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Male Wistar rats received bilateral Fimbria lesions and were postoperatively housed in either standard social conditions or in impoverished conditions (one rat per cage) for 2 weeks in experiment I, and for 7 months in experiment II. The effects of lesion and housing conditions were investigated in the Morris maze spatial orientation task. Fimbria lesions increased the latency to reach the platform during acquisition in both experiments, which indicates that functional recovery of the Morris maze impairment does not occur in 7 months time. Post-operative impoverishment for 2 weeks or for 7 months reduced the lesion induced deficit in Morris maze acquisition, while it had a more general effect in the trial without platform. Interestingly, the impoverishment effects were not more severe after 7 months, but even less easily detected. Thes...
Lack of dystrophin in mdx mice leads to muscle fibre degeneration followed by the formation of new myofibres. This degeneration—regeneration event occurs in clusters. It is accompanied by inflammation and remodelling of the intramuscular terminal nerve fibres. Since the growth-associated protein B-50/GAP-43 has been shown to be involved in axonal outgrowth and synaptic remodelling following neuronal injury, we have investigated the presence of B-50 in gastrocnemius and quadriceps muscles of mdx mice. Using immunocytochemistry we demonstrate increased presence of B-50 in terminal nerve branches at motor endplates of mdx mice, particularly in the clusters of de- and regenerating myofibres. In comparison, the control mice displayed no B-50 immunoreactivity in nerve fibres contacting motor endplates. Our findings indicate that during axona...
We present a new method to compute the absolute free energy of arbitrary solid phases by Monte Carlo simulation. The method is based on the construction of a reversible path from the solid phase under consideration to an Einstein crystal with the same crystallographic structure. As an application of the method we have recomputed the free energy of the fcc hard-sphere solid at melting. Our results agree well with the single occupancy cell results of Hoover and Ree. The major source of error is the nature of the extrapolation procedure to the thermodynamic limit. We have also computed the free energy difference between hcp and fcc hard-sphere solids at densities close to melting. We find that this free energy difference is not significantly different from zero: –0.001
Main urinary bacterial metabolites of phenylalanine (total benzoic and phenylacetic acids) and of tyrosine (total p-hydroxybenzoic acid and p-hydroxyphenylacetic acid) were determined by gas chromatography in controls and patients with cystic ubrosis of the pancreas, coeliac disease, intestinal resection and unclassified enteritis. In various patients, especially in the untreated coeliacs, high amounts of one or more of the abovementioned metabolites were found. In this paper results in controls and patients are presented and discussed.
Starting with an m-diffusion model a matrix description is given of the rotational motion of a dipole molecule undergoing frequent collisions. This treatment gives rise to an analytical expression for the dipole correlation function and for the angular momentum correlation function in which a limited number of parameters from the model appear. It is argued that the collision distribution which determines the rotational diffusion process need not necessarily be a Poisson distribution. In liquids with strong interactions the distribution is governed by the frequency distribution of the medium. This leads to the inclusion of a librational motion in the rotational diffusion model. A comparison of simulations with different collision distributions and experimental data is given
The second-order rate constant of the reaction between the hydrated electron and ferrinitrocytochrome c exhibits a marked pH dependence that could not be fully ascribed to changes in geometrical parameters and in net charge of the protein molecule. The correlation between the pH dependence of the rate constant, the 695-nm absorbance and the ionization state of the nitrated tyrosyl-67 residue indicates that tyrosine-67 is of importance in maintaining the specific structure for the electron transfer mechanism in ferricytochrome c upon reduction.
One of the low molecular weight proteins of bovine lens extract, designated as βs-crystallin, was purified by gel-filtration on Sephadex G-75 and chromatography on DEAE-Sephadex. The isolated protein appeared to be homogeneous as judged by gel-electrophoresis and ultracentrifugal analyses. The molar extinction coefficient at 278 mμ is 5·28 × 104. The N-terminal amino acid did not react with 2,4-dinitrofluorobenzene. There is evidence that the carboxyl-terminal group is glutamic acid. Amino acid analysis was performed with a recovery of 100·9% of the dry weight of the protein. The molecular weight, calculated from the amino acid composition is 28,402 and is consistent with the value determined by the approach-to-equilibrium method. The protein contains 246 amino acid residues with the following composition: Asp22 Thr7 Ser15 Glu31...
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