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1.
Osteoarthritis Cartilage ; 29(3): 380-388, 2021 03.
Article En | MEDLINE | ID: mdl-33388431

OBJECTIVE: We have reported that fibrotic changes in infrapatellar fat pad (IFP) after acute joint inflammation are closely associated with persistent pain in rats. In this study, to examine the effects of anti-fibrotic treatment on persistent pain, we used C-type natriuretic peptides (CNP) at the recovery phase after acute joint inflammation. DESIGN: Thirty-two male Wistar rats were used in this study. Monoiodoacetic acid (MIA) was injected intra-articularly to induce IFP fibrosis and persistent pain. CNP was injected after acute inflammatory phase in the same knee joint. Time-course pain-avoidance behavior tests and histological analyses were performed to examine the effects of CNP. RESULTS: Histological evaluations indicated that intra-articular injection of CNP inhibited fibrotic changes in IFP after acute inflammation. Incapacitance tests indicated that MIA injection into rat knee joint quickly decreased the percent weight on ipsilateral limb. In the vehicle group, the decrease was maintained up to day 28, suggesting that pain persistence occurred after acute inflammation (Day 0/Day 28, Est Dif -8.15, CI -10.78∼-5.53, Linear mixed-effect model). In contrast, the pain was alleviated in the CNP group after day 14 (Day0/Day 14, -0.51, -2.62-1.59). In addition, we observed significant improvement in the degree of articular cartilage degeneration at day 14 in the CNP group (OARSI score: vehicle 16.14 ± 4.37 vs CNP 6.87 ± 3.44, P < 0.01; Wilcoxon rank sum test). CONCLUSION: Fibrotic changes in IFP may play important roles in both persistent pain and articular cartilage degeneration.


Adipose Tissue/drug effects , Antifibrotic Agents/pharmacology , Arthralgia/physiopathology , Arthritis, Experimental/physiopathology , Cartilage, Articular/drug effects , Osteoarthritis, Knee/physiopathology , Adipose Tissue/pathology , Animals , Arthritis, Experimental/chemically induced , Arthritis, Experimental/pathology , Behavior, Animal/drug effects , Cartilage, Articular/pathology , Enzyme Inhibitors/toxicity , Fibrosis , Injections, Intra-Articular , Iodoacetic Acid/toxicity , Natriuretic Peptide, C-Type/pharmacology , Osteoarthritis, Knee/chemically induced , Osteoarthritis, Knee/pathology , Patella , Rats
2.
Sci Rep ; 9(1): 3443, 2019 Mar 05.
Article En | MEDLINE | ID: mdl-30837675

Single crystalline Ni-Mn-Ga is well known as a prototype ferromagnetic shape memory alloy (FSMA) exhibiting a giant magnetic field-induced strain (MFIS), up to 12%, due to the magnetically driven twin boundary rearrangement. The large stroke and fast magnetomechanical response make it important for actuators and sensors. Polycrystalline Ni-Mn-Ga is inexpensive and technologically easy accessible, but constrains from the grain boundaries inhibit the twin boundary motion, whereby a very low MFIS is observed. Here, we have shown for the first time that a polycrystalline Ni-Mn-Ga can be split into the magnetostrain-active single grains which, being specially assembled in a silicone polymer matrix, caused large and fully reversible MFIS of the resulting composite. We termed the unique reversibility of a large MFIS of the composite as the magnetic field-induced rubber-like behavior. The magnetostrain of individual particles was explored by the X-ray µCT 3D imaging. The results suggest novel solutions for development of the low cost magnetic actuators and sensors for haptic applications.

3.
Ultrasound Obstet Gynecol ; 52(5): 609-616, 2018 Nov.
Article En | MEDLINE | ID: mdl-29024133

OBJECTIVE: Diagnosing fetal heart failure remains challenging because it is difficult to know how well the fetal myocardium will perform as loading conditions change. In adult cardiology, natriuretic peptides (NPs) are established markers of heart failure. However, the number of studies investigating NP levels in fetuses is quite limited. The aim of this study was to evaluate the significance of plasma NP levels in the assessment of heart failure in fetuses with a congenital heart defect (CHD) and/or arrhythmia. METHODS: This was a prospective observational study conducted at a tertiary pediatric cardiac center. A total of 129 singletons with CHD and/or arrhythmia and 127 controls were analyzed between 2012 and 2015. Umbilical cord plasma atrial NP, brain NP and N-terminal pro-brain NP levels at birth were compared with ultrasonography findings indicating fetal heart failure, such as cardiovascular profile (CVP) score and morphological characteristics. RESULTS: Fetuses with CHD and/or arrhythmia had higher NP levels than did controls (P < 0.01). NP levels of fetuses with CHD and/or arrhythmia were correlated inversely with CVP score (P for trend < 0.01). No differences in NP levels were found in fetuses with CHD and/or arrhythmia and a CVP score of ≥ 8 in comparison to controls. Multivariate analysis showed that a CVP score of ≤ 5, tachy- or bradyarrhythmia at birth, preterm birth and umbilical artery pH < 7.15 were associated independently with high NP levels (P < 0.01). Among fetuses with a CVP score of ≤ 7, abnormal venous Doppler sonography findings were significantly more common and more severe in fetuses with tachy- or bradyarrhythmia than in those with CHD, and those with tachy- or bradyarrhythmia had higher NP levels than did those with CHD (P = 0.01). Fetuses with right-heart defect and moderate or severe tricuspid valve regurgitation had significantly higher NP levels than did fetuses with other types of CHD (P < 0.01). CONCLUSIONS: Plasma NP levels in fetuses with CHD and/or arrhythmia are correlated with the severity of fetal heart failure. Elevated NP levels are attributed mainly to an increase in central venous pressure secondary to arrhythmia or atrioventricular valve regurgitation due to CHD, rather than to the morphological abnormality itself. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.


Arrhythmias, Cardiac/blood , Biomarkers/blood , Heart Defects, Congenital/blood , Heart Failure/blood , Natriuretic Peptides/blood , Prenatal Diagnosis , Adult , Arrhythmias, Cardiac/congenital , Cohort Studies , Female , Heart Failure/congenital , Humans , Predictive Value of Tests , Pregnancy , Pregnancy Outcome , Prospective Studies
4.
Diabet Med ; 33(12): 1737-1743, 2016 12.
Article En | MEDLINE | ID: mdl-27150701

AIM: To compare the effects of the basal insulin analogues glargine and detemir on endothelial function and adipocytokine levels in people with Type 2 diabetes. METHODS: We studied 32 people with Type 2 diabetes whose blood glucose control was unsatisfactory while receiving only oral hypoglycaemic drugs. Participants were randomized to either insulin glargine or detemir for 24 weeks and then crossed over to the other treatment without a washout period. Flow-mediated vasodilatation, adipocytokine levels (plasminogen activator inhibitor-1 and leptin/adiponectin ratio), and fasting ghrelin levels were monitored. RESULTS: HbA1c levels were significantly decreased by both basal insulin therapies. Body weight was significantly increased by glargine but not by detemir. The proportion of flow-mediated vasodilatation was significantly increased by detemir but not glargine (glargine: from 5.17 ± 0.69 to 5.94 ± 0.83%; detemir: from 4.89 ± 0.78 to 7.92 ± 0.69%). Plasminogen activator inhibitor-1 level was significantly decreased by only detemir (glargine: from 16.4 ± 1.8 to 17.3 ± 2.1; detemir: from 19.2 ± 2.8 to 16.0 ± 1.6 ng/ml). The leptin/adiponectin ratio was significantly increased only by glargine. Acyl ghrelin level was significantly decreased by glargine but not detemir. CONCLUSIONS: These results suggest that the effect on endothelial function and adipocytokine profiles may differ between glargine and detemir in people with diabetes (Trial registration ID: UMIN000004973).


Adipokines/metabolism , Diabetes Mellitus, Type 2/drug therapy , Endothelium, Vascular/physiology , Hypoglycemic Agents/therapeutic use , Insulin Detemir/therapeutic use , Insulin Glargine/therapeutic use , Adiponectin/metabolism , Adult , Aged , Ankle Brachial Index , C-Reactive Protein/metabolism , Cross-Over Studies , Diabetes Mellitus, Type 2/complications , Endothelium, Vascular/drug effects , Female , Ghrelin/metabolism , Humans , Leptin/metabolism , Male , Middle Aged , Obesity/complications , Plasminogen Activator Inhibitor 1/metabolism , Vasodilation/drug effects , Young Adult
5.
Mater Sci Eng C Mater Biol Appl ; 61: 499-505, 2016 Apr 01.
Article En | MEDLINE | ID: mdl-26838877

The rolling rate (r) dependence of textures was investigated in the Ti-26Nb-3Al (mol%) alloy to reveal the conditions required to form the {001}<110> recrystallization texture, which is a desirable orientation for the ß-titanium shape memory alloy. {001}<110> was the dominant cold-rolling texture when r=90% and it was transferred to the recrystallization texture without forming {112}<110>, which is detrimental for the isotropic mechanical properties of the rolled sheet. A further increase in r resulted in the formation of {112}<110> in both rolling and recrystallization textures. Therefore, r should be controlled to form only the {001}<110> rolling texture, because the {112}<110> texture can overwhelm the {001}<110> texture during recrystallization.


Dental Alloys/chemistry
6.
Rev Sci Instrum ; 85(11): 11E126, 2014 Nov.
Article En | MEDLINE | ID: mdl-25430305

The characteristics of oxygen-enriched liquid scintillators with very low afterglow are investigated and optimized for application to a single-hit neutron spectrometer for fast ignition experiments. It is found that 1,2,4-trimethylbenzene has better characteristics as a liquid scintillator solvent than the conventional solvent, p-xylene. In addition, a benzophenon-doped BBQ liquid scintillator is shown to demonstrate very rapid time response, and therefore has potential for further use in neutron diagnostics with fast time resolution.

7.
Neurogastroenterol Motil ; 26(7): 950-61, 2014 Jul.
Article En | MEDLINE | ID: mdl-24766295

BACKGROUND: Rikkunshito, a standardized Japanese herbal medicine, is thought to accelerate gastric emptying and relieve dyspepsia, although no large-scale, randomized, placebo-controlled trials of rikkunshito have been conducted. This study aimed to determine the efficacy and safety of rikkunshito for treating functional dyspepsia (FD). METHODS: FD patients received 2.5 g rikkunshito or placebo three times a day for 8 weeks in this multicenter, randomized, placebo-controlled, parallel-group trial. The primary end point was the proportion of responders at 8 weeks after starting test drug, determined by global patient assessment (GPA). The improvement in four major dyspepsia symptoms severity scale was also evaluated. In addition, plasma ghrelin levels were investigated before and after treatment. KEY RESULTS: Two hundred forty-seven patients were randomly assigned. In the eighth week, the rikkunshito group had more GPA responders (33.6%) than the placebo (23.8%), although this did not reach statistical significance (p = 0.09). Epigastric pain was significantly improved (p = 0.04) and postprandial fullness tended to improve (p = 0.06) in the rikkunshito group at week 8. Rikkunshito was relatively more effective among Helicobacter pylori-infected participants (rikkunshito: 40.0% vs placebo: 20.5%, p = 0.07), and seemed less effective among H. pylori-uninfected participants (rikkunshito: 29.3% vs placebo: 25.6%, p = 0.72). Among H. pylori-positive individuals, acyl ghrelin levels were improved just in rikkunshito group. There were no severe adverse events in both groups. CONCLUSIONS & INFERENCES: Administration of rikkunshito for 8 weeks reduced dyspepsia, particularly symptoms of epigastric pain and postprandial fullness. (UMIN Clinical Trials Registry, Number UMIN000003954).


Drugs, Chinese Herbal/therapeutic use , Dyspepsia/drug therapy , Pain/drug therapy , Adult , Aged , Aged, 80 and over , Double-Blind Method , Dyspepsia/blood , Female , Ghrelin/blood , Humans , Male , Middle Aged , Pain Measurement , Treatment Outcome , Young Adult
8.
Rev Sci Instrum ; 83(10): 10D909, 2012 Oct.
Article En | MEDLINE | ID: mdl-23126912

In the fast-ignition scheme, very hard x-rays (hereinafter referred to as γ-rays) are generated by Bremsstrahlung radiation from fast electrons. Significant backgrounds were observed around the deuterium-deuterium fusion neutron signals in the experiment in 2010. In this paper the backgrounds were studied in detail, based on Monte Carlo simulations, and they were confirmed to be γ-rays from the target, scattered γ-rays from the experimental bay walls (γ'-rays), and neutrons generated by (γ, n) reactions in either the target vacuum chamber or the diagnostic instruments (γ-n neutrons).

9.
Rev Sci Instrum ; 83(5): 053502, 2012 May.
Article En | MEDLINE | ID: mdl-22667617

X-ray line spectra ranging from 17 to 77 keV were quantitatively measured with a Laue spectrometer, composed of a cylindrically curved crystal and a detector. Either a visible CCD detector coupled with a CsI phosphor screen or an imaging plate can be chosen, depending on the signal intensities and exposure times. The absolute sensitivity of the spectrometer system was calibrated using pre-characterized laser-produced x-ray sources and radioisotopes. The integrated reflectivity for the crystal is in good agreement with predictions by an open code for x-ray diffraction. The energy transfer efficiency from incident laser beams to hot electrons, as the energy transfer agency for specific x-ray line emissions, is derived as a consequence of this work.

10.
Rev Sci Instrum ; 81(10): 10D303, 2010 Oct.
Article En | MEDLINE | ID: mdl-21033829

A custom developed (6)Li glass scintillator (APLF80+3Pr) for down-scattered neutron diagnostics in inertial confinement fusion experiments is presented. (6)Li provides an enhanced sensitivity for down-scattered neutrons in DD fusion and its experimentally observed 5-6 ns response time fulfills the requirement for down-scattered neutron detectors. A time-of-flight detector operating in the current mode using the APLF80+3Pr was designed and its feasibility observing down-scattered neutrons was demonstrated. Furthermore, a prototype design for a down-scattered neutron imaging detector was also demonstrated. This material promises viability as a future down-scattered neutron detector for the National Ignition Facility.

11.
Dement Geriatr Cogn Disord ; 30(2): 179-88, 2010.
Article En | MEDLINE | ID: mdl-20798538

AIMS: To describe obsessive-compulsive symptoms (OCS) as under-recognized behavioral and psychological symptoms of dementia of progressive supranuclear palsy (PSP) and to discuss possible mechanisms based on MRI and SPECT findings. METHODS: We studied 74 PSP patients. OCS are defined as persistent and unreasonable, but non-delusional/hallucinatory, ideas and behaviors. Demography, cognition, the widths of middle cerebellar peduncles (MCP) and the inter-caudate distances (ICD), both corrected by the intracranial size (MCP and ICD ratios), and changes on voxel-based SPECT were compared between the subgroups with and without OCS. Finally, the predicative power of various factors to OCS was investigated. RESULTS: We observed OCS in 18 patients (24%). They were obsessed with daily trifles and physical symptoms among other things. OCS was not associated with demography or cognitive levels. OCS-positive patients had significantly smaller MCP and ICD ratios and showed marked uptake decreases in the orbitofrontal cortex, caudate and thalamus. Relative uptake increases in the cerebellum, specifically the tonsils, were milder in OCS-positive than -negative patients. A smaller right MCP, a smaller ICD ratio and lower uptake increases in the right cerebellar were the significant predictors of OCS. CONCLUSIONS: OCS are frequent but under-recognized behavioral and psychological symptoms of dementia in PSP. Dysfunction of the fronto-caudate-thalamus-cerebellum circuit may be involved.


Cerebellum , Compulsive Behavior , Obsessive Behavior , Supranuclear Palsy, Progressive/complications , Thalamus , Aged , Aged, 80 and over , Cerebellum/diagnostic imaging , Cerebellum/pathology , Compulsive Behavior/diagnosis , Compulsive Behavior/etiology , Compulsive Behavior/physiopathology , Compulsive Behavior/psychology , Dementia/diagnosis , Dementia/etiology , Dementia/pathology , Dementia/psychology , Educational Status , Female , Humans , Intelligence Tests , Magnetic Resonance Imaging , Male , Obsessive Behavior/diagnosis , Obsessive Behavior/etiology , Obsessive Behavior/physiopathology , Obsessive Behavior/psychology , Predictive Value of Tests , Sex Factors , Supranuclear Palsy, Progressive/diagnosis , Supranuclear Palsy, Progressive/pathology , Supranuclear Palsy, Progressive/psychology , Thalamus/diagnostic imaging , Thalamus/pathology , Tomography, Emission-Computed, Single-Photon
12.
Placenta ; 31(5): 358-64, 2010 May.
Article En | MEDLINE | ID: mdl-20346506

BACKGROUND: Ghrelin, a peptide hormone produced mainly in the stomach, is an endogenous ligand for the growth hormone secretagogue receptor (GHS-R). The existence of placental ghrelin and its receptor has been confirmed in normal pregnancy. However, few reports have so far referred to placental ghrelin and its receptor in intrauterine growth restriction (IUGR). OBJECTIVES: The dynamics of ghrelin production and its receptor expression was investigated to clarify the role of placental ghrelin in an IUGR pregnancy using pregnant Dahl salt-sensitive (Dahl S) rats as a model for IUGR. METHODS: Pregnant Dahl S rats were fed a high-salt diet to develop hypertensive pregnancy with IUGR (IUGR-preg). The levels of ghrelin peptide in the placenta, stomach and plasma of the dams, together with the expression levels of mRNAs for ghrelin and its functional receptor (GHS-R1a) in the placenta, were measured in the IUGR-preg rats at 2 and 3 weeks of gestation, and compared to those in the control pregnant Dahl S rats fed standard chow (Normal-preg). RESULTS: The levels of placental ghrelin peptide at 2 weeks of gestation and placental ghrelin mRNA at each gestational week in IUGR-preg were significantly higher than those in Normal-preg. The level of GHS-R1a mRNA in the placenta of IUGR-preg, which was lower at 2 weeks of gestation in comparison to Normal-preg, significantly increased from 2 to 3 weeks of gestation. No significant difference was observed in the level of ghrelin peptide in the plasma or stomach of the dams between the two groups. CONCLUSION: The profile of placental ghrelin production and the expression of its receptor using Dhal S rats in the IUGR-preg was different from that in the control. The placental ghrelin-ghrelin receptor system thus continues to work until the term of pregnancy in the IUGR-preg in contrast to Normal-preg, which might act as a compensational mechanism for fetal growth.


Fetal Growth Retardation/metabolism , Ghrelin/metabolism , Placenta/metabolism , Receptors, Ghrelin/metabolism , Animals , Disease Models, Animal , Female , Fetal Growth Retardation/chemically induced , Gastric Mucosa/metabolism , Gene Expression Regulation, Developmental/drug effects , Ghrelin/genetics , Hypertension/chemically induced , Hypertension/metabolism , Placenta/drug effects , Pregnancy , RNA, Messenger/metabolism , Rats , Rats, Inbred Dahl , Receptors, Ghrelin/genetics , Sodium Chloride, Dietary/administration & dosage , Stomach/drug effects
13.
Dement Geriatr Cogn Disord ; 28(4): 288-94, 2009.
Article En | MEDLINE | ID: mdl-19828949

AIMS: Recent studies have suggested that subcortical cognitive impairment (SubCI) and Alzheimer's disease (AD) can be differentiated by visuospatial tasks. We addressed at what severity stage these differences become apparent and what components in visuospatial processes are subject to impairment. METHODS: Sixty patients with AD, 22 with vascular cognitive impairment and 63 with extrapyramidal diseases with cognitive impairment were assessed using the revised Hasegawa Dementia Scale (HDSR), clock drawing/reading/matching tests (CDT, CRT, CMT), figure copying (FIG) and Frontal Assessment Battery (FAB). Patients were categorized according to the HDSR scores in order to control for the severity of global cognitive impairment. Raw scores were converted to Z-scores for comparisons. RESULTS: In the mild stage, results of all measures were comparable between AD and SubCI. In the moderate-severe stage, scores of CDT, CRT, CMT, FIG and FAB were significantly lower in SubCI. The results suggest that (given that global cognition is controlled for) visuo-perception, visuo-construction and semantic-numerical analyses of visual information may be more impaired in SubCI than AD. CONCLUSIONS: AD and SubCI may be difficult to be differentiated in the mild stages, and the visuospatial cognitive system may be extensively defective in SubCI.


Alzheimer Disease/diagnosis , Alzheimer Disease/psychology , Cognition Disorders/diagnosis , Cognition Disorders/psychology , Space Perception/physiology , Visual Perception/physiology , Aged , Diagnosis, Differential , Disease Progression , Female , Frontal Lobe/physiology , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neurologic Examination , Neuropsychological Tests , Socioeconomic Factors
14.
Phys Rev Lett ; 102(23): 235002, 2009 Jun 12.
Article En | MEDLINE | ID: mdl-19658942

We performed integrated experiments on impact ignition, in which a portion of a deuterated polystyrene (CD) shell was accelerated to about 600 km/s and was collided with precompressed CD fuel. The kinetic energy of the impactor was efficiently converted into thermal energy generating a temperature of about 1.6 keV. We achieved a two-order-of-magnitude increase in the neutron yield by optimizing the timing of the impact collision, demonstrating the high potential of impact ignition for fusion energy production.

15.
J Neuroendocrinol ; 20(3): 330-4, 2008 Mar.
Article En | MEDLINE | ID: mdl-18194428

The influence of ghrelin on feeding behaviour during infancy is unknown. To determine whether ghrelin influences milk intake in rat pups, newborn rats received a single i.p. injection of either rat ghrelin (100 microg/kg) or rabbit anti-ghrelin immunoglobulin G (100 microg/kg) every 5 days from postpartum day 5 to day 30 (P5-P30). Milk intake was then assessed by body weight gain following a 2-h suckling period. Ghrelin significantly increased weight gain relative to vehicle-injected controls in P20, P25 and P30 pups, but not in younger animals. Similarly, after 8 h of milk restriction, anti-ghrelin injections significantly decreased weight gain in P25 and P30, but not in younger pups. Interestingly, however, ghrelin did increase independent feeding in P10 and P15 pups using a paradigm in which pups consumed milk from a milk-soaked paper towel. We therefore conclude that ghrelin stimulates milk intake at an early postnatal stage, primarily by affecting adult-type feeding behaviour.


Eating/drug effects , Feeding Behavior/drug effects , Ghrelin/pharmacology , Milk , Animals , Animals, Newborn , Animals, Suckling , Female , Ghrelin/antagonists & inhibitors , Ghrelin/immunology , Immunoglobulin G/pharmacology , Litter Size/physiology , Pregnancy , Rats , Rats, Wistar , Sucking Behavior/drug effects , Weight Gain/drug effects
16.
Tissue Antigens ; 70(6): 506-10, 2007 Dec.
Article En | MEDLINE | ID: mdl-17990989

We investigated killer cell immunoglobulin-like receptor (KIR) genotypes in 92 patients with young-onset type 1 diabetes mellitus (YT1DM: < or =35 years old), 112 patients with adult-onset type 1 diabetes mellitus (AT1DM: >35 years old) and 240 control subjects. There were no differences in the frequency of KIR genotypes between controls and all the patients with T1DM or patients grouped according to age at onset of the disorder. However, when the subjects were classified into three groups according to combinations of the presence or absence of KIR3DS1/KIR3DL1 and its ligand human leukocyte antigen (HLA)-Bw4, or KIR2DL1 and its ligand HLA-C group 2, the genotype distribution was significantly different between the patients with AT1DM and controls [chi(2)= 5.993, 2 degrees of freedom (d.f.), P= 0.0500]. These data suggest that KIR polymorphisms may be associated with the age at onset of T1DM.


Diabetes Mellitus, Type 1/genetics , Receptors, KIR/genetics , Adult , Age of Onset , Diabetes Mellitus, Type 1/epidemiology , Gene Frequency , Genotype , HLA Antigens/genetics , Humans , Japan/epidemiology , Polymorphism, Genetic
17.
Diabetologia ; 49(6): 1264-73, 2006 Jun.
Article En | MEDLINE | ID: mdl-16570155

AIMS/HYPOTHESIS: Ghrelin, a stomach-derived hormone, functions in multiple biological processes, including glucose metabolism and cellular differentiation and proliferation. In this study, we examined whether early treatment with ghrelin can regenerate beta cells of the pancreas in an animal model of diabetes mellitus, the n0-STZ model, in which neonatal rats are injected with streptozotocin (STZ) at birth. METHODS: Following administration of ghrelin to n0-STZ rats from postnatal days 2 to 8, we examined beta cell mass, mRNA expression levels of insulin and of pancreatic and duodenal homeobox 1 (Pdx1) gene, and pancreatic morphology on days 21 and 70. In addition, we investigated the effects of ghrelin on beta cell replication. RESULTS: By day 21, ghrelin treatment increased pancreatic expression of insulin and Pdx1 mRNA in n0-STZ rats. The number of replicating cells was also significantly increased in the ghrelin-treated n0-STZ model. At day 70, n0-STZ rats exhibited hyperglycaemia, despite slight increases in plasma insulin levels. Ghrelin treatment resulted in the improvement of plasma glucose levels, which were associated with normal plasma insulin levels. Pancreatic insulin mRNA and protein levels were significantly increased in ghrelin-treated n0-STZ model animals. CONCLUSIONS/INTERPRETATION: These findings suggest that ghrelin promotes regeneration of beta cells in STZ-treated newborn rats. Thus, early administration of ghrelin may help prevent the development of diabetes in disease-prone subjects after beta cell destruction.


Diabetes Mellitus, Experimental/prevention & control , Peptide Hormones/therapeutic use , Aging , Animals , Animals, Newborn , Blood Glucose/drug effects , Blood Glucose/metabolism , Cell Division , Female , Ghrelin , Insulin/blood , Insulin/genetics , Insulin/metabolism , Insulin Secretion , Insulin-Secreting Cells/cytology , Male , Rats , Rats, Sprague-Dawley , Reverse Transcriptase Polymerase Chain Reaction , Streptozocin/pharmacology
18.
J Endocrinol ; 188(2): 333-44, 2006 Feb.
Article En | MEDLINE | ID: mdl-16461559

Aging is associated with a decrease in growth hormone (GH) secretion, appetite and energy intake. As ghrelin stimulates both GH secretion and appetite, reductions in ghrelin levels may be involved in the reductions in GH secretion and appetite observed in the elderly. However, only preliminary studies have been performed on the role of ghrelin in elderly subjects. In this study, we sought to clarify the physiologic implications of the age-related alterations in ghrelin secretion by determining plasma ghrelin levels and other clinical parameters in healthy elderly subjects. Subjects were > or = 65 years old, corresponding to the SENIEUR protocol, had not had a resection of the upper gastrointestinal tract and had not been treated with hormones. One hundred and five volunteers (49 men and 56 women) were admitted to this study (73.4 +/- 6.3 years old). Plasma levels of acylated ghrelin in elderly female subjects positively correlated with serum IGF-I levels and bowel movement frequency and negatively with systolic blood pressure. In elderly men, desacyl ghrelin levels correlated only weakly with bowel movement frequency. These findings suggest that the plasma levels of the acylated form of ghrelin may influence the age-related alterations in GH/IGF-I regulation, blood pressure and bowel motility. These observational associations warrant further experimental studies to clarify the physiologic significance of these effects.


Defecation/physiology , Insulin-Like Growth Factor I/analysis , Peptide Hormones/blood , Acylation , Aged , Aged, 80 and over , Aging/physiology , Blood Glucose/analysis , Blood Pressure/physiology , Body Mass Index , Female , Ghrelin , Human Growth Hormone/blood , Humans , Insulin/blood , Leptin/blood , Male
19.
Genes Brain Behav ; 5(1): 96-106, 2006 Feb.
Article En | MEDLINE | ID: mdl-16436193

Methods to temporally and spatially regulate gene mutations will provide a powerful strategy to investigate gene function in the brain. To develop these methods, we have established a tightly regulated system for transgene expression in the forebrain using both a tetracycline (Tc)-dependent transcription activator (rtTA) and a repressor (TetR-Kruppel-associated box). In this system, the repressor binds to the Tc-responsive element (TRE) in the absence of doxycycline (Dox), leading to the repression of leaky activation of TRE-mediated transcription caused by weak binding of rtTA to TRE. Upon Dox administration, only the activator binds to TRE and activates transcription. We tested this system in cultured cells by bicistronically expressing both the regulators using an internal ribosome entry site (IRES). In COS-1, HeLa and SHSY5Y cells, leaky transcription activation led by rtTA in the absence of Dox was repressed without decreasing the level of activated transcription in the presence of Dox. Using this system, transgenic mice were produced that express both the regulators using IRES in the forebrain under the control of the alphaCaMKII promoter and were bred with transgenic mice carrying the TRE-dependent reporter transgene. In reverse transcription-polymerase chain reaction and in situ hybridization analyses of the forebrain in adult double transgenic mice, the treatment of Dox induces reporter mRNA expression, which was not detected before the treatment and after the withdraw of Dox following the treatment. These results indicate that this system allows the tight regulation of transgene expression in a Dox-dependent fashion in the forebrain and will be useful in investigating gene function in the brain.


Doxycycline/pharmacology , Gene Expression Regulation/drug effects , Gene Transfer Techniques , Repressor Proteins/drug effects , Response Elements/drug effects , Trans-Activators/drug effects , Animals , COS Cells , Cell Line , Cells, Cultured , Chlorocebus aethiops , Cloning, Molecular/methods , Genes, Reporter/drug effects , Genes, Reporter/genetics , HeLa Cells , Humans , Mice , Mice, Transgenic , Prosencephalon/drug effects , Prosencephalon/metabolism , RNA/analysis , RNA, Messenger/analysis , Repressor Proteins/genetics , Response Elements/genetics , Trans-Activators/genetics
20.
Gut ; 53(2): 187-94, 2004 Feb.
Article En | MEDLINE | ID: mdl-14724148

BACKGROUND: and aim: Although ghrelin, a novel growth hormone releasing peptide localised mainly in the gastric fundus, is reported not only to accelerate food passage and gastrointestinal motility but also to affect appetite and weight control, regulation of gastric ghrelin secretion under the conditions of gastric Helicobacter pylori infection is unknown. The present study was designed to investigate plasma and gastric ghrelin levels in Mongolian gerbils with H pylori colonisation of the gastric mucosa. METHODS: Gerbils orally inoculated with H pylori were examined after inoculation. To examine preproghrelin mRNA expression in the gastric mucosa, cDNA encoding the gerbil preproghrelin and glyceraldehyde-3-phosphate dehydrogenase homologue was isolated and a quantitative reverse transcription-polymerase chain reaction system was established. RESULTS: In gerbils showing H pylori colonisation (H pylori group), expression of preproghrelin mRNA and total ghrelin levels were significantly decreased 17 and 23 weeks later (p<0.01). Although the number of ghrelin immunoreactive cells decreased as the stomach weight increased, the gastric contents of total and active ghrelin in this group were the same as those in controls. Gastric myeloperoxidase activity showed a positive correlation with plasma ghrelin levels. On the other hand, at 17 weeks, plasma ghrelin levels were significantly increased in the H pylori group (p<0.05), suggesting a compensatory increase in secretion of the peptide at this time point. CONCLUSION: The present experimental study demonstrated that gastric and plasma ghrelin dynamics are altered in response to H pylori infection.


Gastric Mucosa/metabolism , Helicobacter Infections/metabolism , Helicobacter pylori , Peptide Hormones/metabolism , Amino Acid Sequence , Animals , Base Sequence , Duodenum/chemistry , Duodenum/metabolism , Food Deprivation , Gastric Mucosa/chemistry , Gerbillinae , Ghrelin , Gonadotropin-Releasing Hormone/genetics , Humans , Immunohistochemistry/methods , Jejunum/chemistry , Jejunum/metabolism , Male , Mice , Models, Animal , Molecular Sequence Data , Peptide Hormones/analysis , Peptide Hormones/blood , Protein Precursors/genetics , RNA, Messenger/analysis , Rats , Reverse Transcriptase Polymerase Chain Reaction , Sequence Homology, Amino Acid
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