Fig. 5. Comparison of representative adaptive support ventilation (ASV) (A1 , B1 ) and controlled mechanical ventilation (CMV) (A2 , B2 ) diaphragm-biopsy specimen with respect to fiber size or phenotype. Histologic analysis was performed on six cross-sections from each muscle under a Nikon optiphot-2 microscope (Nikon Instruments Europe, B.V. Amstelveen, The Netherlands). (A ) Hematoxylin and eosin coloration shows that neither inflammatory infiltrate nor necrosis is present in the CMV and ASV group. (B ) To assess for the slow- and fast-twitch fiber type cross-sectional area (CSA) and relative fiber percentages, immunochemistry was assessed on 10-μm unfixed serial transverse cryostat sections. Two adjacent sections were incubated in 1% bovine serum albumin with the primary antibody 1 h for mouse anti–slow myosin heavy chain. The myosin heavy chains that react with the chosen antibody on each section appeared orange, whereas the dystrophin at the membrane appeared green. Schematic representation (on images ×400) of each muscle section was analyzed by Histolab program (version 5-13-1; Microvision Instrument, Evry, France; license number: 2497), and data were averaged per approximately 500 muscle fibers from each dissected diaphragm of both the CMV and ASV groups. (C ) Both the slow- and the fast-twitch fibers in the CMV group are statistically smaller than those in the ASV group. (D ) Fiber proportion (%) was not different between the CMV and ASV group. NS = not significant.