Rat liver nodules induced by 2-acetylaminofluorene lose an ability to take up indocyanine green in the process of hepatocarcinogenesis.

Indocyanine green (ICG) was injected into rat liver nodules induced by 2-acetylaminofluorene (2-AAF) via portal vein. The relationship between ICG staining and cell atypism of liver nodules was examined by means of histology and DNA flow cytometry. After 2-AAF administration, many small nodules appeared on the liver surface. All hyperplastic nodules were ICG stained until 10 weeks after the administration, but some nodules were not stained after 14 weeks. ICG-stained nodules histologically consisted of benign tissues and borderline lesions, and many of them showed &#34;diploidy&#34; in DNA cytometry. ICG-unstained nodules consisted of hepatocellular carcinoma (HCCs) and borderline lesions, and many of them showed &#34;aneuploidy&#34;. In this way, it has been suggested that HCC could derive from hyperplastic nodules and that they might lose an ability to take up ICG in the process of hepatocarcinogenesis. Immunohistochemical staining for glutathione-S-transferase alpha (GST-alpha), a carrier protein of ICG in hepatocytes, was well correlated with ICG staining in the nodules, suggesting that the loss of ICG uptake in HCC was partly due to the decrease of GST-alpha. Moreover, the appearance of ICG unstained and aneuploid nodules was significantly inhibited in rats which were fed on diet containing Syosaiko-to after the administration of 2-AAF. Chemopreventive effect of Syo-saiko-to on hepatocarcinogenesis was identified.</p

Lightweight High-Speed and High-Force Gripper for Assembly

This paper presents a novel industrial robotic gripper with a high grasping speed (maximum: 1396 mm/s), high tip force (maximum: 80 N) for grasping, large motion range, and lightweight design (0.3 kg). To realize these features, the high-speed section of the quick-return mechanism and load-sensitive continuously variable transmission mechanism are installed in the gripper. The gripper is also equipped with a self-centering function. The high grasping speed and self-centering function improve the cycle time in robotic operations. In addition, the high tip force is advantageous for stably grasping and assembling heavy objects. Moreover, the design of the gripper reduce the gripper's proportion of the manipulator's payload, thus increasing the weight of the object that can be grasped. The gripper performance was validated through kinematic and static analyses as well as experimental evaluations. This paper also presents the analysis of the self-centering function of the developed gripper

The secretion of high molecular weight cathepsin B from cultured human liver cancers.

The biochemical characteristics of cathepsin B secreted from cultured human liver cancer cells were examined. The enzyme activity of culture medium against a synthetic substrate, N-carbobenzoxy-L-arginyl-L-arginine-4-methyl-coumaryl-7-amide, was dependent on the addition of cysteine, and the optimal pH was found to be 6.0. No activity was observed when the enzyme source was fresh medium not used for culture. These results suggest that the enzyme released from liver cancer cells is the thiol-protease cathepsin B. The molecular weight of the enzyme with 90% of the total activity was 40,000. Two cathepsin B molecules were found in liver tissue from patients with hepatocellular carcinoma (HCC); one was equivalent in size to the secreted enzyme, and a smaller one was the same as normal liver cathepsin B (27,000), which was also obtained from HCC-bearing cirrhotic liver. These results demonstrate that two molecules of cathepsin B are synthesized in liver cancer, and that the larger one is released into the surrounding tissue.</p

Potentiation of 17 beta-estradiol synthesis in the brain and elongation of seizure latency through dietary supplementation with docosahexaenoic acid

Several studies have shown that docosahexaenoic acid (DHA) attenuates epileptic seizures; however, the molecular mechanism by which it achieves this effect is still largely unknown. DHA stimulates the retinoid X receptor, which reportedly regulates the expression of cytochrome P450 aromatase (P450arom). This study aimed to clarify how DHA suppresses seizures, focusing on the regulation of 17β-estradiol synthesis in the brain. Dietary supplementation with DHA increased not only the expression of P450arom, but also 17β-estradiol in the cerebral cortex. While DHA did not affect the duration or scores of the seizures induced by pentylenetetrazole, DHA significantly prolonged the seizure latency. A P450arom inhibitor, letrozole, reduced 17β-estradiol levels and completely suppressed the elongation of seizure latency elicited by DHA. These results suggest that DHA delays the onset of seizures by promoting the synthesis of 17β-estradiol in the brain. DHA upregulated the expression of anti-oxidative enzymes in the cerebral cortex. The oxidation in the cerebral cortex induced by pentylenetetrazole was significantly attenuated by DHA, and letrozole completely inhibited this suppressive action. Thus, the anti-oxidative effects of 17β-estradiol may be involved in the prevention of seizures mediated by DHA. This study revealed that 17β-estradiol in the brain mediated the physiological actions of DHA.This work was partially supported by grants from the Ministry of Education, Culture, Sports, Science and Technology, Japan, KAKENHI for Y.I., K.I. and T.Y. (Nos. 26740024, 26460139 and 25340047), a grant from the Mishima Kaiun Memorial Foundation for Y.I. and a grant from the SKYLARK Food Science Institute for Y.I. This work was also financially supported in part by Tokushima Bunri University. We thank Y. Kamihashi, Y. Utagawa, and K. Kojima for their technical assistance. We also acknowledge S. Smiley-Jewell and M. Paz Prada for editing the manuscript. This manuscript has been checked by a professional language editing service, American Journal Experts

Variable-grasping-mode underactuated soft gripper with environmental contact-based operation

A novel robotic gripper with soft surfaces and underactuated joints was proposed. The soft surface was fabricated from a deformable rubber bag filled with incompressible fluid and a microgripper inside the fluid. A ratchet was installed at the underactuated joint so that the joint\u27s rotation caused by contact with an environment, such as a supporting surface, can be preserved, and the actions of scooping and enveloping an object are realized. With one actuator, the gripper realized three modes, i.e., parallel gripper, pinching, and enveloping. The range of graspable objects was wide and included soft, rigid, deformable, fragile, small (boundary length less than 30 mm), large (more than 80 mm long), thin (less than 0.5 mm), and heavy (more than 3 kg) objects.INSPEC Accession Number: 1671251

Loss of ICG uptake in the process of rat hepatocarcinogenesis correlates to the disappearance of glutathione-S-transferase alpha subunit.

Reduced indocyanine green (ICG) uptake is one of the functional changes of human hepatocellular carcinoma (HCC). To clarify the mechanisms of loss of ICG uptake, and determine which subunit of glutathione-S-transferase (GST), alpha or pi, plays a role in ICG transport in hepatocytes, an experimental HCC model was developed that used nodules induced by 2-acetylamino-fluorene (2-AAF) administration. Many of the ICG stained nodules, which consisted of benign and borderline lesions, were GST-alpha positive. However, the percentage of GST-alpha positive cells tended to decrease according to the disappearance of ICG staining in the process of hepatocarcinogenesis. HCCs unstained by ICG were also GST-alpha negative. GST-pi, not detected in normal rat hepatocytes, appeared in an earlier stage of hepatocarcinogenesis before the disappearance of GST-alpha, and was not observed in HCCs. No significant relationship between ICG staining and GST-pi was recognized. These results suggest that GST-alpha synthesis is disturbed in the process of hepatocarcinogenesis and results in loss of ICG uptake in HCCs, and also indicate that GST-pi may be useful for early diagnosis of preneoplastic hepatocytes showing no roles in ICG transport.</p

Immunohistochemical studies of PIVKA-II in hepatocellular carcinoma by indirect immunofluorescence

Tissue PIVKA-II was examined in 32 hepatocellular carcinomas and 2 metastatic liver tumors using indirect immunofluorescence, and the results were compared with the size, histological grading and serum PIVKA-II level. The specificity of this method was confirmed by the disappearance of reactivity in PLC/PRF/5 cells after the addition of vitamin K to the culture medium. Positive PIVKA-II staining was observed as a clustered or a single cell pattern only in the HCC nodules, but not in the surrounding cirrhotic tissue. PIVKA-II staining was observed in all HCC groups regardless of histological grade. There was no relationship between PIVKA-II staining and the size of HCC. PIVKA-II was detected immunohistochemically even in small HCC of patients whose plasma PIVKA-II levels were below the detection limit. These results suggest that PIVKA-II production is a specific phenotype of HCC regardless of its histological grading and demonstrate that this immunofluorescent PIVKA-II staining is more sensitive and useful than plasma PIVKA-II assay for the diagnosis of HCC.</p

Recombinant mouse cytochromes P1-450 and P3-450: enzymatic characterization of the hemoprotein expressed in human cells infected with recombinant vaccinia virus.

We expressed mouse cytochrome P1-450 and P3-450 using recombinant vaccinia virus gene expression system in HeLa cells that were devoid of significant basal levels of P-450. HeLa cells were infected with the recombinant vaccinia virus containing either mouse cytochrome P1-450 or P3-450 cDNA, and the cell lysates were analyzed for the kinetics of P-450 enzyme activity and protein expression at the same time. 7-Ethoxycoumarin O-deethylase and ethoxyresorufin O-deethylase activities were measured as an expression of the cytochrome P-450 enzyme activities. Both cell lines began to express these enzyme activities as early as 12h after infection. The activities increased linearly up to the 24 h time point, and were kept for 36 h. Western immunoblot analysis showed that these cytochrome P-450 proteins were detected at 16 h and reached maximum quantity at 24 h after infection. These data showed a good correlation between cytochrome P-450 enzyme activity and protein concentration throughout the process of P-450 gene expression by vaccinia virus vector, suggesting a complete formation of cytochrome P-450 holoenzyme from the early stage of the protein expression.</p