Spectroscopic and electrochemical studies of hetero-bimetallic copper complexes with Schiff's base ligand

Using Schiff's base ligand, several Cu(II) based bimetallic complexes such as Cu-Cu, Cu-Co, Cu-Ni, Cu-Zn, Cu-Mn have been prepared in a stepwise procedure. The structures of these complexes and the ligand have been proposed on the basis of FAB mass, elemental analysis, UV-vis, IR, electron paramagnetic resonance (EPR) and CV studies. EPR parameters, obtained through complete simulation, suggest that the formation of bimetallic complexes forces the Cu(II) centre to increase the flexibility in comparison with the monometallic Cu(II) complex. However, the nature of the second metal ion in the bimetallic complex effects the distortion around the first metal ion. The reduction of the complexes from Cu(II) to Cu(I) involves a large geometrical change and is found to be irreversible. A large positive shift is seen in the cathodic process, which can be ascribed to increased distortion due to bimetallic coordination. These complexes have potential usage in DNA studies.

Sino-orbital aspergillosis in a diabetic patient

Sino-orbital aspergillosis in a 61-year-old male with uncontrolled non-insulin dependent diabetes mellitus presented with three months history of left ear pain, left side headache with mucopurulent nasal discharge and one week history of progressive swelling and pain with difficulty in opening of the left eye and sudden loss of vision. In spite of surgical debridement and medical management with amphotericin B and itraconazole his visual outcome was poor and the infection was unabated at one month follow up.

Synthesis, physico-chemical and DNA interaction studies of homo- and hetero-trinuclear complexes

Synthesis and characterization of three new trinuclear metal complexes of type Cu3, Cu2Zn and Cu2Ni have been achieved by assembling simple mononuclear complexes, namely 2,2'-bipyridyl 3,4-dihydroxo benzaldehyde copper(II) complex and diethylenetriamine complexes of copper(II), nickel(II) and zinc(II) ions, through the reaction of coordinated ligands. The FAB mass spectra for the complexes show fragmentation pattern in accordance with the molecular formula. The frozen electron paramagnetic resonance (EPR) spectrum of tricopper complex shows two sets of parallel lines with approximately 2:1 ratio. The simulation has been carried out by considering dipolar interaction between the two types of copper ions present in the complex. The trimetallic complexes, Cu3, Cu2Ni and Cu2Zn show strong intercalation type of interaction with Calf thymus DNA in 0.02 mol L(-1) of phosphate buffer containing 60 mmol sodium chloride at pH 7.0 at room temperature. The binding constant is found to be in the order Cu3<Cu2Zn<Cu2Ni. The enhanced binding capability of Cu2Ni complex is attributed to the increased symmetry in the overall structure of the complex and the pronounced binding character of positively charged Ni(II) ions with the purines.

Cytological diagnosis of myxoinflammatory fibroblastic sarcoma: a case report and discussion of differential diagnosis

Myxoinflammatory fibroblastic sarcoma previously known as inflammatory myxohyaline tumour of distal extremities with virocyte or Reed Sternberg like cells is a low grade tumour of the hands and feet. It is a distinctive lesion with features simulating inflammatory conditions, Hodgkin's disease and various sarcomas. It characteristically occurs in the distal extremities and has a propensity to recur locally. We describe cytological appearance of this condition with relevant differential diagnosis. A 51 year old male presented with a swelling over upper 1/3 of medial aspect of left tibia of 4 months duration. Fine needle aspiration smears showed myxoid material, epithelioid cells, spindle cells, vacuolated cells and giant cells along with scattered lymphocytes. Histopathological examination of the excision biopsy specimen was confirmatory.

Comparison of intra-articular analgesics for analgesia after arthroscopic knee surgery

Post Arthroscopic intra-articular analgesia is a better method to avoid post-operative pain after arthroscopic surgery, thus avoiding the adverse effects of systemic analgesics. In this prospective randomized double blind study conducted on 90 patients, 30 patients in group A received 20 ml of intra-articular saline, 30 patients in Group B received 10 ml of intra-articular saline and 10 ml of 0.25% bupivacaine and 30 patients in Group C received 10 ml of 0.25% bupivacaine, 1 ml (30 mg) of ketorolac and 9 ml of saline intra-articularly. Ambulatory status, duration of analgesia and requirement for supplemented analgesia were compared in these three groups. Patients receiving this intra-articular analgesic combination of bupivacaine and ketorolac required significantly less supplemental postoperative analgesics. This combination significantly prolonged the duration of analgesia. Patients receiving this combination of drugs for intra-articular analgesia ambulated earlier.

EPR of vanadyl impurity in zinc ammonium trihydrogen bis(orthophosphate) monohydrate single crystal

The electron paramagnetic resonance spectroscopic investigation of VO(II)-doped zinc ammonium trihydrogen bis(orthophosphate) monohydrate single crystal has been carried out at 300K. The single crystal, rotated along the three orthogonally crystallographic axes, have yielded spin Hamiltonian parameters g and A as: g(xx)=1.978, g(yy)=1.974, g(zz)=1.925 and A(xx)=7.4, A(yy)=7.8, A(zz)=19.4 mT. These spin Hamiltonian parameters reflect a slight deviation from axially symmetry to rhombic, which is elucidated by the interstitial occupation of the vanadyl ion. The isofrequency plots and EPR spectra at few orientations have been simulated using the calculated spin Hamiltonian parameters. The Fermi contact parameter (kappa) and dipolar interaction parameter (P) have been calculated as 0.857 and -128 x 10(-4)cm(-1), respectively. The percentage of metaloxygen bond has been identified as 20%.

Identification of static JT in copper(II) doped hexaimidazole M(II) lattices: M=Co and Ni: an EPR study

Single crystal EPR studies on Cu(II) doped paramagnetic host lattices, hexaimidazole M(II) dichloride tetrahydrate (M=Co and Ni), isomorphous with M=Zn, have been carried out from room temperature to 77K to understand the nature of Jahn-Teller (JT) distortion in these paramagnetic host systems. The paramagnetic impurity, doped in the present two paramagnetic host lattices, shows anisotropic EPR spectra with superhyperfine from ligands, even at room temperature. An interesting observation noticed in the EPR spectra at room temperature is that there are more resonances corresponding to the second site in the paramagnetic hosts than in the diamagnetic host at 4.2K. This difference in behavior between the diamagnetic and paramagnetic host lattices indicates a change in the depth of the JT valleys. The spin Hamiltonian parameters are evaluated for Cu(II) ion in both the host lattices and the relaxation times have been calculated for the ion in cobalt host lattice only.

Characterisation of prehnite by EPMA, Mössbauer, optical absorption and EPR spectroscopic methods

A sample of prehnite from Rayalaseema zone of Andhra Pradesh, India containing about 2.565 wt.% Fe(2)O(3) is used in the present work. The mineral has been characterized by EPMA, optical absorption, EPR, NIR and Mössbauer techniques. Mössbauer studies confirm the presence of iron as an impurity in two sites. An EPR study on powder sample confirm the presence of Fe(III) impurity in the mineral. Optical absorption spectrum also indicates that Fe(III) impurity is present in two sites with octahedral structure. NIR results are due to water fundamentals.

Single crystal EPR study of VO(II) in magnesium potassium phosphate hexahydrate: a case of two substitutional vanadyl ions

Single crystal EPR study of VO(II)-doped magnesium potassium phosphate hexahydrate has been carried out at room temperature. Single crystal rotations in the three orthogonal planes indicate that the paramagnetic impurity has entered the lattice in place of magnesium ions by replacing the equatorial and axial coordinated water molecules. The spin Hamiltonian parameters obtained for the two substitutional sites are: site 1: g1=1.9800, g2=1.9774, g3=1.9296, A1=7.25 mT, A2=8.09 mT, A3=18.69 mT and site 2: g1=1.9802, g2=1.9765, g3=1.9296, A1=6.82 mT, A2=8.48 mT, A3=18.75 mT, respectively. Superhyperfine, from protons of ligand water molecules, has been observed at certain orientations. It has been concluded that VO bond directions of the two substitutional ions are orthogonal to each other.

Total percutaneous correction of a tetralogy of Fallot variant with dominant pulmonary valve stenosis

OBJECTIVE

To study the feasibility, efficacy, and safety of total percutaneous correction of a tetralogy of Fallot variant with dominant pulmonary valve stenosis.

DESIGN

Percutaneous correction of a variant of tetralogy of Fallot with dominant pulmonary valve stenosis, on the basis that there are transcatheter methods for the correction of malalignment-type ventricular septal defect (VSD) (transcatheter patch) and valvar pulmonary stenosis (balloon valvoplasty).

PATIENTS

Two patients with tetralogy of Fallot, 4 and 7 years old, were admitted for percutaneous correction. Their aortic saturations were 72% and 88%. Both had severe right ventricular outflow obstruction with dominant valvar pulmonary stenosis with total gradients of 120 and 70 mm Hg. Large malalignment subaortic VSDs, 14 and 16 mm in diameter, were present. The first patient had a previous percutaneous correction of a small atrial septal defect and an aortopulmonary collateral.

INTERVENTIONS

Balloon valvoplasty was first performed, followed by balloon test occlusion of the VSD and double balloon patch occlusion. Forty eight hours after implantation the supporting balloons were extracted, releasing the patches.

RESULTS

Both patients became acyanotic with oxygen saturations of 96%. There was mild residual infundibular stenosis with 40 and 30 mm Hg gradients. Both VSDs were effectively occluded with only trivial residual shunts. One patient developed mild haemolysis, which resolved spontaneously in a few days. Both patients were doing well at six and 12 months' follow up visits.

CONCLUSIONS

Total percutaneous correction of the tetralogy of Fallot variants with dominant pulmonary valve stenosis is feasible and successful. Larger clinical trials are required to further assess effectiveness and safety.

Single crystal EPR and optical absorption studies of Cu2+ ion in L-arginine sulphophosphate monohydrate--a nonlinear optical crystal

The EPR spectra of Cu2+ ion in L-arginine sulphophosphate monohydrate (LASP), a nonlinear optical material (NLO) have been studied at room temperature. Two magnetically inequivalent interstitial Cu2+ sites in the lattice were identified. The principal values of g- and A-tensors indicate that the symmetry of the electrostatic field around the Cu2+ ion is rhombic. Bonding parameters have been evaluated and the ground state wave function of Cu2+ ion is constructed. The ground state is found to be an admixure of x2 - y2 and 3z2 - r2 orbitals. By correlating EPR and optical absorption spectra the crystal field parameters have been evaluated.

Inhibition of Bacterial Adhesion by Subinhibitory Concentrations of Antibiotics

BACKGROUND

Urinary Tract Infections (UTIs) due to Escherichia coli is one of the most common diseases encountered in clinical practice. Most common recognised pathogenic factor in E.coli is adhesion. There is accumulating evidence that through subinhibitory concentrations (sub-MICs) of many antibiotics do not kill bacteria, they are able to interfere with some important aspects of bacterial cell function.

MATERIALS AND METHODS

A study was conducted to investigate the effect of sub MICs (1/2-1/8 MIC) of ciprofloxacin, ceftazidime, gentamicin, ampicillin and co-trimoxazole on E. coli adhesiveness to human vaginal epithelial cells using three strains ATCC 25922, MTCC 729 and U 105.

RESULTS

The 1/2 MIC of all the antibiotics tested produced the greatest inhibition of bacterial adhesion. Morphological changes were observed with ciprofloxacin, ceftazidime and ampicillin at 1/2 MIC and to a lesser extent at 1/4 and 1/8 MIC. Co-trimoxazole caused the greatest suppression of adhesion at 1/2 MIC of E. coli strain MTCC 729 when compared with the controls, followed by ceftazidime.

CONCLUSION

These results suggest that co-trimoxazole is the most effective antibiotic in the treatment of urinary tract infections caused by uropathogenic E. coli.

Survey of Staphylococcus isolates among hospital personnel, environment and their antibiogram with special emphasis on methicillin resistance

The objective of this study was to find the prevalence of Staphylococcus spp. carriage among hospital personnel and hospital environment and their antibiogram with special emphasis on methicillin resistance. A total of 205 samples from hospital personnel and environment were collected from casualty, oncology and multidisciplinary cardiac unit ward of Kasturba Medical College Hospital, Manipal. Samples were collected using sterile cotton wool swabs and inoculated into brain heart infusion broth. Subcultures were done onto blood agar and MacConkey's agar. Isolates were identified by standard methods up to species level. Antimicrobial susceptibility test was performed according to standardized disc diffusion Kirby-Bauer method. Each of the isolates was screened for methicillin resistance using oxacillin disc on Mueller Hinton agar plate followed by MIC for methicillin and cefoxitin susceptibility test by disc diffusion method. Sixty five out of 205 strains (31.7%) were Staphylococcus spp. and all of them were coagulase negative. Most of the strains belonged to S.epidermidis 49.23% (32/65) followed by S. saprophyticus 26.15% (17/65). Maximum isolates of S.epidermidis were from anterior nares 28.12% (9/32 strains of S.epidermidis). Highest number of methicillin resistant coagulase negative strains (3/9, 33.33%) were isolated from stethoscope of multidisciplinary cardiac unit ward followed by carriers in the anterior nares (2/9, 22.22%). Methicillin resistant coagulase negative staphylococci are prevalent in anterior nares of hospital personnel and in the hospital environment thereby providing a definite source for hospital acquired infection. All isolates were sensitive to vancomycin, ciprofloxacin and amikacin.

Single crystal EPR studies of paramagnetic ions doped zinc potassium phosphate hexahydrate; Part III: Mn(II)-a case of rhombic distortion

Single crystal electron paramagnetic resonance (EPR) studies of Mn(II) doped zinc potassium phosphate hexahydrate have been carried out at room temperature. Single crystal rotations along the three orthogonal axes indicate orthorhombic symmetry with spin-Hamiltonian parameters as: g(xx) = 1.9997; g(yy) = 1.9538; g(zz) = 1.9524, D(xx) = 15.49 mT; D(yy) = 0.22 mT; D(zz) = -15.71 mT, A(xx) = 11.70 mT; A(yy) = 10.53 mT; A(zz) = 10.42 mT and a = 0.8 x 10(-4) cm(-1). A large E term indicates considerable distortion from axial symmetry. The impurity is found to enter the lattice substitutionally. The distortion axis for the impurity has been identified along one of the Zn-O bond directions in the crystal.

Single crystal EPR study of Cu(2+) in cobalt ammonium phosphate hexahydrate: a case of low hyperfine coupling constant and measurement of spin-lattice relaxation times

Single crystal electron paramagnetic resonance (EPR) studies of Cu(II) doped cobalt ammonium phosphate hexahydrate have been carried out from 300 to 77 K, with single crystal rotation in all the three planes at 153 K, since the spectra are well resolved at this temperature. The angular variation studies indicate only one site in substitutional position with spin-Hamiltonian parameters as g: 2.404, 2.155, 2.063 and A: 11.58, 3.49, 2.07 mT. The reduction in one of the principal A value has been explained by considering considerable admixture of d(x(2)-y(2)) ground state with d(zeta(2)) excited state. The admixture coefficients of ground state wave function are: a = 0.2500; b = 0.9663; c = 0.0520; d = 0.0210; e = -0.0210, where a and b correspond to admixture coefficients for d(zeta(2)) and d(x(2)-y(2)) , respectively. Parameters kappa = 0.5140; P = 113 X 10(-4) cm(-1); alpha(2) = 0.7897; alpha = 0.8887; and alpha' = 0.5262 have also been calculated, indicating considerable covalency. The powder spectrum at room temperature is unresolved, whereas it is better resolved at 77 K, with spin-Hamiltonian parameters matching well with the single crystal values of 153 K. Powder spectrum at 77 K has been simulated, which agrees with the experimental one. The spin-lattice relation times are measured from the line width of the resonance lines recorded at different temperature.

Electron Transfer Reaction of Oxo(salen)chromium(V) Ion with Anilines

The kinetics of oxidation of 16 meta-, ortho-, and para-substituted anilines with nine oxo(salen)chromium(V) ions have been studied by spectrophotometric, ESIMS, and EPR techniques. During the course of the reaction, two new peaks with lambda(max) at 470 and 730 nm appear in the absorption spectrum, and these peaks are due to the formation of emeraldine forms of oligomers of aniline supported by the ESIMS peaks with m/z values 274 and 365 (for the trimer and tetramer of aniline). The rate of the reaction is highly sensitive to the change of substituents in the aryl moiety of aniline and in the salen ligand of chromium(V) complexes. Application of the Hammett equation to analyze kinetic data yields a rho value of -3.8 for the substituent variation in aniline and +2.2 for the substituent variation in the salen ligand of the metal complex. On the basis of the spectral, kinetic, and product analysis studies, a mechanism involving an electron transfer from the nitrogen of aniline to the metal complex in the rate controlling step has been proposed. The Marcus equation has been successfully applied to this system, and the calculated values are compliant with the measured values.