Eiji Okabe

The effect of peritoneal rest in combination therapy of peritoneal dialysis and hemodialysis: using the cultured human peritoneal mesothelial cell model.

The effects of peritoneal rest for 24 h during peritoneal dialysis and hemodialysis combination therapy were investigated using cultured human peritoneal mesothelial cell (HPMC) models. Cell activity was investigated by 3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenylterazolium bromide (MTT) assay after exposing HPMCs to peritoneal dialysis fluids (PDFs) with different pH levels. The following PDFs (50 µl/well) were used for exposure durations of 30 or 240 min: acidic heat-sterilized PDFs (L-H PDF, pH 5.5) and neutral heat-sterilized PDFs (N-H PDF, pH 6.7). Control wells were exposed to M-199 Hanks medium containing 20% fetal bovine serum (FBS) for 30 or 240 min. Supernatants were then aspirated from each well and M-199 culture medium containing 20% FBS (50 µl) was added to each well to rest HPMCs for 24 h before investigation of MTT activity. The activity of HPMCs exposed to L-H PDF for 240 min decreased to ∼20% and 15% when compared with controls (glucose concentrations of 1.36% and 3.86%, respectively; P < 0.01 versus control, Tukey–Kramer test), and to ∼60% and 40% after exposure to N-H PDF for 240 min (glucose: 1.36% and 3.86%; P < 0.01). The activity of HPMCs exposed to L-H PDF for 240 min followed by rest was ∼20% and 4% when compared with controls (glucose: 1.36% and 3.86%; P < 0.01) and was 93% and 96% when compared with controls after exposure to N-H PDF for 240 min followed by rest (glucose: 1.36% and 3.86%). These findings suggest that rest for 24 h after exposure to N-H PDF improves the activity of HPMCs.

Synergistic Cytotoxicity of Acidity and 3,4‐Dideoxyglucosone‐3‐ene Under the Existence of Lactate in Peritoneal Dialysis Fluid

Abstract:  Of the non‐physiological compounds in glucose‐rich peritoneal dialysis fluid, we investigated the synergistic cytotoxicity of acidity and 3,4‐Dideoxyglucosone‐3‐ene(3,4‐DGE) under the existence of lactate using human peritoneal mesothelial cells (HPMC). The effect of pH on cell viability at various levels of pH (5.5, 6.7, 7.15), with or without lactate was examined by adding 1N‐HCl to phosphate buffer solution. We also examined the cytotoxic effects of 3,4‐DGE and pH (5.5, 6.7 or 7.15). Additionally, we compared the cytotoxic effects of 3,4‐DGE and pH (5.5, 6.7 or 7.15) under existence of lactate (40meq/L) or absence of lactate. The cells were exposed to these solutions for 2 or 4 h. Cell viability was determined by MTT (3‐[4, 5‐dimethylthiazol‐2‐yl]‐2, 5‐diphenylterazolium bromide) assay. 3,4‐DGE or acidic solution alone had no significant effects on MTT viability under the absence of lactate. However, acidic solutions containing 3,4‐DGE significantly decreased MTT viability under the existence of lactate. The MTT viability of HPMC was not decreased by 3,4‐DGE or acidity alone under the absence of lactate. However, the combination of acidity and 3,4‐DGE markedly decreased MTT viability under the existence of lactate, strongly suggesting the synergistic cytotoxicity of 3,4‐DGE and acidity under the existence of lactate.

Synergistic cytotoxicity of acidity and glucose degradation products in peritoneal dialysis fluid

Of the nonphysiological compounds in glucose-rich peritoneal dialysate, we investigated the cytotoxicity and synergistic cytotoxicity of acidity and glucose degradation products (GDPs) using human peritoneal mesothelial cells (HPMC). The effect of pH on cell viability was examined by adding 1N HCl to a phosphate-buffered solution (pH ≥ 5.5). We also examined the cytotoxic effects of various GDPs [glyoxal (GO), methylglyoxal (MGO), and 3-deoxyglucosone (3DG), alone or in combination] and pH (5.5 or 6.7). The cells were exposed to these solutions for 2 or 4 h. Cell viability was determined by 3,(4,5-dimethylthiazol-2-yl)2,5-diphenyl-tetrazolium bromide (MTT) assay. Although the MTT viability of HPMC was not decreased by GDP or acidity alone, the combination of acidity and GDP markedly decreased MTT viability, strongly suggesting the synergistic cytotoxicity of GDP and acidity.

Glutathione depletion as a mechanism of 3,4-dideoxyglucosone-3-ene-induced cytotoxicity in human peritoneal mesothelial cells: role in biocompatibility of peritoneal dialysis fluids

BACKGROUND The potential detrimental effects of glucose degradation products (GDPs) contained in peritoneal dialysis fluids (PDFs) on peritoneal mesothelial cells (PMCs) may impair intraperitoneal homeostasis in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). A recent study showed that 3,4-dideoxyglucosone-3-ene (3,4-DGE) was the most strongly cytotoxic among all identified GDPs in PDFs. The present study examined the effects of clinically relevant concentrations of 3,4-DGE on the proliferative capacity of PMCs and oxidative injury to them. METHOD The concentrations of eight GDPs in commercially available PDFs were determined by HPLC. The effect of cell growth media spiked with GDPs on the proliferation capacity of PMCs was evaluated. As a marker of the cellular redox status, total cellular glutathione (tGSH) was determined in PMCs incubated with GDPs. The reaction of 3,4-DGE with GSH under nonenzymatic conditions was analysed by liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS). RESULT The concentrations of 3,4-DGE in a heat-sterilized single-compartment standard-type PDF (S-PDF) and in a heat-sterilized dual-chamber-type PDF (N-PDF) were 16 microM and 1.7 microM, respectively. The most cytotoxic GDP was 3,4-DGE, and the concentration at which it causes 50% inhibition of cell growth was 35 microM. A significant decrease in the cellular tGSH levels was observed in the cells treated with 10 microM 3,4-DGE. 3,4-DGE disappeared on incubation with GSH under nonenzymatic conditions for 1 h, and the 3,4-DGE-GSH conjugate was confirmed by accurate mass measurement using LC-ESI-MS. These data demonstrated that the change in the cellular redox status by GSH depletion might be a contributory factor in 3,4-DGE-induced cytotoxicity. CONCLUSION 3,4-DGE is a highly reactive GDP and is responsible for the depletion of the total intracellular glutathione. 3,4-DGE has an intense impact on PMC growth at concentrations found in standard PDFs. It is desired that the amount of 3,4-DGE in PDFs should be minimized.

Risk factors for unexpected death from suffocation in elderly patients hospitalized for pneumonia

Aim:  Unexpected death from suffocation as a result of ortholaryngeal mucinous secretions or vomitus during recovery from pneumonia is devastating for patients, their families and medical professionals. This study aimed to determine the risk factors for unexpected death from suffocation in elderly patients hospitalized for pneumonia.

Impact of 3,4-dideoxyglucosone-3-ene (3,4-DGE) on cytotoxicity of acidic heat-sterilized peritoneal dialysis fluid

Of the glucose degradation products (GDPs) in glucose-rich peritoneal dialysate, we investigated the influence of 3,4-dideoxyglucosone-3-ene (3,4-DGE) on the cytotoxicity of acidic heat-sterilized peritoneal dialysis fluid (L-H PDF) using human peritoneal mesothelial cells (HPMC). We prepared acidified filtration-sterilized PDF (glucose concentration 3.86%) containing eight types of added GDP [3,4-DGE, glyoxal (GO), methylglyoxal (MGO), 3-deoxyglucosone (3-DG), formaldehyde (FA), acetaldehyde (AA), 5-hydroxymethyl-2-furaldehyde (5-HMF), and furfural (FF)] or seven types of GDP (GO, MGO, 3-DG, FA, AA, 5-HMF, and FF). HPMC were exposed to these two types of solution and acidic heat-sterilized PDF (glucose concentration 3.86%, L-H 3.86) for 4 h. Cell viability was determined by 3,(4,5-dimethythiazol-2-yl)2,5-diphenyl-terazolium bromide (MTT) assay. MTT viability was decreased significantly compared with the control when treated with L-H 3.86 or acidified neutral filtration-sterilized PDF (glucose concentration 3.86%) containing eight GDPs. However, no significant decrease in MTT viability was observed when HPMC were treated with acidified neutral filtration-sterilized PDF (glucose concentration 3.86%) containing seven GDPs. Thus, 3,4-DGE strongly affects the cytotoxicity of L-H PDF. It is suggested that the cytotoxicity of L-H PDF is based on the presence of 3,4-DGE.

Pulmão dos criadores de aves complicado por nocardiose pulmonar

We report the case of an 84-year-old male who was admitted to the hospital with persistent cough and dyspnea. An initial chest X-ray revealed pulmonary infiltrates. Nocardia asteroides was detected in sputum, and the patient was treated with antibiotics. However, his symptoms did not completely resolve. He was admitted multiple times, and his symptoms relapsed after every discharge. He was finally suspected of having hypersensitivity pneumonitis and was diagnosed with bird fanciers lung. Pulmonary nocardiosis is likely to develop in patients with chronic pulmonary disorders, such as COPD, as well as in immunosuppressed hosts. To our knowledge, this is the first report of a case of bird fanciers lung complicated by pulmonary nocardiosis.We report the case of an 84-year-old male who was admitted to the hospital with persistent cough and dyspnea. An initial chest X-ray revealed pulmonary infiltrates. Nocardia asteroides was detected in sputum, and the patient was treated with antibiotics. However, his symptoms did not completely resolve. He was admitted multiple times, and his symptoms relapsed after every discharge. He was finally suspected of having hypersensitivity pneumonitis and was diagnosed with bird fanciers lung. Pulmonary nocardiosis is likely to develop in patients with chronic pulmonary disorders, such as COPD, as well as in immunosuppressed hosts. To our knowledge, this is the first report of a case of bird fanciers lung complicated by pulmonary nocardiosis.

Evaluation of prognostic differences in elderly patients with pneumonia treated by between pulmonologists and non-pulmonologists: a propensity score analysis.

The incidence of pneumonia among elderly people is increasing in aged countries, and both pulmonologists and non‐pulmonologists treat such patients.

Prevalence and prognostic influence of bacterial pyuria in elderly patients with pneumonia: A retrospective study

The number of elderly patients with pneumonia is significantly increasing as the populations in many countries age. Although elderly patients with pneumonia are at risk of developing urinary tract infections, no studies have examined the prevalence or the prognostic impact of this complication. The aim of the present study was to investigate the prevalence of comorbid bacterial pyuria and the impact on the prognosis of elderly patients with pneumonia.