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1.
Exp Appl Acarol ; 79(2): 187-194, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31598890

RESUMO

A choice test bioassay was devised to screen compounds as potential semiochemicals (e.g., kairomones or allomones that mediate aggregation, attraction or repellence) for the obligate parasitic mite, Psoroptes ovis. The choice test used filter paper discs in a 1:4 test:control ratio and was found to be a reliable, effective and efficient method. Four mammalian lipid components were assessed as potential attractants-linoleic acid, arachidonic acid, methyl myristate and squalene-, and the insect/tick repellent DEET for potential repellence. Linoleic acid was significantly attractive to P. ovis adult females and has the potential to act as an attractant. Identification of P. ovis semiochemicals, especially attractants, would be beneficial in the development of novel control methods and tools for this species. This is essential considering the increase in resistance to the limited prophylactic chemical treatments in the UK, and the high prevalence of scab infections.


Assuntos
Quimiotaxia , Lipídeos/análise , Infestações por Ácaros/veterinária , Substâncias Protetoras/análise , Psoroptidae/fisiologia , Doenças dos Ovinos/prevenção & controle , Controle de Ácaros e Carrapatos/métodos , Animais , Feminino , Infestações por Ácaros/prevenção & controle , Ovinos
2.
HIV Med ; 16(7): 449-54, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25959989

RESUMO

OBJECTIVES: Pre-antiretroviral therapy (ART) inflammation and coagulation activation predict clinical outcomes in HIV-positive individuals. We assessed whether pre-ART inflammatory marker levels predicted the CD4 count response to ART. METHODS: Analyses were based on data from the Strategic Management of Antiretroviral Therapy (SMART) trial, an international trial evaluating continuous vs. interrupted ART, and the Flexible Initial Retrovirus Suppressive Therapies (FIRST) trial, evaluating three first-line ART regimens with at least two drug classes. For this analysis, participants had to be ART-naïve or off ART at randomization and (re)starting ART and have C-reactive protein (CRP), interleukin-6 (IL-6) and D-dimer measured pre-ART. Using random effects linear models, we assessed the association between each of the biomarker levels, categorized as quartiles, and change in CD4 count from ART initiation to 24 months post-ART. Analyses adjusted for CD4 count at ART initiation (baseline), study arm, follow-up time and other known confounders. RESULTS: Overall, 1084 individuals [659 from SMART (26% ART naïve) and 425 from FIRST] met the eligibility criteria, providing 8264 CD4 count measurements. Seventy-five per cent of individuals were male with the mean age of 42 years. The median (interquartile range) baseline CD4 counts were 416 (350-530) and 100 (22-300) cells/µL in SMART and FIRST, respectively. All of the biomarkers were inversely associated with baseline CD4 count in FIRST but not in SMART. In adjusted models, there was no clear relationship between changing biomarker levels and mean change in CD4 count post-ART (P for trend: CRP, P = 0.97; IL-6, P = 0.25; and D-dimer, P = 0.29). CONCLUSIONS: Pre-ART inflammation and coagulation activation do not predict CD4 count response to ART and appear to influence the risk of clinical outcomes through other mechanisms than blunting long-term CD4 count gain.


Assuntos
Fármacos Anti-HIV/administração & dosagem , Infecções por HIV/imunologia , Inflamação/sangue , Adulto , Biomarcadores/sangue , Coagulação Sanguínea/imunologia , Proteína C-Reativa/imunologia , Contagem de Linfócito CD4 , Progressão da Doença , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/imunologia , Infecções por HIV/sangue , Infecções por HIV/tratamento farmacológico , Humanos , Interleucina-6/imunologia , Masculino , Valor Preditivo dos Testes , Estudos Retrospectivos , Fatores de Risco
3.
Food Chem ; 141(4): 3531-6, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-23993517

RESUMO

Binding products or food 'glues' are used throughout the food industry to increase the meat use rate or to augment economic efficiency. Some of these binders contain thrombin from bovine and porcine blood. The European parliament has recently banned thrombin-based additives and labelling legislation governs their use in the US. A mass spectrometry screening method is available to detect the addition of thrombin agents to foods as there is a need to protect consumers and to avoid misleading trade practices. We report the details of an inter-laboratory trial to determine the transferability of this method to operators in various food testing laboratories, each using a different triple quadrupole mass spectrometer design. The trial was successful with the species origin of the binding agent contained in each of the 43 test materials being correctly reported by the participants. This is consistent with a false positive and false negative rate of 0%. This is the first collaborative study, as far as we are aware, which involves a liquid chromatography mass spectrometry (LC-MS/MS) application to approach a food authenticity issue.


Assuntos
Proteínas Sanguíneas/análise , Produtos Pesqueiros/análise , Aditivos Alimentares/análise , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Carne/análise , Animais , Bovinos , Peptídeos/química , Ovinos , Suínos
4.
Artigo em Inglês | MEDLINE | ID: mdl-21240827

RESUMO

The use of steroids as growth-promoting agents in food production is banned under European Union legislation. Detecting the abuse of testosterone, nandrolone, boldenone, oestradiol and progesterone is complicated by the fact that these steroids are known to be endogenous in certain situations. In this study, the concentrations of characteristic metabolites of each of these steroids were quantified in populations of untreated steers and heifers. Steroid concentration population data were then used by a statistical model (the Chebyshev inequality) to produce threshold concentrations for screening and confirming the abuse of these steroids in steer and non-pregnant heifer urine. In addition to thresholds based on testing one animal (a '1 out of 1' approach), new methods based on testing multiple animals from a herd (a 'y out of n' approach) allowed threshold concentrations to be significantly reduced and hence false compliances to be minimised. In the majority of cases, the suggested thresholds were found to be capable of confirming the abuse of endogenous steroids in steers and heifers. In the case of oestradiol abuse in the female, however, confirmation based on a threshold is not possible and alternative methods such as gas chromatography-combustion-isotope ratio mass spectrometry are required. In addition to the steer and heifer populations, a small number of pregnant animals were also tested, yielding insights into the biosynthetic pathways of some of the steroids.


Assuntos
Esteroides/administração & dosagem , Animais , Calibragem , Bovinos , Creatinina/urina , Feminino , Limite de Detecção , Reino Unido
5.
Thorac Cardiovasc Surg ; 58(8): 459-62, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21110267

RESUMO

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) can be instituted centrally, through the right atrium and ascending aorta, or peripherally, most commonly using the femoral artery and vein. We sought to investigate the impact of the mode of cannulation on the incidence of limb ischemia, perfusion and overall morbidity. METHODS: A retrospective analysis of 50 consecutive patients over 5 years who underwent ECMO by central or peripheral cannulation was performed. RESULTS: There was no difference in the incidence of limb ischemia and end-organ perfusion when peripheral and central cannulation cohorts were compared. Central cannulation was associated with a higher incidence of bleeding from the cannulation site (64% vs. 18%, P = 0.002), blood product utilization and reoperation (66% vs. 14%, P < 0.0001). 30-day mortality was similar in both cohorts (46% peripheral, 50% central, P = 0.8). CONCLUSION: Our results suggest that there is comparable tissue perfusion and limb ischemia with both cannulation techniques. Central cannulation is associated with a higher incidence of bleeding, higher transfusion rates, a greater need for reoperation and greater resource utilization. Therefore, peripheral cannulation is safe and may be advantageous in certain clinical scenarios.


Assuntos
Transfusão de Sangue , Cateterismo Cardíaco , Cateterismo Periférico , Oxigenação por Membrana Extracorpórea/métodos , Extremidades/irrigação sanguínea , Hemorragia/terapia , Isquemia/etiologia , Adulto , Idoso , Transfusão de Sangue/mortalidade , Cateterismo Cardíaco/efeitos adversos , Cateterismo Cardíaco/mortalidade , Cateterismo Periférico/efeitos adversos , Cateterismo Periférico/mortalidade , Oxigenação por Membrana Extracorpórea/efeitos adversos , Oxigenação por Membrana Extracorpórea/mortalidade , Feminino , Artéria Femoral , Veia Femoral , Hemorragia/etiologia , Hemorragia/mortalidade , Humanos , Incidência , Isquemia/mortalidade , Isquemia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fluxo Sanguíneo Regional , Reoperação , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
6.
Cancer Chemother Pharmacol ; 66(2): 389-94, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20480279

RESUMO

PURPOSE: Brostallicin is a DNA minor groove binder which shows enhanced antitumor activity in cells which are resistant to several anticancer agents due to their high glutathione S-transferase (GST)/glutathione content. Phase I and II clinical trials of single-agent brostallicin have shown that myelotoxicity is the dose-limiting toxicity (DLT), while hints of antitumor activity were mainly observed in soft tissue sarcoma. Preclinical studies showing a more than additive antitumor effect of the cisplatin-brostallicin combination paved the way to clinical combination studies. In particular, we set up the first clinical combination study of brostallicin and cisplatin in patients with advanced solid tumors. This study was to be followed by a phase II study in patients with recurrent squamous cell carcinoma of the head and neck (SCCHN). METHODS: Escalating doses of brostallicin were administered in combination with a fixed dose of cisplatin (75 mg/m(2)) in patients with recurrent or metastatic advanced solid tumors who had previously received a cumulative dose of cisplatin not higher than 475 mg/m(2). The recommended dose of brostallicin was expanded in order to have a better estimate of antitumor activity and to better define the safety profile of the combination. RESULTS: Twenty-one patients were treated. Two DLTs (grade 3 fatigue and febrile neutropenia) were observed at dose level 3 (brostallicin 9 mg/m(2)). Dose level 2 (brostallicin 7 mg/m(2) and cisplatin 75 mg/m(2)) was recommended for future phase II studies. Main toxicity was hematologic; in fact, only 1 patient out of 21 did not develop neutropenia and only 2 patients did not have thrombocytopenia. Grade 3-4 neutropenia was observed in 90.5% of patients, grade 3-4 thrombocytopenia in 38.1%, grade 3-4 anemia in 23.8%. The cycle 1 nadir (ANC < 500 x 10(9)/L) for neutrophils was Day 14 (median; range 11-17) with recovery to an ANC of >1,500 3.5 days after nadir (median; range 2-4) at dose level 3. The cycle 1 nadir (median of 51,000 x 10(9)/L) for platelets occurred on Day 13 (median; range 10-15) with recovery to a platelet count of >100,000 4 days after nadir (median; range 2-8). No objective responses were observed, but seven patients had a long lasting (>18 weeks) stable disease. CONCLUSIONS: Further studies of the combination of brostallicin and cisplatin are warranted.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias/tratamento farmacológico , Idoso , Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Cisplatino/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Guanidinas/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Pirróis/administração & dosagem , Caracteres Sexuais
7.
Artigo em Inglês | MEDLINE | ID: mdl-19680936

RESUMO

A method for the determination of cyclamate has been developed and single-laboratory validated for a range of foodstuffs including carbonated and fruit-juice drinks, fruit preserves, spreads, and dairy desserts. The method uses the peroxide oxidation of cyclamate to cyclohexylamine followed by derivatization with trinitrobenzenesulfonic acid and analysis by a modified reversed-phase high-performance liquid chromatography-ultraviolet light (HPLC-UV). Cycloheptylamine is used as an internal standard. The limits of detection were in the range 1-20 mg kg(-1) and the analysis was linear up to 1300 mg kg(-1) cyclamic acid in foods and up to 67 mg l(-1) in beverages. Analytical recovery was between 82% and 123%, and results were recovery corrected. Precision was within experimentally predicted levels for all of the matrices tested and Horrat values for the combined standard uncertainty associated with the measurement of cyclamate between 0.4 (water-based drinks) and 1.7 (spreads). The method was used successfully to test three soft drink samples for homogeneity before analytical performance assessment. The method is recommended for use in monitoring compliance and for formal testing by collaborative trial.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Ciclamatos/análise , Análise de Alimentos/métodos , Edulcorantes/análise , Limite de Detecção , Oxirredução , Padrões de Referência , Reprodutibilidade dos Testes
8.
Artigo em Inglês | MEDLINE | ID: mdl-18608507

RESUMO

The accurate quantification of non-Basmati rice in Basmati rice is central to the successful prosecution of adulteration, where non-Basmati rice has been substituted for Basmati rice. The current method and three alternatives of constructing calibration curves for the measurement of non-Basmati rice in Basmati rice using microsatellite analysis were investigated. The methods compared involved power regression, linear regression (with and without log(10) transformation) and hyperbolic regression of the ratio of Basmati to non-Basmati peak areas. Assessments were made using error uncertainty, standard error at the agreed limit of adulteration, and 95% confidence intervals for five example data sets. The linear regression of the ratio of peak areas to the ratio of content proportions was found to give the most precise calibration and thus enhanced quantification of the level of adulteration of Basmati rice with non-Basmati rice.


Assuntos
DNA de Plantas/análise , Contaminação de Alimentos/análise , Repetições de Microssatélites , Oryza/genética , Calibragem , Contaminação de Alimentos/estatística & dados numéricos , Legislação sobre Alimentos , Especificidade da Espécie
9.
Food Addit Contam ; 24(6): 635-51, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17487605

RESUMO

A protocol for the measurement of 27 polycyclic aromatic hydrocarbons (PAHs) in vegetable oils by GC/MS has undergone single-laboratory validation. PAHs were measured in three oils (olive pomace, sunflower and coconut oil). Five samples of each oil (one unfortified, and four fortified at concentrations between 2 and 50 microg kg(-1)) were analysed in replicate (four times in separate runs). Two samples (one unfortified and one fortified at 2 microg kg(-1)) of five oils (virgin olive oil, grapeseed oil, toasted sesame oil, olive margarine and palm oil) were also analysed. The validation included an assessment of measurement bias from the results of 120 measurements of a certified reference material (coconut oil BCR CRM458 certified for six PAHs). The method is capable of reliably detecting 26 out of 27 PAHs, at concentration <2 microg kg(-1) which is the European Union maximum limit for benzo[a]pyrene, in vegetable oils, olive pomace oil, sunflower oil and coconut oil. Quantitative results were obtained that are fit for purpose for concentrations from <2 to 50 microg kg(-1) for 24 out of 27 PAHs in olive pomace oil, sunflower oil and coconut oil. The reliable detection of 2 microg kg(-1) of PAHs in five additional oils (virgin olive oil, grapeseed oil, toasted sesame oil, olive margarine and palm oil) has been demonstrated. The method failed to produce fit-for-purpose results for the measurement of dibenzo[a,h]pyrene, anthanthrene and cyclopenta[c,d]pyrene. The reason for the failure was the large variation in results. The likely cause was the lack of availability of (13)C isotope internal standards for these PAHs at the time of the study. The protocol has been shown to be fit-for-purpose and is suitable for formal validation by inter-laboratory collaborative study.


Assuntos
Contaminação de Alimentos/análise , Óleos de Plantas/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Óleo de Coco , Análise de Alimentos/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Azeite de Oliva , Óleo de Girassol
10.
Inf Sci (N Y) ; 177(18): 3749-3763, 2007 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-19562097

RESUMO

The primary goal of the study presented in this paper is to develop a novel and comprehensive approach to decision making using fuzzy discrete event systems (FDES) and to apply such an approach to real-world problems. At the theoretical front, we develop a new control architecture of FDES as a way of decision making, which includes a FDES decision model, a fuzzy objective generator for generating optimal control objectives, and a control scheme using both disablement and enforcement. We develop an online approach to dealing with the optimal control problem efficiently. As an application, we apply the approach to HIV/AIDS treatment planning, a technical challenge since AIDS is one of the most complex diseases to treat. We build a FDES decision model for HIV/AIDS treatment based on expert's knowledge, treatment guidelines, clinic trials, patient database statistics, and other available information. Our preliminary retrospective evaluation shows that the approach is capable of generating optimal control objectives for real patients in our AIDS clinic database and is able to apply our online approach to deciding an optimal treatment regimen for each patient. In the process, we have developed methods to resolve the following two new theoretical issues that have not been addressed in the literature: (1) the optimal control problem has state dependent performance index and hence it is not monotonic, (2) the state space of a FDES is infinite.

11.
Artigo em Inglês | MEDLINE | ID: mdl-16626985

RESUMO

We tested the hypothesis that immersion hypothermia enhances the diving capabilities of adult and juvenile muskrats by reducing rates of oxygen consumption (V O2). Declines in abdominal body temperature (T(b)) comparable to those observed in nature (0.5-3.5 degrees C) were induced by pre-chilling animals in 6 degrees C water. Pre-chilling did not reduce diving V O2 of any animal tested in 10 degrees C or 30 degrees C water, irrespective of the nature of the dive. Most behavioural indices of dive performance, including average and cumulative dive times, were unaffected by T(b) reduction in adults, but depressed in hypothermic juveniles (200-400 g). Hypothermia reduced diving heart rate only on short (<25s) dives (16% reduction, P=0.01), but did not affect the temporal onset of diving bradycardia. Post-immersion V O2 was higher for pre-chilled than for normothermic muskrats, but the difference became insignificant on longer (>90 s) dives. Our findings suggest that the mild hypothermia experienced by muskrats in nature has minimal effect on diving and post-immersion metabolic costs, and thus has little impact on the dive performance of this northern semi-aquatic mammal.


Assuntos
Aclimatação/fisiologia , Arvicolinae/fisiologia , Regulação da Temperatura Corporal/fisiologia , Mergulho/fisiologia , Hipotermia/fisiopatologia , Fatores Etários , Animais , Arvicolinae/metabolismo , Metabolismo Basal , Comportamento Animal , Temperatura Corporal , Débito Cardíaco , Feminino , Hipotermia/metabolismo , Hipotermia/reabilitação , Imersão/fisiopatologia , Masculino , Destreza Motora/fisiologia , Oxigênio/metabolismo
12.
Neurology ; 66(7): 1117-9, 2006 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-16606934

RESUMO

The authors conducted a randomized controlled trial to test the safety and immunology of glatiramer acetate in ALS. Twenty treated patients were randomly assigned to daily or biweekly injections. Ten control patients were selected from another trial and followed up concurrently. Injection reactions were the only common adverse event (p = 0.01). Treated patients showed enhanced lymphocyte proliferation (p = 0.02). The safety profile and immune effects support conducting larger trials of dose selection and efficacy.


Assuntos
Imunossupressores/uso terapêutico , Doença dos Neurônios Motores/tratamento farmacológico , Peptídeos/uso terapêutico , Esquema de Medicação , Acetato de Glatiramer , Humanos , Imunossupressores/toxicidade , Injeções/efeitos adversos , Ativação Linfocitária , Doença dos Neurônios Motores/imunologia , Peptídeos/administração & dosagem , Peptídeos/toxicidade , Linfócitos T/imunologia
13.
Int J Gynecol Cancer ; 16(1): 57-64, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16445611

RESUMO

The objectives of this study were to investigate the tolerability of a novel high-dose chemotherapy (HDC) regimen with peripheral blood progenitor cell (PBPC) support in patients with pretreated advanced ovarian cancer and to determine the maximum-tolerated dose (MTD) of topotecan in this setting. Advanced ovarian cancer patients previously treated with platinum-based first-line therapy were enrolled. After PBPC mobilization and harvesting, patients received three consecutive cycles of HDC with PBPC support. Cycle 1 was carboplatin area under the concentration curve 20 and paclitaxel 250 mg/m(2). Cycle 2 was topotecan starting at 5 mg/m(2), dose escalated in 2 mg/m(2) increments, and etoposide 600 mg/m(2). Cycle 3 was thiotepa 500 mg/m(2). After each cycle, PBPCs were infused. Granulocyte colony stimulating factor (5 microg/kg/day) was administered until neutrophil recovery occurred. Seventeen patients were enrolled; all were safety evaluable. The most common nonhematologic toxicity was grade 3 mucositis (44%). Engraftment of PBPCs was successful in all patients after each cycle, and no treatment-related deaths occurred. Of 14 patients with measurable disease, 5 (36%) had complete responses, 2 (14%) had partial responses, and 4 (29%) had stable disease. The median progression-free and overall survivals were 7 and 18 months, respectively. The MTD of topotecan was not reached. The tolerability and activity of this regimen in patients with advanced ovarian cancer warrant further investigation.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma/terapia , Transplante de Células-Tronco Hematopoéticas/métodos , Invasividade Neoplásica/patologia , Neoplasias Ovarianas/terapia , Terapia de Salvação , Adulto , Carcinoma/mortalidade , Carcinoma/patologia , Terapia Combinada , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Humanos , Dose Máxima Tolerável , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Ovarianas/mortalidade , Neoplasias Ovarianas/patologia , Paclitaxel/administração & dosagem , Prognóstico , Análise de Sobrevida , Tiotepa/administração & dosagem , Topotecan/administração & dosagem , Transplante Autólogo , Resultado do Tratamento
14.
Food Addit Contam ; 22(1): 31-8, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15895609

RESUMO

Field trials were initiated to investigate if extrapolation procedures, which were adopted to limit costs of pesticide registration for minor crops, are valid. Three pairs of crops of similar morphology; carrots/swedes, cauliflower/calabrese (broccoli) and French beans/edible-podded peas; were grown in parallel at four different geographical locations within the UK. The crops were treated with both systemic and non-systemic pesticides under maximum registered use conditions, i.e. the maximum permitted application rates and the minimum harvest intervals. Once mature, the crops were harvested and analysed for residues of the applied pesticides. The limits of quantification were in the range 0.005-0.02 mg kg(-1). Analysis of variance and bootstrap estimates showed that in general, the mean residue concentrations for the individual pesticides were significantly different between crop pairs grown on each site. Similarly, the mean residue concentrations of most of the pesticides in each crop across sites were significantly different. These findings demonstrate that the extrapolations of residue levels for most of the selected pesticide/crop combinations investigated; chlorfenvinphos and iprodione from carrots to swedes; carbendazim, chlorpyrifos, diflubenzuron and dimethoate from cauliflower to calabrese; and malathion, metalaxyl and pirimicarb from French beans to edible-podded peas; appear invalid.


Assuntos
Contaminação de Alimentos/análise , Resíduos de Praguicidas/análise , Verduras/química , Análise de Alimentos/métodos , Humanos , Concentração Máxima Permitida , Controle de Qualidade , Especificidade da Espécie
15.
J Comp Physiol B ; 175(2): 87-95, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15592850

RESUMO

Rates of O(2) consumption and CO(2) production, telemetered body temperature (T(b)) and activity level were recorded from adult and subadult water shrews (Sorex palustris) over an air temperature (T(a)) range of 3-32 degrees C. Digesta passage rate trials were conducted before metabolic testing to estimate the minimum fasting time required for water shrews to achieve a postabsorptive state. Of the 228 metabolic trials conducted on 15 water shrews, 146 (64%) were discarded because the criteria for inactivity were not met. Abdominal T(b) of S. palustris was independent of T(a) and averaged 38.64 +/- 0.07 degrees C. The thermoneutral zone extended from 21.2 degrees C to at least 32 degrees C. Our estimate of the basal metabolic rate for resting, postabsorptive water shrews (96.88 +/- 2.93 J g(-1) h(-1) or 4.84 +/- 0.14 ml O(2) g(-1) h(-1)) was three times the mass-predicted value, while their minimum thermal conductance in air (0.282 +/- 0.013 ml O(2) g(-1) h(-1)) concurred with allometric predictions. The mean digesta throughput time of water shrews fed mealworms (Tenebrio molitor) or ground meat was 50-55 min. The digestibility coefficients for metabolizable energy (ME) of water shrews fed stickleback minnows (Culaea inconstans) and dragonfly nymphs (Anax spp. and Libellula spp.) were 85.4 +/- 1.3% and 82.8 +/- 1.1%, respectively. The average metabolic rate (AMR) calculated from the gas exchange of six water shrews at 19-22 degrees C (208.0 +/- 17.0 J g(-1) h(-1)) was nearly identical to the estimate of energy intake (202.9 +/- 12.9 J g(-1) h(-1)) measured for these same animals during digestibility trials (20 degrees C). Based on 24-h activity trials and our derived ME coefficients, the minimum daily energy requirement of an adult (14.4 g) water shrew at T(a) = 20 degrees C is 54.0 kJ, or the energetic equivalent of 14.7 stickleback minnows.


Assuntos
Regulação da Temperatura Corporal/fisiologia , Metabolismo Energético/fisiologia , Movimento/fisiologia , Consumo de Oxigênio , Musaranhos/fisiologia , Animais , Comportamento Animal , Temperatura Corporal , Dieta
16.
Food Addit Contam ; 21(3): 256-64, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15195473

RESUMO

The results from a single laboratory that took part in a series of check-sample exercises for overall migration were used to calculate the measurement uncertainty for the overall migration methodology. The results span 10 years of proficiency testing and cover a range of plastic materials tested using a variety of time and temperature test conditions. Twelve sets of results for overall migration into olive oil and 10 sets of results for overall migration into volatile simulants were used. The measurement uncertainty associated with the determination of overall migration from plastics into olive oil was estimated as +/- 2.6 mg dm-2 for results between 1.2 and 15.4 mg dm-2. The measurement uncertainty associated with the determination of overall migration into volatile simulants was estimated as +/- 1.4 mg dm-2 for results between 2.1 and 13 mg dm-2. These estimates are within the analytical tolerances set in European Union regulations, of 3 and 2 mg dm-2, respectively. The performance of all laboratories participating in these 22 check sample exercises was also evaluated. A very large majority (93%) of the participants used official test methods, sometimes with minor modifications as stated. For the simulant olive oil, an average of 81% of laboratories (13 rounds with an average of 21 participants in each) using official methods was within the tolerance specified in regulations. For the volatile food simulants, an average of 87% of laboratories (11 rounds with an average of 38 participants in each) using official methods was within the tolerance specified. It is concluded from this evaluation of within- and between-laboratory data that the official European Standard methods for overall migration testing are suitable for the analysis of routine samples.


Assuntos
Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Embalagem de Alimentos , Gorduras Insaturadas na Dieta/análise , União Europeia , Contaminação de Alimentos/legislação & jurisprudência , Concentração Máxima Permitida , Azeite de Oliva , Óleos de Plantas/análise , Plastificantes/análise , Plásticos/análise , Reprodutibilidade dos Testes , Incerteza
17.
HIV Clin Trials ; 5(6): 361-70, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15682349

RESUMO

PURPOSE: The combination of abacavir + lamivudine (ABC+3TC) versus didanosine + stavudine (ddI+d4T), each combined with other classes of antiretrovirals (ARVs) in ARV-naive patients, was compared for the combined endpoint of time to plasma HIV RNA >50 copies/mL (at or after the 8-month visit) or death (primary endpoint) in a nested substudy of an ongoing multicenter randomized trial. METHOD: The substudy enrolled 182 patients; mean HIV RNA and CD4+ cell counts at baseline were 5.1 log10 copies/mL and 212 cells/mm3, respectively. RESULTS: After a median follow-up of 28 months, rates of primary endpoint were 57.2 and 67.8 per 100 person-years for the ABC+3TC and ddI+d4T groups (hazard ratio [HR]=0.81, 95% confidence interval [CI] 0.58-1.14, p=.23). CONCLUSION: There was a trend for treatments containing ABC+3TC to be better than treatments containing ddI+d4T with respect to HIV RNA decreases, CD4+ cell count increases, and tolerability.


Assuntos
Fármacos Anti-HIV/administração & dosagem , Infecções por HIV/tratamento farmacológico , HIV-1 , Contagem de Linfócito CD4 , Didanosina/administração & dosagem , Didesoxinucleosídeos/administração & dosagem , Quimioterapia Combinada , Infecções por HIV/sangue , Inibidores da Protease de HIV/administração & dosagem , Humanos , Lamivudina/administração & dosagem , Inibidores da Transcriptase Reversa/administração & dosagem , Estavudina/administração & dosagem , Resultado do Tratamento
18.
Food Addit Contam ; 19(11): 1003-9, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12456270

RESUMO

A study was conducted to determine the natural abundance sulfur isotope ratios in foods containing sulphite preservatives. This involved determining (1) the accuracy and repeatability of sulfur isotope ratios measured using an elemental analyser (EA) coupled to an isotope ratio mass spectrometer (IRMS); and (2) the isotope ratios of 21 samples of commercially available S(IV) oxo-anion compounds, nine samples of S(VI) sulfate salts and the isotope ratios of the sulfate obtained by modified Monier-Williams distillation of SO(2) from 33 retail foods containing sulfite preservatives. The sulfur isotope ratio data for SO(2) recovered from foodstuffs showed a large spread of results, which suggested that the SO(2) derived from sulfite preservatives does not have a distinctive sulfur signature ratio. The range of results (3.1-52.1) overlapped with that found for a range of commercially available sulfite and sulfate reagents commonly used to preserve food (sulfites 2.5-13.7, sulfates 10.0-16.9). Whilst the variability in isotope ratios originated from the food samples themselves, evidence from the analysis of SO(2) gas suggested that isotope fractionation during dissolution, reaction and recovery was also a confounding factor.


Assuntos
Análise de Alimentos/métodos , Conservantes de Alimentos/análise , Sulfitos/análise , Isótopos de Enxofre/análise , Sulfato de Bário/análise , Bebidas/análise , Espectrometria de Massas/métodos , Sulfatos/análise , Óxidos de Enxofre/análise
19.
Food Addit Contam ; 19(8): 770-8, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12227941

RESUMO

Dioxins and dioxin-like PCBs are given toxic equivalency factors (TEFs) in order to calculate the combined toxic equivalence (TEQ) of these contaminants in a sample of food. This study calculates the probability of an average consumer exceeding the recommended tolerable daily intake of 1-4 pg WHO-TEQ kg(-1) bw day(-1) as the amount of salmon in the diet is increased. Probabilistic risk analysis is used to account for the known uncertainties in this calculation. When the TEF uncertainty was excluded with no salmon consumption, the background dietary intake ranged from 1.36 to 1.78 pg TEQ kg(-1) bw day(-1). A weekly consumption of three standard salmon portions resulted in a 36% chance of exceeding the upper limit of the TDI. Inclusion of the TEF uncertainty increased the background dietary intake range from 2.1 to 4.4 pg TEQ kg(-1) bw day(-1), and the weekly consumption of one salmon portion resulted in a 79% chance of the average consumer exceeding the upper TDI. The most important factors contributing to the uncertainty in these results were, in order of magnitude, the TEF for PCB 126 and the sampling uncertainty (sample size) followed by the measurement uncertainty of PCB 126. We recommend that it is more important to increase sample size and produce more precise estimates in the TEF than to improve analytical accuracy.


Assuntos
Dioxinas/análise , Contaminação de Alimentos/análise , Dibenzodioxinas Policloradas/análogos & derivados , Salmão , Animais , Benzofuranos/análise , Dieta , Humanos , Concentração Máxima Permitida , Carne , Método de Monte Carlo , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análise , Medição de Risco/métodos
20.
Food Addit Contam ; 19(1): 22-7, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11811765

RESUMO

A survey of the levels of 3-monochloropropane-1,2-diol (3-MCPD) in a range of selected food products available in the UK is reported. The survey was carried out on behalf of the Food Standards Agency (FSA) to identify the food groups that might provide a significant contribution to 3-MCPD exposure from the diet. Three hundred samples comprising meat, dairy, cereal, soup and miscellaneous products were purchased from retail outlets and analysed using a GC-MS procedure, which had been formally validated by an earlier collaborative trial. 3-MCPD was detected in 89 (30%) of the samples. Three samples, all crackers, contained levels of 3-MCPD > 0.1 mg kg(-1), the highest level being 0.134 mg kg(-1). Levels of 3-MCPD were generally slightly higher in foods after cooking. In all cases where 3-MCPD was detected in cooked foods, it was also present in the uncooked sample.


Assuntos
Esterilizantes Químicos/análise , Contaminação de Alimentos/análise , alfa-Cloridrina/análise , Culinária , Laticínios/análise , Grão Comestível/química , Análise de Alimentos/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Carne/análise , Reino Unido
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