title: Determination of Optimal Sample Size for Quantification of β-Cell Area, Amyloid Area and β-Cell Apoptosis in Isolated Islets.
abstract: Culture of isolated rodent islets is widely used in diabetes research to assess different endpoints, including outcomes requiring histochemical staining. As islet yields during isolation are limited, we determined the number of islets required to obtain reliable data by histology. We found that mean values for insulin-positive β-cell area/islet area, thioflavin S-positive amyloid area/islet area and β-cell apoptosis do not vary markedly when more than 30 islets are examined. Measurement variability declines as more islets are quantified, so that the variability of the coefficient of variation (CV) in human islet amyloid polypeptide (hIAPP) transgenic islets for β-cell area/islet area, amyloid area/islet area and β-cell apoptosis are 13.20% ± 1.52%, 10.03% ± 1.76% and 6.78% ± 1.53%, respectively (non-transgenic: 7.65% ± 1.17% β-cell area/islet area and 8.93% ± 1.56% β-cell apoptosis). Increasing the number of islets beyond 30 had marginal effects on the CV. Using 30 islets, 6 hIAPP-transgenic preparations are required to detect treatment effects of 14% for β-cell area/islet area, 30% for amyloid area/islet area and 23% for β-cell apoptosis (non-transgenic: 9% for β-cell area/islet area and 45% for β-cell apoptosis). This information will be of value in the design of studies using isolated islets to examine β cells and islet amyloid.
authors.affiliation: Division of Metabolism, Endocrinology and Nutrition, VA Puget Sound Health Care System and University of Washington, Seattle, Washington (DTM, LE, ATT, MFH, TS, SZ, SEK)
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Meier
authors.affiliation: Division of Metabolism, Endocrinology and Nutrition, VA Puget Sound Health Care System and University of Washington, Seattle, Washington (DTM, LE, ATT, MFH, TS, SZ, SEK)
authors.forename: Leon
authors.initials: L
authors.lastname: Entrup
authors.affiliation: Division of Metabolism, Endocrinology and Nutrition, VA Puget Sound Health Care System and University of Washington, Seattle, Washington (DTM, LE, ATT, MFH, TS, SZ, SEK)
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Templin
authors.affiliation: Division of Metabolism, Endocrinology and Nutrition, VA Puget Sound Health Care System and University of Washington, Seattle, Washington (DTM, LE, ATT, MFH, TS, SZ, SEK)
authors.forename: Meghan F
authors.initials: MF
authors.lastname: Hogan
authors.affiliation: Division of Metabolism, Endocrinology and Nutrition, VA Puget Sound Health Care System and University of Washington, Seattle, Washington (DTM, LE, ATT, MFH, TS, SZ, SEK)
authors.forename: Thanya
authors.initials: T
authors.lastname: Samarasekera
authors.affiliation: Division of Metabolism, Endocrinology and Nutrition, VA Puget Sound Health Care System and University of Washington, Seattle, Washington (DTM, LE, ATT, MFH, TS, SZ, SEK)
authors.forename: Sakeneh
authors.initials: S
authors.lastname: Zraika
authors.affiliation: Seattle Epidemiologic Research and Information Center, VA Puget Sound Health Care System and Division of General Internal Medicine, VA Puget Sound Health Care System and University of Washington, Seattle, Washington (EJB)
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Boyko
authors.affiliation: Division of Metabolism, Endocrinology and Nutrition, VA Puget Sound Health Care System and University of Washington, Seattle, Washington (DTM, LE, ATT, MFH, TS, SZ, SEK)
authors.forename: Steven E
authors.initials: SE
authors.lastname: Kahn
mesh_terms: D000818:Animals; D017209:Apoptosis; D005260:Female; D050417:Insulin-Secreting Cells / Q000166:cytology*; D058228:Islet Amyloid Polypeptide / Q000032:analysis*; D007515:Islets of Langerhans / Q000166:cytology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D018401:Sample Size
chemical_list: D058228:Islet Amyloid Polypeptide
keywords: amyloid; apoptosis; histology; immunohistochemistry; insulin; islet isolation; pancreatic islet; staining; β cell