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Background: ECG-gated SPECT myocardial perfusion imaging is usually acquired in supine position. However, some patients are not comfortable in this position for a variety of personal or medical reasons. Our aim was to investigate the effect of patient positioning on quantitative SPECT imaging results using normal supine database.Methods: 55 patients (mean age 58.5 ± 8.3 years) were enrolled in this prospective study. Each patient had a pair of ECG-gated stress SPECT myocardial perfusion images acquired on two gamma cameras: one in supine position and the other in upright sitting position. Left ventricular (LV) ejection fraction (EF), end-diastolic (ED), and end-systolic (ES) left ventricular volumes (V), LV mass, summed stress perfusion defect score (SSS), and total severity score (TSS) were calculated automatically relative to a supine normal reference database.Results: There were no significant differences in LVEF using the two cameras (0.65 ± 0.08 vs. 0.66 ± 0.10; P > 0.1). However, EDV, ESV, and LV mass were significantly smaller in sitting position than in supine position (89 vs. 80 ml; 33 vs. 29 ml and 115 vs. 109 ml, respectively, all P < 0.0001). On the other hand, SSS and TSS were significantly higher in sitting position than in supine position (5.16 vs. 8.73 and 166.82 vs. 288.27, both P < 0.0001). Overall, more studies in sitting position were interpreted as abnormal than in supine position (P < 0.05).Conclusion: Patient positioning has a significant impact on quantitative gated SPECT imaging results. Using a supine normal reference database, SSS and TSS were larger in sitting position than in supine position. Thus, for imaging in sitting position, separate normal limits are required. [ABSTRACT FROM AUTHOR]

Objective: To find structural differences between brain metastases of lung and breast cancer, computing their heterogeneity parameters by means of both 2D and 3D texture analysis (TA).Materials and methods: Patients with 58 brain metastases from breast (26) and lung cancer (32) were examined by MR imaging. Brain lesions were manually delineated by 2D ROIs on the slices of contrast-enhanced T1-weighted (CET1) images, and local binary patterns (LBP) maps were created from each region. Histogram-based (minimum, maximum, mean, standard deviation, and variance), and co-occurrence matrix-based (contrast, correlation, energy, entropy, and homogeneity) 2D, weighted average of the 2D slices, and true 3D TA were obtained on the CET1 images and LBP maps.Results: For LBP maps and 2D TA contrast, correlation, energy, and homogeneity were identified as statistically different heterogeneity parameters (SDHPs) between lung and breast metastasis. The weighted 3D TA identified entropy as an additional SDHP. Only two texture indexes (TI) were significantly different with true 3D TA: entropy and energy. All these TIs discriminated between the two tumor types significantly by ROC analysis. For the CET1 images there was no SDHP at all by 3D TA.Conclusion: Our results indicate that the used textural analysis methods may help with discriminating between brain metastases of different primary tumors. [ABSTRACT FROM AUTHOR]

Dicyclohexyl-terephthalamide (DCHT) is an efficient and partially soluble nucleating agent for isotactic polypropylene. Its properties, nucleating efficiency and selectivity were characterized using infrared spectroscopy, calorimetry and polarized light microscopy techniques with special attention to the dissolution and recrystallization of DCHT in the iPP melt. The mechanical properties of the nucleated samples were studied using standard tensile tests. It was found that DCHT possesses dual (α and β) nucleating ability. DCHT is soluble in polypropylene melt and recrystallized from the melt during the cooling. It was observed that a special supermolecular structure is formed in its presence, where micron-sized α-iPP is dispersed finely in the β-iPP matrix. This unique structure promoted good stiffness and toughness simultaneously. [ABSTRACT FROM AUTHOR]

Background: Though sustaining burn injury requiring hospital admission is not too common, there are patients who happen to return to the burn unit with a new injury. Our aim was to characterise the repeatedly burned patients and their cases. The question was whether we can detect an objective reason for this higher susceptibility for burn injuries. Methods: Data of twice- or more times-burned patients (group A) were compared to a randomly chosen group of normal-burned patients (group B) treated at the burn unit of the Department of Dermatology, Debrecen University. Results: Alcohol consumption was found in 12 of 35 cases (34 %) in group A, and in 6 of 168 cases in group B (3.6 %; p < 0.001). In 25 of 35 cases, surgery was neeeded because of deep burns (71 %), and this ratio was 44 % in the control (B) group, in 74 from 168 cases ( p = 0.005). Average length of hospital stay was 13.43 days (95 % CI 11.03-15.83) in group A and 8.18 days (95 % CI 7.27-9.1) in group B ( p < 0.001). Neurological disease-mostly epilepsy-was found in 7 cases of 35 in group A (20 %), whereas in 14 cases of 168 in group B (8.3 %; p = 0.061). Conclusions: Our data show that among repetitively burned patients, there are more alcohol abusers, more patients with deep burns who need surgery and that their average stay in the hospital is longer. These patients also have a neurologic illness (epilepsy) more frequently, although this difference was not statistically significant. Level of Evidence: Level IV, risk/prognostic study [ABSTRACT FROM AUTHOR]

The chain regularity of isotactic polypropylene (iPP) homopolymer and random copolymers was characterized by different thermal fractionation methods in this study. Different stepwise temperature programs were applied in a calorimeter (DSC), in order to develop a method which is significantly faster than stepwise isothermal segregation technique (SIST) and provides reliable information about the chain regularity of iPP. Our studies prove that self-seeding accelerates the crystallization process during annealing in SSA-DSC experiments (successive self-nucleation and annealing). Consequently, the time of isothermal steps can be shortened significantly in the SSA-DSC method. On the other hand, we found that step time should not be too short if the goal of the measurement is the determination of average chain regularity. Our results clearly indicate that both the experimental conditions and the evaluation technique influence the obtained results. A standard experimental procedure is proposed for reliably determining the average chain regularity of iPP. The length of the SSA-DSC temperature program developed in this study is much shorter compared to that of the conventional SIST measurements used recently for such experiments. The proposed SSA-DSC program makes the reliable characterization of a large number of samples on an acceptable timescale possible. [ABSTRACT FROM AUTHOR]

Smith-Lemli-Opitz syndrome (SLOS), a multiple congenital anomaly with severe mental retardation, is caused by decreased activity of 7-dehydrocholesterol reductase. Fifteen Hungarian patients were diagnosed with SLOS on the basis of clinical symptoms, serum cholesterol, 7-dehydrocholesterol, and molecular genetic testing. Their age at the time of diagnosis in mild SLOS ( n = 4, clinical score <20) was 0.5-18 years, cholesterol was 2.37 ± 0.8 mmol/L, and 7DHC was 0.38 ± 0.14 mmol/L. In the group of typical SLOS ( n = 7, score 20-50), the diagnosis was set up earlier (age of 0.1-7 years); t-cholesterol was 1.47 ± 0.7 mmol/L, and 7DHC was 0.53 ± 0.20 mmol/L. Patients with severe SLOS ( n = 4, clinical score > 50) died as newborns and had the lowest t-cholesterol (0.66 ± 0.27 mmol/L), and 7DHC was 0.47 ± 0.14 mmol/L. Correlation coefficient with clinical severity was 0.74 for initial t-cholesterol and 0.669 for Cho/7DHC. Statistically significant difference was between the initial t-cholesterol of mild and severe SLOS ( p = 0.01), and between the Cho/7DHC ratios of groups ( p = 0.004). In severe SLOS, the percentage of α-lipoprotein was significantly lower than in typical ( p = 0.003) and mild SLOS ( p = 0.004). Although serum albumin, total bilirubin, and hemostasis parameters remained in the reference range during cholesterol supplementation ( n = 10) combined with statin therapy ( n = 9), increase of aspartate aminotransferase and alanine aminotransferase in 50 % of the patients probably refers to a reversible alteration of liver function; therefore, statin therapy was suspended. Conclusion: life expectancy is fundamentally determined by the initial t-cholesterol, but dehydrocholesterol and α-lipoprotein have prognostic value. Accumulation of hepatotoxic DHC may inhibit the synthesis of α-lipoproteins, decreasing the reverse cholesterol transport. During statin therapy, we suggest monitoring of lipid parameters and liver function. [ABSTRACT FROM AUTHOR]

Crystallization kinetics of β-nucleated isotactic polypropylene (β-iPP) under isothermal conditions were investigated by differential scanning calorimetry. iPP was nucleated by a trisamide derivative, namely tris-2,3-dimethyl-hexylamide of trimesic acid (TATA). In the presence of TATA possessing dual nucleating ability, the formation of the α- and β-form occurs simultaneously. An isothermal stepwise crystallization method is suggested in this study, which can separate the crystallization process of β- and α-iPP and consequently their crystallization kinetics can be evaluated separately. The results indicated that the mechanism of crystallization changes in temperature especially in the vicinity of the upper critical temperature of the formation of the β-phase. In addition, it was found that the ratio of the growth rates of β- and α-modification determines the characteristics of crystallization and influences the apparent rate constant of crystallization of both polymorphs. [ABSTRACT FROM AUTHOR]

This study intended to determine whether the replacement of vitamin D3 with alfacalcidol results in any bone mineral density (BMD) increase in 76 patients unresponsive to the combination of alendronate and conventional vitamin D3 treatment. In these patients the conventional vitamin D3 had been replaced with alfacalcidol (0.5 μg/day), and then the patients were followed up for a year. After treatment for 1 year, Wilcoxon test revealed a small but statistically significant ( P < 0.001) increase in the BMD values of the forearm and lumbar vertebrae, in the serum calcium and urinary calcium/creatinine ratio in first-voided morning urine. However, the serum alkaline phosphatase activity, phosphorus, parathormone, osteocalcin levels and the urinary d-pyr/creatinine ratio decreased significantly ( P < 0.001). As suggested by our results, combination therapy with alendronate and alfacalcidol increases bone density and improves the biochemical markers of bone turnover, without any substantial increase in the incidence of adverse effects. [ABSTRACT FROM AUTHOR]

Since antagonists of growth hormone-releasing hormone (GH-RH) inhibit proliferation of various tumors, in this study we investigated the effects of GH-RH antagonists MZ-5-156 or JV-1-36 on growth of estrogen-independent MDA-MB-468 human breast cancers xenografted into nude mice. Both GH-RH antagonists administered at a dose of 20 μg/day induced regression of some and growth-arrest of other tumors, while control tumors continued to grow. After 5 weeks of therapy with MZ-5-156 or JV-1-36, final volume and weight of MDA-MB-468 tumors were significantly decreased (all p values <0.001) and serum IGF-I levels as well as tumor IGF-I mRNA expression were reduced as compared with controls. High affinity binding sites for IGF-I were detected by the ligand binding method. Gene expression of human IGF-I receptors, as measured by the RT-PCR, was not significantly different in control and treated MDA-MB-468 tumors. In cell culture, IGF-I did not stimulate, GH-RH slightly stimulated, while MZ-5-156 and JV-1-36 inhibited proliferation of MDA-MB-468 cells known to possess defective insulin and IGF-I receptor signaling. The expression of mRNA for human GH-RH was found in five of 8 tumors treated with GH-RH antagonists, and in one of the five control tumors. These results suggest that GH-RH antagonists inhibit MDA-MB-468 breast cancers possibly through mechanisms involving interference with locally produced GH-RH. [ABSTRACT FROM AUTHOR]

Technetium-99m sestamibi was used for functional investigation of the muscle perfusion of lower extremities in 35 patients with peripheral vascular disease. The aim was to test what useful information could be obtained by additional imaging of the legs in patients referred for risk stratification with dipyridamole myocardial scanning. Posterior images were acquired over the thighs and calves after postocclusive reactive hyperaemia and at rest. Inter- and intraextremity ratios and differences between the stress and rest data were used for the assessment of abnormal circulation. Arteriography was performed in every case, and surgical procedures or transluminal angioplasty in 31 patients. To estimate diagnostic accuracy, the results ofTc-sestamibi scintigraphy were compared with those of angiography and the functional consequences of revascularization procedures. The sensitivity and specificity ofTc-sestamibi scintigraphy were 55% and 25%, respectively, with an overall accuracy of 50%. Apparently methodological error was not responsible for these poor results. Instead, a paradoxically high uptake of the radiopharmaceutical in muscles supplied by significantly stenosed vessels was identified as the main source of both false-negative and false-positive results. This phenomenon resembles the findings of a previous study involving delayed administration of thallium-201 after exercise. In conclusion,Tc-sestamibi scintigraphy has not proved sufficiently reliable to help in the management strategy for patients with peripheral vascular disease. [ABSTRACT FROM AUTHOR]

Presents a letter to the editor about differences in SPET analysis of thyroid-associated orbitopathy.