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1.
J Appl Microbiol ; 129(4): 848-859, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32301544

RESUMEN

AIMS: Antibiotic adjuvants can give a second life to the antibiotics to which bacteria are highly resistant. We evaluated the antimicrobial effects of extracts from Pithecellobium clypearia against methicillin-resistant Staphylococcus aureus (MRSA) and also the potential for synergy with several antibiotics. METHODS AND RESULTS: For this study, four extracts from P. clypearia were tested on MRSA using the broth microdilution method for activity assessment. The ethyl acetate fraction (S20b) had the strongest antibacterial activity against MRSA among the fractions tested. In all, 14 compounds such as gallic acid and luteolin in S20b were analysed by UFLC-Q-TOF-MS/MS. S20b combined with erythromycin showed synergy effects against MRSA and combined with ceftriaxone sodium and levofloxacin showed additive effects against MRSA. Electron microscopy showed that extract S20b damaged the MRSA cell wall and K+ efflux measurements indicated that extract S20b increased cell membrane permeability. Moreover, S20b suppression of PBP2a expression was assessed by Western blot. Furthermore, an in vivo study was used to investigate the therapeutic potential of S20b based on a mouse pneumonia model. CONCLUSIONS: The in vitro study results have shown that S20b not only inhibits MRSA growth directly but also reduces the resistance of MRSA to the evaluated antibacterial agents. Based on the in vivo study, it can be concluded that S20b can treat pneumonia in the mouse model. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is the first research to demonstrate that S20b can inhibit MRSA growth and reduce drug resistance of clinical isolates to antibiotics. S20b has the potential to be used as a therapeutic agent against MRSA and treatment for MRSA pneumonia.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana/efectos de los fármacos , Fabaceae/química , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Extractos Vegetales/farmacología , Infecciones Estafilocócicas/tratamiento farmacológico , Animales , Ceftriaxona/farmacología , Sinergismo Farmacológico , Eritromicina/farmacología , Ácido Gálico/farmacología , Levofloxacino/farmacología , Luteolina/farmacología , Ratones , Pruebas de Sensibilidad Microbiana , Espectrometría de Masas en Tándem
2.
Aliment Pharmacol Ther ; 39(10): 1136-42, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24641590

RESUMEN

BACKGROUND: Patients with inflammatory bowel diseases (IBD) have an increased risk of clostridium difficile infection (CDI). Cathelicidins are anti-microbial peptides that attenuate colitis and inhibit the effect of clostridial toxins. Plasma calcifediol [25(OH)D] stimulates production of cathelicidins. AIM: To examine the association between plasma 25(OH)D and CDI in patients with IBD. METHODS: From a multi-institutional IBD cohort, we identified patients with at least one measured plasma 25(OH)D. Our primary outcome was development of CDI. Multivariate logistic regression models adjusting for potential confounders were used to identify independent effect of plasma 25(OH)D on risk of CDI. RESULTS: We studied 3188 IBD patients of whom 35 patients developed CDI. Patients with CDI-IBD were older and had greater co-morbidity. The mean plasma 25(OH)D level was significantly lower in patients who developed CDI (20.4 ng/mL) compared to non-CDI-IBD patients (27.1 ng/mL) (P = 0.002). On multivariate analysis, each 1 ng/mL increase in plasma 25(OH)D was associated with a 4% reduction in risk of CDI (OR 0.96, 95% CI 0.93-0.99, P = 0.046). Compared to individuals with vitamin D >20 ng/mL, patients with levels <20 ng/mL were more likely to develop CDI (OR 2.27, 95% CI 1.16-4.44). The mean plasma 25(OH)D in patients with CDI who subsequently died was significantly lower (12.8 ± 8.1 ng/mL) compared to those who were alive at the end of follow-up (24.3 ± 13.2 ng/mL) (P = 0.01). CONCLUSIONS: Higher plasma calcifediol [25(OH)D] is associated with reduced risk of C. difficile infection in patients with IBD. Further studies of therapeutic supplementation of vitamin D in patients with inflammatory bowel disease and C. difficile infection may be warranted.


Asunto(s)
Clostridioides difficile/aislamiento & purificación , Infecciones por Clostridium/epidemiología , Enfermedades Inflamatorias del Intestino/complicaciones , Vitamina D/análogos & derivados , Adulto , Anciano , Infecciones por Clostridium/etiología , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Riesgo , Vitamina D/sangre
3.
Eur J Neurol ; 21(5): 752-7, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24506292

RESUMEN

BACKGROUND AND PURPOSE: The aim of this study was to explore whether hearing loss is associated with the risk of Parkinson's disease in the elderly in Taiwan. METHODS: Using claims data of the Taiwan National Health Insurance Program, 4976 patients (aged 65 years or older) with newly diagnosed hearing loss from 2000 to 2010 were identified and 19 904 subjects without hearing loss were randomly selected as comparisons, frequency matched by sex, age and index year of diagnosing hearing loss. The incidence of Parkinson's disease by the end of 2010 and the associated risk factors were investigated. RESULTS: The incidence of Parkinson's disease in the hearing loss group was 1.77-fold higher than that in the non-hearing-loss group (3.11 vs. 1.76 per 1000 person-years). After controlling for confounding factors, the adjusted hazard ratio (HR) of Parkinson's disease was 1.53 (95% CI 1.17, 1.99) for the hearing loss group compared with the non-hearing-loss group. Male sex (HR = 1.33, 95% CI 1.02, 1.74), age (for each year, HR = 1.06, 95% CI 1.04, 1.09), hypertension (HR = 1.70, 95% CI 1.26, 2.30) and cerebrovascular disease (HR = 1.78, 95% CI 1.37, 2.32) were also significantly associated with the risk of Parkinson's disease. CONCLUSIONS: Hearing loss correlates with an increased risk of Parkinson's disease in the elderly. Further studies are needed to confirm whether hearing loss could be a non-motor feature of Parkinson's disease.


Asunto(s)
Envejecimiento , Pérdida Auditiva/epidemiología , Pérdida Auditiva/etiología , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/epidemiología , Factores de Edad , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Humanos , Incidencia , Masculino , Programas Nacionales de Salud , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Factores de Riesgo , Taiwán/epidemiología
4.
Tissue Antigens ; 78(4): 267-70, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21732917

RESUMEN

Two hundred and thirty-six novel human leukocyte antigen (HLA) alleles are described from volunteer donors of the China Marrow Donor Program: 71 HLA-A alleles, 79 HLA-B alleles, 43 HLA-C, 16 HLA-DRB1 alleles, 26 HLA-DQB1 and 1 HLA-DPB1. Two hundred and thirteen (90.3%) of the 236 novel alleles are single nucleotide substitution variants when compared with their most homologous allele. Seventy-eight of these single nucleotide variants are silent substitutions. The remaining novel alleles differ from their most similar allele by two to four nucleotide substitutions. Some of the novel alleles encode amino acid changes at positions not previously reported to be polymorphic, such as codons 57, 62, 67, 41 and 52 in HLA-A alleles; codons 133, 156, 201 and 215 in HLA-B alleles; codons 74, 208 and 225 in HLA-C; codons 25, 32 and 72 in HLA-DRB1; codons 20, 39 and 77 in HLA-DQB1.


Asunto(s)
Alelos , Sitios Genéticos/fisiología , Antígenos HLA-A/genética , Antígenos HLA-B/genética , Antígenos HLA-C/genética , Cadenas beta de HLA-DP/genética , Cadenas beta de HLA-DQ/genética , Cadenas HLA-DRB1/genética , Donantes de Tejidos , Sustitución de Aminoácidos , China , Codón/genética , Femenino , Humanos , Masculino , Programas Nacionales de Salud , Polimorfismo Genético
5.
Maturitas ; 29(3): 215-24, 1998 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-9699192

RESUMEN

Many women approach menopause with uncertainty about what will happen and how to deal with changes that occur. The current study aimed to evaluate the short-term outcome of a health education intervention devised to prepare 45-year old women in general practices. One hundred and seventy-eight 45-year old women registered at five general practices in south London were targeted for the research; 106 of the women responded and 86 of these women formed a usable pre-menopausal sample which was randomly allocated to the preparation intervention and control conditions. Preparation involved two health education sessions carried out in small groups and covering information and discussion of the normal menopause transition in the context of mid-life. The women completed pre- and post-intervention (3 and 15 months) questionnaires which assessed knowledge and beliefs about menopause and a number of health-related behaviours. Knowledge improved significantly at the follow-up assessments for the preparation group but not for the control group. On the whole, the prepared women's beliefs about menopause became less negative following the intervention, although there were also some changes reported by the control group. The proportion of smokers decreased from 25 to 20% for the prepared women although this did not reach statistical significance. There was no change in the prevalence of regular exercise. There was also a decrease in the intention to take hormonal treatments following the intervention. Suggestions for further development of health promotion services for mid-aged women and more holistic health care practices are proposed.


Asunto(s)
Educación en Salud , Menopausia , Medicina Familiar y Comunitaria , Femenino , Estudios de Seguimiento , Conocimientos, Actitudes y Práctica en Salud , Humanos , Londres , Persona de Mediana Edad , Evaluación de Programas y Proyectos de Salud , Estudios Prospectivos , Resultado del Tratamiento
6.
Acta Neurol Scand ; 98(1): 41-8, 1998 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9696526

RESUMEN

OBJECTIVES: Our study was designed to clarify the role of the thalamus in the generation of the electrically elicited long-latency reflexes (LLR) in voluntarily activated hand muscles. MATERIALS AND METHODS: EMG responses of the thenar muscles were evoked by electrical stimulation of the median nerve at the wrist at motor threshold intensity in 10 patients with acute pure sensory stroke due to thalamic infarction. Concomitant recording of somatosensory evoked potentials (SEPs) was performed. The subjects were asked to steadily abduct the thumb at 20-30% of maximal force against a force transducer. Rectified and averaged EMG activities were recorded. RESULTS: The LLR II was missing completely or significantly attenuated in the majority of the patients (9 of 10), of whom 3 also had delayed latency. Abnormal SEPs were documented in 7 patients (7 of 10). In the follow-up, 5 patients had partial reversal of LLR II. LLR II was still pathological in 1 fully recovered patient. CONCLUSION: Our results further confirm the transcortical generation of LLR II and imply that a thalamic relay is present in the afferent limb of the LLR.


Asunto(s)
Infarto Cerebral/diagnóstico , Potenciales Evocados Somatosensoriales/fisiología , Contracción Isométrica/fisiología , Tiempo de Reacción/fisiología , Reflejo de Estiramiento/fisiología , Trastornos de la Sensación/diagnóstico , Enfermedades Talámicas/diagnóstico , Adulto , Vías Aferentes/fisiopatología , Anciano , Infarto Cerebral/fisiopatología , Electromiografía , Femenino , Mano/inervación , Humanos , Masculino , Nervio Mediano/fisiopatología , Persona de Mediana Edad , Valores de Referencia , Trastornos de la Sensación/fisiopatología , Enfermedades Talámicas/fisiopatología , Tálamo/irrigación sanguínea , Tálamo/fisiopatología
7.
Acta Neurol Scand ; 98(6): 412-21, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9875620

RESUMEN

OBJECTIVES: We used an electrical conditioning stimulation followed by transcranial magnetic stimulation (TMS) to facilitate the occurrence of long latency potentials (LLPs) in order to study the relationship between primary motor evoked potentials (MEPs) and LLPs in the lower limbs. MATERIALS AND METHODS: The study group included 6 healthy subjects, 1 patient with right thalamic infarction, and 3 patients with spinal cord injuries. The subjects were subjected to electrical conditioning (C) stimulation delivered to the left big toe at 250 Hz in a train of pulses of 20 ms duration prior to TMS (T) from 0 to 150 ms at an increment of 10 ms. The surface electromyographic signals were recorded at the tibialis anterior and gastrocnemius medialis for 400 ms. RESULTS: The C-T test facilitated both primary MEPs and LLPs with a pattern similar to the primary MEPs of its antagonist. There was no facilitation of the primary MEPs or LLPs in the affected limb of patients with thalamic or spinal cord lesions. CONCLUSION: At appropriate C-T interval, LLPs could be consistently provoked by TMS. The LLPs were absent in the patients with thalamic infarction and spinal cord injuries. It suggests that LLPs might be provoked through a supraspinal control.


Asunto(s)
Condicionamiento Psicológico/fisiología , Potenciales Evocados Motores/fisiología , Pierna/fisiología , Tiempo de Reacción/fisiología , Adulto , Anciano , Infarto Cerebral/fisiopatología , Campos Electromagnéticos , Electromiografía , Femenino , Humanos , Masculino , Contracción Muscular/fisiología , Músculo Esquelético/fisiología , Umbral Sensorial/fisiología , Traumatismos de la Médula Espinal/fisiopatología , Tálamo/irrigación sanguínea , Tálamo/fisiología , Estimulación Eléctrica Transcutánea del Nervio
8.
J Biol Chem ; 270(20): 12123-32, 1995 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-7744861

RESUMEN

A tyrosine phosphatase, i.e. PTPase HA2, was previously isolated from 3T3-L1 cells and characterized using O-phospho Tyrosine19-422/aP2 protein (a target of the insulin receptor tyrosine kinase) as substrate. The nucleotide sequence of a PTPase HA2 cDNA showed it to be a homologue of PTPase 1B. When induced to differentiate into adipocytes, confluent 3T3-L1 preadipocytes undergo mitotic clonal expansion followed by growth arrest and then coordinate expression of adipocyte genes. During clonal expansion, expression of PTPase HA2 increases abruptly and then decreases concomitant with the transcriptional activation of adipocyte genes. Constitutive expression of the PTPase by 3T3-L1 preadipocytes using a PTPase HA2 expression vector prevents adipocyte gene expression and differentiation into adipocytes. Appropriately timed exposure of transfected preadipocytes to vanadate (a PTPase inhibitor), just as clonal expansion ceases restores their capacity to differentiate. Treatment of transfected preadipocytes with vanadate prior to or during clonal expansion fails to reverse PTPase HA2-blocked differentiation, whereas treatment of untransfected preadipocytes during mitotic clonal expansion blocks differentiation. Vanadate added following clonal expansion has no effect on differentiation. Thus, a critical tyrosine phosphorylation event(s) occurs between termination of clonal expansion and initiation of adipocyte gene expression while a critical tyrosine dephosphorylation event(s) occurs during clonal expansion.


Asunto(s)
Células 3T3/efectos de los fármacos , Tejido Adiposo/citología , Proteínas de la Membrana/antagonistas & inhibidores , Procesamiento Proteico-Postraduccional , Proteínas Tirosina Fosfatasas/antagonistas & inhibidores , Vanadatos/farmacología , Células 3T3/citología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Diferenciación Celular/efectos de los fármacos , Clonación Molecular , ADN Complementario/genética , Inducción Enzimática , Vectores Genéticos , Proteínas de la Membrana/genética , Proteínas de la Membrana/fisiología , Ratones , Datos de Secuencia Molecular , Mapeo Peptídico , Fosforilación , Proteína Tirosina Fosfatasa no Receptora Tipo 1 , Proteínas Tirosina Fosfatasas/genética , Proteínas Tirosina Fosfatasas/fisiología , Proteínas Recombinantes de Fusión/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Triglicéridos/metabolismo
9.
Biochem Biophys Res Commun ; 208(3): 1008-15, 1995 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-7702599

RESUMEN

A cDNA encoding a novel insulin-activated adipocyte amino acid transporter (designated AAAT) was cloned from a mouse 3T3-L1 adipocyte library. The deduced amino acid sequence of the cDNA corresponds to a protein of 553 amino acids that possesses 56% amino acid sequence identity to the human neutral amino acid transporter and 42% identity to the rat brain glutamate transporter. Transient transfection of 3T3-L1 preadipocytes with an AAAT expression vector led to insulin-dependent uptake of L-serine and to a lesser extent, uptake of L-alanine and L-glutamate. Expression of the AAAT message is tissue-specific, with the highest level occurring in mouse adipose tissue and a lower level in lung. Unlike other sodium-dependent amino acid transporter mRNAs, the AAAT message is not expressed in brain, kidney, liver or heart and only traces are detected in spleen, thymus and skeletal muscle. Consistent with its high level in adipose tissue, expression of the AAAT message is markedly increased when 3T3-L1 preadipocytes are induced to differentiate into adipocytes.


Asunto(s)
Adipocitos/citología , Proteínas Portadoras/biosíntesis , Expresión Génica/efectos de los fármacos , Insulina/farmacología , Células 3T3 , Adipocitos/metabolismo , Alanina/metabolismo , Secuencia de Aminoácidos , Sistemas de Transporte de Aminoácidos , Aminoácidos/metabolismo , Animales , Secuencia de Bases , Transporte Biológico , Northern Blotting , Proteínas Portadoras/metabolismo , Diferenciación Celular , Clonación Molecular , ADN Complementario , Ratones , Datos de Secuencia Molecular , Especificidad de Órganos , ARN Mensajero/análisis , ARN Mensajero/biosíntesis , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/metabolismo , Homología de Secuencia de Aminoácido , Transcripción Genética , Transfección
10.
J Surg Res ; 53(4): 349-56, 1992 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1405616

RESUMEN

Calcification is a major cause of glutaraldehyde-fixed bioprosthetic valve failure. Recent studies have shown that dystrophic calcification shares basic features with normal bone mineralization, including crystal initiation through the mediation of cell membranes, usually in the form of extracellular vesicles. In this study, we observed that calcification of the myocardium of DBA/2J mice was inhibited or reversed by diets supplemented with 100 mg/kg diet diphenylhydantoin (dilantin) for 70 days, with a calcification incidence of 25% in the dilantin group versus 58% in control. We further studied the effects of dilantin on bioprosthetic valve calcification. Three groups of young male Sprague-Dawley rats (100 g, 9/group) were implanted subcutaneously with 1-cm2 pieces of glutaraldehyde-fixed bovine pericardium. Controls were fed a ground chow for 45 or 90 days postimplantation; experimentals received the same chow for the first 45 days postimplantation and then were fed the same diet supplemented with 1000 mg dilantin/kg for the succeeding 45 days. Calcium content (microgram/mg dry weight) of the implants in the dilantin group was 137 +/- 18.6 versus 214 +/- 34.3 in 90 days control and 79.9 +/- 41.5 in 45 days control (mean +/- SD, P < 0.01 and P < 0.05 respectively, t test). The tibia calcium content of the dilantin group was not significantly different from 90 days control. We conclude that orally administered dilantin inhibits calcification of glutaraldehyde-fixed bovine pericardial implants preferentially. It does not cause decalcification either of implants that have already calcified or of the bones. The anti-calcification effect of dilantin may be associated with its anti-vitamin D effect.


Asunto(s)
Bioprótesis , Calcinosis/prevención & control , Cardiomiopatías/prevención & control , Fenitoína/uso terapéutico , Animales , Peso Corporal/efectos de los fármacos , Calcificación Fisiológica/efectos de los fármacos , Bovinos , Fijadores , Glutaral , Masculino , Ratones , Ratones Endogámicos DBA , Pericardio , Fenitoína/farmacología , Ratas , Ratas Sprague-Dawley
13.
Can J Anaesth ; 39(1): 79-82, 1992 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-1346370

RESUMEN

The neuromuscular effects of ketamine, at cumulative doses of 2.5 and 10 mg.kg-1 iv, were studied by electromyographically quantifying the thumb response evoked by ulnar nerve stimulation in 25 monkeys anaesthetized with pentobarbital-N2O-O2. Ketamine alone at these doses had no neuromuscular effects. When the EMG response was maintained at 50% of control by a continuous infusion of magnesium, vecuronium, or pancuronium, ketamine depressed the responses by an additional 13 +/- 3%, 34 +/- 7% and 32.5 +/- 3.3% (mean +/- SEM), respectively, at the highest dose, P less than 0.05. In contrast, ketamine had no effect on the neuromuscular block produced by incremental doses of alpha-bungarotoxin. These results indicate that ketamine does not act on the postjunctional acetylcholine receptor. It plays a secondary role in neuromuscular block, possibly by prejunctional or postjunctional effects independent of receptor occupation.


Asunto(s)
Bungarotoxinas/farmacología , Ketamina/farmacología , Sulfato de Magnesio/farmacología , Unión Neuromuscular/efectos de los fármacos , Pancuronio/farmacología , Bromuro de Vecuronio/farmacología , Animales , Depresión Química , Macaca
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