Reactivity and molecular modeling of new solvatochromic mixed-ligand copper(II) chelates of 2-acetylbutyrolactone and dinitrogen bases

A new series of solvatochromic mononuclear mixed ligand chelates with the general formula: Cu(AcBL)(L)X; where AcBL=2-acetylbutyrolactonate, L=N,N,N',N'-tetramethylethylenediamine (Me4en), N,N,N',N'-tetramethylpropylene diamine (Me4pn), 1,10-phenanthroline (Phen) or 2,2'-bipyridyl (Bipy) and X=ClO4-, NO3- or Br- have been synthesized and characterized by the analytical and spectral methods, as well as magnetic and molar conductance measurements. The d-d absorption bands of Me4en-chelates as Nujol mulls or weak donor solvents solutions revealed square-planar, distorted octahedral and/or distorted trigonal bipyramid geometries for the perchlorate, nitrate and bromide chelates, respectively. However, an octahedral structure is identified for chelates in strong donor solvents. Perchlorate chelates show a remarkable color change from violet to green as the Lewis basicity of the donor solvent increases, whereas bromide chelates are mainly affected by the Lewis acidity of solvent. Specific and non-specific interactions of solvent molecules with the chelates were investigated on the basis of unified solvation model. Structural parameters of the free ligands and their Cu(II)-chelates have been calculated on the basis of semiempirical PM3 level and correlated with the experimental data.

Structural, molecular orbital and optical characterizations of binuclear mixed ligand copper (II) complex of phthalate with N,N,N',N'-tetramethylethylenediamine and its applications

A new binuclear mixed ligand complex, [Cu2(Phth)(Me4en)2(H2O)2(NO3)2]·H2O (where, Phth=phthalate, and (Me4en)=N,N,N',N'tetramethylethylenediamine) was synthesized and characterized using analytical, spectral, magnetic, molar conductance, thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and transmission electron microscope (TEM) measurements. The XRD data of Cu(II)-complex was analyzed on the basis of Williamson-Hall (W-H) and compared with TEM results. The results indicate that the complex is well crystalline and correspond to hexagonal crystal structure. Analysis of the absorption coefficient near the absorption edge reveals that the optical band gaps are indirect allowed transition with values of 1.17 and 1.78 eV. The d-d absorption bands of the complex (dissolved in various solvents) exhibit a color changes (solvatochromic). Specific and non-specific interactions of solvent molecules with the complex were investigated using Multiple Linear Regression Analysis (MLRA). Transient photocurrent characteristics of Cu(II)-complex/n-Si heterojunctions indicate that photocurrent under illumination increase with increasing of light intensity and explained by continuous distribution of traps. Structural parameters of the free ligands and their Cu(II)-complex were calculated on the basis of semi-empirical PM3 level and compared with the experimental data. The present copper (II) complex was screened for its antimicrobial activity against some Gram-positive and Gram-negative bacteria and fungus strain.

Spectral characterization, molecular modeling and antimicrobial studies on hydrazone metal complexes of 5-acetyl-4-hydroxy-2H-1,3-thiazine-2,6(3H)dione and S-methyl dithiocarbazate

Metal complexes of copper(II), nickel(II), cobalt(II), oxovanadium(IV), chromium(III) and cadmium(II) with a new bridged ONS dibasic tridentate hydrazone (H2L) derived from 5-acetyl-4-hydroxy-2H-1,3-thiazine-2,6(3H)-dione with S-methyl dithiocarbazate have been synthesized and characterized by elemental analysis, molar conductance, magnetic susceptibility measurements, spectral (infrared, electronic, mass, 1H NMR and ESR) studies as well as thermal gravimetric analysis (TGA). The synthesized complexes have dimeric structures with the general formula [ML(NO3)m(H2O)x]2·nH2O·zMeOH, L=dianion of the hydrazone, m=0-1, x=0-2, n=0-4 and z=0-1. The metal complexes exhibited square planar, tetrahedral and octahedral geometrical arrangements, the molar conductivity data indicates that all complexes are neutral. The Coats-Redfern equation was used to calculate the kinetic and thermodynamic parameters for the different thermal decomposition stages of some complexes. Structural parameters of the ligand and its metal complexes have been theoretically computed on the basis of semiempirical PM3 level and the results were correlated with their experimental data. Antibacterial activities of the free ligand and its metal complexes were screened against various organisms.

Diffusion imaging for tumor grading of supratentorial brain tumors in the first year of life

BACKGROUND AND PURPOSE

Supratentorial tumors in the first year of life are typically large and heterogeneous at presentation, making differentiation of these CNS neoplasms on pre-operative imaging difficult. We hypothesize that the ADC value can reliably differentiate high- versus low-grade supratentorial tumors in this patient population.

MATERIALS AND METHODS

A blinded review of ADC maps was performed on 19 patients with histologically proved supratentorial brain tumors diagnosed within the first year of life. Minimum ADC values obtained by region of interest from 2 neuroradiologists were averaged and compared with World Health Organization tumor grade. ADC values for the entire tumor were also obtained by use of a semi-automated histogram method and compared with World Health Organization tumor grade. Data were analyzed by use of Spearman ρ and Student t test, with a value of P < .05 considered statistically significant.

RESULTS

For the manual ADC values, a significant negative correlation was found between the mean minimum ADC and tumor grade (P = .0016). A significant difference was found between the mean minimum ADC of the low-grade (1.14 × 10(-3) mm(2)/s ± 0.30) and high-grade tumors (0.64 × 10(-3) mm(2)/s ± 0.28) (P = .0018). Likewise, the semi-automated method demonstrated a significant negative correlation between the lowest 5th (P = .0002) and 10th (P = .0009) percentile individual tumor ADC values and tumor grade, a significant difference between the mean 5th and 10th percentile ADC values of the low-grade and high-grade groups (P = .0028), and a significant positive correlation with values obtained by manual region-of-interest placement (P < .000001).

CONCLUSIONS

ADC maps can differentiate high- versus low-grade neoplasms for supratentorial tumors presenting in the first year of life, given the significant negative correlation between ADC values and tumor grade.

Structural, molecular orbital and optical characterizations of solvatochromic mixed ligand copper(II) complex of 5,5-Dimethyl cyclohexanate 1,3-dione and N,N,N',N'N″-pentamethyldiethylenetriamine

In this work, a new solvatochromic mononuclear mixed ligand complex with the formula, Cu(DMCHD)(Me5dien)NO3 (where, DMCHD=5,5-Dimethyl cyclohexanate 1,3-dione and (Me5dien)=N,N,N',N'N″-pentamethyldiethylenetriamine was synthesized and characterized by analytical, spectral, magnetic, molar conductance, thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and transmission electron microscope (TEM) measurements. The formation constant-value for copper (II)-DMCHD was found to be much lower than the expected for similar β-diketones, revealing monobasic unidentate nature of this ligand. The d-d absorption bands of the prepared complex exhibit a color changes in various solvent (solvatochromic). Specific and non-specific interactions of solvent molecules with the complex were investigated using Multi Parametric Linear Regression Analysis (MLRA). Structural parameters of the free ligands and their Cu (II) - complex were calculated on the basis of semi-empirical PM3 level and compared with the experimental data. The crystallite size and morphology of Cu(DMCHD)(Me5dien)NO3 were examined using XRD analysis and TEM, revealing that the complex is well crystalline and correspond to the monoclinic crystal structure. The lattice strain and mean crystallite size were estimated by Williamson-Hall (W-H) plot using X-ray diffraction data. The main important absorption parameters such as extinction molar coefficient, oscillator strength and electric dipole strength of the principal optical transitions in the UV-Vis region were calculated. The analysis of absorption coefficient near the fundamental absorption edge reveals that the optical band gaps are direct allowed transitions with values of 2.78 eV and 3.59 eV. The present copper (II) complex was screened for its antimicrobial activity against Staphylococcus Aureus and Bacillus Subtilis as Gram-positive bacteria, Escherichia Coli and Salmonella Typhimurium as Gram-negative bacteria and Candida Albicans as fungus strain.

Synthesis, spectroscopic studies, molecular modeling and antimicrobial activity of binuclear Co(II) and Cu(II) complexes of 4,6-diacetylresorcinol

Reactions of 4,6-diacetylresorcinol with different cobalt(II) and copper(II) salts viz., OAc(-), Cl(-), NO3(-) and SO4(2-), yielded a new series of binuclear metal complexes. Reactions of the ligand with these metal ions in the presence of a secondary ligand (L') [O,O-donor; acetylacetone, N,O-donor; 8-hydroxyquinoline or N,N-donor; 1,10-phenanthroline and N,N,N',N'-tetramethylethylenediamine] in 1:2:2 (L:M:L') molar ratio yielded mixed-ligand complexes with different molar ratios. The metal complexes were characterized by elemental and thermal analyses, IR, electronic, ESR and mass spectra as well as conductivity and magnetic susceptibility measurements. The analytical and spectroscopic data suggested that the H2L ligand behaves as a neutral, monobasic or dibasic tetradentate ligand, depending on the type of the anion and secondary ligand used, through the two phenolic and two carbonyl groups. Electronic spectra, magnetic and conductivity measurements showed that all complexes are octahedral with non-electrolytic nature. The profile of ESR spectra of copper(II) complexes suggested the octahedral geometry and the spin Hamiltonian parameters of the complexes were calculated and discussed. Molecular orbital calculations were performed for metal complexes using Hyperchem 7.52 program on the bases of PM3 level and the results correlated with the experimental data. The free ligand and some of its metal complexes showed antimicrobial activity towards some of Gram-positive and Gram-negative bacteria, yeast (Candida albicans) and fungus (Aspergillus fumigatus).

A genetic study of Wilson's disease in the United Kingdom

Previous studies have failed to identify mutations in the Wilson's disease gene ATP7B in a significant number of clinically diagnosed cases. This has led to concerns about genetic heterogeneity for this condition but also suggested the presence of unusual mutational mechanisms. We now present our findings in 181 patients from the United Kingdom with clinically and biochemically confirmed Wilson's disease. A total of 116 different ATP7B mutations were detected, 32 of which are novel. The overall mutation detection frequency was 98%. The likelihood of mutations in genes other than ATP7B causing a Wilson's disease phenotype is therefore very low. We report the first cases with Wilson's disease due to segmental uniparental isodisomy as well as three patients with three ATP7B mutations and three families with Wilson's disease in two consecutive generations. We determined the genetic prevalence of Wilson's disease in the United Kingdom by sequencing the entire coding region and adjacent splice sites of ATP7B in 1000 control subjects. The frequency of all single nucleotide variants with in silico evidence of pathogenicity (Class 1 variant) was 0.056 or 0.040 if only those single nucleotide variants that had previously been reported as mutations in patients with Wilson's disease were included in the analysis (Class 2 variant). The frequency of heterozygote, putative or definite disease-associated ATP7B mutations was therefore considerably higher than the previously reported occurrence of 1:90 (or 0.011) for heterozygote ATP7B mutation carriers in the general population (P < 2.2 × 10(-16) for Class 1 variants or P < 5 × 10(-11) for Class 2 variants only). Subsequent exclusion of four Class 2 variants without additional in silico evidence of pathogenicity led to a further reduction of the mutation frequency to 0.024. Using this most conservative approach, the calculated frequency of individuals predicted to carry two mutant pathogenic ATP7B alleles is 1:7026 and thus still considerably higher than the typically reported prevalence of Wilson's disease of 1:30 000 (P = 0.00093). Our study provides strong evidence for monogenic inheritance of Wilson's disease. It also has major implications for ATP7B analysis in clinical practice, namely the need to consider unusual genetic mechanisms such as uniparental disomy or the possible presence of three ATP7B mutations. The marked discrepancy between the genetic prevalence and the number of clinically diagnosed cases of Wilson's disease may be due to both reduced penetrance of ATP7B mutations and failure to diagnose patients with this eminently treatable disorder.

Neonatal intracerebral hemorrhage: mechanisms, managements, and the outcomes

Intracerebral hemorrhage is a multifactorial disorder with heterogeneous etiologies and potentially long-term debilitating outcomes. We review all available evidence regarding the current strategies for management of intracerebral hemorrhage. It is clear that prompt detection and treatment does affect the outcome; nevertheless, prevention of intracerebral hemorrhage remains the best strategy.

Tibial angioplasty in diabetic patients: should all vessels be treated?

AIM

Patients with severe critical limb ischemia (CLI) due to tibial disease are commonly treated nowadays with tibial angioplasty. However, the benefits and complications of treating "more than one tibial vessel" have not yet been determined. This study compares the outcome of angioplasty of one vessel versus that of more than one vessel in patients with CLI due to tibial disease.

METHODS

We retrospectively reviewed all consecutive diabetic patients with tibial disease with no concomitant proximal lesions who were treated by angioplasty. Among 82 patients with isolated tibial disease 48 patients were selected. All patients had to have more than one diseased tibial vessel that can be treated by angioplasty. Group A patients (N.=25) had only one tibial vessel treated while group B patients (N.=23) had more than one tibial vessel treated. We compared both groups with respect to patients' characteristics, lesion morphology, and limb salvage rate.

RESULTS

Lesion morphology was worse in group A than B: anterior tibial artery showed more long lesions (17 vs. 8), more multiple lesions (22 vs. 11), and peroneal artery showed more long lesions (23 vs. 10), more multiple lesions (24 vs. 12), and more occlusions (18 vs. 10). Limb salvage rate at 12 months was similar (91%) in both groups. There were 5 complications in each group.

CONCLUSION

The lesion morphology was worse in group A. Simpler lesions in group B motivated performing more than one vessel angioplasty. There was no difference in the limb salvage rate in the medium term among both groups. Additional vessels angioplasty in less diseased arteries was not associated with substantial additional morbidity.

The complexation of a novel squaric bis(thiosemicarbazone); 3,4-bis{[(aminothioxomethyl)amino]azamethylene}cyclobut-ene-1,2-diol

A novel chelating agent (Sqtsc; H(4)L) bearing both hard and soft donor atoms was synthesized by the condensation of squaric acid with thiosemicarbazide. The ligand has two symmetrical sets of donor atoms (SNO), therefore, it was allowed to react with the metal ions at the mole ratio 2:1 (M:L). Mono- and bi-nuclear chelates were obtained in which the ligand showed a variety of modes of bonding viz. (OO)(2-), (SNNS)(2-) and (SNO)(2-) per each metal ion supporting the ambidentate and flexidentate characters of the ligand. The mode of bonding and basicity of the ligand depend mainly on the type of the metal cation and its counter anion. All the obtained complexes have the preferable O(h)-geometry except the VO(II)-complex (7) which has also the preferable square pyramid geometry. Structural elucidation was achieved via elemental and spectral data.

Incidence of vascular malformations in spontaneous intra-cerebral haemorrhage in children

AIM

To assess the incidence of vascular malformations in children presenting with non-traumatic intra-cerebral haemorrhage and outline the need for radiological investigations.

MATERIALS AND METHODS

Between 1993 and 2002, 26 children presented with spontaneous intra-cerebral haemorrhage at a mean age of 26 months (range 1-192 months).

RESULTS

Twenty-two children had, as first treatment, surgical removal of the haematoma and any malformation found. One patient with no evidence of vascular malformation had conservative treatment, two had embolisation and one had stereotactic radiosurgery of arteriovenous malformations (AVMs). The diagnosis of vascular malformation was confirmed histologically and/or radiologically in 16 (61%) patients. Of these 16 patients, 7 were AVMs, 1 thrombosed middle cerebral artery (MCA) aneurysm, 1 cavernous angioma, 6 aggregates of abnormal vessels, 1 vein of Galen aneurysm. Pre-operatively, 12 patients had magnetic resonance imaging (MRI)/magnetic resonance angiography (MRA) and 7 were positive for vascular malformation (1 false positive) with no false negatives. Digital subtraction angiography (DSA) was performed pre-operatively in 7 patients, 4 were positive with no false negatives. There were no re-bleeds at the follow-up period. Five (19%) patients died from the haemorrhage, 7 (27%) had severe neurological deficit and 14 (54%) had no neurological deficit. Residual malformation after surgery requiring additional treatment was found in 3 (16%) patients. All patients with confirmed malformations were followed-up with DSA.

CONCLUSION

MRI/MRA has high sensitivity and specificity in identifying vascular malformations in children presenting acutely with spontaneous intra-cerebral haemorrhage. This may prove useful when pre-operative DSA is not promptly available. After acute clot evacuation, there is high incidence of residual malformation and such patients should be followed-up with DSA.

Spectral and thermal study on the adduct formation between square planar nickel(II) chelates and some bidentate ligands

Adducts of Ni(II)-square planar complexes [Ni(beta-dik)(Me(4)en)](+), with a series of bidentate ligands (L), where beta-dik=acetylacetonate (acac) and benzoylacetonate (bzac), Me(4)en=N,N,N',N'-tetramethylethylenediamine and L=Me(4)en, 2,2'-bipyridine (bipy), ethylenediamine (en) and oxalate (C(2)O(4)(2-)) have been synthesized and characterized by spectral, thermal and magnetic measurements. Formation constants of the adducts formed from a series of ternary mixed Ni(II) complexes with the general formula [Ni(beta-dik)(diam)](+) with 1,10-phenanthroline (phen), 2,2'-bipyridine (bipy) and pyridine were spectrophotometrically determined. Thermodynamic parameters of the adduct formation between nickel(II) square-planar chelates and pyridine (py), 2,2'-bipyridine (bipy) and acetylacetone (acac) were also spectrophotometrically determined in 1,2-dichloroethane. The thermal stability of the isolated adducts was studied using thermogravimetry and the decomposition schemes of the adducts were given.

Long-term effect of Trigonella foenum graecum and its combination with sodium orthovanadate in preventing histopathological and biochemical abnormalities in diabetic rat ocular tissues

Trigonella foenum graecum seed powder (TSP) and Sodium Orthovanadate (SOV) have been shown to demonstrate antidiabetic effects by stabilizing glucose homeostasis and carbohydrate metabolism in experimental type-1 diabetes. However their efficacy in controlling histopathological and biochemical abnormalities in ocular tissues associated with diabetic retinopathy is not known. The purpose of this study was to investigate the comparative efficacy of individual as well as combination therapy of TSP and SOV in 8 weeks diabetic rat lens and retina. Retinas and lenses were taken from control, alloxan-induced diabetic rats and diabetic rats treated separately with insulin, 5%TSP, SOV (0.6 mg/ml) and a combined dose of SOV (0.2 mg/ml) and 5%TSP for 60 days. Control and each experimental group had six rats. Alterations in the activities of enzymes HK (hexokinase), AR (aldose reductase), SDH (sorbitol dehydrogenase), G-6-PD (glucose-6-phosphate dehydrogenase), GPx (glutathione peroxidase), GR (glutathione reductase) and levels of metabolites like sorbitol, fructose, glucose, MDA (malondialdehyde) and GSH (reduced glutathione) were measured in the cytosolic fraction of lenses besides measuring blood glucose levels and glycosylated haemoglobin. Histopathological abnormalities were studied in the lens using photomicrography and retina using transmission electron microscopy. Blood glucose, glycosylated haemoglobin levels and polyol pathway enzymes AR and SDH increased significantly causing accumulation of sorbitol and fructose in the diabetic lens and treatment with SOV and TSP significantly (p < 0.05) decreased these to control levels. Similarly, SOV and TSP treatments modulated the activities of HK, G-6-PD, GPx and GR in the rat lens to control values. Ultrastructure of the diabetic retina revealed disintegration of the inner nuclear layer cells with reduction in rough endoplasmic reticulum and swelling of mitochondria in the bipolar cells; and these histopathological events were effectively restored to control state by SOV and TSP treatments. In this study SOV and TSP effectively controlled ocular histopathological and biochemical abnormalities associated with experimental type-1 diabetes, and a combination regimen of low dose of SOV with TSP demonstrated the most significant effect. In conclusion, the potential of SOV and TSP alone or in low dose combination may be considered as promising approaches for the prevention of diabetic retinopathy and other ocular disorders.

Nutrition in humanitarian crises

It is anticipated that humanitarian crisis situations will continue to occur in countries of the Eastern Mediterranean Region affecting large segments of vulnerable populations. Subsequently the magnitude and effectiveness of the humanitarian response, particularly for food and nutrition, must be based on best practices and sound information of affected populations. To bridge the burgeoning gap between the food and nutrition needs of affected populations and the available resources, four key areas need to be addressed by the humanitarian agencies: adequate knowledge and skills in public health nutrition; effective coordination between humanitarian organizations when conducting nutritional assessments and interventions; efficient and appropriate delivery of services; communication, awareness and advocacy. This paper discusses approaches to how these may be improved.

Nutrition in humanitarian crises

Itis anticipated that humanitarian crisis situations will continue to occur in countries of the Eastern Mediterranean Region affecting large segments of vulnerable populations. Subsequently the magnitude and effectiveness of the humanitarian response, particularly for food and nutrition, must be based on best practices and sound information of affected populations. To bridge the burgeoning gap between the food and nutrition needs of affected populations and the available resources, four key areas need to be addressed by the humanitarian agencies:adequate knowledge and skills in public health nutrition; effective coordination between humanitarian organizations when conducting nutritional assessments and interventions; efficient and appropriate delivery of services; communication, awareness and advocacy. This paper discusses approaches to how these may be improved

Spectral, electrochemical and molecular orbital studies on solvatochromic mixed ligand copper(II) complexes of malonate and diamine derivatives

Solvatochromic mixed ligand complexes of copper(II) with malonate and diamine derivatives, Cu(n)(RMal)(diam)(n)X(m) (where n=1 or 2, m=1-4, RMal, malonic acid (H(2)Mal), diethylmalonate (HDEtMal) or diethylethoxyethylenemalonate (DEtEMal), and diam, ethylenediamine (en), 1,3-propylenediamine (1,3-pn), N,N,N'-trimethylethylenediamine (Me(3)en), N,N,N'-triethylethylenediamine (Et(3)en), N,N,N',N'-tetramethylethylenediamine (Me(4)en), N,N,N',N'-tetramethylpropylenediamine (Me(4)pn), or N-methyl-1,4-diazacycloheptane (medach); and X=ClO(4)(-) or Cl(-)), has been synthesized and characterized by spectroscopic, magnetic, molar conductance and electrochemical measurements. The mass spectra along with the analytical data of the complexes show peaks with m/e corresponding to a bridged binuclear structure for the chloride complexes, while perchlorate complexes showed either mononuclear structure for DEtMal and DEtEMal or bridged binuclear structure for Mal complexes. These results correspond to IR spectral data, which indicated that the modes of ester and carboxylato coordination sites are mono- and/or bidentate. The d-d absorption bands in weak donor solvents suggest square-planar and distorted square pyramidal-trigonal bipyramid geometries for the perchlorate and chloride complexes; respectively. On the other hand, an octahedral structure is identified for complexes in strong donor solvents. Perchlorate complexes show a drastic color change from violet to green as the donation ability of solvent increases, whereas chloride complexes are highly affected by the acceptor properties of the solvent. Cyclic voltammetric measurements on the complexes, proposed a quasi-reversible or irreversible and mainly diffusion controlled reduction process. Such behavior has been explained according to the ECE mechanism. A linear correlation has been found between the Cu(II) reduction potential and the spectral data. Molecular orbital calculations were performed for the ligands on the bases of PM3 level and the results corresponded to the experimental data. The data are discussed in terms of chromotropic concept and its applications as a Lewis acid-base color indicator.

[Kidney cancer. Report of 170 cases]

PURPOSE

The goal of this study is the analysis of the diagnostic and therapeutic aspects of this affection which is usually discovered at a delayed stage in our context.

MATERIAL AND METHODS

A retrospective study of 170 renal cancer, collected during a period of 15 years (1985-2000). Ninety-two men and 78 women were studied, their mean-age was 50 years (15-81 years). The diagnosis was relied on clinical, radiological and histological arguments.

RESULTS

Lumbar pain, hematuria and enormous mass were present in 85 cases (50%). The ultrasound and computed exams permitted the diagnosis and also evaluated the venous and locoregional extension. The treatment consisted on large nephrectomy practiced in 114 patients (67%), abstention in 56 cases (33%) due to the advanced stage of the tumor. The histological exam concludes to clear cell adenocarcinoma in 91.2% of cases.

CONCLUSION

The authors deplore the delayed diagnosis of renal cancer in our context which is responsible of a high rate of abstention (33%); and underline the interest of the early diagnosis for an adequate management.