Present Results In Combination Research Articles

The Role of N-Acetylcysteine Amide (NACA) As Prophylactic Treatment for Acute Graft-Versus-Host Disease

Aim The current study aimed to investigate the role of N-acetylcysteine amide (NACA) as prophylactic treatment for acute graft-versus-host disease (GvHD) and to explore the underlying mechanism of action. Background GvHD remains one of the major complications after allogeneic hematopoietic cell transplantation (allo-HCT). In addition, GvHD is a significant cause of morbidity, mortality and deteriorated life quality in transplanted patients. At the present, several strategies have been suggested as a prophylactic treatment against GvHD. Due to the good anti-proliferative effects on the donor T cells, calcineurin inhibitors (cyclosporine or tacrolimus) in combination with methotrexate (MTX) or mycophenolate mofetil (MMF) are recommended by several transplantation centers. Recently, several studies have reported good results of post-transplant cyclophosphamide treatment because of its ability to induce apoptosis of donor allo-activated T cells and to promote transplant tolerance. However, inevitable off-target effect and dose-related toxicity frequently occur regardless of the treatment selected. Evidence showed that oxidative stress is elevated in the recipients of allo-HCT and is linked to the pathogenesis of GvHD. Methods Using a classic murine GvHD model with complete MHC-mismatched allo-HCT (C57Bl/6 to Balb/c), the effect of NACA on the occurrence and severity of acute GvHD was evaluated. In order to reveal the underling mechanism of action, clinical manifestations, survival, cytokine profiles, ROS accumulation, T cell allo-responses, and target tissue damage in NACA-treated GvHD mice were scrutinized and compared with the same parameters observed in N-acetylcysteine (NAC)-treated GvHD mice. Results We found that NACA treatment significantly prolonged the survival and decreased GvHD severity score, in mice underwent allo-HCT. Moreover, NACA downregulated the pro-inflammatory cytokines, such as IFNγ, TNFα, IL-1β and IL-6, but upregulated the anti-inflammatory IL-4 in the mouse serum. Data also showed that NACA administration significantly reduced ROS accumulation in the spleen on day +7 and day +14 after transplantation. In addition, a modest dividing defect in donor T cells was observed upon NACA administration regardless of the experienced antigen classes, and the remarkably lower percentage of Ki67 expression in donor T cells substantiated their inhibited proliferation. In the meanwhile, NACA restrained Th1 and Th17 differentiation of donor T cells but enhanced the regulatory polarization. Furthermore, the migration capability of donor T cells was suppressed by NACA as well, resulting in a less severe intervention of the GvHD target organs. Importantly, NACA did not alter the engraftment as was observed in the bone marrow and spleen chimera but facilitated the neutrophil engraftment. Opposite to NACA, the effect of NAC on GvHD was not significant. Conclusion The present investigation showed that NACA, rather than NAC, has a prophylactic effect in acute GvHD mouse model.The protective effect is mediated by antioxidation, anti-inflammation and downregulation of T-cell allo-responses without altering the engraftment and its process.NACA treatment has significantly improved survival, lower the severity score and shortened the recovery time. However, it was not able to fully eliminate the occurrence of acute GvHD.It is important to consider the combination of NACA with other clinical-used drugs in order to achieve complete disease remission and minimize treatment-related toxicity.The encouraging present results in combination with the clinical reported results of the use of NACA may open the door for a new prophylactic treatment of GvHD.

Effects of constrained trunk movement on frontal plane gait kinematics

Previously it has been shown that constraining step width in gait coincides with decreased trunk displacements. Conversely, external stabilization of the upper body in gait coincides with decreased step width, but this may in part be due to changes in passive dynamics of the leg. In the present study, trunk kinematics during gait were constrained without external stabilization by using an orthosis, to investigate whether step width and dynamic gait stability in the ML direction are changed in relation to trunk kinematics. Nine healthy young adults walked on a treadmill at three different speeds with no intervention and while wearing a thoracolumbar orthosis. Based on marker trajectories, trunk COM displacement, body COM displacement and velocity, step width, and margin-of-stability in ML direction were calculated. The results showed that the orthosis significantly reduced trunk and body COM displacements. As hypothesized, the restriction of trunk movement coincided with significantly decreased step width, while the margin-of-stability was not affected. These findings indicate that, when trunk movements are constrained, humans narrow step width, while maintaining a constant margin-of-stability. In conclusion, the present results in combination with previous work imply that in gait a reciprocal coupling between trunk kinematics and foot placement in the frontal plane subserves control of stability in the frontal plane.

Effect of specimen thickness on the growth rate of chromia scales on Ni-base alloys in high- and low-pO2 gases

Two types of experiments were carried out to study the oxidation behaviour of NiCr-base model alloys; thermogravimetric measurements for up to 72 h exposure at 1000 °C in synthetic air and isothermal exposures for up to 100 h at 1000 °C in laboratory air and in Ar–4%H2–2%H2O. It was found that there is a significant effect of specimen thickness on the oxidation rate of all studied alloys. The growth rates of the chromia scales decrease with increasing specimen thickness in both air and the Ar–H2–H2O mixture. Based on the present results in combination with recent literature data for ferritic steels, it is postulated that the decrease in rate is the result of compressive growth stresses in the scales which can relax by plastic deformation of the substrate for thin specimens but are maintained at significant levels for thick specimens.

Complexation Thermodynamics of Cucurbit[6]uril with Aliphatic Alcohols, Amines, and Diamines

Using the isothermal calorimetric titration technique, we determined the stability constants (K), reaction enthalpy (ΔH°), and entropy (ΔS°) for complexation of cucurbit[6]uril (CB[6]) with a series of aliphatic alcohols, mono- and diamines, as well as spermidine and spermine, in aqueous solutions of alkali metal chlorides. The K for spermine reached 5.4 × 1010 M− 1 in 0.2 M LiCl, which is the largest amongst the values reported for CB[6]. Propylamine forms the strongest 1:1 complex with CB[6] (K = 21000 M− 1) in 0.1 M Na acetate buffer, which is driven exclusively by entropy. A comparison of K for 1,3-propanediamine versus 1,4-butanediamine reveals an extraordinary >60000-fold enhancement in affinity, which is the largest increment/CH2 ever observed in supramolecular chemistry. The present results in combination with our ESI-MS data reported recently unambiguously demonstrate that CB[6] exists in aqueous solution of alkali metal salts exclusively as a dicationic species, e.g. [CB[6]·2Na]2+.

Transpecific polymorphisms in an inversion linked esterase locus in Drosophila buzzatii.

Nucleotide variation was studied in a 1.1 kb section of the coding region of an Esterase gene (Est-A) that maps in the center of the segments rearranged by polymorphic inversions in the cactophilic Drosophila buzzatii. We examine 30 homozygous second-chromosome lines differing in gene arrangement and three D. koepferae isofemale lines as outgroups. Our data show that Est-A is a highly polymorphic gene at both synonymous and replacement sites. Significant departures from homogeneity in the distribution of the ratio of silent polymorphism to divergence predicted by the neutral theory reveals a local excess of silent polymorphism. This is consistent with the presence of two apparent narrow peaks of elevated silent polymorphism surrounding nonconservative amino acid substitutions. These polymorphisms as well as others at synonymous and nonsynonymous sites are shared with D. koepferae. We suggest that the presence of shared nucleotide polymorphisms is probably due to interspecific gene flow and/or balancing selection acting on replacement variants and/or to a decreased probability of loss of ancestral polymorphisms caused by linkage to an adaptive inversion polymorphism. Recurrent mutation and persistence of neutral ancestral polymorphisms cannot, however, be ruled out. The analysis of the distribution of nucleotide variation among the three chromosomal arrangements sampled reveals that derived arrangements (J and JZ(3)) are less polymorphic than the ancestral ST, and that the widely distributed ST and J arrangements are genetically differentiated. However, a significant number of polymorphisms are shared between arrangements, suggesting frequent exchange either from gene conversion or from double crossovers in heterokaryotypes. Finally, our present results in combination with data of sequence variation at the breakpoints of inversion J suggest that this old gene arrangement has risen in frequency in relatively recent times.

Statistical power and measurement allocation in ergonomic intervention studies assessing upper trapezius EMG amplitude: A case study of assembly work

The present study aimed at exploring the statistical power of ergonomic intervention studies using electromyography (EMG) from the upper trapezius muscle. Data from a previous study of cyclic assembly work were reanalyzed with respect to exposure variability between subjects, between days, and within days. On basis of this information, the precision and power of different data collection strategies were explored. A sampling strategy comprising four registrations of about two min each (i.e. two work cycles) for one day per subject resulted in coefficients of variation between subjects on the 10-, 50-, and 90-APDF-percentiles of 0.44, 0.31, and 0.29, respectively. The corresponding necessary numbers of subjects in a study aiming at detecting a 20% exposure difference between two independent groups of equal size were 154, 78, and 68, respectively ( p≤0.05, power 0.80). Multiple measurement days per subject would improve power, but only to a marginal extent beyond 4 days of recording. Increasing the number of recordings per day would have minor effects. Bootstrap resampling of the data set revealed that estimates of variability and power were associated with considerable uncertainty. The present results in combination with an overview of other occupational studies showed that common-size investigations using trapezius EMG percentiles are at great risk of suffering from insufficient statistical power, even if the expected intervention effect is substantial. The paper suggests a procedure of how to retrieve and use exposure variability information as an aid when studies are planned, and how to allocate measurements efficiently.

Post-garnet Transition of Almandine at High Pressure: Phase Equilibrium and Calorimetric Studies.

High pressure high temperature transition of almandine garnet (Fe3Al2Si3O12) was examined at 20-23. 5 GPa at 1200-1600°C in the oxygen fugacity of iron-wustite buffer, using a multi-anvil apparatus. It was found that almandine dissociates into a mixture of wustite, corundum and stishovite. The dissociation boundary is placed at 20-21 GPa at 1200-1600°C with a slightly negative slope. Enthalpy of formation of almandine was measured by high temperature solution calorimetry and thus enthalpy of the almandine dissociation was obtained. The thermodynamically calculated dissociation boundary agrees with that determined by the phase equilibrium experiments. This dissociation boundary may be used as a pressure standard at around 20 GPa at high temperature. The present results in combination with those on pyrope suggest that almandine-pyrope garnet is stable in a depth range down to the upper part of the Earth's lower mantle.

Solvent and substrate isotope effects on the enolization and carbon-acid ionization of isobutyrophenone

Bromine scavenging was used to measure rates of acid-catalyzed enolization of isobutyrophenone in H2O and in D2O solution and of isobutyrophenone-α-d in D2O solution. The results provide the solvent isotope effect kH +/kD + = 0.56 and the substrate isotope effect kH/kD = 6.2 on the enolization reaction, both of which are consistent with the generally accepted mechanism for this process. The present results in combination with literature information also provide the solvent isotope effect on the enolization equilibrium, KE(H2O)/KE(D2O) = 0.92, and the solvent isotope effect on the ionization of isobutyrophenone as a carbon acid, kaK(H2O)/kaK(D2O) = 5.4, as well as the product of isotopic fractionation factor and medium effect, [Formula: see text], for isobutyrophenone enol and the medium effect, Φ = 0.47, for its enolate ion. The isotope effect on KE is the first ever determined for the keto–enol equilibrium of a simple aldehyde or ketone; its near-unit value is consistent with expectation on the basis of fractionation factors for the species involved. Key words: isobutyrophenone, keto–enol equilibrium, carbon-acid ionization, solvent isotope effects, isotopic fractionation factors.

Aqueous solutions of the alkaline-earth metal chlorides at elevated temperatures. Isopiestic molalities and thermodynamic properties

Isopiestic results for SrCl 2(aq) and BaCl 2(aq) were obtained at T= 498 K and T= 523 K. As a check on previously reported results for MgCl 2(aq) (from T= 383 K to T= 473 K), new isopiestic measurements were made over the temperature range from 383 K to 523 K. The new measurements are slightly different from our previous results. Here, NaCl(aq) was used as the reference electrolyte for computation of osmotic and activity coefficients. Our published model for the thermodynamic properties of CaCl 2(aq) was used in global least-squares treatment of the present results in combination with published results to provide comprehensive equations for the properties of these three electrolyte solutions. At elevated temperature, the available results consist primarily of excess Gibbs free energies (our isopiestic results), particularly for SrCl 2(aq) and BaCl 2(aq). Void regions in the temperature and pressure ranges of acceptable experimental results were estimated by reference to the properties of CaCl- (aq). Trends in the thermodynamic properties of aqueous solutions of the alkaline-earth metal chlorides were uniform at all temperatures and pressures used in the present work.

Absolute photoabsorption and photoionization of formaldehyde in the VUV and soft X-ray regions (3–200 eV)

The absolute photoabsorption spectrum of the valence shell of formaldehyde has been measured using dipole (e,e) spectroscopy from ≈3–200 eV photon energy. Long range absolute oscillator strength (cross section) measurements have been performed at ≈1 eV fwhm resolution, while the low energy discrete structured region (3–20 eV) has been examined in more detail at ≈50 meV fwhm resolution. Absolute oscillator strenghts for many of the individual discrete vibronic transitions have been obtained. In addition, dipole (e,e + ion) coincidence spectroscopy has been used to study the ionic photofragmentation of formaldehyde. Photoion branching ratios, absolute partial photoionization oscillator strenghts and photoionization efficiencies have been obtained from the first IP up to 80 eV photon energy. A dipole induced breakdown scheme for formaldehyde has been derived using the present results in combination with previously published photoelectron-photoion coincidence measurements (R. Bombach et al., Int. J. Mass Spectrum. Ion Phys. 40 (1981) 275) and experimental (D.M.P. Holland, Chem. Phys. 133 (1989) 453) and theoretical (P.W. Langhoff et al., J. Chem. Phys. 69 (1978) 4689) valence shell photoelectron branching ratios. From this breakdown analysis, electronic ion state partial photoionization oscillator strengths for formaldehyde from 14–30 eV photon energy have been derived.

Orientation of tryptophan-26 in coat protein subunits of the filamentous virus Ff by polarized Raman microspectroscopy.

The Ff filamentous virus, which includes the closely related strains fd, fl and M13, serves as a model for membrane protein assembly and is employed extensively as a cloning vector and vehicle for peptide display. The threadlike virion (approximately 6 x 880 nm) comprises a single-stranded DNA genome sheathed by approximately 2700 copies of a 50-residue alpha-helical subunit, the product of viral gene VIII. The pVIII subunit contains a single tryptophan residue (tryptophan-26) which is essential for assembly. We have employed polarized Raman microspectroscopy to determine the orientation of tryptophan-26 in pVIII subunits of oriented fd fibers. The present application is based upon the transfer of tryptophan Raman tensors from a recent study of N-acetyl-L-tryptophan single crystals [Tsuboi et al. (1996) J. Mol. Struct. 379, 43-50]. The polarized Raman spectra of fd indicate that the plane of the indole ring in each pVIII subunit is close to parallel to the virion axis. In this orientation, the line connecting indole ring atoms N1 and C2 is nearly perpendicular to the virion axis, while the indole pseudo-2-fold axis (a line connecting atom C2 to the midpoint of the C5-C6 bond) is approximately 36 degrees from the virion axis. We have used the present results in combination with preferred tryptophan side-chain torsions [chi 1 (C3-C beta-C alpha-N) and chi 2.1 (C2-C3-C beta-C alpha)] in other proteins and a previously determined experimental value of chi 2.1 in fd [Aubrey. K. L., & Thomas, G. J., Jr. (1991) Biophys, J. 60, 1337-1349] to propose a detailed molecular model for the orientation of the tryptophan-26 side chain in the native virus.

Distinctive high frequency spectrum of liquid methyl fluoride

Absorption coefficient and refractive index were measured for methyl fluoride in the frequency range 70-320 GHz and for temperatures ranging from the melting point to the triple point. The present results in combination with previous spectroscopic data give the complete 0-THz dipolar spectrum. The experimental results are well described by the confined rotator model with the exception of the part of the spectrum around 600 GHz where an additional absorption band is observed. The general features of this extra absorption are discussed in the framework of several molecular dynamics mechanisms, and show qualitative agreement with the contribution from induced moments originating in translational motion.

The neurofilament triplet is present in distinct subpopulations of neurons in the central nervous system of the guinea-pig

It is commonly assumed that most, if not all, neurons contain the intermediate filament protein class known as the neurofilament protein-triplet. The following study investigated the distribution of neurofilament protein-triplet immunoreactivity in selected regions of the guinea-pig central nervous system using monoclonal antibodies directed against phosphorylation-independent epitopes on the three subunits under optimal tissue processing conditions. Neurofilament protein-triplet immunoreactivity was present in distinct subpopulations of neurons in the cerebellar cortex, neocortex, hippocampal formation, retina, striatum and medulla oblongata. In many of these regions, labelled neurons represented only a small proportion of the total. The selective distribution of this intermediate filament protein class was confirmed in double-labelling experiments using antibodies to the neurofilament protein-triplet in combination with antibodies to other neuronal markers. The distribution of neurofilament protein-triplet immunoreactivity also correlated with the distribution of staining observed with a silver impregnation method based on Bielschowsky. The present results in combination with previous observations have demonstrated that the neurofilament protein-triplet is found in specific subclasses of neurons in different regions of the nervous system. Content of this intermediate filament protein class does not appear to be correlated with neuronal size or length of projection. These results also suggest that the selectivity of staining between neuronal classes observed with classical silver impregnation methods may be due to the presence or absence of the neurofilament protein-triplet. The present results may also provide a new perspective on the basis of the selective vulnerability of neurons in degenerative diseases.

Suckling-Induced Changes of Vasoactive Intestinal Peptide Concentrations in Hypothalamic Areas Implicated in the Control of Prolactin Release

The present study was designed to investigate whether the vasoactive intestinal peptide (VIP) concentration in hypothalamic nuclei, dorsal raphe nucleus (DR) and pituitary lobes of lactating rats changes in physiological situations when prolactin (PRL) secretion is stimulated (suckling) or inhibited (pup separation). In addition VIP levels in blood plasma were determined in both situations. Acute suckling induced changes in VIP concentration only in the rostral part of the anterior hypothalamic (rAHN) and the paraventricular (PVN) nuclei of all the brain areas examined. VIP concentration in the rAHN increased at 5 min from 3.52 +/- 0.30 (mean +/- SEM) to 8.67 +/- 1.91 ng/mg protein (p less than 0.05) but fell to baseline values after 30 min suckling (p less than 0.05; 5 vs. 30 min). Although changes in VIP concentration in the suprachiasmatic nucleus (SCN) did not attain statistical significance, they followed the same trends as the changes of VIP in the rAHN. The opposite pattern of changes was observed in the PVN with a decrease in VIP concentration following 5 min suckling (p less than 0.01). At 30 min the VIP values showed a trend towards 0-min values. Pup removal did not affect VIP concentrations in the rAHN, PVN, SCN, median eminence, supraoptic nucleus and DR. VIP values were not detectable in the arcuate nucleus in any of the experimental situations examined. Lactation increased VIP concentration only in the rAHN and PVN when lactating rats with their pups were compared with virgin female diestrous rats. VIP concentration in the anterior lobe of the pituitary from lactating rats did not change with pup separation or suckling.(ABSTRACT TRUNCATED AT 250 WORDS)

Suppression and enhancement of humoral antibody formation by herpes simplex virus types 1 and 2.

Intraperitoneal infection of mice and rats by herpes simplex virus type 2 (HSV-2) but not type 1 (HSV-1) resulted in suppression of antibody formation on subsequent challenge with HSV-1 or HSV-2. Application of silica considerably enhanced antibody formation after primary HSV-1 infection, but only slightly after primary HSV-2 infection. Suppression induced by HSV-2 was, however, reduced significantly by injection of silica 21 days later, on the day of the second injection of HSV-2. Suppression could be detected soon after infection by HSV-2. The degree of this suppression depended on the dose of the injected virus and was abolished by u.v. irradiation of the virus prior to inoculation. Likewise the weak antibody response induced by HSV-2 was abolished for both neutralizing and ELISA antibodies. Infections with HSV-1 evoked considerable numbers of HSV-specific antibody-producing B cells, when assessed by an enzyme-linked immunospot assay. The B cell response to HSV-2, however, was very weak. Silica considerably enhanced the number of specific antibody-producing B cells only during primary HSV-1 infections. The present results in combination with earlier data demonstrate the central role of macrophages, which seem to be the primary target affected by silica, for enhancement and suppression of HSV-induced antibody generation.

The nilsson-potential parameters for neutrons at A?-100 and new deformation values for103Mo and105Mo

The half-lives of the first excited levels in odd-neutron nuclei103Mo and105Mo have been measured. From these data, values of the deformation parameter ofɛ=0.31±0.05 and 0.29±0.06 for103Mo and105Mo, respectively, have been deduced assuming prolate spheroidal shapes. The present results in combination with previously determined properties of the ground-state bands of these nuclei are used to determineμ, the magnitude of the coefficient of the 12 term, in the Nilsson Hamiltonian, for the new region of deformation atA∼-100.

Growth stimulation of aged cells in culture.

Human glial cultures of any passage consist of two populations of cells: those with mitotic ability, and the non-dividers. The fraction of non-dividers increases with age of the culture, and dominates in late passages. When cells from midphase II cultures (passage 28) were sparsely seeded in dishes containing agarose partially covered by small, isolated, palladium squares (haptotactic islands) they settled on the palladium squares but not on the agarose. 58% of the cells divided, and formed mini-clones which became density growth inhibited within 10 days in medium with 5% serum. The non-dividers comprised 42%. They showed a characteristic indolent motility pattern. When these cultures were exposed to 15% fetal calf serum and 2 ng/ml mEGF (mouse epidermal growth factor) for another 5 days, nine per cent of the solitary cells had divided, and DNA measurements showed another 20% to have entered the S phase. About 40% of the initial single cells presented morphological alterations after the stimulation which are known to be early signs of entrance into the cell cycle after blockage in G1/G0. The present results in combination with earlier findings suggest that "old" cells approaching the non-dividing state become increasingly insensitive to stimulation by growth-promoting factors.

Cyclic nucleotide-dependent protein kinase activity in malignant and cyclic AMP-induced “differentiated” neuroblastoma cells in culture

The activity of adenosine 3′,5′-cyclic monophosphate (cAMP)-dependent protein kinase was demonstrated in the supernatant (S) fraction (100,000 × g) of mouse and human neuroblastoma (NB) cells. In cAMP-induced “differentiated” mouse NB cells, the cAMP-dependent protein kinase (cAMP-PK) activity did not significantly change. Cyclic GMP did not stimulate the PK activity in S-fraction. The cAMP-PK or cGMP-PK activity was not detected in the membrane (M) fraction. The present results in combination with previous data support the concept that the major portion of binding proteins is distinct from the regulatory subunits of cAMP-PK. For example, the level of binding proteins markedly increases in S-fraction of “differentiated” NB cell, but cAMP-PK activity does not change. cAMP binding proteins are present in the M-fraction, but cAMP-PK activity is not demonstrable. Cyclic GMP binds with the soluble proteins with about 10-fold less binding affinity than cAMP; however, cGMP does not stimulate PK activity.