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M Tanaka

Publications and source records attributed to M Tanaka.

At least 55 records · Page 3Linked to original sources
PubMed2005

Human herpesvirus-6 encephalitis after unrelated cord blood transplantation.

Here we describe 2 patients with acute leukemia in whom human herpesvirus-6 (HHV-6) encephalitis developed after cord blood transplantation. In patients 1 and 2, generalized seizure and coma developed on day 62 and day 15, respectively, after cord blood transplantation, which failed to engraft in patient 1. Magnetic resonance imaging (MRI) of patient 1's brain showed low-intensity signals at the gyri of the bilateral lateral lobes on T1-weighted images and high-intensity signals on T2-weighted images. MRI of patient 2's brain showed high-intensity signals in bilateral white matter on T2-weighted images and on fluid-attenuated inversion recovery (FLAIR) images. Cerebrospinal fluid examination revealed an increased protein level with pleocytosis in patient 1 and a normal protein level without pleocytosis in patient 2. Polymerase chain reaction analysis detected HHV-6 DNA in the cerebrospinal fluid of both patients. Patient 1 recovered after administration of gancyclovir for 3 weeks. However, she again suffered from encephalitis after discontinuation of gancyclovir, and died of sepsis. Patient 2 died from an anoxic brain caused by generalized seizure. When neurological symptoms and signs appear in hematopoietic stem cell transplantation recipients, we should consider HHV-6 encephalitis and promptly and empirically treat them with gancyclovir or foscarnet.

Adult↗
PubMed2005

Neuroprotective effect of mivazerol, an alpha 2-agonist, after transient forebrain ischemia in rats.

BACKGROUND: We examined whether mivazerol, an alpha2-agonist, had neuroprotective effects after transient forebrain ischemia in rats. METHODS: Male Sprague-Dawley rats, anesthetized with halothane, were assigned to one of four groups (n=10 each): control (C, normal saline) and mivazerol 10 microg/kg (M10), 20 microg/kg (M20) and 40 microg/kg (M40) groups. Thirty minutes after drug administration, forebrain ischemia was induced with hemorrhagic hypotension and bilateral carotid artery occlusion for 10 min, and then the brain was reperfused. The neurologic outcome was evaluated 24 h, 48 h and 7 days after ischemia, followed by histologic evaluation. RESULTS: The survival rate during 7 days was significantly lower in group M40 than in groups M10 and M20 (P<0.05). The neurologic outcome was significantly better in groups M10 and M20 than in group M40 7 days after ischemia (P<0.05). The number of intact neurons in hippocampal CA1 was significantly greater in group M20 than in the other groups (P<0.05). Neuronal injury in the neocortex was significantly less in group M20 than in groups C and M40 (P<0.05). CONCLUSIONS: Our results suggest that mivazerol, up to 20 microg/kg, provides neuroprotective effects, whereas 40 microg/kg may exaggerate neuronal injury after transient forebrain ischemia in rats.

Adrenergic alpha-Agonists↗
PubMed2005

Novel protein kinase C-beta isoform selective inhibitor JTT-010 ameliorates both hyper- and hypoalgesia in streptozotocin- induced diabetic rats.

AIM: Activation of protein kinase C (PKC) is thought to play an important role in the pathogenesis of diabetic microvascular complications. PKC-beta is elevated in hyperglycaemic conditions, both in vivo and in vitro. In this study, pharmacological effects of a novel PKC-beta isoform selective inhibitor, JTT-010 ((2R)-3-(2-aminomethyl-2,3-dihydro-1H-3a-azacyclopenta(a)inden-8-yl)-4-phenylaminopyrrole-2,5-dione monomethanesulphonate), on diabetic neuropathy were examined. METHODS: PKC inhibitory activity of JTT-010 was evaluated with an enzyme assay. For the in vivo study, streptozotocin (STZ)-induced diabetic rats were treated with JTT-010 for 12 weeks and tail/sciatic nerve conduction velocity (NCV) evaluated. Hyper/hypoalgesia was evaluated using tail-flick and formalin tests. RESULTS: JTT-010 inhibited PKC-betaI and -betaII with IC50 values of 4.0 and 2.3 nm respectively. For other PKC isoforms, IC50 values were 54 nm or greater. In STZ-induced diabetic rats showing a reduction in tail/sciatic nerve conduction velocities, JTT-010 (0.3-3 mg/kg) ameliorated the reduction of these velocities. In a formalin test, STZ-induced diabetic rats had hyperalgesia in the first phase. JTT-010 reduced nociceptive response at doses of 0.1 mg/kg or higher. Furthermore, STZ-induced diabetic rats showed hypoalgesia in the second phase of the formalin test and tail-flick test. JTT-010 also ameliorates these symptoms at doses of 0.1 mg/kg or higher. CONCLUSIONS: These observations suggest that PKC-beta contributes not only to diabetic hyperalgesia, but also to hypoalgesia and also contributes to defects in NCV. PKC-beta inhibitor, JTT-010, may be beneficial in suppressing the development of diabetic nerve dysfunction, including hyperalgesia and hypoalgesia.

Animals↗
PubMed2005

Microvascular density of rapidly destructive arthropathy of the hip joint.

PURPOSE: To assess the vascularity of the femoral head and determine how it is related to the destruction of the arthritic hip joint. The process of destructive arthropathy in arthritic hip joints is variable. Some patients with osteoarthritis of the hip have rapidly progressive destructive changes resulting in the disappearance of the femoral head. METHOD: Six femoral heads from patients diagnosed with rapidly destructive arthropathy and 6 femoral heads from patients with secondary osteoarthritis caused by acetabular dysplasia were analysed to reveal the association between blood capillaries and osteoclasts. The von Willebrand Factor immunostaining and counterstaining with Mayer's haematoxylin were used to label the microvessels and osteoclasts in formalin-fixed, paraffin-embedded specimens of femoral heads. The numbers of immunostained microvessels and osteoclasts in selected regions were counted. RESULT: The microvascular density of the bone surfaces of rapidly progressive arthritic hips was hypervascular. Osteoclasts were also found in increased numbers on the bone surfaces of rapidly progressive arthritic hips. The higher microvascular density coincided with extensive bone destruction and with the increased osteoclast count. CONCLUSION: These findings suggested that hypervascularity of the granulation in the femoral head may be associated with bone and joint destruction.

Adult↗
PubMed2005

Differential effects of sex steroid hormones on the expression of multiple first exons including a novel first exon of prolactin receptor gene in the rat liver.

In addition to the known four alternative first exons E1(1), E1(2), E1(3) and E1(4) of the rat prolactin receptor (PRL-R) gene, a novel first exon, E1(5), was identified by cDNA cloning of the 5'-end region of PRL-R mRNA in the rat liver. Genomic fragments containing E1(5) and its 5'- or 3'-flanking regions were also cloned from rat kidney genomic DNA. A sequence search for E1(5) revealed that E1(5) is located 49 kb upstream of exon 2 of the PRL-R gene in rat chromosome 2q16. RT-PCR analysis revealed that E1(5) was preferentially expressed in the liver, brain and kidney. Expression profiles of E1(2)-, E1(3)- and E1(5)-PRL-R mRNAs in the liver of male and female rats at 5 days of age and those at 8 weeks of age were examined by RT-PCR. The levels of E1(2)-PRL-R mRNA in the female rat increased remarkably in rats at 8 weeks of age compared with those at 5 days of age, and the levels of E1(5)-PRL-R mRNA in the male rat decreased markedly at 8 weeks of age compared with those at 5 days of age. In the female rat, the levels of E1(2)-PRL-R mRNA at 8 weeks of age decreased with ovariectomy performed at 4 weeks of age and recovered with the administration of beta-oestradiol. On the contrary, the levels of E1(5)-PRL-R mRNA increased with ovariectomy and decreased with the oestrogen treatment. In the male rat liver, the levels of E1(2)-PRL-R mRNA at 8 weeks of age increased strikingly with castration performed at 4 weeks of age and became undetectable with the administration of testosterone. The levels of E1(5)-PRL-R mRNA increased slightly with castration and were restored by testosterone treatment. Removal of gonadal tissues and sex steroid hormone treatment had no effect on the expression levels of E1(3)-PRL-R mRNA in both female and male rat livers. These results indicated that the expression of the PRL-R gene in the liver is regulated by the differential effects of sex steroid hormones on the transcription of the multiple first exons including the novel one.

Animals↗
PubMed2005

Normalization of reversed bio-intact-PTH(1-84)/intact-PTH ratio after parathyroidectomy in a patient with severe secondary hyperparathyroidism.

The conventional intact-PTH assay detects both (1-84)-PTH and C-terminal fragments. The newer PTH assays, bio-intact-PTH assay and whole-PTH assay, use an antibody that binds only if the first amino acid is present, making it specific for the complete molecule, (1-84)-PTH. Thus, the intact-PTH concentrations are theoretically higher than bio-intact-PTH concentrations, and the ratio of bio-intact-PTH/intact-PTH is usually less than 1. These findings are observed in normal subjects and patients with primary and secondary hyperparathyroidism. Here we present a hemodialysis patient with severe secondary hyperparathyroidism who was found to have abnormally higher plasma bio-intact-PTH concentrations than intact-PTH concentrations, and the abnormally high biointact-PTH/intact-PTH ratio improved after parathyroidectomy (PTx). The patient was a 67-year-old man on maintenance hemodialysis since 1995. Since 2003, he was found to have high plasma intact-PTH concentrations and two swollen parathyroid glands in the neck. PTx with forearm autograft was performed in October 2003. Before PTx, an abnormally high ratio of bio-intact-PTH/intact-PTH was detected (840 pg/ml/770 pg/ml, > 1), while the same ratio was improved to normal range (100 pg/ml/200 pg/ml, < 1). Recently, a few patients with parathyroid carcinoma have been found to have higher (1-84)-PTH concentrations than intact-PTH concentrations with abnormally high (1-84)-PTH/intact-PTH ratio. Moreover, a new molecular form of PTH distinct from (1-84)-PTH was detected in these patients. We speculate that the resected parathyroid gland in our patient might have produced a new molecular form of PTH that was less well detected by the conventional intact-PTH assay.

Aged↗
PubMed2005

Identification of Fabry's disease by the screening of alpha-galactosidase A activity in male and female hemodialysis patients.

BACKGROUND: Although previous studies reported that the prevalence of Fabry's disease was 0.16 - 1.2% in hemodialysis (HD) patients based on measurement of a-galactosidase A (alpha-Gal A) activity, few reports detected female patients by the screening for alpha-Gal A. Here we determined the prevalence of Fabry's disease not only in male but also in female HD patients by measuring alpha-Gal A. METHODS: Plasma alpha-Gal A was measured in 696 consecutive males (n = 401) and females (n = 295) on HD. Patients with low plasma alpha-Gal A were examined for leukocyte alpha-Gal A, and patients with low leukocyte alpha-Gal A underwent alpha-Gal A gene sequence analysis for possible mutations, and family survey. RESULTS: Among 15 patients with low plasma alpha-Gal A activity, 4 male patients with low leukocyte alpha-Gal A and 1 female patient revealing low plasma alpha-Gal A were detected in 696 HD patients (0.7% of total patients). 3 of these 5 patients were already diagnosed to have the classical type of Fabry's disease. The other 2 patients were newly diagnosed as Fabry's disease, and did not have typical manifestations of Fabry's disease other than renal failure and left ventricular hypertrophy. DNA analysis of these 2 newly diagnosed patients revealed that each had an alpha-Gal missense mutation, previously identified (E66Q, M2961). CONCLUSION: Fabry's disease should be considered in the etiology of unexplained end-stage renal disease. Not only affected males but also affected females undergoing HD patients can be readily diagnosed by alpha-Gal A activities and gene analysis. These patients and their family members may benefit from enzyme replacement therapy for Fabry's disease.

Adult↗
PubMed2005

Important clues to the diagnosis of pancreatic cancer.

The incidence of pancreatic carcinoma is recently increasing but the prognosis remains extremely poor. Widespread awareness of important clues to the diagnosis is particularly important to improve the prognosis. Dilatation of the main pancreatic duct on ultrasonograms and/or CT scans, hyperamylasemia incidentally found during routine blood examinations, and recent onset diabetes mellitus must lead to thorough imaging studies of the pancreas. Death from pancreatic carcinoma occurs in 0.2-1.9% of all diabetic patients, being more than 300 times frequent compared to general population. Diabetes may be the only clinical sign of pancreatic carcinoma in some patients. In our recent study, of 163 diabetic patients selected by several criteria who underwent ERCP screening, 12 patients (7.4%) proved to have pancreatic carcinoma. The prevalence of pancreatic carcinoma was more frequent in those with a recent onset (<3 years) of diabetes (13.7% (8/58)) than in those with a longer history (>3 years, 3.8% (4/105)). Furthermore, intraductal papillary mucinous neoplasm (IPMN) is reported to be associated with pancreatic carcinoma. Concomitant carcinoma was found in 9 of our series of 94 patients (9.5%) who underwent surgical resection of branch duct IPMN. Of particular interest is the fact that two of the 9 patients had carcinoma in situ that could be diagnosed only by cytology of the pancreatic juice. IPMN may be the only clue to the early diagnosis of pancreatic carcinoma presenting with no clinical symptoms or abnormalities on imaging studies.

Adenocarcinoma, Mucinous↗
PubMed2004

Urine diacetylspermine as a novel tumour maker for pancreatobiliary carcinomas.

BACKGROUND: Serum carcinoembryonic antigen (highly specific) and carbohydrate antigen 19-9 (highly sensitive) have been used as tumour markers for pancreatobiliary cancers. A novel urine tumour marker, diacetylspermine, was compared with the two conventional serum tumour markers in 125 patients with pancreatobiliary diseases. RESULTS: When the diagnosis of benign or malignant condition was examined, the sensitivity of urine diacetylspermine (75%) was higher than that of serum carcinoembryonic antigen (44%; P=0.048) and the same as that of serum carbohydrate antigen 19-9 (75%). The specificity of urine diacetylspermine (81%) was lower than that of serum CEA (92%) and as high as that of serum carbohydrate antigen 19-9 (80%). The efficiency of urine diacetylspermine (79%) was higher than that of serum carcinoembryonic antigen (74%) and the same as that of serum carbohydrate antigen 19-9 (79%). CONCLUSION: These results suggest that urine diacetylspermine is a marker for pancreatobiliary carcinoma, which is as highly sensitive and specific as serum carbohydrate antigen 19-9.

Adult↗
PubMed2004

Regional myocardial perfusion under exchange transfusion with liposomal hemoglobin: in vivo and in vitro studies using rat hearts.

The purpose of this study was to test the hypothesis that exchange transfusion with liposomal hemoglobin (LH) reduces the microheterogeneity of regional myocardial flows while sustaining cardiac function. Neo Red Cell mixed with albumin was used as the LH solution, in which the LH volume fraction was 17 approximately 18% and hemoglobin density was nearly two-thirds smaller than in rat blood. Regional myocardial flows in left ventricular free walls were measured by tracer digitalradiography (100-mum resolution) in anesthetized rats with or without 50% blood-LH exchange transfusion. Within-layer flow distributions showed lower heterogeneity with (n = 8) than without (n = 8) LH transfusion. No extravasation of hemoglobin was confirmed by 3,3-diaminobenzidin staining (n = 2). Carotid flow increased by 68% due to LH transfusion, whereas arterial pressure and heart rate remained unchanged. On the other hand, cross-circulated rat hearts (n = 7) were used to evaluate the effects of 50% blood-LH exchange on coronary flow and tone preservation under 300-beats/min pacing and 100-mmHg perfusion pressure. Blood-LH exchange caused a 71% increase of coronary flow and 10% decrease of percent flow increase during hyperemia after 30-s flow interruption. Myocardial O(2) supply and consumption increased by 9% and 10%, respectively, whereas myocardial O(2) extraction remained unchanged. The large increases of in vivo carotid flow and coronary flow in cross-circulated hearts due to LH coperfusion could be explained by the reduction of apparent flow viscosity. These results suggest that under LH coperfusion, the microheterogeneity of myocardial flows decreases with increased coronary flow while fairly preserving coronary tone and cardiac function.

Animals↗
PubMed2004

Comparison of stent placement and colostomy as palliative treatment for inoperable malignant colorectal obstruction.

BACKGROUND: Stent placement is a useful palliative treatment for inoperable acute malignant colorectal obstruction. However, data comparing stent placement with colostomy are scarce. METHODS: We compared the clinical outcome of 18 patients who had stent placement and 17 patients who underwent only colostomy. RESULTS: The postoperative hospital stay was 22.3 days for stent placement compared with 47.4 days for colostomy (p = 0.016). The duration to readmission was 129.2 days for stent placement and 188.4 days for colostomy. The estimated duration of primary stent patency was 106 days. Mean survival period was 134 days in patients with stent placement and 191 days in patients with colostomy. CONCLUSION: Postoperative hospital stay was shorter in patients with stent placement but duration to readmission and survival were longer in patients with colostomy. However, stent placement increases the option of palliative treatment and is an effective treatment contributing to improving quality of life.

Aged↗
PubMed2004

Picosecond view of microscopic-scale polarization clusters in paraelectric BaTiO3.

The polarization clusters existing in both the ferroelectric and the paraelectric phase of BaTiO3 are directly observed and characterized for the first time by a picosecond soft x-ray laser speckle technique. These dynamic clusters appear continuously across the Curie temperature T(c). The clusters' distance increases approximately linearly with temperature, while their mean size does not change significantly. The polarization exhibits a maximum at a temperature about 5 degrees C above T(c). The clusters' short-range correlation strength diverges as (T-T(c))(-0.41+/-0.02) as temperature decreases toward T(c).

Journal Article↗
PubMed2004

Isolation of an active element from a high-copy-number family of retrotransposons in the sweetpotato genome.

A large number of plant retrotransposons have been characterized, but only three families ( Tnt1, Tto1 and Tos17) have been demonstrated to be transpositionally competent. We have used a novel approach to identify an active member of the Ty1- copia retrotransposon family with estimated 400 copies in the sweetpotato genome. Ty1- copia reverse transcriptase (RTase) sequences from the sweetpotato genome were analyzed, and a group of retrotransposon copies that probably arose by recent transposition events was identified and analyzed further. Transcripts containing long terminal repeats (LTRs) of this group were amplified from callus cDNA by the 3'RACE technique. Patterns of sequence-specific amplification polymorphism (S-SAP) of the LTR sequences in genomic DNA were compared between a normal plant and callus lines derived from it. In this way, a callus-specific S-SAP product was identified, which apparently resulted from the insertion of the retrotransposon detected by 3'RACE during cell culture. We conclude that our approach provides an effective way to identify active elements among the members of high-copy-number retrotransposon families.

Base Sequence↗
PubMed2004

Search for electron neutrino appearance in a 250 km long-baseline experiment.

We present a search for electron neutrino appearance from accelerator-produced muon neutrinos in the K2K long-baseline neutrino experiment. One candidate event is found in the data corresponding to an exposure of 4.8 x 10(19) protons on target. The expected background in the absence of neutrino oscillations is estimated to be 2.4+/-0.6 events and is dominated by misidentification of events from neutral current pi(0) production. We exclude the nu(micro) to nu(e) oscillations at 90% C.L. for the effective mixing angle in the 2-flavor approximation of sin((2)2theta(microe)( approximately 1/2sin((2)2theta(13))>0.15 at Deltam(2)(microe)=2.8 x 10(-3) eV(2), the best-fit value of the nu(micro) disappearance analysis in K2K. The most stringent limit of sin((2)2theta(microe)<0.09 is obtained at Deltam(2)(microe)=6 x 10(-3) eV(2).

Journal Article↗
PubMed2004

Electrocardiographic Q-waves as a predictor of mortality in patients with cerebral infarction.

OBJECTIVE: To determine whether abnormal EKG findings could be predictive factors for death after a stroke event. METHODS: Patients with acute cerebral infarction who were 35 to 98 years old during April 1996 through November 2000 were analyzed (n = 216). A standard 12-lead EKG was recorded for each patient after acute cerebral infarction. The authors prospectively investigated the association between abnormal EKG findings and the risk for death after stroke over a 1-year period. RESULTS: Using multivariate Cox proportional hazards models, the authors found age (hazard ratio of mortality per year 1.10, 95% CI 1.06 to 1.15, p < 0.001), sex (female; hazard ratio of mortality 3.42, 95% CI 1.43 to 8.19, p = 0.006), and the presence of Q-waves in more than two leads (hazard ratio of mortality 2.75, 95% CI 1.23 to 6.14, p = 0.013) were independently associated with death after stroke. CONCLUSION: The presence of Q-waves in more than two leads could be a predictive factor for death after acute cerebral infarction.

Adult↗
PubMed2004

Infrasternal mediastinoscopic surgery for anterior mediastinal masses.

BACKGROUND: Infrasternal mediastinoscopic surgery is a new alternative to the thoracoscopic approach for patients with anterior mediastinal masses. METHODS: We applied this technique to 18 thymectomies, one thymomectomy, and one cystectomy in a total of 20 patients with anterior mediastinal masses and then assessed the surgical results. RESULTS: Infrasternal mediastinoscopic surgery was accomplished in 18 of the 20 patients (90%). The pathological diagnoses included 13 Masaoka stage I thymomas, one stage II thymoma, two stage III thymomas, one thymic cyst, one pericardial cyst, one thymic granuloma, and one mature teratoma. Two patients with stage III thymoma required conversion to sternotomy, one for invasion into the innominate vein and the other for invasion into the pericardium. There was no surgically related mortality or complications in any patients. CONCLUSION: Infrasternal mediastinoscopic surgery is safe and feasible for stage I thymoma and other benign tumors in the anterior mediastinum.

Adult↗