Histo-chemical and cytochemical studies on the succinic dehydroge-nase system with three ditetrazolium salts, NT, Nitro-NT, and Nitro-Bt

1. Histochemical and cytochemical studies with respect to the sites of reaction were made on the succinic dehydrogenase system activity of human and animal tissues using ditetrazolium salts, namely, neotetrazolium chloride, nitro-neotetrazolium chloride, and nitra-blue tetrazolium chloride. 2. The advantages and disadvantages of each ditetrazolium salt for histochemical and cytochemical purposes and the reaction taking place in frozen tissue sections and that in fresh tissue blocks were compared, and the method of procedure suitable for each condition was established with some modification. 3. Selecting conditions suitable for cytochemical purpose, it was shown that the reaction took place at the sites coinciding with mitochondria, and the distribution of the enzyme reaction was also examined. In addition, several new findings in the brains and other tissues cytochemically made clear were pointed out.</p

Suramin prevents the development of diabetic kidney disease by inhibiting NLRP3 inflammasome activation in KK-Ay mice

Aims/Introduction Nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasomes produce IL-18 upon being activated by various stimuli via the P2 receptors. Previously, we showed that serum and urine IL-18 levels are positively associated with albuminuria in patients with type 2 diabetes, indicating the involvement of inflammasome activation in the pathogenesis of diabetic kidney disease (DKD). In the present study, we investigated whether the administration of suramin, a nonselective antagonist of the P2 receptors, protects diabetic KK.Cg-A(y)/TaJcl (KK-Ay) mice against DKD progression. Materials and Methods Suramin or saline was administered i.p. to KK-Ay and C57BL/6J mice once every 2 weeks for a period of 8 weeks. Mouse mesangial cells (MMCs) were stimulated with ATP in the presence or absence of suramin. Results Suramin treatment significantly suppressed the increase in the urinary albumin-to-creatinine ratio, glomerular hypertrophy, mesangial matrix expansion, and glomerular fibrosis in KK-Ay mice. Suramin also suppressed the upregulation of NLRP3 inflammasome-related genes and proteins in the renal cortex of KK-Ay mice. P2X4 and P2X7 receptors were significantly upregulated in the isolated glomeruli of KK-Ay mice and mainly distributed in the glomerular mesangial cells of KK-Ay mice. Although neither ATP nor suramin affected NLRP3 expression in MMCs, suramin inhibited ATP-induced NLRP3 complex formation and the downstream expression of caspase-1 and IL-18 in MMCs. Conclusions These results suggest that the NLRP3 inflammasome is activated in a diabetic kidney and that inhibition of the NLRP3 inflammasome with suramin protects against the progression of early stage DKD

Formation of a Five-Seven Pair Couple Defect in Double-Walled Carbon Nanotubes under Bending Deformation

金沢大学理工研究域　数物科学系Simulations of double-walled carbon nanotubes under bending deformation using the tight-binding molecular dynamics method were carried out. Five- and seven-membered ring pair defects were formed after emission of several atoms from the tube structure. These defect pair couples have different structures corresponding to the number of emitted atoms and stabilize the resulting nanotubes. Our results imply that the defect pair couples represent one of the potential origins of the experimentally observed plastic deformations that have been shown to occur in double-walled carbon nanotubes. The various defects obtained by the simulations are discussed in relation to other defect types. © 2007 American Institute of Physics

Monocyte chemiluminescence and macrophage precursors in the aged.

Age-related alterations in the host defense system have been vigorously investigated because of increased susceptibility to infection and neoplasms in the aged. Although monocyte-macrophages form a major part of the cellular defense against microorganisms, the majority of investigations has been limited to neutrophils and lymphocytes. The present study, designed to determine the influence of age on mononuclear phagocytes, revealed no significant decrease in the absolute number of blood monocytes, but did reveal a tendency for the chemiluminescence of blood monocytes to decrease (p less than 0.10) and a significant decrease in the numbers of macrophage precursors (p less than 0.05) in the aged (over 70 year old), in comparison with controls (under 40 years old). On the basis of these findings, functional alterations of monocyte-macrophages seem to participate in the increased susceptibility to infection in the aged.</p

Comparative analysis of the production of nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) from macrophages exposed to high virulent and low virulent strains of Edwardsiella tarda.

We previously reported that high virulent strain (NUF251) of Edwardsiella tarda has an ability to prevent the production of reactive oxygen species by macrophages, and is even capable of surviving and multiplying within Japanese flounder (Paralichthys olivaceus) peritoneal macrophages, whereas the low virulent strain (NUF194) has no such ability. In this study, we found that NUF251 and NUF194 induced NO and TNF-alpha production from Japanese flounder peritoneal macrophages, and NUF251 caused faster induction of NO release and much higher level of TNF-alpha production than NUF194. In addition, similar differences between two strains in terms of the induction of NO and TNF-alpha production were also observed in mouse macrophage cell line RAW264.7 cells. Our results suggest that the potent ability to induce the production of NO and TNF-alpha from macrophages may be one of the factors responsible for the virulence of E. tarda

Early gastric cancer detection in high-risk patients: a multicentre randomised controlled trial on the effect of second-generation narrow band imaging

Objective: Early detection of gastric cancer has been the topic of major efforts in high prevalence areas. Whether advanced imaging methods, such as second-generation narrow band imaging (2G-NBI) can improve early detection, is unknown. Design: This open-label, randomised, controlled tandem trial was conducted in 13 hospitals. Patients at increased risk for gastric cancer were randomly assigned to primary white light imaging (WLI) followed by secondary 2G-NBI (WLI group: n=2258) and primary 2G-NBI followed by secondary WLI (2G-NBI group: n=2265) performed by the same examiner. Suspected early gastric cancer (EGC) lesions in both groups were biopsied. Primary endpoint was the rate of EGC patients in the primary examination. The main secondary endpoint was the positive predictive value (PPV) for EGC in suspicious lesions detected (primary examination). Results: The overall sensitivity of primary endoscopy for the detection of EGC in high-risk patients was only 75% and should be improved. 2G-NBI did not increase EGC detection rate over conventional WLI. The impact of a slightly better PPV of 2G-NBI has to be evaluated further. Trial registration number: UMIN000014503

Strain-dependent lethal effects on abalone and haemolytic activities of the dinoflagellate Karenia mikimotoi

One of the clonal strains of Karenia mikimotoi NGU04 isolated from Kyushu Island in Japan, showed the most potent fish-killing activity in preliminary experiments. To evaluate shellfish toxicity, two species of juvenile abalone were exposed to the NGU04, and the toxicities were compared with those of two other K. mikimotoi strains. Of the two abalone species tested, N. gigantea showed a higher sensitivity to NGU04 than the hybrid abalone (N. discus hannai male × N. gigantea female) did. In comparative studies using N. gigantea, the NGU04 exhibited stronger toxicity on abalone than other strains. The cell-free culture supernatant and the ruptured cell suspension of the NGU04 showed no significant lethal effects on N. gigantea. The NGU04 showed a stronger haemolytic activity on rabbit erythrocytes than did the other two strains. Furthermore, the haemolytic activities of the NGU04 strain towards erythrocytes of four fish species were also stronger than those of other strains