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1.
Clin Radiol ; 79(6): 404-412, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38565483

RESUMO

Due to the rising demand in cross-sectional thoracic imaging, anterior mediastinal lesions are being identified with increasing frequency. Following iterative and multidisciplinary discussions, the BTOG Thymic Malignancies Special Interest Group have developed an algorithm to standardise the diagnostic approach for these relatively uncommon but important conditions which span from benign (thymic remnant, thymic hyperplasia and thymic cysts) to suspected localised thymomas to suspected more aggressive malignancy (thymic carcinoma, lymphoma and germ cell tumours). For each condition, we provide a brief description, an overview of the key radiological findings and a description of the proposed algorithm including the rationale behind the recommendations. We also highlight the role of magnetic resonance (MR) imaging for the characterisation of anterior mediastinal masses in specific indications when the necessary local resources and expertise exist. In addition, we hope this provides the rationale for service development in MR of the anterior mediastinum where current resource and expertise requires development. Through this standardised pathway, we hope to drive improvements in patient care by rationalising surveillance schedules, avoiding unnecessary resections of benign entities with their associated morbidity and optimising the diagnostic work-up prior to the appropriate treatment of anterior mediastinal malignancies.


Assuntos
Algoritmos , Imageamento por Ressonância Magnética , Neoplasias do Mediastino , Neoplasias do Timo , Humanos , Diagnóstico Diferencial , Imageamento por Ressonância Magnética/métodos , Neoplasias do Mediastino/diagnóstico por imagem , Mediastino/diagnóstico por imagem , Timoma/diagnóstico por imagem , Neoplasias do Timo/diagnóstico por imagem
3.
Acute Med ; 18(3): 197-199, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31536059

RESUMO

The advent of immunotherapy in oncology has led to the emergence of a new spectrum of adverse effects. A number of these have the potential to contribute to life-threatening outcomes; and therefore require prompt identification and aggressive treatment to optimise management. In this report, we describe a case of pembrolizumab-induced CTCAE (common toxicity criteria for adverse events) grade 4 myositis in a non-small cell lung cancer patient.


Assuntos
Adenocarcinoma de Pulmão , Anticorpos Monoclonais Humanizados , Antineoplásicos Imunológicos , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Miosite , Adenocarcinoma de Pulmão/tratamento farmacológico , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/uso terapêutico , Antineoplásicos Imunológicos/efeitos adversos , Antineoplásicos Imunológicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Miosite/induzido quimicamente
4.
Blood Cancer J ; 7(3): e539, 2017 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-28282033

RESUMO

Phosphoinositide-3-kinase and protein kinase B (PI3K-AKT) is upregulated in multiple myeloma (MM). Using a combination of short hairpin RNA (shRNA) lentivirus-mediated knockdown and pharmacologic isoform-specific inhibition we investigated the role of the PI3K p110γ (PI3Kγ) subunit in regulating MM proliferation and bone marrow microenvironment-induced MM interactions. We compared this with inhibition of the PI3K p110δ (PI3kδ) subunit and with combined PI3kδ/γ dual inhibition. We found that MM cell adhesion and migration were PI3Kγ-specific functions, with PI3kδ inhibition having no effect in MM adhesion or migration assays. At concentration of the dual PI3Kδ/γ inhibitor duvelisib, which can be achieved in vivo we saw a decrease in AKT phosphorylation at s473 after tumour activation by bone marrow stromal cells (BMSC) and interleukin-6. Moreover, after drug treatment of BMSC/tumour co-culture activation assays only dual PI3kδ/γ inhibition was able to induce MM apoptosis. shRNA lentiviral-mediated targeting of either PI3Kδ or PI3Kγ alone, or both in combination, increased survival of NSG mice xeno-transplanted with MM cells. Moreover, treatment with duvelisib reduced MM tumour burden in vivo. We report that PI3Kδ and PI3Kγ isoforms have distinct functions in MM and that combined PI3kδ/γ isoform inhibition has anti-MM activity. Here we provide a scientific rationale for trials of dual PI3kδ/γ inhibition in patients with MM.


Assuntos
Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Classe Ib de Fosfatidilinositol 3-Quinase/metabolismo , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , Transdução de Sinais , Microambiente Tumoral , Animais , Apoptose , Adesão Celular , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Sobrevivência Celular/genética , Classe I de Fosfatidilinositol 3-Quinases/antagonistas & inibidores , Modelos Animais de Doenças , Xenoenxertos , Humanos , Interleucina-6/metabolismo , Interleucina-6/farmacologia , Camundongos , Mieloma Múltiplo/tratamento farmacológico , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação , Isoformas de Proteínas , Subunidades Proteicas , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Aliment Pharmacol Ther ; 44(9): 936-945, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27604637

RESUMO

BACKGROUND: Brain change can occur in primary biliary cholangitis (PBC), potentially as a result of cholestatic and/or inflammatory processes. This change is linked to systemic symptoms of fatigue and cognitive impairment. AIM: To identify whether brain change occurs early in PBC. If the change develops early and is progressive, it may explain the difficulty in treating these symptoms. METHODS: Early disease brain change was explored in 13 patients with newly diagnosed biopsy-proven precirrhotic PBC using magnetisation transfer, diffusion-weighted imaging and 1 H magnetic resonance spectroscopy. Results were compared to 17 healthy volunteers. RESULTS: Cerebral magnetisation transfer ratios were reduced in early PBC, compared to healthy volunteers, in the thalamus, putamen and head of caudate with no greater reduction in patients with greater symptom severity. Mean apparent diffusion coefficients were increased in the thalamus only. No 1 H magnetic resonance spectroscopy abnormalities were seen. Serum manganese levels were elevated in all PBC patients, but no relationship was seen with imaging or symptom parameters. There were no correlations between neuroimaging data, laboratory data, symptom severity scores or age. CONCLUSIONS: This is the first study to be performed in this precirrhotic patient population, and we have highlighted that neuroimaging changes are present at a much earlier stage than previously demonstrated. The neuroimaging abnormalities suggest that the brain changes seen in PBC occur early in the pathological process, even before significant liver damage has occurred. If such changes are linked to symptom pathogenesis, this could have important implications for the timing of second-line-therapy use.


Assuntos
Encéfalo/anormalidades , Encéfalo/diagnóstico por imagem , Colangite/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Adulto , Idoso , Diagnóstico Precoce , Feminino , Humanos , Cirrose Hepática Biliar/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade
8.
J Viral Hepat ; 19(2): e89-96, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22239531

RESUMO

Patients with chronic hepatitis C infection may exhibit neuropsychological symptoms and cognitive impairment. Post-mortem studies of hepatitis C virus HCV quasispecies and replicative intermediates indicate that the brain might act as a separate compartment for viral replication and microglia may be the locus for infection and subsequent neuroinflammatory activity. We sought to use two independent in vivo imaging techniques to determine evidence of neuroinflammation in patients with histologically mild chronic hepatitis C. Using positron emission tomography (PET) with a ligand for microglial/brain macrophage activation, (11)C-(R)-PK11195 (PK11195) and cerebral proton magnetic resonance spectroscopy, we determined whether there was evidence of neuroinflammation in a pilot study of 11 patients with biopsy-proven mild chronic hepatitis C, compared to healthy volunteers. Patients were characterized by cognitive testing and the fatigue impact scale to assess for CNS impairment. PK11195 binding potential was significantly increased in the caudate nucleus of patients, compared to normal controls (P = 0.03). The caudate and thalamic binding potential were more significantly increased in six patients with genotype 1 infection (P = 0.007) and positively correlated with viraemia (r = 0.77, P = 0.005). Basal ganglia myo-inositol/creatine and choline/creatine ratios were also significantly elevated in patients with chronic hepatitis C compared to normal controls (P = 0.0004 and P = 0.01, respectively). Using PET, we demonstrated evidence of microglial activation, which positively correlated with HCV viraemia and altered cerebral metabolism in the brains of patients with mild hepatitis C. This provides further in vivo evidence for a neurotropic role for HCV.


Assuntos
Encéfalo/imunologia , Encéfalo/patologia , Hepatite C Crônica/imunologia , Hepatite C Crônica/patologia , Microglia/imunologia , Adulto , Idoso , Encéfalo/diagnóstico por imagem , Encéfalo/virologia , Feminino , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Microglia/virologia , Pessoa de Meia-Idade , Radiografia
9.
J Viral Hepat ; 18(10): e530-4, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21914073

RESUMO

We compared in vivo hepatic (31) P magnetic resonance spectroscopy ((31) P MRS) and hepatic vein transit times (HVTT) using contrast-enhanced ultrasound with a microbubble agent to assess the severity of hepatitis C virus (HCV)-related liver disease. Forty-six patients with biopsy-proven HCV-related liver disease and nine healthy volunteers had (31) P MRS and HVTT performed on the same day. (31) P MR spectra were obtained at 1.5 T. Peak areas were calculated for metabolites, including phosphomonoesters (PME) and phosphodiesters (PDE). Patients also had the microbubble ultrasound contrast agent, Levovist (2 g), injected into an antecubital vein, and time-intensity Doppler ultrasound signals of the right and middle hepatic veins were measured. The HVTT was calculated as the time from injection to a sustained rise in Doppler signal 10% greater than baseline. The shortest times were used for analysis. Based on Ishak histological scoring, there were 15 patients with mild hepatitis, 20 with moderate/severe hepatitis and 11 with cirrhosis. With increasing severity of disease, the PME/PDE ratio was steadily elevated, while the HVTT showed a monotonic decrease. Both imaging modalities could separate patients with cirrhosis from the mild and moderate/severe hepatitis groups. No statistical difference was observed in the accuracy of each test to denote mild, moderate/severe hepatitis and cirrhosis (Fisher's exact test P =1.00). (31) P MRS and HVTT show much promise as noninvasive imaging tests for assessing the severity of chronic liver disease. Both are equally effective and highly sensitive in detecting cirrhosis.


Assuntos
Hepatite C/diagnóstico , Hepatite C/patologia , Fígado/patologia , Espectroscopia de Ressonância Magnética/métodos , Ultrassonografia/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Microbolhas , Pessoa de Meia-Idade , Isótopos de Fósforo/metabolismo , Sensibilidade e Especificidade , Índice de Gravidade de Doença
10.
J Viral Hepat ; 17(11): 778-83, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20002308

RESUMO

Microbubble measurement of hepatic vein transit times (HVTT) may have the potential to assess severity of hepatitis C virus (HCV)-related liver disease, where there is a shorter HVTT with more severe disease. We investigated the utility of this test as a marker of response to antiviral treatment. Thirty-seven patients with biopsy-proven HCV-related disease undergoing antiviral treatment were studied. All had baseline scans and then repeat scans 6 months after the end of treatment. HVTT using Levovist were obtained from the right and middle hepatic veins, and the shorter time was used for analysis. The aspartate aminotransferase to platelet ratio index (APRI) scores were calculated retrospectively. There were seven patients with mild hepatitis, 23 with moderate/severe hepatitis and seven with cirrhosis. The mean baseline HVTT in responders ± SE increased from 27.3 ± 2.29 s to 33.5 ± 2.8 s posttreatment (P = 0.01). In the 10 nonresponders, the HVTT remained the same; 43.3 ± 9 s baseline compared to 44 ± 7.8 s posttreatment (P = 0.84). This trend was also seen with the APRI score where in responders, the mean score decreased from 1.1 ± 0.2 to 0.74 ± 1 (P = 0.03) and in nonresponders, the score remained unchanged; 0.88 ± 0.2 compared to 0.84 ± 0.2 (P = 0.31). HVTT measurement lengthened, while APRI scores decreased in patients who responded to antiviral treatment while both remained the same, shortened (HVTT) or increased (APRI), respectively, in patients who were nonresponders. These results are encouraging and indicate that these tests could be potentially used as markers of response to treatment and could obviate the need for serial biopsies in antiviral future treatment studies.


Assuntos
Antivirais/farmacocinética , Meios de Contraste/farmacocinética , Monitoramento de Medicamentos/métodos , Veias Hepáticas/diagnóstico por imagem , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/patologia , Microbolhas , Adulto , Idoso , Aspartato Aminotransferases/sangue , Feminino , Seguimentos , Hepatite C Crônica/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Radiografia , Fatores de Tempo , Resultado do Tratamento
11.
J Viral Hepat ; 17(8): 537-45, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19804501

RESUMO

Combinations of noninvasive markers may improve discrimination of chronic liver disease severity. The aims of this study were to compare four validated serum and ultrasound-based markers of hepatic disease severity head-to-head with liver biopsy and to assess optimal combinations with consideration of cost. A total of 67 patients with biopsy-proven chronic hepatitis C underwent all four techniques on the same visit [aspartate aminotransferase (AST) to platelet ratio index (APRI); Enhanced Liver Fibrosis (ELF) panel; transient elastography (TE) and ultrasound microbubble hepatic transit times (HTT)]. Markers were combined according to increasing financial cost and ordinal regression used to determine contributions. APRI, ELF, TE and HTT predicted cirrhosis with diagnostic accuracy of 86%, 91%, 90% and 83% respectively. ELF and TE were the most reliable tests with an intra-class correlation of 0.94 each. Either ELF or TE significantly enhanced the prediction of fibrosis stage when combined with APRI, but when combined together, did not improve the model further. Addition of third or fourth markers did not significantly improve prediction of fibrosis. Combination of APRI with either ELF or TE effectively predicts fibrosis stage, but combinations of three or more tests lead to redundancy of information and increased cost.


Assuntos
Aspartato Aminotransferases/sangue , Meios de Contraste/farmacologia , Técnicas de Imagem por Elasticidade/métodos , Hepatite C Crônica/patologia , Cirrose Hepática/patologia , Adolescente , Adulto , Idoso , Aspartato Aminotransferases/economia , Técnicas de Imagem por Elasticidade/economia , Hepatite C Crônica/sangue , Hepatite C Crônica/diagnóstico por imagem , Humanos , Cirrose Hepática/sangue , Cirrose Hepática/diagnóstico por imagem , Pessoa de Meia-Idade , Contagem de Plaquetas/economia , Contagem de Plaquetas/métodos , Curva ROC , Análise de Regressão , Reprodutibilidade dos Testes , Adulto Jovem
12.
HPB (Oxford) ; 10(2): 77-82, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18773060

RESUMO

Cholangiocarcinoma (CCA) is a fatal cancer of the biliary epithelium, arising either within the liver (intrahepatic, ICC) or in the extrahepatic bile ducts (extrahepatic ECC). Globally, CCA is the second most common primary hepatic malignancy. Several recent epidemiological studies have shown that the incidence and mortality rates of ICC are increasing. This review of the literature on the international epidemiological rates of CCA, both intra- and extrahepatic, explores possible explanations for the trends found. The possible role of epidemiological artifact in the findings is discussed and the known risk factors for CCA are summarized. These include primary sclerosing cholangitis, liver fluke infestation, congenital fibropolycystic liver, bile duct adenomas, and biliary papillomatosis, hepatolithiasis, chemical carcinogens such as nitrosamines, Thorotrast, chronic viral hepatitis, cirrhosis, chronic non-alcoholic liver disease and obesity. Potential pathways involved in the molecular pathogenesis of CCA are also summarized.

13.
Thorax ; 63(4): 306-11, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18024535

RESUMO

RATIONALE: Chronic obstructive pulmonary disease (COPD) is associated with a 2-3-fold increase in the risk of ischaemic heart disease, stroke and sudden death. The mechanisms responsible for this association are not clear and appear to be independent of smoking history. OBJECTIVE: We test the hypothesis that patients with COPD have increased arterial stiffness and blood pressure in comparison with age and smoking matched controls. METHODS: In a prospective case control study, we recruited 102 patients with COPD and 103 healthy controls matched for age and smoking status. Patients were assessed by clinical history and spirometry, with arterial stiffness and blood pressure determined using radial artery applanation tonometry and sphygmomanometry. RESULTS: Patients with COPD had increased arterial stiffness compared with matched controls, with elevated augmentation pressure (17 (1) vs 14 (1) mm Hg; p = 0.005) and a reduced time to wave reflection (131 (1) vs 137 (2) ms; p = 0.004). These differences were associated with increases in both diastolic (82 (1) vs 78 (1) mm Hg; p = 0.005) and systolic blood pressure (147 (2) vs 132 (2) mm Hg; p<0.001). Serum C reactive protein concentrations were threefold higher in patients (6.1 (0.9) vs 2.3 (0.4) mg/l; p = 0.001). Data are presented as mean (SEM). CONCLUSIONS: Patients with COPD have increased arterial stiffness and blood pressure in comparison with controls matched for age and smoking status. We speculate that increased systemic inflammation and vascular dysfunction could potentially explain the excess cardiovascular morbidity and mortality associated with COPD.


Assuntos
Morte Súbita Cardíaca/etiologia , Isquemia Miocárdica/etiologia , Doença Pulmonar Obstrutiva Crônica/complicações , Acidente Vascular Cerebral/etiologia , Estudos de Casos e Controles , Elasticidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/fisiopatologia , Estudos Prospectivos , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Pulso Arterial , Artéria Radial/fisiologia , Fatores de Risco , Acidente Vascular Cerebral/fisiopatologia , Resistência Vascular/fisiologia
15.
World J Gastroenterol ; 13(36): 4791-7, 2007 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-17828808

RESUMO

Transient elastography is a recently developed non-invasive technique for the assessment of hepatic fibrosis. The technique has been subject to rigorous evaluation in a number of studies in patients with chronic liver disease of varying aetiology. Transient elastography has been compared with histological assessment of percutaneous liver biopsy, with high sensitivity and specificity for the diagnosis of cirrhosis, and has also been used to assess pre-cirrhotic disease. However, the cut-off values between different histological stages vary substantially in different studies, patient groups and aetiology of liver disease. More recent studies have examined the possible place of transient elastography in clinical practice, including risk stratification for the development of complications of cirrhosis. This review describes the technique of transient elastography and discusses the interpretation of recent studies, emphasizing its applicability in the clinical setting.


Assuntos
Cirrose Hepática/diagnóstico , Fígado/diagnóstico por imagem , Humanos , Cirrose Hepática/complicações , Ultrassonografia/tendências
16.
Oral Dis ; 13(1): 88-92, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17241436

RESUMO

OBJECTIVE: To compare the effect of a single 5-mg dose of pilocarpine hydrochloride on the salivary flow rate in three groups of xerostomic patients. SUBJECTS AND METHODS: Forty-five patients were divided into three groups according to the etiology of their xerostomia: (i) radiotherapy; (ii) Sjögren's syndrome; and (iii) sialosis and xerogenic medications. Following the oral administration of a 5-mg pilocarpine hydrochloride tablet blood pressure, heart rate, body temperature and saliva secretion rates were monitored hourly for 3 h and adverse events were reported. RESULTS: The most significant and persistent elevation of salivary flow rate was observed in the sialosis/drug-induced group followed by the Sjögren's syndrome group. The radiotherapy group presented a significant elevation of salivary secretion rate after 1 and 2 h, but returned to baseline at 3 h. No significant changes in vital signs were reported, except for low diastolic pressure measured at 1 h in the radiotherapy group. Several adverse events were recorded throughout the trial; however, only one patient withdrew from the study. CONCLUSION: Treatment with pilocarpine hydrochloride tablets may improve saliva secretion in patients taking xerogenic medications and/or suffering from metabolic sialosis expanding the beneficial potential of this sialogogue.


Assuntos
Agonistas Muscarínicos/uso terapêutico , Pilocarpina/uso terapêutico , Xerostomia/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Pressão Sanguínea/efeitos dos fármacos , Temperatura Corporal/efeitos dos fármacos , Estudos de Coortes , Tontura/induzido quimicamente , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Feminino , Seguimentos , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Agonistas Muscarínicos/administração & dosagem , Agonistas Muscarínicos/efeitos adversos , Pilocarpina/administração & dosagem , Pilocarpina/efeitos adversos , Radioterapia/efeitos adversos , Saliva/efeitos dos fármacos , Saliva/metabolismo , Taxa Secretória/efeitos dos fármacos , Sialadenite/complicações , Síndrome de Sjogren/complicações , Sudorese/efeitos dos fármacos , Micção/efeitos dos fármacos , Xerostomia/etiologia
17.
J Thromb Haemost ; 4(10): 2262-9, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16836660

RESUMO

OBJECTIVES: To determine if polymorphisms of the tissue plasminogen activator (t-PA) gene influence acute endogenous t-PA release in patients with coronary heart disease (CHD). METHODS: Forearm blood flow and plasma t-PA concentrations were measured in response to intra-brachial infusion of substance P and sodium nitroprusside in 96 patients with stable CHD. Genotyping was performed using a Taqman polymerase chain reaction assay specifically designed to detect the polymorphisms of interest: (i) Alu-repeat insertion/deletion sequence; (ii) C-->T substitution in an upstream enhancer region (-7351 C/T); (iii) T-->C in exon 6 (20 099 T/C); and (iv) T-->A (27 445 T/A) in intron 10. RESULTS: Substance P and sodium nitroprusside caused dose-dependent increases in forearm blood flow in all patients (P < 0.001 for all) that were independent of the four genetic polymorphisms. Similarly, there were no differences in basal plasma t-PA antigen concentrations or net t-PA release between genotypes. Compared to non-smokers, smokers exhibited impaired substance P-induced vasodilatation (P < 0.001) and t-PA release (P = 0.05). CONCLUSIONS: Despite confirming our previous findings in cigarette smokers, we have found no effect of polymorphisms of the t-PA gene on two complementary aspects of endothelial function. We conclude that genetic variation of the t-PA locus is unlikely to have a major influence on acute t-PA release in subjects with established CHD.


Assuntos
Doença das Coronárias/genética , Doença das Coronárias/patologia , Polimorfismo Genético , Ativador de Plasminogênio Tecidual/genética , Ativador de Plasminogênio Tecidual/metabolismo , Idoso , Feminino , Fibrinólise/genética , Deleção de Genes , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Nitroprussiato/farmacologia , Substância P/farmacologia , Ativador de Plasminogênio Tecidual/fisiologia
18.
Gut ; 55(4): 547-53, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16210399

RESUMO

BACKGROUND AND AIMS: One proposed mechanism whereby hepatic encephalopathy (HE) leads to loss of brain function is dysregulated synthesis of neurosteroids. Mitochondrial synthesis of neurosteroids is regulated by "peripheral benzodiazepine binding sites" (PBBS). Expressed in the brain by activated glial cells, PBBS can be measured in vivo by the specific ligand [11C](R)-PK11195 and positron emission tomography (PET). Recently, it has been suggested that PBBS expressing glial cells may play a role in the general inflammatory responses seen in HE. Therefore, we measured PBBS in vivo in the brains of patients with minimal HE using [11C](R)-PK11195 PET. METHODS: Five patients with minimal HE and biopsy proven cirrhosis of differing aetiology were assessed with a neuropsychometric battery. Regional expression of PBBS in the brain was detected by [11C](R)-PK11195 PET. RESULTS: All patients showed brain regions with increased [11C](R)-PK11195 binding. Significant increases in glial [11C](R)-PK11195 binding were found bilaterally in the pallidum, right putamen, and right dorsolateral prefrontal region. The patient with the most severe cognitive impairment had the highest increases in regional [11C](R)-PK11195 binding. CONCLUSION: HE is associated with increased cerebral binding of [11C](R)-PK11195 in vivo, reflecting increased expression of PBBS by glial cells. This supports earlier experimental evidence in rodent models of liver failure, suggesting that an altered glial cell state, as evidenced by the increase in cerebral PBBS, might be causally related to impaired brain functioning in HE.


Assuntos
Benzodiazepinas/metabolismo , Encéfalo/metabolismo , Encefalopatia Hepática/metabolismo , Idoso , Sítios de Ligação , Estudos de Coortes , Feminino , Encefalopatia Hepática/psicologia , Humanos , Cirrose Hepática/metabolismo , Cirrose Hepática/psicologia , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons/métodos , Psicometria/métodos
19.
Gut ; 54(6): 829-34, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15888793

RESUMO

BACKGROUND: Intrahepatic cholestasis of pregnancy (ICP) affects approximately 0.7% of pregnancies in the UK and is associated with prematurity, fetal distress, and intrauterine death. Homozygous mutations in the ATP8B1 gene cause cholestasis with a normal serum gamma-glutamyl transpeptidase (gamma-GT), and have been reported in two forms of cholestasis: progressive familial intrahepatic cholestasis type 1 (PFIC1) and benign recurrent intrahepatic cholestasis (BRIC). AIMS: To establish whether mutations in ATP8B1 are associated with ICP in British cases PATIENTS: Sixteen well phenotyped women with ICP without raised gamma-GT were selected for sequence analysis. Subsequently, 182 patients and 120 controls were examined for the presence of the variants detected. METHODS: All coding exons were sequenced in 16 cases. Eight ICP cases, including two women carrying a mutation, were investigated using in vivo hepatic (31)P magnetic resonance spectroscopy (MRS) RESULTS: Two heterozygous ATP8B1 transitions (208G>A and 2599C>T) that resulted in amino acid substitutions were identified; 208G>A was identified in three cases. MRS revealed an increased phosphodiester signal (Mann-Whitney U test, p = 0.03) and a decreased phosphomonoester/phosphodiester ratio (p = 0.04) in ICP cases compared with controls. CONCLUSIONS: We were able to demonstrate ATP8B1 mutations in ICP. MRS studies suggest that susceptibility to ICP is associated with a relative rise in biliary phospholipid. These data also suggest that MRS may be used for non-invasive assessment of the liver and biliary constituents in cholestasis.


Assuntos
Adenosina Trifosfatases/genética , Colestase Intra-Hepática/genética , Mutação/genética , Complicações na Gravidez , Colestase Intra-Hepática/metabolismo , Ésteres/metabolismo , Feminino , Testes Genéticos/métodos , Heterozigoto , Humanos , Fígado/metabolismo , Espectroscopia de Ressonância Magnética , Gravidez , Complicações na Gravidez/metabolismo , Análise de Sequência
20.
Gut ; 54(1): 122-7, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15591516

RESUMO

BACKGROUND: Hepatic steatosis is associated with obesity and type II diabetes. Proton magnetic resonance spectroscopy (1H MRS) is a non-invasive method for measurement of tissue fat content, including intrahepatocellular lipids (IHCL) and intramyocellular lipids (IMCL). PATIENTS AND METHODS: We used 1H MRS and whole body magnetic resonance imaging (MRI) to assess the relationship between IHCL accumulation, total body adipose tissue (AT) content/distribution, and IMCL content in 11 subjects with biopsy proven hepatic steatosis and 23 normal volunteers. RESULTS: IHCL signals were detectable in all subjects but were significantly greater in hepatic steatosis (geometric mean (GM) 11.5 (interquartile range (IQR) 7.0-39.0)) than in normal volunteers (GM 2.7 (IQR 0.7-9.3); p=0.02). In the study group as a whole, IHCL levels were significantly greater in overweight compared with lean subjects (body mass index (BMI) >25 kg/m2 (n=23): GM 7.7 (IQR 4.0-28.6) v BMI <25 kg/m2 (n=11): GM 1.3 (IQR 0.3-3.6; p=0.004)). There was a significant association between IHCL content and indices of overall obesity (expressed as a percentage of body weight) for total body fat (p=0.001), total subcutaneous AT (p=0.007), and central obesity (subcutaneous abdominal AT (p=0.001) and intra-abdominal AT (p=0.001)), after allowing for sex and age. No correlation between IHCL content and IMCL was observed. A significant correlation was observed between serum alanine aminotransferase and liver fat content (r=0.57, p=0.006). CONCLUSIONS: Our results suggest that hepatic steatosis appears to be closely related to body adiposity, especially central obesity. MRS may be a useful method for monitoring IHCL in future interventional studies.


Assuntos
Fígado Gorduroso/metabolismo , Fígado/química , Obesidade/metabolismo , Triglicerídeos/análise , Abdome/patologia , Tecido Adiposo/patologia , Adulto , Idoso , Antropometria , Fígado Gorduroso/etiologia , Fígado Gorduroso/patologia , Feminino , Humanos , Lipídeos/análise , Fígado/patologia , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/química , Obesidade/complicações , Obesidade/patologia
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