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.

Ex Input:
CONTEXT Gastroesophageal reflux (GER) has not previously been widely regarded as a hereditary disease. A few reports have suggested, however, that a genetic component may contribute to the incidence of GER, especially in its severe or chronic forms.
OBJECTIVE To identify a genetic locus that cosegregates with a severe pediatric GER phenotype in families with multiple affected members.
DESIGN A genome-wide scan of families affected by severe pediatric GER using polymorphic microsatellite markers spaced at an average of 8 centimorgans (cM), followed by haplotyping and by pairwise and multipoint linkage analyses.
SETTING General US community, with research performed in a university tertiary care hospital. SUBJECTS Affected and unaffected family members from 5 families having multiple individuals affected by severe pediatric GER, identified through a patient support group.
MAIN OUTCOME MEASURES Determination of inheritance patterns and linkage of a genetic locus with the severe pediatric GER phenotype by logarithm-of-odds (lod) score analysis, considering a lod score of 3 or greater as evidence of linkage.
RESULTS In these families, severe pediatric GER followed an autosomal dominant hereditary pattern with high penetrance. A gene for severe pediatric GER was mapped to a 13-cM region on chromosome 13q between microsatellite markers D13S171 and D13S263. A maximum multifamily 2-point lod score of 5.58 and a maximum multifamily multipoint lod score of 7.15 were obtained for marker D13S1253 at map position 35 cM when presumptively affected persons were modeled as unknown (a maximum multipoint score of 4.88 was obtained when presumptively affected persons were modeled as unaffected).
CONCLUSION These data suggest that a gene for severe pediatric GER maps to chromosome 13q14. JAMA. 2000;284:325-334

Ex Output:
Mapping of a gene for severe pediatric gastroesophageal reflux to chromosome 13q14.

Ex Input:
To explore the structural basis of alternative splicing, we have analyzed the splicing of pre-mRNAs containing an optional exon, E4, from the preprotachykinin gene. This gene encodes substance P and related tachykinin peptides by alternative splicing of a common pre-mRNA. We have shown that alternative splicing of preprotachykinin pre-mRNA occurs by preferential skipping of optional E4. The competing mechanism that incorporates E4 into the final spliced RNA is constrained by an initial block to splicing of the immediate upstream intervening sequence (IVS), IVS3. This block is relieved by sequential splicing, in which the immediate downstream IVS4 is removed first. The structural change resulting from the first splicing event is directly responsible for activation of IVS3 splicing. This structural rearrangement replaces IVS4 sequences with E5 and its adjacent IVS5 sequences. To determine how this structural change promoted IVS3 splicing, we asked what structural change(s) would restore activity of IVS3 splicing-defective mutants. The most significant effect was observed by a 2-nucleotide substitution that converted the 5' splice site of E4 to an exact consensus match, GUAAGU. Exon 5 sequences alone were found not to promote splicing when present in one or multiple copies. However, when a 15-nucleotide segment of IVS5 containing GUAAGU was inserted into a splicing-defective mutant just downstream of the hybrid exon segment E4E5, splicing activity was recovered. Curiously, the 72-nucleotide L2 exon of adenovirus, without its associated 5' splice site, activates splicing when juxtaposed to E4. Models for the activation of splicing by an RNA structural change are discussed.

Ex Output:
A Sequential splicing mechanism promotes selection of an optimal exon by repositioning a downstream 5' splice site in preprotachykinin pre-mRNA.

Ex Input:
BACKGROUND Recent studies indicate the presence of a small, stem-like cell population in several human cancers that is crucial for the tumour (re)population.
OBJECTIVE Six established prostate cancer (PCa) cell lines-DU145, DuCaP, LAPC-4, 22Rv1, LNCaP, and PC-3-were examined for their stem cell properties in vitro.
DESIGN, SETTINGS, AND PARTICIPANTS The colony-forming efficiency and self-renewal ability of morphologically distinguishable holoclones and paraclones were tested with low-density plating and serial passaging. Expression of the putative stem cell marker CD133 and breast cancer resistance protein (BCRP) was examined with flow cytometry, and immunohistochemical stainings were made for CD133, alpha2-integrin, nestin, BCRP, cytokeratin 5 (CK5), and cytokeratin 18 (CK18).
RESULTS AND LIMITATIONS Five out of six cell lines formed clear holo-, mero-, and paraclones. Unlike paraclones, we can maintain DU145 holoclones in culture for several passages, which is indicative of self-renewal ability. Using fluorescence-activated cell sorting (FACS) analysis only in DU145 cells, a small fraction (0.01%) of CD133(+) cells was detected. CD133(+) cells; however, like DU145 BCRP(+) (0.15%) cells, they were not more clonogenic, and they did not show more holoclone formation than the marker-negative cells or unselected cells. Immunohistochemistry revealed alpha2-integrin and BCRP as potential stem cell markers and CK5 with the combination of CK18 to distinguish transient amplifying cells.
CONCLUSIONS These results indicate the possible presence of stem-like cells in several established PCa cell lines. CD133 selection does not enrich for stem-like cells in PCa cell lines.

Ex Output:
Stem cell characteristics in prostate cancer cell lines.