Biomedical subjects

S Endo

Publications and source records attributed to S Endo.

At least 37 records · Page 2Linked to original sources

PubMed2005

Impairment of conditioned freezing to tone, but not to context, in Fyn-transgenic mice: relationship to NMDA receptor subunit 2B function.

We previously demonstrated that transgenic mice overexpressing Fyn tyrosine kinase exhibit higher seizure susceptibility and enhanced tyrosine phosphorylation of several proteins, including the N-methyl-D-aspartate (NMDA) receptor subunit 2B (NR2B). In the present study, we analysed behavioural phenotypes, especially conditioned fear responses, of Fyn-transgenic (TG) mice to better understand the role of Fyn in learned emotional behaviour. Tone-dependent conditioned freezing was significantly attenuated in Fyn-TG mice, whereas context-dependent freezing was unaffected. Neither massed nor spaced conditioning ameliorated the attenuation of tone-dependent freezing. However, the selective NR2B antagonist ifenprodil, when administered before conditioning, restored tone-dependent freezing in Fyn-TG mice at a dose that did not affect freezing in wild-type (WT) mice. These results suggest that impairment of tone-dependent conditioned freezing in Fyn-TG mice is caused by disruption of the NR2B-containing NMDA receptor function. Tyrosine phosphorylation of brain proteins, including NR2B, was enhanced in Fyn-TG mice compared with that in WT mice. We also found that ifenprodil significantly suppressed the enhanced tyrosine phosphorylation. Thus, our data support the notion that NMDA receptor activity is tightly correlated with protein tyrosine phosphorylation, and Fyn might be one key molecule that controls tone-dependent conditioned freezing through the regulation of NMDA receptor function.

Acoustic Stimulation↗

PubMed2005

Inhibition of IL-6 overproduction by steroid treatment before transsternal thymectomy for myasthenia gravis: does it help stabilize perioperative condition?

Overproduction of interleukin (IL)-6 plays an important role in the pathophysiology of myasthenia gravis (MG), and thymectomy can cause myasthenic crisis because of surgically induced overproduction of IL-6. Preoperative steroid therapy is beneficial in preventing MG crisis during the perioperative period. The purpose of this study was to clarify the effect of preoperative steroid therapy on proinflammatory mediators during the perioperative period of transsternal thymectomy for MG. The study group comprised 20 consecutive MG patients undergoing transsternal thymectomy during the period March 2002 through March 2004. Seventeen of these patients received dose-escalated steroid therapy before thymectomy (steroid treatment group) and three did not (non-steroid treatment group). Serum concentrations of C-reactive protein (CRP) and IL-6 were determined during the perioperative period; clinical outcomes were reviewed, and the results were compared between the two groups. Peak serum IL-6 and CRP concentrations were significantly lower in the steroid treatment group than in the non-steroid treatment group. Amongst perioperative variables subjected to multiple regression analysis, preoperative steroid treatment were found to be the most significant independent predictor of inhibited IL-6 production on postoperative day 1. No postoperative respiratory failure occurred in the steroid treatment group, but it did occur in the non-steroid treatment group. Preoperative steroid therapy can ameliorate IL-6 overproduction and may help stabilize the patient's postoperative condition.

Aged↗

PubMed2005

Histone deacetylase inhibitors, N-butyric acid and trichostatin A, induce caspase-8- but not caspase-9-dependent apoptosis in human malignant glioma cells.

Histone deacetylase (HDAC) inhibitors have both apoptotic and differentiating effects on various tumor cells. However, the mechanisms underlying the effect of HDAC inhibitors remain unclear. In this study, we investigated the function of anti-proliferative effects of HDAC inhibitors, N-butyric acid and trichostatin A, on human malignant glioma cell lines, U251-MG and D54. MTT assay showed a dose-dependent inhibition of cellular proliferation in both cell lines. Cell cycle analysis revealed increased sub-G1 population in both lines, and G1 arrest only in U251-MG cells. Induction of apoptosis was also supported by the occurrence of DNA fragmentation in tumor cells treated with HDAC inhibitors. Furthermore, caspase inhibition assay indicated that HDAC inhibitor-induced apoptosis was caspase-dependent. Neither mitochondrial membrane potential nor the expression of caspase-9 was changed by treatment with HDAC inhibitors, suggesting the possibility that HDAC inhibitor-induced apoptosis was not mediated by the mitochondrial cell death pathway. On the other hand, immunoblot assay confirmed increased expression of caspase-8 in both lines, and elevation of p21 but not p27 protein in U251-MG cells following HDAC inhibitor treatment. Taken together, the HDAC inhibitors, N-butyric acid and trichostatin A, induce caspase-8- but not caspase-9-dependent apoptosis with or without p21-mediated G1 arrest in human malignant glioma cells.

Apoptosis↗

PubMed2005

[Non-tuberculous mycobacterial infection along the staple-suture line after segmentectomy for small peripheral lung cancer; report of a case].

A 60-year-old non-immunocompromised man who had undergone right upper lobectomy and subsequent left superior segmentectomy for small peripheral lung cancers (stage I well-differentiated adenocarcinomas) 2 years earlier, was referred to us for further investigation of an asymptomatic abnormal shadow observed on a chest radiograph. Chest computed radiography showed air-space consolidation along the staple-suture line associated with the left superior segmentectomy, the abnormality was 4 x 5 x 5 cm. Completion lower lobectomy was performed because transbronchial biopsy did not provide for a definite diagnosis. Pathological examination revealed a large granuloma infected by Mycobacterium intercellulare. The lung parenchyma may be exposed along the staple-suture line and somewhat vulnerable to infection in cases of partial pulmonary resection. We should be aware of this possibility after lesser pulmonary resection for small peripheral lung cancer.

Adenocarcinoma↗

PubMed2004

Mini-laparoscopic appendectomy using a needle loop retractor offers optimal cosmetic results.

BACKGROUND: Do conventional laparoscopic appendectomy (LA) techniques provide truly satisfying results for patients and surgeons? We have devised a more advanced technique that improves cosmesis. METHODS: A 2-mm scope is inserted at the umbilicus, and a 12-mm working trocar is inserted through a suprapubic incision placed below the line of pubic hair. A needle loop retractor (NLR) is inserted to hold the appendix in the lower right abdomen. In this NLR, a stainless steel wire is placed within a needle having a diameter of 2 mm. From the suprapubic trocar, a bipolar coagulator is inserted to transect the appendiceal mesentery. A series of 30 patients underwent this procedure. RESULTS: There were no conversions to laparotomy and no intra- or postoperative complications. CONCLUSIONS: Laparoscopic appendectomy using a 2-mm scope, suprapubic trocar, and an NLR yields optimal cosmetic results. For surgeons, the NLR allows the appendix to be held more firmly than then a 5- or 2-mm grasping forceps is used.

Adult↗

PubMed2004

A case of delayed brain abscess due to a retained intracranial wooden foreign body: a case report and review of the last 20 years.

A 13-year-old female is presented. When she was six years old, she had fallen, holding wooden chopsticks and got stuck with a chopstick in the right upper eyelid. She was brought to a physician immediately, but a residual foreign body was missed and no particular symptom had developed during 7 years. She visited our department with fever and headache, and a brain abscess and an intracranial foreign body were found on computed tomography (CT) and magnetic resonance image (MRI) 7 years after the penetrating injury. She underwent removal of the object and abscess by craniotomy and recovered without neurological abnormalities. Since intracranial retained wooden foreign bodies frequently cause delayed complications of severe central nervous system infection, surgical removal is necessary even in the absence of symptoms.

Adolescent↗

PubMed2004

Association of pontine small infarction (lacuna) with disturbance of postural stability.

Neuronal degeneration within the brainstem has been reported in patients with impaired postural stability. However, the functional significance of these abnormalities is unknown at present. In the present study, we evaluated the relationship between the presence of pontine lacunae and postural stability measured by stabilometry. A total of 209 consecutive patients without neurological signs were divided into three groups according to the territory of lacunae on magnetic resonance imaging: (1) non-lacunar group, (2) pontine lacunar group, and (3) non-pontine lacunar group. Stabilometry was performed and statokinesigram measures including each Romberg quotient were compared among the three groups. Using multivariate analysis, postural stability was found to be disturbed in the pontine lacunar group compared with the other groups. The data of stabilometry in this group were compatible with disturbance of the central controlling system for keeping postural stability. Pontine lacuna is associated with patients with postural instability. This result may be related to the deterioration of the central coordination system for posture and locomotion.

Adult↗

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

Extrapyramidal motor symptoms versus striatal infarction volume after focal ischemia in mongolian gerbils.

Few behavioral tests are available to evaluate extrapyramidal dysfunctions after focal cerebral ischemia in rodents, although extrapyramidal motor dysfunctions are often observed clinically in patients with cerebral infarction. We evaluated the methamphetamine (MP)-induced rotation test for the detection and quantification of extrapyramidal motor dysfunction induced by striatal infarction in gerbils after focal cerebral ischemia. Mongolian gerbils (n=79) underwent the left common carotid artery occlusion (CCAO) for 10, 15, or 20 min. Spontaneous and MP-induced rotation tests were repeated postischemia, and the results compared with the extent of ischemic tissue injury. The density of dopaminergic neurons immunostained with a tyrosine hydroxylase antibody in the substantia nigra pars compacta (SNpc) also was measured. Histological examination revealed selective neuronal death of the hippocampal cornu ammonis 1 (CA1) sector in 10-min CCAO animals, infarction confined to the striatum and hippocampal neuronal death in 15-min CCAO animals, and widespread hemispheric infarction in 20-min CCAO animals. Dopaminergic neurons in the SNpc were preserved in 10- and 15-min CCAO animals but were significantly reduced in 20-min CCAO animals. In MP-induced rotation tests, 15-min CCAO animals showed biased rotation ipsilateral to the lesioned side. Biased rotation persisted 4 weeks postischemia, and the number of rotations significantly correlated with the regional infarction volume of the striatum. Twenty-minute CCAO animals showed biased rotation contralateral to the lesioned side; rotation number was not correlated with the infarction volume. Our results show that biased rotation behavior is a sensitive parameter of the extent of striatal injury after focal cerebral ischemia provided the lesion is not extended to the ipsilateral cortex. MP-induced rotation in rodents probably coordinates with the extrapyramidal motor dysfunction after striatal infarction in patients with vascular Parkinsonism.

Animals↗

PubMed2004

Impact of neuronavigation and image-guided extensive resection for adult patients with supratentorial malignant astrocytomas: a single-institution retrospective study.

Neuronavigation has become an effective therapeutic modality and is used routinely for intra-axial tumor removal. This retrospective study was conducted to evaluate the clinical impact of neuronavigation and image-guided extensive resection for adult patients with supratentorial malignant astrocytomas. Between 1990 and 2002, 76 adult patients with pathologically confirmed malignant astrocytomas underwent craniotomy and removal of the tumors at the Toyama Medical and Pharmaceutical University Hospital. Of these 76 patients, 42 were treated using neuronavigation with conventional microneurosurgery and the other 34 were treated with conventional microneurosurgery alone. Postoperative early MRI with contrast enhancement was done, and gross total resection was defined as the complete absence of residual tumor. Survival time was analyzed with the Kaplan-Meier method. Prognostic factors were obtained from the Cox proportional hazards model. In univariate analysis, age (< 65), grade 3, preoperative KPS (>/= 80), use of neuronavigation, and gross total resection were significantly associated with longer survival. However, when the data were submitted to multivariate analysis, grade 3, preoperative KPS (>/= 80), and gross total resection were independent prognostic factors. The median survival periods of patients receiving gross total resection (vs. partial resection) and neuronavigation (vs. no neuronavigation) were 16 (vs. 9) months and 16 (vs. 10) months, respectively. The percentage of a gross total resection was significantly higher in the neuronavigation group compared to that in the no-navigation group (64.3 % vs. 38.2 %, p < 0.05). Neurological deterioration occurred in 4 of 42 (9.5 %) and in 6 of 34 (17.6 %) patients after surgery with neuronavigation and surgery without neuronavigation, respectively, although this difference was not statistically significant. Our results showed that neuronavigation increases the radicality in the resection of malignant astrocytomas and is objectively useful for improving survival time.

Adolescent↗

PubMed2004

Surgical anatomy and efficient modification of procedures for selective extradural anterior clinoidectomy.

OBJECTIVE: The surgical anatomy of structures surrounding the anterior clinoid process (ACP) was examined in 39 cadavers to enable safe performance of selective extradural anterior clinoidectomy. METHODS: The lateral portion of the optic canal (OC) at the end of the orbit was defined as point A, and the lateral margin of the dural insertion into the superior orbital fissure (SOF) as B. A vertical line from A to the lateral margin of the ACP was assumed to define a crossing, defined as C. Distances between A and B, C and B, and C and A were measured. The length and width of OC and the optic strut were also measured. RESULTS: The mean distances between A and B, C and B, and C and A were 11.8, 8.9 and 6.3 mm, respectively. The mean length and width of OC were 8.9 and 5.7 mm, and those of the optic strut 5.4 and 2.4 mm, respectively. CONCLUSION: We propose a modified, efficient procedure for selective extradural anterior clinoidectomy, as follows. Drilling is started from the point approximately 9 mm posterior to the lateral margin of the dural insertion into the SOP, and pointed medially in the direction with a right angle to the lateral margin of the ACP. After drilling about 6 mm to reach the lateral border of the OC, unroofing of the OC is carried out to remove the ACP en bloc by fracturing of the optic strut. Using the present procedure, the distance of drilling of the lesser wing of the sphenoid bone is minimized.

Adult↗

PubMed2004

Microdosimetry of neutron field for boron neutron capture therapy at Kyoto university reactor.

Microdosimetric single event spectrum in a human body simulated by an acrylic phantom has been measured for the clinical BNCT field at the Kyoto University Reactor (KUR). The recoil particles resulting from the initial reaction and subsequent interactions, namely protons, electrons, alpha particles and carbon nuclei are identified in the microdosimetric spectrum. The relative contributions to the neutron dose from proton, alpha particles and carbon are estimated to be about 0.9, 0.07 and 0.3, respectively, four depths between 5 and 41 mm. We estimate that the dose averaged lineal energy, yD decreased with depth from 64 to 46 keV microm(-1). Relative biological effectiveness (RBE) of this neutron field using a response function for the microdosimetric spectrum was estimated to decrease from 3.6 to 2.9 with increasing depth.

Academic Medical Centers↗

PubMed2004

[Clinicopathologic features of small-sized peripheral lung cancer; is intentional limited resection appropriate for selected patients?].

We sought to determine the eligibility of patients with early peripheral lung cancer for intentional limited resection. The clinicopathologic features of 103 patients who underwent lobectomy and mediastinal nodal dissection for early stage peripheral lung cancer measuring 2 cm or less in maximum dimension between 1992 and 2002 were examined retrospectively. The lymph node metastasis and residual cancer after thoracoscopic partial resection were analyzed by the following categories. Three groups were divided by maximum dimension of the primary lesion in the resected specimen; 10 mm or less (n = 11), 15 mm or less (n = 33), and 20 mm or less (n = 59). Two groups were divided by lesion histology; bronchioloalveolar adenocarcinoma (BAC) [n = 42] and invasive lung cancer (n = 61). Residual cancer was found in the residual lobe after thoracoscopic partial resection in 3 of 43 patients who had no diagnosis preoperatively. Their maximum dimensions were 15 mm or less. No lymph node metastasis was detected in the patients with tumor measuring 10 mm or less, and BAC. Intentional limited resection without mediastinal nodal dissection is appropriate for patients with tumor measuring 10 mm or less and BAC. Further investigation associated with partial resection is necessary.

Adenocarcinoma, Bronchiolo-Alveolar↗

PubMed2004

[Chest wall epithelioid sarcoma].

Two relatively rare cases of epithelioid sarcoma located in the chest wall are reported herein. The first was a tumor, 3.8 x 5.5 x 2.4 cm in size, originating in the left erector spinae muscle of a man 64 years of age. He experienced local recurrence 3 times even after wide resections, and he died of systemic metastasis 22 months after the initial surgery. The second was a tumor, 2.2 x 2.0 x 1.5 cm in size, originating in the left seventh intercostal muscle of a woman 24 years of age. A metastatic tumor occurred in the same muscle, and wide resection including the seventh and eighth intercostal muscles was performed. There has been no recurrence for 1.5 years since surgery. Metastasis of chest wall epithelioid sarcoma in the muscle in which the primary lesion resides should be considered, even if the primary lesion is small.

Adult↗

PubMed2004

[A large nontuberculous mycobacterial granuloma mimicking lung cancer; report of a case].

A 45-year-old woman with no immunodeficiency or clinical symptoms presented to our hospital for treatment of an enlarging spherical lung tumor in 4.0-cm-diameter. Chest radiography 8 years ago had shown a 1.5-cm-diameter tumor. Chest computed tomography (CT) showed the solitary tumor, located in the right apical segment, to have an irregular margin without satellite lesions or cavitations. Mycobacterium avium complex (MAC) was cultured in tumor specimens incised during transbronchial biopsy. Right upper lobectomy was performed because of resistance to 6-month antituberculosis treatment. Pathological findings showed a MAC-infected granuloma with caseous necrosis. Postoperative course was uneventful and she had no recurrence 3 years after surgery. These findings suggest that nontuberculous mycobacterial granuloma can enlarge without clinical manifestations or any satellite lesions and cavitations, leading to a misdiagnosis of lung cancer.

Diagnosis, Differential↗

PubMed2004

[Feasibility of short-term antibiotic prophylaxis after pulmonary resection].

How long to administer antibiotics after lung surgery is controversial. We investigated the feasibility of short-duration cefmetazole sodium administration as antibiotic prophylaxis after lung cancer surgery. A total of 40 patients were randomized into either a short-duration prophylaxis group (n=20) that was given 4 g of cefmetazole sodium for 2 days or a long-duration patients group (n=20) that was given 14 g of cefmetazole sodium for 7 days. Daily changes in body temperature, WBC, and plasma CRP concentration were determined for 9 days after surgery. The data were compared statistically between the 2 groups. Postoperative infection occurred in 20% of patients in the short-duration group and in 30% of patients in the long-duration group. The mean hospital stay after surgery was 15.5 days in the short-duration group and 18.6 days in the long-duration group. All variables did not differ significantly between the 2 groups. Our results indicate that short-duration antibiotic administration is an effective prophylactic treatment after surgery for lung cancer.

Aged↗

PubMed2003

Protein phosphatase 2A inhibition induces cerebellar long-term depression and declustering of synaptic AMPA receptor.

Phosphorylation of synaptic (RS)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) (AMPA) receptors (AMPARs) is an essential component of cerebellar long-term depression (LTD), a form of synaptic plasticity involved in motor learning. Here, we report that protein phosphatase 2A (PP-2A) plays a specific role in controlling synaptic strength and clustering of AMPARs at synapses between granule cells and Purkinje cells. In 22- to 35-day cerebellar cultures, specific inhibition of postsynaptic PP-2A by fostriecin (100 nM) or cytostatin (10-60 microM) induced a gradual and use-dependent decrease of synaptic current evoked by the stimulation of a single granule cell, without altering receptor kinetics nor passive electrical properties. By contrast, PP-2A inhibition had no effect on immature Purkinje cells (12-15 days). Concurrent PP-2A inhibition and AMPAR stimulation induced a reduction of miniature synaptic currents and a reduction of AMPAR density at synapses. Either PP-2A inhibitor alone or AMPA stimulation alone had no significant effect. Inhibition of PP-1 by inhibitor 1 (10-27 units/microl) had no effect on synaptic current. Synaptic depression induced by PP-2A inhibition occluded subsequent induction of LTD by conjunctive stimulation and was abolished by a calcium chelator or a protein kinase inhibitor, suggesting a shared molecular pathway and involvement of PP-2A in LTD induction.

Animals↗

PubMed2003

Determination of indices of the corpus callosum associated with normal aging in Japanese individuals.

Indices of the corpus callosum with normal aging and their sex differences were elucidated using quantitative MRI. We studied 94 Japanese men (mean+/-SD 57.3+/-20.8 years, range 6-90 years) and 111 Japanese women (mean+/-SD 61.2+/-17.6 years, range 9-86 years) who had no intracranial lesions on MRI and no history of neurological illness. The widths of the rostrum, body and splenium, the anterior to posterior length, and the maximum height in the midsagittal image were selected for measurement. The Evans index, which is the relative ratio of lateral ventricle expansion, and the maximum width of the third ventricle in the axial image were also estimated for comparison. The widths of rostrum, body and splenium of the corpus callosum became thinner with age. Conversely, the anterior to posterior length and the maximum height of the corpus callosum increased with age. The ratio of the width of the body to the length of the corpus callosum and the ratio of the width of the body to the height of the corpus callosum are best correlated with age. No sex differences in regional size of corpus callosum, including these two ratios, were observed in any raw measures, although ventricular indices were larger in men than women. Evaluation of the ratio of the width of the body to its length and the ratio of the width of the body to its height may enable accurate estimation of normal or pathological changes of the corpus callosum. Aging and pathological atrophy of corpus callosum can be evaluated without any adjustment for gender.

Adolescent↗