Relationship between the intracellular reactive oxygen species and the induction of oxidative DNA damage in human neutrophil-like cells

To clarify the mechanisms of intracellular induction of oxidative DNA damage, we have investigated the concentrations of intracellular reactive oxygen species and the amounts of 8-hydroxydeoxyguanosine (8OHdG), a mutagenic oxidative DNA damage, in human neutrophil-like cells, dimethylsulfoxide-differentiated HL60 (DMSO-HL60). We determined intracellular concentrations of hydrogen peroxide and superoxide by flow cytometry with dichlorofluorescein diacetate and hydroethidine, respectively. We determined the 8OHdG amounts with an electrochemical detector connected to HPLC after anaerobic sample processing. DMSO-HL60 releases superoxide upon stimulation with phorbol myristate acetate, and the released superoxide dismutates to hydrogen peroxide. Stimulation of DMSO-HL60 with 100 nM phorbol myristate acetate increased intracellular hydrogen peroxide, superoxide and 8OHdG (control). Addition of 1000 U/ml catalase decreased hydrogen peroxide (31.3% of control) and 8OHdG (20.3%). Addition of 100 U/ml SOD decreased superoxide (18.7%) and 8OHdG (41.6%). Addition of 1 mM deferoxamine decreased 8OHdG (30.4%), but increased hydrogen peroxide (129.6%). Addition of 200 microM 4-acetamido-4'- isothiocyanostilbene-2,2'-disulfonic acid decreased superoxide (59.9%) and 8OHdG (42.0%). Addition of 0.4% ethanol had no effect on superoxide concentration (102.2%), but tended to decrease hydrogen peroxide (83.5%) and 8OHdG (84.3%). Pretreatment of DMSO-HL60 with 0.1 mM FeSO4 increased 8OHdG (117.3%), but decreased hydrogen peroxide (75.8%). These findings indicate that the extracellularly released superoxide and hydrogen peroxide diffuse into the cell, but that such reactive oxygen species are not the direct molecules to induce 8OHdG. Our results suggest that 8OHdG is induced by the hydroxyl radical which is generated from intracellular hydrogen peroxide and superoxide-reduced Fe.     

Detection of proliferating cell nuclear antigen (PCNA) in peripheral blood mononuclear cells and sera of patients with malignant lymphoma

The proximity of farms to badger setts was compared between farms that had experienced a tuberculosis breakdown and those that had not, over the 6 year period from 1988 to 1993. The data were derived from a badger removal study conducted in East Offaly County in the Republic of Ireland. Badger removal began in 1989 and continued through 1993; by the end of 1990, approximately 80% of all badgers caught in the 6 year period had been removed. All badgers were examined, grossly, for evidence of tuberculosis. Tuberculosis status of the approximately 900 study herds was based on the results of the single intradermal comparative skin test and/or lesions of bovine tuberculosis. All herds were tested at least once annually. The number of herds experiencing bovine tuberculosis declined over the period, particularly in the years 1992 and 1993. The data on farm and badger sett location were stored and analysed, initially, in a geographical information system. Owing to the badger removal programme, the distance between the barn yard of a typical farm and the nearest occupied badger sett increased, by about 300 m year-1, and by about 600 m year-1 to the closest infected sett. In bivariate analyses, in the years 1988 and 1989, the risk of tuberculosis declined with increasing distance to a badger sett containing one or more tuberculous badgers. In multivariable logistic regression analyses, year and the average number of cattle tested per farm per year were controlled. A second identical analysis was conducted to control for the repeated observations on the same herds using generalised estimating equations. In both analyses, the risk of a multiple reactor tuberculosis breakdown decreased for herds at least 1000 m away from an infected badger sett, and increased as the number of infected badgers per infected sett increased. Despite the significantly reduced risk of a breakdown with increasing distance to infected badger setts, the relationship was not strong (sensitivity and specificity of the model in the low 70% range) and explained only 9-19% of tuberculosis breakdowns.     

Compositional design of Pb(Zr, Ti)O3 for highly reliableferroelectric memories

We have investigated Pb(Zr,Ti)O₃ (PZT) film composition suitable for highly reliable ferroelectric RAM (FeRAM) application. To obtain a wide operational margin for 2T/2C (two transistors and two capacitors) FeRAMs, the PZT film capacitor is needed to have a low coercive voltage (V_c) and a high dielectric constant on the polarization switching (ϵ_S) and a low dielectric constant on the nonswitching (ϵ_N), or essentially a large ϵ_S/ϵ_N ratio. Concerning the B-site composition in the perovskite structure, it is found that lowering the Zr/Ti ratio from 47/53 to Ti-richer ones increases the ratio of ϵ_S/ϵ_N as a positive effect on the wide operational margin, but increased V_c as a negative effect. Taking the balance of these factors into consideration, it is concluded that an optimum composition, such as Zr/Ti=30/70, provides the maximum operational margin. The A-site composition, on the other hand, affects the long-term reliability of a PZT capacitor. The endurance to the fatigue and imprint are enhanced by reduction of the Pb-excess and dope of La in the A-site. A La-doped PZT (Zr/Ti =30/70) capacitor is successfully integrated to the 8 kbit FeRAM macro with double-layer Al wiring to confirm the feasibility of this capacitor     

Bilateral synchronous testicular seminomas: a case report and review of the Japanese literature

A 39-year-old man was referred to our hospital with right testicular swelling. Ultrasonography and magnetic resonance imaging revealed bilateral, synchronous testicular tumors. Bilateral high inguinal orchiectomy was performed. Histological examination revealed anaplastic seminomas. Prophylactic radiation therapy was performed in the para-aortic and pelvic regions postoperatively, and no signs of metastasis have been found during the follow-up period of more than 5 months. Including the present case, 186 cases of bilateral testicular tumors reported in Japan are reviewed.     

Demulsification of o/w emulsion and subsequent water treatment using powder adsorbent

Demulsification of stable oil-in-water emulsion was studied using powder adsorbent. Among various adsorbents tested, activated carbon was found to be the most efficient regardless of the type of surfactants used. The more dose of activated carbon for the demulsification was required, the higher concentration of the surfactant as well as the larger amount of oil and the bigger size of the lipophilic and hydrophilic groups. Empirical equations were obtained to correlate the dose of activated carbon to the residual concentration of oil as a function of the initial concentration of surfactant.     

Thermal fracture mechanisms in ceramic thermal barrier coatings

Ceramic thermal barrier coatings (TBCs) represent an attractive method of increasing the high-tempera-ture limits for systems such as diesel engines, gas turbines, and aircraft engines. However, the dissimilari-ties between ceramics and metal, as well as the severe temperature gradients applied in such systems, cause thermal stresses that can lead to cracking and ultimately spalling of the coating. This paper reviews the research that has considered initiation of surface cracks, initiation of interfacial edge cracks, and the effect of a transient thermal load on interface cracks. The results of controlled experiments are presented together with analytical models. The implications of these findings to the differences between diesel en-gines and gas turbines are discussed. The importance of such work for determining the proper design cri-teria for TBCs is underlined.     

A method of estimating the rate of miniature end-plate potential occurrences based on parametric time series modeling

This paper presents a parametric method of estimating the rate of miniature end-plate potential (MEPP) occurrences. We consider the case where the rate of MEPP occurrences is raised by the constant deporalization of presynaptic terminals by using high-concentration potassium solutions. Under such conditions, since MEPP occurrences cannot be identified by eye due to waveform superposition, it is necessary to estimate the rate with the aid of statistical techniques instead of counting the occurrences by eye. In this paper it is assumed according to the literatures that the MEPP data are modeled as a stationary Poisson impulse process filtered by the linear system the impulse response function of which is the sum of two exponentials. Then, the discretized MEPP data are shown to be a second-order autoregressive (AR(2)) process, driven by the sum of 2 first-order moving average (MA(1)) processes (the residual time series). An explicit formula for estimating the rate can be derived by combining the second- and third-order moments of the residual time series. The validity of the proposed estimation method is verified through Monte Carlo simulations in which the rate is varied ranging from 100 to 10,000 s-1. Likewise, the proposed method is applied to estimation of the rate of actual MEPP data, which were observed at the frog's neuromuscular junction under high-concentration potassium solutions.     

A 128-kb FeRAM macro for contact/contactless smart-card microcontrollers

This paper describes a 128-kb FeRAM macro for smart-card microcontrollers. This macro, which was designed and fabricated using a 0.35-/spl mu/m three-metal CMOS and a Capacitor-on-Metal/Via-stacked-Plug (CMVP) process technology, is ideally suited for recent system LSIs such as smart-card microcontrollers. It has a flexible memory size ranging from 32 to 128 kb, a low consumption current of 0.3 mA, and endurance of more than 10/sup 8/ write/read cycles under a wide range of supply voltages, from 2.7 to 5.5 V. These characteristics, which are required of not only contact-type smart-card microcontrollers but also contactless-type ones, were achieved by using four newly developed circuit technologies: 1) a three-metal CMVP memory cell; 2) a voltage-regulating architecture; 3) a main/sub bitline and wordline structure; and 4) a dynamic-type offset sense amplifier.     

A 146-mm/sup 2/ 8-gb multi-level NAND flash memory with 70-nm CMOS technology

An 8-Gb multi-level NAND Flash memory with 4-level programmed cells has been developed successfully. The cost-effective small chip has been fabricated in 70-nm CMOS technology. To decrease the chip size, a one-sided pad arrangement with compacted core architecture and a block address expansion scheme without block redundancy replacement have been introduced. With these methods, the chip size has been reduced to 146 mm/sup 2/, which is 4.9% smaller than the conventional chip. In terms of performance, the program throughput reaches 6 MB/s at 4-KB page operation, which is significantly faster than previously reported and very competitive with binary Flash memories. This high performance has been achieved by the combination of the multi-level cell (MLC) programming with write caches and with the program voltage compensation technique for neighboring select transistors. The read throughput reaches 60 MB/s using 16I/O configuration.