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Biomedical subjects

Y Nomura

Publications and source records attributed to Y Nomura.

At least 19 recordsLinked to original sources

Factors related to renal dysfunction in patients with anorexia nervosa.

OBJECTIVE: Anorexia nervosa (AN) patients were surveyed to determine which disease factors were related to AN influenced renal dysfunction. METHODS: Data were from forty-five AN patients hospitalized in our department between 1995 and 2002. The patients were classified into three groups based on the type of anorexia: restricting (n=18), self-induced vomiting (n=13), and laxative abuse (n=14). Twenty-four hour-creatinine clearance (Ccr) was calculated within two weeks of hospitalization for comparison among the three groups. RESULTS: The Ccr level of the laxative abuse group was significantly lower than that of the restricting group (65.8+/-31.4 ml/min vs restricting type: 104+/-23.3 ml/min, p=0.002). The laxative abuse group had a significantly longer duration of illness than the restricting group (p<0.0001). Multiple regression analysis revealed the duration of illness to be a risk factor for renal function deterioration in AN patients (r=0.580, p<0.001). DISCUSSION: Renal function should be carefully followed during the treatment of AN patients with a long duration of illness, especially those with long-term laxative abuse.

Adolescent↗

Genotoxicity of dental resin polymerization initiators in vitro.

The polymerization initiators for resins cured using visible light usually consist of a photosensitizer, primarily camphorquinone (CQ), and a reducing agent, which is often a tertiary amine (DMPT, DMAEMA), while the initiator used for self-curing resins consists of benzoyl peroxide (BPO) and a tertiary amine (DMPT). The genotoxicities of camphorquinone (CQ), benzoyl peroxide (BPO), dimethyl-para-toluidine (DMPT), 2-dimethylamino-ethyl-methacrylate (DMAEMA), and 1-allyl-2-thiourea (ATU) were examined using the bioluminescent bacterial genotoxicity test. 4-Nitroquinoline-N-oxide (4NQO) was prepared for comparison with these chemicals. Acetone solutions of the five polymerization initiators and 4NQO were prepared. Benzoyl peroxide (BPO), dimethyl-para-toluidine (DMPT), and 1-allyl-2-thiourea (ATU) showed significant genotoxic activity at 24 h in the bioluminescent bacterial genotoxicity test, at concentrations of approximately 5 microM, 4 mM, and 1 mM, respectively. 2-Dimethyloamino-ethyl-methacrylate (DMAEMA) did not have genotoxic activity and CQ had questionable genotoxic activity. In comparison, 4NQO had strong genotoxicity, at 4 microM, roughly the same as that of BPO. Therefore, BPO should be used carefully in clinical dentistry.

4-Nitroquinoline-1-oxide↗

Malignant mixed mullerian tumor in a rabbit (Oryctolagus cuniculus): case report with immunohistochemistry.

A rabbit (Oryctolagus cuniculus) with a homologous malignant mixed müllerian tumor (MMMT) of the uterus with decidualization in the sarcomatous components is described. On histologic examination, the neoplasm was characterized by a carcinomatous and a sarcomatous component with invasion of the myometrium. The epithelial component was a well-differentiated carcinoma, and the nonepithelial component contained large amounts of intracytoplasmic glycogen. The changes in stromal cells were morphologically similar to changes usually found in decidual cells in the pregnant uterus or in deciduosarcomas in rabbits. Results of immunohistochemical analysis indicated that the epithelial components stained positive with cytokeratin (CK7, AE1/3) and the decidual-stromal cells stained positive for vimentin, but did not stain with alpha-SMA, actin, and desmin. This case fulfills all the criteria of an MMMT in having a carcinomatous and a sarcomatous component, but differs from cases of MMMT in women in that the sarcomatous component had decidualized. To the authors' knowledge, this is the first report of a malignant mixed müllerian tumor in rabbits.

Animals↗

Involvement of cyclooxygenase-1, prostaglandin E2 and EP1 receptors in acid-induced HCO3- secretion in stomach.

We investigated the cyclooxygenase (COX) isoforms as well as prostaglandin E receptor EP subtypes responsible for acid-induced gastric HCO(3)(-) secretion in rats and EP receptor-knockout (-/-) mice. Under urethane anesthesia, a chambered stomach (in the presence of omeprazole) was perfused with saline, and HCO(3)(-) secretion was measured at pH 7.0 using a pH-stat method and by adding 2 mM HCl. Mucosal acidification was achieved by exposing the stomach for 10 min to 50 or 100 mM HCl. Acidification of the mucosa increased the secretion of HCO(3)(-) in the stomach of both rats and WT mice, in an indomethacin-inhibitable manner. The acid-induced gastric HCO(3)(-) secretion was inhibited by prior administration of indomethacin and SC-560 but not rofecoxib in rats and mice. Acidification increased the PGE(2) content of the rat stomach, and this response was significantly attenuated by indomethacin and SC-560 but not rofecoxib. This response was also attenuated by ONO-8711 (EP1 antagonist) but not AE3-208 (EP4 antagonist) in rats and disappeared in EP1 (-/-) but not EP3 (-/-) mice. PGE(2) increased gastric HCO(3)(-) secretion in both rats and WT mice, and this action was inhibited by ONO-8711 and disappeared in EP1 (-/-) but not EP3 (-/-) mice. These results support a mediator role for endogenous PGs in the gastric response induced by mucosal acidification and clearly indicate that the enzyme responsible for production of PGs in this process is COX-1. They further show that the presence of EP1 receptors is essential for the increase in the secretion of HCO(3)(-) in response to mucosal acidification in the stomach.

Animals↗

Optic flow dominates visual scene polarity in causing adaptive modification of locomotor trajectory.

Locomotion and posture are influenced and controlled by vestibular, visual and somatosensory information. Optic flow and scene polarity are two characteristics of a visual scene that have been identified as being critical in how they affect perceived body orientation and self motion. The goal of this study was to determine the role of optic flow and visual scene polarity on adaptive modification in locomotor trajectory. An object is said to have visual polarity, or to be "visually polarized", when it contains an identifiable principal axis with one end distinct from the other. Two computer-generated virtual reality scenes were shown to subjects during 20 min of treadmill walking. One scene was a highly polarized scene, while the other was composed of objects displayed in a non-polarized fashion. Both virtual scenes depicted constant rate self motion equivalent to walking counterclockwise around the perimeter of a room. Subjects performed Stepping Tests blindfolded before and after scene exposure to assess adaptive changes in locomotor trajectory. Subjects showed a significant difference in heading direction, between pre- and post-adaptation Stepping Tests, when exposed to either scene during treadmill walking. However, there was no significant difference in the subjects' heading direction between the two visual scene polarity conditions. Therefore, it was inferred from these data that optic flow has a greater role than visual polarity in influencing adaptive locomotor function.

Adaptation, Psychological↗

Exposure to a rotating virtual environment during treadmill locomotion causes adaptation in heading direction.

The objective of this study was to investigate the adaptive effects of variation in the direction of optic flow, experienced during linear treadmill walking, on modifying locomotor trajectory. Subjects (n=30) walked on a motorized linear treadmill at 4.0 km h(-1) for 24 min while viewing the interior of a 3D virtual scene projected on to a screen 1.5 m in front of them. The virtual scene depicted constant self-motion equivalent to either (1) walking around the perimeter of a room to one's left (Rotating Room group) or (2) walking down the center of a hallway (Infinite Corridor group). The scene was static for the first 4 min and then constant rate self-motion was simulated for the remaining 20 min. Before and after the treadmill locomotion adaptation period subjects performed five stepping trials. In each trial they marched in place to the beat of a metronome at 90 steps min(-1) for a total of 100 steps while blindfolded in a quiet room. The subject's final heading direction (deg) and final X (fore-aft, cm) and final Y (medio-lateral, cm) positions were measured for each trial. During the treadmill locomotion adaptation period subjects' 3D torso position was measured. We found that subjects in the Rotating Room group, as compared with the Infinite Hallway group: (1) showed significantly greater deviation during post-exposure testing in the heading direction and Y position opposite to the direction of optic flow experienced during treadmill walking; and (2) showed a significant monotonically increasing torso yaw angular rotation bias in the direction of optic flow during the treadmill adaptation exposure period. Subjects in both groups showed greater forward translation (in the +X direction) during the post-treadmill stepping task that differed significantly from their pre-exposure performance. Subjects in both groups reported no perceptual deviation in position during the stepping tasks. We infer that viewing simulated rotary self-motion during treadmill locomotion causes adaptive modification of sensorimotor integration in the control of position and trajectory during locomotion, which functionally reflects adaptive changes in the integration of visual, vestibular, and proprioceptive cues. Such an adaptation in the control of position and heading direction during locomotion, because of the congruence of sensory information, demonstrates the potential for adaptive transfer between sensorimotor systems and suggests a common neural site for processing and self-motion perception and concurrent adaptation in motor output.

Adaptation, Physiological↗

Temporary restorative resins using non-phthalate ester plasticizers.

OBJECTIVE: This study examined temporary restorative resins that use non-phthalate ester plasticizers. METHODS: Three non-phthalate plasticizers were tested: tri-ethyl citrate (TEC), tri-butyl citrate (TBC), and di-butyl sebacate (DBS). The experimental resins were compared with resins that use a phthalate ester plasticizer (di-butyl phthalate, DBP) and commercial products (Dura Seal, Plast Seal, and Fit Seal). For the experimental resins, the ratio of plasticizer to PMMA/MMA resin was varied from 30 to 60% (wt). The mechanical properties of the experimental resins were evaluated using a modified diametral compressive strength and the resistance to explorer insertion. RESULTS: The strengths of the experimental resins with plasticizer concentrations ranging from 40 to 50% (TEC, TBC, and DBP) or from 30 to 40% (DBS), by weight, were equivalent to the strengths of commercial temporary restorative resins. A similar tendency was seen for the resistance to explorer insertion. CONCLUSIONS: The results suggest that new temporary restorative resins can be prepared by choosing the appropriate proportions of resin monomer and non-phthalate ester plasticizer.

Citrates↗

Preliminary results of moisture checker for Mucus in diagnosing dry mouth.

OBJECTIVE: To evaluate the ability of Moisture Checker for Mucus (MCM), a device which measures the weight percent of water content in the oral mucosal epithelium, for the diagnosis of dry mouth. METHOD: Forty-three consecutive patients seen at the Dry Mouth Clinic of Tsurumi University were divided into two groups by the diagnostic criteria of hyposalivation defined by the stimulated salivary flow rate < or =10 ml per 10 min. The MCM values in the buccal, tongue and labial mucosa in each group were compared. RESULTS: The value of the normal salivation group was significantly higher when compared with that of the hyposalivation group both in the buccal and tongue mucosa, P = 0.01 and P = 0.046, respectively. CONCLUSION: Moisture Checker for Mucus has the potential to be a useful device in the screening of hyposalivation.

Adult↗

Differences in heat resistance among pathogenic Yersinia enterocolitica depended on growth temperature and serotype.

To gain a better understanding about the effect of growth temperature on heat resistance of Yersinia enterocolitica, we determined decimal reduction times at 60 degrees C (D60-values) for O:3; O:5,27; O:8; and O:9 strains harboring virulence plasmid coding for Yersinia outer membrane protein and experimentally virulence plasmid-deleted strains after they were grown to stationary phase at 7, 25, or 37 degrees C. Bacteria were inoculated into Trypticase soy broth and were incubated at several temperatures. D60-values of O:3; O:5,27; and O:8 strains were larger when they were grown at 37 degrees C than at 7 or 25 degrees C, despite the presence or absence of virulence plasmids. However, similar D60-values were observed in O:9 strains, despite growth at 7, 25, or 37 degrees C. The results indicate two types of Y. enterocolitica strains, growth temperature-dependent and -independent, and a Yersinia outer membrane protein that is not directly involved in growth temperature-dependent heat resistance.

Bacterial Outer Membrane Proteins↗

Serious cardiac and pulmonary calcification in a young peritoneal dialysis patient: potential role of continuous correction of acidosis.

We describe a 40-month-old male infant with renal failure, treated with peritoneal dialysis, who developed massive calcification of soft tissues including the heart and lungs with subsequent cardiopulmonary insufficiency. A diagnosis of Jeune syndrome was made. After starting peritoneal dialysis, the patient exhibited an intractable metabolic acidosis of unknown etiology necessitating treatment with intravenous or oral sodium bicarbonate. Myocardial calcification was first detected by 2-dimensional echocardiography performed 3 months after starting dialysis. The patient was not suitable for renal transplantation because of his cardiac dysfunction and died of cardiac and respiratory failure at the age of 6 years. Although the patient exhibited a variety of risk factors for ectopic calcification including hyperphosphatemia, hyperparathyroidism, high calcium-phosphate product and treatment with vitamin D, the early and massive soft tissue calcification may have been accelerated by correction of the metabolic acidosis. Therefore, the use of sodium bicarbonate may be involved in the etiology of the myocardial calcification.

Acidosis↗

Leachability of plasticizer and residual monomer from commercial temporary restorative resins.

OBJECTIVES: This study was performed to determine the compositions of commercial temporary restorative resins and to evaluate the leachability of plasticizer and residual monomer from them. METHODS: The chemicals in four commercial temporary restorative resins (Dura Seal, Fit Seal, Plast Seal Quick, and Poly Seal) were detected by GCMS and HPLC. The amounts of plasticizers and residual monomers that leached from cured resin samples immersed in ethanol for 1 h to 14 d were determined by HPLC. RESULTS: Phthalate esters used as plasticizers contained 40-55 wt% either di-n-butyl phthalate (DBP) or butyl phthalyl butyl glycolate. The resin monomer included methyl methacrylate (MMA) or a mixture of MMA and 2-hydroxyethyl methacrylate (HEMA); 1,3-butanediol dimethacrylate was added as a cross-linking agent. Each resin contained 40-60 wt% monomer. The amounts of phthalate esters leached increased with immersion time up to 7 d, reaching 120-190 microg/mg, and did not change subsequently. The residual monomers leached gradually for up to 3d and did not change subsequently. The amount of leached residual monomer (MMA, HEMA) was 20-90 microg/mg after 3d storage. More than 50% of the leachable plasticizers and monomers were eluted from the cured resins within 24 and 3 h, respectively. CONCLUSIONS: The amounts of leached plasticizers and residual monomers were extremely large compared with the concentrations of endocrine disrupters and their potentially genotoxic effects. Therefore, it is very important to evaluate the leachability of these compounds from temporary restorative resins.

Acrylic Resins↗

Periodic structures and diurnal variation in blood pressure and heart rate in relation to microgravity on space station MIR.

Four Russian crew members were studied on space station MIR, and blood pressure (BP) and heart rate (HR) data were continuously collected. BP and HR data were collected on earth 1 day before orbital flight to the space station, then at weeks 8, 16 and 24 during space flight, and again 1 or 2 days after returning to earth. Time serial data for BP and HR were analyzed by spectral analysis with the MemCalc system (Suwa Trust, Sapporo, Japan). Periodic structures of diurnal variation in systolic blood pressure (SBP), diastolic blood pressure (DBP) and HR were compared at 24-hour, 12-hour and 8-hour intervals, these being determined as the main periodic components for the assessment of BP and HR variability. The 24-h mean levels of SBP and HR during space flight were unchanged. Waking SBP was not different from pre-flight values. During sleep, in-flight changes in HR did not differ from pre-flight values. SBP during sleep in orbit increased to over pre-flight values. Waking DBP was reduced during flight. The SBP and HR phases over a 24-hour cycle were shortened with a more pronounced shortening in weeks 8 and 16 compared with pre-flight values, and at week 24 recovered to preflight values. The 12, 8-hour-cycle remained unchanged, and were similar to pre-flight values. At the space station, the astronauts' mission was carried out under strict control of sleeping and waking hours; therefore, their 24-hour schedule is an artificially constructed situation. Main periodicity structures were maintained by strict control of lifestyle during long-term space flight. The conclusions reached were as follows: 1) SBP levels during sleep in a space environment increased compared with those on earth; 2) the periodicity phase of BP and HR shifted toward to 24-hour cycle as a result of long-term space flight, even though these periods shortened after a few months compared with pre-space flight values.

Adult↗

Rapid increase in the prevalence of obesity in elementary school children.

OBJECTIVE: Three critical periods have been suggested for the development of obesity during childhood: fetal, ages 4-6 y, and adolescence. The prevalence of obesity in elementary school children is increasing in Japan, and the present study examines whether this rising prevalence occurs during the elementary school period (age 6-11 y) or is occurring prior to entry into elementary school. DESIGN: Repeated cross-sectional sampling of cohorts of children for the prevalence of obesity. SETTING AND PARTICIPANTS: The data from 81 264 first grade and 87 849 seventh grade children (94 and 87% of the total populations, respectively) between 1989 and 2002 in Kagoshima City were analyzed. Data were also obtained from nationwide surveys published by the Ministry of Japan between 1989 and 2001. MEASUREMENTS: Obesity was defined by the body mass index for an age- and sex-specific 95th percentile cutoff point in Japanese children. Trends in obesity and odds ratios of the prevalence of obesity were also determined. RESULTS: The period 1989-2001/2 showed significant increases in the prevalence of obesity for both genders, in both first and seventh grades, and in both Kagoshima City and nationwide. The odds ratios for the prevalence of obesity of 12-y-old children calculated against the prevalence of obesity within the same cohort at 6 y old revealed that a significant risk for development of obesity during the elementary school years applied only to boys from around 1993 onward in Kagoshima City and applied throughout the study period in nationwide Japan. CONCLUSION: Obesity prevalence increases for boys during elementary school years but does not significantly increase for girls. A rising trend for becoming obese before starting elementary school was present for both boys and girls over the period 1989-2001. Educational programs to improve nutrition and physical activity, especially for boys, are becoming increasingly necessary.

Anthropometry↗

The effects of veno-venous extracorporeal membrane oxygenation on hypoxic fetal lambs.

OBJECTIVE: The purpose of this study was to determine the applicability of veno-venous extracorporeal membrane oxygenation (V-V ECMO) to support fetal oxygenation in utero. METHODS: An ECMO system with a centrifugal pump was applied to ten chronically instrumented fetal lambs, at 126 or 127 days of gestation. Blood was obtained through a double-lumen catheter inserted into the right atrium. After oxygenation, the blood was returned through a single-lumen catheter into either the carotid artery (veno-arterial; V-A ECMO) or the right atrium (V-V ECMO). After fetal hypoxia had been experimentally produced, V-A ECMO or V-V ECMO was instituted to maintain fetal oxygenation. We compared fetal blood gases with both routes of ECMO. RESULTS: Oxygen partial pressure (pO(2)) in the fetal cranial carotid artery decreased to 12.9 +/- 0.6 mmHg after reducing the fraction inspiratory oxygen of the mother. After instituting V-A ECMO, pO(2) was found to be 23.5 +/- 2.6 mmHg; after instituting V-V ECMO, pO(2) was found to be 20.3 +/- 1.9 mmHg. Thus, fetal acidosis increased under both procedures. Fetal heart rate and blood pressure were not altered significantly during the experiments. CONCLUSIONS: This study indicates that V-V ECMO could more effectively and less traumatically maintain oxygenation in hypoxic fetal lambs.

Animals↗

Effects of dental resin metabolites on estrogenic activity in vitro.

Three monomers (Bis-GMA, UDMA, and TEGDMA) and five polymerization initiators (CQ, BPO, DMPT, DMAEMA, and ATU) commonly used in dental composite resins were tested for estrogenic activity using a reporter gene assay (yeast two-hybrid system) in vitro, and compared with bisphenol-A (BPA). Estrogenic activity was indicated by agonist and antagonist activity, with (+S9) and without (-S9) metabolic activation using rat liver cells. No estrogenic agonist activity was seen for each monomer and polymerization initiator in either the -S9 and +S9 tests in the concentration ranges examined in this study. On the other hand, estrogen antagonist activity was found with BPO and DMPT. BPO showed antagonist activity at a concentration of approximately 1800 nM with the -S9 test, but not with the +S9 test. With DMPT, antagonist activity was not seen with the -S9 test, but it was seen at a concentration of approximately 610 nM using the +S9 test. With BPA, the +S9 test indicated antagonist activity at a concentration of approximately 780 nM. The estrogen antagonist activities of DMPT and BPA appeared to be similar. CQ, DMAEMA, ATU, and the three monomers did not show antagonist activity as demonstrated by the -S9 or +S9 tests within the concentration range tested in this study.

Journal Article↗