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1.
Ann Surg ; 277(3): e569-e577, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-34387206

RESUMO

OBJECTIVE: Rapid evaporative ionization mass spectrometry (REIMS) is a metabolomic technique analyzing tissue metabolites, which can be applied intraoperatively in real-time. The objective of this study was to profile the lipid composition of colorectal tissues using REIMS, assessing its accuracy for real-time tissue recognition and risk-stratification. SUMMARY BACKGROUND DATA: Metabolic dysregulation is a hallmark feature of carcinogenesis; however, it remains unknown if this can be leveraged for real-time clinical applications in colorectal disease. METHODS: Patients undergoing colorectal resection were included, with carcinoma, adenoma and paired-normal mucosa sampled. Ex vivo analysis with REIMS was conducted using monopolar diathermy, with the aerosol aspirated into a Xevo G2S QToF mass spectrometer. Negatively charged ions over 600 to 1000 m/z were used for univariate and multivariate functions including linear discriminant analysis. RESULTS: A total of 161 patients were included, generating 1013 spectra. Unique lipidomic profiles exist for each tissue type, with REIMS differentiating samples of carcinoma, adenoma, and normal mucosa with 93.1% accuracy and 96.1% negative predictive value for carcinoma. Neoplasia (carcinoma or adenoma) could be predicted with 96.0% accuracy and 91.8% negative predictive value. Adenomas can be risk-stratified by grade of dysplasia with 93.5% accuracy, but not histological subtype. The structure of 61 lipid metabolites was identified, revealing that during colorectal carcinogenesis there is progressive increase in relative abundance of phosphatidylglycerols, sphingomyelins, and mono-unsaturated fatty acid-containing phospholipids. CONCLUSIONS: The colorectal lipidome can be sampled by REIMS and leveraged for accurate real-time tissue recognition, in addition to riskstratification of colorectal adenomas. Unique lipidomic features associated with carcinogenesis are described.


Assuntos
Adenoma , Carcinoma , Neoplasias Colorretais , Humanos , Lipidômica , Espectrometria de Massas , Neoplasias Colorretais/patologia , Lipídeos , Carcinogênese , Adenoma/diagnóstico , Adenoma/cirurgia , Adenoma/metabolismo
2.
Liver Int ; 43(9): 1890-1900, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37208943

RESUMO

BACKGROUND AND AIMS: Sleeve gastrectomy (VSG) leads to improvement in hepatic steatosis, associated with weight loss. The aims of this study were to investigate whether VSG leads to weight-loss independent improvements in liver steatosis in mice with diet-induced obesity (DIO); and to metabolically and transcriptomically profile hepatic changes in mice undergoing VSG. METHODS: Mice with DIO were treated with VSG, sham surgery with subsequent food restriction to weight-match to the VSG group (Sham-WM), or sham surgery with return to unrestricted diet (Sham-Ad lib). Hepatic steatosis, glucose tolerance, insulin and glucagon resistance, and hepatic transcriptomics were investigated at the end of the study period and treatment groups were compared with mice undergoing sham surgery only (Sham-Ad lib). RESULTS: VSG led to much greater improvement in liver steatosis than Sham-WM (liver triglyceride mg/mg 2.5 ± 0.1, 2.1 ± 0.2, 1.6 ± 0.1 for Sham-AL, Sham-WM and VSG respectively; p = 0.003). Homeostatic model assessment of insulin resistance was improved following VSG only (51.2 ± 8.8, 36.3 ± 5.3, 22.3 ± 6.1 for Sham-AL, Sham-WM and VSG respectively; p = 0.03). The glucagon-alanine index, a measure of glucagon resistance, fell with VSG but was significantly increased in Sham-WM (9.8 ± 1.7, 25.8 ± 4.6 and 5.2 ± 1.2 in Sham Ad-lib, Sham-WM and VSG respectively; p = 0.0003). Genes downstream of glucagon receptor signalling which govern fatty acid synthesis (Acaca, Acacb, Me1, Acly, Fasn and Elovl6) were downregulated following VSG but upregulated in Sham-WM. CONCLUSIONS: Changes in glucagon sensitivity may contribute to weight-loss independent improvements in hepatic steatosis following VSG.


Assuntos
Fígado Gorduroso , Glucagon , Camundongos , Animais , Glicemia , Redução de Peso , Obesidade/complicações , Obesidade/cirurgia , Fígado Gorduroso/complicações , Gastrectomia/efeitos adversos
3.
Biomed Pharmacother ; 176: 116888, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38861859

RESUMO

OBJECTIVES: Co-agonists at the glucagon-like peptide-1 and glucagon receptors (GLP1R/GCGR) show promise as treatments for metabolic dysfunction-associated steatotic liver disease (MASLD). Although most co-agonists to date have been heavily GLP1R-biased, glucagon directly acts on the liver to reduce fat content. The aims of this study were to investigate a GCGR-biased co-agonist as treatment for hepatic steatosis in mice. METHODS: Mice with diet-induced obesity (DIO) were treated with Dicretin, a GLP1/GCGR co-agonist with high potency at the GCGR, Semaglutide (GLP1R monoagonist) or food restriction over 24 days, such that their weight loss was matched. Hepatic steatosis, glucose tolerance, hepatic transcriptomics, metabolomics and lipidomics at the end of the study were compared with Vehicle-treated mice. RESULTS: Dicretin lead to superior reduction of hepatic lipid content when compared to Semaglutide or equivalent weight loss by calorie restriction. Markers of glucose tolerance and insulin resistance improved in all treatment groups. Hepatic transcriptomic and metabolomic profiling demonstrated many changes that were unique to Dicretin-treated mice. These include some known targets of glucagon signaling and others with as yet unclear physiological significance. CONCLUSIONS: Our study supports the development of GCGR-biased GLP1/GCGR co-agonists for treatment of MASLD and related conditions.


Assuntos
Fígado Gorduroso , Peptídeo 1 Semelhante ao Glucagon , Camundongos Endogâmicos C57BL , Obesidade , Receptores de Glucagon , Redução de Peso , Animais , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Redução de Peso/efeitos dos fármacos , Receptores de Glucagon/agonistas , Receptores de Glucagon/metabolismo , Masculino , Fígado Gorduroso/tratamento farmacológico , Fígado Gorduroso/metabolismo , Camundongos , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Dieta Hiperlipídica/efeitos adversos , Fígado/metabolismo , Fígado/efeitos dos fármacos , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Resistência à Insulina , Peptídeos Semelhantes ao Glucagon/farmacologia
4.
Cancers (Basel) ; 11(8)2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31408970

RESUMO

The FOXFIRE (5-Fluorouracil, OXaliplatin and Folinic acid ± Interventional Radio-Embolisation) clinical trial combined systemic chemotherapy (OxMdG: Oxaliplatin, 5-fluorouracil and folic acid) with Selective Internal Radiation Therapy (SIRT or radio-embolisation) using yttrium-90 resin microspheres in the first-line management for liver-dominant metastatic colorectal cancer (CRC). We report clinical outcomes for patients having hepatic resection after this novel combination therapy and an exploratory analysis of histopathology. Multi-Disciplinary Teams deemed all patients inoperable before trial registration and reassessed them during protocol therapy. Proportions were compared using Chi-squared tests and survival using Cox models. FOXFIRE randomised 182 participants to chemotherapy alone and 182 to chemotherapy with SIRT. There was no statistically significant difference in the resection rate between groups: Chemotherapy alone was 18%, (n = 33); SIRT combination was 21% (n = 38) (p = 0.508). There was no statistically significant difference between groups in the rate of liver surgery, nor in survival from time of resection (hazard ratio (HR) = 1.55; 95% confidence interval (CI) = 0.83-2.89). In the subgroup studied for histopathology, microsphere density was highest at the tumour periphery. Patients treated with SIRT plus chemotherapy displayed lower values of viable tumour in comparison to those treated with chemotherapy alone (p < 0.05). This study promotes the feasibility of hepatic resection following SIRT. Resin microspheres appear to preferentially distribute at the tumour periphery and may enhance tumour regression.

5.
Mucosal Immunol ; 12(5): 1212-1219, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31239514

RESUMO

Gut-associated lymphoid tissue (GALT) is a key location for the HIV reservoir. The observation that B-cell-T-cell doublets are enriched for CD32a (a low-affinity IgG receptor) in peripheral blood raises interesting questions, especially as these cells have been associated with HIV DNA in some studies. We sought to determine if similar doublets were present in GALT, the significance of these doublets, and their implications for the HIV reservoir. Given the importance of GALT as a reservoir for HIV, we looked for expression of CD32 on gut CD4 T cells and for evidence of doublets, and any relationship with HIV DNA in HIV + individuals initiated on antiretroviral therapy (ART) during primary HIV infection (PHI). Tonsil tissue was also available for one individual. As previously shown for blood, CD32high CD4 cells were mainly doublets of CD4 T cells and B cells, with T-cell expression of ICOS in tonsil and gut tissue. CD4 T cells associated with CD32 (compared with 'CD32-' CD4 cells) had higher expression of follicular markers CXCR5, PD-1, ICOS, and Bcl-6 consistent with a T follicular helper (TFH) phenotype. There was a significant correlation between rectal HIV DNA levels and CD32 expression on TFH cells. Together, these data suggest that CD32high doublets are primarily composed of TFH cells, a subset known to be preferentially infected by HIV.


Assuntos
Infecções por HIV/genética , Infecções por HIV/virologia , HIV-1/fisiologia , Nódulos Linfáticos Agregados/metabolismo , Nódulos Linfáticos Agregados/virologia , Receptores de IgG/genética , Linfócitos T Auxiliares-Indutores/metabolismo , Linfócitos T Auxiliares-Indutores/virologia , Adulto , Idoso , Terapia Antirretroviral de Alta Atividade , Linfócitos B/imunologia , Linfócitos B/metabolismo , Biomarcadores , Contagem de Linfócito CD4 , Feminino , Expressão Gênica , Infecções por HIV/imunologia , Infecções por HIV/metabolismo , Humanos , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Nódulos Linfáticos Agregados/imunologia , Receptores de IgG/metabolismo , Linfócitos T Auxiliares-Indutores/imunologia , Carga Viral
6.
J Clin Invest ; 129(9): 3640-3656, 2019 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-31162141

RESUMO

Physiological effects of cellular hypoxia are sensed by prolyl hydroxylase (PHD) enzymes which regulate HIFs. Genetic interventions on HIF/PHD pathways reveal multiple phenotypes that extend the known biology of hypoxia. Recent studies unexpectedly implicate HIF in aspects of multiple immune and inflammatory pathways. However such studies are often limited by systemic lethal effects and/or use tissue-specific recombination systems, which are inherently irreversible, un-physiologically restricted and difficult to time. To study these processes better we developed recombinant mice which express tetracycline-regulated shRNAs broadly targeting the main components of the HIF/PHD pathway, permitting timed bi-directional intervention. We have shown that stabilization of HIF levels in adult mice through PHD2 enzyme silencing by RNA interference, or inducible recombination of floxed alleles, results in multi-lineage leukocytosis and features of autoimmunity. This phenotype was rapidly normalized on re-establishment of the hypoxia-sensing machinery when shRNA expression was discontinued. In both situations these effects were mediated principally through the Hif2a isoform. Assessment of cells bearing regulatory T cell markers from these mice revealed defective function and pro-inflammatory effects in vivo. We believe our findings have shown a new role for the PHD2/Hif2a couple in the reversible regulation of T cell and immune activity.


Assuntos
Prolina Dioxigenases do Fator Induzível por Hipóxia , Interferência de RNA/imunologia , Transdução de Sinais , Linfócitos T Reguladores , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/imunologia , Prolina Dioxigenases do Fator Induzível por Hipóxia/genética , Prolina Dioxigenases do Fator Induzível por Hipóxia/imunologia , Camundongos , Camundongos Transgênicos , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/metabolismo
7.
Sci Rep ; 7(1): 8979, 2017 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-28827587

RESUMO

Colon cancer induces a state of mucosal dysbiosis with associated niche specific changes in the gut microbiota. However, the key metabolic functions of these bacteria remain unclear. We performed a prospective observational study in patients undergoing elective surgery for colon cancer without mechanical bowel preparation (n = 18). Using 16 S rRNA gene sequencing we demonstrated that microbiota ecology appears to be cancer stage-specific and strongly associated with histological features of poor prognosis. Fusobacteria (p < 0.007) and ε- Proteobacteria (p < 0.01) were enriched on tumour when compared to adjacent normal mucosal tissue, and fusobacteria and ß-Proteobacteria levels increased with advancing cancer stage (p = 0.014 and 0.002 respecitvely). Metabonomic analysis using 1H Magic Angle Spinning Nuclear Magnetic Resonsance  (MAS-NMR) spectroscopy, demonstrated increased abundance of taurine, isoglutamine, choline, lactate, phenylalanine and tyrosine and decreased levels of lipids and triglycerides in tumour relative to adjacent healthy tissue. Network analysis revealed that bacteria associated with poor prognostic features were not responsible for the modification of the cancer mucosal metabonome. Thus the colon cancer mucosal microbiome evolves with cancer stage to meet the demands of cancer metabolism. Passenger microbiota may play a role in the maintenance of cancer mucosal metabolic homeostasis but these metabolic functions may not be stage specific.


Assuntos
Neoplasias Colorretais/microbiologia , Neoplasias Colorretais/patologia , Microbioma Gastrointestinal , Mucosa Intestinal/química , Mucosa Intestinal/microbiologia , Metaboloma , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Humanos , Espectroscopia de Ressonância Magnética , Metabolômica , Metagenômica , Microbiota , Filogenia , Estudos Prospectivos , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
8.
PLoS One ; 12(1): e0170285, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28114394

RESUMO

BACKGROUND: Kveim-reagent (Kv) skin testing was a historical method of diagnosing sarcoidosis. Intradermal injection of treated sarcoidosis spleen tissue resulted in a granuloma response at injection site by 4-6 weeks. Previous work indicates proteins as the possible trigger of this reaction. We aimed to identify Kv-specific proteins and characterise the ex vivo response of Peripheral Blood Mononuclear Cells (PBMCs) from sarcoidosis, tuberculosis and healthy control patients when stimulated with both Kv and selected Kv-specific proteins. METHODS: Kv extracts were separated by 1D-SDS-PAGE and 2D-DIGE and then underwent mass spectrometric analysis for protein identification. Sarcoidosis and control PBMCs were first stimulated with Kv and then with three selected recombinant protein candidates which were identified from the proteomic analysis. PBMC secreted cytokines were subsequently measured by Multiplex Cytokine Assay. RESULTS: We observed significantly increased IFN-γ and TNF-α secretion from Kv-stimulated PBMCs of sarcoidosis patients vs. PBMCs from healthy volunteers (IFN-γ: 207.2 pg/mL vs. 3.86 pg/mL, p = 0.0018; TNF-α: 2375 pg/mL vs. 42.82 pg/mL, p = 0.0003). Through proteomic approaches we then identified 74 sarcoidosis tissue-specific proteins. Of these, 3 proteins (vimentin, tubulin and alpha-actinin-4) were identified using both 1D-SDS-PAGE and 2D-DIGE. Data are available via ProteomeXchange with identifier PXD005150. Increased cytokine secretion was subsequently observed with vimentin stimulation of sarcoidosis PBMCs vs. tuberculosis PBMCs (IFN-γ: 396.6 pg/mL vs 0.1 pg/mL, p = 0.0009; TNF-α: 1139 pg/mL vs 0.1 pg/mL, p<0.0001). This finding was also observed in vimentin stimulation of sarcoidosis PBMCs compared to PBMCs from healthy controls (IFN-γ: 396.6 pg/mL vs. 0.1 pg/mL, p = 0.014; TNF-α: 1139 pg/mL vs 42.29 pg/mL, p = 0.027). No difference was found in cytokine secretion between sarcoidosis and control PBMCs when stimulated with either tubulin or alpha-actinin-4. CONCLUSIONS: Stimulation with both Kveim reagent and vimentin induces a specific pro-inflammatory cytokine secretion from sarcoidosis PBMCs. Further investigation of cellular immune responses to Kveim-specific proteins may identify novel biomarkers to assist the diagnosis of sarcoidosis.


Assuntos
Imunidade Celular , Indicadores e Reagentes/química , Proteômica , Sarcoidose/imunologia , Adulto , Eletroforese em Gel de Poliacrilamida , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Espectrometria de Massas em Tandem
9.
J Am Soc Mass Spectrom ; 27(2): 255-64, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26466600

RESUMO

In this study, we make a direct comparison between desorption electrospray ionization-mass spectrometry (DESI-MS) and ultraperformance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS) platforms for the profiling of glycerophospholipid (GPL) species in esophageal cancer tissue. In particular, we studied the similarities and differences in the range of GPLs detected and the congruency of their relative abundances as detected by each analytical platform. The main differences between mass spectra of the two modalities were found to be associated with the variance in adduct formation of common GPLs, rather than the presence of different GPL species. Phosphatidylcholines as formate adducts in UPLC-ESI-MS accounted for the majority of differences in negative ion mode and alkali metal adducts of phosphatidylcholines in DESI-MS for positive ion mode. Comparison of the relative abundance of GPLs, normalized to a common peak, revealed a correlation coefficient of 0.70 (P < 0.001). The GPL profile detected by DESI-MS is congruent to UPLC-ESI-MS, which reaffirms the role of DESI-MS for lipidomic profiling and a potential premise for quantification.


Assuntos
Cromatografia Líquida/métodos , Neoplasias Esofágicas/química , Glicerofosfolipídeos/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Neoplasias Esofágicas/metabolismo , Humanos , Potássio/química , Processamento de Sinais Assistido por Computador , Sódio/química
10.
Toxicol Res (Camb) ; 5(6): 1594-1603, 2016 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30090460

RESUMO

Several hundred cases of Hirmi Valley Liver Disease (HVLD), an often fatal liver injury, occurred from 2001 to 2011 in a cluster of rural villages in Tigray, Ethiopia. HVLD is principally caused by contamination of the food supply with plant derived pyrrolizidine alkaloids (PAs), with high exposure to the pesticide DDT among villagers increasing their susceptibility. In an untargeted global approach we aimed to identify metabolic changes induced by PA exposure through 1H NMR spectroscopic based metabolic profiling. We analysed spectra acquired from urine collected from HVLD cases and controls and a murine model of PA exposure and PA/DDT co-exposure, using multivariate partial least squares discriminant analysis. In the human models we identified changes in urinary concentrations of tyrosine, pyruvate, bile acids, N-acetylglycoproteins, N-methylnicotinamide and formate, hippurate, p-cresol sulphate, p-hydroxybenzoate and 3-(3-hydroxyphenyl) propionic acid. Tyrosine and p-cresol sulphate were associated with both exposure and disease. Similar changes to tyrosine, one-carbon intermediates and microbial associated metabolites were observed in the mouse model, with tyrosine correlated with the extent of liver damage. These results provide mechanistic insight and implicate the gut microflora in the human response to challenge with toxins. Pathways identified here may be useful in translational research and as "exposome" signals.

11.
World J Gastrointest Endosc ; 7(1): 66-72, 2015 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-25610536

RESUMO

AIM: To investigate whether dysplastic Barrett's Oesophagus can be safely and effectively treated endoscopically in low volume centres after structured training. METHODS: After attending a structured training program in Amsterdam on the endoscopic treatment of dysplastic Barrett's Oesophagus, treatment of these patients was initiated at St Marys Hospital. This is a retrospective case series conducted at a United Kingdom teaching Hospital, of patients referred for endoscopic treatment of Barrett's oesophagus with high grade dysplasia or early cancer, who were diagnosed between January 2008 and February 2012. Data was collected on treatment provided (radiofrequency ablation and endoscopic resection), and success of treatment both at the end of treatment and at follow up. Rates of immediate and long term complications were assessed. RESULTS: Thirty-two patients were referred to St Marys with high grade dysplasia or intramucosal cancer within a segment of Barrett's Oesophagus. Twenty-seven met the study inclusion criteria, 16 of these had a visible nodule at initial endoscopy. Treatment was given over a median of 5 mo, and patients received a median of 3 treatment sessions over this time. At the end of treatment dysplasia was successfully eradicated in 96% and intestinal metaplasia in 88%, on per protocol analysis. Patients were followed up for a median of 18 mo. At which time complete eradication of dysplasia was maintained in 86%. Complications were rare: 2 patients suffered from post-procedural bleeding, 4 cases were complicated by oesophageal stenosis. Recurrence of cancer was seen in 1 case. CONCLUSION: With structured training good outcomes can be achieved in low volume centres treating dysplastic Barrett's Oesophagus.

12.
Trials ; 15: 200, 2014 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-24888266

RESUMO

BACKGROUND: There is a need for evidence of the clinical effectiveness of minimally invasive surgery for the treatment of esophageal cancer, but randomized controlled trials in surgery are often difficult to conduct. The ROMIO (Randomized Open or Minimally Invasive Oesophagectomy) study will establish the feasibility of a main trial which will examine the clinical and cost-effectiveness of minimally invasive and open surgical procedures for the treatment of esophageal cancer. METHODS/DESIGN: A pilot randomized controlled trial (RCT), in two centers (University Hospitals Bristol NHS Foundation Trust and Plymouth Hospitals NHS Trust) will examine numbers of incident and eligible patients who consent to participate in the ROMIO study. Interventions will include esophagectomy by: (1) open gastric mobilization and right thoracotomy, (2) laparoscopic gastric mobilization and right thoracotomy, and (3) totally minimally invasive surgery (in the Bristol center only). The primary outcomes of the feasibility study will be measures of recruitment, successful development of methods to monitor quality of surgery and fidelity to a surgical protocol, and development of a core outcome set to evaluate esophageal cancer surgery. The study will test patient-reported outcomes measures to assess recovery, methods to blind participants, assessments of surgical morbidity, and methods to capture cost and resource use. ROMIO will integrate methods to monitor and improve recruitment using audio recordings of consultations between recruiting surgeons, nurses, and patients to provide feedback for recruiting staff. DISCUSSION: The ROMIO study aims to establish efficient methods to undertake a main trial of minimally invasive surgery versus open surgery for esophageal cancer. TRIAL REGISTRATION: The pilot trial has Current Controlled Trials registration number ISRCTN59036820(25/02/2013) at http://www.controlled-trials.com; the ROMIO trial record at that site gives a link to the original version of the study protocol.


Assuntos
Neoplasias Esofágicas/cirurgia , Esofagectomia/métodos , Laparoscopia , Projetos de Pesquisa , Toracotomia , Protocolos Clínicos , Análise Custo-Benefício , Inglaterra , Neoplasias Esofágicas/economia , Neoplasias Esofágicas/patologia , Esofagectomia/efeitos adversos , Esofagectomia/economia , Estudos de Viabilidade , Feminino , Custos de Cuidados de Saúde , Humanos , Laparoscopia/efeitos adversos , Laparoscopia/economia , Masculino , Projetos Piloto , Toracotomia/efeitos adversos , Toracotomia/economia , Resultado do Tratamento
13.
PLoS One ; 8(6): e61870, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23826075

RESUMO

We employed a random mutagenesis approach to identify novel monogenic determinants of type 2 diabetes. Here we show that haplo-insufficiency of the histone methyltransferase myeloid-lineage leukemia (Mll2/Wbp7) gene causes type 2 diabetes in the mouse. We have shown that mice heterozygous for two separate mutations in the SET domain of Mll2 or heterozygous Mll2 knockout mice were hyperglycaemic, hyperinsulinaemic and developed non-alcoholic fatty liver disease. Consistent with previous Mll2 knockout studies, mice homozygous for either ENU mutation (or compound heterozygotes) died during embryonic development at 9.5-14.5 days post coitum. Heterozygous deletion of Mll2 induced in the adult mouse results in a normal phenotype suggesting that changes in chromatin methylation during development result in the adult phenotype. Mll2 has been shown to regulate a small subset of genes, a number of which Neurod1, Enpp1, Slc27a2, and Plcxd1 are downregulated in adult mutant mice. Our results demonstrate that histone H3K4 methyltransferase Mll2 is a component of the genetic regulation necessary for glucose homeostasis, resulting in a specific disease pattern linking chromatin modification with causes and progression of type 2 diabetes, providing a basis for its further understanding at the molecular level.


Assuntos
Teste de Tolerância a Glucose , Resistência à Insulina/genética , Proteína de Leucina Linfoide-Mieloide/genética , Sequência de Aminoácidos , Animais , Genes Letais , Histona-Lisina N-Metiltransferase , Ilhotas Pancreáticas/patologia , Camundongos , Camundongos Knockout , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Proteína de Leucina Linfoide-Mieloide/química , Reação em Cadeia da Polimerase , Homologia de Sequência de Aminoácidos
14.
Hepat Res Treat ; 2011: 524027, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22114737

RESUMO

Background & Aims. Assess the clinical utility of the Prati criteria and normal ALT (<40 IU/L) in a cohort of patients with chronic hepatitis B infection (CHB). Methods. Serology, radiology, and histology were obtained in 140 patients with CHB. Results. HBeAg(+) group: 7 patients (7/56-12% HBeAg(+) group) misclassified as "immunotolerant", with HBV DNA > 6 log copies/ml and normal ALT, who in fact had moderate/severe fibrosis on liver biopsy. HBeAg(-) group: 10 patients with normal ALT and moderate/severe fibrosis on liver biopsy; 4 of these patients had >3 log copies/ml HBV DNA levels and 6 patients misclassified as "inactive carriers" with negative HBV DNA levels normal ALT and moderate/severe fibrosis (6/84-7% HBeAg(-) group). Two male HBeAg(+) and three male HBeAg(-) patients with ALT between 20 and 30 IU/L and moderate/severe fibrosis on liver biopsy would have been further mischaracterised using the Prati criteria for normal ALT. Age and ethnic group were more important predictors of moderate/severe fibrosis in multivariate analysis. Conclusion. HBeAg status, age, ethnic origin with longitudinal assessment of LFTs and viral load should be studied in patients with "normal ALT" at the upper end of normal range (ALT 20-40 IU/L) to appropriately classify patients and identify patients for liver fibrosis assessment to inform treatment decisions.

15.
Infect Immun ; 71(9): 5077-86, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12933850

RESUMO

Citrobacter rodentium, an attaching-effacing bacterial pathogen, establishes an acute infection of the murine colonic epithelium and induces a mild colitis in immunocompetent mice. This study describes the role of T-cell subsets and B lymphocytes in immunity to C. rodentium. C57Bl/6 mice orally infected with C. rodentium resolved infection within 3 to 4 weeks. Conversely, systemic and colonic tissues of RAG1(-/-) mice orally infected with C. rodentium contained high and sustained pathogen loads, and in the colon this resulted in a severe colitis. C57Bl/6 mice depleted of CD4(+) T cells, but not CD8(+) T cells, were highly susceptible to infection and also developed severe colitis. Mice depleted of CD4(+) T cells also had diminished immunoglobulin G (IgG) and IgA antibody responses to two C. rodentium virulence-associated determinants, i.e., EspA and intimin, despite having a massively increased pathogen burden. Mice with an intact T-cell compartment, but lacking B cells ( micro MT mice), were highly susceptible to C. rodentium infection. Systemic immunity, but not mucosal immunity, could be restored by adoptive transfer of convalescent immune sera to infected micro MT mice. Adoptive transfer of immune B cells, but not naïve B cells, provided highly variable immunity to recipient micro MT mice. The results suggest that B-cell-mediated immune responses are central to resolution of a C. rodentium infection but that the mechanism through which this occurs requires further investigation. These data are relevant to understanding immunity to enteric attaching and effacing bacterial pathogens of humans.


Assuntos
Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Citrobacter freundii/imunologia , Citrobacter freundii/patogenicidade , Infecções por Enterobacteriaceae/imunologia , Transferência Adotiva , Animais , Anticorpos Antibacterianos/biossíntese , Antígenos de Bactérias , Proteínas de Bactérias/imunologia , Colo/imunologia , Colo/patologia , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/patologia , Feminino , Genes RAG-1 , Imunocompetência , Hospedeiro Imunocomprometido , Depleção Linfocítica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Virulência
16.
Immunogenetics ; 55(6): 362-9, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12942209

RESUMO

The natural outcome and response to treatment in hepatitis C virus (HCV) infection varies between individuals. Whereas some variation may be attributable to viral and environmental variables, it is probable that host genetic background also plays a significant role. Interleukin (IL)-10 has a key function in the regulation of cellular immune responses and in the suppression of pro-inflammatory cytokine secretion. Functional polymorphisms in the IL-10 gene have been described. We investigated the role of these polymorphisms in the outcome of HCV infection, treatment response and development of fibrosis in a case-control association study. Self-limiting infection was associated with the IL-10 (-592) AA genotype (OR=2.05; P=0.028). Persistent infection was associated with the IL-10 (-1082) GG genotype (OR=0.48; P=0.018). Sustained response to interferon therapy was associated with the IL-10 (-1082) GG genotype (OR=2.28; P=0.005) and the haplotype GCC (OR=2.27; P=0.020). The IL-10 (-1082) AA genotype and the ATA/ATA and ACC/ACC homozygous haplotypes were more frequent among patients with rapid fibrosis. Furthermore, the microsatellites IL-10.R and IL-10.G were associated with interferon response with IL-10R.2 conveying susceptibility (OR=1.80; P=0.034), and IL-10R.3 and IL-10.G13 being protective (OR=0.47; P=0.003 and OR=0.59; P=0.042, respectively). We conclude that polymorphisms in the IL-10 promoter appear to have some influence on the outcome of HCV infection, treatment and development of fibrosis.


Assuntos
Hepatite C/genética , Interleucina-10/genética , Regiões Promotoras Genéticas , Progressão da Doença , Feminino , Fibrose , Haplótipos , Hepatite C/fisiopatologia , Hepatite C/terapia , Humanos , Masculino , Polimorfismo Genético , Resultado do Tratamento
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