Colorimetric and thin-layer chromatographic methods for field assay of chloroquine and its metabolites in urine

Three field-adapted methods for the quantification of the antimalarial drug chloroquine are described. Two of the methods are modifications of the Haskins test and are based on ion-pair formation between chloroquine and methyl orange in either dichloromethane or chloroform. Absorbance values measured at 420 nm with a hand-held, battery-operated filter photometer were linearly related to chloroquine concentrations in urine up to 100 μmol/l (32 μg/ml) for both methods. The contribution of the desethylchloroquine metabolite to the measured absorbance for both methods is less than that of chloroquine; the relative sensitivity for this metabolite is about 50% of that of chloroquine for both methods. The detection limit for modification I is 1 μmol/l (0.3 μg/ml), while that for modification II is 3 μmol/l (1 μg/ml). A single dose of chloroquine diphosphate (300 mg as base) administered to each of three volunteers yielded detectable levels by modification I of chloroquine in the urine for 28 days after dosing. Results for the colorimetric methods correlated well with the liquid chromatographic reference method used. The related thin-layer chromatographic method confirmed the presence of chloroquine and desethylchloroquine in the urine and permitted independent estimation of the concentration of these two compounds if desired. The two colorimetric methods may be used in remote locations where no electricity is available.     

High-dose infliximab prophylaxis in endotoxin-induced uveitis.

PURPOSE: The aim of this study to analyze the preventive effect of high-dose infliximab in endotoxin-induced uveitis (EIU) in rabbits. METHODS: An experimental study was conducted on 64 rabbits. Salmonella typhimurium lipopolysaccharide endotoxin was intravitreally injected. Infliximab was intravenously (i.v.) injected 24 h before the intravitreal injection (20 mg/kg). The animals were randomly assigned to five groups: group A, saline intravitreal injection; group B, Infliximab i.v. group C, infliximab + saline; group D, intravitreal endotoxin and group E, infliximab i.v. + intravitreal endotoxin. With two masked observers, a microscopic examination of aqueous humor (cells, tumor necrosis factor [TNF] alpha) and aqueous protein level were performed 24 h after an endotoxin injection and 48 h after an infliximab infusion. RESULTS: Infliximab treatment, at a dose of 20 mg/kg, significantly improved all the parameters. Inflammatory cell infiltration was significantly reduced in the iris, ciliary body, and anterior chamber (U Mann-Whitney test, P = 0.01). Associated with a lower level of TNF-alpha and protein exudate in aqueous humor (U Mann-Whitney test, P = 0.01). CONCLUSIONS: Infliximab, at a dose of 20 mg/kg, is effective in the prophylaxis of the EIU.     

The value of a diagnostic setup for full fixed maxillary implant prosthetics.

The concept of prosthesis-directed implant-supported restoration is well accepted. The implementation of this principle for patients requesting full fixed implant-supported maxillary prosthetics has not been thoroughly described. We present a technique for the evaluation and preprosthetic surgical management of patients who are edentulous in the maxilla and wish to have fixed implant-supported crown and bridge prosthetics.     

Opiate receptor subtype binding in gerbil hippocampus is altered by forebrain ischemia

A role for endogenous opioids in trauma-induced brain injury has been supported by pharmacological studies. The present series of experiments were initiated to extend these observations by measuring opiate receptor subtype binding in gerbil hippocampus following 7 days recovery from a 10 min ischemic insult. Quantitative in vitro autoradiography was utilized to measure mu [( 3H]DAGO), kappa [( 3H]bremazocine + 10 microM morphiceptin + 100 nM DSLET), delta [( 3H]DSLET + 10 microM morphiceptin) and lambda [( 3H]naloxone + 300 nM diprenorphine) binding. While ischemic tissue samples at the level of the dorsal hippocampus showed complete loss of CA1 pyramidal cells, we observed no significant alterations in mu or delta binding suggesting a non-pyramidal cell localization of these receptors. Kappa binding decreased significantly to 88% of control in the CA1 and CA3 regions while lambda binding in the stratum lucidum (CA3) increased to 165% of control. Our results show that opiate receptor subtypes are differentially affected by an ischemic insult.