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C Juliano

Publications and source records attributed to C Juliano.

24 records · Page 2Linked to original sources

An immunofluorescent study of the microtubule organization in Trichomonas vaginalis using antitubulin antibodies.

The flagellated protozoon Trichomonas vaginalis, parasite of the human urogenital tract, possesses a well developed microtubule system organized in highly differentiated structures. We have shown by immunoblotting that monospecific anti-sheep brain tubulin antibodies are able to react with the microtubular tubulin of T. vaginalis. These antibodies were used to study the microtubular system of T. vaginalis both in interphase and mitosis by indirect immunofluorescence. The interphase microtubular pattern, characterized by an axostyle, a pelta, four anterior flagella, and a recurrent flagellum, displayed remarkable changes at the onset of mitosis: the axostyle disappeared, and two pole bodies connected by a short spindle became evident; chromosomal fibers arose while pole-to-pole fibers elongated. The last phases of mitosis were marked by the disappearance of chromosomal fibers, the appearance of two small axostyles, and the depolymerization of the pole-to-pole bundle. At the end of mitosis, the normal interphase microtubule pattern was observed.

Animals↗

Inhibition of Trichomonas vaginalis replication by the microtubule stabilizer taxol.

Taxol, a plant alkaloid stabilizer of microtubules, inhibits in vitro the replication of the human pathogenic flagellate Trichomonas vaginalis in a dose-dependent fashion. Micromolar concentrations of the drug induce massive assembly of microtubules, resistant to antimicrotubule agents, and block the mitosis of the protozoa at an early stage preceding the formation of the spindle fibers and the depolymerization of the axostylar microtubules. Some hypotheses involving the inactivation of the microtubule-organizing centers and the stabilization of axostylar microtubules are formulated to explain the mechanism of action of taxol.

Alkaloids↗

"In vitro" effect of microtubule inhibitors on Trichomonas vaginalis.

This paper describes the effects of some antimicrotubular drugs (mebendazole, flubendazole, thiabendazole, colchicine, griseofulvin, vinblastine and isopropyl-N-phenylcarbamate or IPC) on growth and viability of Trichomonas vaginalis. Among the inhibitors tested, mebendazole and flubendazole irreversibly inhibit protozoa growth at low concentration (greater than or equal to 1 microgram/ml), while colchicine and griseofulvin act at higher concentrations and thiabendazole and IPC are ineffective. In order to explain mechanism of action of these drugs, some microtubule-correlated functions such as shape modification and mitotic index were studied. Our results support the hypothesis that the main targets for these compounds are the cytoplasmic microtubules of Trichomonas vaginalis.

Animals↗

Spray-dried microspheres containing ketoprofen formulated into capsules and tablets.

In this study, microspheres were prepared by a spray-drying technique using solutions of ketoprofen and two polymers, cellulose acetate butyrate (CAB) and hydroypropylmethylcellulose phthalate (HPMCP), in different weight ratios. Different total concentrations were used in the feed solutions: 3, 6 and 9% w/v. The spray-dried microparticles were characterized in terms of shape (SEM), size (light scattering method), production yield and encapsulation efficiency. They were formulated into capsules; tablets were prepared by direct compression of the microparticles mixed with maltose and, in some cases, hydroypropylmethylcellulose (HPMC). In vitro release studies were performed both at acidic and neutral pHs. The spray-drying process of solutions of ketoprofen with polymeric blends of cellulose derivatives leads to microparticles which, depending on their final formulation (capsules or tablets), can give a rapid or prolonged drug release. The formulations here described can be proposed for the oral administration of NSAIDs.

Anti-Inflammatory Agents, Non-Steroidal↗

Compressed biodegradable matrices of spray-dried PLGA microspheres for the modified release of ketoprofen.

A spray-drying technique was used to prepare poly(lactide-co-glycolide) (PLGA) drug loaded microspheres. Ketoprofen was chosen as a model NSAID drug. The microspheres were characterized in terms of morphology, drug content and release behaviour. The spray-dried particles were subject to a direct compression process for the preparation of biodegradable matrix tablets. The spray-dried powders were found to have good compaction properties. Tablets were also prepared from a mixture of microspheres and microcrystalline cellulose, mannitol and hydroxypropylmethylcellulose or sodium alginate. The release of ketoprofen in phosphate buffer (pH 7.4) was significantly sustained, indicating the suitability of using tabletted spray-dried PLGA microspheres for controlled drug delivery. The results show that spray-dried PLGA particles have promising properties as direct compression and release controlling excipients in matrix tablets for oral administration.

Administration, Oral↗