The effect of atherogenic infusions of the triglyceride-rich, lipid emulsion, Lipofundin-S, on the in vitro growth characteristics of rat aortic smooth muscle cells.

This study shows that arterial smooth muscle cells (SMC) isolated from rats receiving atherogenic doses of the lipid emulsion, Lipofundin-S, alter their in vitro growth properties. Compared to cells from control animals, SMC isolated from Lipofundin-S-infused rats show a reduction in both saturation density and response to increasing serum concentrations, without a change in the baseline proliferation. Also, SMC isolated from lipid-treated animals and grown for five days in the presence of 30, 150, or 300 pg/ml estradiol show a 30% increase in growth vs. cells from controls. Epinephrine at 1 microM stimulates growth in SMC from control rats, while causing no growth enhancement over five days in cells from lipid-infused animals. Thus, atherogenic infusions of Lipofundin-S into rats cause phenotypic changes in arterial SMC which can be passed to successive cell generations in vitro.     

Coronary flow characteristics after a Bentall procedure with or without sinuses of Valsalva.

OBJECTIVES: The sinuses of Valsalva are known to contribute to the normal function of the aortic valve. Little is known about their role in promoting coronary artery blood flow. The aim of this study was to compare coronary artery flow characteristics among patients undergoing a Bentall operation by means of a conventional cylindrical Dacron conduit or with a new conduit with pseudosinuses of Valsalva or in patients retaining their natural sinuses of Valsalva after aortic valve and supracoronary ascending aorta replacement. METHODS: One year after a Bentall procedure with a standard cylindrical Dacron conduit (7 patients, group A) or with the new conduit (7 patients, group B), or after aortic valve and ascending aortic replacement (control group, 7 patients, group C) coronary flow velocity reserve and diastolic to systolic time integral ratio at baseline and after maximal hyperemia (with 40 microg of adenosine) were assessed by using a 0.014-in. Doppler guidewire positioned in the middle portion of the left anterior descending coronary artery. All patients were in NYHA class I, sinus rhythm and free of coronary disease. RESULTS: Arterial blood pressures and heart rate were comparable among groups. Intracoronary Doppler measurements did not show any significant difference in coronary vascular reserve between the three groups (3.6+/-0.4 vs 3.1+/-0.7 vs 3.7+/-0.5, P = 0.2). A greater diastolic component at baseline was present in group B patients (5.5+/-1.9 vs 3.5+/-0.9 in group A and 3.7+/-0.9 in group C, P = 0.024). After maximal hyperemia the diastolic component increased slightly in group A patients (8%) while both in groups B and C significantly decreased (-15 and -20%, respectively) (P = 0.017). CONCLUSIONS: The presence of pseudosinuses of Valsalva does not influence coronary flow reserve. After maximal coronary vasodilation the increase in the systolic component of coronary flow is more evident in the presence of sinuses or pseudosinuses of Valsalva, thus suggesting that coronary flow pattern may be affected by the presence of sinuses.     

Rhythmic movements in idiopathic REM sleep behavior disorder.

Reported are two cases of video-PSG captured head-rolling occurring, in the context of REM Sleep Behavior Disorder (RBD) episodes, in two patients affected with idiopathic RBD and without past personal or familiar history of Rhythmic Movement Disorder during sleep. It has been speculated that the activation of neuronal pathways which underlie REM-related loss of motor control in RBD, may involve the Central Pattern Generator neuronal networks leading to the induction of Rhythmic Movements during RBD episodes, thereby allowing the re-emergence, in pathological conditions in later life, of a motor behavior typically seen in the early stage of life.     

Top-down and bottom-up processes in the extrastriate cortex of cirrhotic patients: an ERP study.

OBJECTIVE: This study aims to evaluate the efficiency of top-down and bottom-up processes in the extrastriate cortex of cirrhotic patients without overt hepatic encephalopathy (HE). METHODS: Reaction times (RTs), accuracy and event-related potentials (ERPs) were recorded during the execution of a visual Simon task in 17 cirrhotic patients and 10 healthy controls. Amplitude and latency of the P1 and N1 (indexes of bottom-up processes) and of the N2pc (index of top-down processes) were measured. RESULTS: Patients were slower than controls, and patients with minimal HE (MHE) were slower than patients without MHE. The distribution analysis of RTs showed that the Simon effect decays with slower RTs in all the groups and that the shape of the distribution was different in MHE patients. No differences were found between cirrhotic patients and controls for P1 and N1 amplitude and latency. In contrast, N2pc latency was delayed in cirrhotic patients compared to controls independently of MHE. CONCLUSIONS: In the extrastriate cortex of cirrhotic patients without HE, top-down processes are altered whereas bottom-up processes are preserved. SIGNIFICANCE: The analysis of exogenous and endogenous visual components of ERPs provides a model to study the functional dissociation between top-down and bottom-up processes inside the extrastriate cortex.     

Transglutaminase in cell proliferation and transformation

Transglutaminase (TGase) activity was reduced in intact mitogen-stimulated human peripheral blood lymphocytes (PBL) when compared to intact resting PBL. Moreover, a treatment of the same quiescent immunocompetent cells with purified liver TGase and Ca²⁺ completely suppressed the mitogen-induced blast transformation. A decrease in TGase activity in neoplastically transformed seminal vesicle epithelial cells with respect to their normal parent counterpart was also observed. Our data support the notion of a possible implication of TGase in cell proliferation and transformation.     

Experimental Calcification of the Myocardium: Ultrastructural and Histochemical Investigations

Focal areas of calcification are frequent in rat myocardium 30 and 60 days after administration of dihydrotachysterol. These areas are PAS-positive, stain deeply with alcian blue and show high affinity for colloidal iron. Calcification is almost completely confined to intracellular structures. Small clusters of needle-shaped crystals are first found in apparently undamaged mitochondria in undamaged myocardial cells. When all the mitochondria are calcified, the cell degenerates, and inorganic crystals are laid down in relationship with its myofilaments. In other myocardial cells, clusters of amorphous or finely granular inorganic substance are found in both mitochondria and myofibrils. Both structures show signs of advanced degeneration. Inorganic substance has only occasionally been found within the structures of the sarcoplasmic reticulum. These structures do not seem to be involved in myocardial calcification under the present experimental conditions. Calcification of myocardial cells gives rise to a cellular reaction. Many macrophagic cells surround the calcified areas, which are rapidly reabsorbed. The present results show that myocardial mitochondria are actively engaged in controlling the intracellular concentration and movement of calcium ions. Their role in the myocardial contraction-relaxation cycle and the possible mechanism of myocardial calcification are discussed.