Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022568 (keratitis)
 5,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The first medical cure of Acanthamoeba keratitis was obtained by use of propamidine isethionate. Since then, it has been the basic drug recommended for use in treatment. Because some Acanthamoeba strains have been reported to be resistant to propamidine and propamidine was found to be only weakly cysticidal, superior homologs such as butamidine, pentamidine, hexamidine, heptamidine, octamidine, and nonamidine were tested for their amoebicidal effects on two Acanthamoeba strains isolated from patients with keratitis. Trophozoicidal and cysticidal efficiencies were found to be increased from propamidine to nonamidine; i.e., when the alkyl chain connecting the two benzene rings in their molecular structures was elongated, in comparison with propamidine, hexamidine and octamidine were the most amoebicidal molecules. As a result of these data, a kinetic study carried out on propamidine, hexamidine, and octamidine demonstrated that the amoebicidal effects resulted from two events: the diffusion of molecules through the plasma membrane or the double wall of trophozoites or cysts, respectively, and the lethal effects of molecules on amoebic protoplasm. The diffusion kinetics were increased when the alkyl chain was elongated, i.e., with an increase in the lipophilic properties of molecules. In contrast, the lethal effect kinetics were found to be unchanged by this elongation, indicating that they originated from the cationic surface-active properties induced by the protonated amidine groups attached to each benzene ring, which themselves remained unchanged from one molecule to the other. These results strongly advocate the immediate replacement of propamidine by hexamidine in the medical treatment of Acanthamoeba keratitis; in France, 0.1% hexamidine eyedrops are available (Desomedine). The results also advocate clinical investigations on the efficiency and toxicity of octamidine, which appears to be the most amoebicidal diamidine in vitro.
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PMID:Amoebicidal efficiencies of various diamidines against two strains of Acanthamoeba polyphaga. 772 93

Microemulsion systems composed of Span20/80+Tween20/80+n-butanol+H2O+isopropyl palmitate (IPP)/isopropyl myristate (IPM) were investigated as model systems of drug carriers for eye drops. Effects of chloramphenicol, normal saline, sodium hyaluronate and various oils on the phase behavior were studied. The phase transition was investigated by the electrical conductivity measurements. The electrical conductivity of the microemulsion was affected by the encapsulation of the drug into the system, and the addition of normal saline and sodium hyaluronate. The chloramphenicol is used to treat the diseases such as trachoma and keratitis. However, this drug in the common eye drops hydrolyzes easily. The main product of the hydrolysis is glycols. Here, the chloramphenicol was trapped into the oil-in-water (o/w) microemulsions and its stability was investigated by the high performance liquid chromatography (HPLC) assays in the accelerated experiments of 3 months. Its location in the microemulsion formulations was determined by means of 1H NMR spectroscopy. The results of HPLC revealed that the contents of the glycols in the microemulsion formulations were much lower than that in the commercial eye drops at the end of the accelerated experiments. It implied that the stability of the chloramphenicol in the microemulsion formulations was increased remarkably. The NMR experiments confirmed that the chloramphenicol molecules should be trapped into the hydrophilic shells of the microemulsion drops, which was composed of many oxyethylene groups. The nitro-groups of the chloramphenicol molecules were near the alpha2-CH2 of the surfactant molecules and the benzene rings of the chloramphenicol molecules were near the oxyethylene groups of the surfactant molecules. It was this reason that enabled the chloramphenicol molecules in the microemulsions to be screened from the bulk water and its stability to be increased remarkably.
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PMID:Phase behavior of the microemulsions and the stability of the chloramphenicol in the microemulsion-based ocular drug delivery system. 1603 10

Microemulsion composed of Span20 + Tween20 isopropyl myristate (IPM) + H2O were investigated as potential drug delivery systems for eye drops. The system is important in that all its components are food grade so that the microemulsion is almost free of toxicity and irritation. The phase transition was investigated using the electrical conductivity measurements. The chloramphenicol is used to treat the eye diseases such as trachoma and keratitis. However, this drug in the common eye drops hydrolyzes easily. The main product of the hydrolysis is glycol. Here, the chloramphenicol was trapped into the oil-in-water (o/w) microemulsions free of alcohols. Its stability was investigated by the high performance liquid chromatography (HPLC) assays in the accelerated experiments of 3 months. The location of the chloramphenicol molecules in the microemulsion formulations was determined by means of dynamic light scattering (DLS) and 1H NMR spectroscopy. The results of HPLC revealed that the content of the glycols in the microemulsion formulation was much lower than that in the commercial eye drops at the end of the accelerated experiments. It implied that the stability of the chloramphenicol in the microemulsion formulations was increased remarkably. The results of DLS and NMR confirmed that the chloramphenicol molecules should be trapped into the hydrophilic shells of the microemulsion drops, which were composed of many oxyethylene groups. The benzene rings of the chloramphenicol molecules were near the group of alpha2-CH2 and the oxyethylene groups of the surfactant molecules. It was this reason that enabled the chloramphenicol molecules in the microemulsions to be screened from the bulk water and its stability to be increased remarkably.
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PMID:Studies on the stability of the chloramphenicol in the microemulsion free of alcohols. 1642 26