Hiroaki Mikasa

Coronary Atherosclerosis Is Associated With Macrophage Polarization in Epicardial Adipose Tissue

OBJECTIVES The purpose of this report was to assess the link between macrophage polarization in epicardial adipose tissue and atherosclerosis in patients with coronary artery disease (CAD). BACKGROUND Macrophage accumulation enhances chronic inflammation in adipose tissue, but macrophage phenotypic change in human epicardial adipose tissue and its role in atherogenesis are unknown. METHODS Samples were obtained from epicardial and subcutaneous adipose tissue during elective cardiac surgery (CAD, n = 38; non-CAD, n = 40). Infiltration of M1/M2 macrophages was investigated by immunohistochemical staining with antibodies against CD11c and CD206, respectively. Expression of pro- and anti-inflammatory adipocytokines in adipose tissue was evaluated by real-time quantitative polymerase chain reaction. RESULTS Infiltration of macrophages and expression of pro- and anti-inflammatory cytokines were enhanced in epicardial fat of patients with CAD compared with that in non-CAD patients (p < 0.05). The ratio of M1/M2 macrophages was positively correlated with the severity of CAD (r = 0.312, p = 0.039). Furthermore, the expression of pro-inflammatory cytokines was positively correlated, and the expression of anti-inflammatory cytokines was negatively correlated with the ratio of M1/M2 macrophages in epicardial adipose tissue of CAD patients. By contrast, there was no significant difference in macrophage infiltration and cytokine expression in subcutaneous adipose tissue between the CAD and non-CAD groups. CONCLUSIONS The ratio of M1/M2 macrophages in epicardial adipose tissue of CAD patients is changed compared with that in non-CAD patients. Human coronary atherosclerosis is associated with macrophage polarization in epicardial adipose tissue.

Absorption dynamics of CO2 bubbles in a pressurized liquid flowing downward and its simulation in seawater

The absorption process of carbon dioxide from a single bubble to the surrounding liquid at elevated pressure is studied both experimentally and theoretically. Experiments are conducted in a laboratory-scale column through which the liquid flows downward to hold each injected bubble nearly stationary. The system is pressurized up to 0.6 MPa and sodium chloride is added to water. A simple theoretical model is used to simulate the basic features of the absorption dynamics for bubbles ascending in shallow ocean. The bubble size is found to initially decrease almost linearly with time. The addition of NaCl significantly reduces the absorption rate of CO2. An analysis of shape or surface oscillations of the bubble reveals that this effect arises from the suppression of wavy fluctuations along the gas-liquid interface. The model predicts that the rate of bubble size reduction is almost independent of time and pressure for bubbles larger than 1 mm, reproducing the experimental results reasonably well.

Determination of 8-hydroxy-deoxyguanosine formation in rat organs: assessment of paraquat-evoked oxidative DNA damage.

Paraquat has previously been shown to cause the oxidative damage to DNA in variety of cells and tissues. However, although paraquat‐evoked strand breaks has been extensively studied to assess the DNA damage, the effect of paraquat on base modifications, another marker for the oxidative damage, has not yet been investigated. To further characterize paraquat‐evoked DNA damage, the effect of paraquat on 8‐hydroxy‐deoxyguanosine (8‐OH‐dG) formation in various rat organs was examined. Paraquat markedly increased 8‐OH‐dG contents in various organs, particularly in brain, lung and heart, and this increase reached the maximum levels at 5 days after the drug administration. In contrast, the formation of 8‐hydroxy‐guanosine (8‐OH‐G), a marker for the oxidative damage to RNA, was not significantly affected by paraquat. These results indicate that paraquat causes base modifications as well as strand breaks as a consequence of the oxidative damage to DNA.

Improvement of the anoxia-induced mitochondrial dysfunction by membrane modulation

The mitochondrial dysfunction induced by anoxia in vitro was improved with chlorpromazine, cepharanthine, bromophenacyl bromide, and mepacrine without affecting phospholipid or adenine nucleotide metabolisms. The drugs inhibited lipid peroxidation by Fe2+, mitochondrial disruption by Ca2+, and membrane perturbation by lysolecithin, and retained the activity to control H+ permeability across mitochondrial membranes. The drugs appeared to preserve the functions by acting to suppress the development of membrane deterioration which may have resided in the deenergization of mitochondria in the absence of oxygen.

Unusual metabolism of sulfur-containing amino acids in rats treated with dl-propargylglycine

S-(2-Hydroxy-2-carboxyethyl)homocysteine, S-(3-hydroxy-3-carboxy-n-propyl)-cysteine, N-acylated S-(beta-carboxyethyl)cysteine, and N-acylated S-(3-hydroxy-3-carboxy-n-propyl) cysteine were excreted in the urine after DL-propargylglycine treatment. Cystathionine was also accumulated in several tissues of DL-propargylglycine-treated rats. N-Monoacetylcystathione was found in the liver of rats and was also detected in the kidney and serum. Cystathionine gamma-lyase activity in liver decreased to about 4% of that of control rats 24 h after the DL-propargylglycine injection, and alanine aminotransferase activity decreased to about 35% of that of control rats. On the other hand, aspartate aminotransferase and cystathionine beta-synthese activity did not show significant changes from those of control rats. The ability of normal tissues to synthesize cystathionine utilizing cystathionine beta-synthase was 1.98 +/- 0.40 mumol/min/g in liver, 0.61 +/- 0.13 in kidney, and 0.18 +/- 0.015 in brain. The maximal contents of cystathionine in rat tissues and the administered amounts of DL-propargylglycine agreed well with the ability to synthesize cystathionine in each tissue.

Adsorption and elution of metals on hair

The adsorption of zinc and lead on hair was dependent on the acidity of the hair and/or the medium in which the hair sample was immersed, suggesting that hair is an ion exchanger. The pKa was estimated to be between 4.5 and 5.0. The coexistence of mercuric ion or PCMB reduced zinc adsorption by only a few percent, whereas zinc inhibited mercuric ion adsorption to a greater extent. These facts suggest that the binding sites in hair for metals are located on functional groups like carboxyl groups rather than sulfhydryl groups.The removal and/or elution of metals from hair were observed for 18 elements by various washing procedures. By treating hair with a water solution of detergent, alkaline metals were eluted to a great extent, whereas alkaline earth metals were eluted to some extent. The other metals did not vary with any procedures tested.

High antitumor activity of pladienolide B and its derivative in gastric cancer

The antitumor activity of pladienolide B, a novel splicing inhibitor, against gastric cancer is totally unknown and no predictive biomarker of pladienolide B efficacy has been reported. We investigated the antitumor activity of pladienolide B and its derivative on gastric cancer cell lines and primary cultured cancer cells from carcinomatous ascites of gastric cancer patients. The effect of pladienolide B and its derivative on six gastric cancer cell lines was investigated using a MTT assay and the mean IC50 values determined to be 1.6 ± 1.2 (range, 0.6–4.0) and 1.2 ± 1.1 (range, 0.4–3.4) nM, respectively, suggesting strong antitumor activity against gastric cancer. The mean IC50 value of pladienolide B derivative against primary cultured cells from 12 gastric cancer patients was 4.9 ± 4.7 nM, indicative of high antitumor activity. When 18 SCID mice xenografted with primary cultured cells from three patients were administered the pladienolide B derivative intraperitoneally, all tumors completely disappeared within 2 weeks after treatment. Histological examination revealed a pathological complete response for all tumors. In the xenograft tumors after treatment with pladienolide B derivative, immature mRNA were detected and apoptotic cells were observed. When the expressions of cell‐cycle proteins p16 and cyclin E in biopsied gastric cancer specimens were examined using immunohisctochemistry, positivities for p16 and cyclin E were significantly and marginally higher, respectively, in the low‐IC50 group compared with the high‐IC50 group, suggesting the possibility that they might be useful as predictive biomarkers for pladienolide B. In conclusion, pladienolide B was very active against gastric cancer via a mechanism involving splicing impairment and apoptosis induction.

Novel des-γ-carboxy prothrombin in serum for the diagnosis of hepatocellular carcinoma.

Serum des‐γ‐carboxy prothrombin (DCP) levels using a newly developed electrochemiluminescence immunoassay (ECLIA, novel DCP [NX‐DCP]) were measured, and the utility of NX‐DCP and DCP/NX‐DCP ratio for the diagnosis of hepatocellular carcinoma (HCC) was investigated. Antigenic differences in DCP between HCC and non‐HCC patients were elucidated.

Determination of glutathione and glutathione disulfide in rat tissues using isotachophoretic analyzer

Abstract A method for measurement of both glutathione (GSH) and glutathione disulfide (GSSG) in biological samples has been developed by using an isotachophoretic analyzer. The determination of the amount of GSH was carried out by measuring a zone length of GSH in isotachophoresis. The method gave recoveries of 92 to 106% for GSH and was quite specific for GSH. The measurement of GSSG levels was carried out by measuring differences in the length of mixed zones containing GSSG determined before and after reduction of GSSG by treatment with dithiothreitol or glutathione reductase. The method gave recoveries of 80 to 103% for GSSG. The results determined by using this method for GSH and GSSG levels in rat tissues agreed well with earlier reports.

Biochemical investigations on prolidase and prolinase in erythrocytes from patients with prolidase deficiency.

Prolidase (EC 3.4.13.9) deficiency is a rare autosomal recessive disease affecting the degradation of collagen associated with chronic ulcerative dermatities, mental retardation and massive urinary excretion of iminodipeptides [l-lo]. Prolidase deficiency can be diagnosed by the assay of prolidase activity in erythrocytes [11,12], leucocytes [3] and cultured skin fibroblasts [4,9,11]. These reports have utilized Gly-Pro as the substrate and indicated almost complete deficiency of the enzyme. Butterworth et al has recently reported that prolidase in cultured skin fibroblasts from the patient is altered rather than absent, such that activity against Gly-Pro is very low, but only moderately reduced against other substrates [13,14] and separated two peaks by DEAE-cellulose ion-exchange chromatography [15]. We described in previous papers biochemical aspects and dermatological features from two siblings with prolidase deficiency and massive excretion of iminodipeptides [5,7,9]. The older sister presented the typical clinical symptoms of the desease, but the younger sister developed no clinical symptoms. The relationships between prolidase deficiency and the clinical manifestations are yet unknown. The present investigation shows several characteristics of prolidase and prolinase (EC 6.4.13.8) in erythrocytes from two siblings with prolidase deficiency, then parents and controls subjects.