295 research outputs found
Radicular Cyst with Actinomycotic Infection in an Upper Anterior Tooth
No full textActinomycosis is an infection caused by filamentous, branching, Gram- positive anaerobic bacteria. It rarely infects the jawbone. This case report describes a patient with a left maxillary central incisor with an apical lesion and actinomycotic infection. A 23-year-old male patient underwent conventional root canal treatment of tooth 21, in a local dental clinic for about I year. However, percussion pain and a sinus tract that originated from tooth 21 were still present after treatment. Nonsurgical root canal treatment of tooth 21 was performed again but failed to relieve the symptoms. Therefore, apicoectomy and retrograde filling of the apical root canal with mineral trioxide aggregate were carried out. Periradicular bony defect was grafted by biocompatible material, and postoperative antibiotics (250 mg amoxicillin) were given three times daily for 5 days. Pathological examination of the removed periapical tissue showed a radicular cyst with actinomycosis . At the 9-month postoperative recall, the sinus tract had disappeared and radiographic examination showed heating of the apical lesion. Periradicular actinomycosis is one important reason for failure of nonsurgical endodontic treatment. Clinically, if the tooth shows a recurrent sinus tract and poor response to conventional root canal treatment combined with antibiotic control, apical actinomycotic I infection should be highly suspected, and an alternative endodontic surgical approach is needed for successful treatment
Upper Extremity Pain in Spinal Cord Injured Patients Post-Rehabilitation:a Preliminary Report
No full textHermann Kuen: A Bavarian Painter in the Service of the Auerspergs of Vlašim
Get PDFText přibližuje činnost bavorského malíře Hermanna Kuena v letech 1781–1805 v české Vlašimi u knížat z Auerspergu. Vzhledem k nedochovanosti jeho děl má význam biografická a sociologizující rovina, které sledují jeho pohyb v sociálních strukturách. Kuen se tak posouvá od malíře barokních církevních fresek 70. let do role hlavního dekoratéra krajinářského parku Karla Josefa Auersperga ve Vlašimi. A to v I. fázi parku, kdy Kuen vytváří mimo jiné exotickou výmalbu pavilonů, ale zřejmě i v pozdně sentimentální fázi parku za Viléma I. Auersperga kolem 1800, kdy je patrně také spoluautorem iluzivní fasády zámku.Hermann Kuen: A Bavarian Painter in the Service of the Auerspergs of VlašimThe text describes the activities of the Bavarian painter Hermann Kuen in the years 1781–1805 in the Bohemian town of Vlašim with the Princes of Auersperg. Due to the fact that his works are not preserved, the biographical and sociological levels, which trace his movement in social structures, are of importance. Kuen thus moves from being a painter of Baroque church frescoes in the 1770s to the role of chief decorator of the landscape park of Karel Josef Auersperg in Vlašim. This is in Phase I of the park, when Kuen creates, among other things, exotic paintings of the pavilions, but probably also in the late sentimental phase of the park under William I. Auersperg around 1800, when he is probably also the co-author of the illusory facade of the castle
Reply. Response to Kwok Kuen Tsang\u27s \u27Ideological disempowerment of teachers\u27
Get PDFIn this article the author examines Kwok Kuen Tsang\u27s article on the ideological disempowerment of educators and relates to it research on emotional labour in education. It also reflects on the educational implications of the observation of ideological disempowerment of educators. It emphasises the need for democratisation of education so that educators can be at the frontline of discussions and commitments to wellbeing, of students and educators alike, in education. (DIPF/Orig.
Dynamic expression of Dab2 in the mouse embryonic central nervous system
Get PDFAuthor name used in this publication: Kwok-Kuen CheungVersion of RecordPublishedC
NMR characterization of intrinsically disordered alpha-synuclein: implication for aggregation in Parkinson's disease
No full textA broad range of human diseases arise from the loss of the native function of a specific peptide or protein. The pathological conditions of these diseases are generally referred to as protein misfolding and aggregation problem. An increasing number of misfolded proteins are associated with the deposition of protein aggregation in the brain cells resulting in neurodegenerative diseases, for example, the aggregated α-synuclein (αSyn) in sporadic Parkinson’s disease.
αSyn is an intrinsically disordered protein and the aggregation kinetics are sensitive to the changes of amino acids and chemical environments. The structural conversion of αSyn from an unfolded monomeric ensemble to a well-ordered fibril remains unclear. In this work, nuclear magnetic resonance (NMR) was applied to characterize the aggregation-prone species including homologous mouse αSyn and human αSyn at low pH. Comparison of human and mouse αSyn at pH 7.4 and at supercooled aqueous solution presents a less compact mouse αSyn ensemble with transient inter-chain interactions at the N-terminal region. Characterization of αSyn conformational ensembles at both neutral and low pH shows that the altered charge distribution at low pH changes the structural properties of these ensembles and leads to rapid aggregation. Paramagnetic relaxation enhancement (PRE) experiments using mixed isotope (15N) and spin labeled αSyn further illustrate different intermolecular contacts of low-populated transient complex at neutral and low pH. A head-to-tail αSyn complex transiently stabilized by the electrostatic interactions at neutral pH is observed while a tail-to-tail αSyn complex via hydrophobic interactions at low pH is seen. This work provides novel structural insight into the molecular conversion of αSyn at the very early nucleation state.
In addition to understanding the aggregation mechanism of αSyn, an approach that deconvolutes the strong modulation of fast hydrogen exchange (HX) rates on the transverse relaxation rate (R2) of disordered proteins is also presented. This work shows an HX-free R2 profile of αSyn at pH 7.4 and provides an opportunity to understand NMR relaxation of disordered proteins or unstructured loop regions in folded proteins at fast HX conditions such as high pH or high temperature.Ph.D.Includes bibliographical references (p. 153-165)by Kuen-Phon W
Arecoline induced cell cycle arrest, apoptosis, and cytotoxicity to human endothelial cells
No full textBetel quid (BQ) chewing is a common oral habit in South Asia and Taiwan. BQ consumption may increase the risk of oral squamous cell carcinoma (OSCC), oral submucous fibrosis (OSF), and periodontitis as well as systemic diseases (atherosclerosis, hypertension, etc.). However, little is known about the toxic effect of BQ components on endothelial cells that play important roles for angiogenesis, carcinogenesis, tissue fibrosis, and cardiovascular diseases. EAhy 926 (EAHY) endothelial cells were exposed to arecoline, a major BQ alkaloid, for various time periods. Cytotoxicity was estimated by 3-(4, 5- dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay. The cell cycle distribution of EAHY cells residing in sub-G0/G1, G0/G1, S-, and G2/M phases was analyzed by propidium iodide staining of cellular DNA content and flow cytometry. Some EAHY cells retracted, became round-shaped in appearance, and even detached from the culture plate after exposure to higher concentrations of arecoline (> 0.4 mM). At concentrations of 0.4 and 0.8 mM, arecoline induced significant cytotoxicity to EAHY cells. At similar concentrations, arecoline induced G2/M cell cycle arrest and increased sub-G0/G1 population, a hallmark of apoptosis. Interestingly, prolonged exposure to arecoline (0.1 mM) for 12 and 21 days significantly suppressed the proliferation of EAHY cells, whereas EAHY cells showed adaptation and survived when exposed to 0.05 mM arecoline. These results suggest that BQ components may contribute to the pathogenesis of OSF and BQ chewing-related cardiovascular diseases via toxicity to oral or systemic endothelial cells, leading to impairment of vascular function. During BQ chewing, endothelial damage may be induced by areca nut components and associate with the pathogenesis of OSF, periodontitis, and cardiovascular diseases
Application of Mass Spectrometry in the Study of Some Isoquinoline Alkaloids
Get PDFTitle: Application of Mass Spectrometry in the Study of Some Isoquinoline Alkaloids, Author: Chi-Kuen Yu, Location: ThodeThe structures of three new tetrahydroprotoberberine alkaloids,
caseanadine, cavidine and apocavidine have been determined on the basis
of mass spectral and p.m.r. data. The mass spectra of spirobenzylisoquinoline alkaloids with
different oxygenated substituents in the five-membered ring have been
recorded. Fragmentation mechanisms are proposed to account for the
major peaks in all the spectra. High resolution mass measurements have
been used to aid in the interpretation of the spectra. The structure
of a new spirobenzylisoquinoline alkaloid, F-38, has been elucidated by
spectroscopic methods.ThesisDoctor of Philosophy (PhD
Investigation of a scanned cylindrical ultrasound system for breast hyperthermia
No full text[[abstract]]This paper investigates the feasibility of a scanned cylindrical ultrasound system for producing uniform heating from the central to the superficial portions of the breast or localized heating within the breast at a specific location. The proposed system consists of plane ultrasound transducer(s) Mounted on a scanned cylindrical Support. The breast was immersed in water and Surrounded by this system during the treatment. The control parameters considered are the size of the transducer, the ultrasound frequency, the scan angle and the shifting distance between the axes of the breast and the system. Three-dimensional acoustical and thermal models were used to calculate the temperature distribution. Non-perfused phantom experiments were performed to verify the simulation results. Simulation results indicate that high frequency ultrasound Could be used for the Superficial heating, and the scan angle of the transducer could be varied to obtain an appropriate high temperature region to cover the desired treatment region. Low frequency ultrasound Could be used for deep heating and the high temperature region could be moved by shifting the system. In addition, a combination of low and high frequency ultrasound could result in it portion treatment from the central to the superficial breast or an entire breast treatment. Good agreement was obtained between non-perfused experiments and simulation results. The findings of this study can be used to determine the effects of the control parameters of this system, as well as to select the optimal parameters for a specific treatment
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