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P Overath

Publications and source records attributed to P Overath.

117 records · Page 7Linked to original sources

Correlation of in vivo and in vitro phase transitions of membrane lipids in Escherichia coli.

A double mutant of Escherichia coli unable to synthesize or degrade unsaturated fatty acids can incorporate fatty acids with various hydrocarbon chain structures into the membrane phospholipids. The temperature characteristic of three physiological properties of cells grown with different fatty acids (growth, respiration, and efflux of thiomethylgalactoside) is compared with the physical properties of the isolated phosphatidylethanolamines in monolayers at an air-water interface. Breaks in the temperature characteristic of the properties measured in vivo correspond to phase transitions in the lipid films from a liquid-expanded to a condensed form. It is concluded that a liquid-like state of the lipid phase is required for proper membrane function.

Carbon Isotopes↗

Topical treatment with hexadecylphosphocholine (Miltex) efficiently reduces parasite burden in experimental cutaneous leishmaniasis.

Ether-lipids and alkylphosphocholines have been found to have anti-leishmanial activity. Oral treatment with hexadecylphosphocholine (HePC) efficiently reduces parasite burden in murine visceral leishmaniasis. Drugs for the treatment of cutaneous leishmaniasis are most commonly administered parenterally, whereas efficient drugs for topical treatment are not in current use. Here we investigate the efficacy of topical treatment with HePC in mice infected with Leishmania mexicana or L. major, causative agents of cutaneous leishmaniasis in the New and Old World, respectively. BALB/c, CBA/J and C57BL/6 inbred mice do not control infection with L. mexicana because they do not mount an efficient Th1-type anti-parasitic lymphocyte response. In contrast, C57BL/6 mice are resistant to an infection with L. major, developing only transient lesions that heal spontaneously owing to an efficient Th1 response. BALB/c, CBA/J and C57BL/6 mice were infected subcutaneously with L. mexicana amastigotes, causing nodular lesions after 5 months. Topical treatment with HePC (Miltex) was highly effective in reducing parasite burden and healed established lesions. The treatment did not induce a Th1 response in L. mexicana-infected susceptible mice and most of the mice relapsed. In resistant C57BL/6 mice infected subcutaneously with 2 x 10(6) L. major promastigotes at the tail base, nodular lesions developed after 2 weeks. Topical treatment with Miltex reduced the parasite load and the mice healed their lesions much faster than the untreated infected controls. The clinical application of Miltex for treatment of cutaneous leishmaniasis may be highly efficient because humans, similarly to resistant mice, in general do not relapse after healing. Clinical trials should be straightforward considering that Miltex is an approved drug for the treatment of breast cancer metastases.

Administration, Topical↗