TASK DEFINITION: In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
PROBLEM: Context: Although the C5 variant of cholinesterase is known to be a cause of hypercholinesterasemia, the pathophysiological significance of the C5 variant and the C5 variant-related hypercholinesterasemia in cardiovascular diseases remain unclear. The present study aimed to clarify the pathophysiological significance of the C5 variant as a risk or protective factor for coronary artery disease (CAD) in patients with severe hypercholinesterasemia.', 'Severe hypercholinesterasemia was defined as serum cholinesterase (ChE) activity >= 450 IU/L (>= 2.0 SD). We screened 11,648 consecutive outpatients between 2005 and 2011 at Toho University, Sakura Medical Center. In patients with severe hypercholinesterasemia, phenotyping of the C5 variant was conducted using polyacrylamide gel electrophoresis and alpha-naphthyl butyrate staining.', '157 subjects (1.4% of 11,648 outpatients screened) were diagnosed with severe hypercholinesterasemia (mean serum ChE activity 574 109 IU/L), and the frequency of the C5 variant was 45.2%. Subjects with the C5 variant had higher age, lower body mass index, milder dyslipidemia and liver dysfunction, and lower rates of hypertension and CAD compared with subjects without the C5 variant. Multivariate logistic regression model demonstrated that the presence of C5 variant independently lowered the risk of CAD, with odds ratio 0.071 (95% confidence interval (CI) 0.007 - 0.763, p = 0.029).\Question: Is c5 variant associated with decreased risk of coronary artery disease in outpatients with severe hypercholinesterasemia?

SOLUTION: The prevalence of the C5 variant was relatively high, and the C5 variant is associated with decreased risk of CAD in outpatients with severe hypercholinesterasemia.

PROBLEM: Context: Human breast tumors are heterogeneous and consist of phenotypically diverse cells. Breast cancer cells with a CD44+/CD24- phenotype have been suggested to have tumor-initiating properties with stem cell-like and invasive features, although it is unclear whether their presence within a tumor has clinical implications. There is also a large heterogeneity between tumors, illustrated by reproducible stratification into various subtypes based on gene expression profiles or histopathological features. We have explored the prevalence of cells with different CD44/CD24 phenotypes within breast cancer subtypes.', 'Double-staining immunohistochemistry was used to quantify CD44 and CD24 expression in 240 human breast tumors for which information on other tumor markers and clinical characteristics was available. Gene expression data were also accessible for a cohort of the material.', 'A considerable heterogeneity in CD44 and CD24 expression was seen both between and within tumors. A complete lack of both proteins was evident in 35% of the tumors, while 13% contained cells of more than one of the CD44+/CD24-, CD44-/CD24+ and CD44+/CD24+ phenotypes. CD44+/CD24- cells were detected in 31% of the tumors, ranging in proportion from only a few to close to 100% of tumor cells. The CD44+/CD24- phenotype was most common in the basal-like subgroup--characterized as negative for the estrogen and progesterone receptors as well as for HER2, and as positive for cytokeratin 5/14 and/or epidermal growth factor receptor, and particularly common in BRCA1 hereditary tumors, of which 94% contained CD44+/CD24- cells. The CD44+/CD24- phenotype was surprisingly scarce in HER2+ tumors, which had a predominantly CD24+ status. A CD44+/CD24- gene expression signature was generated, which included CD44 and alpha6-integrin (CD49f) among the top-ranked overexpressed genes.\Question: Does the CD44+/CD24- phenotype is enriched in basal-like breast tumors?

SOLUTION: We demonstrate an association between basal-like and particularly BRCA1 hereditary breast cancer and the presence of CD44+/CD24- cells. Not all basal-like tumors and very few HER2+ tumors, however, contain CD44+/CD24- cells, emphasizing that a putative tumorigenic ability may not be confined to cells of this phenotype and that other breast cancer stem cell markers remain to be identified.

PROBLEM: Context: We aimed at analyzing the frequency, clinical characteristics, and trends associated with the occurrence of diabetic ketoacidosis (DKA) at the onset of type 1 diabetes on the basis of long-term follow-up data.', 'A total of 106 pediatric diabetes centers in Germany and Austria participated in this study. Data from 14,664 patients with type 1 diabetes collected between 1995 and 2007 were suitable for evaluation. DKA was defined and classified according to the International Society for Pediatric and Adolescent Diabetes consensus guidelines.', 'DKA was observed in 21.1% of patients. The frequency of DKA, including the severe form, remained unchanged throughout the 13-year observation period. The frequency of DKA was particularly striking among children <5 years of age (26.5%).\Question: Is ketoacidosis at diabetes onset still frequent in children and adolescents : a multicenter analysis of 14,664 patients from 106 institutions?

SOLUTION:
Ketoacidosis occurring at diabetes onset continues to be a difficult problem. Our data show no significant change in the frequency and magnitude of DKA over the last 13 years.