Conflicts of interest, conflicting interests, and interesting conflicts, part 2

This study investigates 2 patterns of maternal behavior typical of mammals, using a heteropteran insect as the study animal. Sehirus cinctus, a burrower bug (Heteroptera: Cydnidae), exhibits relatively well-developed maternal behavior that includes guarding eggs and provisioning offspring. Mothers remained maternally responsive to stimulus eggs for 24-48 hr following removal of their own eggs, but the response grew weaker with longer separation times. A proportion of nulliparous females also exhibited maternal responsiveness when presented with stimulus eggs. Males, however, never responded parentally to eggs. The results of this study highlight similarities in general female responsiveness to stimulus young and differences in male responsiveness to stimulus young among certain invertebrates and vertebrates.     

Formation of 1,N6-etheno-2''-deoxyadenosine adducts by trans,trans-2, 4-Decadienal

This study was designed to investigate the effect of glucogon-like peptide-1 (GLP-1) on pancreatic beta-cell function in normal, Zucker diabetic fatty (ZDF) rats, a model for non-insulin-dependent diabetes mellitus (NIDDM or type II diabetes) and their heterozygous siblings. Pancreas perfusion and enzyme-linked immunosorbent assay (ELISA) were used to detect the changes in insulin release under fasting and hyperglycemic conditions and following stimulation with GLP-1. Animals from the ZDF/Gmi-fa rats (ZDF) were grouped according to age, sex, and phenotype (obese or lean), and compared with LA lean rats. Glucose stimulation (10 mmol/L) in obese rats showed repressed response in insulin release. Glucose plus GLP-1 stimulation caused increased insulin release in all groups. The degree of this response differed between groups: lean > obese; young > adult; female > male. The LA lean control group was most sensitive, while the ZDF overtly diabetic group had the lowest response. In addition, the pulsatile pattern of insulin secretion was suppressed in ZDF rats, especially in obese groups. These results support the hypothesis that GLP-1 can effectively stimulate insulin secretion. Insulin release was defective in ZDF obese rats and could be partially restored with GLP-1. ZDF lean rats also showed suppression of beta-cell function and there was a difference in beta-cell function related to sex in ZDF strain. This study documents the efficacy of GLP-1 to stimulate insulin release and contributes to our understanding of the pathophysiological mechanisms underlying NIDDM.     

Potent 2''-amino-, and 2''-fluoro-2''-deoxyribonucleotide RNA inhibitors of keratinocyte growth factor

BACKGROUND: Results of in vitro studies have documented colonic absorption of lactose in the newborn. A stable isotope model was developed for assessing the entry rate of intact lactose into the portal circulation in newborn piglets. METHODS: In experiment 1, unlabeled and [D-1-(13C)]-lactose were infused into two separate mesenteric veins, and in experiment 2, labeled lactose was infused into a mesenteric vein and unlabeled lactose was infused into the colon. The 13C-enrichment of plasma lactose was assessed by high performance liquid chromatography gas chromatography combined with mass spectrometry. RESULTS: The isotopic estimate of the mesenteric venous infusion rate of lactose was 91% of the theoretical. In the second experiment 13% of the unlabeled lactose infused into the colon reached the portal circulation. CONCLUSIONS: The current study provides the first, direct, in vivo confirmation of colon absorption of intact lactose. The tracer model could be used to evaluate intestinal or colonic absorption of other organic compounds not endogenously synthesized, including vitamins or drugs.     

Critical evaluation and optimization of the thermodynamic properties and phase diagrams of the MnO-TiO2, MgO-TiO2, FeO-TiO2, Ti2O3-TiO2, Na2O-TiO2, and K2O-TiO2 systems

All available thermodynamic and phase diagram data have been critically assessed for all phases in the MnO-TiO₂, MgO-TiO₂, FeO-TiO₂, Ti₂O₃-TiO₂, Na₂O-TiO₂, and K₂O-TiO₂ systems at 1 bar pressure from 298 K to above the liquidus temperatures. All reliable thermodynamic and phase diagram data have been simultaneously optimized to obtain, for each system, one set of model equations for the Gibbs energy of the liquid slag as a function of composition and temperature and equations for the Gibbs energies of all compounds as functions of temperature. The modified quasichemical model was used for the molten slag phases.     

Src homology-2 domains: structure, mechanisms, and drug discovery

The purpose of this study was to examine the trainability of anticipation in intermediate tennis players. In particular, the study examined whether video presentations could improve on-court tennis serve returns. A series of separate A-B designs across 6 participants was implemented, with baseline and intervention scores for on-court serve-return performance being recorded. Intervention consisted of 2 phases: a training phase and an on-court testing phase. The training phase, which employed a changing criterion design, consisted of a series of tennis-serve video presentations that were replayed with gradually increasing speed. All serves were occluded on racquet/ball contact, and participants were asked to predict the type, depth, and width of the serve. Following completion of the training phase, participants were again tested on their ability to return tennis serves on the tennis court. On-court results suggested that anticipation ability and performance did improve as a result of the intervention.     

X射线荧光光谱法测定矾土中硅、铁、钾、钙、钛、锰、铝、镁、磷等氧化物含量

建立了X射线荧光光谱法测定矾土中硅、铁、钾、钙、钛、锰、铝、镁、磷等氧化物的方法。以四硼酸锂做熔剂、溴化锂做脱模剂制备玻璃熔片 ,以标准物质和高纯试剂制备标准片做校正曲线 ,并对吸收增强效应和光谱重叠做出校正。通过测定标准样品进行比较 ,本法没有显著性差异。回收率为 86.7%～ 10 6.2 %。     

Electrical conductivity of ZrN-Al2O3, Mo-Al2O3, and ZrN-Mo composite powders

Conclusions A study was made of the electrical conductivity of sintered ZrN-Al₂O₃, Mo-Al₂O₃, and ZrN-Mo composite materials. When the conducting phase in such a system forms a skeleton and there is virtually no reaction between its phases, the composition dependence of its electrical conductivity is satisfactorily described by Eq. (1). For the ZrN-Al₂O₃ system, whose components react with each other, experimental values of electrical resistivity obtained at temperatures at which the reaction takes place differ appreciably from values yielded by calculation. The electrical resistivity of specimens of this system sintered in nitrogen is an order higher than that of specimens sintered under identical temperature and time conditions in argon, which is a result of more intense oxidation of the ZrN grains and of the formation of the nonconducting zirconia on their surfaces. The electrical resistivity vs composition curve for the ZrN-Mo system has, at a ZrN content of 15 vol.%, an inflection, which, according to Kurnakov's law, is indicative of the formation in this system of a limited solid solution.Translated from Poroshkovaya Metallurgiya, No. 10(214), pp. 56–60, October, 1980.     

The thermodynamic activity of MnO in melts containing SiO2, B2O3, and TiO2

The activity of MnO in the systems MnO-Ti₂ and MnO-B₂O₃, and in pseudobinary sections in the systems MnO-TiO₂-SiO₂, MnO-TiO₂-B₂O₃ and MnO-SiO₂-B₂O₃ have been measured at temperatures in the range of 1400 to 1550 °C by means of the technique in which equilibrium is established between the melt, a gaseous atmosphere of fixed oxygen pressure and a Pt-Mn foil immersed in the melt. The excess free energies of melts in the system MnO-TiO₂ at 1500 and 1550 °C are closely represented by the regular solution formalism withG _xs = −55280N _MnO ·N _{TiO 2} J, and the form of the variation ofa _MnO, within the narrow composition range amenable to study at 1400 °C in the system MnO-B₂O₃, is characteristic of a system of polyanions. The negative deviations ofa _MnO from a proposed model behavior, observed in melts in the systems MnO-SiO₂-TiO₂ and MnO-B₂O₃-TiO₂, are explained in terms of the influence of preferred ionic interactions between Ti₄₊ and O₂ and between Mn₂₊ and the O₋ groups on the polysilicate or polyborate anions. The activity of MnO is independent of composition in the system 2MnO · SiO₂−3MnO · B₂O₃ and the thermodynamics of mixing are calculated from application of polymer theory. The influence of B₂O₃ and TiO₂ on the activity of MnO in manganese silicates is discussed with reference to the proposed use of B₂O₃ and/or TiO₂ as substitutes for CaF₂ as the flux for steelmaking slags.     

Temperament ratings at 2 weeks, 2 months, and 1 year: Differential stablity of activity and emotionality.

To determine the usefulness of a temperament perspective in the study of young infants, the mothers of 36 newborns completed the Rothbart (1978) Infant Behavior Questionnaire (IBQ) approximately at 2 weeks and at 2 months after their infants were born and, again, when their infants reached 1 year of age. Moreover, both mothers and infants were observed at home in interaction at 1 month. IBQ activity level, responsivity, and irritability exhibited stability from 2 weeks to 2 months and from 2 months to 12 months. However, only irritability was stable from 2 weeks to 12 months. Although stability of their rank ordering was apparent, IBQ ratings generally increased by the end of 1 year. Observed infant alertness and crying at 1 month were significantly related to IBQ irritability at the first two times of measurement. In contrast, maternal behaviors were associated with later IBQ estimates. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interfacial modification and impact properties of Nb/MoSi2 laminate composites by the addition of ZrO2, NbSi2, and SiC particles

In this study, the results of a thermodynamical estimation indicate that the impact properties of Nb/MoSi₂ laminate composites can be improved by suppressing the interfacial reaction. The effects of addition of SiC, NbSi₂, and ZrO₂ on the impact properties and interfacial reaction of Nb/MoSi₂ laminate composites are also examined. Laminate composites, which comprise alternate layers of matrix mixture and Nb foil, were fabricated by the hot press process. Addition of ZrO₂ particle is clearly demonstrated to increase both the impact value and the sintered density of Nb/MoSi₂ laminate composites. The thickness of the interfacial reaction layer in Nb/MoSi₂ laminate composites dramatically decreases with increasing volume fraction of ZrO₂ particle. The suppression of the interfacial reaction is caused by the formation of ZrSiO₄ in the MoSi₂-ZrO₂ matrix mixture. In addition, it appears that the reduction of the reaction layer promotes the plastic deformation of Nb foil and the interfacial delamination in laminate composites.     

A study of the precision of confocal, ratiometric, Fura-2-based [Ca2+] measurements

Increased ammonia has been considered a key factor in the pathogenesis of hepatic encephalopathy. The high concentration of ammonia interferes with oxidative metabolism in the brain through an inhibitory effect on the tricarboxylic acid cycle (TCA). Inhibition of the TCA cycle may result in depletion of ATP. Due to the involvement of astrocytes in brain detoxification of ammonia, these cells are good candidates for studying ammonia's effect on energy stores in the brain. C6-glioma cells, which have altered glycolytic rates, may show greater sensitivity to the toxicity of ammonium chloride than astrocytes. To study the effect of ammonium chloride on energy storage of both astrocytes and C6-glioma, we observed the acute and chronic effects of NH4Cl (7.5 or 15 mM) on the metabolism of isolated astrocytes and C6-glioma cells. Primary astrocytes were isolated from the cerebral hemispheres of 1-2 day old Sprague-Dawley rats, and C6-glioma cells were purchased from the American Type Culture Collection (ATCC). Following treatment of the cells with ammonia, glucose, lactate, glutamate, ATP, and PCr were assayed. Our data showed that at 15 min following treatment with NH4Cl, there were no significant differences in the concentration of metabolites measured in astrocytes. However, following 15 min of treatment with NH4Cl, the concentration of some metabolites, for example, ATP and lactate, changed significantly in C6-glioma cells. We have shown that 24 h of treatment was sufficient time to see significant biochemical changes but not morphological changes in either cell type. Simultaneous biochemical and morphological changes were observed 48 h following treatment in C6-glioma cells and at 9-10 days following treatment in primary astrocytes. In primary astrocytes at 24 h following treatment, glucose utilization increased. This high utilization of glucose was in accordance with the increase in lactate and glutamate production and the decrease in ATP and PCr formation. In C6-glioma cells the utilization of glucose increased but this high utilization of glucose was consistent with a significant decrease in the concentration of lactate, glutamate and ATP.     

Solitary capillary hemangioblastoma, cellular variant. Clinical, radiological, and anatomo-pathological study of 2 cases

Two cases of the rare cellular variant of the solitary capillary haemangioblastoma are reported. On MR study both tumors appeared as cerebellar contrast-enhancing masses, without evidence of intra- or perilesional blood vessels. Histologically, they showed compact groups of polygonal or rectangular cells separated by compressed small capillaries. There were no reticulin fibres among cell clusters. The stromal cells were found to be immunopositive for neuron-specific enolase (NSE), factor VIII-related antigen (von Wille-brand factor), Ulex europaeus lectin, and glial frillary acidic protein (GFAP). The findings are discussed in light of the pertinent literature.     

Functional differences between BHRF1, the Epstein-Barr virus-encoded Bcl-2 homologue, and Bcl-2 in human epithelial cells

BHRF1, a component of the restricted early antigen complex of the Epstein-Barr virus lytic cycle, encodes a 17-kDa protein with both sequence and functional homology to the antiapoptotic Bcl-2 oncogene. Recent work has suggested that BHRF1 behaves like Bcl-2 in protecting cells from apoptosis induced by a range of stimuli. In this study, the effect of BHRF1 and Bcl-2 on the growth and differentiation of the SCC12F human epithelial cell line was examined. The levels of stable transfected BHRF1 expression achievable in SCC12F cells was consistently lower than that obtained with Bcl-2. While both BHRF1 and Bcl-2 inhibited epithelial differentiation, the effect of Bcl-2 was more pronounced, resulting in an almost complete blockade of differentiation in organotypic raft cultures. However, BHRF1-expressing SCC12F cells proliferated at a much higher rate than SCC12F cells expressing Bcl-2, and this effect was supported by cell cycle analysis which demonstrated that BHRF1, but not Bcl-2, promotes rapid transit through the cell cycle. These data highlight important differences between BHRF1 and Bcl-2 and suggest that BHRF1 may function to promote the survival and proliferation of lytically infected cells. The proliferative properties of BHRF1 described in this study, together with the demonstration that other oncogenic gamma herpesviruses encode Bcl-2 homologues, suggests that these proteins may serve to increase the susceptibility of virus-infected cells to oncogenic transformation, thereby contributing to the development of virus-associated tumors.     

Effect of DP-1904, a thromboxane A2 synthase inhibitor, on passive Heymann nephritis in rats

Despite the fact that aneuploidy is a major genetic cause of human morbidity and mortality, antimutagenicity studies have used predominantly short-term tests that detect gene mutations, chromosomal aberrations, and micronuclei. Therefore, the major deficiency in the use of short-term tests for antimutagenicity studies is those that detect chromosomal malsegregation leading to aneuploidy. Thus, we initiated a study on the utility of short-term tests for the detection of antianeugenic activity. We selected strain D61.M of Saccharomyces cerevisiae, nocodazole, and chlorophyllin as a model short-term test, aneugen, and antimutagen, respectively, for our initial study. Chlorophyllin strongly inhibited the aneugenic activity of nocodazole, but had no effect on the endpoints when tested alone, in strain D61.M. To our knowledge, this is the first report of an antianeugen. Furthermore, we conclude that strain D61.M can be used as a relatively simple, inexpensive, and rapid short-term test for the study of antianeugenicity.     

Phosphate capacity of CaO-AI2O3 slags containing CaF2, BaO,Li2O,or Na2O

Phosphorus partition ratios between CaO-Al₂O₃ and CaO-Al₂O₃-CaF₂ fluxes and Fe-C_sat-P alloys have been measured as a function of slag composition at 1500 °C. The effects of additions of BaO, Li₂O, and Na₂O to the CaO-Al₂O₃-CaF₂ system on the phosphorus partition ratios at 1400 °C and 1300 °C have been measured. From the partition ratio, and assuming that the oxygen potential is controlled by C-CO equilibrium, the phosphate capacities of the fluxes were calculated. Also, the activities of Li₂O and Na₂O were measured as a function of slag composition at 1300 °C by equilibrating the flux and the metal with Pb-Li or Pb-Na alloy and CO in a graphite crucible. The results indicate that phosphorus partition ratios with carbon-saturated iron and the phosphate capacities for additions of more basic oxides decrease in the following order: Na₂Oτ;Li₂Oτ;BaO. The activities of Li₂O and Na₂O in calcium aluminate fluxes have large negative deviations from ideal behavior; the activity coefficients at infinite dilution are on the order of 0.05 and 10^-5, respectively. Formerly Graduate Student, Department of Metallurgical Engineering and Materials Science, Carnegie Mellon University