E/e' Ratio and Diastolic Function Between Deep Vein Catheterization and Internal Fistula Treatment in Patients with Chronic Kidney Disease.

Objective: To examine the relationship between diastolic function and the ratio of early diastolic mitral inflow to early diastolic mitral annular velocity (E/e') in patients with chronic renal disease who had deep vein catheterization and internal fistula. Methods: The clinical data of 50 uremia patients treated at The Affiliated Dongyang Hospital of Wenzhou Medical University from January 2020 to January 2022 were retrospectively analyzed. To assess the differences in E/e' ratio and patients' diastolic function between the two groups, they were split into two teams according to the various therapy modalities: the internal fistula team (n = 42) and the deep vein catheterization team (n = 8). Results: After treatment, the left ventricular end-diastolic diameter (LVd), E peak, a peak and E/A value, the volume and area of four chambers of the left ventricle (LV), the volume and area of two chambers of LV in both groups were significantly lower than those before treatment (P < .001). After treatment, the LVd left ventricular end-systolic diameter (LVs), the four-chamber volume of LV, and the two-chamber volume and area of LV in patients with internal fistula were significantly lower than those in patients with deep vein catheterization (P < .001). After treatment, E peak, A peak and E/A value, e' interventricular septum, E/e' value of interventricular septum, e' lateral wall, and E of lateral wall in patients with internal fistula group. Conclusion: Both deep vein catheterization and internal fistula treatment can improve the diastolic function and reduce the pulmonary pressure of uremic patients to a certain extent, but internal fistula treatment is better than deep vein catheterization in reducing LVd, LVs, LV four-chamber volume, LV two-chamber volume and area, and the effects of both in improving the E/e ratio of patients are not obvious.

Metabolomics analysis of urine from rats administered with long-term, low-dose acrylamide by ultra-performance liquid chromatography-mass spectrometry.

1. To study the toxic effect of chronic exposure to acrylamide (AA) at low-dose levels, we applied metabolomics approach based on ultra-performance liquid chromatography/mass spectrometry (UPLC-MS). A total of 40 male Wistar rats were randomly assigned to different groups: control, low-dose AA (0.2 mg/kg.bw), middle-dose AA (1 mg/kg.bw) and high-dose AA (5 mg/kg.bw). The rats continuously received AA via drinking water for 16 weeks. Rat urine samples were collected at different time points for measurement of metabolomic profiles. 2. Thirteen metabolites, including the biomarkers of AA exposure (AAMA, GAMA and iso-GAMA), were identified from the metabolomic profiles of rat urine. Compared with the control group, the treated groups showed significantly increased intensities of GAMA, AAMA, iso-GAMA, vinylacetylglycine, 1-salicylate glucuronide, PE (20:1(11Z)/14:0), cysteic acid, L-cysteine, p-cresol sulfate and 7-ketodeoxycholic acid, as well as decreased intensities of 3-acetamidobutanal, 2-indolecarboxylic acid and kynurenic acid in rat urine. Notably, three new candidate biomarkers (p-cresol sulfate, 7-ketodeoxycholic acid and 1-salicylate glucuronide) in rat urine exposed to AA have been found in this study. 3. The results indicate exposure to AA disrupts the metabolism of lipids and amino acids, induces oxidative stress.

Secondary NAD+ deficiency in the inherited defect of glutamine synthetase.

Glutamine synthetase (GS) deficiency is an ultra-rare inborn error of amino acid metabolism that has been described in only three patients so far. The disease is characterized by neonatal onset of severe encephalopathy, low levels of glutamine in blood and cerebrospinal fluid, chronic moderate hyperammonemia, and an overall poor prognosis in the absence of an effective treatment. Recently, enteral glutamine supplementation was shown to be a safe and effective therapy for this disease but there are no data available on the long-term effects of this intervention. The amino acid glutamine, severely lacking in this disorder, is central to many metabolic pathways in the human organism and is involved in the synthesis of nicotinamide adenine dinucleotide (NAD(+)) starting from tryptophan or niacin as nicotinate, but not nicotinamide. Using fibroblasts, leukocytes, and immortalized peripheral blood stem cells (PBSC) from a patient carrying a GLUL gene point mutation associated with impaired GS activity, we tested whether glutamine deficiency in this patient results in NAD(+) depletion and whether it can be rescued by supplementation with glutamine, nicotinamide or nicotinate. The present study shows that congenital GS deficiency is associated with NAD(+) depletion in fibroblasts, leukocytes and PBSC, which may contribute to the severe clinical phenotype of the disease. Furthermore, it shows that NAD(+) depletion can be rescued by nicotinamide supplementation in fibroblasts and leukocytes, which may open up potential therapeutic options for the treatment of this disorder.

Fatal hyperammonemia and carbamoyl phosphate synthetase 1 (CPS1) deficiency following high-dose chemotherapy and autologous hematopoietic stem cell transplantation.

Fatal hyperammonemia secondary to chemotherapy for hematological malignancies or following bone marrow transplantation has been described in few patients so far. In these, the pathogenesis of hyperammonemia remained unclear and was suggested to be multifactorial. We observed severe hyperammonemia (maximum 475 µmol/L) in a 2-year-old male patient, who underwent high-dose chemotherapy with carboplatin, etoposide and melphalan, and autologous hematopoietic stem cell transplantation for a neuroblastoma stage IV. Despite intensive care treatment, hyperammonemia persisted and the patient died due to cerebral edema. The biochemical profile with elevations of ammonia and glutamine (maximum 1757 µmol/L) suggested urea cycle dysfunction. In liver homogenates, enzymatic activity and protein expression of the urea cycle enzyme carbamoyl phosphate synthetase 1 (CPS1) were virtually absent. However, no mutation was found in CPS1 cDNA from liver and CPS1 mRNA expression was only slightly decreased. We therefore hypothesized that the acute onset of hyperammonemia was due to an acquired, chemotherapy-induced (posttranscriptional) CPS1 deficiency. This was further supported by in vitro experiments in HepG2 cells treated with carboplatin and etoposide showing a dose-dependent decrease in CPS1 protein expression. Due to severe hyperlactatemia, we analysed oxidative phosphorylation complexes in liver tissue and found reduced activities of complexes I and V, which suggested a more general mitochondrial dysfunction. This study adds to the understanding of chemotherapy-induced hyperammonemia as drug-induced CPS1 deficiency is suggested. Moreover, we highlight the need for urgent diagnostic and therapeutic strategies addressing a possible secondary urea cycle failure in future patients with hyperammonemia during chemotherapy and stem cell transplantation.