Granular flow experiment using artificial gravity generator at International Space Station

Studying the gravity-dependent characteristics of regolith, fine-grained granular media covering extra-terrestrial bodies is essential for the reliable design and analysis of landers and rovers for space exploration. In this study, we propose an experimental approach to examine a granular flow under stable artificial gravity conditions for a long duration generated by a centrifuge at the International Space Station. We also perform a discrete element simulation of the granular flow in both artificial and natural gravity environments. The simulation results verify that the granular flows in artificial and natural gravity are consistent. Further, regression analysis of the experimental results reveals that the mass flow rate of granular flow quantitatively follows a well-known physics-based law with some deviations under low-gravity conditions, implying that the bulk density of the granular media decreases with gravity. This insight also indicates that the bulk density considered in simulation studies of space probes under low-gravity conditions needs to be tuned for their reliable design and analysis.

Effect of Calcium-phosphate Desensitizers on Staining Susceptibility of Acid-eroded Enamel

OBJECTIVE

To investigate the effect of calcium-phosphate-based desensitizers, Teethmate AP paste (TMAP) and Teethmate Desensitizer (TMD) (Kuraray Noritake Dental, Tokyo, Japan), on the prevention of staining on acid-eroded enamel.

METHODS AND MATERIALS

Forty polished enamel samples (4×4×1 mm) from bovine incisors were randomly divided into five groups (n=8). After immersion in 50 mL of 0.5% citric acid (pH 2.5) for 15 minutes to form acid-eroded surfaces, the surfaces were subjected to different treatments with TMAP, TMD, and NaF (0.21% means 950 ppm) for five minutes. Another eroded group was not treated with desensitizer. For the control group, the samples were not eroded or treated. All the samples were stored in artificial saliva (AS) at pH 7.2 for 24 hours at 37°C. The TMAP, TMD, or NaF was reapplied at eight and 16 hours during the 24 hours of storage time. The surface roughness (Sa) was evaluated following ISO 25178 for surface texture using confocal laser scanning microscopy (VK-X 150 series, Keyence, Osaka, Japan) before acid erosion, after acid erosion, and after 24 hours of incubation in AS. Afterward, the color difference was measured with a dental colorimeter (Shade Eye NCC, Shofu, Kyoto, Japan) before and after staining with tea solution.

RESULTS

One-way repeated measures analysis of variance showed that acid erosion significantly increased Sa (p<0.001). TMAP- and TMD-treated groups exhibited lower Sa values than the NaF group and the no-desensitizer treatment group. The greatest staining was observed in the NaF group and the no-desensitizer group, while the TMAP and TMD groups significantly decreased the formation of stains.

CONCLUSIONS

Acid-eroded enamel increased surface roughness and tended to absorb more stains. However, the application of TMAP and TMD moderated the roughness and thus prevented the formation of extrinsic stains.

Raising children in Fukushima

Before the accident at Fukushima Daiichi nuclear power plant in March 2011, I never thought about radiation. After the accident, I originally evacuated with my two sons, but we returned home a few weeks later to be with my husband and parents-in-law as I felt that life with my family was what mattered and the very basis of my happiness. Today, 5 years after the accident, some people are able to think positively about the situation, and some remain uncertain. This article offers my experience and thoughts as a mother to help enable others to feel less stressed about eating food produced in Fukushima, and suggests ideas to help lift their spirits.

Use of new minimum intervention dentistry technologies in caries management

Preservation of natural tooth structure requires early detection of the carious lesion and is associated with comprehensive patient dental care. Processes aiming to detect carious lesions in the initial stage with optimum efficiency employ a variety of technologies such as magnifying loupes, transillumination, light and laser fluorescence (QLF® and DIAGNOdent® ) and autofluorescence (Soprolife® and VistaCam®), electric current/impedance (CarieScan(®) ), tomographic imaging and image processing. Most fluorescent caries detection tools can discriminate between healthy and carious dental tissue, demonstrating different levels of sensitivity and specificity. Based on the fluorescence principle, an LED camera (Soprolife® ) was developed (Sopro-Acteon, La Ciotat, France) which combined magnification, fluorescence, picture acquisition and an innovative therapeutic concept called light-induced fluorescence evaluator for diagnosis and treatment (LIFEDT). This article is rounded off by a Soprolife® illustration about minimally or even non-invasive dental techniques, distinguishing those that preserve or reinforce the enamel and enamel-dentine structures without any preparation (MIT1- minimally invasive therapy 1) from those that require minimum preparation of the dental tissues (MIT2 - minimally invasive therapy 2) using several clinical cases as examples. MIT1 encompasses all the dental techniques aimed at disinfection, remineralizing, reversing and sealing the caries process and MIT2 involves a series of specific tools, including microburs, air abrasion devices, sonic and ultrasonic inserts and photo-activated disinfection to achieve minimal preparation of the tooth. With respect to minimally invasive treatment and prevention, the use of lasers is discussed. Furthermore, while most practices operate under a surgical model, Caries Management by Risk Assessment (CaMBRA) encourages a medical model of disease prevention and management to control the manifestation of the disease, or keep the oral environment in a state of balance between pathological and preventive factors. Early detection and diagnosis and prediction of lesion activity are of great interest and may change traditional operative procedures substantially. Fluorescence tools with high levels of magnification and observational capacity should guide clinicians towards a more preventive and minimally invasive treatment strategy.

Evaluation of new treatment for incipient enamel demineralization using 45S5 bioglass

Bioglass 45S5 is a silica-based bioactive glass capable of depositing a layer of hydroxyl carbonate apatite on the surface of the glass when immersed in body fluids. The present paper studies a new technique for treating early human dental enamel caries lesions by using a paste composed of 45S5 bioglass and phosphoric acid. Artificial caries lesions were induced in enamel flat surfaces by means of a decalcification solution. All specimens were exposed to a brushing-abrasion challenge to test the durability of any newly formed layer resulting from the application of 45S5 bioglass paste. The specimens treated with bioglass paste showed complete coverage with a layer of brushite crystals. The brushing-abrasion challenge did not statistically affect the percentage of enamel coverage with the crystalline layer formed by the application of bioglass (p<0.05). These crystals were converted to hydroxyapatite crystals when stored in artificial saliva for 14 days. The current technique suggests the possibility of restoring incipient enamel erosive lesion with an abrasion durable layer of hydroxyapatite crystals.

Dental Pulp Dendritic Cells Migrate to Regional Lymph Nodes

Dendritic cell (DC) migration to regional lymph nodes (RLNs) is an essential step in adaptive immunity, and cell-surface antigens on migrating DCs greatly affect the quality and quantity of subsequent immune responses. Although MHC class II+ DC-like cells exist in the dental pulp, the lineage and function of these cells remain unknown. Here, we identified migratory DCs from the dental pulp after cusp trimming and acid etching in KikGR mice, in which the photoconvertible fluorescent protein changed from green to red upon violet light exposure. Two major cell fractions from the dental pulp had migrated to the RLNs at 16 hrs after cusp treatment, which showed the following lineage markers in the main and second fractions: CD11chighCD11b++Ly6Clow Ly6Glow F4/80+ and CD11cmedCD11b+++Ly6C++Ly6G+++F4/80-, respectively. These lineage markers indicate that the former cells were DCs that had migrated through afferent lymphoid vessels, and the latter were granulocytes recruited via blood circulation. Migratory dental pulp DCs were mature, expressing the highest levels of CD273 (B7-DC) and CD86 co-stimulators and MHC class II. Our results suggest that cariogenic-bacteria-exposed dental pulp DCs migrate to RLNs and there trigger adaptive immune responses.

The effect of glutathione on 2-hydroxyethylmethacrylate cytotoxicity and on resin-dentine bond strength

AIM

To evaluate the influence of reduced glutathione (GSH) application on 2-hydroxyethylmethacrylate (HEMA) cytotoxicity on rat pulpal cells and evaluate the effect of etched-dentine treatment with GSH on the immediate microtensile bond strength (μTBS) of etch-and-rinse adhesive.

METHODOLOGY

The cytotoxicity of 10 mmol L(-1) HEMA, 10 mmol L(-1) HEMA + 1 mmol L(-1) GSH, 10 mmol L(-1) HEMA + 5 mmol L(-1) GSH and 10 mmol L(-1) HEMA + 10 mmol L(-1) GSH was compared (6 h and 24 h). Cells viability was measured by means of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, followed by morphological observation of cells. Etched-dentine surfaces were rinsed and treated with one of the following solutions: 2% GSH, 5% GSH or 10% GSH, bonded with Adper Single Bond Plus (3M, ESPE, St. Paul, MN, USA) and restored with resin composite. The control group received no GSH treatment. After 1 day of water-storage at 37 °C, the specimens were subjected to μTBS testing. Cytotoxicity and μTBS data were analysed by one-way anova and Tukey post hoc tests (P < 0.05).

RESULTS

There were significant differences between the groups. HEMA elicited a remarkable toxic effect. 10 mmol L(-1) GSH prevented HEMA-induced damage at both exposure times. Whilst 5 mmol L(-1) GSH lost its protective effect at 24-h exposure time and 1 mmol L(-1) GSH showed no protective effect at both exposure times, GSH had no significant effect on the immediate μTBS; however, 5% GSH had higher bond strength value when compared to 10% GSH (P = 0.003).

CONCLUSION

Controlled concentrations of GSH had a protective effect against HEMA cytotoxicity. GSH had neither positive nor negative influence on μTBS.

Monomer-Collagen Interactions Studied by Saturation Transfer Difference NMR

Functional monomers in dentin adhesives are involved in wetting dental substrates, demineralization, and the formation of calcium salts. However, the interaction of these monomers with collagen is not understood at a molecular/atomic level. We performed saturation transfer difference (STD) NMR spectroscopy to investigate the binding interaction of 2 functional monomers, 4-methacryloyloxyethyl trimellitate anhydride (4-META) and 10-methacryloyloxydecyl dihydrogenphosphate (MDP), with atelocollagen as a triple-helical peptide model. High STD intensities were detected on the protons in the aliphatic region in MDP, whereas they were not detected for 4-META. The STD results imply that MDP has a relatively stable interaction with the collagen, because of the hydrophobic interactions between the hydrophobic MDP moieties and the hydrophobic collagen surface. This finding indicates that MDP-collagen complexation accounts for stable dentin bonding.

Protocol dependence of mechanical properties in granular systems

We study the protocol dependence of the mechanical properties of granular media by means of computer simulations. We control a protocol of realizing disk packings in a systematic manner. In 2D, by keeping material properties of the constituents identical, we carry out compaction with various strain rates. The disk packings exhibit the strain rate dependence of the critical packing fraction above which the pressure becomes non-zero. The observed behavior contrasts with the well-studied jamming transitions for frictionless disk packings. We also observe that the elastic moduli of the disk packings depend on the strain rate logarithmically. Our results suggest that there exists a time-dependent state variable to describe macroscopic material properties of disk packings, which depend on its protocol.

Effect of hesperidin in vitro on root dentine collagen and demineralization

OBJECTIVES

Caries progress might be controlled when collagen matrix could be preserved after demineralization. The aim of this pH cycling study was to investigate the effect of hesperidin, a citrus flavonoid antioxidant, on dentine collagen and remineralization in dentine lesion, and compared with that of chlorhexidine.

METHODS

The pH cycling was employed on bovine root dentine by demineralization for 14 h, incubation in testing solutions (hesperidin or chlorhexidine) for 2 h and remineralization with bacteria-derived collagenase for 8 h, for 8 days. Calcium release was measured by means of an atomic absorption spectrophotometer, and degraded collagen matrix by collagenase was investigated by assaying hydroxyproline. The lesion depth and mineral loss was evaluated by means of transverse microradiography.

RESULTS

The effect of testing solutions had a significant difference on the results of chemical analyses (p<0.0115 for calcium release; p<0.0008 for degradated collagen). The lesion depth and mineral loss were reduced in the lesions where were incubated with hesperidin and chlorhexidine. The remineralization in deep lesions was found when the matrix was incubated in hesperidin, whilst no mineral uptake in deep lesion when incubated in chlorhexidine.

CONCLUSION

Hesperidin preserved collagen and inhibited demineralization, and enhanced remineralization even under the fluoride-free condition.

CO2 Laser Improves 45S5 Bioglass Interaction with Dentin

Bioglass 45S5 is a bioactive glass that can create a layer of calcium-phosphate crystals on mineralized hard tissues. In this study, 45S5 bioglass was mixed with phosphoric acid and irradiated with CO2 laser and examined as a possible aid in the treatment of dentin hypersensitivity. The dentinal surface modified by the aforementioned technique was chemically and micro-morphologically examined with a field emission scanning electron microscope (FE-SEM) equipped with an energy-dispersive x-ray spectroscope (EDS), and the crystalline structures of the examined dentinal surfaces were examined by x-ray diffraction (XRD). Moreover, the mechanical properties of the newly formed layer were examined by nanoindentation. The results showed that 45S5 bioglass could occlude the dentinal tubule orifices with calcium-phosphate crystals. The application of CO2 laser potentially improved the mechanical organization of these crystals.

Measurement of adiponectin production from differentiated metabolic stem cells

To treat metabolic syndrome, fat tissue dysfunction should be corrected rather than controlling conventional risk factors such as hypertension, dyslipidemia, and diabetes mellitus. For this purpose, accumulating evidence suggests increasing plasma adiponectin levels can be a key treatment strategy, especially in setting of food or drug selection. Here we report that adipocyte precursors obtained from several sites of fat tissue, which we call Metabolic Stem Cells (MSC), could be used as a novel screening system to identify adiponectin enhancing drugs or food for individual patients. MSC were prepared from fat tissues collected from 29 patients. They were differentiated in cultures into mature adipocytes. The time course of adiponectin production was independent of the number of mature adipocytes and gradually decreased at 48 h after differentiation. Pioglitazone, a full PPARgamma agonist, stabilized adiponectin production at days 8-16 after differentiation, whereas telmisartan, a partial PPARgamma agonist, showed variable response. Dividing the adiponectin secretion of day 12 by that of day 10 provided an estimate of adiponectin-producing activity irrespective of the number of MSC-derived adipocytes in culture. Using this score of adiponectin-production activity, we successfully assessed 16 agents in a 96-well plate. The effect of each agent on adiponectin production showed a similar pattern, independent of the site of isolated adipose tissue. Our results show that MSC can be used as a tool for selecting drugs that enhance adiponectin-production activity.

Reduced carotid atherosclerosis in asthmatic patients treated with inhaled corticosteroids

Although inflammation is an important component of atherosclerosis, it is unknown whether inhaled corticosteroids (ICS) as anti-inflammatory drugs prevent atherosclerosis. In the present study, carotid atherosclerosis was evaluated by ultrasonography in 150 asthmatic patients who had been regularly treated with ICS, and in 150 matched nonasthmatic controls, with an assessment of atherosclerotic risk factors. Carotid intima-media thickness was significantly lower in the asthmatic patients than in the controls. The prevalence of carotid plaque tended to be lower in the asthmatic patients than in the controls. Defined carotid atherosclerosis was diagnosed in 51 of the asthmatic patients, who were older, with a higher prevalence of males, a higher prevalence of dyslipidaemia and a lower mean daily dose of ICS than the 99 patients without carotid atherosclerosis. Stepwise multiple logistic regression analysis identified age, male sex and dyslipidaemia as positive risk factors for carotid atherosclerosis. The mean daily dose of ICS was a negative risk factor. Carotid atherosclerosis is reduced in asthmatic patients treated with ICS compared with matched controls. This study suggests that ICS may have protective effects against atherosclerosis.

Effect of long- and short-term treatments with pravastatin on diabetes mellitus and pancreatic fibrosis in the Otsuka-Long-Evans-Tokushima fatty rat

BACKGROUND AND PURPOSE

The effects of statins on diabetes mellitus (DM) are controversial, and their effects on pancreatic fibrosis are poorly defined. We investigated the effect of long- and short-term treatments with pravastatin on the development of DM and pancreatic fibrosis in DM-prone Otsuka-Long-Evans-Tokushima Fatty (OLETF) rats.

EXPERIMENTAL APPROACH

Male OLETF rats were divided into four groups at 12 weeks of age. The first group received a standard rat diet until the end of the experimental period at age 80 weeks. The second group was given a diet containing 0.05% pravastatin from 12 weeks of age, before the onset of DM and pancreatic fibrosis, and the third group was given the same pravastatin diet from 28 weeks of age, after the onset of DM and pancreatic fibrosis, until age 80 weeks. The fourth group received the same pravastatin diet only for 16 weeks, from 12 to 28 weeks of age, and switched to a standard diet. Progressions of DM and pancreatic fibrosis were evaluated.

KEY RESULTS

Long-term treatments with pravastatin, either from 12 or 28 weeks of age, decreased serum glucose concentration and fibrotic area, elevated superoxide dismutase activity and down-regulated transforming growth factor-beta1 mRNA in the pancreas. In contrast, after a short-term treatment with pravastatin, these parameters markedly deteriorated after its cessation.

CONCLUSIONS AND IMPLICATIONS

The results suggest that long-term treatment with pravastatin improves DM and pancreatic fibrosis via anti-oxidative and anti-fibrotic properties, whereas cessation of pravastatin abolishes these beneficial effects, and accelerates DM and pancreatic fibrosis.

Increased expression of Smad6 deteriorates murine acute experimental pancreatitis in two models

BACKGROUND

Smad6 is implicated in the inhibition of bone morphogenetic protein signalling. However, the function of Smad6 in the pancreas remains obscure.

METHODS

To elucidate the unknown function of Smad6, we developed transgenic mice selectively expressing Smad6 in pancreatic acinar cells using a plasmid construct coding rat elastase 1 enhancer/promoter.

RESULTS

Smad6 transgenic mice had no specific distinguishing phenotype such as body weight, pancreatic wet weight and concentrations of pancreatic protein. However, Smad6 transgenic mice reacted to hyperstimulation by caerulein injection or a diet containing 0.5% ethionine. Maximal amylase release stimulated by CCK-8 was significantly decreased in Smad6 transgenic mice acini, and trypsin activities in transgenic mice acini were significantly increased after stimulation of CCK-8. There was no difference in effect of CCK-8 stimulation on the subsequent increase in intracellular free Ca2+ concentration ([Ca2+](i)) between wild-type and transgenic mice acini. These findings suggest that reduced pancreatic enzyme secretion was caused by the disorder of its downstream signal transduction pathways in acinar cells. The amino acid sequence at the N-terminus of Smad6 was similar to that of synaptosome-associated protein (SNAP) 25 interacting protein, which plays an important role in regulating exocytosis of pancreatic enzymes in acinar cells. Pancreatic SNAP25 protein levels in transgenic mice were decreased after caerulein-induced pancreatitis.

CONCLUSIONS

These results suggest that elevated expression of Smad6 inhibits normal function of SNAP25-interacting protein and SNAP25, reduces amylase secretion in acinar cells, and increases the susceptibility of acinar cells to the onset of pancreatitis.

Endoscopic mucosal resection for early gastric cancer: comparison of two modifications of the cap method

BACKGROUND AND STUDY AIM

Endoscopic mucosal resection using a cap (EMR-C) is an established method for curative resection of early neoplastic lesions; prelooping of the snare may however be difficult and lead to imprecise resection. We therefore compared two modifications of the conventional technique using outer snare placement with an accessory channel in a prospective, nonrandomized study.

PATIENTS AND METHODS

Between October 2004 and March 2007, 54 patients (men 37, women 17; mean age 71 years) underwent EMR. One method involved an internally retained snare (IRS) cap, with a fixed prelooped snare inside the cap; the other method used an externally guided snare (EGS) cap with the snare guided over an oblique cap. The main outcome parameters were specimen size, en bloc resection, and complications.

RESULTS

There was no difference between use of the IRS and EGS cap methods in relation to specimen size (27.6 vs. 27.1 mm), or rates of en bloc resection (88.9 % vs. 83.3 %); only one perforation occurred, and this was in the EGS group.

CONCLUSION

Both techniques appeared to provide similar efficacy, the inner rim of the IRS cap stabilizes aspiration of the lesion compared with the EGS cap that does not have it.

Grasping-forceps-assisted endoscopic submucosal dissection using a novel irrigation cap-knife for large superficial early gastric cancer

The technique of endoscopic submucosal dissection (ESD) needs special skills and involves a long procedure. We therefore developed a new type of dissection knife, the irrigation cap-knife (the Kume cap-knife attachment, which uses a fixed snare), that facilitates ESD by just sliding over the muscle layer with a coagulating current. The ESD procedure using the irrigation cap-knife was performed in seven patients with intramucosal gastric cancer. The tumor was separated from the surrounding normal mucosa using the insulated-tip knife. Submucosal dissection was then performed by pushing our device along the muscle layer while applying a coagulating current, at the same time as a grasping forceps, deployed through the accessory channel, was used to push the lesion away from the muscle layer. The rate of en bloc resection was 100% (7/7). The irrigating cap-knife was extremely useful for ESD of large intramucosal cancers in the stomach.

Green tea polyphenol (-)-epigallocatechin-3-gallate inhibits ethanol-induced activation of pancreatic stellate cells

BACKGROUND

Activated pancreatic stellate cells (PSCs) play a central role in the pathogenesis of pancreatic fibrogenesis and inflammation. Ethanol, a major cause of chronic pancreatitis, directly induces PSC activation and oxidative stress. Inhibition of PSC activation or stimulation to PSC might be an effective therapeutic strategy for the prevention of pancreatic fibrosis, and (-)-epigallocatechin-3-gallate (EGCG), a major component of green tea extracts, is a potent antioxidant of polyphenols. Therefore, we examined the mechanisms through which ethanol induces oxidative stress on PSCs and evaluated the effect of EGCG on activation and cell functions of ethanol-stimulated PSCs.

MATERIALS AND METHODS

The PSCs were isolated from the pancreas of male Wister rats with Nycodenz gradient methods and cells between passages one and four were used. Isolated PSCs were cultured with ethanol (50 mM) in the absence or presence of EGCG (5 microM or 25 microM).

RESULTS

The EGCG pre-treatment abolished ethanol-induced lipid peroxidation of the cell membrane, loss of total superoxide dismutase (SOD) activity and suppressed ethanol-induced gene expressions of Mn- and Cu/Zn-SOD. EGCG also suppressed ethanol-induced p38 mitogen-activated protein (MAP) kinase phosphorylation, alpha-smooth muscle actin production in PSCs and activated transforming growth factor-beta1 secretion into the medium. Furthermore, EGCG inhibited ethanol-induced type-I procollagen production and collagen secretion. In addition, EGCG inhibited transformation of freshly isolated cells to activated myofibroblast-like phenotype.

CONCLUSIONS

Our results suggest that green tea and polyphenols could prevent pancreatic fibrosis by inhibiting PSC activation through the antioxidative effect.

How to improve repetition ability in patients with Wernicke's aphasia: the effect of a disguised task

Dissociation "automatico-voluntaire" is a symptom observed in aphasic patients. We elucidated the difference between voluntary and involuntary speech output in a quantitative manner using the same task materials in nine patients with Wernicke's aphasia. All the patients exhibited better ability and less paraphasias in a repetition task elicited in a disguised condition than in an ordinary repetition condition. This result indicates that the output difficulty in Wernicke's aphasia might be a disability of volitional control over the language system.

Cholecystokinin-1 receptor protein up-regulation during pancreatic regeneration after acute haemorrhagic pancreatitis in rats

BACKGROUND

Cholecystokinin (CCK) plays an important role in regeneration after acute pancreatitis in rats. The present study was aimed to elucidate the role of CCK-1 receptor (CCK-1R) in acute pancreatitis. We investigated the serial changes in CCK-1R mRNA and protein levels and their immunolocalization after acute haemorrhagic pancreatitis induced in male Wistar rats by retrograde intraductal infusion of 4% sodium taurocholate (100 micro L 100 g(-1) body weight).

METHODS

Histological changes were evaluated by haematoxylin and eosin staining. Pancreatic CCK-1R mRNA was determined by Northern blot analysis. Pancreatic CCK-1R protein was evaluated by immunoblot analysis and immunohistochemistry with a polyclonal antibody against rat CCK-1R protein.

RESULTS

Histological findings revealed that newly formed acinar cells were detected at the periphery of tubular complexes on day 14, and normal architecture of lobules was observed focally on day 21. Pancreatic CCK-1R mRNA peaked on day 3 and thereafter gradually decreased. Cholecystokinin-1R protein rapidly increased after induction of pancreatitits, reaching a maximal level on day 3. On day 3, intense immunoreactivity for CCK-1R protein was observed in both the cytoplasm of vacuolized acinar cells and the tubular complexes. In the regenerative process after acute haemorrhagic pancreatitis in rats, the expression of pancreatic CCK-1R mRNA and protein increased, and intense immunoreactivity for CCK-1R protein was observed in tubular complexes in the cytoplasm of regenerated acinar cells.

CONCLUSION

These results suggest that CCK-1R contributes to pancreatic regeneration after acute haemorrhagic pancreatitis and that tubular complexes are involved in the process of acinar cell regeneration following pancreatic injury.

Gene expression profiling identifies liver X receptor alpha as an estrogen-regulated gene in mouse adipose tissue

Estrogens reduce adipose tissue mass in both humans and animals. The molecular mechanisms for this effect are, however, not well characterized. We took a gene expression profiling approach to study the direct effects of estrogen on mouse white adipose tissue (WAT). Female ovariectomized mice were treated for 10, 24 and 48 h with 17beta-estradiol or vehicle. RNA was extracted from gonadal fat and hybridized to Affymetrix MG-U74Av2 arrays. 17beta-Estradiol was shown to decrease mRNA expression of liver X receptor (LXR) alpha after 10 h of treatment compared with the vehicle control. The expression of several LXRalpha target genes, such as sterol regulatory element-binding protein 1c, apolipoprotein E, phospholipid transfer protein, ATP-binding cassette A1 and ATP-binding cassette G1, was similarly decreased. We furthermore identified a 1.5 kb LXRalpha promoter fragment that is negatively regulated by estrogen. Several genes involved in lipogenesis and lipolysis were identified as novel targets that could mediate estrogenic effects on adipose tissue. Finally, we show that ERalpha is the main estrogen receptor expressed in mouse white adipose tissue (WAT) with mRNA levels several hundred times higher than those of ERbeta mRNA.

Risk factors for asymptomatic atherosclerosis in Japanese type 2 diabetic patients without diabetic microvascular complications

Atherosclerotic vascular diseases are frequently associated with diabetes mellitus. There has been increasing evidence showing that the atherosclerotic diseases in diabetic patients are distinct from diabetic microvascular complications as to their pathophysiology and epidemiology. However, we have no information on the prevalence of asymptomatic atherosclerosis in diabetic patients before the onset of microvascular diseases. In the present investigation, we aimed to evaluate risk factors for the atherosclerosis in type 2 diabetic patients without the microvascular diseases. For this purpose, we evaluated atherosclerotic change of carotid arteries in 125 Japanese type 2 diabetic patients who had neither atherosclerotic vascular diseases nor diabetic microvascular complications. When atherosclerotic change was defined as the mean intima-media thickness (IMT) of >/= 1.1 mm and/or the presence of plaque lesion, 50% of patients had atherosclerosis of the carotid arteries. Risk factors for the carotid atherosclerosis were age, low-density lipoprotein (LDL)-cholesterol, hypertension, and diabetes treatment. Age and LDL-cholesterol were associated with mean IMT. Age, diabetes treatment, LDL-cholesterol, and hypertension were positively associated with plaque lesion, while high-density lipoprotein (HDL)-cholesterol was negatively associated with it. Fasting plasma glucose, glycosylated hemoglobin (HbA(1c)), and known diabetes duration remained unassociated with any parameters of asymptomatic atherosclerosis of the carotid arteries. These results indicate that glycemic control is unrelated with asymptomatic atherosclerosis in type 2 diabetic patients without diabetic microvascular complications. Conventional risk factors and diabetes treatment are independently associated with atherosclerosis of the carotid arteries in these patients.

Effects of the prostaglandin I2 analogue, beraprost sodium, on vascular cell adhesion molecule-1 expression in human vascular endothelial cells and circulating vascular cell adhesion molecule-1 level in patients with type 2 diabetes mellitus

Beraprost sodium is an orally active prostaglandin (PG)I(2) analogue, which has antiplatelet and vasodilating properties. In this study, we investigated the effects of beraprost on the expression of vascular cell adhesion molecule-1 (VCAM-1), one of the key molecules involved in atherosclerosis, in cultured vascular endothelial cells. In addition, we examined the effects of beraprost on circulating VCAM-1 level and atherosclerosis progression in patients with type 2 diabetes mellitus. Beraprost significantly decreased tumor necrosis factor-alpha (TNF-alpha)-induced VCAM-1 expression in human vascular endothelial cells. Beraprost also repressed human monocytoid U937 cell adhesion to the vascular endothelial cells. Twenty-five patients with type 2 diabetes mellitus who had atherosclerotic change of carotid arteries were enrolled for an open prospective study: 11 patients received beraprost for 3 years, while the other 14 did not. The 3-year changes of circulating VCAM-1 level, as well as those of carotid arterial intima-media thickness (IMT) were significantly lower in the patients receiving the beraprost treatment than that in the patients without the treatment. Thus, beraprost had an ability to repress the expression of VCAM-1 in human vascular endothelial cells. In addition, beraprost lowered circulating VCAM-1 level and prevented the increase of carotid IMT in patients with type 2 diabetes mellitus. Considering that circulating VCAM-1 and IMT are predictive of future vascular events, beraprost may have a beneficial effect on progression of atherosclerosis in diabetic patients.

Serum pepsinogen can predict response to H2-receptor antagonist in patients with functional dyspepsia

BACKGROUND

Therapy for the relief of symptoms of functional dyspepsia is unpredictable.

AIM

To identify which patients may benefit from antisecretory therapy.

METHODS

Twenty-seven patients with functional dyspepsia were selected to receive H2-receptor antagonist (H2RA) treatment for 4 weeks. Serum pepsinogen A, pepsinogen C and gastrin were measured, and Helicobacter pylori status was determined. Symptoms were assessed at baseline and after H2RA treatment.

RESULTS

Fourteen patients were identified as H2RA responders and the remaining patients were non-responders. No differences were found between responders and non-responders with regard to serum pepsinogen A, pepsinogen C, gastrin and H. pylori status. However, the pepsinogen A/C ratio was significantly higher in responders than in non-responders. Ten of the 13 functional dyspepsia patients (77%) with a high value of the pepsinogen A/C ratio (> or = 4.5) achieved symptom resolution by H2RA, compared with only one of the eight patients (13%) with a low value of the pepsinogen A/C ratio (< or = 3.0).

CONCLUSIONS

The serum pepsinogen A/C ratio seems to identify those functional dyspepsia patients for whom acid control provides benefit. This ratio may be a practical tool for the management of functional dyspepsia patients.

A case of POEMS syndrome associated with reactive amyloidosis and Waldenström's macroglobulinaemia

A72-year-old Japanese man presented with a 5-year history of fatigue, night sweats, oedema of dorsum of foot, muscle weakness, and paresthesia of the lower extremities. On examination, the patient fulfilled the diagnostic criteria for POEMS syndrome, but was unusual in that he also had underling Waldenström's macroglobulinaemia with IgM kappa. The M protein of POEMS syndrome is usually IgG and IgA with lambda light chains. To our knowledge, there are only three cases of POEMS syndrome with IgM kappa including our case. Autopsy findings revealed that small lymphocytes were more prominent than plasma cells in the bone marrow. These plasma cells were stained with IgM kappa. Amyloid deposits identified by Congo red stain were detected predominantly in the vascular walls of the gastrointestinal tract, pancreas and kidney. This amyloid protein was classified as amyloid associated protein. This is the first case of POEMS syndrome associated with reactive amyloidosis and Waldenström's macroglobulinaemiae.

Increased gastric acid secretion in cholecystokinin-1 receptor-deficient Otsuka Long-Evans Tokushima fatty rats

BACKGROUND

It is hypothesized that cholecystokinin stimulates acid secretion directly and indirectly by binding to CCK-2 (CCK-B/gastrin) receptors on both parietal and enterochromaffin-like cells. At the same time, however, it inhibits acid responses by stimulating the paracrine secretion of somatostatin from D cells and thereby exerts a tonic inhibition on the parietal cells. To test the validity of this hypothesis, we determined gastric acid secretion in the CCK-1 (CCK-A) receptor-deficient Otsuka Long-Evans Tokushima fatty (OLETF) rats.

METHODS

Gastric acid secretion was determined in the acute fistula OLETF and the control Long-Evans Tokushima Otsuka (LETO) rats. Plasma concentrations of gastrin, CCK, somatostatin and histamine were determined by radioimmunoassay. The levels of CCK-2 receptor mRNA in the mucosa of the glandular stomach were determined by Northern blot analysis.

RESULTS

Pentagastrin- and CCK-8-stimulated as well as basal acid outputs in OLETF rats were significantly higher than those in LETO rats. CCK-2 receptor antagonist reduced basal acid outputs and completely suppressed CCK-8-stimulated acid secretion in both strains. CCK-8 enhanced the pentagastrin-stimulated gastric acid output in OLETF rats, but not in LETO rats. In LETO rats, CCK-1 receptor antagonist increased CCK-8-stimulated gastric acid secretions to those in OLETF rats. The level of CCK-2 receptor mRNA in the stomach in OLETF rats was 2-fold higher than that in LETO rats. In OLETF rats, plasma concentrations of CCK and histamine were higher, whereas somatostatin concentrations were lower than those in LETO rats, with no change in basal plasma gastrin concentrations.

CONCLUSIONS

These results in the CCK-1 receptor-deficient OLETF rats confirmed that CCK stimulates acid secretion by binding to CCK-2 receptors, but at the same time inhibits acid responses by stimulating the paracrine secretion of somatostatin from D cells in the gastric mucosa.

Pancreatic cancer complicated by disseminated intravascular coagulation associated with production of tissue factor

A 54-year-old man was diagnosed as having pancreatic cancer and disseminated intravascular coagulation. His plasma tissue factor level on the 11th hospital day was 996 pg/ml (normal range, 120-270 pg/ml). He was treated with gabexate mesilate, antithrombin III, and low-molecular-weight heparin. However, he died of multiple organ failure on the 17th hospital day. The histological finding was poorly differentiated ductal adenocarcinoma of the pancreas, and the production of tissue factor in this lesion was revealed. Tissue factor is a factor that initiates blood coagulation; thus, its expression in pancreatic cancer is one of the causes of coagulation abnormalities in this disease. Although one report has demonstrated immunoreactivity for tissue factor in pancreatic cancer, the patient's detailed clinical course was not mentioned in that report. This is the first report to prove that pancreatic cancer produced tissue factor in a patient with disseminated intravascular coagulation.

Precordial compression without airway management induces lung injury in the rodent cardiac arrest model with central apnea

To investigate whether the lung injury induced by precordial compression without ventilation or not, in the cardiac-arrest animal model with central apnea. Thirty male Sprague-Dawley rats were anesthetized with halothane. The cardiac arrest was induced by 100 mg/kg ketamine (IV) and accompanied with central apnea. They were allocated to four groups by means of resuscitation. Group A was treated with only precordial compression without the other treatments. In group B with tracheotomy and precordial compression. In group C was performed tracheotomy, oxygenation, and precordial compression. The animals in group D were treated with tracheotomy, oxygen administration, artificial ventilation, and precordial compression. Four minutes after cardiac arrest, the resuscitation was started and continued for 20 min. PaCO(2) in the group without mechanical ventilation increased significantly after the start of the resuscitation. All animals were sacrificed after resuscitation procedure. The wet/dry weight ratio of lung in group A (6.9+/-0.8) was significantly higher than that of the other groups B, C and D (5.9+/-0.6, 5.7+/-0.4 and 5.6+/-0.4, P<0.05 in each). The pathological findings also demonstrated the lung injuries, such as edema, migration, and destruction of structure in group A. The precordial compression alone did not improve CO(2) elimination in the gasping-less cardiac arrest model, as well as maybe inducing more severe lung injury than that with the protective management. This experimental model raises the possibility that chest compressions without airway management might result in lung injury.

Role of TGF-beta1, extracellular matrix, and matrix metalloproteinase in the healing process of the pancreas after induction of acute necrotizing pancreatitis using arginine in rats

INTRODUCTION

Pancreatic tissues are almost completely restored to normal after an attack of acute pancreatitis, once the cause of the disease is removed. Transforming growth factor (TGF)-beta and extracellular matrix (ECM) are known to play an important role in the process of wound healing in pathologic diseases. Tissue repair is a process regulated by a balance between synthesis and degradation of ECM.

AIMS

To elucidate the role of TGF-beta, ECM, and matrix metalloproteinase (MMP) in the process of regeneration occurring after acute necrotizing pancreatitis.

METHODOLOGY

Acute necrotizing pancreatitis was induced by intraperitoneal injection of 500 mg/100 g body weight of L-arginine in male Wistar rats. Expression of TGF-beta1 and ECM messenger RNA (mRNA) was determined by Northern blot analysis, and that of MMP-1 and MMP-2 mRNA was examined by the reverse transcription polymerase chain reaction (RT-PCR). Immunoreactivity for ECM components, TGF-beta1, and MMP-2 in the pancreas was assessed by using a monoclonal antibody.

RESULTS

TGF-beta1 mRNA expression reached a peak value on day 2.5, with a decrease on day 3, and reached the control level on day 7. Procollagen types III and IV and fibronectin mRNA reached a peak value on day 2.5, whereas the expression level of procollagen type I mRNA was maximal on day 3, and gradually decreased to control levels by day 7. MMP-2 mRNA was significantly elevated on day 3, and peaked on day 5, whereas MMP-1 mRNA levels did not change throughout the observation period. Immunoreactivity for MMP-2 was observed around disrupted acinar cells and interstitial spaces on day 3, and maximally on day 7. Immunoreactivity for fibronectin was detected around disrupted acinar cells and interstitial spaces. On day 7, it was less than on day 5 around disrupted acinar cells and interstitial spaces, whereas in the regenerated acinar cells, it was undetected.

CONCLUSION

Our results show that TGF-beta1 mRNA expression peaked earlier than that of ECM mRNA. Furthermore, increased level of the MMP-2 transcript was followed by disappearance of fibronectin. Our findings suggest that TGF-beta1 plays an important role in ECM production in the early phase of acute pancreatitis, and that MMP-2 is involved in the subsequent healing process.