Synthesis of some novel quinone diimine derivatives of benzo-15-crown-5 for application in Hg(2+) recognition.

A series of novel fluoroionophore bearing derivatives of benzo-15-crown-5 were synthesized by the amination of benzo-15-crown-5 followed by condensation with different quinones in the presence of titanium tetrachloride (TiCl4 ) and 1,4-diazabicyclo-[2.2.2]octane. The compounds were characterized by infrared, (1) H and (13) C nuclear magnetic resonance, mass spectroscopy and elemental analysis. Absorption and fluorescence spectral characteristics of these compounds were studied. It was observed that the anthraquinone derivative was acting as an Hg(2+) ion sensor.

A comparative study of the treatment techniques for controlling THM-precursors in raw and drinking water.

Silica gel adsorption, strong base anion exchange IRA 400-OH form resin were evaluated for the treatment of trihalomethane precursors present in raw and drinking water. A powdered silica gel having 60 to 120 mesh size and a previously dried IRA 400-OH form resin having 20-50 mesh size have been applied to artificial water samples and a specific analytical approach was used for selective removal of humic acid present in the water. This study aims to evaluate the role of contact time, pH, adsorption dose, concentration of humic acid (H.A.), flow rate on the reduction of THM-precursors as a result of adsorption of H.A. while passing raw water through silica gel and IRA 400 OH form resin column. Freundlich adsorption isotherm constants K for silica gel and IRA 400-OH form resin were determined as 1.13 x 10(-3) and 4.2 x 10(-3) mg/g respectively and l/n were found to be 0.9927 and 1.069 respectively.

Ternary complexes of palladium (II) with levamisole and L-amino acids.

The complexes of general formula [(LMS)2Pd(amino acid)]Cl with LMS = levamisole, and amino acid = L-alanine, L-phenylglycine, L-phenylalanine, L-valine, L-methionine, and L-proline, were synthesized by the interaction of [(LMS)2PdCl2] with the sodium salts of L-amino acids. The newly synthesized complexes are characterized by elemental analysis, conductivity, magnetic susceptibility, optical rotation measurements, and UV-Vis, IR and 13C NMR spectral data. Levamisole is coordinated to palladium via the N-7 nitrogen and the amino acids through the amino nitrogen and carboxylate oxygen, except for L-methionine which binds the metal via nitrogen and sulfur atoms. Optically active [(LMS)2Pd(amino acid)]Cl complexes are obtained when L-amino acids or D,L-amino acids are used for the synthesis of these complexes. L-Methionine and L-proline complexes induce new cell forms in Baker's yeast (Saccharomyces cerevisiae) cells.

Comparative treatment of experimental Staphylococcus aureus endophthalmitis.

PURPOSE: To compare treatment strategies for Staphylococcus aureus endophthalmitis, we created an animal model in an aphakic rabbit eye and tested six different approaches to treatment. METHODS: Rabbit eyes were rendered aphakic, and three weeks postoperatively, S. aureus organisms were injected into the vitreous cavity. One group was maintained as a control. Twenty-four hours after bacterial injection, six different treatment groups were created for comparison. Clinical inflammation scores, culture results 48 hours after treatment, histopathologic gradings, and development of total corneal opacity three weeks after treatment were assessed. RESULTS: Injection of vancomycin hydrochloride into the vitreous cavity was more effective than injection of cefazolin sodium (P = .01) in reducing the percentage of eyes that had positive culture results and also resulted in lower inflammation scores. Vitrectomy plus injection of either antibiotic was more effective than injection of the same antibiotic alone in reducing culture-positive results and reducing clinical inflammation scores. addition of systemic corticosteroids to intravitreal antibiotic injection did not improve any measure of outcome. Vitrectomy and injection of intravitreal vancomycin was the most effective strategy to sterilize the vitreous cavity, resulting in the lowest inflammation scores and the smallest percentage of eyes with opaque corneas. CONCLUSION: In an animal model of S. aureus endophthalmitis, the combination of vitrectomy and injection of intraocular vancomycin was the most effective strategy for rapidly controlling the infective process and improving the outcomes measured three weeks after treatment.

Extraction and spectrophotometric determination of lead(II) with pyridine-2-acetaldehyde salicyloylhydrazone.

Lead(II) reacts with pyridine-2-acetaldehyde salicyloylhydrazone (PASH) in the pH range 8.6-9.3 to form a yellow-green, 1:2 chelate which can be extracted into chloroform. Beer's law is obeyed in the concentration range 1.5-6.2 mug ml(-1) of lead(II). The molar absorptivity of the extracted species is 1.93 x 10(4) l mol(-1) cm(-1) at 380 nm. The proposed method is sensitive, simple, rapid, accurate and has been satisfactorily applied for the determination of lead in synthetic mixtures, alloys, water and soil samples.

Effects of silver on adherence of bacteria to urinary catheters: in vitro studies.

Strains of Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Enterococcus faecalis, and Klebsiella pneumoniae, mostly from complicated urinary tract infections, showed reduced adherence to silver-treated silicone or latex catheters as compared with latex or silicone catheters. The relative degrees of cell adherence to catheters at 2 h or 18 h, as indicated by radiolabeled cell assays, were in general agreement with growth rate-reduction assays and scanning-electron-microscopy data. For strains of E. coli, the correlation between cell hydrophobicity and degree of adherence to catheters was not significant. Antibiotic resistance (tetracycline, sulfathiazine, neomycin, kanamycin) and silver resistance were not associated. The radiolabel adherence procedure provided a quantitative method for evaluating the relative antimicrobial efficacy of silver-treated catheters.

Adaptation and growth of Serratia marcescens in contact lens disinfectant solutions containing chlorhexidine gluconate.

Serratia marcescens (11 of 12 strains) demonstrated an ability to grow in certain chlorhexidine-based disinfecting solutions recommended for rigid gas-permeable contact lenses. For a representative strain, cells that were grown in nutrient-rich medium, washed, and inoculated into disinfecting solution went into a nonrecoverable phase within 24 h. However, after 4 days, cells that had the ability to grow in the disinfectant (doubling time, g = 5.7 h) emerged. Solutions supporting growth of S. marcescens were filter sterilized. These solutions, even after removal of the cells, showed bactericidal activity against Pseudomonas aeruginosa and a biphasic survival curve when rechallenged with S. marcescens. Adaptation to chlorhexidine by S. marcescens was not observed in solutions formulated with borate ions. For chlorhexidine-adapted cells, the MIC of chlorhexidine in saline was eightfold higher than that for unadapted cells. Cells adapted to chlorhexidine showed alterations in the proteins of the outer membrane and increased adherence to polyethylene. Cells adapted to chlorhexidine persisted or grew in several other contact lens solutions with different antimicrobial agents, including benzalkonium chloride.

Hemagglutination (fimbriae) and hydrophobicity in adherence of Serratia marcescens to urinary tract epithelium and contact lenses.

The capacity of 59 isolates of Serratia marcescens, obtained from urinary tract infections, wounds, and contact lenses or their paraphernalia, to agglutinate erythrocytes from different animal species was tested. Three main patterns were found: mannose-sensitive agglutination of guinea-pig, fowl or horse erythrocyte; mannose-resistant agglutination of chicken or pigeon erythrocytes alone or in combination with mannose-sensitive agglutination; and no agglutination. Hemagglutination capacity was associated with isolates from urinary tract infection, but not with isolates associated with contact lenses. Adherence to human urinary tract epithelium did not correlate with the hemagglutination patterns nor with the origin of the isolates. Some strains of different hemagglutination pattern were selected for the study of hydrophobicity and adherence to contact lens polymers. Hydrophobicity, as determined by degree of partition in hexadecane and water (BATH-values), correlated neither with degree of adherence to contact lens polymers nor with the hemagglutination pattern. For a representative strain there was an excellent correlation (r2 = 0.98) between adherence and the water content (hydrophobicity) of the lens polymers. These results suggest that, as with tissues, other factors interact with hydrophobicity in causing adherence to plastics.

DNA relatedness, karyotyping and gene probing of Candida tropicalis, Candida albicans and its synonyms Candida stellatoidea and Candida claussenii.

Isolates of Candida albicans with varied phenotypes, including sucrose-negative variants (C. stellatoidea, serotypes A and B) and avirulent germ tube-negative forms (C. claussenii) showed significant (greater than 90%) DNA relatedness to classical C. albicans, but insignificant relatedness to C. tropicalis and sucrose-negative C. tropicalis. A transverse alternating-field gel electrophoresis procedure (TAFE) showed discrete karyotype patterns among the phenotypic variants of C. albicans including the sucrose-negative C. stellatoidea. The number of chromosome-sized DNA bands for C. tropicalis (7 bands) were within the range of bands observed for C. albicans (5 to 10 bands). The general DNA-migration pattern for C. albicans appeared distinct from that of C. tropicalis. An aspartyl proteinase (PrA) gene probe from C. albicans hybridized with chromosomal DNA from C. albicans, C. claussenii and C. stellatoidea but not with that from C. tropicalis.

Comparative efficacies of soft contact lens disinfectant solutions against microbial films in lens cases.

Biofilms of Pseudomonas aeruginosa, Serratia marcescens, Staphylococcus epidermidis, Streptococcus pyogenes, and Candida albicans, established in the wells of a polyethylene contact lens case, retained viability to certain soft contact lens disinfectant solutions after exposure for the manufacturer's minimum recommended disinfection times. The relative order of resistance of bacterial biofilms was as follows: S marcescens was greater than P aeruginosa, which was greater than S epidermidis, which was greater than S pyogenes. Air drying of biofilms for 10 hours increased the efficacy of the disinfectant solutions, but drying was not enough to decrease the incidence of recovery to 0% for all solutions. Hydrogen peroxide was more effective against biofilms than disinfectant solutions formulated with chlorhexidine gluconate or polyquaternium-1 or polyaminopropyl biguanide. We recommend that determination of efficacy of contact lens disinfectant solutions should include challenges against biofilms.

Microbial contamination of contact lens storage cases and solutions.

We compared microbial contamination of contact lens storage cases of asymptomatic contact lens wearers (Group 1; No. = 118; sampled once) and of contact lens wearers with manufacturer's lens-care instructions reinforced (Group 2; No. = 62; sampled three, six, 12, and 20 weeks after initial advisement). A significantly higher incidence of contamination of contact lens storage cases and solutions was observed among samples from Group 1 (132 of 247 samples) as compared to samples from Group 2 (30 of 500 samples; P = .000). Contact lens storage cases of individuals in Group 2 who used hydrogen peroxide systems (four of 78) showed a significantly lower incidence of contamination as compared to individuals who used other chemical disinfection (11 of 62 soft lens users; 10 of 59 rigid gas-permeable lens users; P = .041). Biofilms, adhered microorganisms embedded in a glycocalyx, in contact lens storage cases were not always inactivated by the addition of fresh solutions. Cleaning and periodic replacement of contact lens storage cases is recommended.

Involvement of a cell wall receptor in the mode of action of an anti-Candida toxin of Pichia anomala.

Hanes-Woolf, Dixon, and Hill plots of growth rates of Candida albicans RC1 grown in various concentrations of glucose and a Pichia anomala WC65 toxin suggested the presence of toxin-binding sites. Indirect immunofluorescence microscopy with antitoxin antibodies demonstrated binding of the toxin to the cell wall. Resistance to the toxin of a mutant Saccharomyces cerevisiae deficient in cell wall beta-1-6-D-glucan suggests that the glucan either served as the receptor or influenced the number or composition of the receptor. Immunofluorescence that appeared to be associated with the cell membrane of toxin-treated spheroplasts of C. albicans was also observed. Spheroplasts of the resistant mutant of S. cerevisiae were sensitive to the toxin.

Electrophoretic karyotyping of typical and atypical Candida albicans.

Electrophoretic karyotypes of atypical isolates of Candida albicans, e.g., strains that were germ tube negative, failed to express proteinase activity, demonstrated low virulence for mice, formed hyperchlamydoconidia, produced hyperhyphae, or were sucrose negative (including the type strain of Candida stellatoidea), were compared with those of typical C. albicans. Karyotypes of whole-cell DNA of classical C. albicans examined with transverse alternating-field electrophoresis under specific conditions were composed of seven DNA bands with a specific migration pattern. Certain atypical strains and representatives of the three serotypes of C. stellatoidea produced discrete karyotypes with 5 to 10 bands. All isolates demonstrated a significant degree of DNA relatedness, suggesting their conspecificity. Densitometric tracings of DNA bands provided an objective and standardized method for comparing bands within the gels.

Purification and characterization of the anti-Candida toxin of Pichia anomala WC 65.

Pichia anomala WC 65 secretes a toxin that is inhibitory to a variety of yeasts, including strains of the animal pathogen Candida albicans. The toxin was purified to homogeneity by ultrafiltration, ethanol precipitation, ion-exchange chromatography with a Mono Q column, and gel permeation chromatography with a Superose 12 column. The toxin had a molecular weight of 83,300 as determined by electrophoresis on sodium dodecyl sulfate-polyacrylamide gradient gels and a molecular weight of 85,290 as determined by gel permeation chromatography. The isoelectric point of the toxin was pH 5.0. The toxin was stable between pH 2.0 and 5.0. Chemical analysis of the purified toxin indicated that the toxin was a glycoprotein composed of about 86% protein and 14% carbohydrate. At high concentrations, the toxin showed a tendency to aggregate, with loss of biological activity against C. albicans, Pichia bimundalis, and Saccharomycodes ludwigii. Purified toxin expressed killing activity against C. albicans in contrast to the static activity of the crude toxin.

Anti-Candida albicans activity of Pichia anomala as determined by a growth rate reduction assay.

Killer toxin activity of Pichia anomala WC65 appeared fungicidal for P. bimundalis WC38 and fungistatic for Candida albicans RC1. Inhibitory activity against sensitive C. albicans showed a linear relationship between toxin concentrations and the inverse of the reduced growth rates. The plot of toxin concentrations against growth rates was hyperbolic, as is characteristic of saturation kinetics. Sensitivity of C. albicans to the toxin decreased with increased cell age. The measurement of growth rate reduction provided a simple and accurate method for quantitation of toxin.