Murat Turkyilmaz

Assessment of tissue viability after frostbite injury by technetium-99m-sestamibi scintigraphy in an experimental rabbit model

Abstract. Frostbite causes injury to the tissue by direct ice-crystal formation at the cellular level with cellular dehydration and microvascular occlusion. Muscle that initially appears viable on reperfusion may subsequently become necrotic because of microcirculatory collapse. Since muscle is a sensitive tissue in frostbite injury, we used technetium-99m-sestamibi limb scintigraphy to assess tissue viability in an experimental rabbit model. Twelve rabbits were used for this investigation. The right hind limb of the rabbits was immersed to the ankle joint in a container filled with 90% ethanol at –25°C for 10 min. Frostbitten limbs were allowed to thaw in air at room temperature. Imaging and pathological examination of the affected limbs were performed 2 h, 24 h, 48 h and 72 h after freezing. In 2-h images, initial hypoperfusion was seen that corresponded to circulatory collapse. In 24-h images, there was hyperperfusion (so-called period of temporary reperfusion), corresponding to circulatory restoration. In 48-h images, a second hypoperfusion corresponded to viable but ischaemic tissue. In 72-h images, there was non-perfusion of the limb that correlated with the pathologically determined diagnosis of necrosis. All scintigraphic patterns correlated with pathological findings. We suggest that these scintigraphic patterns in soft tissue may be helpful in distinguishing between frank infarction and reversible ischemia and therefore may be useful in selecting early therapeutic or surgical interventions to salvage bone and soft tissue. Further studies are needed to show the usefulness of 99mTc sestamibi scintigraphy in clinical frostbite cases.

Ternary complexes of vanadium(IV) with 4-(2-pyridylazo)-resorcinol (PAR) and ditetrazolium chlorides (DTC)

Complex formation and liquid-liquid extraction have been studied for ternary complexes of vanadium(IV) with 4-(2-pyridylazo)-resorcinol (PAR) and ditetrazolium chlorides (DTC) in a water-chloroform medium. The specific ditetrazolium compounds investigated were i) 3,3′-(4,4′-biphenylene)-bis(2,5-diphenyl-2H-tetrazolium) chloride (Neotetrazolium chloride, NTC); ii) 3,3′-(3,3′-dimetoxy-4,4′-biphenylene)-bis(2,5-diphenyl-2H-tetrazolium) chloride (Blue Tetrazolium chloride, BTC); and iii) 3,3′-(3,3′-dimetoxy-4,4′-biphenylene)-bis[2-(4-nitrophenyl)-5-phenyl-2H-tetrazolium] chloride (Nitro Blue Tetrazolium chloride, NBT). Molar absorptivity coefficients and the composition of the complexes have been calculated. Association constants (β) have also been obtained for the interactions between the vanadium(IV) — PAR anionic chelates [VO(PAR)2]2− (I) and [VO(OH)2(PAR)2]4− (II), and ditetrazolium cations (DT2+). Some special features of NBT as an extraction-spectrophotometric reagent for vanadium(IV) have been discussed. Unlike NTC and BTC which form complexes with both I and II, NBT associates only with II. The pH interval for complete extraction of (NBT2+)2[VO(OH)2(PAR)2] is broader and allows work at lower pH values the other ion-associates of V(IV,V)-PAR that were studied. NBT is -therefore the appropriate reagent both for direct V(IV) determination and for V(IV)/V(V) separation. Some additional characteristics for the V(IV)-PAR-NBT-water-chloroform system have been determined: extraction constant, distribution constant, recovery factor, limit of detection and limit of quantification. Beer’s law is valid up to 1.4 μg mL−1 vanadium(IV) with molar absorptivity coefficient of 3.55×104 L mol−1 cm−1 at λmax=559 nm.

Synthesis, spectroscopic, and thermal properties of some azomethine complexes of Cu(II), Ni(II), and Pt(II)

Four polydentate azomehines and their mono- and binuclear Pt(II), Cu(II), and Ni(II) complexes were synthesized and characterized. The resulting complexes were characterized by FTIR, magnetic measurements, elemental analysis, conductivity measurements, and thermal analysis. Electronic spectra and magnetic susceptibility measurements sustain the proposed distorted square-planar structures for the copper complexes. The electronic spectra display the characteristic pattern of square-planar stereochemistry for the other complexes. The thermal analyses have evidenced the thermal intervals of stability and also the thermodynamic effects that accompany them. Azomethine complexes have a similar thermal behavior for the selected metal ions. The decomposition processes as water elimination, chloride anion removal as well as degradation of the organic ligands were observed.

Complexation, thermal and catalytic studies of N-substituted piperazine, morpholine and thiomorpholine with some metal ions

Several Cu(II), Pt(II) and Ni(II) complexes of N-substituted, piperazine (NN donor), morpholine (NO donor) and thiomorpholine (NS donor) derivatives were synthesized and their thermal behavior and catalytic activity in epoxidation reaction of cis-diphenylethylene were studied using oxygen sources NaOCl. The coordination compounds of Cu(II), Pt(II) and Ni(II) having general formula [MLCl]Cl, [ML2l]Cl2 or [ML]Cl2 with tetra coordinated geometry around metal ions have been isolated as solid. All the ligands and complexes were identified by spectroscopic methods and elemental analysis, magnetic measurements, electrical conductance and thermal analysis. A square planer structures have been proposed for all complexes. The thermal stability of the complexes discussed in terms of ligands donor atoms, geometry and central metal ions. The complexes have a similar thermal behavior for the selected metal ions. The thermogravimetric analyses suggest high thermal stability for most complexes followed by thermal decomposition in different steps. The decomposition processes were observed as water elimination, chloride anion removal and degradation of the organic ligands. Catalytic ability of the complexes were examined and found that all the complexes can effectively catalyze the epoxidation of cis-stilbene with NaOCl.

Synthesis, spectroscopic characterization, X-ray structure and DFT studies on 4-(2-hydroxyphenyl)-4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridin-5-ium chloride hydrate.

The title molecular salt, 4-(2-hydroxyphenyl)-4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridin-5-ium chloride hydrate (C(12)H(14)N(3)O(+)·Cl-·H(2)O), was synthesized and characterized by IR-NMR spectroscopy and single-crystal X-ray diffraction. In addition to the molecular geometry from X-ray experiment, the molecular geometry, vibrational frequencies and gauge-independent atomic orbital (GIAO) (1)H and (13)C NMR chemical shift values of the title compound in the ground state have been calculated using the density functional theory (DFT/B3LYP) method with the 6-31++G(d,p) and 6-311++G(d,p) basis sets, and compared with the experimental data. Besides, molecular electrostatic potential (MEP) distribution and non-linear optical properties of the title compound were investigated by theoretical calculations at the B3LYP/6-311++G(d,p) level.

Spectroscopic and structural properties of N-(acetamide) morpholinium bromide.

A new crystal of N-(acetamide) morpholinium (NAM) bromide has been prepared in methanol at room temperature and characterized by single crystal X-ray analysis, elemental analysis, GS-MS, FTIR, NMR((1)H,(13)C, DEPTH and HETCOR). The N-(acetamide) morpholinium crystallizes in the orthorhombic crystal system, Pnma with unit cell a=12.798(9) Å, b=7.222(5) Å, c=9.244(5) Å, β=90.00, V=854.4(9) Å(3), Z=4. The X-ray structure determination revealed that there are strong inner and intermolecular hydrogen bonds in the crystal.

Structure, Spectroscopic, Magnetic, Fluorescence, and Thermal Studies of Bis(perchlorate)tetrakis(pyrazole)copper(II)

The complex bis(perchlorate)tetrakis(pyrazole)copper(II) has been prepared and characterized by single crystal X-ray analysis, FT-IR, UV-VIS spectroscopy and thermal methods. [Cu(ClO4)2(pyzl)4] crystallizes in the monoclinic system, space group C2/c, with a = 14.5186(11), b = 9.9513(7), c = 15.8564(11) Å, β = 115.5290(10)° V = 2067.2(3) Å3 and z = 4. The molecular and crystal structure are stabilized by inter and intra molecular hydrogen bonds. The complex formation kinetics was studied at 310 nm. The activation parameters of the complex formation kinetics were determined as, ΔH#: 200 kJ/mol, ΔS#: 268 J/K. mol. The FT-IR spectra has been measured and assigned in the range of 4000-400 cm−1. The Cl-O and N-H stretching vibrations confirms the presence of intramolecular hydrogen bonds. The magnetic moment of the complex was found to be 1.73 BM. The fluorescence quenching of pyrazole by Copper(II) was also studied in methanol.

1,1'-(Piperazine-1,4-di-yl)dipropan-2-ol.

The asymmetric unit of the crystal contains one-fourth of the title compound, C10H22N2O2, with the centre of the piperazine ring located at a site of 2/m symmetry. The piperazine ring adopts a chair conformation. The methine and methylene C atoms of the 2-hydroxypropyl groups show symmetry-imposed disorder over two equally occupied and mutually exclusive sets of positions. Only intramolecular O—H⋯N contacts are observed.

Synthesis, Structural Analysis, and Biological Activities of Some Imidazolium Salts

Four newly synthesized imidazolium salts were characterized by nuclear magnetic resonance, vibrational spectra, and mass spectra. Then, the density functional theory calculations were performed to obtain the molecular configurations on which the theoretical nuclear magnetic resonance and infrared spectra were consequently obtained. The comparison of calculated spectra with the experimental spectra for each molecule leads to the conclusion that the theoretical results can be assumed to be a good approach to their molecular configurations. The in vitro biological activities of the salts on the selected bacteria and cancer cell lines were determined by using the broth dilution method according to Clinical and Laboratory Standards Institute guidelines. The 1,3-bis(2-hydroxyethyl) imidazolidinium bromide and 3-(2-ethoxy-2-oxoethly)-1-(3-aminopropyl)-1H-imidazol-3-ium bromide showed efficiency on Bacillus cereus ATCC 11778. The 3-bis(2-carboxyethyl)-4-methyl-1-H-imidazol-3-ium bromide was effective on HeLa while a similar effect was observed on Hep G2 with 3-(2-carboxyethyl)-1-(3-aminopropyl)-1H-imidazol-3-ium bromide.

Binuclear and mononuclear Cu(II) and Ni(II) complexes of tetra- and hexadentate ligands

Two tetradentate ligands, 1,2-bis(2-hydroxyethylthio)ethane S2O2 (L1) and N,N′-bis(2-hydoxypropyl)piperazine N2O2 (L2), were prepared by organization of some mononuclear complexes of Cu(II) and Ni(II). A new binuclear Schiff base ligand with a 1,4-dipropoxybutane spacer provided by the reaction of salicylaldehyde and 1,4-bis(3-aminopropoxy)butane served as an octadentate, N2O4 (L3) ligand, in designing some binuclear complexes with metal ions. All the ligands were characterized by elemental analyses, FTIR, 1H and 13C NMR and GC–MS. The complexes were characterized by elemental analyses, FTIR, thermal methods, electronic spectra, conductivity and magnetic measurements. The metal ions coordinate to the ligands with four donor atoms in square planar geometry. The thermal stabilities of the complexes were discussed in terms of metal ions and type of donor atoms. The complexes were characterized by electronic spectra and magnetic susceptibility measurements to establish the proposed four-coordinated square planar geometry. The TG chart indicates high thermal stability for complexes. The decomposition processes consisted of three stages: The first two stages involve the loss of water and chloride anions and the last stage indicates degradation of the organic ligands. The antifungal activity of the ligands and their complexes was tested against several fungal species: Aspergillus nigar, Aspergillus flavus and Candida albicans. The results show that complexes have significant antifungal activities compared to their parent ligands.