SNAP/CLIP-Tags and Strain-Promoted Azide-Alkyne Cycloaddition (SPAAC)/Inverse Electron Demand Diels-Alder (IEDDA) for Intracellular Orthogonal/Bioorthogonal Labeling.

Labeling a protein of interest (POI) with a fluorescent reporter is a powerful strategy for studying protein structures and dynamics in their native environments. Compared to fluorescent proteins, synthetic dyes provide more choices in photophysical or photochemical attributes to microscopic characterizations. The specificity of bioorthogonal reactions in conjunction with the fidelity of subcellular destinations of genetically encoded protein tags can be employed to label POIs in live and fixed cells in a two-step process. In the present study the orthogonality of the strain-promoted azide-alkyne cycloaddition (SPAAC) and the inverse electron demand Diels-Alder (IEDDA) reaction is corroborated in concurrent labeling of two different intracellular targets. An azido group and a strained alkene are first installed at specific subcellular locations via orthogonal enzymatic reactions of the genetically incorporated SNAP- and CLIP-tags. The subsequent bioorthogonal reactions with fluorophores carrying matching reactive functionalities result in simultaneous dual labeling. The two-step "orthogonal-bioorthogonal" labeling process would increase the utilities of SNAP/CLIP-tags and, as a consequence, would expand the capability of decorating biological specimens with functionalities beyond fluorophores to potentially include spin labels, radioactive tracers, or catalysts.

CuII -Catalyzed Oxidative Formation of 5-Alkynyltriazoles.

In an alcoholic solvent under the catalysis of Cu(OAc)2 ⋅H2 O, organic azide and terminal alkyne could oxidatively couple to afford 5-alkynyl-1,2,3-triazole (alkynyltriazole) at room temperature under an atmosphere of O2 in a few hours. The involvement of 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) is essential, without which the redox neutral coupling instead proceeds to produce 5-H-1,2,3-triazole (protiotriazole) as the major product. Therefore, DBN switches the redox neutral coupling between terminal alkyne and organic azide, the copper-catalyzed "click" reaction to afford protiotriazole, to an oxidation reaction that results in alkynyltriazole. The organic base DBN is effective in accelerating the copper(II)-catalyzed oxidation of terminal alkyne or copper(I) acetylide, which is intercepted by an organic azide to produce alkynyltriazole. The proposed mechanistic model suggests that the selectivity between alkynyl- and protiotriazole, and other acetylide or triazolide oxidation products is determined by the competition between copper(I)-catalyzed redox neutral cycloaddition and copper(II)/O2 -mediated acetylide oxidation after the formation of copper(I) acetylide.

A ten-year review of the literature on the use of standardized patients in teaching and learning: 1996-2005.

BACKGROUND: Although there is a growing body of literature on the educational use of standardized patients (SP) in teaching and learning, there have been no reviews on their value. OBJECTIVE: To determine whether the educational use of SPs has an effect on the knowledge, skills, and behaviour of learners in the health professions. METHODS: English-language articles covering the period 1996-2005 were reviewed to address the issue of to what extent has the use of SPs affected the knowledge, skills and performance of learners. Out of 797 abstracts, 69 articles, which met the review criteria, were selected. An adaptation of Kirkpatrick's model was used to classify and analyse the articles. RESULTS: Most of the learners were students in medicine and nursing. SPs were used mostly to teach communication skills and clinical skills. The study designs were case-control (29%), pre-test/post-test (24.6%), post-test only (26.1%) and qualitative studies (20.3%). METHODOLOGICAL ISSUES: Most of the studies had weak research designs. More rigorous designs with control or comparison groups should be used in future research. CONCLUSIONS: Most studies reported that the educational use of SPs was valuable. More rigorous studies would support the evidence-based use of SPs in teaching and learning.

Gender and ethnic differences in chronic myelogenous leukemia prognosis and treatment response: a single-institution retrospective study.

BACKGROUND: In the last decade the importance of ethnicity, socio-economic and gender differences in relation to disease incidence, diagnosis, and prognosis has been realized. Differences in these areas have become a major health policy focus in the United States. Our study was undertaken to examine the demographic and clinical features of chronic myelogenous leukemia (CML) patients presenting initially at the LAC+USC Medical Center, which serves an ethnically diverse population. RESULTS: Patients were evenly split by gender, overwhelmingly Hispanic (60.9%), and quite young (median age 39, range 17-65) compared with previously reported CML patient populations. Previous CML studies identified significant anemia (Hgb <12 g/dl), significant thrombocytosis (platelets >450 x 109/l), and significant leukocytosis (WBC >50 x 109/l) as significant adverse pretreatment prognostic factors. Using these indicators, in addition to the validated Hasford and Sokal scores, patients were stratified and analyzed via gender and ethnicity. A significantly greater proportion of women presented with significant anemia (p = 0.019, Fisher's exact test) and significant thrombocytosis (p = 0.041, Fisher's exact test) compared to men, although no differences were found in risk stratification or treatment response. MCV values for women were significantly (p = 0.02, 2-sample t-test) lower than those for men, suggesting iron deficiency anemia. Focusing on ethnicity, Hispanics as a whole had significantly lower Hasford risk stratification (p = 0.046, Fisher's exact test), and significantly greater likelihood (p = 0.016, Fisher's exact test) of achieving 3-month complete haematological remission (CHR) compared with non-Hispanics at LAC+USC Medical Center, though differences in treatment outcome were no longer significant with analysis limited to patients treated with first-line imatinib. CONCLUSION: Female CML patients at LAC+USC Medical Center present with more significant adverse pre-treatment prognostic factors compared to men, but achieve comparable outcomes. Hispanic patients present with lower risk profile CML and achieve better treatment responses compared to non-Hispanic patients as a whole; these ethnic differences are no longer significant when statistical analysis is limited to patients given imatinib as first-line therapy. Our patients achieve response rates inferior to those of large-scale national studies. This constellation of findings has not been reported in previous studies, and is likely reflective of a unique patient population.