Seasonal fluctuations in the response of Italian Mediterranean buffaloes to synchronization of ovulation and timed artificial insemination

A comprehensive study of the efficiency of synchronization of ovulation and timed artificial insemination (TAI) was undertaken in a large group of Italian Mediterranean buffaloes at a commercial dairy. A total of 2791 synchronization protocols were carried out on 857 animals over 3 years. Of these protocols, 823 (29.5%) did not proceed beyond Day 7 (due to the absence of a vascularized CL) and 620 (22.2%) were discontinued on Day 10 (due to the absence of follicles >1.0 cm and tonic uteri); hence, 1443 (51.7%) protocols did not progress to TAI. Data were analyzed for four periods: P1, transition to spring (from breeding season to low breeding season); P2, low breeding season; P3, transition to fall (low breeding season to breeding season); and P4, breeding season. No differences were found among the four periods in terms of the proportion of protocols that did not result in TAI. Of the 857 buffaloes, 660 (77%) conceived and delivered a calf. The average number of TAI per pregnancy was 2.1 and ranged from 1.9 to 2.3 across years. Logistic regression analysis showed that buffaloes that calved during P3 had a higher odds ratio for pregnancy (1.380; P < 0.05) than buffaloes that calved in other periods. Pregnancy was also influenced by the calving to service period (odds ratio = 0.977; P < 0.01) and the pregnancy per AI (P/AI) at successive TAI (odds ratio = 1.480; P < 0.01). The pregnancy per AI at the first TAI (424/857, 49.5%) was greater (P < 0.01) than in subsequent TAI. The occurrence of late embryonic mortality (between Days 27 and 45 after TAI) was similar among the four periods. These findings indicated that there are distinct seasonal differences in the response of Italian Mediterranean buffaloes to synchronization and TAI.     

Uranium complexes of cyclic O,O-bidentate ligands with the P-N-P backbone

The formation of uranium complexes of novel ligands belonging to phosphorylated 2-oxo-1,2-azaphospholane series, namely 2-ethoxy-1-diethoxyphosphoryl-2-oxo-1,2λ⁵-azaphospholane (1a) and both individual R^∗,R^∗- and R^∗,S^∗-diastereomers of the related 2-oxo-2-phenyl-1,2λ⁵-azaphospholanes 1b,c with different surrounding at the exocyclic phosphorus atom, has been studied. The structures of the complexes of ML composition obtained in the reaction with uranyl nitrate in 1:1 ratio were found to depend on the difference in donor properties of the oxygen atom of endo- and exocyclic phosphoryl groups. The ligand 1a possessing the greater difference, serves as O-monodentate one with metal-oxygen bonding via the endocyclic PO function while both isomers of 1b,c coordinate to uranyl cation in a O,O-bidentate fashion. In solutions the ML complexes reacted with air oxygen to afford (μ₂-peroxo)-bridged uranium complexes [{UO₂(L)NO₃}₂(μ₂-O₂)] which structures were confirmed by X-ray crystallography data.     

Leishmanicidal effect of LLD-3 (1), a nor-triterpene isolated from Lophanthera lactescens

Leishmanicidal activity of 6α, 7α, 15β, 16β, 24-pentacetoxy-22α-carbometoxy-21β,22β-epoxy-18β−hydroxy-27,30-bisnor-3,4-secofriedela-1,20 (29)-dien-3,4 R-olide (LLD-3 (1)) isolated from Lophanthera lactescens Ducke, a member of the Malpighiaceae, was demonstrated against intramacrophage amastigote forms (IC₅₀ of 0.41 μg/mL). The in vitro leishmanicidal effect of Glucantime, the first choice drug for leishmaniasis treatment, was increased by LLD-3 (1) association. The leishmanicidal effect of LLD-3 (1) was not due to stimulation of nitric oxide production by macrophages. LLD-3 (1) was also not cytotoxic for mouse peritoneal macrophages or B cells as assessed by the XTT and Trypan blue exclusion assays. LLD-3 (1) was unable to affect proliferation of naïve or activated B and T cells, as well as the B cells immunoglobulin synthesis. Cellularity of different tissues, liver and kidney functions were not altered in mice treated with LLD-3 (1), as well as the histology pattern of different organs. Our results add LLD-3 (1) as a potential drug candidate for treatment of leishmaniasis.     

Ultrastructural characterization of cell types in root tips of barley (Hordeum vulgare L.)

Some ultrastructural characteristics of cell types in barley root tip and root cap were recorded and compared with the aim to identify these cells by electron microscopy, even if positional information is limited in the ultrathin section. Root cap and root body initials could be distinguished according to the type of proplastids. Cap and apical cells also differed at the level of dictyosomes and the relative quantity of the dense substance in the enlarging vacuoles. The maturity of cap cells could be judged from the degree of vacuolization and the size of starch grains (statoliths) in the plastids.     

Times to exhaustion at 100% of velocity at [(V)\dot]\textO\text2 \dot V{\text{O}}_{\text{2}} max and modelling of the time-limit / velocity relationship in elite long-distance runners

The aim of this study was to measure running times to exhaustion (Tlim) on a treadmill at 100% of the minimum velocity which elicits _{max max} in 38 elite male long - distance runners _max = 71.4 ± 5.5 ml.kg^–1.min^–1 and _max = 21.8 ± 1.2 km.h^–1). The lactate threshold (LT) was defined as a starting point of accelerated lactate accumulation around 4 mM and was expressed in _max. Tlim value was negatively correlated with _max (r = -0.362, p< 0.05) and _max (r = –0.347, p< 0.05) but positively with LT (%v _max) (r = 0.378, p < 0.05). These data demonstrate that running time to exhaustion at _max in a homogeneous group of elite male long-distance runners was inversely related to _max and experimentally illustrates the model of Monod and Scherrer regarding the time limit-velocity relationship adapted from local exercise for running by Hughson et al. (1984) .     

Cu(II) complexes with labile apical coordination: Synthesis, crystal structure, H NMR investigation, and oxidation properties of mononuclear [Cu(dien)(2-PhIm)(ClO4)] (1), [Cu(dien)(2-MeBzIm)] (2), complexes

The compounds [Cu(dien)(2-PhIm)(ClO₄)](ClO₄) (1); [Cu(dien)(2-MeBzIm)](ClO₄)₂ (2); where dien = diethylenetriamine, 2-PhIm = 2-phenylimidazole and 2-MeBzIm = 2-methylbenzimidazole, were synthesized and characterized. The complexes possessing [Cu(II)dien] moiety as common, the former containing 2-phenylimidazole, yielded square pyramidal geometry with apical perchlorate coordination [Cu1-O(5) = 2.449 Å], while the latter with 2-methylbenzimidazole formed square planar geometry with weak perchlorate contact [Cu1-O(8) = 2.596 Å] in its apical position. The effect of solvent and the variable temperature ¹H NMR investigation combinedly explore the geometrical rearrangement towards five coordination around Cu(II) metal center by accommodating the solvent molecule in its fifth coordination. Possessing easily labile perchlorate anion, both these complexes were investigated for their oxidation capability using 3,5-di-tert-butyl catechol (DTBC). The rate constant determined for the oxidation of DTBC to corresponding quinone indicates that they are catalytically quite similar and the k_cat of 1 ≈ 2. The crystal structure and the NMR investigations are discussed in detail.     

Protonation and Zn(II) complexation with versatile valine and glycylglycine N-pyrimidines derivatives: crystal structures of layered {[Zn(HL1)2] · 2H2O}n and [Zn(HL2)2(H2O)4]

Protonation and Zn(II) complexation of N-substituted amino acids, valine (H₂L1) and glycylglycine (H₂L2), with 4-amino-1,6-dihydro-1-methyl-5-nitroso-6-oxopyrimidin-2-yl as substituent, were studied by potentiometric and UV-Vis measurements. Bianions L1 and L2 suffer three protonation steps in aqueous medium corresponding to the amide and carboxylate groups of the amino acidic moiety, and the nitrogen atom of the nitroso group of the pyrimidine fragment. Both ligands form mononuclear Zn(II) complexes in aqueous solutions. The binding donor groups are the nitroso and/or the oxo groups of the pyrimidinic moiety or the carboxylate group, depending on whether the ligands are neutral or anionic, respectively. Weak metal-to-ligand interactions were observed independently of the functionality used by the corresponding ligand on bonding to Zn(II). The reaction of ZnCl₂ with the monodeprotonated ligands (1:1) yields a polynuclear 2D {[Zn(HL1)₂] · 2H₂O}_n and a mononuclear [Zn(HL2)₂(H₂O)₄] complexes, showing the influence of the susbtituent on the amino acids fragment as well as the versatility of this class of compounds when acting as ligands.     

Oral-aboral axis specification in the sea urchin embryo: III. Role of mitochondrial redox signaling via H2O2

In sea urchin embryos, specification of the secondary (oral-aboral) axis occurs via nodal, expression of which is entirely zygotic and localized to prospective oral ectoderm at blastula stage. The initial source of this spatial anisotropy is not known. Previous studies have shown that oral-aboral (OA) polarity correlates with a mitochondrial gradient, and that nodal activity is dependent both on mitochondrial respiration and p38 stress-activated protein kinase. Here we show that the spatial pattern of nodal activity also correlates with the mitochondrial gradient, and that the latter correlates with inhomogeneous levels of intracellular reactive oxygen species. To test whether mitochondrial H₂O₂ functions as a redox signal to activate nodal, zygotes were injected with mRNA encoding either mitochondrially-targeted catalase, which quenches mitochondrial H₂O₂ and down-regulates p38, or superoxide dismutase, which augments mitochondrial H₂O₂ and up-regulates p38. Whereas the former treatment inhibits the initial activation of nodal and entrains OA polarity toward aboral when confined to half of the embryo via 2-cell stage blastomere injections, the latter does not produce the opposite effects. We conclude that mitochondrial H₂O₂ is rate-limiting for the initial activation of nodal, but that additional rate-limiting factors, likely also involving mitochondria, contribute to the asymmetry in nodal expression.     

Formation and structural chemistry of the unusual cyanide-bridged dinuclear species [Ru2(NN)2(CN)7] (NN = 2,2′-bipyridine or 1,10-phenanthroline)

Crystallisation of simple cyanoruthenate complex anions [Ru(NN)(CN)₄]²⁻ (NN = 2,2′-bipyridine or 1,10-phenanthroline) in the presence of Lewis-acidic cations such as Ln(III) or guanidinium cations results, in addition to the expected [Ru(NN)(CN)₄]²⁻ salts, in the formation of small amounts of salts of the dinuclear species [Ru₂(NN)₂(CN)₇]³⁻. These cyanide-bridged anions have arisen from the combination of two monomer units [Ru(NN)(CN)₄]²⁻ following the loss of one cyanide, presumably as HCN. The crystal structures of [Nd(H₂O)_5.5][Ru₂(bipy)₂(CN)₇] · 11H₂O and [Pr(H₂O)₆][Ru₂(phen)₂(CN)₇] · 9H₂O show that the cyanoruthenate anions form Ru-CN-Ln bridges to the Ln(III) cations, resulting in infinite coordination polymers consisting of fused Ru₂Ln₂(μ-CN)₄ squares and Ru₄Ln₂(μ-CN)₆ hexagons, which alternate to form a one-dimensional chain. In [CH₆N₃]₃[Ru₂(bipy)₂(CN)₇] · 2H₂O in contrast the discrete complex anions are involved in an extensive network of hydrogen-bonding involving terminal cyanide ligands, water molecules, and guanidinium cations. In the [Ru₂(NN)₂(CN)₇]³⁻ anions themselves the two NN ligands are approximately eclipsed, lying on the same side of the central Ru-CN-Ru axis, such that their peripheries are in close contact. Consequently, when NN = 4,4′-^tBu₂-2,2′-bipyridine the steric bulk of the t-butyl groups prevents the formation of the dinuclear anions, and the only product is the simple salt of the monomer, [CH₆N₃]₂[Ru(^tBu₂bipy)(CN)₄] · 2H₂O. We demonstrated by electrospray mass spectrometry that the dinuclear by-product [Ru₂(phen)₂(CN)₇]³⁻ could be formed in significant amounts during the synthesis of monomeric [Ru(phen)(CN)₄]²⁻ if the reaction time was too long or the medium too acidic. In the solid state the luminescence properties of [Ru₂(bipy)₂(CN)₇]³⁻ (as its guanidinium salt) are comparable to those of monomeric [Ru(bipy)(CN)₄]²⁻, with a ³MLCT emission at 581 nm.