TASK DEFINITION: In this task, you are given an abstract of article. Your task is to generate title for this article. Preferred titles are under thirty words.
PROBLEM: The cholesterol side-chain cleavage enzyme, cytochrome P450scc, initiates the biosynthesis of all steroid hormones. Adrenal and gonadal strategies for P450scc gene transcription are essentially identical and depend on the orphan nuclear receptor steroidogenic factor-1, but the placental strategy for transcription of P450scc employs cis-acting elements different from those used in the adrenal strategy and is independent of steroidogenic factor-1. Because placental expression of P450scc is required for human pregnancy, we sought factors that bind to the -155/-131 region of the human P450scc promoter, which participates in its placental but not adrenal or gonadal transcription. A yeast one-hybrid screen of 2.4 x 10(6) cDNA clones from human placental JEG-3 cells yielded two unique clones; one is the previously described transcription factor LBP-1b, which is induced by HIV, type I infection of lymphocytes, and the other is a new factor, termed LBP-9, that shares 83% amino acid sequence identity with LBP-1b. When expressed in transfected yeast, both factors bound specifically to the -155/-131 DNA; antisera to LBP proteins supershifted the LBP-9.DNA complex and inhibited formation of the LBP-1b. DNA complex. Reverse transcriptase-polymerase chain reaction detected LBP-1b in human placental JEG-3, adrenal NCI-H295A, liver HepG2, cervical HeLa, and monkey kidney COS-1 cells, but LBP-9 was detected only in JEG-3 cells. When the -155/-131 fragment was linked to a minimal promoter, co-expression of LBP-1b increased transcription 21-fold in a dose-dependent fashion, but addition of LBP-9 suppressed the stimulatory effect of LBP-1b. The roles of LBP transcription factors in normal human physiology have been unclear. Their modulation of placental but not adrenal P450scc transcription underscores the distinctiveness of placental strategies for steroidogenic enzyme gene transcription.

SOLUTION: Cloning of factors related to HIV-inducible LBP proteins that regulate steroidogenic factor-1-independent human placental transcription of the cholesterol side-chain cleavage enzyme, P450scc.

PROBLEM: The Expanded Program on Immunization (EPI) is using a simplified cluster sampling method, based on the random selection of 210 children in 30 clusters of 7 children each, to estimate immunization coverage levels. This article analyzes the results of this method in actual and computer simulated surveys. Results from 60 actual surveys conducted in 25 countries were available for analysis, for a total of 446 sample estimations of immunization coverage. 83% of the sample results had 95% confidence limits within + or - 10%, and none of the surveys had 95% confidence limits exceeding + or - 13%. In addition, 12 hypothetical population strata with immunization coverage rates ranging from 10%-99% were established for the purposes of computer simulation, and 10 hypothetical communities were established by allocating to them various proportions of each of the strata. These simulated surveys also supported the validity of the EPI method: over 95% of the results were less than + or - 10% from the actual population mean. The precision of this method, as estimated from the results of both actual and simulated surveys, is considered satisfactory for the requirements of the EPI. Among the actual surveys, the proportion of results whose confidence limits exceeded + or - 10% was greatest (50%) when immunization coverage in the sample was 45%-54%.

SOLUTION: Cluster sampling to assess immunization coverage: a review of experience with a simplified sampling method.

PROBLEM: Heterogeneity within the self-renewal durability of adult hematopoietic stem cells (HSCs) challenges our understanding of the molecular framework underlying HSC function. Gene expression studies have been hampered by the presence of multiple HSC subtypes and contaminating non-HSCs in bulk HSC populations. To gain deeper insight into the gene expression program of murine HSCs, we combined single-cell functional assays with flow cytometric index sorting and single-cell gene expression assays. Through bioinformatic integration of these datasets, we designed an unbiased sorting strategy that separates non-HSCs away from HSCs, and single-cell transplantation experiments using the enriched population were combined with RNA-seq data to identify key molecules that associate with long-term durable self-renewal, producing a single-cell molecular dataset that is linked to functional stem cell activity. Finally, we demonstrated the broader applicability of this approach for linking key molecules with defined cellular functions in another stem cell system.

SOLUTION:
Combined Single-Cell Functional and Gene Expression Analysis Resolves Heterogeneity within Stem Cell Populations