Prognostic impact of coronary microcirculation abnormalities in systemic sclerosis: a prospective study to evaluate the role of non-invasive tests

INTRODUCTION: Microcirculation dysfunction is a typical feature of systemic sclerosis (SSc) and represents the earliest abnormality of primary myocardial involvement. We assessed coronary microcirculation status by combining two functional tests in SSc patients and estimating its impact on disease outcome. METHODS: Forty-one SSc patients, asymptomatic for coronary artery disease, were tested for coronary flow velocity reserve (CFR) by transthoracic-echo-Doppler with adenosine infusion (A-TTE) and for left ventricular wall motion abnormalities (WMA) by dobutamine stress echocardiography (DSE). Myocardial multi-detector computed tomography (MDCT) enabled the presence of epicardial stenosis, which could interfere with the accuracy of the tests, to be excluded. Patient survival rate was assessed over a 6.7- ± 3.5-year follow-up. RESULTS: Nineteen out of 41 (46%) SSc patients had a reduced CFR (≤2.5) and in 16/41 (39%) a WMA was observed during DSE. Furthermore, 13/41 (32%) patients showed pathological CFR and WMA. An inverse correlation between wall motion score index (WMSI) during DSE and CFR value (r = -0.57, P <0.0001) was observed; in addition, CFR was significantly reduced (2.21 ± 0.38) in patients with WMA as compared to those without (2.94 ± 0.60) (P <0.0001). In 12 patients with abnormal DSE, MDCT was used to exclude macrovasculopathy. During a 6.7- ± 3.5-year follow-up seven patients with abnormal coronary functional tests died of disease-related causes, compared to only one patient with normal tests. CONCLUSIONS: A-TTE and DSE tests are useful tools to detect non-invasively pre-clinical microcirculation abnormalities in SSc patients; moreover, abnormal CFR and WMA might be related to a worse disease outcome suggesting a prognostic value of these tests, similar to other myocardial diseases

Grafting of the 2,8-dithia-5-aza-2,6-pyridinophane macrocycle on SBA-15 mesoporous silica for the removal of Cu2+ and Cd2+ ions from aqueous solutions: synthesis, adsorption, and complex stability studies

Silica-based mesoporous materials have received growing attention in metal recovery from industrial processes, although, in general, the adsorption of metal ions by silanols is rather poor. Nevertheless, a great improvement of metal ion removal from aqueous solutions can be achieved by grafting metal-chelators on the particles’ surface. Combining the metal-chelating properties of organic ligands with the high surface area of mesoporous silica particles makes these hybrid nanostructured materials a new horizon in metal recovery, sensing and controlled storage of metal ions in industrial and mining processes. Here, the 2,8-dithia-5-aza-2,6-pyridinophane (L) macrocycle was grafted on SBA-15 mesoporous silica to obtain the SBA-L mesoporous adsorbent for the removal and controlled recovery of Cd2+ and Cu2+ ions from aqueous solution in a broad pH range (4-11). By grafting about 0.3 mmol g−1 of L on SBA-15 a maximum loading capacity of 20.9 mg g−1 and 31.8 mg g−1 was obtained for Cu2+ and Cd2+, respectively. The adsorption kinetics can be described with the pseudo-second order model, while the adsorption isotherm (298 K) followed the Langmuir model. The latter, together with potentiometric studies, suggests that the adsorption mechanism is based on metal chelation by the grafted macrocycle. In summary, SBA-L is an effective copper(ii) and cadmium(ii) chelator for possible applications where metal removal, storage and recovery are of basic importance

A unique case of polymorphism in polyiodide networks resulting from the reaction of the drug methimazole and I2

The oxidation of thioamide methimazole (C4H6N2S) with molecular diiodine in water afforded the ionic compound [2(C4H5N2S–SN2C4H6)]I3I5 (1) in 1-triclinic and 1-monoclinic polymorphs. The polymorphic nature of [C4H5N2S–SN2C4H6]2I3I5 has been highlighted by comparing the structure of the 1-triclinic form with that of the 1-monoclinic form reported in the literature. No significant geometric differences are observed for the cations in the two polymorphs. The polymorphism is essentially due to a different arrangement in the polyiodide network of the [I5]− and [I3]− components. The FT-Raman spectrum of 1-triclinic shows the characteristic bands in the range 200–50 cm−1 which are in good agreement with the structural features of the polyiodide network. The molecular electrostatic potential maps of the cation methimazole-disulfide [C4H5N2S–SN2C4H6]+ and the bis-cation methimazole-disulfide {[C4H5N2S–SN2C4H6]+}2 in 1-triclinic have been studied to clearly identify the electrostatic potential energy distributions over the cations, and the electron belt and σ-hole areas responsible for the directionality of the non-covalent interactions in the polyiodides. It is suggested that the cation methimazole-disulfide may be a reaction intermediate in the inhibition of thyroid hormones by methimazole

The Nature of the Chemical Bond in Linear Three-Body Systems: From I3− to Mixed Chalcogen/Halogen and Trichalcogen Moieties

The 3 centre-4 electrons (3c-4e) and the donor/acceptor or charge-transfer models for the description of the chemical bond in linear three-body systems, such as I3− and related electron-rich (22 shell electrons) systems, are comparatively discussed on the grounds of structural data from a search of the Cambridge Structural Database (CSD). Both models account for a total bond order of 1 in these systems, and while the former fits better symmetric systems, the latter describes better strongly asymmetric situations. The 3c-4e MO scheme shows that any linear system formed by three aligned closed-shell species (24 shell electrons overall) has reason to exist provided that two electrons are removed from it to afford a 22 shell electrons three-body system: all combinations of three closed-shell halides and/or chalcogenides are considered here. A survey of the literature shows that most of these three-body systems exist. With some exceptions, their structural features vary continuously from the symmetric situation showing two equal bonds to very asymmetric situations in which one bond approaches to the value corresponding to a single bond and the second one to the sum of the van der Waals radii of the involved atoms. This indicates that the potential energy surface of these three-body systems is fairly flat, and that the chemical surrounding of the chalcogen/halogen atoms can play an important role in freezing different structural situations; this is well documented for the I3− anion. The existence of correlations between the two bond distances and more importantly the linearity observed for all these systems, independently on the degree of their asymmetry, support the state of hypervalency of the central atom

Dental twinning in the primary dentition: new archaeological cases from Italy

Dental twinning (or “double teeth”) is a rare developmental condition that implies the fusion of two or more adjacent teeth. Clinical literature reports individual cases and extensive population studies to clarify causation, distribution, heritability and differential diagnosis of the different types of dental twinning (i.e. fusion, gemination, and accretion) whereas, documentation for past populations is still scarce. Aims: the present study documents four new archaeological cases of dental twinning of deciduous teeth from four different Italian archeological sites and positions them within the framework of the known literature.Materials and methods: the observed cases include five deciduous teeth from four subadults from Sardinia (Monte Sirai, 7th-4th cent. BCE and Santa Filitica, 7th cent. CE), Campania (Velia, 1st-2nd cent. CE) and Latium (Villamagna, 13th-15th cent. CE). The identification, descriptions and differential diagnoses of the anomalies were performed with the use of morphological analyses and, in one case, radiographic means.Results: all cases fall within the category of double teeth; each involving a different set of processes (gemination and dental fusion), teeth (deciduous central incisors, lateral incisors and canines), locations (upper and lower) and occurrence (unilateral and bilateral). Conclusion: to this day, cases reported in literature of dental twinning in archaeological samples are sparse and limited to specific geographical areas. This study adds four more cases from Italy suggesting such anomalies should be recorded in dental analyses in order to, one day, obtain a more reliable modelling of the frequencies and distributions in past populations

Dental twinning in the primary dentition: new archaeological cases from Italy

Dental twinning (or “double teeth”) is a rare developmental condition that implies the fusion of two or more adjacent teeth. Clinical literature reports individual cases and extensive population studies to clarify causation, distribution, heritability and differential diagnosis of the different types of dental twinning (i.e. fusion, gemination, and accretion) whereas, documentation for past populations is still scarce. Aims: the present study documents four new archaeological cases of dental twinning of deciduous teeth from four different Italian archeological sites and positions them within the framework of the known literature.Materials and methods: the observed cases include five deciduous teeth from four subadults from Sardinia (Monte Sirai, 7th-4th cent. BCE and Santa Filitica, 7th cent. CE), Campania (Velia, 1st-2nd cent. CE) and Latium (Villamagna, 13th-15th cent. CE). The identification, descriptions and differential diagnoses of the anomalies were performed with the use of morphological analyses and, in one case, radiographic means.Results: all cases fall within the category of double teeth; each involving a different set of processes (gemination and dental fusion), teeth (deciduous central incisors, lateral incisors and canines), locations (upper and lower) and occurrence (unilateral and bilateral). Conclusion: to this day, cases reported in literature of dental twinning in archaeological samples are sparse and limited to specific geographical areas. This study adds four more cases from Italy suggesting such anomalies should be recorded in dental analyses in order to, one day, obtain a more reliable modelling of the frequencies and distributions in past populations

reactivity of the drug methimazole and its iodine adduct with elemental zinc

The reactivity of zinc complexes with N,S-donor molecules may be of relevance to the study of Zn-metalloproteins and -metalloenzymes. In this context, the zinc complex [Zn(MeImSH)2I2] was synthesised by the reaction of zinc powder with the 1:1 iodine adduct of the drug methimazole [(MeImSH)·I2]. The molecular structure of the complex, elucidated by X-ray diffraction analysis, showed a tetrahedral zinc(II) centre coordinated by two neutral methimazole units (through the sulfur atoms) and two iodides. From the reaction of MeImSH and Zn powder, the complex [Zn(MeImSH)(MeImS)2] (MeImS = deprotonated form of methimazole) was separated and characterised. An analysis of the crystal packing of the neutral complexes [Zn(MeImSH)2X2] (X = I, Br and Cl) and the ionic complex [Zn(MeImSH)3I]I showed that in all of the complexes the sulfur atom, in addition to binding to the metal centre, contributes to the formation of 1-D chains built via C(4)–H⋯S and N–H⋯X interactions in the neutral complexes, and via C(4)–H⋯S and N–CH3⋯S interactions in the ionic complex [Zn(MeImSH)3I]I. The deprotonation/protonation of the coordinated methimazole units can modulate the coordination environment at the Zn core. From the reaction of complex [Zn(MeImSH)3I]I with a strong non-coordinating organic base, we have shown that, as a consequence of the NH deprotonation of methimazole S-coordinated to zinc(II), the ligand coordination mode changes from S-monodentate to N,S-bridging. Correspondingly, in the complex [Zn(MeImSH)(MeImS)2], the MeImS that displays the N,S-bridging mode at zinc can be N-protonated and thereby changes to the S-monodentate coordination

Stabilization of caesium ions by simple organic molecules: crystal structures of Cs(OXL) (OXL = oxalurate anion), and CsOH/cyanuric acid co-crystal Cs3(CYH3)4(OH)3 (CYH3 = cyanuric acid)

The reaction in water between CsOH and parabanic acid (PBH2) leads to the formation of the caesium salt of the oxalurate anion Cs(OXL), while the reaction with cyanuric acid (CYH3) leads to the formation of the CsOH co-crystal of cyanuric acid Cs3(CYH3)4(OH)3. The X-ray crystal structures of these compounds show that both the organic moieties OXL and CYH3 form robust homomeric ribbons based on strong and articulated N–HO hydrogen bonds. The stabilization of the Cs+ ions can occur regardless of whether the ribbon of organic units is negatively charged or neutral. In Cs(OXL), each cation displays nine-fold coordination with Cs–O distances in the range of 2.975(3)–3.601(4) Å; in Cs3(CYH3)4(OH)3, two of the Cs+ cations (Cs1 and Cs2) display a nine-fold coordination with Cs–O distances in the range of 3.007(9)–3.823(13) Å and one (Cs3) is ten-fold coordinated with Cs–O distances in the range of 3.161(14)– 3.653(17) Å. The molecular electrostatic potential maps of OXL and di-OXL anions have been reported and discussed

Silver(I) coordination polymers based on nitrile-functionalized mixed-donor ligands of different flexibility

The nitrile-functionalized derivatives of 2,8-dithia-5-aza-2,6-pyridinophane ([12]anePyNS2)(Py = Pyridine), 1-aza-4,7,10-trithiacyclododecane ([12]aneNS3), and N,N’-bis(2-pyridylmethyl)-propylenediamine (Pypn), referred to as L10, L11 and L12, respectively, have been prepared. Following the reaction of these ligands with silver(I) salts, the three coordination polymers (CPs) {[Ag(L10)](BF4)}∞, {[Ag(L11)](BF4)∙1⁄2MeCN}∞, and {[Ag(L12)](NO3)}∞, have been isolated and structurally characterized. The structural features of the three CPs depends more on the nature of the un-functionalized ligands rather than on the presence of the nitrile groups. A comparative analysis of the structures of the three CPs is performed in relation to the structures of polymeric silver(I) compounds obtained with nitrile-functionalized pendant arms of related aza- and mixed donor macrocyclic ligands (L1–L9) reported in the literature