Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Acute Med ; 22(3): 120-129, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37746680

RESUMO

OBJECTIVE: To compare the SUHB mobility scale (i.e., stable(S), unstable gait(U), needing help to walk(H), or bedridden(B)) and the Emergency Severity Index (ESI) associations with admission and mortality outcomes. DESIGN: Post-hoc analysis of a prospective observational study including all consenting presenting to the ED over a period of 3 weeks. Odd ratios and AUCs were calculated to assess predictive performance of SUHB and compared with ESI. RESULTS: Out of 2422 patients, 65% presented with a stable gait, 45% with an ESI level 3. With increasing mobility impairment on the SUHB scale, the probability for admission and mortality increased. SUHB had a higher AUC than ESI for 1-year mortality. CONCLUSION: SUHB was a better predictor than ESI of long-term mortality. The scale, which is rapid, requires little additional training, and no extra costs, could be used as a useful supplement to the triage process.


Assuntos
Benchmarking , Serviço Hospitalar de Emergência , Humanos , Prognóstico , Hospitalização , Triagem
2.
Parasite Immunol ; 40(8): e12539, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29878381

RESUMO

The avian mite Dermanyssus gallinae (poultry red mite, PRM) is of major economic and veterinary importance for the poultry and egg industry worldwide. The accumulating reports on the opportunistic nonavian feeding of D. gallinae raise concerns on PRM host expansion. However, the consequent threats to human health remain largely unclear. PRM infestation in humans is usually manifested as a local or generalized noncharacteristic skin reaction referred to as gamasoidosis. This report presents the current state of the art and the new developments on PRM-associated dermatitis, sharing neither the authors' personal experience nor focusing on differential diagnosis. Specifically, it reflects the outcome of the critical assessment of the available literature by European medical and veterinary experts in the field under the "One Health" approach.


Assuntos
Galinhas/parasitologia , Dermatite/diagnóstico , Especificidade de Hospedeiro , Infestações por Ácaros/diagnóstico , Ácaros/patogenicidade , Doenças das Aves Domésticas/parasitologia , Animais , Dermatite/parasitologia , Feminino , Humanos , Inflamação/parasitologia , Infestações por Ácaros/parasitologia , Saúde Única , Estudos Retrospectivos , Pele/parasitologia , Virulência , Zoonoses
3.
Eur J Intern Med ; 31: 20-4, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27053291

RESUMO

BACKGROUND: Patients with nonspecific complaints (NSC) such as generalized weakness present frequently to acute care settings. These patients are at risk of adverse health outcomes. The aim of our study was to test the hypothesis whether D-dimers are predictive for 30-day mortality in patients with NSCs. METHODS: Delayed type cross-sectional diagnostic study with a 30-day follow-up period, registered with ClinicalTrials.gov (NCT00920491). This study took place in 2 EDs in Northwestern Switzerland. Patients were enrolled in the study if they were over 18years of age, gave informed consent, and if they presented with NSCs such as generalized weakness. D-dimer levels were determined at ED presentation. RESULTS: The final study population consisted of 524 patients. Median age was 82years (IQR=75 to 87years); 40.5% were men. There were 489 survivors and 35 non-survivors at 30-day follow-up. Twenty-one (60%) of the non-survivors were males. D-dimer levels were significantly higher in non-survivors than in survivors (p<0.001). Univariate Cox regression models for D-dimer resulted in a C-index of 0.77 for prediction of mortality. A model including sex, age, Katz ADL and D-dimer in a multivariate Cox regression lead to a C-Index of 0.80. CONCLUSION: D-dimer testing might be an effective risk stratification tool in patients with NSC by helping to identify patients at low risk of short-term mortality with a sensitivity of 0.97 and a negative likelihood ratio of 0.121. The use of D-dimers for risk stratification in patients with NSC should be confirmed with prospective studies.


Assuntos
Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Mortalidade , Debilidade Muscular/diagnóstico , Medição de Risco/métodos , Triagem/métodos , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/análise , Estudos de Coortes , Estudos Transversais , Serviço Hospitalar de Emergência , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Análise Multivariada , Debilidade Muscular/etiologia , Valor Preditivo dos Testes , Modelos de Riscos Proporcionais , Índice de Gravidade de Doença , Suíça/epidemiologia
4.
Tree Physiol ; 35(10): 1095-105, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26377873

RESUMO

An increase in temperature along with a decrease in summer precipitation in Central Europe will result in an increased frequency of drought events and gradually lead to a change in species composition in forest ecosystems. In the present study, young oaks (Quercus robur L. and Quercus petraea (Matt.) Liebl.) were transplanted into large mesocosms and exposed for 3 years to experimental warming and a drought treatment with yearly increasing intensities. Carbon and oxygen isotopic (δ(13)C and δ(18)O) patterns were analysed in leaf tissue and tree-ring cellulose and linked to leaf physiological measures and tree-ring growth. Warming had no effect on the isotopic patterns in leaves and tree rings, while drought increased δ(18)O and δ(13)C. Under severe drought, an unexpected isotopic pattern, with a decrease in δ(18)O, was observed in tree rings but not in leaves. This decrease in δ(18)O could not be explained by concurrent physiological analyses and is not supported by current physiological knowledge. Analysis of intra-annual tree-ring growth revealed a drought-induced growth cessation that interfered with the record of isotopic signals imprinted on recently formed leaf carbohydrates. This missing record indicates isotopic uncoupling of leaves and tree rings, which may have serious implications for the interpretation of tree-ring isotopes, particularly from trees that experienced growth-limiting stresses.


Assuntos
Secas , Temperatura Alta , Quercus/crescimento & desenvolvimento , Câmbio/crescimento & desenvolvimento , Isótopos de Carbono/análise , Isótopos de Oxigênio/análise , Folhas de Planta/crescimento & desenvolvimento , Estações do Ano , Especificidade da Espécie , Suíça
5.
Plant Biol (Stuttg) ; 15 Suppl 1: 220-9, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23279296

RESUMO

Being tolerant to heat and drought, oaks are promising candidates for future forestry in view of climate change in Central Europe. Air warming is expected to increase, and drought decrease soil N availability and thus N supply to trees. Here, we conducted a model ecosystem experiment, in which mixed stands of young oaks (Quercus robur, Q. petraea and Q. pubescens) were grown on two different soils and subjected to four climate treatments during three growing seasons: air warming by 1-2 °C, drought periods (average precipitation reduction of 43-60%), a combination of these two treatments, and a control. In contrast to our hypotheses, neither air warming nor drought significantly affected N availability, whereas total amounts, vertical distribution and availability of soil N showed substantial differences between the two soils. While air warming had no effect on tree growth and N accumulation, the drought treatment reduced tree growth and increased, or tended to increase, N accumulation in the reduced biomass, indicating that growth was not limited by N. Furthermore, (15) N-labelling revealed that this accumulation was associated with an increased uptake of nitrate. On the basis of our results, climate change effects on N dynamics are expected to be less important in oak stands than reduced soil water availability.


Assuntos
Adaptação Fisiológica , Secas , Temperatura Alta , Nitrogênio/metabolismo , Quercus/metabolismo , Solo , Estresse Fisiológico , Ar , Biomassa , Clima , Ecossistema , Aquecimento Global , Modelos Biológicos , Nitratos/metabolismo , Quercus/crescimento & desenvolvimento , Quercus/fisiologia , Chuva , Especificidade da Espécie , Água
6.
Plant Biol (Stuttg) ; 15 Suppl 1: 198-209, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22934888

RESUMO

Climate-tolerant tree species and/or provenances have to be selected to ensure the high productivity of managed forests in Central Europe under the prognosticated climate changes. For this purpose, we studied the responses of saplings from three oak species (i.e. Quercus robur, Q. petraea and Q. pubescens) and provenances of different climatic origin (i.e. low or high rainfall, low or high temperature habitats) with regard to leaf nitrogen (N) composition as a measure of N nutrition. Saplings were grown in model ecosystems on either calcareous or acidic soil and subjected to one of four treatments (control, drought, air warming or a combination of drought and air warming). Across species, oak N metabolism responded to the influence of drought and/or air warming with an increase in leaf amino acid N concentration at the expense of structural N. Moreover, provenances or species from drier habitats were more tolerant to the climate conditions applied, as indicated by an increase in amino acid N (comparing species) or soluble protein N (comparing provenances within a species). Furthermore, amino acid N concentrations of oak leaves were significantly higher on calcareous compared to acidic soil. From these results, it can be concluded that seeds from provenances or species originating from drier habitats and - if available - from calcareous soil types may provide a superior seed source for future forest establishment.


Assuntos
Clima , Ecossistema , Aquecimento Global , Nitrogênio/metabolismo , Folhas de Planta/metabolismo , Quercus/metabolismo , Solo , Aclimatação/genética , Ar , Aminoácidos/metabolismo , Secas , Aptidão Genética , Temperatura Alta , Concentração de Íons de Hidrogênio , Folhas de Planta/fisiologia , Quercus/fisiologia , Chuva , Especificidade da Espécie , Estresse Fisiológico/genética , Temperatura , Água
7.
Plant Biol (Stuttg) ; 15 Suppl 1: 157-68, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22672383

RESUMO

The drought- and thermo-tolerant Quercus pubescens, a tree species growing on both acidic and calcareous soils in the sub-Mediterranean region, was exposed to soil drought (-60% to -80% soil water content) and air warming (+1.2 °C daytime temperature), singly and in combination. The experiment was conducted on two natural forest soils with similar texture but different pH (acidic and calcareous soils). The physiological (photosynthesis) and biochemical (antioxidant system) responses of Q. pubescens were investigated. On acidic soil, Q. pubescens had a higher reactive oxygen species (ROS) content than on calcareous soil, confirming that this species is better adapted to the latter soil type. A down-regulation of ascorbate-glutathione cycle enzymes suggests that ROS were used as signalling molecules. Air warming stimulated stomatal opening, while soil drought induced stomatal closure in the late afternoon and reduced Rubisco carboxylation efficiency. Photosynthetic performance in the combined treatment was higher than under single drought stress and similar to control and air warming. Q. pubescens biochemical responses depended on soil pH. On acidic soil, Q. pubescens trees exposed to air warming used ROS as signalling molecules. On calcareous soil, these trees were able to balance both soil drought and air warming stress, avoiding ROS toxic effects by increasing antioxidant enzyme activitiy and maintaining a high enzymatic antioxidant defence. When combined, drought and air warming induced either more severe (higher oxidative pressure and impairment of the light-harvesting complex) or different responses (decline of the thermal energy dissipation capacity) relative to the single stressors. Overall, however, Q. pubescens preserved the functionality of the photosynthetic apparatus and controlled the antioxidant system response, thus confirming its drought and thermo-tolerance and therefore its potential to adapt to the ongoing climate change.


Assuntos
Adaptação Fisiológica , Antioxidantes/metabolismo , Secas , Temperatura Alta , Fotossíntese/fisiologia , Quercus/fisiologia , Solo , Ar , Clima , Regulação para Baixo , Ecossistema , Aquecimento Global , Concentração de Íons de Hidrogênio , Complexos de Proteínas Captadores de Luz/metabolismo , Estresse Oxidativo , Estômatos de Plantas , Quercus/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo , Estresse Fisiológico , Água
8.
Plant Biol (Stuttg) ; 15 Suppl 1: 138-47, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22288508

RESUMO

Global climate change is expected to increase annual temperatures and decrease summer precipitation in Central Europe. Little is known of how forests respond to the interaction of these climate factors and if their responses depend on soil conditions. In a 3-year lysimeter experiment, we investigated the growth response of young mixed oak stands, on either acidic or calcareous soil, to soil water regime, air-warming and drought treatments corresponding to an intermediate climate change scenario. The air-warming and drought treatments were applied separately as well as in combination. The air-warming treatment had no effect on soil water availability, evapotranspiration or stand biomass. Decreased evapotranspiration from the drought-exposed stands led to significantly higher air and soil temperatures, which were attributed to impaired transpirational cooling. Water limitation significantly reduced the stand foliage, shoot and root biomass as droughts were severe, as shown in low leaf water potentials. Additional air warming did not enhance the drought effects on evapotranspiration and biomass, although more negative leaf water potentials were observed. After re-watering, evapotranspiration increased within a few days to pre-drought levels. Stands not subjected to the drought treatment produced significantly less biomass on the calcareous soil than on the acidic soil, probably due to P or Mn limitation. There was no difference in biomass and water regime between the two soils under drought conditions, indicating that nutrient availability was governed by water availability under these conditions. The results demonstrate that young oak stands can cope with severe drought and therefore can be considered for future forestry.


Assuntos
Adaptação Fisiológica , Secas , Temperatura Alta , Transpiração Vegetal , Quercus/fisiologia , Solo , Água/fisiologia , Ar , Biomassa , Ecossistema , Aquecimento Global , Manganês , Fósforo , Estruturas Vegetais/crescimento & desenvolvimento , Estruturas Vegetais/fisiologia , Quercus/crescimento & desenvolvimento , Estresse Fisiológico , Árvores
9.
Plant Biol (Stuttg) ; 15 Suppl 1: 185-97, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23009690

RESUMO

Three Central European oak species, with four provenances each, were experimentally tested in 16 large model ecosystem chambers for their response to passive air warming (AW, ambient +1-2 °C), drought (D, -43 to -60% irrigation) and their combination (AWD) for 3 years on two forest soil types of pH 4 or 7. Throughout the entire experiment, the influence of the different ambient and experimental climates on the oak trees was strong. The morphological traits of the Quercus species were affected in opposing ways in AW and D treatments, with a neutral effect in the AWD treatment. Biochemical parameters and LMA showed low relative plasticity compared to the morphological and growth parameters. The high plasticity in physiologically important parameters of the three species, such as number of intercalary veins or leaf size, indicated good drought acclimation properties. The soil type influenced leaf chlorophyll concentration, C/N and area more than drought, whereas foliage mass was more dependent on drought than on soil type. Through comparison of visible symptom development with the water deficits, a drought tolerance threshold of -1.3 MPa was determined. Although Q. pubescens had xeromorphic leaf characteristics (small leaf size, lower leaf water content, high LMA, pilosity, more chlorophyll, higher C/N) and less response to the treatments than Q. petraea and Q. robur, it suffered more leaf drought injury and shedding of leaves than Q. petraea. However, if foliage mass were used as the criterion for sustainable performance under a future climate, Q. robur would be the most appropriate species.


Assuntos
Aclimatação , Secas , Aquecimento Global , Temperatura Alta , Folhas de Planta/fisiologia , Quercus/fisiologia , Solo , Ar , Carbono/metabolismo , Clorofila/metabolismo , Clima , Ecossistema , Nitrogênio/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Quercus/crescimento & desenvolvimento , Quercus/metabolismo , Especificidade da Espécie , Estresse Fisiológico , Água
10.
Plant Biol (Stuttg) ; 15 Suppl 1: 169-76, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22776350

RESUMO

Oaks are commonly considered as drought- and heat-tolerant trees that might benefit from a warmer and drier climate. Their tolerance to drought has been frequently studied in the past, whereas studies dealing with elevated temperature or its combination with drought are very limited in number. In this study we investigated seasonal photosynthetic patterns in three European oak species (Quercus robur, Q. petraea, Q. pubescens) exposed in lysimeter-based open-top chambers (OTC) to elevated daytime temperature, drought and their combination. Stomatal and non-stomatal traits of photosynthesis were followed over an entire growing season and related to changes in daytime temperature, soil moisture and pre-dawn leaf water potential (Ψ(PD) ). Elevated daytime temperature enhanced net photosynthesis (P(N) ) in a season-dependent manner, with higher mid-summer rates than in controls exposed to ambient temperature. Drought imposed in early and mid-summer reduced the soil moisture content and caused a gradual decline in Ψ(PD) , stomatal conductance (g(S) ) and P(N) . Drought effects on Ψ(PD) and P(N) were exacerbated when drought was combined with elevated daytime temperature. In general, P(N) tended to be more affected by low soil moisture content or low Ψ(PD) in Q. robur than in Q. petraea and Q. pubescens. Non-stomatal limitations may have contributed to the drought-induced decline of P(N) in Q. robur, as indicated by a down-regulation of PSII photochemistry (F(V) /F(M) ) and decreased chlorophyll content. Taken together, our findings show that European oaks may benefit from elevated temperature, but detrimental effects can be expected when elevated temperature occurs simultaneously with drought.


Assuntos
Adaptação Fisiológica , Secas , Temperatura Alta , Fotossíntese/fisiologia , Quercus/fisiologia , Estações do Ano , Estresse Fisiológico , Clorofila/metabolismo , Clima , Regulação para Baixo , Aquecimento Global , Complexo de Proteína do Fotossistema II/fisiologia , Folhas de Planta , Estômatos de Plantas , Quercus/metabolismo , Solo , Especificidade da Espécie , Água
11.
J Inherit Metab Dis ; 27(5): 707-9, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15669691

RESUMO

Electrospray ionization tandem mass spectrometry is a widely applied method for the analysis of acylcarnitines in blood samples spotted on filter paper cards (Guthrie cards). When the filter paper cards are contaminated by EMLA cream, highly intense signals at m/z 221 and 235 are detected under ESI-MS/MS conditions, monitoring for precursors of m/z 85. These signals correspond to the active ingredients prilocaine and lidocaine in EMLA and overlap with the signals from the isotopically labelled internal standards (2H3)propionyl carnitine and (2H3)butyrylcarnitine. This interference prevents the proper quantification of the two short-chain acylcarnitines when samples are analysed without derivatization.


Assuntos
Carnitina/análogos & derivados , Carnitina/análise , Química Clínica/instrumentação , Espectrometria de Massas por Ionização por Electrospray/instrumentação , Química Clínica/métodos , Humanos , Lidocaína/química , Prilocaína/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Fatores de Tempo
13.
Mol Genet Metab ; 69(4): 302-11, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10870848

RESUMO

We analyzed the urinary acylglycine excretion in 26 patients with mitochondrial energy metabolism disorders and in 55 patients with organic acidurias by electrospray tandem mass spectrometry (ESI-MS/MS), monitoring precursor ions of m/z 90. Urinary concentrations of the different acylglycines were quantified using deuterated internal standards. Normal values for the most important acylglycines were established. In MCAD and MAD (neonatal form) deficiencies, typical excretion patterns of urinary acylglycines were found in all the samples. In isovaleric aciduria, propionic aciduria, and 3-methylcrotonylglycinuria typical glycine conjugates were always found. Methylmalonic aciduria (mutase deficiency), multiple carboxylase deficiency, and 3-hydroxy-3-methylglutaric aciduria revealed pathological acylglycine profiles, even if not specific for the disease. In all these diseases acylglycine excretion seems to be less influenced by the clinical status than organic acid excretion. This method is a useful diagnostic tool for these metabolic disorders, complementary to organic acids and acylcarnitine profiles.


Assuntos
Glicina/urina , Espectrometria de Massas/métodos , Erros Inatos do Metabolismo/urina , Mitocôndrias/metabolismo , Acil-CoA Desidrogenase , Adolescente , Adulto , Amidoidrolases/deficiência , Biotinidase , Carbono-Nitrogênio Ligases/deficiência , Criança , Pré-Escolar , Ácidos Graxos Dessaturases/deficiência , Glicina/análogos & derivados , Hemiterpenos , Humanos , Lactente , Recém-Nascido , Meglutol/urina , Erros Inatos do Metabolismo/enzimologia , Ácido Metilmalônico/urina , Mitocôndrias/patologia , Ácidos Pentanoicos/urina , Propionatos/urina
15.
Inflamm Res ; 48(6): 291-5, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10442479

RESUMO

There is increasing evidence that enteral histaminosis is a major cause of food intolerance resulting from dysfunctional metabolism of endogenous histamine in certain food stuffs. However, this phenomenon has been poorly characterised and, due to the lack of epidemiological data, the existence of this condition has been underestimated, which may lead to incorrect diagnosis. This short commentary highlights a stricter regimen of diagnostic procedure in order to take into account the many causes of food intolerance. The underlying mechanisms ascribed particularly to non-immunologically food reactions require more rigorous research and further work is vital.


Assuntos
Hipersensibilidade Alimentar/diagnóstico , Histamina/metabolismo , Mucosa Intestinal/metabolismo , Protocolos Clínicos , Hipersensibilidade Alimentar/etiologia , Hipersensibilidade Alimentar/terapia , Humanos
16.
Anal Biochem ; 268(1): 64-71, 1999 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-10036163

RESUMO

A set of 10 different recombinant human parvalbumins was used to establish a method for the investigation of the Ca2+-binding properties of proteins by electrospray ionization mass spectrometry (ESI-MS). Human PVWT was found to bind 2 mol Ca2+ ions/mol of protein, whereas its mutants (PVE101V, PVD90A, PVE62V, PVD51A, PVD90A,E101V, PVE62V,E101V, PVD51A,D90A, PVD51A,E62V, PVD51A,E62V, D90A,E101V) containing inactivating substitutions in the Ca2+-binding loops bind 0 or 1 Ca2+ ion per protein molecule, depending on the degree of inactivation. These findings fully agree with previously reported results obtained by flow dialysis experiments. The RP-HPLC desalted metal-free proteins were analyzed in 10 mM ammonium acetate at pH 7.0. The experimental conditions were optimized with the recombinant parvalbumin test system before analyzing the Ca2+-binding properties of rat and murine parvalbumins in muscle tissue extracts. ESI-MS revealed that (i) rat and murine alpha-parvalbumins each bind specifically two Ca2+ ions per protein molecule and (ii) both extracted parvalbumins were found to be posttranslationally modified; each protein is acetylated at the N-terminus. Finally, during our investigations of the murine parvalbumin a sequencing error was detected at the C-terminus where the amino acid at position 109 is Ser and not Thr as mentioned in the SwissProt data base (Accession No. P32848). This work demonstrates the great potential of the ESI-MS technique as a sensitive, specific, and rapid method for direct identification and determination of the stoichiometry of Ca2+-binding proteins and other metalloproteins.


Assuntos
Cálcio/metabolismo , Espectrometria de Massas/métodos , Parvalbuminas/metabolismo , Animais , Humanos , Camundongos , Dados de Sequência Molecular , Peso Molecular , Mutação , Parvalbuminas/genética , Processamento de Proteína Pós-Traducional , Ratos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
17.
Biochem Biophys Res Commun ; 225(1): 146-50, 1996 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-8769108

RESUMO

S100A12 has been isolated from human neutrophils. The molecular weight and the amino acid sequence of S100A12 was determined by electrospray-mass spectrometry, tandem mass spectrometry and Edman microsequence analysis. Interestingly, a sequence comparison of S100A12 with all known human S100 proteins revealed that S100A12 is the most divergent of the S100 proteins.


Assuntos
Peptídeo Relacionado com Gene de Calcitonina/química , Proteínas de Ligação ao Cálcio/química , Proteínas do Tecido Nervoso/química , Neutrófilos/química , Proteínas S100 , Sequência de Aminoácidos , Animais , Proteínas de Ligação ao Cálcio/sangue , Proteínas de Ligação ao Cálcio/isolamento & purificação , Bovinos , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Humanos , Espectrometria de Massas , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Proteína S100A12 , Homologia de Sequência de Aminoácidos , Suínos
18.
Biochem Biophys Res Commun ; 217(1): 257-63, 1995 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-8526920

RESUMO

The Ca(2+)-binding proteins regulate a number of cellular and extracellular activities and deregulations of S100 gene expression are associated with several human diseases. For example, S100A7 is upregulated in psoriatic skin, implicating a link with psoriasis, a chronic inflammatory dermatosis. We purified human S100A7 and determined its protein sequence by tandem mass spectrometry and Edman microsequence analysis. Interestingly, a sequence comparison of S100A7 with all known human S100 proteins showed that S100A7 is the most divergent of all S100 proteins.


Assuntos
Proteínas de Ligação ao Cálcio/genética , Sequência de Aminoácidos , Proteínas de Ligação ao Cálcio/química , Citosol/química , Humanos , Espectrometria de Massas , Membranas/química , Dados de Sequência Molecular , Estrutura Molecular , Psoríase/genética , Proteína A7 Ligante de Cálcio S100 , Proteínas S100 , Homologia de Sequência de Aminoácidos
19.
World J Microbiol Biotechnol ; 11(5): 519-24, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24414906

RESUMO

Extracellular polygalacturonase (PG) production was estimated in vitro, using liquid cultures of three species of brown-rot decay fungi (Postia placenta, Gloeophyllum trabeum and Serpula incrassata), by cup-plate assay, assay of reducing sugars, and decrease in viscosity. Although all three experimental assays demonstrated that PG was induced by pectin in all three fungi, decrease in viscosity gave the best correlation with decay capacity in soil block tests. PG activity, determined as an increase in reducing sugar activity, was greatest in G. trabeum and weakest in S. incrassata. The optimum pH for PG activity was between pH 2.5 and 4.5. Oxalic acid production was also enhanced by pectin and functioned synergistically with PG activity. We conclude that these fungi produce PG that is best induced by pectin and that PG activity exceeds production of xylanase and endoglucanase activity in vitro. Polygalacturonase is likely to act synergistically with oxalic acid to solubilize and hydrolyse the pectin in pit membranes and middle lamellae. Thus, production of PG and oxalic acid should facilitate early spread of hyphae and enhance the lateral flow of wood-decay enzymes and agents into adjacent tracheids and the wood cell wall, thus initiating the diffuse decay caused by brown-rot fungi.

20.
Biol Mass Spectrom ; 23(5): 262-6, 1994 May.
Artigo em Inglês | MEDLINE | ID: mdl-8204682

RESUMO

Fast atom bombardment (FAB) tandem mass spectrometry has been used to analyse the biologically potent, partially modified retro-inverso (PMRI) synthetic isomer of tuftsin: this compound represents the active peptide of the fraction of gamma-globulin (leukokinin) which binds specifically to blood neutrophilic leukocytes and monocytes. Protonated molecules and fragment ions were collisionally dissociated at low energies in a triple-quadrupole mass spectrometer to yield a complete picture of the reactions that occur in the condensed and in the gas phase. The study shows that, when retro-inversion is within the N-terminal amino acid, charge localization at the basic sites (possibly at the N-terminus) induces a marked decomposition of the molecule, the loss of ammonia being the most favourable fragmentation process. Also, artifacts are formed in the liquid phase via bimolecular reactions promoted by the high-energy beam. The findings indicate that despite the fact that PMRI isomers of this type are stable against exo-peptidases and also stable under acidic conditions, they appear to be labile under conditions where the energy deposition, due to FAB is necessarily high.


Assuntos
Tuftsina/análogos & derivados , Tuftsina/análise , Sequência de Aminoácidos , Cromatografia Líquida de Alta Pressão , Cromatografia por Troca Iônica , Dados de Sequência Molecular , Espectrometria de Massas de Bombardeamento Rápido de Átomos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...