RESUMEN
AIM: To identify, in vitro, the best fruit juice to use as oral contrast agent in magnetic resonance cholangiopancreatography (MRCP) and to test, in vivo, the best natural juice and the new parameters in MRCP sequences identified in vitro. MATERIALS AND METHODS: The in vitro evaluations consisted of measuring the T2 values of a pure solution of manganese (Mn) and iron (Fe) at different concentrations, measuring the content of Mn and Fe in five commercial juices and their T2 relaxation times, and identifying the optimal juice dilution for suppressing the gastrointestinal fluid signal. The new parameters of MRCP sequences were tested in vivo. RESULTS: Manganese alone strongly influenced the shortening of the T2 values (p=0.004). The T2 value with an echo time (TE) of ≥1,000 ms enabled sufficient intestinal fluid suppression in the case of high juice dilution. A flip angle of 90° maximised the differences between the high signal from static fluids, such as the bile and the fluid in the gastrointestinal tract, using fast imaging employing steady-state acquisition (FIESTA) sequences (p<0.001). CONCLUSION: The shortening of the T2 relaxation time depended only on the Mn concentration. All the commercial juices had an Mn concentration sufficient to suppress the gastrointestinal fluid signal using long TE sequences. The oral ingestion of commercial juice before MRCP was enough to suppress the signal from the gastrointestinal fluids, regardless of its dilution after ingestion. When using FIESTA sequences, a flip angle of 90° allowed the best suppression of gastrointestinal fluid signals.
Asunto(s)
Pancreatocolangiografía por Resonancia Magnética/métodos , Medios de Contraste/administración & dosificación , Jugos de Frutas y Vegetales , Administración Oral , Medios de Contraste/química , Humanos , Técnicas In Vitro , Hierro/química , Manganeso/químicaRESUMEN
Chronic inflammation is an established risk factor for the onset of cancer, and the inflammatory cytokine IL-6 has a role in tumorigenesis by enhancing proliferation and hindering apoptosis. As factors stimulating proliferation also downregulate p53 expression by enhancing ribosome biogenesis, we hypothesized that IL-6 may cause similar changes in inflamed tissues, thus activating a mechanism that favors neoplastic transformation. Here, we showed that IL-6 downregulated the expression and activity of p53 in transformed and untransformed human cell lines. This was the consequence of IL-6-dependent stimulation of c-MYC mRNA translation, which was responsible for the upregulation of rRNA transcription. The enhanced rRNA transcription stimulated the MDM2-mediated proteasomal degradation of p53, by reducing the availability of ribosome proteins for MDM2 binding. The p53 downregulation induced the acquisition of cellular phenotypic changes characteristic of epithelial-mesenchymal transition, such as a reduced level of E-cadherin expression, increased cell invasiveness and a decreased response to cytotoxic stresses. We found that these changes also occurred in colon epithelial cells of patients with ulcerative colitis, a very representative example of chronic inflammation at high risk for tumor development. Histochemical and immunohistochemical analysis of colon biopsy samples showed an upregulation of ribosome biogenesis, a reduced expression of p53, together with a focal reduction or absence of E-cadherin expression in chronic colitis in comparison with normal mucosa samples. These changes disappeared after treatment with anti-inflammatory drugs. Taken together, the present results highlight a new mechanism that may link chronic inflammation to cancer, based on p53 downregulation, which is activated by the enhancement of rRNA transcription upon IL-6 exposure.
Asunto(s)
Colitis Ulcerosa/metabolismo , Neoplasias del Colon/metabolismo , Transición Epitelial-Mesenquimal/efectos de los fármacos , Interleucina-6/farmacología , ARN Ribosómico/genética , Proteína p53 Supresora de Tumor/metabolismo , Adulto , Antiinflamatorios/uso terapéutico , Cadherinas/metabolismo , Línea Celular Tumoral , Colitis Ulcerosa/tratamiento farmacológico , Colitis Ulcerosa/patología , Neoplasias del Colon/tratamiento farmacológico , Neoplasias del Colon/patología , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Células Hep G2 , Humanos , Masculino , Persona de Mediana Edad , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , ARN Ribosómico/metabolismo , Proteínas Ribosómicas/metabolismo , Ribosomas/genética , Ribosomas/metabolismo , Transducción de Señal , Proteína p53 Supresora de Tumor/genéticaRESUMEN
To date, the effects of long-term testosterone (T) administration on the human vagina are not completely understood. Thus, the aim of this study was to investigate the effects of long-term T treatment on vaginal tissue histology, estrogen receptor alpha (ERα) and beta (ERß) expression and proliferation in female to male transsexual subjects (FtM). We compared vaginal samples from FtM subjects with those of premenopausal women (PrM) and postmenopausal women (M) not receiving any hormonal treatment for at least 2 years. Vaginal tissue samples from 16 FtM subjects treated with T (intramuscular injections of 100 mg Testoviron Depot/7-10 days for at least 1 year), undergoing sex reassignment surgery, and 16 PrM and 16 M subjects undergoing a vaginal hysterectomy for prolapse, were collected. For each sample, morphology, glycogen content, proliferation (ki-67), ERα and ERß expression were evaluated. Vaginal samples from FtM showed a loss of normal architecture of the epithelium, intermediate and superficial layers were completely lost, and glycogen content was depleted. T administration resulted in a strong proliferation reduction when compared with both M and PrM subjects. Stromal and epithelial ERα as well as ERß were significantly decreased in FtM when compared with PrM subjects. In conclusion, our data suggests that systemic T administration at supraphysiological dosage, determines profound changes in histomorphology and reduces ERs expression and proliferation of vaginal epithelium.
Asunto(s)
Epitelio/efectos de los fármacos , Receptor alfa de Estrógeno/análisis , Receptor beta de Estrógeno/análisis , Procedimientos de Reasignación de Sexo , Testosterona/administración & dosificación , Vagina/efectos de los fármacos , Adulto , Anciano , Combinación de Medicamentos , Epitelio/anatomía & histología , Femenino , Glucógeno/análisis , Humanos , Antígeno Ki-67/análisis , Persona de Mediana Edad , Posmenopausia , Premenopausia , Transexualidad , Vagina/anatomía & histologíaRESUMEN
A relatively fast analytical method for the identification and quantification of the post-transcriptional changes (PTCs) occurring in circulating human serum albumin (HSA) was developed. HSA is the most abundant protein in plasma and it represents the main determinant of plasma oncotic pressure, thus being the main modulator of fluid distribution between body compartments. Cirrhotic patients have low levels of HSA. Moreover, recent studies have demonstrated that during liver cirrhosis HSA presents PTCs affecting its properties. The HSA isoforms derived from these modifications could represent promising biomarkers for liver disease. Human plasma samples were collected from a cirrhotic patient (CH) and from an aged-matched non- cirrhotic subject (CT), purified by reverse-phase chromatography and analysed by an electrospray ionization quadrupole time-of-flight (ESI-Q-ToF) spectrometer. The deconvoluted ESI mass spectra from healthy subjects were all characterized by peaks attributed to mercaptoalbumin, nitrosylated, cysteinylated, glycated and N- terminal truncated HSA isoforms. The relative abundance of each isoform was derived and transformed into a relative per cent amount and the results were compared to those obtained analysing HSA from a CH plasma. The method was validated in terms of intra-day and inter-day reproducibility, both for quantitative results and PTCs molecular weight determination. The optimized method resulted in being effective in disclosing changes in HSA isoforms relative abundance and then it could be used for the systematic screening of cirrhotic patients to identify promising new biomarkers for liver diseases.
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Fibrosis/metabolismo , Espectrometría de Masas/métodos , Espectrometría de Masas/normas , Albúmina Sérica/análisis , Albúmina Sérica/metabolismo , Biomarcadores/análisis , Biomarcadores/metabolismo , Química Clínica/métodos , Química Clínica/normas , Humanos , Tamizaje Masivo/métodos , Tamizaje Masivo/normas , Persona de Mediana Edad , Procesamiento Proteico-Postraduccional , Reproducibilidad de los Resultados , Albúmina Sérica/química , Relación Estructura-ActividadRESUMEN
Recent data report an important role of testosterone (T) in modulating female sexual responses, but little is known about the expression and distribution of androgen receptor (AR) in the human vagina. Therefore, the aims of our study were to evaluate the expression of AR in the human vagina in premenopausal (PrM) and menopausal (M) women and in T-treated women. Vaginal biopsies were obtained from PrM and postmenopausal women and from women with gender identity disorder (female to male (FtM)) receiving exogenous T. AR gene and protein expression levels in vaginal tissues were determined by real-time PCR and western blot analysis, respectively, whereas the localization of AR in vaginal mucosa and stroma was performed by immunohistochemistry. ARs were detected by immunostaining both in the mucosa and stroma. In vaginal mucosa, AR density score decreases with age but does not change with T administration. In stromal tissue, AR density score does not change with age but significantly increases with T administration (P<0.01). AR protein expression was significantly increased in FtM subjects (P<0.001). The expression of AR messenger RNA (mRNA) evaluated by Real-time PCR showed a significantly higher mRNA expression in FtM versus M patients (P<0.01) and in PrM versus M subjects (P<0.05). In conclusion, we found AR protein and mRNA expression both in the epithelium and stroma of the human vagina in all groups of women. A negative correlation exists between age and AR expression in the vaginal mucosa. T administration increases AR expression in both the mucosa and stroma.