Center for Biologics Evaluation and Research

About: Center for Biologics Evaluation and Research is a facility organization based out in Silver Spring, Maryland, United States. It is known for research contribution in the topics: Virus & Vaccination. The organization has 3024 authors who have published 4648 publications receiving 228078 citations. The organization is also known as: CBER.

The H89 cAMP-dependent protein kinase inhibitor blocks Plasmodium falciparum development in infected erythrocytes.

Abstract: In Plasmodium falciparum, the causative agent of human malaria, the catalytic subunit gene of cAMP-dependent protein kinase (Pfpka-c) exists as a single copy. Interestingly, its expression appears developmentally regulated, being at higher levels in the pathogenic asexual stages than in the sexual forms of parasite that are responsible for transmission to the mosquito vector. Within asexual parasites, PfPKA activity can be readily detected in schizonts. Similar to endogenous PKA activity of noninfected red blood cells, the parasite enzyme can be stimulated by cAMP and inhibited by protein kinase inhibitor.Importantly, ex vivo treatment of infected erythrocytes with the classical PKA-C inhibitor H89 leads to a block in parasite growth. This suggests that the PKA activities of infected red blood cells are essential for parasite multiplication. Finally, structural considerations suggest that drugs targeting the parasite, rather than the erythrocyte enzyme, might be developed that could help in the fight against malaria.

Importance of B cells, but not specific antibodies, in primary and secondary protective immunity to the intracellular bacterium Francisella tularensis live vaccine strain.

Abstract: Although there appears to be little if any role for specific antibodies in protection against intracellular bacteria, such as the model pathogen F. tularensis live vaccine strain (LVS), the role of B cells themselves in primary and secondary infection with such bacteria has not been examined directly. We show here that mice deficient in mature B cells and antibodies (B-cell knockout mice) are marginally compromised in controlling primary sublethal infection but are 100-fold less well protected against secondary lethal challenge than are their normal counterparts. This defect in optimal specific protective immunity was readily reconstituted by the transfer of primed, and to a lesser degree, unprimed B cells, but not by the transfer of specific antibodies. The results indicate a previously unappreciated role for B cells in secondary immunity to intracellular pathogens through a function other than antibody production.

Analysis of ahpC gene mutations in isoniazid-resistant clinical isolates of Mycobacterium tuberculosis.

Abstract: The ahpC genes of 57 clinical isolates and one in vitro mutant of Mycobacterium tuberculosis were evaluated by nucleotide sequence analyses. Although compensatory ahpC promoter mutations were identified in 8 catalase-negative, katG-defective strains, the ahpC genes of 25 catalase-positive, isoniazid-resistant isolates and 25 drug-sensitive strains were not altered.

Recommendation of short tandem repeat profiling for authenticating human cell lines, stem cells, and tissues

Abstract: Cell misidentification and cross-contamination have plagued biomedical research for as long as cells have been employed as research tools Examples of misidentified cell lines continue to surface to this day Efforts to eradicate the problem by raising awareness of the issue and by asking scientists voluntarily to take appropriate actions have not been successful Unambiguous cell authentication is an essential step in the scientific process and should be an inherent consideration during peer review of papers submitted for publication or during review of grants submitted for funding In order to facilitate proper identity testing, accurate, reliable, inexpensive, and standardized methods for authentication of cells and cell lines must be made available To this end, an international team of scientists is, at this time, preparing a consensus standard on the authentication of human cells using short tandem repeat (STR) profiling This standard, which will be submitted for review and approval as an American National Standard by the American National Standards Institute, will provide investigators guidance on the use of STR profiling for authenticating human cell lines Such guidance will include methodological detail on the preparation of the DNA sample, the appropriate numbers and types of loci to be evaluated, and the interpretation and quality control of the results Associated with the standard itself will be the establishment and maintenance of a public STR profile database under the auspices of the National Center for Biotechnology Information The consensus standard is anticipated to be adopted by granting agencies and scientific journals as appropriate methodology for authenticating human cell lines, stem cells, and tissues