Weight Loss Is Associated With Increased Serum 25‐Hydroxyvitamin D in Overweight or Obese Women

Low circulating concentrations of vitamin D metabolites have been associated with increased risk for several diseases and clinical conditions. Large observational studies and surveys have shown that obesity is independently associated with lower serum 25‐hydroxyvitamin D (25(OH)D) concentration. Few studies have examined the effect of weight loss on serum 25(OH)D concentration. The purpose of this study was to prospectively examine the effect of weight loss on serum 25(OH)D concentration. Data were collected from 383 overweight or obese women who participated in a 2‐year clinical trial of a weight‐loss program, in which 51% (N = 195) lost at least 5% of baseline weight by 24 months, 18% (N = 67) lost 5–10%, and 33% (N = 128) lost >10%. Women who did not lose weight at 24 months had an increase in serum 25(OH)D of 1.9 (9.7) ng/ml (mean (SD)); 25(OH)D increased by 2.7 (9.1) ng/ml for those who lost 5–10% of baseline weight; and 25(OH)D increased by 5.0 (9.2) ng/ml for those who lost >10% of baseline weight (P = 0.014). At baseline, 51% (N = 197) of participants met or exceeded the recommended serum concentration of 20 ng/ml. By study end, 64% (N = 230) of overweight or obese women met this goal, as well as 83% (N = 20) of those whose weight loss achieved a normal BMI. These findings suggest that weight loss, presumably associated with a reduction in body fat, is associated with increased serum 25(OH)D concentration in overweight or obese women.     

Synthesis and biological evaluation of anti-Toxoplasma gondii activity of a novel scaffold of thiazolidinone derivatives

We designed and synthesised novel N-substituted 1,3-thiazolidin-4-one derivatives for the evaluation of their anti-Toxoplasma gondii efficacy. This scaffold was functionalised both at the N1-hydrazine portion with three structurally different moieties and at the lactam nitrogen with substituted benzyl groups selected on the basis of our previous structure-activity relationships studies. Using three different assay methods, the compounds were assessed in vitro to determine both the levels of efficacy against the tachyzoites of T. gondii (IC₅₀?=?5–148?μM), as well as any evidence of cytotoxicity towards human host cells (TD₅₀?=?68 to ≥320?μM). Results revealed that ferrocene-based thiazolidinones can possess potent anti-tachyzoite activity (TI =2–64).     

When are genetic methods useful for estimating contemporary abundance and detecting population trends?

The utility of microsatellite markers for inferring population size and trend has not been rigorously examined, even though these markers are commonly used to monitor the demography of natural populations. We assessed the ability of a linkage disequilibrium estimator of effective population size (N_e) and a simple capture-recapture estimator of abundance (N) to quantify the size and trend of stable or declining populations (true N = 100–10,000), using simulated Wright–Fisher populations. Neither method accurately or precisely estimated abundance at sample sizes of S = 30 individuals, regardless of true N. However, if larger samples of S = 60 or 120 individuals were collected, these methods provided useful insights into abundance and trends for populations of N = 100–500. At small population sizes (N = 100 or 250), precision of the N_e estimates was improved slightly more by a doubling of loci sampled than by a doubling of individuals sampled. In general, monitoring N_e proved a more robust means of identifying stable and declining populations than monitoring N over most of the parameter space we explored, and performance of the N_e estimator is further enhanced if the N_e/N ratio is low. However, at the largest population size (N = 10,000), N estimation outperformed N_e. Both methods generally required ≥ 5 generations to pass between sampling events to correctly identify population trend.     

Adult male–female social bond advertising: The primary function of coordinated singing intensity in a small ape

Adult male and female coordinated singing occur in diverse animal taxa. Adult male–female social bond advertising and strengthening have been proposed as two important functional hypotheses of coordinated singing. Here we studied these two functions in four groups of cao vit gibbon (Nomascus nasutus), a small ape that lives in polygynous family groups and adult members coordinated their sex-specific songs to produce complex duets or trios (three members sing together), using 6-year field behavioral data. In this study, we used the number of successful great call sequences per bout or per minute, and latency period from start of the adult male call to the first successful great call sequence to represent singing intensity. We used the proportion of proximity, behavioral synchronization, and grooming between adult male and female to represent bond strength. We used linear mixed-effects model to investigate the correlation between singing intensity and adult male–female social bond strength. We found a negative correlation between all three bond strength indicators and female latency period (N = 209), and a positive correlation between the number of successful great call sequences per bout (N = 253) and per minute (N = 254) and proximity. We used paired Wilcoxon signed-rank test to investigate if adult gibbons increase bond strength after singing. We found proximity (hourly level: N = 45; daily level: N = 54), behavioral synchronization (hourly level: N = 57; daily level: N = 49), and grooming (daily level: N = 34) in most of the groups did not increase significantly after singing in an hourly or daily level. Together, these results indicate that cao vit gibbon coordinated singing serves primarily in adult male–female social bond advertising and distinct singing intensity indicators advertise different information on adult male–female social bond strength.     

Environmental and topographic variables shape genetic structure and effective population sizes in the endangered Yosemite toad

Aim Describing the landscape variables that accurately reflect how environmental and topographic variations affect population connectivity and demography is a major goal of landscape genetics and conservation biology. However, few landscape genetics studies have quantified the relationships between landscape variables and effective population size (N_e), although N_e is a key conservation and population genetics parameter. In this study, I estimated genetic structure and effective population sizes in the Yosemite toad (Bufo canorus) and tested for associations with environmental and geographic variables. Location Yosemite National Park, California, USA. Methods I estimated F_ST, D_ps and N_e using 10 microsatellite loci amplified from 781 individuals from 24 populations. I used three landscape variables (environmental variation, topography and slope) to generate geographic distance models and a series of regression analyses to identify the variables that contributed to genetic structure in this species. I also tested for correlations between N_e and a suite of variables, including geographic and genetic isolation, habitat suitability, elevation, temperature and precipitation. Results I found substantial variation in genetic distances between populations (F_ST = 0.004–0.396, D_ps = 0.045–0.839) and in effective population sizes (N_e = 9–52). Environmental variation and slope played important roles in explaining variation in genetic distances, and precipitation variables were significantly correlated with N_e. Main conclusions These results show that environmental and topographic variables are both important for understanding population connectivity in B. canorus and provide some of the first evidence, in any species, for a link between environmental variables and effective population size.     

Synthesis,characterization, and electrocatalytic behaviour of hydrothermally grown nanostructured La2O3 and La2O3/K-complex

Rare earth metals play a conspicuous role in magnetic resonance imaging (MRI) for detecting cancerous cells. The alkali metal potassium is a neurotransmitter in the sodium–potassium pump in biomedical sciences. This unique property of rare earth metals and potassium drew our attention to carry forward this study. Therefore, in this work, previously synthesized potassium (K) complexes formed by the reflux of 4-N,N-dimethylaminobenzoic acid (DBA) and potassium hydroxide in methanol, and named [(μ2–4-N,N-dimethylaminobenzoate-κO)(μ2–4-N,N-dimethylaminobenzoic acid-κO)(4-N,N-dimethylaminobenzoic acid-κO) potassium(I) coordination polymer)] were treated hydrothermally with La₂O₃ nanomaterials to obtain a nanohybrid La₂O₃/K-complex. After that, the K-complex was analyzed using single-crystal X-ray diffraction and ¹H and ¹³C NMR spectroscopy. In addition, the structural and morphological properties of the as-prepared nanostructured La₂O₃/K-complex were also characterized, which involved an investigation using X-ray diffraction (XRD)spectroscopy, Fourier transform infrared (FTIR) spectroscopy, atomic force spectroscopy (AFM), transmission electron microscopy (TEM), and energy dispersive X-ray (EDX) analysis. After this, the electrochemical redox behaviour of the synthesized nanohybrid material was studied using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Therefore, the results from these studies revealed that the as-prepared material was a La₂O₃/K-complex that has a promising future role in sensing various analytes, as it showed effective electrocatalytic behaviour.     

Syntheses and conformational studies of poly(Nε-methyl-L-lysine), poly(Nδ-methyl-L-ornithine), poly(Nδ-ethyl-L-ornithine), and their carbobenzoxy derivatives

The helix–coil transitions of poly(N^ε-methyl, N^ε-carbobenzoxy-L -lysine), poly(N^δ-methyl, N^δ-carbobenzoxy-L -ornithine), and poly(N^δ-ethyl, N^δ-carbobenzoxy-L -ornithine) in chloroform–dichloroacetic acid and their corresponding decarbobenzoxylated polypeptides in alkaline solutions were followed by optical rotation measurements. The introduction of a methyl or an ethyl group to the side chains of the carbobenzoxy derivatives of poly(L -lysine) and poly(L -ornithine) appeared to weaken the helical conformation at 25°C. The thermodynamic quantities of the three water-soluble polypeptides were calculated from the data on potentiometric titrations at several temperatures. For uncharged coil-to-helix transition, ΔH = ?370 cal/mol and ΔS = ?1.1 eu/mol for poly(N^ε-methyl-L -lysine), and ΔH = ?540 cal/mol and ΔS = ?1.6 eu/mol for poly(N^δ-ethyl-L -ornithine) (all on molar residue basis). The absolute values of ΔH and ΔS dropped in the region of pH-induced transition and eventually both quantities became positive. The initiation factor σ was about 2 × 10^?3, which was essentially independent of temperature. For poly(N^δ-methyl-L -ornithine) the coil-to-helix transition was not complete even when the polymer was uncharged at high pH.     

Safety assessment of food and herbal products containing hepatotoxic pyrrolizidine alkaloids: interlaboratory consistency and the importance of N-oxide determination

Introduction  – Two recent mass spectrometry‐based reports concerning Senecio scandens yielded remarkably dissimilar pyrrolizidine alkaloid constituents. In both studies, and in a related analysis of Senecio scandens and Tussilago farfara using micellar electrokinetic chromatography, the presence of hazardous N‐oxides of the alkaloids was either not considered or was inadequately considered. This raises concerns about the effectiveness of the methodologies used in these, and similar, studies in assessing the pyrrolizidine alkaloid content and the safety of food, food supplements and medicines for human use. Objective  – To highlight essential analytical requirements for confident assessment of pyrrolizidine alkaloid‐related safety of food and herbal products for human use. Methodology  – Direct infusion‐ESI MS and HPLC‐ESI MS were used to analyse samples derived from liquid–liquid partitioning experiments and from strong cation exchange, solid‐phase extraction of pyrrolizidine alkaloids and their N‐oxides. Results  – A simple solvent partitioning experiment using pure senecionine and senecionine‐N‐oxide, two constituents reported in one of the mass spectrometry‐based studies of S. scandens, clearly demonstrated the inadequacy of the reported method to detect and quantitate hazardous pyrrolizidine alkaloid N‐oxide components. A preliminary LCMS analysis of commercially‐prepared extracts of comfrey roots (Symphytum officinale and S. uplandicum s. l.) was used as a model to highlight the analytical importance of N‐oxides in the safety assessment of pyrrolizidine alkaloid‐containing medicinal herbs. Conclusions  – This study highlighted significant differences in the reported identification of pyrrolizidine alkaloids from the same plant species, and clearly demonstrated the inadequacy of some procedures to include N‐oxides in the assessment of pyrrolizidine alkaloid‐related safety of food and herbal products. Copyright © 2008 John Wiley & Sons, Ltd.     

Characterization of microsatellite loci in sea urchins (Strongylocentrotus spp.)

We present six dinucleotide repeats that were developed and characterized in Strongylocentrotus droebachiensis and also tested in S. purpuratus. Four of these loci are polymorphic in S. droebachiensis (13–20 alleles, N= 100) and five are polymorphic in S. purpuratus (5–12 alleles, N= 10). We are currently using these markers to investigate the population substructure of shallow water populations of S. droebachiensis in the north Atlantic.     

Internet of things-enabled photomultiplier tube- and smartphone-based electrochemiluminescence platform to detect choline and dopamine using 3D-printed closed bipolar electrodes

There is a growing demand to realize low-cost miniaturized point-of-care testing diagnostic devices capable of performing many analytical assays. To fabricate such devices, three-dimensional printing (3DP)-based fabrication techniques provide a turnkey approach with marked precision and accuracy. Here, a 3DP fabrication technique was successfully utilized to fabricate closed bipolar electrode-based electrochemiluminescence (ECL) devices using conductive graphene filament. Furthermore, using these ECL devices, Ru(bpy)₃²⁺/TPrA- and luminol/H₂O₂-based electrochemistry was leveraged to sense dopamine and choline respectively. For ECL signal capture, two distinct approaches were used, first a smartphone-based miniaturized platform and the second with a photomultiplier tube embedded with the internet of things technology. Choline sensing led to a linear range 5–700 μM and 30–700 μM with a limit of detection (LOD) of 1.25 μM (R² = 0.98, N = 3) and 3.27 μM (R² = 0.97, N = 3). Furthermore, dopamine sensing was achieved in a linear range 0.5–100 μM with an LOD = 2 μM (R² = 0.99, N = 3) and LOD = 0.33 μM (R² = 0.98, N = 3). Overall, the fabricated devices have the potential to be utilized effectively in real-time applications such as point-of-care testing.     

Glycoform Analysis of N-Glycans Linked to Glycoproteins Expressed in Rice Culture Cells: Predominant Occurrence of Complex Type N-Glycans

Although it has been found that plant endo-β-N-acetylglucosaminidase shows strong activity towards denatured glycoproteins and glycopeptides with high-mannose type N-glycans and free high-mannose type N-glycans bearing the chitobiosyl unit, the endogenous substrates for plant endoglycosidase have not yet been identified. Recently we purified and characterized an endo-β-N-acetylglucosaminidase from rice culture cells and identified the gene encoded (Maeda, M., and Kimura, Y., Trends Glycosci. Glycotech., 17, 205–214 (2005)). Furthermore, we found structural features of free N-glycans in the cells, indicating that high-mannose type species (Man_9-5GlcNAc₁) occur at concentration of several micromolar (μM). Hence, in this study we analyzed glycoform of N-glycans linked to glycoproteins expressed in rice culture cells to see whether endogenous glycoproteinous substrate occurs in reasonable amounts. Structural analysis revealed that more than 95% of total N-glycans linked to glycoproteins in the rice cells had the plant complex type structure, including Lewis a epitope-harboring type, although high-mannose type structures account for less than 5% of total N-glycans.     

Interaction between the C‐terminal domains of measles virus nucleoprotein and phosphoprotein: A tight complex implying one binding site

The intrinsically disordered C‐terminal domain (N_TAIL) of the measles virus (MeV) nucleoprotein undergoes α‐helical folding upon binding to the C‐terminal X domain (XD) of the phosphoprotein. The N_TAIL region involved in binding coupled to folding has been mapped to a conserved region (Box2) encompassing residues 489–506. In the previous studies published in this journal, we obtained experimental evidence supporting a K_D for the N_TAIL–XD binding reaction in the nM range and also showed that an additional N_TAIL region (Box3, aa 517–525) plays a role in binding to XD. In striking contrast with these data, studies published in this journal by Kingston and coworkers pointed out a much less stable complex (K_D in the μM range) and supported lack of involvement of Box3 in complex formation. The objective of this study was to critically re‐evaluate the role of Box3 in N_TAIL–XD binding. Since our previous studies relied on N_TAIL‐truncated forms possessing an irrelevant Flag sequence appended at their C‐terminus, we, herein, generated an N_TAIL devoid of Box3 and any additional C‐terminal residues, as well as a form encompassing only residues 482–525. We then used isothermal titration calorimetry to characterize the binding reactions between XD and these N_TAIL forms. Results effectively argue for the presence of a single XD‐binding site located within Box2, in agreement with the results by Kingston et al., while providing clear experimental support for a high‐affinity complex. Altogether, the present data provide mechanistic insights into the replicative machinery of MeV and clarify a hitherto highly debated point.     

Identification of a radical formed in the reaction mixture of rat brain homogenate with a ferrous ion/ascorbic acid system using HPLC–EPR and HPLC–EPR–MS

Identification of a free radical is performed for the reaction mixture of rat brain homogenate with a ferrous ion/ascorbic acid system using EPR, high performance liquid chromatography–electron paramagnetic resonance spectrometry (HPLC–EPR) and high performance liquid chromatography–electron paramagnetic resonance–mass spectrometry (HPLC–EPR–MS). EPR measurements of the reaction mixtures showed prominent signals with hyperfine coupling constants (α^N = 1.58 mT and α^Hβ = 0.26 mT). No EPR spectrum was detectable without rat brain homogenate, suggesting that the radical is derived from rat brain homogenate. An HPLC–EPR analysis of the reaction mixture showed a peak with retention time of 33.7 min. An HPLC–EPR–MS analysis of the peak gave two ions at m/z 224 and 137, suggesting that α-(4-pyridyl-1-oxide)-N-tert-butylnitrone (4-POBN)/ethyl radical adduct forms in the reaction mixture.     

Purification and Characterization of a Co(II)-Sensitive α-Mannosidase from Ginkgo biloba Seeds

An α-mannosidase was purified from developing Ginkgo biloba seeds to apparently homogeneity. The molecular weight of the purified α-mannosidase was estimated to be 120 kDa by SDS–PAGE in the presence of 2-mercaptoethanol, and 340 kDa by gel filtration, indicating that Ginkgo α-mannosidase may function in oligomeric structures in the plant cell. The N-terminal amino acid sequence of the purified enzyme was Ala–Phe–Met–Lys–Tyr–X–Thr–Thr–Gly–Gly–Pro–Val–Ala–Gly–Lys–Ile–Asn–Val–His–Leu–. The α-mannosidase activity for Man₅GlcNAc₁ was enhanced by the addition of Co²⁺, but the addition of Zn²⁺, Ca²⁺, or EDTA did not show any significant effect. In the presence of cobalt ions, the hydrolysis rate for pyridylaminated Man₆GlcNAc₁ was significantly faster than that for pyridylaminated Man₆GlcNAc₂, suggesting the possibility that this enzyme is involved in the degradation of free N-glycans occurring in developing plant cells (Kimura, Y., and Matsuo, S., J. Biochem., 127, 1013–1019 (2000)). To our knowledge, this is the first report showing that plant cells contain an α-mannosidase, which is activated by Co²⁺ and prefers the oligomannose type free N-glycans bearing only one GlcNAc residue as substrate.     

Synthesis of protected oligo (γ-methyl-L-glutamates) and study of their conformation in solution and at the air–water interface

Oligopeptides having the general formula N-carbobenzoxy(γ-methyl-L -glutamyl)_n-dimethyl-L -glutamate (with n = 1, 3, 5, 7, 11) were prepared, using both solid-phase synthesis and conventional peptide couplings in solution. The appearance of an ordered structure with increasing chain length was studied in organic solvents and at the air–water interface. The results obtained by thin-layer chromatography were interpreted. All the studies have demonstrated a very similar behaviour of this type of oligopeptide in solution and in monolayers.     

Synthesis and conformational study of poly(N -benzyl-L-lysine) and its benzyloxycarbonyl derivative

The solvent-and pH-induced conformational changes are examined in order to investigate the influence of benzyl group. Polymer was prepared via N^?-benzyloxycarbonyl, N^?-benzyl-N^α-carboxy-L -lysine anhydride. The resulting poly (N^?-benzyloxycarbonyl, N^?-benzyl-L -lysine) was obtained in high yield and had a high molecular weight. The protected polymer was removed into poly (N^?-benzyl-L -lysine) by treating it with hydrogen bromide. From the results of the ORD and CD, the protected polymer has a righthanded α-helix, showing [m′]₂₃₃ = –10,300, [θ]₂₂₀ = –27,600 and [θ]₂₀₇ = –25,100 in dioxane. The breakdown of the helical conformation is found to occur at 8% dichloroacetic acid in chloroform-dichloroacetic acid mixture. In the pH range 3.35–6.90, poly (N^?-benzyl-L -lysine) is in a random coil structure. In the pH range 7.50–13.0, the polypeptide has a right-handed α-helix structure; [m′]₂₃₃ = –12,000, [0]₂₂₀ = –27,200, and [0]₂₀₇ = –27,000. In comparison with poly-L -lysine, the coil-to-helix transition is observed at lower pH range in 50% n-propanol. Above pH 8 by heating, the α ? β transition of poly (N^?-benzyl-L -lysine) is not observed in an aqueous media.     

Enantioselectivity in the metabolism of mexiletine by conjugation in female patients with the arrhythmic form of chronic Chagas' heart disease

The phenomenon of enantioselectivity in the metabolism of mexiletine (MEX) conjugation was investigated in eight female patients with the arrhythmic form of chronic Chagas' heart disease treated with racemic mexiletine hydrochloride (two 100 mg capsules every 8 hr). Blood samples were collected up to 24 hr after the administration of the morning dose, with discontinuation of the subsequent doses during the study period. Plasma concentrations of N‐hydroxymexiletine glucuronide were calculated as the difference between the concentrations of unchanged and total (unchanged + conjugated) MEX enantiomers. Total plasma MEX concentrations were analyzed by HPLC after enzymatic hydrolysis with β‐glucuronidase, the formation of diastereomeric derivatives with the chiral reagent N‐acetyl‐l ‐cysteine/o‐phthalaldehyde, and fluorescence detection. The differences in the pharmacokinetic parameters of the enantiomers were evaluated by the paired t‐test. The plasma concentrations of the (+)‐(S)‐MEX did not differ before and after enzymatic hydrolysis. The pharmacokinetic parameters calculated for (−)‐(R)‐N‐hydroxymexiletine glucuronide are presented as means (95% confidence interval): maximum plasma concentration C_max = 194.0 ng · ml⁻¹ (154.3–233.7), time to maximum plasma concentration t_max = 1.4 hr (0.3–2.5), area under the plasma concentration versus time curve AUC^0–24 = 2099.2 ng · h · ml⁻¹ (1585.6–2612.6), elimination half‐life t_1/2β = 12.8 hr (9.9–15.6) and extent of conjugation of 31.6% (24.3–38.9%). The present data indicate stereospecific conjugation of (−)‐(R)‐N‐hydroxymexiletine in the female patients with the arrhythmic form of Chagas' heart disease. Chirality 11:29–32, 1999. © 1999 Wiley‐Liss, Inc.     

Fine structure of DNA melting curves.

Theoretical calculations predict that the differential melting curves for random polynucleotide sequences having lengths up to several tens of thousands of base pairs have a clear-cut fine structure. This structure appears in the form of multiple narrow peaks 0.3–0.4°C wide on the bell shaped main curve. The differential melting curves have different shapes for different specific sequences. The theory also predicts the disappearance of the fine structure when the length of the sequence increases and when circular, covalently closed DNA is considered instead of the open structure. The predictions of the theory were confirmed by the measurements of differential melting curves for open and covalently closed circular forms of DNA for PM2 phage (N = 10⁴ base pairs) and also for other phage DNA's of different length: T7 (N = 3.8 × 10⁴); S_D (N = 9.2 × 10⁴); T2 (N = 17 × 10⁴). It was shown that the effect of fine structure results mainly from the cooperative melting out of DNA regions 300–500 base pairs long.     

Multiple estimates of effective population size for monitoring a long‐lived vertebrate: an application to Yellowstone grizzly bears

Effective population size (N_e) is a key parameter for monitoring the genetic health of threatened populations because it reflects a population's evolutionary potential and risk of extinction due to genetic stochasticity. However, its application to wildlife monitoring has been limited because it is difficult to measure in natural populations. The isolated and well‐studied population of grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem provides a rare opportunity to examine the usefulness of different N_e estimators for monitoring. We genotyped 729 Yellowstone grizzly bears using 20 microsatellites and applied three single‐sample estimators to examine contemporary trends in generation interval (GI), effective number of breeders (N_b) and N_e during 1982–2007. We also used multisample methods to estimate variance (N_eV) and inbreeding N_e (N_eI). Single‐sample estimates revealed positive trajectories, with over a fourfold increase in N_e (≈100 to 450) and near doubling of the GI (≈8 to 14) from the 1980s to 2000s. N_eV (240–319) and N_eI (256) were comparable with the harmonic mean single‐sample N_e (213) over the time period. Reanalysing historical data, we found N_eV increased from ≈80 in the 1910s–1960s to ≈280 in the contemporary population. The estimated ratio of effective to total census size (N_e/N_c) was stable and high (0.42–0.66) compared to previous brown bear studies. These results support independent demographic evidence for Yellowstone grizzly bear population growth since the 1980s. They further demonstrate how genetic monitoring of N_e can complement demographic‐based monitoring of N_c and vital rates, providing a valuable tool for wildlife managers.