A metabolomic endotype of bioenergetic dysfunction predicts mortality in critically ill patients with acute respiratory failure

Acute respiratory failure (ARF) requiring mechanical ventilation, a complicating factor in sepsis and other disorders, is associated with high morbidity and mortality. Despite its severity and prevalence, treatment options are limited. In light of accumulating evidence that mitochondrial abnormalities are common in ARF, here we applied broad spectrum quantitative and semiquantitative metabolomic analyses of serum from ARF patients to detect bioenergetic dysfunction and determine its association with survival. Plasma samples from surviving and non-surviving patients (N = 15/group) were taken at day 1 and day 3 after admission to the medical intensive care unit and, in survivors, at hospital discharge. Significant differences between survivors and non-survivors (ANOVA, 5% FDR) include bioenergetically relevant intermediates of redox cofactors nicotinamide adenine dinucleotide (NAD) and NAD phosphate (NADP), increased acyl-carnitines, bile acids, and decreased acyl-glycerophosphocholines. Many metabolites associated with poor outcomes are substrates of NAD(P)-dependent enzymatic processes, while alterations in NAD cofactors rely on bioavailability of dietary B-vitamins thiamine, riboflavin and pyridoxine. Changes in the efficiency of the nicotinamide-derived cofactors' biosynthetic pathways also associate with alterations in glutathione-dependent drug metabolism characterized by substantial differences observed in the acetaminophen metabolome. Based on these findings, a four-feature model developed with semi-quantitative and quantitative metabolomic results predicted patient outcomes with high accuracy (AUROC = 0.91). Collectively, this metabolomic endotype points to a close association between mitochondrial and bioenergetic dysfunction and mortality in human ARF, thus pointing to new pharmacologic targets to reduce mortality in this condition.

Nonfamilial tumoral calcinosis associated with chronic renal failure and secondary hyperparathyroidism: report of two cases with clinicopathological, immunohistochemical, and electron microscopic findings

The clinical and pathological findings, including those of immunohistochemical and ultrastructural studies, of two cases of tumoral calcinosis-like lesion (TCL) are described. Both cases were associated with chronic renal failure and hyperparathyroidism. One case presented as a rapidly growing 20-cm multiloculated, cystic, calcific gluteal mass on the sacrum, which was not clinically suspected to be related to hyperparathyroidism. The other case presented as a 2.5-cm calcific mass on the right foot that recurred after surgical excision as a 7-cm mass, which was clinically presumed to be related to secondary hyperparathyroidism. Light microscopic and immunohistochemical studies on both cases and ultrastructural studies on one case indicated that the calcifying process involved histiocytes and osteoclast-like giant cells of histiocytic origin lining the cystic cavities. Hydroxyapatite crystal formation and calcification appeared to develop predominantly from intracytoplasmic membrane bound vesicles and also from mitochondria. These findings are similar to those recently reported for familial tumoral calcinosis, which support its having a mechanism of calcification comparable with that of a TCL.

Herpes simplex hepatitis before and after acyclovir treatment. Immunohistochemical and in situ hybridization study

A healthy 20-year-old woman developed herpes simplex virus (HSV) hepatitis. The diagnosis was made by needle biopsy of the liver, and the patient was intravenously treated with acyclovir for 15 consecutive days (total dose, 21 g). The liver biopsy specimen and liver tissue obtained at autopsy were processed for immunoperoxidase staining with rabbit anti-HSV and for DNA-DNA in situ hybridization. The liver biopsy tissue revealed massive necrosis of hepatocytes, which were strongly positive for HSV with both immunoperoxidase and in situ hybridization methods. The liver tissue obtained at autopsy showed regenerative nodules of hepatocytes, surrounded by connective tissue stroma. Within the connective tissue there were completely necrotic hepatocytes, which were positive for HSV with the immunoperoxidase method but almost completely negative with the in situ hybridization method, except for a very few HSV DNA-positive hepatocytic nuclei. It was concluded that immunoperoxidase staining with anti-HSV is a sensitive method with which to detect ongoing and previous HSV infection, whereas the in situ hybridization method is specific for HSV-DNA from viable HSV.