Maturation and Function of the Intercalated Disc: Report of Two Pediatric Cases Focusing on Cardiac Development and Myocardial Hyperplasia

Figures

• 

  Figure 1. Hyperplasia and cardiomyocyte proliferation in pediatric patient tissues. (A) Immunohistochemical labeling of cardiomyocytes (α-actinin), proliferating cells (Ki67), and nuclei (DAPI), at 40×. (B) Comparison of two pediatric patients (patient S, 4 weeks postnatal; patient T, 6 weeks postnatal) to age-matched (control R, 5 weeks postnatal) and histology-matched (control Q, 39 weeks in utero) controls showed increased nuclei count and proliferation-positive nuclei (white arrows). CM—Cardiomyocyte. A total of 6–8 images were analyzed based on 4 independent tissue slice stainings per individual. The scale bar represents 50 µM.

• 

  Figure 2. Immature intercalated disc maturation in pediatric patient tissues. Immunohistochemical labeling of cardiomyocytes (α-actinin), N-cadherin (N-CAD), and nuclei (DAPI) at 60×. Comparison of two pediatric patients (patient S, 4 weeks postnatal; patient T, 6 weeks postnatal) to age-matched (control R, 5 weeks postnatal) and histology-matched (control Q, 39 weeks in utero) controls showed increased diffuse and lateral expression of the intercalated disc (white arrows). A total of 6–8 images were captured based on 4 independent tissue slice stainings per individual; representative images are shown. The scale bar represents 50 µM.

• 

  Figure 3. Limited fibrosis formation in pediatric patient tissues. (A) Masson’s trichrome staining of myocardial tissues. (B) A quantitative comparison of two pediatric patients (patient S, 4 weeks postnatal; patient T, 6 weeks postnatal) to age-matched (control R, 5 weeks postnatal) and histology-matched (control Q, 39 weeks in utero) controls did not show overt collagen deposition (depicted in blue). A total of 3–4 images were captured based on 2 independent tissue slice stainings per individual; representative images are shown. The scale bar represents 100 µM.