Expression of aryl hydrocarbon receptor (AHR) and AHR-interacting protein in pituitary adenomas: pathological and clinical implications.

peer reviewedaudience: researcher, professionalGermline mutations of the aryl hydrocarbon receptor (AHR)-interacting protein (AIP) gene confer a predisposition to pituitary adenomas (PA), usually in the setting of familial isolated PA. To provide further insights into the possible role of AIP in pituitary tumour pathogenesis, the expression of AIP and AHR was determined by real-time RT-PCR and/or immunohistochemistry (IHC) in a large series of PA (n=103), including 17 with AIP mutations (AIP(mut)). Variable levels of AIP and AHR transcripts were detected in all PA, with a low AHR expression (P<0.0001 versus AIP). Cytoplasmic AIP and AHR were detected by IHC in 84.0 and 38.6% of PA respectively, and significantly correlated with each other (P=0.006). Nuclear AHR was detected in a minority of PA (19.7%). The highest AIP expression was observed in somatotrophinomas and non-secreting (NS) PA, and multivariate analysis in somatotrophinomas showed a significantly lower AIP immunostaining in invasive versus non-invasive cases (P=0.019). AIP expression was commonly low in other secreting PA. AIP immunostaining was abolished in a minority of AIP(mut) PA, with a frequent loss of cytoplasmic AHR and no evidence of nuclear AHR. In contrast, AIP overexpression in a subset of NS PA could be accompanied by nuclear AHR immunopositivity. We conclude that down-regulation of AIP and AHR may be involved in the aggressiveness of somatotrophinomas. Overall, IHC is a poorly sensitive tool for the screening of AIP mutations. Data obtained on AHR expression suggest that AHR signalling may be differentially affected according to PA phenotype

Expression of aryl hydrocarbon receptor (AHR) and AHR-interacting protein in pituitary adenomas: pathological and clinical implications.

Germline mutations of the aryl hydrocarbon receptor (AHR)-interacting protein (AIP) gene confer a predisposition to pituitary adenomas (PA), usually in the setting of familial isolated PA. To provide further insights into the possible role of AIP in pituitary tumour pathogenesis, the expression of AIP and AHR was determined by real-time RT-PCR and/or immunohistochemistry (IHC) in a large series of PA (n=103), including 17 with AIP mutations (AIP(mut)). Variable levels of AIP and AHR transcripts were detected in all PA, with a low AHR expression (P<0.0001 versus AIP). Cytoplasmic AIP and AHR were detected by IHC in 84.0 and 38.6% of PA respectively, and significantly correlated with each other (P=0.006). Nuclear AHR was detected in a minority of PA (19.7%). The highest AIP expression was observed in somatotrophinomas and non-secreting (NS) PA, and multivariate analysis in somatotrophinomas showed a significantly lower AIP immunostaining in invasive versus non-invasive cases (P=0.019). AIP expression was commonly low in other secreting PA. AIP immunostaining was abolished in a minority of AIP(mut) PA, with a frequent loss of cytoplasmic AHR and no evidence of nuclear AHR. In contrast, AIP overexpression in a subset of NS PA could be accompanied by nuclear AHR immunopositivity. We conclude that down-regulation of AIP and AHR may be involved in the aggressiveness of somatotrophinomas. Overall, IHC is a poorly sensitive tool for the screening of AIP mutations. Data obtained on AHR expression suggest that AHR signalling may be differentially affected according to PA phenotype

Hypoxia Promotes Danger-mediated Inflammation via Receptor for Advanced Glycation End Products in Cystic Fibrosis

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Idiopathic scrotal hematoma simulating a testicular torsion, in association with cryptorchidism : US findings

Background: An acute scrotum concerns endoscrotal organs (testicles, spermatic cord, tunica vaginalis) and is characterized by pain, swelling and hyperemia of the hemi-scrotum. It represents one of the most common surgical emergencies in children often caused by testicular torsion; the diagnosis is mostly clinical but must be supported by ultrasonographic examination of the scrotal region in association with a colour Doppler study of the spermatic cord vessels and glandular parenchyma. An idiopathic scrotal hematoma is a very rare condition that can simulate it. Case Report: A 3-day-old full-term baby, otherwise in good health, showed swelling and pain of the left inguinal-scrotal region. A testicular torsion was suspected, so the baby underwent an ultrasound examination of the testis and spermatic cord that showed a left scrotal hematoma with superior displacement of the didymus; the right testicle was located in the internal inguinal canal. Surgical intervention confirmed the sonographic diagnosis of left testicular hematoma and of the right cryptorchidism. Conclusions: Although testicular torsion is the most frequent cause of acute scrotum, the possibility of a persistent idiopathic scrotal haematoma and/or haematoma secondary to a trauma of the inguino-scrotal region, must be always taken into account. US diagnosis can avoid unnecessary emergency surgical treatment, required in case of testicular torsion