Effects of delayed (24 h postintervention) β-irradiation therapy after coronary angioplasty and stenting in de novo native coronary artery lesions

BACKGROUND

The effects of brachytherapy performed 24 h postintervention in de novo native coronary artery lesions.

METHODS AND RESULTS

Thirty-nine patients with 39 de novo coronary artery lesions were randomised to prompt (immediately after intervention, n=21) or delayed (24 h later, n=18) beta brachytherapy ((90)Sr/(90)Y) after been successfully revascularized with stenting. Clinical follow-up data up to 21 months (median time) were compared. After irradiation and at 6-month follow-up, paired volumetric analysis of the stented segment and the 5-mm proximal and distal reference segments was performed; this included measurements of the external elastic membrane, lumen, plaque, and media (external elastic membrane minus lumen), stent and intima hyperplasia (stent minus lumen). Baseline clinical and angiographic characteristics were similar in the two groups. Postintervention measurements of stent, lumen, and intima hyperplasia volumes as well as postintervention minimum lumen cross-sectional areas were not different. In the stented segments and in the segments 5 mm proximal and distal to the stent, similar changes of all IVUS measurements were measured in the two patient groups, but in the lumen volume at the proximal stent edge of patients irradiated 24 h postinjury. At 21 months median follow-up time, target lesion revascularization (TLR) was performed in 8 patients (38%) in the prompt irradiation group compared with 3 (17%) in the delayed (P=.17).

CONCLUSION

Beta irradiation is similarly effective whether performed immediately after percutaneous coronary intervention or 24 h later.

Research and education directions in Medical Informatics at the Aristotle University of Thessaloniki

The field of Medical Informatics is one of the most active fields both in research and education at the Aristotle University of Thessaloniki. The nucleus of this scientific field at the Aristotle University resides in the Medical School and in particular in the Laboratory of Medical Informatics. Education programs exist in undergraduate, graduate and post-graduate levels, and are targeted towards medical students and doctors and information technology related students and professionals. Research projects cover a wide area of medical informatics including medical information processing and management, electronic health records design and implementation, medical decision support, biological systems simulation, telemedicine applications, integration and communication issues related to regional health information systems, and quality assessment of health services and systems. The description and brief presentation of the output of these educational and research directions shall be presented in this paper.

Effects of storage conditions and fruit processing on the degradation of parathion methyl on apples and lemons

Degradation of parathion methyl on lemon and apple on the trees, during storage of these fruits in refrigerated rooms, and during juice production was studied. The pesticide was applied to the trees according to the recommended application procedures. Apples and lemons received a single application of parathion methyl at 40 g active ingredient/100 litres. Residues were determined with a simple gas-chromatographic method; the recovery rate of parathion methyl from apples and lemons was 85-108% and the limit of determination was 0.004 mg kg(-1). The half-lives of parathion methyl on the trees were 7 days for apples and 5 days for lemons. The duration of storage of the fruits in a refrigerated room have been largely extended to 65 and 63 days, respectively. The high acidity of lemons was found not to affect the degradation rate of parathion methyl. When fruit juice was produced from both apples and lemons, parathion methyl residues were detected in apple but not in lemon juice.

Mining association rules from clinical databases: an intelligent diagnostic process in healthcare

Data mining is the process of discovering interesting knowledge, such as patterns, associations, changes, anomalies and significant structures, from large amounts of data stored in databases, data warehouses, or other information repositories. Mining Associations is one of the techniques involved in the process mentioned above and used in this paper. Association is the discovery of association relationships or correlations among a set of items. The algorithm that was implemented is a basic algorithm for mining association rules, known as a priori. In Healthcare, association rules are considered to be quite useful as they offer the possibility to conduct intelligent diagnosis and extract invaluable information and build important knowledge bases quickly and automatically. The problem of identifying new, unexpected and interesting patterns in medical databases in general, and diabetic data repositories in specific, is considered in this paper. We have applied the a priori algorithm to a database containing records of diabetic patients and attempted to extract association rules from the stored real parameters. The results indicate that the methodology followed may be of good value to the diagnostic procedure, especially when large data volumes are involved. The followed process and the implemented system offer an efficient and effective tool in the management of diabetes. Their clinical relevance and utility await the results of prospective clinical studies currently under investigation.

Comparison of classical and ultrasound-assisted isolation procedures of cellulose from kenaf (Hibiscus cannabinus L.) and eucalyptus (Eucalyptus rodustrus Sm.)

A comparative study of classical and ultrasound-assisted extraction and purification of cellulose from kenaf (Hibiscus cannabinus L.) and eucalyptus (Eucalyptus rodustrus Sm.), has been conducted. The isolated cellulose samples were studied by diffuse reflectance infrared Fourier transform spectroscopy and 13C nuclear magnetic resonance (13C-NMR) spectroscopy and the crystallinity was also determined. The use of ultrasound decreased the total time of treatment, in addition the purity of the obtained cellulose was very high.

Probing jump diffusion in crystalline solids with neutron spin-echo spectroscopy

Neutron spin-echo spectroscopy has been applied to jump diffusion in a crystalline solid. Definite advantages of spin-echo spectroscopy over quasielastic neutron scattering are the direct visual discrimination of fast and slow diffusion processes and the high resolution in the time-energy domain. The potential of the method is demonstrated by way of Ni diffusion in the intermetallic alloy NiGa.

Identification of uric acid and xanthine oxidase in atherosclerotic plaque

Concentrations of uric acid in carotid endarterectomy specimens in men and women were measured using high-performance liquid chromatography in comparison wo nonatherosclerotic control specimens.

A neural network approach in diabetes management by insulin administration

Diabetes management by insulin administration is based on medical experts' experience, intuition, and expertise. As there is very little information in medical literature concerning practical aspects of this issue, medical experts adopt their own rules for insulin regimen specification and dose adjustment. This paper investigates the application of a neural network approach for the development of a prototype system for knowledge classification in this domain. The system will further facilitate decision making for diabetic patient management by insulin administration. In particular, a generating algorithm for learning arbitrary classification is employed. The factors participating in the decision making were among other diabetes type, patient age, current treatment, glucose profile, physical activity, food intake, and desirable blood glucose control. The resulting system was trained with 100 cases and tested on 100 patient cases. The system proved to be applicable to this particular problem, classifying correctly 92% of the testing cases.

Deconvolution and wavelet-based methods for membrane current estimation from simulated fractionated electrograms

In infarcted myocardium, extracellular recordings exhibit multiple deflections due to irregular pathway of the electric impulse. In this work the problem of distinguishing local from distant deflections is tackled. In order to evaluate the proposed methods in a controlled setting, simulated data are used, following both Beeler-Reuter and Luo-Rudy kinetics. The input is an array of electrograms positioned on grid-points of a rectangular grid and the output is an array of estimates of the membrane current. First, deconvolution techniques are used in the form of spatial filtering for membrane current estimation from the extracellular recordings. Second, the extracellular recordings undergo wavelet based transformation, followed by a spatial filter which enhances local activity deflections and suppresses distant activity deflections. It is shown that wavelet filtering of the extracellular recordings acts as an evaluator of the efficiency of the deconvolution techniques for the membrane current estimation. Subsequently, activation times based on the results from the two methods are used for the reconstruction of the propagation pattern in a zig-zag case in two-dimensional grids. It is shown that the wavelet-based method is more robust, and can work well even in cases where the grid interval in the y direction is four times larger than the single cell size.

Enzymatic acylation of hydroxypropyl cellulose in organic media and determination of ester formation by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy

Esters were prepared by acylation of hydroxypropyl cellulose with fatty acid catalyzed by immobilized lipase from Candida antarctica in tert-butanol. The nature of the substrates used, the initial water activity of the system, and the molecular weight of the hydroxypropyl cellulose were investigated. Moreover, Fourier transform-infrared (FT-IR) spectroscopy was used for determination of ester content on hydroxypropyl cellulose. Specifically, a linear relationship was established between the peak height assigned to the absorption of the esterified carboxyl groups of the cellulose and the ester content. At optimum reaction conditions, the ester content on the hydroxypropyl cellulose was about 11%.

Effect of intracoronary gamma-radiation therapy on in-stent restenosis: An intravascular ultrasound analysis from the gamma-1 study

BACKGROUND

The aim of this study was to use serial volumetric intravascular ultrasound to evaluate the effect of gamma-radiation on recurrent in-stent restenosis.

METHODS AND RESULTS

After successful reintervention, patients were randomized to receive either (192)Ir or placebo. Intravascular ultrasound studies with motorized pullback (0.5 mm/s) were performed immediately after irradiation and at 8-month follow-up in 70 patients. Paired volumetric analysis of the stented segment and of 5-mm proximal and distal reference segments was performed; this included measurements of the external elastic membrane, lumen, plaque and media (external elastic membrane minus lumen), stent, and intimal hyperplasia (stent minus lumen). Baseline proximal reference, stent, and distal reference measurements were similar in both groups. The changes in proximal and distal reference measurements of the external elastic membrane, plaque and media, and lumen areas were similar in both groups. However, the decrease in stented segment lumen volume was less in the (192)Ir patients than the placebo patients (-25+/-34 mm(3) versus -48+/-42 mm(3); P:=0.0225), and the increase in the volume of intimal hyperplasia in the stented segment was less in the (192)Ir patients than in the placebo patients (28+/-37 mm(3) versus 50+/-40 mm(3); P:=0.0352). When averaged over the length of the stented segment (32+/-13 mm versus 33+/-14 mm; P:=0.9), the increase in mean area of intimal hyperplasia was 0.8+/-1.0 mm(2) in the (192)Ir group and 1.6+/-1.2 mm(2) in the control group (P:=0.0065). Late stent-vessel wall malapposition was noted in one placebo patient and no (192)Ir patients.

CONCLUSIONS

gamma-Radiation therapy can effectively prevent recurrent in-stent restenosis by inhibiting neointimal formation within the stent. At the stent edge, there were no significant differences between (192)Ir and placebo patients.

Laparoscopic repair of a congenital diaphragmatic hernia in an adult

A patient undergoing laparoscopic Nissen fundoplication had an intraoperative finding of a left Bochdalek hernia, which was repaired with an onlay of fenestrated PTFE. This appears to be the first report of such a case.

Prospects of medical informatics education in Greece: can we bridge the gap?

Medical Informatics education is a complex task,, since it aims in educating inhomogeneous groups of people coming from different disciplines. In Greece, recently considerable advancements in the medical informatics education field are made. These advancements aim in bridging gaps in various areas of MI users interactions. In particular, an overview of the strategy of the Greek ministry of education shall be given, some examples of MI related educational programs shall be referred to, and finally the MI educational structure used in the Aristotelian University shall be presented in detail, laying out the strategy of this University for bridging various types of gaps.

Prevention of primary cytomegalovirus disease in organ transplant recipients with oral ganciclovir or oral acyclovir prophylaxis

BACKGROUND

Optimal prophylaxis against cytomegalovirus (CMV) disease for organ transplant patients at risk for primary infection (donor seropositive, recipient seronegative, D+R-) remains to be determined. We hypothesized that prolonged oral ganciclovir therapy following intravenous therapy would provide increased protection.

METHODS

A total of 155 evaluable D+R- organ transplant recipients from 13 transplant centers were entered into the study: all received intravenous ganciclovir (5 mg/kg/day) for 5-10 days and then either oral acyclovir (400 mg tid) or oral ganciclovir (1 g tid) for an additional 12 weeks. Patients were assigned to their treatment groups at a central randomization site, with a separate randomization scheme for each of the organs transplanted (kidney, heart, or liver). In the case of kidney transplants, the patients were stratified according to source of the kidney (living related vs. cadaveric donor). The primary endpoint was the incidence of CMV disease in the first six months post-transplant.

RESULTS

Treatment with oral ganciclovir was associated with a significant decrease in the incidence of symptomatic disease or viremia when compared with the oral acyclovir group (32% vs. 50%, P<0.05). This difference was most marked in terms of tissue invasive disease: only 3 of 15 symptomatic patients in the ganciclovir group vs. 10 of 21 in the acyclovir group developed tissue-invasive infection (P<0.05). There was a significant difference in the time to CMV disease or viremia in the two groups: mean time 212+/-17 days post-transplant for the acyclovir group vs. 291+/-13 days for the ganciclovir group (P<0.001). The incidence of allograft rejection was 34% in the ganciclovir group and 46% in the acyclovir group (P=NS). Leukopenia was more common in the ganciclovir group (P<0.05), but in no case did it require drug discontinuation. Ganciclovir resistance did not develop in this study.

CONCLUSION

Prophylaxis with oral ganciclovir following a brief course of intravenous ganciclovir provides useful protection against primary CMV disease.

Decay of methidathion on Greek soultanina grapes during storage and on the vines

Decomposition of the pesticide methidathion on and in soultanina (Thomson seedless) grapes was studied. Vines, uncovered and covered were sprayed with the pesticide. Samples were collected and analyzed in regular time intervals. Two lots were collected, the first of them, 2 h after spraying and the second 20 days later, and were stored in a commercial refrigerated room. Degradation of the pesticide was studied for about 50 days for the grapes on the vines and 130 days for the grapes stored in the refrigerated room. The half-life of the pesticide methidathion was found to be 5 days for the uncovered vines, 7 days for the covered vines and 64 days for the grapes stored in the refrigerator.

Spatial filtering methods for local activation determination in fractionated electrograms from simulated infarcted hearts

The purpose of this work is the enhancement of local activation in multiphasic extracellular recordings coming from infarcted myocardial tissue and, consequently, the distinction of local from distal activation. Deconvolution procedures are applied, in the form of spatial filtering, in order to estimate transmembrane currents from the extracellular recordings. Simulated data are used in order to test the methods. The current source estimates are compared to the actual transmembrane currents and to Laplacian estimates.