Diffusion weighted imaging with reverse encoding distortion correction: Improvement of image quality and distortion for accurate ADC evaluation in in vitro and in vivo studies.

PURPOSE: The purpose of this in vivo study was to determine the effect of reverse encoding direction (RDC) on apparent diffusion coefficient (ADC) measurements and its efficacy for improving image quality and diagnostic performance for differentiating malignant from benign tumors on head and neck diffusion-weighted imaging (DWI). METHODS: Forty-eight patients with head and neck tumors underwent DWI with and without RDC and pathological examinations. Their tumors were then divided into two groups: malignant (n = 21) and benign (n = 27). To determine the utility of RDC for DWI, the difference in the deformation ratio (DR) between DWI and T2-weighted images of each tumor was determined for each tumor area. To compare ADC measurement accuracy of DWIs with and without RDC for each patient, ADC values for tumors and spinal cord were determined by using ROI measurements. To compare DR and ADC between two methods, Student's t-tests were performed. Then, ADC values were compared between malignant and benign tumors by Student's t-test on each DWI. Finally, sensitivity, specificity and accuracy were compared by means of McNemar's test. RESULTS: DR of DWI with RDC was significantly smaller than that without RDC (p < 0.0001). There were significant differences in ADC between malignant and benign lesions on each DWI (p < 0.05). However, there were no significant difference of diagnostic accuracy between the two DWIs (p > 0.05). CONCLUSION: RDC can improve image quality and distortion of DWI and may have potential for more accurate ADC evaluation and differentiation of malignant from benign head and neck tumors.

Small Cell Lung Cancer Staging: Prospective Comparison of Conventional Staging Tests, FDG PET/CT, Whole-Body MRI, and Coregistered FDG PET/MRI.

BACKGROUND. Whole-body MRI and FDG PET/MRI have shown encouraging results for staging of thoracic malignancy but are poorly studied for staging of small cell lung cancer (SCLC). OBJECTIVE. The purpose of our study was to compare the performance of conventional staging tests, FDG PET/CT, whole-body MRI, and FDG PET/MRI for staging of SCLC. METHODS. This prospective study included 98 patients (64 men, 34 women; median age, 74 years) with SCLC who underwent conventional staging tests (brain MRI; neck, chest, and abdominopelvic CT; and bone scintigraphy), FDG PET/CT, and whole-body MRI within 2 weeks before treatment; coregistered FDG PET/MRI was generated. Two nuclear medicine physicians independently reviewed conventional tests and FDG PET/CT examinations in separate sessions, and two chest radiologists independently reviewed whole-body MRI and FDG PET/MRI examinations in separate sessions. Readers assessed T, N, and M categories; TNM stage; and Veterans Administration Lung Cancer Study Group (VALSG) stage. Reader pairs subsequently reached consensus. Stages determined clinically during tumor board sessions served as the reference standard. RESULTS. Accuracy for T category was higher (p < .05) for whole-body MRI (94.9%) and FDG PET/MRI (94.9%) than for FDG PET/CT (85.7%). Accuracy for N category was higher (p < .05) for whole-body MRI (84.7%), FDG PET/MRI (83.7%), and FDG PET/CT (81.6%) than for conventional staging tests (75.5%). Accuracy for M category was higher (p < .05) for whole-body MRI (94.9%), FDG PET/MRI (94.9%), and FDG PET/CT (94.9%) than for conventional staging tests (84.7%). Accuracy for TNM stage was higher (p < .05) for whole-body MRI (88.8%) and FDG PET/MRI (86.7%) than for FDG PET/CT (77.6%) and conventional staging tests (72.4%). Accuracy for VALSG stage was higher (p < .05) for whole-body MRI (95.9%), FDG PET/MRI (95.9%), and FDG PET/CT (98.0%) than for conventional staging tests (82.7%). Interobserver agreement, expressed as kappa coefficients, ranged from 0.81 to 0.94 across imaging tests and staging endpoints. CONCLUSION. FDG PET/CT, whole-body MRI, and coregistered FDG PET/MRI outperformed conventional tests for various staging endpoints in patients with SCLC. Whole-body MRI and FDG PET/MRI outperformed FDG PET/CT for T category and thus TNM stage, indicating the utility of MRI for assessing extent of local invasion in SCLC. CLINICAL IMPACT. Incorporation of either MRI approach may improve initial staging evaluation in SCLC.

Peripheral benzodiazepine receptor/18 kDa translocator protein positron emission tomography imaging in a rat model of acute brain injury.

OBJECTIVE: The activation of microglia in various brain pathologies is accompanied by an increase in the expression of peripheral benzodiazepine receptor/18 kDa translocator protein (PBR/TSPO). However, whether activated microglia have a neuroprotective or neurotoxic effect on neurons in the brain is yet to be determined. In this study, we investigated the ability of the novel PBR/TSPO ligand FEPPA to detect activated microglia in an animal model of primary neurotoxic microglia activation. METHODS: [18F] FEPPA positron emission tomography (PET) imaging was performed before and after intraperitoneal administration of lipopolysaccharide (LPS) (LPS group) or saline (control group) in a unilateral 6-hydroxydopamine (6-OHDA) lesion rat model of Parkinson's disease. Images were compared between these groups. After imaging, the brains were collected, and the activated microglia at the disease sites were analyzed by the expression of inflammatory cytokines and immunohistochemistry staining. These results were then comparatively examined with those obtained by PET imaging. RESULTS: In the unilateral 6-OHDA lesion rat model, the PBR/TSPO PET signal was significantly increased in the LPS group compared with the saline group. As the increased signal was observed 4 h after the injection, we considered it an acute response to brain injury. In the post-imaging pathological examination, activated microglia were found to be abundant at the site where strong signals were detected, and the expression of the inflammatory cytokines TNF-α and IL-1ß was increased. Intraperitoneal LPS administration further increased the expression of inflammatory cytokines, and the PBR/TSPO PET signal increased concurrently. The increase in inflammatory cytokine expression correlated with enhanced signal intensity. CONCLUSIONS: PET signal enhancement by PBR/TSPO at the site of brain injury correlated with the activation of microglia and production of inflammatory cytokines. Furthermore, because FEPPA enables the detection of neurotoxic microglia on PET images, we successfully constructed a novel PET detection system that can monitor neurodegenerative diseases.

GABAergic modulation of serotonin release in the rat subfornical organ area.

The present study was carried out to examine whether γ-aminobutyric acid (GABA) receptor mechanisms are involved in the release of serotonin (5-hydroxytryptamine, 5-HT) in the subfornical organ (SFO) using intracerebral microdialysis techniques. Perfusion with the GABA receptor antagonists as well as agonists was performed in the region of the SFO through a microdialysis probe and extracellular concentrations of 5-HT and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) were measured in freely moving rats. Perfusion with the GABAA receptor antagonist bicuculline (10 and 50µM), but not the GABAB receptor antagonist phaclofen (10 and 50µM), increased dialysate 5-HT and 5-HIAA concentrations in the SFO area, suggesting that the GABAergic system may tonically inhibit the 5-HT release in the SFO area through GABAA receptors. Higher perfusion with the GABAA receptor agonist muscimol (50µM) or the GABAB receptor agonist baclofen (250µM) decreased extracellular levels of 5-HT and 5-HIAA in the SFO area. Nonhypotensive hypovolemia induced by subcutaneous injection of polyethylene glycol (PEG, 30%, 5ml) significantly enhanced the 5-HT and 5-HIAA concentrations in the SFO area. The enhanced 5-HT and 5-HIAA levels elicited the PEG treatment were reduced by perfusion with muscimol (10µM), but not by baclofen (50µM). These results show the involvement of both GABAA and GABAB receptors in the modulation of the 5-HT release in the SFO area, and imply that the GABAA receptor mechanism may be importance for the serotonergic regulatory system of body fluid balance.

Radiosynthesis and in vivo evaluation of two imidazopyridineacetamides, [(11)C]CB184 and [ (11)C]CB190, as a PET tracer for 18 kDa translocator protein: direct comparison with [ (11)C](R)-PK11195.

OBJECTIVE: We report synthesis of two carbon-11 labeled imidazopyridines TSPO ligands, [(11)C]CB184 and [(11)C]CB190, for PET imaging of inflammatory process along with neurodegeneration, ischemia or brain tumor. Biodistribution of these compounds was compared with that of [(11)C]CB148 and [(11)C](R)-PK11195. METHODS: Both [(11)C]CB184 and [(11)C]CB190 having (11)C-methoxyl group on an aromatic ring were readily prepared using [(11)C]methyl triflate. Biodistribution and metabolism of the compounds were examined with normal mice. An animal PET study using 6-hydroxydopamine treated rats as a model of neurodegeneration was pursued for proper estimation of feasibility of the radioligands to determine neuroinflammation process. RESULTS: [(11)C]CB184 and [(11)C]CB190 were obtained via O-methylation of corresponding desmethyl precursor using [(11)C]methyl triflate in radiochemical yield of 73 % (decay-corrected). In vivo validation as a TSPO radioligand was carried out using normal mice and lesioned rats. In mice, [(11)C]CB184 showed more uptake and specific binding than [(11)C]CB190. Metabolism studies showed that 36 % and 25 % of radioactivity in plasma remained unchanged 30 min after intravenous injection of [(11)C]CB184 and [(11)C]CB190, respectively. In the PET study using rats, lesioned side of the brain showed significantly higher uptake than contralateral side after i.v. injection of either [(11)C]CB184 or [(11)C](R)-PK11195. Indirect Logan plot analysis revealed distribution volume ratio (DVR) between the two sides which might indicate lesion-related elevation of TSPO binding. The DVR was 1.15 ± 0.10 for [(11)C](R)-PK11195 and was 1.15 ± 0.09 for [(11)C]CB184. CONCLUSION: The sensitivity to detect neuroinflammation activity was similar for [(11)C]CB184 and [(11)C](R)-PK11195.

Cerebral antioxidant enzyme increase associated with learning deficit in type 2 diabetes rats.

In this study, we examined alterations in the enzymatic antioxidant defenses associated with learning deficits induced by type 2 diabetes, and studied the effects of the peroxisome proliferator-activated receptor γ agonist pioglitazone on these learning deficits. Learning ability was assessed by visual discrimination tasks in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, as a model of spontaneous type 2 diabetes. Levels of the antioxidant enzymes glutathione peroxidase (GPx), Cu(2+)-Zn(2+) superoxide dismutase (CuZn-SOD) and manganese SOD were measured in the cortex, hippocampus and striatum. Half the rats received oral pioglitazone (20mg/kg/day) from the early stage of diabetes (22 weeks old) to 27 weeks old. OLETF rats showed learning deficits compared with control, Long-Evans Tokushima Otsuka (LETO) rats. GPx levels in the cortex and hippocampus were increased in OLETF rats compared with LETO rats, with an inverse correlation between GPx in the hippocampus and learning score. CuZn-SOD levels were also increased in the hippocampus in OLETF rats. Pioglitazone reduced blood glucose and increased serum adiponectin levels, but had no effect on learning tasks or antioxidant enzymes, except for CuZn-SOD. These results suggest that an oxidative imbalance reflected by increased brain antioxidant enzymes plays an important role in the development of learning deficits in type 2 diabetes. Early pioglitazone administration partly ameliorated diabetic symptoms, but was unable to completely recover cerebral oxidative imbalance and functions. These results suggest that diabetes-induced brain impairment, which results in learning deficits, may have occurred before the appearance of the symptoms of overt diabetes.

A possible connection between psychosomatic symptoms and daily rhythmicity in growth hormone secretion in healthy Japanese students.

BACKGROUND: Students suffering from psychosomatic symptoms, including drowsiness and feelings of melancholy, often have basic lifestyle problems. The aim of this study was to investigate whether psychosomatic complaints may be related to circadian dysfunction. METHODS: We examined 15 healthy students (4 men and 11 women) between 21 and 22 years old. To assess the presence of psychosomatic symptoms among the subjects, we developed a self-assessment psychosomatic complaints questionnaire consisting of five items pertaining to physical symptoms and five items concerning mental symptoms. The subjects rated their psychosomatic symptoms twice a day (08:00 and 20:00 h). We also assessed growth hormone secretion patterns by fluorescence enzyme immunoassay (FEIA). Salivary samples were collected from the subjects at home five times a day (20:00, 24:00, 04:00, 08:00, and 12:00 h) in Salivette tubes. RESULTS: The results indicated a relationship between the self-assessment scores and the salivary levels of growth hormone. Subjects with high self-assessment scores showed significant variability in growth hormone secretion over the day, whereas subjects with low self-assessment scores did not. CONCLUSION: Psychosomatic symptoms may be associated with circadian dysfunction, as inferred from blunted rhythmicity in growth hormone secretion.

Specific timing of taurine supplementation affects learning ability in mice.

The effects of taurine supplementation on visual discrimination in mice were examined. Taurine, 2-aminoethane-sulphonic acid, found in high concentrations in the central nervous system of mammals and in human milk, has been shown to be essential for development. Male mice were divided into four groups according to taurine supplementation periods. 1) Lifelong: taurine (400 mg/kg/day) was dissolved in distilled water and provided as drinking water. In the prenatal period, taurine was given via the mother. After weaning mice were administered taurine in drinking water. 2) Pre-weaning: mice were exposed to taurine prior to weaning, 3) Post-weaning: mice were exposed to taurine after weaning. 4) CONTROL: no supplementation of taurine. It was shown that the Lifelong group required a longer period of time to acquire visual discrimination than the CONTROL group. Conversely, in the Post-weaning group, mice learned the task faster than CONTROLs. Visual discrimination learning time in the Pre-weaning group showed no significant difference compared with that in the CONTROL group. From these results, we suggest that the perinatal to early postnatal period is a "sensitive period" where taurine supplementation can result in retardation of learning in later life. At the same time, taurine supplementation after weaning improved visual discrimination learning. Thus, timing of taurine supplementation affected learning.

The endothelin-1 receptor-mediated pathway is not involved in the endothelin-1-induced defenestration of liver sinusoidal endothelial cells.

BACKGROUND/AIMS: We previously reported that endothelin (ET)-1 may be involved in the contraction of hepatic sinusoidal endothelial fenestrae (SEF). Rho has emerged as an important regulator of the actin cytoskeleton and consequently cell morphology. To clarify the role of ET receptors [endothelin A receptor (ETAR) and endothelin B receptor (ETBR)] in ET-1-induced defenestration, we studied the size of hepatic SEF under various experimental conditions. METHODS: Liver sinusoidal endothelial cells (LSECs) isolated from rat livers by collagenase perfusion were cultured and divided into four groups: control, ET-1 (10(-6) -10(-10) M)-treated, ET-1+selective ETAR antagonist (BQ610)-treated and ET-1+ETBR antagonist (BQ788)-treated groups. SEF morphology was observed by scanning electron microscopy. Protein expressions of ETAR and ETBR, Rho A and phosphorylated myosin light-chain kinase were analyzed by Western blotting. F-actin stress fiber formation was observed by confocal microscopy. Active Rho was measured by Ren's modification. Intracellular free Ca2+ concentration ([Ca2+]i) was measured by fluorescence digital imaging using fura-2 AM by Aqua cosmos. RESULTS: ET-1 induced a reduction in the number and size of SEF. ETAR antagonist pretreatment inhibited defenestration induced by low ET-1 concentrations (10(-8) -10(-10) M), whereas ETBR antagonist pretreatment did not block defenestration at low to high ET-1 concentrations (10(-6) -10(-10) M). F-actin stress fibers, Rho A levels and phosphorylated myosin light-chain kinase levels remained the same in various treatments. Active Rho was not detected in control and various treatments. ET-1 did not increase [Ca2+]i. Western blot showed prominent ETBR but scarce ETAR protein expression in LSECs. CONCLUSIONS: The present findings demonstrated that ETBR- and ETAR-induced contractile mechanisms are not involved in ET-1-induced defenestration, and that Rho is also not activated. Therefore, ET-1 induces hepatic defenestration by mechanisms other than receptor-mediated contraction.

Involvement of NMDA receptor mechanisms in the modulation of serotonin release in the lateral parabrachial nucleus in the rat.

Microdialysis was employed to investigate whether N-methyl-d-asparatate (NMDA) glutamate receptor mechanisms are involved in the modulation of serotonin (5-hydoxytryptamine, 5-HT) release in the region of the lateral parabrachial nucleus (LPBN) in freely moving rats. Perfusion of NMDA (10 and 50 microM) through the microdialysis probe significantly enhanced extracellular concentrations of 5-HT and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the LPBN area. Local perfusion of the NMDA antagonist dizocilpine (MK801, 10 and 50 microM) did not change the basal 5-HT and 5-HIAA levels in the LPBN area. MK801 (10 microM) administered together with NMDA antagonized the stimulant effect of NMDA (10 microM). The intake of 0.3M NaCl and water induced by subcutaneous injections of the diuretic furosemide (FURO, 10 mg/kg) and the angiotensin converting enzyme inhibitor captopril (CAP, 5 mg/kg) produced significant increases in the 5-HT and 5-HIAA concentrations in the LPBN area. The increased levels of 5-HT and 5-HIAA caused by the combined treatment with FURO and CAP were attenuated by perfusion of MK801 (10 microM). These results indicate the participation of NMDA receptors in the control of 5-HT release in the LPBN area.

Suppression of proinflammatory cytokine production in macrophages by lansoprazole.

Macrophages (MPs) produce increased levels of proinflammatory cytokines in Crohn's disease; these cytokines are thought to play a central role in the occurrence of the disease. Biologics are currently available for anti-cytokine therapy, but treating intestinal inflammation through direct suppression of proinflammatory cytokine production could be more effective. P-ATPase inhibitors have been reported to be anti-inflammatory, and these inhibitors might suppress the production of MP proinflammatory cytokines. In this study, we examined the effect of two types of ATPase inhibitors on the expression patterns of typical proinflammatory cytokines. Peritoneal MPs from 6- to 8-week-old mice were cultured for 48 h in the presence of lansoprazole (P-ATPase inhibitor), bafilomycin A(1) (V-ATPase inhibitor), or the control solvent dimethylsulfoxide. The MPs were then examined for cytokine expression by quantitative real-time polymerase chain reaction (PCR), and culture supernatants were examined for cytokine production with a multiplex assay in a suspension array system. The possible existence of P-ATPase mRNA in MPs was explored using reverse-transcriptase PCR. P-ATPase mRNA was not detected in MP cells. However, all examined proinflammatory cytokines decreased significantly in their mRNA and protein expression in the lansoprazole-treated group. Conversely, bafilomycin A(1) increased the levels of these cytokines. Lansoprazole might be useful for the treatment of inflammatory bowel diseases (IBDs), including Crohn's disease, as it suppresses the production of relevant MP proinflammatory cytokines. However, because P-ATPase was not detected in MPs, the mechanism is unclear and remains to be studied further in an IBD animal model.

Non-NMDA glutamatergic receptors modulate acetylcholine release in the rat subfornical organ area.

The present study was designed to examine whether glutamatergic receptor mechanisms modulate the release of acetylcholine (ACh) in the region of the subfornical organ (SFO) using intracerebral microdialysis methods in freely moving rats. Perfusion of either non-N-methyl-d-aspartate (NMDA) agonist quisqualic acid (QA, 50 microM) or kainic acid (KA, 50 microM) through the microdialysis probe significantly enhanced the ACh release in the SFO area. Local perfusion of the non-NMDA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 10 and 50 microM) did not change the basal release of ACh. CNQX (10 microM) administered together with either QA (50 microM) or KA (50 microM) in the SFO area antagonized the stimulant effect of the agonists on the ACh release. In urethane-anesthetized rats, repetitive electrical stimulation (500 microA, 10 Hz) of the medial septum (MS) significantly increased dialysate ACh concentrations in the region of the SFO. The increase in the ACh release elicited by the MS stimulation was significantly potentiated by perfusion of QA (50 microM), and the QA-induced potentiation was prevented by CNQX (10 microM) treated together with QA. These results show that the glutamatergic synaptic inputs enhance the ACh release in the SFO area through non-NMDA receptors. The data further suggest that the septal cholinergic inputs to the SFO area are potentiated by non-NMDA receptor mechanisms.

Expression of adhesion molecules on mature cholangiocytes in canal of Hering and bile ductules in wedge biopsy samples of primary biliary cirrhosis.

AIM: To examine the expression of intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) expression on canals of Hering (CoH) and bile ductules associated with the autoimmune process of bile duct destruction in primary biliary cirrhosis (PBC). METHODS: Ten wedged liver biopsies of PBC (five cases each of stages 2 and 3) were studied. The liver specimens were processed for transmission electron microscopy. Immunohistochemistry was performed using anti-ICAM-1 and anti-LFA-1 mouse mAbs. In situ hybridization was done to examine the messenger RNA expression of ICAM-1 in formalin-fixed, paraffin-embedded sections using peptide nucleic acid probes and the catalyzed signal amplification (CSA) technique. Immunogold-silver staining for electron microscopy was performed using anti-ICAM and anti-LFA-1 mouse mAbs. The immunogold particles on epithelial cells of bile ductules and cholangiocytes of CoH cells were counted and analyzed semi-quantitatively. Western blotting was performed to confirm ICAM-1 protein expression. RESULTS: In liver tissues of PBC patients, immunohistochemistry showed aberrant ICAM-1 expression on the plasma membrane of epithelial cells lining bile ductules, and also on mature cholangiocytes but not on hepatocytes in CoH. LFA-1-positive lymphocytes were closely associated with epithelial cells in bile ductules. ICAM-1 expression at protein level was confirmed by Western blot. In situ hybridization demonstrated ICAM-1 mRNA expression in bile ductules and LFA-1 mRNA in lymphocytes infiltrating the bile ductules. By immunoelectron microscopy, ICAM-1 was demonstrated on the basal surface of epithelial cells in bile ductules and on the luminal surfaces of cholangiocytes in damaged CoH. Cells with intermediate morphology resembling progenitor cells in CoH were not labeled with ICAM-1 and LFA-1. CONCLUSION: De novo expression of ICAM-1 both on mature cholangiocytes in CoH and epithelial cells in bile ductules in PBC implies that lymphocyte-induced destruction through adhesion by ICAM-1 and binding of LFA-1-expressing activated lymphocytes takes place not only in bile ductules but also in the CoH.

CLOCK/BMAL1 is involved in lipid metabolism via transactivation of the peroxisome proliferator-activated receptor (PPAR) response element.

Lipid absorption and metabolism are regulated by feeding and by the circadian system. It has been suggested that the expression of enzymes involved in lipid metabolism is directly controlled by the clock system. This study was designed to examine whether or not the CLOCK/BMAL1 heterodimer has transcriptional activity for genes via the peroxisome proliferator-activated receptor response element (PPRE). Male mice 8-12 weeks old were maintained under a 12:12 hour light-dark cycle for at least two weeks before the day of the experiment. The mRNA profiles of BMAL1 and of the PPAR target genes acyl-CoA oxidase (AOX), 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase and cellular retinol binding protein II (CRBPII) were measured in intestine. The direct effects of CLOCK/BMAL1 on the promoter activities of those three enzymes were assessed in vitro by luciferase assay. The expression of PPAR target genes changed in a cyclical manner that followed expression of BMAL1. The promoter activities of the three enzymes were increased by CLOCK/BMAL1 expression. After deletion of the PPRE from the CRBPII construct, CLOCK/BMAL1 did not affect transactivation. CLOCK/BMAL1 transactivates PPAR target genes via the PPRE.

High expressions of caveolins on the proliferating bile ductules in primary biliary cirrhosis.

AIM: An increase in bile ductular structures is observed in diverse human liver diseases, especially in primary biliary cirrhosis (PBC). These structures harbor the progenitor cell component of the liver. Caveolins are cholesterol-binding proteins involved in the regulation of several intracellular processes including cholesterol transport. This study aims to examine the role of caveolin in PBC. METHODS: Immunohistochemical and Western blotting studies were performed on human liver specimens obtained from patients with PBC and normal liver samples. The expression of caveolin (CAV)-1 and -2 was determined using specific antibodies. RESULTS: In normal liver, scanty immunostaining for CAV-1 and -2 was observed in bile ductules. In PBC liver samples, the expression levels of CAV-1 and -2 were increased on proliferating bile ductules especially in stage 3 cases, but was sparse on interlobular bile duct in stage 1 specimens. Especially, the regenerating bile ductules at the interface of portal tracts and necrotic areas were immunostained intensely for CAV-1 and -2. These phenomena were confirmed by Western blot. CONCLUSION: The present results demonstrate increased expression of caveolins in proliferating bile ductules in PBC, which may be related to the homeostasis of cholesterol transport in regenerating bile ductules in PBC liver.

Sinusoidal endothelial fenestrae organization regulated by myosin light chain kinase and Rho-kinase in cultured rat sinusoidal endothelial cells.

The presence of actin filaments in the neighborhood of sinusoidal endothelial fenestrae (SEF) indicates that the cytoskeleton of sinusoidal endothelial cells (SEC) plays an important role in the modulation of SEF. We examined the roles of Rho-kinase and myosin light chain kinase (MLCK) in the organization of SEF. Cultured SEC were treated with MLCK inhibitor (ML-7) and Rho-kinase inhibitor (Y-27632). SEF morphology was observed by scanning electron microscopy. F-actin stress fibers were observed by confocal microscopy and heavy meromyosin-decorated reaction under transmission electron microscopy. Y-27632 caused disassembly of stress fibers in the center of the cell, while SEF clustered and dilated. However, stress fibers located in the periphery of the cell were not severely affected by Y-27632. ML-7 caused disruption and/or shortening of peripheral stress fibers, leaving the central stress fibers relatively intact. ML-7, but not Y-27632, caused cells to lose the spreading morphology, indicating that the peripheral fibers play a major role in keeping the flattened state of the cell. Thus, there are at least two different stress fiber systems in SEC. The central stress fiber system and SEF microfilaments depend more on the activity of Rho-kinase, while the peripheral stress fiber system depends on MLCK. These results indicate that Rho modulates fenestral changes in SEC via regulation of the actin cytoskeleton.

[Magnesium deficiency--benefits of "life salt nuti ma-su"].

One of essential minerals magnesium tastes bitter, so human love to remove magnesium from salt. But magnesium is also essential for cell functions in the body. Salts are getting purifying only NaCl from sea water. It means other minerals are gone out. So other essential minerals easily are getting to deficiency in the body. Recently the technique of purification of salt from sea water has developed. But the contents of magnesium other than [NaCl] is getting decrease. So deficiency symptom is easily occurred. The important role of magnesium is control of higher function of nervous system, behavior, memory and learning in the human. So we have to intake a lot of magnesium from many kinds of salts including sea water.

Actin filaments around endothelial fenestrae in rat hepatic sinusoidal endothelial cells.

The presence of microfilaments in the vicinity of sinusoidal endothelial fenestrae (SEF) suggests that the cytoskeleton of liver sinusoidal endothelial cells (LSEC) plays an important role in the modulation of SEF. In this study, we investigated actin filaments around SEF in LSECs. Monolayers of LSEC culture were established by infusing a rat liver with collagenase for 30 min and then culturing in RMPI medium for 24 h. Cells were reacted with 0.1% Triton X for 5 s and 15% glycerinated PHEM buffer (60 mM PIPES, 25 mM HEPES, 10 mM EGTA, 2 mM MgCl, pH 6.9) containing heavy meromyosin for 10 min and observed under a transmission electron microscope. By electron microscopy with the modified heavy meromyosin decorated reaction, actin filaments were clearly demonstrated around SEF in LSEC.

Extracellular level of basolateral amygdalar dopamine responding to reversal of appetitive-conditioned discrimination in young and old rats.

Young and old rats, aged 3 and 24 months old, respectively, were conditioned to press a lever under lamp-on conditions for reward acquisition and lamp-off for no reward using a variable interval reinforcement schedule that averaged 15 s; i.e., the minimal requirement was 4 responses/min. Over a 30-day period, young and old groups showed increased response to lamp-on from 22 to 35/min and from 10 to 23/min, respectively, and shortened response to lamp-off after initial training. Response to lamp-on as a percentage of total response to lamp-on and -off (the discrimination ratio) was over 80%. For the next 30 days, reversal learning was imposed to reinforce discrimination of the lamp-off state. Young rats showed a steadily increasing discrimination ratio from 40% to 70%, and old rats from 30% to 60%. In comparison with the initial training, young rats showed a total response increase from 50% to 60%, while old rats showed an approximately 5% decrease without loss of reward-obtaining efficiency. In vivo microdialysis during reversal revealed that young rats had higher dopamine transmission in the basolateral amygdala than old rats. The dopamine level was positively correlated with the number of responses to state of reward in young rats and negatively with the numbers of both NRF and RF responses to lamp-on and -off states in old rats. These results suggest that in reversal discrimination, basolateral amygdalar dopamine efflux correlates with the manner of age-related conditioned response rather than the ability to learn.