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Sample records for ii malformation pt

  1. Visual Fixation in Chiari Type II Malformation

    PubMed Central

    Salman, Michael S.; Sharpe, James A.; Lillakas, Linda; Dennis, Maureen; Steinbach, Martin J.

    2011-01-01

    Chiari type II malformation is a congenital deformity of the hindbrain. Square wave jerks are horizontal involuntary saccades that interrupt fixation. Cerebellar disorders may be associated with frequent square wave jerks or saccadic oscillations such as ocular flutter. The effects of Chiari type II malformation on visual fixation are unknown. We recorded eye movements using an eye tracker in 21 participants with Chiari type II malformation, aged 8 to 19 years while they fixated a target for 1 minute. Thirty-eight age-matched healthy participants served as controls. Square wave jerks’ parameters were similar in the 2 groups. Saccadic oscillations were not seen. Chiari type II malformation is not associated with pathological square wave jerks or abnormal saccadic oscillations. The congenital nature of this deformity may permit compensation that preserves stable visual fixation. Alternatively, the deformity of Chiari type II malformation may spare parts of the cerebellum that usually cause fixation instability when damaged. PMID:19182152

  2. Type II congenital pulmonary airway malformation in an esophageal lung

    PubMed Central

    Martínez-Martínez, Blanca Estela; Furuya, María Elena Yuriko; Martínez-Muñiz, Irma; Vargas, Mario H; Flores-Salgado, Rosalinda

    2013-01-01

    A seven-month-old girl, born prematurely (birth weight 1000 g) from a twin pregnancy, was admitted to hospital due to recurrent pneumonia and atelectasis. She experienced cough and respiratory distress during feeding. The right hemithorax was smaller than the left, with diminished breath sounds and dullness. Chest x-rays revealed decreased lung volume and multiple radiolucent images in the right lung, as well as overdistention of the left lung. An esophagogram revealed three bronchial branches arising from the lower one-third of the esophagus, corresponding to the right lung and ending in a cul-de-sac. A diagnosis of esophageal lung was established. On bronchography, the right lung was absent and the trachea only continued into the left main bronchus. Echocardiography and angiotomography revealed agenesis of the pulmonary artery right branch. The surgical finding was an esophageal right lung, which was removed; the histopathological diagnosis was type II congenital pulmonary airway malformation in an esophageal lung. PMID:23762890

  3. Presentation and management of hydromyelia in children with Chiari type-II malformation.

    PubMed

    La Marca, F; Herman, M; Grant, J A; McLone, D G

    1997-02-01

    Hydromyelia in patients with myelomeningocele and Chiari-II malformation is a relatively frequent finding on MRI studies. However, not all children develop symptoms from the hydromyelia that requires treatment. Furthermore, treatment of hydromyelia in spina bifida patients is rather complex due to the associated malformations. The authors retrospectively analyzed 231 MRI studies carried out on spina bifida patients who presented neurological deterioration. Hydromyelia was found in 48.5% of the patients. Forty-five children with severe hydromyelia required treatment. These patients were first divided into 2 groups: those with holocord hydromyelia, and those with a segmental lesion. Fifteen patients presented symptoms characteristic of symptomatic Chiari-II malformation: neck rigidity; swallowing difficulty; pain in the upper extremeties; weakness or spasticity in the upper extremeties. Eighteen patients presented symptoms typical of the tethered cord syndrome: scoliosis; worsening bladder and/or bowel function; pain in the lower extremeties; weakness or spasticity in the lower extremeties. Twelve patients presented a mixed-type symptomatology. These patients subsequently underwent posterior cervical decompression, tethered cord release or insertion of a hydromyelia-pleural shunt according to the type of presenting symptoms and to the extent of the hydromyelic lesion. A pattern of successful treatment was identified for each type of presenting clinical and radiological picture. This has allowed the authors to determine an algorithm for optimal treatment of hydromyelia associated with Chiari-II malformation and myelomeningocele, which is proposed here. PMID:9419035

  4. Bis(thiosemicarbazonato) chelates of Co(II), Ni(II), Cu(II), Pd(II) and Pt(II)

    NASA Astrophysics Data System (ADS)

    Chandra, Sulekh; Singh, R.

    1985-01-01

    Bis chelates of Co(II), Ni(II), Cu(II), Pd(II) and Pt(II) with the enolic form of diethyl ketone and methyl n-propyl thiosemicarbazones were synthesized and characterized by elemental analyses, magnetic moments, i.r. and electronic and electron spin resonance spectral studies. All the complexes were found to have the composition ML 2 [where M = Co(II), Ni(II), Cu(II), Pd(ii) and Pt(II) and L = thiosemicarbazones of diethyl ketone and methyl n-propyl ketone]. Co(II) and Cu(II) complexes are paramagnetic and may have polymeric six-coordinate octahedral and square planar geometries, respectively. The Ni(II), Pd(II) and Pt(II) complexes are diamagnetic and may have square planar geometries. Pyridine adducts (ML 2·2Py) of Ni(II) and Cu(II) complexes were also prepared and characterized.

  5. Accurate energy levels for singly ionized platinum (Pt II)

    NASA Technical Reports Server (NTRS)

    Reader, Joseph; Acquista, Nicolo; Sansonetti, Craig J.; Engleman, Rolf, Jr.

    1988-01-01

    New observations of the spectrum of Pt II have been made with hollow-cathode lamps. The region from 1032 to 4101 A was observed photographically with a 10.7-m normal-incidence spectrograph. The region from 2245 to 5223 A was observed with a Fourier-transform spectrometer. Wavelength measurements were made for 558 lines. The uncertainties vary from 0.0005 to 0.004 A. From these measurements and three parity-forbidden transitions in the infrared, accurate values were determined for 28 even and 72 odd energy levels of Pt II.

  6. Oxidation of Half-Lantern Pt2(II,II) Compounds by Halocarbons. Evidence of Dioxygen Insertion into a Pt(III)-CH3 Bond.

    PubMed

    Sicilia, V; Baya, M; Borja, P; Martín, A

    2015-08-01

    The half-lantern compound [{Pt(bzq)(μ-N^S)}2] (1) [bzq = benzo[h]quinoline, HN^S = 2-mercaptopyrimidine (C4H3N2HS)] reacts with CH3I and haloforms CHX3 (X = Cl, Br, I) to give the corresponding oxidized diplatinum(III) derivatives [{Pt(bzq)(μ-N^S)X}2] (X = Cl 2a, Br 2b, I 2c). These compounds exhibit half-lantern structures with short intermetallic distances (∼2.6 Å) due to Pt-Pt bond formation. The halogen abstraction mechanisms from the halocarbon molecules by the Pt2(II,II) compound 1 were investigated. NMR spectroscopic evidence using labeled reagents support that in the case of (13)CH3I the reaction initiates with an oxidative addition through an SN2 mechanism giving rise to the intermediate species [I(bzq)Pt(μ-N^S)2Pt(bzq)((13)CH3)}]. However, with haloforms the reactions proceed through a radical-like mechanism, thermally (CHBr3, CHI3) or photochemically (CHCl3) activated, giving rise to mixtures of species [X(bzq)Pt(μ-N^S)2Pt(bzq)R] (3a-c) and [X(bzq)Pt(μ-N^S)2Pt(bzq)X] (2a-c). In these cases the presence of O2 favors the formation of species 2 over 3. Transformation of 3 into 2 was possible upon irradiation with UV light. In the case of [I(bzq)Pt(μ-N^S)2Pt(bzq)((13)CH3)}] (3d), in the presence of O2 the formation of the unusual methylperoxo derivative [I(bzq)Pt(μ-N^S)2Pt(bzq)(O-O(13)CH3)}] (4d) was detected, which in the presence of (13)CH3I rendered the final product [{Pt(bzq)(μ-N^S)I}2] (2c) and (13)CH3OH. PMID:26197039

  7. Toxic variability and radiation sensitization by Pt(II) analogs in Salmonella typhimurium cells

    SciTech Connect

    Richmond, R.C.; Khokhar, A.R.; Teicher, B.A.; Douple, E.B.

    1984-09-01

    A rationale is presented for the development of toxic, i.e., cytocidal, antitumor drugs as clinical hypoxic cell radiation sensitizers. Pt(II) complex-induced hypoxic cell radiation sensitization may occur from Pt(II) complex in free solution and Pt(II) bound to DNA. Although both the free solution and the bound compartments may operate, the free solution compartment is more likely amenable to experimental and clinical control in the case of systemically active Pt drugs. Assuming equivalent cell uptake of different Pt(II) complexes, the free solution compartment of Pt(II) sensitization can be increased by utilizing less toxic analogs of the antitumor drug cis-dichlorodiammineplatinum(II). One such less toxic Pt(II) sensitizer currently in clinical use is found to be cis-(1,1-cyclobutanedicarboxylato)diammineplatinum(II). A new finding of both clinical and mechanistic usefulness is described: irradiation of hypoxic solutions of four cis-Pt(II) complexes, but not two trans-Pt(II) complexes, creates products that cause toxicity in excees of the unirradiated solutions.

  8. Probing the solvent shell with 195Pt chemical shifts: density functional theory molecular dynamics study of Pt(II) and Pt(IV) anionic complexes in aqueous solution.

    PubMed

    Truflandier, Lionel A; Autschbach, Jochen

    2010-03-17

    Ab initio molecular dynamics (aiMD) simulations based on density functional theory (DFT) were performed on a set of five anionic platinum complexes in aqueous solution. (195)Pt nuclear magnetic shielding constants were computed with DFT as averages over the aiMD trajectories, using the two-component relativistic zeroth-order regular approximation (ZORA) in order to treat relativistic effects on the Pt shielding tensors. The chemical shifts obtained from the aiMD averages are in good agreement with experimental data. For Pt(II) and Pt(IV) halide complexes we found an intermediate solvent shell interacting with the complexes that causes pronounced solvent effects on the Pt chemical shifts. For these complexes, the magnitude of solvent effects on the Pt shielding constant can be correlated with the surface charge density. For square-planar Pt complexes the aiMD simulations also clearly demonstrate the influence of closely coordinated non-equatorial water molecules on the Pt chemical shift, relating the structure of the solution around the complex to the solvent effects on the metal NMR chemical shift. For the complex [Pt(CN)(4)](2-), the solvent effects on the Pt shielding constant are surprisingly small. PMID:20166712

  9. The Vestibulo-ocular Reflex During Active Head Motion in Chiari II Malformation

    PubMed Central

    Salman, Michael S.; Sharpe, James A.; Lillakas, Linda; Dennis, Maureen; Steinbach, Martin J.

    2008-01-01

    Background Chiari type II malformation (CII) is a developmental anomaly of the cerebellum and brainstem, which are important structures for processing the vestibulo-ocular reflex (VOR). We investigated the effects of the deformity of CII on the angular VOR during active head motion. Methods Eye and head movements were recorded using an infrared eye tracker and magnetic head tracker in 20 participants with CII [11 males, age range 8-19 years, mean (SD) 14.4 (3.2) years]. Thirty-eight age-matched healthy children and adolescents (21 males) constituted the control group. Participants were instructed to ‘look’ in darkness at the position of their thumb, placed 25 cm away, while they made horizontal and vertical sinusoidal head rotations at frequencies of about 0.5 Hz and 2 Hz. Parametric and non-parametric tests were used to compare the two groups. Results The VOR gains, the ratio of eye to head velocities, were abnormally low in two participants with CII and abnormally high in one participant with CII. Conclusion The majority of participants with CII had normal VOR performance in this investigation. However, the deformity of CII can impair the active angular VOR in some patients with CII. Low gain is attributed to brainstem damage and high gain to cerebellar dysfunction. PMID:18973069

  10. Reactions of Pd(II) and Pt(II) Complexes With Tetraethylthiouram Disulfide

    PubMed Central

    Cervantes, G.; Molins, E.; Miravitlles, C.

    1997-01-01

    The reactions of tetraethylthiouram disulfide (DTS), an inhibitor of the nephrotoxicity of Pt(II) drugs, an efficient agent in the treatment of chronic alcoholism, in the treatment of HIV infections, AIDS and heavy metal toxicity, and a fungicide and herbicide, with K2[PtCl4], in ratio 1:1 and 1:2, gave the compounds [PtCl2DTS] and [Pt(S2CNEt2)2] respectively. The reaction of the complexes K2[PdCl4], Pd(AcO)2 and [PdCl2(PhCN)2], where PhCN = Benzonitrile, with tetraethylthiouram disulfide in ratio 1:1 or 1:2, yielded orange crystals identified as [Pd(S2CNEt2)2]. The crystals were suitable for study by X-ray diffraction. The -S-S- bridge in the tetraethylthiouram disulfude molecule was broken and the two molecules of the thiocarbamate derivative were bound to the Pd(II) by the equivalents sulfur atoms. All the compounds were characterized by IR, 1H and 13C NMR spectroscopies. PMID:18475812

  11. Arnold‐Chiari‐II malformation and cognitive functioning in spina bifida

    PubMed Central

    Vinck, A; Maassen, B; Mullaart, R; Rotteveel, J

    2006-01-01

    Spina bifida is a multifaceted neurological condition with complex neuropsychological sequelae. The cognitive outcome in spina bifida has frequently been attributed to the severity of the hydrocephalus. However, because of complex neuropathology, the influence of hydrocephalus alone does not sufficiently explain the deficits in the cognitive profile in spina bifida. To date, little is known of the role of Arnold‐Chiari‐II malformation (ACM) in the cognitive profile of these patients. Aim of the current study is to delineate the specific contribution of the ACM in spina bifida by comparing children with ACM and those without ACM. 46 children between 6 and 15 years of age underwent a neuropsychological assessment covering intelligence and a wide range of cognitive functions, such as visuo‐motor processing, attention, memory, word fluency and speed of information processing. Comparisons were made between patients with ACM (ACM+) and those without ACM (ACM−); all children with ACM+ also had hydrocephalus. Confounding effects of global cognitive impairment were excluded, such that groups were matched on verbal IQ. Because of complex neuropathology, which is inherent to spina bifida, the method applied was based on a comparison of cognitive profiles of the study group with profiles of patients with cerebellar damage and hydrocephalus found in the literature. Impaired visual analysis and synthesis, verbal memory, and verbal fluency, even after correction for global cognitive impairment, were observed in children with ACM. The hypothesis that in addition to impairment in visual analysis and synthesis, which are related to both hydrocephalus and ACM, specific deficiencies in verbal memory and fluency may be attributed to ACM is supported. PMID:16690692

  12. Computational molecular characterization of the flavonoid Morin and its Pt(II), Pd(II) and Zn(II) complexes.

    PubMed

    Payán-Gómez, Sergio A; Flores-Holguín, Norma; Pérez-Hernández, Antonino; Piñón-Miramontes, Manuel; Glossman-Mitnik, Daniel

    2011-05-01

    In this work, we make use of a model chemistry within density functional theory (DFT) recently presented, which is called M05-2X, to calculate the molecular structure of the flavonoid Morin and its Pt(II), Pd(II) and Zn(II) complexes, as well to predict their IR and UV-Vis spectra, the dipole moment and polarizability, the free energy of solvation in different solvents as an indication of solubility, the HOMO and LUMO orbitals, and the chemical reactivity parameters that arise from Conceptual DFT. The calculated values are compared with the available experimental data for these molecules. PMID:20628776

  13. A theoretical study of an unusual Y-shaped three-coordinate Pt complex: Pt(0) σ-disilane complex or Pt(II) disilyl complex?

    PubMed

    Takagi, Nozomi; Sakaki, Shigeyoshi

    2012-07-18

    The unusual Y-shaped structure of the recently reported three-coordinate Pt complex Pt[NHC(Dip)(2)](SiMe(2)Ph)(2) (NHC = N-heterocyclic carbene; Dip = 2,6-diisopropylphenyl) was considered a snapshot of the reductive elimination of disilane. A density functional theory study indicates that this structure arises from the strong trans influence of the extremely σ-donating carbene and silyl ligands. Though this complex can be understood to be a Pt(II) disilyl complex bearing a distorted geometry due to the Jahn-Teller effect, its (195)Pt NMR chemical shift is considerably different from those of Pt(II) complexes but close to those of typical Pt(0) complexes. Its Si···Si bonding interaction is ~50% of the usual energy of a Si-Si single bond. The interaction between the Pt center and the (SiMe(2)Ph)(2) moiety can be understood in terms of donation and back-donation interactions of the Si-Si σ-bonding and σ*-antibonding molecular orbitals with the Pt center. Thus, we conclude that this is likely a Pt(0) σ-disilane complex and thus a snapshot after a considerable amount of the charge transfer from disilane to the Pt center has occurred. Phenyl anion (Ph(-)) and [R-Ar](-) [R-Ar = 2,6-(2,6-iPr(2)C(6)H(3))(2)C(6)H(3)] as well as the divalent carbon(0) ligand C(NHC)(2) also provide similar unusual Y-shaped structures. Three-coordinate digermyl, diboryl, and silyl-boryl complexes of Pt and a disilyl complex of Pd are theoretically predicted to have similar unusual Y-shaped structures when a strongly donating ligand coordinates to the metal center. In a trigonal-bipyramidal Ir disilyl complex [Ir{NHC(Dip)(2)}(PH(3))(2)(SiMe(3))(2)](+), the equatorial plane has a similar unusual Y-shaped structure. These results suggest that various snapshots can be shown for the reductive eliminations of the Ge-Ge, B-B, and B-Si σ-bonds. PMID:22680620

  14. High pressure Raman spectroscopic studies of Pt(II) complex trans-PtCl2(PEt3)2

    NASA Astrophysics Data System (ADS)

    Bajaj, Naini; Poswal, H. K.; Bhatt, Himal; Deo, M. N.; Sharma, Surinder M.

    2016-05-01

    We report here the high pressure Raman spectroscopy of the Pt(II) complex trans-PtCl2(P(C2H5)3)2 up to 5 GPa. We have analyzed the metal-ligand stretching modes as well as ligand internal vibrational modes of the complex under pressure. Many characteristic Raman modes show pressure induced splitting at pressures as low as 1 GPa. On careful analysis of the skeletal region, the new modes appeared could be corroborated with the position of corresponding modes in the infrared spectrum, thus indicating a loss of inversion symmetry in the trans- isomer.

  15. Tunable Excited-State Properties and Dynamics as a Function of Pt-Pt Distance in Pyrazolate-Bridged Pt(II) Dimers.

    PubMed

    Brown-Xu, Samantha E; Kelley, Matthew S J; Fransted, Kelly A; Chakraborty, Arnab; Schatz, George C; Castellano, Felix N; Chen, Lin X

    2016-02-01

    The influence of molecular structure on excited-state properties and dynamics of a series of cyclometalated platinum dimers was investigated through a combined experimental and theoretical approach using femtosecond transient absorption (fs TA) spectroscopy and density functional theory (DFT) calculations. The molecules have the general formula [Pt(ppy)(μ-R2pz)]2, where ppy = 2-phenylpyridine, pz = pyrazolate, and R = H, Me, Ph, or (t)Bu, and are strongly photoluminescent at room temperature. The distance between the platinum centers in this A-frame geometry can be varied depending on the steric bulk of the bridging pyrazolate ligands that exert structural constraints and compress the Pt-Pt distance. At large Pt-Pt distances there is little interaction between the subunits, and the chromophore behaves similar to a monomer with excited states described as mixtures of ligand-centered and metal-to-ligand charge transfer (LC/MLCT) transitions. When the Pt(II) centers are brought closer together with bulky bridging ligands, they interact through their dz(2) orbitals and the S1 and T1 states are best characterized as metal-metal-to-ligand charge transfer (MMLCT) in character. The results of the femtoseconds TA experiments reveal that intersystem crossing (ISC) occurs on ultrafast time scales (τS1 < 200 fs), while there are two relaxation processes occurring within the triplet manifold, τ1 = 0.5-3.2 ps and τ2 = 20-70 ps; the longer time constants correspond to the presence of bulkier bridging ligands. DFT calculations illustrate that the Pt-Pt distances further contract in the T1 (3)MMLCT states; therefore, slower relaxation may be related to a larger structural reorganization. Subsequent investigations using faster time resolution are planned to measure the ISC process as well as to identify any potential coherent interaction(s) between the platinum centers that may occur. PMID:26759897

  16. Molecular tectonics: heterometallic coordination networks based on a Pt(II) organometallic metallatecton.

    PubMed

    Zigon, Nicolas; Kyritsakas, Nathalie; Hosseini, Mir Wais

    2015-08-28

    Combinations of a neutral organometallic tecton based on a square planar Pt(ii) complex bearing two triphenylphosphine groups and two 4-ethynylpyridyl coordinating moieties in trans positions, with various metal halides (MX2, M = Co(ii), Ni(ii), Cd(ii), X = Cl(-) or Br(-)) lead to the formation of 2D grid type heterobimetallic coordination networks in the crystalline phase. PMID:26204438

  17. Amphibian malformations

    USGS Publications Warehouse

    National Wildlife Health Center

    1998-01-01

    Frog malformations have been reported from 42 states. The broad geographic distribution of these malformations warrants national attention. Scientists at the USGS National Wildlife Health Center in Madison, Wisconsin are studying this problem in an effort to document its scope and to determine the causes of the observed malformations.

  18. FT-Raman spectroscopy of structural isomers of Pt(II) complex PtCl2(PEt3)2

    NASA Astrophysics Data System (ADS)

    Bhatt, Himal; Deo, M. N.; Vishwakarma, S. R.; Bajaj, Naini; Sharma, Surinder M.

    2015-06-01

    We report here the detailed spectroscopic aspects of the structural isomers of Pt(II) complex PtCl2(P(C2H5)3)2 using FT-Raman spectroscopy. A comparison of the structural contraction instigated by lowering the temperature up to liquid nitrogen temperature in the cis and trans isomers has been presented. The lattice region lying in the far infrared region upto 50cm-1 has been analyzed in detail to probe the structural modifications. It was found that the ambient temperature lower symmetry structure of the cis isomer is preserved at low temperatures. The trans isomer, stabilizing in a high symmetry structure at room temperature, transforms to a low symmetry structure on lowering the temperature, which can be attributed to a loss of inversion symmetry of the trans isomer.

  19. Intracranial vascular malformations: imaging of charged-particle radiosurgery. Part II. Complications

    SciTech Connect

    Marks, M.P.; Delapaz, R.L.; Fabrikant, J.I.; Frankel, K.A.; Phillips, M.H.; Levy, R.P.; Enzmann, D.R.

    1988-08-01

    Seven of 24 patients with intracranial vascular malformations who were treated with helium-ion Bragg-peak radiosurgery had complications of therapy. New symptoms and corresponding radiologic abnormalities developed 4-28 months after therapy. Five patients had similar patterns of white matter changes and mass effect on computed tomographic scans and magnetic resonance images. The abnormalities were centered in the radiation field. Gray matter changes and abnormal enhancement in the thalamus and hypothalamus outside the radiation field developed in one patient. This patient also had vasculopathic changes on angiograms. Rapidly progressive large vessel vasculopathy developed in another patient and caused occlusion of major vessels. Thus, different mechanisms may be involved in the complications of heavy-ion radiosurgery.

  20. Synthesis and Antiproliferative Activity of Steroidal Thiosemicarbazone Platinum (Pt(II)) Complexes.

    PubMed

    Huang, Yanmin; Kong, Erbin; Gan, Chunfang; Liu, Zhiping; Lin, Qifu; Cui, Jianguo

    2015-01-01

    Steroidal compounds exhibit particular physiological activities. In this paper, some steroidal thiosemicarbazones platinum (Pt(II)) complexes were synthesized by the condensation of steroidal ketones with thiosemicarbazide using estrone, chenodeoxycholic acid, and 7-deoxycholic acid as starting materials and complexation of steroidal thiosesemicarbazones with Pt(II). The complexes were characterized by IR, NMR, and MS, and their antiproliferative activities were evaluated. The results showed that some steroidal thiosemicarbazones platinum (Pt(II)) complexes displayed moderate cytotoxicity to HeLa and Bel-7404 cells. Thereinto, complex 6 showed an excellent inhibited selectivity to HeLa cells with an IC50 value of 9.2 μM and SI value of 21.7. At the same time, all compounds were almost inactive to HEK293T (normal kidney epithelial cells). The information obtained from the studies may be useful for the design of novel chemotherapeutic drugs. PMID:26635511

  1. Synthesis and Antiproliferative Activity of Steroidal Thiosemicarbazone Platinum (Pt(II)) Complexes

    PubMed Central

    Huang, Yanmin; Kong, Erbin; Gan, Chunfang; Liu, Zhiping; Lin, Qifu; Cui, Jianguo

    2015-01-01

    Steroidal compounds exhibit particular physiological activities. In this paper, some steroidal thiosemicarbazones platinum (Pt(II)) complexes were synthesized by the condensation of steroidal ketones with thiosemicarbazide using estrone, chenodeoxycholic acid, and 7-deoxycholic acid as starting materials and complexation of steroidal thiosesemicarbazones with Pt(II). The complexes were characterized by IR, NMR, and MS, and their antiproliferative activities were evaluated. The results showed that some steroidal thiosemicarbazones platinum (Pt(II)) complexes displayed moderate cytotoxicity to HeLa and Bel-7404 cells. Thereinto, complex 6 showed an excellent inhibited selectivity to HeLa cells with an IC50 value of 9.2 μM and SI value of 21.7. At the same time, all compounds were almost inactive to HEK293T (normal kidney epithelial cells). The information obtained from the studies may be useful for the design of novel chemotherapeutic drugs. PMID:26635511

  2. Indole-7-carbaldehyde thiosemicarbazone as a flexidentate ligand toward ZnII, CdII, PdII and PtII ions: cytotoxic and apoptosis-inducing properties of the PtII complex.

    PubMed

    Ibrahim, Abeer A; Khaledi, Hamid; Hassandarvish, Pouya; Mohd Ali, Hapipah; Karimian, Hamed

    2014-03-14

    A new thiosemicarbazone (LH2) derived from indole-7-carbaldehyde was synthesized and reacted with Zn(II), Cd(II), Pd(II) and Pt(II) salts. The reactions with zinc and cadmium salts in 2 : 1 (ligand-metal) molar ratio afforded complexes of the type MX2(LH2)2, (X = Cl, Br or OAc), in which the thiosemicarbazone acts as a neutral S-monodentate ligand. In the presence of potassium hydroxide, the reaction of LH2 with ZnBr2 resulted in deprotonation of the thiosemicarbazone at the hydrazine and indole nitrogens to form Zn(L)(CH3OH). The reaction of LH2 with K2PdCl4 in the presence of triethylamine, afforded Pd(L)(LH2) which contains two thiosemicarbazone ligands: one being dianionic N,N,S-tridentate while the other one is neutral S-monodentate. When PdCl2(PPh3)2 was used as the Pd(II) ion source, Pd(L)(PPh3) was obtained. In a similar manner, the analogous platinum complex, Pt(L)(PPh3), was synthesized. The thiosemicarbazone in the latter two complexes behaves in a dianionic N,N,S-tridentate fashion. The platinum complex was found to have significant cytotoxicity toward four cancer cells lines, namely MDA-MB-231, MCF-7, HT-29, and HCT-116 but not toward the normal liver WRL-68 cell line. The apoptosis-inducing properties of the Pt complex was explored through fluorescence microscopy visualization, DNA fragmentation analysis and propidium iodide flow cytometry. PMID:24442181

  3. Exploring excited states of Pt(II) diimine catecholates for photoinduced charge separation.

    PubMed

    Scattergood, Paul A; Jesus, Patricia; Adams, Harry; Delor, Milan; Sazanovich, Igor V; Burrows, Hugh D; Serpa, Carlos; Weinstein, Julia A

    2015-07-14

    The intense absorption in the red part of the visible range, and the presence of a lowest charge-transfer excited state, render Platinum(II) diimine catecholates potentially promising candidates for light-driven applications. Here, we test their potential as sensitisers in dye-sensitised solar cells and apply, for the first time, the sensitive method of photoacoustic calorimetry (PAC) to determine the efficiency of electron injection in the semiconductor from a photoexcited Pt(II) complex. Pt(II) catecholates containing 2,2′-bipyridine-4,4′-di-carboxylic acid (dcbpy) have been prepared from their parent iso-propyl ester derivatives, complexes of 2,2′-bipyridine-4,4′-di-C(O)OiPr, (COOiPr)2bpy, and their photophysical and electrochemical properties studied. Modifying diimine Pt(II) catecholates with carboxylic acid functionality has allowed for the anchoring of these complexes to thin film TiO2, where steric bulk of the complexes (3,5-di(t)Bu-catechol vs. catechol) has been found to significantly influence the extent of monolayer surface coverage. Dye-sensitised solar cells using Pt(dcbpy)((t)Bu2Cat), 1a, and Pt(dcbpy)(pCat), 2a, as sensitisers, have been assembled, and photovoltaic measurements performed. The observed low, 0.02–0.07%, device efficiency of such DSSCs is attributed at least in part to the short excited state lifetime of the sensitisers, inherent to this class of complexes. The lifetime of the charge-transfer ML/LLCT excited state in Pt((COO(I)Pr)2bpy)(3,5-di-(t)Bu-catechol) was determined as 250 ps by picosecond time-resolved infrared spectroscopy, TRIR. The measured increase in device efficiency for 2a over 1a is consistent with a similar increase in the quantum yield of charge separation (where the complex acts as a donor and the semiconductor as an acceptor) determined by PAC, and is also proportional to the increased surface loading achieved with 2a. It is concluded that the relative efficiency of devices sensitised with these particular

  4. Novel Pt(II) complexes containing pyrrole oxime; synthesis, characterization and DNA binding studies

    NASA Astrophysics Data System (ADS)

    Erdogan, Deniz Altunoz; Özalp-Yaman, Şeniz

    2014-05-01

    Since the discovery of anticancer activity and subsequent clinical success of cisplatin (cis-[PtCl2(NH3)2]), platinum-based compounds have since been widely synthesized and studied as potential chemotherapeutic agents. In this sense, three novel nuclease active Pt(II) complexes with general formula; [Pt(NH3)Cl(L)] (1), [Pt(L)2] (2), and K[PtCl2(L)] (3) in which L is 1-H-pyrrole-2-carbaldehyde oxime were synthesized. Characterization of complexes was performed by elemental analysis, FT-IR, 1H NMR and mass spectroscopy measurements. Interaction of complexes (1-3) with calf thymus deoxyribonucleic acid (ct-DNA) was investigated by using electrochemical, spectroelectrochemical methods and cleavage studies. The hyperchromic change in the electronic absorption spectrum of the Pt(II) complexes indicates an electrostatic interaction between the complexes and ct-DNA. Binding constant values between 4.42 × 103 and 5.09 × 103 M-1 and binding side size values between 2 and 3 base pairs were determined from cyclic voltammetry (CV) and differential pulse voltammetry (DPV) studies.

  5. Pt···H Nonclassical Interaction in Water-Dissolved Pt(II) Complexes: Coaction of Electronic Effects with Solvent-Assisted Stabilization.

    PubMed

    Kroutil, Ondřej; Předota, Milan; Chval, Zdeněk

    2016-04-01

    The structure of the hydration shell of cisplatin, cis-[Pt(NH3)2Cl2], and its aquated derivatives cis-[Pt(NH3)2Cl(H2O)](+), cis-[Pt(NH3)2OH(H2O)](+), and cis-[Pt(NH3)2(H2O)2](2+) were studied by a number of density functional molecular dynamics (DFT-MD) simulations (from 30 to 250 ps) in which Pt(II) complexes were immersed in a periodic box with 72 explicit water molecules. Furthermore, Pt(II) complex-water binding energy curves and full DFT optimizations of clusters derived from the lowest potential energy DFT-MD frames offered a deeper insight into the structure of the first hydration shell and electronic changes connected with the formation of a nonclassical Pt···H-O-H (Pt···Hw) hydrogen bond (inverse hydration). The probability of a Pt···Hw interaction decreases with increasing charge of the platinum complex due to disadvantageous electrostatics. The main stabilization comes from the charge transfer being followed by polarization and dispersion. Ligands form a framework for the network of H-bond interactions between the solvent molecules, which play an important role in the promotion/suppression of the formation of the Pt···Hw interactions. In the +2 charged diaqua complex the Pt···Hw interaction is still attractive but cannot compete with classical H bonds between solvent molecules. Thus, the formation of a Pt···Hw interaction is the result of a suitable solvent H-bonding network and the probability of its incidence decreases with increasing flexibility of the solvent. PMID:26974182

  6. A structurally diverse Ru(II),Pt(II) tetrametallic motif for photoinitiated electron collection and photocatalytic hydrogen production.

    PubMed

    Knoll, Jessica D; Arachchige, Shamindri M; Brewer, Karen J

    2011-02-18

    Coupling a reactive metal to light absorbers affords molecular devices for photoinitiated electron collection and photocatalytic conversion of substrates to fuels. A new Ru(II),Pt(II) tetrametallic supramolecule, [{(phen)(2)Ru(dpp)}(2)Ru(dpq)PtCl(2)](PF(6))(6), and the trimetallic precursors, [{(phen)(2)Ru(dpp)}(2)RuCl(2)](PF(6))(4) and [{(phen)(2)Ru(dpp)}(2)Ru(dpq)](PF(6))(6), have been synthesized, and their redox, spectroscopic, spectroelectrochemical, photophysical and photocatalytic properties studied. They efficiently absorb UV and visible light. The electrochemistry of [{(phen)(2)Ru(dpp)}(2)Ru(dpq)PtCl(2)](PF(6))(6) suggests a lowest-lying terminal Ru→dpq charge-separated state that quenches the emission of the parent complex with non-unity population of the emissive (3)MLCT excited state. Photolysis of [{(phen)(2)Ru(dpp)}(2)Ru(dpq)PtCl(2)](6+) at 470 nm with DMA gives multielectron reduction, storing electrons in a new manner on the central (dpp)(2)Ru(II)(dpq) moiety. Addition of H(2)O to the photolysis system produces 21 μmol of H(2) in 5 h, with 115 turnovers of the tetrametallic photocatalyst. PMID:21328554

  7. Spin Crossover in Fe(II)-M(II) Cyanoheterobimetallic Frameworks (M = Ni, Pd, Pt) with 2-Substituted Pyrazines.

    PubMed

    Kucheriv, Olesia I; Shylin, Sergii I; Ksenofontov, Vadim; Dechert, Sebastian; Haukka, Matti; Fritsky, Igor O; Gural'skiy, Il'ya A

    2016-05-16

    Discovery of spin-crossover (SCO) behavior in the family of Fe(II)-based Hofmann clathrates has led to a "new rush" in the field of bistable molecular materials. To date this class of SCO complexes is represented by several dozens of individual compounds, and areas of their potential application steadily increase. Starting from Fe(2+), square planar tetracyanometalates M(II)(CN)4(2-) (M(II) = Ni, Pd, Pt) and 2-substituted pyrazines Xpz (X = Cl, Me, I) as coligands we obtained a series of nine new Hofmann clathrate-like coordination frameworks. X-ray diffraction reveals that in these complexes Fe(II) ion has a pseudo-octahedral coordination environment supported by four μ4-tetracyanometallates forming its equatorial coordination environment. Depending on the nature of X and M, axial positions are occupied by two 2X-pyrazines (X = Cl and M(II) = Ni (1), Pd (2), Pt (3); X = Me and M(II) = Ni (4), Pd (5)) or one 2X-pyrazine and one water molecule (X = I and M(II) = Ni (7), Pd (8), Pt (9)), or, alternatively, two distinct Fe(II) positions with either two pyrazines or two water molecules (X = Me and M(II) = Pt (6)) are observed. Temperature behavior of magnetic susceptibility indicates that all compounds bearing FeN6 units (1-6) display cooperative spin transition, while Fe(II) ions in N5O or N4O2 surrounding are high spin (HS). Structural changes in the nearest Fe(II) environment upon low-spin (LS) to HS transition, which include ca. 10% Fe-N distance increase, lead to the cell expansion. Mössbauer spectroscopy is used to characterize the spin state of all HS, LS, and intermediate phases of 1-9 (see abstract figure). Effects of a pyrazine substituent and M(II) nature on the hyperfine parameters in both spin states are established. PMID:27120049

  8. Water-Free Proton Conduction in Discotic Pyridylpyrazolate-based Pt(II) and Pd(II) Metallomesogens.

    PubMed

    Cuerva, Cristián; Campo, José A; Cano, Mercedes; Sanz, Jesús; Sobrados, Isabel; Diez-Gómez, Virginia; Rivera-Calzada, Alberto; Schmidt, Rainer

    2016-07-18

    In this work we report on water-free proton conductivity in liquid-crystal pyridylpyrazolate-based Pt(II) and Pd(II) complexes [M(pz(R(n,n)py))2] (pz(R(n,n)py) = 3-(3,5-dialkyloxyphenyl)-5-(pyridin-2-yl)pyrazolate, R(n,n) = C6H3(OCnH2n+1)2; n = 4, 12, 16, M = Pd; n = 12, M = Pt) with potential application as electrolyte materials in proton exchange membrane fuel cells. The columnar ordering of the complexes in the liquid-crystalline phase opens nanochannels, which are used for fast proton exchange as detected by impedance spectroscopy and NMR. The NMR spectra indicate that the proton conduction mechanism is associated with a novel C-H···N proton transfer, which persists above the clearing point of the material. The highest conductivity of ∼0.5 μS cm(-1) at 180 °C with an activation energy of 1.2 eV is found for the Pt(II) compound in the mesophase. The Pd(II) complexes with different chain length (n = 4, 12, and 16) show lower conductivity but smaller activation energies, in the range of 0.74-0.93 eV. PMID:27362555

  9. Synthesis, Characterization, and Antibacterial Studies of Pd(II) and Pt(II) Complexes of Some Diaminopyrimidine Derivatives

    PubMed Central

    Ajibade, Peter A.; Idemudia, Omoruyi G.

    2013-01-01

    Pd(II) and Pt(II) complexes of trimethoprim and pyrimethamine were synthesized and characterized by elemental analysis, UV-Vis, FTIR, and NMR spectroscopy. The complexes are formulated as four coordinate square planar species containing two molecules of the drugs and two chloride or thiocyanate ions. The coordination of the metal ions to the pyrimidine nitrogen atom of the drugs was confirmed by spectroscopic analyses. The complexes were screened for their antibacterial activities against eight bacterial isolates. They showed varied activities with the active metal complexes showing more enhanced inhibition than either trimethoprim or pyrimethamine. The Pd(II) complexes of pyrimethamine showed unique inhibitory activities against P. aeruginosa and B. pumilus, and none of the other complexes or the drugs showed any activity against these bacteria isolates. The MIC and MBC determinations revealed that these Pd(II) complexes are the most active. Structure activity relationship showed that Pt(II) complexes containing chloride ions are more active, while for Pd(II) complexes containing thiocyanate ions showed more enhanced activity than those containing chloride ions. PMID:23573071

  10. Is tooth agenesis related to brainstem anomalies in myelomeningocele patients with Chiari II malformations?

    PubMed

    Linderström, Annelie; Samuelsson, Lars; Huggare, Jan

    2002-12-01

    Defects in the prenatal development of the brainstem can result in cranial nerve deficiencies. As the development of tooth germ is dependent on n. trigeminus, which originates from the brainstem, the hypothesis underlying this study was that anomalies of the brainstem would lead to an increased prevalence of tooth agenesis. Twenty-three patients (13 F and 10 M, age range 6-37 years) were studied, all with myclomeningocele and brainstem anomalies (Chiari II). They were examined retrospectively from the data in journals and dental radiographs and compared to available data on the prevalence of tooth agenesis in the Swedish population. Our hypothesis was rejected, since there was insignificant difference in the frequency of agenesis in our material (8.7%) compared with that of the Swedish population (7.4%). PMID:12512882

  11. Chiari Malformation

    MedlinePlus

    Chiari malformations (CMs) are structural defects in the cerebellum. The cerebellum is the part of the brain that controls balance. With CM, brain tissue extends into the spinal canal. It can happen when part of the skull is too ...

  12. Arteriovenous Malformation

    MedlinePlus

    ... to the formation of brain AVMs. NIH Patient Recruitment for Arteriovenous Malformation Clinical Trials At NIH Clinical Center Throughout the U.S. and Worldwide NINDS Clinical Trials Organizations Column1 Column2 Brain Aneurysm Foundation 269 Hanover Street, ...

  13. Brain Malformations

    MedlinePlus

    Most brain malformations begin long before a baby is born. Something damages the developing nervous system or causes it ... medicines, infections, or radiation during pregnancy interferes with brain development. Parts of the brain may be missing, ...

  14. A label-free colorimetric aptasensor for simple, sensitive and selective detection of Pt (II) based on platinum (II)-oligonucleotide coordination induced gold nanoparticles aggregation.

    PubMed

    Fan, Daoqing; Zhai, Qingfeng; Zhou, Weijun; Zhu, Xiaoqing; Wang, Erkang; Dong, Shaojun

    2016-11-15

    Herein, a gold nanoparticles (AuNPs) based label-free colorimetric aptasensor for simple, sensitive and selective detection of Pt (II) was constructed for the first time. Four bases (G-G mismatch) mismatched streptavidin aptamer (MSAA) was used to protect AuNPs from salt-induced aggregation and recognize Pt (II) specifically. Only in the presence of Pt (II), coordination occurs between G-G bases and Pt (II), leading to the activation of streptavidin aptamer. Streptavidin coated magnetic beads (MBs) were used as separation agent to separate Pt (II)-coordinated MSAA. The residual less amount of MSAA could not efficiently protect AuNPs anymore and aggregation of AuNPs will produce a colorimetric product. With the addition of Pt (II), a pale purple-to-blue color variation could be observed by the naked eye. A detection limit of 150nM and a linear range from 0.6μM to 12.5μM for Pt (II) could be achieved without any amplification. PMID:27281107

  15. A Novel Intergenic ETnII-β Insertion Mutation Causes Multiple Malformations in Polypodia Mice

    PubMed Central

    Lehoczky, Jessica A.; Thomas, Peedikayil E.; Patrie, Kevin M.; Owens, Kailey M.; Villarreal, Lisa M.; Galbraith, Kenneth; Washburn, Joe; Johnson, Craig N.; Gavino, Bryant; Borowsky, Alexander D.; Millen, Kathleen J.; Wakenight, Paul; Law, William; Van Keuren, Margaret L.; Gavrilina, Galina; Hughes, Elizabeth D.; Saunders, Thomas L.; Brihn, Lesil; Nadeau, Joseph H.; Innis, Jeffrey W.

    2013-01-01

    Mouse early transposon insertions are responsible for ∼10% of spontaneous mutant phenotypes. We previously reported the phenotypes and genetic mapping of Polypodia, (Ppd), a spontaneous, X-linked dominant mutation with profound effects on body plan morphogenesis. Our new data shows that mutant mice are not born in expected Mendelian ratios secondary to loss after E9.5. In addition, we refined the Ppd genetic interval and discovered a novel ETnII-β early transposon insertion between the genes for Dusp9 and Pnck. The ETn inserted 1.6 kb downstream and antisense to Dusp9 and does not disrupt polyadenylation or splicing of either gene. Knock-in mice engineered to carry the ETn display Ppd characteristic ectopic caudal limb phenotypes, showing that the ETn insertion is the Ppd molecular lesion. Early transposons are actively expressed in the early blastocyst. To explore the consequences of the ETn on the genomic landscape at an early stage of development, we compared interval gene expression between wild-type and mutant ES cells. Mutant ES cell expression analysis revealed marked upregulation of Dusp9 mRNA and protein expression. Evaluation of the 5′ LTR CpG methylation state in adult mice revealed no correlation with the occurrence or severity of Ppd phenotypes at birth. Thus, the broad range of phenotypes observed in this mutant is secondary to a novel intergenic ETn insertion whose effects include dysregulation of nearby interval gene expression at early stages of development. PMID:24339789

  16. Sorption behavior of the Pt(II) complex anion on manganese dioxide (δ-MnO2): a model reaction to elucidate the mechanism by which Pt is concentrated into a marine ferromanganese crust

    NASA Astrophysics Data System (ADS)

    Maeno, Mamiko Yamashita; Ohashi, Hironori; Yonezu, Kotaro; Miyazaki, Akane; Okaue, Yoshihiro; Watanabe, Koichiro; Ishida, Tamao; Tokunaga, Makoto; Yokoyama, Takushi

    2016-02-01

    It is difficult to directly investigate the chemical state of Pt in marine ferromanganese crusts (a mixture of hydrous iron(III) oxide and manganese dioxide (δ-MnO2)) because it is present at extremely low concentration levels. This paper attempts to elucidate the mechanism by which Pt is concentrated into marine ferromanganese crust from the Earth's continental crust through ocean water. In this investigation, the sorption behavior of the Pt(II) complex ions on the surface of the δ-MnO2 that is a host of Pt was examined as a model reaction. The δ-MnO2 sorbing Pt was characterized by X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) to determine the chemical state of the Pt. Hydrolytic Pt(II) complex ions were specifically sorbed above pH 6 by the formation of a Mn-O-Pt bond. XPS spectra and XANES spectra for δ-MnO2 sorbing Pt showed that the sorbed Pt(II) was oxidized to Pt(IV) on δ-MnO2. The extended X-ray absorption fine structure (EXAFS) analysis showed that the coordination structure of Pt sorbed on δ-MnO2 is almost the same as that of the [Pt(OH)6]2- complex ion used as a standard. Therefore, the mechanism for the concentration of Pt in marine ferromanganese crust may be an oxidative substitution (penetration of Pt(IV) into structure of δ-MnO2) by a reduction-oxidation reaction between Pt(II) in [PtCl4-n(OH)n]2- and Mn(IV) in δ-MnO2 through a Mn-O-Pt bond.

  17. Synergistic Effects of Metals in a Promising Ru(II) -Pt(II) Assembly for a Combined Anticancer Approach: Theoretical Exploration of the Photophysical Properties.

    PubMed

    Alberto, Marta E; Russo, Nino; Adamo, Carlo

    2016-06-27

    Ru(II) -Pt(II) complexes are a class of bioactive molecules of interest as anticancer agents that combine a light-absorbing chromophore with a cisplatin-like unit. The results of a DFT and TDDFT investigation of a Ru(II) complex and its conjugate with a cis-PtCl2 moiety reveal that a synergistic effect of the metals makes the assembly a promising multitarget anticancer drug. Inspection of type I and type II photoreactions and spin-orbit coupling computations reveals that the cis-PtCl2 moiety improves the photophysical properties of the Ru(II) chromophore, ensuring efficient singlet oxygen generation and making the assembly suitable for photodynamic therapy. At the same time, the Ru(II) chromophore promotes a new alternative activation mechanism of the Pt(II) ligand via a triplet metal-to-ligand charge transfer ((3) MLCT) state, before reaching the biological target. The importance of the supramolecular architecture is accurately derived, opening interesting new perspectives on the use of bimetallic Ru(II) -Pt(II) assemblies in a combined anticancer approach. PMID:27249166

  18. Investigation of interaction between the Pt(II) ions and aminosilane-modified silica surface in heterogeneous system

    NASA Astrophysics Data System (ADS)

    Nowicki, Waldemar; Gąsowska, Anna; Kirszensztejn, Piotr

    2016-05-01

    UV-vis spectroscopy measurements confirmed the reaction in heterogeneous system between Pt(II) ions and ethylenediamine type ligand, n-(2-aminoethyl)-3-aminopropyl-trimethoxysilane, immobilized at the silica surface. The formation of complexes is a consequence of interaction between the amine groups from the ligand grafted onto SiO2 and ions of platinum. A potentiometric titration technique was to determine the stability constants of complexes of Pt(II) with immobilized insoluble ligand (SG-L), on the silica gel. The results show the formation of three surface complexes of the same type (PtHSG-L, Pt(HSG-L)2, PtSG-L) with SG-L ligand, in a wide range of pH for different Debye length. The concentration distribution of the complexes in a heterogeneous system is evaluated.

  19. A Dual-Targeting, p53-Independent, Apoptosis-Inducing Platinum(II) Anticancer Complex, [Pt(BDIQQ)]Cl

    PubMed Central

    Suntharalingam, Kogularamanan; Wilson, Justin J.; Lin, Wei; Lippard, Stephen J.

    2014-01-01

    The therapeutic index and cellular mechanism of action of [Pt(BDIQQ)]Cl, a monocationic, square-planar platinum(II) complex, are reported. [Pt(BDIQQ)]Cl was used to treat several cell lines, including wild type and cisplatin-resistant ovarian carcinoma cells (A2780 and A2780CP70) and non-proliferating lung carcinoma cells (A549). [Pt(BDIQQ)]Cl selectively kills cancer over healthy cells and exhibits no cross-resistance with cisplatin. The mechanism of cell killing was established through detailed cell-based assays. [Pt(BDIQQ)]Cl exhibits dual-threat capabilities, targeting nuclear DNA and mitochondria simultaneously. [Pt(BDIQQ)]Cl induces DNA damage, leading to p53 enrichment, mitochondrial membrane potential depolarisation, and caspase-mediated apoptosis. [Pt(BDIQQ)]Cl also accumulates in the mitochondria, resulting in direct mitochondrial damage. Flow cytometric studies demonstrated that [Pt(BDIQQ)]Cl has no significant effect on cell cycle progression. Remarkably, p53-status is a not a determinant of [Pt(BDIQQ)]Cl activity. In p53-null cells, [Pt(BDIQQ)]Cl induces cell death through mitochondrial dysfunction. Cancers with p53-null status could therefore be targeted using [Pt(BDIQQ)]Cl. PMID:24514456

  20. Synthesis, Characterization and Antiproliferative Activity of the Co(II), Ni(II), Cu(II), Pd(II) and Pt(II) Complexes of 2-(4-Thiazolyl)Benzimidazole (Thiabendazole)

    PubMed Central

    Glowiak, Tadeusz; Opolski, Adam; Wietrzyk, Joanna

    2001-01-01

    Complexes of 2-(4-thiazolyi)benzimidazole (thiabendazole, THBD) with Co(II), Ni(II), Cu(ll) of general formula ML2(NO3)2 H2O and complexes of Pd(II) and Pt(II) of general formula ML2Cl2 H2O have been obtained and characterized by elemental analyses, IR and far IR spectroscopy and magnetic measurements. The X-ray crystal structure of the copper(II) complex has been determined. The in vitro cell proliferation inhibitory activity of these compounds was examined against human cancer cell lines A 549 (lung carcinoma), HCV-29 T (urinary bladder carcinoma), MCF-7 (breast cancer), T47D (breast cancer), MES-SA (uterine carcinoma) and HL-60 (promyelocytic leukemia). Pt-THBD has been found to exhibit an antileukemic activity of the HL-60 line cells matching that of an arbitrary criterion. PMID:18475995

  1. 1H, 13C, 15N and 195Pt NMR studies of Au(III) and Pt(II) chloride organometallics with 2-phenylpyridine.

    PubMed

    Pazderski, Leszek; Pawlak, Tomasz; Sitkowski, Jerzy; Kozerski, Lech; Szłyk, Edward

    2009-11-01

    (1)H, (13)C, (15)N and (195)Pt NMR studies of gold(III) and platinum(II) chloride organometallics with N(1),C(2')-chelated, deprotonated 2-phenylpyridine (2ppy*) of the formulae [Au(2ppy*)Cl(2)], trans(N,N)-[Pt(2ppy*)(2ppy)Cl] and trans(S,N)-[Pt(2ppy*)(DMSO-d(6))Cl] (formed in situ upon dissolving [Pt(2ppy*)(micro-Cl)](2) in DMSO-d(6)) were performed. All signals were unambiguously assigned by HMBC/HSQC methods and the respective (1)H, (13)C and (15)N coordination shifts (i.e. differences between chemical shifts of the same atom in the complex and ligand molecules: Delta(1H)(coord) = delta(1H)(complex) - delta(1H)(ligand), Delta(13C)(coord) = delta(13C)(complex) - delta(13C)(ligand), Delta(15N)(coord) = delta(15N)(complex) - delta(15N)(ligand)), as well as (195)Pt chemical shifts and (1)H-(195)Pt coupling constants discussed in relation to the known molecular structures. Characteristic deshielding of nitrogen-adjacent H(6) protons and metallated C(2') atoms as well as significant shielding of coordinated N(1) nitrogens is discussed in respect to a large set of literature NMR data available for related cyclometallated compounds. PMID:19691018

  2. Chiari Malformation

    MedlinePlus

    ... Ones & When? Smart School Lunches Emmy-Nominated Video "Cerebral Palsy: Shannon's Story" 5 Things to Know About Zika & ... spine that can lead to nerve damage or paralysis. Chiari malformations also can happen after brain or spinal surgery. Doctors haven't identified a ...

  3. Mass Spectrometric Strategies to Improve the Identification of Pt(II)-Modification Sites on Peptides and Proteins

    NASA Astrophysics Data System (ADS)

    Li, Huilin; Snelling, Jonathon R.; Barrow, Mark P.; Scrivens, James H.; Sadler, Peter J.; O'Connor, Peter B.

    2014-07-01

    To further explore the binding chemistry of cisplatin ( cis-Pt(NH3)2Cl2) to peptides and also establish mass spectrometry (MS) strategies to quickly assign the platinum-binding sites, a series of peptides with potential cisplatin binding sites (Met(S), His(N), Cys(S), disulfide, carboxyl groups of Asp and Glu, and amine groups of Arg and Lys, were reacted with cisplatin, then analyzed by electron capture dissociation (ECD) in a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS). Radical-mediated side-chain losses from the charge-reduced Pt-binding species (such as CH3S• or CH3SH from Met, SH• from Cys, CO2 from Glu or Asp, and NH2 • from amine groups) were found to be characteristic indicators for rapid and unambiguous localization of the Pt-binding sites to certain amino acid residues. The method was then successfully applied to interpret the top-down ECD spectrum of an inter-chain Pt-crosslinked insulin dimer, insulin + Pt(NH3)2 + insulin (>10 kDa). In addition, ion mobility MS shows that Pt binds to multiple sites in Substance P, generating multiple conformers, which can be partially localized by collisionally activated dissociation (CAD). Platinum(II) (Pt(II)) was found to coordinate to amine groups of Arg and Lys, but not to disulfide bonds under the conditions used. The coordination of Pt to Arg or Lys appears to arise from the migration of Pt(II) from Met(S) as shown by monitoring the reaction products at different pH values by ECD. No direct binding of cisplatin to amine groups was observed at pH 3 ~ 10 unless Met residues were present in the sequence, but noncovalent interactions between cisplatin hydrolysis and amination [Pt(NH3)4]2+ products and these peptides were found regardless of pH.

  4. A curious interplay in the films of N-heterocyclic carbene PtII complexes upon deposition of alkali metals

    PubMed Central

    Makarova, Anna A.; Grachova, Elena V.; Niedzialek, Dorota; Solomatina, Anastasia I.; Sonntag, Simon; Fedorov, Alexander V.; Vilkov, Oleg Yu.; Neudachina, Vera S.; Laubschat, Clemens; Tunik, Sergey P.; Vyalikh, Denis V.

    2016-01-01

    The recently synthesized series of PtII complexes containing cyclometallating (phenylpyridine or benzoquinoline) and N-heterocyclic carbene ligands possess intriguing structures, topologies, and light emitting properties. Here, we report curious physicochemical interactions between in situ PVD-grown films of a typical representative of the aforementioned PtII complex compounds and Li, Na, K and Cs atoms. Based on a combination of detailed core-level photoelectron spectroscopy and quantum-chemical calculations at the density functional theory level, we found that the deposition of alkali atoms onto the molecular film leads to unusual redistribution of electron density: essential modification of nitrogen sites, reduction of the coordination PtII centre to Pt0 and decrease of electron density on the bromine atoms. A possible explanation for this is formation of a supramolecular system “Pt complex-alkali metal ion”; the latter is supported by restoration of the system to the initial state upon subsequent oxygen treatment. The discovered properties highlight a considerable potential of the PtII complexes for a variety of biomedical, sensing, chemical, and electronic applications. PMID:27151364

  5. A curious interplay in the films of N-heterocyclic carbene Pt(II) complexes upon deposition of alkali metals.

    PubMed

    Makarova, Anna A; Grachova, Elena V; Niedzialek, Dorota; Solomatina, Anastasia I; Sonntag, Simon; Fedorov, Alexander V; Vilkov, Oleg Yu; Neudachina, Vera S; Laubschat, Clemens; Tunik, Sergey P; Vyalikh, Denis V

    2016-01-01

    The recently synthesized series of Pt(II) complexes containing cyclometallating (phenylpyridine or benzoquinoline) and N-heterocyclic carbene ligands possess intriguing structures, topologies, and light emitting properties. Here, we report curious physicochemical interactions between in situ PVD-grown films of a typical representative of the aforementioned Pt(II) complex compounds and Li, Na, K and Cs atoms. Based on a combination of detailed core-level photoelectron spectroscopy and quantum-chemical calculations at the density functional theory level, we found that the deposition of alkali atoms onto the molecular film leads to unusual redistribution of electron density: essential modification of nitrogen sites, reduction of the coordination Pt(II) centre to Pt(0) and decrease of electron density on the bromine atoms. A possible explanation for this is formation of a supramolecular system "Pt complex-alkali metal ion"; the latter is supported by restoration of the system to the initial state upon subsequent oxygen treatment. The discovered properties highlight a considerable potential of the Pt(II) complexes for a variety of biomedical, sensing, chemical, and electronic applications. PMID:27151364

  6. A curious interplay in the films of N-heterocyclic carbene PtII complexes upon deposition of alkali metals

    NASA Astrophysics Data System (ADS)

    Makarova, Anna A.; Grachova, Elena V.; Niedzialek, Dorota; Solomatina, Anastasia I.; Sonntag, Simon; Fedorov, Alexander V.; Vilkov, Oleg Yu.; Neudachina, Vera S.; Laubschat, Clemens; Tunik, Sergey P.; Vyalikh, Denis V.

    2016-05-01

    The recently synthesized series of PtII complexes containing cyclometallating (phenylpyridine or benzoquinoline) and N-heterocyclic carbene ligands possess intriguing structures, topologies, and light emitting properties. Here, we report curious physicochemical interactions between in situ PVD-grown films of a typical representative of the aforementioned PtII complex compounds and Li, Na, K and Cs atoms. Based on a combination of detailed core-level photoelectron spectroscopy and quantum-chemical calculations at the density functional theory level, we found that the deposition of alkali atoms onto the molecular film leads to unusual redistribution of electron density: essential modification of nitrogen sites, reduction of the coordination PtII centre to Pt0 and decrease of electron density on the bromine atoms. A possible explanation for this is formation of a supramolecular system “Pt complex-alkali metal ion” the latter is supported by restoration of the system to the initial state upon subsequent oxygen treatment. The discovered properties highlight a considerable potential of the PtII complexes for a variety of biomedical, sensing, chemical, and electronic applications.

  7. Platinum-Containing Polyoxometalates: syn- and anti-[Pt(II) 2 (α-PW11 O39 )2 ](10-) and Formation of the Metal-Metal-Bonded di-Pt(III) Derivatives.

    PubMed

    Lin, Zhengguo; Izarova, Natalya V; Kondinski, Aleksandar; Xing, Xiaolin; Haider, Ali; Fan, Linyuan; Vankova, Nina; Heine, Thomas; Keita, Bineta; Cao, Jie; Hu, Changwen; Kortz, Ulrich

    2016-04-11

    The first examples of dimeric, di-Pt(II) -containing heteropolytungstates are reported. The two isomeric di-platinum(II)-containing 22-tungsto-2-phosphates [anti-Pt(II) 2 (α-PW11 O39 )2 ](10-) (1 a) and [syn-Pt(II) 2 (α-PW11 O39 )2 ](10-) (2 a) were synthesized in aqueous pH 3.5 medium using one-pot procedures. Polyanions 1 a and 2 a contain a core comprising two face-on PtO4 units, with a Pt⋅⋅⋅Pt distance of 2.9-3 Å. Both polyanions were investigated by single-crystal XRD, IR, TGA, UV/Vis, (31) P NMR, ESI-MS, CID-MS/MS, electrochemistry, and DFT. On the basis of DFT and electrochemistry, we demonstrated that the {Pt2 (II) } moiety in 1 a and 2 a can undergo fully reversible two-electron oxidation to {Pt2 (III) }, accompanied by formation of a single Pt-Pt bond. Hence we have discovered the novel subclass of Pt(III) -containing heteropolytungstates. PMID:26938929

  8. Inelastic neutron scattering study of Pt(II) complexes displaying anticancer properties.

    PubMed

    de Carvalho, Luís A E Batista; Marques, M Paula M; Martin, Christine; Parker, Stewart F; Tomkinson, John

    2011-05-01

    The well-known platinum(II) chemotherapeutic drugs cisplatin [cis-(NH(3))(2)PtCl(2)] and carboplatin [Pt(NH(3))(2)C(6)O(4)H(6)], as well as the analogous transplatin [trans-(NH(3))(2)PtCl(2)], were studied by inelastic neutron scattering (INS) spectroscopy, coupled to quantum mechanical methods, and some ancillary work with X-ray diffraction on powders. An assignment of the experimental spectra was carried out based on the calculated INS transition frequencies and intensities (at the DFT level), thereby achieving a good correspondence between the calculated and observed data. Unusually good-quality INS spectra were obtained from about 250 mg, which is the smallest sample of a hydrogenous compound for which a successful INS interpretation has been reported. The knowledge of the local configuration of this kind of complexes is essential for an accurate understanding of their activity, which will pave the way for the rational design of novel third-generation drugs comprising cisplatin- and carboplatin-like moieties. PMID:21523878

  9. Mechanistic elucidation of linker and ancillary ligand substitution reactions in Pt(II) dinuclear complexes.

    PubMed

    Ongoma, Peter O; Jaganyi, Deogratius

    2013-02-28

    The rate of substitution of aqua ligands by three nucleophiles, thiourea (TU), N,N-dimethylthiourea (DMTU) and N,N,N,N-tetramethylthiourea (TMTU), for the complexes [cis-{PtOH2(NH3)2}2-μ-pyrazine](ClO4)2 (pzn), [cis-{PtOH2(NH3)2}2-μ-2,3-dimethylpyrazine](ClO4)2 (2,3pzn), [cis-{PtOH2(NH3)2}2-μ-2,5-pyrazine](ClO4)2 (2,5pzn) and [cis-{PtOH2(NH3)2}2-μ-2,6-dimethylpyrazine](ClO4)2 (2,6pzn) was investigated under pseudo first-order conditions as a function of concentration and temperature by stopped-flow and UV-Visible spectrophotometry. The reaction proceeded in three consecutive steps; each step follows first order kinetics with respect to each complex and nucleophile. The pseudo first-order rate constants, k(obs(1/2/3)), for sequential substitution of the aqua ligands and subsequent displacement of the linker obeyed the rate law: k(obs(1/2/3)) = k((1/2/3))[nucleophile]. The steric hindrance properties of the pyrazine-bridging ligand control the overall reaction pattern. The order of reactivity of the complexes is 2,3pzn ≈ 2,5pzn < 2,6pzn < pzn. The difference in reactivity attributed to the steric crowding at the Pt(II) centre imposed by the methyl groups reduces the lability of the aqua complexes. The order of reactivity of the nucleophiles decreases with the increase in steric demand TU > DMTU > TMTU. 1H and 195Pt NMR spectroscopic results confirmed the observed dissociation of the bridging ligand from the metal centre of the cis-dinuclear complexes and its derivatives in the third step. The dissociation process is accelerated by the introduction of the steric effect on the linker in conjunction with the increased ligand field strength imparted by additional thiourea ligands at each metal centre. The large negative entropy of activation ΔS(≠) values in all cases support an associative substitution mechanism. PMID:23223554

  10. Sensitizing the sensitizer: the synthesis and photophysical study of bodipy-Pt(II)(diimine)(dithiolate) conjugates.

    PubMed

    Lazarides, Theodore; McCormick, Theresa M; Wilson, Kristina C; Lee, Soohyun; McCamant, David W; Eisenberg, Richard

    2011-01-19

    The dyads 3, 4, and 6, combining the Bodipy chromophore with a Pt(bpy)(bdt) (bpy = 2,2'-bipyridine, bdt = 1,2-benzenedithiolate, 3 and 6) or a Pt(bpy)(mnt) (mnt = maleonitriledithiolate, 4) moiety, have been synthesized and studied by UV-vis steady-state absorption, transient absorption, and emission spectroscopies and cyclic voltammetry. Comparison of the absorption spectra and cyclic voltammograms of dyads 3, 4, and 6 and those of their model compounds 1a, 2, 5, and 7 shows that the spectroscopic and electrochemical properties of the dyads are essentially the sum of their constituent chromophores, indicating negligible interaction of the constituent chromophores in the ground state. However, emission studies on 3 and 6 show a complete absence of both Bodipy-based fluorescence and the characteristic luminescence of the Pt(bpy)(bdt) unit. Dyad 4 shows a weak Pt(mnt)-based emission. Transient absorption studies show that excitation of the dyads into the Bodipy-based (1)ππ* excited state is followed by singlet energy transfer (SEnT) to the Pt(dithiolate)-based (1)MMLL'CT (mixed metal-ligand to ligand charge transfer) excited state (τ(SEnT)(3) = 0.6 ps, τ(SEnT)(4) = 0.5 ps, and τ(SEnT)(6) = 1.6 ps), which undergoes rapid intersystem crossing to the (3)MMLL'CT state due to the heavy Pt(II) ion. The (3)MMLL'CT state is then depopulated by triplet energy transfer (TEnT) to the low-lying Bodipy-based (3)ππ* excited state (τ(SEnT)(3) = 8.2 ps, τ(SEnT)(4) = 5 ps, and τ(SEnT)(6) = 160 ps). The transition assignments are supported by TD-DFT calculations. Both energy-transfer processes are shown to proceed via a Dexter electron exchange mechanism. The much longer time constants for dyad 6 relative to 3 are attributed to the significantly poorer coupling and resonance of charge-separated species that are intermediates in the electron exchange process. PMID:21175161

  11. Targeting cytochrome C oxidase in mitochondria with Pt(II)-porphyrins for photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Börsch, Michael

    2010-02-01

    Mitochondria are the power house of living cells, where the synthesis of the chemical "energy currency" adenosine triphosphate (ATP) occurs. Oxidative phosphorylation by a series of membrane protein complexes I to IV, that is, the electron transport chain, is the source of the electrochemical potential difference or proton motive force (PMF) of protons across the inner mitochondrial membrane. The PMF is required for ATP production by complex V of the electron transport chain, i.e. by FoF1-ATP synthase. Destroying cytochrome C oxidase (COX; complex IV) in Photodynamic Therapy (PDT) is achieved by the cationic photosensitizer Pt(II)-TMPyP. Electron microscopy revealed the disruption of the mitochondrial christae as a primary step of PDT. Time resolved phosphorescence measurements identified COX as the binding site for Pt(II)-TMPyP in living HeLa cells. As this photosensitizer competed with cytochrome C in binding to COX, destruction of COX might not only disturb ATP synthesis but could expedite the release of cytochrome C to the cytosol inducing apoptosis.

  12. Bis(dimethylsulfoxide)carbonateplatinum(ii), a new synthon for a low-impact, versatile synthetic route to anticancer Pt carboxylates.

    PubMed

    Bergamini, Paola; Marvelli, Lorenza; Ferretti, Valeria; Gemmo, Chiara; Gambari, Roberto; Hushcha, Yekatsiaryna; Lampronti, Ilaria

    2016-06-28

    The work describes a new low-impact synthetic route to Pt(ii)-carboxylate complexes, a class of compounds provided with established anticancer activity. The process is based on the ligand substitution on [PtCO3(Me2SO-S)2] (), a new synthon that can be easily prepared in water with high yield, is stable as a solid, and is reactive in solution where all its ligands can be easily replaced. It reacts with acidic O-donors releasing CO2 as the only side-product, whose development also supplies a driving force toward the products. The substitution of carbonate led to new Pt-DMSO carboxylate complexes , while the total substitution of the ligands of complex gave new Pt-phosphino carboxylates in high yields. The X-ray crystal structures of complexes [Pt(d(-)-quinate-O,O')(Me2SO-S)2] (), [Pt(salicylate)(Me2SO-S)2] () and [Pt(salicylate)(PPh3)2] () were determined. The tests of the antiproliferative activity of complexes on two human tumoral cell lines, A2780 (cisplatin-sensitive) and SKOV-3 (cisplatin-resistant), showed that the PTA (PTA = 1,3,5-triaza-7-phosphaadamantane) complexes were the most active on both cell lines. PMID:27291141

  13. Anorectal malformations

    PubMed Central

    Gangopadhyay, Ajay Narayan; Pandey, Vaibhav

    2015-01-01

    Anorectal malformations (ARMs) are among the more frequent congenital anomalies encountered in paediatric surgery, with an estimated incidence ranging between 1 in 2000 and 1 in 5000 live births. Antenatal diagnosis of an isolated ARM is rare. Most cases are diagnosed in the early neonatal period. There is a wide spectrum of presentation ranging from low anomalies with perineal fistula having simple management to high anomalies with complex management. Advances in the imaging techniques with improvement in knowledge of the embryology, anatomy and physiology of ARM cases have refined diagnosis and initial management. There has been marked improvement in survival of such patient over the last century. The management of ARM has moved forward from classical procedures to PSARP to minimal invasive procedures. But still the fecal and urinary incontinence can occur even with an excellent anatomic repair, mainly due to associated problems. There has been a paradigm shift in approach to these patients which involves holistic approach to the syndrome of Anorectal malformations with a long term goal of achievement of complete fecal and urinary continence with excellent quality of life. PMID:25552824

  14. Study of the interaction of DNA with cisplatin and other Pd(II) and Pt(II) complexes by atomic force microscopy.

    PubMed Central

    Onoa, G B; Cervantes, G; Moreno, V; Prieto, M J

    1998-01-01

    Modifications in the structure of a 260 bp DNA (hlyM) fragment from Escherichia coli caused by interaction with Pd(II) and Pt(II) complexes were studied. Cisplatin and transplatin [cis- and trans-PtCl2(NH3)2 respectively], Pt2Cl2(Spym)4 (Spym = 2-mercaptopyrimidine anion), Pd-famotidine and Pt-famotidine were incubated with DNA for 24 h at 37 degrees C and then observed with an atomic force microscope. Atomic force microscopy (AFM) provides the opportunity for nanometer resolution in research on the interaction between nucleic acids and metal complexes. The complexes induced noticeable changes in DNA topography according to their different characteristics and structure. In the case of cisplatin a shortening in DNA strands was observed. Transplatin and Pt2Cl2(Spym)4 caused shortening and compaction, whilst an aggregation of two strands was observed for the Pt-famotidine compound but not for the Pd-famotidine compound or the metal-free famotidine. PMID:9490794

  15. New N^C^N-coordinated Pd(ii) and Pt(ii) complexes of a tridentate N-heterocyclic carbene ligand featuring a 6-membered central ring: synthesis, structures and luminescence.

    PubMed

    Moussa, Jamal; Haddouche, Kamel; Chamoreau, Lise-Marie; Amouri, Hani; Gareth Williams, J A

    2016-08-01

    We describe Pd(ii) and Pt(ii) complexes of an N^C^N-coordinating pincer-like ligand featuring two lateral pyridine rings and a 6-membered carbene core. Their crystal structures display 1-dimensional chains with short π-π and M(ii)M(ii) interactions. Such interactions also impact on the photophysical properties, with the Pt(ii) complex being luminescent in the solid state at room temperature. PMID:27465432

  16. An Extended Chain and Trinuclear Complexes Based on Pt(II)-M (M = Tl(I), Pb(II)) Bonds: Contrasting Photophysical Behavior.

    PubMed

    Forniés, Juan; Giménez, Nora; Ibáñez, Susana; Lalinde, Elena; Martín, Antonio; Moreno, M Teresa

    2015-05-01

    The syntheses and structural characterizations of a Pt-Tl chain [{Pt(bzq)(C6F5)2}Tl(Me2CO)]n 1 and two trinuclear Pt2M clusters (NBu4)[{Pt(bzq)(C6F5)2}2Tl] 2 and [{Pt(bzq)(C6F5)2}2Pb] 3 (bzq = 7,8-benzoquinolinyl), stabilized by donor-acceptor Pt → M bonds, are reported. The one-dimensional heterometallic chain 1 is formed by alternate "Pt(bzq)(C6F5)2" and "Tl(Me2CO)" fragments, with Pt-Tl bond separations in the range of 2.961(1)-3.067(1) Å. The isoelectronic trinuclear complexes 2 (which crystallizes in three forms, namely, 2a, 2b, and 2c) and 3 present a sandwich structure in which the Tl(I) or Pb(II) is located between two "Pt(bzq)(C6F5)2" subunits. NMR studies suggest equilibria in solution implying cleavage and reformation of Pt-M bonds. The lowest-lying absorption band in the UV-vis spectra in CH2Cl2 and tetrahydrofuran (THF) of 1, associated with (1)MLCT/(1)L'LCT (1)[5dπ(Pt) → π*(bzq)]/(1)[(C6F5) → bzq], displays a blue shift in relation to the precursor, suggesting the cleavage of the chain maintaining bimetallic Pt-Tl fragments in solution, also supported by NMR spectroscopy. In 2 and 3, it shows a blue shift in THF and a red shift in CH2Cl2, supporting a more extensive cleavage of the Pt-M bonds in THF solutions than in CH2Cl2, where the trinuclear entities are predominant. The Pt-Tl chain 1 displays in solid state a bright orange-red emission ascribed to (3)MM'CT (M' = Tl). It exhibits remarkable and fast reversible vapochromic and vapoluminescent response to donor vapors (THF and Et2O), related to the coordination/decoordination of the guest molecule to the Tl(I) ion, and mechanochromic behavior, associated with the shortening of the intermetallic Pt-Tl separations in the chain induced by grinding. In frozen solutions (THF, acetone, and CH2Cl2) 1 shows interesting luminescence thermochromism with emissions strongly dependent on the solvent, concentration, and excitation wavelengths. The Pt2Tl complex 2 shows an emission close to 1, ascribed to

  17. In vitro alkylating of alpha, beta-unsaturated amidoesters, diethyl pyridylmethylphosphonates and their cis-Pt(II)complexes.

    PubMed

    Najman-Bronzewska, L; Ochocki, J

    1997-03-01

    The alkylating ability of alpha,beta-unsaturated amidoesters 1a-8d, diethyl pyridylmethylphosphonate esters and their cis-platinum(II) complexes has been investigated based on the test with 4-(4'-nitrobenzyl)pyridine (NBP) (Preussmann Test). Of the compounds tested for alkylating activity, only cis-platinum(II) phosphonate complexes were found to possess activity. The highest activity was found for CiS-[PtCl2(4-pmpe)2] where 4-pmpe is diethyl 4-pyridylmethylphosphonate. The results show a correlation between alkylating activity in vitro and cytotoxic activity in vivo for platinum(II) complexes. PMID:9157465

  18. TD-DFT Benchmark on Inorganic Pt(II) and Ir(III) Complexes.

    PubMed

    Latouche, Camille; Skouteris, Dimitrios; Palazzetti, Federico; Barone, Vincenzo

    2015-07-14

    We report in the present paper a comprehensive investigation of representative Pt(II) and Ir(III) complexes with special reference to their one-photon absorption spectra employing methods rooted in density functional theory and its time dependent extension. We have compared nine different functionals ranging from generalized gradient approximation (GGA) to global or range-separated hybrids, and two different basis sets, including pseudopotentials for 4 iridium and 7 platinum complexes. It turns out that hybrid functionals with the same exchange part give comparable results irrespective of the specific correlation functional (i.e., B3LYP is very close to B3PW91 and PBE0 is very close to MPW1PW91). More recent functionals, such as CAM-B3LYP and M06-2X, overestimate excitation energies, whereas local functionals (BP86 -GGA-, M06-L -Meta GGA-) strongly underestimate transition energies with respect to experimental results. As expected, basis set effects are weak, and the use of a triple-ζ polarized (def2-TZVP) basis set does not significantly improve the computed excitation energies with respect to a classical double-ζ basis set (LANL2DZ) augmented by polarization functions, but it significantly raises the computational effort. PMID:26575764

  19. Comparison of reactivity of Pt(II) center in the mononuclear and binuclear organometallic diimineplatinum complexes toward oxidative addition of methyl iodide

    NASA Astrophysics Data System (ADS)

    Hashemi, Majid

    2016-01-01

    The reactivities of Pt(II) center in a series of organometallic mononuclear Pt(II), binuclear Pt(II) and binuclear mixed-valence Pt(II)-Pt(IV) complexes toward oxidative addition of MeI have been compared from a theoretical point of view. The nucleophilicity index and electron-donation power were calculated for each of these complexes. The energies of HOMO and dZ2 orbital were determined for these complexes. Very good correlations were found between logk2 (k2 is the experimentally determined second order rate constant for the oxidative addition of MeI on these complexes) and nucleophilicity index or electron-donation power for these complexes. The correlation between logk2 and the energy of HOMO or the energy of dZ2 orbital were also very good. The condensed-to-atom Fukui functions for electrophilic attack on these complexes showed that the Pt(II) center is the preferred site for the oxidative addition of MeI. All of these observations are in agreement with the proposed SN2 type mechanism in the oxidative addition of MeI on the Pt(II) center in these complexes.

  20. Poly(styrenesulfonic acid)-impregnated alginate capsule for the selective sorption of Pd(II) from a Pt(IV)-Pd(II) binary solution.

    PubMed

    Wei, Wei; Lin, Shuo; Reddy, D Harikishore Kumar; Bediako, John Kwame; Yun, Yeoung-Sang

    2016-11-15

    Poly(styrenesulfonic acid)-impregnated alginate capsule (PSSA-AC) was prepared using a simple fabrication process, and used for selective separation of Pd(II) and Pt(IV) from their mixture. Evaluation of the pH effect revealed that PSSA-AC had good Pd(II) selectivity especially when the pH was between 3 and 5 at which neutral species Pd(OH)2 are present. Experiments on metal penetration through the Ca(2+)-alginate film showed that anionic species hardly penetrate through the alginate film (acting as an ionic barrier). The selective sorption mechanism is proposed as the following steps: (1) selective penetration of the neutral Pd(OH)2 through the ionic barrier (Ca(2+)-alginate shell) and then (2) chelation reaction of the neutral Pd(OH)2 with the SO3(-) groups of PSSA in the core. The maximum Pd(II) uptake was 291.19±17.48mg/g, which was about 32 times higher than that of Pt(IV). The results of the sorption/desorption test indicated that the PSSA-AC has good reusability potential. Even through one cycle of sorption/desorption, Pd(II) and Pt(IV) were successfully separated from their mixture with significantly high purities of 98.65% Pd(II) and 98.71% Pt(IV). This study reports for the first time the feasibility and potential of ionic barrier-based sorbents as selective separation of precious metals which have different speciations. PMID:27399150

  1. Alternating current characterization of nano-Pt(II) octaethylporphyrin (PtOEP) thin film as a new organic semiconductor

    NASA Astrophysics Data System (ADS)

    M, Dongol; M, M. El-Nahass; A, El-Denglawey; A, A. Abuelwafa; T, Soga

    2016-06-01

    Alternating current (AC) conductivity and dielectric properties of thermally evaporated Au/PtOEP/Au thin films are investigated each as a function of temperature (303 K–473 K) and frequency (50 Hz–5 MHz). The frequency dependence of AC conductivity follows the Jonscher universal dynamic law. The AC-activation energies are determined at different frequencies. It is found that the correlated barrier hopping (CBH) model is the dominant conduction mechanism. The variation of the frequency exponent s with temperature is analyzed in terms of the CBH model. Coulombic barrier height W m , hopping distance R ω , and the density of localized states N(E F) are valued at different frequencies. Dielectric constant ε 1(ω,T) and dielectric loss ε 2(ω,T) are discussed in terms of the dielectric polarization process. The dielectric modulus shows the non-Debye relaxation in the material. The extracted relaxation time by using the imaginary part of modulus (M″) is found to follow the Arrhenius law.

  2. Discrete polygonal supramolecular architectures of isocytosine-based Pt(ii) complexes at the solution/graphite interface.

    PubMed

    El Garah, Mohamed; Sinn, Stephan; Dianat, Arezoo; Santana-Bonilla, Alejandro; Gutierrez, Rafael; De Cola, Luisa; Cuniberti, Gianaurelio; Ciesielski, Artur; Samorì, Paolo

    2016-09-25

    Polygonal supramolecular architectures of a Pt(ii) complex including trimers, tetramers, pentamers and hexamers were self-assembled via hydrogen bonding between isocytosine moieties; their structure at the solid/liquid interface was unravelled by in situ scanning tunneling microscopy imaging. Density functional theory calculations provided in-depth insight into the thermodynamics of their formation by exploring the different energy contributions attributed to the molecular self-assembly and adsorption processes. PMID:27561126

  3. The Next Generation of Platinum Drugs: Targeted Pt(II) Agents, Nanoparticle Delivery, and Pt(IV) Prodrugs.

    PubMed

    Johnstone, Timothy C; Suntharalingam, Kogularamanan; Lippard, Stephen J

    2016-03-01

    The platinum drugs, cisplatin, carboplatin, and oxaliplatin, prevail in the treatment of cancer, but new platinum agents have been very slow to enter the clinic. Recently, however, there has been a surge of activity, based on a great deal of mechanistic information, aimed at developing nonclassical platinum complexes that operate via mechanisms of action distinct from those of the approved drugs. The use of nanodelivery devices has also grown, and many different strategies have been explored to incorporate platinum warheads into nanomedicine constructs. In this Review, we discuss these efforts to create the next generation of platinum anticancer drugs. The introduction provides the reader with a brief overview of the use, development, and mechanism of action of the approved platinum drugs to provide the context in which more recent research has flourished. We then describe approaches that explore nonclassical platinum(II) complexes with trans geometry or with a monofunctional coordination mode, polynuclear platinum(II) compounds, platinum(IV) prodrugs, dual-threat agents, and photoactivatable platinum(IV) complexes. Nanoparticles designed to deliver platinum(IV) complexes will also be discussed, including carbon nanotubes, carbon nanoparticles, gold nanoparticles, quantum dots, upconversion nanoparticles, and polymeric micelles. Additional nanoformulations, including supramolecular self-assembled structures, proteins, peptides, metal-organic frameworks, and coordination polymers, will then be described. Finally, the significant clinical progress made by nanoparticle formulations of platinum(II) agents will be reviewed. We anticipate that such a synthesis of disparate research efforts will not only help to generate new drug development ideas and strategies, but also will reflect our optimism that the next generation of approved platinum cancer drugs is about to arrive. PMID:26865551

  4. The Next Generation of Platinum Drugs: Targeted Pt(II) Agents, Nanoparticle Delivery, and Pt(IV) Prodrugs

    PubMed Central

    Johnstone, Timothy C.; Suntharalingam, Kogularamanan; Lippard, Stephen J.

    2016-01-01

    The platinum drugs, cisplatin, carboplatin, and oxaliplatin, prevail in the treatment of cancer,, but new platinum agents have been very slow to enter the clinic. Recently, however, there has been a surge of activity, based on a great deal of mechanistic information, aimed at developing non-classical platinum complexes that operate via mechanisms of action distinct from those of the approved drugs. The use of nanodelivery devices has also grown and many different strategies have been explored to incorporate platinum warheads into nanomedicine constructs. In this review, we discuss these efforts to create the next generation of platinum anticancer drugs. The introduction provides the reader with a brief overview of the use, development, and mechanism of action of the approved platinum drugs to provide the context in which more recent research has flourished. We then describe approaches that explore non-classical platinum(II) complexes with trans geometry and with a monofunctional coordination mode, polynuclear platinum(II) compounds, platinum(IV) prodrugs, dual-treat agents, and photoactivatable platinum(IV) complexes. Nanodelivery particles designed to deliver platinum(IV) complexes will also be discussed, including carbon nanotubes, carbon nanoparticles, gold nanoparticles, quantum dots, upconversion nanoparticles, and polymeric micelles. Additional nanoformulations including supramolecular self-assembled structures, proteins, peptides, metal-organic frameworks, and coordination polymers will then be described. Finally, the significant clinical progress made by nanoparticle formulations of platinum(II) agents will be reviewed. We anticipate that such a synthesis of disparate research efforts will not only help to generate new drug development ideas and strategies, but also reflect our optimism that the next generation of platinum cancer drugs is about to arrive. PMID:26865551

  5. Aggregation effect on the luminescence properties of phenylbipyridine Pt(II) acetylide complexes. A theoretical prediction with experimental evidence.

    PubMed

    Amar, Anissa; Meghezzi, Hacène; Boixel, Julien; Le Bozec, Hubert; Guerchais, Véronique; Jacquemin, Denis; Boucekkine, Abdou

    2014-08-14

    We report a combined theoretical and experimental study of both the structural and optical properties of phosphorescent cyclometalated square-planar (phenylbipyridyl)platinum(II) acetylide complexes, namely (Pt(tBu2-ĈN̂N)(C≡C-Ph)] and (Pt(hex2-ĈN̂N)(C≡C-thienyl)] that exhibit, at high concentrations, an additional emission band at longer wavelength. The geometry optimizations of both the ground and the lowest triplet excited states of the considered monomers and different possible dimers have been performed in solution using several density functional theory (DFT) functionals corrected for dispersion effects. For the dimers, which are shown to exhibit a head-to-tail configuration, a significant shortening of the Pt···Pt distance, compared to that in the ground state, is observed in the first triplet state. Moreover, we show that trimeric species are highly improbable in solution. The UV-visible absorption spectra of the complexes are well rationalized using a vertical time-dependent DFT (TD-DFT) protocol relying on a global hybrid exchange-correlation functional. Finally, the new emission band at high concentration of the complexes can be assigned to a metal-metal to ligand charge transfer excited state ((3)MMLCT). PMID:25079349

  6. Conjugatable water-soluble Pt(II) and Pd(II) porphyrin complexes: novel nano- and molecular probes for optical oxygen tension measurement in tissue engineering.

    PubMed

    Giuntini, F; Chauhan, V M; Aylott, J W; Rosser, G A; Athanasiadis, A; Beeby, A; MacRobert, A J; Brown, R A; Boyle, R W

    2014-07-01

    Measurement of oxygen tension in compressed collagen sheets was performed using matrix-embedded optical oxygen sensors based on platinum(II) and palladium(II) porphyrins supported on polyacrylamide nanoparticles. Bespoke, fully water-soluble, mono-functionalised Pt(II) and Pd(II) porphyrin complexes designed for conjugation under mild conditions were obtained using microwave-assisted metallation. The new sensors display a linear response (1/τ vs. O2) to varying oxygen tension over a biologically relevant range (7.0 × 10(-4) to 2.7 × 10(-1) mM) in aqueous solutions; a behaviour that is maintained following conjugation to polyacrylamide nanoparticles, and following embedding of the nanosensors in compressed collagen sheets, paving the way to innovative approaches for real-time resolution of oxygen gradients throughout 3D matrices useful for tissue regeneration. PMID:24818569

  7. 1H, 13C and 15N nuclear magnetic resonance coordination shifts in Au(III), Pd(II) and Pt(II) chloride complexes with phenylpyridines.

    PubMed

    Pazderski, Leszek; Tousek, Jaromír; Sitkowski, Jerzy; Kozerski, Lech; Szłyk, Edward

    2009-08-01

    1H, 13C and 15N nuclear magnetic resonance studies of gold(III), palladium(II) and platinum(II) chloride complexes with phenylpyridines (PPY: 4-phenylpyridine, 4ppy; 3-phenylpyridine, 3ppy; and 2-phenylpyridine, 2ppy) having the general formulae [Au(PPY)Cl3], trans-/cis-[Pd(PPY)2Cl2] and trans-/cis-[Pt(PPY)2Cl2] were performed and the respective chemical shifts (delta1H, delta13C and delta15N) reported. 1H, 13C and 15N coordination shifts (i.e. differences between chemical shifts of the same atom in the complex and ligand molecules: Delta(coord)(1H) = delta(complex)(1H)-delta(ligand)(1H), Delta(coord)(13C) = delta(complex)(13C)-delta(ligand)(13C), Delta(coord)(15N) = delta(complex)(15N)-delta(ligand)(15N)) were discussed in relation to the type of the central atom (Au(III), Pd(II) and Pt(II)), geometry (trans-/cis-) and the position of a phenyl group in the pyridine ring system. PMID:19472306

  8. 1H, 13C, 195Pt and 15N NMR structural correlations in Pd(II) and Pt(II) chloride complexes with various alkyl and aryl derivatives of 2,2'-bipyridine and 1,10-phenanthroline.

    PubMed

    Pawlak, Tomasz; Pazderski, Leszek; Sitkowski, Jerzy; Kozerski, Lech; Szłyk, Edward

    2011-02-01

    (1)H, (13)C, (195)Pt and (15)N NMR studies of platinide(II) (M = Pd, Pt) chloride complexes with such alkyl and aryl derivatives of 2,2'-bipyridine and 1,10-phenanthroline as LL = 6,6'-dimethyl-bpy, 5,5'-dimethyl-bpy, 4,4'-di-tert-butyl-bpy, 2,9-dimethyl-phen, 2,9-dimethyl-4,7-diphenyl-phen, 3,4,7,8-tetramethyl-phen, having the general [M(LL)Cl(2)] formula were performed and the respective chemical shifts (δ(1H), δ(13C), δ(195Pt), δ(15N)) reported. (1)H high-frequency coordination shifts (Δ(coord)(1H) = δ(complex)(1H)-δ(ligand)(1H)) mostly pronounced for nitrogen-adjacent protons and methyl groups in the nearest adjacency of nitrogen, as well as (15)N low-frequency coordination shifts (Δ(coord)(15H) = δ(complex)(15H)-δ(ligand)(15H)) were discussed in relation to the molecular structures. PMID:21254225

  9. Azide vs Alkyne Functionalization in Pt(II) Complexes for Post-treatment Click Modification: Solid-State Structure, Fluorescent Labeling, and Cellular Fate.

    PubMed

    Wirth, Regina; White, Jonathan D; Moghaddam, Alan D; Ginzburg, Aurora L; Zakharov, Lev N; Haley, Michael M; DeRose, Victoria J

    2015-12-01

    Tracking of Pt(II) complexes is of crucial importance toward understanding Pt interactions with cellular biomolecules. Post-treatment fluorescent labeling of functionalized Pt(II)-based agents using the bioorthogonal Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction has recently been reported as a promising approach. Here we describe an azide-functionalized Pt(II) complex, cis-[Pt(2-azidobutyl)amido-1,3-propanediamine)Cl2] (1), containing the cis geometry and difunctional reactivity of cisplatin, and present a comparative study with its previously described alkyne-functionalized congener. Single-crystal X-ray diffraction reveals a dramatic change in the solid-state arrangement with exchange of the alkyne for an azide moiety wherein 1 is dominated by a pseudo-chain of Pt-Pt dimers and antiparallel alignment of the azide substituents, in comparison with a circular arrangement supported by CH/π(C≡C) interactions in the alkyne version. In vitro studies indicate similar DNA binding and click reactivity of both congeners observed by fluorescent labeling. Interestingly, complex 1 shows in vitro enhanced click reactivity in comparison to a previously reported azide-appended Pt(II) complex. Despite their similar behavior in vitro, preliminary in cellulo HeLa studies indicate a superior imaging potential of azide-functionalized 1. Post-treatment fluorescent labeling of 1 observed by confocal fluorescence microscopy shows nuclear and intense nucleolar localization. These results demonstrate the potential of 1 in different cell line localization studies and for future isolation and purification of Pt-bound targets. PMID:26512733

  10. New Pt(II)(dithiolate) Compounds Possessing an Energetically Accessible Diphosphine-Based LUMO: Syntheses, Redox Properties, and Solid-State Structures of PtCl2(pbpcd), Pt(tdt)(pbpcd), and Pt(tdt)(bpcd)

    SciTech Connect

    Hunt, Sean W; Yang, Li; Wang, Xiaoping; Nesterov, Vladimir; Richmond, Michael G.

    2010-01-01

    The new ligand 2-(pyren-1-ylidene)-4,5-bis- (diphenylphosphino)-4-cyclopenten-1,3-dione (pbpcd) has been synthesized from the Knoevenagel condensation using 1-pyrenecarboxaldehyde with 4,5-bis(diphenylphosphino)- 4-cyclopenten-1,3-dione (bpcd). Displacement of the cod ligand in PtCl2(cod) by pbpcd furnishes PtCl2 (pbpcd) (2) in near quantitative yield. Treatment of 2 with the dipotassium salt of toluene-3,4-dithiol (K2tdt) affords the dithiolate compound Pt(tdt)(pbpcd) (3) as a 1:1 mixture of diastereomers. An alternative synthesis of 3 from Pt(tdt)(bpcd) (5) and 1-pyrenecarboxaldehyde also affords 3 in 23% yield. The pbpcd ligand and all new diphosphinesubstituted compounds have been isolated and fully characterized in solution by IR and NMR spectroscopies, and the solid-state structures of 2_CH2Cl2, 3_toluene, and 5_CH2Cl2 established by X-ray diffraction analyses. The solid-state structure of each product exhibits a square-planar architecture at the metal center. The redox properties of the pbpcd ligand and the tdt-substituted compound 3 have been explored by cyclic and differential-pulse voltammetry, and these data are discussed with respect to extended Huckel MO calculations and the nature of the HOMO and LUMO levels in each compound.

  11. Spectroscopic, thermal characterization and cytotoxic activity of bi-, tri- and tetra-nuclear Pd(II) and Pt(II) complexes with diSchiff base ligands

    NASA Astrophysics Data System (ADS)

    Hegazy, Wael Hussein

    2014-10-01

    In this paper; new di-, tri-, and tetra-nuclear Pd(II) and Pt(II) complexes of N,N‧-bis(3,4-dihydroxybenzylidene)ethan-1,2-diamine (EDH4), N,N‧-bis(3,4-dihydroxy-benzylidene)-benzene-1,2-diamine (PDH4) and N,N‧-bis-(3,4-dihydroxybenzylidene)-4,5-dimethyl-1,2-diamine (MPDH4) ligands were synthesized by two different methods. The first method involve the synthesis of the three ligands from condensation reaction of 3,4-dihydroxybenzaldehyde (L‧H2) with ethylenediamine (en), o-phenylenediamine (o-PD), or 4,5-dimethyl-1,2-phenylendiamine (DMPD) in a mole ratio of 2:1 followed by the reaction of the resulting Schiff bases ligands with Pd(II) or Pt(II) ions in the presence of 2,2‧-dipyridyl (L) to form the di- and tri-nuclear metal complexes. The second method involve the condensation of the Pd complex LPd(II)L‧, (L = 2,2‧-dipyridyl, L‧ = 4-formylbenzene-1,2-bis(olate)) with en, o-PD, or DMPD in a mole ratio of 2:1, respectively, followed by reaction with PdCl2 to form di-, tri-, and tetra-nuclear palladium(II) complexes, respectively. Structures of ligands and metal complexes are characterized by physical properties, FT-IR spectra and nuclear magnetic resonance. The geometries of metal complexes are suggested according to elemental analysis, electronic absorption spectra, thermal analysis, atomic absorption, magnetic susceptibility and molar conductance. Cytotoxic activity against lung large cell carcinoma (H460), prostate carcinoma (DU145), breast adenocarcinoma (MCF-7), amelanotic melanoma (M-14), colon adenocarcinoma (HT-29), and chronic myelogenous leukemia (K562) is also reported.

  12. Swift heavy ion irradiation of Pt nanocrystals: II. Structural changes and H desorption

    SciTech Connect

    Giulian, R.; Araujo, L.L.; Kluth, P.; Sprouster, D.J.; Schnohr, C.S.; Byrne, A.P.; Ridgway, M.C.

    2014-09-24

    The structural properties and H desorption from embedded Pt nanocrystals (NCs) following irradiation with swift heavy ions were investigated as a function of energy and fluence. From x-ray absorption near-edge spectroscopy analysis, Pt-H bonding was identified in NCs annealed in a forming gas (95% N{sub 2} + 5% H{sub 2}) ambient. The H content decreased upon irradiation and the desorption process was NC-size dependent such that larger NCs required a higher fluence to achieve a H-free state. Pt-H bonding and NC dissolution both perturbed the NC structural parameters (coordination number, bond-length and mean-square relative displacement) as determined with extended x-ray absorption fine structure measurements.

  13. Ni(II), Pd(II) and Pt(II) complexes of (1H-1,2,4-triazole-3-ylimino)methyl]naphthalene-2-ol. Structural, spectroscopic, biological, cytotoxicity, antioxidant and DNA binding

    NASA Astrophysics Data System (ADS)

    Gaber, M.; El-Ghamry, H. A.; Fathalla, S. K.

    2015-03-01

    Metal complexes of the general formula [ML(H2O)Cl]nH2O; n = 1 for M = Ni and Pt and n = 2 for M = Pd, L = Schiff base (HL) derived from the condensation of 3-amino-1,2,4-triazole and 2-hydroxy-1-naphthaldehyde, were prepared. The synthesized ligand and its metal complexes were characterized on the basis of elemental analyses, spectral and magnetic studies as well as thermal analysis. The IR spectra revealed that the ligand is coordinated to the metal ions in bidentate manner via the N-atom of the azomethine group and the phenolic OH group. Square planar geometry was proposed for Pd(II) and Pt(II) complexes and tetrahedral for Ni(II) complex. The ligand and its metal complexes were screened against the sensitive organisms Escherichia coli as Gram-negative bacteria, Staphylococcus aureus as Gram-positive bacteria, Aspergillus flavus and Candida albicans as fungi. Moreover, the anticancer activity of the ligand and its metal complexes was evaluated in liver carcinoma (HEPG2) cell line. The results obtained indicated that the Schiff base ligand is more effective than its metal complexes towards the tested cell line. Ni(II), Pd(II) and Pt(II) complexes as well as the free Schiff base ligand were tested for their antioxidant activities. The DNA-binding properties of the studied complexes have been investigated by electronic absorption and viscosity measurements.

  14. Direct functionalization of M-C (M = Pt(II), Pd(II)) bonds using environmentally benign oxidants, O2 and H2O2.

    PubMed

    Vedernikov, Andrei N

    2012-06-19

    Atom economy and the use of "green" reagents in organic oxidation, including oxidation of hydrocarbons, remain challenges for organic synthesis. Solutions to this problem would lead to a more sustainable economy because of improved access to energy resources such as natural gas. Although natural gas is still abundant, about a third of methane extracted in distant oil fields currently cannot be used as a chemical feedstock because of a dearth of economically and ecologically viable methodologies for partial methane oxidation. Two readily available "atom-economical" "green" oxidants are dioxygen and hydrogen peroxide, but few methodologies have utilized these oxidants effectively in selective organic transformations. Hydrocarbon oxidation and C-H functionalization reactions rely on Pd(II) and Pt(II) complexes. These reagents have practical advantages because they can tolerate moisture and atmospheric oxygen. But this tolerance for atmospheric oxygen also makes it challenging to develop novel organometallic palladium and platinum-catalyzed C-H oxidation reactions utilizing O(2) or H(2)O(2). This Account focuses on these challenges: the development of M-C bond (M = Pt(II), Pd(II)) functionalization and related selective hydrocarbon C-H oxidations with O(2) or H(2)O(2). Reactions discussed in this Account do not involve mediators, since the latter can impart low reaction selectivity and catalyst instability. As an efficient solution to the problem of direct M-C oxidation and functionalization with O(2) and H(2)O(2), this Account introduces the use of facially chelating semilabile ligands such as di(2-pyridyl)methanesulfonate and the hydrated form of di(2-pyridyl)ketone that enable selective and facile M(II)-C(sp(n)) bond functionalization with O(2) (M = Pt, n = 3; M = Pd, n = 3 (benzylic)) or H(2)O(2) (M = Pd, n = 2). The reactions proceed efficiently in protic solvents such as water, methanol, or acetic acid. With the exception of benzylic Pd(II) complexes, the

  15. Coordination of Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), Pd(II) and Pt(II) with 2,5-hexanedione bis(thiosemicarbazone), HBTS: crystal structure of cis-[Pd(HBTS)]Cl2 and 1-(2,5-dimethyl-1H-pyrrol-yl)-thiourea.

    PubMed

    Jeragh, Bakir; El-Asmy, Ahmed A

    2014-09-15

    Metal complexes of Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, Pd2+ or Pt2+ with 2,5-hexanedione bis(thiosemicarbazone), HBTS; have been prepared and spectroscopically investigated. The empirical formulae of the complexes were suggested based on the elemental analysis. Single crystal of Pd(II) has been solved to be cis-form of square-planar geometry by the X-ray crystallography. 1H and 13C NMR spectra have been recorded for HBTS, Zn(II), Cd(II), Hg(II), Pd(II) and Pt(II) complexes, in DMSO-d6, showing the mode of chelation. The ligand acts as a neutral or a binegative tetradentate (N2S2) or neutral bidentate on the basis of FT-IR. The magnetic moments and electronic spectra provide information about the geometry of the complexes which supported by calculating the ligand field parameters for the Co(II) and Fe(III) complexes. The Ni(II) complex has subnormal magnetic moment (0.71 BM) indicative of a mixed stereochemistry of square-planar and tetrahedral structure. [Cu(HBTS-2H)] measured 0.93 BM indicating high interaction between the copper centers. The ligand may be ordered at the top of the spectrochemical series which giving high ligand field splitting energy (10 Dq=17,900 cm(-1) for Co2+ complex). The mass spectra of some complexes proved their stable chemical formulae while the TGA depicts the degradation steps and the final residue. In evaporating the mother liquor during the preparation of HBTS, new compound is obtained naming 1-(2,5-dimethyl-1H-pyrrol-yl)thiourea and its crystal was solved. PMID:24813284

  16. Coordination of Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), Pd(II) and Pt(II) with 2,5-hexanedione bis(thiosemicarbazone), HBTS: Crystal structure of cis-[Pd(HBTS)]Cl2 and 1-(2,5-dimethyl-1H-pyrrol-yl)-thiourea

    NASA Astrophysics Data System (ADS)

    Jeragh, Bakir; El-Asmy, Ahmed A.

    2014-09-01

    Metal complexes of Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, Pd2+ or Pt2+ with 2,5-hexanedione bis(thiosemicarbazone), HBTS; have been prepared and spectroscopically investigated. The empirical formulae of the complexes were suggested based on the elemental analysis. Single crystal of Pd(II) has been solved to be cis-form of square-planar geometry by the X-ray crystallography. 1H and 13C NMR spectra have been recorded for HBTS, Zn(II), Cd(II), Hg(II), Pd(II) and Pt(II) complexes, in DMSO-d6, showing the mode of chelation. The ligand acts as a neutral or a binegative tetradentate (N2S2) or neutral bidentate on the basis of FT-IR. The magnetic moments and electronic spectra provide information about the geometry of the complexes which supported by calculating the ligand field parameters for the Co(II) and Fe(III) complexes. The Ni(II) complex has subnormal magnetic moment (0.71 BM) indicative of a mixed stereochemistry of square-planar and tetrahedral structure. [Cu(HBTS-2H)] measured 0.93 BM indicating high interaction between the copper centers. The ligand may be ordered at the top of the spectrochemical series which giving high ligand field splitting energy (10Dq = 17,900 cm-1 for Co2+ complex). The mass spectra of some complexes proved their stable chemical formulae while the TGA depicts the degradation steps and the final residue. In evaporating the mother liquor during the preparation of HBTS, new compound is obtained naming 1-(2,5-dimethyl-1H-pyrrol-yl)thiourea and its crystal was solved.

  17. High-efficiency turquoise-blue electrophosphorescence from a Pt(II)-pyridyltriazolate complex in a phosphine oxide host

    NASA Astrophysics Data System (ADS)

    Bhansali, Unnat S.; Polikarpov, Evgueni; Swensen, James S.; Chen, Wei-Hsuan; Jia, Huiping; Gaspar, Daniel J.; Gnade, Bruce E.; Padmaperuma, Asanga B.; Omary, Mohammad A.

    2009-12-01

    We demonstrate high-efficiency turquoise-blue electrophosphorescence from bis[3,5-bis(2-pyridyl)-1,2,4-triazolato]platinum(II) [Pt(ptp)2] doped in 4-(diphenylphosphoryl)-N ,N-diphenylaniline(HM-A1). Organic light-emitting diodes (OLEDs) with 5% Pt(ptp)2:HM-A1 attain peak power efficiency of 61.2 lm/W, versus 40.8 lm/W for analogous devices employing the standard turquoise-blue phosphor bis[(4,6-difluorophenyl)-pyridinato-N,C2'](picolinato)iridium(III) (FIrpic). Devices with x% Pt(ptp)2:HM-A1 exhibit blue emission maxima (λmax˜480 nm) with monotonic increase in excimer/monomer intensity ratio at higher doping levels within 1%-10%, causing color shift toward green and less charge balance. This work represents a significant step toward optimizing future white OLEDs from the same phosphor via combination of low-doped and higher-doped or neat films.

  18. Iso-chemical potential trajectories in the P-T plane for He II

    NASA Technical Reports Server (NTRS)

    Maytal, B.; Nissen, J. A.; Van Sciver, S. W.

    1990-01-01

    Trajectories of constant chemical potential in the P-T plane serve as an integral formulation of London's equation. The trajectories are useful for analysis and synthesis of fountain effect pump performance. A family of trajectories is generated from available numerical codes.

  19. Study on propagation characteristics of temporal soliton in Scarff II PT-symmetric potential based on intensity moments

    NASA Astrophysics Data System (ADS)

    Deng, Yangbao; Deng, Shuguang; Tan, Chao; Xiong, Cuixiu; Zhang, Guangfu; Tian, Ye

    2016-05-01

    When a temporal soliton propagates in the inhomogeneous nonlinear medium with Scarff II parity-time (PT)-symmetric potential, we investigate the propagation characteristics of a temporal soliton based on intensity moments. Under the condition of Scarff II PT-symmetric potential, the propagation characteristics of a temporal soliton are affected by the dispersion coefficient, nonlinear coefficient and chirp. After a detailed analysis of the intensity evolution and the second-order intensity moment parameter, we find that the intensity and pulse width (PW) of a chirped-free temporal soliton are invariant during nonlinear propagation when the dispersion coefficients are the constant, exponential decreasing function and periodic modulated function, respectively. The intensity and PW of a chirped temporal soliton vary periodically when the dispersion coefficient is a periodic modulated function. So the chirp has no effect on propagation behavior of a temporal soliton. When the dispersion coefficients are the constant or exponential decreasing function, the intensity of a chirped temporal soliton is gradually increased, while the PW of a chirped temporal soliton is gradually decreased. Thus the temporal soliton is compressed and the chirp has a great effect on the propagation behavior of a temporal soliton. The results will be helpful to manipulation of nonlinear propagation of the laser pulses.

  20. Intraoral venous malformation with phleboliths

    PubMed Central

    Mohan, Ravi Prakash S.; Dhillon, Manu; Gill, Navneet

    2011-01-01

    The most common type of vascular malformation is the venous malformation and these are occasionally associated with phleboliths. We report a case of a 45 year old woman with intraoral venous malformation with phleboliths. PMID:24151422

  1. Synthesis and photoelectric properties of new Dawson-type polyoxometalate-based dimeric and oligomeric Pt(II)-acetylide inorganic-organic hybrids.

    PubMed

    Liu, Li; Hu, Lei; Liu, Qian; Du, Zu-Liang; Li, Fa-Bao; Li, Guang-Hua; Zhu, Xun-Jin; Wong, Wai-Yeung; Wang, Lei; Li, Hua

    2015-01-01

    A new synthesis route for preparing Dawson-type polyoxometalate (POM) based inorganic-organic hybrid materials is presented. Two new heteropolytungstate-based dimeric and oligomeric Pt(II) acetylide inorganic-organic hybrid compounds (2PtOD and PPtOD) were prepared by Hagihara's dehydrohalogenating coupling of a terminal diacetylene POM hybrid containing diphosphoryl functionality and an appropriate platinum(II) halide precursor. This method provides a rigid covalent linkage between the POM and the organometallic Pt(II) acetylide moiety. The redox potential of the polyanion can be tuned by grafting the organic and organometallic groups on it. The photoelectric properties of hybrid LB films derived from these inorganic-organic composites were studied. PMID:25382654

  2. Novel monofunctional platinum (II) complex Mono-Pt induces apoptosis-independent autophagic cell death in human ovarian carcinoma cells, distinct from cisplatin

    PubMed Central

    Guo, Wen-Jie; Zhang, Yang-Miao; Zhang, Li; Huang, Bin; Tao, Fei-Fei; Chen, Wei; Guo, Zi-Jian; Xu, Qiang; Sun, Yang

    2013-01-01

    Failure to engage apoptosis appears to be a leading mechanism of resistance to traditional platinum drugs in patients with ovarian cancer. Therefore, an alternative strategy to induce cell death is needed for the chemotherapy of this apoptosis-resistant cancer. Here we report that autophagic cell death, distinct from cisplatin-induced apoptosis, is triggered by a novel monofunctional platinum (II) complex named Mono-Pt in human ovarian carcinoma cells. Mono-Pt-induced cell death has the following features: cytoplasmic vacuolation, caspase-independent, no nuclear fragmentation or chromatin condensation, and no apoptotic bodies. These characteristics integrally indicated that Mono-Pt, rather than cisplatin, initiated a nonapoptotic cell death in Caov-3 ovarian carcinoma cells. Furthermore, incubation of the cells with Mono-Pt but not with cisplatin produced an increasing punctate distribution of microtubule-associated protein 1 light chain 3 (LC3), and an increasing ratio of LC3-II to LC3-I. Mono-Pt also caused the formation of autophagic vacuoles as revealed by monodansylcadaverine staining and transmission electron microscopy. In addition, Mono-Pt-induced cell death was significantly inhibited by the knockdown of either BECN1 or ATG7 gene expression, or by autophagy inhibitors 3-methyladenine, chloroquine and bafilomycin A1. Moreover, the effect of Mono-Pt involved the AKT1-MTOR-RPS6KB1 pathway and MAPK1 (ERK2)/MAPK3 (ERK1) signaling, since the MTOR inhibitor rapamycin increased, while the MAPK1/3 inhibitor U0126 decreased Mono-Pt-induced autophagic cell death. Taken together, our results suggest that Mono-Pt exerts anticancer effect via autophagic cell death in apoptosis-resistant ovarian cancer. These findings lead to increased options for anticancer platinum drugs to induce cell death in cancer. PMID:23580233

  3. Synthesis, spectral and theoretical studies of Ni(II), Pd(II) and Pt(II) complexes of 5-mercapto-1,2,4-triazole-3-imine-2'-hydroxynaphthaline.

    PubMed

    Gaber, Mohamed; El-Ghamry, Hoda; Atlam, Faten; Fathalla, Shaimaa

    2015-02-25

    Ni(II), Pd(II) and Pt(II) complexes of 5-mercapto-1,2,4-triazole-3-imine-2'-hydroxynaphthaline have been isolated and characterized by elemental analysis, IR, (1)H NMR, EI-mass, UV-vis, molar conductance, magnetic moment measurements and thermogravimetric analysis. The molar conductance values indicated that the complexes are non-electrolytes. The magnetic moment values of the complexes displayed diamagnetic behavior for Pd(II) and Pt(II) complexes and tetrahedral geometrical structure for Ni(II) complex. From the bioinorganic applications point of view, the interaction of the ligand and its metal complexes with CT-DNA was investigated using absorption and viscosity titration techniques. The Schiff-base ligand and its metal complexes have also been screened for their antimicrobial and antitumor activities. Also, theoretical investigation of molecular and electronic structures of the studied ligand and its metal complexes has been carried out. Molecular orbital calculations were performed using DFT (density functional theory) at B3LYP level with standard 6-31G(d,p) and LANL2DZ basis sets to access reliable results to the experimental values. The calculations were performed to obtain the optimized molecular geometry, charge density distribution, extent of distortion from regular geometry, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), Mulliken atomic charges, reactivity index (ΔE), dipole moment (D), global hardness (η), softness (σ), electrophilicity index (ω), chemical potential and Mulliken electronegativity (χ). PMID:25282021

  4. Synthesis, spectral and theoretical studies of Ni(II), Pd(II) and Pt(II) complexes of 5-mercapto-1,2,4-triazole-3-imine-2‧-hydroxynaphyhaline

    NASA Astrophysics Data System (ADS)

    Gaber, Mohamed; El-Ghamry, Hoda; Atlam, Faten; Fathalla, Shaimaa

    2015-02-01

    Ni(II), Pd(II) and Pt(II) complexes of 5-mercapto-1,2,4-triazole-3-imine-2‧-hydroxynaphthaline have been isolated and characterized by elemental analysis, IR, 1H NMR, EI-mass, UV-vis, molar conductance, magnetic moment measurements and thermogravimetric analysis. The molar conductance values indicated that the complexes are non-electrolytes. The magnetic moment values of the complexes displayed diamagnetic behavior for Pd(II) and Pt(II) complexes and tetrahedral geometrical structure for Ni(II) complex. From the bioinorganic applications point of view, the interaction of the ligand and its metal complexes with CT-DNA was investigated using absorption and viscosity titration techniques. The Schiff-base ligand and its metal complexes have also been screened for their antimicrobial and antitumor activities. Also, theoretical investigation of molecular and electronic structures of the studied ligand and its metal complexes has been carried out. Molecular orbital calculations were performed using DFT (density functional theory) at B3LYP level with standard 6-31G(d,p) and LANL2DZ basis sets to access reliable results to the experimental values. The calculations were performed to obtain the optimized molecular geometry, charge density distribution, extent of distortion from regular geometry, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), Mulliken atomic charges, reactivity index (ΔE), dipole moment (D), global hardness (η), softness (σ), electrophilicity index (ω), chemical potential and Mulliken electronegativity (χ).

  5. Recent results of high p(T) physics at the CDF II

    SciTech Connect

    Tsuno, Soushi; /Okayama U.

    2005-02-01

    The Tevatron Run II program has been in progress since 2001. The CDF experiment has accumulated roughly five times as much data as did Run I, with much improved detectors. Preliminary results from the CDF experiment are presented. The authors focus on recent high p{sub T} physics results in the Tevatron Run II program.

  6. Synthesis, cytotoxicity, DNA interaction and cell cycle studies of trans-diiodophosphine Pt(II) complexes.

    PubMed

    Medrano, Angeles; Dennis, Stephen M; Alvarez-Valdés, Amparo; Perles, Josefina; McGregor Mason, Tracey; Quiroga, Adoracion G

    2015-02-28

    Platinum complexes, bearing aliphatic amines and phosphine ligands in trans configuration with iodide as leaving groups, are synthesized and characterized. The crystal structure of trans-PtI2(isopropylamine)(PPh3) is reported. The complex bearing isopropylamine is demonstrated to be the best candidate as its cytotoxic activity is comparable to or better than cisplatin. A remarkably higher interaction of the complexes with DNA is reported as compared to the parent chlorido series. Cell cycle studies of the complexes in six human cell lines are performed and also compared with the previous series. PMID:25310702

  7. Radiosensitization of DNA in presence of Pt(II)-based compounds

    NASA Astrophysics Data System (ADS)

    Śmiałek, Małgorzata A.; Ptasińska, Sylwia; Gow, Jason; Pieve, Chiara Da; Mason, Nigel J.

    2014-04-01

    X-ray irradiation of plasmid DNA in presence of platinum (II)-based compounds was carried out in order to assess the radiosensitization capabilities of these drugs. In present investigations pBR322 plasmid DNA was used to monitor the effectiveness of chosen compounds in inducing strand breaks. Samples were incubated in the presence of potential radiosensitisers: platinum (II) bromide and cis-diamminedibromoplatinum (II). The results were examined against a common cancer chemotherapy drug cis-diamminedichloroplatinum (II). It was found that platinum (II) bromide can greatly increase the levels of single- and double-strand break formation observed in the irradiated samples with respect to the samples containing platinum as a radiosensitizer only, possessing very little chemotherapeutic activity. The suggested drugs exhibit much higher level of radiosensitivity than widely used cisplatin and thus may be good candidates for cancer treatment.

  8. Cerebellar and Brainstem Malformations.

    PubMed

    Poretti, Andrea; Boltshauser, Eugen; Huisman, Thierry A G M

    2016-08-01

    The frequency and importance of the evaluation of the posterior fossa have increased significantly over the past 20 years owing to advances in neuroimaging. Conventional and advanced neuroimaging techniques allow detailed evaluation of the complex anatomic structures within the posterior fossa. A wide spectrum of cerebellar and brainstem malformations has been shown. Familiarity with the spectrum of cerebellar and brainstem malformations and their well-defined diagnostic criteria is crucial for optimal therapy, an accurate prognosis, and correct genetic counseling. This article discusses cerebellar and brainstem malformations, with emphasis on neuroimaging findings (including diagnostic criteria), neurologic presentation, systemic involvement, prognosis, and recurrence. PMID:27423798

  9. Pediatric neuroanesthesia. Arteriovenous malformations.

    PubMed

    Newfield, P; Hamid, R K

    2001-06-01

    Intracranial arteriovenous malformations can occur singly, multiply, and in conjunction with aneurysms and denovo, family, or in conjunction with connective-tissue disorders. Intracranial hemorrhage is the most common presentation, occurring in 20% to 50% of cases. In children, seizures are the second most common presentation occurring in 15% to 20% of cases. The modalities available treatment of arteriovenous malformations are microsurgery, embolization, and stereotactic radiosurgery with heavy particles, alpha knife, or linear accelerator. Induction, maintenance, and emergence from anesthesia are designed to prevent rupture of arteriovenous malformation and aneurysm and to improve intracranial compliance in the presence of an intracranial hematoma, during both diagnostic (CT, MR scanning) and therapeutic procedures. PMID:11469062

  10. Rational Design of an Electron-Reservoir Pt(II) Complex for Efficient Photocatalytic Hydrogen Production from Water.

    PubMed

    Whang, Dong Ryeol; Park, Soo Young

    2015-10-12

    Herein we report a Pt(II) complex containing a 4,4'-bis[4-(triphenylsilyl)phenyl]-2,2'-bipyridine ligand as a molecular catalyst for water splitting. Systematic studies of the electrochemical and electronic properties of this catalyst, in comparison with two control complexes, reveal electron-reservoir characteristics upon two-electron reduction. A turnover number of 510,000 was recorded by employing this complex as a water reduction catalyst in combination with a state-of-the-art photosensitizer and N,N-dimethylaniline as a sacrificial electron donor, which represents a large improvement over the control complexes that do not contain the tetraphenylsilyl ligand substitution. PMID:26315804

  11. Experimental and Theoretical Investigation for the Level of Conjugation in Carbazole-Based Precursors and Their Mono-, Di-, and Polynuclear Pt(II) Complexes.

    PubMed

    Al-Balushi, Rayya A; Haque, Ashanul; Jayapal, Maharaja; Al-Suti, Mohammed K; Husband, John; Khan, Muhammad S; Koentjoro, Olivia F; Molloy, Kieran C; Skelton, Jonathan M; Raithby, Paul R

    2016-07-01

    A series of trimethylsilyl-protected monoalkynes (Me3SiC≡C-R) and bis-alkynes (Me3 SiC≡C-R-C≡CSiMe3) incorporating carbazole spacer groups (R = carbazole-2-yl, carbazole-3-yl, carbazole-2,7-diyl, N-(2-ethylhexyl)carbazole-2,7-diyl, carbazole-3,6-diyl, N-(2-ethylhexyl)carbazole-3,6-diyl), together with the corresponding terminal monoalkynes (H-C≡C-R) and bis-alkynes (H-C≡C-R-C≡C-H), have been synthesized and characterized. The CuI-catalyzed dehydrohalogenation reaction between trans-[(Ph)(Et3P)2PtCl], trans-[(Et3P)2PtCl2], and trans-[(P(n)Bu3)2PtCl2] and the terminal alkynes in (i)Pr2NH/CH2Cl2 affords a series of Pt(II) mono- and diynes, while the dehydrohalogenation polycondensation reactions with trans-[(P(n)Bu3)2PtCl2] under similar reaction conditions yields four Pt(II) poly-ynes of the form trans-[(P(n)Bu3)2Pt-C≡C-R-C≡C-]n. The acetylide-functionalized carbazole ligands and the mono-, di-, and polynuclear Pt(II) σ-acetylide complexes have been characterized spectroscopically, with a subset analyzed using single-crystal X-ray diffraction. The Pt(II) mono-, di-, and poly-ynes incorporating the carbazole spacers are soluble in common organic solvents, and solution absorption spectra show a consistent red-shift between the 2- and 2,7- as well as 3- and 3,6-carbazole complexes. Computational modeling is used to explain the observed spectral shifts, which are related to the enhanced electronic delocalization in the latter systems. These results also indicate that the inclusion of carbazole-2,7-diyl units into rigid-rod organometallic polymers should enhance electronic transport along the chains. PMID:27284807

  12. Experimental and quantum-chemical studies of 1H, 13C and 15N NMR coordination shifts in Au(III), Pd(II) and Pt(II) chloride complexes with picolines.

    PubMed

    Pazderski, Leszek; Tousek, Jaromír; Sitkowski, Jerzy; Malináková, Katerina; Kozerski, Lech; Szłyk, Edward

    2009-03-01

    (1)H, (13)C and (15)N NMR studies of gold(III), palladium(II) and platinum(II) chloride complexes with picolines, [Au(PIC)Cl(3)], trans-[Pd(PIC)(2)Cl(2)], trans/cis-[Pt(PIC)(2)Cl(2)] and [Pt(PIC)(4)]Cl(2), were performed. After complexation, the (1)H and (13)C signals were shifted to higher frequency, whereas the (15)N ones to lower (by ca 80-110 ppm), with respect to the free ligands. The (15)N shielding phenomenon was enhanced in the series [Au(PIC)Cl(3)] < trans-[Pd(PIC)(2)Cl(2)] < cis-[Pt(PIC)(2)Cl(2)] < trans-[Pt(PIC)(2)Cl(2)]; it increased following the Pd(II) --> Pt(II) replacement, but decreased upon the trans --> cis-transition. Experimental (1)H, (13)C and (15)N NMR chemical shifts were compared to those quantum-chemically calculated by B3LYP/LanL2DZ + 6-31G**//B3LYP/LanL2DZ + 6-31G*. PMID:19097135

  13. Measurement of low $p_{T}$ $D^{0}$ meson production cross section at CDF II

    SciTech Connect

    Mussini, Manuel

    2011-05-01

    In this thesis we present a study of the production of D0 meson in the low transverse momentum region. In particular the inclusive differential production cross section of the D0 meson (in the two-body decay channel D0 → K-π+) is obtained extending the published CDF II measurement to pT as low as 1.5 GeV/c. This study is performed at the Tevatron Collider at Fermilab with the CDF II detector.

  14. High-efficiency turquoise-blue electrophosphorescence from a Pt(II)-pyridyltriazolate complex in phosphine oxide host

    SciTech Connect

    Bhansali, Unnat S; Polikarpov, Evgueni; Swensen, James S; Chen, Wei; Jia, Huiping; Gaspar, Daniel J; Gnade, Bruce E; Padmaperuma, Asanga B; Omary, Mohammad A

    2009-12-10

    We have demonstrated high-efficiency turquoise-blue electrophosphorescence from the complex Pt(ptp)2 = bis[3,5–bis(2–pyridyl)–1,2,4–triazolato]platinum(II) doped in the wide band-gap, ambipolar phosphine oxide host HM-A1 = 4-(diphenylphosphoryl)-N,N-diphenylaniline. For devices with 5% Pt(ptp)2 doping in HM-A1, we have achieved a peak external quantum efficiency and power efficiency of (11.8 ± 0.6) % and (61.2 ± 5.9) lm/W with high-pixel values of 13.1 % and 70.6 lm/W, respectively. These parameters maintained (10.6 ± 0.2) % and (40.3 ± 1.2) lm/W at a brightness of 1000 cd/m2 with high-pixel values of 10.8 % and 41.6 lm/W. Examination of several device structures suggests that the high performance is due to improved charge transport and exciton confinement in the emissive region. Devices with 1-10% doping concentration exhibit turquoise-blue emissions (λmax ~ 480 nm) with a monotonic decrease in monomer/excimer intensity ratio upon increasing the doping concentration. Devices with 5% doping exhibit sufficient blue contribution to attain white light upon combination with highly-doped or neat emissive layers of the same phosphor; the work herein represents a significant backdrop toward optimizing such white OLEDs given the performance metrics above, which to our knowledge represent the highest performance for OLEDs that exhibit blue emission maxima.

  15. Rich spectroscopic and molecular dynamic studies on the interaction of cytotoxic Pt(II) and Pd(II) complexes of glycine derivatives with calf thymus DNA.

    PubMed

    Eslami Moghadam, Mahboube; Saidifar, Maryam; Divsalar, Adeleh; Mansouri-Torshizi, Hassan; Saboury, Ali Akbar; Farhangian, Hossein; Ghadamgahi, Maryam

    2016-01-01

    Some amino acid derivatives, such as R-glycine, have been synthesized together with their full spectroscopic characterization. The sodium salts of these bidentate amino acid ligands have been interacted with [M(bpy)(H2O)2](NO3)2 giving the corresponding some new complexes with formula [M(bpy)(R-gly)]NO3 (where M is Pt(II) or Pd(II), bpy is 2,2'-bipyridine and R-gly is butyl-, hexyl- and octyl-glycine). Due to less solubility of octyl derivatives, the biological activities of butyl and hexyl derivatives have been tested against chronic myelogenous leukemia cell line, K562. The interaction of these complexes with highly polymerized calf thymus DNA has been extensively studied by means of electronic absorption, fluorescence and other measurements. The experimental results suggest that these complexes positive cooperatively bind to DNA presumably via groove binding. Molecular dynamic results show that the DNA structure is largely maintained its native structure in hexylglycine derivative-water mixtures and at lower temperatures. The simulation data indicates that the more destabilizing effect of butylglycine is induced by preferential accumulation of these molecules around the DNA and due to their more negative free energy of binding via groove binding. PMID:25734364

  16. Electrophilic Pt(II) Complexes: Precision Instruments for the Initiation of Transformations Mediated by the Cation–Olefin Reaction

    PubMed Central

    2015-01-01

    A discontinuity exists between the importance of the cation–olefin reaction as the principal C–C bond forming reaction in terpene biosynthesis and the synthetic tools for mimicking this reaction under catalyst control; that is, having the product identity, stereochemistry, and functionality under the control of a catalyst. The main reason for this deficiency is that the cation–olefin reaction starts with a reactive intermediate (a carbocation) that reacts exothermically with an alkene to reform the reactive intermediate; not to mention that reactive intermediates can also react in nonproductive fashions. In this Account, we detail our efforts to realize catalyst control over this most fundamental of reactions and thereby access steroid like compounds. Our story is organized around our progress in each component of the cascade reaction: the metal controlled electrophilic initiation, the propagation and termination of the cyclization (the cyclase phase), and the turnover deplatinating events. Electrophilic Pt(II) complexes efficiently initiate the cation–olefin reaction by first coordinating to the alkene with selection rules that favor less substituted alkenes over more substituted alkenes. In complex substrates with multiple alkenes, this preference ensures that the least substituted alkene is always the better ligand for the Pt(II) initiator, and consequently the site at which all electrophilic chemistry is initiated. This control element is invariant. With a suitably electron deficient ligand set, the catalyst then activates the coordinated alkene to intramolecular addition by a second alkene, which initiates the cation–olefin reaction cascade and generates an organometallic Pt(II)-alkyl. Deplatination by a range of mechanisms (β-H elimination, single electron oxidation, two-electron oxidation, etc.) provides an additional level of control that ultimately enables A-ring functionalizations that are orthogonal to the cyclase cascade. We particularly

  17. Synthesis of N4 donor macrocyclic Schiff base ligands and their Ru (II), Pd (II), Pt (II) metal complexes for biological studies and catalytic oxidation of didanosine in pharmaceuticals

    NASA Astrophysics Data System (ADS)

    Ravi krishna, E.; Muralidhar Reddy, P.; Sarangapani, M.; Hanmanthu, G.; Geeta, B.; Shoba Rani, K.; Ravinder, V.

    2012-11-01

    A series of tetraaza (N4 donor) macrocyclic ligands (L1-L4) were derived from the condensation of o-phthalaldehyde (OPA) with some substituted aromatic amines/azide, and subsequently used to synthesize the metal complexes of Ru(II), Pd(II) and Pt(II). The structures of macrocyclic ligands and their metal complexes were characterized by elemental analyses, IR, 1H &13C NMR, mass and electronic spectroscopy, thermal, magnetic and conductance measurements. Both the ligands and their complexes were screened for their antibacterial activities against Gram positive and Gram negative bacteria by MIC method. Besides, these macrocyclic complexes were investigated as catalysts in the oxidation of pharmaceutical drug didanosine. The oxidized products were further treated with sulphanilic acid to develop the colored products to determine by spectrophotometrically. The current oxidation method is an environmentally friendly, simple to set-up, requires short reaction time, produces high yields and does not require co-oxidant.

  18. Synthesis and Characterization of Novel Cu(II), Pd(II) and Pt(II) Complexes with 8-Ethyl-2-hydroxytricyclo(7.3.1.0(2,7))tridecan-13-one-thiosemicarbazone: Antimicrobial and in Vitro Antiproliferative Activity.

    PubMed

    Pahonțu, Elena; Paraschivescu, Codruța; Ilieș, Diana-Carolina; Poirier, Donald; Oprean, Camelia; Păunescu, Virgil; Gulea, Aurelian; Roșu, Tudor; Bratu, Ovidiu

    2016-01-01

    New Cu(II), Pd(II) and Pt(II) complexes, (Cu(L)(H₂O)₂(OAc)) (1), (Cu(HL)(H₂O)₂(SO₄)) (2), (Cu(L)(H₂O)₂(NO₃)) (3), (Cu(L)(H₂O)₂(ClO₄)) (4), (Cu(L)₂(H₂O)₂) (5), (Pd(L)(OAc))H₂O (6), and (Pt(L)₂) (7) were synthesized from 8-ethyl-2-hydroxytricyclo(7.3.1.0(2,7))tridecan-13-one thiosemicarbazone (HL). The ligand and its metal complexes were characterized by IR, ¹H-NMR, (13)C-NMR, UV-Vis, FAB, EPR, mass spectroscopy, elemental and thermal analysis, magnetic susceptibility measurements and molar electric conductivity. The free ligand and the metal complexes have been tested for their antimicrobial activity against E. coli, S. enteritidis, S. aureus, E. faecalis, C. albicans and cytotoxicity against the NCI-H1573 lung adenocarcinoma, SKBR-3 human breast, MCF-7 human breast, A375 human melanoma and HL-60 human promyelocytic leukemia cell lines. Copper complex 2 exhibited the best antiproliferative activities against MCF-7 human breast cancer cells. A significant inhibition of malignant HL-60 cell growth was observed for copper complex 2, palladium complex 6 and platinum complex 7, with IC50 values of 1.6 µM, 6.5 µM and 6.4 µM, respectively. PMID:27213326

  19. Thiosemicarbazone-Pt(II) Complex Causes a Growth Inhibitory Effect on Human Mesenchymal Stem Cells.

    PubMed

    Garcia-Ruiz, Josefa Predestinacion; Matesanz Garcia, Ana Isabel; Souza, Ana Perez; Castelo, Pilar Souza

    2015-01-01

    We showed di[3,5-diacetyl-1,2,4-triazolbis(4-cyclohexylthiosemicarbazonato) platinum(II)] complex, (W8), endowed with important antitumor properties. Here, we analysed whether W8 can affect human bone marrow-derived Mesenchymal Stem Cells, (hMSCs), involved in tissue repair, immunomodulatory properties and also capacity for homing to injure-tumor sites in ovarian cancer. Specifically, we analysed the effect of W8 on cell proliferation, response to scratch, and whether copper-derived cellular mechanism is used by this platinum(II) complex being studied. Results showed that W8 causes a significant inhibition of cell proliferation at µM concentration. This effect is directly related to the alteration of cytoskeletal proteins and inhibition of the response to scratch induced by the presence of foetal bovine serum. This strongly supports the notion of W8 triggers the energetic metabolism of hMSCs and adds an extra support by the results showing W8 relationship with the cellular copper ions. W8, acting in hMSCs, regulates in addition the inhibition of cell proliferation, the inhibition of tumor angiogenesis and metastasis. PMID:25974080

  20. A common single-site Pt(II)-O(OH)x- species stabilized by sodium on "active" and "inert" supports catalyzes the water-gas shift reaction.

    PubMed

    Yang, Ming; Liu, Jilei; Lee, Sungsik; Zugic, Branko; Huang, Jun; Allard, Lawrence F; Flytzani-Stephanopoulos, Maria

    2015-03-18

    While it has long been known that different types of support oxides have different capabilities to anchor metals and thus tailor the catalytic behavior, it is not always clear whether the support is a mere carrier of the active metal site, itself not participating directly in the reaction pathway. We report that catalytically similar single-atom-centric Pt sites are formed by binding to sodium ions through -O ligands, the ensemble being equally effective on supports as diverse as TiO2, L-zeolites, and mesoporous silica MCM-41. Loading of 0.5 wt % Pt on all of these supports preserves the Pt in atomic dispersion as Pt(II), and the Pt-O(OH)x- species catalyzes the water-gas shift reaction from ∼120 to 400 °C. Since the effect of the support is "indirect," these findings pave the way for the use of a variety of earth-abundant supports as carriers of atomically dispersed platinum for applications in catalytic fuel-gas processing. PMID:25746682

  1. Control over the Self-Assembly Modes of Pt(II) Complexes by Alkyl Chain Variation: From Slipped to Parallel π-Stacks.

    PubMed

    Allampally, Naveen Kumar; Mayoral, María José; Chansai, Sarayute; Lagunas, María Cristina; Hardacre, Christopher; Stepanenko, Vladimir; Albuquerque, Rodrigo Q; Fernández, Gustavo

    2016-06-01

    We report the self-assembly of a new family of hydrophobic, bis(pyridyl) Pt(II) complexes featuring an extended oligophenyleneethynylene-derived π-surface appended with six long (dodecyloxy (2)) or short (methoxy (3)) side groups. Complex 2, containing dodecyloxy chains, forms fibrous assemblies with a slipped arrangement of the monomer units (dPt⋅⋅⋅Pt ≈14 Å) in both nonpolar solvents and the solid state. Dispersion-corrected PM6 calculations suggest that this organization is driven by cooperative π-π, C-H⋅⋅⋅Cl and π-Pt interactions, which is supported by EXAFS and 2D NMR spectroscopic analysis. In contrast, nearly parallel π-stacks (dPt⋅⋅⋅Pt ≈4.4 Å) stabilized by multiple π-π and C-H⋅⋅⋅Cl contacts are obtained in the crystalline state for 3 lacking long side chains, as shown by X-ray analysis and PM6 calculations. Our results reveal not only the key role of alkyl chain length in controlling self-assembly modes but also show the relevance of Pt-bound chlorine ligands as new supramolecular synthons. PMID:27113990

  2. Pulmonary vascular malformations.

    PubMed

    Liechty, Kenneth W; Flake, Alan W

    2008-02-01

    Pulmonary vascular malformations have historically been diagnosed in a wide range of age groups, but the extensive use of prenatal imaging studies has resulted in the majority of lesions being diagnosed in utero. Among this group of lesions, bronchopulmonary sequestrations (BPS), hybrid lesions with both congenital cystic adenomatoid malformation (CCAM) and BPS, aberrant systemic vascular anastomoses, and pulmonary arteriovenous malformations (PAVM), are the most common. The biologic behavior of these lesions and the subsequent therapy is, in large part, determined by the age of the patient at diagnosis. In the fetus, large BPS or hybrid lesions can result in fetal hydrops and in utero fetal demise. In the perinatal period, pulmonary hypoplasia from the mass effect or air trapping within the cystic component of hybrid lesions can result in life-threatening respiratory distress. In the postnatal period, communication of the lesion with the aero-digestive system can result in recurrent pneumonia. Alternatively, increased pulmonary blood flow from the systemic arterial supply can result in hemorrhage, hemoptysis, or high output cardiac failure. In addition, there have been several reports of malignant degeneration. Finally, the broad spectrum encompassed by these lesions makes classification and subsequent communication of the lesions confusing and difficult. This paper will review the components of these lesions, their associated anomalies, the diagnosis and natural history, and finally, current concepts in the management of pulmonary vascular malformations. PMID:18158137

  3. Probing the biological evaluations of a new designed Pt(II) complex using spectroscopic and theoretical approaches: human hemoglobin as a target.

    PubMed

    Abazari, Omid; Shafaei, Zahra; Divsalar, Adeleh; Eslami-Moghadam, Mahbubeh; Ghalandari, Behafarid; Saboury, Ali Akbar

    2016-05-01

    In recent years, using heavy metal compounds such as platinum as anticancer agent is one of the common ways in chemical therapy. In this study, a new anticancer compound of glycine derivatives of Pt(II) complex (amyl-glycine1, 10-phenanthroline Platinum nitrate) was designed, and the biological effects of this novel compound on the alterations in the function and structure of human hemoglobin (Hb) at different temperatures of 25 and 37°C were assessed by applying various spectroscopic (fluorescence and circular dichroism (CD)) and theoretical methods. Fluorescence data indicated the strong ability of Pt(II) complex to quench the intrinsic fluorescence of Hb. The binding constant, number of binding sites, and thermodynamic parameters at two temperatures were calculated, and the results indicated the major possibility of occurring van der Waals force or hydrogen bond interactions in the Pt(II) complex-Hb interaction. For evaluating the alteration of secondary structure of Hb upon interaction with various concentrations of complex, far-UV CD spectra were used and it was observed that in high dose of complex, significant changes were occurred which is indicative of some side effects in overdosing of this complex. On the other hand, the molecular docking results illustrate that are well in agreement in obtaining data with spectroscopy. Above results suggested that using Pt(II) complex as an anticancer agent, model drug in high-dose usage might cause some disordering in structure and function of Hb as well as improve understanding of the side effects of newly designed metal anticancer drugs undergoing. PMID:26274094

  4. Optical and electrochemical characteristics of ethylenediamine complexes of Pt(II) and Ir(III) with metalated 2-phenyl- and 2-naphthylbenzothiazole

    NASA Astrophysics Data System (ADS)

    Katlenok, E. A.; Balashev, K. P.

    2016-05-01

    The cyclometalated complexes [Pt(C^N)En]PF6 and [Ir(C^N)2En]PF6 ((C^N)- are deprotonated forms of 2-phenylbenzothiazole or 2-naphthylbenzothiazole and En is ethylenediamine) are studied by 1H NMR, IR, electronic absorption, and emission spectroscopy, as well as by voltammetry. Metalation of heterocyclic ligands leads to the formation of five-membered {M(C^N)} cycles in the composition of squareplanar Pt(II) complexes and octahedral Ir(III) complexes of the cis-C,C structure. A bathochromic shift of the metal-to-cyclometalated ligand charge transfer bands and a decrease in the potential difference between the single-electron waves of metal-centered oxidation and ligand-centered reduction of complexes upon substitution of 2-phenylbenzothiazole by 2-naphthylbenzothiazole and of Pt(II) by Ir(II) are shown. The phosphorescence of complexes in the visible region is assigned to the radiative transition from the metal-modified intraligand electronic excited state.

  5. 15N NMR coordination shifts in Pd(II), Pt(II), Au(III), Co(III), Rh(III), Ir(III), Pd(IV), and Pt(IV) complexes with pyridine, 2,2'-bipyridine, 1,10-phenanthroline, quinoline, isoquinoline, 2,2'-biquinoline, 2,2':6', 2'-terpyridine and their alkyl or aryl derivatives.

    PubMed

    Pazderski, Leszek

    2008-01-01

    The 15N NMR data for 105 complexes of Pd(II), Pt(II), Au(III), Co(III), Rh(III), Ir(III), Pd(IV), and Pt(IV) complexes with simple azines such as pyridine, 2,2'-bipyridine, 1,10-phenanthroline, quinoline, isoquinoline, 2,2'-biquinoline, 2,2':6', 2''-terpyridine and their alkyl or aryl derivatives have been reviewed. The 15N NMR coordination shifts, i.e. the differences between the 15N chemical shifts of the same nitrogen in the molecules of the complex and the ligand (Delta(15N) (coord) = delta(15N) (compl)--delta(15N) (lig)), have been related to some structural features of the reviewed coordination compounds, like the type of the central ion and the character of auxiliary ligands (mainly in trans position). These Delta(15N) (coord) parameters are negative, their absolute magnitudes (ca 30-150 ppm) generally increasing in the metal order Au(III) < Pd(II) < Pt(II) and Rh(III) < Co(III) < Pt(IV) < Ir(III), as well as with the enhanced trans influence of the other donor atoms (H, C < Cl < N). PMID:18855335

  6. BSA-stabilized Pt nanozyme for peroxidase mimetics and its application on colorimetric detection of mercury(II) ions.

    PubMed

    Li, Wei; Chen, Bin; Zhang, Haixiang; Sun, Yanhua; Wang, Jun; Zhang, Jinli; Fu, Yan

    2015-04-15

    Bovine serum albumin (BSA) is chosen as the nucleation templates to synthesize Pt-based peroxidase nanomimetics with the average diameter of 2.0nm. The efficient Pt nanozymes consist of 57% Pt(0) and 43% Pt(2+), which possess highly peroxidase-like activity with the Km values of 0.119mM and 41.8mM toward 3,3',5,5'-tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2), respectively. Interestingly, Hg(2+) is able to down-regulate the enzymatic activity of Pt nanoparticles, mainly through the interactions between Hg(2+) and Pt(0). It is the first report to explore a colorimetric Hg(2+) sensing system on the basis of peroxidase mimicking activities of Pt nanoparticles. One of our most intriguing results is that BSA-stabilized Pt nanozymes demonstrate the ability to sense Hg(2+) ions in aqueous solution without significant interference from other metal ions. The Hg(2+) detection limit of 7.2nM is achieved with a linear response range of 0-120nM, and the developed sensing system is potentially applicable for quantitative determination of Hg(2+) in drinking water. PMID:25437360

  7. Pt(II) Phosphors Featuring Both Dicarbene and Functional Biazolate Chelates: Synthesis, Luminescent Properties, and Applications in Organic Light-Emitting Diodes.

    PubMed

    Liao, Jia-Ling; Chi, Yun; Wang, Jin-Yun; Chen, Zhong-Ning; Tsai, Zheng-Hua; Hung, Wen-Yi; Tseng, Meu-Rurng; Lee, Gene-Hsiang

    2016-07-01

    Pt(II) metal complexes [Pt(C^C)(X^X)] comprising three functional dianionic azolate chelates (X^XH2: bipzH2 = 5,5'-di(trifluoromethyl)-3,3'-bipyrazole, bitzH2 = 5,5'-di(trifluoromethyl)-3,3'-bi-1,2,4-triazole, and phpzH2 = 3-(trifluoromethyl)-5-(4-(trifluoromethyl)phenyl)-1H-pyrazole), together with three different charge-neutral dicarbene chelates (i.e., C^C = 1,1'-methylene bis(3-methyl-imidazol-2-ylidene), 1,1'-methylene bis(3-isopropyl-imidazol-2-ylidene), and 1,1'-(propane-1,3-diyl) bis(3-isopropyl-imidazol-2-ylidene), were synthesized and found to show bright solid-state emission depending on the associated X^X and C^C chelates. Pt(II) complexes 1a, 2, and 6 were examined by X-ray diffraction studies, confirming the square-planar skeleton. These Pt(II) metal complexes are found to be nonemissive in degassed solution at RT. The photophysical measurements as neat powder reveals emission maxima ranging from purple to sky blue emission and with high quantum yields for the majority of them. (Time-dependent) density functional theory (DFT/TD-DFT) calculations were executed to elucidate the emission process that was predominated by the combined3LLCT/(3)LMCT/(3)IL character, where LLCT and LMCT and IL stand for ligand-to-ligand charge transfer, ligand-to-metal charge transfer, and intraligand ππ* transition processes. Organic light-emitting devices comprising complex 5a achieved high efficiency (8.9%, 19.4 cd·A(-1), 22.5 lm·W(-1)) with a sky blue emission showing CIEx,y coordinates of (0.18, 0.32). PMID:27302056

  8. Investigation of the interactions between Pt(II) and Pd(II) derivatives of 5,10,15,20-tetrakis (N-methyl-4-pyridyl) porphyrin and G-quadruplex DNA.

    PubMed

    Sabharwal, Navin C; Mendoza, Oscar; Nicoludis, John M; Ruan, Thomas; Mergny, Jean-Louis; Yatsunyk, Liliya A

    2016-04-01

    G-quadruplexes are non-canonical DNA structures formed by guanine-rich DNA sequences that are implicated in cancer and aging. Understanding how small molecule ligands interact with quadruplexes is essential both to the development of novel anticancer therapeutics and to the design of new quadruplex-selective probes needed for elucidation of quadruplex biological functions. In this work, UV-visible, fluorescence, and circular dichroism spectroscopies, fluorescence resonance energy transfer (FRET) melting assays, and resonance light scattering were used to investigate how the Pt(II) and Pd(II) derivatives of the well-studied 5,10,15,20-tetrakis(N-methyl-4-pyridyl)porphyrin (TMPyP4) interact with quadruplexes formed by the human telomeric DNA, Tel22, and by the G-rich sequences from oncogene promoters. Our results suggest that Pt- and PdTMPyP4 interact with Tel22 via efficient π-π stacking with a binding affinity of 10(6)-10(7) M(-1). Under porphyrin excess, PtTMPyP4 aggregates using Tel22 as a template; the aggregates reach maximum size at [PtTMPyP4]/[Tel22] ~8 and dissolve at [PtTMPyP4]/[Tel22] ≤ 2. FRET assays reveal that both porphyrins are excellent stabilizers of human telomeric DNA, with stabilization temperature of 30.7 ± 0.6 °C for PtTMPyP4 and 30.9 ± 0.4 °C for PdTMPyP4 at [PtTMPyP4]/[Tel22] = 2 in K(+) buffer, values significantly higher as compared to those for TMPyP4. The porphyrins display modest selectivity for quadruplex vs. duplex DNA, with selectivity ratios of 150 and 330 for Pt- and PdTMPyP4, respectively. This selectivity was confirmed by observed 'light switch' effect: fluorescence of PtTMPyP4 increases significantly in the presence of a variety of DNA secondary structures, yet the strongest effect is produced by quadruplex DNA. PMID:26748794

  9. Tetrakis- and tris(1-Methyluracil) complexes of Pt(II): formation and properties of a carbon-bonded nucleobase species as well as of heternonuclear derivatives.

    PubMed

    Holland, Lars; Shen, Wei-Zheng; Micklitz, Wolfgang; Lippert, Bernhard

    2007-12-24

    The reaction of K2PtCl4 with an excess of 1-methyluracilate (1-MeU) in water at 60 degrees C leads to the formation of two major products, K2[Pt(1-MeU-N3)4].10H2O (1) and trans-K[Pt(1-MeU-N3)2(1-MeU-C5)(H2O)].3H2O (2). Addition of CuCl2 to an aqueous solution of 2 yields the mixed-metal complex trans-[PtCl(1-MeU-N3,O4)2(1-MeU-C5,O4)Cu(H2O)].H2O (4). Single-crystal X-ray analysis was carried out for 1 and 4. In both compounds, the heterometals (K+ in 1 and Cu2+ in 4) are bonded to exocyclic oxygens atoms of the 1-MeU ligands, giving rise to intermetallic distances of 3.386(2) and 3.528(2) A in 1 and 2.458(1) A in 4. The shortness of the Pt-Cu separation in 4 is consistent with a dative bond between PtII and CuII. The aqua ligand in 2 is readily substituted by a series of other ligands (e.g., 1-MeC, 9-MeGH, and CN-), as demonstrated by 1H NMR spectroscopy, with 3J(195Pt-1H(6)) coupling constants being sensitive indicators. Acid-base equilibria of 1 and 2 have been studied in detail and reveal some unexpected features: 1 has a relatively high basicity, with protonation starting below pH 5, and first and second pKa values being ca. 3.4 and 0.4, respectively. These pKa values are markedly higher than those of related neutral 2:1 or cationic 1:1 complexes and are attributed to both charge effects (-2 charge of 1) and a favorable stabilization of oxygen-protonated species by the arrangement of four exocyclic oxygen groups of 1-MeU ligands at either sides of the platinum coordination planes. Whereas in 2, H+ affinities of the three uracil ligands are in the normal range, there is a surprisingly low acidity of N(3)H of the C5-bonded uracil with a pKa of approximately 12.2, which compares with 9.75 for free 1-methyluracil. This implies that the C5-bonded PtII does not induce the typical acidifying effect of a PtII metal entity when bonded to a ring nitrogen atom of a neutral nucleobase. Rather, the effect is qualitatively similar to that of a metal ion bonded to N3 of an

  10. Etiologies of uterine malformations.

    PubMed

    Jacquinet, Adeline; Millar, Debra; Lehman, Anna

    2016-08-01

    Ranging from aplastic uterus (including Mayer-Rokitansky-Kuster-Hauser syndrome) to incomplete septate uterus, uterine malformations as a group are relatively frequent in the general population. Specific causes remain largely unknown. Although most occurrences ostensibly seem sporadic, familial recurrences have been observed, which strongly implicate genetic factors. Through the study of animal models, human syndromes, and structural chromosomal variation, several candidate genes have been proposed and subsequently tested with targeted methods in series of individuals with isolated, non-isolated, or syndromic uterine malformations. To date, a few genes have garnered strong evidence of causality, mainly in syndromic presentations (HNF1B, WNT4, WNT7A, HOXA13). Sequencing of candidate genes in series of individuals with isolated uterine abnormalities has been able to suggest an association for several genes, but confirmation of a strong causative effect is still lacking for the majority of them. We review the current state of knowledge about the developmental origins of uterine malformations, with a focus on the genetic variants that have been implicated or associated with these conditions in humans, and we discuss potential reasons for the high rate of negative results. The evidence for various environmental and epigenetic factors is also reviewed. © 2016 Wiley Periodicals, Inc. PMID:27273803

  11. A developmental and genetic classification for midbrain-hindbrain malformations

    PubMed Central

    Millen, Kathleen J.; Dobyns, William B.

    2009-01-01

    Advances in neuroimaging, developmental biology and molecular genetics have increased the understanding of developmental disorders affecting the midbrain and hindbrain, both as isolated anomalies and as part of larger malformation syndromes. However, the understanding of these malformations and their relationships with other malformations, within the central nervous system and in the rest of the body, remains limited. A new classification system is proposed, based wherever possible, upon embryology and genetics. Proposed categories include: (i) malformations secondary to early anteroposterior and dorsoventral patterning defects, or to misspecification of mid-hindbrain germinal zones; (ii) malformations associated with later generalized developmental disorders that significantly affect the brainstem and cerebellum (and have a pathogenesis that is at least partly understood); (iii) localized brain malformations that significantly affect the brain stem and cerebellum (pathogenesis partly or largely understood, includes local proliferation, cell specification, migration and axonal guidance); and (iv) combined hypoplasia and atrophy of putative prenatal onset degenerative disorders. Pertinent embryology is discussed and the classification is justified. This classification will prove useful for both physicians who diagnose and treat patients with these disorders and for clinical scientists who wish to understand better the perturbations of developmental processes that produce them. Importantly, both the classification and its framework remain flexible enough to be easily modified when new embryologic processes are described or new malformations discovered. PMID:19933510

  12. Gamma Knife radiosurgery for cerebral arteriovenous malformations in children/adolescents and adults. Part II: Differences in obliteration rates, treatment-obliteration intervals, and prognostic factors

    SciTech Connect

    Nicolato, Antonio . E-mail: antonio.nicolato@mail.azosp.vr.it; Lupidi, Francesco; Sandri, Marco F. Dr. Econom.; Foroni, Roberto; Zampieri, Piergiuseppe; Mazza, Carlo; Pasqualin, Alberto; Beltramello, Alberto; Gerosa, Massimo

    2006-03-01

    Purpose: To evaluate and compare obliteration rates (OBRs) and treatment-obliteration intervals (TOIs) for cerebral arteriovenous malformations (cAVMs) treated with Gamma Knife radiosurgery in children/adolescents and adults; and to determine factors predicting the OBR and TOI in these two populations. Methods and Materials: This study concerned 62 children/adolescents and 193 adults observed for {>=}3 years. Fisher exact two-tailed and Wilcoxon rank-sum tests, multiple logistics, and Cox proportional hazard models were used for statistical analysis. Results: The overall OBR was 85.5% in children/adolescents and 87.6% in adults (p 0.671), but children/adolescents showed higher 36-month actuarial OBRs (69.35%) and shorter median TOIs (25.7 months) than adults (66.84% and 28.2 months; p 0.006 and p = 0.017, respectively). In children/adolescents, lower Spetzler-Martin grades (p = 0.043) and younger age (p = 0.019) correlated significantly with OBRs, and lower Spetzler-Martin grades (p 0.024) and noneloquent cAVM locations (p = 0.046) with TOIs. In adults, low flow through the cAVM and <6.2-cm{sup 3} volume were associated with both OBR and TOI (p 0.012 and p = 0.002, respectively). Conclusions: The differences in OBRs within 3 years and TOIs, although slight, seem to show that pediatric cAVMs behave differently from those in adults after Gamma Knife radiosurgery.

  13. 3D-RISM-MP2 Approach to Hydration Structure of Pt(II) and Pd(II) Complexes: Unusual H-Ahead Mode vs Usual O-Ahead One.

    PubMed

    Aono, Shinji; Mori, Toshifumi; Sakaki, Shigeyoshi

    2016-03-01

    Solvation of transition metal complexes with water has been one of the fundamental topics in physical and coordination chemistry. In particular, Pt(II) complexes have recently attracted considerable interest for their relation to anticancer activity in cisplatin and its analogues, yet the interaction of the water molecule and the metal center has been obscured. The challenge from a theoretical perspective remains that both the microscopic solvation effect and the dynamical electron correlation (DEC) effect have to be treated simultaneously in a reasonable manner. In this work we derive the analytical gradient for the three-dimensional reference interaction site model Møller-Plesset second order (3D-RISM-MP2) free energy. On the basis of the three-regions 3D-RISM self-consistent field (SCF) method recently proposed by us, we apply a new layer of the Z-vector method to the CP-RISM equation as well as point-charge approximation to the derivatives with respect to the density matrix elements in the RISM-CPHF equation to remarkably reduce the computational cost. This method is applied to study the interaction of H2O with the d(8) square planar transition metal complexes in aqueous solution, trans-[Pt(II)Cl2(NH3)(glycine)] (1a), [Pt(II)(NH3)4](2+) (1b), [Pt(II)(CN)4](2-) (1c), and their Pd(II) analogues 2a, 2b, and 2c, respectively, to elucidate whether the usual H2O interaction through O atom (O-ahead mode) or unusual one through H atom (H-ahead mode) is stable in these complexes. We find that the interaction energy of the coordinating water and the transition metal complex changes little when switching from gas to aqueous phase, but the solvation free energy differs remarkably between the two interaction modes, thereby affecting the relative stability of the H-ahead and O-ahead modes. Particularly, in contrast to the expectation that the O-ahead mode is preferred due to the presence of positive charges in 1b, the H-ahead mode is also found to be more stable. The O

  14. Development of sensitive and selective food sensors using new Re(I)-Pt(II) bimetallic complexes to detect volatile biogenic sulfides formed by meat spoilage.

    PubMed

    Chow, Cheuk-Fai; Ho, Pui-Yu; Sun, Dong; Lu, Yu-Jing; Wong, Wing-Leung; Tang, Qian; Gong, Cheng-Bin

    2017-02-01

    Detection of volatile biogenic sulfides (VBS) plays a crucial role in food safety because the amounts of these compounds can reflect the freshness of meat. A new indicator-displacement assay with Re(I)-Pt(II) complexes, [Re(Lig)(CO)3(bridge)]-[Pt(DMSO)(Cl)2] (1: Lig=5-phenyl-1,10-phenanthroline and bridge=NCS(-); 2: Lig=5-phenyl-1,10-phenanthroline and bridge=CN(-); 3: Lig=2,2'-biquinoline and bridge=NCS(-)), was demonstrated to be a very effective sensing method to VBS. The results indicated that the control of Re(I)-bridge-Pt(II) and Re(I)-ligand combination are able to regulate their sensing selectivity and sensitivity. This system was successfully applied to detect CH3SCH3 in real rotten pork with a linear luminometric response up to 20.0mgkg(-1) (R=0.997) with the detection limit as 0.05 mgkg(-1). Complex 1 also gave comparable results on the detection of VBS with respect to those determined by GCMS with recovery range from 76% to 102% (RSD%=13.8). PMID:27596434

  15. Poly [1,1'-bis(ethynyl)-4,4'-biphenyl(bis-tributylphosphine)Pt(II)] solutions used as low dose ionizing radiation dosimeter

    SciTech Connect

    Bronze-Uhle, E. S.; Graeff, C. F. O.; Batagin-Neto, A.; Fernandes, D. M.; Fratoddi, I.; Russo, M. V.

    2013-06-17

    In this work, the effect of gamma radiation on the optical properties of polymetallayne poly[1,1'-bis(ethynyl)-4,4'-biphenyl(bis-tributylphosphine)Pt(II)] (Pt-DEBP) in chloroform solution is studied. The samples were irradiated at room temperature with doses from 0.01 Gy to 1 Gy using a {sup 60}Co gamma ray source. A new band at 420 nm is observed in the emission spectra, in superposition to the emission maximum at 398 nm, linearly dependent on dose. We propose to use the ratio of the emission amplitude bands as the dosimetric parameter. This method proved to be robust, accurate, and can be used as a dosimeter in medical applications.

  16. Giant cystic cerebral cavernous malformation with multiple calcification - case report.

    PubMed

    Kim, Il-Chun; Kwon, Ki-Young; Rhee, Jong-Joo; Lee, Jong-Won; Hur, Jin-Woo; Lee, Hyun-Koo

    2013-09-01

    Cerebral cavernous malformation with giant cysts is rare and literature descriptions of its clinical features are few. In this case study, the authors describe the clinical symptoms, radiological findings, and pathological diagnosis of cerebral cavernous malformations with giant cysts, reviewing the relevant literature to clearly differentiate this from other disease entities. The authors present a case of a 19-year-old male with a giant cystic cavernous malformation, who was referred to the division of neurosurgery due to right sided motor weakness (grade II/II). Imaging revealed a large homogenous cystic mass, 7.2×4.6×6 cm in size, in the left fronto-parietal lobe and basal ganglia. The mass had an intra-cystic lesion, abutting the basal portion of the mass. The initial diagnosis considered this mass a glioma or infection. A left frontal craniotomy was performed, followed by a transcortical approach to resect the mass. Total removal was accomplished without post-operative complications. An open biopsy and a histopathological exam diagnosed the mass as a giant cystic cavernous malformation. Imaging appearances of giant cavernous malformations may vary. The clinical features, radiological features, and management of giant cavernous malformations are described based on pertinent literature review. PMID:24167810

  17. Detailed Evaluation of the Geometric and Electronic Structures of One-electron Oxidized Group 10 (Ni, Pd, and Pt) Metal(II)-(Disalicylidene)diamine Complexes

    PubMed Central

    Stack, T. Daniel P.

    2009-01-01

    The geometric and electronic structures of a series of one-electron oxidized group 10 metal salens (Ni, Pd, Pt) have been investigated in solution and in the solid state. Ni (1) and Pd (2) complexes of the tetradentate salen ligand N,N’-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine (H2Salcn) have been examined along with the Pt (3) complex of the salen ligand N,N’-bis(3,5-di-tert-butylsalicylidene)-1,2-ethylenediamine (H2Salen). All three oxidized compounds exist as ligand radical species in solution and in the solid state. The solid state structures of [1]+ and [3]+ exhibit a symmetric coordination sphere contraction relative to the neutral forms. By contrast, the coordination sphere of the Pd derivative [2]+ exhibits a pronounced asymmetry in the solid state. In solution, the oxidized derivatives display intense low-energy NIR transitions consistent with their classification as ligand radical compounds. Interestingly, the degree of communication between the phenolate moieties depends strongly on the central metal ion, within the Ni, Pd, and Pt series. Electrochemical measurements and UV-Vis-NIR spectroscopy, in conjunction with DFT calculations provide insights into the degree of delocalization of the one-electron hole in these systems. The Pd complex [2]+ is the least delocalized and is best described as a borderline Class II/III intervalence complex based on the Robin-Day classification system. The Ni [1]+ and Pt [3]+ analogues are Class III (fully delocalized) intervalence compounds. Delocalization is dependent on the electronic coupling between the redox-active phenolate ligands, mediated by overlap between the formally filled metal dxz orbital and the appropriate ligand molecular orbital. The degree of coupling increases in the order Pd < Ni < Pt for the one-electron oxidized group 10 metal salens. PMID:19639970

  18. Tuneable reactivity with PPh3 and SnX2 of four- and five-coordinate Pd(II) and Pt(II) complexes containing polyphosphines.

    PubMed

    Fernández-Anca, Damián; García-Seijo, M Inés; García-Fernández, M Esther

    2013-07-28

    The reactivity of the unusual d(8) trigonal-bipyramidal systems [MX(PP3)]X (X = Cl: M = Pd(1a), Pt(2a); X = Br: M = Pd(3a), Pt(4a); X = I: M = Pd(5a), Pt(6a); PP3 = tris[2-(diphenylphosphino)ethyl]phosphine) in CHCl3-CH3OH, the square-pyramidal compounds [MCl(NP3)]Cl (M = Pd(7a); Pt(8a); NP3 = tris[2-(diphenylphosphino)ethyl]amine) in CD3OD-DMF and the distorted square-planar mononuclear [MX(PNP)]X (M = Pd: X = Cl(10a); M = Pt: X = I(10b); PNP = bis[2-(diphenylphosphino)ethyl]amine) and the heteronuclear [PdAu2X4(PP3)] [X = I(9a), Cl(14a), Br(15a)] and [MAuX2(PP3)]X [M = Pd: X = Cl(16a); M = Pt: X = Cl(17a), Br(18a)] species in CDCl3 with PPh3 + SnX2 has been explored to establish the factors that influence the nature of the products. With the mononuclear precursors the course of the reaction is strongly dependent on the tripodal or linear arrangement of the polydentate ligand and in the former case on the halogen. Thus, while for chlorides (1a-2a, 7a-8a) and bromides (3a-4a) the reaction led to the trigonal-bipyramidal compounds [M(SnCl3)(AP3)][SnCl3] [A = P: M = Pd(1), Pt(2); A = N: M = Pd(7), Pt(8)], [MBr(PP3)][SnBr3] [M = Pd(4), Pt(6)] containing M-Sn and M-Br bonds, respectively, for iodides (5a-6a) resulted in the unknown neutral square-planar compounds [MI2(PP(PO)2)(SnI2)2] [M = Pd(9) and Pt(10)] bearing two dangling P=O-SnI2 units and P2MI2 environments. However, complexes of the type [PtCl(PP2PO)X]X' [X = SnCl2, X' = [SnCl3](-)(11)] and [M(PP(PO)2)2X4]X'2 [X = SnCl2, X' = [SnCl3](-): M = Pd(12), Pt(13)] showing P=O-SnCl2 arms were obtained by direct reaction of [PtCl(PP2PO)]Cl (11a) and [M(PP(PO)2)2]Cl2 [M = Pd(12a), Pt(13a)] with SnCl2 in CH3OH. Although complex 9 was also prepared by interaction of the heteronuclear iodide 9a with PPh3 + SnI2 in CDCl3, the use of the neutral and ionic heteronuclear chlorides and bromides (14a-18a) as starting materials afforded the distorted square-planar ionic systems [MAuX'(PP3)(PPh3)][SnX3]2 [M = Pd: X = Cl, X' = Sn

  19. Metal Complexes with Very Large Dipole Moments: the Anionic Carborane Nitriles 12-NC-CB11X11(-) (X = H, F, CH3) as Ligands on Pt(II) and Pd(II).

    PubMed

    Šembera, Filip; Plutnar, Jan; Higelin, Alexander; Janoušek, Zbyněk; Císařová, Ivana; Michl, Josef

    2016-04-18

    The anionic nitriles 1-R-12-NC-CB11H10(-) (R = H, CH3, I, COOH), 12-NC-1-H-CB11Me10(-), and 12-NC-1-H-CB11F10(-) were prepared, and three of them were examined for complex formation with (Et3P)2Pt(II) and (Et3P)2Pd(II). Several stable internally charge-compensated zwitterionic complexes were obtained and characterized. RI-BP86/SV(P) calculations suggest that their dipole moments exceed 20 D. An attempt to measure the dipole moments in solution failed due to insufficient solubility in solvents of low polarity. PMID:27018918

  20. End modification of a linear DNA duplex enhances NER-mediated excision of an internal Pt(II)-lesion.

    PubMed

    Mason, Tracey McGregor; Smeaton, Michael B; Cheung, Joyce C Y; Hanakahi, Les A; Miller, Paul S

    2008-05-01

    The study of DNA repair has been facilitated by the development of extract-based in vitro assay systems and the use of synthetic DNA duplexes that contain site-specific lesions as repair substrates. Unfortunately, exposed DNA termini can be a liability when working in crude cell extracts because they are targets for DNA end-modifying enzymes and binding sites for proteins that recognize DNA termini. In particular, the double-strand break repair protein Ku is an abundant DNA end-binding protein that has been shown to interfere with nucleotide excision repair (NER) in vitro. To facilitate the investigation of NER in whole-cell extracts, we explored ways of modifying the exposed ends of synthetic repair substrates to prevent Ku binding and improve in vitro NER efficiency. Replacement of six contiguous phosphodiester linkages at the 3'-ends of the duplex repair substrate with nuclease-resistant nonionic methylphosphonate linkages resulted in a 280-fold decrease in binding affinity between Ku and the modified duplex. These results are consistent with the published crystal structure of a Ku/DNA complex [Walker et al. (2001) Nature 412, 607-614] and show that the 3'-terminal phosphodiester linkages of linear DNA duplexes are important determinants in DNA end-binding by Ku. Using HeLa whole-cell extracts and a 149-base pair DNA duplex repair substrate, we tested the effects of modification of exposed DNA termini on NER-mediated in vitro excision of a 1,3-GTG-Pt(II) intrastrand cross-link. Methylphosphonate modification at the 3'-ends of the repair substrate resulted in a 1.6-fold increase in excision. Derivatization of the 5'-ends of the duplex with biotin and subsequent conjugation with streptavidin to block Ku binding resulted in a 2.3-fold increase excision. By combining these modifications, we were able to effectively reduce Ku-derived interference of NER excision in vitro and observed a 4.4-fold increase in platinum lesion excision. These modifications are easy to

  1. Anticancer activity of a chelating nitrogen mustard bearing tetrachloridoplatinum(iv) complex: better stability yet equipotent to the Pt(ii) analogue.

    PubMed

    Karmakar, Subhendu; Chatterjee, Saptarshi; Purkait, Kallol; Mukherjee, Arindam

    2016-08-01

    Two Pt(iv) complexes cis,cis,trans-[Pt(IV)(L1)Cl4] (1a) & cis,cis,trans-[Pt(IV)(L2)Cl4] (2a) containing the nitrogen mustard moieties -N(CH2CH2Cl)2 & -NHCH2CH2Cl, were prepared in a single step from the Pt(ii) complexes containing -N(CH2CH2OH)2 (1) & -NHCH2CH2OH (2) moieties respectively using only thionyl chloride. The characterization of both the Pt(iv) complexes was performed by NMR, IR, UV and elemental analysis. Complex 1a was also characterized by single crystal X-ray diffraction. 1a crystallized in the I2/a space group. 1a exhibited much higher solution stability than 2a in kinetic studies by (1)H NMR. 1a shows a prodrug like activity as it converts to its Pt(ii) congener, [Pt(II)(L1)Cl2] (3) after 2 days in buffered solution. The binding experiment of 1a with model nucleobase 9-ethylguanine (9-EtG), showed that 1a converts to 3 and forms mono-adducts with 9-EtG. In the presence of reduced glutathione (GSH), the formation of 3 from 1a is quicker and upon the formation of 3 it binds almost instantaneously to GSH to form cis-[PtCl(L1)SG] (3c). Complex 3c transformed within a day to give a free aziridinium ion of L1 (3b) by dissociation. The in vitro cytotoxicity of the complexes and the clinical anticancer drug cisplatin show that 1a is potent against MCF-7, A549, HepG2 and MIA PaCa-2. The potency is highest against MIA PaCa-2 exhibiting an IC50 value of 4.4 ± 0.5 μM. The in vitro cytotoxicity data also showed that between the two complexes only 1a is active against MCF-7, A549 and MIA PaCa-2 in normoxia and hypoxia, both in the presence and absence of added GSH. Even in the presence of excess GSH in hypoxia, 1a exhibits significant cytotoxicity against MIA PaCa-2 and MCF-7 with IC50 values of 4.5 ± 0.3 and 11.2 ± 1.8 μM respectively. Platinum accumulation studies by ICP-MS display greater internalization of 1a, than 2a, 3 and cisplatin inside MCF-7 cells. 1a arrests cell cycle at the G2/M phase in MCF-7, exhibits capability to inhibit metastasis, induces

  2. Treatment of congenital malformations.

    PubMed

    Brucker, Sara Yvonne; Rall, Katharina; Campo, Rudi; Oppelt, Peter; Isaacson, Keith

    2011-03-01

    The prevalence of müllerian malformations is 1 in 200, or 0.5%. A third of the anomalies are septate, a third bicornuate uteri, 10% arcuate uterus, 10% didelphis and unicornuate uterus, and < 5% uterine and vaginal aplasia. Correct diagnosis of the malformation is most important but often very difficult. Correct treatment can only be performed if the malformation is clear. Longitudinal vaginal septums have to be removed due to potential obstetric problems. Transverse vaginal septums can cause hematocolpos and pain and have to be incised crosswise and excised so as not to shorten the vagina at the same time. Congenital vaginal agenesis occurs in Mayer-Rokitansky-Kuster-Hauser syndrome patients and in androgen insensitivity syndrome. The first choice for surgical treatment should be the new laparoscopic-assisted creation of a neovagina. Septate uterus has to be distinguished from a bicornuate uterus. Even if it is not proven to be a cause for infertility, the chance of miscarriage can be diminished by performing hysteroscopic metroplasty. Repair of a uterine septum in infertility patients often improves pregnancy rates. In contrast, surgical repair of a bicornuate uterus requires an abdominal metroplasty. This should only be performed if the patient has recurrent fetal loss due to the uterine structural defect. In a unicornuate uterus it is most important to determine if there is a second uterine horn that can cause cyclic pain if it has functioning endometrium. The only surgical option in these cases is to remove the rudimentary uterus with endometrium and hematometra, respectively. PMID:21437824

  3. Linking of Antitumor trans NHC-Pt(II) Complexes to G-Quadruplex DNA Ligand for Telomeric Targeting.

    PubMed

    Betzer, Jean-François; Nuter, Frédérick; Chtchigrovsky, Mélanie; Hamon, Florian; Kellermann, Guillaume; Ali, Samar; Calméjane, Marie-Ange; Roque, Sylvain; Poupon, Joël; Cresteil, Thierry; Teulade-Fichou, Marie-Paule; Marinetti, Angela; Bombard, Sophie

    2016-06-15

    G-quadruplex structures (G4) are promising anticancerous targets. A great number of small molecules targeting these structures have already been identified through biophysical methods. In cellulo, some of them are able to target either telomeric DNA and/or some sequences involved in oncogene promotors, both resulting in cancer cell death. However, only a few of them are able to bind to these structures G4 irreversibly. Here we combine within the same molecule the G4-binding agent PDC (pyridodicarboxamide) with a N-heterocyclic carbene-platinum complex NHC-Pt already identified for its antitumor properties. The resulting conjugate platinum complex NHC-Pt-PDC stabilizes strongly G-quadruplex structures in vitro, with affinity slightly affected as compared to PDC. In addition, we show that the new conjugate binds preferentially and irreversibly the quadruplex form of the human telomeric sequence with a profile in a way different from that of NHC-Pt thereby indicating that the platination reaction is oriented by stacking of the PDC moiety onto the G4-structure. In cellulo, NHC-Pt-PDC induces a significant loss of TRF2 from telomeres that is considerably more important than the effect of its two components alone, PDC and NHC-Pt, respectively. PMID:27115175

  4. Arteriovenous Malformation Management

    SciTech Connect

    Yakes, Wayne F.; Rossi, Plinio; Odink, Henk

    1996-11-15

    Arteriovenous malformations (AVM) are rare vascular lesions that can present with a myriad of clinical presentations. In our institutions, initial workup consists of a clinical exam, color Doppler imaging, and magnetic resonance imaging. After the initial noninvasive workup, arteriography, at times closed system venography, and ethanol endovascular repair of the AVM is performed under general anesthesia. Depending on the size of the lesion, additional Swan-Ganz line and arterial line monitoring are performed. Patients are usually observed overnight and uneventfully discharged the following day if no complication occurs. Patients are followed at periodic intervals despite cure of their lesion. Long-term follow-up is essential in AVM management.

  5. Chiari-like Malformation.

    PubMed

    Loughin, Catherine A

    2016-03-01

    Chiari-like malformation is a condition of the craniocervical junction in which there is a mismatch of the structures of the caudal cranial fossa causing the cerebellum to herniate into the foramen magnum. This herniation can lead to fluid buildup in the spinal cord, also known as syringomyelia. Pain is the most common clinical sign followed by scratching. Other neurologic signs noted are facial nerve deficits, seizures, vestibular syndrome, ataxia, menace deficit, proprioceptive deficits, head tremor, temporal muscle atrophy, and multifocal central nervous system signs. MRI is the diagnostic of choice, but computed tomography can also be used. PMID:26631589

  6. Synthesis, structure, and optical properties of Pt(II) and Pd(II) complexes with oxazolyl- and pyridyl-functionalized DPPM-type ligands: a combined experimental and theoretical study.

    PubMed

    Zhang, Shuanming; Pattacini, Roberto; Braunstein, Pierre; De Cola, Luisa; Plummer, Edward; Mauro, Matteo; Gourlaouen, Christophe; Daniel, Chantal

    2014-12-15

    New square-planar complexes [Pt(1(-H))2] (2a) [1(-H) = (oxazolin-2-yl)bis(diphenylphosphino)methanide] and [Pd(1(-H))2] (2b), of general formula [M{(Ph2P)2C---C---NCH2CH2O}2] (M = Pt, 2a; M = Pd, 2b), result from deprotonation of 2-{bis(diphenylphosphino)methyl}oxazoline (1) at the PCHP site. The new, functionalized dppm-type ligand 4-{bis(diphenylphosphino)methyl}pyridine, (Ph2P)2CH(4-C5H4N) (4), was prepared by double lithiation and phosphorylation of 4-picoline. In the presence of NEt3, the reactions of 2 equiv of 4 with [PtCl2(NCPh)2] and [Pd(acac)2] (acac = acetylacetonate) afforded [Pt(4(-H))2] (5a) [4(-H) = bis(diphenylphosphino)(pyridin-4-yl)methanide] and [Pd(4(-H))2] (5b), of general formula [M{(Ph2P)2C(4-C5H4N)}2] (M = Pt, 5a; M = Pd, 5b), respectively. In the absence of base, the reactions of 2 equiv of 4 with [PtCl2(NCPh)2] and [PdCl2(NCPh)2] afforded (5a·2HCl) (6a) and (5b·2HCl) (6b), respectively, in which the PCHP proton of 4 has migrated from carbon to nitrogen to give a pyridinium derivative of general formula [M{(Ph2P)2C(4-C5H4NH)}2]Cl2 (M = Pt, 6a; M = Pd, 6b). The complexes 3a, 5a·2MeOH, and 6b·4CH2Cl2 have been structurally characterized by X-ray diffraction. The absorption/emission properties of the Pt(II) complexes 2a and 5a and the Pd(II) complexes 2b and 5b have been investigated by UV-vis spectroscopy and theoretical analysis based on density functional theory. The UV-vis absorption spectra of the neutral complexes recorded in dilute N,N'-dimethylformamide solutions are dominated by intense spin-allowed intraligand transitions in the region below 350 nm. The complexes exhibit charge-transfer bands between 350 and 500 nm. The experimental and theoretical absorption spectra agree qualitatively and point to two low-lying ligand-to-metal charge transfer states that contribute to the bands observed between 350 and 500 nm. The complexes are emissive in frozen solutions at 77 K, in the pure solid state, and when doped into films of poly

  7. Quantification of Outer-Sphere Macrochelate Formation in the Ternary cis-Diammine-Platinum(II)-Bis-2'-deoxyguanosine 5'-Monophosphate Complex, cis-(NH(3))(2)Pt(dGMP)(2)(2)(-), and Formation of Quaternary Mixed Metal Ion Species with Magnesium(II), Copper(II), or Zinc(II) in Aqueous Solution.

    PubMed

    Song, Bin; Oswald, Gerda; Zhao, Jing; Lippert, Bernhard; Sigel, Helmut

    1998-09-21

    The acid-base properties of cis-(NH(3))(2)Pt(dG)(2)(2)(-), where both dG(2)(-) (=2'-deoxyguanosine 5'-monophosphate) are N7-coordinated to the same Pt(II) [the complex is abbreviated as Pt(dG)(2)(2)(-)], are summarized [on the basis of potentiometric pH titration data from B. Song et al. (Metal-Based Drugs 1996, 3, 131-141)] and a micro acidity constant scheme is developed which allows quantification of the intrinsic acidity of the two P(O)(2)(OH)(-) groups present in this ternary complex (I = 0.1 M, NaNO(3); 25 degrees C). On the basis of comparisons with the corresponding acid-base properties of cis-(NH(3))(2)Pt(dCMP.H-N3)(2) [(dCMP.H)(-) = phosphate-monoprotonated 2'-deoxycytidine 5'-monophosphate] it is concluded that intramolecular, outer-sphere macrochelates form via Pt(NH(3)).O(3)P hydrogen bonds. The formation degree of these macrochelates is quantified; it amounts in aqueous solution in each case (in its lower limit) to about 40% for the various possibilities which exist for the formation of these chelates in the cis-(NH(3))(2)Pt(dG)(2) complexes. The stability constants of the mixed metal ion complexes, M[Pt(H;dG)(dG)](+) and M[Pt(dG)(2)], were also determined via potentiometric pH titrations. On the basis of previous measurements with simple phosphate monoesters and phosphonate derivatives, i.e., R-PO(3)(2)(-) with R being a noncoordinating residue (Sigel, H.; et al., Helv. Chim. Acta 1992, 75, 2634-2656), it is shown that the stability of the two mixed metal ion complexes is largely governed by the basicity of the phosphate groups (as quantified via the mentioned microconstants) indicating that the effect of the N7-bound Pt(II) on the phosphate-metal ion binding properties is relatively small. These results suggest that, e.g., a metal ion bound to a nucleobase residue in a nucleotide or in a nucleic acid affects only slightly the metal ion binding capabilities of its phosphate residue or its phosphate backbone. PMID:11670649

  8. Structural correlations for (1)H, (13)C and (15)N NMR coordination shifts in Au(III), Pd(II) and Pt(II) chloride complexes with lutidines and collidine.

    PubMed

    Pazderski, Leszek; Pawlak, Tomasz; Sitkowski, Jerzy; Kozerski, Lech; Szłyk, Edward

    2010-06-01

    (1)H, (13)C and (15)N NMR studies of gold(III), palladium(II) and platinum(II) chloride complexes with dimethylpyridines (lutidines: 2,3-lutidine, 2,3lut; 2,4-lutidine, 2,4lut; 3,5-lutidine, 3,5lut; 2,6-lutidine, 2,6lut) and 2,4,6-trimethylpyridine (2,4,6-collidine, 2,4,6col) having general formulae [AuLCl(3)], trans-[PdL(2)Cl(2)] and trans-/cis-[PtL(2)Cl(2)] were performed and the respective chemical shifts (delta(1H), delta(13C), delta(15N)) reported. The deshielding of protons and carbons, as well as the shielding of nitrogens was observed. The (1)H, (13)C and (15)N NMR coordination shifts (Delta(1H) (coord), Delta(13C) (coord), Delta(15N) (coord); Delta(coord) = delta(complex) - delta(ligand)) were discussed in relation to some structural features of the title complexes, such as the type of the central atom [Au(III), Pd(II), Pt(II)], geometry (trans- or cis-), metal-nitrogen bond lengths and the position of both methyl groups in the pyridine ring system. PMID:20474019

  9. Synthesis of a New Bimetallic Re(I)-NCS-Pt(II) Complex as Chemodosimetric Ensemble for the Selective Detection of Mercapto-Containing Pesticides.

    PubMed

    Chow, Cheuk-Fai; Ho, Keith Yat-Fung; Gong, Cheng-Bin

    2015-06-16

    Detection of mercapto-containing pesticides plays a crucial role in food and water safety. A new Re(I)-NCS-Pt(II) complex, [Re(4,4'-di-tert-butyl-2,2'-bipyridine)(CO)3(NCS)]-[Pt(DMSO)(Cl)2] (1), was synthesized and characterized. The synthetic procedure, characterization results, and photophysical data for 1 are reported in this paper. Solvated complex 1 demonstrated luminescent chemodosimetric selectivity for phorate, demeton, and aldicarb (three common mercapto-containing pesticides) with method detection limits (MDLs) of 1.00, 2.87, and 2.08 ppm, respectively. The binding constants (log K) of 1 toward them were in the 3.24-3.44 range. The analyte selectivity of the complex was found to be dependent on the bridging linkage (C≡N and N═C═S) between the Re(I) and Pt(II) centers. The solid-supported dosimetric device 1 was fabricated by blending complex 1 with Al2O3 and poly(vinyl chloride) (PVC) powder. The MDLs of the device toward the mercapto-containing pesticides were 0.48-0.60 ppm. The device was applicable to pesticides in real water bodies such as taps, rivers, lakes, and underground water bodies with excellent recoveries and relative standard deviations of 76.2-108.0% and 2.9-6.7%, respectively. Its spectrofluorimetric changes could be analyzed by naked eye within 20 min with a linear luminometric response toward increases in the phorate concentration (0-8.0 ppm) with R = 0.999. PMID:26039794

  10. Pincer-CNC mononuclear, dinuclear and heterodinuclear Au(iii) and Pt(ii) complexes supported by mono- and poly-N-heterocyclic carbenes: synthesis and photophysical properties.

    PubMed

    Gonell, S; Poyatos, M; Peris, E

    2016-04-01

    A family of cyclometallated Au(iii) and Pt(ii) complexes containing a CNC-pincer ligand (CNC = 2,6-diphenylpyridine) supported by pyrene-based mono- or bis-NHC ligands have been synthesized and characterized, together with the preparation of a Pt-Au hetero-dimetallic complex based on a Y-shaped tris-NHC ligand. The photophysical properties of all the new species and of two related Ru(ii)-arene complexes were studied and compared. Whereas the pyrene-based complexes only exhibit emission in solution, those containing the Y-shaped tris-NHC ligand are only luminescent when dispersed in poly(methyl methacrylate) (PMMA). In particular, the pyrene-based complexes were found to be emissive in the range of 373-440 nm, with quantum yields ranging from 3.1 to 6.3%, and their emission spectra were found to be almost superimposable, pointing to the fluorescent pyrene-centered nature of the emission. This observation suggests that the emission properties of the pyrene fragment may be combined with some of the numerous applications of NHCs as supporting ligands allowing, for instance, the design of biological luminescent agents. PMID:26911885

  11. Brain arteriovenous malformations.

    PubMed

    Ferrara, Adi R

    2011-01-01

    An arteriovenous malformation (AVM) is a particular abnormality of blood vessels. Brain AVMs are congenital, but symptoms usually do not appear until the second decade of life - if at all. The most common presenting symptom is a brain hemorrhage, but other possible symptoms include neurological deficits, seizures and headaches. Until recently, the gold standard for diagnosing AVM was conventional angiography. However, computed tomography and magnetic resonance angiography are now the first-line diagnostic tools for AVMs. This article reviews the presenting symptoms, diagnostic procedures and treatment options for brain AVMs, including embolization, micro-surgery and radiosurgery. This article is a Directed Reading. Your access to Directed Reading quizzes for continuing education credit is determined by your CE preference. For access to other quizzes, go to www.asrt.org/store. PMID:21771938

  12. Surgical management of arteriovenous malformation.

    PubMed

    Visser, Anniek; FitzJohn, Trevor; Tan, Swee T

    2011-03-01

    This article presents our experience in managing a series of consecutive patients with arteriovenous malformation (AVM) referred to our Vascular Anomalies Centre over a 14-year period. These patients were culled from our prospective Vascular Anomalies Database 1996-2010. The medical records of these patients were reviewed to supplement the data collected. Out of 1131 patients with vascular anomalies, 53 patients (22 males, 31 females) with AVM were identified. Their mean age was 29 (range: 3-88) years with 14 stage-III, 34 stage-II and five stage-I AVMs, affecting the head and neck area (n=32), lower limb (n=13), upper limb (n=7) and trunk (n=1). Eight patients with eight stage-III and 14 patients with 15 stage-II AVMs underwent definitive surgery following preoperative embolisation in 10 patients. Seventeen patients required reconstruction with free flaps (n=8) or local or regional flaps (n=9), tissue expansion (n=4), tendon recession (n=1), tendon transfer (n=1), osseo-integration (n=1) and skin grafting (n=5). Fourteen patients required a combination of reconstructive techniques. During an average follow-up of 54 (range: 10-135) months, two (8.7%) lesions recurred but were improved following surgery. One patient with life-threatening stage-III AVM underwent 'palliative' surgery following preoperative embolisation and the lesion had improved and remained stable during the 4-year follow-up period. AVM is a challenging clinical problem that requires a multidisciplinary team approach. Complete surgical excision remains the gold-standard treatment and immediate reconstruction is an integral part of definitive surgery for AVM. The heterogeneous nature of AVM requires treatment to be tailored for individual patients and the complex excision defects necessitate expertise in a variety of reconstructive techniques. Our experience shows a recurrence rate of 8.7% following definitive surgery for AVM. PMID:20663728

  13. Search for new physics in high pT like-sign dilepton events at CDF II

    DOE PAGESBeta

    Aaltonen, T.

    2011-10-25

    We present a search for new physics in events with two high pT leptons of the same electric charge, using data with an integrated luminosity of 6.1 fb-1. The observed data are consistent with standard model predictions. We set 95% C.L. lower limits on the mass of doubly-charged scalars decaying to like-sign dileptons, mH±± > 190 - 245 GeV/c2, depending on the decay mode and coupling.

  14. Systemic to pulmonary vascular malformation.

    PubMed

    Pouwels, H M; Janevski, B K; Penn, O C; Sie, H T; ten Velde, G P

    1992-11-01

    A case is reported of life-threatening haemoptysis as a result of an anomalous communication between a bronchial artery and pulmonary vein, demonstrated by angiography. The patient recovered following bilobectomy of the right lower and middle lobes. When a systemic artery is involved in an arteriovenous malformation of the lung, haemodynamics are different compared with those present in malformations fed by the pulmonary artery. This implicates other clinical features, options for surgical intervention and prognosis. In reviewing the literature, a relationship with Rendu-Osler-Weber disease is absent in these specific malformations. PMID:1486979

  15. Arteriovenous malformations of the bladder.

    PubMed

    Grunberger, I; DeAsis, A; Torno, R; Godec, C J

    1989-01-01

    We report a rare case of a localized arteriovenous malformation of the bladder mimicking a bladder tumor and presenting with gross hematuria. The mass was successfully resected transurethrally. PMID:2908934

  16. Embolization of uterine arteriovenous malformation

    PubMed Central

    Chen, Yan; Wang, Guoyun; Xie, Fubo; Wang, Bo; Tao, Guowei; Kong, Beihua

    2013-01-01

    Background: Uterine arteriovenous malformation is a rare but potential life-threatening source of bleeding. A high index of suspicion and accurate diagnosis of the condition in a timely manor are essential because instrumentation that is often used for other sources of uterine bleeding can be lead to massive hemorrhage. Case: We describe here a case of uterine arteriovenous malformation. A 32-year-old woman presented abnormal vaginal bleeding following the induced abortion. A diagnosis of uterine arteriovenous malformation made on the basis of Doppler ultrasonraphy was confirmed through pelvic angiography. The embolization of bilateral uterine arteries was performed successfully. Conclusion: Uterine arteriovenous malformation should be suspected in patient with abnormal vaginal bleeding, especially who had the past medical history incluing cesarean section, induced abortion, or Dillation and Curethage and so on. Although angiography remains the gold standard, Doppler ultrasonography is also a good noninvasive technique. The transcatheter uterine artery embolization offers a safe and effective treatment PMID:24639742

  17. Spin-orbit effects in square-planar Pt(II) complexes with bidentate and terdentate ligands: theoretical absorption/emission spectroscopy.

    PubMed

    Gourlaouen, Christophe; Daniel, Chantal

    2014-12-21

    The absorption and emission properties of five Pt(ii) planar complexes with bidentate ligands, namely [Pt(bpy)Cl2] (bpy = 2,2'-bipyridine) and [Pt(ppy)Cl2](-) (ppy = 2-phenylpyridine) , and terdentate ligands, namely [Pt(tpy)Cl](+) (tpy = 2,2':6',2''-terpyridine) , [Pt(phbpyR)Cl] (phbpy = 6-phenyl-2,2'-bipyridine; R = H) and [Pt(dpybR)Cl] (dpyb = 2,6-di(2-pyridyl)benzene; R = CH3) were investigated by means of density functional theory (DFT) and time-dependent DFT (TD-DFT) methods including solvent correction and spin-orbit coupling (SOC). The DFT optimized structures of the five complexes in the electronic ground state are in agreement with the experimental X-ray data and the theoretical absorption spectra reproduce quantitatively the main features of the experimental spectra. It is shown that the structures remain nearly planar in the low-lying singlet and triplet excited states of charge transfer character, metal-to-ligand (MLCT) or halide (Cl) to ligand (XLCT) whereas a significant distortion corresponding to the out-of-plane-bending of the Pt-Cl bond characterizes the geometry of the metal-centered (MC) states. In cyclometalated complexes , and this distortion is energetically unfavorable and not competitive with radiative decay via the low-lying MLCT and XLCT excited states. The absorption spectra of all complexes are significantly affected by spin-orbit coupling (red-shift and broadening), especially in the non-cyclometalated complexes and characterized by the presence of pure low-lying (3)MC states. The SOC effects are less important in the terpyridine complex the lowest part of its spectrum being contaminated by mixed (3)MLCT/(3)XLCT states. In the cyclometalated complexes and the presence of several LC states in the lowest part of the spectra is responsible for a small shift to the red as compared to the other complexes. The solvatochromism that characterizes the absorption of this class of molecules in the visible region is interpreted by the MLCT

  18. How to modify 7-azaindole to form cytotoxic Pt(II) complexes: highly in vitro anticancer effective cisplatin derivatives involving halogeno-substituted 7-azaindole.

    PubMed

    Štarha, Pavel; Trávníček, Zdeněk; Popa, Alexandr; Popa, Igor; Muchová, Tereza; Brabec, Viktor

    2012-10-01

    The platinum(II) dichlorido and oxalato complexes of the general formula cis-[PtCl(2)(nHaza)(2)] (1-3) [Pt(ox)(nHaza)(2)] (4-6) involving 7-azaindole halogeno-derivatives (nHaza) were prepared and thoroughly characterized. A single-crystal X-ray analysis of cis-[PtCl(2)(3ClHaza)(2)]·DMF (1·DMF; 3ClHaza symbolizes 3-chloro-7-azaindole) revealed a distorted square-planar arrangement with both the 3ClHaza molecules coordinated through their N7 atoms in a cis fashion. In vitro cytotoxicity of the complexes was evaluated by an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay against the HOS (osteosarcoma), MCF7 (breast adenocarcinoma) and LNCaP (prostate adenocarcinoma) human cancer cell lines. The dichlorido complexes 1-3 (IC(50)=3.8, 3.9, and 2.5 μM, respectively) showed significantly higher in vitro anticancer effect against HOS as compared with cisplatin, whose IC(50)=37.7 μM. The biological effect of cisplatin against MCF7 (IC(50)=24.5 μM) and LNCaP (IC(50)=3.8 μM) was also exceeded by 1-3 (except for 2 against LNCaP), but the difference can be classified as significant only in the case of 1 (IC(50)=3.4 μM) and 3 (IC(50)=2.0 μM) against MCF7. The molecular pharmacological studies (RNA synthesis by T7 RNA polymerase in vitro) proved that 1-3 bind to DNA in a similar manner as cisplatin, since the RNA synthesis products of 1-3 and cisplatin showed a similar sequence profile of major bands. PMID:22922312

  19. Malformations of cortical development

    PubMed Central

    Pang, Trudy; Atefy, Ramin; Sheen, Volney

    2012-01-01

    Background Malformations of cortical development (MCD) are increasingly recognized as an important cause of epilepsy and developmental delay. MCD encompass a wide spectrum of disorders with various underlying genetic etiologies and clinical manifestations. High resolution imaging has dramatically improved our recognition of MCD. Review Summary This review will provide a brief overview of the stages of normal cortical development, including neuronal proliferation, neuroblast migration, and neuronal organization. Disruptions at various stages lead to characteristic MCD. Disorders of neurogenesis give rise to microcephaly (small brain) or macrocephaly (large brain). Disorders of early neuroblast migration give rise to periventricular heterotopia (neurons located along the ventricles), whereas abnormalities later in migration lead to lissencephaly (smooth brain) or subcortical band heterotopia (smooth brain with a band of heterotopic neurons under the cortex). Abnormal neuronal migration arrest give rise to over-migration of neurons in cobblestone lissencephaly. Lastly, disorders of neuronal organization cause polymicrogyria (abnormally small gyri and sulci). This review will also discuss the known genetic mutations and potential mechanisms that contribute to these syndromes. Conclusion Identification of various gene mutations has not only given us greater insight into some of the pathophysiologic basis of MCD, but also an understanding of the processes involved in normal cortical development. PMID:18469675

  20. Spin crossover behaviour in one-dimensional Fe(II) compounds based on the [M(CN)4](2-) (M = Pd, Pt) units.

    PubMed

    Zhang, Shao-Liang; Zhao, Xin-Hua; Wang, Yuan-Min; Shao, Dong; Wang, Xin-Yi

    2015-05-28

    Four one-dimensional heterobimetallic coordination polymers {Fe(pic)2[M(CN)4]}n (M = Pd(II) () and Pt(II) (), pic = 2-picolylamine), and {Fe(pypz)2[M(CN)4]}n (M = Pd(II) () and Pt(II) (), pypz = 2-(1H-pyrazol-3-yl)pyridine) have been synthesized and characterized by infrared spectroscopy, X-ray diffraction, magnetic measurements and differential scanning calorimetry (DSC). Single-crystal X-ray analyses show that all the compounds are 1D neutral zigzag chain structures in which the planar [M(CN)4](2-) anion acts as a μ2-bridging ligand, and the two pic/pypz molecules as chelating coligands. Examination of the intermolecular contacts in compounds reveals the existence of the hydrogen bonding interactions involving the hydrogen donor groups of the pic and pypz ligands and the nitrogen atoms of the non-bridging cyanide groups of the [M(CN)4](2-) anions. Weak π-π interactions were also found to be important for the formation of the 3D structures of compounds and . The SCO properties of all compounds were confirmed by the detailed structural analyses of the coordination environments of the Fe(II) centres, DSC analyses, and magnetic susceptibility measurements. Compounds and exhibit complete SCO behaviour with very narrow thermal hysteresis loops centred near the room temperature (T1/2↓ = 270 K and T1/2↑ = 272 K for and T1/2↓ = 272 K and T1/2↑ = 274 K for ), whereas and exhibit abrupt SCO at 186 and 180 K, respectively. Compared to the mononuclear species of the pic and pypz ligands, the SCO temperatures are adjusted by the different ligand field strength of the [M(CN)4)](2-) units. The cooperativity from both the coordination bonds and supramolecular interaction leads to the observation of the hysteresis loops in the Fe-pic systems and the abrupt SCO transition in the Fe-pypz systems. Furthermore, the light-induced excited-spin-state trapping (LIESST) effect was observed for . PMID:25924017

  1. Near-IR Electrochromic Film Prepared by Oxidative Electropolymerization of the Cyclometalated Pt(II) Chloride with a Triphenylamine Group.

    PubMed

    Qiu, Dongfang; Bao, Xiaoyu; Zhao, Qian; Yang, Qichao; Feng, Yuquan; Wang, Hongwei; Yang, Chunxia; Liu, Kecheng

    2015-09-01

    A cyclometalated platinum chloride [(L)PtCl] {L = 4-[p-(diphenylamino)phenyl]-6-phenyl-2,2'-bipyridine} was successfully synthesized and characterized by (1)H NMR, (13)C NMR, MALDI-TOF MS, elemental analysis, and X-ray crystallography. Its oxidative electropolymerization proceeds smoothly on the working Pt and ITO electrodes by cyclic voltammetry. The film thickness can be easily tuned by controlling the CV scan number. The orange hybrid polymer film shows the nondiffusion-controlled redox processes and a unusually inverse dependence of ac impedance on its thickness. As a result of switching of the MLCT/ICT and dication absorption transitions, the adherent metallopolymer film exhibits the low-voltage-controlled anodic coloration near-IR electrochromism with significant optical contrast ratio (ΔT% = 88.8% at 820 nm), fast response time (1.9 s for the coloration step and 2.3 s for the bleaching step), and high coloration efficiency (CE = 363.3 C(-1)·cm(2)). PMID:26270128

  2. New bioactive 2,6-diacetylpyridine bis(p-chlorophenylthiosemicarbazone) ligand and its Pd(II) and Pt(II) complexes: synthesis, characterization, cytotoxic activity and DNA binding ability.

    PubMed

    Matesanz, Ana I; Hernández, Carolina; Souza, Pilar

    2014-09-01

    Preparation and characterization of 2,6-diacetylpyridine bis((4)N-p-chlorophenylthiosemicarbazone) ligand, H2L, and its palladium(II) and platinum(II) complexes [PdL] and [PtL], is described. The molecular structure of the two new complexes has been determined by single crystal X-ray diffraction. The ligand acts as dianionic tetradentate donor coordinating to the metal center in a square planar geometry through the pyridine nitrogen atom and the azomethine nitrogen and thione sulfur atoms from one thiosemicarbazone arm, the fourth coordination position is occupied by the hydrazine nitrogen atom of the other arm. New free ligand and its metal complexes have been evaluated for antiproliferative activity in vitro against NCI-H460, T-47D, A2780 and A2780cisR human cancer cell lines. The cytotoxicity data suggest that these compounds may be endowed with important antitumor properties, especially H2L and [PtL] since they are capable of not only circumvent cisplatin resistance in A2780cisR cells but also exhibit high antiproliferative activity in breast cancer T-47D cells. The interaction of H2L with calf thymus DNA was also investigated and its binding constant (Kb) determined. PMID:24857803

  3. Pulmonary Arteriovenous Malformations

    PubMed Central

    2014-01-01

    Within the past decade, pulmonary arteriovenous malformations (PAVMs) have evolved from rare curiosities to not uncommon clinical states, with the latest estimates suggesting a prevalence of ∼1 in 2,600. PAVMs provide anatomic right-to-left shunts, allowing systemic venous blood to bypass gas exchange and pulmonary capillary bed processing. Hypoxemia and enhanced ventilatory demands result, although both are usually asymptomatic. Paradoxical emboli lead to strokes and cerebral abscesses, and these commonly occur in individuals with previously undiagnosed PAVMs. PAVM hemorrhage is rare but is the main cause of maternal death in pregnancy. PAVM occlusion by embolization is the standard of care to reduce these risks. However, recent data demonstrate that currently recommended management protocols can result in levels of radiation exposure that would be classified as harmful. Recent publications also provide a better appreciation of the hematologic and cardiovascular demands required to maintain arterial oxygen content and oxygen consumption in hypoxemic patients, identify patient subgroups at higher risk of complications, and emphasize the proportion of radiologically visible PAVMs too small to treat by embolization. This review, therefore, outlines medical states that exacerbate the consequences of PAVMs. Chief among these is iron deficiency, which is commonly present due to concurrent hereditary hemorrhagic telangiectasia: iron deficiency impairs hypoxemia compensations by restricting erythropoiesis and increases the risk of ischemic strokes. Management of periodontal disease, dental interventions, pulmonary hypertension, and pregnancy also requires specific consideration in the setting of PAVMs. The review concludes by discussing to what extent previously recommended protocols may benefit from modification or revision. PMID:25420112

  4. Pulmonary arteriovenous malformations.

    PubMed

    Shovlin, Claire L

    2014-12-01

    Within the past decade, pulmonary arteriovenous malformations (PAVMs) have evolved from rare curiosities to not uncommon clinical states, with the latest estimates suggesting a prevalence of ~1 in 2,600. PAVMs provide anatomic right-to-left shunts, allowing systemic venous blood to bypass gas exchange and pulmonary capillary bed processing. Hypoxemia and enhanced ventilatory demands result, although both are usually asymptomatic. Paradoxical emboli lead to strokes and cerebral abscesses, and these commonly occur in individuals with previously undiagnosed PAVMs. PAVM hemorrhage is rare but is the main cause of maternal death in pregnancy. PAVM occlusion by embolization is the standard of care to reduce these risks. However, recent data demonstrate that currently recommended management protocols can result in levels of radiation exposure that would be classified as harmful. Recent publications also provide a better appreciation of the hematologic and cardiovascular demands required to maintain arterial oxygen content and oxygen consumption in hypoxemic patients, identify patient subgroups at higher risk of complications, and emphasize the proportion of radiologically visible PAVMs too small to treat by embolization. This review, therefore, outlines medical states that exacerbate the consequences of PAVMs. Chief among these is iron deficiency, which is commonly present due to concurrent hereditary hemorrhagic telangiectasia: iron deficiency impairs hypoxemia compensations by restricting erythropoiesis and increases the risk of ischemic strokes. Management of periodontal disease, dental interventions, pulmonary hypertension, and pregnancy also requires specific consideration in the setting of PAVMs. The review concludes by discussing to what extent previously recommended protocols may benefit from modification or revision. PMID:25420112

  5. A theoretical investigation on hydrolysis mechanism of biologically relevant Pt(II)/Pd(II) complexes with σ-donor and π-acceptor carrier ligand

    NASA Astrophysics Data System (ADS)

    Reddy B., Venkata P.; Mitra, Ishani; Mukherjee, Subhajit; Sengupta, P. S.; Dodda, Subba Reddy; Moi, Sankar Ch.

    2016-07-01

    The hydrolysis mechanism of cytotoxic agents complex 1 cis-[Pt(pic)Cl2] and complex 2 cis-[Pd(pic)Cl2] (where pic = 2-aminomethylpyridine) have been studied in solvent phase using DFT. The stationary states on potential energy surfaces were fully optimized and characterized. The rate constants and activation parameters of both the substitution processes has been calculated in CPCM model and the values were found to be k1 = 3.29 × 10-4 s-1, k2 = 8.88 × 10-9 s-1 for complex 1 and k1 = 0.13 × 10-1 s-1, k2 = 2.0 × 10-10 s-1 for complex 2 respectively. The second step is the rate-limiting process having higher activation energy compared to that of the first step for both the complexes.

  6. Why study human limb malformations?

    PubMed Central

    Wilkie, Andrew OM

    2003-01-01

    Congenital limb malformations occur in 1 in 500 to 1 in 1000 human live births and include both gross reduction defects and more subtle alterations in the number, length and anatomy of the digits. The major causes of limb malformations are abnormal genetic programming and intra-uterine disruption to development. The identification of causative gene mutations is important for genetic counselling and also provides insights into the mechanisms controlling limb development. This article illustrates some of the lessons learnt from the study of human limb malformation, organized into seven categories. These are: (1) identification of novel genes, (2) allelic mutation series, (3) pleiotropy, (4) qualitative or (5) quantitative differences between mouse and human development, (6) physical and teratogenic disruption, and (7) unusual biological phenomena. PMID:12587917

  7. Evolutionary origin of cardiac malformations.

    PubMed

    Taussig, H B

    1988-10-01

    The author has proposed in previous publications that isolated cardiac malformations have an evolutionary origin. This is partly supported by the fact that isolated cardiac malformations found in humans occur also in other placental mammals as well as in birds. External gross examination of the heart in just over 5,000 birds was carried out during a 3 year period. Anomalies included one instance of duplicate hearts, two specimens in which no heart could be identified and in a fourth, a yellow-rumped warbler, the heart lay in the neck outside of the thoracic cavity. Published reports of similar occurrences of an ectopically placed heart concern birds, cattle and humans. The fact that various species of both placental mammals and birds show evidence of heritability for heart defects, and that these species cannot interbreed, combined with the fact that birds and mammals have many similar malformations, points to either a common external causative factor or a common origin. Genes that code the malformed heart must be transmitted with that part of the genetic makeup common to all birds and mammals. Malformations caused by teratogens produce widespread organ injury to a potentially normal embryo whereas the evolutionary malformation is an organ-specific anomaly in an otherwise normal mammal or bird and occurs in widely separated species. The implications of this theory are important for parents of children with an isolated congenital heart defect who may have ingested one or another drug or chemical or have been exposed to toxins or infectious agents before or after conception of the affected offspring. PMID:3047192

  8. Imaging of congenital pulmonary malformations.

    PubMed

    Praticò, Francesco Emanuele; Corrado, Michele; Della Casa, Giovanni; Parziale, Raffaele; Russo, Giuseppe; Gazzani, Silvia Eleonora; Rossi, Enrica; Borgia, Daniele; Mostardi, Maurizio; Bacchini, Emanuele; Cella, Simone; De Filippo, Massimo

    2016-01-01

    Congenital pulmonary malformations represent a broad spectrum of anomalies that may result in varied clinical and pathologic pictures, ranging from recurrent pulmonary infections and acute respiratory distress syndrome, which require timely drug therapy, up to large space-occupying lesions needing surgical treatment. This classification includes three distinct anatomical and pathological entities, represented by Congenital Cystic Adenomatoid Malformation, Bronchopulmonary Sequestration and Congenital Lobar Emphysema. The final result in terms of embryological and fetal development of these alterations is a Congenital Lung Hypoplasia. Since even Bronchial Atresia, Pulmonary Bronchogenic Cysts and Congenital Diaphragmatic Hernias are due to Pulmonary Hypoplasia, these diseases will be discussed in this review (1, 2). PMID:27467867

  9. Experimental and quantum-chemical studies of 1H, 13C and 15N NMR coordination shifts in Pd(II) and Pt(II) chloride complexes with quinoline, isoquinoline, and 2,2'-biquinoline.

    PubMed

    Pazderski, Leszek; Tousek, Jaromír; Sitkowski, Jerzy; Kozerski, Lech; Szłyk, Edward

    2007-12-01

    1H, 13C, and 15N NMR studies of platinide(II) (M=Pd, Pt) chloride complexes with quinolines (L=quinoline-quin, or isoquinoline-isoquin; LL=2,2'-biquinoline-bquin), having the general formulae trans-/cis-[ML2Cl2] and [M(LL)Cl2], were performed and the respective chemical shifts (delta1H, delta13C, delta15N) reported. 1H coordination shifts of various signs and magnitudes (Delta1Hcoord=delta1Hcomplex-delta1Hligand) are discussed in relation to the changes of diamagnetic contribution to the relevant 1H shielding constants. The comparison to the literature data for similar complexes containing auxiliary ligands other than chlorides exhibited a large dependence of delta1H parameters on electron density variations and ring-current effects (inductive and anisotropic phenomena). The influence of deviations from planarity, concerning either MN2Cl2 chromophores or azine ring systems, revealed by the known X-ray structures of [Pd(bquin)Cl2] and [Pt(bquin)Cl2], is discussed in respect to 1H NMR spectra. 15N coordination shifts (Delta15Ncoord=delta15Ncomplex-delta15Nligand) of ca. 78-100 ppm (to lower frequency) are attributed mainly to the decrease of the absolute value of paramagnetic contribution in the relevant 15N shielding constants, this phenomenon being noticeably dependent on the type of a platinide metal and coordination sphere geometry. The absolute magnitude of Delta15Ncoord parameter increased by ca 15 ppm upon Pd(II)-->Pt(II) replacement but decreased by ca. 15 ppm following trans-->cis transition. Experimental 1H, 13C, 15N NMR chemical shifts are compared to those quantum-chemically calculated by B3LYP/LanL2DZ+6-31G**//B3LYP/LanL2DZ+6-31G*, both in vacuo and in CHCl3 or DMF solution. PMID:18044805

  10. Genetics Home Reference: Dandy-Walker malformation

    MedlinePlus

    ... All Close All Description Dandy-Walker malformation affects brain development, primarily development of the cerebellum , which is the ... Walker malformation , signs and symptoms caused by abnormal brain development are present at birth or develop within the ...

  11. Intracranial vascular malformations: MR and CT imaging

    SciTech Connect

    Kucharczyk, W.; Lemme-Pleghos, L.; Uske, A.; Brant-Zawadzki, M.; Dooms, G.; Norman, D.

    1985-08-01

    Twenty-four patients with 29 cerebrovascular malformations were evaluated with a combination of computed tomography (CT), angiography, and magnetic resonance (MR) imaging. Characteristics of the malformations on MR images were reviewed retrospectively, and a comparative evaluation of MR and CT images was made. Of 14 angiographically evident malformations, 13 intra-axial lesions were detected on both CT and MR images, and one dural malformation gave false-negative results on both modalities. The appearance of parenchymal lesions on MR images closely mirrored characteristic CT findings. Angiographically evident malformations have a highly characteristic appearance on MR images. MR may be more sensitive than CT in the detection of small hemorrhagic foci associated with cryptic arteriovenous malformations and may add specificity in the diagnosis of occult malformations in some cases, but MR is less sensitive than CT for the detection of small calcified malformations.

  12. Arteriovenous malformation of nose-revision surgery.

    PubMed

    Srinivas, C V; Kailash, N; Kailas, Gayattre; Divya Jyothi, N

    2012-12-01

    Areteriovenous malformations are rare in the head and neck region and generally arise from intracranial vessels. We present one rare case with spontaneous arteriovenous malformations related to the nose. PMID:24294582

  13. Femtosecond Measurements Of Size-Dependent Spin Crossover In FeII(pyz)Pt(CN)4 Nanocrystals

    DOE PAGESBeta

    Sagar, D. M.; Baddour, Frederick G.; Konold, Patrick; Ullom, Joel; Ruddy, Daniel A.; Johnson, Justin C.; Jimenez, Ralph

    2016-01-07

    We report a femtosecond time-resolved spectroscopic study of size-dependent dynamics in nanocrystals (NCs) of Fe(pyz)Pt(CN)4. We observe that smaller NCs (123 or 78 nm cross section and < 25 nm thickness) exhibit signatures of spin crossover (SCO) with time constants of ~ 5-10 ps whereas larger NCs with 375 nm cross section and 43 nm thickness exhibit a weaker SCO signature accompanied by strong spectral shifting on a ~20 ps time scale. For the small NCs, the fast dynamics appear to result from thermal promotion of residual low-spin states to high-spin states following nonradiative decay, and the size dependence ismore » postulated to arise from differing high-spin vs low-spin fractions in domains residing in strained surface regions. The SCO is less efficient in larger NCs owing to their larger size and hence lower residual LS/HS fractions. Our results suggest that size-dependent dynamics can be controlled by tuning surface energy in NCs with dimensions below ~25 nm for use in energy harvesting, spin switching, and other applications.« less

  14. Synthesis and Characterization of New Schiff Bases Derived from N (1)-Substituted Isatin with Dithiooxamide and Their Co(II), Ni(II), Cu(II), Pd(II), and Pt(IV) Complexes

    PubMed Central

    Abdul-Ghani, Ahlam J.; Khaleel, Asmaa M. N.

    2009-01-01

    Three new Schiff bases of N-substituted isatin LI, LII, and LIII = Schiff base of N-acetylisatin, N-benzylisatin, and N-benzoylisatin, respectively, and their metal complexes C1a,b = [Co2(LI)2Cl3]Cl, C2 = [Ni(LI)2Cl2]0.4BuOH, C3 = [CuLICl(H2O)]Cl ⋅ 0.5BuOH, C4 = [Pd(LI)2Cl]Cl, C5 = [Pt(L1)2Cl2]Cl2 ⋅ 1.8EtOH.H2O, C6a = [CoLIICl]Cl ⋅ 0.4H2O ⋅ 0.3DMSO, C6b = [CoLIICl]Cl ⋅ 0.3H2O ⋅ 0.1BuOH, C7 = [NiLIICl2], C8 = [CuLII]Cl2 ⋅ H2O , C9 = [Pd(LII)2]Cl2, C10 = [Pt(LII)2.5Cl]Cl3, C11a = [Co(LIII)]C12 ⋅ H2O, C11b = [Co(LIII)]Cl2 ⋅ 0.2H2O, and C12 = [Ni(LIII)2]Cl2, C13 = [Ni(LIII)2]Cl2 were reported. The complexes were characterized by elemental analyses, metal and chloride content, spectroscopic methods, magnetic moments, conductivity measurements, and thermal studies. Some of these compounds were tested as antibacterial and antifungal agents against Staphylococcus aureus, Proteus vulgaris, Candida albicans, and Aspergillus niger. PMID:19865487

  15. Platinum carbonyl clusters stabilized by Sn(ii)-based fragments: syntheses and structures of [Pt6(CO)6(SnCl2)2(SnCl3)4](4-), [Pt9(CO)8(SnCl2)3(SnCl3)2(Cl2SnOCOSnCl2)](4-) and [Pt10(CO)14{Cl2Sn(OH)SnCl2}2](2.).

    PubMed

    Bortoluzzi, Marco; Ceriotti, Alessandro; Ciabatti, Iacopo; Della Pergola, Roberto; Femoni, Cristina; Carmela Iapalucci, Maria; Storione, Alba; Zacchini, Stefano

    2016-03-15

    The reaction of [Pt15(CO)30](2-) with increasing amounts of SnCl2 affords [Pt8(CO)10(SnCl2)4](2-) (), [Pt10(CO)14{Cl2Sn(OH)SnCl2}2](2-) (), [Pt6(CO)6(SnCl2)2(SnCl3)4](4-) (), [Pt9(CO)8(SnCl2)3(SnCl3)2(Cl2SnOCOSnCl2)](4-) () and [Pt5(CO)5{Cl2Sn(OR)SnCl2}3](3-) (R = H, Me, Et, and (i)Pr) (). and have been previously described, whereas are herein reported for the first time. The species are the main products of the reaction under different experimental conditions, whereas and are by-products of the synthesis of and , respectively. From a structural point of view, the clusters all show a perfect segregation of the two metals, which are composed of a low valent Pt core decorated on the surface by Sn(ii) fragments such as SnCl2, [SnCl3](-), [Cl2Sn(OH)SnCl2](-) and [Cl2SnOCOSnCl2](2-). These fragments behave as two electron donor ligands via each Sn-atom (and also the C-atom in the case of [Cl2SnOCOSnCl2](2-)). The [Cl2SnOCOSnCl2](2-) ligand is rather unique and may be viewed as a bis-stannyl-carboxylate, a carbon dioxide μ3:k(3)-C,O,O'-CO2 or a carbonite ion [CO2](2-) stabilized by coordination to metal atoms. Compounds have been fully characterised via IR spectroscopy, X-ray crystallography and DFT calculations. PMID:26795720

  16. Pt(II) metal complexes tailored with a newly designed spiro-arranged tetradentate ligand; harnessing of charge-transfer phosphorescence and fabrication of sky blue and white OLEDs.

    PubMed

    Liao, Kuan-Yu; Hsu, Che-Wei; Chi, Yun; Hsu, Ming-Kuan; Wu, Szu-Wei; Chang, Chih-Hao; Liu, Shih-Hung; Lee, Gene-Hsiang; Chou, Pi-Tai; Hu, Yue; Robertson, Neil

    2015-04-20

    Tetradentate bis(pyridyl azolate) chelates are assembled by connecting two bidentate 3-trifluoromethyl-5-(2-pyridyl)azoles at the six position of pyridyl fragment with the tailored spiro-arranged fluorene and/or acridine functionalities. These new chelates were then utilized in synthesizing a series of Pt(II) metal complexes [Pt(Ln)], n = 1-5, from respective chelates L1-L5 and [PtCl2(DMSO)2] in 1,2-dimethoxyethane. The single-crystal X-ray structural analyses were executed on 1, 3, and 5 to reveal the generalized structures and packing arrangement in crystal lattices. Their photophysical properties were measured in both solution and solid state and are discussed in the context of computational analysis. These L1-L5 coordinated Pt(II) species exhibit intense emission, among which complex 5 shows remarkable solvatochromic phosphorescence due to the dominant intraligand charge transfer transition induced by the new bis(pyridyl azolate) chelates. Moreover, because of the higher-lying highest occupied molecular orbital of acridine, complex 5 can be considered as a novel bipolar phosphor. Successful fabrication of blue and white organic light-emitting diodes (OLEDs) using Pt(II) complexes 3 and 5 as the phosphorescent dopants are reported. In particular, blue OLEDs with 5 demonstrated peak efficiencies of 15.3% (36.3 cd/A, 38.0 lm/W), and CIE values of (0.190, 0.342) in a double-emitting layer structure. Furthermore, a red-emitting Os(II) complex and 5 were used to fabricate warm-white OLEDs to achieve peak external quantum efficiency, luminance efficiency, and power efficiency values as high as 12.7%, 22.5 cd/A, and 22.1 lm/W, respectively. PMID:25848710

  17. Segmented Pt/Ru, Pt/Ni, and Pt/RuNi nanorods as model bifunctional catalysts for methanol oxidation.

    PubMed

    Liu, Fang; Lee, Jim Yang; Zhou, Wei Jiang

    2006-01-01

    Five-segment (Pt-Ru-Pt-Ru-Pt, Pt-Ni-Pt-Ni-Pt, and Pt-RuNi-Pt-RuNi-Pt) nanorods with the same overall rod length and the same total Pt segment length were prepared by sequential electrodeposition of the metals into the pores of commercially available anodic aluminum oxide (AAO) membranes. Field-emission scanning electron microscopy (FESEM) showed that the nanorods were about 210 nm in diameter and about 1.5 microm in length. The alternating Pt and oxophilic metal(s) segments could be easily differentiated in backscattered-electron images. X-ray diffraction (XRD) analysis of the nanorods indicated that Pt and Ni were polycrystalline with fcc structures, Ru was hcp, and the co-deposited RuNi adopted the nickel fcc structure with some negative shifts in the Bragg angles. The chemical states of Pt, Ru, and Ni on the nanorod surface were assayed by X-ray photoelectron spectroscopy (XPS), and the presence of Pt(0), Pt(II), Pt(IV), Ru(0), Ru(VI), Ni(0), and Ni(II) was observed. The nanorods were catalytically active for the room-temperature electrooxidation of methanol in acidic solutions. The relative rates of reaction showed the Pt-RuNi pair sites as having the lowest overpotential to dissociate water, the highest catalytic activity in methanol oxidation, and the strongest CO-tolerance in the potential window employed. The use of segmented nanorods with identifiable Pt-oxophilic metal(s) interfaces removes many of the ambiguities in the interpretation of experimental data from conventional alloy catalysts, thereby enabling a direct comparison of the activities of various types of pair sites in methanol oxidation. PMID:17193567

  18. Supramolecular Macrocyclic Pd(II) and Pt(II) Squares and Rectangles with Aryldithiolate Ligands and their Excellent Catalytic Activity in Suzuki C-C Coupling Reaction.

    PubMed

    Vivekananda, K V; Dey, S; Maity, D K; Bhuvanesh, N; Jain, V K

    2015-11-01

    Addition of 1,4-benezenedithiol and 4,4'-biphenyldithiol to M(OTf)2 (M = cis-[Pt(PEt3)2](2+) or cis-[Pd(dppe)](2+)) (dppe = 1,2-bis(diphenylphosphino)ethane) gave self-assembled tetranuclear complexes [M2{S(C6H4)nS}]2(OTf)4 (n = 1, 2). The same reaction with 1,4-benezenedimethanethiol yielded octanuclear supramolecular coordination complexes (SCC) [M2{SCH2C6H4CH2S}]4(OTf)8. These complexes were characterized by NMR, mass, and UV-vis spectroscopies, cyclic voltammetry, as well as density functional theory studies and represent the first examples of SCCs constructed by thiolate groups and square-planar metal ions. The rectangular shape of tetranuclear complexes and square shape of octanuclear complex are confirmed by single-crystal structures and computational studies. The palladium complexes showed excellent catalytic activity in Suzuki C-C cross-coupling reactions with high turnover numbers (2 × 10(7)), even with low catalyst loading. PMID:26444245

  19. Reconstruction of middle ear malformations

    PubMed Central

    Schwager, Konrad

    2008-01-01

    Malformations of the middle ear are classified as minor and major malformations. Minor malformations appear with regular external auditory canal, tympanic membrane and aerated middle ear space. The conducting hearing loss is due to fixation or interruption of the ossicular chain. The treatment is surgical, following the rules of ossiculoplasty and stapes surgery. In major malformations (congenital aural atresia) there is no external auditory canal and a deformed or missing pinna. The mastoid and the middle ear space may be underdevelopped, the ossicular chain is dysplastic. Surgical therapy is possible in patients with good aeration of the temporal bone, existing windows, a near normal positioned facial nerve and a mobile ossicular chain. Plastic and reconstructive surgery of the pinna should proceed the reconstruction of the external auditory canal and middle ear. In cases of good prognosis unilateral aural atresia can be approached already in childhood. In patients with high risk of surgical failure, bone anchored hearing aids are the treatment of choice. Recent reports of implantable hearing devices may be discussed as an alternative treatment for selected patients. PMID:22073077

  20. Overgrowth syndromes with vascular malformations.

    PubMed

    Hagen, Solveig L; Hook, Kristen P

    2016-03-01

    This review provides a clinically-oriented summary of the most commonly encountered overgrowth syndromes associated with vascular malformations. This manuscript will outline morphologic features, clinical evaluation and management of this complex group of patients. Recent genetic advances have aided in classification and help to explain overlapping clinical features in many cases. PMID:27607325

  1. Noble metal (Ru{sup III}, Pd{sup II}, Pt{sup II}) substituted {open_quotes}sandwich{close_quotes} type polyoxometalates: Preparation, characterization, and catalytic activity in oxidations of alkanes and alkenes by peroxides

    SciTech Connect

    Neumann, R.; Khenkin, A.M.

    1995-11-08

    The polyoxometalates substituted with noble metals, Pd(II), Pt(II) and Ru(III), K{sub 12}([WZnPd{sup II}{sub 2}(H{sub 2}O){sub 2}](ZnW{sub 9}O{sub 34}){sub 2}){center_dot}38H{sub 2}O, K{sub 12}[WZnPt{sup II}{sub 2}(H{sub 2}O){sub 2}][(ZnW{sub 9}O{sub 34}){sub 2}]{center_dot}36H{sub 2}O, and Na{sub 11}[WZnRu{sup III}{sub 2}(OH)(H{sub 2}O)][(ZnW{sub 9}O{sub 34}){sub 2}]{center_dot}42H{sub 2}O, were prepared by exchange of labile zinc atoms with noble metal atoms from the isostructural starting material, N{sub 12}-[WZn{sub 3}(H{sub 2}O){sub 2}][(ZnW{sub 9}O{sub 34}){sub 2}]{center_dot}46H{sub 2}O. Magnetic susceptibility studies as a function of temperature provide convincing evidence of two ruthenium (III) centers with no magnetic interaction between them. The catalytic activity of these compounds was tested for the oxidation of alkenes and alkanes using aqueous 30% hydrogen peroxide and 70% tert-butyl hydroperoxide as oxidants. The alkene oxidation proceeded in high reactivity and moderate selectivity to the epoxide product using 30% H{sub 2}O{sub 2}. Kinetic profiles as well as UV-vis and IR spectra before, during and after the reaction indicate that the catalysts are stable throughout the reaction. Formation of epoxides rather than ketonization in the reaction of terminal alkenes as well as low reactivity with iodosobenzene indicates that the reaction is tungsten centered and not noble metal centered. Oxidation of alkenes with tert-butyl hydroperoxide gave mostly allylic oxidation and/or addition of tert-butyl alcohol to the double bond. Oxidation of cyclic alkanes such as cyclohexane and adamantane was successful with tert-butyl hydroperoxide with catalytic activity 10 times higher than previously found for transition metal substituted Keggin compounds. Ratios of hydroxylation of adamantane at tertiary vs secondary positions indicates different active species in the palladium-, platinum-, and ruthenium substituted-polyoxometalates.

  2. Neurogenic dysphagia resulting from Chiari malformations.

    PubMed

    Pollack, I F; Pang, D; Kocoshis, S; Putnam, P

    1992-05-01

    Between 1980 and 1989, 15 of 46 patients (11 children, 4 adults) who underwent suboccipital craniectomy and cervical laminectomy for symptomatic Chiari malformations presented with manifestations of neurogenic dysphagia. Each of these patients had normal swallowing function before the development of dysphagic symptoms. Dysphagia was progressive in all 15 and, in most cases, preceded the onset of other severe brain stem signs. The rate of symptom progression varied depending on the age of the patient. Whereas the six infants (all Chiari II) deteriorated rapidly after the onset of initial symptoms, the five older children (two Chiari I, three Chiari II) and four adults (all Chiari I) showed a more gradual deterioration. In 11 patients with severe dysphagia, barium video esophagograms, pharyngoesophageal motility studies, continuous esophageal pH monitoring, and appropriate scintigraphic studies were useful in defining the scope of the swallowing impairment and determining whether perioperative nasogastric or gastrostomy feedings, gastric fundoplication, and/or tracheostomy were needed to maintain adequate nutrition and avoid aspiration. These patients all had widespread dysfunction of the swallowing mechanism, with a combination of diffuse pharyngoesophageal dysmotility, cricopharyngeal achalasia, nasal regurgitation, tracheal aspiration, and gastroesophageal reflux. The pathophysiology of these swallowing impairments and their relation to the hindbrain malformation is discussed. Postoperative outcome with regard to swallowing function correlated with the severity of preoperative symptoms. The four patients with mild dysphagia showed rapid improvement in swallowing function after surgery. Seven patients with more severe impairment but without other signs of severe brain stem compromise, such as central apnea or complete bilateral vocal cord paralysis, also improved, albeit more slowly. In contrast, the outcome in the four patients who developed other signs of severe

  3. Amplatzer vascular plugs in congenital cardiovascular malformations

    PubMed Central

    Barwad, Parag; Ramakrishnan, Sivasubramanian; Kothari, Shyam S; Saxena, Anita; Gupta, Saurabh K; Juneja, Rajnish; Gulati, Gurpreet Singh; Jagia, Priya; Sharma, Sanjiv

    2013-01-01

    Background: Amplatzer vascular plugs (AVPs) are devices ideally suited to close medium-to-large vascular communications. There is limited published literature regarding the utility of AVPs in congenital cardiovascular malformations (CCVMs). Aims: To describe the use of AVPs in different CCVMs and to evaluate their safety and efficacy. Materials and Methods: All patients who required an AVP for the closure of CCVM were included in this retrospective review of our catheterization laboratory data. The efficacy and safety of AVPs are reported. Results: A total of 39 AVPs were implanted in 31 patients. Thirteen (33%) were AVP type I and 23 (59%) were AVP type II. AVP type III were implanted in two patients and type IV in one patient. The major indications for their use included closure of pulmonary arteriovenous malformation (AVM) (n = 7), aortopulmonary collaterals (n = 7), closure of a patent Blalock-Taussig shunt (n = 5), systemic AVM (n = 5), coronary AVM (n = 4), patent ductus arteriosus (PDA) (n = 3), pulmonary artery aneurysms (n = 3), and venovenous collaterals (n = 2). Deployment of the AVP was done predominantly via the 5 – 7F Judkin's right coronary guide catheter. Overall 92% of the AVPs could be successfully deployed and resulted in occlusion of the target vessel in all cases, within 10 minutes. No procedure-related or access site complication occurred. Conclusions: AVPs are versatile, easy to use, and effective devices to occlude the vascular communications in a variety of settings. AVP II is especially useful in the closure of tubular structures with a high flow. PMID:24688229

  4. Galenic arteriovenous malformation with precocious puberty.

    PubMed

    Ventureyra, E C; Badejo, A

    1984-01-01

    Pineal lesions may appear with precocious puberty. In this report, a patient with precocious puberty and macrogenitosomia caused by an arteriovenous malformation in the pineal region is presented. This vascular malformation was not visualized during investigations 3 years before the present series. It appears that the vascular malformation increased considerably in size within a 3-year period. This case suggests that some arteriovenous malformations may take a malignant course, increasing rapidly in size and behaving like tumors by causing destruction and compression of surrounding structures. This case seems to be unique because, to the best of our knowledge, an arteriovenous malformation associated with precocious puberty has never been described previously. PMID:6689808

  5. Atlas Assimilation Patterns in Different Types of Adult Craniocervical Junction Malformations

    PubMed Central

    Ferreira, Edson Dener Zandonadi; Botelho, Ricardo Vieira

    2015-01-01

    Study Design. This is a cross-sectional analysis of resonance magnetic images of 111 patients with craniocervical malformations and those of normal subjects. Objective. To test the hypothesis that atlas assimilation is associated with basilar invagination (BI) and atlas's anterior arch assimilation is associated with craniocervical instability and type I BI. Summary of Background Data. Atlas assimilation is the most common malformation in the craniocervical junction. This condition has been associated with craniocervical instability and BI in isolated cases. Methods. We evaluated midline Magnetic Resonance Images (MRIs) (and/or CT scans) from patients with craniocervical junction malformation and normal subjects. The patients were separated into 3 groups: Chiari type I malformation, BI type I, and type II. The atlas assimilations were classified according to their embryological origins as follows: posterior, anterior, and both arches assimilation. Results. We studied the craniometric values of 111 subjects, 78 with craniocervical junction malformation and 33 without malformations. Of the 78 malformations, 51 patients had Chiari type I and 27 had BI, of whom 10 presented with type I and 17 with type II BI. In the Chiari group, 41 showed no assimilation of the atlas. In the type I BI group, all patients presented with anterior arch assimilation, either in isolation or associated with assimilation of the posterior arch. 63% of the patients with type II BI presented with posterior arch assimilation, either in isolation or associated with anterior arch assimilation. In the control group, no patients had atlas assimilation. Conclusion. Anterior atlas assimilation leads to type I BI. Posterior atlas assimilation more frequently leads to type II BI. Separation in terms of anterior versus posterior atlas assimilation reflects a more accurate understanding of the clinical and embryological differences in craniocervical junction malformations. Level of Evidence: N/A PMID

  6. Structural and in vitro cytotoxicity studies on 1H-benzimidazol-2-ylmethyl-N-phenyl amine and its Pd(II) and Pt(II) complexes

    NASA Astrophysics Data System (ADS)

    Abdel Ghani, Nour T.; Mansour, Ahmed M.

    2011-10-01

    [MLCl 2]· zH 2O (L = (1H-benzimidazol-2-ylmethyl)-N-phenyl amine; M = Pd, z = 0; M = Pt, z = 1) and [PdL(OH 2) 2]·2X·zH 2O (X = Br, I, NO 3, z = 0; X = SCN, z = 1) complexes were synthesized as potential anticancer compounds and characterized by elemental analysis, spectral and thermal methods. FT-IR and 1H NMR studies revealed that the benzimidazole L is coordinated to the metal ions via the pyridine-type nitrogen (N py) of the benzimidazole ring and secondary amino group (NH sec). Quantum mechanical calculations of energies, geometries, vibrational wavenumbers, and 1H NMR of the benzimidazole L and its complexes were carried out by density functional theory using B3LYP functional combined with 6-31G(d) and LANL2DZ basis sets. Natural bond orbitals (NBOs) and frontier molecular orbitals were performed at B3LYP/LANL2DZ level of theory. The synthesized ligand, in comparison to its metal complexes was screened for its antibacterial activity. The benzimidazole L is more toxic against the bacterium Staphylococcus aureus (MIC = 58 μg/mL) than the standard tetracycline (MIC = 82 μg/mL). The complexes showed cytotoxicity against breast cancer, Colon Carcinoma, and human heptacellular Carcinoma cells. The platinum complex ( 6) displays cytotoxicity (IC 50 = 12.4 μM) against breast cancer compared with that reported for cis-platin 9.91 μM.

  7. Intraneural Venous Malformations of the Median Nerve

    PubMed Central

    González Rodríguez, Alba; Midón Míguez, José

    2016-01-01

    Venous malformations arising from the peripheral nerve are a rare type of vascular malformation. We present the first case of an intraneural venous malformation of the median nerve to be reported in a child and review the previous two cases of median nerve compression due to a venous malformation that have been reported. These cases presented with painless masses in the volar aspect of the wrist or with symptoms suggestive of carpal tunnel syndrome. Clinical suspicion should lead to the use of Doppler ultrasonography as the first-line diagnostic tool. Magnetic resonance imaging and histopathology can confirm the diagnosis, as phleboliths are pathognomonic of venous malformations. Surgical treatment appears to be the only modality capable of successfully controlling the growth of an intraneural malformation. Sclerotherapy and radiotherapy have never been used to treat this type of malformation. PMID:27462571

  8. Measurement of the W Boson Mass with the D0 Run II Detector using the Electron P(T) Spectrum

    SciTech Connect

    Andeen, Timothy R., Jr.; /Northwestern U.

    2008-06-01

    This thesis is a description of the measurement of the W boson mass using the D0 Run II detector with 770 pb{sup -1} of p{bar p} collision data. These collisions were produced by the Tevatron at {radical}s = 1.96 TeV between 2002 and 2006. We use a sample of W {yields} e{nu} and Z {yields} ee decays to determine the W boson mass with the transverse momentum distribution of the electron and the transverse mass distribution of the boson. We measure M{sub W} = XXXXX {+-} 37 (stat.) {+-} 26 (sys. theo.) {+-} 51 (sys. exp.) MeV = XXXXX {+-} 68 MeV with the transverse momentum distribution of the electron and M{sub W} = XXXXX {+-} 28 (stat.) {+-} 17 (sys. theo.) {+-} 51 (sys. exp.) MeV = XXXXX {+-} 61 MeV with the transverse mass distribution.

  9. Cooperation between cis and trans influences in cis-Pt(II)(PPh(3))(2) complexes: structural, spectroscopic, and computational studies.

    PubMed

    Rigamonti, Luca; Forni, Alessandra; Manassero, Mario; Manassero, Carlo; Pasini, Alessandro

    2010-01-01

    The relevance of cis and trans influences of some anionic ligands X and Y in cis-[PtX(2)(PPh(3))(2)] and cis-[PtXY(PPh(3))(2)] complexes have been studied by the X-ray crystal structures of several derivatives (X(2) = (AcO)(2) (3), (NO(3))(2) (5), Br(2) (7), I(2) (11); and XY = Cl(AcO) (2), Cl(NO(3)) (4), and Cl(NO(2)) (13)), density functional theory (DFT) calculations, and one bond Pt-P coupling constants, (1)J(PtP). The latter have allowed an evaluation of the relative magnitude of both influences. It is concluded that such influences act in a cooperative way and that the cis influence is not irrelevant when rationalizing the (1)J(PtP) values, as well as the experimental Pt-P bond distances. On the contrary, in the optimized geometries, evaluated through B3LYP/def2-SVP calculations, the cis influence was not observed, except for compounds ClPh (21), Ph(2) (22), and, to a lesser extent, Cl(NO(2)) (13) and (NO(2))(2) (14). A natural bond order analysis on the optimized structures, however, has shown how the cis influence can be related to the s-character of the Pt hybrid orbital involved in the Pt-P bonds and the net atomic charge on Pt. We have also found that in the X-ray structures of cis-[PtX(2)(PPh(3))(2)] complexes the two Pt-X and the two Pt-P bond lengths are different each other and are related to the conformation of the phosphine groups, rather than to the crystal packing, since this feature is observed also in the optimized geometries. PMID:19950913

  10. trans-thionate derivatives of Pt(II) and Pd(II) with water-soluble phosphane PTA and DAPTA ligands: antiproliferative activity against human ovarian cancer cell lines.

    PubMed

    Guerrero, Elena; Miranda, Susana; Lüttenberg, Sebastian; Fröhlich, Nils; Koenen, Jan-Moritz; Mohr, Fabian; Cerrada, Elena; Laguna, Mariano; Mendía, Aránzazu

    2013-06-01

    A series of PTA and DAPTA platinum(II) and palladium(II) thionate complexes of the type trans-[M(SN)2P2] were prepared from the reaction of cis-[MCl2P2] [M = Pt, Pd; P = PTA (1,3,5-triaza-7-phosphaadamantane), DAPTA (3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane)] with the in situ generated sodium salts of the heterocyclic thiones S-m-methylpyrimidine-2-thione, S-4,6-dimethylpyrimidine-2-thione, S-4,6-dihydroxypyrimidine-2-thione, benzothiazole-2-thione, benzoxazole-2-thione, S-1,3,4,-thiadiazole-2-thione, S-4,5-H-thiazolan-2-thione, and S-pyrimidine-4(1H)-one-2-thione. The X-ray structures of six of the compounds confirm the trans disposition and, only in the case of [Pd2Cl2(S-pyrimidine-4(1H)-one-2-thionate)2(PTA)2], a dinuclear structure with a Pd-Pd distance of 3.0265(14)Å was observed. In vitro cytotoxicities against human ovarian cancer cell lines A2780 and A2780cisR were evaluated for ten complexes showing a high inhibition of cellular growth with a comparable inhibitory potency (IC50) against A2780 cells to that of cisplatin. Notably, the compounds also show significant (up to 7-fold higher) activity in cisplatin-resistant A2780cisR cell lines. PMID:23692403

  11. Congenital malformations in diabetic offspring.

    PubMed

    Temesio, P; Belitzky, R; Gallego, L; Martell, M; Pose, S V

    1977-01-01

    A retrospective study of 215 deliveries in diabetic mothers at Hospital de Clínicas (Montevideo, Uruguay) has been performed. Presence of congenital malformations (CM) was considered in relation to age of the mothers, class of maternal diabetes, maternal angiopathy, treatment and metabolic control. The prevalence of CM in the series was 9.8%. None of the factors analyzed seems to be statistically linked to the prevalence of CM. PMID:613685

  12. [Maternal imagination and congenital malformations].

    PubMed

    Van Heiningen, Teunis Willem

    2011-01-01

    Since antiquity philosophers and scientists tried to explain the cause of congenital malformations. In early modern medicine maternal imagination was largely accepted as their true cause, This concept was rejected by Blondel, a London physician. Around 1750 Wolff introduced the Hemmungsbildung as the cause of congenital malformations, a concept adopted in 1781 by Blumenbach. Later on Soemmerring (1784), Crichton (1785) and Meckel the younger adopted Blumenbach's concept. In 1824 Suringar further developed it. More and more the excessive development of fetal blood vessels or nerves was rejected as a possible cause, although from time to time these ideas were adopted again. In the early 1800s Etienne Geoffroy Saint-Hilaire (1811) and Vrolik (1817) developed a classification of monstra. These attempts urged Isidore Geoffroy Saint-Hilaire (Etienne's son) and Vrolik the younger (Gerard's son) to develop it further. Nevertheless, around 1840 Vrolik had to admit that although we are well acqainted with the various malformations, we are still ignorant of the primary cause of these phenomena. Meanwhile the dispute between the adherents of the theory of preformation and those who had adopted the concept of epigenesis exercised many minds. In the second half of the eighteenth century the latter theory became more and more adopted and this fact cleared the way for the ideas introduced by Wolff and Blumenbach, because it was consistent with the idea of a gradual development of fetal structures. PMID:22073754

  13. C-H Bond Activation of Methane by PtII-N-Heterocyclic Carbene Complexes. The Importance of Having the Ligands in the Right Place at the Right Time

    SciTech Connect

    Prince, Bruce M.; Cundari, Thomas R

    2012-02-13

    A DFT study of methane C–H activation barriers for neutral NHC–PtII–methoxy complexes yielded 22.8 and 26.1 kcal/mol for oxidative addition (OA) and oxidative hydrogen migration (OHM), respectively. Interestingly, this is unlike the case for cationic NHC–PtII–methoxy complexes, whereby OHM entails a calculated barrier of 26.9 kcal/mol but the OA barrier is only 14.4 kcal/mol. Comparing transition state (TS) and ground state (GS) geometries implies an ~10 kcal/mol “penalty” to the barriers arising from positioning the NHC and OMe ligands into a relative orientation that is preferred in the GS to the orientation that is favored in the TS. The results thus imply an intrinsic barrier arising from C–H scission of ~15 ± 2 kcal/mol for NHC–PtII–methoxy complexes. Calculations show the importance of designing C–H activation catalysts where the GS active species is already structurally “prepared” and which either does not need to undergo any geometric perturbations to access the methane C–H activation TS or is not energetically prohibited from such perturbations.

  14. Surgical and Endovascular Treatment for Spinal Arteriovenous Malformations

    PubMed Central

    ENDO, Toshiki; ENDO, Hidenori; SATO, Kenichi; MATSUMOTO, Yasushi; TOMINAGA, Teiji

    2016-01-01

    Spinal arteriovenous malformation (AVM) is a broad term that constitutes diverse vascular pathologies. To date, various classification schemes for spinal AVM have been proposed in literature, which helped neurosurgeons understand the pathophysiology of the disease and determine an optimal treatment strategy. To discuss indications and results of surgical and endovascular interventions for spinal AVM, this article refers to the following classification proposed by Anson and Spetzler in 1992: type I, dural arteriovenous fistula (AVF); type II, glomus intramedullary AVM; type III, juvenile malformations; and type IV, perimedullary AVF. In general, complete obliteration of the fistula is a key for better outcome in type I dural and type IV perimedullary AVFs. On the other hand, in type II glomus and type III juvenile malformations, functional preservation, instead of pursuing angiographical cure, is the main goal of the treatment. In such cases, reduction of the shunt flow can alleviate clinical symptoms. Proper management of spinal AVM should start with neurological examination and understanding of angioarchitectures, which provide critical information that guides the indication and modality of intervention. Finally, close collaboration of the microsurgical and endovascular teams are mandatory for successful treatment. PMID:26948701

  15. Cryptic vascular malformations involving the brainstem

    SciTech Connect

    Yeates, A.; Enzmann, D.

    1983-01-01

    Six patients with angiographically cryptic vascular malformations involving the brainstem were examined with computed tomography (CT). The clinical and CT findings of cryptic vascular malformations of the brainstem are described and distinguished from those of brainstem glioma and multiple sclerosis. Calcification within a brainstem lesion that displays relatively little mass effect and shows little contrast enhancement, particularly when associated with a long history of waxing and waning brainstem symptoms, should suggest a vascular malformation.

  16. Congenital pulmonary airway malformation: A report of two cases

    PubMed Central

    Bolde, Saroj; Pudale, Smita; Pandit, Gopal; Ruikar, Kirti; Ingle, Sachin B

    2015-01-01

    Congenital pulmonary airway malformation (CPAM), previously known as congenital cystic adenomatoid malformation is a congenital disorder of the lung similar to bronchopulmonary sequestration. In CPAM, usually an entire lobe of lung is replaced by a non-working cystic piece of abnormal lung tissue. This abnormal tissue will never function as normal lung tissue. The underlying cause for CPAM is not known. It occurs in approximately 1 in every 30000 pregnancies. The association between CPAM and malignancy has been well documented. There is a small risk (0.7%) of malignant transformation within the cyst. So early diagnosis and surgical resection is important to prevent the grave complications. Herein, we are reporting two interesting cases of CPAM and one belonged to Type II and other belonged to Type III of Stocker’s classification. PMID:25984523

  17. Chiari Malformations and Syringohydromyelia in Children.

    PubMed

    Poretti, Andrea; Boltshauser, Eugen; Huisman, Thierry A G M

    2016-04-01

    Chiari malformations are a heterogeneous group of disorders with distinct clinical anatomical features all of which involve the hindbrain. Our understanding of Chiari malformations increased tremendously over the past decades, and progress in neuroimaging was instrumental for that. Conventional and advanced neuroimaging of the brain and spine play a key role in the workup of children with suspected Chiari malformations. In addition, neuroimaging studies in Chiari malformations may guide the management, serve as a predictor of outcome, and shed light on the pathogenesis. PMID:27063663

  18. Diffuse malformations of cortical development.

    PubMed

    Bahi-Buisson, Nadia; Guerrini, Renzo

    2013-01-01

    Malformations of cortical development (MCD) represent a major cause of developmental disabilities and severe epilepsy. Advances in imaging and genetics have improved the diagnosis and classification of these conditions. Up to now, eight genes have been involved in different types of MCD. Lissencephaly-pachygyria and subcortical band heterotopia (SBH) represent a malformative spectrum resulting from mutations of either LIS1 or DCX genes. LIS1 mutations cause a more severe malformation in the posterior brain regions. DCX mutations usually cause anteriorly predominant lissencephaly in males and SBH in female patients. Additional forms are X-linked lissencephaly with corpus callosum agenesis and ambiguous genitalia associated with mutations of the ARX gene. Lissencephaly with cerebellar hypoplasia (LCH) encompass heterogeneous disorders named LCH types a to d. LCHa is related to mutation in LIS1 or DCX, LCHb with mutation of the RELN gene, and LCHd could be related to the TUBA1A gene. Polymicrogyria encompasses a wide range of clinical, etiological, and histological findings. Among several syndromes, recessive bilateral fronto-parietal polymicrogyria has been associated with mutations of the GPR56 gene. Bilateral perisylvian polymicrogyria has been associated with mutations in the SRPX2 gene in a few individuals and with linkage to chromosome Xq28 in a some other families. X-linked bilateral periventricular nodular heterotopia (PNH) consists of PNH with focal epilepsy in females and prenatal lethality in males. Filamin A (FLNA) mutations have been reported in some families and in sporadic patients. It is possible to infer the most likely causative gene by brain imaging studies and other clinical findings. PMID:23622213

  19. Developmental venous anomaly, capillary telangiectasia, cavernous malformation, and arteriovenous malformation: spectrum of a common pathological entity?

    PubMed

    Kalani, M Yashar S; Zabramski, Joseph M; Martirosyan, Nikolay L; Spetzler, Robert F

    2016-03-01

    Vascular malformations of the central nervous system are thought to originate from abnormal developmental processes during embryogenesis. Reports have cited the dynamic nature of these lesions and their "maturation" into other types of malformations. Herein we report on three patients with vascular malformations who exhibited dynamic alterations with stepwise progression of their lesions. These cases lend support to the hypothesis that these malformations may constitute the spectrum of a single disease caused by alterations in a common developmental program and that accumulating injury (e.g., by radiation) may allow one malformation type to mature into another. This concept warrants further investigation. PMID:26743915

  20. Megadolicho vascular malformation of the intracranial arteries.

    PubMed

    Lodder, J; Janevski, B; van der Lugt, P J

    1981-01-01

    A patient is presented suffering a hemiparesis. Megadolicho-vascular malformation of the intracranial part of the internal carotid arteries and some of its branches and of the basilar artery was suggested by CT and confirmed by angiography. The value of CT compared with angiography in relation to intracranial megadolicho vascular malformations is discussed. PMID:6273040

  1. Fundamental studies of titanium oxide-Pt(1 0 0) interfaces II. Influence of oxidation and reduction reactions on the surface structure of TiO x films on Pt(1 0 0)

    NASA Astrophysics Data System (ADS)

    Matsumoto, Taketoshi; Batzill, Matthias; Hsieh, Shuchen; Koel, Bruce E.

    2004-11-01

    Chemical reactions of titanium-oxide ultrathin films on Pt(1 0 0) and associated changes in the surface structure have been studied by STM (scanning tunneling microscopy), LEED (low energy electron diffraction), AES (Auger electron spectroscopy) and TPD (temperature programmed desorption). Such reactions and changes have important consequences for understanding and modeling of catalysis of related systems and the oxide structures formed have an additional significance in their subsequent use as masks or templates on Pt(1 0 0) in studies relevant to nanotechnology. In a previous paper [Matsumoto et al., Surf. Sci., submitted] we characterized a monolayer-oxide film exhibiting a (3 × 5) structure on Pt(1 0 0) as due to Ti 2O 3. Herein, we characterize changes that occur in this film during subsequent oxidation and reduction reactions, and propose models for the structures of TiO x films that are formed. O 3 (ozone) or NO 2 (nitrogen dioxide) oxidation of the (3 × 5)-Ti 2O 3 film at 600 K and subsequent annealing to 700-950 K in vacuum produced disordered oxide regions and domains of a (4 × 13) structure that we attribute to a TiO 2 film with a square -Ti-O- net. This film is transformed further after annealing at 1000-1100 K to (3 × 5)-Ti 2O 3 domains and domains exhibiting a (2√2 × 2√2) R45° structure that we attribute to a Ti 5O 8 film. Additional heating of this film to 1200 K forms primarily a (3 × 5)-Ti 2O 3 oxide film. Three dimensional clusters of TiO 2 are also produced by these oxidation and annealing procedures. Initial oxidation of a "flat" (3 × 5) oxide film at 600 K reconstructs this surface to form a multilayer, porous oxide film, and more extensive oxidation eventually forms a much less porous oxide film with pyramidal oxide crystallites. Oxidation of the (3 × 5) structure using NO (nitric oxide) differs from that above in that the (4 × 13) structure was not observed, but oxidation does produce the (2√2 × 2√2) R45° structure due to

  2. Acute Porphyria in a Patient with Arnold Chiari Malformation

    PubMed Central

    Shen, Jianbin; O’Keefe, Kevin; Webb, Lisa B.; DeGirolamo, Angela

    2015-01-01

    Patient: Female, 33 Final Diagnosis: Acute porphyria Symptoms: Abdominal pain • alternating bowel habits Medication: Metronidazole • bactrim • oxybutynin Clinical Procedure: EMG • porhyria workup Specialty: Neurology Objective: Rare disease Background: Acute porphyria and Arnold Chiari malformation are both uncommon genetic disorders without known association. The insidious onset, non-specific clinical manifestations, and precipitating factors often cause diagnosis of acute porphyria to be missed, particularly in patients with comorbidities. Case Report: A women with Arnold Chiari malformation type II who was treated with oxybutynin and antibiotics, including Bactrim for neurogenic bladder and recurrent urinary tract infection, presented with non-specific abdominal pain, constipation, and diarrhea. After receiving Flagyl for C. difficile colitis, the patient developed psychosis, ascending paralysis, and metabolic derangements. She underwent extensive neurological workup due to her congenital neurological abnormalities, most of which were unremarkable. As a differential diagnosis of Guillain Barré syndrome, acute porphyria was then considered and ultimately proved to be the diagnosis. After hematin administration and intense rehabilitation, the patient slowly recovered from the full-blown acute porphyria attack. Conclusions: This case report, for the first time, documents acute porphyria attack as a result of a sequential combination of 3 common medications. This is the first case report of the concomitant presence of both acute porphyria and Arnold Chiari malformation, 2 genetic disorders with unclear association. PMID:25697467

  3. Pathogenesis of Brain Arteriovenous Malformations

    PubMed Central

    KOMIYAMA, Masaki

    2016-01-01

    Brain arteriovenous malformations (bAVMs) represent a high risk of intracranial hemorrhages, which are substantial causes of morbidity and mortality of bAVMs, especially in children and young adults. Although a variety of factors leading to hemorrhages of bAVMs are investigated extensively, their pathogenesis is still not well elucidated. The author has reviewed the updated data of genetic aspects of bAVMs, especially focusing on clinical and experimental knowledge from hereditary hemorrhagic telangiectasia, which is the representative genetic disease presenting with bAVMs caused by loss-of-function in one of the two genes: endoglin and activin receptor-like kinase 1. This knowledge may allow us to infer the pathogensis of sporadic bAVMs and in the development of new medical therapies for them. PMID:27076383

  4. Osteopetrosis and Chiari type I malformation: a rare association

    PubMed Central

    Ekici, Mehmet Ali; Cıkla, Ulaş; Bauer, Andrew; Başkaya, Mustafa K.

    2015-01-01

    Osteopetrosis (OP) is hereditary X-linked, autosomal recessive (ARO), or autosomal dominant (ADO) skeletal disease. ARO has two subtypes, which are infantile malignant and intermediate type. ARO and X-linked OP have poor clinical outcome. ADO is called adult benign type because of the normal life expectancy, which has type I and type II. Here, the authors present an ADO patient with Chiari type I. Concomitant ADO with Chiari type I malformation is an extremely rare condition. Literature research yielded only one case report to date. PMID:26503583

  5. Increased incidence of spontaneous malformations in pups and increased litter size from pinealectomized dams.

    PubMed

    Kachi, Takashi; Tanaka, Dai; Watanabe, Seiji; Suzuki, Reiko; Tonosaki, Yoshikazu

    2004-06-01

    The aim of the present study was to clarify whether maternal pinealectomy increases: (i) the incidence of spontaneous malformations in offspring; and (ii) litter size. More than 30 female rats in each of the control groups (normal and sham-pinealectomized) and the pinealectomized group were mated repeatedly with normal male rats and pups were autopsied mostly before weaning. No malformations were seen in offspring from the normal and sham-pinealectomized groups (n = 350 and n = 736, respectively). In contrast, in offspring from pinealectomized mothers (n = 1123), spontaneous malformations were found in five (taillessness in three and unilateral hydronephrosis or large renal cyst in the other two) or maybe six (unilateral renal hypoplasia in another) pups. This increased incidence of malformations in the latter group was statistically significant (P < 0.034 or 0.017 (Fisher's exact test), respectively). The frequency of still-born cases was not higher in pups born from pinealectomized mothers. The mean litter size was larger in the pinealectomized group compared with the control groups (P < 0.005-0.001, Student's t-test) at the first delivery (at approximately 100 days of age), but was not different at later deliveries at older ages. Our results suggest that the maternal pineal hormone suppresses: (i) the incidence of spontaneous malformations in offspring until mothers reach an old age; and (ii) litter size during the reproductively maturational phase of life. PMID:15218625

  6. Ten metal complexes of vitamin B3/niacin: Spectroscopic, thermal, antibacterial, antifungal, cytotoxicity and antitumor studies of Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), Cd(II), Pt(IV) and Au(III) complexes

    NASA Astrophysics Data System (ADS)

    Al-Saif, Foziah A.; Refat, Moamen S.

    2012-08-01

    Ten coordination compounds, namely Mn(NA)2Cl2·4H2O (1), Fe(NA)Cl3(H2O)2 (2), Co(NA)2(NO3)2·6H2O (3), Ni(NA)Cl2·5H2O (4), Cu(NA)Cl2·3H2O (5), Zn(NA)(NO3)2·H2O (6), Pd(NA)2Cl2·H2O (7), Cd(NA)Cl2·H2O (8), Pt(NA)2Cl4·5H2O (9) and Au(NA)Cl3 (10) were obtained by the reactions of the corresponding transition metal salts with vitamin B3/niacin (NA) in the presence of 1:4 (v:v) distilled water: methanol solvent at 70 °C for about 30 min, and their suggested structures were determined by elemental analyses, molar conductivity, (infrared, UV-vis) spectra, effective magnetic moment in Bohr magnetons, electron spin resonance (ESR), thermal analysis (TG), X-ray powder diffraction (XRD) as well as scanning electron microscopy (SEM). The results revealed that in complexes 1, 3, 7, and 9 both of two NA ligand coordinates one metal ion to form four or six coordinated structures, while in compound 10, one NA ligand coordinate to Au+++ ion to form a square-planar geometry with N-bonded pyridine ligand is suggested, and (2, 4, 5, 6 and, 8) complexes have 1:1 structures. Antimicrobial and antitumor activities were assessment against some kind of (G+ and G-) bacteria, fungi and breast carcinoma cells (MCF-7-cell line).

  7. Advanced Imaging of Chiari 1 Malformations.

    PubMed

    Fakhri, Akbar; Shah, Manish N; Goyal, Manu S

    2015-10-01

    Type I Chiari malformations are congenital deformities involving cerebellar tonsillar herniation downward through the foramen magnum. Structurally, greater than 5 mm of tonsillar descent in adults and more than 6 mm in children is consistent with type I Chiari malformations. However, the radiographic severity of the tonsillar descent does not always correlate well with the clinical symptomatology. Advanced imaging can help clinically correlate imaging to symptoms. Specifically, cerebrospinal fluid (CSF) flow abnormalities are seen in patients with type I Chiari malformation. Advanced MRI involving cardiac-gated and phase-contrast MRI affords a view of such CSF flow abnormalities. PMID:26408061

  8. Vascular Malformations: Approach by an Interventional Radiologist

    PubMed Central

    Pimpalwar, Sheena

    2014-01-01

    Children with vascular malformations are best managed with a multidisciplinary team of specialists. Interventional radiology may deliver primary treatment such as staged sclerotherapy and embolization for malformations that are poor candidates for primary surgical resection or play a supportive role such as preoperative or intraoperative embolization. A thorough understanding of vascular morphology and flow dynamics is imperative to choosing the best treatment tool and technique. In this review, the author discusses the selection of techniques and tools used to treat vascular malformations based on their angiographic morphology. PMID:25045335

  9. Catalytic dehydrocoupling of amine-boranes and amines into diaminoboranes: isolation of a Pt(ii), Shimoi-type, η(1)-BH complex.

    PubMed

    Roselló-Merino, Marta; Rama, Raquel J; Díez, Josefina; Conejero, Salvador

    2016-06-28

    The platinum complex [Pt(I(t)Bu')(I(t)Bu)][BAr(F)] is a very efficient catalyst in the synthesis of diaminoboranes through dehydrocoupling of amine-boranes and amines. Shimoi-type, η(1)-BH complexes are key intermediates in the process. PMID:27297877

  10. Update on the management of anorectal malformations.

    PubMed

    Bischoff, Andrea; Levitt, Marc A; Peña, Alberto

    2013-09-01

    Thirty-three years ago, on 10 August 1980, in Mexico City, the first patient with an anorectal malformation was operated on using the posterior sagittal approach. At that time it was not obvious that we were actually opening a "Pandora's box" that continues to give many positive surprises, a few disappointments, and the constant hope that each day we can learn more about how to improve the quality of life of children born with all different types of anorectal malformations. In November 2012, patient number 3000 in our database was operated in the city of Cochabamba, Bolivia; during one of our International Courses of Anorectal Malformations and Colorectal Problems in Children. The goal of this article is to give a brief update on the current management of patients with anorectal malformation, based on the multiple lessons learned during this period. PMID:23913263

  11. Revision surgery for Chiari malformation decompression.

    PubMed

    Mazzola, Catherine A; Fried, Arno H

    2003-09-15

    Chiari malformations comprise four different hindbrain anomalies originally described by Hans Chiari, a professor of pathology at the German University in Prague. There are four basic Chiari malformations. The reasons for revision of Chiari malformation decompression may be for conservative or inadequate initial decompression or the development of postoperative complications. Another reason involves cases of both hindbrain herniation and syringomyelia in patients who have undergone adequate posterior fossa decompression without resolution of symptoms, signs, or radiological appearance of their syrinx cavity. Additionally, symptom recurrence has been reported in association with various types of dural grafts. Reoperation or revision surgery for patients with Chiari malformations is common and may not be due to technical error or inadequate decompression. The types of revision surgeries, their indications, and initial presentations will be reviewed. PMID:15347221

  12. The Microcephaly-Capillary Malformation Syndrome

    PubMed Central

    Mirzaa, Ghayda M.; Paciorkowski, Alex R.; Smyser, Christopher D.; Willing, Marcia C.; Lind, Anne C.; Dobyns, William B.

    2012-01-01

    We report on three children from two families with a new pattern recognition malformation syndrome consisting of severe congenital microcephaly (MIC), intractable epilepsy including infantile spasms, and generalized capillary malformations that was first reported recently in this journal [Carter et al. (2011); Am J Med Genet A 155: 301–306]. Two of our reported patients are an affected brother and sister, suggesting this is an autosomal recessive severe congenital MIC syndrome. PMID:21815250

  13. Malformation and plastic surgery in childhood

    PubMed Central

    Siegert, Ralf; Magritz, Ralph

    2014-01-01

    Malformations of the head and neck show a huge variety of clinical symptoms with functional and esthetic consequences. Often times its rehabilitation requires multi-staged and multi-disciplinary procedures and concepts. These must consider eating, speech, mimic expression, hearing and “esthetics” or at least “normality”. A survey of the most common head and neck malformations and their treatment options are presented here. PMID:25587361

  14. Spontaneous arteriovenous malformations in the cervical area

    PubMed Central

    Greenberg, J.

    1970-01-01

    Four patients with spontaneous arteriovenous malformations of cervical vessels have been presented. The embryology of these vessels has been discussed in order to suggest an explanation for the apparent difference in the incidence of arteriovenous malformations involving the internal carotid artery and those involving either the vertebral or the external carotid arteries. A fifth case (S.T.) is presented as a probable iatrogenic arteriovenous fistula and is to be added to the steadily growing reports of this phenomenon. Images PMID:5431722

  15. Lymphangiosarcoma complicating extensive congenital mixed vascular malformations.

    PubMed

    Al Dhaybi, Rola; Agoumi, Mehdi; Powell, Julie; Dubois, Josée; Kokta, Victor

    2010-09-01

    Pediatric hepatic angiosarcoma is a very rare malignant vascular tumor. A few cases have shown pediatric hepatic angiosarcoma occurring on a background of preexisting vascular lesions. We report the case of a newborn girl who presented extensive limbs and upper trunk cutaneous mixed vascular malformations at birth. These malformations were associated with thrombocytopenia. Cutaneous biopsies revealed complex vascular malformations with a significant lymphatic component. Compressive body suit therapy led to regression of the limbs' cutaneous vascular malformations. At the age of 9 months, the patient presented multiple heterogeneous hepatosplenic nodules. Aggressive treatment with prednisone, vincristine, and hepatosplenic embolizations resulted in initial improvement of the hepatosplenic lesions for few months, followed by an increase of the lesions with failure of response to treatment despite adding alpha-interferon-2b to treatment. The patient died at the age of 19 months. The autopsy's pathological examination revealed a hepatic-based angiosarcoma with plurimetastatic dissemination to the spleen, lungs, peritoneum, pleura, mesenteric linings as well as the serosa of the stomach and small intestine. Multiple cutaneous and visceral complex capillaro-lymphatico-venous malformations were also identified. We hypothesize that these multiple extensive mixed vascular malformations were associated with chronic lymphedema which probably predisposed to the development of the angiosarcoma in our patient. PMID:20863270

  16. Venous Malformation: update on etiopathogenesis, diagnosis & management

    PubMed Central

    Dompmartin, Anne; Vikkula, Miikka; Boon, Laurence M

    2011-01-01

    The aim of this review was to discuss the current knowledge on etiopathogenesis, diagnosis and therapeutic management of venous malformations. Venous malformations (VMs) are slow-flow vascular anomalies. They are simple, sporadic or familial (cutaneo-mucosal venous malformation or glomuvenous malformations), combined (e.g. capillaro-venous, capillaro-lymphaticovenous malformations) or syndromic (Klippel-Trenaunay, Blue Rubber Bleb Naevus and Maffucci). Genetic studies have identified causes of familial forms and of 40% of sporadic VMs. Another diagnostic advancement is the identification of elevated D-dimer level as the first biomarker of venous malformations within vascular anomalies. Those associated with pain are often responsive to Low Molecular Weight Heparin which should also be used to avoid disseminated intravascular coagulopathy secondary to intervention, especially if fibrinogen level is low. Finally, development of a modified sclerosing agent, ethylcellulose–ethanol, has improved therapy. It is efficient and safe, and widens indications for sclerotherapy to sensitive and dangerous areas such as hands, feet and periocular area. PMID:20870869

  17. Crossed-Wire Laser Microwelding of Pt-10 Pct Ir to 316 LVM Stainless Steel: Part II. Effect of Orientation on Joining Mechanism

    NASA Astrophysics Data System (ADS)

    Huang, Y. D.; Pequegnat, A.; Zou, G. S.; Feng, J. C.; Khan, M. I.; Zhou, Y.

    2012-04-01

    With the increasing complexity of medical devices and with efforts to reduce manufacturing costs, challenges arise in joining dissimilar materials. In this study, the laser weldability of dissimilar joints between Pt-10 pct Ir and 316 low-carbon vacuum melted (LVM) stainless steel (SS) crossed wires was investigated by characterizing the weld geometry, joint strength, morphology of weld cross sections, and differences in joining behavior, depending on which material is subject to the incident laser beam. With the Pt-Ir alloy on top, a significant amount of porosity was observed on the surface of the welds as well as throughout the weld cross sections. This unique form of porosity is believed to be a result of preferential vaporization of 316 LVM SS alloying elements that become mixed with the molten Pt-10 pct Ir during welding. The joining mechanism documented in micrographs of cross-sectioned welds was found to transition from laser brazing to fusion welding. It is inferred that the orientation of the two dissimilar metals ( i.e., which material is subject to the incident laser beam) plays an important role in weld quality of crossed-wire laser welds.

  18. Stellar (n,{gamma}) cross sections of p-process isotopes. II. {sup 168}Yb, {sup 180}W, {sup 184}Os, {sup 190}Pt, and {sup 196}Hg

    SciTech Connect

    Marganiec, J.; Dillmann, I.; Pardo, C. Domingo; Kaeppeler, F.; Walter, S.

    2010-09-15

    The neutron-capture cross sections of {sup 168}Yb, {sup 180}W, {sup 184}Os, {sup 190}Pt, and {sup 196}Hg have been measured by means of the activation technique. The samples were irradiated in a quasistellar neutron spectrum of kT=25 keV, which was produced at the Karlsruhe 3.7-MV Van de Graaff accelerator via the {sup 7}Li(p,n){sup 7}Be reaction. Systematic uncertainties were investigated in repeated activations with different samples and by variation of the experimental parameters, that is, irradiation times, neutron fluxes, and {gamma}-ray counting conditions. The measured data were converted into Maxwellian-averaged cross sections at kT=30 keV, yielding 1214{+-}61, 624{+-}54, 590{+-}43, 511{+-}46, and 201{+-}11 mb for {sup 168}Yb, {sup 180}W, {sup 184}Os, {sup 190}Pt, and {sup 196}Hg, respectively. The present results either represent first experimental data ({sup 168}Yb, {sup 184}Os, and {sup 196}Hg) or could be determined with significantly reduced uncertainties ({sup 180}W and {sup 190}Pt). These measurements are part of a systematic study of stellar (n,{gamma}) cross sections of the stable p isotopes.

  19. Experimental and computational study on 2,2‧-[(1E,2E)-hydrazine-1,2-diylidenedi(1E)eth-1-yl-1-ylidene]diphenol and its Ni(II), Pt(II), Pd(II) complexes

    NASA Astrophysics Data System (ADS)

    Alyar, Saliha; Özbek, Neslihan; Yıldırım, Sema Öztürk; İde, Semra; Butcher, Ray J.

    2014-09-01

    2,2‧-[(1E,2E)-hydrazine-1,2-diylidenedi(1E)eth-1-yl-1-ylidene]diphenol and its dimeric, binuclear Ni(II), Pd(II) and Pt(II) metal complexes were synthesized. Hydrazine derivative and its complexes were characterized by elemental analyses, LC-MS, IR, electronic spectra, 1H and 13C NMR spectra, conductivity and magnetic measurements. 1H and 13C shielding tensors for crystal structure were calculated with GIAO/DFT/B3LYP/6-311++G(d,p) methods in CDCl3. The vibrational band assignments were performed at B3LYP/6-311++G(d,p) theory level combined with scaled quantum mechanics force field (SQMFF) methodology. The antibacterial activities of synthesized compounds were studied against some Gram-positive and Gram-negative bacteria by using the microdilution and disk diffusion method. As the antibacterial activity results evidently show, the compound possessed a broad spectrum of activity against the tested bacteria.

  20. Spectrum of urorectal septum malformation sequence.

    PubMed

    Shah, Krupa; Nayak, Shalini S; Shukla, Anju; Girisha, Katta M

    2016-05-01

    Urorectal septum malformation sequence (URSMS) is a rare spectrum of malformations involving various organ systems. Here, we present eight cases of URSMS, noted in autopsy, with different degrees of complexity, seven being the complete type and one being the partial type. All cases had gastrointestinal tract malformation in the form of the imperforate anus and indeterminate genitalia. Other gastrointestinal tract anomalies were anal agenesis in two cases, anorectal agenesis in two cases, and malformed lower intestinal tract in four cases. The associated renal abnormality was noted in five cases, which were unilateral renal agenesis, dysplastic kidney, hydronephrosis, horseshoe kidney, and unilateral hypoplastic ectopic kidney. External genital malformation, present in both male and female fetuses, included a knob-like structure at perineum in female fetuses, genital fold hypoplasia and penile aplasia or hypoplasia in male fetuses. Skeletal abnormalities included two cases of sacral agenesis and one case of lumbosacral dysraphism. Other anomalies included a case with alobar holoprosencephaly, truncus arteriosus with hypoplastic lungs in one case, and three cases with abdominal wall defects. It is our attempt to delineate a spectrum of abnormalities associated with URSMS. PMID:26663027

  1. Synthesis of the donor acceptor ligand 2-(4-dimethylaminobenzylidene)-4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (dbpcd) and X-ray diffraction structure of the platinum(II) compound PtCl2(dbpcd) 1.5CH2Cl2

    SciTech Connect

    Atim, Silvia; Wang, Xiaoping; Richmond, Michael G.

    2010-01-01

    The synthesis of the donor acceptor ligand 2-(4-dimethylaminobenzylidene)-4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (dbpcd) from the Knoevenagel condensation of 4-(dimethylamino)benzaldehyde with 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) is reported. This new ligand reacts with PtCl2(cod) to afford the platinum(II) complex PtCl2(dbpcd) in high yield. The dbpcd ligand and PtCl2(dbpcd) have been isolated and characterized by IR and NMR spectroscopies, cyclic voltammetry, MO calculations at the extended H ckel level, and X-ray diffraction analysis in the case of PtCl2(dbpcd).

  2. Synthesis and characterization of (di-tert-butylbipyridine)bis(pyridine-4-thiolato)platinum(II), Pt(dbbpy)(S-4-py){sub 2}: A synthon for supramolecular systems containing the platinum diimine bis(thiolate) chromophore

    SciTech Connect

    Paw, W.; Lachicotte, R.J.; Eisenberg, R.

    1998-08-10

    The notion of using the Pt diimine dithiolate chromophore in a multicomponent system for light-driven reactions has stimulated the design and synthesis of related complexes having ligands capable of functioning as bridges. Complexes of one such ligand, dipyridocatecholate or phenanthroline-5,6-diolate, have recently been reported. In the present study, the dithiolate ligand is replaced by two thiolates having pyridyl groups for connection to another metal. The authors describe herein the synthesis, characterization, and X-ray structure determination of the resultant complex, Pt(dbbpy)(S-4-py){sub 2} (dbbpy = 4,4{prime}-di-tert-butyl-2,2{prime}-bipyridine, S-4-py = pyridine-4-thiolate). Diimine bis(thiolate) complexes of platinum(II) have not been studied as extensively as the corresponding dithiolate systems, but they appear to have a similar electronic structure with an intense solvatochromic absorption band in the visible region of the spectrum and an associated charge-transfer emission that is observable at 77 K.

  3. Time-resolved photoelectron spectroscopy of a dinuclear Pt(II) complex: Tunneling autodetachment from both singlet and triplet excited states of a molecular dianion.

    PubMed

    Winghart, Marc-Oliver; Yang, Ji-Ping; Vonderach, Matthias; Unterreiner, Andreas-Neil; Huang, Dao-Ling; Wang, Lai-Sheng; Kruppa, Sebastian; Riehn, Christoph; Kappes, Manfred M

    2016-02-01

    Time-resolved pump-probe photoelectron spectroscopy has been used to study the relaxation dynamics of gaseous [Pt2(μ-P2O5H2)4 + 2H](2-) after population of its first singlet excited state by 388 nm femtosecond laser irradiation. In contrast to the fluorescence and phosphorescence observed in condensed phase, a significant fraction of the photoexcited isolated dianions decays by electron loss to form the corresponding monoanions. Our transient photoelectron data reveal an ultrafast decay of the initially excited singlet (1)A2u state and concomitant rise in population of the triplet (3)A2u state, via sub-picosecond intersystem crossing (ISC). We find that both of the electronically excited states are metastably bound behind a repulsive Coulomb barrier and can decay via delayed autodetachment to yield electrons with characteristic kinetic energies. While excited state tunneling detachment (ESETD) from the singlet (1)A2u state takes only a few picoseconds, ESETD from the triplet (3)A2u state is much slower and proceeds on a time scale of hundreds of nanoseconds. The ISC rate in the gas phase is significantly higher than in solution, which can be rationalized in terms of changes to the energy dissipation mechanism in the absence of solvent molecules. [Pt2(μ-P2O5H2)4 + 2H](2-) is the first example of a photoexcited multianion for which ESETD has been observed following ISC. PMID:26851919

  4. Time-resolved photoelectron spectroscopy of a dinuclear Pt(II) complex: Tunneling autodetachment from both singlet and triplet excited states of a molecular dianion

    NASA Astrophysics Data System (ADS)

    Winghart, Marc-Oliver; Yang, Ji-Ping; Vonderach, Matthias; Unterreiner, Andreas-Neil; Huang, Dao-Ling; Wang, Lai-Sheng; Kruppa, Sebastian; Riehn, Christoph; Kappes, Manfred M.

    2016-02-01

    Time-resolved pump-probe photoelectron spectroscopy has been used to study the relaxation dynamics of gaseous [Pt2(μ-P2O5H2)4 + 2H]2- after population of its first singlet excited state by 388 nm femtosecond laser irradiation. In contrast to the fluorescence and phosphorescence observed in condensed phase, a significant fraction of the photoexcited isolated dianions decays by electron loss to form the corresponding monoanions. Our transient photoelectron data reveal an ultrafast decay of the initially excited singlet 1A2u state and concomitant rise in population of the triplet 3A2u state, via sub-picosecond intersystem crossing (ISC). We find that both of the electronically excited states are metastably bound behind a repulsive Coulomb barrier and can decay via delayed autodetachment to yield electrons with characteristic kinetic energies. While excited state tunneling detachment (ESETD) from the singlet 1A2u state takes only a few picoseconds, ESETD from the triplet 3A2u state is much slower and proceeds on a time scale of hundreds of nanoseconds. The ISC rate in the gas phase is significantly higher than in solution, which can be rationalized in terms of changes to the energy dissipation mechanism in the absence of solvent molecules. [Pt2(μ-P2O5H2)4 + 2H]2- is the first example of a photoexcited multianion for which ESETD has been observed following ISC.

  5. Structure Effect of Some New Anticancer Pt(II) Complexes of Amino Acid Derivatives with Small Branched or Linear Hydrocarbon Chains on Their DNA Interaction.

    PubMed

    Kantoury, Mahshid; Eslami Moghadam, Mahboube; Tarlani, Ali Akbar; Divsalar, Adeleh

    2016-07-01

    The aim of this study was to investigate the structure effect and identify the modes of binding of amino acid-Pt complexes to DNA molecule for cancer treatment. Hence, three novel water soluble platinum complexes, [Pt(phen)(R-gly)]NO3 (where phen is 1,10-phenanthroline, R-gly is methyl, amyl, and isopentyl-glycine), have been synthesized and characterized by spectroscopic methods, conductivity measurements, and chemical analysis. The anticancer activities of synthesized complexes were investigated against human breast cancer cell line of MDA-MB 231. The 50% cytotoxic concentration values were determined to be 42.5, 58, and 70 μm for methyl-, amyl-, and isopentyl-gly complexes, respectively. These complexes were interacted with calf thymus DNA (ct-DNA) via positive cooperative interaction. The modes of binding of the complexes to DNA were investigated by fluorescence spectroscopy and circular dichroism in combination with a molecular docking study. The result indicates that complexes with small or branched hydrocarbon chains can intercalate with DNA. This is while amyl complexes with linear chains interacted additionally via groove binding. The results of the negative value of Gibbs energy for binding of isopentyl-platinum to DNA and those of the molecular docking were coherent. Furthermore, the docking results demonstrated that hydrophobic interaction plays an important role in the complex-DNA interaction. PMID:26833921

  6. Meningitis after cochlear implantation in Mondini malformation.

    PubMed

    Page, E L; Eby, T L

    1997-01-01

    Although the potential for CSF leakage and subsequent meningitis after cochlear implantation in the malformed cochlea has been recognized, this complication has not been previously reported. We report a case of CSF otorhinorrhea and meningitis after minor head trauma developing 2 years after cochlear implantation in a child with Mondini malformation. Leakage of CSF was identified from the cochleostomy around the electrode of the implant, and this leak was sealed with a temporalis fascia and muscle plug. Although this complication appears to be rare, care must be taken to seal the cochleostomy in children with inner ear malformations at the initial surgery, and any episode of meningitis after surgery must be thoroughly investigated to rule out CSF leakage from the labyrinth. PMID:9018266

  7. Sex hormone exposure during pregnancy and malformations.

    PubMed

    Briggs, M H; Briggs, M

    1979-01-01

    This general review of the effects of exposure to sex hormones during pregnancy and subsequent fetal malformation presents summaries of animal studies, develops the data indicating virilization and feminization in humans, documents chromosome abnormalities, and presents data on the connection of steroid exposure in utero and somatic malformations. Fetal exposure can occur 3 different ways, through hormonal pregnancy test, via obstetrical use of hormones, or because of continued maternal use of oral contraceptives after conception. In the latter case, an ongoing prospective study indicates that accidental ingestion of oral contraceptives after conception is not harmful to the fetus if taken during early pregnancy. Tables present summaries of numerous large surveys and retrospective studies linking particular sex hormones (exogenous) to particular fetal malformations including neural tube defects and other constellations of developmental problems. The question of exogenous hormone effects on the personality of infants who were exposed in utero is addressed. PMID:400321

  8. Anorectal Malformation: Paediatric Problem Presenting in Adult.

    PubMed

    Chavan, Rahulkumar N; Chikkala, Bhargav; Das, Cinjini; Biswas, Somak; Sarkar, Diptendra Kumar; Pandey, Sushil Kumar

    2015-01-01

    This is a case report of 22-year-old girl admitted with abdominal distension, vomiting, and chronic constipation since birth. Abdomen was distended, and perineal examination revealed imperforate anus with vestibular fistula (ARM). So far worldwide very few cases have been reported about anorectal malformation presenting in adulthood, and thus extremely little data is available in the literature about an ideal management of anorectal malformation in adults. In our case in the treatment instead of conventional procedure of posterior sagittal anorectoplasty (PSARP) anal transposition was done and till two years after the definitive treatment during follow-up patient has been doing well with Kelly's score of six. Our experience suggests that anal transposition provides satisfactory outcome in adults presenting late with anorectal malformation. PMID:26539301

  9. Anorectal Malformation: Paediatric Problem Presenting in Adult

    PubMed Central

    Chavan, Rahulkumar N.; Chikkala, Bhargav; Das, Cinjini; Biswas, Somak; Sarkar, Diptendra Kumar; Pandey, Sushil Kumar

    2015-01-01

    This is a case report of 22-year-old girl admitted with abdominal distension, vomiting, and chronic constipation since birth. Abdomen was distended, and perineal examination revealed imperforate anus with vestibular fistula (ARM). So far worldwide very few cases have been reported about anorectal malformation presenting in adulthood, and thus extremely little data is available in the literature about an ideal management of anorectal malformation in adults. In our case in the treatment instead of conventional procedure of posterior sagittal anorectoplasty (PSARP) anal transposition was done and till two years after the definitive treatment during follow-up patient has been doing well with Kelly's score of six. Our experience suggests that anal transposition provides satisfactory outcome in adults presenting late with anorectal malformation. PMID:26539301

  10. Percutaneous Cryotherapy of Vascular Malformation: Initial Experience

    SciTech Connect

    Cornelis, F.; Neuville, A.; Labreze, C.; Kind, M.; Bui, B.; Midy, D.; Palussiere, J.; Grenier, N.

    2013-06-15

    The present report describes a case of percutaneous cryotherapy in a 36-year-old woman with a large and painful pectoral venous malformation. Cryoablation was performed in a single session for this 9-cm mass with 24 h hospitalisation. At 2- and 6-month follow-up, the pain had completely disappeared, and magnetic resonance imaging demonstrated a significant decrease in size. Percutaneous cryoablation shows promise as a feasible and apparently safe method for local control in patients with symptomatic venous vascular malformations.

  11. Retroperitoneal vascular malformation mimicking incarcerated inguinal hernia.

    PubMed

    Dubey, Indu Bhushan; Sharma, Anuj; Singh, Ajay Kumar; Mohanty, Debajyoti

    2011-01-01

    A 30-year-old man presented to the Department of Surgery with a painful groin swelling on right side. Exploration revealed a reddish-blue hemangiomatous mass in the scrotum extending through inguinal canal into the retroperitoneum. On further dissection swelling was found to be originating from right external iliac vein. The swelling was excised after ligating all vascular connections. The histopathological examination of excised mass confirmed the diagnosis of venous variety of vascular malformation. This is the first reported case of vascular malformation arising from retroperitoneum and extending into inguinoscrotal region, presenting as incarcerated inguinal hernia. PMID:21633582

  12. Mayer-Rokitansky syndrome and anorectal malformation.

    PubMed

    Patankar, Shreeprasad P; Kalrao, Vijay; Patankar, Shilpa S

    2004-12-01

    Mayer Rokitansky Kuster Houser syndrome (MRKH syndrome) is characterized by Mullerian duct structures agenesis, vaginal atresia being the commonest variant. It can be associated with renal, skeletal, spine and other malformations. Patient with Mayer Rokitansky syndrome has a varied presentation from newborn period to adolescence. Thorough investigations are required for classification of the syndrome and diagnosis of associated anomalies. The MRKH syndrome patient may require complex vaginal reconstructive surgery and a detailed counseling about the potentials of menstruation and fertility. Here we are presenting a patient having association of anorectal malformation, Mullerian duct agenesis and renal anomaly. PMID:15630325

  13. Congenital Malformations Leading to Paradoxical Embolism.

    PubMed

    Bruckheimer, Elchanan

    2016-05-01

    The absolute separation of the right and left circulations and the filtration of blood by the pulmonary circulation are essential to prevent the passage of thrombotic material from the venous system into the systemic arterial circulation. Any breach of the intracardiac septae or circumvention of the pulmonary capillary network may cause a paradoxical embolus. The most common causes are atrial septal defects and pulmonary arteriovenous malformations. This article discusses unusual connections and pathways related to congenital malformations. Although anticoagulation is necessary to prevent paradoxical emboli, the hematologic disturbances and the most appropriate therapy in these patients warrant further investigation. PMID:27150173

  14. Neurodevelopmental malformations of the cerebellar vermis in genetically engineered rats

    EPA Science Inventory

    The cerebellar vermis is particularly vulnerable to neurodevelopmental malformations in humans and rodents. Sprague-Dawley, and Long-Evans rats exhibit spontaneous cerebellar malformations consisting of heterotopic neurons and glia in the molecular layer of the vermis. Malformati...

  15. Microstructure and magnetization reversal of L10-FePt/[Co/Pt]N exchange coupled composite films

    NASA Astrophysics Data System (ADS)

    Guo, H. H.; Liao, J. L.; Ma, B.; Zhang, Z. Z.; Jin, Q. Y.; Wang, H.; Wang, J. P.

    2012-04-01

    Two series of perpendicular exchange coupled composites (ECC) films are prepared by dc magnetron sputtering, FePt(5)/[Co(0.2)/Pt(0.3)]N (ECC-I-N) and FePt(5)/[Co(0.2)/Pt(0.6)]N (ECC-II-N), respectively. Structure analyses reveal the epitaxial growth on (001) oriented L10 FePt island-like grains of [Co/Pt]N with (200) orientation. Coercivity HC and remanent coercivity HCR of both series samples decrease sharply compared to FePt, with the increase of the thickness of [Co/Pt]N. The angular dependence of HCR shows excellent angular tolerance.

  16. Preparation of Pt Nanocatalyst on Carbon Materials via a Reduction Reaction of a Pt Precursor in a Drying Process.

    PubMed

    Lee, Jae-Young; Lee, Woo-Kum; Rim, Hyung-Ryul; Joung, Gyu-Bum; Weidner, John W; Lee, Hong-Ki

    2016-06-01

    Platinum (Pt) nanocatalyst for a proton-exchange membrane fuel cell (PEMFC) was prepared on a carbon black particle or a graphite particle coated with a nafion polymer via a reduction of platinum(II) bis(acetylacetonate) denoted as Pt(acac)2 as a Pt precursor in a drying process. Sublimed Pt(acac)2 adsorbed on the nafion-coated carbon materials was reduced to Pt nanoparticles in a glass reactor at 180 degrees C of N2 atmosphere. The morphology of Pt nanoparticles on carbon materials was observed by scanning electron microscopy (SEM) and the distribution of Pt nanoparticles was done by transmission electron microscopy (TEM). The particle size was estimated by analyzing the TEM image using an image analyzer. It was found that nano-sized Pt particles were deposited on the surface of carbon materials, and the number density and the average particle size increased with increasing reduction time. PMID:27427723

  17. [Lymphatic malformations in the head and neck area].

    PubMed

    Wiegand, S; Werner, J A

    2016-02-01

    Lymphatic malformations are congenital malformations of the lymphatic system. They are mainly located in the head and neck area, and grow proportional to the patients' body growth. Depending on the morphology, it can be distinguished between macrocystic, microcystic and mixed lymphatic malformations. Due to their infiltrative growth, microcystic lymphatic malformations are particularly difficult to treat. Therapeutic approaches include conventional surgical resection, laser therapy, sclerotherapy and systemic drug therapies. PMID:26820157

  18. Acquired pulmonary arteriovenous malformation secondary to hydatid cyst operation.

    PubMed

    Gezer, S; Turut, H; Oz, G; Demirag, F; Tastepe, I

    2007-10-01

    Pulmonary arteriovenous malformations are abnormal communications between pulmonary arteries and pulmonary veins. The majority of the cases are congenital in origin, and acquired pulmonary arteriovenous malformations are very rare. We present a case here, which - to the best of our knowledge - is the first acquired pulmonary arteriovenous malformation secondary to a hydatid cyst operation in the literature, and we discuss the etiology, clinical presentation, diagnostic modalities and treatment of acquired pulmonary arteriovenous malformations. PMID:17902072

  19. Spinal arteriovenous malformations: Is surgery indicated?

    PubMed Central

    Singh, Bikramjit; Behari, Sanjay; Jaiswal, Awadhesh K.; Sahu, Rabi Narayan; Mehrotra, Anant; Mohan, B. Madan; Phadke, Rajendra V.

    2016-01-01

    Purpose: To identify clinico-radiological distinguishing features in various types of spinal arteriovenous malformations (AVM) with an aim to define the role of surgical intervention. Materials and Methods: Hero's modified Di Chiro classification differentiated four types of spinal AVMs on digital subtraction angiogram (DSA) in 74 patients: I. Dural arteriovenous fistulae (n = 35, 47.3%); II. Glomus/intramedullary (n = 13, 17.6%); III. Juvenile/metameric (n = 4, 5.4%); and, IV. Ventral perimedullary fistula (n = 21, 28.4%). A patient with extradural AVM remained unclassified. Demographic profiles, DSA features and reason for surgical referral were recorded. Statistical comparison of discrete variables like gender, spinal cord level, presentation and outcome was made using Chi-square test; and, continuous variables like age, feeder number, duration of symptoms and number of staged embolizations by one way analysis of variance with Boneferoni post hoc comparison. Embolization alone (n = 39, 52.7%), surgery alone (n = 16, 21.6%), and combined approach (n = 4, 5.4%) were the treatments offered (15 were treated elsewhere). Results: Type I-AVM occurred in significantly older population than other types (P = 0.01). Mean duration of symptoms was 13.18 ± 12.8 months. Thoracic cord involvement predominated in type-I and III AVMs (P = 0.01). Number of feeding arteries were 1 in 59.7%; 2 in 29.0%; and, multiple in 11.3% patients, respectively. Staged embolization procedures in type-III AVM were significant (P < 0.01). Surgical referral was required due to: Vessel tortuosity/insufficient parent vessel caliber (n = 7); residual AVM (n = 4); low flow AVM (n = 3); and, multiple feeders (n = 2). Check DSA (n = 34) revealed complete AVM obliteration in 26 and minor residual lesion in eight patients. Neurological status improved in 26 and stabilized in 25 patients. Conclusions: Differentiating between Type I-IV AVMs has a significant bearing on their management. Surgical

  20. Genetic basis of congenital cardiovascular malformations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cardiovascular malformations are a singularly important class of birth defects and due to dramatic improvements in medical and surgical care, there are now large numbers of adult survivors. The etiologies are complex, but there is strong evidence that genetic factors play a crucial role. Over the la...

  1. Coexistent arteriovenous malformation and hippocampal sclerosis.

    PubMed

    Prayson, Richard A; O'Toole, Elizabeth E

    2016-06-01

    Cavernous angiomas or cavernomas have been occasionally described in patients presenting with medically intractable epilepsy. Reports of cavernomas associated with a second pathology potentially causative of seizures have rarely been documented; most commonly, the second pathology is focal cortical dysplasia or less frequently, hippocampal sclerosis. To our knowledge, cases of arteriovenous malformation arising in this clinical setting and associated with hippocampal sclerosis have not been previously described. We report a 56-year-old woman who initially presented at age 24years with staring spells. Imaging studies revealed an arteriovenous malformation in the right parietal lobe. At age 51years, she represented with signs and symptoms related to a hemorrhage from the malformation. The patient underwent Gamma Knife radiosurgery (Elekta AB, Stockholm, Sweden) of the lesion. She subsequently developed seizures, refractory to medical management. MRI studies showed atrophy in the right hippocampus. She underwent resection of the right parietal lobe and hippocampus. Histopathologic examination of the right parietal lesion revealed an arteriovenous malformation marked by focally prominent vascular sclerosis, calcification and adjacent hemosiderin deposition. The hippocampus was marked by prominent neuronal loss and gliosis in the CA1 region, consistent with CA1 sclerosis or hippocampal sclerosis International League Against Epilepsy type 2. PMID:26899356

  2. Genetics Home Reference: cerebral cavernous malformation

    MedlinePlus

    ... R, Awad IA, Ginsberg MH. Cerebral cavernous malformations proteins inhibit Rho kinase to stabilize vascular integrity. J Exp Med. 2010 Apr 12;207(4):881-96. doi: 10.1084/jem.20091258. Epub 2010 Mar 22. Citation on ... CCM1 and CCM2 protein interactions in cell signaling: implications for cerebral cavernous ...

  3. Congenital vascular malformations in scintigraphic evaluation

    PubMed Central

    Pilecki, Stanisław; Gierach, Marcin; Gierach, Joanna; Świętaszczyk, Cyprian; Junik, Roman; Lasek, Władysław

    2014-01-01

    Summary Background Congenital vascular malformations are tumour-like, non-neoplastic lesions caused by disorders of vascular tissue morphogenesis. They are characterised by a normal cell replacement cycle throughout all growth phases and do not undergo spontaneous involution. Here we present a scintigraphic image of familial congenital vascular malformations in two sisters. Material/Methods A 17-years-old young woman with a history of multiple hospitalisations for foci of vascular anomalies appearing progressively in the upper and lower right limbs, chest wall and spleen. A Parkes Weber syndrome was diagnosed based on the clinical picture. Due to the occurrence of new foci of malformations, a whole-body scintigraphic examination was performed. A 12-years-old girl reported a lump in the right lower limb present for approximately 2 years, which was clinically identified as a vascular lesion in the area of calcaneus and talus. Phleboscintigraphy visualized normal radiomarker outflow from the feet via the deep venous system, also observed in the superficial venous system once the tourniquets were released. In static and whole-body examinations vascular malformations were visualised in the area of the medial cuneiform, navicular and talus bones of the left foot, as well as in the projection of right calcaneus and above the right talocrural joint. Conclusions People with undiagnosed disorders related to the presence of vascular malformations should undergo periodic follow-up to identify lesions that may be the cause of potentially serious complications and to assess the results of treatment. Presented scintigraphic methods may be used for both diagnosing and monitoring of disease progression. PMID:24567769

  4. Templation of a square grid copper(II) 4,4'-bipyridine network by a 3D PtS-related Cu(I)-Cu(II) 4,4'-bipyridine crystal.

    PubMed

    Abrahams, C T; Abrahams, B F; Hudson, T A; Robson, R

    2016-01-11

    Two cationic networks, [Cu(I)Cu(II)(4,4'bipy)4(H2O)2](3+) and [Cu(II)(4,4'bipy)2(H2O)2](2+) have been formed from a solution in which Cu(I) undergoes aerial oxidation. Whilst the topologies of the two networks are different the arrangement of Cu centres is almost identical, a structural feature which presumably allows for [Cu(I)Cu(II)(4,4'bipy)4(H2O)2](3+) to serve as a crystalline template for [Cu(II)(bipy)2(H2O)2](2+). PMID:26553590

  5. Prothrombin time (PT)

    MedlinePlus

    PT; Pro-time; Anticoagulant-prothrombin time; Clotting time: protime; INR; International normalized ratio ... PT is measured in seconds. Most of the time, results are given as what is called INR ( ...

  6. Bilateral congenital cystic adenomatiod malformation of the lungs: a case report.

    PubMed

    Atalabi, O M; Ogunseyinde, A O; Obajimi, M O; Falade, A G; Adebo, A O; Jite, I E

    2006-06-01

    A six weeks old infant presented with scalp ulcer and fever. and on examination was found to have resonant percussion notes bilaterally. The initial chest radiograph revealed multiple lucencies which were initially thought to be due to diaphragmatic hernia, but the dilemma was resolved by Computerised tomography which revealed the lucencies to be multiple cysts characteristics of Congenital Cystic Adenomatiod Malformation (CCAM) type II. PMID:17209318

  7. Genetic animal models of malformations of cortical development and epilepsy.

    PubMed

    Wong, Michael; Roper, Steven N

    2016-02-15

    Malformations of cortical development constitute a variety of pathological brain abnormalities that commonly cause severe, medically-refractory epilepsy, including focal lesions, such as focal cortical dysplasia, heterotopias, and tubers of tuberous sclerosis complex, and diffuse malformations, such as lissencephaly. Although some cortical malformations result from environmental insults during cortical development in utero, genetic factors are increasingly recognized as primary pathogenic factors across the entire spectrum of malformations. Genes implicated in causing different cortical malformations are involved in a variety of physiological functions, but many are focused on regulation of cell proliferation, differentiation, and neuronal migration. Advances in molecular genetic methods have allowed the engineering of increasingly sophisticated animal models of cortical malformations and associated epilepsy. These animal models have identified some common mechanistic themes shared by a number of different cortical malformations, but also revealed the diversity and complexity of cellular and molecular mechanisms that lead to the development of the pathological lesions and resulting epileptogenesis. PMID:25911067

  8. Supramolecular assembly of achiral alkynylplatinum(II) complexes and carboxylic β-1,3-glucan into different helical handedness stabilized by Pt⋅⋅⋅Pt and/or π-π interactions.

    PubMed

    Chung, Clive Yik-Sham; Tamaru, Shun-ichi; Shinkai, Seiji; Yam, Vivian Wing-Wah

    2015-03-27

    Two-component ensembles of alkynylplatinum(II) terpyridine (tpy) complexes and carboxylic β-1,3-glucan (CurCOOH) have been investigated by using spectroscopic and microscopic techniques, as well as time-dependent UV/Vis absorption and circular dichroism (CD) experiments. Microscopic images of [Pt(tpy){C≡CC6 H4 (CH2 NMe3 -4)}](OTf)2 (1) have revealed spherical nanostructures, whereas helical fibrous structures of different lengths, depending on the concentration of complex 1 and CurCOOH, were observed. The helical assemblies have been found to show low-energy metal-metal-to-ligand charge transfer (MMLCT) absorption and triplet MMLCT ((3) MMLCT) emission, which are indicative of Pt⋅⋅⋅Pt and/or π-π interactions between the complex 1 molecules. Interestingly, the ensemble has been demonstrated to show different handedness and even a change in handedness over time under different experimental conditions. Low temperatures, low concentrations of CurCOOH, high concentrations of complex 1, or successive addition of CurCOOH into complex 1 solution favor the formation of right-handed helical assemblies, whereas high temperatures, high concentrations of CurCOOH, low concentrations of complex 1, or single-batch addition of CurCOOH into complex 1 solution result in a fast chiroptical inversion of the ensemble solution, giving rise to the left-handed helical assemblies as the dominant species. The results have been rationalized by considering the competing kinetically and thermodynamically controlled assembly-elongation of the ensemble, which leads to the formation of right-handed and left-handed helical assemblies, respectively. The change in the handedness of the ensemble has been demonstrated to stem from the formation of two-component assemblies with supramolecular interactions, in contrast to the template- induced chiral amplification commonly observed in other systems. PMID:25693972

  9. Role of the acceptor in tuning the properties of metal [M(II) = Ni, Pd, Pt] dithiolato/dithione (donor/acceptor) second-order nonlinear chromophores: combined experimental and theoretical studies.

    PubMed

    Espa, Davide; Pilia, Luca; Makedonas, Christodoulos; Marchiò, Luciano; Mercuri, M Laura; Serpe, Angela; Barsella, Alberto; Fort, Alain; Mitsopoulou, Christiana A; Deplano, Paola

    2014-01-21

    The mixed-ligand complexes [M(II)(Et2dazdt)(mnt)] (M = Ni, 1; Pd, 2; Pt, 3) [Et2dazdt = N,N'-diethyl-perhydrodiazepine-2,3-dithione; mnt = maleonitrile-2,3-dithiolate] have been prepared and fully characterized. X-ray diffractometric studies on 1-3 (the structure of 1 was already known) show that the crystals are isostructural (triclinic, P-1), and two independent molecular entities are present in the unit cell. These entities differ in the orientation of the ethyl substituents with respect to the epta-atomic ring. In the C2S2MS2C2 dithiolene core the four sulfur atoms define a square-planar coordination environment of the metal where the M-S bond distances involving the two ligands are similar, while the C-S bond distances in the C2S2 units exhibit a significant difference in Et2dazdt (dithione) and mnt (dithiolato) ligands. 1-3 show in the visible region one or two moderately strong absorption peaks, having ligand-to-ligand charge-transfer (CT) character with some contribution of the metal, and show negative solvatochromism and molecular quadratic optical nonlinearity, which was determined by the EFISH (electric-field-induced second-harmonic generation) technique. These complexes are redox active and show two reversible reduction waves and one irreversible oxidation wave. Theoretical calculations based on DFT and TD-DFT calculations on complexes 1-3 as well as on [Pt(Bz2pipdt)(mnt)] (4) and [Pt(Bz2pipdt)(dmit)] (5) highlight the factors which affect the optical properties of these second-order redox-active NLO chromophores. Actually, the torsion angle of the dithione system (δ2) inversely correlates either with the oscillator strengths of the main transition of the complexes or with their beta values. The high beta value of 5 can be attributed both to its lowest torsion angles and to the extent of the π system of its dithiolate ligand, dmit. PMID:24405208

  10. RASA1 analysis guides management in a family with capillary malformation-arteriovenous malformation

    PubMed Central

    Flore, Leigh Anne; Leon, Eyby; Maher, Tom A.; Milunsky, Jeff M.

    2012-01-01

    Capillary malformation-arteriovenous malformation (CM-AVM; MIM 60354) is an autosomal dominant disorder characterized by multifocal cutaneous capillary malformations, often in association with fast-flow vascular lesions, which may be cutaneous, subcutaneous, intramuscular, intraosseus, or cerebral arteriovenous malformations or arteriovenous fistulas. CM-AVM results from heterozygous mutations in the RASA1 gene. Capillary malformations of the skin are common, and clinical examination alone may not be able to definitively diagnose-or exclude- CM-AVM. We report a family in which the proband was initially referred for a genetic evaluation in the neonatal period because of the presence of a cardiac murmur and minor dysmorphic features. Both he and his mother were noted to have multiple capillary malformations on the face, head, and extremities. Echocardiography revealed dilated head and neck vessels and magnetic resonance imaging and angiography of the brain revealed a large infratentorial arteriovenous fistula, for which he has had two embolization procedures. RASA1 sequence analysis revealed a heterozygous mutation, confirming his diagnosis of CM-AVM. We established targeted mutation analysis for the proband's mother and sister, the latter of whom is a healthy 3-year-old whose only cutaneous finding is a facial capillary malformation. This revealed that the proband's mother is also heterozygous for the RASA1 mutation, but his sister is negative. Consequently, his mother will undergo magnetic resonance imaging and angiography screening for intracranial and spinal fast-flow lesions, while his sister will require no imaging or serial evaluations. Targeted mutation analysis has been offered to additional maternal family members. This case illustrates the benefit of molecular testing in diagnosis and making screening recommendations for families with CM-AVM.

  11. Functional toxicity and tolerance patterns of bioavailable Pd(II), Pt(II), and Rh(III) on suspended Saccharomyces cerevisiae cells assayed in tandem by a respirometric biosensor.

    PubMed

    Frazzoli, Chiara; Dragone, Roberto; Mantovani, Alberto; Massimi, Cristiana; Campanella, Luigi

    2007-12-01

    Toxicological implications of exposure to bioavailable platinum group metals, here Pd, Pt, and Rh, are still to be clarified. This study obtained by a biosensor-based method preliminary information on potential effects on cellular metabolism as well as on possible tolerance mechanisms. Aerobic respiration was taken as the toxicological end point to perform tandem tests, namely functional toxicity test and tolerance test. Cells were suspended in the absence of essential constituents for growth. The dose-response curves obtained by exposure (2 h) to the metals (nanogram per gram range) suggested the same mechanisms of action, with Rh showing the greatest curve steepness and the lowest EC50 value. Conservative (95% lower confidence interval) EC10 values were 187, 85 and 51 ng g(-1) for Pt, Pd, and Rh respectively. Tolerance patterns were tested during the same runs. The full tolerance obtained after 12 h of exposure to each metal suggested mitochondrial inhibition of aerobic respiration as a target effect. The hazard rating of the metals in the tolerance test changed in the Rh EC50 range, where Rh showed the lowest toxicity. The observed tolerance might suggest a protective mechanism such as metallothionein induction at concentrations around the EC50 values. The performance of the bioassay was satisfactory, in terms of the limit of detection, repeatability, reproducibility, roboustness, sensibility, and stability; the method's critical uncertainty sources were identified for improvements. PMID:17960368

  12. PT -symmetry Wave Chaos

    NASA Astrophysics Data System (ADS)

    West, Carl T.; Kottos, Tsampikos; Prosen, Tomaz

    2010-03-01

    We study a new class of chaotic systems with dynamical localization, where gain/loss processes break the hermiticity, while allowing for parity-time PT symmetry. For a value γPT of the gain/loss parameter the spectrum undergoes a spontaneous phase transition from real (exact phase) to complex values (broken phase). We develop a one parameter scaling theory for γPT, and show that chaos assists the exact PT-phase. Our results will have applications to the design of optical elements with PT-symmetry.

  13. Animal Models in Studying Cerebral Arteriovenous Malformation

    PubMed Central

    Xu, Ming; Xu, Hongzhi; Qin, Zhiyong

    2015-01-01

    Brain arteriovenous malformation (AVM) is an important cause of hemorrhagic stroke. The etiology is largely unknown and the therapeutics are controversial. A review of AVM-associated animal models may be helpful in order to understand the up-to-date knowledge and promote further research about the disease. We searched PubMed till December 31, 2014, with the term “arteriovenous malformation,” limiting results to animals and English language. Publications that described creations of AVM animal models or investigated AVM-related mechanisms and treatments using these models were reviewed. More than 100 articles fulfilling our inclusion criteria were identified, and from them eight different types of the original models were summarized. The backgrounds and procedures of these models, their applications, and research findings were demonstrated. Animal models are useful in studying the pathogenesis of AVM formation, growth, and rupture, as well as in developing and testing new treatments. Creations of preferable models are expected. PMID:26649296

  14. GI-Associated Hemangiomas and Vascular Malformations

    PubMed Central

    Yoo, Stephen

    2011-01-01

    Hemangiomas and vascular malformations of the gastrointestinal tract, rare clinical entities, present as overt or occult bleeding. They can be distributed throughout the intestinal digestive system, or present as a singular cavernous hemangioma or malformation, which is often located in the rectosigmoid region. Misdiagnosis is common despite characteristic radiographic features such as radiolucent phleboliths on plain film imaging and a purplish nodule on endoscopy. Adjunctive imaging such as computed tomography and magnetic resonance imaging are suggested as there is potential for local invasion. Endorectal ultrasound with Doppler has also been found to be useful in some instances. Surgical resection is the mainstay of treatment, with an emphasis on sphincter preservation. Nonsurgical endoscopic treatment with banding and sclerotherapy has been reported with success, especially in instances where an extensive resection is not feasible. PMID:22942801

  15. FTO variant associated with malformation syndrome.

    PubMed

    Rohena, Luis; Lawson, Michelle; Guzman, Edwin; Ganapathi, Mythily; Cho, Megan T; Haverfield, Eden; Anyane-Yeboa, Kwame

    2016-04-01

    Common FTO variants are associated with obesity. However, it has recently been shown that homozygous FTO c.947G>A variant, which predicts p.R316Q, and c.956C>T, which predicts p.S319F, are associated with a malformation syndrome inherited in an autosomal recessive pattern. We present a similar homozygous FTO c.965G>A variant that predicts p.R322Q, associated with a lethal malformation syndrome in a consanguineous Yemeni family. Functional studies showed that the p.R316Q, p.S219F, and p.R322Q variants render the FTO protein inactive. We further expand on the phenotype of homozygous FTO loss-of-function mutations to include eye abnormalities, gingival overgrowth, craniosynostosis, and cutaneous photosensitivity. PMID:26697951

  16. Geometry matters: inverse cytotoxic relationship for cis/trans-Ru(ii) polypyridyl complexes from cis/trans-[PtCl2(NH3)2].

    PubMed

    Wachter, Erin; Zamora, Ana; Heidary, David K; Ruiz, José; Glazer, Edith C

    2016-08-01

    Two thermally activated ruthenium(ii) polypyridyl complexes, cis-Ru(bpy)2Cl2 and trans-Ru(qpy)Cl2 were investigated to determine the impact of the geometric arrangement of the exchangable ligands on the potential of the compounds to act as chemotherapeutics. In contrast to the geometry requirements for cisplatin, trans-Ru(qpy)Cl2 was 7.1-9.5× more cytotoxic than cis-Ru(bpy)2Cl2. This discovery could open up a new area of metal-based chemotherapeutic research. PMID:27352966

  17. Statins and congenital malformations: cohort study

    PubMed Central

    Hernandez-Diaz, Sonia; Fischer, Michael A; Seely, Ellen W; Ecker, Jeffrey L; Franklin, Jessica M; Desai, Rishi J; Allen-Coleman, Cora; Mogun, Helen; Avorn, Jerry; Huybrechts, Krista F

    2015-01-01

    Objective To examine the teratogenic potential of statins. Design Cohort study. Setting United States. Participants A cohort of 886 996 completed pregnancies linked to liveborn infants of women enrolled in Medicaid from 2000 to 2007. Methods We examined the risk of major congenital malformations and organ specific malformations in offspring associated with maternal use of a statin in the first trimester. Propensity score based methods were used to control for potential confounders, including maternal demographic characteristics, obstetric and medical conditions, and use of other drugs. Results 1152 (0.13%) women used a statin during the first trimester. In unadjusted analyses, the prevalence of malformations in the offspring of these women was 6.34% compared with 3.55% in those of women who did not use a statin in the first trimester (relative risk 1.79, 95% confidence interval 1.43 to 2.23). Controlling for confounders, particularly pre-existing diabetes, accounted for this increase in risk (1.07, 0.85 to 1.37). There were also no statistically significant increases in any of the organ specific malformations assessed after accounting for confounders. Results were similar across a range of sensitivity analyses. Conclusions Our analysis did not find a significant teratogenic effect from maternal use of statins in the first trimester. However, these findings need to be replicated in other large studies, and the long term effects of in utero exposure to statins needs to be assessed, before use of statins in pregnancy can be considered safe. PMID:25784688

  18. Synthesis and Characterization of Pt(IV) Fluorescein Conjugates to Investigate Pt(IV) Intracellular Transformations

    PubMed Central

    Song, Ying; Suntharalingam, Kogularamanan; Yeung, Jessica S.; Royzen, Maksim; Lippard, Stephen J.

    2013-01-01

    Pt(IV) anticancer compounds typically operate as prodrugs that are reduced in the hypoxic environment of cancer cells, losing two axial ligands in the process to generate active Pt(II) species. Here we report the synthesis of two fluorescent Pt(IV) prodrugs of cisplatin in order to image and evaluate the Pt(IV) reduction process in simulated and real biological environments. Treatment of the complexes dissolved in PBS buffer with reducing agents typically encountered in cells, glutathione or ascorbate, afforded a 3- to 5-fold fluorescence turn-on owing to reduction and loss of their fluorescein-based axial ligands, which are quenched when bound to platinum. Both Pt(IV) conjugates displayed moderate cytotoxicity against human cancer cell lines, with IC50 values higher than that of cisplatin. Immunoblotting and DNA flow cytometry analyses of one of the complexes, Pt(IV)FL2, revealed that it damages DNA, causing cell cycle arrest in S or G2/M depending on exposure time, with ultimately triggering of apoptotic cell death. Fluorescence microscopic studies prove that Pt(IV)FL2 enters cells intact and undergoes reduction intracellularly. The results are best interpreted in terms of a model in which the axial fluorescein ligands are expelled through lysosomes, with the platinum(II) moiety generated in the process binding to genomic DNA, which results in cell death. PMID:23957697

  19. Magnetic Resonance Imaging of Malformations of Midbrain-Hindbrain.

    PubMed

    Abdel Razek, Ahmed Abdel Khalek; Castillo, Mauricio

    2016-01-01

    We aim to review the magnetic resonance imaging appearance of malformations of midbrain and hindbrain. These can be classified as predominantly cerebellar malformations, combined cerebellar and brain stem malformations, and predominantly brain stem malformations. The diagnostic criteria for the majority of these morphological malformations are based on neuroimaging findings. The predominantly cerebellar malformations include predominantly vermian hypoplasia seen in Dandy-Walker malformation and rhombencephalosynapsis, global cerebellar hypoplasia reported in lissencephaly and microlissencephaly, and unilateral cerebellar hypoplasia seen in PHACES, vanishing cerebellum, and cerebellar cleft. Cerebellar dysplasias are seen in Chudley-McCullough syndrome, associated with LAMA1 mutations and GPR56 mutations; Lhermitte-Duclos disease; and focal cerebellar dysplasias. Cerebellar hyperplasias are seen in megalencephaly-related syndromes and hemimegalencephaly with ipsilateral cerebellomegaly. Cerebellar and brain stem malformations include tubulinopathies, Joubert syndrome, cobblestone malformations, pontocerebellar hypoplasias, and congenital disorders of glycosylation type Ia. Predominantly brain stem malformations include congenital innervation dysgenesis syndrome, pontine tegmental cap dysplasia, diencephalic-mesencephalic junction dysplasia, disconnection syndrome, and pontine clefts. PMID:26599961

  20. Neuroembryology and brain malformations: an overview.

    PubMed

    Sarnat, Harvey B; Flores-Sarnat, Laura

    2013-01-01

    Modern neuroembryology integrates descriptive morphogenesis with more recent insight into molecular genetic programing and data enabled by cell-specific tissue markers that further define histogenesis. Maturation of individual neurons involves the development of energy pumps to maintain membrane excitability, ion channels, and membrane receptors. Most malformations of the nervous system are best understood in the context of aberrations of normal developmental processes that result in abnormal structure and function. Early malformations usually are disorders of genetic expression along gradients of the three axes of the neural tube, defective segmentation, or mixed lineages of individual cells. Later disorders mainly involve cellular migrations, axonal pathfinding, synaptogenesis, and myelination. Advances in neuroimaging now enable the diagnosis of many malformations in utero, at birth, or in early infancy in the living patient by abnormal macroscopic form of the brain. These images are complimented by modern neuropathological methods that disclose microscopic, immunocytochemical, and subcellular details beyond the resolution of MRI. Correlations may be made of both normal and abnormal ontogenesis with clinical neurological and EEG maturation in the preterm or term neonate for a better understanding of perinatal neurological disease. Precision in terminology is a key to scientific communication. PMID:23622157

  1. Malformations of cortical development and epilepsy.

    PubMed

    Leventer, Richard J; Guerrini, Renzo; Dobyns, William B

    2008-01-01

    Malformations of cortical development (MCDs) are macroscopic or microscopic abnormalities of the cerebral cortex that arise as a consequence of an interruption to the normal steps of formation of the cortical plate. The human cortex develops its basic structure during the first two trimesters of pregnancy as a series of overlapping steps, beginning with proliferation and differentiation of neurons, which then migrate before finally organizing themselves in the developing cortex. Abnormalities at any of these stages, be they environmental or genetic in origin, may cause disruption of neuronal circuitry and predispose to a variety of clinical consequences, the most common of which is epileptic seizures. A large number of MCDs have now been described, each with characteristic pathological, clinical, and imaging features. The causes of many of these MCDs have been determined through the study of affected individuals, with many MCDs now established as being secondary to mutations in cortical development genes. This review will highlight the best-known of the human cortical malformations associated with epilepsy. The pathological, clinical, imaging, and etiologic features of each MCD will be summarized, with representative magnetic resonance imaging (MRI) images shown for each MCD. The malformations tuberous sclerosis, focal cortical dysplasia, hemimegalencephaly, classical lissencephaly, subcortical band heterotopia, periventricular nodular heterotopia, polymicrogyria, and schizencephaly will be presented. PMID:18472484

  2. Chiari I malformations: clinical and radiologic reappraisal.

    PubMed

    Elster, A D; Chen, M Y

    1992-05-01

    Clinical findings and magnetic resonance (MR) images in 68 patients with Chiari I malformations were retrospectively analyzed to identify those radiologic features that correlated best with clinical symptoms. A statistically significant (P = .03) female predominance of the malformation was observed, with a female: male ratio of approximately 3:2. Associated skeletal anomalies were seen in 24% of patients. Syringomyelia was detected in 40% of patients, most commonly between the C-4 and C-6 levels. Of the 25 patients who presented with spinal symptoms, 23 (92%) proved to have a syrinx at MR imaging. When the syrinx extended into the medulla (n = 3), however, brain stem symptoms predominated. Patients with objective brain stem or cerebellar signs had the largest mean tonsillar herniations. Patients with tonsillar herniations greater than 12 mm were invariably symptomatic, but approximately 30% of patients with tonsils herniating 5-10 mm below the foramen magnum were asymptomatic at MR imaging. "Incidental" Chiari I malformations are thus much more common than previously recognized, and careful clinical assessment remains the cornerstone for proper diagnosis and management. PMID:1561334

  3. Combined Lymphedema and Capillary Malformation of the Lower Extremity

    PubMed Central

    Maclellan, Reid A.; Chaudry, Gulraiz

    2016-01-01

    Background: Primary lymphedema and capillary malformation are independent vascular malformations that can cause overgrowth of the lower extremity. We report a series of patients who had both types of malformations affecting the same leg. The condition is unique but may be confused with other types of vascular malformation overgrowth conditions (eg, Klippel–Trenaunay and Parkes Weber). Methods: Our Vascular Anomalies Center and Lymphedema Program databases were searched for patients with both capillary malformation and lymphedema. Diagnosis of lymphedema–capillary malformation was made by history, physical examination, and imaging studies. Because lymphedema–capillary malformation has phenotypical overlap with other conditions, only patients who had imaging confirming their diagnosis were included in the analysis. Clinical and radiological features, morbidity, and treatment were recorded. Results: Eight patients (4 females and 4 males) had confirmed lymphedema–capillary malformation. Referring diagnosis was Klippel–Trenaunay syndrome (n = 4), diffuse capillary malformation with overgrowth (n = 3), or lymphatic malformation (n = 1). The condition was unilateral (n = 6) or bilateral (n = 2). Morbidity included infection (n = 6), difficulty fitting clothes (n = 6), bleeding or leaking vesicles (n = 5), leg length discrepancy (n = 4), and difficulty ambulating (n = 3). All patients were managed with compression regimens. Operative management was liposuction (n = 3), treatment of phlebectatic veins (n = 3), staged skin/subcutaneous excision (n = 1), and/or epiphysiodesis (n = 1). Conclusions: Lymphedema and capillary malformation can occur together in the same extremity. Both conditions independently cause limb overgrowth primarily because of subcutaneous adipose deposition. Compression garments and suction-assisted lipectomy can improve the condition. Lymphedema–capillary malformation should not be confused with other vascular malformation overgrowth

  4. Adjusting the DNA Interaction and Anticancer Activity of Pt(II) N-Heterocyclic Carbene Complexes by Steric Shielding of the Trans Leaving Group.

    PubMed

    Muenzner, Julienne K; Rehm, Tobias; Biersack, Bernhard; Casini, Angela; de Graaf, Inge A M; Worawutputtapong, Pawida; Noor, Awal; Kempe, Rhett; Brabec, Viktor; Kasparkova, Jana; Schobert, Rainer

    2015-08-13

    Five platinum(II) complexes bearing a (1,3-dibenzyl)imidazol-2-ylidene ligand but different leaving groups trans to it were examined for cytotoxicity, DNA and cell cycle interference, vascular disrupting properties, and nephrotoxicity. The cytotoxicity of complexes 3a-c increased with the steric shielding of their leaving chloride ligand, and complex 3c, featuring two triphenylphosphanes, was the most efficacious, with submicromolar IC50 concentrations. Complexes 3a-c interacted with DNA in electrophoretic mobility shift and ethidium bromide binding assays. The cationic complex 3c did not bind coordinatively to DNA but led to its aggregation, damage that is not amenable to the usual repair mechanisms. Accordingly, it arrested the cell cycle of melanoma cells in G1 phase, whereas cis-dichlorido[(1,3-dibenzyl)imidazol-2-ylidene](dimethyl sulfoxide) platinum(II) 3a induced G2/M phase arrest. Complex 3c also disrupted the blood vessels in the chorioallantoic membrane of fertilized chicken eggs. Ex vivo studies using precision-cut tissue slices suggested the nephrotoxicities of 3a-c to be clinically manageable. PMID:26182125

  5. Cardiovascular malformations and other cardiovascular abnormalities in neurofibromatosis 1.

    PubMed

    Lin, A E; Birch, P H; Korf, B R; Tenconi, R; Niimura, M; Poyhonen, M; Armfield Uhas, K; Sigorini, M; Virdis, R; Romano, C; Bonioli, E; Wolkenstein, P; Pivnick, E K; Lawrence, M; Friedman, J M

    2000-11-13

    Although it is well recognized that a peripheral vasculopathy may occur in patients with neurofibromatosis 1 (NF1), it is unclear whether cardiovascular abnormalities are more common. We reviewed the frequency of cardiovascular abnormalities, in particular, cardiovascular malformations (CVMs), among 2322 patients with definite NF1 in the National Neurofibromatosis Foundation International Database from 1991-98. Cardiovascular malformations were reported in 54/2322 (2.3%) of the NF1 patients, only 4 of whom had Watson syndrome or NF1-Noonan syndrome. There was a predominance of Class II "flow" defects [Clark, 1995: Moss and Adams' Heart Disease in Infants, Children, and Adolescents Including the Fetus and Young Adult. p 60-70] (43/54, 80%) among the NF1 patients with CVMs. Pulmonic stenosis, that was present in 25 NF1 patients, and aortic coarctation, that occurred in 5, constitute much larger proportions of all CVMs than expected. Of interest was the paucity of Class I conotruncal defects (2 patients with tetralogy of Fallot), and the absence of atrioventricular canal, anomalous pulmonary venous return, complex single ventricle and laterality defects. Besides the 54 patients with CVMs, there were 27 patients with other cardiac abnormalities (16 with murmur, 5 with mitral valve prolapse, 1 with intracardiac tumor, and 5 with electrocardiogram abnormalities). No patient in this study had hypertrophic cardiomyopathy. There were 16 patients who had a peripheral vascular abnormality without an intracardiac CVM, plus an additional 4 patients among those with a CVM who also had a peripheral vascular abnormality. PMID:11078559

  6. Mono- and dinuclear complexes of a new binucleating porphyrin,. alpha. ,. alpha. -5,15-bis(o-(nicotinoylamino)phenyl)-2,8,12,18-tetraethyl-3,7,13,17-tetramethylporphyrin. Crystal structures of a mononuclear nickel(II) complex and a binuclear Cu-Pt complex

    SciTech Connect

    Woo, L.K.; Maurya, M.R.; Jacobson, R.A.; Yang, Shumei; Ringrose, S.L. )

    1992-03-04

    The synthesis and characterization of a new binucleating porphyrin ligand, {alpha},{alpha}-5,15-bis(o-(nicotinoylamido)phenyl)-2,8,12,18-tetraethyl-3,7,13,17-tetramethylporphyrin, (H{sub 2}(DPE))-(py){sub 2} is reported. Treatment of (H{sub 2}(DPE))-(py){sub 2} with methanol solutions of Ni(II) or Cu(II) leads to the formation of mononuclear metal complexes, (M(DPE))-(py){sub 2}, in which the metal has inserted into the porphyrin core, leaving the pyridine binding site free. Addition of a second metal to form a binuclear complex, (M(DPE))-(py){sub 2}M{prime}Cl{sub 2}, can be accomplished using the reagent M{prime}(DMSO){sub 2}Cl{sub 2}, M{prime} = Pd, Pt, and Zn. (Ni(DPE))-(py){sub 2} and (Cu(DPE))-(py){sub 2}PtCl{sub 2} have been characterized by single-crystal X-ray analysis. Pt-Pt distances between the two molecules in the asymmetric unit are 3.766 (3) {angstrom}.

  7. Experimental and quantum-chemical studies of 1H, 13C and 15N NMR coordination shifts in Pd(II) and Pt(II) chloride complexes with methyl and phenyl derivatives of 2,2'-bipyridine and 1,10-phenanthroline.

    PubMed

    Pazderski, Leszek; Tousek, Jaromír; Sitkowski, Jerzy; Kozerski, Lech; Szłyk, Edward

    2007-12-01

    1H, 13C and 15N NMR studies of platinide(II) (M=Pd, Pt) chloride complexes with methyl and phenyl derivatives of 2,2'-bipyridine and 1,10-phenanthroline [LL=4,4'-dimethyl-2,2'-bipyridine (dmbpy); 4,4'-diphenyl-2,2'-bipyridine (dpbpy); 4,7-dimethyl-1,10-phenanthroline (dmphen); 4,7-diphenyl-1,10-phenanthroline (dpphen)] having a general [M(LL)Cl2] formula were performed and the respective chemical shifts (delta1H, delta13C, delta15N) reported. 1H high-frequency coordination shifts (Delta1Hcoord=delta1Hcomplex-delta1Hligand) were discussed in relation to the changes of diamagnetic contribution in the relevant 1H shielding constants. The comparison to literature data for similar [M(LL)(XX)], [M(LL)X2] and [M(LL)XY] coordination or organometallic compounds containing various auxiliary ligands revealed a large dependence of delta1H parameters on inductive and anisotropic effects. 15N low-frequency coordination shifts (Delta15Ncoord=delta 15Ncomplex-delta15Nligand) of ca 88-96 ppm for M=Pd and ca 103-111 ppm for M=Pt were attributed to both the decrease of the absolute value of paramagnetic contribution and the increase of the diamagnetic term in the expression for 15N shielding constants. The absolute magnitude of Delta15Ncoord parameter increased by ca 15 ppm upon Pd(II)-->Pt(II) transition and by ca 6-7 ppm following dmbpy-->dmphen or dpbpy-->dpphen ligand replacement; variations between analogous complexes containing methyl and phenyl ligands (dmbpy vs dpbpy; dmphen vs dpphen) did not exceed+/-1.5 ppm. Experimental 1H, 13C, 15N NMR chemical shifts were compared to those quantum-chemically calculated by B3LYP/LanL2DZ+6-31G**//B3LYP/LanL2DZ+6-31G*, both in vacuo and in DMSO or DMF solution. PMID:18044804

  8. Cardiovascular malformations in Smith-Lemli-Opitz syndrome

    SciTech Connect

    Lin, A.E.; Ardinger, H.H.; Ardinger, R.H. Jr.

    1997-01-31

    We reviewed 215 patients (59 new, 156 from the literature) with Smith-Lemli-Opitz syndrome (SLOS), and found that 95 (44%) had a cardiovascular malformation (CVM). Classifying CVMs by disordered embryonic mechanisms, there were 5 (5.3%) class I (ectomesenchymal tissue migration abnormalities), 56 (58.9%) class II (abnormal intracardiac blood flow), 25 (26.3%) class IV (abnormal extracellular matrix), and 5 (5.3%) class V (abnormal targeted growth). Comparing the frequencies of individual CVMs in this series with a control group (the Baltimore-Washington Infant Study), there were 6 individual CVMs which showed a significant difference from expected values. When frequencies of CVMs in SLOS were analyzed by mechanistic class, classes IV and V were significantly more frequent, and class I significantly less frequent, than the control group. Although CVMs in SLOS display mechanistic heterogeneity, with an overall predominance of class II CVMs, the developmental error appears to favor alteration of the cardiovascular developmental mechanisms underlying atrioventricular canal and anomalous pulmonary venous return. This information should assist the clinical geneticist evaluating a patient with possible SLOS, and should suggest research direction for the mechanisms responsible for the SLOS phenotype. 102 refs., 1 fig., 7 tabs.

  9. Treatment of left ventricular assist device-associated arteriovenous malformations with thalidomide.

    PubMed

    Ray, Ranjan; Kale, Parag P; Ha, Richard; Banerjee, Dipanjan

    2014-01-01

    Gastrointestinal bleeding because of arteriovenous malformations (AVMs) is an increasingly recognized complication of continuous flow left ventricular assist devices (LVADs). Currently, therapeutic options for LVAD-associated AVMs are limited and often require repeated endoscopic procedures and reduction or cessation of anticoagulation. Thalidomide has been utilized in the treatment of refractory bleeding because of gastrointestinal vascular malformations. Here we describe the case of a 66-year-old man with severe ischemic cardiomyopathy implanted with a continuous flow HeartMate II. His postoperative course was complicated by multiple hospital admissions for gastrointestinal bleeding because of LVAD-associated AVMs refractory to repeated argon plasma laser coagulation. Anticoagulation was discontinued with subsequent pump stoppage because of thrombus requiring urgent surgical pump exchange. Following this, thalidomide was initiated and anticoagulation with warfarin was continued. Since initiation of thalidomide, the patient has not had further gastrointestinal bleeding or evidence of pump thrombus in the subsequent 1 year. PMID:24830804

  10. Opercular malformations: clinical and MRI features in 11 children.

    PubMed

    Rolland, Y; Adamsbaum, C; Sellier, N; Robain, O; Ponsot, G; Kalifa, G

    1995-11-01

    Opercular malformations are rare and complex brain malformations for which only very fragmented neuropathological descriptions have been reported. They are related to an abnormal development of both sylvian fissure and frontoparietal operculum. We report a retrospective clinical and MRI study of 11 patients presenting with opercular malformations. A congenital pseudobulbar syndrome was observed in six cases, various motor disorders in seven cases, mental retardation in six cases and epilepsy in four cases. The purpose of this study is to evaluate the main features of opercular malformations in children and to try to characterise this entity on the basis of its clinical features and MRI pattern. PMID:8577527