Hungarian Radiology

[Calcification of the tentorium cerebelli]

BILONKA Viola, BENDE Mariann

OCTOBER 10, 2005

Hungarian Radiology - 2005;79(05)

[A 16-year-old female patient with high temperature and headache was hospitalized because of suspicion of meningitis. Cranial CT showed a mild hydrocephalus, massive falx calcification and calcification in the projection of the tentorium. Excluding several well known reasons of the calcification the findings was thought to be a physiological variation. The child recovered after some days and left the hospital. The authors based on prior publications on tentorium calcification consider this finding a physiological-phylogenetic origin.]

COMMENTS

0 comments

Further articles in this publication

Hungarian Radiology

[REVIEW OF THE LITERATURE]

GYENES György

Hungarian Radiology

[X. National Congress of the Association of Hungarian Radiographers]

MALÉTA Andrea

Hungarian Radiology

[Networks]

LOMBAY Béla

Hungarian Radiology

[Forum of Young Radiologists]

SOMOGYI Rita

Hungarian Radiology

[The force transmission of the distal endings of stent delivery systems]

SZIKRA Péter, VÖRÖS Erika, SZTRIHA László, SZÓLICS Alex, CSIKÁSZ Tamás

[INTRODUCTION - In cases of endovascular treatment of internal carotid artery stenosis, one of the most important aspects is to minimise embolic complications. Dislodging emboli may be influenced by the shape and size of tapered endings of stent delivery systems. Our team performed measurements and calculations on the emergence of force of the various tapered endings. MATERIAL AND METHOD - Five different commercially available stent dilivery systems were investigated. The thickness of the devices were measured and taking 5 mm normal artery diameter, the lumen size was calculated, above which the delivery system should dilate the lumen mechanically. By means of geometrical computer-constructions and measurements, we analysed the forces directed ahead and laterally, emerging on the surface of tapered endings during the passing through the stenosis. RESULTS - The stent delivery systems were between 5.0 and 5.9 F in diameter, and even the stent delivery system of lowest profile would dilate a stenosis of over 89%. The different endings are tapered with variable lengths. The force transmission on the vessel wall of different directions was distinct at the various points of the cone surfaces. The forces directed ahead were less than those directed laterally on the larger part of a cone surface. Irregularity of the cone surfaces distributed the forces unfavorably. Considering the features of tapered endings, the atraumatic introduction of the devices required a range of upper limits of stenoses between 89.76-98.04%, which are more feasible values than those deternined by shaft sizes. CONCLUSIONS - Our experimental work suggests, that the shape and size of the endings of stent delivery systems influence the forces affecting vessel wall plaques, and in this manner, embolic complications, during carotid stenting. The lowest risk of embolisation could be induced by using the longest and smoothest tapered endings.]

All articles in the issue

Related contents

Clinical Neuroscience

[Evolution of human brain and intelligence]

LAKATOS László, JANKA Zoltán

[The biological evolution, including human evolution is mainly driven by environmental changes. Accidental genetic modifications and their innovative results make the successful adaptation possible. As we know the human evolution started 7-8 million years ago in the African savannah, where upright position and bipedalism were significantly advantageous. The main drive of improving manual actions and tool making could be to obtain more food. Our ancestor got more meat due to more successful hunting, resulting in more calory intake, more protein and essential fatty acid in the meal. The nervous system uses disproportionally high level of energy, so better quality of food was a basic condition for the evolution of huge human brain. The size of human brain was tripled during 3.5 million years, it increased from the average of 450 cm3 of Australopithecinae to the average of 1350 cm3 of Homo sapiens. A genetic change in the system controlling gene expression could happen about 200 000 years ago, which influenced the development of nervous system, the sensorimotor function and learning ability for motor processes. The appearence and stabilisation of FOXP2 gene structure as feature of modern man coincided with the first presence and quick spread of Homo sapiens on the whole Earth. This genetic modification made opportunity for human language, as the basis of abrupt evolution of human intelligence. The brain region being responsible for human language is the left planum temporale, which is much larger in left hemisphere. This shows the most typical human brain asymmetry. In this case the anatomical asymmetry means a clearly defined functional asymmetry as well, where the brain hemispheres act differently. The preference in using hands, the lateralised using of tools resulted in the brain asymmetry, which is the precondition of human language and intelligence. However, it cannot be held anymore, that only humans make tools, because our closest relatives, the chimpanzees are able not only to use, but also to make tools, and they can be tought how to produce quite difficult ones. Some brain characteristics connected to human consciousness and intelligence, like brain asymmetry, the “consciousness” or “theory of mind” based on mirror neurons are surprisingly present in monkeys. Nevertheless, the human intelligence is extremly flexible and different, while the animal intelligence is specialised, producing one thing at high level. Based on recent knowledge the level of intelligence is related anatomically to the number of cortical neurons and physiologically to the speed of conductivity of neural pathways, the latter being dependent on the degree of myelinisation. The improvement of cognitive functions including language is driver by the need of more effective communication requiring less energy, the need of social dominance, the competitive advantages within smaller groups and species or against other species, which improves the opportunity for obtaining food. Better mental skills give also sexual dominance, which is beneficial for stabilising “cleverness” genes. The evolutionary history of human consciousness emphasises its adaptive survival helping nature. The evolution of language was the basic condition of conscious thinking as a qualitative change, which fundamentally differentiate us from all other creatures.]

Hungarian Immunology

[Transmission of antibodies from mother to offspring: evolutionary aspects]

BAINTNER Károly

[The earliest known form of transmission of antibody is the transport from the maternal circulation into the yolk during vitellogenesis (in birds and reptiles), followed by endodermal uptake and transport into the embryonal circulation. During the early mammalian evolution lacteal secretion and the development of the placenta opened new ways to feed the young. These changes also resulted in alterations in sites and mechanisms of transmission of immunoglobulins. In a few species (e.g. rabbit and rodents) the yolk-less yolk sac gained a new function, i.e. the absorption of uterine secretion. In most of the mammalian species the neonatal type Fc-receptor (FcRn) plays a key role in the transmission and confers IgG-selectivity on the process. In ungulates undigested colostral proteins, including antibodies, are absorbed non-selectively by the gut, mediated by sizable transport vacuoles. The limited postnatal transmission period (24 to 48 h) is compensated by the considerable length of the small intestine and the efficiency of absorption. In the human chorioallantoic placenta the two steps of transmission (maternal secretion and absorption by the offspring) were reduced to a single step. Absorption of IgG is often carried out in a proteolytic environment (yolk sac, gut lumen, intestinal vacuoles), and as a result, different mechanisms evolved for the protection of antibody.]

Hypertension and nephrology

[The role of vitamin D receptor and the risk reducing effect of vitamin D receptor agonists in chronic kidney disease]

KISS István, KULCSÁR Imre, BARABÁS Noémi, KERKOVITS Lóránt

[Vitamin D3 is produced in the skin and is modified in the liver and kidney to the active metabolite form, 1,25-dyhydroxyvitamin D3 (calcitriol). Calcitriol binds to a nuclear receptor, the vitamin D receptor (VDR), and activates processes that bind to vitamin D. The classical effects of vitamin D receptor activator or agonist (VDRA) therapy for the treatment of secondary hyperparathyroidism in patients with chronic kidney disease primarily involves suppressive effects on the parathyroid gland, and regulation of calcium and phosphorus absorption in the intestine an mobilization in bone. Several VDR agonists have been developed for the treatment of osteoporosis, hyperparathyroidism secondary to chronic kidney disease (CKD), and psoriasis. Secondary hyperparathyroidism (SHPT) is a common and serious consequence of CKD. SHPT is a complex condition characterized by a decline in 1,25-dihidroxi vitamin D and consequent VDR activation, abnormalities in serum calcium and phosphorus levels, parathyroid gland hyperplasia, elevated parathyroid hormone (PTH) secretion, and systemic mineral and bone abnormalities. There are three classes of drug used for treatment of SHPT (non-selective and selective VDR activators, and calcimimetics). Observational studies in hemodialysis patients report improved cardiovascular and allcause survival among those received VDRA therapy compared with those not on VDRA therapy. The survival benefits of selective VDRA paricalcitol appear to be linked to "non classical" action of VDRA, possibly through VDRA-mediated modulation of gene expression. VRDAs are reported to have beneficial effects such as anti-inflammatory and antithrombotic effects, inhibition of vascular calcification and stiffening, inhibition of vascular smooth muscle cell proliferation, and regression of left ventricular hypertrophy. VDRA are also reported to negatively regulate the renin-angiotensin system, which plays a key role in hypertension, myocardial infarction and stroke. Data from epidemiological, preclinical and clinical studies have shown that vitamin D and/or 25(OH) vitamin D deficiency is associated with increased risk for cardiovascular disease (CVD). The selective VDR agonists are associated direct protective effects on glomerular architecture and antiproteinuric effects in response to renal damage. Emerging evidence suggest that VDR plays important roles in modulating cardiovascular, immunological, metabolic and other function. Paricalcitol may prove to have a substantial beneficial effect on cardiac disease and its outcome in patients with CKD.]