Dating Components of Human Atherosclerotic Plaques

Rationale: Atherosclerotic plaques that give rise to acute clinical symptoms are typically characterized by degradation of the connective tissue and plaque rupture. Experimental studies have shown that mechanisms to repair vulnerable lesions exist, but the rate of remodeling of human plaque tissue has not been studied. Objective: In the present study, we determined the biological age of different components of advanced human atherosclerotic plaques by analyzing tissue levels of (14)C released into the atmosphere during the nuclear weapons tests in the late 1950s and early 1960s. Methods and Results: Atherosclerotic plaques were obtained from 10 patients (age 46 to 80 years) undergoing carotid surgery. Different regions of the plaques were dissected and analyzed for (14)C content using accelerator mass spectrometry. At the time of surgery, the mean biological age of the cap region was 6.4+/-3.2 years, which was significantly lower than that of the shoulder region (12.9+/-3.0 years, P<0.01), the interface toward the media (12.4+/-3.3 years, P<0.01), and the core (9.8+/-4.5 years, P<0.05). Analysis of proliferative activity and rate of apoptosis showed no signs of increased cellular turnover in the cap, suggesting that the lower (14)C content reflected a more recent time of formation. Conclusions: These results show that the turnover time of human plaque tissue is very long and may explain why regression of atherosclerotic plaque size rarely is observed in cardiovascular intervention trials

Efficient internalization into low-passage glioma cell lines using adenoviruses other than type 5: an approach for improvement of gene delivery to brain tumours

There is a need for improvement of the commonly used adenovirus vectors based on serotype 5. This study was performed on three adenovirus serotypes with a CAR-binding motif (Ad4p, Ad5p and Ad17p) and three non-CAR-binding serotypes (Ad11p, Ad16p and Ad21p). The capacity of these alternative adenovirus vector candidates to deliver DNA into low-passage glioma cell lines from seven different donors was evaluated. The non-CAR-binding serotype Ad16p was the most efficient serotype with regard to import of its DNA, as well as initiation of hexon protein expression. Ad16p established hexon expression in 60–80 % of the cell population in gliomas from all donors tested. The other non-CAR-binding serotypes, Ad11p and Ad21p, showed hexon expression in 25–60 and 40–80 % of cells, respectively. The corresponding figure for the best CAR-binding serotype, Ad5p, was only 25–65 %, indicating greater variability between cells from different donors than serotype Ad16p had. The other CAR-binding serotypes, Ad4p and Ad17p, were refractory to some of the gliomas, giving a maximum of only 45 and 40 % hexon expression, respectively, in the most permissive cells. Interestingly, the transduction capacity of the CAR-binding serotypes was not correlated to the level of CAR expression on the cells

14C emission from Swedish nuclear power plants and its Eeffect on the 14C levels in the environment

The radionuclide 14C is produced in all types of nuclear reactors mainly by neutron-induced reactions in oxygen (17O), nitrogen (14N) and carbon (13C). Part of the 14C created is continuously released during normal operation as airborne effluents in various chemical forms (such as CO2, CO and hydrocarbons) to the surroundings. Because of the biological importance of carbon and the long physical half-life of 14C, it is of interest to measure the releases and their incorporation into living material. The 14C activity concentrations in annual tree rings and air around two Swedish nuclear power plants (Barsebäck and Forsmark) as well as the background 14C activity levels from two reference sites in southern Sweden during 1973-1996 are presented in this report. In order to verify the reliability of the method some investigations have been conducted at two foreign nuclear sites, Sellafield fuel reprocessing plant in England, and Pickering nuclear generating station in Canada, where the releases of 14C are known to be substantial. Furthermore, results from some measurements in the vicinity of Paldiski submarine training centre in Estonia are presented. The results of the 14C measurements of air, vegetation and annual tree rings around the two Swedish nuclear power plants show very low enhancements of 14C, if at all above the uncertainty of the measurements. Even if the accuracy of the measurements of the annual tree rings is rather good (1-2%) the contribution of 14C from the reactors to the environment is so small that it is difficult to separate it from the prevailing background levels of 14C. This is the case for all sampling procedures: in air and vegetation as well as in annual tree rings. Only on a few occasions an actual increase is observed. However, although the calculations suffer from rather large uncertainties, the calculated release rate from Barsebäck is in fair agreement with reported release data. The results of this investigation show that the effective doses to man related to the releases of 14C from the Swedish light-water reactors at Barsebäck and Forsmark are very low, especially compared to the situation at other nuclear installations, such as the fuel reprocessing plant at Sellafield, England, and the heavy-water reactors at Pickering nuclear generating station, Canada. Lund/Malmö February 200

Direct association between diet and the stability of human atherosclerotic plaque

This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Mediterranean diet has been suggested to explain why coronary heart disease mortality is lower in southern than northern Europe. Dietary habits can be revealed by isotope ratio mass spectrometry (IRMS) measurement of carbon (δ(13)C) and nitrogen (δ(15)N) in biological tissues. To study if diet is associated with human plaque stability, atherosclerotic plaques from carotid endarterectomy on 56 patients (21 Portuguese and 35 Swedish) were analysed by IRMS and histology. Plaque components affecting rupture risk were measured. Swedish plaques had more apoptosis, lipids and larger cores, as well as fewer proliferating cells and SMC than the Portuguese, conferring the Swedish a more rupture-prone phenotype. Portuguese plaques contained higher δ(13)C and δ(15)N than the Swedish, indicating that Portuguese plaques were more often derived from marine food. Plaque δ(13)C correlated with SMC and proliferating cells, and inversely with lipids, core size, apoptosis. Plaque δ(15)N correlated with SMC and inversely with lipids, core size and apoptosis. This is the first observational study showing that diet is reflected in plaque components associated with its vulnerability. The Portuguese plaques composition is consistent with an increased marine food intake and those plaques are more stable than those from Swedish patients. Marine-derived food is associated with plaque stability.info:eu-repo/semantics/publishedVersio

The single stage AMS machine at Lund University: Status report

In May 2003 Lund University, Sweden, ordered a new AMS facility from National Electrostatics Corp. (NEC), Wisconsin. The system is the first low energy, open air, single stage AMS system (SSAMS). The machine is equipped with a dual ion source sequential injector, which allows measurements of carbon with the masses 12, 13 and 14. The machine operates at 250 kV with the gas stripper, high energy magnet and detector mounted on a high voltage deck and with the injector at ground potential. The new machine was installed during August-October 2004 and about 500 samples were dated during the first nine months. The dual ion source injector allows both low-activity samples for radiocarbon dating and high-activity samples for medicine, biochemistry and ecology studies to be measured, with minimum risk of cross-contamination. The precision in radiocarbon dating is 50 years or better and this is expected to improve with careful tuning of the machine. The background for processed graphite equates to about 43 000 radiocarbon years. (c) 2007 Elsevier B.V. All rights reserved

The channeling technique applied to disorder analysis of single crystals of the fluorite type

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