Search

30日齢のホルスタイン種子牛1頭(雄)が、急性に落ち着きなく寝起きを繰り返し、起立時には腹部を蹴り上げるなどの疝痛症状を示した。排便量は少なく、腹部は進行性に膨満し振盪にて拍水音が聴取された。血液一般検査では、白血球数の著しい増加が顕著であった。腹部X線検査では、ガスが膨満しループ状になった小腸が腹腔内全域に観察された。右〓部切開による試験的開腹では、ガスで膨満した小腸が腹腔内に充満していた。触診にて腸問膜根の約180°反時計方向への捻転を確認し、これを用手的に整復した。術後、症例は速やかに回復した。

OBJECTIVE: The aim of this study was to test the effect of gut manipulation by either novel synbiotics or by metronidazole on either endotoxemia or the severity of liver damage in the course of acute pancreatitis from alcohol ingestion. METHODS: Sprague–Dawley rats were fed for 1 week through an intragastric tube a liquid diet with either: (i) 1 mL t.i.d. of a mixture of synbiotics (Lactobacillus acidophilus, Lactobacillus helveticus and Bifidobacterium in an enriched medium); (ii) 20 mg/kg t.i.d. metronidazole; or (iii) standard diet. Then, acute pancreatitis was induced by caerulein and when the disease was full-blown, rats were fed an alcohol-rich diet. Synbiotic and metronidazole treatment was given for a further 2 weeks. Transaminase and endotoxemia levels were measured before treatment, after 6 h, after 24 h and 2 weeks later, at the time the rats were killed. Liver samples were obtained for histological analysis. RESULTS: Synbiotics but not metronidazole improved the acute pancreatitis-induced increase in endotoxemia and transaminase levels. The addition of alcohol worsened these variables to a limited extent in the synbiotic-treated group, while metronidazole had a negative effect on liver damage. CONCLUSIONS: Gut flora pretreatment with synbiotics was able to effectively protect against endotoxin/bacterial translocation, as well as liver damage in the course of acute pancreatitis and concomitant heavy alcohol consumption. The beneficial effect of synbiotics on liver histology seems to be correlated with endotoxemia. Metronidazole did not produce such a beneficial effect; in fact, it further worsened liver damage when alcohol was added to the background of ongoing acute pancreatic inflammation.

Heme oxygenase (HO) is the rate-limiting enzyme in the catabolism of heme, followed by production of biliverdin, free iron and carbon monoxide (CO). Three mammalian HO isozymes have been identified, one of which, HO-1, is a stress-responsive protein induced by various oxidative agents. HO-2 and HO-3 genes are constitutively expressed. Recent studies demonstrate that the expression of HO-1 in response to different inflammatory mediators may contribute to the resolution of inflammation and have protective effects in several organs against oxidative injury. Although the mechanism underlying the anti-inflammatory actions of HO-1 remains poorly defined, both CO and biliverdin/bilirubin have been implicated in this response. In the intestinal tract, HO-1 is shown to be transcriptionally induced in response to oxidative stress, preconditioning and acute inflammation. Recent studies suggest that the induction of HO-1 expression plays a critical protective role in intestinal damage models induced by trinitrobenzene sulphonic acid or dextran sulphate sodium, indicating that activation of HO-1 may act as an endogenous defensive mechanism to reduce inflammation and tissue injury in the intestinal tract. These in vitro and in vivo data suggest that HO-1 may be a novel therapeutic target in patients with inflammatory bowel disease.

A laser interferometer gravitational wave detector requires an ultra high vacuum in the tubes in which the laser beams pass. To avoid noise due to scattered light from the surface of tubes, the surface should be treated with “black” coating without increasing the outgassing rate. We found that diamond-like Carbon (DLC) coatings are suitable for this aim. An outgassing rate of 3×10 −9 Pa m 3 s −1 m −2 at 50 h was achieved for DLC coatings on SUS304 without baking. This rate was better than the surface of SUS316 with baking. The reflectivity of the DLC surface was 5% at minimum for a laser beam of Nd:YAG ( λ=1064 nm ) which is used as a light source for the gravitational wave detector.

OBJECTIVES: The aims of the present study were to investigate the plasma concentration of endotoxin in patients with inflammatory bowel disease (IBD), the effect of metronidazole (MNZ) and of symbiotics on that concentration, and the relationship to IBD activity. METHODS: The study group comprised 26 patients with quiescent ulcerative colitis (UC), all of whom were on maintenance mesalazine treatment (1200− 2400 mg/day). The control group comprised 15 subjects. Blood samples were taken from all study subjects to measure: routine blood chemistry, endotoxin concentration, lipopolysaccharide binding protein (LBP) and macrophage-colony stimulating factor (M-CSF). All the IBD patients were randomly enrolled for a 2-week oral daily treatment regimen with either MNZ (250 mg t.i.d.) or the symbiotic mixture SCM-III (Lactobacillus acidophilus, L. helveticus and Bifidobacteria brevis in an ion- and vitamin-enriched medium; 3 mL t.i.d.). Following a 6-week washout period during which the patients continued their maintenance treatment, the cross-over study of the new treatments was begun. Blood parameters were checked at entry and 2 weeks after each treatment schedule. RESULTS: The concentration of endotoxin level in the UC patients, as a whole, was comparable with that of the control subjects. However, a separate group of patients with long-standing disease and pancolitis showed a statistically significant increase in toxin. SCM-III, but not MNZ, normalized this parameter. There was no statistical change in LBP and plasma endotoxin-inhibiting capacity in the IBD patients. The M-CSF concentration was increased in the UC group, particularly in the pancolitis subgroup. SCM-III, but not MNZ, significantly decreased the M-CSF concentration in the UC patients, but there was only an insignificant trend toward decrease in the subgroup. There was a significant correlation between M-CSF and endotoxin in the pancolitis subgroup (r: 0.74, P

OBJECTIVE: A preliminary in vitro study with hepatocyte culture showed that concentrations as low as 10 µg/mL of PN-M001 are able to significantly mitigate CCl4 hepatocyte damage (P 45%, P 15-fold, P

OBJECTIVE: The aim of this investigation was to assess the role of different therapeutic options aimed at modifying the gut microecology in experimental liver cirrhosis in view of the cytokine cascade and splanchnic and systemic hemodynamics. METHODS: Cirrhosis was induced in male Sprague-Dawley rats by carbon tetrachloride (CCL4). After the 6th week of CCL4 administration rats were divided into 5 groups for the remaining 6 weeks: (A) saline b.i.d; (B) lactulose 0.5 g b.i.d.; (C) rifaximine 1 mg b.i.d; (D) 2 mL b.i.d of a probiotic mixture and (E) 1 week of rifaximine followed by 5 weeks of probiotic. RESULTS: Rats with cirrhosis and ascites showed a significantly high concentration of either portal, splanchnic and systemic endotoxin, as well as plasma TNF-α concentration (P

AIM: The aim of the present study was to assess fecal organic acid excretion and gut flora changes in a group of patients with compensated liver cirrhosis without hepatic encephalopathy by comparing pro­biotic therapy with more common therapeutic approaches. METHODS: Thirty patients with compensated Child B liver cirrhosis were allocated into one of three matched groups, which were randomly given one of three 3-week oral treatments: (i) lactitol 20 g t.i.d.; (ii) 400 mg rifaximin b.i.d.; or (iii) the synbiotic SCM-III (Microflorana-F, Named, Lesmo, Italy) 10 mL t.i.d. Stool samples were collected at both the time of entry into the study and at the end of the trial period for the assessment of intestinal bacterial flora and for the determination of fecal pH and of organic acid concentration. RESULTS: All three tested compounds significantly increased the total anaerobic bacterial count to the same extent. The change was mainly due to a reduction in the Bacteriodes population and an expansion of the bifidobacteria population. However, only SCM-III significantly decreased the total count of Bacteroides and Clostridium. Lactitol and SCM-III decreased (to a similar extent) the fecal pH compared with healthy controls and with pretreatment values (P

The aim of this study was to assess the immunomodulatory effect of KC-1317 (a symbiotic mixture containing Saccharomyces boulardii lysate in a cranberry, colostrum-derived lactoferrin, fragaria, and lactose mixture) supplementation in immune-compromised but otherwise healthy elderly subjects. A liquid formulation of KC-1317 was administered in a randomized controlled trial (RCT) fashion to healthy volunteers (65-79 years) previously selected for low natural killer (NK) cell activity, and this parameter was checked at the completion of the study. A significant improvement in NK cell activity of KC-1317 consumers was observed as compared to placebo at the end of 2 months. Although preliminary, these beneficial immune-modulatory effects of KC-1317 in aged individuals might indicate its employment within a wider age-management strategy.

The electrical transport of nano-wires with a constriction is theoretically studied by using the single and two-band tight-binding models. It is shown that the characteristic features of the conductance obtained, such as plateau, oscillation and deviation from the quantized value, can be explained by the electronic state of the constriction, especially the number and the Fermi wavelength of the sub-bands (transverse channels). It is also shown that the minimum quantized conductance e2/h is obtained in ferromagnetic wires when the electronic state of one of the spin channels has a hybridization gap at or near the Fermi level.

Inorganic siliceous porous materials with different average pore diameters were applied to the adsorptive separation of methylalumoxane (MAO) used as co-catalyst in α-olefin polymerization. The co-catalytic performance of the separated MAO was investigated by propylene polymerization with rac-ethylene(bisindenyl)zirconium dichloride (rac-Et(Ind)2ZrCl2). The polymerization activity and the stereoregularity of the resulting polymer were markedly dependent upon the pore size of the porous material used for adsorptive separation. From the results obtained by the solvent extraction of the produced polymers, it was suggested that the adsorptive separation of MAO by porous materials is helpful in the characterization of MAO, and at least two different species of MAO are present.

Composite analysis of the winter stratospheric circulation with respect to the phase of the equatorial QBO is made by using the NCEP/NCAR reanalysis data over 40 years (1958–1997). It is found that the composite difference in the Southern Hemisphere is large not in midwinter but in early spring (November). It is also found that the level of the QBO reference which makes the large composite difference in the Southern Hemisphere is higher than in the Northern Hemisphere.

Tunnel conductance and magnetoresistance in tunnel junctions with amorphous insulating barriers are studied by numerical simulations based on the linear response theory. The effects of the disorder within the barrier on the tunnel conductance and magnetoresistance are clarified.

Local protuberances in negatively biased probe current (NBPC) after the incidence of moderately high power microwave pulses in a plasma-filled corrugated waveguide are observed. The aim of the present experiment is a fundamental study in the research of high power plasma-filled backward wave oscillators. Protuberances in NBPC profile and the peaks of standing waves of the RF electric field are observed always at the identical axial positions where the radius of the corrugated wall is the minimum. The electron energy distribution after the incidence of the microwave approaches the Druyvesteyn distribution rather than conventional Maxwellian distribution that is observed before microwave incidence. The protuberances in NBPC are found to consist of a uniform increase in electron temperature and of a localized rise in plasma density that is calculated from ion saturation currents. Physical reasons for the observations are discussed in some detail.

Agar diffusion analysis demonstrated that rat cystatin S, a cysteine proteinase inhibitor, inhibited the growth of all tested strains of a human oral, Gram-negative anaerobic periodontopathogen Porphyromonas gingivalis. Its specific inhibitory activity against this tissue-invasive bacterium but not against other tested oral bacterial species emphasized the importance of specific cysteine proteinases for growth of P. gingivalis.

The diffusion behavior of polymer latex particles in dispersion near the quartz interface has been estimated by evanescent wave dynamic light scattering (EVDLS) technique. The diffusion coefficient of the particles was measured as a function of the distance between the particle and interface. The apparent diffusion coefficient estimated by EVDLS was small for particles near the interface and increased upon increasing the distance from the interface, and then saturated at a certain value which is close to the value expected for free-motion. The range of the distance over which diffusion was affected by interaction with the interface depended on the added salt concentration. This means that the diffusion of the particle is influenced by an electrostatic interaction between the particle and quartz interface in addition to the hydrodynamic effect near the wall. This range was found to be more than 800 nm at 0 M salt condition but about 400 nm at 10-4 and 10-3 M salt conditions. Hence it is appropriate to say that the hydrodynamic effect reaches up to 400 nm and the electrostatic effect is longer ranged, more than 800 nm, for the system studied here. The EVDLS technique is a very powerful tool for quantitative estimations of the dynamic behavior of the particle near the interface and for estimation of the range where the wall effect is dominant. EVDLS will give us an answer to the question of “where is the ‘interface’ and where is the ‘bulk’?”.

Forced vibration tests were carried out at the Hamaoka (BWR) Unit 4 R/B (reactor building) in Japan in April and May of 1992. Fundamental dynamic characteristics of the R/B were obtained, including its interaction with the adjacent T/B (turbine building) and the soil–structure interaction. Results for the preceding R/Bs are compared, and probable causes for fluctuations in the resonance curve around the 1st peak are discussed. Furthermore, simulation analyses of the fundamental dynamic characteristics of the soil–structure system were conducted, using a basic lumped-mass soil–structure model (lattice model), and strong correlation with the measured data was obtained. Other detailed simulation models were employed to investigate the effects of simultaneously induced vertical response and response of the adjacent turbine building on the lateral response of the reactor building.

The central signal-processing unit for a portable multimedia terminal in the coming wide-band wireless communication age should meet the following three requirements: (1) high-performance for processing video-class wide-band digital signals, (2) low-power for extended battery life, (3) programmability to cope with applications with a small chip count. Conventional DSPs lack the high-performance, while emerging media processors consume too much power. This DSP exploits task-level, coarse-grained parallelism inherent in multimedia applications. This chip achieves performance in a power-efficient manner, while maintaining the programmability of conventional DSPs.

The mechanism of hearing impairment due to diabetes mellitus was examined in relation to changes in the level of the immunoreaction for the protein gene product 9.5 in the cochlea of spontaneously diabetic WBN/Kob rats. At 7 months (33 weeks) of age, when half of the males of this strain manifest diabetes, male WBN/Kob rats were divided into two groups as follows: one group consisted of prediabetic animals showing slightly decreased tolerance to glucose with a normal plasma concentration of glucose, normal urinary excretion of glucose, and functional hearing impairment (assessed in terms of elevation of hearing threshold). The second group consisted of diabetic animals with glucose intolerance, high plasma glucose level, polyuria, urinary glucose excretion, and more apparent elevation of hearing threshold. According to morphometric analysis of the spiral ganglion, the number of ganglion cells was significantly smaller in both the prediabetic and the diabetic animals than in the age-matched control Wistar rats. The staining intensity for protein gene product 9.5 was increased in some spiral ganglion cells of diabetic animals, but decreased in others according to quantitative immunohistochemical analysis. On the other hand, the immunoreactivity for protein gene product 9.5 was similar in the prediabetic animals to that in the control Wistar rats. These results suggest that numerical and immunohistochemical changes in the spiral ganglion cells reflect the onset and degree of the diabetic hearing impairment. [Diabetologia (1997) 40: 173–178]

We built an in-house oligonucleotide array on which 394 genes were selected based on our Serial Analysis of Gene Expression (SAGE) data and previously reported array data and listed several genes related to cancer progression. Among these, we focused on SEC11A, which encodes the SPC18 protein. SEC11A mRNA expression was measured by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) in gastric cancer (GC) tissue samples. Expression and distribution of SPC18 protein were investigated by immunohistochemical analysis in two independent GC cohorts (Hiroshima cohort, n=99 and Chiba cohort, n=989). To determine the effect of SPC18 on cell viability and invasiveness in vitro, MTT and Boyden chamber invasion assays were performed. To evaluate the influence of SPC18 on cell growth in vivo, GC cells were injected into severe combined immunodeficiency mice. Levels of TGF-α and EGF in media from the GC cells were measured by enzyme-linked immunosorbent assay (ELISA). Studies in human tissue revealed overexpression of SEC11A mRNA in 40% of 42 GC samples by qRT-PCR. Immunohistochemical analysis of SPC18 revealed that 26 and 20% of GC cases were SPC18-positive in the Hiroshima and Chiba cohorts, respectively. In both cohorts, the Kaplan-Meier analysis showed poorer survival in SPC18-positive GC cases than in SPC18-negative GC cases. Forced expression of SPC18 activates GC cell growth in vitro and in vivo. The levels of TGF-α in culture media from GC cells were reduced by knockdown of SPC18. These results indicate that SPC18 contributes to malignant progression through promotion of TGF-α secretion in GC.

Fas ligand (FasL) is a membrane-type cytokine belonging to the TNF family, and induces apoptosis through its cell-surface receptor, Fas. To determine the cell types that express FasL, various mouse tissues and cell lines were examined by Northern hybridization using a mouse FasL cDNA as a probe. Among tissues, lymphoid organs (thymus, lymph node, spleen), lung, and small intestine express low levels of FasL mRNA, suggesting the role of FasL in the general immune system and mucosal immunity. The testis expressed FasL mRNA most abundantly; however, the size of FasL mRNA in the testis was slightly shorter than those in other tissues. Distribution of FasL mRNA in a panel of cell lines indicated that the FasL expression is rather restricted to the cells of T cell lineage. Activation of the splenocytes with the T cell activators such as PMA and ionomycin, Con A, anti-CD3, or even IL-2 alone induced the expression of the FasL. CD8+ splenocytes expressed the FasL more abundantly than did the CD4+ splenocytes upon activation by Con A and IL-2. Among CD4+ CTL cell lines, the FasL was expressed in all Th1 and Th0, and some Th2 clones.

A 1/3-inch progressive scan CCD image sensor has been developed for image capture in computers and multi-functional digital video cameras. This device shows a high vertical resolution of 480 TV lines and 60 frames/sec image capture. The number of effective pixel is suitable for the digital TV standard and the horizontal driving frequency is 13.5 MHz. >

As a method for protecting electronic equipments from lightning attacks, mounting of SPD (surge protective device) which consists of a gas discharge tube (GDT), metal oxide varistor (MOV), and others is useful. In protecting equipment by SPD, overvoltage protection and energy harmonization become important. Above all, when overvoltage protection is thought of, response characteristics become important. Response characteristics depend on wavefront length and peak value applied to the equipment. In this paper, using 5 types of GDT, experiments were conducted on response characteristics when voltage waveforms having varying wavefront lengths were applied to investigate the response characteristics. Specially, the response characteristics for steep wavefront are specified.

Miniaturized acceleration data loggers were attached to the lower mandible of common carp Cyprinus carpio to remotely identify feeding behaviour. Whether the acceleration signal could distinguish the quantity and quality of food was also investigated. The frequency and amplitude of the lower mandible stroke, calculated from surging acceleration determined by continuous wavelet transformation, significantly increased during the feeding period compared to that during the non-feeding period. These characteristic movement patterns were maintained for mean ±s.e. 187·3 ± 38·2 s when the fish were fed a single item of food and for mean ±s.e. 419·3 ± 28·6 s when they consumed multiple items. The dominant cycle and amplitude calculated according to feeding event duration, however, did not differ significantly between the two types of diets the fish consumed. Surging acceleration could detect mean ±s.e. 89·8 ± 13·5% of feeding events, although the false detection rate was mean ±s.e. 25·9 ± 10·9%. The results indicate that the mandible acceleration measurement method could be utilized to detect and record the feeding events in fishes that use a suction feeding mode similar to C. carpio.

We tested the activity of the marine nutraceutical CL-1222 added with a coenzyme Q10 (CoQ10)-lutein-selenium component (Celergen(®), Laboratoires-Dom, Switzerland) to protect human fibroblasts against ultraviolet A (UVA)-induced photoaging. Cells obtained from 22- to 39-year-old healthy donors were pretreated with CL-1222 before UV irradiation, as compared with same quantity of the CoQ10-lutein-selenium component. As compared to untreated control, UVA-irradiated samples exhibited a significant increase of secreted matrix metalloproteinase-1 (MMP-1) (p0.001) with over four-fold MMP-1 upregulation (p0.001). Samples treated with CL-1222, but not with the CoQ10-lutein-selenium component, showed a significant decrease of MMP-1 secretion (p0.01) and expression decrease (60%, p0.01) with54% elastase activity inhibition (p0.01). This preliminary study shows that such marine nutraceuticals can significantly protect against UV-irradiation irrespective of the CoQ10-lutein-selenium component with a specific protective gene expression modulation amenable to novel clinical applications.

Using an antiserum against tumor necrosis factor (TNF)-alpha and an interleukin (IL-1) receptor antagonist, we studied putative roles of these cytokines in mediating the endotoxin-induced elevation of plasma adrenocorticotropic hormone (ACTH) and corticosterone levels in freely moving rats. Intravenous administration of Escherichia coli lipopolysaccharide (LPS) increased plasma ACTH and corticosterone levels in a dose-dependent manner. The plasma corticosterone reached to its highest level among a series of experiments after the administration of even the smallest dose (0.03 microgram/kg) tested. Plasma ACTH and corticosterone levels in these rats were completely inhibited by the intravenous administration of anti-murine TNF-alpha-rabbit antiserum (anti-TNFAS) after the administration of LPS but not by the intravenous administration of IL-1 receptor antagonist (IL-1RA). On the other hand, both recombinant human IL-1RA and anti-TNFAS significantly inhibited plasma ACTH increase stimulated with 10 micrograms/kg LPS. These findings indicate that 1) when the plasma corticosterone increase induced by intravenous LPS remains below its maximum, the effect is exclusively mediated by TNF-alpha, and 2) when a larger amount of LPS is administered, both IL-1 beta and TNF-alpha participate at least in part in the hypothalamic-pituitary-adrenal axis activation.

Rats experimentally infected with Trypanosoma cruzi Y strain exhibited hypertrophy of the submandibular gland at 18 days after infection. SDS-PAGE of infected rats saliva revealed the presence of an additional band with an apparent molecular weight of about 13KDa. Electrophoresis of protein saliva and immunochemical analysis with antibody against rat cystatin S confirmed that the protein was identical to that induced by beta adrenergic stimulation.

A 256-Mb DRAM with refresh-free-FIFO function for storage of moving pictures has been developed using 0.25-/spl mu/m CMOS technology. An operating current of 73 mA (reduction of 52% compared with a conventional circuit) has been achieved at 100 MHz based on introducing (1) a suppressed High(H)-level differential data transfer scheme which ran be operated at 0.6 V, (2) a new pre-charge method which features a 1/2 VCC precharge level in read cycle and VSS pre-charge level in write cycle, and (3) a divided operation of array circuits for serial access. >

We report one case of parkinsonism induced by cisapride and one case of Parkinson's disease whose symptoms were worsened by cisapride. Case 1. A 75-year-old female who had suffered from constipation and loss of appetite, was treated with cisapride for her gastro-intestinal symptoms. One year later, she developed progressive parkinsonian gait, cogwheel rigidity She showed parkinsonian gait, cogwheel rigidity and slowness in motion. Two months after cisapride was discontinued, her parkinsonism and depression disappeared. Case 2. A 66-year-old female with Parkinson's disease was given cisapride for constipation. Two months after starting cisapride, her akinesia and rigidity deteriorated gradually, and she became bed-ridden with dysphagia and dyspnea. After cisapride was discontinued, her parkinsonian symptoms improved gradually, and she became ambulant three months later. Cisapride is a benzamide derivative with a prokinetic action. Experimental studies have revealed that it has indirect cholinomimetic effects and potentially stimulates the gastrointestinal motor activity without blocking dopamine receptors or activating muscarinic cholinergic receptors. However, the present cases showed that cisapride could be a dopamine receptor blocker, and either induce or worsen parkinsonism. Therefore, cisapride should be avoided or very carefully used in parkinsonian patients and old people.

第2回極域科学シンポジウム/第33回極域生物シンポジウム 11月17日（木） 統計数理研究所 3階リフレッシュフロア

This paper reports a 0-level or wafer-level thin film packaging technology for MEMS using polycrystalline silicon-germanium (poly-SiGe) as the base material complemented with a metal seal. Hermetic packages with a cavity pressure below 0.3mbar are demonstrated on a SOI-based torsional-mode Si resonator. Monitoring the quality factor of these resonators revealed that the low pressure is retained for over 6 months while storing at ambient pressure and room temperature. Moreover, the package survived several months under harsh testing conditions with temperatures up to 125°C and 85% relative humidity. This thin film SiGe-based technology has large potential for the on-wafer packaging of a broad range of MEMS devices.

Expression of the IL-5 gene in T cells is induced in response to Ag stimulation; however, functional analysis of the IL-5 gene has been limited by lack of an appropriate transfection assay to facilitate measurement of the IL-5 promoter activity in response to T cell activation signals. Here, we describe a transient transfection system with which the IL-5 promoter activity can be assayed quantitatively. Using mouse thymoma line EL-4 cells, which produce several lymphokines including IL-2, IL-3, IL-4, IL-10, and GM-CSF in response to PMA, the effect of cAMP on IL-5 production was examined. These cells produce a low level of IL-5 when stimulated with PMA alone; however, N6, O2-dibutyryl cAMP (Bt2cAMP), in combination with PMA, augmented by more than tenfold the IL-5 production at the mRNA and the protein levels. Likewise, a transient transfection assay revealed that Bt2cAMP activated the IL-5 promoter more than tenfold, in a PMA-dependent manner, thereby indicating that two signals, PMA and cAMP, are required for optimal activation of the IL-5 promoter. Activation of the IL-5 promoter in response to Bt2cAMP and PMA depends on the region spanning from nucleotide position -1,200 to +33 relative to the transcription initiation site. Action of cAMP on the IL-5 promoter is mimicked by cotransfection of the expression plasmid containing cDNA encoding the catalytic subunit of protein kinase A, hence, cAMP probably exerts its action through the signaling pathway that involves protein kinase A. In contrast, Bt2cAMP almost completely inhibited the PMA-dependent activation of the endogenous IL-2 gene as well as the transfected IL-2 promoter. These results indicate that the IL-5 gene in EL-4 cells is positively regulated by cAMP in a manner opposite that for the IL-2 gene.

For identification of the protein-tyrosine kinases that are expressed in embryo stomach and gastric cancer, a 16-day rat embryo stomach and two human gastric cancer cDNA expression libraries were screened with an anti-phosphotyrosine antibody. Eight cDNAs encoding protein-tyrosine kinase were isolated, and Northern blot analysis revealed that five out of eight clones were highly expressed in rat embryo stomach, but not in adult rat stomach. From nucleotide sequence analysis, these five cDNAs were identified as elk, erk, esk, TTK and fyn, respectively. We report here that the expression levels of two families of receptor type tyrosine kinase genes, elk/erk and esk/TTK are developmentally regulated in rat stomach and highly expressed in human gastric cancer tissues. These findings suggest that elk/erk and esk/TTK genes play important roles in embryonic development and carcinogenesis of the stomach.

第32回極域生物シンポジウムポスター発表