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Biomedical subjects

Y Arai

Publications and source records attributed to Y Arai.

At least 37 records · Page 2Linked to original sources
PubMed2004

Single air contrast arthrography for temporomandibular joint disorder using limited cone beam computed tomography for dental use.

MRI has the problem of artefacts caused by metal or body motion and is also incompatible for patients with claustrophobia. Arthrography is invasive and involves the risk of perforation or allergy to a contrast medium. This report discusses a patient with temporomandibular joint (TMJ) disorder who required soft tissue imaging of the TMJ. As she had claustrophobia and a reaction to iodine, air contrast arthrography and pumping manipulation therapy using limited cone beam computed tomography for dental use (3DX) was performed. We conclude that the 3DX examination method used in the study is practical as a diagnostic procedure and thus recommend this method to be used for patients with TMJ disorder in the presence of iodine contraindication.

Air↗
PubMed2004

Evaluation of the usefulness of the limited cone-beam CT (3DX) in the assessment of the thickness of the roof of the glenoid fossa of the temporomandibular joint.

OBJECTIVES: The purpose of this study was to evaluate the usefulness of the limited cone-beam X-ray CT (3DX) (Morita Co., Japan) in measuring the thickness of the roof of the glenoid fossa (RGF) of the temporomandibular joint (TMJ). MATERIALS AND METHODS: Twenty-one TMJs removed at autopsy from 21 cadavers were investigated macroscopically using dissection and 3DX imaging. A Digimatic Outside Micrometer and a 3DX-image tool were used to measure the minimum thickness of the RGF. Multiple measurements were made to identify the thinnest area. Once the thinnest areas had been identified, three linear measurements were made and the average value was used for statistical analysis. RESULTS: The average macroscopic examination measurement was 1.37 mm (range 0.55-3.6 mm) and the average 3DX image measurement was 1.22 mm (range: 0.51-3.0 mm). There was no significant difference between these two groups using the Mann-Whitney U-test (P < 0.05). The Spearman's correlation coefficient by rank between these two groups was r = 0.93(P < 0.001). CONCLUSION: These results suggest that bone thickness measurements of the RGF by 3DX imaging was effective.

Adult↗
PubMed2003

Are there inequities in the assessment of dementia under Japan's LTC insurance system?

BACKGROUND: Just two years after its inception, Japan's Long-term Care (LTC) insurance system is facing considerable criticism about whether or not it has developed a fair and appropriate way of allocating resources to the nation's disabled elderly population, especially those people with dementia. OBJECTIVE: The present study has investigated: (i) the relation of the Government-Certified Disability Index (GCDI) of the LTC insurance system to characteristics of people with dementia and their family caregivers; and (ii) whether the GCDI scores adequately reflect needs of people with DAT (dementia of Alzheimer's type) and VD (vascular-type dementia). METHODS: Subjects were assessed on their visits to outpatient clinics for their Activities of Daily Living (ADL), behavioural disturbances, MMSE, GCDI, service utilization and caregiver burden. Correlation analyses were conducted to examine the relationships among these variables, which were subsequently compared between the DAT and VD patients. RESULTS AND CONCLUSIONS: The GCDI was found to be associated with patients' ADLs and MMSE scores, and not with behavioural disturbances or caregiver burden. Compared to VD patients, people with DAT tended to have more behavioural disturbances but better ADL functioning. As a result, DAT patients were classified as 'less disabled' on their GCDI than VD patients, even though their caregivers felt as much burden as the caregivers of VD patients. These results show that the GCDI probably underestimates the impact of behaviour problems. Suggestions are made for a more balanced assessment of demented patients that is more consistent with their needs.

Activities of Daily Living↗
PubMed2003

Enhancement of 5-hydroxytryptamine-induced head-twitch response after olfactory bulbectomy.

5-Hydroxytryptamine(2A) receptor agonists evoke the head-twitch response in mice. The head-twitch response in olfactory bulbectomized mice elicited by the administration of 5-hydroxytryptamine (40 microgram/mouse, i.c.v.) was increased about threefold as compared with controls on the 14th day after the operation. The injection of ketanserin (1 mg/kg, i.p.), a 5-hydroxytryptamine(2A) receptor antagonist, inhibited this enhancement of 5-hydroxytryptamine-induced head-twitch response after olfactory bulbectomized. On the 14th day, the number of head-twitch response induced by 5-hydroxytryptophan (40, 80 and 160 mg/kg, i.p.), a precursor of 5-hydroxytryptamine, did not differ between olfactory bulbectomized and control mice. Monoamine oxidase-B activity in the forebrain of olfactory bulbectomized mice was higher than that in controls while monoamine oxidase-A activities were unchanged. The 5-hydroxytryptamine uptake into synaptosomes in the forebrain homogenates of olfactory bulbectomized mice was lower than that in controls. These findings indicate that olfactory bulbectomized causes the enhancement of head-twitch response by a supersensitivity of 5-hydroxytryptamine(2A) receptors in cerebral cortex derived from degeneration of neurons projecting from the olfactory bulb.

5-Hydroxytryptophan↗
PubMed2003

Development of a vibratory microinjection method.

To reduce cellular damage by pronuclear microinjection and nuclear transfer, we have recently developed a vibratory microinjection method. A micropipette was fixed to a piezoelectric ceramic with a resonance frequency of 70 kHz. When this micropipette was vibrated, it easily entered a mouse-fertilized egg without any sharp depression of the cell body, whereas a sharp, deep depression at the insertion site was observed when the micropipette was not vibrated. A depression rate defined as a rate of a depth of depression over an original cell diameter was utilized as an index of cellular deformation. The depression rates with and without vibration were 11.1 +/- 5.2% (N = 24) and 40.4 +/- 8.8% (N = 16), respectively (P < 0.0001, Student's t-test). In conclusion, the vibratory microinjection method is a new, useful option for gene transfer because it resulted in much less cellular deformation, therefore implicating less cellular damage.

Animals↗
PubMed2002

Flow measurements via two-particle azimuthal correlations in Au + Au collisions at sqrt [s(NN)]=130 GeV.

Two-particle azimuthal correlation functions are presented for charged hadrons produced in Au+Au collisions at the Relativistic Heavy Ion Collider (sqrt [s(NN)]=130 GeV). The measurements permit determination of elliptic flow without event-by-event estimation of the reaction plane. The extracted elliptic flow values (v2) show significant sensitivity to both the collision centrality and the transverse momenta of emitted hadrons, suggesting rapid thermalization and relatively strong velocity fields. When scaled by the eccentricity of the collision zone epsilon, the scaled elliptic flow shows little or no dependence on centrality for charged hadrons with relatively low p(T). A breakdown of this epsilon scaling is observed for charged hadrons with pT >1.0 GeV/c.

Journal Article↗
PubMed2002

Measurement of Lambda and Lambda(macro) particles in Au+Au collisions at the square root of S(NN) = 130 GeV.

We present results on the measurement of Lambda and Lambda(macro) production in Au+Au collisions at square root of (S (NN) = 130 GeV with the PHENIX detector at the Relativistic Heavy Ion Collider. The transverse momentum spectra were measured for minimum bias and for the 5% most central events. The Lambda;/Lambda ratios are constant as a function of p(T) and the number of participants. The measured net Lambda density is significantly larger than predicted by models based on hadronic strings (e.g., HIJING) but in approximate agreement with models which include the gluon-junction mechanism.

Journal Article↗
PubMed2002

Net charge fluctuations in Au + Au interactions at sqrt[s(NN)]=130 GeV.

Data from Au + Au interactions at sqrt[s(NN)]=130 GeV, obtained with the PHENIX detector at the Relativistic Heavy-Ion Collider, are used to investigate local net charge fluctuations among particles produced near midrapidity. According to recent suggestions, such fluctuations may carry information from the quark-gluon plasma. This analysis shows that the fluctuations are dominated by a stochastic distribution of particles, but are also sensitive to other effects, like global charge conservation and resonance decays.

Journal Article↗
PubMed2002

Centrality dependence of pi(+/-), K(+/-), p, and (-)p production from sqrt[s(NN)] = 130 GeV Au + Au collisions at RHIC.

Identified pi(+/-), K(+/-), p, and (-)p transverse momentum spectra at midrapidity in sqrt[s(NN)] = 130 GeV Au+Au collisions were measured by the PHENIX experiment at RHIC as a function of collision centrality. Average transverse momenta increase with the number of participating nucleons in a similar way for all particle species. Within errors, all midrapidity particle yields per participant are found to be increasing with the number of participating nucleons. There is an indication that K(+/-), p, and (-)p yields per participant increase faster than the pi(+/-) yields. In central collisions at high transverse momenta (p(T) > or =2 GeV/c), (-)p and p yields are comparable to the pi(+/-) yields.

Journal Article↗
PubMed2002

Transverse-mass dependence of two-pion correlations in Au+Au collisions at square root[s(NN)] = 130 GeV.

Two-pion correlations in square root[s(NN)] = 130 GeV Au+Au collisions at RHIC have been measured over a broad range of pair transverse momentum k(T) by the PHENIX experiment at RHIC. The k(T) dependent transverse radii are similar to results from heavy-ion collisions at square root[s(NN)] = 4.1, 4.9, and 17.3 GeV, whereas the longitudinal radius increases monotonically with beam energy. The ratio of the outwards to sidewards transverse radii (R(out)/R(side)) is consistent with unity and independent of k(T).

Journal Article↗
PubMed2002

Measurement of single electrons and implications for charm production in Au+Au collisions at square root[s(NN)] = 130 GeV.

Transverse momentum spectra of electrons from Au+Au collisions at square root[s(NN)] = 130 GeV have been measured at midrapidity by the PHENIX experiment at the Relativistic Heavy Ion Collider. The spectra show an excess above the background from photon conversions and light hadron decays. The electron signal is consistent with that expected from semileptonic decays of charm. The yield of the electron signal dN(e)/dy for p(T) > 0.8 GeV/c is 0.025+/-0.004(stat)+/-0.010(syst) in central collisions, and the corresponding charm cross section is 380+/-60(stat)+/-200(syst) microb per binary nucleon-nucleon collision.

Journal Article↗
PubMed2002

Monitoring cytomegalovirus infection by antigenemia assay and two distinct plasma real-time PCR methods after hematopoietic stem cell transplantation.

We compared a CMV virus load determined by real-time PCR with an antigenemia value to analyze the correlation between these two methods. We also compared the values for virus load determined by the two distinct real-time PCR methods, which amplify the US17 region and immediate-early (IE) gene of CMV, respectively, to evaluate the reliability of these methods. Two hundred and sixty-five samples were obtained weekly from 29 patients, who had engraftment after unrelated bone marrow transplantation or HLA-mismatched related blood stem cell transplantation. CMV infection was detected in 115 samples from 22 patients by US17-PCR and 69 samples from 20 patients by the antigenemia assay. Fifty-eight samples were positive for both assays, but 57 and 11 samples were positive only for US17-PCR and antigenemia, respectively. A good correlation of the results of US17-PCR and antigenemia was demonstrated (r = 0.61). All antigenemia-positive samples and randomly selected antigenemia-negative samples were subjected to IE-PCR. The results of IE-PCR showed a good correlation with those of antigenemia (r = 0.64). Furthermore, the best correlation was observed between US17-PCR and IE-PCR (r = 0.83). In conclusion, both real-time PCR methods showed a good correlation with the antigenemia assay, and could be used to monitor CMV infection after hematopoietic stem cell transplantation.

Antigens, Viral↗
PubMed2002

Twenty-year changes in the prevalence of overweight in Japanese adults: the National Nutrition Survey 1976-95.

The aim of this study was to describe the 20-year changes in body mass index (BMI; kgm(-2)) and the prevalence of overweight in Japanese adults. Cross-sectional annual nationwide surveys (National Nutrition Survey, Japan) were carried out with a large probability sample of the Japanese population. Data sets of the 1976-95 surveys, comprising 91983 men and 120822 women (> or =20 years of age), were used. The analyses were carried out in age and gender groups, and by residential area according to the size of the municipality (metropolitan areas, cities and small towns). The mean BMI increaseed in men with an increment of +0.44 kg m(-2) 10 years(-1) and slightly decreased in women, by -0.09 kg m(-2) 10 years(-1), after adjustment for age. A decreasing trend of mean BMI was most significant in the female 20-29 years age-group (-0.38 kg m(-2) 10 years(-1)), in contrast to an increasing trend observed in elderly women (60-69 and 70+ years age-groups). The prevalence of preobese (BMI: 25-29.9kg m(-2)) and obese (BMI > or = 30 kg m(-2)) men increased from 14.5% and 0.8%, respectively, in the time-period 1976-80 to 20.5% and 2.01% during 1991-95. The increasing trend was most evident in the youngest age-group (20-29 years) and in those from small towns. The overall prevalence of preobese and obese women did not change during the 20-year study period. The prevalence in younger women decreased, this trend being more prominent in metropolitan areas. Although the prevalence of overweight (BMI > or =25 kg m(-2)) in Japanese men and elderly women has increased in the last 20 years, the mean BMI in younger women, especially those in metropolitan areas, has decreased. A population approach to control obesity and prevent obesity-associated diseases should be mainly focused on men and women older than 40 years of age.

Adult↗
PubMed2002

Patterns of outcome of caregiving for the impaired elderly: a longitudinal study in rural Japan.

This longitudinal study investigates the experiences among Japanese caregivers who provide informal care at home to the impaired elderly over one year. Little is known about longitudinal changes in caregivers' burden in Japan. Between 1998-1999, 47 pairs of impaired elderly and their caregivers were followed in Matsuyama Town in a rural area of northern Japan. Caregivers were interviewed initially and then again 12 months later. Findings indicated that the mean score of the Zarit Burden Interview at Time 2 was significantly lower than that of Time 1, suggesting that caregivers adapted to their role over time. Outcomes were further categorized as successful and unsuccessful, depending on the pattern of change over one year. Two factors were related to the outcome in univariate analyses: caring for someone with dementia, and caregiver being a spouse. Logistic regression demonstrated that caring for someone with dementia was five times more likely to be associated with an unsuccessful outcome. The caregiver spouse was five times more likely to be associated with a successful outcome, while daughters-in-law were more likely to have an unsuccessful outcome. The present study suggests that (1) changes in well-being among caregivers in Japan are similar to those observed in most studies in the West, and (2) there was evidence of both the adaptation and wear-and-tear models among caregivers over time.

Aged↗
PubMed2002

Mediastinal abscess successfully treated by percutaneous drainage using a unified CT and fluoroscopy system.

We report two patients with mediastinal abscess developing after surgery for oesophageal cancer who were treated by percutaneous drainage using a unified CT and angiography system, which allows both CT and fluoroscopy to be conducted with the patient on the same bed. Fine needle puncture is performed under CT guidance and this needle is used as a tandem for insertion of the drainage needle under fluoroscopic guidance, making safe puncture possible whilst confirming the position of the needle tip. Moreover, contrast medium can be injected from the drainage tube, allowing the extent of the abscess cavity to be determined by fluoroscopy and CT, thereby making accurate drainage possible.

Abscess↗
PubMed2002

Severe obstruction of the superior vena cava caused by tumor invasion. Recanalization using a PTFE-covered Z stent.

Bare stents are commonly used for the treatment of malignant vena cava stenoses. However, the therapeutic effect of treatment using bare stents for cases with intraluminal tumor invasion is not satisfactory. We report a case with severe obstruction of the superior vena cava caused by tumor invasion of mediastinal lymph node metastases from colon cancer, which was successfully treated by the recanalization of superior vena cava using a polytetrafluoroethylene-covered Z stent. The covered stent could not be fully expanded at first, and re-obstruction developed at the stented site due to thrombus formation soon after stenting. So, the additional balloon dilatation made the stent expend fully on another day of stenting. After the balloon dilatation blood flow improved immediately and the clinical symptoms associated with the superior vena cava obstruction resolved. Thereafter no symptomatic recurrence has been observed in 12 months of follow-up period.

Angioplasty, Balloon↗