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M Hayashi

Publications and source records attributed to M Hayashi.

At least 37 records · Page 2Linked to original sources
PubMed2006

Fatal intratumoral hemorrhage immediately after gamma knife radiosurgery for brain metastases: case report.

Radiosurgical treatment of brain tumors is sometimes considered to be free from significant acute complications or adverse effects. A rare case of fatal intratumoral hemorrhage immediately after gamma knife radiosurgery (GKR) for brain metastasis is reported. A 46-year-old woman with lung cancer complicated by systemic dissemination experienced an acute episode of headache, speech disturbances, and right-side hemiparesis. She had no history of arterial hypertension or coagulation disorders. CT and MRI disclosed multiple brain metastases. The largest tumor, which was located in the left frontal lobe and caused a significant mass effect, was removed microsurgically without any complications. GKR for nine residual metastases was done on the fourth postoperative day. The marginal dose, which corresponded to the 50% prescription isodose line, constituted 20 Gy. No complications were noticed during frame fixation, treatment itself, or frame removal. Fifteen minutes after the end of the GKR session the patient acutely fell into a deep coma. Urgent CT disclosed a massive hemorrhage in the left cerebellar hemisphere in the vicinity of the radiosurgically treated lesion. The patient died 4 days later and autopsy confirmed the presence of intratumoral hemorrhage. In conclusion, GKR for metastatic brain tumors should not be considered as a risk-free procedure and, while extremely rare, even fatal complications can occur after treatment.

Brain Neoplasms↗
PubMed2006

Co-production of vascular endothelial cadherin and inducible nitric oxide synthase by endothelial cells in periapical granuloma.

AIM: To clarify the mechanisms of inflammatory cell migration in human periapical granulomas by examining vascular endothelial (VE) cadherin and inducible nitric oxide synthase (iNOS)-producing cells. METHODOLOGY: Periapical tissues were obtained from patients during endodontic surgery and were divided into two portions. After fixing the tissues with acetone or 4% paraformaldehyde in phosphate-buffered saline, 5-microm-thick paraffin or cryostat sections were prepared, respectively. The paraffin sections of the inflamed tissues were evaluated histologically with haematoxylin-eosin stains. Cryostat sections of the tissue, diagnosed as periapical granulomas, were then examined by either immunohistochemistry using anti-human VE-cadherin or iNOS antibodies (Abs) for the characterization of infiltrating cells. In addition, co-localization of VE-cadherin and iNOS production was also analysed by two-colour immunofluorescence image analysis. RESULTS: Endothelial cells were strongly stained with iNOS Abs. Macrophages, lymphocytes, polymorphonuclear leucocytes and fibroblasts also exhibited iNOS production. These iNOS-positive cells accumulated around the blood vessels. On the other hand, VE-cadherin production was exhibited in only endothelial cells. Two-colour immunofluorescence image analysis using VE-cadherin and iNOS Abs demonstrated that iNOS-producing endothelial cells also showed VE-cadherin production. CONCLUSIONS: Vascular endothelial-cadherin produced by endothelial cells could be regulated by iNOS-producing cells in periapical granulomas and might play a pivotal role in vascular permeability.

Adult↗
PubMed2006

Mitogen-activated protein kinase/extracellular signal-regulated protein kinase activation of cultured human dental pulp cells by low-power gallium-aluminium-arsenic laser irradiation.

AIM: To examine whether low-power laser irradiation (LPLI) promotes cellular proliferation of human dental pulp-derived fibroblast-like cells (dental pulp cells). METHODOLOGY: Dental pulp cells were obtained by primary culture of human dental pulp tissues from extracted third molar teeth. The phosphorylation of the mitogen-activated protein kinase (MAPK) family after LPLI of these cells was investigated by Western blotting. By using a specific MAPK/ERK kinase (MEK) inhibitor (PD098059), the specific effect of LPLI on the MAPK pathway was also investigated by Western blotting as described above. The incorporation of [3H]thymidine into the cells after LPLI was determined, and statistical analysis was performed by Wilcoxon signed-ranks test. RESULTS: Extracellular signal-regulated protein kinase (ERK) 1/2 was phosphorylated between 5 and 30 min after LPLI. Moreover, PD098059 inhibited LPLI-mediated ERK1/2 activation. LPLI did not affect p38 MAPK or c-Jun N-terminal kinase (JNK) phosphorylation. But LPLI did not stimulate [3H]thymidine incorporation into these cells. CONCLUSIONS: These results indicated that LPLI activated MAPK/ERK, a signal for proliferation, differentiation and survival, but did not activate the stress signals p38 MAPK and JNK in human dental pulp cells.

Dental Pulp↗
PubMed2006

Effect of mineral trioxide aggregate on proliferation of cultured human dental pulp cells.

AIM: To investigate the effect of mineral trioxide aggregate (MTA) on the proliferation of human dental pulp (HDP) cells ex-vivo. METHODOLOGY: Human dental pulp cells were cultured with MTA or calcium hydroxide-containing cement (Dycal) using culture plate inserts. Control cells were cultured with culture plate inserts only. Cell proliferation was measured for up to 14 days using a Cell Counting kit, and the concentration of calcium ions released from the tested materials was assessed using a Calcium E-test kit. To confirm that the effect of MTA was attributable to released calcium ions, cell proliferation was measured in the presence of exogenous calcium chloride as a source of calcium ions while in the absence of MTA. RESULTS: Mineral trioxide aggregate significantly stimulated cell proliferation after 12 days, whereas Dycal had no such effect. The number of calcium ions released from MTA was significantly higher than that released from Dycal. Following the addition of calcium chloride, cell proliferation increased in a dose-dependent manner after 12 days. Moreover, cell proliferation showed a similar pattern whether a given concentration of calcium ions was produced by calcium chloride or by release from MTA. CONCLUSIONS: In this ex-vivo study, the elution components such as calcium ions from MTA had higher proliferation ability of HDP cells than control and Dycal.

Adult↗
PubMed2006

Fatal thrombosis of antithrombin-deficient mice is rescued differently in the heart and liver by intercrossing with low tissue factor mice.

BACKGROUND: We previously reported that the targeted disruption of murine antithrombin (AT) gene resulted in embryonic lethality before 16.5 gestational days (gd) because of severe cardiac and hepatic thrombosis. OBJECTIVE AND METHODS: To investigate the influences of lowered tissue factor (TF) activity upon hypercoagulation of AT-/- embryos, we crossed AT+/- with low TF (mTF-/- hTF+) mice to yield homozygous AT-deficient mice with the extremely low TF activity, that is expressed from the inserted human TF mini gene. RESULTS: AT-/- embryos either with 50% TF (AT-/- mTF+/- hTF+) or with low (approximately 1% TF, AT-/- mTF-/- hTF+) were not born, although the survival was prolonged until 18.5 gd. In both genotypes, histological examination showed disseminated thrombosis in hepatic sinusoidal space or in the portal veins, suggesting that the thrombogenesis caused loss of hepatic blood flow. As in original AT-/-, AT-/- mTF+/- hTF+ showed subcutaneous (s.c.) bleeding and also suffered from the myocardial degeneration apparently because of coronary thrombus formation. However, AT-/- mTF-/- hTF+ had no skin hemorrhage and the thrombosis and degeneration were completely abolished in the heart. Myocardium of adult low TF mice had exhibited fibrosis secondary to hemorrhage; however, it was significantly decreased in low TF mice with AT+/-. CONCLUSIONS: Our current model suggests that, in the heart, TF plays an important role in the thrombogenesis and it counterbalances AT-dependent anticoagulation. AT may be a potent anticoagulant during mice development and the activation and subsequent regulation of TF-procoagulant activity take place differently between the liver and the heart. These differences appear to point to local regulatory mechanisms in murine hemostasis.

Animals↗
PubMed2006

Pathology of fatal highly pathogenic H5N1 avian influenza virus infection in large-billed crows (Corvus macrorhynchos) during the 2004 outbreak in Japan.

Highly pathogenic H5N1 avian influenza viruses were isolated in 9 large-billed crows that died in Kyoto and Osaka prefectures in Japan from March to April in 2004. We studied 3 of the 9 crows using standard histologic methods, immunohistochemistry, and virus isolation. The most prominent lesions were gross patchy areas of reddish discoloration in the pancreas. The consistent histologic lesions included severe multifocal necrotizing pancreatitis, focal degeneration and necrosis of neuron and glial cells in the central nervous system, and focal degeneration of cardiac myocytes. All of these tissues contained immunohistochemically positive influenza viral antigens. The virus was isolated from the brain, lung, heart, liver, spleen, and kidney of the crows examined. Thus we concluded that highly pathogenic avian influenza virus was associated with clinical disease, severe pathologic changes, and death in the 3 crows.

Animals↗
PubMed2006

[Blunt right atrial rupture].

Atrial rupture without other major injury following blunt chest trauma is rare, but carries high mortality rate. Here we report 3 cases of blunt atrial rupture. All patients presented with hypotension and loss of consciousness. Echocardiography and computed tomography (CT) demonstrated pericardial effusion in all cases. All patients underwent surgery with a median sternotomy. Tear of the right atrium was seen in 2 patients, and no remarkable tear was seen in 1 patient. One of the 3 patients underwent surgery using cardiopulmonary bypass because he showed cardiogenic shock. Pericardiocentesis before the operation was not effective. All patients were discharged uneventfully. Echocardiography and CT were useful for diagnosis of cardiac rupture. In most reported cases, the cardiac tear has been repaired without using cardiopulmonary bypass. However, it is difficult to diagnose location of the tear, therefore, the repair became safer using cardiopulmonary bypass for the patients with cardiogenic shock. This article has described the mechanisms and generation of blunt chest trauma lesions.

Adult↗
PubMed2006

Clinical characteristics of vaginal discharge in bacterial vaginosis diagnosed by Nugent's criteria.

PURPOSE OF INVESTIGATION: To determine which clinical signs have an important contribution in bacterial vaginosis (BV) diagnosed by Nugent's criteria. METHODS: This was a cross-sectional study of 58 women undergoing vaginal examination at Hayashi women's clinic, Hyogo Prefecture. Characteristics of vaginal discharge (color, amount, odor, and pH level) and the number of clue cells were compared among normal, intermediate, and BV groups. BV was diagnosed by using Nugent's criteria. RESULTS: The incidence of BV in our study population was 25.9%. Compared to the non-BV group, women in the BV group were found more often to have yellowish color and a moderate amount of discharge (66.67% vs 33.33%, NS; 55.56% vs 44.44%, NS), odorous discharge (100% vs 0%, p < 0.05) and furthermore, pH level and the number of clue cells were significantly higher. CONCLUSION: Odor, pH level and the number of clue cells in the vaginal discharge were helpful clinical signs for early detection of BV diagnosed by Nugent's criteria.

Cross-Sectional Studies↗
PubMed2006

An attempt to study the economic loss arising from Schistosoma japonicum infection and the benefits derived from treatment.

From the northern and southern portions of Leyte Province, which are endemic for schistosomiasis, a total of 801 infected individuals were interviewed, examined, and classified into mild, moderate, severe and very severe forms of disease with an assumed loss of working capacity for each category. The frequency rate or number of spells of illness for the past year under observation were correlated with the degree of incapacity to get the total days lost per person per year. Following a series of computations, of which the disability rate was considered as the most important, a total of 45.4 days lost per infected person per year was arrived at. Treatment of the disease with praziquantel was carried out and the patients were followed up one year after treatment, at which time the same methodology was applied. The results show that the 45.4 days lost prior to treatment went down to 4 days lost. There was an economic gain of 41.4 days as a result of treatment. This can be expressed in terms of financial value if we consider half of the infected cases as breadwinners receiving a minimum wage. It should be noted that a number of assumptions in this study were made. It is, however, hoped that this work will serve as a guide and a starting point for others to carry out related studies on economic loss and subsequent economic benefits to justify budgetary requests/allocations for the implementation of various preventive and control measures.

Adolescent↗
PubMed2005

STAT3-mediated constitutive expression of SOCS3 in an undifferentiated rat trophoblast-like cell line.

In the trophoblast, constitutive expression of SOCS3 is important for the negative regulation of trophoblast giant cell differentiation. In this study, we analyzed the signaling pathway regulating the constitutive SOCS3 expression in undifferentiated Rcho-1 cells, which were derived from rat choriocarcinoma and consist of trophoblast stem cells that are capable of differentiating to trophoblast giant cells in vitro. PD98059, an MEK inhibitor, repressed the SOCS3 expression but AG490, a JAK2 inhibitor, did not. Promoter deletion analysis revealed that the STAT response element (SRE) in the SOCS3 promoter is necessary for the promoter activity. Overexpression of STAT3 increased the SOCS3 promoter activity, whereas expression of dominant-negative STAT3 reduced it. Constitutive STAT3 tyrosine phosphorylation that was not inhibited by either AG490 or PD98059 was demonstrated. Electrophoretic mobility shift assays showed the existence of a protein that bound to SRE and was supershifted with STAT3 antibody. This binding reaction was inhibited by neither AG490 nor PD98059. These findings imply that the ERK/MAPK pathway and STAT3 are involved in the constitutive activation of SOCS3 in undifferentiated Rcho-1 cells. Moreover, they indicate that the constitutive STAT3 tyrosine phosphorylation and the DNA binding activity of STAT3 do not depend on the ERK/MAPK or JAK kinase pathway. These results suggest that a trophoblast-specific STAT3 activation pathway is important for the regulation of giant cell differentiation.

Animals↗
PubMed2005

Simultaneous determination of nineteen hallucinogenic tryptamines/beta-calbolines and phenethylamines using gas chromatography-mass spectrometry and liquid chromatography-electrospray ionisation-mass spectrometry.

To investigate the trend of non-controlled drugs of abuse, simultaneous analytical methods were developed using GC-MS and LC-ESI-MS for 8 tryptamines/beta-carbolines, 6 phenethylamines of typically non-controlled substances in Japan, and, additionally, five legally controlled tryptamines and phenethylamines originally found in fungi or plants. Moreover, the proposed methods were applied to analyses of these drugs in 99 kinds of products (a total number of 123 products purchased at adult shops or via the Internet over the past 2 years in Japan), which potentially advertised psychotropic/psychoactive effects. The samples were extracted with methanol under ultrasonication. After centrifugation, the extracts were filtered prior to injections. GC-MS analysis was performed using a DB-5MS capillary column. Regarding the LC-ESI-MS analysis; the separation of the target drugs was optimized on an ODS column in acetonitrile/MeOH (7:3)-10 mM ammonium formate buffer (pH 3.5)/acetonitrile (95:5) by a linear gradient program and a quantitative analysis was carried out by the monitoring of each [M+H]+ in the positive ion mode of ESI-MS. As a result of the analyses using GC-MS and LC-ESI-MS, 5-MeO-DIPT (the synthetic substance known by the street name "Foxy") was found in 8 out of the 99 kinds of products. Additionally, AMT (from brown powder), DMT (from dried plant), harmine and harmaline (from dried plant) were also found in some of the 99 products. These analytical methods could be useful for the investigation of the distribution of the non-controlled psychotropic tryptamines/beta-carbolines and phenethylamines in the market.

Calibration↗
PubMed2005

Developmental changes in the expression of growth-associated protein-43 mRNA in the monkey thalamus: northern blot and in situ hybridization studies.

The expression of growth-associated protein-43 has been related to axonal elongation and synaptic sprouting. Using the Northern blot analysis, we investigated the developmental changes of growth-associated protein-43 mRNA in the thalamus of macaque monkeys. The amount of growth-associated protein-43 mRNA was high at embryonic day 125, and decreased at postnatal day 1. It increased again at postnatal day 8, reached its peak value at postnatal days 50-70, and then decreased gradually until postnatal year 1. We previously reported that the amount of growth-associated protein-43 mRNA in the cerebral cortex decreased roughly exponentially during perinatal and postnatal periods and that it approached the asymptote by postnatal day 70 [Oishi T, Higo N, Umino Y, Matsuda K, Hayashi M (1998) Development of GAP-43 mRNA in the macaque cerebral cortex. Dev Brain Res 109:87-97]. The present findings may indicate that extensive synaptic growth of thalamic neurons continues even after that of cortical neurons has finished. We then performed in situ hybridization to investigate whether the expression level of growth-associated protein-43 mRNA was different among various thalamic nuclei. In the infant thalamus (postnatal days 70-90), moderate to intense expression of growth-associated protein-43 mRNA was detected in all thalamic nuclei. Quantitative analysis in the infant thalamus indicated that the expression levels were different between the nuclear groups that are defined by the origin of their afferents. The expression in the first order nuclei, which receive their primary afferent fibers from ascending pathways [Guillery RW (1995) Anatomical evidence concerning the role of the thalamus in corticocortical communication: a brief review. J Anat 187 (Pt 3):583-592], was significantly higher than that in the higher order nuclei. While moderate expression was also detected in the adult dorsal thalamus, the expression in the first order nuclei was almost the same as that in the higher order nuclei. Thus, the in situ hybridization experiments indicated that the transient postnatal increase in the amount of growth-associated protein-43 mRNA, which was shown by the Northern blot analysis, was mainly attributed to enhanced expression in the first order nuclei during the postnatal period. This may be a molecular basis for environmentally induced modification of thalamocortical synapses.

Animals↗
PubMed2005

The role of Gamma Knife radiosurgery in the treatment of pineal parenchymal tumours.

OBJECT: The aim of this study was to document the possible role of Gamma Knife radiosurgery, suitable for the treatment of deep and well limited tumors, in the management of pineal parenchymal tumors (PPT). POPULATION AND METHODS: We reviewed retrospectively a series of 13 patients with PPT treated by Gamma Knife radiosurgery during 16 procedures. Mean age was 31 (range 10 to 74). Eight patients had pineocytomas (61.5%), and 5 had pineoblastomas (38.5%). Radiosurgery was performed alone in 6 cases, after partial microsurgical resection in 3 cases, in association with chemotherapy in 3 cases and following conventional fractionated radiotherapy in 1 case. The marginal dose to these tumors ranged from 11 to 20 Gy (mean 15 Gy). RESULTS: With a mean follow-up of 34 months (range 6 to 88), all tumors responded to treatment and disappeared or ceased growing. Two patients with pineoblastoma had tumor size progression out of the initial target requiring several radiosurgery procedures. At the end of the follow-up period, 10 out of 12 patients were alive. Two patients with pineoblastoma died because of carcinomatous meningitis or tumor size progression. We observed no mortality or major morbidity related to radiosurgery. CONCLUSION: This study confirms that radiosurgery can be an effective and safe primary treatment modality for patients with pineocytomas. It should have a role in multimodality therapy which includes microsurgical resection, fractionated radiotherapy and chemotherapy for the management of malignant pineal tumors.

Adolescent↗
PubMed2005

Influence of fat pad removal on patellar tendon length during growth.

During various knee operations, the changes caused by the surgical invasion to the infrapatellar fat pad (IPF) is still unknown. If any changes exist, it will have great influence especially on growing generations. Eighty-four Japanese white rabbits (6-month-old) were divided into three groups: the resection group involving resection of the IPF, the graft group involving resection and reimplantation of the IPF, and the no-surgery group. All these surgical procedures were done in right knees. In all left knees, only arthrotomy was performed, serving as the sham side. After 3, 6, 12, and 24 weeks of the operation, the rabbits were killed. Lengths of the patellar tendon and patellar were measured in lateral X-ray. In order to eliminate individual differences in the patellar height, we defined a new index as percent patellar height (PPH) which indicated the percentage of the patellar height of surgery side compared with that of the sham side. The PPH was 90.6% (3 weeks), 83.0% (6 weeks), 73.6% (12 weeks), and 74.7% (24 weeks) in the resection group, while it was 88.4% (6 weeks), and 88.9% (24 weeks) in the graft group. Postsurgical scar tissue formation occurring where the IPF was removed prevented the normal growth of the patellar tendon. Reimplantation of the IPF lessened the adhesion of the patellar tendon to the surrounding tissue, and better growth of the tendon. These results showed that preservation of the IPF in young individuals could be crucial for the normal growth of the patellar tendon, and critical as well for the prevention of the degeneration of the articular surface.

Adipose Tissue↗
PubMed2005

The relationship between 24-hour blood pressure readings, subcortical ischemic lesions and vascular dementia.

BACKGROUND: Twenty-four-hour blood pressure (BP) readings have been found to correlate with hypertensive target organ damage. Lacunar infarcts (LI) and white matter lesions (WML) probably represent manifestations of cerebral hypertensive target organ damage. This study was conducted to better delineate the relationships between 24-hour BP measurements, LI/WML and small vessel disease cognitive impairment/vascular dementia (CI/VD). METHODS: Two hundred patients with first-time symptomatic LI were examined with 24-hour BP monitoring. The degree of nocturnal BP dip, (daytime BP - nighttime BP)/daytime BP, was categorized into three groups: dippers (>0.1), nondippers (0-0.1) and reverse dippers (<0). WML were subdivided into periventricular hyperintensities (PVH) and subcortical hyperintensities. RESULTS: The breakdown of patients was: 50% nondippers, 27.5% reverse dippers and 22.5% dippers. Forty-one patients (20.5%) were found to have CI and dementia. Male sex (OR 3.35; 95% CI 1.20-9.34), advanced PVH (OR 14.42; 95% CI 5.62-36.98) and absence of a dipping status (nondipper: OR 12.62; 95% CI 1.37-115.95; reverse dipper: OR 11.95; 95% CI 1.27-112.11) were independently associated with CIVD after multivariate analysis. High nighttime systolic BP (OR 3.93; 95% CI 1.38-11.17), high daytime (OR 2.06; 95% CI 1.03-4.04) and nighttime diastolic BP (OR 2.48; 95% CI 1.13-5.45) and absence of a dipping status (nondipper: OR 2.7; 95% CI 1.03-7.05; reverse dipper: OR 3.78; 95% CI 1.38-10.34) were significantly associated with PVH. CONCLUSIONS: High prevalence of a nondipping status was found in the LI cohort. A nondipping status appears to be directly associated with CIVD independent of PVH. This study indicates the need for further studies to investigate whether or not controlling nighttime BP will help reduce the risk for CI/VD development.

Aged↗
PubMed2005

Effect of quantum interference on tunneling photoionization rates of N2 and O2 molecules.

In this work, we reexamine the photoionization rates of N(2) and O(2) molecules using the previously published photoionization rate theory which is based on the original atomic Keldysh theory [K. Mishima et al., Phys. Rev. A 66, 033401 (2002); ibid.66, 053408 (2002)]. We have found that the constructive quantum interference takes place for N(2) molecule while the destructive quantum interference plays an important role for O(2) molecule. This is consistent with the experimental and theoretical results reported in the literature. The formulas derived in this paper clearly show that this is due to the different symmetries of the valence orbitals of N(2) and O(2) molecules.

Journal Article↗
PubMed2005

Influence of explorer tip diameter in identifying restoration margin discrepancies.

OBJECTIVES: Evaluations of the marginal adaptation of restorations in clinical trials rely on subjective assessments by evaluators. The purpose of the present study was to assess the use of dental explorers with different tip diameters to detect simulated marginal discrepancies. METHODS: Using three devices simulating vertical steps, horizontal gaps, and the combination of vertical and horizontal discrepancies and explorers with five different tip diameters, 10 experienced dental faculty members were asked to identify discrepancies at the boundary between Alfa (replacement unnecessarily) and Bravo (replacement questionable) ratings, according to modified United States Public Health Service criteria. RESULTS: A significant correlation was found between the tip diameters of the explorers and the Alfa/Bravo boundaries for the horizontal gaps, but not for the vertical steps. CONCLUSION: It was concluded that the tip diameter of dental explorers had no significant effect on the detection of vertical steps, but had a significant effect on the detection of horizontal gaps. The diagnosis of restoration marginal discrepancies and the rating of marginal adaptation in clinical trials may subsequently be found to be best achieved using techniques other than the probing of restoration margins.

Dental Instruments↗