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1.
A. N. Chalazonitis MD Ph.D D. Koumarianos RT J. Tzovara MD P. Chronopoulos MD 《Journal of digital imaging》2003,16(2):216-229
Over the past decade, the technology that permits images to be digitized and the reduction in the cost of digital equipment allows quick digital transfer of any conventional radiological film. Images then can be transferred to a personal computer, and several software programs are available that can manipulate their digital appearance. In this article, the fundamentals of digital imaging are discussed, as well as the wide variety of optional adjustments that the Adobe Photoshop 6.0 (Adobe Systems, San Jose, CA) program can offer to present radiological images with satisfactory digital imaging quality. 相似文献
2.
To determine whether cholinergic spinal cord neurons can develop preferential projections in vitro within sympathetic ganglia (SGs) of appropriate levels of the neuraxis, organotypic explants of fetal mouse spinal cord (E13) from cervical, thoracic (upper and lower) and lumbar segments were co-cultured with either pairs of neonatal SGs: the rostral superior cervical ganglion (SCG) or a caudally located upper lumbar ganglion (LG). After 3.5-4 weeks of co-culture, levels of the enzyme, choline acetyltransferase (ChAT), were measured in individual spinal cord explants and SCGs or double LGs (to match the target mass of a single SCG). Interaction was assumed to occur primarily between an SCG or LG doublet and the adjacent ipsilateral half of the co-cultured cord segment. An index of cholinergic interaction was defined as the ganglion ChAT activity per unit ChAT activity in half co-cultured cord segment. The index of interaction with the SCG was highest with the T1/T2 (1.4) as compared with the T10/T11 (0.79), L1/L2 (0.38) and C2/C3 (0.11) segments. In contrast, the index of cholinergic interaction with double LGs was highest with the more caudally located T10/T11 (0.62) cord segment as compared with the rostral T1/T2 (0.33), cervical C2/C3 (0.2) and lumbar L1/L2 (0.17) segments. Ganglion compound action potentials evoked in LGs by stimulation of the ipsilateral portion of T10/T11 cord were blocked by the ganglionic antagonist, hexamethonium, as previously observed in co-cultures of SCGs with T1/T2 cord. These results indicate that pools of preganglionic neurons in thoracic cord segments can develop in vitro preferential cholinergic projections within SGs of appropriate position. Cervical and lumbar cord segments which contain a preponderance of somatic motoneurons over preganglionic neurons did not interact as effectively with either type of SG. The preferential cholinergic projections from rostral thoracic cord explants within co-cultured SCGs and from caudal thoracic cord explants within co-cultured SCGs and from caudal thoracic cord explants within LGs may reflect some degree of positional preference intrinsic to embryonic spinal cord neurons and/or their appropriate target SGs, consistent with the positional specificity expressed by preganglionic neurons and SGs in situ. 相似文献
3.
Ultrasound-guided fine needle aspiration biopsy (FNAB) is currently used as an alternative combined modality, which enables accurate detection and evaluation of solid and cystic abnormal lesions. It's easily performed, with low cost and most effective as it decreases the number of unnecessary operational procedures; that take place to rule-out malignancy. The aim of this paper is to suggest the schedule of an effective protocol, easily approached by residents and physicians with minimal, or no experience on ultrasound interventional procedures. Our tutorial is based on more than 350 fine needle aspiration biopsies that were carried-out in our Institution during the last two years. It includes images and graphics of patients preparation, needle selection, sampling and aspiration technique. On-site cytologic preparation and brief references on possible complications and common piifalls are also described. 相似文献
4.
Chalazonitis A Pham TD Li Z Roman D Guha U Gomes W Kan L Kessler JA Gershon MD 《The Journal of comparative neurology》2008,509(5):474-492
The effects of bone morphogenetic protein (BMP) signaling on enteric neuron development were examined in transgenic mice overexpressing either the BMP inhibitor, noggin, or BMP4 under control of the neuron specific enolase (NSE) promoter. Noggin antagonism of BMP signaling increased total numbers of enteric neurons and those of subpopulations derived from precursors that exit the cell cycle early in neurogenesis (serotonin, calretinin, calbindin). In contrast, noggin overexpression decreased numbers of neurons derived from precursors that exit the cell cycle late (gamma-aminobutyric acid, tyrosine hydroxylase [TH], dopamine transporter, calcitonin gene-related peptide, TrkC). The numbers of TH- and TrkC-expressing neurons were increased by overexpression of BMP4. These observations are consistent with the idea that phenotypic expression in the enteric nervous system (ENS) is determined, in part, by the number of proliferative divisions neuronal precursors undergo before their terminal mitosis. BMP signaling may thus regulate enteric neuronal phenotypic diversity by promoting the exit of precursors from the cell cycle. BMP2 increased the numbers of TH- and TrkC-expressing neurons developing in vitro from immunoselected enteric crest-derived precursors; BMP signaling may thus also specify or promote the development of dopaminergic TrkC/NT-3-dependent neurons. The developmental defects in the ENS of noggin-overexpressing mice caused a relatively mild disturbance of motility (irregular rapid transit and increased stool frequency, weight, and water content). Although the function of the gut thus displays a remarkable tolerance for ENS defects, subtle functional abnormalities in motility or secretion may arise when ENS defects short of aganglionosis occur during development. 相似文献
5.
L A Greene W Shain A Chalazonitis X Breakfield J Minna H G Coon M Nirenberg 《Proceedings of the National Academy of Sciences of the United States of America》1975,72(12):4923-4927
Clonal mouse neuroblastoma cells without tyrosine 3-monooxygenase [EC 1.14.16.2; tyrosine hydroxylase; L-tyrosine, tetrahydropteridine:oxygen oxidoreductase (3-hydroxylating)] activity were fused with normal cells from embryonic mouse sympathetic ganglia. One of the 37 hybrid cell lines obtained possesses high tyrosine 3-monooxygenase activity and synthesizes dopamine. These cells also have excitable membranes and generate action potentials in response to electrical stimuli. Thus hybrid cells, generated by fusion of neuroblastoma cells with normal cells from the nervous system, can acquire neural properties not found with the parental neuroblastoma cells. 相似文献
6.
A Chalazonitis P J Rice R E Zigmond 《The Journal of pharmacology and experimental therapeutics》1980,213(1):139-143
The activity of the enzyme tyrosine hydroxylase (TH) can be increased in the rat superior cervical ganglion by stimulating the preganglionic cervical sympathetic trunk. Since nicotinic, muscarinic and alpha adrenergic receptors have been implicated in ganglionic transmission, the role of each of these receptors in the trans-synaptic regulation of TH activity has been studied. Chlorisondamine, administered at a dose which completely blocks ganglion transmission, blocked the increase in TH activity. Atropine and dihydroergotamine, injected at doses which block peripheral muscarinic and alpha adrenergic receptors, respectively, did not significantly affect the increase in enzyme activity. Thus, of these three receptor systems, only nicotinic receptors seem to play a major role in the increase in TH activity produced by preganglionic nerve stimulation. Simultaneous measurements of tyrosine hydroxylase, dopa decarboxylase and dopamine-beta-hydroxylase activities indicate that both TH and dopamine-beta-hydroxylase activities increase after stimulation of the cervical sympathetic trunk, although dopa decarboxylase activity is unchanged. The time courses of the increase in TH and dopamine-beta-hydroxylase activities were similar, both reaching maximum values 3 days after the end of a 90-min period of nerve stimulation. 相似文献
7.
Chalazonitis AN Condilis N Tilentzoglou AC Pontikis J Tzovara J 《Annali italiani di chirurgia》2006,77(6):529-532
A rare case with clinical condition of first sternocostal degenerative arthritis with intra-articular fluid collection that developed after long-lasting intense exercise (weight-lifting) for twenty years is reported. Imaging findings and differential diagnoses of the case are presented. 相似文献
8.
Ioannis V Kalogeropoulos Athanasios N Chalazonitis Sofia Tsolaki Fotios Laspas Nikolaos Ptohis Ioannis Neofytou Dimitra Rontogianni 《World journal of gastroenterology : WJG》2009,15(15)
Primary non-Hodgkin's lymphoma of the esophagus is a rare disease. A case of primary isolated non- Hodgkin's lymphoma of the esophagus in a 77-yearold man without acquired immunodeficiency syndrome is presented. We describe the clinical features and the imaging findings (barium swallow, endoscopic ultrasonography and CT) of a biopsy proven B-cell lymphoma with diffuse transmural involvement of the esophagus wall, which was discovered incidentally. We also briefly review the literature. 相似文献
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10.
Guo-Guang Chen Alcmene Chalazonitis Ke-Fei Shen Stanley M. Crain 《Brain research》1988,462(2):372-377
The duration of the calcium component of the action potential (APD) of dorsal root ganglion (DRG) neurons in mouse spinal cord-ganglion explants has been shown to be dually modulated via excitatory and inhibitory opioid receptors. In order to determine if opioid-induced APD prolongation is modulated by receptors that are positively coupled to the adenylate cyclase (AC)/cyclic AMP second messenger system, whole-cell recordings were made from mouse DRG neurons grown in dissociated cell cultures. Tests for opioid responsivity were carried out after intracellular dialysis of an inhibitor of cAMP-dependent protein kinase (PKI). In control recordings, both DADLE-induced APD prolongation as well as shortening were prevented by co-perfusion with the opioid antagonist, diprenorphine (10 nM). Intracellular dialysis of PKI in these neurons completely blocked opioid-induced APD prolongation but did not attenuate APD shortening generally elicited by higher opioid concentrations. Bath perfusion of 10 nM DADLE elicited APD prolongation in 59% of the DRG neurons (n = 34) tested with control solution in the recording pipette, whereas none showed APD prolongation when the pipette contained PKI (n = 18). In control tests with 1 microM DADLE, the APD was prolonged in 37% of the cells and shortened in 26% (n = 19); in contrast, a matched group of PKI-treated cells showed no APD prolongation, whereas 42% showed APD shortening (n = 26). The results support the hypothesis that opioid-induced APD prolongation in DRG neurons is mediated by opioid receptor subtypes that are positively coupled via Gs to AC/cAMP-dependent voltage-sensitive ionic conductances. 相似文献