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Notes: We present a thermodynamic analysis of global validity for effectively one-variable, irreversible chemical systems with multiple steady states. A hypothetical reaction chamber is held at constant temperature and volume and is connected by selectively permeable membranes to reservoirs of reactant(s) and product(s), each at constant selected pressures. An appropriate free energy function, which yields criteria of evolution to equilibrium for the composite system of reaction chamber and reservoirs, is a hybrid of Gibbs and Helmholtz free energies. The one variable in the reaction chamber is the pressure of a chemical intermediate which varies in time according to a given reaction mechanism. With the hybrid free energy, the kinetics for a given mechanism, and a concept of instantaneous indistinguishability of systems with different mechanisms, we establish a thermodynamic driving force, or species-specific affinity, for the intermediate. The species-specific affinity vanishes at steady states, and upon its differentiation we obtain necessary and sufficient conditions for the stability of steady states and for critical points. The integral of the species-specific affinity globally provides valid Liapunov functions for the evolution of the intermediate. These results are independent of the number of steady states of the system, and they hold both near to and far from equilibrium. For a large class of mechanisms with a single intermediate, the integral of the species-specific affinity appears in the irreversible partof the time-dependent transition probability of the single-variable Master equation and in its stationary solution. Hence for these mechanisms we obtain a direct interpretation of the stochastic results in terms of thermodynamic quantities. The time rate of change in the pressure of the intermediate multiplied by its species-specific affinity yields a species-specific term in the dissipation. The total system dissipation (or entropy production) is not in general a minimum at a nonequilibrium steady state, but the species-specific term is minimized at every such state. The expression of the stationary solution of the master equation in terms of the species-specific affinity provides a generalization of the Einstein relation for the probability of equilibrium fluctuations to far-from-equilibrium conditions. The functional form of the species-specific term in the dissipation parallels a form that appears in Boltzmann's H theorem for the momentum relaxation of a dilute gas.

Notes: The transport properties of dilute monatomic gases depend on the two body interactions between like atoms. When two ground state oxygen atoms interact, they can follow any of 18 potential energy curves corresponding to O2, all of which contribute to the transport properties of the ground state atoms. Transport collision integrals have been calculated for those interactions with an attractive minimum in the potential by accurately representing ab initio quantum mechanical potential energy curves with the Hulburt–Hirschfelder potential. Repulsive ab initio potential energy curves have been accurately represented either with the exponential repulsive potential or with an exponential repulsive potential with an additional Gaussian term to model a shoulder-like feature on the repulsive wall. Results are given for viscosity, thermal conductivity, and diffusion and they are compared with previous theoretical calculations.

Notes: Abstract: A fusion protein containing a Drosophila choline acetyltransferase (ChAT) cDNA insert was purified from a λ gtll lysate of Escherichia coli. The cDNA insert, which contained a 728-amino acid coding region for ChAT, was used for immunizing rabbits. Three different antisera were produced that could recognize native Drosophila ChAT with low titer. In addition, all three antisera stained enzyme polypeptides using the Western blot technique at high titers. The antisera recognized ChAT polypeptides with molecular masses of 67 and 54 kilodaltons in Western blots of partially purified enzyme; these polypeptides had previously been identified using monoclonal anti-ChAT antibodies and are the major components of completely purified enzyme. It was surprising that when these antisera were used to stain Western blots of Drosophila head homogenates, the major immunoreactive band had a molecular mass of 75 kilodaltons. The relationship of this 75-kilodal-ton polypeptide to ChAT activity was investigated by fractionating fresh fly head homogenates using rapid HPLC gel filtration chromatography. Analysis of column fractions for enzyme activity and immunoreactive polypeptides indicated that the 75- and 67-kilodalton polypeptides can be resolved and are both enzymatically active. In addition, a correlation was observed between the relative immunostaining intensities of both the 75- and 67-kilodalton bands and ChAT activity when supernatants from fresh fly head homogenates were autolyzed at 37°C. Our results indicate that ChAT is present in fresh Drosophila heads primarily as an active enzyme with a molecular mass of 75 kilodaltons. The previously reported molecular mass of 67 kilodaltons for native Drosophila ChAT as well as ChAT polypeptides in partially purified enzyme preparations may have resulted from proteolysis of the 75-kilodalton form of the enzyme. Recombinant DNA technology provides a good approach to raise high-titered, sequence-directed polyclonal antibodies to ChAT without the difficulties encountered in purifying the enzyme directly from Drosophila.

Notes: Abstract: Partially purified preparations of GABAa/benzodiazepine receptor from rat brain were found to contain high levels of a protein kinase activity that phosphorylated a small number of proteins in the receptor preparations, including a 50-kilodalton (kD) phosphoprotein that comigrated on two-dimensional electrophoresis with purified, immunolabeled, and photolabeled receptor α subunit. Further evidence that the comigrating 50-kD phosphoprotein was, in fact, the receptor α subunit was obtained by peptide mapping analysis: the 50-kD phosphoprotein yielded one-dimensional peptide maps identical to those obtained from iodinated, purified α subunit. Phosphoamino acid analysis revealed that the receptor α subunit is phosphorylated on serine residues by the protein kinase activity present in receptor preparations. Preliminary characterization of the receptor-associated protein kinase activity suggested that it may be a second messenger-independent protein kinase. Protein kinase activity was unaltered by cyclic AMP, cyclic GMP, calcium plus calmodulin, calcium plus phosphatidylserine, and various inhibitors of these protein kinases. Examination of the substrate specificity of the receptor-associated protein kinase indicated that the enzyme preferred basic proteins as substrates. Endogenous phosphorylation experiments indicated that the receptor α subunit may also be phosphorylated in crude membranes by a protein kinase activity present in those membranes. As with phosphorylation of the receptor in purified preparations, its phosphorylation in crude membranes also appeared to be unaffected by activators and inhibitors of second messenger-dependent protein kinases. These findings raise the possibility that the phosphorylation of the α subunit of the GABAa/ benzodiazepine receptor by a receptor-associated protein kinase plays a role in modulating the physiological activity of the receptor in vivo.

Notes: This study tested three psychophysiological hypotheses generated from assumptions underlying post-Jacobsonian progressive relaxation techniques and assumptions that conflict with the rationale for Jacobson's progressive relaxation method. Twenty-eight subjects tensed and released tension from the forearm extensor and frontalis muscles during a series of trials interspersed with intervals of relaxation. Correlations between self-report of tension and EMG were moderate during relaxation, but did not increase across successive tense-release trials, thus indicating no increase in self-awareness of muscle tension. As predicted by Jacobson, paying attention to either muscle produced increased tension in the frontal area, but Jacobson's prediction of increases in forearm tension while paying attention to the forearm was not confirmed. Evidence was equivocal for the existence of the “pendulum effect” predicted by Bernstein and Borkovec. Tense-release trials produced gradual decreases in frontal EMG, but no changes in forearm EMG. Declines below baseline in self-reported muscle tension occurred only several minutes after the end of the tense-release trials, and did so for the forearm despite lack of EMG decreases in that area. This finding may reflect the influence of cognitive rather than muscular processes.

Notes: Summary. Thirty-three patients with unexplained infertility underwent a total of 42 programmed superovulation cycles in a gamete intrafallopian transfer (GIFT) programme. The date of oocyte retrieval was decided in advance and the cycle preceding oocyte collection was modified with norethisterone from mid-cycle until 14 days before the scheduled laparoscopy. This was followed by a fixed schedule superovulation regimen. Serum oestradiol, progesterone and luteinizing hormone were monitored and the data analysed retrospectively. A single ultrasound scan was performed on the day of laparoscopy to exclude ovulation. Thirty-eight GIFT procedures were performed, resulting in 11 (29%) clinical pregnancies of which four twin and four singleton pregnancies are continuing. There was a significant correlation between the oestradiol response pattern and the maturity of oocytes retrieved, the fertilization rate of supernumerary oocytes and the pregnancy rate. Programmed cycles may be conveniently combined with GIFT, and basic endocrinological monitoring can be used to identify cycles with a poor prognosis before laparoscopy.