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2.
Nature ; 615(7953): 705-711, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36922598

RESUMO

Artificial sweeteners are used as calorie-free sugar substitutes in many food products and their consumption has increased substantially over the past years1. Although generally regarded as safe, some concerns have been raised about the long-term safety of the consumption of certain sweeteners2-5. In this study, we show that the intake of high doses of sucralose in mice results in immunomodulatory effects by limiting T cell proliferation and T cell differentiation. Mechanistically, sucralose affects the membrane order of T cells, accompanied by a reduced efficiency of T cell receptor signalling and intracellular calcium mobilization. Mice given sucralose show decreased CD8+ T cell antigen-specific responses in subcutaneous cancer models and bacterial infection models, and reduced T cell function in models of T cell-mediated autoimmunity. Overall, these findings suggest that a high intake of sucralose can dampen T cell-mediated responses, an effect that could be used in therapy to mitigate T cell-dependent autoimmune disorders.


Assuntos
Sacarose , Edulcorantes , Linfócitos T , Animais , Camundongos , Sacarose/análogos & derivados , Edulcorantes/administração & dosagem , Edulcorantes/efeitos adversos , Edulcorantes/farmacologia , Edulcorantes/uso terapêutico , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/patologia , Inocuidade dos Alimentos , Sinalização do Cálcio/efeitos dos fármacos , Receptores de Antígenos de Linfócitos T/efeitos dos fármacos , Receptores de Antígenos de Linfócitos T/imunologia , Infecções Bacterianas/imunologia , Neoplasias/imunologia , Autoimunidade/efeitos dos fármacos , Autoimunidade/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia
3.
Int J Pharm ; 628: 122191, 2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-36191816

RESUMO

Amorphous solid dispersions (ASDs) are formulations with enhanced drug solubility and dissolution rate compared to their crystalline counterparts, however, they can be inherently thermodynamically unstable. This can lead to amorphous phase separation and drug re-crystallisation, phenomena that are typically faster and more dominant at the product's surfaces. This study investigates the use of high-resolution time of flight-secondary ion mass spectrometry (ToF-SIMS) imaging as a surface analysis technique combined with image-analysis for the early detection, monitoring and quantification of surface amorphous phase separation in ASDs. Its capabilities are demonstrated for two pharmaceutically relevant ASD systems with distinct re-crystallisation behaviours, prepared using hot melt extrusion (HME) followed by pelletisation or grinding: (1) paracetamol-hydroxypropyl methylcellulose (PCM-HPMC) pellets with drug loadings of 10%-50% w/w and (2) indomethacin-polyvinylpyrrolidone (IND-PVP) ground material with drug loadings of 20%-85% w/w. PCM-HPMC pellets showed intense phase separation, reaching 100% PCM surface coverage within 1-5 months. In direct comparison, IND-PVP HME ground material was more stable with only a moderate formation of isolated IND-rich clusters. Image analysis allowed the reliable detection and quantification of local drug-rich clusters. An Avrami model was applied to determine and compare phase separation kinetics. The combination of chemical sensitivity and high spatial resolution afforded by SIMS was crucial to enable the study of early phase separation and re-crystallisation at the surface. Compared with traditional methods used to detect crystalline material, such as XRPD, we show that ToF-SIMS enabled detection of surface physical instability already at early stages of drug cluster formation in the first days of storage.


Assuntos
Povidona , Espectrometria de Massa de Íon Secundário , Solubilidade , Composição de Medicamentos/métodos , Povidona/química , Derivados da Hipromelose/química , Indometacina/química , Estabilidade de Medicamentos
4.
Health Technol Assess ; 25(58): 1-86, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34663491

RESUMO

BACKGROUND: Tranexamic acid reduces blood loss in surgery and the risk of death in trauma patients. Meta-analyses of small trials suggest that tranexamic acid decreases the number of deaths from gastrointestinal bleeding, but these meta-analyses are prone to selection bias. OBJECTIVE: The trial provides reliable evidence of the effect of tranexamic acid on mortality, rebleeding and complications in significant acute gastrointestinal bleeding. DESIGN: A multicentre, randomised, placebo-controlled trial and economic analysis. Patients were assigned by selecting one treatment pack from a box of eight, which were identical apart from the pack number. Patients, caregivers and outcome assessors were masked to allocation. The main analyses were by intention to treat. SETTING: The setting was 164 hospitals in 15 countries, co-ordinated from the London School of Hygiene & Tropical Medicine. PARTICIPANTS: Adults with significant upper or lower gastrointestinal bleeding (n = 12,009) were eligible if the responsible clinician was substantially uncertain about whether or not to use tranexamic acid. The clinical diagnosis of significant bleeding implied a risk of bleeding to death, including hypotension, tachycardia or signs of shock, or urgent transfusion, endoscopy or surgery. INTERVENTION: Tranexamic acid (a 1-g loading dose over 10 minutes, then a 3-g maintenance dose over 24 hours) or matching placebo. MAIN OUTCOME MEASURES: The primary outcome was death due to bleeding within 5 days of randomisation. Secondary outcomes were all-cause and cause-specific mortality; rebleeding; need for endoscopy, surgery or radiological intervention; blood product transfusion; complications; disability; and days spent in intensive care or a high-dependency unit. RESULTS: A total of 12,009 patients were allocated to receive tranexamic acid (n = 5994, 49.9%) or the matching placebo (n = 6015, 50.1%), of whom 11,952 (99.5%) received the first dose. Death due to bleeding within 5 days of randomisation occurred in 222 (3.7%) patients in the tranexamic acid group and in 226 (3.8%) patients in the placebo group (risk ratio 0.99, 95% confidence interval 0.82 to 1.18). Thromboembolic events occurred in 86 (1.4%) patients in the tranexamic acid group and 72 (1.2%) patients in the placebo group (risk ratio 1.20, 95% confidence interval 0.88 to 1.64). The risk of arterial thromboembolic events (myocardial infarction or stroke) was similar in both groups (0.7% in the tranexamic acid group vs. 0.8% in the placebo group; risk ratio 0.92, 95% confidence interval 0.60 to 1.39), but the risk of venous thromboembolic events (deep-vein thrombosis or pulmonary embolism) was higher in tranexamic acid-treated patients than in placebo-treated patients (0.8% vs. 0.4%; risk ratio 1.85, 95% confidence interval 1.15 to 2.98). Seizures occurred in 38 patients who received tranexamic acid and in 22 patients who received placebo (0.6% vs. 0.4%, respectively; risk ratio 1.73, 95% confidence interval 1.03 to 2.93). In the base-case economic analysis, tranexamic acid was not cost-effective and resulted in slightly poorer health outcomes than no tranexamic acid. CONCLUSIONS: Tranexamic acid did not reduce death from gastrointestinal bleeding and, although inexpensive, it is not cost-effective in adults with acute gastrointestinal bleeding. FUTURE WORK: These results caution against a uniform approach to the management of patients with major haemorrhage and highlight the need for randomised trials targeted at specific pathophysiological processes. LIMITATIONS: Although this is one of the largest randomised trials in gastrointestinal bleeding, we cannot rule out a modest increase or decrease in death due to bleeding with tranexamic acid. TRIAL REGISTRATION: Current Controlled Trials ISRCTN11225767, ClinicalTrials.gov NCT01658124 and EudraCT 2012-003192-19. 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. 25, No. 58. See the NIHR Journals Library website for further project information.


Acute gastrointestinal bleeding (bleeding from the gut) is a common emergency and an important cause of death and illness worldwide. In the UK, more than 65,000 people each year are admitted to hospital because of acute gastrointestinal bleeding; approximately 10% of them die within 30 days. Gastrointestinal bleeding is also common in low- and middle-income countries. The care of patients with gastrointestinal bleeding has improved in recent decades, but death rates remain high. Gastrointestinal bleeding is often caused by stomach ulcers, but also by liver damage owing to alcohol or hepatitis C infection. An effective and affordable treatment for gastrointestinal bleeding could save many lives and may reduce the need for blood transfusions, which is important because blood is a scarce resource in some health-care settings. Tranexamic acid, also known as TXA, is a cheap drug that reduces bleeding in other conditions. It helps blood to clot, thereby decreasing bleeding. A trial in bleeding accident victims found that tranexamic acid reduced the chances of bleeding to death, without any increase in side effects. We wanted to find out if tranexamic acid safely improves outcomes in patients with gastrointestinal bleeding, particularly to prevent deaths. To investigate this, the HALT-IT (Haemorrhage ALleviation with Tranexamic acid ­ Intestinal system) trial studied 12,009 patients with significant gastrointestinal bleeding in 164 hospitals across 15 countries. Half of the patients received tranexamic acid and the other half received a dummy drug, called a placebo. The treatments were assigned randomly and given in addition to all other treatments needed. Neither the patient nor the doctor knew which treatment a patient received. The trial showed that tranexamic acid did not reduce deaths from gastrointestinal bleeding. Instead, tranexamic acid was linked to an increased risk of complications, including unwanted blood clots (such as deep-vein thrombosis) and seizures. The economic analysis indicated that giving tranexamic acid to patients with gastrointestinal bleeding does not represent value for money for the NHS.


Assuntos
Antifibrinolíticos , Acidente Vascular Cerebral , Ácido Tranexâmico , Adulto , Antifibrinolíticos/uso terapêutico , Transfusão de Sangue , Análise Custo-Benefício , Hemorragia Gastrointestinal/tratamento farmacológico , Humanos
5.
Anal Chem ; 93(7): 3436-3444, 2021 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-33571411

RESUMO

We introduce a technique for the directed transfer of molecules from an adjacent reservoir onto a sample surface inside the vacuum chamber of a ToF-SIMS instrument using gas cluster ion beam (GCIB) sputtering. An example application for in situ matrix-enhanced secondary ion mass spectrometry (ME SIMS) is provided. This protocol has attractive features since most modern SIMS instruments are equipped with a GCIB gun. No solvents are required that would delocalize analytes at the surface, and the transfer of matrix molecules can be interlaced with SIMS depth profiling and 3D imaging sputtering and analysis cycles, which is not possible with conventional ME SIMS strategies. The amount of molecular deposition can be finely tuned, which is important for such a surface sensitive technique as SIMS. To demonstrate the concept, we used 2,5-DHB as a matrix for the enhancement of three drug molecules embedded in a tissue homogenate. By automatic operation of sputter deposition and erosion (cleanup) cycles, depth profiling could be achieved with ME SIMS with good repeatability (<4% RSD). Furthermore, we explored several different matrix compounds, including α-CHCA and aqueous solutions of Brønsted acids (formic acid) and 3-nitrobenzonitrile, a volatile compound known to spontaneously produce ions. The latter two matrix compounds were applied at cryogenic measurement conditions, which extend the range of matrices applicable for ME SIMS. Enhancement ratios range from 2 to 13, depending on the analytes and matrix. The method works in principle, but enhancement ratios for the drug molecules are rather limited at this point. Further study and optimization is needed, and the technique introduced here provides a tool to perform systematic studies of matrix compounds and experimental conditions for their potential for signal enhancement in ME SIMS.

6.
Lancet ; 395(10219): 226-239, 2020 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-31791690

RESUMO

This final report of the Lancet Commission into liver disease in the UK stresses the continuing increase in burden of liver disease from excess alcohol consumption and obesity, with high levels of hospital admissions which are worsening in deprived areas. Only with comprehensive food and alcohol strategies based on fiscal and regulatory measures (including a minimum unit price for alcohol, the alcohol duty escalator, and an extension of the sugar levy on food content) can the disease burden be curtailed. Following introduction of minimum unit pricing in Scotland, alcohol sales fell by 3%, with the greatest effect on heavy drinkers of low-cost alcohol products. We also discuss the major contribution of obesity and alcohol to the ten most common cancers as well as measures outlined by the departing Chief Medical Officer to combat rising levels of obesity-the highest of any country in the west. Mortality of severely ill patients with liver disease in district general hospitals is unacceptably high, indicating the need to develop a masterplan for improving hospital care. We propose a plan based around specialist hospital centres that are linked to district general hospitals by operational delivery networks. This plan has received strong backing from the British Association for Study of the Liver and British Society of Gastroenterology, but is held up at NHS England. The value of so-called day-case care bundles to reduce high hospital readmission rates with greater care in the community is described, along with examples of locally derived schemes for the early detection of disease and, in particular, schemes to allow general practitioners to refer patients directly for elastography assessment. New funding arrangements for general practitioners will be required if these proposals are to be taken up more widely around the country. Understanding of the harm to health from lifestyle causes among the general population is low, with a poor knowledge of alcohol consumption and dietary guidelines. The Lancet Commission has serious doubts about whether the initiatives described in the Prevention Green Paper, with the onus placed on the individual based on the use of information technology and the latest in behavioural science, will be effective. We call for greater coordination between official and non-official bodies that have highlighted the unacceptable disease burden from liver disease in England in order to present a single, strong voice to the higher echelons of government.


Assuntos
Alcoolismo/epidemiologia , Hepatopatias/epidemiologia , Hepatopatias/prevenção & controle , Obesidade/epidemiologia , Bebidas Alcoólicas/economia , Alcoolismo/complicações , Alcoolismo/terapia , Comércio , Redes Comunitárias/organização & administração , Comorbidade , Efeitos Psicossociais da Doença , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Legislação sobre Alimentos , Hepatopatias/diagnóstico , Hepatopatias/etiologia , Transplante de Fígado/estatística & dados numéricos , Obesidade/complicações , Pacotes de Assistência ao Paciente , Escócia , Reino Unido/epidemiologia
8.
Trials ; 20(1): 467, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31362765

RESUMO

BACKGROUND: Acute gastrointestinal (GI) bleeding is an important cause of mortality worldwide. Bleeding can occur from the upper or lower GI tract, with upper GI bleeding accounting for most cases. The main causes include peptic ulcer/erosive mucosal disease, oesophageal varices and malignancy. The case fatality rate is around 10% for upper GI bleeding and 3% for lower GI bleeding. Rebleeding affects 5-40% of patients and is associated with a four-fold increased risk of death. Tranexamic acid (TXA) decreases bleeding and the need for blood transfusion in surgery and reduces death due to bleeding in patients with trauma and postpartum haemorrhage. It reduces bleeding by inhibiting the breakdown of fibrin clots by plasmin. Due to the methodological weaknesses and small size of the existing trials, the effectiveness and safety of TXA in GI bleeding is uncertain. The Haemorrhage ALleviation with Tranexamic acid - Intestinal system (HALT-IT) trial aims to provide reliable evidence about the effects of TXA in acute upper and lower GI bleeding. METHODS: The HALT-IT trial is an international, randomised, double-blind, placebo-controlled trial of tranexamic acid in 12,000 adults (increased from 8000) with acute upper or lower GI bleeding. Eligible patients are randomly allocated to receive TXA (1-g loading dose followed by 3-g maintenance dose over 24 h) or matching placebo. The main analysis will compare those randomised to TXA with those randomised to placebo on an intention-to-treat basis, presenting the results as effect estimates (relative risks) and confidence intervals. The primary outcome is death due to bleeding within 5 days of randomisation and secondary outcomes are: rebleeding; all-cause and cause-specific mortality; thromboembolic events; complications; endoscopic, radiological and surgical interventions; blood transfusion requirements; disability (defined by a measure of patient's self-care capacity); and number of days spent in intensive care or high-dependency units. Subgroup analyses for the primary outcome will consider time to treatment, location of bleeding, cause of bleed and clinical Rockall score. DISCUSSION: We present the statistical analysis of the HALT-IT trial. This plan was published before the treatment allocation was unblinded. TRIAL REGISTRATION: Current Controlled Trials, ID: ISRCTN11225767. Registered on 3 July 2012; Clinicaltrials.gov, ID: NCT01658124. Registered on 26 July 2012.


Assuntos
Antifibrinolíticos/uso terapêutico , Hemorragia Gastrointestinal/tratamento farmacológico , Ácido Tranexâmico/uso terapêutico , Antifibrinolíticos/efeitos adversos , Interpretação Estatística de Dados , Método Duplo-Cego , Hemorragia Gastrointestinal/diagnóstico , Hemorragia Gastrointestinal/mortalidade , Humanos , Estudos Multicêntricos como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Ácido Tranexâmico/efeitos adversos , Resultado do Tratamento
9.
Lancet ; 392(10162): 2398-2412, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30473364

RESUMO

This report presents further evidence on the escalating alcohol consumption in the UK and the burden of liver disease associated with this major risk factor, as well as the effects on hospital and primary care. We reiterate the need for fiscal regulation by the UK Government if overall alcohol consumption is to be reduced sufficiently to improve health outcomes. We also draw attention to the effects of drastic cuts in public services for alcohol treatment, the repeated failures of voluntary agreements with the drinks industry, and the influence of the industry through its lobbying activities. We continue to press for reintroduction of the alcohol duty escalator, which was highly effective during the 5 years it was in place, and the introduction of minimum unit pricing in England, targeted at the heaviest drinkers. Results from the introduction of minimum unit pricing in Scotland, with results from Wales to follow, are likely to seriously expose the weakness of England's position. The increasing prevalence of obesity-related liver disease, the rising number of people diagnosed with type 2 diabetes and its complications, and increasing number of cases of end-stage liver disease and primary liver cancers from non-alcoholic fatty liver disease make apparent the need for an obesity strategy for adults. We also discuss the important effects of obesity and alcohol on disease progression, and the increased risk of the ten most common cancers (including breast and colon cancers). A new in-depth analysis of the UK National Health Service (NHS) and total societal costs shows the extraordinarily large expenditures that could be saved or redeployed elsewhere in the NHS. Excellent results have been reported for new antiviral drugs for hepatitis C virus infection, making elimination of chronic infection a real possibility ahead of the WHO 2030 target. However, the extent of unidentified cases remains a problem, and will also apply when new curative drugs for hepatitis B virus become available. We also describe efforts to improve standards of hospital care for liver disease with better understanding of current service deficiencies and a new accreditation process for hospitals providing liver services. New commissioning arrangements for primary and community care represent progress, in terms of effective screening of high-risk subjects and the early detection of liver disease.


Assuntos
Política de Saúde , Hepatopatias/epidemiologia , Hepatopatias/prevenção & controle , Consumo de Bebidas Alcoólicas/epidemiologia , Consumo de Bebidas Alcoólicas/prevenção & controle , Bebidas Alcoólicas/economia , Comorbidade , Custos e Análise de Custo , Erradicação de Doenças , Progressão da Doença , Feminino , Indústria Alimentícia , Hepatite B Crônica/epidemiologia , Hepatite B Crônica/prevenção & controle , Hepatite C Crônica/epidemiologia , Hepatite C Crônica/prevenção & controle , Mortalidade Hospitalar , Humanos , Hepatopatias/mortalidade , Hepatopatias Alcoólicas/epidemiologia , Hepatopatias Alcoólicas/prevenção & controle , Manobras Políticas , Masculino , Neoplasias/epidemiologia , Obesidade/epidemiologia , Obesidade/prevenção & controle , Prevalência , Reino Unido/epidemiologia
10.
J Lipid Res ; 59(6): 1058-1070, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29626102

RESUMO

7-Oxocholesterol (7-OC), 5,6-epoxycholesterol (5,6-EC), and its hydrolysis product cholestane-3ß,5α,6ß-triol (3ß,5α,6ß-triol) are normally minor oxysterols in human samples; however, in disease, their levels may be greatly elevated. This is the case in plasma from patients suffering from some lysosomal storage disorders, e.g., Niemann-Pick disease type C, or the inborn errors of sterol metabolism, e.g., Smith-Lemli-Opitz syndrome and cerebrotendinous xanthomatosis. A complication in the analysis of 7-OC and 5,6-EC is that they can also be formed ex vivo from cholesterol during sample handling in air, causing confusion with molecules formed in vivo. When formed endogenously, 7-OC, 5,6-EC, and 3ß,5α,6ß-triol can be converted to bile acids. Here, we describe methodology based on chemical derivatization and LC/MS with multistage fragmentation (MSn) to identify the necessary intermediates in the conversion of 7-OC to 3ß-hydroxy-7-oxochol-5-enoic acid and 5,6-EC and 3ß,5α,6ß-triol to 3ß,5α,6ß-trihydroxycholanoic acid. Identification of intermediate metabolites is facilitated by their unusual MSn fragmentation patterns. Semiquantitative measurements are possible, but absolute values await the synthesis of isotope-labeled standards.


Assuntos
Ácidos e Sais Biliares/sangue , Ácidos e Sais Biliares/química , Análise Química do Sangue/métodos , Espectrometria de Massas/métodos , Oxisteróis/sangue , Oxisteróis/química , Humanos
11.
Anal Chem ; 89(22): 11944-11953, 2017 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-29039651

RESUMO

ToF-SIMS is a label-free imaging method that has been shown to enable imaging of amiodarone in single rat macrophage (NR8383) cells. In this study, we show that the method extends to three other cell lines relevant to drug discovery: human embryonic kidney (HEK293), cervical cancer (HeLa), and liver cancer (HepG2). There is significant interest in the variation of drug uptake at the single cell level, and we use ToF-SIMS to show that there is great diversity between individual cells and when comparing each of the cell types. These single cell measurements are compared to quantitative measurements of cell-associated amiodarone for the population using LC/MS/MS and cell counting with flow cytometry. NR8383 and HepG2 cells uptake the greatest amount of amiodarone with an average of 2.38 and 2.60 pg per cell, respectively, and HeLa and Hek 293 have a significantly lower amount of amiodarone at 0.43 and 0.36 pg per cell, respectively. The amount of cell-associated drug for the ensemble population measurement (LC/MS/MS) is compared with the ToF-SIMS single cell data: a similar amount of drug was detected per cell for the NR8383, and HepG2 cells at a greater level than that for the HEK293 cells. However, the two techniques did not agree for the HeLa cells, and we postulate potential reasons for this.


Assuntos
Amiodarona/farmacocinética , Espectrometria de Massa de Íon Secundário , Amiodarona/análise , Animais , Linhagem Celular , Cromatografia Líquida , Citometria de Fluxo , Células HEK293 , Células HeLa , Células Hep G2 , Humanos , Ratos , Espectrometria de Massas em Tandem , Fatores de Tempo
13.
Anal Chem ; 89(9): 4781-4785, 2017 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-28394122

RESUMO

We present a novel in situ mask method for the preparation of cross-sections of organic materials such as polymer multilayer films suitable for chemical imaging of buried interfaces. We demonstrate this method on a model buried interface system consisting of a piece of Scotch tape adhered to a PET substrate and a protective film used in consumer packaging. A high dose of gallium from a focused ion beam (FIB) was used to produce a damaged overlayer on the surface of the organic sample. The damaged layer has a significantly slower sputter rate compared to the native undamaged organic material. Therefore, during gas cluster ion beam (GCIB) depth profiling experiments the damaged layer functions as a mask, protecting the sample beneath and producing a cross-section at the edge of the mask. The FIB itself cannot be used directly to prepare the cross-section since the organic materials are easily damaged. A four step workflow is described including a final cleaning procedure to remove redeposited material from the cross-section. The workflow is completed in a few hours for samples up to 100 µm thickness. The method does not require sample embedding and is suited to automated analysis, which can be important benefits for industrial analysis where a variety of samples are analyzed routinely.

14.
Chem Commun (Camb) ; 53(9): 1506-1509, 2017 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-28085162

RESUMO

Correlative NanoSIMS and EM imaging of amiodarone-treated macrophages shows the internalisation of the drug at a sub-cellular level and reveals its accumulation within the lysosomes, providing direct evidence for amiodarone-induced phospholipidosis. Chemical fixation using tannic acid effectively seals cellular membranes aiding intracellular retention of diffusible drugs.


Assuntos
Amiodarona/farmacologia , Antiarrítmicos/farmacologia , Macrófagos/efeitos dos fármacos , Nanotecnologia , Fosfolipídeos/metabolismo , Espectrometria de Massa de Íon Secundário , Amiodarona/química , Antiarrítmicos/química , Humanos , Pulmão/citologia , Pulmão/efeitos dos fármacos , Lisossomos/química , Lisossomos/metabolismo , Microscopia Eletrônica
15.
Anal Biochem ; 524: 56-67, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28087213

RESUMO

Cholesterolomics can be regarded as the identification and quantification of cholesterol, its precursors post squalene, and metabolites of cholesterol and of its precursors, in a biological sample. These molecules include 1,25-dihydroxyvitamin D3, steroid hormones and bile acids and intermediates in their respective biosynthetic pathways. In this short article we will concentrate our attention on intermediates in bile acid biosynthesis pathways, in particular oxysterols and cholestenoic acids. These molecular classes are implicated in the aetiology of a diverse array of diseases including autoimmune disease, Parkinson's disease, motor neuron disease, breast cancer, the lysosomal storage disease Niemann-Pick type C and the autosomal recessive disorder Smith-Lemli-Opitz syndrome. Mass spectrometry (MS) is the dominant technology for sterol analysis including both gas-chromatography (GC)-MS and liquid chromatography (LC)-MS and more recently matrix-assisted laser desorption/ionisation (MALDI)-MS for tissue imaging studies. Here we will discuss exciting biological findings and recent analytical improvements.


Assuntos
Colesterol/metabolismo , Hormônios Esteroides Gonadais/metabolismo , Vitamina D/análogos & derivados , Animais , Doenças Autoimunes/metabolismo , Neoplasias da Mama/metabolismo , Doenças do Sistema Nervoso Central/metabolismo , Feminino , Humanos , Masculino , Síndrome de Smith-Lemli-Opitz/metabolismo , Vitamina D/metabolismo
17.
Anal Chem ; 88(9): 4808-16, 2016 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-27014929

RESUMO

In this study, the impact of sprayer design and geometry on performance in desorption electrospray ionization mass spectrometry (DESI-MS) is assessed, as the sprayer is thought to be a major source of variability. Absolute intensity repeatability, spectral composition, and classification accuracy for biological tissues are considered. Marked differences in tissue analysis performance are seen between the commercially available and a lab-built sprayer. These are thought to be associated with the geometry of the solvent capillary and the resulting shape of the primary electrospray. Experiments with a sprayer with a fixed solvent capillary position show that capillary orientation has a crucial impact on tissue complex lipid signal and can lead to an almost complete loss of signal. Absolute intensity repeatability is compared for five lab-built sprayers using pork liver sections. Repeatability ranges from 1 to 224% for individual sprayers and peaks of different spectral abundance. Between sprayers, repeatability is 16%, 9%, 23%, and 34% for high, medium, low, and very low abundance peaks, respectively. To assess the impact of sprayer variability on tissue classification using multivariate statistical tools, nine human colorectal adenocarcinoma sections are analyzed with three lab-built sprayers, and classification accuracy for adenocarcinoma versus the surrounding stroma is assessed. It ranges from 80.7 to 94.5% between the three sprayers and is 86.5% overall. The presented results confirm that the sprayer setup needs to be closely controlled to obtain reliable data, and a new sprayer setup with a fixed solvent capillary geometry should be developed.


Assuntos
Adenocarcinoma/diagnóstico , Neoplasias Colorretais/diagnóstico , Lipídeos/análise , Fígado/química , Imagem Molecular , Espectrometria de Massas por Ionização por Electrospray , Animais , Humanos , Suínos
18.
BMC Public Health ; 16: 111, 2016 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-26888538

RESUMO

BACKGROUND: Internationally, studies show that similar levels of alcohol consumption in deprived communities (vs. more affluent) result in higher levels of alcohol-related ill health. Hypotheses to explain this alcohol harm paradox include deprived drinkers: suffering greater combined health challenges (e.g. smoking, obesity) which exacerbate effects of alcohol harms; exhibiting more harmful consumption patterns (e.g. bingeing); having a history of more harmful consumption; and disproportionately under-reporting consumption. We use a bespoke national survey to assess each of these hypotheses. METHODS: A national telephone survey designed to test this alcohol harm paradox was undertaken (May 2013 to April 2014) with English adults (n = 6015). Deprivation was assigned by area of residence. Questions examined factors including: current and historic drinking patterns; combined health challenges (smoking, diet, exercise and body mass); and under-reported consumption (enhanced questioning on atypical/special occasion drinking). For each factor, analyses examined differences between deprived and more affluent individuals controlled for total alcohol consumption. RESULTS: Independent of total consumption, deprived drinkers were more likely to smoke, be overweight and report poor diet and exercise. Consequently, deprived increased risk drinkers (male >168-400 g, female >112-280 g alcohol/week) were >10 times more likely than non-deprived counterparts to drink in a behavioural syndrome combining smoking, excess weight and poor diet/exercise. Differences by deprivation were significant but less marked in higher risk drinkers (male >400 g, female >280 g alcohol/week). Current binge drinking was associated with deprivation independently of total consumption and a history of bingeing was also associated with deprivation in lower and increased risk drinkers. CONCLUSIONS: Deprived increased/higher drinkers are more likely than affluent counterparts to consume alcohol as part of a suite of health challenging behaviours including smoking, excess weight and poor diet/exercise. Together these can have multiplicative effects on risks of wholly (e.g. alcoholic liver disease) and partly (e.g. cancers) alcohol-related conditions. More binge drinking in deprived individuals will also increase risks of injury and heart disease despite total alcohol consumption not differing from affluent counterparts. Public health messages on how smoking, poor diet/exercise and bingeing escalate health risks associated with alcohol are needed, especially in deprived communities, as their absence will contribute to health inequalities.


Assuntos
Consumo de Bebidas Alcoólicas/efeitos adversos , Transtornos Relacionados ao Uso de Álcool/complicações , Comportamentos Relacionados com a Saúde , Saúde , Estilo de Vida , Classe Social , Adolescente , Adulto , Idoso , Intoxicação Alcoólica/complicações , Alcoolismo/complicações , Consumo Excessivo de Bebidas Alcoólicas/complicações , Estudos Transversais , Feminino , Humanos , Hepatopatias Alcoólicas/etiologia , Masculino , Pessoa de Meia-Idade , Características de Residência , Fatores de Risco , Fumar , Inquéritos e Questionários , Adulto Jovem
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