Exchange coupling in cyano-bridged homodinuclear Cu(II) and Ni(II) complexes: synthesis, structure, magnetism, and density functional theoretical study.

The synthesis and structural characterization of several new cyano-bridged copper(II) and nickel(II) homodinuclear complexes is presented. The measure of magnetic properties for these complexes is complemented with a computational study of the exchange coupling for several model structures representing this family of compounds. The influence of several factors on the coupling constant has been examined, coordination position occupied by the bridging ligand, distortions of the coordination environment, and relative disposition of the cyanide ion with respect to the M-M vector. Comparison of experimental and calculated coupling constants allows for the rationalization of the most relevant features of the exchange interaction between two identical metal ions through a cyano bridge.

Copper(II) complexes with 4-amino-N-[4,6-dimethyl-2-pyrimidinyl]benzenesulfonamide. Synthesis, crystal structure, magnetic properties, EPR, and theoretical studies of a novel mixed mu-carboxylato, NCN-bridged dinuclear copper compound.

New Cu(II) complexes of sulfamethazine (4-amino-N-[4,6-dimethyl-2-pyrimidinyl]benzenesulfonamide, HL) [Cu(2)(CH(3)COO)(2)(L)(2)].2dmf (1) and ([Cu(L)(2)].2H(2)O)(infinity) (2) were prepared and structurally characterized. Compound 1 crystallizes in the monoclinic system, space group P2(1)/n, with a = 8.9486(9) A, b = 15.0956(12) A, c = 16.542(3) A, beta = 105.584(15) degrees, and Z = 2. Compound 2 crystallizes in the monoclinic system, space group P2(1)/c, with a = 13.8097(8) A, b = 14.5765(4) A, c = 13.7853(15) A, beta = 96.033(9) degrees, and Z = 1. In compound 1 two copper ions are linked by two syn-syn acetates and two nonlinear NCN bridging groups pertaining to the deprotonated sulfamethazine ligands. Each copper center presents a nearly square planar geometry. Magnetic susceptibility data for 1 show a strong antiferromagnetic coupling with 2J = -216.7 cm(-)(1). The EPR spectra at the X- and Q-band frequencies present the signals corresponding to the dinuclear entity, being the zero-field splitting parameter, D = 0.265 cm(-)(1). The antiferromagnetic exchange coupling is discussed using DFT calculations on some model compounds with NCN bridging ligands and also on model structures with mixed mu-acetato and NCN bridges. The copper in the polymeric compound 2 is five coordinate. The CuN(5) chromophore has a highly distorted square pyramidal geometry with small axial N-Cu-N angles of 65.53(14) and 59.90(13) degrees. In the structure a sulfamethazinate anion binds to one copper through the sulfonamido and pyrimidine N atoms and to an adjacent copper via the amino N atom.

Exchange coupling in carboxylato-bridged dinuclear copper(II) compounds: a density functional study.

A computational study of the exchange coupling is presented for a selected sample of carboxylato-bridged dinuclear copper(II) compounds. Model calculations have been used to examine the influence of several factors on the coupling constants: a) the electron-withdrawing power of the bridging ligands; b) the nature of the axial ligands; c) the number of bridging carboxylato groups; d) some structural distortions frequently found in this family of compounds; and e) the coordination mode of the carboxylato bridge. Coupling constants calculated for some complete structures, as determined by X-ray diffraction, are in excellent agreement with experimental data, confirming the ability of the computational strategy used in this work to predict the coupling constant for compounds for which experimental data are not yet available.

[Warthin tumor. Report of eight cases and review of the literature]. / Tumor de Warthin. A propósito de ocho casos y revisión de la literatura.

We have studied 8 patients with Warthin's tumor of the parotid gland (WT). Seven of them were men and smoked more than a packet daily. Seven were operated with conservative superficial parotidectomy and the other one with total parotidectomy with facial preservation. Two had postoperative peripheral facial paresia which disappeared with medical treatment in few days. One of the operated suffered from postoperative Frey's syndrome.

[Hyoid fracture and traumatic subcutaneous cervical emphysema from an attempted hanging. Apropos a case]. / Fractura de hioides y enfisema cervical subcutáneo traumático por intento de ahorcamineto. A propósito de un caso.

We describe a patient with a history of psychiatric disorder who was brought to our hospital after attempted suicide by hanging. Severe subcutaneous facial, palpebral and cervical emphysema was present, with dysphonia, dysphagia and slight respiratory difficulty. Fiberoptic bronchoscopy revealed upper airway obstruction due to edema in an intact airway. Successive CAT scans gave evidence of hyoid fracture and laryngocele, in addition to the corresponding emphysema of the subcutaneous area and pneumomediastinum. Given the persistence of dysphagia, we ordered esophageal tests, which showed functional alteration of the upper esophageal sphincter. Suprasternal cervicotomy to drain the pneumomediastinum and laryngeal microsurgery to treat the laryngocele resolved the problem.

Fractura de hioides y enfisema cervical subcutáneo traumático por intento de ahorcamiento. a propósito de un caso / Hyoid bone fracture and subcutaneous emphysema due to trauma from attempted hanging: a case report

Presentamos el caso de un paciente con antecedentes psiquiátricos que, tras un intento de autólisis mediante ahorcamiento, fue remitido a nuestro centro. Se apreciaba un gran enfisema subcutáneo facial, palpebral y cervical, con disfonía, disfagia y discreta dificultad respiratoria. La fibrobroncoscopia demostró obstrucción de las vías altas por edema, con integridad de la vía aérea. Varias TAC cervicales sucesivas evidenciaron, además del enfisema subcutáneo y el neumomediastino correspondiente, la existencia de una fractura de hioides, así como la existencia de un laringocele. Ante la persistencia de la disfagia, se realizaron pruebas de función esofágica, demostrándose una alteración funcional del esfínter esofágico superior. Una cervicotomía suprasternal, para el drenaje del neumomediastino, y una microcirugía laríngea, para el tratamiento el laringocele, solucionaron el problema (AU)

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Asymmetry and magnetism in bis(oximato)-bridged heterobimetallic compounds: a computational approach.

A density functional study of exchange coupling was carried out for a series of heterobinuclear oximato-bridged transition metal complexes. Model calculations were used to examine the influence of the electronic configuration of the metal atoms on the coupling constants. This analysis was complemented by a study of the variation of the coupling constant with the most usual structural distortions within this family of compounds. The influence of the nature of the terminal ligands as well as that of the symmetry on the bridge were also investigated.

Cholesterol and 25-hydroxycholesterol retention in specimens of liver and aorta prepared for electron microscopy. I. Standard fixation methods and metabolism of the labeled sterols.

In the present work, several preparatory procedures commonly used for electron microscopy (EM) were evaluated as to their ability to preserve cholesterol (CHO) and CHO derivatives in tissue. We also determined in several rat tissues to what extent the sterols used as tracers are metabolized. Sprague-Dawley rats were injected intraperitoneally with [1 alpha,2 alpha(n)-3H]cholesterol ([3H]CHO) and 25-hydroxy-[26,27-3H]cholesterol ([3H]25-OH-CHO). Lipids of the liver, aorta and brain were extracted one and five days after injection, and the distribution of the labeled lipids was followed by thin-layer chromatography. When labeled CHO was injected as tracer, most of the radioactivity remained associated with the CHO fraction. When 25-hydroxycholesterol (25-OH-CHO) was used, we found that it was mostly metabolized to yield more polar compounds. Our results show that the loss of CHO and CHO derivatives from tissues depends not only on the preparatory procedure used for EM, but also on the type of tissue studied.

Cholesterol and 25-hydroxycholesterol retention in specimens of liver and aorta prepared for electron microscopy. II. Effect of filipin, osmium, digitonin and saponin.

Sprague-Dawley rats were injected intraperitoneally with [1 alpha, 2 alpha(n)-3H]cholesterol or 25-hydroxy-[26,27-3H]cholesterol, and one and five days later liver and aortic tissues were fixed. The extent to which these sterols were lost from the tissues during preparation for electron microscopy (EM) was examined utilizing different fixation procedures and various protective agents. Radioactive tracers, scintillation counting and standard EM techniques were used. Although most of the procedures examined caused major lipid losses, useful fixation procedures that allow retention of cholesterol or 25-hydroxy-cholesterol in liver and aortic tissues were found and are described here.

[Standardization of forced spirometry. Analysis of the basal pulmonary function (PEF, FEF2575, FEF50) in a selected group of children]. / Estandarización de la espirometría forzada. Análisis de la función pulmonar basal (PEF, FEF2575, FEF50) en una población infantil de referencia.

This is a study of the ventilatory function (FEF2575, FEF50, PEF) by dry spirometer Vitalograph in 1,566 children of both sexes with ages ranging from 7 to 14 years; 1,156 children (73.6%) were selected as reference population. Height was the biometric parameter with the greatest correlation to the functional variables studied in both sexes, except to PEF in females. Significant differences were observed in functional variables between male and female subjects. Multiple and simple linear regression equations and percentiles tables for each sex are presented.

[Basal pulmonary function studies (FVC, FEV) in a selected child population]. / Estudio de la función pulmonar basal (FVC, FEV1) en una población infantil de referencia.

This is a study of the ventilatory function (FVC, FEV1) by dry spirometer Vitalograph in 1566 children of both sexes with ages ranging from 7 to 14; 1156 children (73.6 per 100) were selected as reference population. Height was the biometric parameter with the greatest correlation to the functional variables studied in both sexes. Significant differences were observed in functional variables between male and female subjects. Multiple and simple linear prediction equations and percentiles tables for each sex are presented. The results of the present study are compared with those of previously published of children.

[Epidemiologic study of risk factors associated with the development of respiratory pathology in children]. / Estudio epidemiológico de los factores de riesgo asociados con el desarrollo de patología respiratoria en la población infantil.

A total of 1,566 children the area of Valencia (Spain), of both sexes and aged 7 to 14 received an epidemiological questionnaire recommended by the American Thoracic Society. Antecedents of asthma were recorded in 79 cases (5%), with a predominance among males; 73.3% of these children presented their first crisis before age three. Eighty-seven children were habitual smokers (5.6%), again with a predominance among males-most of these children being between 13 and 14 years old. A family history of smoking was observed in 82.8% of the children who were habitual smokers. A greater predominance of smoking mothers was observed at higher socio-economical levels--with no significant differences between parents. The incidence of respiratory pathology (cough and antecedents of bronchitis) was higher among children whose mothers (or both parents) were smokers. On comparing the two areas of the city with the greatest difference in air pollution level, no significant differences were observed in respiratory morbidity among the child population.

[Repercussion of risk factors associated with the development of chronic bronchial pathology on pulmonary function in children]. / Estudio de la repercusión de los factores de riesgo asociados al desarrollo de patología bronquial crónica en el funcionalismo pulmonar en una población infantil.

Of a total of 1,566 children, 1,416 of both sexes and aged 7 to 14 were subjected to functional respiratory exploration with a Vitalograph dry spirometer. The impact of tobacco smoke--as active and/or passive smokers--on the spirometric variables (FVC, FEV1, FEF2572, FEF50) evaluated by variance analysis (ANOVA) revealed no significant reductions. Asthma was the single antecedent of respiratory morbidity showing significant reductions in FEF2575, FEF50 among males alone; no significant reductions were observed for any of the other spirometric variables. No significant decreases were found in the spirometric variables on comparing two areas of the same city with the greatest difference in air pollution level.

Autoradiography of endothelium in whole rat aorta by a new method.

This report describes a method for studying the arterial endothelial kinetics in the rat by autoradiography of the luminal surface of the endothelium. The procedure involves stripping off the adventitia, sticking the 'whole' artery on a glass slide, and covering the endothelium (with some layers of the media as a support) with the nuclear emulsion. This method gives endothelial autoradiographies with very good optical quality, so that counting the labelled cells is as easy as in the Häutchen preparations. It also eliminates uncertainties due to the occasional lack of endothelium in some areas and the interference of smooth muscle layers, problems which are frequent in the Häutchen techniques used so far. The present method has been tested in rats fed an atherogenic diet for one day and 1, 2, 3 and 4 weeks and in the corresponding controls.

Cholesterol oxygenated derivatives induce erythrocyte accumulation and endothelium alterations in the aorta of rats. Turnover of endothelial cells in the apparently intact areas remains unchanged.

In this work we have studied the effect of cholesterol autooxidation derivatives on the aortic endothelium of rat. Endothelial alterations were evident after 24 h treatment. Areas showing many spindle shaped nuclei and focal accumulation of erythrocytes were observed. Moreover, in some preparations areas with destroyed and missing endothelium were observed. Autoradiography using 3H-thymidine does not show differences in the mitotic activity between control and treated animals in those areas showing apparently intact endothelium. Therefore, we conclude that cholesterol derivatives present ability to produce important lesions in aortic endothelium and that this effect is similar to that described when cholesterol is used.