ABSTRACT
Fedotovite K_{2}Cu_{3}O(SO_{4})_{3} is a candidate of new quantum spin systems, in which the edge-shared tetrahedral (EST) spin clusters consisting of Cu^{2+} are connected by weak intercluster couplings forming a one-dimensional array. Comprehensive experimental studies by magnetic susceptibility, magnetization, heat capacity, and inelastic neutron scattering measurements reveal the presence of an effective S=1 Haldane state below Tâ 4 K. Rigorous theoretical studies provide an insight into the magnetic state of K_{2}Cu_{3}O(SO_{4})_{3}: an EST cluster makes a triplet in the ground state and a one-dimensional chain of the EST induces a cluster-based Haldane state. We predict that the cluster-based Haldane state emerges whenever the number of tetrahedra in the EST is even.
ABSTRACT
We report on comprehensive results identifying the ground state of a triangular-lattice structured YbZnGaO_{4} as a spin glass, including no long-range magnetic order, prominent broad excitation continua, and the absence of magnetic thermal conductivity. More crucially, from the ultralow-temperature ac susceptibility measurements, we unambiguously observe frequency-dependent peaks around 0.1 K, indicating the spin-glass ground state. We suggest this conclusion holds also for its sister compound YbMgGaO_{4}, which is confirmed by the observation of spin freezing at low temperatures. We consider disorder and frustration to be the main driving force for the spin-glass phase.
ABSTRACT
The two-spotted spider mite, Tetranychus urticae, usually lives in kin groups under common webs. Because only the first mating results in fertilisation in female T. urticae, adult males guard quiescent deutonymph females, those at the stage immediately before maturation, to ensure paternity. Therefore, the cost of precopulatory guarding time seems considerable for males. Moreover, the fitness indices of daughters from intra-population crosses were significantly lower than those of daughters from inter-population crosses, indicating that inbreeding depression exists in T. urticae. Therefore, we hypothesised that T. urticae males should be choosy in guarding familiar females to avoid inbreeding depression. Furthermore, webs should be a key element of the environment shared by familiar individuals. In this study, we demonstrated the inbreeding avoidance mechanism of T. urticae males in relation to webs produced by familiar females (known webs) or unfamiliar females (unknown webs). Regardless of surrounding webs (known or unknown), males preferred unfamiliar to familiar females. We further examined whether males detect unfamiliar females by their webs. When males had experienced a female's web without encountering that female, they subsequently preferred females that did not produce the surrounding webs in which the choice experiment was conducted. Results suggest that putative kin recognition for inbreeding avoidance in T. urticae males is based on the relationship between webs and females, and not on the discrimination of webs in shared environments.
Subject(s)
Sexual Behavior, Animal , Tetranychidae/physiology , Animals , Female , Inbreeding , Male , ReproductionABSTRACT
Adenovirus serotype 5 (Ad5) is frequently used as an effective vector for induction of therapeutic transgenes in cancer gene therapy or of tumor cell lysis in oncolytic virotherapy. Ad5 can infect target cells through binding with the coxsackie and adenovirus receptor (CAR). Thus, the infectious ability of Ad5-based vectors depends on the CAR expression level in target cells. There are conventional methods to evaluate the CAR expression level in human target cells, including flow cytometry, western blotting and immunohistochemistry. Here, we show a simple system for detection and assessment of functional CAR expression in human tumor cells, using the green fluorescent protein (GFP)-expressing telomerase-specific replication-competent adenovirus OBP-401. OBP-401 infection induced detectable GFP expression in CAR-expressing tumor cells, but not in CAR-negative tumor cells, nor in CAR-positive normal fibroblasts, 24 h after infection. OBP-401-mediated GFP expression was significantly associated with CAR expression in tumor cells. OBP-401 infection detected tumor cells with low CAR expression more efficiently than conventional methods. OBP-401 also distinguished CAR-positive tumor tissues from CAR-negative tumor and normal tissues in biopsy samples. These results suggest that GFP-expressing telomerase-specific replication-competent adenovirus is a very potent diagnostic tool for assessment of functional CAR expression in tumor cells for Ad5-based antitumor therapy.
Subject(s)
Adenoviridae/genetics , Telomerase/genetics , Virus Replication/genetics , Cell Line, Tumor , Coxsackie and Adenovirus Receptor-Like Membrane Protein/genetics , Gene Transfer Techniques , Genetic Vectors/genetics , Green Fluorescent Proteins/genetics , Humans , Oncolytic Viruses/genetics , Telomerase/metabolism , Transcription, Genetic , Transformation, GeneticABSTRACT
Vascular calcification, especially medial artery calcification, is associated with increased morbidity and mortality in patients with diabetes mellitus and end-stage kidney disease. Advanced glycation end products (AGEs) accumulated in these patients may be associated with vascular calcification, although their actions are obscure. Since AGEs can induce oxidative stress, which leads to vascular damage, we investigated an in vitro study to elucidate the effects of AGEs and the roles of NAD(P)H oxidase in the pathogenesis of vascular calcification. A7r5, rat vascular smooth muscle cells (VSMCs) were incubated in calcification medium with glycolaldehyde-derived AGE (AGE3) to measure calcium deposition and 8-hydroxydeoxyguanosine (8-OHdG) and to determine mRNA levels of osteopontin (OPN), osteocalcin (OCN), Runx2, Nox-1, Nox-4, and p22(phox) by real-time PCR. Calcium deposition was increased by AGE3 in a dose-dependent manner (100-300 µg/dl) in A7r5 cells. Expression levels of Runx2, OPN, and OCN mRNAs were significantly higher in AGE3 treatment than those in control BSA. Increased 8-OHdG concentration in the culture medium and higher expression of Nox-1, Nox-4, and p22(phox) mRNAs (3-6-fold) were observed in cells treated with AGE3. AGE3-stimulated calcium deposition was significantly decreased in the cells transfected by either small interfering RNA for Nox-4 or p22(phox), compared to the controls. In contrast, no significant effect was shown in silencing of Nox-1. Excessive oxidative stress and osteoblastic transition of VSMCs are involved in the pathogenesis of AGEs-induced vascular calcification. NAD(P)H oxidase plays important roles in this process.
Subject(s)
Gene Expression Regulation, Enzymologic , Glycation End Products, Advanced/metabolism , Muscle Proteins/biosynthesis , Muscle, Smooth, Vascular/enzymology , Myocytes, Smooth Muscle/enzymology , NADH, NADPH Oxidoreductases/biosynthesis , NADPH Oxidases/biosynthesis , Vascular Calcification/enzymology , Animals , Cell Line , Glycation End Products, Advanced/pharmacology , Humans , Muscle, Smooth, Vascular/pathology , Myocytes, Smooth Muscle/pathology , NADPH Oxidase 1 , NADPH Oxidase 4 , Rats , Vascular Calcification/pathologyABSTRACT
The Shozu Herpes Zoster (SHEZ) Study was designed to clarify the incidence of and predictive and immunological factors for herpes zoster in a defined community-based Japanese population. As part of this series, a total of 5683 residents aged ≥50 years received a varicella-zoster virus (VZV) skin test with VZV antigen, and 48 h later, the erythema and oedema were assessed by measuring the longest diameter. The diameters of both the erythema and oedema decreased with the increasing age of the subject. Sixty-three subjects contracted herpes zoster within a year after receiving the VZV skin test. Analysis of the herpes zoster incidence rate vs. the skin test reaction revealed that the shorter the diameter of erythema or oedema, the greater the likelihood of herpes zoster. These results demonstrated that the VZV skin test is an excellent surrogate marker for predicting the risk of herpes zoster.
Subject(s)
Antigens, Viral/immunology , Herpes Zoster/epidemiology , Herpesvirus 3, Human/immunology , Aged , Aged, 80 and over , Female , Herpes Zoster/diagnosis , Herpes Zoster/immunology , Humans , Immunity, Cellular , Incidence , Japan/epidemiology , Likelihood Functions , Male , Middle Aged , Skin TestsABSTRACT
OBJECTIVES: To identify the risk factors for clinically relevant pancreatic fistula after distal pancreatectomy with a flexible cartridge stapler, TL60. METHODS: Forty consecutive patients who underwent a distal pancreatectomy by the TL60 stapler were retrospectively reviewed in association with postoperative complications. RESULTS: The overall morbidity rate was 43% (17 patients), and mortality was null. Pancreatic fistula was the most frequent postoperative complication, seen in 11 patients (27.5%): grade A in 4 (10%) and grade B in 7 (17.5%). No grade C pancreatic fistula was observed. Univariate analyses of risk factors demonstrated that pancreas-related factors, including diabetes mellitus, thickness and texture of the pancreatic parenchyma, transection line for the pancreas, pancreatic duct ligation, and use of artificial patches had no impact on the occurrence of pancreatic fistula. A multivariable logistic regression analysis identified operative time (≥ 300 min) as the only notable predictor of clinically relevant pancreatic fistula (odds ratio = 3.253, 95% confidence interval 1.739-5.752; p = 0.031). CONCLUSION: Distal pancreatectomy with the use of the TL60 stapler eliminated the risk of pancreas-related factors for the occurrence of clinically relevant pancreatic fistula.
Subject(s)
Pancreatectomy/methods , Pancreatic Fistula/prevention & control , Postoperative Complications/prevention & control , Surgical Staplers , Surgical Stapling/methods , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Logistic Models , Male , Middle Aged , Operative Time , Pancreatectomy/adverse effects , Pancreatectomy/instrumentation , Pancreatic Diseases/surgery , Pancreatic Fistula/etiology , Pancreatic Neoplasms/surgery , Postoperative Complications/etiology , Retrospective Studies , Risk Factors , Young AdultABSTRACT
Campylobacter jejuni was monitored in 4 chicken farms during the period 2003 to 2006 to elucidate the mechanisms of transmission. Three farms (1 to 3), located at least 14 km from each other, belonged to an integrated poultry company, which also provided the farms with day-old chicks from several hatcheries as well as chicken feed. Another farm (4), which belonged to a different company, was located 270 m from farm 1. A total of 206 C. jejuni isolates obtained from the 4 farms were classified into 10 flaA-based RFLP types. Identical RFLP types were found in isolates obtained from chickens originating from multiple hatcheries and reared in different chicken houses on individual farms. Flocks were colonized by strains with 1 or 2 RFLP types in each production cycle, sometimes differing between cycles. Identical RFLP types were found in isolates obtained from the environment around the chicken houses. Using multilocus sequence typing, strains with different RFLP types could be distinguished from each other. Identical RFLP and multilocus sequence typing profiles were found in isolates obtained from farms 1 and 4, and from farms 1 and 2. These results suggest that C. jejuni in these farms comes from common sources external to the farms, even if the farms belong to different companies and obtain chicks from different suppliers.
Subject(s)
Campylobacter Infections/veterinary , Campylobacter jejuni/genetics , Chickens , Flagellin/genetics , Polymorphism, Restriction Fragment Length , Poultry Diseases/transmission , Animals , Bacterial Typing Techniques/veterinary , Campylobacter Infections/transmission , Campylobacter jejuni/classification , Campylobacter jejuni/isolation & purification , Japan , Multilocus Sequence Typing/veterinary , Polymerase Chain Reaction/veterinaryABSTRACT
Little is known about the correlation between genotype and drug susceptibility in Mycobacterium avium (Mav) strains isolated from patients with Mav infections. To examine whether drug susceptibility profile of Mav is associated with genotype, we carried out variable-number tandem-repeat (VNTR) typing and drug susceptibility testing for Mav isolates from Japanese with nodular-bronchiectasis (NB)-type and cavitary disease (CA)-type diseases. We performed M. avium tandem repeat (MATR)-VNTR typing and drug susceptibility testing by the broth dilution method, using macrolides, rifamycins, ethambutol, isoniazid, aminoglycosides, and quinolones, for Mav isolates from patients with NB and CA-type diseases (NB-Mav and CA-Mav). Based on the VNTR genotyping, the Mav strains were grouped into three clusters. There was no difference with respect to the distribution of NB-Mav and CA-Mav among the clusters. We observed a strong association between VNTR genotype and susceptibility to quinolones (levofloxacin, moxifloxacin, gatifloxacin, sitafloxacin, and garenoxacin) and ethambutol. There was essentially no significant difference in drug susceptibility between NB- and CA-Mav strains, although NB-Mav was somewhat more resistant to fluoroquinolones, especially gatifloxacin, than CA-Mav. There was a significant association between VNTR genotype and susceptibility to quinolones and ethambutol in Mav isolates from Japanese patients.
Subject(s)
Antitubercular Agents/pharmacology , Minisatellite Repeats , Molecular Typing , Mycobacterium avium/classification , Mycobacterium avium/drug effects , Tuberculosis/microbiology , Aged , Aged, 80 and over , Cluster Analysis , Female , Genotype , Humans , Japan , Male , Microbial Sensitivity Tests , Middle Aged , Mycobacterium avium/genetics , Mycobacterium avium/isolation & purificationABSTRACT
BACKGROUND: The interaction between prostate cancer cells and osteoblasts is critical for the development of bone metastasis. Metastatic cancer cells may physically contact osteoblasts in the bone microenvironment; however, the biological significance of this interaction is not fully understood. METHODS: Human prostate cancer cells (the osteolytic cell line PC-3 and the osteoblastic cell line MDA-PCa 2b) and human osteoblasts (hFOB1.19) were cocultured under two different conditions (bilayer and contact conditions). Differential gene expression profiles of prostate cancer cells were then investigated using microarray analysis. Differentially expressed genes were analysed using RT-PCR and western blotting, and the effect of anti-cadherin neutralising antibodies on their expression was assayed. The osteoclastogenic activity of cells grown under these different conditions was also investigated using an in vitro assay. RESULTS: When PC-3 or MDA-PCa 2b cells were cocultured with hFOB1.19 cells under contact conditions, the expression of eight genes was upregulated and that of one gene was downregulated in PC-3 cells compared with gene expression in bilayer culture. No differentially expressed genes were detected in MDA-PCa 2b cells. Four of the eight upregulated genes (interleukin-1ß (IL-1ß), cyclooxygenase-2 (COX-2), IL-6 and the third component of complement (C3)) have already been reported to participate in osteoclastogenesis. Indeed, a cell lysate of PC-3 cells grown under contact coculture conditions significantly enhanced osteoclastogenesis in vitro (P<0.005). neutralisation of cadherin-11 with a specific antibody inhibited upregulation of COX-2 and C3 mRNA in PC-3 cells. In contrast, neutralisation of N-cadherin induced upregulation of COX-2 mRNA. CONCLUSION: Physical contact between osteolytic prostate cancer cells and osteoblasts may upregulate osteoclastogenesis-related gene expression in prostate cancer cells and enhance osteoclastogenesis. Additionally, cadherin-11 and N-cadherin are involved in this process. These data provide evidence supporting new therapies of prostate cancer bone metastasis that target direct cancer-cell-osteoblast cell-cell contact.
Subject(s)
Bone Resorption/metabolism , Osteoblasts/metabolism , Osteoclasts/metabolism , Osteolysis/metabolism , Prostatic Neoplasms/metabolism , Animals , Antigens, CD/metabolism , Cadherins/metabolism , Cell Line, Tumor , Gene Expression Profiling , Humans , Male , Mice , Mice, NudeABSTRACT
Simpson-Golabi-Behmel syndrome (SGBS) is an overgrowth/multiple congenital anomalies syndrome with an X-linked inheritance. Most cases of SGBS are attributed to mutations in the glypican 3-gene (GPC3), which is highly expressed in the mesodermal embryonic tissues and involves in a local growth regulation. Typical clinical features include pre/postnatal overgrowth, developmental delay, macrocephaly, characteristic facies with prominent eyes and macroglossia, diaphragmatic hernia, congenital heart defects, kidney anomalies, and skeletal anomalies. Obligate carrier females with GPC3 mutations are usually asymptomatic or with mild symptoms. It is thought that skewed X-inactivation is the underlining mechanism for the female patients to present with findings of SGBS. We identified three siblings with typical SGBS (two male and one female cases) and their mother with very mild symptoms in a family carrying c.256C>T (p.Arg86X) mutation in GPC3. X-inactivation studies on the androgen-receptor gene (AR) and the Fragile XE (FRAXE) gene were performed with blood, buccal swabs, and fibroblasts in the carrier females. The studies with blood showed moderately skewed X-inactivation with paternal X-chromosome being preferentially inactivated (71-80% inactivated) in the female patient with SGBS and no skewing was shown in the mother with very mild symptoms. The X-inactivation studies in the mother showed inactivation of the X-chromosome with the mutation by 57%. This suggests that loss of the functional GPC3 protein by 43% is closed to the threshold to develop the SGBS phenotype. Studies with buccal swabs and fibroblasts failed to show different X-inactivation patterns between the two female individuals.
Subject(s)
Abnormalities, Multiple/genetics , Arrhythmias, Cardiac/genetics , Gigantism/genetics , Glypicans/genetics , Heart Defects, Congenital/genetics , Intellectual Disability/genetics , X Chromosome Inactivation/genetics , Female , Fragile X Syndrome/genetics , Genetic Diseases, X-Linked , Humans , Male , Mutation , Phenotype , Receptors, AndrogenABSTRACT
UNLABELLED: Although recent animal studies have shown that undercarboxylated osteocalcin acts as a hormone regulating glucose metabolism and fat mass, little is known about the relationships in humans. We reported here for the first time that undercarboxylated osteocalcin were associated with glucose/fat metabolism in patients with type 2 diabetes. INTRODUCTION: Recent studies have shown that undercarboxylated osteocalcin (ucOC) acts as a hormone regulating glucose metabolism and fat mass. We investigated the relationship between ucOC as well as other bone turnover markers [serum OC, bone-specific alkaline phosphatase (BAP), and urinary N-terminal cross-linked telopeptide of type-I collagen] versus serum levels of glucose, fasting serum C-peptide, and adiponectin as well as the amount of fat mass in type 2 diabetes. METHODS: A total of 180 men and 109 postmenopausal women were consecutively recruited, and radiographic and biochemical characteristics were collected. Fat mass was measured by dual X-ray absorptiometry (DXA) and computed tomography (CT). RESULTS: In men, ucOC negatively correlated with percent trunk fat (%trunk fat; by DXA) and visceral/subcutaneous fat ratio (by CT) as well as fasting plasma glucose and HbA(1c) (at least p < 0.05). Multiple regression analysis showed that these associations were still significant independent of age, duration of diabetes, body stature, and renal function as well as glucose or fat metabolism, whereas BAP, another bone formation marker, did not correlate with any variable. On the other hand, although ucOC also negatively correlated with %fat and %trunk fat as well as HbA(1c) (at least p < 0.05) in postmenopausal women, we found no significant association in multiple regression analysis. CONCLUSIONS: These findings suggest that ucOC is associated with plasma glucose level and fat mass in men with type 2 diabetes.
Subject(s)
Adipose Tissue/pathology , Blood Glucose/analysis , Diabetes Mellitus, Type 2/blood , Osteocalcin/blood , Absorptiometry, Photon/methods , Adiponectin/blood , Adult , Aged , Aged, 80 and over , Biomarkers/blood , Body Composition/physiology , Bone Remodeling/physiology , Diabetes Mellitus, Type 2/pathology , Female , Humans , Male , Middle Aged , Postmenopause/blood , Subcutaneous Fat/pathology , Tomography, X-Ray Computed/methods , Young AdultABSTRACT
SUMMARY: We found that serum osteocalcin, femoral bone mineral density (F-BMD), and 1/3R-BMD were decreased during pioglitazone treatment in patients with type 2 diabetes. Moreover, baseline atherosclerosis parameter, serum insulin-like growth factor-I (IGF-I), and urinary N-terminal cross-linked telopeptide of type I collagen (uNTX) values were associated with changes in bone mineral density (BMD). Therefore, these parameters could assess the risk of BMD reduction in patients treated with pioglitazone. INTRODUCTION: The aim of this study was to investigate the effects of pioglitazone or metformin on bone mass and atherosclerosis in patients with type 2 diabetes. METHODS: A total of 55 Japanese patients were enrolled in this 1-year open-label study and randomized to either pioglitazone (n = 22, 15-30 mg/day) or metformin (n = 23, 500-750 mg/day) groups. BMD at the lumbar spine, femoral neck (F), and one third of the radius (1/3R), bone markers, and atherosclerosis parameters were measured. RESULTS: In the pioglitazone group, serum osteocalcin significantly decreased at 6 months (p < 0.05), although it almost recovered to baseline level at 12 months. F-BMD significantly decreased at 6 months (p < 0.05), and 1/3R-BMD significantly decreased at 6 and 12 months (p < 0.05), while bone markers or BMD at any site were not changed in the metformin group. Although atherosclerosis parameters were not changed in the pioglitazone group, intima-media thickness (IMT)-mean significantly increased at 6 months (p < 0.05) and plaque score significantly increased at 6 and 12 months (p < 0.01) in the metformin group. In the pioglitazone group, %changes in F-BMD were significantly and negatively correlated with baseline IMT-Max, IMT-mean, and plaque scores (r = -0.61, p < 0.01; r = -0.71, p < 0.01; and r = -0.68, p < 0.01, respectively), and %changes in 1/3R-BMD were significantly and negatively correlated with baseline uNTX and IMT-Max (r = -0.57, p < 0.01 and r = -0.48, p < 0.05, respectively) and positively with IGF-I (r = 0.45, p < 0.05). CONCLUSIONS: Baseline IMT, uNTX, and IGF-I could assess the risk of BMD reduction in diabetic patients treated with pioglitazone.
Subject(s)
Atherosclerosis/prevention & control , Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/adverse effects , Osteoporosis/chemically induced , Thiazolidinediones/adverse effects , Aged , Atherosclerosis/diagnostic imaging , Atherosclerosis/metabolism , Biomarkers/metabolism , Blood Glucose/metabolism , Body Weight/drug effects , Bone Density/drug effects , Collagen/urine , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/physiopathology , Female , Femur Neck/physiopathology , Humans , Hypoglycemic Agents/therapeutic use , Insulin-Like Growth Factor I/metabolism , Lumbar Vertebrae/physiopathology , Male , Metformin/adverse effects , Metformin/therapeutic use , Middle Aged , Osteocalcin/blood , Osteoporosis/metabolism , Osteoporosis/physiopathology , Pioglitazone , Radius/physiopathology , Risk Assessment/methods , Thiazolidinediones/therapeutic use , UltrasonographyABSTRACT
Strontium ranelate is known to reduce fracture risk in osteoporotic patients by stimulating bone formation and suppressing bone resorption. However, the mechanism by which strontium exerts this beneficial effect on bone is unclear. We examined whether or not the calcium-sensing receptor (CaR), which is activated by divalent cations including Sr (2+), is involved in this mechanism. Both strontium ranelate and strontium chloride dose-dependently stimulated phosphorylation of extracellular signal-regulated kinase (ERK) in Human Embryonic Kidney 293 cells transiently transfected with the human CaR. Strontium ranelate also dose- and time-dependently stimulated phosphorylation of ERK in mouse osteoblastic MC3T3-E1 cells expressing the CaR endogenously. Strontium ranelate increased mRNA expression of osteocalcin and bone morphogenetic protein-2 in MC3T3-E1 cells as well as mineralization and proliferation of the cells. Pretreatments of NPS2390, a CaR inhibitor, almost totally antagonized strontium ranelate-induced mineralization and proliferation of MC3T3-E1 cells. These findings indicate that strontium ranelate induces not only osteoblast proliferation but also its differentiation and mineralization by activating the CaR, and confirm that the therapeutic efficacy of strontium ranelate for osteoporosis may be partly mediated by the CaR.
Subject(s)
Calcification, Physiologic/drug effects , Cell Differentiation/drug effects , Organometallic Compounds/pharmacology , Osteoblasts/drug effects , Receptors, Calcium-Sensing/metabolism , Thiophenes/pharmacology , Animals , Bone Morphogenetic Protein 2/genetics , Bone Morphogenetic Protein 2/metabolism , Calcium/pharmacology , Cell Line , Cell Proliferation/drug effects , Extracellular Signal-Regulated MAP Kinases/metabolism , Gene Expression Regulation/drug effects , Humans , Mice , Osteoblasts/cytology , Osteoblasts/enzymology , Osteoblasts/metabolism , Osteocalcin/genetics , Osteocalcin/metabolism , Phosphorylation/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Calcium-Sensing/genetics , TransfectionABSTRACT
Mycobacterium avium (Mav) lung infections, called nodular-bronchiectasis (NB)-type M. avium complex (MAC) disease, are globally increasing. To elucidate whether there are unusual populations of Mav, causing NB-type disease rather than cavitary (CA)-type disease, we compared the virulence of Mav isolates from patients with NB-type (NB-Mav) and those from CA-type (CA-Mav) diseases, based on intracellular growth in various types of human cells. Five strains each of NB-Mav and CA-Mav were compared with each other for their invasiveness and ability to intracellularly replicate in various types of cultured cells of human origin. The two types of Mav isolates showed a similar ability, on average, to replicate in macrophages and lung epithelial cells. Moreover, they showed a similar ability to induce the production of reactive nitrogen intermediates and reactive oxygen intermediates by macrophages and susceptibility to antimicrobial molecules. Therefore, it appears that there is no essential difference in virulence in terms of infectivity to human macrophages and lung cells between Mav strains isolated from NB-MAC disease and those from CA-MAC disease. These findings indicate the importance of further studies to elucidate the mechanism for the establishment of NB-type MAC diseases based on host immunological conditions rather than the pathogenic nature of MAC organisms themselves.
Subject(s)
Mycobacterium avium Complex/isolation & purification , Mycobacterium avium Complex/pathogenicity , Mycobacterium avium-intracellulare Infection/microbiology , Mycobacterium avium-intracellulare Infection/pathology , Anti-Infective Agents/pharmacology , Bronchiectasis/microbiology , Bronchiectasis/pathology , Cell Line , Epithelial Cells/microbiology , Female , Humans , Lung Abscess/microbiology , Lung Abscess/pathology , Macrophages/microbiology , Male , Microbial Sensitivity Tests , Mycobacterium avium Complex/growth & development , Mycobacterium avium Complex/immunology , Reactive Nitrogen Species/metabolism , Reactive Oxygen Species/metabolism , VirulenceABSTRACT
The purpose of this study was to investigate the asymmetry of force fluctuation and mechanomyogram (MMG) signal during low intensity isometric knee extension. Twelve healthy males (21+/-1 years) performed unilateral force matching tasks; sustained isometric knee extension for 15 s at levels corresponding to 10% and 20% maximal voluntary contraction (MVC) with the visual feedback of force. During the force matching tasks, MMG was detected by an accelerometer arrangement placed on the vastus lateralis. Power spectrum density of the MMG was obtained by the fast Fourier transformation method, and mean power frequency (MPF) was calculated. Force fluctuation, amplitude of MMG and MPF of MMG were significantly increased in 20% MVC task compared to the 10% MVC task in both limbs. Significant differences between stronger MVC limb and weaker MVC limb were not observed in force fluctuation, amplitude of MMG and MPF of MMG during 10% and 20% MVC tasks. These results suggest that the asymmetry of force steadiness during low intensity isometric knee extension was not observed because there was no difference regarding mechanical characteristics in active muscle between stronger and weaker limbs.
Subject(s)
Isometric Contraction/physiology , Knee Joint/physiology , Muscle Strength/physiology , Exercise Test , Humans , Male , Myography/methods , Physical Exertion/physiology , Recruitment, Neurophysiological/physiology , Young AdultABSTRACT
In this study, the inelastic neutron scattering probe of SIKA in ANSTO is employed to investigate the magnon dispersion curve in ferromagnetic SrRuO3 single crystal epitaxial films and to better understand the underlying mechanisms. This report presents the successful measurement of a magnon peak from the SrRuO3 films which contained an amount of material of only 0.9 mg. We reveal one significant magnon dispersion curve along [002] following the quadratic E â Q 2 ) relation, which shows a magnon gap of 0.32 meV. We have discussed several possible mechanisms, such as the higher symmetry structure and the impurity levels, which may contribute to this smaller gap.
ABSTRACT
We used dexamethasone (DEX)-treated osteoblastic MC3T3-E1 cells, and investigated the effects of an AMP-activated protein kinase activator, 5-aminoimidazole-4-carboxamide-1-beta- D-ribonucleoside (AICAR), a Rho-associated protein kinase inhibitor, fasudil hydrochrolide, as well as HMG-CoA reductase inhibitors, simvastatin and pitavastatin, all of which inhibit the mevalonate pathway. DEX (10(-8) M) significantly enhanced mRNA expression of bone morphogenetic protein (BMP)-2 antagonists, follistatin and Dan, and addition of each of 10 (-4) M AICAR, 10 (-5) M fasudil, 10(-6) M simvastatin, and 10(-6) M pitavastatin significantly reversed the enhancement in mRNA expression of follistatin and Dan and stimulated that of BMP-2 in the cells (p<0.05). DEX (10(-8) M) also significantly suppressed mineralization in the cells, and addition of each of these agents significantly reversed the suppression of mineralization (p<0.05). These findings suggest that the mevalonate pathway was involved in glucocorticoid-induced osteoblast dysfunction, and that its inhibition might promote bone formation through BMP-2 and alleviate glucocorticoid-induced osteoporosis.
Subject(s)
Bone Morphogenetic Protein 2/metabolism , Calcification, Physiologic/drug effects , Dexamethasone/pharmacology , Down-Regulation , Mevalonic Acid/metabolism , Osteoblasts/physiology , Signal Transduction/drug effects , Animals , Bone Morphogenetic Protein 2/genetics , Cell Line , Gene Expression/drug effects , Mice , Osteoblasts/drug effectsABSTRACT
It is well known that parathyroid hormone (PTH) possesses an anabolic effect on bone. However, the mechanisms are not fully elucidated. So far, it is unclear whether or not PTH could stimulate the expression of bone morphogenetic protein-2 (BMP-2), a strong mediator for bone formation. Growing evidence suggests that BMP-2 expression is regulated by the mevalonate pathway and Rho-associated protein kinase (ROK) activity. This study was performed to examine if PTH affects BMP-2 expression and to clarify its involvement of the mevalonate pathway. Osteoblastic MC3T3-E1 cells were treated with human PTH-(1-34) to determine BMP-2 mRNA expression levels by real-time PCR and to measure the ROK activity by the kinase assay. Incubation with 10 (-9)-10 (-8) M of hPTH-(1-34) for 6 h induced significant upregulation of BMP-2 mRNA levels in MC3T3-E1 cells. Short-term treatment of hPTH-(1-34) suppressed Rho kinase activity and mevalonate kinase mRNA levels. PTH-induced BMP-2 mRNA upregulation was selectively reversed by geranylgeranyl pyrophosphate (GGPP) pretreatment, but not by mevalonate pretreatment. These findings suggest that BMP-2 mRNA expression was upregulated by PTH in MC3T3-E1 cells mediated by mevalonate pathway suppression followed by ROK inhibition. We have now demonstrated for the first time that PTH stimulated BMP-2 mRNA expression via the mevalonate pathway and ROK in osteoblastic MC3T3-E1 cells.
Subject(s)
Bone Morphogenetic Protein 2/genetics , Osteoblasts/drug effects , Osteoblasts/enzymology , Parathyroid Hormone/pharmacology , Phosphotransferases (Alcohol Group Acceptor)/antagonists & inhibitors , Up-Regulation/drug effects , rho-Associated Kinases/antagonists & inhibitors , Animals , Bone Morphogenetic Protein 2/metabolism , Cell Line , Dose-Response Relationship, Drug , Humans , Mice , Models, Biological , Phosphotransferases (Alcohol Group Acceptor)/genetics , Phosphotransferases (Alcohol Group Acceptor)/metabolism , Polyisoprenyl Phosphates/pharmacology , Protein Kinase Inhibitors/pharmacology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Time FactorsABSTRACT
Deficiency of lysosomal α-L-iduronidase results in systemic accumulation of glycosaminoglycans (GAGs). Cardiac lesions due to accumulation of GAGs include hypertrophic cardiomyopathy, valvular insufficiency/stenosis, and coronary artery stenosis due to intimal proliferation. Cardiac dysfunction is one of the most common causes of death in patients with mucopolysaccharidosis type I (MPS I). Enzyme replacement therapy (ERT) with laronidase has shown clear effects in reduction of hepatomegaly and it has been unclear whether ERT could improve or prevent the cardiac lesions. Postmortem findings in a 3 1/2-year-old boy diagnosed with MPS I at age 2 years are described. He received ERT with laronidase at 100 U/kg/week for one year. He suddenly developed cardiorespiratory failure and died the next day after C2-3 spinal surgery for instability. Postmortem examination showed hypertrophic cardiomyopathy, severe aortic valve and mitral valve thickening with shortened chordae, and endocardial fibroelastosis. Histology of the cardiac tissue revealed increased perivascular and interstitial connective tissue in the myocardium and intimal thickening causing stenosis in the cardiac vessels. Electron-microscopic (EM) studies of the thickened endocardium revealed numerous histiocytes with enlarged lysosomes. EM examination of the liver and the cardiac muscle revealed no accumulation of GAGs. ERT with laronidase showed clear effects in removing GAGs from the liver and the cardiac muscle. However, it did not show a clear effect on the thickened endocardium, myocardial perivascular and interstitial connective tissue or intimal thickening in the epicardial vessels.