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Biomedical subjects

H Yamaguchi

Publications and source records attributed to H Yamaguchi.

At least 19 recordsLinked to original sources

Premedication with cyclooxygenase-2 inhibitor meloxicam reduced postoperative pain in patients after oral surgery.

The efficacy of the selective cyclooxygenase-2 (COX-2) inhibitor meloxicam for treatment of postoperative oral surgical pain was assessed in a randomized controlled trial. Patients undergoing unilateral mandibular 3rd molar extraction surgery were allocated to 3 groups, A, B and C. After oral premedication of meloxicam 10 mg in group A, ampiroxicam 27 mg in group B and placebo in group C, surgery was completed within 30 min under local anaesthesia using 2% lidocaine. For postoperative pain relief the patients were allowed to take oral loxoprofen (60 mg per tablet). Postoperative pain was evaluated at the clinic on the 1st, 7th and 14th postoperative day (POD) using a visual analogue scale (VAS), as was the number of loxoprofen tablets consumed, and the results were compared among the 3 groups with statistical significance of P<0.05. VAS scores on 1 POD were significantly lower in group A than in group C. Loxoprofen consumption on the day of surgery and 1 POD was significantly lower in group A than in group C (P<0.01). Total analgesic consumption was significantly lower in groups A and B than in group C (P<0.02). The COX-2 inhibitor, meloxicam 10 mg used for premedication reduced postoperative pain compared with control in oral surgery.

Administration, Oral↗

Frameshift proteins in autosomal dominant forms of Alzheimer disease and other tauopathies.

Frameshift (+1) proteins such as APP(+1) and UBB(+1) accumulate in sporadic cases of Alzheimer disease (AD) and in older subjects with Down syndrome (DS). We investigated whether these proteins also accumulate at an early stage of neuropathogenesis in young DS individuals without neuropathology and in early-onset familial forms of AD (FAD), as well as in other tauopathies, such as Pick disease (PiD) or progressive supranuclear palsy (PSP). APP(+1) is present in many neurons and beaded neurites in very young cases of DS, which suggests that it is axonally transported. In older DS patients (>37 years), a mixed pattern of APP(+1) immunoreactivity was observed in healthy looking neurons and neurites, dystrophic neurites, in association with neuritic plaques, as well as neurofibrillary tangles. UBB(+1) immunoreactivity was exclusively present in AD type of neuropathology. A similar pattern of APP(+1) and UBB(+1) immunoreactivity was also observed for FAD and much less explicit in nondemented controls after the age of 51 years. Furthermore, we observed accumulation of +1 proteins in other types of tauopathies, such as PiD, frontotemporal dementia, PSP and argyrophylic grain disease. These data suggest that accumulation of +1 proteins contributes to the early stages of dementia and plays a pathogenic role in a number of diseases that involve the accumulation of tau.

Adult↗

Manipulation of the small intestine as a cause of the increased inflammatory response after open compared with laparoscopic surgery.

BACKGROUND: Laparoscopic surgery of the gastrointestinal tract involves a reduced immune response compared with open surgery. The aim of this study was to assess manual handling of the gut in open procedures as the principal cause of the enhanced immune response. METHODS: Eighteen Landrace pigs underwent gastrectomy by three different methods: conventional open wound with bowel manipulation, laparoscopically assisted gastrectomy, and gastrectomy without manipulation using a combination of open wound and laparoscopic surgical devices. Local inflammatory changes were assessed by ascites formation, intestinal adhesion development and intestinal inflammatory gene expression. Associated systemic inflammatory changes were determined by measuring portal and systemic plasma endotoxin levels, plasma inflammatory cytokine levels, liver inflammatory gene expression and transaminase levels. RESULTS: Significantly more postoperative intra-abdominal fluid and adhesions were seen in the open group. The expression of inflammatory cytokines was significantly greater in the intestine and liver in the open group. Portal and systemic levels of endotoxin, inflammatory cytokines and transaminases were also higher. CONCLUSION: Manual handling of organs during gastrectomy is an important contributor to the molecular and humoral inflammatory response to surgery, supporting the use of minimally invasive techniques in gastrointestinal surgery.

Animals↗

Sonic hedgehog is an early developmental marker of intraductal papillary mucinous neoplasms: clinical implications of mRNA levels in pancreatic juice.

Intraductal papillary mucinous neoplasms (IPMNs) are common cystic tumours of the pancreas. Sonic hedgehog (SHH) is involved in gastric epithelial differentiation and pancreatic carcinogenesis. However, a comprehensive analysis of SHH expression in IPMN has not yet been performed. In the present study, one-step quantitative real-time reverse transcription-polymerase chain reaction with gene-specific priming was used to examine mRNA levels in various types of clinical samples. SHH expression in IPMN was measured and the possible association of gastric epithelial differentiation with development of IPMN was evaluated. In bulk tissue analyses (IPMNs, 11 pancreatic cancer, and 20 normal pancreatic tissues), IPMN expressed significantly higher levels of SHH than did normal pancreas (IPMN versus normal pancreas, p = 0.0025; pancreatic cancer versus normal pancreas, p = 0.0132), but SHH expression did not differ between IPMN and pancreatic cancer (p = 0.3409). In microdissection analyses (infiltrating ductal carcinoma cells from 20 sections, IPMN cells from 20 sections, pancreatitis-affected epithelial cells from 11 sections, and normal epithelial cells from 12 sections), IPMN cells expressed significantly higher levels of SHH than did cancer cells, normal cells, or pancreatitis-affected ductal cells (all comparisons, p < 0.008). Pancreatic juice analyses (20 samples from pancreatic cancers, 31 samples from IPMNs, and 27 samples from chronic pancreatitis) revealed that SHH expression differed significantly between IPMN juice and pancreatitis juice (p < 0.0001), and between cancer juice and pancreatitis juice (p = 0.0125). Receiver operating characteristic curve analyses revealed that SHH measurement in pancreatic juice was useful for discriminating IPMN from chronic pancreatitis (area under the curve = 0.915; 95% confidence interval: 0.796-0.976). The data suggest that overexpression of SHH is an early event in the development of IPMN and that SHH measurement in pancreatic juice may provide some advantages for the treatment or follow-up of a subset of patients with IPMN or chronic pancreatitis.

Biomarkers, Tumor↗

MTH1, an oxidized purine nucleoside triphosphatase, protects the dopamine neurons from oxidative damage in nucleic acids caused by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine.

We previously reported that 8-oxoguanine (8-oxoG) accumulates in the cytoplasm of dopamine neurons in the substantia nigra of patients with Parkinson's disease and the expression of MTH1 carrying an oxidized purine nucleoside triphosphatase activity increases in these neurons, thus suggesting that oxidative damage in nucleic acids is involved in dopamine neuron loss. In the present study, we found that levels of 8-oxoG in cellular DNA and RNA increased in the mouse nigrostriatal system during the tyrosine hydroxylase (TH)-positive dopamine neuron loss induced by the administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). MTH1-null mice exhibited a greater accumulation of 8-oxoG in mitochondrial DNA accompanied by a more significant decrease in TH and dopamine transporter immunoreactivities in the striatum after MPTP administration, than in wild-type mice. We thus demonstrated that MTH1 protects the dopamine neurons from oxidative damage in the nucleic acids, especially in the mitochondrial DNA of striatal nerve terminals of dopamine neurons.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

Biological effects of flowable resin composite on erythrocytes and lymphocytes using an in vitro model.

AIM: The purpose of the study was to evaluate the biological effects of a flowable resin composite on erythrocytes and rat spleen lymphocytes (RSL) using an in vitro model. METHODOLOGY: Rat spleen lymphocytes were placed into microcentrifuge tubes as a pulp model. An artificial pulp exposure was made through the top of the microcentrifuge tube with a 16G needle. The exposure site was filled with a flowable resin composite and photo-polymerized, and the other specimens were not polymerized. The survival rates were determined by a haemocytometer. Red blood cell (RBC) suspension (0.5%) was reacted with the flowable resin composite. The haemolytic activity was evaluated at room temperature (20 degrees C) using a supernatant of each sample by measuring 545 nm of absorbency with a spectrophotometer. To evaluate the effect of flowable resin composite on RBCs, supernatant and precipitated samples were analysed by sodium dodecyl sulphate-polyacrylamide gel (SDS-PAGE). RESULTS: The cell survival rate of the polymerized group was significantly lower compared with that of the nonpolymerized group at the same areas (P < 0.05). The values of haemolysis (absorbency) were 2.16 for the polymerized group, 2.14 for the nonpolymerized group, and 2.18 for the control group (saline). There were no significant differences among them (P > 0.05). The protein component in the supernatant and precipitate exhibited the same reaction with flowable resin composite regardless of the completion of the polymerization, resulting in no change of protein band mobility on SDS-PAGE. CONCLUSIONS: The degree of haemolysis was not influenced by the completion of polymerization. The flowable resin composite tested provoked an adverse effect on lymphocytes when it was not polymerized and the degree of haemolysis was not affected by the status of the polymerization.

Animals↗

Neuropeptide W is present in antral G cells of rat, mouse, and human stomach.

Neuropeptide W (NPW) is a 30-amino-acid peptide initially isolated from the porcine hypothalamus as an endogenous ligand for the G protein-coupled receptors GPR7 and GPR8. An intracerebroventricular administration of NPW increased serum prolactin and corticosterone concentrations, decreased dark-phase feeding, raised energy expenditure, and lowered body weight. Peripherally, GPR7 receptors are abundantly expressed throughout the gastrointestinal tract; the presence of NPW in the gastrointestinal endocrine system, however, remains unstudied. Using monoclonal and polyclonal antibodies raised against rat NPW, we studied the localization of NPW in the rat, mouse, and human stomach by light and electron microscopy. NPW-immunoreactive cells were identified within the gastric antral glands in all three species. Double immunohistochemistry and electron-microscopic immunohistochemistry studies in rats demonstrated that NPW is present in antral gastrin (G) cells. NPW immunoreactivity localized to round, intermediate-to-high-density granules in G cells. NPW-immunoreactive cells accounted for 90% chromagranin A- and 85% gastrin-immunoreactive endocrine cells in the rat gastric antral glands. Using reversed-phase HPLC coupled with enzyme immunoassays specific for NPW, we detected NPW30 and its C-terminally truncated form, NPW23, in the gastric mucosa. Plasma NPW concentration of the gastric antrum was significantly higher than that of the systemic vein, suggesting that circulating NPW is derived from the stomach. Plasma NPW concentration of the gastric antrum decreased significantly after 15-h fast and increased after refeeding. This is the first report to clarify the presence of NPW peptide in the stomachs of rats, mice, and humans. In conclusion, NPW is produced in gastric antral G cells; our findings will provide clues to additional mechanisms of the regulation of gastric function by this novel brain/gut peptide.

Animals↗

[Extensive educational program for high performance medical technologists].

The education system for medical technologists has recently been revolutionized, their educational periods vary from 2 to 9 years, and some already have doctoral degrees. In such a new situation, our faculty thinks that the most important point for new medical technologists is the ability to have a broad view of the clinical fields, especially the view of patients. Special training in bed-side education and a stint in several divisions, such as the surgical operation room, rehabilitation. radiological examination room, pharmacy, central storage room of medical records, and medical informatics, and so on, of the hospital is a powerful tool to obtain a broad view of the various clinical fields and can be essential for developing high performance medical technologists. As nine years have passed since starting this education, we evaluated this practice through systematic personal communication. As a result, it was found to be extremely effective for many reasons such as having a continuous image of the patient when they examine the blood sample in the hospital laboratory, showing advanced laboratory performance, and having no mental barrier to visiting the wards and so on. The abilities of our alumni are praised highly by many large scale hospitals around the country and 50% of them are working in the clinical laboratory division of these hospitals. About 40% are working in the division of research and development in various companies. We express sincere thanks to the director and all cooperative individuals for this course in the Osaka University Hospital.

Curriculum↗

Differential absorbed dose distributions in lineal energy for neutrons and gamma rays at the mono-energetic neutron calibration facility.

Absorbed dose distributions in lineal energy for neutrons and gamma rays of mono-energetic neutron sources from 140 keV to 15 MeV were measured in the Fast Neutron Laboratory at Tohoku University. By using both a tissue-equivalent plastic walled counter and a graphite-walled low-pressure proportional counter, absorbed dose distributions in lineal energy for neutrons were obtained separately from those for gamma rays. This method needs no knowledge of energy spectra and dose distributions for gamma rays. The gamma-ray contribution in this neutron calibration field >1 MeV neutron was <3%, while for <550 keV it was >40%. The measured neutron absolute absorbed doses per unit neutron fluence agreed with the LA150 evaluated kerma factors. By using this method, absorbed dose distributions in lineal energy for neutrons and gamma rays in an unknown neutron field can be obtained separately.

Absorption↗

Observation of cold, long-lived antiprotonic helium ions.

Cold, two-body antiprotonic helium ions p 4He2+ and p 3He2+ with 100-ns-scale lifetimes, occupying circular states with the quantum numbers ni=28-32 and li=ni-1 have been observed. They were produced by cooling three-body antiprotonic helium atoms in an ultra-low-density helium target at temperature T approximately 10 K by atomic collisions, and then removing their electrons by inducing a laser transition to an autoionizing state. The lifetimes of p 3He2+ against annihilation induced by collisions were shorter than those of p 4He2+, and decreased for larger-ni states.

Journal Article↗

Experimental microdosimetric distributions of protons, from 19 to 65 MeV, using an A150-walled Low Pressure Proportional Counter.

Microdosimetric distributions of protons, from 19 to 65 MeV, were measured using an A150-walled Low Pressure Proportional Counter at the cyclotron facility in the National Institute of Radiological Sciences. The measured distributions were found to be very different from the spectra assumed by the Continuous Slowing Down Approximation. The measurements consisted of determining the energy deposition by direct incident protons, by secondary electrons produced in the wall of the detector and by scattered protons at the wall. The secondary electron and the scattered proton distributions were studied using analytical functions and the MCNPX Monte Carlo code, respectively.

Electrons↗

The cell death machinery controlled by Bax and Bcl-XL is evolutionarily conserved in Ciona intestinalis.

Bax and Bcl-XL are key regulators of apoptosis in mammals. Here we report the functional characterization of two Bcl-2 homologues, ciBax and ciBcl-XL, in a basal invertebrate-chordate ascidian Ciona intestinalis. CiBax is a Ciona homologue of the BH1-3 pro-apoptotic protein Bax, whereas ciBcl-XL is a Bcl-XL-like anti-apoptotic protein. Molecular modeling analysis showed that ciBax and ciBcl-XL share both sequence and structural similarities to human Bax and Bcl-XL, respectively. Like their human counterparts, ciBax could form a homodimer or oligomers as well as heterodimerize with ciBcl-XL, and overexpression of ciBax caused apoptosis that could be attenuated by ciBcl-XL. Mutagenesis studies showed that the BH3 domain of ciBax is critical for its cell death-inducing function and also for its interaction with ciBcl-XL. In Ciona embryos, ectopic expression of ciBax but not its BH3 deletion mutant resulted in cell dissociation and apoptosis after late gastrula stage of embryonic development. Moreover, not only wild type ciBcl-XL but also a mutant ciBcl-XL(F101V), which is unable to interact with ciBax, could block cell dissociation and developmental deficit in Ciona embryos induced by overexpression of ciBax. Taken together, these findings suggest that functional homologues of both the BH1-3 death effector Bax and the pro-survival Bcl-XL exist in sea squirt Ciona intestinalis, and they control the cell death machinery independent of their heterodimerization.

Animals↗

Angular distributions for (3,4)(Lambda)H bound states in the (3,4)He(e,e(')K+) reaction.

The (3,4)(Lambda)H and (4)(Lambda)H hypernuclear bound states have been observed for the first time in kaon electroproduction on (3,4)He targets. The production cross sections have been determined at Q(2)=0.35 GeV2 and W=1.91 GeV. For either hypernucleus the nuclear form factor is determined by comparing the angular distribution of the (3,4)He(e,e(')K+)(3,4)(Lambda)H processes to the elementary cross section 1H(e,e K+)Lambda on the free proton, measured during the same experiment.

Journal Article↗

Involvement of the TRAP-1 homologue, Dd-TRAP1, in spore differentiation during Dictyostelium development.

Tumor necrosis factor receptor-associated protein 1 (TRAP1) is a member of the molecular chaperone HSP90 (90-kDa heat shock protein) family. We have previously demonstrated that Dictyostelium discoideum TRAP1 (Dd-TRAP1) synthesized at the vegetative growth phase is retained during the whole course of D. discoideum development, and that at the multicellular slug stage, it is located in prespore-specific vacuoles (PSVs) of prespore cells as well as in the cell membrane and mitochondria. Thereupon, we examined the function of Dd-TRAP1 in prepore and spore differentiation, using Dd-TRAP1-knockdown cells (TRAP1-RNAi cells) produced by the RNA interference method. As was expected, Dd-TRAP1 contained in the PSV was found to be exocytosed during sporulation to constitute the outer-most layer of the spore cell wall. In the TRAP1-RNAi cells, PSV formation and therefore prespore differentiation were significantly impaired, particularly under a heat stress condition. Although the TRAP1-RNAi cells formed apparently normal-shaped spores with a cellulosic wall, the spores were less resistant to heat and detergent treatments, as compared with those of parental MB35 cells derived from Ax-2 cells. These findings strongly suggest that Dd-TRAP1 may be closely involved in late development including spore differentiation, as well as in early development as realized by its induction of prestarvation response.

Animals↗

Quantum interference effects in the magnetopiezoresistance of InAs/AlGaSb quasi-one-dimensional electron systems.

We measured the low temperature magnetopiezoresistance of a quasi-one-dimensional electron system by fabricating an InAs/AlGaSb micromechanical cantilever. The magnetopiezoresistance curve showed aperiodic but reproducible oscillation, which was similar to the differential magnetoresistance curve obtained for the same device. A detailed comparison with model calculations strongly suggests that the quantum interference effects that cause the conductance fluctuations in the magnetoresistance are responsible for the peculiar behavior of the magnetopiezoresistance.

Journal Article↗

A seasonal variation in the onset of postoperative adhesive small bowel obstruction is related to changes in the climate.

BACKGROUND: Postoperative small bowel obstruction following abdominal procedures is more common in patients who have undergone laparotomy. However, little is known about the influence of climate on the incidence of postoperative small bowel obstruction. METHODS: To evaluate whether seasonal climatic variations are a risk factor for postoperative small bowel obstruction, hospital-based, retrospective case series was designed from medical records of 230 patients suffering from postoperative small bowel obstruction admitted to the Tokyo University Branch Hospital. Detailed analysis of weather charts from the Japanese Meteorological Agency and review of medical records for selected patients who were diagnosed with postoperative small bowel obstruction. The obstruction was diagnosed by abdominal X-ray imaging, clinical examination, and patient interviews. RESULTS: A total of 233 patients diagnosed with postoperative small bowel obstruction were identified. Analysis of the medical records of these 233 patients revealed that the variables associated with an increased risk of postoperative small bowel obstruction included low ambient temperatures of 5-10 degrees C, an increase in air humidity by 40-50% and air pressure of 1010-1015 hPa. CONCLUSION: The typical winter weather in Tokyo is characterised by low temperatures, low humidity and moderate air pressure. These winter climate conditions could be correlated with an increased incidence of postoperative small bowel obstruction in Tokyo during our period.

Adolescent↗