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Early-age cracking of concrete can significantly affect the durability performance of concrete structures. Thermal stress evolution during hydration is the main contribution to early-age cracking of concrete materials, which associates with interacted chemical and physical processes. To control thermal cracking in practice, experience-oriented mix design is usually implemented, which may become ineffective and lose extensibility from one to another case since the thermal stress evolution is usually coupled with different environmental factors in reality (e.g., humidity conditions, temperature rise conditions and restraint degrees). In this case, the thermal stress evolution of concrete materials become sophisticated to be accurately modeled. Though related research has been widely studied, a constitutive model that can simulate thermal stress evolution of concrete with reliable experimental validation has been seldom reported. Recently, the temperature stress testing machine (TSTM) developed by this laboratory has been found to provide reliable evaluation for thermal stress of concrete with varied temperature rise conditions and restraint degrees. In view of that, this research presents a theoretical model to understand the interactive behavior between cement matrix and aggregate on the basis of TSTM, which traces the thermal stress evolution of concrete with varied temperature rise conditions and correlates the free deformation with restrained stress under full restraint degree.

Funder: King Abdulaziz City for Science and Technology; doi: http://dx.doi.org/10.13039/501100004919, Bulk high temperature superconductors based on the rare-earth copper oxides can be used effectively as trapped field magnets capable of generating large magnetic fields. The top-seeded infiltration growth (TSIG) processing technique can provide a more homogeneous microstructure and therefore more uniform superconducting properties than samples grown using conventional melt growth processes. In the present investigation, the properties of bulk, single grain superconductors processed by TSIG and magnetised by the pulsed-field magnetisation technique using a copper-wound solenoid have been studied. A trapped field of ∼3 T has been achieved in a 2-step buffer-assisted TSIG-processed Y-Ba-Cu-O (YBCO) sample at 40 K by magnetising the bulk superconductor completely via a single-pulse magnetisation process. Samples were also subjected to pulsed-field magnetisation at 65 K and by conventional field-cooled magnetisation at 77 K for comparison. Good correlation was observed between the microstructures, critical current densities and trapped field performance of bulk samples fabricated by TSIG and magnetised by pulsed-field and field-cooled magnetisation. The homogeneous distribution of Y2BaCuO5 inclusions within the microstructure of bulk YBCO samples fabricated by the 2-step buffer-assisted TSIG process reduces inhomogeneous flux penetration into the interior of the sample. This, in turn, results in a lower temperature rise of the bulk superconductor during the pulsed-field magnetisation process and a more effective and reliable magnetisation process.

The aim of this study was to determine whether l-methyl-[

The main form of treatment of a chordoma of the mobile spine is total en bloc spondylectomy (TES), but the clinical results are not satisfactory. Stand-alone carbon ion radiotherapy (CIRT) for bone and soft-tissue sarcomas has recently been reported to have a high rate of local control with a low rate of local recurrence.We report two patients who underwent TES after CIRT for treating a chordoma in the lumbar spine with good medium-term outcomes. At operation, there remained histological evidence of viable tumour cells in both cases. After the combination use of TES following CIRT, neither patient showed signs of recurrence at the follow-up examination. These two cases suggest that CIRT should be combined with total spondylectomy in the treatment of chordoma of the mobile spine.Cite this article: Bone Joint J 2013;95-B:1392–5.

Purpose To compare retrospectively outcome after photon radiotherapy alone, radiochemotherapy with temozolomide (TMZ), and carbon ion radiotherapy in patients with high-grade gliomas and to generate a hypothetical outcome curve for C12 and TMZ. Patients and methods Patients treated within a Phase I/II Trial with a carbon ion boost were compared retrospectively with randomly chosen patients treated with photons or photons in combination with TMZ in a retrospective analysis. Per treatment group, 16 patients with anaplastic astocytoma (AA), and 32 patients with glioblastoma (GBM) were included. Treatment outcome with focus on progression-free survival (PFS) and overall survival (OS) was analyzed. Results Median OS for patients with GBM was 9months with RT, 14months with RCHT group, and 18months in the C12 group. There was no significant difference between the C12 and the RCHT group. For patients with AA, median OS was 13months for RT, 39months for RCHT, and 35months after C12. The difference from RCHT to C12 was not significant. Median PFS for patients with GBM was 5months in the RT group, 6months in the RCHT group, and 8months in the C12 group. There was a significant difference between the RCHT group and the C12 group. For AA, median PFS was 15months with RT, 6months with RCHT, and 34 with C12. Comparing subgroups, C12 was significantly different from RCHT. Based on the significant OS increase from RT to RCHT, and from RT to C12, we projected the potential increase in outcome when combined C12 and TMZ would have been applied. A generated hypothetical curve based on the abovementioned outcome as well as preclinical examinations suggests there might be a benefit from the addition of C12 in patients with high-grade gliomas. Conclusions This exploratory retrospective study suggests a potential benefit of carbon ions in patients with high-grade gliomas. This hypothesis is now being evaluated prospectively in GBM within the randomized CLEOPATRA clinical trial.

The objective of this study was to investigate the effect of dietary supplementation with 5-aminolevulinic acid (5-ALA) on the immune system, inflammatory response, and growth performance of broiler chickens. The levels of cluster of differentiation 3 (CD3) mRNA in the spleens of chickens gradually increased with dietary 5-ALA concentration, while the expression levels of interleukin (IL)-2 decreased. Mitogen-induced proliferation of splenic mononuclear cells and blood mononuclear cell phagocytosis in chickens fed 0.001 and 0.01% 5-ALA-supplemented diets were significantly greater than in chickens fed a basal diet (control). Plasma thiobarbituric acid reactive substance (TBARS) concentration gradually increased along with 5-ALA supplement concentration. These results provide the first evidence that the use of dietary 0.001 and 0.01% 5-ALA supplementation induces the T-cell immune system via mild oxidative stress in chickens. Three hours after Escherichia coli lipopolysaccharide-induced immune stimulation, the levels of mRNA encoding pro-inflammatory cytokines, such as IL-6 and tumor necrosis factor-like ligand 1A (TL1A), in chickens fed a 0.001% 5-ALA-supplemented diet were significantly lower than those in chickens exposed to other treatments. The plasma caeruloplasmin concentration in chickens fed a 0.001% 5-ALA-supplemented diet was significantly lower than in controls or in chickens fed diets supplemented with other concentrations of 5-ALA 24 h after injection of LPS. In addition, BW at 21 and 50 d of age was significantly higher in chickens fed a 0.001% 5-ALA-supplemented diet than in control chickens. The findings suggest that supplementation of diets with 0.001% 5-ALA could prevent the catabolic changes induced by immunological stimulation. These results show that 5-ALA might be useful as an immunomodulator to stimulate T-cells via mild oxidative stress in growing broiler chickens, thereby improving the growth performance.

The insulin/PI3K/Akt signaling pathway is strongly involved in the differentiation of C2C12 cells, as has been demonstrated by the addition of IGFs and insulin to culture media. In this study, we have characterized the role of insulin in chick myoblast proliferation and differentiation in vitro and in vivo, and have revealed novel details of how this exogenous hormone influences myogenic genes during differentiation. Chick myoblast cells cultured in differentiation medium (DMEM containing 2% FBS) supplemented with insulin exhibited a significant decrease in MyoD and myogenin mRNA expression after 12h of culture compared to cells cultured in differentiation media alone. MyoD and myogenin immunoreactive proteins in cells cultured in differentiation medium supplemented with insulin were quite low compared to those in control culture. Supplementation of the differentiation media containing insulin with LY294002 (a PI3K inhibitor) induced myoblast differentiation. A significant increase in MyoD and myogenin mRNA expression was observed in these cells after incubation for 12h, and the level of expression was similar to that of control cells incubated with differentiation media alone. The DNA content and the phosphor-Erk1/2 protein level were increased by the addition of insulin to the differentiation medium. These results suggest that insulin and its signaling pathway play an inhibitory role in chick myoblast differentiation. A high level of Pax7 mRNA was observed in the skeletal muscle of 3-day-old chicks administered insulin or tolbutamide at 1-day-of-age. In addition, body weight at 21 and 50 days-of-age was significantly greater for chickens administered insulin or tolbutamide at 1-day-of-age than for control chickens. These results detail not only species-specific differences in insulin action for myoblasts but also provide novel information that may be used for the improvement of chicken meat production.

In carbon-ion radiotherapy treatment planning, the planar integrated dose (PID) measured in water is applied to the patient dose calculation with density scaling using the stopping power ratio. Since body tissues are chemically different from water, this dose calculation can be subject to errors, particularly due to differences in inelastic nuclear interactions. In recent studies, the authors proposed and validated a PID correction method for these errors. In the present study, the authors used this correction method to assess the influence of these nuclear interactions in body tissues on tumor dose in various clinical cases.Using 10-20 cases each of prostate, head and neck (HN), bone and soft tissue (BS), lung, liver, pancreas, and uterine neoplasms, the authors first used treatment plans for carbon-ion radiotherapy without nuclear interaction correction to derive uncorrected dose distributions. The authors then compared these distributions with recalculated distributions using the nuclear interaction correction (corrected dose distributions).Median (25%/75% quartiles) differences between the target mean uncorrected doses and corrected doses were 0.2% (0.1%/0.2%), 0.0% (0.0%/0.0%), -0.3% (-0.4%/-0.2%), -0.1% (-0.2%/-0.1%), -0.1% (-0.2%/0.0%), -0.4% (-0.5%/-0.1%), and -0.3% (-0.4%/0.0%) for the prostate, HN, BS, lung, liver, pancreas, and uterine cases, respectively. The largest difference of -1.6% in target mean and -2.5% at maximum were observed in a uterine case.For most clinical cases, dose calculation errors due to the water nonequivalence of the tissues in nuclear interactions would be marginal compared to intrinsic uncertainties in treatment planning, patient setup, beam delivery, and clinical response. In some extreme cases, however, these errors can be substantial. Accordingly, this correction method should be routinely applied to treatment planning in clinical practice.

Peroxisome proliferator-activated receptor gamma (PPARgamma) is a transcription factor that regulates adipocyte differentiation and modulates lipid metabolism in mammals. The aim of the present study was to investigate whether the administration of PPARgamma ligands, adipogenic cocktail, or both to newly hatched chicks regulates adipocyte differentiation in vivo and modulates fat deposition in growing broiler chickens. Levels of PPARgamma, CCAAT/enhancer binding protein alpha, and adipocyte fatty acid-binding protein mRNA in the abdominal fat pad of 7-d-old broiler chicks given a single intraperitoneal dose of troglitazone, a synthetic PPARgamma ligand, at 1 d old were significantly greater than those in control chickens. This suggests administration of troglitazone enhanced adipocyte differentiation in vivo. Adipose tissue weight in 28-d-old chickens similarly administered triolein emulsion containing troglitazone or adipogenic cocktail (i.e., dexamethasone, insulin, isobutyl-methylxanthine, and oleic acid) was also significantly less than that of control chickens. However, there was no significant difference in BW between treated and control chickens. Although BW and carcass composition were not different between troglitazone-treated and control chickens, at 48 d of age abdominal fat pad weight and feed intake were significantly decreased in chickens treated with troglitazone compared with controls. These results demonstrate that a single intraperitoneal injection of troglitazone to newly hatched chicks reduces fat deposition in mature broiler chickens.

An apparatus available for metastable-atom electron emission microscopy (MEEM) and photoelectron emission microscopy (PEEM) was constructed for the present study, based on our electron trajectory simulations. In MEEM, information on the local electronic states at the topmost layer is selectively obtained. The mesoscopic (μm-scale) images during initial oxidation of Ni(1 1 1) at temperature of 300–700 K were monitored and compared with the spectroscopic data. The MEEM images obtained upon thermal collision of He ∗ (2 3 S) are shaded in ascending order of brightness: the chemisorbed, clean, and oxidized surfaces. Their brightness is in good agreement with the emission yield estimated from the corresponding electron emission spectra. During nucleation and lateral growth of oxide at 300 K, the PEEM and MEEM images reveal dappled and sometimes periodic patterns, probably due to surface defects that lingered even after the surfaces were cleaned. The evolution of the images suggests that the initial oxidation proceeds via successive multinucleation. It is also found that the μm-scale patterns of oxide strongly depend on the substrate temperature and dose pressure of gaseous oxygen. The oxide formation in the mesoscopic scale is discussed in terms of a diffusion-reaction field.

The initial oxidation of Ni(1 1 1) in the temperature range of 550–700 K has been monitored by photoelectron emission microscopy (PEEM) and metastable-atom electron emission microscopy (MEEM). The PEEM and MEEM images show uniform patterns for the chemisorbed overlayer, reflecting the electronic homogeneity as seen at the μm scale. During the nucleation and lateral growth of oxide, however, the μm-scale pattern due to the formation of oxide domains appears and its evolution depends strongly on the substrate temperature and dose pressure of gaseous O 2 . Our data indicate that the high-temperature oxidation is regarded as a successive multi-nucleation process in a reaction-diffusion field.

A new phase of AlOOH (tentatively called δ-AlOOH) was synthesized at 21 GPa and 1000 °C and its crystal structure was identified by a powder X-ray diffraction method. Rietveld refinement revealed that this aluminum oxide hydroxide has an orthorhombic unit cell, a = 4.7134(1) A, b = 4.2241(1) A, c = 2.83252(8) A, V = 56.395 (5) A3, and Z = 2 in the space group of P21 nm. A calculated density is 3.533 g cm−3, which is about 4.48 and 15.04% denser than that of diaspore and boehmite, respectively. The δ-[Al0.86Mg0.07Si0.07]OOH is also stable at 21 GPa and 1000 °C, coexisting with majorite and phase egg, and its cell parameters are a = 4.710(1) A, b = 4.215(1) A, c = 2.839(1) A, and V = 56.37(1) A3.

In austenitic steels used for light water reactors (LWRs), neutron irradiation induces many kinds of degradation. For example, irradiation assisted stress corrosion cracking (IASCC) and swelling are two forms of this degradation. Although there are a great number of studies on radiation induced segregation (RIS) and void swelling at high temperatures (> 400° C ) corresponding to fast and fusion reactor conditions, up to now there have been few irradiation studies at low temperatures. This paper presents microchemical and microstructural changes in type 347 and 310+Nb stainless steels due to light ion irradiation. These samples were implanted with He+ and irradiated with 2 MeV H 2 + at 300°C, 350°C and 400°C. This simulated generation of transmutant He in a fusion environment. In addition, at 300°C test pieces stressed close to the yield stress were also irradiated with the same ions. The irradiation tests were carried out using the Dynamitron accelerator at Tohoku University.

Effects of dose rate on microstructural evolution in a simple model austenitic ternary alloy are examined. Annealed specimens are irradiated with fast neutrons at several positions in the core and above core in FFTF/MOTA between 390°C and 435°C in a wide range of doses and dose rates. In Fe–15Cr–16Ni, swelling seems to increase linearly with dose without incubation dose. Cavities are observed even in the specimens irradiated to 0.07 dpa at 1.9×10 −9 dpa/s . Both cavity nucleation and growth are enhanced by low dose rates. These are mainly caused by accelerated formation of dislocation loops at lower dose rates. Low dose rates enhance swelling by shortening incubation dose for the onset of steady-state swelling. In the specimens irradiated at higher dose rates to higher doses, high density of dislocation increases average cavity diameter, however decreases cavity density.

Quartz and feldspar minerals extracted from tephras were used for thermoluminescence (TL) dating of the paleolithic sites which are located in northeast Japan. Six narrow band optical filters from 415 nm to 630 nm and a broad band filter were used for TL measurements to confirm the dose dependence of luminescence with different wavelengths. Three tephras were dated as 306 ± 37 ka, 429 ± 93 ka and 490 ± 40 ka. The results of TL dating of tephra associated with paleolithic sites surveyed in this area from the early 1980s, which rarige from 9.7 ka to 500 ka, are compared with the ages obtained by the other scientific dating techniques; fission track dating, ESR dating, paleomagnetism and tephrochronology.

The effect of surgery on neutrophil leukotriene B4 (LTB4) generation and arachidonic acid content was examined in 9 patients undergoing major surgery for esophageal cancer and 10 patients undergoing lesser surgery. Plasma IL-8 and neutrophil LTB4 generation was increased significantly 6 h after surgery regardless of the extent of surgery. This finding was associated with a decrease in neutrophil arachidonate content. In patients who underwent major surgery, neutrophil LTB4 generation decreased progressively on the 1st, 2nd, and 4th postoperative days, and this decrease paralleled a further decrease in neutrophil arachidonate content. These findings suggest that neutrophils are activated by surgery, thereby consuming their arachidonic acid, and that neutrophil LTB4 generation is influenced by postoperative arachidonate levels.

Electron spin resonance (ESR) of Fe3+ ions and of radiation-induced centers in quartz (E’, peroxy and Al centers) was studied to distinguish between burnt and unburnt stone tools and to determine their age. The yellow stone tool with a reddish edge discovered at the paleolithic site in Kamitakamori, northern Japan, was investigated. The ESR spectrum intensity of Fe3+ ions around g=4.3 and the color of the material changed at 600°C and 240°C, respectively, which indicates that the red part was heated at 240–600°C. The E′ center in the red part was used for dating because isochronal annealing experiments showed low thermal stability of the Al center and overlap of broad signals at g=2.0086 onto the peroxy center. Assuming the same efficiency of defect formation in the red part as of that in the laboratory-heated material at 450°C, the obtained age of 520–770 ka is in concordance with the ages of the tephra layers at the site.

To clarify the erosion mechanism of spheroidal graphite cast iron, the authors carried out erosion tests and observed the continuous structural change in the vertical section near the surface. The erosion of spheroidal graphite cast iron progresses as follows: (1) the spheroidal graphites on the surface layer deform gradually; (2) lips grow in the impact direction; (3) they expand and drop off. Although the erosion progresses with the repetition of lip-growth and dropping off, the cycle differs depending on the materials. The wear growth rate, which serves as the standard cycle of lip-growth and drop off, decreases as the pearlite ratio increases and corresponds well to the erosion rate. We also confirmed that our continuous observation method is practical and useful for elucidating the erosion mechanism.

Objectives. This study compared the effect of a nitric oxide donor on limiting the size of infarct resulting from myocardial ischemia-reperfusion between atherosclerotic and nonatherosclerotic models. Background. Endothelial-derived relaxation in coronary arteries affected by ischemia is substantially impaired after reperfusion, and this impairment may exacerbate the myocardial ischemia-reperfusion injury. In animals with experimental atherosclerosis, release of endothelial-derived relaxing factor is also decreased, and the propagation of myocardial infarction could be exacerbated. Methods. We examined the extent of myocardial injury induced by ischemia (30 min) and reperfusion (48 hr) in rabbits fed a cholesterol-rich (1%) or normal diet for 10 weeks. We also evaluated the effect of a nitric oxide donor (S-nitroso-N-acetylpenicillamine [SNAP]), a nitric oxide precursor (l-arginine) or a degradation product of SNAP (N-acetylpenicillamine) on infarct size in these models. Results. Severity of myocardial injury was significantly exacerbated in cholesterol-fed rabbits (75.2 ± 4.4% [mean ± SEM]) compared with that in non-cholesterol-fed rabbits (53.2 ± 5.2%). This exacerbation was prevented by treatment with SNAP (50.2 ± 6.4%) but not with l-arginine (70.5 ± 6.0%) or N-acetylpenicillamine (70.4 ± 4.8%) in cholesterol-fed rabbits. However, SNAP did not limit infarct size in non-cholesterol-fed rabbits (60.8 ± 4.2%). The rate-pressure product was similar during the course of the experiment in all the groups. Conclusions. Myocardial damage induced by ischemia-reperfusion was significantly exacerbated in rabbits fed a long-term cholesterol-rich diet but was effectively reversed by treatment with a nitric oxide donor. However, this agent did not limit infarct size in normal rabbits. Thus, a nitric oxide donor reduces myocardial infarct size in atherosclerotic but not in nonatherosclerotic rabbits.

We have developed a 3D-stacked image sensor chip composed of CMOS image sensor (CIS) layer, correlated double sampling circuit (CDS) layer, and analog-to-digital converter (ADC) array layer using the chip-based 3D heterogeneous integration technology. Three kinds of chips, CIS chip, CDS chip, and ADC chip, which were fabricated by different technologies, are processed and stacked vertically to form a prototype 3D-stacked image sensor. Through-Si vias (TSVs) and metal micro-bumps are formed in chip-level before stacking. The fundamental characteristics are evaluated in the fabricated prototype 3D-stacked image sensor.

Improvements of power integrity (PI) on high-speed system have been studied from the point view of many structures in huge papers[1][2][3]. In this study, the PI simulation for the A-D mixed 3D stack chip system by TSV is done in many kinds of power sources. We already studied on the interposer with large area MIM capacitor was effective for the 3D system [4][5], that understood as an area structure made lower input impedance ever GHz region. As a result, we can find which the input impedance is related largely with the DeCap TSV distribution pitch. Consideration of approach wiring to distributed DeCap TSVs is the key issue for the better PI performance as the result.

We demonstrate the chip-based 3D heterogeneous integration technology for realizing highly parallel 3D-stacked image sensor. Three kinds of chips, CMOS image sensor chip, analog circuit chip, and ADC array chip, which were fabricated by different technologies, are processed and stacked vertically to form a prototype 3D-stacked image sensor. Through-Si vias (TSVs) and metal micro-bumps are formed in chip-level before stacking. The fundamental characteristics are evaluated in the fabricated prototype 3D-stacked image sensor.

We investigated the transient response characteristic of through silicon via (TSV) in a high-resistivity silicon interposer. For this investigation, signal ground (SG)-TSV-chain pairs in high-resisitivity silicon (>1000 Ω·cm) were prepared. Various pulse waves (swing: -1.8-0 V or 0-+1.8 V, pulse width: 250 ps-100 ms, duty ratio: 1/1) were applied to a SG-TSV-chain pair by using a pulse generator, and output signal was obtained using a sampling oscilloscope. From the rise and fall time of output signal, it was found that the change in transient response characteristic according to the frequency and voltage of the applied pulse wave was very small. This result demonstrates that the change in TSV capacitance with the input signal is very small and that high-resistivity silicon is effective for high speed signal processing.

We introduce the automotive application of 3D integration of a semiconductor and TSV technology in this paper. We chose the stereo camera of the driving support system as the application of this trial production, because it has strong requirement about the size, the performance and the reliability from the market, and also it is sensitive device but easy to find the error.

Goto-Kakizaki (GK) rat, a rodent model of spontaneously occurring non-insulin dependent diabetes mellitus (NIDDM), exhibits impaired glucose-stimulated insulin secretion. To explore the background of the β-cell dysfunction in NIDDM, we investigated whether and how the expression pattern of factors that would potentially be involved in the glucose-stimulated insulin secretion machinery is changed in GK rats. Using quantitative reverse transcription-PCR (RT-PCR) method, we found that the gene expression of CD38, a type 2 membrane protein which has ADP-ribosyl cyclase activity, is reduced by approximately 50% in islets of GK rats. Despite previous studies showing reduction in the FAD-linked mitochondrial glycerol-3-phosphate dehydrogenase (mGPDH) activity in GK rats, the mGPDH mRNA amounts were equal to those in the control Wistar rats, suggesting a difference that arose post-transcriptionally. These observations support the idea that multiple defects of the glucose-responsive insulin secreting machinery are involved in the development of diabetes in GK rats.

A process has been developed to utilize the large quantities of ash discharged from coal-fired fluidized-bed combustion boilers as road base material. Since the 1980s, the fluidized-bed boiler has been the subject of much study because it can burn fuels such as anthracite that cannot be burnt in pulverized coal-fired boilers and other conventional boilers, and because it eliminates the need for a flue gas desulfurizing facility. However, the disposal of fluidized-bed combustion ash is increasingly difficult, and therefore costlier, because of tighter legislation on waste management. Meanwhile, the excavation of road base material is also subject to stricter regulations due to fears of environmental impact. This has caused a shortage of material for road construction in some areas. It would be useful if ash from fluidized-bed combustion could be processed into road base material. There would be an enormous demand for such a product. A simple and low-cost road base material production process has, therefore, been developed where the ash is mixed with water, molded, steamed, aged and crushed into small pieces. This paper discusses the conditions required to yield optimum products and the paving test results.

Nitric oxide (NO) is believed to be an effector molecule that mediates interleukin (IL)-1 beta-induced destruction and dysfunction of pancreatic beta-cells. We have demonstrated that both exogenous NO and NO generated endogenously by IL-1 beta brought about apoptosis of isolated rat pancreatic islet cells as well as pancreatic beta-cell tumor-derived cell line HIT. This apoptosis was characterized by cleavage of DNA into nucleosomal fragments of 180-200 bp and morphologically by nuclear shrinkage, chromatic condensation, and apoptotic body formation. The IL-1 beta-induced internucleosomal DNA cleavage occurred in a time- and dose-dependent manner. Actinomycin D, cycloheximide, and nitric oxide synthase inhibitors inhibited the DNA cleavage, which was correlated with the amount of NO produced, indicating that NO produced by HIT cells themselves could mediate the apoptosis. Furthermore, in the presence of tumor necrosis factor (TNF)-alpha, large amounts of NO were produced by IL-1 beta and DNA cleavage occurred more noticeably, although TNF-alpha alone did not generate NO. Streptozotocin (STZ), a diabetogenic reagent containing a nitroso moiety, also released NO and induced internucleosomal DNA cleavage in HIT cells. These results suggest that NO-induced internucleosomal DNA cleavage is an important initial step in the destruction and dysfunction of pancreatic beta-cells induced by inflammatory stimulation or treatment with STZ.

Two basic helix-loop-helix (bHLH) transcription factors, E47 and E12, are involved in cell-specific gene expression as part of dimeric complexes which interact with the cis-acting motif E-box. Although both generated from a single gene (E2A) by means of alternative splicing, the structural difference in these bHLH regions between the two suggests that the two bHLH proteins may differ in some of their functions. As a step toward elucidating the individual implications of E47 and E12, we investigated the mRNA expression ratios of their homologues (A1 and kA1, respectively) in mouse tissues and cell lines. Both the A1 and kA1 mRNAs were ubiquitously expressed in all tissues examined. However, their ratios varied: e.g., skeletal muscle, 2.2 ±0.3 (mean ±SE); spleen, 2.0±0.2; pancreatic islet cells, 1.2±0.2. The A1 kA1 ratios in the cell lines investigated were similar to those of their original tissues. In conclusion, the ubiquity in mRNA expression observed for both the E47 and E12 homologues in mouse provides support for their involvement in a broad range of transcriptional regulation. The variation in the A1 kA1 expression ratios, on the other hand, supports the idea that A1 (E47) and kA1 (E12) each have some unique roles in the functions of these E2A gene-encoded bHLH proteins.