Phleboliths from venous malformations of the head and neck

2013 ◽  
Vol 28 (2) ◽  
pp. 86-92 ◽  
Author(s):  
B Eivazi ◽  
A J Fasunla ◽  
C Güldner ◽  
P Masberg ◽  
J A Werner ◽  
...  

Objectives/Hypothesis Phleboliths in venous malformations (VM) of the head and neck are often observed and may cause significant symptoms. Only a few articles refer to the morphology and composition of the phleboliths in VM. The objective of this study was to analyse and to demonstrate their composition and morphology. Methods Patients with VM presenting to a vascular anomalies centre during a three-year period were identified. The incidence of phleboliths was analysed followed by morphological and structural analysis with cone beam tomography and X-ray diffraction. Results Phleboliths were identified in 28/98 patients with VM of the head and neck. Seven patients underwent conventional surgery to reduce the volume of the VM or to remove the phleboliths, which were localized in the cheek (3 cases), submandibular region (2 cases), infrahyoidal neck or upper eyelid (1 case each). The structural analysis showed that more advanced lamination and an increasing radiopacity of the cortex was observed in larger phleboliths. X-ray powder diffraction analysis revealed that the main constituent in the pulverized phleboliths was carbonate-fluorohydroxylapatite. Conclusion This study shows in a vivid way that phleboliths from VM of the head and neck area show a laminar structure and consist of apatite, without any indication of differences in their chemical composition. Treatment of localized intravascular coagulopathy in VM might be able to prevent the formation and the progression of phleboliths. Hypothetically, another option might be lithotripsy.

Author(s):  
E. Loren Buhle ◽  
Pamela Rew ◽  
Ueli Aebi

While DNA-dependent RNA polymerase represents one of the key enzymes involved in transcription and ultimately in gene expression in procaryotic and eucaryotic cells, little progress has been made towards elucidation of its 3-D structure at the molecular level over the past few years. This is mainly because to date no 3-D crystals suitable for X-ray diffraction analysis have been obtained with this rather large (MW ~500 kd) multi-subunit (α2ββ'ζ). As an alternative, we have been trying to form ordered arrays of RNA polymerase from E. coli suitable for structural analysis in the electron microscope combined with image processing. Here we report about helical polymers induced from holoenzyme (α2ββ'ζ) at low ionic strength with 5-7 mM MnCl2 (see Fig. 1a). The presence of the ζ-subunit (MW 86 kd) is required to form these polymers, since the core enzyme (α2ββ') does fail to assemble into such structures under these conditions.


1996 ◽  
Vol 20 (6) ◽  
pp. 765-770 ◽  
Author(s):  
A. Nath ◽  
S. Gupta ◽  
P. Mandal ◽  
S. Paul ◽  
H. Schenk

Crystals ◽  
2016 ◽  
Vol 6 (8) ◽  
pp. 87 ◽  
Author(s):  
Cinzia Giannini ◽  
Massimo Ladisa ◽  
Davide Altamura ◽  
Dritan Siliqi ◽  
Teresa Sibillano ◽  
...  

2010 ◽  
Author(s):  
I. Jerjen ◽  
V. Revol ◽  
C. Kottler ◽  
Th. Luethi ◽  
U. Sennhauser ◽  
...  

2022 ◽  
Vol 1048 ◽  
pp. 141-146
Author(s):  
Madihally Nagaraja ◽  
Geetha Thippeswamy ◽  
Sushma Prashanth ◽  
Jayadev Pattar ◽  
Mahesh Hampapatna Mahesh

Composite of polyaniline-MgCl has been synthesized using oxidative polymerization method. Synthesized samples were characterized for structural analysis using FTIR and XRD. Morphological studies were carried by SEM micrographs. Current-Voltage (I-V) properties are obtained through Kiethly source meter. FTIR spectrum of polyaniline-MgCl composite indicates all the characteristic peaks of polyaniline. X-ray diffraction patterns represented the amorphous nature of polyaniline-MgCl composite. SEM micrographs confirmed the presence of MgCl particles in polyaniline matrix. I-V characteristics have shown the ohmic type behavior of polyaniline and polyaniline-MgCl composite.


Optica ◽  
2018 ◽  
Vol 5 (6) ◽  
pp. 733 ◽  
Author(s):  
Zheyuan Zhu ◽  
Ryan A. Ellis ◽  
Shuo Pang

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