Molecular Cloning of Plasmodium vivax Calcium-Dependent Protein Kinase 4

A family of calcium-dependent protein kinases (CDPKs) is a unique enzyme which plays crucial roles in intracellular calcium signaling in plants, algae, and protozoa. CDPKs of malaria parasites are known to be key regulators for stage-specific cellular responses to calcium, a widespread secondary messenger that controls the progression of the parasite. In our study, we identified a gene encoding Plasmodium vivax CDPK4 (PvCDPK4) and characterized its molecular property and cellular localization. PvCDPK4 was a typical CDPK which had well-conserved N-terminal kinase domain and C-terminal calmodulin-like structure with 4 EF hand motifs for calcium-binding. The recombinant protein of EF hand domain of PvCDPK4 was expressed in E. coli and a 34 kDa product was obtained. Immunofluorescence assay by confocal laser microscopy revealed that the protein was expressed at the mature schizont of P. vivax. The expression of PvCDPK4-EF in schizont suggests that it may participate in the proliferation or egress process in the life cycle of this parasite.

Sec13 induces genomic instability in U2OS cells

Sec13p has been known as an endoplasmic reticulum-Golgi transport protein. Recently, it has also been shown to be required for the formation of septation in the fission yeast Schizosaccharomyces pombe. In the present study, we focused on the role of a human homolog of Saccharomyces cerevisiae SEC13, Sec13 protein during mitosis in U2OS cells. We found that the expression of Sec13 was constant throughout the cell cycle, and localized to the kinetochores at metaphase during mitosis. By using green fluorescent protein technology, we observed that Sec13 is required for evasion of mitotic arrest in response to spindle damage, leading to G1-like phase and apoptotic cell death. In addition, cells expressing exogenous Sec13 showed giant nuclei compared to endogenous ones in the absence of nocodazole. These results demonstrate that Sec13 is involved in the regulation of the metaphase/anaphase transition and may be functionally associated with mitotic machinery to maintain genomic stability during mitosis.

Senior Medical Students' Attitudes toward and Knowledge about Breastfeeding / 예방의학회지

OBJECTIVES: This study surveyed medical students attending clerkship to assess their attitude toward and knowledge about breastfeeding, and self-confidence to manage common breast-feeding problems. METHODS: A self-report questionnaire was administered to the 323 medical students at four medical colleges in Taegu in May 1997. The response rate was 92.9%, but the respondents used in the final data analysis were 245 (75.8%) due to missing variables. RESULTS: Overall, respondents showed equivocal attitudes toward breastfeeding (mean score 2.9 on a 6-point scale). Knowledge about breastfeeding was substantially low with the median % correct 39.2%. Of nine knowledge areas, weak areas were especially "contraindications and barriers to breastfeeding", "use of breastfeeding aids", "expression and storage of breast milk". Those reported to be confident to manage common breastfeeding problems were only 25.7%. Correlations between knowledge and self-confidence were not statistically significant except in college A (r=0.35, p<0.05). Correlations between knowledge and attitude were not significant. CONCLUSIONS: These results suggest that medical students attending clerkship in Taegu show equivocal attitudes toward breastfeeding, low self-confidence to manage common breastfeeding problems and have substantially limited level of knowledge. There should be more concerted efforts to improve this situation on the part of those involved in breastfeeding education.

Comparison of Two Different Hepatoma cell Lines Expressing Herpes Simplex Virus Thymidine Kinase ( HSVtk ) on Their Semsotovotu and Bystander Effect of Ganciclovir (GCV ) / 대한암학회지

No abstract available.