Appetizing rancidity of apoptotic cells for macrophages: oxidation, externalization, and recognition of phosphatidylserine.

Programmed cell death (apoptosis) functions as a mechanism to eliminate unwanted or irreparably damaged cells ultimately leading to their orderly phagocytosis in the absence of calamitous inflammatory responses. Recent studies have demonstrated that the generation of free radical intermediates and subsequent oxidative stress are implicated as part of the apoptotic execution process. Oxidative stress may simply be an unavoidable yet trivial byproduct of the apoptotic machinery; alternatively, intermediates or products of oxidative stress may act as essential signals for the execution of the apoptotic program. This review is focused on the specific role of oxidative stress in apoptotic signaling, which is realized via phosphatidylserine-dependent pathways leading to recognition of apoptotic cells and their effective clearance. In particular, the mechanisms involved in selective phosphatidylserine oxidation in the plasma membrane during apoptosis and its association with disturbances of phospholipid asymmetry leading to phosphatidylserine externalization and recognition by macrophage receptors are at the center of our discussion. The putative importance of this oxidative phosphatidylserine signaling in lung physiology and disease are also discussed.

Inter-species differentiation of benign Theilerias by genomic fingerprinting with arbitrary primers.

A method was developed to obtain reproducible DNA fingerprints from five distinct purified benign Theileria genomic DNAs by PCR-based amplification. Randomly amplified polymorphic DNA (RAPD) profiles were obtained from 10 randomly designed 12-mers. However, nine of the 10 primers could generate the difference in RAPD-PCR profiles which allowed discrimination of Theileria species. The method has advantage of being simple, fast and sensitive for diagnosis and characterization of the parasites since it does not require prior DNA sequence information to construct species-specific probes or primers. The results are also beneficial for a proper understanding of the epidemiology and designing rational control programmes for Theileriosis in Asian and South-East Asian countries.

Intra-species differentiation of Trypanosoma evansi by DNA fingerprinting with arbitrary primered polymerase chain reaction.

A method was developed to obtain reproducible DNA fingerprints from isolates of Trypanosoma evansi by PCR-based amplification using arbitrary primers (AP-PCR). Only one out of 10 randomly designed 12-mer primers generated DNA fingerprint profiles that revealed intra-species differences in T. evansi. The technique was applied in association with parasitological and serological examinations to investigate animal-to-animal transmission during an outbreak of surra in Thailand. The AP-PCR method has the advantage of being simple, fast and sensitive to diagnosis and characterization of the parasites since it does not require prior DNA sequence information. The technique should prove useful for the proper understanding of epidemiology and for designing rational control programs for trypanosomosis.