Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 81
Filtrar
1.
J Mol Cell Cardiol ; 130: 216-233, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30998979

RESUMO

BACKGROUND: The cardioprotective effects of metformin remain poorly defined. Interleukin (IL)-33/ST2L signaling is a novel cardioprotective pathway, which is antagonized by the soluble isoform sST2. No data exist about the regulation of ST2 expression. This study aimed to evaluate the pathophysiological implication of Yin-Yang 1 (Yy1) transcription factor in cardiac remodeling and the expression of the soluble ST2 isoform. METHODS AND RESULTS: Myocardial infarction (MI) was induced in Wistar rats randomly receiving metformin or saline solution by permanent ligation of the left anterior coronary artery. In addition, a model of cardiomyocyte "biochemical strain" was used. Metformin administration improved post-MI cardiac remodeling, an effect that was associated with increased IL-33 and reduced sST2 levels in the myocardium. The anti-remodeling effects of metformin were also associated with a decrease in the transcription factor Yy1 intranuclear level and lower levels of phosphorylated HDAC4 within the cytoplasmic space. These effects were also observed in a cardiomyocyte biochemical strain model, where Yy1 silencing or HDAC4 inhibition blocked sST2 production in cardiomyocytes. Metformin blocked the HDAC4 phosphorylation induced by MI, preventing its export from the nucleus to the cytosol. The presence of dephosphorylated HDAC4 in the nucleus acted as a co-repressor of Yy1, repressing sST2 expression. CONCLUSION: The transcription factor Yy1 regulates sST2 expression, and repression of Yy1 by metformin results in lower levels of sST2 that are associated with favorable myocardial remodeling. The manipulation of YY1 or its co-repressor HDAC4 emerge as new targets to modulate ST2/IL33 signaling and prevent adverse cardiac remodeling.


Assuntos
Regulação da Expressão Gênica , Infarto do Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Receptores de Interleucina-1/biossíntese , Transdução de Sinais , Fator de Transcrição YY1/metabolismo , Animais , Histona Desacetilases/metabolismo , Interleucina-33/metabolismo , Masculino , Metformina/farmacologia , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/patologia , Miócitos Cardíacos/patologia , Ratos , Ratos Wistar , Fator de Transcrição YY1/antagonistas & inibidores
2.
Eur J Neurol ; 25(3): 556-e33, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29266547

RESUMO

BACKGROUND AND PURPOSE: Forced vital capacity (FVC) <80% is one of the key indications for starting non-invasive ventilation (NIV) in amyotrophic lateral sclerosis (ALS). It was hypothesized that a very early start of NIV could lengthen the free interval before death compared to later-start NIV; as a secondary outcome, the survival rate of patients on NIV without tracheotomy was also evaluated. METHODS: This retrospective study was conducted on 194 ALS patients, divided into a later group (LG) with FVC <80% at NIV prescription (n = 129) and a very early group (VEG) with FVC ≥80% at NIV prescription (n = 65). Clinical and respiratory functional data and time free to death between groups over a 3-year follow-up were compared. RESULT: At 36 months from diagnosis, mortality was 35% for the VEG versus 52.7% for the LG (P = 0.022). Kaplan-Meier survival curves adjusted for tracheotomy showed a lower probability of death (P = 0.001) for the VEG as a whole (P = 0.001) and for the non-bulbar (NB) subgroup (P = 0.007). Very early NIV was protective of survival for all patients [hazard ratio (HR) 0.45; 95% confidence interval (CI) 0.28-0.74; P = 0.001] and for the NB subgroup (HR 0.43; 95% CI 0.23-0.79; P = 0.007), whilst a tracheotomy was protective for all patients (HR 0.27; 95% CI 0.15-0.50; P = 0.000) and both NB (HR 0.26; 95% CI 0.12-0.56; P = 0.001) and bulbar subgroups (HR 0.29; 95% CI 0.11-0.77; P = 0.013). Survival in VEG patients on NIV without tracheotomy was three times that for the LG (43.1% vs. 14.7%). CONCLUSION: Very early NIV prescription prolongs the free time from diagnosis to death in NB ALS patients whilst tracheotomy reduces the mortality risk in all patients.


Assuntos
Esclerose Lateral Amiotrófica/mortalidade , Esclerose Lateral Amiotrófica/terapia , Ventilação não Invasiva/estatística & dados numéricos , Avaliação de Resultados em Cuidados de Saúde , Traqueostomia/estatística & dados numéricos , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Ventilação não Invasiva/métodos , Insuficiência Respiratória/mortalidade , Estudos Retrospectivos , Fatores de Tempo , Traqueostomia/métodos
3.
Insect Mol Biol ; 21(2): 235-45, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22243654

RESUMO

Coptotermes formosanus is one of the most destructive wood-feeding termites. To understand the molecular mechanisms that regulate the development of the termite, a normalized C. formosanus cDNA library was constructed using mixed RNA isolated from workers, soldiers, nymphs and alates of both sexes. The sequencing of this library generated 131 636 expressed sequence tags (ESTs) and 25 939 assembled unigenes. The carbohydrate-active enzymes (CAZymes) revealed in this library were analysed in the present report. A total of 509 putative CAZymes were identified. Diverse cellulolytic enzymes were uncovered from both the host termite and from symbionts harboured by the termite, which were possibly the result of the high efficiency of cellulose utilization. CAZymes associated with trehalose biosynthetic and metabolic pathways were also identified, which are potential regulators of the physiological activities of trehalose, an important insect blood sugar. Representative CAZyme coding genes in glycoside hydrolase family 1 (GH1) were quantitatively analysed. The results showed that the five GH1 ß-glucosidase genes were expressed differentially among different castes and one of them was female alate-specific. Overall, the normalized EST library provides a comprehensive genetic resource of C. formosanus and will serve a diverse range of research areas. The CAZymes represent one of the repositories of enzymes useful for physiological studies and applications in sugar-based biofuel production.


Assuntos
Metabolismo dos Carboidratos , Isópteros/enzimologia , Predomínio Social , Transcriptoma , Sequência de Aminoácidos , Animais , Celulases/metabolismo , Esterases/genética , Esterases/metabolismo , Etiquetas de Sequências Expressas , Feminino , Expressão Gênica , Biblioteca Gênica , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Isópteros/genética , Masculino , Dados de Sequência Molecular , Polissacarídeo-Liases/genética , Polissacarídeo-Liases/metabolismo , Alinhamento de Sequência , Trealose/biossíntese
4.
Sci Rep ; 11(1): 4943, 2021 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-33654146

RESUMO

The pandemic of COVID-19 is continuously spreading, becoming a worldwide emergency. Early and fast identification of subjects with a current or past infection must be achieved to slow down the epidemiological widening. Here we report a Raman-based approach for the analysis of saliva, able to significantly discriminate the signal of patients with a current infection by COVID-19 from healthy subjects and/or subjects with a past infection. Our results demonstrated the differences in saliva biochemical composition of the three experimental groups, with modifications grouped in specific attributable spectral regions. The Raman-based classification model was able to discriminate the signal collected from COVID-19 patients with accuracy, precision, sensitivity and specificity of more than 95%. In order to translate this discrimination from the signal-level to the patient-level, we developed a Deep Learning model obtaining accuracy in the range 89-92%. These findings have implications for the creation of a potential Raman-based diagnostic tool, using saliva as minimal invasive and highly informative biofluid, demonstrating the efficacy of the classification model.


Assuntos
COVID-19/diagnóstico , Saliva/química , Análise Espectral Raman/métodos , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/análise , Comorbidade , Biologia Computacional , Aprendizado Profundo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Distribuição Normal , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
5.
J Cardiovasc Transl Res ; 13(5): 864-866, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-31970669

RESUMO

Recently, novel findings about the interleukin 1ß (IL-1 ß) axis in acute decompensated heart failure (ADHF) have been published. There is a positive correlation between IL-1 ß and interleukin-1 receptor like 1 (sST2) in ADHF patients. Is there also a correlation between the values of IL-1 ß and sST2 in chronic heart failure patients?


Assuntos
Insuficiência Cardíaca/sangue , Proteína 1 Semelhante a Receptor de Interleucina-1/sangue , Interleucina-1beta/sangue , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Doença Crônica , Feminino , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
6.
Sci Rep ; 10(1): 10175, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32576912

RESUMO

Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease leading to progressive and irreversible muscle atrophy. The diagnosis of ALS is time-consuming and complex, with the clinical and neurophysiological evaluation accompanied by monitoring of progression and a long procedure for the discrimination of similar neurodegenerative diseases. The delayed diagnosis strongly slows the potential development of adequate therapies and the time frame for a prompt intervention. The discovery of new biomarkers could improve the disease diagnosis, as well as the therapeutic and rehabilitative effectiveness and monitoring of the pathological progression. In this work saliva collected from 19 patients with ALS, 10 affected by Parkinson's disease, 10 affected by Alzheimer's disease and 10 healthy subjects, was analysed using Raman spectroscopy, optimizing the parameters for detailed and reproducible spectra. The statistical multivariate analysis of the data revealed a significant difference between the groups, allowing the discrimination of the disease onset. Correlation of Raman data revealed a direct relationship with paraclinical scores, identifying multifactorial biochemical modifications related to the pathology. The proposed approach showed a promising accuracy in ALS onset discrimination, using a fast and sensitive procedure that can make more efficient the diagnostic procedure and the monitoring of therapeutic and rehabilitative processes in ALS.


Assuntos
Esclerose Lateral Amiotrófica/diagnóstico , Biomarcadores/metabolismo , Saliva/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/metabolismo , Esclerose Lateral Amiotrófica/metabolismo , Progressão da Doença , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/diagnóstico , Doença de Parkinson/metabolismo
7.
Br Dent J ; 224(4): 255-260, 2018 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-29472686

RESUMO

Botulinum toxin is widely used in facial rhytide treatments. The duration of its effects influences treatment intervals, cost and convenience to the patient. These are key factors in successful aesthetic procedures. A review of the literature found that duration of effect was between two and six months, with most experiencing loss of maximal contraction for three to four months. Treatments may last between three to four months, and occasionally up to six months. No specific definition of effectiveness/efficacy has been described and used to measure comparable end points. Additional research should help clarify the impact of brand, age, gender, ethnicity, repetition of treatment and zinc-phytase supplementation.


Assuntos
Toxinas Botulínicas/uso terapêutico , Envelhecimento da Pele/efeitos dos fármacos , Toxinas Botulínicas/administração & dosagem , Humanos , Injeções Subcutâneas , Fatores de Tempo , Resultado do Tratamento
8.
Nat Biotechnol ; 19(1): 66-70, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11135555

RESUMO

Infection of the mammary gland, in addition to causing animal distress, is a major economic burden of the dairy industry. Staphylococcus aureus is the major contagious mastitis pathogen, accounting for approximately 15-30% of infections, and has proved difficult to control using standard management practices. As a first step toward enhancing mastitis resistance of dairy animals, we report the generation of transgenic mice that secrete a potent anti-staphylococcal protein into milk. The protein, lysostaphin, is a peptidoglycan hydrolase normally produced by Staphylococcus simulans. When the native form is secreted by transfected eukaryotic cells it becomes glycosylated and inactive. However, removal of two glycosylation motifs through engineering asparagine to glutamine codon substitutions enables secretion of Gln(125,232)-lysostaphin, a bioactive variant. Three lines of transgenic mice, in which the 5'-flanking region of the ovine beta-lactoglobulin gene directed the secretion of Gln(125,232)-lysostaphin into milk, exhibit substantial resistance to an intramammary challenge of 104 colony-forming units (c.f.u.) of S. aureus, with the highest expressing line being completely resistant. Milk protein content and profiles of transgenic and nontransgenic mice are similar. These results clearly demonstrate the potential of genetic engineering to combat the most prevalent disease of dairy cattle.


Assuntos
Lisostafina/biossíntese , Glândulas Mamárias Animais/fisiologia , Leite/fisiologia , Infecções Estafilocócicas/prevenção & controle , Staphylococcus/genética , Substituição de Aminoácidos , Animais , Asparagina , Bovinos , Feminino , Engenharia Genética , Glutamina , Lactação , Lisina , Lisostafina/metabolismo , Mastite Bovina/prevenção & controle , Camundongos , Camundongos Transgênicos , Leite/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/metabolismo
9.
Food Funct ; 7(2): 992-1001, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26751429

RESUMO

The protective effects of the antioxidants present in food are of great relevance for cardiovascular health. This study evaluates whether the extracts from reformulated meat products with a reduction in fat and/or sodium content exert a cardioprotective effect against ischemia-induced oxidative stress in cardiomyocytes, compared with non-meat foods. Ischemic damage caused loss of cell viability, increased reactive oxygen species and lipid peroxidation and decreased the antioxidant activity. Pretreatment for 24 h with digested or non-digested extracts from reformulated meat products led to protection against ischemia-induced oxidative damage: increased cell viability, reduced oxidative stress and restored the antioxidant activity. Similar results were obtained using extracts from tuna fish, but not with the extracts of green peas, salad or white beans. These results suggest that reformulated meat products have a beneficial impact in protecting cardiac cells against ischemia, and they may represent a source of natural antioxidants with benefits for cardiovascular health.


Assuntos
Antioxidantes/farmacologia , Doença da Artéria Coronariana/prevenção & controle , Produtos da Carne/análise , Substâncias Protetoras/farmacologia , Animais , Linhagem Celular , Gorduras na Dieta/análise , Manipulação de Alimentos , Peroxidação de Lipídeos/efeitos dos fármacos , Camundongos , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Sódio na Dieta/análise
10.
FEBS Lett ; 360(1): 62-6, 1995 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-7875303

RESUMO

The susceptibility of the potent mitogen Pasteurella multocida toxin (PMT) to various proteases was investigated. PMT at a toxin to protease molar ratio of 1:1 was resistant to 8 of the 11 proteases tested after one hour. With longer incubation, PMT remained resistant to 7 proteases, and this correlated with a retention of biological activity, indicating that PMT might not require proteolytic cleavage at least until it bound to a cell receptor. Previous evidence had suggested that PMT is processed in the cell via an endosome or lysosome. We have shown that PMT became susceptible to proteolysis when the pH was lowered to 5 or below. This supports the previous suggestion that PMT is processed via a low pH compartment in the cell.


Assuntos
Proteínas de Bactérias , Toxinas Bacterianas/metabolismo , Lisossomos/metabolismo , Mitógenos/metabolismo , Pasteurella multocida/metabolismo , Células 3T3 , Animais , Detergentes , Concentração de Íons de Hidrogênio , Hidrólise , Camundongos , Desnaturação Proteica , Ureia/química
11.
FEBS Lett ; 277(1-2): 59-64, 1990 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-2269370

RESUMO

Pasteurella multocida toxin is a potent mitogen for cultured Swiss 3T3 cells where it causes an accumulation of inositol phosphates and activation of protein kinase C. The gene sequence described here coded for a 146 kDa protein. The ORF was preceded by a ribosome binding site and followed by a stem loop. There was no evidence for a signal sequence. The gene had a low G + C base ratio which differs from the rest of the Pasteurella genome. There was no significant homology with other known proteins, although a motif found in certain bacterial toxins which are ADP-ribosyl transferases is present. A recombinant expressing only part of the PMT gene was not mitogenic.


Assuntos
Proteínas de Bactérias , Toxinas Bacterianas/genética , Genes Bacterianos , Mitógenos , Pasteurella/genética , Sequência de Aminoácidos , Sequência de Bases , Dados de Sequência Molecular , Solubilidade
12.
FEBS Lett ; 342(1): 81-4, 1994 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-8143855

RESUMO

Pasteurella multocida toxin (PMT) is a potent mitogen for Swiss 3T3 fibroblasts and cytotoxic to embryonic bovine lung cells. Site-directed mutagenesis was used to investigate the functional significance of a three amino acid motif in PMT that is present in five other bacterial protein toxins which exhibit ADP-ribosyl transferase activity. Crude lysates of mutant clones were fully cytotoxic for embryonic bovine lung cells. Purified mutant toxin was also as effective at stimulating inositol phosphate turnover and nucleic acid synthesis as wild type toxin. We conclude that this motif has no functional significance in Pasteurella multocida toxin.


Assuntos
Proteínas de Bactérias , Toxinas Bacterianas/farmacologia , Mitógenos/farmacologia , Pasteurella multocida , Células 3T3 , Sequência de Aminoácidos , Animais , Toxinas Bacterianas/química , Toxinas Bacterianas/genética , Toxinas Bacterianas/toxicidade , Sequência de Bases , Bovinos , Morte Celular/efeitos dos fármacos , Células Cultivadas , DNA/biossíntese , Fosfatos de Inositol/metabolismo , Camundongos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Poli(ADP-Ribose) Polimerases/metabolismo
13.
Am J Clin Nutr ; 40(1): 8-13, 1984 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6741856

RESUMO

This study was designed to reevaluate the kinetics of vitamin A losses in the plastic intravenous infusion system used clinically in premature infants and to attempt to establish an improved method of delivery that would avoid significant and unpredictable losses. The losses of retinol, retinyl acetate, and retinyl palmitate were assessed in the presence of various concentrations of the emulsifier Tween 20. For a period of more than 24 h and at a concentration of 0.0085% Tween 20, retinol and retinyl acetate were delivered at 17.4 and 33.9% of the originally intended dose, respectively, while retinyl palmitate was at 100%. At 1% Tween 20, retinyl acetate was completely delivered but even at 2% Tween 20 only 51% of the retinol was delivered. The data suggest that predictable infusions of vitamin A may be attained by using retinyl palmitate rather than retinol in multivitamin preparations.


Assuntos
Vitamina A/administração & dosagem , Adsorção , Cromatografia Líquida , Infusões Parenterais , Plásticos , Polissorbatos
14.
FEMS Microbiol Lett ; 156(2): 223-6, 1997 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-9513269

RESUMO

Several naturally occurring antibiotic resistance plasmids were isolated from Pasteurella multocida type D strains. One plasmid, pPM1, was used to study transfer of DNA among P. multocida strains, and could be transferred into Escherichia coli and some P. multocida isolates. However, pPM1 could only be transferred into the toxigenic P. multocida LFB3 at very low frequency. Plasmid recovered from the electrotransformants could be transferred to LFB3 at high frequency. These plasmid DNAs were resistant to PstI, and sensitive to DpnI digestion. Sensitivity to DpnI was common to all the P. multocida DNAs, but resistance to PstI was confined to LFB3. Plasmid pPM1 treated with PstI methylase was able to transform LFB3 at an increased frequency compared to unmethylated DNA, suggesting that LFB3 has a restriction system which cleaves at or near PstI sites.


Assuntos
Desoxirribonucleases de Sítio Específico do Tipo II/farmacologia , Pasteurella multocida/genética , Plasmídeos/isolamento & purificação , DNA Metiltransferases Sítio Específica (Adenina-Específica)/farmacologia , DNA Bacteriano/análise , Pasteurella multocida/efeitos dos fármacos , Pasteurella multocida/enzimologia , Mapeamento por Restrição
15.
FEMS Microbiol Lett ; 141(2-3): 189-93, 1996 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-8768521

RESUMO

The expression of the Pasteurella multocida toxin (PMT) gene toxA was investigated. Growth in vitro at 30 degrees C or added iron caused less than 4-fold repression of toxA expression. The putative repressor TxaR was expressed in Escherichia coli but deletion and frameshift mutations abolishing TxaR production had no effect on toxA expression. Naturally occurring non-toxigenic mutants which contained the toxA gene had no large rearrangements near toxA or changes in toxA promoter structure. Thus PMT is constitutively expressed and is only regulated in a minor way.


Assuntos
Proteínas de Bactérias , Toxinas Bacterianas/genética , Regulação Bacteriana da Expressão Gênica , Pasteurella multocida/genética , Pasteurella multocida/metabolismo , Sequência de Bases , Western Blotting , Dados de Sequência Molecular , Plasmídeos , Regiões Promotoras Genéticas , Proteínas Repressoras/metabolismo , Mapeamento por Restrição
16.
FEMS Microbiol Lett ; 180(1): 15-20, 1999 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-10547439

RESUMO

Pasteurella multocida toxin is a potent mitogen that is believed to act intracellularly. On transverse urea gradient gels at pH 8.0 the toxin displayed one major unfolding transition at 4 M urea. However, at pH 6.1 the unfolding transition took place at 3.5 M urea. Circular dichroism spectra also indicated that a structural change took place at acidic pH. In addition it was found that the toxin that had been denatured in 8 M urea refolded in solution with a high recovery of biological activity. These findings are discussed in terms of the likely domain structure of the P. multocida toxin.


Assuntos
Proteínas de Bactérias , Toxinas Bacterianas/química , Células 3T3 , Animais , Dicroísmo Circular , Eletroforese em Gel de Campo Pulsado , Camundongos , Desnaturação Proteica , Dobramento de Proteína , Ureia
17.
FEMS Microbiol Lett ; 116(1): 113-21, 1994 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-8132151

RESUMO

The regulation of the spvR promoter from the Salmonella dublin virulence plasmid was monitored using promoter-reporter gene fusion constructs. Activity was dependent upon the presence of the spv region and was affected by the number of copies of the spv region present within the cell. Activity remained constant throughout exponential growth, and increased rapidly with the onset of stationary phase, under both aerobic and anaerobic conditions. Additionally, the level of spvR expression was controlled by the availability of iron, activity being greatest under low iron conditions in stationary phase. The spvA gene product negatively regulated spvR expression in a dose-dependent manner, indicating that SpvA provides a negative feedback mechanism for this operon.


Assuntos
Regulação Bacteriana da Expressão Gênica , Genes Reguladores , Plasmídeos/genética , Salmonella/genética , Salmonella/patogenicidade , Animais , Sequência de Bases , Genes Bacterianos , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Mapeamento por Restrição , Infecções por Salmonella/microbiologia , Virulência/genética
18.
J Chromatogr A ; 932(1-2): 119-27, 2001 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-11695856

RESUMO

Solid-phase microextraction (SPME)-gas chromatography-mass spectrometry was used to identify the cuticular hydrocarbons of the subterranean termite Coptotermes formosanus Shiraki. Headspace SPME and direct contact SPME methods were evaluated and compared to the hexane extraction method. Variables, such as temperature, time, number of termites, condition of the termites, and the type of SPME fiber were evaluated. Methods were refined to increase the reproducibility as well as the sensitivity. Both SPME methods were successfully used for the identification of all the major termite cuticular hydrocarbons. Using the headspace SPME method, other compounds of interest could also be identified, such as fatty acids. Using the direct contact SPME method, termites could be repeatedly studied over time to monitor chemical changes.


Assuntos
Hidrocarbonetos/análise , Isópteros/química , Animais , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
19.
Vet Microbiol ; 18(2): 135-46, 1988 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3218075

RESUMO

The pathogenicity of 3 strains of Bordetella bronchiseptica designated B58, PV6 and B65 was compared by intranasal infection of gnotobiotic piglets. Strain B58 was a phase 1 isolate that produced haemolysin, an adhesin for calf erythrocytes, adenylate cyclase, mouse lethal factor, dermonecrotic factor and cytotoxin. B65 was a variant of B58 that produced no detectable haemolysin, adhesin or adenylate cyclase and 10-fold smaller amounts than B58 of mouse lethal factor, dermonecrotic factor and cytotoxin. Strain PV6 was a phase 1 isolate that produced only haemolysin, adhesin and adenylate cyclase. After nasal infection of gnotobiotic pigs, 10(3.2)-10(6.2) colony forming units ml-1 (cfu ml-1) of strains B58 and PV6 were cultured from nasal washings during the next 25 days. In contrast, only 10(1.0)-10(2.8) cfu ml-1 of strain B65 were recovered during the same period. Only pigs infected with strain B58 had turbinate atrophy when they were slaughtered 25 days after infection and neutralising antibody to cytotoxin was detected only in these pigs. These results suggested that the cytotoxin, which may be the same as the mouse lethal and dermonecrotic factors, was the cause of turbinate atrophy. They also support the view that the adhesin for calf erythrocytes is required for colonisation of the nasal cavity in vivo.


Assuntos
Infecções por Bordetella/veterinária , Bordetella/patogenicidade , Citotoxinas/biossíntese , Doenças Nasais/veterinária , Doenças dos Suínos/patologia , Conchas Nasais , Animais , Bordetella/metabolismo , Infecções por Bordetella/microbiologia , Infecções por Bordetella/patologia , Doenças Nasais/microbiologia , Doenças Nasais/patologia , Suínos , Doenças dos Suínos/microbiologia , Virulência
20.
JPEN J Parenter Enteral Nutr ; 8(3): 269-73, 1984.
Artigo em Inglês | MEDLINE | ID: mdl-6539829

RESUMO

Conflicting reports exist regarding the relative tocopherol isomer content of Intralipid ranging from 99% as alpha-tocopherol to as much as 90% as gamma-tocopherol. Our direct assay of Intralipid as well as plasma levels measured in premature infants receiving Intralipid confirm the existence of a low alpha, high gamma-tocopherol content and imply the need for alpha-tocopherol supplementation in patients receiving Intralipid, particularly the relatively tocopherol-deficient premature infant. Furthermore, the observation of abnormal erythrocyte hemolysis test values despite "normal" total tocopherol plasma concentrations may be explained by high plasma levels of non-alpha, biologically less active isomers. The quantitation of tocopherol isomers helps explain this discrepancy and suggests the need for future studies of vitamin E status to employ measurements of tocopherol isomers in reporting results.


Assuntos
Emulsões Gordurosas Intravenosas/análise , Recém-Nascido Prematuro , Vitamina E/análise , Vitamina E/sangue , alfa-Tocoferol/análogos & derivados , Peso ao Nascer , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Isomerismo , Masculino , Fatores de Tempo , Tocoferóis , Vitamina E/administração & dosagem , Vitamina E/análogos & derivados
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA