K-252a-induced polyploidization and differentiation of a human megakaryocytic cell line, Meg-J: transient elevation and subsequent suppression of cyclin B1 and cdc2 expression in the process of polyploidization

Megakaryocytes are unique haemopoietic cells which undergo DNA replication, giving rise to polyploid cells. However, little is known about the mechanism of megakaryocytic polyploidization. To address this issue, we used the human megakaryocytic cell line Meg-J. In the presence of K-252a (an indolocarbasole derivative), Meg-J cells stopped proliferation and exhibited additional megakaryocytic features, including morphological changes, polyploidization, and increases in the levels of surface expression of platelet glycoprotein (GP) IIb/IIa and GPIb. Thrombopoietin (TPO) promoted the K-2 52a-induced polyploidization and megakaryocytic differentiation. In the process of K-252a-induced polyploidization, levels of expression of both cdc2 and cyclin B1 were elevated transiently and subsequently decreased. This suggested that the polyploidization process in Meg-J cells was at least in part associated with a transient elevation and subsequent decrease in the expression of cdc2/cyclin B1 complex, a critical kinase involved in G2/M cell cycle transition.     

Intraluminal duodenal diverticulum with malposition of the ampulla of Vater

Intraluminal duodenal diverticulum is a rare congenital anomaly, sometimes associated with malposition of the ampulla of Vater. When the diverticulum is excised, the position of the ampulla should be determined carefully to avoid injury to pancreaticobiliary ducts. We report two patients with symptomatic intraluminal duodenal diverticulum and malposition of the ampulla. The ampulla was located on the rim of the diverticulum in one patient; in the others, the ampullary site was the posterior wall of the duodenum. Both patients underwent successful excision of the diverticulum without ductal injuries. As we have been unable to find any case with an ampullary location on the anterior wall of the duodenum, anterior duodenotomy followed by identification of the ampulla must precede excision of the diverticulum in order to avoid pancreaticobiliary ductal injuries.     

Electrical transport properties of fullerene peapods interacting with light

In this paper, we investigate the transport properties of field-effect transistors (FETs) based on various kinds of fullerene (C(60), C(70), and C(84)) peapods. The encapsulation of various fullerenes inside single-walled carbon nanotubes (SWNTs) is characterized by TEM and Raman spectroscopy. Our results indicate that the transport characteristics of p-type SWNTs are extremely sensitive to the encapsulation of various kinds of fullerene. In the absence of light illumination, the threshold voltage of p-type SWNTs shifts towards positive values after C(60) and C(70) encapsulation, and ambipolar transport characteristics are observed for C(84) peapods. The photoinduced electron transfer phenomenon is observed for fullerene peapods under light illumination. The optical response for C(60) and C(70) peapod FET devices is reflected in a shift of threshold voltage towards negative values, and a recoverable characteristic is observed when light is off. After a long period of light illumination, in contrast to p-type C(60) and C(70) peapods, an n-type transport characteristic is observed on C(84) peapods.     

Simultaneous determination of aminoglycoside antibiotics in milk by liquid chromatography with tandem mass spectrometry

A multiresidue method was developed for determination of nine aminoglycoside antibiotics (streptomycin, dihydrostreptomycin, spectinomycin, neomycin, kanamycin, gentamicin, destomycin A, apramycin, and tobramycin) in milk by LC/MS/MS. The drugs were extracted with 0.01 mol/L potassium dihydrogen phosphate containing 2% trichloroacetic acid, and the extracted solution was cleaned on cation-exchange cartridge columns (Oasis WCX and Oasis MCX). LC separation was performed on a TSK-gel VMpak25 column (50 mmx2.0 mm i.d.) using gradient elution with 0.1% formic acid and acetonitrile containing 0.1% formic acid as the mobile phase. Recoveries of the drugs spiked at 0.01 or 0.1 microg/g in milk ranged from 66.1 to 110.8%, with a coefficient of variation of less than 17.1%. Limits of quantification of the drugs in milk were 0.001 approximately 0.01 microg/g. This method was used for analysis of milk from a lactating cow treated for clinical mastitis with two intramammary infusions of kanamycin (KM). Milk samples were analyzed during the withdrawal times at 12-hour intervals. KM concentrations were lower than the Japanese provisional MRLs (0.4 microg/g) at 60 hours after infusion, and subsequently fell to 0.01 microg/g.     

Development of a method to lower recontamination after chemical decontamination by depositing Pt nano particles: (II) consideration of the Pt effect on oxide composition

The Pt coating (Pt-C) process has been developed to lower the recontamination by ⁶⁰Co which was incorporated in oxides on piping surface after chemical decontamination. In order to determine the suppression mechanism of ⁶⁰Co deposition by Pt-C, it is important to investigate the formation of oxide film ⁶⁰Co deposition behavior on oxide with Pt-C specimens. In this paper, we observed the composition change of oxide after a ⁶⁰Co deposition test under the hydrogen water chemistry condition, and considered the ⁶⁰Co deposition behavior on oxide for Pt-C specimens. The Ni and Co metal concentrations in oxide were dramatically changed by Pt-C process. The Ni metal concentrations in oxide for specimens with and without the Pt-C process were 11.2% and 18.0%, respectively. On the other hand, the Co metal concentrations in oxide for specimens with and without the Pt-C process were 1.2% and 0.2%, respectively. This composition change of the oxides indicated that ⁶⁰Co incorporation for the Pt-C specimens was suppressed by replacing ⁶⁰Co with Ni. We concluded that the Ni²⁺ ions were incorporated into the 8a site of the oxide spinel structure instead of Co²⁺ ions due to the effect of the conversion deposition energy.     

Prognostic determinants in extrahepatic bile duct cancer

BACKGROUND/AIMS: The understanding of histopathological prognostic factors is critical to improving surgical outcome. This study investigated the microscopic features of cancer of the extrahepatic bile duct in order to clarify the prognostic determinants affecting surgical outcome. METHODOLOGY: In 90 cancers of the extrahepatic bile duct, the correlation between several microscopic parameters and survival was investigated. Lymphatic, venous, and perineural invasion, and the surgical margin (tumor-free or tumor-positive) were examined with serial step-wise sectioned specimens. RESULTS: Seven pT1-tumors showed no venous or perineural invasion and no lymph node involvement and were associated with prolonged survival (5 year survival, 86%) compared with pT2,3 tumors (23%). In pT2,3 tumors, lymphatic, venous, and perineural invasion was found in 80%, 47%, and 88%, respectively, with no significant differences in occurrence of these parameters according to the origin of the primary tumor. As for survival with pT2,3 tumors, lymph node involvement (58%) and status of the surgical margin were significant parameters (p=.0330 and p=.0309, respectively). In addition, these latter parameters differed significantly according to the origin of the primary tumor. CONCLUSION: In cancer of the extrahepatic bile duct, lymph node involvement and status of the surgical margin were the most important microscopic parameters affecting prognosis.     

A 125-mm/sup 2/ 1-Gb NAND flash memory with 10-MByte/s program speed

A single 3-V only, 1-Gb NAND flash memory has been successfully developed. The chip has been fabricated using 0.13-/spl mu/m CMOS STI technology. The effective cell size including the select transistors is 0.077 /spl mu/m/sup 2/. To decrease the chip size, a new architecture is introduced. The in-series connected memory cells are increased from 16 to 32. Furthermore, as many as 16 k memory cells are connected to the same wordline. As a result, the chip size is decreased by 15%. A very small die size of 125 mm/sup 2/ and an excellent cell area efficiency of 70% are achieved. As for the performance, a very fast programming and serial read are realized. The highest program throughput ever of 10.6-MByte/s is realized: 1) by quadrupling the page size and 2) by newly introducing a write cache. In addition, the garbage collection is accelerated to 9.4-MByte/s. In addition, the write cache accelerates the serial read operation and a very fast 20-MByte/s read throughput is realized.     

The enhancing effect of anionic alpha-helical peptide on cationic peptide-mediating transfection systems

A peptide consisting of 12 amino acids including 3 glutamic acids (LAEL-LAEL-LAEL; 4(3)E) underwent pH-dependent conformational change from random coil to alpha-helix when the pH was decreased from 7.4 to 5.0 in the presence of egg PC. This alpha-helical 4(3)E had higher membrane-perturbation activity at acidic conditions compared with neutral conditions. When 4(3)E was incorporated with plasmid DNA-cationic peptide complex that utilizes an endocytosis pathway for uptake into cultured cells, high transfection efficiency was observed, indicating that 4(3)E can enhance the transfection activity of cationic peptide. It is likely that 4(3)E in the multi-complex of the plasmid DNA and the cationic peptide effectively disrupts the endosomal membrane and increases the population of the complex which could transfer to cytosol. The small lysosome-disruptive peptide is very probably useful as the enhancer molecule for the gene transfer techniques mediated by the endocytosis pathway.