Assessment of global and regional left ventricular function and volumes with 64-slice MSCT: A comparison with 2D echocardiography

Background  In patients with coronary artery disease (CAD), LV function and volumes are important parameters for long-term prognosis. Multislice computed tomography (MSCT) allows noninvasive assessment of the coronary arteries, but the accuracy of 64-slice MSCT for the assessment of left ventricular (LV) volumes and function is unknown. Methods and Results  A head-to-head comparison between 64-slice MSCT and 2-dimensional (2D) echocardiography was performed in 40 patients with known or suspected CAD. The LV end-diastolic volume (LVEDV) and LV end-systolic volume (LVESV) were determined and the LV ejection fraction (LVEF) was derived. Regional wall motion was assessed visually using a 17-segment model. A 3-point scoring system was used to assign to each segment a wall motion score: 1 = normokinesia, 2 = hypokinesia, 3 = akinesia or dyskinesia. Two-dimensional echocardiography served as the gold standard. MSCT agreed well with 2D echocardiography for assessment of LVEDV (r = 0.97; p < .0001) and LVESV (r = 0.98; p < .0001). An excellent correlation between MSCT and 2D echocardiography was shown for the evaluation of LVEF (r = 0.91; p < .0001). Agreement for the assessment of regional wall motion was excellent (96%, κ = 0.82). Conclusions  An accurate assessment of global and regional LV function and volumes is feasible with 64-slice MSCT. This work was supported by The Netherlands Heart Foundation, The Hague, The Netherlands, grant numbers 2002B105 (J.D.S.) and 2001D032 (J.W.J.).     

Collaboration: a concept analysis

Collaboration is a complex phenomenon, yet one that is of significance to nursing This concept analysis presents definitions and defining characteristics of collaboration so that the concept may be used in the creation of operational definitions, or to develop and evaluate tools for measuring collaboration Antecedents, consequences and empirical referents of collaboration are explored Model, contrary and related cases are presented to clarify this concept further     

Characterization of lymphocyte β-adrenoceptor activity and Gs-protein in patients with rheumatic heart valvular disease

Summary— In order to test whether the β-adrenoceptor activity in rheumatic heart valvular disease depends on the ventricular load conditions, we determined their density and binding affinity to [¹²⁵I]-iodocyanopindolol in lymphocytes, as well as plasma catecholamine and cAMP levels in 69 patients with regurgitant and stenotic lesions of the aortic and mitral valves. The patients were classified as having left ventricular pressure overload (LVP), left ventricular volume overload (LVV), mixed lesions (MOL) or right ventricular pressure overload (RVP). The β-adrenoceptor activity was determined by radioligand binding methods, catecholamines by high performance liquid chromatography using an electrochemical detector and cAMP by radioimmunoassay. The mean β-adrenoceptor density (B_max) of the control group was 60.1 ± 9.5 /mol ( n = 29) per 10⁶ lymphocytes. In the study population, the density was decreased by 83% in LVP, 78% in LVV, 87% in MOL and 86% in RVP. Plasma norepinephrine was elevated by 89% in LVP and 60% in MOL, epinephrine by 43% in LVP, 50% in VOL, 115% in MOL and 20% in RVP, while dopamine was not significantly changed, and cAMP was slightly elevated in all four groups. Screening for activating mutational changes in the G_sα-protein gave negative results, possibly dissociating the elevation in plasma cAMP from stimulatory effects of such abnormalities in the G_s-protein signaling. These results show a significant attenuation in lymphocyte β-adrenoceptor density of patients with rheumatic heart valvular disease, irrespective of the type of the prevailing ventricular load conditions. The reduction in receptor density is accompanied by a significant increase in plasma norepinephrine levels in patients with a left ventricular pressure overload and epinephrine in those with volume overload.     

Cadmium carcinogenesis in male Wistar [Crl:(WI)BR] rats: dose-response analysis of effects of zinc on tumor induction in the prostate, in the testes, and at the injection site

The ability of zinc acetate to modify the carcinogenic effects of CdCl2 in male Wistar [Crl:(WI)BR] rats was studied over a 2-year period. Groups of rats received a single s.c. injection of Cd (30.0 mumol/kg) in the dorsal thoracic midline or i.m. in the right thigh at time 0. Zinc was given in three separate s.c. doses of 0.1, 0.3, or 1.0 mmol/kg (at -6, 0, and +18 h relative to cadmium) in the lumbosacral area or p.o. at 100 ppm in the drinking water (-2 to +100 weeks). Cadmium treatments (s.c.) resulted in the appearance of tumors at the injection site and in the testes. The incidence of s.c. injection site tumors (mostly mixed sarcomas) was markedly reduced by high dose (1.0 mmol/kg) s.c. zinc (50% reduction) and was almost abolished by p.o. zinc (92% reduction). Testicular tumors (mostly Leydig cell adenomas) induced by s.c. cadmium were reduced in a dose-related fashion by zinc and were found to be highly dependent on the ability of zinc to prevent the chronic degenerative effects of cadmium in the testes. Oral zinc had no effect on s.c. cadmium-induced testicular tumors, while i.m. cadmium alone did not induce these tumors. In rats in which s.c. cadmium-induced testicular tumors and chronic degenerative effects were prevented by zinc (1.0 mmol/kg, s.c.), a marked elevation in prostatic tumors (exclusively adenomas) occurred (control, 9.6%; cadmium plus high zinc 29.6%). Cadmium given i.m., which did not result in testicular tumors or degeneration, also induced an elevated incidence (42.3%) of prostatic tumors, again indicating a dependence on testicular function. Prostatic tumor incidence was also significantly elevated (25.0%) in rats receiving 1.0 mmol/kg zinc, s.c., in combination with i.m. cadmium. These results indicate that zinc inhibition of cadmium carcinogenesis is a complex phenomenon, depending not only on dose and route but also on the target site in question.     

Malignant Centroblastic-Histiocytic Lymphoma of the Skin

A mixed B-cell type centroblastic lymphoma with extraordinarily many histiocytes in a 68-year-old man is reported. Multiple skin tumours were the only clinical manifestation during the first 5 months. The disease then progressed to the lymph nodes, spleen, and parenchymal organs, but the bone marrow remained unaffected until death, 11 months after the onset of signs. C3d receptors were the only surface markers of the centroblasts. The histiocytes were normal with respect to morphology, muramidase staining, and Fc and C3b receptors. This highly unusual spread from skin to lymphoid and parenchymal organs is discussed in the light of lymphoid cell kinetics.