Izumi Yoshida

A New Device to Monitor Blood Volume in Hemodialysis Patients

We developed a new optical device (Nikkiso) to assess changes through blood volume monitoring (BVM) during hemodialysis and were able to determine the ideal levels in which changes in blood volume percentage (BV%) occur among hemodialysis patients in one hemodialysis center. We evaluated both the reliability of BVM and these ideal levels in a multicenter group. The purpose of this manuscript is to develop a navigating system to set dry weight in a variety of situations as the final goal. First, based on the obtained BVM (BV%BVM) measurements, the relationships between BV% and hematocrit (BV%HT) and between BV% and CRIT‐LINE (BV%CLM; Hema Metrics, Kaysville, UT, USA) were then evaluated. In 30 hemodialysis patients, there was a close correlation between both BV%BVM vs. BV%HT and BV%BVM vs. BV%CLM (n = 30, r = 0.967, P < 0.001, and n = 36, r = 0.7867, P < 0.001, respectively). Second, BV% data were obtained from 464 treatment cases performed on 26 subjects in one satellite hemodialysis center on patients whose body weight was deemed clinically suitable. The formulas for the levels of BV% (standardized by the percent change in body weight at the end of hemodialysis treatment: BW%end) were determined.

Evaluation of Cerebral Oxygenation in Patients Undergoing Long-Term Hemodialysis

Background/Aims: Patients undergoing hemodialysis (HD) have higher occurrence rates of cerebral diseases, including uremic encephalopathy, cognitive impairment, dementia, and cerebrovascular disease, than the general population. During HD, ultrafiltration is performed to maintain an adequate fluid condition and is associated with subsequent blood volume (BV) reduction. We aimed to (1) monitor changes in cerebral oxygenation and BV reduction during HD, and (2) clarify the mechanism that influences cerebral oxygenation in HD patients. Methods: Eighteen HD patients and 12 healthy controls were recruited. Regional saturation of oxygen (rSO2) was continuously monitored in the frontal cortex using INVOS 5100C before, during, and after HD, and in healthy controls. Relative change in BV (%ΔBV) was simultaneously monitored during HD using a BV monitor. Results: Before HD, patients had significantly lower rSO2 values than controls (56.1 ± 1.4 vs. 70.4 ± 2.5%, p < 0.001). Although %ΔBV significantly decreased from 20 min to the end of HD (20 min: -3.3 ± 0.3%, p < 0.05; end of HD: -12.0 ± 1.0%, p < 0.01), changes in rSO2 values during HD were not significant. No relationship existed between rSO2 values and blood pressure levels, hemoglobin levels, oxygen pressure, HCO3- , oxygen saturation, and arterial O2 content before and after HD. Furthermore, changes in rSO2 were not correlated with changes in these parameters. Conclusion: rSO2 values before HD were significantly lower in HD patients than in healthy controls. rSO2 values were maintained during HD and were not influenced by BV reduction.

Identification and evaluation of anti-inflammatory compounds from Kaempferia parviflora

The rhizome of Kaempferia parviflora has been used in traditional Thai medicine. In this study, we identified and compared specific compounds from the hexane extract of K. parviflora with those from other Zingiberaceous plants by using gas chromatography–mass spectrometry. We identified 5,7-dimethoxyflavone (DMF), 5-hydroxy-3,7,3′,4′-tetramethoxyflavone (TMF), estimated 3,5,7-trimethoxyflavone, 5-hydroxy-7,4′-dimethoxyflavone, 3,5,7,4′-tetramethoxyflavone, and investigated their anti-inflammatory effects in rat basophilic leukemia (RBL-2H3) cells stimulated with an IgE antigen or a calcium ionophore. We found that DMF and TMF more potently inhibited antigen-induced degranulation than did nobiletin, a well-known anti-inflammatory agent. In addition, compared to RBL-2H3 cells stimulated with a calcium ionophore, those treated with DMF and TMF showed more marked inhibition of the degranulation and the production and mRNA expression of inflammatory mediators. These results suggest that DMF and TMF inhibit an early step in the high-affinity IgE receptor signaling cascade rather than intracellular calcium release and protein kinase C activation. Graphical Abstract The extracts from Kaempferia parviflora effectively suppress the antigen-mediated degranulation in RBL-2H3 cells.

Marked Atherosclerosis in a Patient with Familiar Lecithin: Cholesterol Acyltransferase Deficiency Associated with End-Stage Renal Disease and Diabetes Mellitus

Familial lecithin:cholesterol acyltransferase (LCAT) deficiency is a rare genetic disorder of the lipid metabolism caused by the absence of LCAT activity in plasma. It is not generally accompanied by atherosclerosis in spite of low high-density lipoprotein cholesterol levels nor by diabetes mellitus. However, reports of long-term follow-up or autopsy findings are rare, and the true incidence of atherosclerosis in LCAT deficiency is not clear. We report on the long-term observation of a patient with familial LCAT deficiency who developed renal failure, diabetes mellitus, and marked atherosclerosis. The patient died of sepsis from foot ulcers 7 years after starting hemodialysis and 13 years after the diagnosis. Marked atherosclerosis characterized by medial calcification in small arteries was observed at autopsy. The genesis of the atherosclerosis seemed to be on the basis of a combination of factors.

Factors affecting cerebral oxygenation in hemodialysis patients: cerebral oxygenation associates with pH, hemodialysis duration, serum albumin concentration, and diabetes mellitus.

Background Patients undergoing hemodialysis (HD) often develop cerebral disease complications. Furthermore, cerebral regional saturation of oxygen (rSO2) was previously reported to be significantly lower in HD patients than in healthy subjects. We aimed to identify the factors affecting the cerebral rSO2 in HD patients. Methods Fifty-four HD patients (38 men and 16 women; mean age, 67.7 ± 1.2 years, HD duration, 6.5 ± 1.9 years) were recruited. Cerebral rSO2 was monitored at the forehead before HD using an INVOS 5100C (Covidien Japan, Tokyo, Japan). Results The rSO2 levels were significantly lower in HD patients compared with healthy controls (49.5 ± 1.7% vs. 68.9 ± 1.6%, p <0.001). Multiple regression analysis showed that cerebral rSO2 independently associated with pH (standardized coefficient: -0.35), HD duration (standardized coefficient: -0.33), and serum albumin concentration (standardized coefficient: 0.28). Furthermore, the rSO2 was significantly lower in HD patients with diabetes mellitus (DM), compared with patients without DM (46.8 ± 1.7% vs. 52.1 ± 1.8%, p <0.05). Conclusions In HD patients, cerebral rSO2 was affected by multiple factors, including pH, HD duration, and serum albumin concentration. Furthermore, this is the first report describing significantly lower levels of rSO2 in HD patients with DM than in those without DM.

Aculeatin, a coumarin derived from Toddalia asiatica (L.) Lam., enhances differentiation and lipolysis of 3T3-L1 adipocytes

Toddalia asiatica (L.) Lam. (T. asiatica) has been utilized traditionally for medicinal purposes such as the treatment of diabetes. Currently, the extract is considered to be a good source of anti-diabetic agents, but the active compounds have yet to be identified. In this study, we investigated the effects of fractionated T. asiatica extracts on the differentiation of 3T3-L1 preadipocytes and identified aculeatin as a potential active agent. When 3T3-L1 preadipocytes were treated with aculeatin isolated from T. asiatica in the presence of insulin, aculeatin increased cellular triglyceride levels and glycerol-3-phosphate dehydrogenase activity. This indicated that aculeatin could enhance the differentiation of preadipocytes into adipocytes. Further analyses using a DNA microarray and real-time quantitative reverse-transcription PCR showed an increase in the expression of peroxisome proliferator-activated receptor-γ target genes (Pparg, Ap2, Cd36, Glut4 and Adipoq) by aculeatin, suggesting that aculeatin enhances the differentiation of 3T3-L1 cells by modulating the expression of genes critical for adipogenesis. Interestingly, after treatment of differentiated adipocytes with aculeatin, glucose uptake and lipolysis were enhanced. Overall, our results suggested that aculeatin is an active compound in T. asiatica for enhancing both differentiation and lipolysis of adipocytes, which are useful for the treatment of lipid abnormalities as well as diabetes.

5,6-Dehydrokawain from Alpinia zerumbet promotes osteoblastic MC3T3-E1 cell differentiation

Bone homeostasis is maintained by balancing bone formation and bone resorption, but an imbalance between them is associated with various bone-related diseases such as osteoporosis and rheumatoid arthritis. We found that 5,6-dehydrokawain (DK) and dihydro-5,6-dehydrokawain (DDK), which were isolated as promising compounds from Alpinia zerumbet rhizomes, promote differentiation of osteoblastic MC3T3-E1 cells. DK and DDK increased the alkaline phosphatase activity and matrix mineralization of MC3T3-E1 cells. DK exerts larger effects than DDK. The gene expression of runt-related transcription factor 2 and osterix, which are essential transcription factors in the early period of osteoblast differentiation, was significantly increased by DK treatment. The mRNA level of distal-less homeobox 5 was also enhanced by DK treatment, and DK activated the p38 mitogen-activated protein kinase pathway. Therefore, DK may have clinical potential for preventing osteoporosis, and could be considered as a potential anabolic therapeutic agent. Graphical abstract 5,6-Dehydrokawain (DK) and dihydro-5,6-dehydrokawain (DDK) from Alpinia zerumbet rhizomes, promote differentiation of osteoblastic MC3T3-E1 cells.

Localization of Low-KM cAMP Phosphodiesterase in Rat Nephron Segments

To evaluate the roles of cAMP degradation on hormonal actions in the kidney, we examined the segmental distribution and activities of cAMP-phosphodiesterase (PDE), a key enzyme for cAMP hydrolysis, in dissected segments of the rat nephron and characterized the isozyme compositions with subtype-specific inhibitors. Summary of the nephron distribution of PDE activities showed that cAMP-PDE activities were detected in all nephron segments and the distal convoluted tubules (DCTs) had the highest activity. Both in proximal convoluted tubules (PCTs) and medullary collecting ducts (MCDs), more than 80% of the total cAMP-PDE activities were inhibited by a nonspecific PDE inhibitor, 3-isobutyl-1-methylxanthine (IBMX). In PCTs, rolipram (type-IV PDE inhibitor) was an equally potent inhibitor of IBMX, while 8-methoxymethyl-IBMX (MM-IBMX, type-I PDE inhibitor) and cilostamide (type-III PDE inhibitor) inhibited cAMP-PDE by 35 and 57%, respectively. In MCDs, inhibition by rolipram (40%) was less than that by MM-IBMX (70%) or cilostamide (66%). Rolipram potentiated the parathyroid hormone (PTH)-induced cAMP content in PCTs most effectively. Rolipram and MM-IBMX increased the vasopressin (AVP)-stimulated cAMP content equally in MCDs. Cilostamide had no effect on the cAMP content stimulated by PTH or AVP in PCTs and MCDs. These results indicate that PDE activities were unevenly distributed along the rat nephron and cAMP-PDE was composed of at least three isoforms, namely type I, III and IV in PCTs and MCDs. Among these, type-IV PDE was responsible for hydrolysis of cAMP in PCTs, and type-I and IV PDE were responsible for that in MCDs.

Inhibitory effects of Kaempferia parviflora extract on monocyte adhesion and cellular reactive oxygen species production in human umbilical vein endothelial cells

PurposeThe rhizome of Kaempferia parviflora (KP) is used in traditional Thai medicine. In this study, we investigated the effects of an ethanol KP extract and two of its components [5,7-dimethoxyflavone (DMF) and 5-hydroxy-3,7,3′,4′-tetramethoxyflavone (TMF)] on monocyte adhesion and cellular reactive oxygen species (ROS) production in human umbilical vein endothelial cells (HUVECs), which provide an in vitro model of events relevant to the development and progression of atherosclerosis.MethodsRAW264.7 mouse macrophage-like cells were incubated with various concentrations of KP extract or polymethoxyflavonoids and stimulated with lipopolysaccharide prior to measuring nitrite levels in the culture media. Monocyte adhesion was evaluated by measuring the fluorescently labeled human monocytic leukemia THP-1 cells that is attached to tumor necrosis factor-α (TNF-α)-stimulated HUVECs. Cellular ROS production was assessed by measuring cellular antioxidant activity using pyocyanin-stimulated HUVECs.ResultsKP extract and DMF reduced nitrite levels (as indicator of nitric oxide production) in LPS-stimulated RAW264.7 cells and also inhibited THP-1 cell adhesion to HUVECs. These treatments induced mRNA expression of endothelial nitric oxide synthase in TNF-α-stimulated HUVECs and downregulated that of various cell adhesion molecules, inflammatory mediators, and endothelial function-related genes. Angiotensin-converting enzyme activity was inhibited by KP extract in vitro. Furthermore, KP extract, DMF, and TMF inhibited the production of cellular ROS in pyocyanin-stimulated HUVECs.ConclusionKP extract, DMF, and TMF showed potential anti-inflammatory and antioxidant effects in these in vitro models, properties that would inhibit the development and progression of atherosclerosis.

Toddaculin, Isolated from of Toddalia asiatica (L.) Lam., Inhibited Osteoclastogenesis in RAW 264 Cells and Enhanced Osteoblastogenesis in MC3T3-E1 Cells.

Osteoporosis with bone loss is widely recognized as a major health problem. Bone homeostasis is maintained by balancing bone formation and bone resorption. The imbalance caused by increased bone resorption over bone formation can lead to various bone-related diseases such as osteoporosis and rheumatoid arthritis. Osteoclasts are the principal cells responsible for bone resorption and the main targets of anti-resorptive therapies. However, excessive inhibition of osteoclast differentiation may lead to inhibition of osteoblast differentiation. Therefore, it is important to screen for new compounds capable of inhibiting bone resorption and enhancing bone formation. Toddalia asiatica (L.) Lam. has been utilized traditionally for medicinal purposes such as the treatment of rheumatism. Currently, the extract is considered to be a good source of pharmacological agents for the treatment of bone-related diseases, but the active compounds have yet to be identified. We investigated whether toddaculin, derived from Toddalia asiatica (L.) Lam., affects both processes by inhibiting bone resorption and enhancing bone formation. Towards this end, we used pre-osteoclastic RAW 264 cells and pre-osteoblastic MC3T3-E1 cells. We found that toddaculin not only inhibited the differentiation of osteoclasts via activation of the NF-κB, ERK 1/2, and p38 MAPK signaling pathways, but it also induced differentiation and mineralization of osteoblasts by regulating differentiation factors. Thus, toddaculin might be beneficial for the prevention and treatment of osteoporosis.