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Y Nakagawa

Publications and source records attributed to Y Nakagawa.

At least 19 recordsLinked to original sources
PubMed2006

Maturation-dependent change and regional variations in acoustic stiffness of rabbit articular cartilage: an examination of the superficial collagen-rich zone of cartilage.

OBJECTIVE: The purpose of the study was to investigate maturation-dependent changes of acoustic (ultrasound) stiffness and other ultrasound features of articular cartilage in healthy rabbit knees. METHODS: Five groups of rabbits of various ages (3 weeks, 8 weeks, 6 months, 1 year, 2.5 years) consisting of five rabbits per group were examined. Signal intensity (index of stiffness), signal duration (index of surface irregularity) and interval between signals (index of thickness) of the ultrasound reflection from articular cartilage were examined at four sites: posterior lateral femoral condyle, posterior medial femoral condyle, lateral tibial plateau, and medial tibial plateau. The sites were observed macroscopically and microscopically with a light microscope and a polarized light microscope. RESULTS: At the lateral and medial condyles and the lateral tibial plateau, signal intensity was least in 3-week-old specimens. The intensity increased until 6 months or 1 year of age. At these sites, the signal durations and intervals between signals were least at the ages of 6 months or 1 year. At the medial tibial plateau, the intensity was the least at 2.5 years of age and the interval between signals was least at 3 weeks of age; there was no effect of age on signal duration. Cartilage surfaces of all specimens were smooth and no degenerative changes were macroscopically or microscopically evident. The surface brightness of cartilage under the polarized light microscope was consistent with signal intensity values. CONCLUSIONS: The response of articular cartilage to ultrasound was maturation-dependent. Acoustic properties differed from mechanical stiffness properties, which were determined using indentation. Ultrasound may detect properties of the surface collagen of the articular cartilage.

Aging↗
PubMed2006

Posterior endoscopic surgery for lumbar disc herniation with contralateral symptoms - a report of two cases.

We report two cases of lumbar disc herniation with contralateral nerve root involvement, surgically treated with a microendoscopic disectomy system (METRx-MED system). The nerve root of the symptomatic side (contralateral to the side of the disc herniation) had been compressed to the superior facet by herniated disc from the opposite side. Endoscopic observation revealed inflammatory findings of the nerve root on the symptomatic side, such as fibrosis, adhesion, redness and swelling. In contrast, on the non-symptomatic side (ipsilateral side of the disc herniation), the nerve root had been merely compressed by the herniated disc but did not demonstrate any inflammatory findings. Excision of the herniated disc and decompression of the non-symptomatic nerve root should be done first, approaching from the disc herniation side. After that, through the same approach, the nerve root of the opposite (symptomatic) side should be decompressed.

Adolescent↗
PubMed2006

A survey of the appropriate use of antiseptic agents in the operating room of several key health care facilities. A comparison between surveys in 2000 and 2004.

Since 2000, new hand and environmental hygiene guidelines have been published by the Center for Disease Control and Prevention (CDC) based on scientific evidence. Accordingly, we expected that the use of disinfectants in clinical settings had been changed. To compare the use and amount of disinfectants before and after the publication of these guidelines, we conducted a questionnaire-based survey on the use of antiseptic agents in operating rooms (ORs) in 6 key hospitals over a period of a month in 2000 and 2004. As a result, the amount of disinfectants used in ORs was reduced in all hospitals in 2004. Especially, amphoteric detergents and glutaral products showed significant reductions in the total amount used in the 6 hospitals, by 94.8 and 96.8%, respectively. The use of povidone-iodine (PVP-I) was decreased by 23.4% overall, although it was increased in 3 hospitals by 11.0-58.6%. The number of applications of PVP-I on the surgical site did not change; however, the site was left to dry without wiping after PVP-I application more frequently in 2004 than in 2000. The time for surgical scrubbing was shortened in 2004, but brush scrubbing was still used as often as in 2000. Many of the hospitals used brush scrubbing in conjunction with alcohol-based rubs. These results indicated changes in infection control measures in hospital settings after publication of the new CDC guidelines; environmental disinfection had been limited and excessive use of disinfectants reevaluated.

Anti-Infective Agents, Local↗
PubMed2006

[Clinical analysis of operative and hospital deaths in primary lung cancer].

In our department, there were 313 thoracic surgeries for primary lung cancer from January 1994 to December 2003. We clinically reviewed for the operative and hospital death (n=18, 5.8%). The patients were 16 males and 2 females (70.6 +/- 5.6 years old). The surgical procedures were 4 pneumonectomies, 13 lobectomies (3 bronchoplasties) and 1 partial resection. The mean interval until postoperative death was 122.5 +/- 156.1 days. There were 5 direct operative deaths within 30 days (1.6%). There were 4 cancer deaths, 2 hemoptyses, 2 operative bleeding, 2 thromboses, 2 cerebral hemorrhages, 1 pyothorax, 1 pneumonia, 1 respiratory failure, 1 multiple organ failure after chemotherapy and 2 unexplained deaths. The patients with pneumonectomy or aged significantly had high mortality. For postoperative complications such as hemoptysis or bleeding, perioperative management that takes these issues into consideration is needed. Furthermore, we must carefully review the preoperative evaluation and combined treatment, because there were many cancer deaths among cases showing early recurrence and metastasis.

Adenocarcinoma↗
PubMed2005

Discovery of the short gamma-ray burst GRB 050709.

Gamma-ray bursts (GRBs) fall into two classes: short-hard and long-soft bursts. The latter are now known to have X-ray and optical afterglows, to occur at cosmological distances in star-forming galaxies, and to be associated with the explosion of massive stars. In contrast, the distance scale, the energy scale and the progenitors of the short bursts have remained a mystery. Here we report the discovery of a short-hard burst whose accurate localization has led to follow-up observations that have identified the X-ray afterglow and (for the first time) the optical afterglow of a short-hard burst; this in turn led to the identification of the host galaxy of the burst as a late-type galaxy at z = 0.16 (ref. 10). These results show that at least some short-hard bursts occur at cosmological distances in the outskirts of galaxies, and are likely to be caused by the merging of compact binaries.

Journal Article↗
PubMed2005

Spontaneous lymphocyt ic thyroiditis in interferon regulatory factor-1 deficient non-obese diabetic mice.

Interferon regulatory factor-1 (IRF-1) is a transcription factor involved in interferon-mediated immune reaction, CD8+ T cell differentiation and development of T helper 1 immune reaction. We have recently demonstrated that IRF-1 is pivotal in iodine-induced lymphocytic thyroiditis (LT) in non-obese diabetic (NOD) mice. However, it remains unclear whether the mechanism involved in spontaneous LT is identical with iodine-induced LT in NOD mice. To determine the role of IRF-1 in spontaneous LT, we used IRF-1 deficient NOD mice as well as IRF-1 +/+ and +/- mice which were free from treatments for LT induction, and LT was evaluated at 24 weeks of age. IRF-1 +/+, +/- and -/- mice developed LT spontaneously, and there were no differences among the 3 IRF-1 genotypes in the incidence and severity of LT. Whereas both CD4+ and CD8+ T cells were present in the diseased thyroid of IRF-1 +/+ mice, CD8+ T cells were absent in the thyroid of IRF-1 -/- mice. MHC class II antigen expression was induced in the inflamed thyroid of IRF-1 -/- mice comparable to IRF-1 +/+ mice. There was a selective reduction in the number of CD8+ T cells in the spleen of IRF-1 -/- mice. IFNgamma production, but not IL-10, by concanavalin A-stimulated splenocytes was significantly reduced in IRF-1 deficient mice. These results suggest that IRF-1 plays only a minor role in spontaneous LT in NOD mice and, furthermore, the mechanism involved in spontaneous LT is different from that of iodine-induced LT in NOD mice.

Animals↗
PubMed2005

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↗
PubMed2004

Verification of the computational dosimetry system in JAERI (JCDS) for boron neutron capture therapy.

Clinical trials for boron neutron capture therapy (BNCT) by using the medical irradiation facility installed in Japan Research Reactor No. 4 (JRR-4) at Japan Atomic Energy Research Institute (JAERI) have been performed since 1999. To carry out the BNCT procedure based on proper treatment planning and its precise implementation, the JAERI computational dosimetry system (JCDS) which is applicable to dose planning has been developed in JAERI. The aim of this study was to verify the performance of JCDS. The experimental data with a cylindrical water phantom were compared with the calculation results using JCDS. Data of measurements obtained from IOBNCT cases at JRR-4 were also compared with retrospective evaluation data with JCDS. In comparison with phantom experiments, the calculations and the measurements for thermal neutron flux and gamma-ray dose were in a good agreement, except at the surface of the phantom. Against the measurements of clinical cases, the discrepancy of JCDS's calculations was approximately 10%. These basic and clinical verifications demonstrated that JCDS has enough performance for the BNCT dosimetry. Further investigations are recommended for precise dose distribution and faster calculation environment.

Algorithms↗
PubMed2004

Characteristics of BDE dependent on 10B concentration for accelerator-based BNCT using near-threshold 7Li(p,n)7Be direct neutrons.

The characteristics boron-dose enhancer (BDE) was evaluated as to the dependence on the (10)B concentration for BNCT using near-threshold (7)Li(p,n)(7)Be direct neutrons. The treatable protocol depth (TPD) was utilized as an evaluation index. MCNP-4B calculations were performed for near-threshold (7)Li(p,n)(7)Be at a proton energy of 1.900MeV and for a polyethylene BDE. Consequently, the TPD was increased by increasing T/N ratio, i.e., the ratio of the (10)B concentration in the tumor ((10)B(Tumor)) to that in the normal tissue ((10)B(Normal)), and by increasing (10)B(Tumor) and (10)B(Normal) for constant T/N ratio. It has been found that the BDE becomes unnecessary from the viewpoint of increasing the TPD, when (10)B(Tumor) is over a certain level.

Beryllium↗
PubMed2004

Radiation injury of boron neutron capture therapy using mixed epithermal- and thermal neutron beams in patients with malignant glioma.

The purpose of this study was to clarify the radiation injury in acute or delayed stage after boron neutron capture therapy (BNCT) using mixed epithermal- and thermal neutron beams in patients with malignant glioma. Eighteen patients with malignant glioma underwent mixed epithermal- and thermal neutron beam and sodium borocaptate between 1998 and 2004. The radiation dose (i.e. physical dose of boron n-alpha reaction) in the protocol used between 1998 and 2000 (Protocol A, n = 8) prescribed a maximum tumor volume dose of 15 Gy. In 2001, a new dose-escalated protocol was introduced (Protocol B, n = 4); it prescribes a minimum tumor volume dose of 18 Gy or, alternatively, a minimum target volume dose of 15 Gy. Since 2002, the radiation dose was reduced to 80-90% dose of Protocol B because of acute radiation injury. A new Protocol was applied to 6 glioblastoma patients (Protocol C, n = 6). The average values of the maximum vascular dose of brain surface in Protocol A, B and C were 11.4+/-4.2 Gy, 15.7+/-1.2 and 13.9+/-3.6 Gy, respectively. Acute radiation injury such as a generalized convulsion within 1 week after BNCT was recognized in three patients of Protocol B. Delayed radiation injury such as a neurological deterioration appeared 3-6 months after BNCT, and it was recognized in 1 patient in Protocol A, 5 patients in Protocol B. According to acute radiation injury, the maximum vascular dose was 15.8+/-1.3 Gy in positive and was 12.6+/-4.3 Gy in negative. There was no significant difference between them. According to the delayed radiation injury, the maximum vascular dose was 13.8+/-3.8 Gy in positive and was 13.6+/-4.9 Gy in negative. There was no significant difference between them. The dose escalation is limited because most patients in Protocol B suffered from acute radiation injury. We conclude that the maximum vascular dose does not exceed over 12 Gy to avoid the delayed radiation injury, especially, it should be limited under 10 Gy in the case that tumor exists in speech center.

Adult↗
PubMed2004

Improvement of dose calculation accuracy for BNCT dosimetry by the multi-voxel method in JCDS.

To carry out boron neutron capture therapy (BNCT) clinical trials based on accurate dosimetry of several dose components given to a patient, we had developed the JAERI computational dosimetry system (JCDS), which can determine the absorbed doses by numerical simulation. The verification results of initial version of JCDS indicated that JCDS causes characteristic discrepancy, when JCDS estimates a sharp change arising such as near the surface. The aim of this study is to improve the accuracy of the BNCT dosimetry efficiently. The multi-voxel calculation method that reconstructs the original voxel model by combining several voxel cell sizes such as 0.125, 1 and 8 cm(3) has been developed. To verify the accuracy of the method, the calculation results were compared with the phantom experimental data. Furthermore, to verify its practicality to BNCT, retrospective evaluation of an actual BNCT in JRR-4 was performed by the multi-voxel method. The results of the comparison with the phantom experiments demonstrated that the calculation accuracy for the distributions of the thermal neutron flux was improved by employing the multi-voxel method. The computing time using the multi-voxel method increased only approximately 33% compared to the conventional uniform 1cm(3) voxel method. These results proved that the multi-voxel calculation enables JCDS to more accurately estimate the absorbed doses to a patient by efficient calculations.

Boron Neutron Capture Therapy↗
PubMed2004

Effects of diet consistency on the expression of insulin-like growth factors (IGFs), IGF receptors and IGF binding proteins during the development of rat masseter muscle soon after weaning.

A soft diet facilitates the development of faster-type fibres in rat masseter muscle in the 9 days after weaning compared with a hard diet. To determine whether insulin-like growth factors (IGFs), IGF receptors (IGFRs) and IGF binding proteins (IGFBPs) are involved in this fibre-type alteration, the expression of myosin heavy chain (MHC), IGF, IGFR and IGFBP mRNAs in the masseter muscle of rats fed a hard or soft diet for 9 days after weaning was analysed using competitive, reverse transcriptase-polymerase chain reaction. A soft diet decreased the expression of MHC IIa (slower type) by 70%, but increased the expression of MHC IIx (intermediate type) and IIb (faster type) by 80 and 582%, respectively, compared with a hard diet. These findings verified that a soft diet facilitates the development of faster-type fibres in rat masseter muscle compared with a hard diet. A soft diet induced reductions of 25-76% (P < 0.05-0.01) in the expression of IGF-I, IGF-II, IGFR2, IGFBP4 and IGFBP6 compared with a hard diet, but induced a 25% (P < 0.05) increase only in expression of IGFBP3. These findings suggest that the changes in expression of IGF-I, IGF-II, IGFR2, IGFBP3, IGFBP4 and IGFBP6 are associated with the fibre-type alteration of rat masseter muscle in response to diet consistency soon after weaning.

Animals↗
PubMed2004

Biotransformation of chlorpropham (CIPC) in isolated rat hepatocytes and xenoestrogenic activity of CIPC and its metabolites by in vitro assays.

1: The metabolism and action of chlorpropham (isopropyl N-(3-chlorophenyl)carbamate; CIPC, a post-harvest agent) were studied in freshly isolated rat hepatocytes, and the oestrogen-like activity of CIPC and its metabolites was assessed by in vitro assays. The exposure of hepatocyte suspensions to CIPC caused concentration- (0.25-1.0 mM) and time- (0-3 h) dependent cell death, which was assessed by Trypan blue exclusion, accompanied by losses of cellular adenosine triphosphate and adenine nucleotide pools, and formation of cell bleb. 2: CIPC at a weakly toxic level (0.25 or 0.5 mM) was metabolized to isopropyl N-(3-chloro-4-hydroxyphenyl)carbamate (4OH-CIPC) and subsequently to its glucuronide and sulfate conjugates (major metabolites) or alternatively to the minor metabolites 3-chloroaniline (3CA) and 3-chloroacetanilide. CIPC (0.25 mM) added to hepatocyte suspensions was distributed equally between hepatocytes and the extracellular medium during the incubation. The glucuronide rather than the sulfate conjugate of 4OH-CIPC predominantly increased in the medium with time, while the amount of unconjugated free 4OH-CIPC in the extracellular medium increased by approximately threefold compared with the amount in the cell fraction after 0.5 h and then decreased rapidly accompanied by increases in the conjugates. This indicates that unconjugated free 4OH-CIPC produced in hepatocytes was temporarily excreted in the extracellular medium and subsequently converted to the conjugates via re-influx into hepatocytes. 3: Diethylstilbestrol (DES), bisphenol A (BPA) and 4-hydroxybenzoic acid butyl ester (butylparaben), which are known xenoestrogenic compounds, competitively displaced 17beta-oestradiol bound to the oestrogen receptor-alpha (ERalpha) in a concentration-dependent manner; IC50 values of DES, BPA, butylparaben and its derivative 3-chloro-4-hydroxybenzoic acid butyl ester (3-chloro-butylparaben) were approximately 10(-8), 10(-5), 5 x 10(-5) and 5 x 10(-4) M, respectively. In contrast, neither CIPC nor 4OH-CIPC impaired the binding of 17beta-oestradiol to ERalpha at concentrations ranging from 10(-9) to 10(-4) M, whereas at concentrations of >5 x 10(-4) M, the binding affinity of 4OH-CIPC was greater than that of CIPC. In a proliferation assay of MCF-7 cells, CIPC, 4OH-CIPC and 3CA did not increase cell numbers at concentrations ranging from 10(-9) to 10(-5) M, but these compounds at a concentration of 10(-4) M induced a considerable decrease in cell numbers relative to the control. The results suggest that even if CIPC is metabolized to 4OH-CIPC by hepatocytes, the chlorine adjacent to the 4-hydroxy group added to the intermediate as well as 3-chloro-butylparaben obstructs the appearance of oestrogen-like effects via an interaction between the intermediate and the ER.

Animals↗
PubMed2004

Placental growth by the estrogen-dependent angiogenic factors, vascular endothelial growth factor and basic fibroblast growth factor, throughout gestation.

Angiogenesis is essential for the development and growth of the human placenta throughout gestation, under the influence of enriched estrogen. This prompted us to study the clinical implications of estrogen-dependent angiogenic factors derived from the human placenta. Fifty-eight women ranging from 6 to 41 weeks' gestational age (25 in the first trimester, 12 in the second trimester and 21 in the third trimester) underwent abortion and delivery. The levels of angiogenic factors in the placenta were determined by enzyme immunoassay, and the mRNA and protein of vascular endothelial growth factor (VEGF) variants were analyzed by reverse transcriptase-polymerase chain reaction and Western blotting, respectively. The levels of VEGF, especially VEGF165, and bFGF correlated with placental weights throughout gestation. Estrogen-dependent VEGF, especially VEGF165, and bFGF might work on growth via angiogenesis in the human placenta throughout all trimesters of gestation.

Alternative Splicing↗
PubMed2004

Augmentation of leptin and hypoxia-inducible factor 1alpha mRNAs in the pre-eclamptic placenta.

The placenta is a major source of leptin in the fetomaternal circulation, although its physiological role remains to be clarified. Leptin in the fetomaternal circulation is proposed to be a marker of acute stress in the fetus, and the fetus suffering from pre-eclampsia would be under chronic stress. In 16 pre-eclamptic placentas, the expressions of leptin, hypoxia-inducible factor 1alpha (HIF1alpha) and leptin receptor mRNAs were analyzed by semi-quantitative reverse-transcriptase-polymerase chain reaction and compared with clinical data. The co-expressions of leptin and the isoforms of the leptin receptor were observed in all the pre-eclamptic placentas. Leptin mRNA was significantly augmented in the pre-eclamptic placentas, although the level in fetal plasma was not high. The level of the expression of leptin mRNA was correlated with the placental HIF1alpha mRNA level and fetal body weight, but not with the levels of the leptin receptor isoforms in the pre-eclamptic placentas. This observation may suggest that autocrine/paracrine regulation of leptin exists in the human placenta and is upregulated in the pre-eclamptic placenta.

Adult↗
PubMed2004

Recurrent isolation of an uncommon yeast, Candida pararugosa, from a sarcoma patient.

A yeast was repeatedly isolated from the saliva of a sarcoma patient. A relatively uncommon species, Candida maris, was identified based on the API 20C profile. The yeast species most frequently obtained from the patient's mother and from clinic staff was Candida albicans. A comparison of the yeast obtained from the patient with the type strain of C. maris strongly suggested that the former was not representative of C. maris. Analysis of partial ribosomal DNA sequences of the patient strain and from the type strain of C. maris showed that the two are phylogenetically not closely related. The patient strain was very close to Candida pararugosa, a relatively uncommon asporogenous yeast. DNA reassociation studies among C. pararugosa and patient isolates showed that they were conspecific. We could not determine the source of the yeast infection. This case will alert hospital staff to be aware of the possibility of unexpected environmental microorganisms as causes of infections, colonizations and persistent environmental contamination events in immunocompromised patients.

Animals↗
PubMed2004

Features of retinal arterial macroaneurysms in patients with uveitis.

AIM: To determine the frequency and clinical characteristics of retinal arterial macroaneurysms in patients with uveitis. METHODS: A retrospective review of the clinical, photographic, and angiographic records of 1007 patients with uveitis, examined at the Osaka University Hospital uveitis clinic between January 1995 and April 2002, was performed. All of the records were examined to determine whether macroaneurysms were present, and when present, to determine the laterality, type, location, clinical course, and the presence of associated systemic and ocular diseases. RESULTS: Of the 1007 patients with uveitis, only 14 (1.4%) had macroaneurysms. 12 of these 14 patients had peripheral multifocal chorioretinitis (PMC), and five of these 12 were diagnosed with sarcoidosis and the other seven without sarcoidosis. There was only one case with sarcoidosis without PMC, and the remaining case was uveitis of unknown origin. There were 18 macroaneurysms in all cases and 17 (94.4%) were the exudative type, and the remaining one was the haemorrhagic type. Two patients had been treated for systemic hypertension but the others had no signs of systemic hypertension or cardiovascular disease. CONCLUSIONS: Macroaneurysms are not characteristically found in patients with uveitis, but the majority are found in patients with PMC. The majority of the macroaneurysms were the exudative type, and the conclusion is that patients with PMC should be carefully examined for exudative macroaneurysms.

Adult↗