Low Hemoglobin Level Is Associated with the Development of Delirium after Hepatectomy for Hepatocellular Carcinoma Patients

Background

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide and liver resection is the only potential curative treatment option for those patients. Postoperative complications specific to elderly surgical patients such as delirium will be increasingly relevant in the coming decades. Herein, we aimed to investigate the risk factors for postoperative delirium in patients who have received hepatectomy for HCC.

Methods

This is a single medical center observational study and the study subjects comprised 401 individuals who underwent liver resection for hepatocellular carcinoma during January 2009 to October 2013. Multivariate analysis was used to examine whether preoperative, intra-operative, or postoperative variables were associated with the development of delirium.

Results

Of the 401 patients who underwent hepatectomy, 34 developed postoperative delirium (8.4%). In the majority of those patients, symptoms and signs of the syndrome occurred on postoperative day 2 and the mean duration of symptoms was 3.61 ± 3.71 days. Multivariate analysis revealed that advanced age (>71 years) [odds ratio (OR) = 1.133, 95% confidence interval (CI): 1.071–1.200, p<0.001], prolonged operative time (>190 minutes) (OR = 1.009, 95% CI: 1.000–1.017, p = 0.038), a decreased postoperative hemoglobin level (< 10.16 g/dL) (OR = 0.777, 95% CI: 0.613–0.983, p = 0.036), and history of hypnotic drug use (OR = 3.074, 95% CI: 1.045–9.039, p = 0.041) were independent risk factors for the development of postoperative delirium after hepatectomy.

Conclusions

Although the mechanism of postoperative delirium is not well understood, numbers of studies have shown that patients with postoperative delirium tend to have prolonged hospital stay, worse postoperative outcome and an increased risk of short- and long-term mortality. In this study, we found that advanced age, prolonged operative time, postoperative low hemoglobin level and history of hypnotic drug use are independent risk factors for postoperative delirium.     

Alpha-Synuclein Induces Lysosomal Rupture and Cathepsin Dependent Reactive Oxygen Species Following Endocytosis

α-synuclein dysregulation is a critical aspect of Parkinson''s disease pathology. Recent studies have observed that α-synuclein aggregates are cytotoxic to cells in culture and that this toxicity can be spread between cells. However, the molecular mechanisms governing this cytotoxicity and spread are poorly characterized. Recent studies of viruses and bacteria, which achieve their cytoplasmic entry by rupturing intracellular vesicles, have utilized the redistribution of galectin proteins as a tool to measure vesicle rupture by these organisms. Using this approach, we demonstrate that α-synuclein aggregates can induce the rupture of lysosomes following their endocytosis in neuronal cell lines. This rupture can be induced by the addition of α-synuclein aggregates directly into cells as well as by cell-to-cell transfer of α-synuclein. We also observe that lysosomal rupture by α-synuclein induces a cathepsin B dependent increase in reactive oxygen species (ROS) in target cells. Finally, we observe that α-synuclein aggregates can induce inflammasome activation in THP-1 cells. Lysosomal rupture is known to induce mitochondrial dysfunction and inflammation, both of which are well established aspects of Parkinson''s disease, thus connecting these aspects of Parkinson''s disease to the propagation of α-synuclein pathology in cells.     

Exploring the low-pressure growth limit: evolution of Bacillus subtilis in the laboratory to enhanced growth at 5 kilopascals

Growth of Bacillus subtilis cells, normally adapted at Earth-normal atmospheric pressure (～101.3 kPa), was progressively inhibited by lowering of pressure in liquid LB medium until growth essentially ceased at 2.5 kPa. Growth inhibition was immediately reversible upon return to 101.3 kPa, albeit at a slower rate. A population of B. subtilis cells was cultivated at the near-inhibitory pressure of 5 kPa for 1,000 generations, where a stepwise increase in growth was observed, as measured by the turbidity of 24-h cultures. An isolate from the 1,000-generation population was obtained that showed an increase in fitness at 5 kPa when compared to the ancestral strain or a strain obtained from a parallel population that evolved for 1,000 generations at 101.3 kPa. The results from this preliminary study have implications for understanding the ability of terrestrial microbes to grow in low-pressure environments such as Mars.     

The nonhomologous DNA end joining pathway is important for chromosome stability in primary fibroblasts

There are two types of chromosome instability, structural and numerical, and these are important in cancer. Many structural abnormalities are likely to involve double-strand DNA (dsDNA) breaks. Nonhomologous DNA end joining (NHEJ) and homologous recombination are the major pathways for repairing dsDNA breaks. NHEJ is the primary pathway for repairing dsDNA breaks throughout the G0, G1 and early S phases of the cell cycle [1]. Ku86 and DNA ligase IV are two major proteins in the NHEJ pathway. We examined primary dermal fibroblasts from mice (wild type, Ku86(+/-), Ku86(-/-), and DNA ligase IV(+/-)) for chromosome breaks. Fibroblasts from Ku86(+/-) or DNA ligase IV(+/-) mice have elevated frequencies of chromosome breaks compared with those from wild-type mice. Fibroblasts from Ku86(-/-) mice have even higher levels of chromosome breaks. Primary pre-B cells from the same animals did not show significant accumulation of chromosome breaks. Rather the pre-B cells showed increased cell death. These studies demonstrate that chromosome breaks arise frequently and that NHEJ is required to repair this constant spontaneous damage.