A molybdenum crown cluster forms discrete inorganic-organic nanocomposites with metalloporphyrins.
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Journal Article↗
Biomedical subjects
Hiroyuki Tanaka
Publications and source records attributed to Hiroyuki Tanaka.
Continuous flow immunosensor for highly selective and real-time detection of sub-ppb levels of 2-hydroxybiphenyl by using surface plasmon resonance imaging.
A biosensor based on surface plasmon resonance (SPR) is developed for the detection of 2-hydroxybiphenyl (HBP). A monoclonal antibody against HBP (abbreviated hereafter as HBP-mAb) is developed and used for the detection of HBP by competitive SPR-based immunoassay and enzyme linked immunosorbent assay (ELISA) methods. A novel HBP-hapten compound, HBP-bovine serum albumin conjugate (HBP-BSA), derived by binding several HBP units with BSA by an aliphatic chain spacer is used in the development of antibody and for the functionalization of immunoprobes. HBP-BSA linked to the Au surface of the SPR sensor chip undergoes inhibitive immunoreaction with HBP-mAb in the presence of free HBP. The SPR-based immunoassay provides a rapid determination (response time: approximately 20 min) of the concentration of HBP in the range of 0.1-1000 ppb (ng/ml). Regeneration of the sensor chip is gained by treating the antibody-anchored SPR sensor chip with a pepsin solution (100 ppm (microg/ml); pH 2.0) for few minutes. The SPR sensor chip is reusable for the detection of HBP for more than 20 cycles with average loss of 0.35% reactivity per regeneration step. HBP concentration is determined as low as 0.1 and 3 ppb using the SPR sensor and ELISA measurements, respectively. The developed SPR sensor for HBP is free from interference by coexisting benzo[a]pyrene (BaP), 2,4-dichlorophenoxyacetic acid (2,4-D) and benz[a]anthracene; SPR angle shift obtained to the flow of HBP is almost same irrespective to the presence or absence of a same concentration of these carcinogenic polycyclic aromatic hydrocarbons together. The SPR sensor for HBP is proved to be applicable in simultaneous detection of HBP and BaP in parallel with another SPR sensor for BaP.
Biosensing Techniques↗
Genetic and biochemical analyses of Pfh1 DNA helicase function in fission yeast.
The Schizosaccharomyces pombe pfh1+ gene (PIF1 homolog) encodes an essential enzyme that has both DNA helicase and ATPase activities and is implicated in lagging strand DNA processing. Mutations in the pfh1+ gene suppress a temperature-sensitive allele of cdc24+, which encodes a protein that functions with Schizosaccharomyces pombe Dna2 in Okazaki fragment processing. In this study, we describe the enzymatic properties of the Pfh1 helicase and the genetic interactions between pfh1 and cdc24, dna2, cdc27 or pol 3, all of which are involved in the Okazaki fragment metabolism. We show that a full-length Pfh1 fusion protein is active as a monomer. The helicase activity of Pfh1 displaced only short (<30 bp) duplex DNA regions efficiently in a highly distributive manner and was markedly stimulated by the presence of a replication-fork-like structure in the substrate. The temperature-sensitive phenotype of a dna2-C2 or a cdc24-M38 mutant was suppressed by pfh1-R20 (a cold-sensitive mutant allele of pfh1) and overexpression of wild-type pfh1+ abolished the ability of the pfh1 mutant alleles to suppress dna2-C2 and cdc24-M38. Purified Pfh1-R20 mutant protein displayed significantly reduced ATPase and helicase activities. These results indicate that the simultaneous loss-of-function mutations of pfh1+ and dna2+ (or cdc24+) are essential to restore the growth defect. Our genetic data indicate that the Pfh1 DNA helicase acts in concert with Cdc24 and Dna2 to process single-stranded DNA flaps generated in vivo by pol -mediated lagging strand displacement DNA synthesis.
Adenosine Triphosphatases↗
Crocin prevents the death of rat pheochromyctoma (PC-12) cells by its antioxidant effects stronger than those of alpha-tocopherol.
Crocin is a pharmacologically active component of Crocus sativus L. (saffron) used in traditional Chinese medicine. We report here the effects of crocin on neuronally differentiated pheochromocytoma (PC-12) cells deprived of serum/glucose. Depriving the PC-12 cells of serum/glucose caused peroxidation of their cell membrane lipids and decreased intercellular superoxide dismutase (SOD) activity. Treating the PC-12 cells with 10 microM crocin inhibited the formation of peroxidized lipids, partly restored the SOD activity, and maintained the neuron's morphology. These antioxidant effects of crocin were more effective than those of alpha-tocopherol at the same concentration. Crocin also suppressed the activation of caspase-8 caused by serum/glucose deprivation. These results together with our previous data suggest that crocin is a unique and potent antioxidant that combats oxidative stress in neurons.
Animals↗
Global pollution monitoring of polybrominated diphenyl ethers using skipjack tuna as a bioindicator.
To elucidate the global distribution of polybrominated diphenyl ethers (PBDEs), these chemicals were determined in the muscle of skipjack tuna (Katsuwonus pelamis) collected from offshore waters of various regions in the world (Japan, Taiwan, Philippines, Indonesia, Seychelles, and Brazil, and the Japan Sea, East China Sea, South China Sea, Indian Ocean, and North Pacific Ocean). PBDEs were detected in almost all the skipjack tuna collected from the locations surveyed (from < 0.1 to 53 ng/g of lipid), indicating widespread contamination by these compounds in the marine environment. Residue levels of PBDEs in these samples from the northern hemisphere seem to be higher than those from the southern hemisphere, which is plausibly due to larger usage of these compounds in the northern hemisphere. Higher concentrations of PBDEs were detected in the samples from waters around the East China Sea (up to 53 ng/g of lipid). Developing countries around the East China Sea are supposedly the "hot spots" releasing these chemicals into the marine environment. With regard to the composition of PBDE congeners, the percentage contribution by lower brominated congeners (BDE15, -28, and -47) showed an increasing trend with increasing latitude. On the other hand, higher brominated congeners (BDE153, -154, and -183) showed a reverse trend. These patterns suggest that lower brominated congeners of PBDEs (di-, tri-, and tetra-BDEs) were preferentially transported from pollution sources to northern colder regions through the atmosphere. PBDEs may have a high potency to cause global pollution like PCBs.
Animals↗
Perfusion flow assessment of coronary shunt during off-pump coronary artery bypass grafting.
BACKGROUND: Coronary shunts are widely used to prevent myocardial ischemia during off-pump coronary artery bypass graft (OPCAB) procedures. Although clinical effectiveness has been reported, actual perfusion flow has not been well assessed. The purpose of this study was to evaluate actual shunt flow and its pattern during passive coronary perfusion in clinical OPCAB. METHODS: In 15 OPCAB cases, the coronary perfusion flow of the external shunt (1.7 or 2.0 mm) during anastomosis and the free flow of the shunt were measured with an in-line electromagnetic or ultrasonic flow probe. The perfused coronary blood vessel was either the left anterior descending coronary artery or the right coronary artery. The inflow vessel of the external shunt was either the femoral artery (FA) or the ascending aorta (AA). RESULTS: Free flow values of a 1.7-mm FA shunt, 1.7-mm AA shunt, and 2.0-mm FA shunt were 34+/- 7, 39 +/- 3, and 44 +/- 7 mL/min. Perfusion flows were 13 +/- 4, 14 +/- 3, and 22 +/- 4 mL/min, respectively. Perfusion flow was significantly lower than free flow and correlated well with coronary resistance. Although inflow site did not influence net perfusion flow, diastolic/systolic flow fraction ratio was significantly greater when the shunt was perfused from the FA. CONCLUSIONS: External shunt from FA would provide limited but effective perfusion flow with a physiological pattern, which is passively regulated by coronary resistance.
Aged↗
Role of interleukin-5 and eosinophils in allergen-induced airway remodeling in mice.
Asthma is a chronic inflammatory disease characterized by variable bronchial obstruction, hyperresponsiveness, and by tissue damage known as airway remodeling. In the present study we demonstrate that interleukin (IL)-5 plays an obligatory role in the airway remodeling observed in experimental asthma. BALB/c mice sensitized by intraperitoneal injections of ovalbumin and exposed daily to aerosol of ovalbumin for up to 3 wk, develop eosinophilic infiltration of the bronchi and subepithelial and peribronchial fibrosis. The lesions are associated with increased amounts of hydroxyproline in the lungs and elevated levels of eosinophils and transforming growth factor (TGF)-beta1 in the bronchoalveolar lavage fluid. After 1 wk of allergen challenge, TGF-beta is mainly produced by eosinophils accumulated in the peribronchial and perivascular lesions. At a later stage of the disease, the main source of TGF-beta is myofibroblasts, identified by alpha-smooth muscle actin mAb. We show that all these lesions, including fibrosis, are abolished in sensitized and allergen-exposed IL-5 receptor-null mice, whereas they are markedly accentuated in IL-5 transgenic animals. More importantly, treatment of wild-type mice with neutralizing anti-IL-5 antibody, administered before each allergen challenge, almost completely prevented subepithelial and peribronchial fibrosis. These findings demonstrated that eosinophils are involved in allergen-induced subepithelial and peribronchial fibrosis probably by producing a fibrogenic factor, TGF-beta1.
Actins↗
A one-step immunochromatographic assay for detecting ginsenosides Rb1 and Rg1.
An immunochromatographic strip test has been developed for detecting ginsenosides Rb1 (G-Rb1) and Rg1 (G-Rg1). This qualitative assay system is useful as a rapid screening method for detecting G-Rb1 and G-Rg1 in plants and plant preparations. Our assay is a competitive immunoassay that uses anti-G-Rb1 and anti-G-Rg1 monoclonal antibodies (MAbs) and a detection reagent that contains colloidal gold particles coated with anti-G-Rb1 and anti-G-Rg1 MAbs. Detection limits are 2 microg mL(-1) for both G-Rb1 and G-Rg1.
Animals↗
FLRT3, a cell surface molecule containing LRR repeats and a FNIII domain, promotes neurite outgrowth.
The mature peripheral nervous system has the ability to survive and to regenerate its axons following axonal injury. After nerve injury, the distal axonal and myelin segment undergoes dissolution and absorption by the surrounding cellular environment, a process called Wallerian degeneration. Using cDNA microarrays, we isolated FLRT3 as one of the up-regulated genes expressed in the distal segment of the sciatic nerve 7 days after transection relative to those of the intact sciatic nerve. FLRT3 is a putative type I transmembrane protein containing 10 leucine-rich repeats, a fibronectin type III domain, and an intracellular tail. The neurons plated on CHO cells expressing FLRT3 extended significantly longer neurites than those plated on wild-type CHO cells, demonstrating that FLRT3 promotes neurite outgrowth. FLRT3 mRNA was especially abundant in the basal ganglia, the granular layer of cerebellum, and the hippocampus, except the CA1 region in the adult rat brain. Thus, FLRT3 may contribute to regeneration following axonal injury.
Animals↗
PCDDs, PCDFs, and coplanar PCBs in albatross from the North Pacific and Southern Oceans: levels, patterns, and toxicological implications.
Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (coplanar PCBs) were determined in five albatross species collected from the North Pacific and Southern Oceans to assess the north-south differences in residue levels, accumulation patterns, and toxic potential. Black-footed and Laysan albatrosses from the North Pacific Ocean contained higher levels of PCDD/Fs and coplanar PCBs than albatrosses from the Southern Ocean, indicating that emission sources of these contaminants were predominant in the northern hemisphere. Residue levels in albatrosses from the remote North Pacific Ocean far from the point source of pollution were comparable to or higher than those in terrestrial and coastal birds from contaminated areas in developed nations, suggesting the specific exposure and accumulation of PCDD/Fs and coplanar PCBs in albatross. The long life span and ingestion of plastic resin pellets by albatrosses could be the plausible explanations for the elevated accumulation of persistent and lipophilic contaminants including PCDD/Fs and coplanar PCBs in these birds. Relative proportions of PCDFs and coplanar PCBs in albatross were higher than those observed in birds inhabiting terrestrial and coastal areas, suggesting that these toxic chemicals may have higher transportability by air and water than PCDDs. Congener patterns of PCDD/Fs in albatross showed less variability as compared to those in terrestrial species, indicating that contamination patterns of PCDD/Fs were similar within the open ocean environment. Contributions of PCDD/Fs to total TEQs in albatrosses from the open ocean were generally lower than those in terrestrial birds, suggesting different toxic potency of PCDD/Fs and coplanar PCBs on animals inhabiting open ocean and terrestrial environment. Whereas albatrosses from southern oceans retained lower TEQ concentrations, possible adverse effects of PCDD/Fs and coplanar PCBs to black-footed and Laysan albatrosses of the North Pacific Ocean may be suspected from TEQ levels.
Animals↗
Multiple hepatic peribiliary cysts with cirrhosis.
Multiple hepatic peribiliary cysts were found in three autopsy cases of patients who had had underlying liver diseases and obstructive jaundice. Macroscopically, the cysts were visible and present exclusively in the hepatic hilum and larger portal tracts. Histologically, the cysts were of varying size and were lined by a single layer of cuboidal or flattened epithelial cells without atypia. Intimate association between the cysts and peribiliary glands was found in the walls of large bile ducts. All three cases were associated with liver cirrhosis in patients with portal hypertension, and two of the patients had also had hepatocellular carcinoma. These findings support the previous assumption that multiple hepatic peribiliary cysts may be closely related to a portal hypertensive condition. Although peribiliary cysts have been considered to be clinically asymptomatic in general, in one of our patients, the cystic dilatation appeared to have been responsible for the progression of obstructive jaundice.
Aged↗
Technical considerations using a composite graft for aortic root replacement.
We performed modified aortic root replacement using a composite graft in seven patients over a 7-year-period. Six patients underwent emergency surgery for acute aortic dissection and one patient underwent elective surgery for an aortic aneurysm. To make the composite graft, we chose an artificial valve that was 1 mm larger than the graft, and when performing the proximal anastomosis, we sutured only the graft edge using the horizontal mattress suture technique, applying an additional running suture for reinforcement. The button technique was routinely used for coronary reattachment. To assess hemostasis of the aortic proximal and coronary suture line, cardioplegia was injected via the left atrial vent, which enabled us to confirm hemostasis before performing the distal anastomosis. Blood loss and the need for blood transfusion were minimized by this modified technique. None of the six survivors has required reoperation during 7-year period. Our technique of aortic root replacement based on a composite graft with some operative modifications seems to be safe and reliable, resulting in a satisfactory outcome.
Aged↗
Bone assessment of female long-distance runners.
The objective of the present study was to investigate the effects of long-distance training on the bones in different growth stages by evaluating the bones of female high school athletes and female adult athletes who engage in long-distance training. Thirteen female high school athletes (aged 15-17 years) and 7 female adult athletes (aged 21-25 years) were enrolled in the present study. Bone mineral density (BMD) and bone mineral content (BMC) were measured using dual X-ray absorptiometry (DXA). Cortical bone status was also evaluated by measuring the tibial speed of sound (t-SOS). The bone metabolic status was evaluated by osteocalcin (OC) and tartrate-resistant acid phosphatase (TRAP). OC ( P < 0.01) and lumbar BMD ( P < 0.05) were significantly higher in high school athletes who were in the modeling period than in the adult athletes. Leg BMD ( P < 0.01) and t-SOS ( P < 0.05) were significantly higher in adult athletes who were in the remodeling period than in high school athletes. When lumbar BMD and leg BMD were compared according to menstrual conditions, the high school athletes with regular menstruation showed a significantly higher level of bone density than those having irregular or absent menstruation. These results indicate that the effect of long-distance training on bone metabolism is influenced strongly by sex hormones during late puberty. We concluded that the effect of long-distance training on bone metabolism in the female high school athletes (i.e., during puberty) was different from that in the adult athletes.
Acid Phosphatase↗
Direct action of 1,25-dihydroxyvitamin D on bone: VDRKO bone shows excessive bone formation in normal mineral condition.
In the present study, the direct role of Vitamin D in bone metabolism was investigated. Vitamin D has been suggested to be an important hormone for bone metabolism, but there has been little evidence that Vitamin D actively participates in this process. Here, we show the direct action of Vitamin D by transplanting the bone of the Vitamin D receptor null mutant mice (VDR-/-) to the wild-type mouse. This procedure allowed us to investigate the changes in the bone without VDR in the normal humoral environment. Unexpectedly, the volume and the density of the VDR-/- bone transplanted to the wild-type mouse were significantly increased compared with the control (wild-type bone transplanted to the wild-type mouse). We show that Vitamin D has key roles in bone metabolism negatively.
Alkaline Phosphatase↗
Arsenic accumulation and distribution in tissues of black-footed albatrosses.
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Animals↗
Phylogeny, historical biogeography, and character evolution in bumble bees (Bombus: Apidae) based on simultaneous analysis of three nuclear gene sequences.
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Animals↗
Double-patch technique for postinfarction ventricular septal perforation.
A modified infarct-exclusion technique for postinfarction ventricular septal perforation is presented. The perforation is closed directly by a small patch next to the conventional patch, and biological glue is applied between the patches to induce stable polymerization. The patch stuck to the infarcted septum, and no residual shunt was observed in any patient because the wide adhesion prevents excessive pressure on the suture line. Seven of 9 patients in whom this method was used had good results. This technique appears suited for repair of ventricular septal perforations, especially those with extensive fresh infarction.
Cardiac Surgical Procedures↗
Crocin prevents the death of PC-12 cells through sphingomyelinase-ceramide signaling by increasing glutathione synthesis.
Crocin is a pharmacologically active component of Crocus sativus L. (saffron) that has been used in traditional Chinese medicine. In a previous study, we demonstrated that crocin inhibits apoptosis in PC-12 cells by affecting the function of tumor necrosis factor-alpha. In this study, we found that depriving cultured PC-12 cells of serum/glucose causes a rapid increase in cellular ceramide levels, followed by an increase in the phosphorylation of c-jun kinase (JNK). The accumulation of ceramide was found to depend on the activation of magnesium-dependent neutral sphingomyelinase (N-SMase), but not on de novo synthesis. The serum/glucose-deprived PC-12 cells also decreased the cellular levels of glutathione (GSH), which is the potent inhibitor of N-SMase. Treating the PC-12 cells with crocin prevented N-SMase activation, ceramide production, and JNK phosphorylation. We also found that the chemical can enhance the activities of GSH reductase and gamma-glutamylcysteinyl synthase (gamma-GCS), contributing to a stable GSH supply that blocks the activation of N-SMase. Thus our data suggest that crocin combats the serum/glucose deprivation-induced ceramide formation in PC-12 cells by increasing GSH levels and prevents the activation of JNK pathway, which is reported to have a role of the signaling cascade downstream ceramide for neuronal cell death.
Aminoacyltransferases↗