A PKC-Dependent Recruitment of MMP-2 Controls Semaphorin-3A Growth-Promoting Effect in Cortical Dendrites

There is increasing evidence for a crucial role of proteases and metalloproteinases during axon growth and guidance. In this context, we recently described a functional link between the chemoattractive Sema3C and Matrix metalloproteinase 3 (MMP3). Here, we provide data demonstrating the involvement of MMP-2 to trigger the growth-promoting effect of Sema3A in cortical dendrites. The in situ analysis of MMP-2 expression and activity is consistent with a functional growth assay demonstrating in vitro that the pharmacological inhibition of MMP-2 reduces the growth of cortical dendrites in response to Sema3A. Hence, our results suggest that the selective recruitment and activation of MMP-2 in response to Sema3A requires a PKC alpha dependent mechanism. Altogether, we provide a second set of data supporting MMPs as effectors of the growth-promoting effects of semaphorins, and we identify the potential signalling pathway involved

Effects of Lycopene on the Initial State of Atherosclerosis in New Zealand White (NZW) Rabbits

BACKGROUND: Lycopene is the main carotenoid in tomatoes, where it is found in high concentrations. Strong epidemiological evidence suggests that lycopene may provide protection against cardiovascular diseases. We therefore studied the effects of lycopene on diet-induced increase in serum lipid levels and the initiation of atherosclerosis in New Zealand White (NZW) rabbits. METHODOLOGY/PRINCIPAL FINDINGS: The animals, divided into four groups of 9 animals each, were fed either a standard diet, a high-cholesterol diet containing 0.5% cholesterol, a high-cholesterol diet containing placebo beadlets, or a high-cholesterol diet plus 5 mg/kg body weight/day of lycopene (in the form of lycopene beadlets), for a period of 4 weeks. We found significantly elevated lycopene plasma levels in the animal group treated with lycopene beadlets. Compared to the high-cholesterol and the placebo group, this was associated with a significant reduction of 50% in total cholesterol and LDL cholesterol serum levels in the lycopene group. The amount of cholesteryl ester in the aorta was significantly decreased by lycopene. However, we did not observe a significant decrease in the extent of aortic surface lipid accumulation in the lycopene group. In addition, no differences in the intima-media thickness among groups were observed. Endothelial-dependent and endothelial-independent vasodilation in isolated rabbit aortic and carotid rings did not differ among any of the animal groups. CONCLUSIONS: Lycopene supplementation for 4 weeks increased lycopene plasma levels in the animals. Although we found strongly reduced total and LDL cholesterol serum levels as well as significantly lower amounts of cholesteryl ester in the aortae in the lycopene-treated group, no significant differences in initial lesions in the aortae were detected

Valence instability in YbPd<SUB>2</SUB>Si<SUB>2</SUB>: magnetic susceptibility, X-ray absorption, and photoemission studies

The bulk and surface valence states of Yb were determined for the intermetallic compound YbPd<SUB>2</SUB>Si<SUB>2</SUB> by magnetic susceptibility (χ), L<SUB>III</SUB>-edge x-ray absorption, and valence-band photoemission measurements. In the susceptibility data this compound exhibits the characteristic features of homogeneously mixed-valent systems: enhanced Pauli paramagnetism at low temperatures, a maximum in χ at about 30 K, and Curie-Weiss behavior at high temperatures. The observed temperature dependence of χ is discussed in light of interconfigurational fluctuation (ICF) as well as Fermi-liquid models. The mixed-valent state of Yb is also borne out in the L<SUB>III</SUB>-edge x-ray absorption spectra, which reveal a weak temperature dependence of the Yb mean valence v̅ in agreement with the results from an analysis of the χ data in light of the ICF model. Valence-band photoemission spectra support our view of a homogeneously mixed-valent state of Yb; they further identify a valence transition to the divalent state in the outermost surface layer. 4f binding energies are found to be 0.80±0.05 eV higher at the surface as compared to the bulk. All three methods suggest that-within the limits of accuracy-the room-temperature mean valence of Yb in YbPd<SUB>2</SUB>Si<SUB>2</SUB> is close to the high-temperature limit given by the ionic ICF model

"Rostocker künstliches Herz"--gegenwärtiger Stand und Ausblick.

The authors report on their experiences gained by animal experiments (calf) and their attempts (human corpses) concerning adaptation of the apparatus to the human thorax. At the present time they do not see a chance for its routine clinical use. The main reason why is the impossibility to install the extrathoracic driving system into the thoracic cage and last not least the wear of the material used for the heart chambers

Erfahrungen mit dem Rostocker künstlichen Herz.

A totally artificial heart--the Rostock totally artificial heart (Rostock TAH) was implanted in calves. We can give the following deductions after 27 examinations: -- The Rostock TAH was tested successfully in endurance test about 7 months; it show no sign of wear. -- The surgical technique of the implantation was standardised and a successful experimentation is possible. -- The longest survival time was 15 days. The hemodynamic early results were very good in 3 other animals. -- Modifications of the Rostock TAH were taken up relating to the dimensions of the artificial ventriculi and by mounting a screw cap for avoiding an air embolism. -- Adaption tests in the corpse show that the present form of the artificial heart is not ideal for a possible application in man. -- The problem is still existing in developing a suitable drive system locates intrathoracically. The present drive and control system on a pneumatic base is qualified only for the animal experiment but not for a possible application in man