492 research outputs found
Variations and morphometric analysis of the proximal segment of the superior cerebellar artery
Introduction
The superior cerebral artery is a clinically significant vessel, but little is known about its radiological anatomy. The aim of this study was to describe the anatomical variations of the proximal segment of the superior cerebellar artery using Computed Tomography Angiography.
Materials and methods
The study group consisted of 200 subjects (54.5% female, mean age±SD 56.2±17.2 years) that had undergone head Computed Tomography Angiography. Subjects with any intracranial pathologies were excluded. Images in Maximum Intensity Projections were used to study the anatomical anomalies of the superior cerebellar artery.
Results
In 200 subject 388 superior cerebellar arteries were found. Twelve (3.09%) SCAs were duplicated in 11 patients and all originated from the basilar artery. In 8 (4.00%) patients the superior cerebellar artery was absent. The origin of the SCA was most often bilateral, mainly from the basilar artery (76.29%). The superior cerebellar artery diameter, measured at the site of the origin, was statistically significantly different depending on the place of the origin: wider when originating from the basilar artery as a single vessel (1.48±0.42mm vs. 1.34±0.52mm; p=0.03) and narrower when originating as duplicated one (1.38±0.48mm vs. 1.46±0.44mm; p=0.55).
Conclusion
Superior cerebellar artery usually originates bilaterally from the basilar artery as a single trunk. Its diameter is significantly wider in that type in comparison to other anatomical variations
Applications of the Cracow X-ray microprobe in tomography
A nuclear microprobe at the IFJ PAN in Cracow has found numerous applications in different fields of research, mostly in biophysics, medical sciences, geology, and material research. In order to extend the research possibilities, a new X-ray microprobe was constructed. This new microprobe consists of three experimental lines dedicated to: (i) X-ray irradiation of biological specimens, (ii) elemental analysis of samples by micro X-ray fluorescence or total reflection X-ray fluorescence methods and (iii) computer microtomography. In this paper the computer microtomography line was described. The line consists of an open type Hamamatsu L9191 X-ray tube with microfocusing to about 2 μm, a high resolution X-ray sensitive CCD camera, and a precise goniometer composed of six piezoelectric motors. Depending on the required X-ray energy, the Hamamatsu tube is used with Ti, Mo, Ag, or W targets. A small focus size and short focus-to-object distance enable to obtain images of samples with a magnification of more than 1000× and resolution of the order of 2 μm. The computer microtomography measurements are carried out using home developed codes combined with commercial software. Details of the microprobe construction and preliminary results of the computer microtomography experiments are presented
The reliability of the specimens for neuropathological evaluation in pituitary adenomas treated via transphenoidal route
Introduction: There are some discrepancies between immunohistochemical staining results and clinical picture of pituitary adenomas. Such a discordance may be caused by multiple factors. The problem of securing the histopathological material during the transsphenoidal pituitary surgery and its reliability for neuropathological evaluation deserves a special attention. The surgical biopsy does not always meet the criteria required for a immunohistochemical staining and sometimes not even for the routine histopatho-logical examination.
Aims: To determine the frequency of unreliable material for histopathological examination and factors influencing the reliability of histopathological specimens after surgery for pituitary adenomas.
Material and methods: The hematoxylin and eosin sections were examined in detail. with a special attention to the presence of incidental findings, i.e. admixture of normal pituitary gland tissue, signs of hemorrhage, necrosis, thermal artifacts, inflammatory changes, respiratory epithelium, vessels or cholesterol granuloma. The impact of incidental findings on further immunohistochemical analysis was investigated. The relationship between the magnetic resonance imaging (MRI)- determined tumor size and the area of histopathological specimen was assessed and considered as a reliability parameter.
Results: The unreliable material was estimated at the level of 11.8%. It was assessed that hemorrhages, neurohypophysis, necrosis and quantity of collected histopathological material had the statistically sig-nificant impact on the reliability of the histopathological material. The statistical analysis did not show any relation between the reliability of the histopathological material and the MRI-determined volume of the tumor. Conclusions: The presence of some additional tissue elements and artifacts in the histopathological specimen makes the immunohistochemical evaluation difficult or even impossible. However, this problem is related to a relatively low percentage of cases, mainly small tumors
Lipoprotein lipase regulates hematopoietic stem progenitor cell maintenance through DHA supply.
Lipoprotein lipase (LPL) mediates hydrolysis of triglycerides (TGs) to supply free fatty acids (FFAs) to tissues. Here, we show that LPL activity is also required for hematopoietic stem progenitor cell (HSPC) maintenance. Knockout of Lpl or its obligatory cofactor Apoc2 results in significantly reduced HSPC expansion during definitive hematopoiesis in zebrafish. A human APOC2 mimetic peptide or the human very low-density lipoprotein, which carries APOC2, rescues the phenotype in apoc2 but not in lpl mutant zebrafish. Creating parabiotic apoc2 and lpl mutant zebrafish rescues the hematopoietic defect in both. Docosahexaenoic acid (DHA) is identified as an important factor in HSPC expansion. FFA-DHA, but not TG-DHA, rescues the HSPC defects in apoc2 and lpl mutant zebrafish. Reduced blood cell counts are also observed in Apoc2 mutant mice at the time of weaning. These results indicate that LPL-mediated release of the essential fatty acid DHA regulates HSPC expansion and definitive hematopoiesis
Guidelines for the rearrangement of Auschwitz Museum based on web pictures analysis
This paper attempts to answer the question whether the exhibition of the Auschwitz
Museum communicates its message properly to the audience or it should be modernised/
rearranged. The aim of the study is so to investigate the way visitors currently look at
Auschwitz via the filter of social media. Between November 2014 until January 2015 the
number of Instagram pictures with hashtag “Auschwitz” posted on-line nearly doubled to
astonishing 80.000 images. In August 2016 the number of images reached over 151.000
making Instagram the essential tool for web picture analysis. In this case, the use of found
photography was especially important for the authenticity of correlation between the visitor
and one’s architectural surrounding. Specifically, using Instagram and Instagram feed sites,
e.g. websta.me we address the questions of how people react to the architecture of the dead
camp, how they photograph this place and what is the emphasis of captured images in this
particular place
Związek między inwazyjnością gruczolaków przysadki a indeksem proliferacyjnym mierzonym immunoekspresją topoizomerazy IIα
Introduction: Cavernous sinus invasion by pituitary adenoma affects surgical procedure radicality and consequently the postoperative course and prognosis in pituitary adenoma treatment. The search for pituitary adenoma aggressive behaviour markers is still a matter of debate.
Material and methods: This study evaluates the relation of pituitary adenoma invasiveness to the expression of topoisomerase IIα in 72 patients who underwent transsphenoidal pituitary surgery. The assessment of tumour growth was conducted according to the Hardy scale as modified by Wilson and the Knosp scale. Topoisomerase IIα expression in tumour specimens was evaluated using immunohistochemical staining.
Results: There was a correlation between the Knosp scale degree and the topoisomerase IIα expression (Spearman R = 0.3611, p < 0.005). The Kruskal-Wallis H test (p = 0.0034) showed that there was a statistically significant topoisomerase IIα expression increase in tumours classified as grade E on the Hardy scale. The topoisomerase IIα expression correlated also with tumour size (Spearman R = 0.4117, p < 0.001). Higher levels of expression were observed in macroadenomas, as compared to microadenomas (p < 0.05, Mann-Whitney test). Topoisomerase IIα expression correlated with cavernous sinus invasion.
Conclusions: The topoisomerase IIα expression correlated more with invasiveness than with extensiveness, which might make it an eminently useful marker in the assessment of aggressive pituitary adenoma behaviour.Introduction. Cavernous sinus invasion by pituitary adenoma affects surgical procedure radicality, and consequently the postoperative course and prognosis in pituitary adenomas treatment. The search for pituitary adenoma aggressive behaviour markers is still a matter of debate. Material and methods. This study evaluates the relation of pituitary adenoma invasiveness to the expression of topoisomerase IIα in 72 patients who underwent transsphenoidal pituitary surgery. The assessment of tumour growth was conducted according to the Hardy scale as modified by Wilson and the Knosp scale. Topoisomerase IIα expression in tumours specimens was evaluated using immunohistochemical staining. Results. There was a correlation between the Knosp scale degree and the topoisomerase IIα expression (Spearman R=0.3611, p < 0.005). The Kruskal-Wallis H test (p=0.0034) showed that there was a statistically significant topoisomerase IIα expression increase in tumours classified as grade E on the Hardy scale. The topoisomerase IIα expression correlated also with tumour size (Spearman R=0.4117, p < 0.001). Higher levels of expression were observed in macroadenomas, as compared to microadenomas (p < 0.05, Mann-Whitney test). Topoisomerase IIα expression correlated with cavernous sinus invasion. Conclusions. The topoisomerase IIα expression correlated more with invasiveness than with extensiveness, which might make it an eminently useful marker in the assessment of aggressive pituitary adenoma behaviour
Evidence for As lattice location and Ge bound exciton luminescence in ZnO implanted with 73As and 73Ge
The results of photoluminescence (PL) measurements performed on high quality single crystal ZnO implanted
with radioactive 73Ga and 73As, both of which decay to stable 73Ge, are presented. Identical effects are observed in the two cases, with a sharp line at 3.3225(5) eV found to grow in intensity in accordance with the growth rate of the Ge daughter atom populations. On the strength of the well-established result that Ga occupies Zn sites, we conclude from the identical outcomes for 73Ga and 73As implantations that implanted As also preferentially occupies Zn sites. This result supports the findings of others that As preferentially occupies the Zn rather than the O site in ZnO. The thermal quenching energy of the 3.3225(5) eV line is found to be only 2.9(1) meV in contrast to its large spectral shift of 53.4(1) meV with respect to the lowest energy free exciton. The PL is attributed to exciton recombination at neutral Ge double donors on Zn sites involving transitions that leave the donor in an excited state
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