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Biomedical subjects

T Nagao

Publications and source records attributed to T Nagao.

At least 163 records · Page 9Linked to original sources
PubMed1999

Treatment of infant acute lymphoblastic leukemia in Japan. Childhood Leukemia Study Group of the Ministry of Health and Welfare (Kouseisho).

Although current chemotherapeutic regimens cure as many as 70% of children with acute lymphoblastic leukemia (ALL), infants continue to show a poor outcome. In this paper, we describe the outcome in 37 ALL infants treated between 1989 and 1995 in Japan. Patients had characteristic findings of infant ALL, including hyperleukocytosis > 100 x 10(9)/l (15/37, 41%), blast cells with a CD10-negative phenotype (30/37, 81%), and 11q23/MLL involvement (21/37, 57%). Seven were treated according to Aggressive Treatment Research Group protocol, 15 according to the Ministry of Health and Welfare protocol, and 15 according to protocols of other institutions. The 3-year overall event-free survival (EFS) was 33%. The EFS was 13% for infants aged < 26 weeks at diagnosis and 43% for infants aged > 26 weeks. Infants who had blast cells with CD10 negative phenotype with 11q23/MLL involvement were also associated with poor prognosis. However, infants with CD10 positive blasts without 11q23/MLL involvement had a better outcome (EFS 75%). These results suggest that intensive chemotherapy is effective for patients with good prognostic factors, but for infants with poor prognostic factors a more aggressive approach such as stem cell transplantation might be necessary.

Female↗
PubMed1999

[Contralateral cerebellar infarction after aneurysmal clipping with pterional craniotomy: report of two cases].

A 77-year-old woman underwent right fronto-temporal craniotomy for a right ruptured IC-PC aneurysm (case 1), and a 44-year-old woman underwent right fronto-temporal craniotomy for a right ruptured BA-SCA aneurysm (case 2). They were clipped completely without any troubles during surgery. But postoperative CT scan demonstrated contralateral cerebellar infarction. We recognized left-hand tremor as a neurological deficit caused by cerebellar infarction in case 1. Concerning the mechanism of contralateral cerebellar infarction after pterional craniotomy, we think that it could be; --1) changing of venous blood flow by overdrainage of cerebrospinal fluid, 2) destruction of the bridging vein because of cerebral transformation with rapid decompression, 3) ischemia caused by brain retraction and compression during operation, 4) hypertension or hypoxia during operation, 5) crossed cerebellar diaschosis, and so on. In our 2 cases, we believe that perioperative CSF overdrainage caused the contralateral cerebellar infarction or CCD. To avoid this kind of infarction, we should try to take more protective and careful procedures as well as closer perioperative management.

Adult↗
PubMed1999

Coronary artery aneurysm associated with fistula in adults: collective review and a case report.

Coronary artery fistulae (CAF) are infrequent congenital anomalies. The combination of coronary artery aneurysms and coronary artery fistulae (coronary artery aneurysm associated with fistula, CAAAF) is extremely rare, and only 50 cases, including the current case, have been reported. Coronary artery fistulae may result in coronary ischemia, congestive heart failure, and endocarditis. Complications of coronary artery aneurysms include thrombosis, distal emboli, and aneurysm rupture. Aneurysm repair, fistulous closure and/or coronary artery bypass grafts are definite treatments for CAAAF. We present here a 72-year-old female with CAAAF. Furthermore, all reported CAAAF cases are reviewed.

Aged↗
PubMed1999

Spinal epidural varices.

A 16-year-old male experienced a sudden attack of back pain while walking through the corridor of school which required emergent hospitalization. Except for the back pain, no neurological symptoms were noted. Magnetic resonance (MR) imaging indicated an angiopathy-like flow void in the epidural region at Th 3-5 which seemed to explain the patient's back pain. Thoracic laminectomy at Th 3-5 and resection of the affected site were performed. Pathologically, the resected lesion only had a dilated normal vein and no findings indicating vascular deformity. The patient's outcome was good and no relapse of pain has occurred for about 2 years since the operation. Although some authors have reported vascular deformity with spinal epidural hemorrhage or varices with lumbar hernia of the intervertebral disc, there is no report concerning spinal epidural varices with pain only. The present case seemed to be a rare event and is reported here.

Adolescent↗
PubMed1999

Emergency off-pump coronary artery bypass grafting under a beating-heart.

BACKGROUND: Coronary artery bypass grafting (CABG) on a beating heart has been successfully performed for high risk patients, and is known to be less invasive than conventional CABG using cardiopulmonary bypass (CPB). We expanded the indication of beating-heart CABG in patients requiring emergency coronary revascularization. METHODS: A retrospective chart review was performed for patients who had undergone emergency CABG on a beating heart (EM-BH group), elective CABG on a beating heart (Elective-BH group) and emergency CABG under CPB (EM-CPB group), between January 1, 1997 and June 30, 1998. RESULTS: Four cases (1 male and 3 females with a mean age of 67.8 +/- 5.4) in the EM-BH group, 67 cases (48 males and 19 females with mean age of 67.3 +/- 7.8) in the Elective-BH group, and 41 cases (29 males and 12 females with mean age of 63.3 +/- 10.4) in the EM-CPB group were analyzed. The number of the grafts was 1.75 +/- 0.50 in EM-BH group, 1.37 +/- 0.55 in the Elective-BH group, and 2.95 +/- 1.07 in the EM-CPB group. The intubation period, ICU stay, and the postoperative hospital stay were significantly shorter in the EM-BH group (6.0 hours intubation, 1.5 days ICU stay, and 11.5 days postoperative hospital stay) and Elective-BH group (6.8 +/- 11.0 hours intubation, 1.6 +/- 1.5 days ICU stay, and 12.7 +/- 5.2 days postoperative hospital stay) than in the EM-CPB group (20.1 +/- 22.5 hours intubation, 3.6 +/- 2.4 days ICU stay, and 21.8 +/- 14.9 days postoperative hospital stay). CONCLUSION: The postoperative recovery period for EM-BH patients was almost the same as that for elective cases of beating-heart CABG, and was significantly shorter than that of conventional emergency CABG under CPB. Selected patients with coronary ischemia can be safely treated by beating-heart surgery.

Aged↗
PubMed1999

Hospital-based historical cohort study of 234 histologically proven Japanese patients with IPF.

BACKGROUND AND AIM OF THE WORK: Variable clinical courses have been recognized in patients with idiopathic pulmonary fibrosis (IPF), but the disease is known to have a fundamentally unfavorable outcome. In addition, we have yet to fully understand whether the regional or population differences are negligible or not. Therefore, we analyzed the clinical outcomes in Japanese IPF patients in a hospital-based historical cohort study. METHODS: A questionnaire was used to collect records for retrospective analysis of the IPF patients. We analyzed data collected from 51 hospitals and clinics in Japan on 234 Japanese IPF patients (males 170, females 64) with IPF who had been followed up after diagnosis. RESULTS: 1. Five and ten years after the detection of exertional dyspnea, the overall survival rates were 41.0% and 20.1%, respectively. A higher age at the time of detection (over 59) was related to a decrease in survival rates. 2. The incidence of complications was no higher in the corticosteroid-treated cases than in the untreated cases. The effects of corticosteroid treatment on survival was not confirmed in this type of study. CONCLUSIONS: The survival rates of histologically proven Japanese patients with IPF were similar to the rates previously reported in different populations. Age at the detection of exertional dyspnea was critical in terms of the survival rate.

Adrenal Cortex Hormones↗
PubMed1999

[Application of measuring 99mTc-MAG3 plasma clearance based on one-compartment model (MPC method) to renal transplantation].

Measurement of 99mTc-MAG3 plasma clearance (CLmag) based on one-compartment model (MPC method) was applied to renal transplantation and evaluated for the factors which might affect the calculated results, especially concerning renal depth. Correlation coefficient of CLmag between MPC method using real renal depth and Russell or Bubeck single sampling method was good (r = 0.852 or 0.876, respectively). Regression equation between MPC method and Russell method was y = 1.044x - 3.0 and was more closer to y = x than that between MPC method and Bubeck method. CLmag of MPC method calculated by estimated renal depth from the abdominal thickness was also similar to that by real renal depth. Even if the fixed renal depth, 4 cm, was applied, the coefficient and regression equation between MPC method and Russell method were r = 0.884 and y = 1.004x - 10.2. In conclusion, MPC method is applicable to the evaluation of renal transplants. Though measuring renal depth is best, calculation with fixed renal depth of 4 cm might be practically acceptable.

Adult↗
PubMed1999

Hyperpolarization caused by serotonin contributes to endothelium-dependent relaxations in the porcine coronary artery.

AIM: The present study was designed to investigate the contribution of membrane hyperpolarization to endothelium-dependent relaxations induced by serotonin in the porcine coronary artery. METHODS: Rings with and without endothelium of porcine coronary arteries were suspended in conventional organ chambers for the measurement of isometric force. The cell membrane potential of the vascular smooth muscle cells was measured using glass microelectrodes, in the presence of indometacin, ketanserin, and/or N omega-nitro-L-arginine. RESULTS: Serotonin induced a transient endothelium-, and concentration-dependent relaxation in rings contracted with prostaglandin F2 alpha in the presence of N omega-nitro-L-arginine (maximal relaxation: 19%). The N omega-nitro-L-arginine resistant relaxation was abolished by high K+ and tetrabutylammonium chloride. Serotonin also caused an endothelium-, concentration-dependent membrane hyperpolarizations with a maximal amplitude of -8.8 mV. The nitro-L-arginine resistant relaxations and hyperpolarizations were abolished by methiothepin, but not by glibenclamide. The time course of the endothelium-dependent relaxations and hyperpolarizations was similar. CONCLUSION: These results suggest a contribution of cell membrane hyperpolarization to the endothelium-dependent relaxations induced by serotonin in the porcine coronary artery.

Animals↗
PubMed1998

C-terminal peptide of fusarium heterosporum lipase is necessary for its increasing thermostability.

Saccharomyces cerevisiae bearing a lipase cDNA from Fusarium heterosporum produced two lipases, A and B. Lipase B was significantly more stable to temperature than lipase A, but their optimum temperatures were similar. Lipase B was composed of one polypeptide (301 amino acids), and lipase A was composed of two polypeptides (275 and 26 amino acids) generated by the cleavage between Arg275 and Asp276 with a trypsin-like protease. It was suggested that the C-terminal peptide (26 amino acids) tightened the lipase structure when bound to the catalytic domain (275 amino acids) through a peptide bond. The tight structure was loosened by cleavage of the C-terminal peptide, even though the peptide interacted noncovalently with the catalytic domain, possibly through charged amino acids, in which it is rich. Deletion of the C-terminal peptide greatly decreased the lipase production by the recombinant S. cerevisiae, although its transcriptional level was the same as that of cells carrying the wild-type gene. These facts suggested that the C-terminal peptide affected the lipase production in the post-transcriptional step.

Amino Acid Sequence↗
PubMed1998

Translocation of HSP27 to cytoskeleton by repetitive hypoxia-reoxygenation in the rat myoblast cell line, H9c2.

We investigated the possible changes in the distribution of HSP27 after a brief hypoxia-reoxygenation stress in the rat myoblast cell line, H9c2, as a model of ischemic preconditioning. Cells were exposed to 4 cycles of 5 min. of hypoxia and 5 min. of reoxygenation. In the normoxic condition, HSP27 was exclusively found in the cytosolic fraction. After the hypoxia-reoxygenation cycle, HSP27 redistributed to the cytoskeletal fraction, which was blocked by 10 microM SB 203580, a specific inhibitor of p38 MAP kinase. Cells treated with the repetitive hypoxia-reoxygenation developed resistance against cell death induced by hypoxia for 24 hours. The changes in localization of HSP27 found in the present study may reflect the mechanism of preconditioning in the cardiac myocyte.

Animals↗
PubMed1998

Functional interaction between benzothiazepine- and dihydropyridine binding sites of cardiac L-type Ca2+ channels.

We have previously shown, in a radioligand binding study with single ventricular myocytes, that benzothiazepine and dihydropyridine binding sites interact with each other. To further examine whether this interaction between the two binding sites is reflected in the function of L-type Ca2+ channels, the blocking action of diltiazem, nitrendipine, and the combination of these two drugs on L-type Ca2+ channel currents was investigated using baby hamster kidney cells expressing the alpha 1C, alpha 2/delta, beta and gamma subunits of the Ca2+ channel. The effects of diltiazem and nitrendipine were additive at room temperature but synergistic at 33 degrees C. The use-dependent block by 3 microM of diltiazem was significantly enhanced from 28% to 68% by addition of 30 nM of nitrendipine, which by itself did not have a blocking effect. Thus, we conclude that benzothiazepine- and dihydropyridine binding sites interact and potentiate their blocking action on L-type Ca2+ channels in a temperature-dependent manner.

Animals↗
PubMed1998

Salivary gland malignant myoepithelioma: a clinicopathologic and immunohistochemical study of ten cases.

BACKGROUND: Malignant myoepithelioma (MME) of the salivary gland, also known as myoepithelial carcinoma, is rare and its biologic behavior has not been clarified fully. METHODS: Ten cases of MME were analyzed for their clinicopathologic features and immunohistochemical characteristics, focusing on prognostic factors and tumor differentiation. In addition, six cases of benign myoepithelioma (BME) also were examined for comparison. RESULTS: The ten patients with MME (3 men and 7 women) ranged in age from 48-81 years (mean, 61.9 years). Seven cases of MME arose in the parotid salivary gland, two in the submandibular salivary gland, and one in minor salivary glands of the soft palate. In the current series, the incidence of MME was 0.45% among 1945 cases of major salivary gland tumors. Seven cases of MME developed from a benign preexisting tumor (six in pleomorphic adenoma and one in BME). Four of nine patients with MME died of the disease and two patients developed a recurrence. It was shown that MMEs were comprised of one cell type or a combination of two cell populations; these included, in order of incidence, epithelioid, spindle, and plasmacytoid cells. Patients with MME with marked cellular pleomorphism and perineural invasion had a poor prognosis. Immunohistochemically, putative myoepithelial markers such as muscle actins, cytokeratin 14, vimentin, and calponin, and S-100 protein were expressed highly in MME. High and low molecular weight cytokeratins and epithelial membrane antigen also frequently were positive in MME. p53 expression was observed in five MME cases, four of which either recurred or were fatal. Cellular proliferative activity assessed by mitotic count and the Ki-67 labeling index was significantly higher in MME cases than in BME cases. In limited cases, such cellular proliferative activity was shown to have prognostic value. Ultrastructurally, the tumor cells displayed certain myoepithelial characteristics. CONCLUSIONS: MME is a rare salivary gland tumor showing clinicopathologic diversity and presenting with various stages of myoepithelial differentiation. Histologic aggressiveness, marked cellular pleomorphism, p53 expression, and high cell proliferative activity were found to be correlated with a poor clinical outcome.

Actins↗
PubMed1998

Effect of lipo-prostaglandin E1 on crescentic-type anti-glomerular basement membrane nephritis in rats.

The antinephritic effect of lipo-prostaglandin E1, prostaglandin E1 ((1R,2R,3R)-3-hydroxy-2-[(E)-(3S)-3-hydroxy-1-octenyl]-5-oxocyclopent ane heptanoic acid) incorporated in lipid microspheres was investigated using an experimental model of nephritis, crescentic-type anti-glomerular basement membrane nephritis. Lipo-prostaglandin E1 was given i.v. twice a day at 20, 40 and 80 microg/kg and azathioprine, an immunosuppressive agent, at 20 mg/kg was given p.o. once daily from the autologous phase, in which glomerulonephritis was fully developed (the 21 st day after injection of the anti-glomerular basement membrane serum), to the 50th day. Lipo-prostaglandin E1 (40 and 80 microg/kg x 2 per day) significantly inhibited the development of glomerular alterations as well as the elevation of proteinuria and plasma creatinine. Lipo-prostaglandin E1 (20 microg/kg x 2 per day) and azathioprine (20 mg/kg per day) significantly inhibited only the glomerular histopathological changes. Lipo-prostaglandin E1 at three doses significantly decreased the deposition of both rabbit immunoglobulin G and rat immunoglobulin G on the glomerular basement membrane in nephritic rats, but azathioprine apparently inhibited only the deposition of rat immunoglobulin G. A single administration of lipo-prostaglandin E1 inhibited the elevation of platelet aggregation and restored the decrease in renal tissue blood flow in nephritic rats. In addition, a single administration of lipo-prostaglandin E1 inhibited the elevation of glomerular thromboxane B2 and 6-keto prostaglandin F1alpha production in nephritic rats. These results suggest that lipo-prostaglandin E1 may be an effective agent for the treatment of glomerulonephritis. Its antinephritic effect may be due to the inhibition of platelet aggregation, an increase in renal tissue blood flow, a decrease in rabbit and rat immunoglobulin G deposition, and amelioration of the abnormal metabolism of arachidonic acid.

6-Ketoprostaglandin F1 alpha↗
PubMed1998

5-hydroxydecanoate selectively reduces the initial increase in extracellular K+ in ischemic guinea-pig heart.

The aim of the present study was to determine the effect of 5-hydroxydecanoate (5-HD) on extracellular K+ levels during global ischemia for 30 min employing K+-sensitive electrodes in isolated guinea-pig hearts. 5-HD (100 microM) reduced the K+ accumulation during the early period of ischemia, but did not inhibit the elevation of extracellular K+ in the latter half of the ischemic period which was selectively enhanced by ouabain (3 microM). Thus, 5-HD appears to exert a similar mode of action as glibenclamide on extracellular K+ accumulation in the ischemic guinea-pig hearts. The present study also strengthens the previous conclusion that an ATP-sensitive K+ channel contributes only to the initial increasing phase of extracellular K+ accumulation during ischemia in guinea-pig hearts.

Animals↗
PubMed1998

Developmental rescue of Drosophila cephalic defects by the human Otx genes.

The molecular mechanisms of head development are a central question in vertebrate and invertebrate developmental biology. The anteriorly expressed homeobox gene otd in Drosophila and its homolog Otx in mouse are required for the early development of the most anterior part of the body, suggesting that a fundamental genetic program of cephalic development might be conserved between vertebrates and invertebrates. We have examined this hypothesis by introducing the human Otx genes into flies. By inducing expression of the human Otx homologs with a heat shock promoter, we found that both Otx1 and Otx2 functionally complement the cephalic defects of a fly otd mutant through specific activation and inactivation of downstream genes. Combined with previous morphological studies, these results are consistent with the view that a common molecular ground plan of cephalization was invented before the diversification of the protostome and the deuterostome in the course of metazoan evolution.

Amino Acid Sequence↗
PubMed1998

Comparative study of behavioral development between high and low shuttlebox avoidance rats.

Previously, we reported that high- and low-avoidance animals (HAA and LAA, respectively), selectively bred for different avoidance response rates in a shuttlebox avoidance test, showed additional behavioral differences in wheel cage activity and in water maze performance after weaning. In the present study, physical and behavioral development were examined in HAA and LAA during the preweaning period. As compared to HAA, LAA offspring showed lower body weight, delayed eye opening, poorer performance in pivoting and negative geotaxis, and increased open-field activity. A fostering study indicated that these differences observed in eye opening, pivoting, negative geotaxis, open-field activity, swimming speed, shuttlebox avoidance and wheel cage activity were independent of maternal care. Only the pup weight was strongly dependent on the maternal line. These results indicate that behavioral differences between HAA and LAA observed in the pre- and postweaning periods may be linked to the avoidance genotype, but the difference in pup weight may be caused by maternal care.

Animals↗
PubMed1998

Basal cell adenocarcinoma of the salivary glands: comparison with basal cell adenoma through assessment of cell proliferation, apoptosis, and expression of p53 and bcl-2.

BACKGROUND: Basal cell adenocarcinoma (BCAC) of the salivary gland is a rare tumor and recently described entity. Eleven cases of BCAC are presented here and compared with basal cell adenoma (BCA) through assessment of cell proliferative activity, apoptosis, and expression of p53, bcl-2, and epidermal growth factor receptor (EGFR) because these two tumors show close similarity in some cytologic and architectural characteristics. METHODS: Formalin fixed, paraffin embedded sections of 11 cases of BCAC and 9 cases of BCA, selected from the authors' files of 1851 primary tumors of the major salivary gland, were examined using immunostaining for Ki-67 (MIB-1), p53, bcl-2, and EGFR. In addition, apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling. RESULTS: The incidence of BCAC was 0.6% among patients with major salivary gland tumors in the current series. Nine cases of BCAC arose in the parotid gland and two were of submandibular gland origin. Approximately 50% of the patients had recurrences, but no patient developed metastases or died of disease. Vascular involvement (75%), perineural invasion (36%), and necrosis (45%) were common features. Cell proliferative activity, including mitotic count, Ki-67 labeling index (LI), and apoptotic index were significantly higher in BCAC than BCA. More than four mitotic figures per ten high-power fields or a Ki-67 LI > 5% appeared to be limited to cases of BCAC. Considering those cases expressing p53 or EGFR in > 10% of tumor cells as positive, 6 of the 11 BCAC cases were positive for p53 and 3 were positive for EGFR. In contrast, all BCA cases were negative for p53 and EGFR. Although all cases of BCA were strongly positive for bcl-2 (> 50% of tumor cells), 3 of 11 cases of BCAC were completely negative. CONCLUSIONS: BCAC is a rare salivary gland tumor with a relatively high recurrence rate. Examination of cell proliferation, apoptosis, and expression of p53, bcl-2, and EGFR were found to be useful in distinguishing malignant basal cell tumors from their benign counterparts arising in the salivary gland.

Adenocarcinoma↗