Transition metal complexes of buparvaquone as potent new antimalarial agents. 1. Synthesis,X-ray crystal-structures,electrochemistry and antimalarial activity against Plasmodium falciparum

New Cu(II), Ni(II), Co(II), Fe(II), and Mn(II) metal complexes of buparvaquone [3-trans(4-tert.-butylcyclohexyl)methyl-2-hydroxy-1,4-naphthoquione] (L1H) have been synthesized and characterized using IR, electron paramagnetic resonance (EPR) spectroscopy, microanalytical methods and single crystal X-ray diffraction methods. The single crystal structures were determined for ligand L1H [space group P-1 with a=6.2072(14) A, b=10.379 (2) A, c=13.840 (3) A, V=878.7(3) A(3), Z=2, D(calcd.)=1.234 mg/m(3)] and copper complex [Cu(L1)(2)(C(2)H(5)OH)(2)] C1 [space group I2/a with a=17.149(14) A, b=9.4492(8) A, c=26.946(3) A, V=4335.3(7)A(3), Z=4, D(calcd.)=1.233 mg/m(3)]. All the metal complexes along with the parent ligand have been studied for their electrochemical properties using cyclic voltammetric techniques. The compounds were tested for their in vitro antimalarial activity against Plasmodium falciparum strains. A correlation between the antimalarial activity and the redox property of these complexes is presented. The copper complex C1 exhibits significantly higher growth inhibitory activity both in vitro and in vivo than the parent ligand.     

Scaling of peak moment arms of elbow muscles with upper extremity bone dimensions.

It is often assumed that moment arms scale with size and can be normalized by body segment lengths or limb circumferences. However, quantitative scaling relationships between moment arms and anthropometric dimensions are generally not available. We hypothesized that peak moment arms of the elbow flexor and extensor muscles scale with the shorter distance (D(s)) between the elbow flexion axis and a muscle's origin and insertion. To test this hypothesis, we estimated moment arms of six muscles that cross the elbow, digitized muscle attachment sites and bone surface geometry, and estimated the location of the elbow flexion axis in 10 upper extremity cadaveric specimens which ranged in size from a 5'0" female to a 6'4" male. D(s) accurately reflected the differences in peak moment arms across different muscles, explaining 93-99% of the variation in peaks between muscles in the same specimen. D(s) also explained between 55% and 88% of the interspecimen variation in peak moment arms for brachioradialis, biceps, and ECRL. Triceps peak moment arm was significantly correlated to the anterior-posterior dimension of the ulna measured at the olecranon (r(2)=0.61, p=0.008). Radius length provides a good measure of the interspecimen variation in peaks for brachioradialis, biceps, and ECRL. However, bone lengths were not significantly correlated to triceps moment arm or anterior-posterior bone dimensions. This work advances our understanding of the variability and scaling dimensions for elbow muscle moment arms across subjects of different sizes.     

The sugar,biomass and biofuel potential of temperate by tropical maize hybrids

The demand for biofuels has created a market for feedstocks to meet future energy requirements. Temperate × tropical maize (Zea mays L.) hybrids, which combine high biomass and fermentable stalk sugars, have yet to be considered as a biomass feedstock. Our objective was to evaluate biological potential, genetic variability and impact of nitrogen (N) on biomass, stalk sugar, and biofuel potential of temperate × tropical maize (TTM) hybrids. Twelve TTM hybrids, two grain and silage hybrids were grown in 2008, followed in 2009 by seven earshoot‐bagged TTM hybrids. In both years, they were grown with and without supplemental N (202 kg ha^?1) in Champaign, IL. Plants were sampled for total and partitioned biomass, and analyzed for concentration and content of sugar. The TTM hybrids were 40% taller, exhibited later reproductive maturity, greater flowering asynchrony, and remained green longer. All hybrids responded to supplemental N by producing more biomass and grain, a lower percent of biomass partitioned to stalk and leaf, whereas TTM also had a decreased concentration of sugar. Total average biomass yields were 24 Mg ha^?1 for both the TTM and grain hybrids. However, TTM partitioned 50% more biomass to the stalk and produced 50% more sugar, and had less than half the grain of the commercial hybrids, indicating grain production and sugar accumulation are inversely related. When grain formation was prevented by earshoot bagging, TTM hybrids produced, without supplemental N fertilizer, an average of 4024 kg ha^?1 of sugar, which was three‐ to four‐fold greater than the non earshoot‐bagged TTM and ear removed hybrid. Calculated estimates for ethanol production, considering the potential from sugar, stover and grain, indicate TTM can yield nearly the amount of ethanol per hectare as modern grain hybrids, but with a decreased requirement for supplemental fertilizer N.     

Comprehensive screening for human immunodeficiency virus type 1 subtype-specific CD8 cytotoxic T lymphocytes and definition of degenerate epitopes restricted by HLA-A0207 and -C(W)0304 alleles

For this report, the rapid identification and characterization of human immunodeficiency virus type 1 (HIV-1)-derived broadly cross-subtype-reactive CD8 cytotoxic T lymphocyte (CTL) epitopes were performed. Using a gamma interferon (IFN-gamma) Elispot assay-based approach and a panel of recombinant vaccinia viruses expressing gag, env, pol, and nef genes representing the seven most predominant subtypes and one circulating recombinant form of HIV-1, the subtype specificity and cross-subtype reactivity of a CD8 response were directly measured from circulating peripheral blood mononuclear cells (PBMC). Enhanced sensitivity of detection of CD8 responses from cryopreserved PBMC was achieved using autologous vaccinia virus-infected B-lymphoblastoid cell lines as supplemental antigen-presenting cells. Of eleven subjects studied, six exhibited broadly cross-subtype-reactive CD8-mediated IFN-gamma production (at least seven of eight subtypes recognized) to at least one major gene product from HIV-1. Screening of subjects showing broadly cross-subtype-specific responses in the vaccinia virus-based enzyme-linked immunospot (Elispot) assay using a panel of overlapping peptides resulted in the identification of cross-subtype responses down to the 20-mer peptide level in less than 3 days. Three subjects showed broad cross-subtype reactivity in both the IFN-gamma Elispot assay and the standard chromium release cytotoxicity assay. Fine mapping and HLA restriction analysis of the response from three subjects demonstrated that this technique can be used to define epitopes restricted by HLA-A, -B, and -C alleles. In addition, the ability of all three epitopes to be processed from multiple subtypes of their parent proteins and presented in the context of HLA class I molecules following de novo synthesis is shown. While all three minimal epitopes mapped here had previously been defined as HIV-1 epitopes, two are shown to have novel HLA restriction alleles and therefore exhibit degenerate HLA binding capacity. These findings provide biological validation of HLA supertypes in HIV-1 CTL recognition and support earlier studies of cross-subtype CTL responses during HIV-1 infection.     

Interactions between interferon γ and retinoic acid with transforming growth factor β in the induction of immune recognition molecules

The cell-surface expression of major histocompatibility (MHC) antigens and the adhesion molecule intercellular adhesion molecule 1 (ICAM-1) is essential for target cell recognition by T lymphocytes. The expression of both classes of molecule is induced by various cytokines, notably interferon (IFN). Since transforming growth factor (TGF) has been recently reported to antagonise HLA-DR induction by IFN we have examined, using a number of murine and human cell lines, the effect of TGF on IFN-induced MHC class I and class II and ICAM-1 expression. All of the cell lines tested expressed elevated class I MHC following IFN treatment. Class II MHC induction was seen on most but not all of the cells, the exceptions being among a panel of human colorectal carcinoma cell lines. A striking difference between cells of different origin was noted in the response to TGF. TGF was found to antagonise IFN-induced class I and class II MHC expression on C3H 10T1/2 murine fibroblasts, early-passage BALB/c mouse embryo fibroblasts, a murine oligodendroglioma cell line, and on MRC5 human fibroblasts and two human glioblastoma cell lines. Class II MHC was much more strongly inhibited (sometimes completely) than class I MHC. TGF also inhibited induction of class I MHC expression by IFN. However, TGF did not inhibit class I or class II MHC induction by IFN in any of the nine colorectal carcinoma cell lines, although two of five of the lines tested were growth-inhibited by TGF. On the other hand, human ICAM-1 induction by IFN was not affected by simultaneous treatment with TGF in any of the cell lines. The down-regulation of IFN-induced MHC antigens by TGF is not, therefore, the result of a general antagonism of IFN. Retinoic acid has recently been reported to induce ICAM-1 expression on human tumour cells. We have confirmed this observation on MRC5, and the two human glioblastoma cell lines, however six colorectal carcinoma cell lines tested did not respond. In contrast to IFN-induced ICAM-1 expression, retinoic-acid-induced ICAM-1 expression was inhibited by TGF on two of the three responsive lines.     

Modification of γ-Aminobutyric AcidA Receptor Binding and Function by N-Ethoxycarbonyl-2-Ethoxy-1,2-Dihydroquinoline In Vitro and In Vivo: Effects of Aging

The irreversible protein-modifying reagent N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) was used to investigate binding site characteristics on the gamma-aminobutyric acidA (GABAA) receptor complex. In vitro, preincubation with EEDQ led to a concentration-dependent decrease in receptor number for benzodiazepine, t-butylbicyclophosphorothionate (TBPS), and GABA binding sites in cerebral cortex. The effect was maximal at the highest concentration of EEDQ used (10(-4) M) and was greatest for the benzodiazepine site. Pretreatment of membranes with the benzodiazepine antagonist Ro 15-1788, 1 or 10 microM, or the agonist lorazepam, 10 microM, largely prevented the effects of EEDQ. Scatchard analysis indicated no effect of EEDQ, 10(-4) M, on apparent affinity, but a decrease in receptor density for each site. Administration of EEDQ to mice, 12.5 mg/kg i.p., led to a substantial (55-65%) decrease in number of benzodiazepine binding sites in cortex after 4 h. Slightly smaller changes were observed for TBPS and GABA binding. No changes were observed in apparent affinity at any site. Prior administration of Ro 15-1788, 5 mg/kg, prevented the effect of EEDQ on benzodiazepine binding. Density of benzodiazepine binding sites gradually recovered over time, and receptor density returned to control values by 96 h after EEDQ injection. Number of binding sites in cortex for TBPS and GABA also increased over time after EEDQ. Benzodiazepine sites in cerebellum were decreased proportionally to cortex after EEDQ, and increased over a similar time course. Function of the GABAA receptor in chloride uptake in cortex was markedly reduced (65%) by EEDQ.(ABSTRACT TRUNCATED AT 250 WORDS)     

Glycerol Phosphate Dehydrogenase, Glucose-6-Phosphate Dehydrogenase, and Lactate Dehydrogenase: Activities in Oligodendrocytes, Neurons, Astrocytes, and Myelin Isolated from Developing Rat Brains

Abstract: Glycerol phosphate dehydrogenase (GPDH), glucose-6-phosphate dehydrogenase (G6PDH), and lactate dehydrogenase (LDH) activities were determined in Oligodendrocytes, neurons, and astrocytes isolated from the brains of developing rats. The activity of each enzyme was significantly lower in both neurons and astrocytes than in Oligodendrocytes. The GPDH activity in Oligodendrocytes increased more than 4-fold during development, and at 120 days cells of this type had 1.4-fold the specific activity of forebrain homogenates. The G6PDH activities in Oligodendrocytes from 10-day-old rats were 1.4-fold the activities in the forebrain homogenates. The activities of this enzyme in Oligodendrocytes were progressively lower at later ages, such that at 120 days the cells had 0.8 times the specific activities of homogenates. The Oligodendrocytes had 0.6 times the homogenate activities of LDH at 10 days, and this ratio had decreased to 0.2 by 120 days. These enzymes were also measured in myelin isolated from 20-, 60-, and 120-day-old rats. By 120 days the specific activities of G6PDH and LDH in myelin were <8% of the respective activities in homogenates. The GPDH activity in myelin was, however, at least 20% the specific activity in the homogenates, even in the oldest animals. It is proposed that LDH could be used as a marker for oligodendroglial cytoplasm in subfractions of myelin and in myelin-related membrane vesicles.