Csaba Hegedus

Accuracy of In Vivo Carotid B-Mode Ultrasound Compared With Pathological Analysis Intima-Media Thickening, Lumen Diameter, and Cross-Sectional Area

Background and Purpose— This study aimed to determine the correlation of in vivo ultrasound measurements of intima-media thickening (IMT), lumen diameter, and cross-sectional area of the common carotid artery (CCA) with corresponding measurements obtained by gross pathology and histology. Methods— Sixty-six moribund neurological patients (mean age 71 years) underwent B-mode ultrasound of the CCA a few days before death. During autopsy, carotid specimens were removed in toto. Carotid arteries were ligated and cannulated for injection of a hydrophilic embedding material under standardized conditions. The carotid bifurcation was frozen and cut manually in 3-mm cross slices. Digital image analysis was carried out to determine the diameter and the cross-sectional area of the frozen slices of the CCA. IMT was assessed by light microscope. Ultrasonic and planimetric data were compared. Results— Mean measurements of lumen diameter and cross-sectional area were 7.13±1.27 mm and 0.496±0.167 cm2, respectively, by ultrasound, and 7.81±1.45 mm and 0.516±0.194 cm2, respectively, by planimetric analysis of the unfixed redistended carotid arteries (R2=0.389 and 0.497). The mean IMT was 1.005±0.267 mm by ultrasound and 0.67±0.141 mm histologically, resulting in a mean difference of −31%. Conclusions— Transcutaneous B-mode ultrasound provides a reliable approach for in vivo measurements of the cross-sectional area and, less exactly, of the lumen diameter of the CCA. Compared with histological results, in vivo ultrasound measurements of the IMT are systematically larger.

Comparative Microstructural Study of the Diffusion Zone between NiCr Alloy and Different Dental Ceramics

Our knowledge on the bonding mechanisms between the metal and ceramic parts of dental systems is very limited. This work tested the hypothesis that the details of the interface processes can be described in the framework of a chemical diffusion model. The development of interfacial phases was investigated by cross-sectional analytical transmission electron microscopy between a NiCr (Wiron 99) alloy and three different dental ceramics (Carat, Vita VMK 95, and Vision). All systems were investigated at normal firing conditions (suggested by the manufacturer) and at increased firing times as well. The conclusions are based on the results that the formation of a nanocrystalline Cr2O3 layer and amorphous silicon oxide inclusions were detected in the early stage of the firing process in all investigated systems, and that, in the case of Carat and Vision ceramics, formation of complex NiCr and NiCrTi oxides was also observed at longer annealing times. It is shown by transmission electron microscopy that, in the reaction processes taking place at the NiCr alloy/dental ceramics interface, nanocrystalline Cr2O3 first forms and amorphous silicon oxide inclusions appear, then, at longer firing times, complex NiCr and NiCrTi oxides form.

Poly(ADP-Ribose) Polymerase Mediates Inflammation in a Mouse Model of Contact Hypersensitivity

Mrowietz U, Christophers E, Altmeyer P (1999) Treatment of severe psoriasis with fumaric acid esters: scientific background and guidelines for therapeutic use. The German Fumaric Acid Ester Consensus Conference. Br J Dermatol 141:424–9 Nelson KC, Carlson JL, Newman ML, Sternberg P Jr, Jones DP, Kavanagh TJ et al. (1999) Effect of dietary inducer dimethylfumarate on glutathione in cultured human retinal pigment epithelial cells. Invest Ophthalmol Vis Sci 40:1927–35

A novel method of macropathologic and arteriographic examination of carotid specimens obtained from autopsy

Twenty carotid bifurcations were examined. During autopsy, carotid bifurcations were removed in toto. Unfixed carotids were ligated and cannulated for injection of an angiographic contrast medium followed by injection of a tissue-embedding medium at physiologic pressure and temperature. The carotid bifurcation was frozen and cut manually in 3-mm cross-sections. Photographs were then taken of every slice. Angiography, filling with tissue-embedding material, and sectioning were successful in all cases. In the macropathologic sections, the extent, configuration and location of atherosclerotic lesions could be identified.

Preparation and application of highly porous aerogel-based bioactive materials in dentistry

In this study, the possibility of preparation and application of highly porous silica aerogel-based bioactive materials are presented. The aerogel was combined with hydroxyapatite and β-tricalcium phosphate as bioactive and osteoinductive agents. The porosity of aerogels was in the mesoporous region with a maximum pore diameter of 7.4 and 12.7 nm for the composite materials. The newly developed bioactive materials were characterized by scanning electron microscopy. The in vitro biological effect of these modified surfaces was also tested on SAOS-2 osteogenic sarcoma cells by confocal laser scanning microscopy.

3D reconstruction based on hard tissue microtome cross-section pictures in dentistry

The aim of this study was to examine the accuracy of the computerized 3D surface analyzing and volume measuring method in dentistry. Two different types of test objects were used in the first part of the measurements. Each sample of the two groups was cross-sectioned using a hard tissue microtome. The sections were photographed on both sides and were projected on a graphical tablet and analyzed using a computer program. The measured and calculated parameters were compared. In the second part, 200 microm thick horizontal sections were prepared from 11 human incisor roots using the hard tissue microtome. This way, five sections were prepared from the apical 2 mm of each root. The effects of section thickness and number were modeled by decreasing the inclusion rate of the obtained number of sections from 10 to 2 and its influence on the calculated results was determined. This method was suitable for the approximation and analysis of 3D parameters. The results indicated that using 200-300 microm section thickness, the measured values were approximately 8-21% lower than the real parameters.

Beneficial cardiac effects of cicletanine in conscious rabbits with metabolic syndrome

Background and Purpose: High-fat diet and consequent metabolic syndrome (MS) can lead to elevated risk for cardiac arrhythmias. This preclinical study was to investigate if cicletanine (CIC) could produce cardioprotective effects in conscious rabbits exhibiting the main symptoms of MS. Methods: NZW rabbits that had undergone an 8-week-long cholesterol-enriched diet (1.5%) were instrumented with a pacemaker electrode and randomly assigned into 3 groups according to the oral treatment of either CIC (50 mg·kg−1) or sotalol (25 mg·kg−1) and their placebo b.i.d. over 5 days. Study groups were subjected to either “arrhythmia challenge” by programmed electrical stimulation in the “Arrhythmogenesis” study (N = 54) or global myocardial ischemia by rapid pacing in the “Ventricular Overdrive Pacing-induced Myocardial Ischemia” study (N = 18). The antiarrhythmic effect was evaluated by the establishment of the incidence of programmed electrical stimulation–induced arrhythmias. Proarrhythmia indicators (eg, QTc, Tpeak–Tend) were also measured to assess the cardiac safety profile of CIC. To evaluate the background of antiarrhythmic effect, cardiac cyclic nucleotide (cyclic 3′,5′-guanosine monophosphate [cGMP], cyclic 3′,5′-adenosine monophosphate [cAMP]) and nitric oxide content were determined. The antiischemic effect was characterized by change of intracavital ST segment. Results: Cicletanine treatment significantly decreased the incidence of ventricular arrhythmias, increased cardiac cGMP and nitric oxide content and reduced cardiac cAMP level. Cicletanine did not modify significantly QTc and Tpeak–Tend interval. The ST-segment change in response to rapid pacing was reduced significantly by CIC. (P < 0.05). Conclusions: Cicletanine exerts beneficial cardiac effects in rabbits with symptoms of MS, which may be of influence with regard to the clinical application of the drug.

β-Tricalcium phosphate silica aerogel as an alternative bioactive ceramic for the potential use in dentistry

ABSTRACT In this study, a mesoporous silica aerogel with β-tricalcium phosphate (β-TCP-AE) was manufactured. The effect of β-TCP-AE on gene expressions (BMP2, BMP7, Runx2 and OSX) of SAOS-2 cells was tested. For the in vivo evaluation, the ‘calvaria critical-size defect’ model was used: following 1 and 3 months of the artificial surgical bone defects filled with β-TCP-AE, histopathological analyses were performed. Gene expression studies demonstrated a mild osteoblastic differentiation of the SAOS-2 cells triggered after seven days of β-TCP-AE treatment. Digital histology of rat’s calvarial bone defects reconstructed with β-TCP-AE showed that after 1 month, calcifications and early ossifications developed with the presence of capillary-rich fibrous inflammation and remnants of exogenous compounds which nearly disappeared by the third month, and replaced with multiple newly formed bone islets mediated by osteoblasts. Based on our results, this bioceramic compound appears to have favourable properties for the use as a scaffold in the reconstructive medical practice.

Functional Shaping of the Maxillary Denture Base in Oral Rehabilitation Patient: A Case Report

Aim: The restoration of phonation and swallowing for oral rehabilitation patients is a challenging part of the rehabilitation process. The final configuration of the oral surface of the maxillary denture base can be difficult and time consuming. Special impression technique of the oral cavity has been carried out in a patient with partially resected tongue to create the replica of the necessary shape of the palatal region of the denture. The aim of this report is to present the technique and the advantages of the use of irreversible hydrocolloid impression material during the rehabilitation process of a surgically treated patient with oral cancer. Method: A small amount of irreversible hydrocolloid impression material placed on the oral surface of the maxillary record base makes it possible to determine the preliminary configuration of the surface. Then the final surface is created by replacing the impression material by wax, and by modifying the configuration according to functional tests carried out during trial placement. Results: The patient presented in this paper reported improved swallowing function and phonation six weeks after denture placement. The functional x-ray examination made three months after denture delivery showed apparent improvement of the swallowing function. The current article demonstrates how easy it was to apply irreversible hydrocolloid impression material in this specific case.

Functionalization of Amorphous Chalcogenide and Titanium Oxide Layers by Gold Nanoparticles

The technology problems of fabricating different, nanometers sized gold particles in the layered composites like light-sensitive chalcogenide glass/gold nanoparticles/transparent substrate or titanium/titanium oxide/gold nanoparticles were investigated in our work. Combination of ion implantation, plasma deposition with annealing processes results physical routes for creation of gold nanoparticles in the mentioned structures, which possess plasmon effects. These functionalized structures are planned to use for investigations of optical recording processes, biocompatibility of titanium implants.