Lung transplantation with lungs procured from donors after circulatory death (DCD) has been established as an alternative technique to traditional donation after brain death (DBD) with comparable outcomes. Recently, in situ thoracoabdominal normothermic regional perfusion (TA‐NRP) has emerged as a novel technique employed in the procurement of cardiac allografts after circulatory death. TA‐NRP, in contrast to ex situ machine perfusion, has the advantage of allowing in situ assessment of donor organs prior to final acceptance. However, there are some concerns that this technique may adversely impact the quality of lung allografts. Here, we present a case of a successful bilateral sequential lung transplantation in a patient with postinflammatory pulmonary fibrosis due to acute respiratory distress syndrome (ARDS), with lungs procured after normothermic in situ lung perfusion. Apart from the lungs, heart, liver, and kidneys were also successfully transplanted from this donor.
COVID-19, the syndrome caused by the novel coronavirus SARS-CoV-2, has spread throughout the world, causing the death of at least three million people. For the over 81 million who have recovered, however, the long-term effects are only beginning to manifest. We performed a bilateral lung transplant on a 31-year-old male patient for chronic hypoxic respiratory failure, severe pulmonary hypertension and radiographically identified pulmonary fibrosis five months after an acute COVID-19 infection. The explant demonstrated moderate pulmonary vascular remodeling with intimal thickening and medial hypertrophy throughout, consistent with pulmonary hypertension. The parenchyma demonstrated an organizing lung injury in the proliferative phase, with severe fibrosis, histiocytic proliferation, type II pneumocyte hyperplasia, and alveolar loss consistent with known COVID-19 pneumonia complications. This report highlights a novel histologic finding in severe, chronic COVID-19. Although the findings in acute COVID-19 pneumonia have been well-examined at autopsy, the chronic course of this complex disease is not yet understood. The case presented herein suggests that COVID-induced pulmonary hypertension may become more common as more patients survive severe SARS-CoV-2-related pneumonia. Pulmonologists and pulmonary pathologists should be aware of this possible association and look for the clinical, radiographic, and histologic criteria in the appropriate clinical setting.
Cytoplasmic NADP+-isocitrate dehydrogenase (NADP+-IDH) has been purified and characterized, and its gene sequenced in many animal, plant, and yeast species. However, much less information is available on this enzyme-gene in insects. As a first step in investigating the biochemical and molecular mechanisms by which NADP+-IDH contributes to adaptations for flight vs. reproduction in insects, the enzyme was purified to homogeneity in the wing-dimorphic cricket, Gryllus firmus, characterized, and its corresponding gene sequenced. Using a combination of polyethylene glycol precipitation, Cibacron-Blue affinity chromatography, and hydrophobic interaction chromatography the enzyme was purified 291-fold (7% yield; specific activity = 15.8 µmol NADPH/min/mg protein). The purified enzyme exhibited a single band on SDS PAGE (46.3 kD), but consisted of two N-terminal amino acid sequences that differed in the first two amino acids. Purified enzyme exhibited standard Michaelis-Menten kinetics at pH 8.0 and 28° C (KM(NADP+) = 2.3 ± 0.4 µM; KM(Na+-Isocitrate) = 14.7 + 1.8 µM). Subunit molecular mass and KMS were similar to published values for NADP+-IDHs from a variety of vertebrate and two insect species. PCR amplification of an internal sequence using genomic DNA followed by 3′ and 5′ RACE yielded a nucleotide sequence of the mature protein and translated amino-acid sequences that exhibited high similarity (40–50% and 70–80%, respectively) to sequences from insect and vertebrate NADP+-IDHs. Two potential ATG start codons were identified. Both Nterminal amino-acid sequences matched the nucleotide sequence, consistent with both enzyme forms being transcribed from the same gene, although these variants could also be encoded by different genes. Bioinformatic analyses and differential centrifugation indicated that the majority, if not all, of the enzyme is cytoplasmic. The enzyme exhibited high specific activity in fat body, head and gut, and a single band on native PAGE.
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