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Biomedical subjects

T Kameyama

Publications and source records attributed to T Kameyama.

At least 19 recordsLinked to original sources

[Unusual total anomalous pulmonary venous connection; report of a case].

We report a case of a 7-hour-old infant with total anomalous pulmonary venous connection having abberant origin of the vertical vein. His clinical condition presented hemodynamically severe pulmonary vein obstruction as common pulmonary vein atresia. Without making the definitive diagnosis, he underwent the operation at 11 hours after birth under cardiopulmonary bypass. During the operation, we could not identify the drainage vein. Although we ligated the vessel sized less than 2 mm in diameter draining into superior vena cava which was suspected to be the vertical vein. After the operation pulmonary edema was severe, but his clinical condition improved by using nitric oxide without extracorporeal membrane oxygenation (ECMO) support. Postoperative cardiac catheterization showed normal cardiac function without pulmonary venous obstruction, and moreover identified the drainage vein originated from right upper pulmonary vein. To the best of our knowledge, this is the first case where the vertical vein originated from right upper pulmonary vein. Immediate surgical treatment before the circuratory exacerbation improve the outcome for this congenital anomaly.

Humans↗

[Isolated coronary artery bypass grafting in octogenarians].

We evaluate the outcomes of isolated coronary artery bypass grafting (CABG) in high-risk octogenarians. There are 20 cases in 5 years, which contain 1 re-operation case, and 10 emergency cases. Nineteen cases were performed off-pump CABG (OPCAB), and conventional CABG was performed for only 1 case because of unstable hemodynamics with intraaortic balloon pumping (IABP). We generally performed CABG with aorta no-touch technique. There is no death case, and no serious complication like stroke. We used 23 artery and 11 vein grafts for CABG, and mean number of grafts per patient was 1.8+/-0.7. And "hybrid therapy" with percutaneous transluminal coronary angioplasty (PTCA) was done for 5 cases. Octogenarians are at increased risk for perioperative morbidity and mortality after CABG, but we have performed OPCAB for them and have had good results. And we think that aorta no-touch technique, proper selection and use of graft are important.

Aged↗

Inactivated periods of constant orthodontic forces related to desirable tooth movement in rats.

AIM: To examine the effects of inactive periods of force on the amount of tooth displacement and root resorption during experimental tooth movement in rats. SAMPLE: Sixty 11-week-old male Sprague-Dawley rats. METHOD: The maxillary first molar (M1) was moved mesially using a removable titanium-nickel alloy closed coil spring for 14 days. The rats were divided into four groups with, 0, 1, 4, and 9 hours of inactivation per day. RESULTS: Tooth displacement in the 0- and 1-hour groups was significantly greater than that in the 9-hour group. The area of root resorption in the 4- and 9-hour groups was significantly less than that in the 0- and 1-hour groups. There was no significant difference in root resorption between 0- and 1-hour groups, and also between 4- and 9-hour groups. CONCLUSION: The distance of tooth displacement gradually decreased as the inactive period increased, whereas root resorption suddenly decreased between 1 and 4 hours of inactive orthodontic force.

Animals↗

Relapsing herpes simplex encephalitis: pathological confirmation of viral reactivation.

This case is reported to raise awareness of herpes simplex encephalitis as a persisting brain disorder. A 66 year old immunocompetent man developed status epilepticus and died of pneumonia in the course of progressive hemiparesis, cognitive decline, and atrophy of the brain over a five year period after herpes simplex encephalitis. In addition to a completely destroyed left temporal lobe, necropsy revealed active encephalitis consisting of necrosis and lymphocyte infiltration with a large number of intranuclear inclusions in the neurones and glial cells in the markedly oedematous parenchyma of the right frontal and parietal lobes. Herpes simplex virus type 1 (HSV-1) antigen was detected by immunohistochemistry, HSV-1 DNA by in situ hybridisation, and herpes simplex virus nucleocapsids by electronmicroscopy. These clinical and pathological findings suggest that direct viral reactivation might result in a relapse of herpes simplex encephalitis, causing progressive clinical deterioration associated with the persistence of HSV-1 in the brain. This is the first case report demonstrating HSV-1 antigen, HSV-1 DNA, and herpes simplex virus nucleocapsids in a case of relapsing herpes simplex encephalitis.

Atrophy↗

Effects of repeated administration of (-)-nicotine on AF64A-induced learning and memory impairment in rats.

It has been reported that pretreatment with (-)-nicotine prevents glutamate- and amyloid beta protein (Abeta)-induced cytotoxicity in vitro. However, few studies on the neuroprotective effects of (-)-nicotine in vivo have been reported. We examined whether repeated administration of (-)-nicotine exhibits neuroprotective effects in AF64A-treated rats. (-)-Nicotine (0.1 and 0.2 mg/kg, s.c.) was administered once a day for 28 days. On day 14, AF64A (2.5 nmol/side) was injected bilaterally into the hippocampus. Intrahippocampal injection of AF64A showed severe impairment of learning and memory in rats in the water maze and passive avoidance tests. Repeated administration of (-)-nicotine (0.1 and 0.2 mg/kg, s.c.) did not reverse the impairment of memory induced by AF64A in the water maze test. Interestingly, the (-)-nicotine (0.1 and 0.2 mg/kg, s.c.)-treated group showed weak impairment of learning and memory after AF64A treatment compared to the (AF64A + saline)-treated group in the passive avoidance test. These results suggested that (-)-nicotine may have neuroprotective effects against the neurotoxicity induced by AF64A.

Acetylcholine↗

Respiratory modulation of muscle sympathetic nerve activity in patients with chronic heart failure.

BACKGROUND: Sympathoexcitation and respiratory instability are closely related to worsening of chronic heart failure. To elucidate the dynamic nature of respiratory modulation of sympathetic activity in patients with heart failure, we studied within-breath variation of muscle sympathetic nerve activity (MSNA) under various ventilatory volumes. METHODS AND RESULTS: MSNA, blood pressure, and respiratory flow were recorded in 23 patients with left ventricular ejection fraction </=45%. Within-breath suppression of MSNA (neural silence) was found in 11 patients (MSNA bursts: 71+/-10/100 heartbeats) but not in the remaining 12 patients (MSNA bursts: 88+/-8/100 heartbeats). Patients without neural silence had a smaller tidal volume (391+/-70 versus 267+/-75 mL/m(2), P<0.01) and a higher respiratory rate (15+/-2 versus 19+/-4 breaths/min, P<0.01) during spontaneous respiration than those with neural silence. The relationship between tidal volume and minimal amplitude of MSNA bursts in each breath was obtained during random-interval breathing and fitted by an exponential function. The curve of patients without neural silence was shifted to the right and upward, which suggests that a greater tidal volume was required to suppress MSNA (227+/-70 versus 437+/-195 mL/m(2), P<0.01). CONCLUSIONS: Sympathoexcitation in patients with chronic heart failure is closely related to both a decrease in resting tidal volume and an attenuated sympathoinhibitory effect of lung inflation reflex.

Aged↗

Endomorphins 1 and 2, endogenous mu-opioid receptor agonists, impair passive avoidance learning in mice.

The effects of intracerebroventricular administration of endomorphin-1 and endomorphin-2, endogenous mu-opioid receptor agonists, on passive avoidance learning associated with long-term memory were investigated in mice. Endomorphin-1 (10 and 17.5 microg) and endomorphin-2 (17.5 microg) produced a significant decrease in step-down latency in a passive avoidance learning task. beta-Funaltrexamine (5 microg) almost completely reversed the endomorphin-1 (17.5 microg)- and endomorphin-2 (17.5 microg)-induced shortening of step-down latency, although neither naltrindole (4 ng) nor nor-binaltorphimine (4 microg) produced any significant effects on the effects of endomorphins 1 and 2. These results suggest that endomorphins 1 and 2 impair long-term memory through the mediation of mu-opioid receptors in the brain.

Analgesics, Opioid↗

Expression of SART3 antigen and induction of CTLs by SART3-derived peptides in breast cancer patients.

We recently reported the SART3 tumour-rejection antigen as possessing tumour epitopes capable of inducing HLA-class I-restricted cytotoxic T lymphocytes (CTLs). This study investigated expression of the SART3 antigen in breast cancer to explore an appropriate molecule for use in specific immunotherapy of breast cancer patients. The SART3 antigen was detected in all of the breast cancer cell lines tested, 30 of 40 (75%) breast cancer tissue samples, and 0 of 3 non-tumourous breast tissue samples. SART3 derived peptides at positions 109-118 and 315-323 induced HLA-A24 restricted CTLs that reacted to breast cancer cells from the peripheral blood mononuclear cells (PBMCs) of breast cancer patients. Therefore, the SART3 antigen and its peptides could be an appropriate molecule for use in specific immunotherapy of the majority of HLA-A24-positive breast cancer patients.

Adenocarcinoma↗

Differential expression of plexin-A subfamily members in the mouse nervous system.

Plexins comprise a family of transmembrane proteins (the plexin family) which are expressed in nervous tissues. Some plexins have been shown to interact directly with secreted or transmembrane semaphorins, while plexins belonging to the A subfamily are suggested to make complexes with other membrane proteins, neuropilins, and propagate chemorepulsive signals of secreted semaphorins of class 3 into cells or neurons. Despite that much information has been gathered on the plexin-semaphorin interaction, the role of plexins in the nervous system is not well understood. To gain insight into the functions of plexins in the nervous system, we analyzed spatial and temporal expression patterns of three members of the plexin-A subfamily (plexin-A1, -A2, and -A3) in the developing mouse nervous system by in situ hybridization analysis in combination with immunohistochemistry. We show that the three plexins are differentially expressed in sensory receptors or neurons in a developmentally regulated manner, suggesting that a particular plexin or set of plexins is shared by neuronal elements and functions as the receptor for semaphorins to regulate neuronal development.

Animals↗

Reduced expression of CD9 in oral squamous cell carcinoma: CD9 expression inversely related to high prevalence of lymph node metastasis.

Because CD9 is implicated in cell growth, cell adhesion and cell motility, altered CD9 expression might be involved in cancer invasion and metastasis. We have studied the immunolocalization of CD9 in oral squamous cell carcinoma (SCC). Sections prepared from paraffin-embedded specimens from patients with SCC of the oral cavity were stained with a monoclonal anti-CD9 antibody by means of the streptoavidin biotin method. Significant reduction or complete loss of CD9 expression was observed in cancer cells at the periphery of the cancer nests in the advancing front of invading tumor. Among 78 cases of oral SCCs examined, 46 (59.0%) cases were completely negative for CD9 expression. Loss of CD9 expression in cancer tissue strongly correlated with a high incidence of cervical lymph node metastasis and poorer prognosis (P=0.001). Thus a close examination of CD9 in SCC tissue would be useful for the prognosis of patients with oral carcinoma.

Aged↗

Involvement of cyclic AMP systems in morphine physical dependence in mice: prevention of development of morphine dependence by rolipram, a phosphodiesterase 4 inhibitor.

In this study, we examined whether morphine dependence was inhibited by rolipram, a cyclic AMP selective phosphodiesterase inhibitor in mice, since a role for the cyclic AMP systems in the development of morphine dependence has been reported. Mice, which received morphine (10 mg kg(-1) s.c.) twice a day for 5 days showed withdrawal syndromes such as jumping, rearing and forepaw tremor following naloxone challenge (5 mg kg(-1) i.p.) on the 6th day. Such mice exhibited a significant elevation of cyclic AMP levels in the thalamus compared to control mice. However, co-administration of rolipram (1 mg kg(-1) i.p.) with morphine for 5 days significantly attenuated the severity of the withdrawal syndrome and the increase in the cyclic AMP levels after the administration of naloxone. In naïve mice, acute morphine treatment (10 mg kg(-1) s.c.) decreased cyclic AMP levels in the thalamus and cerebral cortex 10 min later. The decrease of cyclic AMP levels induced by acute morphine treatment was blocked by co-administration of rolipram (1 mg kg(-1) i.p.). However, acute rolipram did not affect the naloxone-precipitated morphine withdrawal syndrome. These results suggest that the elevation of the cyclic AMP levels is involved in the development of morphine withdrawal syndrome and that blockade of the morphine-induced reduction of cyclic AMP levels by chronic rolipram inhibits the development of dependence and the behavioural and biochemical changes induced by naloxone. Furthermore, rolipram may be a useful drug for attenuating the development of morphine dependence.

3',5'-Cyclic-AMP Phosphodiesterases↗

Long-lasting antinociceptive effects of a novel dynorphin analogue, Tyr-D-Ala-Phe-Leu-Arg psi (CH(2)NH) Arg-NH(2), in mice.

Tyr-D-Ala-Phe-Leu-Arg psi (CH(2)NH) Arg-NH(2) (SK-9709) is a dynorphin derivative in which the peptide bond was replaced with a psi (CH(2)NH) bond. In the present study, the antinociceptive effects of SK-9709 were determined in an acetic acid-induced writhing test and a hot-plate test. In the acetic acid-induced writhing test, significant antinociceptive effects were observed after subcutaneous (s.c.), intracerebroventricular (i.c.v.) and intrathecal (i.t.) injection of SK-9709, with maximal effects at 120, 30 and 15 min, respectively. The antinociceptive effects were dose-dependent and ED(50) values (range of 95% confidence limits) after s.c., i.c.v. and i.t. injection were 1.36 (0.61 - 3.02) micromol kg(-1), 2.11 (1.18 - 3.79) and 0.79 (0.61 - 1.03) nmol per mouse, respectively. The effects of SK-9709 (s.c., i.c.v. and i.t.) were reversed by the opioid receptor antagonist naloxone (1.36 micromol kg(-1), s.c.). The effects of SK-9709 (s.c.) were also reversed by the selective mu-opioid receptor antagonist beta-funaltrexamine (4.7 nmol per mouse, i.c.v.), and kappa-opioid receptor antagonist nor-binaltorphimine (4.9 nmol per mouse, i.t.). In the hot-plate test, the antinociceptive effect of SK-9709 (s.c., i.c.v. and i.t.) was also dose-dependent with the maximal peak effect at 120, 15 and 15 min similarly to the acetic acid-induced writhing test. The antinociceptive effects were dose-dependent and ED(50) values (range of 95% confidence limits) after s.c., i.c.v. and i.t. injection were 39.1 (5.4 - 283.0) micromol kg(-1), 6.5 (4.0 - 10.7) and 7.4 (5.0 - 11.0) nmol per mouse, respectively. These findings indicated that systemically administered SK-9709 produced long-lasting antinociceptive effects and these effects were mediated by both supra-spinal mu- and spinal kappa-opioid receptors.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗

Anxiety and pain suppress the natural killer cell activity in oral surgery outpatients.

OBJECTIVE: Psychological stress has an influence on natural killer cell (NK) activity, which plays a central role in protection against microbial infection and cancer. Anxiety concerning cancer is a typical type of psychological stress observed in patients and is associated with various diseases. In this study, we examined whether anxiety about cancer reduces the NK activity or quality of life (QOL), or both, of outpatients. PATIENTS AND METHODS: NK activity was determined by means of a 4-hour 51 chromium-release assay, and a QOL questionnaire by the World Health Organization called QOL-BRIEF was also used. One hundred forty-four patients were asked a variety of questions about anxiety with respect to cancer and pain on their first visit to the outpatient clinic of our Department of Oral Surgery. RESULTS: The NK activity in patients with anxiety about cancer was significantly lower (P < .001) than that in those with no such anxiety. In contrast, NK activity was not influenced by any other factor tested, including differences in diseases and QOL scores. CONCLUSION: Anxiety about cancer may be one of the primary factors for suppression of NK activity in oral surgery outpatients.

Adult↗

Reliable, minimally invasive oromandibular reconstruction using metal plate rolled with pectoralis major myocutaneous flap.

The purpose of this study was to minimize the surgical invasiveness to the donor site and the amount of the primary reconstruction time after oromandibular tumor resection. Oromandibular reconstruction was performed only using a pectoralis major myocutaneous flap and a metal plate. The pectoralis major myocutaneous flap was grafted to the oral cavity defect by rolling and wrapping around the metal plate with the muscle of the flap. No early postoperative complications have been noted in all seven patients. An average of 2 years and 1 month has past since surgery, and to date no infections, plate exposure, or plate breakage have been observed in any of the patients. The safety of the oromandibular reconstruction using a metal plate was improved by rolling the muscle of the pectoralis major myocutaneous flap around the metal plate. The present method was shown to be a rational technique that allowed primary reconstruction of the oral cavity and mandible in a minimally invasive manner in a short time.

Adult↗

Relation of fibrillatory wave amplitude with hemostatic abnormality and left atrial appendage dysfunction in patients with chronic nonrheumatic atrial fibrillation.

Large left atrium (LA) and LA appendage (LAA) dysfunction are known to relate to cardiogenic thromboembolism, so the present study investigated the relation of the atrial fibrillatory wave (F wave) amplitude to hemostatic markers and LAA function. Transthoracic and transesophageal echocardiographic studies were performed in 82 consecutive patients with chronic, nonrheumatic atrial fibrillation (AF). Patients were divided into 2 groups according to F wave amplitude in lead V1 on the 12-lead ECG: coarse AF (the greatest amplitude of F wave > or =1 mm, n=44) and fine AF (<1 mm, n=38). Plasma levels of thrombin-antithrombin III complex, D-dimer, platelet factor 4 and beta-thromboglobulin were determined. Compared with patients with coarse AF, those with fine AF had lower LAA peak flow velocity (p<0.05) and higher prevalence of embolic cerebral infarction (50% vs 27%, p<0.05). Platelet activity did not differ between the 2 groups; however, plasma levels of thrombin-antithrombin III complex and D-dimer were significantly higher in patients with fine AF than in those with coarse AF (p<0.05). Multiple logistic regression analysis showed that fine AF was independently associated with cerebral embolism. Therefore, the presence of fine F wave in V1 would be a useful marker of LAA dysfunction and hypercoagulability, and indicate a risk for cerebral embolism in patients with chronic, nonrheumatic AF.

Aged↗

A transesophageal echocardiographic study on risk factors for stroke in elderly patients with atrial fibrillation: a comparison with younger patients.

STUDY OBJECTIVES: Atrial fibrillation (AF) becomes an increasingly important cause of stroke as patients get older. The aim of the study was to determine whether risk factors of cerebral embolism among elderly patients with AF differed from those of younger patients by using transesophageal echocardiography (TEE). DESIGN AND SETTING: Cross-sectional study at a university hospital. METHODS: Cardiovascular lesions with the potential for thromboembolism in patients with AF were investigated using TEE. Left atrial spontaneous echocardiographic contrast (SEC), peak flow velocity in the left atrial appendage (LAA-flow), and aortic atherosclerosis of the thoracic aorta were assessed in 67 elderly (> or = 70 years old) and 135 younger (< 70 years old) patients. All patients underwent either brain CT (n = 54) or MRI (n = 148) to assess presence of cerebral infarction. RESULTS: Cerebral infarction due to embolism was noted in 113 patients with AF. There was a higher prevalence of cerebral embolism in elderly patients when compared with younger patients (78% vs 45%; p < 0.001). Cerebral embolism found in younger patients was associated with high grade of SEC and lower LAA-flow (p < 0.05). In addition to these TEE findings, aortic atherosclerosis was more severe in elderly patients with cerebral embolism than in those without cerebral embolism (p < 0.0001). By multivariate logistic analysis, LAA-flow was an independent predictor of cortical infarction in younger patients, but not in elderly patients, whereas aortic atherosclerosis was a useful marker in predicting embolic risk in elderly patients. CONCLUSIONS: TEE findings indicative of left atrial blood stasis were useful to identify the embolic risk of younger patients with AF, while atherosclerosis of the thoracic aorta appears to be an important marker for cerebral embolism in elderly patients.

Age Factors↗

New cyclic depsipeptide antibiotics, clavariopsins A and B, produced by an aquatic hyphomycetes, Clavariopsis aquatica. 1. Taxonomy, fermentation, isolation, and biological properties.

Clavariopsins were isolated from the fermentation broth of Clavariopsis aquatica AJ 117363. Clavariopsins are cyclic depsipeptide antibiotics with the molecular weight of 1,153 and 1,139. Clavariopsins showed in vitro antifungal activity against not only Aspergillus fumigatus but also, although to a lesser extent, A. niger and Candida albicans.

Animals↗

New cyclic depsipeptide antibiotics, clavariopsins A and B, produced by an aquatic hyphomycetes, Clavariopsis aquatica. 2. Structure analysis.

The structures of new cyclic decadepsipeptides, clavariopsins A and B, were determined to be cyclo[-(R)-2-hydroxyisovaleryl-L-pipecoyl-L-MeVal-L-Val-L-MeAsp-L-MeIle-L-MeIle-Gly L-MeVal-L-Tyr(OMe)-] and cyclo[-(R)-2-hydroxyisovaleryl-L-pipecolyl-L-Val-L-Val-L-MeAsp-L-Melle-L-MeIle-Gly-L-MeVal-L-Tyr(OMe)-], respectively, by spectroscopic analyses, especially using 2D NMR techniques. The absolute stereochemistry was elucidated by the advanced Marfey's method and chiral HPLC analysis.

Anti-Bacterial Agents↗