Desaturation of saturated fatty acids by rat liver microsomes

A method was developed for the rapid determination of the initial velocity of the desaturation of saturated fatty acids. In the reaction, DPNH was a more efficient electron donor than TPNH. Fatdeficient rats have a 2.5-fold greater level of acyl desaturase per milligram of liver microsomal protein than did animals fed lab chow. Increasing the chain length of the acyl substrate from 10∶0 to 18∶0 increases the rate of monoene formation, but 19∶0 is desaturated at a rate lower than that for 15∶0. The energy of activation (Ea) for the overall desaturation reaction has been determined for 12∶0 through 19∶0. The Ea values for desaturation of 13∶0 and 16∶0 are markedly lowr than for the other acids. An interaction between the alkyl chain of the substrate and polyunsaturated acids of the microsomal membrane-bound phospholipids is postulated to explain the recurring 3-carbon pattern of the relative reaction rates of the various acyl substrates.     

Pyrolysis chromatography of lipids. I. Mass spectrometric identification of pyrolysis products of hydrocarbons

The products of pyrolysis at 600C of normal paraffins C₁₀−C₁₈, 2-methyl octadecane, 4-methyl octadecane, 6-methyl octadecane, cyclohexyl decane, cyclopentyl decane, 2,2,4,4,6,8,8-heptamethyl nonane, pristane and phytane were studied by means of a pyrolysis gas chromatograph directly coupled to a mass spectrometer. n-Paraffins yield a homologous series of n-olefins. Branched paraffins yield two homologous series, one of n-olefins and one of branched olefins. The n-olefin corresponding to the position of the branch is not formed. Interpretation of pyrolograms is similar in principle to the interpretation of mass spectra. Presented at the Symposium on “Mass Spectrometry of Lipids”, AOCS Cincinnati, October 1965.     

Comparison of blast furnace penetration with model studies

A new correlation of the penetration of air into the blast furnace is presented, which agrees with data taken on blast furnaces at Wheeling Steel Corp. Data taken by rodding the tuyeres are examined critically and the variance between the figures at the different tuyeres is discussed.     

Locus of control and mastery in a reformatory: A field study of defensive externality.

145 males (mean age 21.9 yrs) enrolled in an incentive-based reformatory were administered Rotter's Internal–External Locus of Control (LOC) Scale, Marlowe–Crowne Social Desirability Scale, and several measures of expectancy/importance of success and failure. After success or failure at mastery attempts, Ss made causal attributions derived from both J. B. Rotter's (1966) and B. Weiner's (1972) theories. Results show that internal LOC inmates, relative to externals, demonstrated greater mastery and attributed more responsibility to themselves for success, even with social desirability controlled. Defensive externality hypotheses involving both major moderators of LOC, interpersonal trust and action taking, as well as 4 proposed aspects of defensive externality were not supported. Contrary to predictions, trust-defensive externals made more internal nondefensive attributions after failure than trust-congruent externals did. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measuring outcomes in nursing centers: otitis media as a sample case

While it is generally recognized that NPs offer affordable, quality health care, few studies have measured outcomes of clients who seek primary care services from NPs. This pilot study describes the outcomes of children with otitis media who received care from NPs employed in an academic nursing center. Outcome measurements included issues related to timing, level of analysis, and attribution. Parents of 27 children participated in a telephone survey consisting of seven questions relating to the care their children received from NPs and their recovery path. Although every respondent reported having a positive visit at the nursing center, concerns for NPs surfaced during the process of measuring outcomes. This study emphasizes the need for measuring outcomes in nursing clinics and demonstrates one way to measures client outcomes, revealing both general health care and specific nursing practice implications.     

Perfluorocarbons are effective oxygen carriers in cardiopulmonary bypass

Intravascular perfluorochemical (PFC) emulsions together with a high oxygen (O2) tension may increase the delivery of dissolved O2 to useful levels. A severely anemic model of cardiopulmonary bypass (CPB) was used to test the hypothesis that a novel PFC emulsion (PFCE; Oxygent [Alliance Pharmaceutical Corp., San Diego, CA] 90% w/v perflubron) used at a high PO2 during bypass delivers sufficient O2 to ameliorate hypoxic myocardial contractile dysfunction. Acutely anemic dogs (N = 42; hematocrit = 15.8 +/- 0.6% [mean +/- SEM] before CPB and 10.9 +/- 0.1% during CPB) were divided into four groups. Group 1 was a control (n = 12). As CPB was initiated, groups 2 (n = 10), 3 (n = 10), and 4 (n = 10) had 1.35 g PFC.kg-1, 2.7 g PFC.kg-1, or 5.4 g PFC.kg-1 added via the venous return cannula. Pre-CPB and post-CPB cardiac function was measured by the first derivative of left ventricular pressure (dP/dtmax). The dP/dtmax on separation from CPB was: group 1, 619 +/- 96; group 2, 738 +/- 56; group 3, 782 +/- 101; and group 4, 828 +/- 100 (p < 0.05 groups 3 and 4 versus group 1). Mortality during the first hour after separation from CPB was higher in group 1 than in PFCE treated dogs; however, this trend did not attain statistical significance (p < 0.065). The PFC dose was higher in survivors than in nonsurvivors (2.6 +/- 0.4 g PFC.kg-1 versus 1.2 +/- 0.5 g PFC.kg-1; p < 0.05). A PFCE used at a high PO2 provides sufficient physically dissolved O2 to relieve myocardial hypoxic injury in a severely anemic model of CPB. Current PFCEs are effective O2 carriers. This finding suggests that they can be used as a temporary erythrocyte substitute to diminish the need for allogeneic transfusions during cardiac operations.     

Synchrotron infrared measurements of protein phosphorylation in living single PC12 cells during neuronal differentiation

Protein phosphorylation is a post-translational modification that is essential for the regulation of many important cellular activities, including proliferation and differentiation. Current techniques for detecting protein phosphorylation in single cells often involve the use of fluorescence markers, such as antibodies or genetically expressed proteins. In contrast, infrared spectroscopy is a label-free and noninvasive analytical technique that can monitor the intrinsic vibrational signatures of chemical bonds. Here, we provide direct evidence that protein phosphorylation in individual living mammalian cells can be measured with synchrotron radiation-based Fourier transform-infrared (SR-FT-IR) spectromicroscopy. We show that PC12 cells stimulated with nerve growth factor (NGF) exhibit statistically significant temporal variations in specific spectral features, correlating with changes in protein phosphorylation levels and the subsequent development of neuron-like phenotypes in the cells. The spectral phosphorylation markers were confirmed by bimodal (FT-IR/fluorescence) imaging of fluorescently marked PC12 cells with sustained protein phosphorylation activity. Our results open up new possibilities for the label-free real-time monitoring of protein phosphorylation inside cells. Furthermore, the multimolecule sensitivity of this technique will be useful for unraveling the associated molecular changes during cellular signaling and response processes.     

Human Myt1 is a cell cycle-regulated kinase that inhibits Cdc2 but not Cdk2 activity

Activation of the Cdc2.cyclin B kinase is a pivotal step of mitotic initiation. This step is mediated principally by the dephosphorylation of residues threonine 14 (Thr14) and tyrosine 15 (Tyr15) on the Cdc2 catalytic subunit. In several organisms homologs of the Wee1 kinase have been shown to be the major activity responsible for phosphorylating the Tyr15 inhibitory site. A membrane-bound kinase capable of phosphorylating residue Thr14, the Myt1 kinase, has been identified in the frog Xenopus laevis and more recently in human. In this study, we have examined the substrate specificity and cell cycle regulation of the human Myt1 kinase. We find that human Myt1 phosphorylates and inactivates Cdc2-containing cyclin complexes but not complexes containing Cdk2 or Cdk4. Analysis of endogenous Myt1 demonstrates that it remains membrane-bound throughout the cell cycle, but its kinase activity decreased during M phase arrest, when Myt1 became hyperphosphorylated. Further, Cdc2. cyclin B1 was capable of phosphorylating Myt1 in vitro, but this phosphorylation did not affect Myt1 kinase activity. These findings suggest that human Myt1 is negatively regulated by an M phase-activated kinase and that Myt1 inhibits mitosis due to its specificity for Cdc2.cyclin complexes.