Ultrastructural pathology of the alveolar type II pneumocytes of human donor lungs

Abstract

Alveolar type II pneumocytes (PII) were studied in 12 human donor lungs perfused with modified Euro-Collins solution during single-lung transplantation (SLTx). While one lung was transplanted, the contralateral donor lung (cDL) was fixed at the time of SLTx for examination by electron microscopy, stereology, and microanalysis. Three groups were then formed: group A (n = 7), cDL without contusions, uneventful early postoperative course; group B (n = 3), cDL with conclusions, uneventful early postoperative course; group C (n = 2), cDL without contusions, early postoperative respiratory dysfunction. The major findings were that the presence of contusions had no effect on PII ultrastructure and that intracellular surfactant-storing lamellar bodies of cDL in group C were characterized by a higher volume-to-surface ratio (VsR) and larger area per cell profile than group A. Correlation analysis based on pooled data (groups A and C) showed that ischaemic time had little effect on PII ultrastructure and bore no relationship to postoperative clinical variables. The duration of preoperative donor intubation had a pronounced influence on ultrastructure and postoperative clinical variables. The stereologically estimated amount of intracellular surfactant and mitochondrial VsR were the only ultrastructural parameters that were significantly associated with early postoperative oxygenation. Lamellar bodies were the only ultrastructural components found to have a significant relationship to postoperative intubation time. The ultrastructural integrity of type II pneumocytes of human donor lungs is an important determinant of early respiratory function following clinical lung transplantation.

Poly(inosinic-cytidylic) Acid–Triggered Exacerbation of Experimental Asthma Depends on IL-17A Produced by NK Cells

“…Photomicrographs were recorded by a digital camera (DP-25; Olympus, Tokyo, Japan) attached to a microscope (BX-51; Olympus) at 40-and 100-fold magnification using Olympus cell^A software. For mucus assessment, systematic uniform random samples of lung tissue were taken according to standard methods (17) including the orientator technique (18). The surface area of mucin-containing goblet cells (S gc ) per total surface area of airway epithelial basal membrane (S ep ) and the volume of PASstained epithelial mucin (V mucin ) per S ep were determined using a computer-assisted stereology tool box (newCAST, Visiopharm, Hoersholm, Denmark) (19,20), according to the following formulas: S ge /S ep = + Igc / + Iep and V mucin /S ep = LP 3 (+P mucin /2) 3 + Iep , where + Igc is the sum of intersections of test lines with goblet cells, + Iep is the sum of all intersections of test lines with the epithelial basal membrane, +P mucin is the sum of all points hitting mucin, and LP is the test-line length at final magnification.…”

High-Quality Lung Fixation by Controlled Closed Loop Perfusion for Stereological Analysis in a Large Animal Model

“…The perfusion fixation was performed for 15 min (11)(12)(13)(14)(15)(16)(17)(18)(19)) (median [min-max]), which encompassed a closed loop perfusion time with the fixative solution of 9 min (7)(8)(9)(10)(11). Perfusion pressure (determined as inflow pressure minus a left atrial pressure of 0, i.e., open to atmosphere) was 12.5 mm Hg [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] and subsequently 20 mm Hg (14-33) during perfusion with the fixative.…”

“…Perfusion pressure (determined as inflow pressure minus a left atrial pressure of 0, i.e., open to atmosphere) was 12.5 mm Hg [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] and subsequently 20 mm Hg (14-33) during perfusion with the fixative. Continuous airway pressure applied to the lungs was 12.5 mbar (9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)). An illustration of the pressure tracings from animal 14 during the fixation procedure is given in Figure 3.…”

“…Both routes of fixation have their merits and limitations [7][8][9]. Physical fixation by rapid freezing can be applied for small lung pieces but is not suitable for stereological analysis because the whole lung should be available for systematic uniform random sampling.…”

Bronchial artery revascularization restores peribronchial tissue oxygenation after lung transplantation

“…It has been suggested that bronchial artery revascularization (BAR) can improve graft function from the early post-operative period by mitigating ischemia-reperfusion injury. [3][4][5] We previously demonstrated increased marker enzyme activities for type II pneumocytes and pulmonary endothelium in standard lung transplantation compared with BAR. 6 To date, there is no information with regard to tissue oxygenation of the severed bronchial and lung tissue during and after lung transplantation.…”