , Assistência Ambulatorial , Distribuição de Qui-Quadrado , Revisão de Uso de Medicamentos , Feminino , Fármacos Gastrointestinais/administração & dosagem , Fármacos Gastrointestinais/efeitos adversos , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Síndrome do Intestino Curto/diagnóstico , Resultado do Tratamento , Adulto Jovem
11.
Eur J Vasc Endovasc Surg ; 44(3): 244-50, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22819738

RESUMO

AIM: We sought to better define the impact of sex on 'in-hospital outcomes' after carotid endarterectomy (CEA) or stenting (CAS). METHODS: Hospital discharge databases for all carotid interventions obtained from the New York State (NYS) Department of Health, Statewide Planning and Research Cooperative System between 2000 and 2009 (29,917 women, 39,771 men) were analysed. Mortality, stroke and composite event (stroke/death) were compared between procedures after matching of patients by propensity score. Acute myocardial infarction (AMI) was our secondary 'end' point. RESULTS: More than 90% of patients in both sexes were asymptomatic (27,439 women and 36,295 men). Compared to men, asymptomatic women experienced more strokes after CEA (women: 1.38%, men: 1.16%, P = 0.03) and higher AMI rates after both procedures (CEA; women: 0.75%, men: 0.51%, P = 0.0009, CAS; women: 0.96%, men: 0.28%, P = 0.01). Between procedures, symptomatic women undergoing CAS showed higher rates of mortality (CAS: 4.19%, CEA: 0.47%, P = 0.01) and combined (stroke/mortality) events (CAS: 12.09%, CEA: 6.05%, P = 0.02). In all other cohorts, no statistically significant difference was found between the procedures. CONCLUSIONS: Compared to CEA, CAS led to inferior in-hospital outcomes only in symptomatic women in the last decade in NYS. Men and asymptomatic women showed comparable outcomes after both procedures, whereas asymptomatic females were more prone to AMI after both interventions. These sex-associated differences should be taken into account for the treatment of carotid artery disease.


Assuntos
Angioplastia/instrumentação , Doenças das Artérias Carótidas/terapia , Endarterectomia das Carótidas , Pacientes Internados/estatística & dados numéricos , Stents , Idoso , Angioplastia/efeitos adversos , Angioplastia/mortalidade , Doenças Assintomáticas , Doenças das Artérias Carótidas/complicações , Doenças das Artérias Carótidas/mortalidade , Doenças das Artérias Carótidas/cirurgia , Endarterectomia das Carótidas/efeitos adversos , Endarterectomia das Carótidas/mortalidade , Feminino , Mortalidade Hospitalar , Humanos , Tempo de Internação , Modelos Logísticos , Masculino , Infarto do Miocárdio/etiologia , New York , Pontuação de Propensão , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores Sexuais , Acidente Vascular Cerebral/etiologia , Fatores de Tempo , Resultado do Tratamento
12.
Arch Soc Esp Oftalmol ; 83(5): 329-31, 2008 May.
Artigo em Espanhol | MEDLINE | ID: mdl-18464184

RESUMO

CASE REPORT: We report a case of Coats' disease in a 10-year-old-girl who presented with a profound visual deficit, exudative retinal detachment, vascular telangiectasias and subretinal lipid, who underwent treatment with an intravitreal injection of bevacizumab (AVASTIN(TM)). Serial examinations documented an involutional response with a reduction of the subretinal fluid, exudates and macular thickness. DISCUSSION: The aetiology of Coats' disease remains uncertain, as does its optimal management. Although resolution of a case depends partially on age, and can even occur spontaneously on rare occasions, intravitreal injections of bevacizumab should be considered when planning treatment.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Doenças Retinianas/tratamento farmacológico , Vasos Retinianos , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Anticorpos Monoclonais Humanizados , Bevacizumab , Criança , Feminino , Humanos
13.
Acta pediatr. esp ; 66(2): 77-82, feb. 2008. ilus, tab
Artigo em Es | IBECS | ID: ibc-64844

RESUMO

La leche materna es una fuente importante de bacterias comensales, mutualistas o probióticas para el intestino infantil. Entre las bacterias predominantes destacan diversas especies de estafilococos, estreptococos y bacterias lácticas. Por tanto, este fluido representa uno de los factores clave en el desarrollo de la microbiota intestinal infantil. El número de especies que coexisten en la leche de una mujer sana suele ser bajo, hecho que explicaría por qué la microbiota intestinal de los lactantes está compuesta por un reducido espectro de especies y por qué el desarrollo de una microbiota más diversa coincide con el inicio del destete. Las bacterias de la leche podrían desempeñar un papel importante en la prevención de enfermedades infecciosas y en la maduración del sistema inmunitario. Algunos estudios recientes indican que al menos una parte de las bacterias comensales existentes en la leche podrían proceder de la microbiota intestinal materna y accederían a la glándula mamaria a través de la ruta entero mamaria(AU)


Breast milk is an important source of commensal, mutualist or probiotic bacteria for infants’ intestines. Among the predominant bacteria, several species of staphylococcus, streptococcus and lactic bacteria stand out. Therefore, that fluid represents one of the key factors in the development of an infant’s intestinal microbiota. The number of species that coexist in the milk of a healthy woman tends to be low, which would explain why the intestinal microbiota of breastfed infants is made up of a reduced spectrum of species and why the development of a more diverse microbiota coincides with the start of weaning. The bacteria of the milk could play an important role in the prevention of infectious diseases and in the maturation of the immune system. Certain recent studies show that at least part of the commensal bacteria in the milk could come from the maternal intestinal microbiota and would access the mammary gland via the entero mammary pathway(AU)


Assuntos
Humanos , Masculino , Feminino , Lactente , Nutrição do Lactente/fisiologia , Leite Humano/microbiologia , Leite Humano/fisiologia , Estreptococos Viridans/isolamento & purificação , Bactérias/isolamento & purificação , Bactérias/patogenicidade , Intoxicação Alimentar Estafilocócica/complicações , Leite Humano/virologia , Estado Nutricional/fisiologia , Microbiologia de Alimentos
14.
Scand J Immunol ; 66(2-3): 208-16, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17635798

RESUMO

Autoimmune hepatitis is an immune cell-mediated chronic liver disease of unknown cause that leads, when untreated, to cirrhosis and liver failure. Importantly, this disease affects not only adults but children as well. Genetic susceptibility is clearly important and the major susceptibility factor identified up to now is the HLA-DRB1 locus, but other genes may play a role as well. HLA-DRB1 alleles present in South American patients differ from those found in patients in other parts of the world. In addition, we have recently identified two chromosomal regions where additional susceptibility factors may be found in Brazilian patients, namely, the class III MHC region and the 5q31 region where the IL-4 and IL-13 genes are located. This review discusses the current knowledge of the pathogenesis of this autoimmune disease occurring in the setting of an immune-privileged organ, the liver, and compares the data on gene polymorphisms studied in Brazil and in other parts of the world.


Assuntos
Hepatite Autoimune/epidemiologia , Hepatite Autoimune/imunologia , Brasil/epidemiologia , Hepatite Autoimune/classificação , Hepatite Autoimune/genética , Humanos
15.
Int J Food Microbiol ; 112(1): 35-43, 2006 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-16843562

RESUMO

In this study, Lactobacillus salivarius CECT 5713 was originally isolated from feces of a one-month-old breast-fed infant. Since it has been suggested that the gut microbiota of breast-fed infants reflects that of the maternal breast milk, we investigated if this specific strain was present in breast milk of the respective mother. RAPD and PFGE analysis revealed the presence of the strain L. salivarius CECT 5713 in this biological fluid. To our knowledge, this is the first report of a L. salivarius strain isolated from breast milk. L. salivarius CECT 5713 produced l-lactate, acetate and hydrogen peroxide, which may be responsible for its antimicrobial activity against most of the indicator organisms used in this study; in addition, this strain showed a high survival rate after exposition to conditions simulating those found in the gastrointestinal tract. Finally, it was strongly adhesive to Caco-2 and HT-29 cells did not produce biogenic amines and were unable to degrade gastric mucin in vitro.


Assuntos
Fezes/microbiologia , Lactobacillus/isolamento & purificação , Lactobacillus/fisiologia , Leite Humano/microbiologia , Probióticos , Ácido Acético/metabolismo , Adulto , Aderência Bacteriana , Células CACO-2 , Contagem de Colônia Microbiana , Feminino , Mucinas Gástricas/metabolismo , Células HT29 , Humanos , Recém-Nascido , Ácido Láctico/metabolismo , Lactobacillus/metabolismo
16.
Int J Food Microbiol ; 104(3): 267-77, 2005 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-15975679

RESUMO

Lactobacillus coryniformis CECT 5711, a strain isolated from a goat's milk cheese, displayed a broad-spectrum antimicrobial activity; as a consequence, its ability to produce the antagonistic compounds associated to lactic acid bacteria, including bacteriocins, hydrogen peroxide, lactic acid, acetic acid, and reuterin (3-hydroxypropionaldehyde, 3-HPA) was investigated. Production of bacteriocins or hydrogen peroxide by this strain could not be detected. However, in addition to lactic acid and acetic acid, it produced reuterin and cobalamin, a cofactor required for conversion of glycerol to 3-HPA through a glycerol dehydratase. The gene encoding a glycerol dehydratase subunit was detected by PCR and the corresponding amplicon was sequenced. This strain showed a high survival after exposition to conditions simulating those existing in the gastrointestinal tract as well as a notable ability to adhere to intestinal cells, which suggests that its reuterin-producing ability may be used for the host benefit. In addition, the strain showed a strong beta-galactosidase activity. Production of biogenic amines and degradation of mucin could not be detected.


Assuntos
Aldeídos/análise , Queijo/microbiologia , Gliceraldeído/análogos & derivados , Lactobacillus/isolamento & purificação , Lactobacillus/metabolismo , Leite/microbiologia , Propano/análise , Aldeídos/metabolismo , Animais , Antibiose , Aderência Bacteriana , Bacteriocinas/biossíntese , Fermentação , Microbiologia de Alimentos , Gliceraldeído/análise , Gliceraldeído/metabolismo , Cabras , Propano/metabolismo , Vitamina B 12/metabolismo , beta-Galactosidase/metabolismo
17.
Eur J Immunogenet ; 31(2): 63-71, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15086345

RESUMO

The major histocompatibility complex (MHC) class I chain-related A (MICA) gene, located near HLA-B, codes for protein products with structural similarities to those of classical MHC class I genes, but which neither bind beta(2)-microglobulin nor present peptide. Expressed predominantly on gastrointestinal and tumour epithelial cells, they are stress-induced and interact with C-type lectin like receptor (NKG2D) on gammadelta, alphabeta CD8+ T cells and natural killer (NK) cells. MICA is highly polymorphic, with 54 extracellular allelic sequences described. We typed 200 healthy subjects in a sample of the São Paulo population by extended polymerase chain reaction-sequence-specific primers (PCR-SSP) to characterize the MICA polymorphism and analysed MICA/HLA-B linkage disequilibrium. The MICA*008 group (g) was predominant (47%), with several HLA-B associations. Rare combinations MICA*008g-HLA-B37, MICA*008g-B72 and MICA*010-HLA-B52 were detected. Given the extent of this polymorphism and its possible relevance for disease association, we determined MICA and HLA-B alleles in 33 Behçet's patients, in an attempt to clarify the associated genetic marker. Our results showed an increase of MICA*006, but not MICA*009, in the patient group (6/33) compared with controls (3/200) (18.2% vs. 1.5%; P(c) = 0.005). Both alleles were always in association with HLA-B51, suggesting that HLA-B is indeed the primary susceptibility locus (P = 0.00008) and that MICA*006 may be an additional risk factor.


Assuntos
Antígenos de Histocompatibilidade Classe I/genética , Polimorfismo Genético , Brasil , Frequência do Gene , Genética Populacional , Antígenos HLA-B/genética , Haplótipos , Humanos , Desequilíbrio de Ligação , Fenótipo , Reação em Cadeia da Polimerase/métodos
18.
J Chromatogr A ; 1061(2): 211-6, 2004 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-15641364

RESUMO

Polystyrene is widely used in formulations intended for children use. The main problem with this plastic is the residual styrene, which can migrate from the product, and therefore, be in contact with children. The acute toxicity of styrene is well known, raising the need of an efficient and fast method of analysis for this compound. Several extraction methods have been evaluated and compared for the determination of residual styrene monomer in polystyrene granules used in toys: supercritical fluid extraction (SFE), microwave-assisted extraction (MAE), Soxhlet extraction, headspace emission and dissolution-precipitation. The analyte was subsequently detected by gas chromatography (GC) with MS detection. The results indicated that the most efficient method was dissolution-precipitation giving even higher extraction efficiency than SFE. For validating the method, PS samples spiked with known quantities of styrene at three concentration levels were prepared to calculate the extraction recovery. The founded validation data proved the suitability of the proposed method.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Poliestirenos/química , Estireno/química
19.
Int J Food Microbiol ; 88(2-3): 197-200, 2003 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-14596990

RESUMO

Variations in length and sequence of the 16S/23S spacer region of Enterococcus faecium provided the basis for development of simple PCR and dot-blot hybridisation assays that enabled the differentiation of potentially probiotic Enterococcus faecium strains from Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. Such assays may be useful for differentiation of yoghurt starter cultures and enterococcal strains when they are simultaneously present in probiotic food products.


Assuntos
Técnicas de Tipagem Bacteriana , Enterococcus faecium/classificação , Lactobacillus/classificação , Streptococcus/classificação , Iogurte/microbiologia , Adulto , Animais , Sequência de Bases , DNA Bacteriano/química , DNA Ribossômico/química , Enterococcus faecium/genética , Microbiologia de Alimentos , Humanos , Immunoblotting/métodos , Lactente , Lactobacillus/genética , Produtos da Carne/microbiologia , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/métodos , Probióticos , RNA Ribossômico 16S/genética , RNA Ribossômico 23S/genética , Alinhamento de Sequência , Streptococcus/genética
20.
J Chromatogr A ; 976(1-2): 301-7, 2002 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-12462622

RESUMO

A new method to determine N-nitrosamines in latex products has been developed by combination of supercritical fluids and chemical derivatization. A new design for a liquid trap has been introduced. A factorial fractional design was used in order to evaluate the influence of the different factors affecting the process. Factors such as pressure, temperature, static and dynamic time, restrictor temperature and volume of an hydrobromic acid-acetic anhydride mixture (1:10, v/v) were included in the design. CO2 was used as the extraction fluid. Gas chromatography with nitrogen and phosphorus sensitive detection was employed to achieve good sensitivity attending to the molecular structure of these compounds (N-nitrosamines and their corresponding secondary amines). The obtained results have shown to be useful to increase selectivity and reduce sample handling.


Assuntos
Látex/química , Nitrosaminas/análise , Cromatografia Gasosa
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