58 research outputs found

    Review of juxtaglomerular cell tumor with focus on pathobiological aspect

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    Juxtaglomerular cell tumor (JGCT) generally affects adolescents and young adults. The patients experience symptoms related to hypertension and hypokalemia due to renin-secretion by the tumor. Grossly, the tumor is well circumscribed with fibrous capsule and the cut surface shows yellow or gray-tan color with frequent hemorrhage. Histologically, the tumor is composed of monotonous polygonal cells with entrapped normal tubules. Immunohistochemically, tumor cells exhibit a positive reactivity for renin, vimentin and CD34. Ultrastructurally, neoplastic cells contain rhomboid-shaped renin protogranules. Genetically, losses of chromosomes 9 and 11 were frequently observed. Clinically, the majority of tumors showed a benign course, but rare tumors with vascular invasion or metastasis were reported. JGCT is a curable cause of hypertensive disease if it is discovered early and surgically removed, but may cause a fatal outcome usually by a cerebrovascular attack or may cause fetal demise in pregnancy. Additionally, pathologists and urologists need to recognize that this neoplasm in most cases pursues a benign course, but aggressive forms may develop in some cases

    Detection and quantification of human adenovirus genomes in Acanthamoeba isolated from swimming pools

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    ABSTRACT Acanthamoeba is the most common free-living environmental amoeba, it may serve as an important vehicle for various microorganisms living in the same environment, such as viruses, being pathogenic to humans. This study aimed to detect and quantify human adenoviruses (HAdV) in Acanthamoebas isolated from water samples collected from swimming pools in the city of Porto Alegre, Southern Brazil. Free-living amoebae of the genus Acanthamoeba were isolated from water samples, and isolates (n=16) were used to investigate the occurrence of HAdVs. HAdV detection was performed by quantitative real-time polymerase chain reaction (qPCR). HAdVs were detected in 62.5% (10/16) of Acanthamoeba isolates, ranging from 3.24x103 to 5.14x105 DNA copies per milliliter of isolate. HAdV viral loads found in this study are not negligible, especially because HAdV infections are associated with several human diseases, including gastroenteritis, respiratory distress, and ocular diseases. These findings reinforce the concept that Acanthamoeba may act as a reservoir and promote HAdV transmission through water

    Local ties controlin application of laser time transfer

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    In many fundamental physical experiments time plays an important role. The standard way for the comparison of time and frequency is the application of GNSS signals and the Two-Way Satellite Time and Frequency Transfer - TWSTFT. This technique is based on radiofrequency signal transmission. Recently, there was a rapid increase of optical time comparison development, which uses the Satellite Laser Ranging network (SLR). Currently the French project T2L2 is in operation on board of Jason 2 and the European Space Agency project ELT in support of the Atomic Clock Ensemble in Space (ACES) is under development. The goal of both projects is the time synchronization with a precision below 40 ps rms and an absolute error well below 100 ps. Comparing the results of the optical time transfer with the GNSS time comparison requires unprecedented control of the local ties between the different observation techniques. One of the possible methods is the application of the Two Way Time Transfer (TWTT) on a single coaxial cable. Such a system can be implemented using two or more event timers, which are interconnected by a standard coaxial cable

    Expression of thyroid transcription factor 1 in primary brain tumours

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    Background: Thyroid transcription factor 1 (TTF-1) is expressed in a proportion of carcinomas derived from follicular thyroid cells and respiratory epithelium. Immunohistochemical detection of this protein was shown previously to be a helpful aid in tumour diagnosis, specifically in deciding whether a tumour is primary to the lung/thyroid gland or metastatic. Recently, TTF-1 expression was also observed in certain areas of postnatal brain. Aim/Method: To investigate the expression of TTF-1 protein in a spectrum of 73 primary brain tumours including astrocytomas, glioblastomas, ependymomas, oligodendrogliomas, medulloblastomas, and gangliogliomas of different sites. Results: All the tumours were negative for TTF-1 except for two ependymomas of the third ventricle. Conclusions: The expression of TTF-1 in brain tumours appears to be site specific rather than associated with tumour dedifferentiation. The presented expression of TTF-1 protein in certain primary brain tumours should be taken into consideration when interpreting the immunohistochemical staining of brain tumours of uncertain primary site

    Vagal paragangliomas

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