Figure 5.

Electron microscopic analysis of hearts obtained from HIV-infected individuals shows that areas with compromised connexin 43 (Cx43) localization and calcium metabolism have extensive mitochondrial proliferation and decreased myofibril width. Areas with normal and increased Cx43 expression were identified and subjected to electron microscopy analysis. A and B: Representative sections from an HIV⁻ heart. Black lines with circles indicate myofibril width. C and D: Representative sections from an HIV⁺ heart showing mitochondrial proliferation (arrows) and a decrease in myofibril width (black lines with circles). E: Quantification of mitochondrial numbers in heart tissue showing a significant increase in HIV⁺ tissues. F: Quantification of myofibril width in heart tissues obtained from uninfected and HIV-infected individuals. There are no statistically significant differences between uninfected and HIV-infected individuals in myofibril width. However, analysis of tissues obtained from HIV-infected individuals indicates the presence of two distinct populations of myofibrils, one with normal width and a compromised one that is significantly different that that uninfected individual. Data are expressed as means ± SD. n = 5 grids per patient from five different individuals were analyzed (F). P = 0.01, HIV small myofibers compared with uninfected conditions (F). Scale bar = 1.9 μm.