Does hepatocyte transplantation in a chemically induced acute hepatic failure make sense?

PURPOSE: The aim of this study was to compare the effects of topically applied transforming growth factor-beta 2 (TGF-beta 2) and interleukin 6 (IL-6), alone and combined with fibronectin, on the rate of corneal wound healing in rabbits. METHODS: Twenty-eight rabbits were used for the experiment. After the right eye of each rabbit was debrided with n-heptyl alcohol, the animals were divided into four treatment groups (six rabbits per group) and one control group (four rabbits). The debrided eyes were treated, beginning immediately after wounding and continuing every 2 hours from 8 a.m. to 8 p.m. for 48 hours. Group 1 received TGF-beta 2; group 2 IL-6; group 3, TFR-beta 2 and purified fibronectin; group 4, IL-6 and fibronectin; control group, balanced salt solution. At set intervals each eye was stained with fluorescein and photographed; epithelial defects were measured with a computer-assisted digitizer. The healing rate was calculated by linear regression analysis. RESULTS: The mean healing rates in groups 1, 2, 3, 4, and controls were respectively 1.65 +/- 0.16, 1.68 +/- 0.11, 1.99 +/- 0.12, 2.23 +/- 0.09, and 0.93 +/- 0.18 mm2/h. Mean epithelial healing rates for all drug-treatment groups were significantly faster than controls. The healing rates of groups 3 and 4 were significantly faster than groups 1 and 2. CONCLUSIONS: We conclude that cytokines, in combination with extracellular matrix proteins, facilitate corneal epithelial wound healing in vivo, possibly by making corneal epithelial cells more sensitive to fibronectin receptors.     

Results of human islet allotransplantation in cystic fibrosis and type I diabetic patients

The relationship between aplastic anaemia (AA) and pregnancy remains uncertain. To assess whether an association between pregnancy and severe aplastic anaemia (SAA) exists, we compared the frequency of pregnancy in 35 young women with newly diagnosed SAA with the expected frequency in the general population. The observed pregnancy rate in the SAA group was 3-6%. This percentage approximates the expected pregnancy rate of 4.4% in the general population and is not compatible with a strong association between pregnancy and SAA.     

Effect of reduced myristoylated alanine-rich C kinase substrate expression on hippocampal mossy fiber development and spatial learning in mutant mice: transgenic rescue and interactions with gene background

The myristoylated alanine-rich C kinase substrate (MARCKS) is a prominent protein kinase C (PKC) substrate in brain that is expressed highly in hippocampal granule cells and their axons, the mossy fibers. Here, we examined hippocampal infrapyramidal mossy fiber (IP-MF) limb length and spatial learning in heterozygous Macs mutant mice that exhibit an approximately 50% reduction in MARCKS expression relative to wild-type controls. On a 129B6(N3) background, the Macs mutation produced IP-MF hyperplasia, a significant increase in hippocampal PKCepsilon expression, and proficient spatial learning relative to wild-type controls. However, wild-type 129B6(N3) mice exhibited phenotypic characteristics resembling inbred 129Sv mice, including IP-MF hypoplasia relative to inbred C57BL/6J mice and impaired spatial-reversal learning, suggesting a significant contribution of 129Sv background genes to wild-type and possibly mutant phenotypes. Indeed, when these mice were backcrossed with inbred C57BL/6J mice for nine generations to reduce 129Sv background genes, the Macs mutation did not effect IP-MF length or hippocampal PKCepsilon expression and impaired spatial learning relative to wild-type controls, which now showed proficient spatial learning. Moreover, in a different strain (B6SJL(N1), the Macs mutation also produced a significant impairment in spatial learning that was reversed by transgenic expression of MARCKS. Collectively, these data indicate that the heterozygous Macs mutation modifies the expression of linked 129Sv gene(s), affecting hippocampal mossy fiber development and spatial learning performance, and that MARCKS plays a significant role in spatial learning processes.     

Dimerization of native myosin LC2(RLC)-free subfragment 1 from adult rabbit skeletal muscle

We reinvestigated whether the native myosin LC2-free-subfragment 1 (S1) dimer exists by using viscometry, capillary electrophoresis, and laser light scattering. We found that the intrinsic viscosity of the monomer is [eta]m = 6.7 cm3/g and its translation diffusion coefficient is (c = 0) = 4.43 x 10(-)7 cm2/s. For the dimer, [eta]d = 19.8 cm3/g and (c = 0) = 2.54 x 10(-)7 cm2/s. Using the Svedberg equation and introducing the values of the sedimentation coefficients (5.05 S for the monomer and 6.05 S for the dimer), we find the following molecular weights: Mr,m = 108 000 Da and Mr,d = 213 000 Da, which agree well with previous determinations. Capillary electrophoresis successfully separated S1(A1) and S1(A2), in a monomer buffer, and S1(A1) and S1(A2) and a heterodimer S1(A1)-S1(A2), in a dimer buffer. An interesting feature of the monomer-dimer equilibrium is the presence of temperature transitions, whose positions and widths depend upon the buffer conditions. At low temperatures, a pure dimer was observed, whereas at high temperatures only the monomer was present. The dimerization site on both myosin and S1 is extremely labile.     

Kinetics of phase separation in polyurethane/polystyrene semi-1 interpenetrating polymer networks. 1. Light transmission studies

The phase separation of different in-situ semi-1 interpenetrating polymer networks (IPNs) based on polyurethane and polystyrene has been followed by light transmission. The effect of the presence ab initio of small amounts of homopolystyrene in the initial reaction mixture on the phase separation process has also been examined. If gelation of the polyurethane occurs before the onset of phase separation, the latter is impeded or strongly limited, and transparent semi-1 IPNs are obtained. In the opposite case, phase separation is macroscopic and the material is turbid.     

Perspectives of application of anti-CD4 antibodies in the treatment of autoimmune diseases

Escherichia coli JM83 [F- ara delta(lac-proAB) rpsL [phi 80d delta (lacZ)M15]] in midlog growth phase at 30 degrees C were exposed to 60 Hz sinusoidal magnetic field of 3 mT of nonuniform diverging flux, inducing a nonuniform electric field with a maximum intensity of 32 microV/cm using an inductor coil. Exposed and unexposed control cells were maintained at 30.8 +/- 0.1 degrees C and 30.5 +/- 0.1 degrees C, respectively. Quadruplicate samples of exposed and unexposed E. coli cells were simultaneously radiolabeled with 35S-L-methionine at 10 min intervals over 2 hr. Radiochemical incorporation into proteins was analyzed via liquid scintillation counting and by denaturing 12.5% polyacrylamide gel electrophoresis. The results showed that E. coli exposed to a 60 Hz magnetic field of 3 mT exhibited no qualitative or quantitative changes in protein synthesis compared to unexposed cells. Thus small prokaryotic cells (less than 2 microns x 0.5 micron) under constant-temperature conditions do not alter their protein synthesis following exposure to 60 Hz magnetic fields at levels at 3 mT.     

Estimation of parameters of a multifractal process

Multifractal functions are widely used to model irregular signals such as turbulence, data stream or road traffic. Here, we consider multifractal functions defined as lacunar wavelet series observed in a white noise model. These random functions are statistically characterized by two parameters. The first parameter governs the intensity of the wavelet coefficients while the second one governs its sparsity. We construct estimators of these two parameters and discuss statistical properties of this important model: the rate of the Fisher information and a testing procedure to check the multifractal feature of an observed noisy signal.