Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
1.
J Exp Biol ; 216(Pt 18): 3522-30, 2013 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-23737563

RESUMO

To investigate whether mechanoreception is used in non-visual feeding in larval striped bass (Morone saxatilis), the ontogeny of superficial neuromasts along the lateral line was described using the vital stain FM1-43FX and fluorescent microscopy. The number of neuromasts visible along one flank increased from 11 at first feeding [5 to 7 days post-hatch (dph)] to >150 by the juvenile stage (27 dph). A neomycin dose response (0, 1, 2 and 5 mmol l(-1)) was evaluated for neuromast ablation of bass aged 10, 13, 17 and 20 dph. Using these same age groups, the ability of bass to catch Artemia salina prey in both dark and light tank-based feeding trials was compared between larvae with neuromasts ablated using neomycin (5 mmol l(-1)) and controls. Neomycin significantly reduced the incidence of feeding in the light and dark. Among larvae that fed, those in the dark treated with neomycin caught fewer Artemia (~5 prey h(-1); P<0.05) than controls (16 prey h(-1) at 10 dph; 72 prey h(-1) at 20 dph). In the light, by contrast, neomycin treatment had no significant effect on prey capture by larvae age 13 to 20 dph, but did inhibit feeding of 10 dph larvae. Verification that neomycin was specifically ablating the hair cells of superficial neuromasts and not affecting either neuromast innervation, olfactory pits, or taste cells was achieved by a combination of staining with FM1-43FX and immunocytochemistry for tubulin and the calcium binding proteins, S100 and calretinin.


Assuntos
Bass/fisiologia , Comportamento Alimentar , Sistema da Linha Lateral/citologia , Animais , Artemia/fisiologia , Comportamento Alimentar/efeitos dos fármacos , Células Ciliadas Auditivas/citologia , Células Ciliadas Auditivas/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/fisiologia , Sistema da Linha Lateral/efeitos dos fármacos , Sistema da Linha Lateral/inervação , Neomicina/farmacologia , Comportamento Predatório/efeitos dos fármacos , Olfato/efeitos dos fármacos , Paladar/efeitos dos fármacos , Visão Ocular/efeitos dos fármacos
2.
Health Technol Assess ; 23(48): 1-114, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31532358

RESUMO

BACKGROUND: Invasive mechanical ventilation (IMV) is a life-saving intervention. Following resolution of the condition that necessitated IMV, a spontaneous breathing trial (SBT) is used to determine patient readiness for IMV discontinuation. In patients who fail one or more SBTs, there is uncertainty as to the optimum management strategy. OBJECTIVE: To evaluate the clinical effectiveness and cost-effectiveness of using non-invasive ventilation (NIV) as an intermediate step in the protocolised weaning of patients from IMV. DESIGN: Pragmatic, open-label, parallel-group randomised controlled trial, with cost-effectiveness analysis. SETTING: A total of 51 critical care units across the UK. PARTICIPANTS: Adult intensive care patients who had received IMV for at least 48 hours, who were categorised as ready to wean from ventilation, and who failed a SBT. INTERVENTIONS: Control group (invasive weaning): patients continued to receive IMV with daily SBTs. A weaning protocol was used to wean pressure support based on the patient's condition. Intervention group (non-invasive weaning): patients were extubated to NIV. A weaning protocol was used to wean inspiratory positive airway pressure, based on the patient's condition. MAIN OUTCOME MEASURES: The primary outcome measure was time to liberation from ventilation. Secondary outcome measures included mortality, duration of IMV, proportion of patients receiving antibiotics for a presumed respiratory infection and health-related quality of life. RESULTS: A total of 364 patients (invasive weaning, n = 182; non-invasive weaning, n = 182) were randomised. Groups were well matched at baseline. There was no difference between the invasive weaning and non-invasive weaning groups in median time to liberation from ventilation {invasive weaning 108 hours [interquartile range (IQR) 57-351 hours] vs. non-invasive weaning 104.3 hours [IQR 34.5-297 hours]; hazard ratio 1.1, 95% confidence interval [CI] 0.89 to 1.39; p = 0.352}. There was also no difference in mortality between groups at any time point. Patients in the non-invasive weaning group had fewer IMV days [invasive weaning 4 days (IQR 2-11 days) vs. non-invasive weaning 1 day (IQR 0-7 days); adjusted mean difference -3.1 days, 95% CI -5.75 to -0.51 days]. In addition, fewer non-invasive weaning patients required antibiotics for a respiratory infection [odds ratio (OR) 0.60, 95% CI 0.41 to 1.00; p = 0.048]. A higher proportion of non-invasive weaning patients required reintubation than those in the invasive weaning group (OR 2.00, 95% CI 1.27 to 3.24). The within-trial economic evaluation showed that NIV was associated with a lower net cost and a higher net effect, and was dominant in health economic terms. The probability that NIV was cost-effective was estimated at 0.58 at a cost-effectiveness threshold of £20,000 per quality-adjusted life-year. CONCLUSIONS: A protocolised non-invasive weaning strategy did not reduce time to liberation from ventilation. However, patients who underwent non-invasive weaning had fewer days requiring IMV and required fewer antibiotics for respiratory infections. FUTURE WORK: In patients who fail a SBT, which factors predict an adverse outcome (reintubation, tracheostomy, death) if extubated and weaned using NIV? TRIAL REGISTRATION: Current Controlled Trials ISRCTN15635197. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 48. See the NIHR Journals Library website for further project information.


Patients who become very unwell may require help from a breathing machine. This requires the patient to be given drugs to put them to sleep (sedation) and have a tube placed through their mouth directly into the windpipe (tube ventilation). This can be life-saving, but may cause harm if used for long periods of time. Non-invasive ventilation (mask ventilation) provides breathing support through a mask that covers the face. Mask ventilation has several advantages over tube ventilation, such as less need for sedation, and it enables the patient to cough and communicate. In previous studies, switching patients from tube to mask ventilation when they start to get better seemed to improve survival rates and reduce complications. The Breathe trial tested if using a protocol to remove tube ventilation and replace it with mask ventilation is better than continuing with tube ventilation until the patient no longer needs breathing machine support. The trial recruited 364 patients. Half of these patients were randomly selected to have the tube removed and replaced with mask ventilation and half were randomly selected to continue with tube ventilation until they no longer needed breathing machine support. The mask group spent 3 fewer days receiving tube ventilation, although the overall time needing breathing machine help (mask and tube) did not change. Fewer patients in the mask group needed antibiotics for chest infections. After removing the tube, twice as many patients needed the tube again in the mask group as in the tube group. There were no differences between the groups in the number of adverse (harm) events or the number of patients who survived to leave hospital. Mask ventilation was no more expensive than tube ventilation. In conclusion, mask ventilation may be an effective alternative to continued tube ventilation when patients start to get better in intensive care.


Assuntos
Unidades de Terapia Intensiva , Ventilação não Invasiva , Respiração Artificial , Resultado do Tratamento , Desmame do Respirador , Análise Custo-Benefício , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Avaliação da Tecnologia Biomédica , Reino Unido
3.
J Pharm Biomed Anal ; 35(1): 117-26, 2004 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-15030886

RESUMO

We describe the application of 1H NMR spectroscopy and chemometrics to the analysis of extracts of Artemisia annua. This approach allowed the discrimination of samples from different sources, and to classify them according to anti-plasmodial activity without prior knowledge of this activity. The use of partial least squares analysis allowed the prediction of actual values for anti-plasmodial activities for independent samples not used in producing the models. The models were constructed using approximately 70% of the samples, with 30% used as a validation set for which predictions were made. Models generally explained >90% of the variance, R(2) in the model, and had a predictive ability, Q(2) of >0.8. This approach was also able to correlate 1H NMR spectra with cytotoxicity (R2=0.9, Q2=0.8). This work demonstrates the potential of NMR spectroscopy and chemometrics for the development of predictive models of anti-plasmodial activity.


Assuntos
Antiprotozoários , Artemisia annua/química , Plasmodium falciparum/efeitos dos fármacos , Animais , Antiprotozoários/isolamento & purificação , Antiprotozoários/farmacologia , Antiprotozoários/toxicidade , Artemisininas/isolamento & purificação , Artemisininas/farmacologia , Artemisininas/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Espectroscopia de Ressonância Magnética , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Extratos Vegetais/toxicidade , Valor Preditivo dos Testes , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Sesquiterpenos/toxicidade
4.
J Ethnopharmacol ; 90(1): 33-8, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14698505

RESUMO

The SRB assay was used to test cytotoxicity against three human cancer cell lines and one normal cell line of 11 Thai medicinal plant species used by traditional doctors in treating cancer patients. The extraction procedures used were similar to those practised by Thai traditional doctors (ethanolic and water extracts). Extracts were tested against the human large cell lung carcinoma cell line COR-L23, the human breast adenocarcinoma cell line MCF-7 and human colon adenocarcinoma cell line LS-174T and normal human keratinocytes SVK-14. The results showed that three plants; Dioscorea membranacea Pierre ex Prain & Burkill, Dioscorea birmanica Prain & Burkill (Dioscoreaceae) and Siphonodon celastrineus Griff. (Celastraceae), exhibited high cytotoxic activity showing a certain degree of selectivity against the different cell types.


Assuntos
Extratos Vegetais/farmacologia , Plantas Medicinais , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Tailândia
5.
Planta Med ; 68(8): 734-8, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12221598

RESUMO

There is increasing interest in evaluating the clinical efficacy of herbal medicines. However, there are significant analytical problems associated with quality control and the measurement of the overall composition of such complex, multi-component mixtures as normally required in the pharmaceutical industry. Here we describe a novel NMR spectroscopic and pattern recognition analytical approach to investigate composition and variability of a commonly used herbal medicine. 600 MHz (1)H-NMR spectroscopy and principal components analysis (PCA) was used to discriminate between batches of 14 commercially available feverfew samples based on multi-component metabolite profiles. Two of the batches were significantly different from the other twelve. The twelve remaining classes could be classified into discrete groups by PCA on the basis of minor differences in overall chemical composition. NMR based pattern recognition (PR) analysis of extracts proved to be superior to PR analysis of HPLC traces of the same mixtures. This work indicates the potential value of NMR combined with PCA for the characterisation of complex natural product mixtures, and the discrimination of samples containing allegedly identical ingredients.


Assuntos
Química Farmacêutica/métodos , Espectroscopia de Ressonância Magnética , Extratos Vegetais/química , Plantas Medicinais/química , Tanacetum parthenium/química , Cromatografia Líquida de Alta Pressão , Controle de Qualidade
6.
Phytother Res ; 16(1): 33-5, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11807962

RESUMO

Three acylated iridoid glycosides (E)-6-O-(2", 4"-diacetyl-3" -O-p-methoxycinnamoyl)-alpha-L-rhamnopyranosyl catalpol (scopolioside A) (1), (E)-6-O-(2"-acetyl-3", 4"-di-O,O-p-methoxycinnamoyl)-alpha-L-rhamnopyranosyl catalpol (scrophuloside A(4)) (2) and (E)-6-O-(2",3"-diacetyl-4"-O-p-methoxycinnamoyl)-alpha-L-rhamnopyranosyl catalpol (scrovalentinoside) (3) have been isolated from the dried seed pods of Scrophularia nodosa by HPLC. Their structures were determined by 1D and 2D NMR, UV/Vis and mass spectroscopy and by comparison with published data. All three compounds were shown in vitro to stimulate the growth of human dermal fibroblasts. The effect was negatively dose-dependent for 2 and 3 for which fibroblast growth stimulation was highest at 0.78 microg/mL but was not significantly different from the control at 100 microg/mL. The presence of these compounds in the mature seed pods may explain the ethnobotanical use of this plant in Europe for healing wounds.


Assuntos
Cinamatos/farmacologia , Glucosídeos/farmacologia , Glicosídeos/farmacologia , Iridoides/farmacologia , Piranos/farmacologia , Scrophulariaceae , Cicatrização/efeitos dos fármacos , Sequência de Carboidratos , Linhagem Celular , Cinamatos/química , Cinamatos/isolamento & purificação , Relação Dose-Resposta a Droga , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Glucosídeos/química , Glucosídeos/isolamento & purificação , Glicosídeos/química , Glicosídeos/isolamento & purificação , Humanos , Glucosídeos Iridoides , Glicosídeos Iridoides , Iridoides/isolamento & purificação , Dados de Sequência Molecular , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Piranos/química , Piranos/isolamento & purificação
7.
Planta Med ; 70(3): 250-5, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15114503

RESUMO

In order to improve the accuracy and consistency of control phytomedicine preparations worldwide, regulatory authorities are requesting research into new analytical methods for the stricter standardisation of phytomedicines. Such methods have to be both objective and robust, and should address the reproducibility of the content of the chemical profiles. NMR-based metabolomics, which combines high-resolution (1)H-NMR spectroscopy with chemometric analysis, has been employed as an innovative way to meet those demands. In this paper, chamomile flowers from three different geographical regions, namely, Egypt, Hungary and Slovakia were characterised using 1H-NMR spectroscopy followed by principal component analysis. It was found that the origin, purity and preparation methods contributed to the differences observed in prepared chamomile extracts. In addition, this method also enabled the elucidation of the molecular information embedded in the spectra responsible for the observed variability. The metabolomic strategy employed in the current study should provide an efficient tool for the quality control and authentication of phytomedicines.


Assuntos
Matricaria , Fitoterapia , Extratos Vegetais/química , Flores , Humanos , Espectroscopia de Ressonância Magnética , Fitoterapia/normas , Controle de Qualidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA