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Y Sudo

Publications and source records attributed to Y Sudo.

At least 37 records · Page 2Linked to original sources
PubMed2001

Photo-induced proton transport of pharaonis phoborhodopsin (sensory rhodopsin II) is ceased by association with the transducer.

Phoborhodopsin (pR; also sensory rhodopsin II, sRII) is a retinoid protein in Halobacterium salinarum and works as a receptor of negative phototaxis. Pharaonis phoborhodopsin (ppR; also pharaonis sensory rhodopsin II, psRII) is a corresponding protein of Natronobacterium pharaonis. In bacterial membrane, ppR forms a complex with its transducer pHtrII, and this complex transmits the light signal to the sensory system in the cytoplasm. We expressed pHtrII-free ppR or ppR-pHtrII complex in H. salinarum Pho81/wr(-) cells. Flash-photolysis experiments showed no essential changes between pHtrII-free ppR and the complex. Using SnO2 electrode, which works as a sensitive pH electrode, and envelope membrane vesicles, we showed the photo-induced outward proton transport. This membranous proton transport was also shown using membrane vesicles from Escherichia coli in which ppR was functionally expressed. On the other hand, the proton transport was ceased when ppR formed a complex with pHtrII. Using membrane sheet, it was shown that the complex undergoes first proton uptake and then release during the photocycle, the same as pHtrII-free ppR, although the net proton transport ceases. Taking into consideration that the complex of sRII (pR) and its transducer undergoes extracellular proton circulation (J. Sasaki and J. L., Biophys. J. 77:2145-2152), we inferred that association with pHtrII closes a cytoplasmic channel of ppR, which lead to the extracellular proton circulation.

Archaeal Proteins↗
PubMed2001

Increased expression of WAF1 in intrahepatic bile ducts in primary biliary cirrhosis relates to apoptosis.

BACKGROUND/AIMS: In primary biliary cirrhosis (PBC), the intrahepatic small bile ducts are selectively damaged by immune attacks, followed by progressive loss mainly due to apoptosis. Compared to the intercellular signaling such as the CD95/CD95 ligand interaction, little is known about alterations in intracellular cell cycle regulatory proteins and genotoxic damage in this apoptotic process. WAF1 is a potent and reversible inhibitor of cell cycle progression at both the G1 and G2 checkpoint and upregulated WAF1 induces irreversible G1 arrest and apoptosis. Transcriptional activation of the WAF1 gene is induced by the upregulated p53 in response to DNA damage. In this study, the cell cycle regulatory process of apoptosis in PBC was examined with respect to expression of WAF1. METHODS: Immunostaining for WAF1 and p53 was performed using 11 liver sections of PBC and 26 control livers. In addition, Ki67, apoptosis (TUNEL-positive), and human telomerase RNA (hTR) were also detected. RESULTS: WAF1 was expressed in the nuclei of several epithelial cells in most damaged bile ducts in PBC but infrequently or rarely in controls. Some of these cells were also positive for p53, while the remainder were not. Ki67 immunostaining and TUNEL disclosed that the bile ducts in PBC showed increased cell division as well as enhanced apoptosis. Immunostaining of Ki67 and TUNEL staining showed that WAF1-positive cells were not proliferating, while some WAF1-positive cells were undergoing apoptosis. Moreover, the bile ducts lacked hTR expression, implying progressive shortening of telomeres during increased cell divisions. CONCLUSIONS: It seems possible that in PBC, expression of WAF1 on biliary epithelial cells relates to the apoptosis. p53 may be involved in this upregulation. This may be due to physiological upregulation of WAF1 and p53 in response to genotoxic damage such as oxidative stress associated with cholangitis, suggesting other processes than CD95/CD95 ligand interaction in biliary epithelial apoptosis in PBC.

Aged↗
PubMed2001

Scavenger cells with gram-positive bacterial lipoteichoic acid infiltrate around the damaged interlobular bile ducts of primary biliary cirrhosis.

BACKGROUND/AIMS: Gram-positive bacterial DNA is frequently detectable in gallbladder bile of primary biliary cirrhosis (PBC) patients. To advance these findings, lipoteichoic acid (LTA) of gram-positive bacteria with high antigenicity was examined in liver specimens and bile from PBC patients and controls. METHODS: LTA was examined by Western blotting in the gallbladder bile from 15 PBC, 11 cholecystolithiasis and six normal subjects, and by immunohistochemistry in liver specimens from 16 PBC, six primary sclerosing cholangitis (PSC), eight chronic viral hepatitis C (CVH-C) and five normal subjects. RESULTS: In the gallbladder bile, there was no significant difference in the positive rate of LTA between PBC and controls. LTA-containing mononuclear cells were frequently detected in the portal tracts, particularly around the bile ducts and in hepatic sinusoids in PBC, while they were infrequent or occasional in control livers. These LTA-containing cells were sinusoidal endothelial cells and Kupffer cells, and portal monocytes, which frequently expressed scavenger receptor class B type 1. CONCLUSIONS: LTA derived from bacterial fragments may reach the bile, not only in the diseased state but also under normal conditions. Such LTA may be involved in the development and progression of portal tract lesions, particularly bile duct lesions, in PBC.

Adult↗
PubMed2001

Cortical activity associated with vocalization and reading proper.

To determine whether motor and premotor areas are involved in silent reading, we report a positron emission tomography study on reading aloud and covert reading. The anterior insula, primary sensorimotor cortex and supplementary motor area were activated separately in reading aloud compared with covert reading, but they were not activated in covert reading compared with fixation control, nor in a conjunction involving reading aloud and covert reading, suggesting the role of articulation or vocalization.

Brain Mapping↗
PubMed2001

Cortical activation in reading assessed by region of interest-based analysis and statistical parametric mapping.

Reanalysis of our positron emission tomography study on the reading of Japanese Kanji (morphograms) and Kana (phonograms) with Statistical Parametric Mapping (SPM) Version 96 (Cogn. Brain Res. 9 (2000) 111) were described in comparison with our previous region of interest (ROI)-based analysis. Some areas were activated in one analysis but not in the other, which was due to the methodological differences. Furthermore, we conducted cognitive subtraction analysis between Kanji and Kana and between Kana words and nonwords and confirmed that Kana words activated the lateral occipital gyri more extensively than Kanji words.

Adolescent↗
PubMed2001

Photochemistry and photoinduced proton-transfer by pharaonis phoborhodopsin.

Phoborhodopsin (pR or sensory rhodopsin II, sRII) is a photoreceptor of the negative phototaxis of Halobacterium salinarum, and pharaonis phoborhodopsin (ppR or pharaonis sensory rhodopsin II, psRII) is a corresponding protein of Natronobacterium pharaonis. The photocycle of ppR is essentially as follows: ppR(498) --> ppRK(approximately 540) --> ppRKL(512) --> ppRL(488) --> ppRM(390) --> ppRO(560) --> ppR (numbers in parenthesis denote the maximum absorbance). The photocycle is very similar to that of bacteriorhodopsin, but the rate of initial pigment recovery is about two-orders of magnitude slower. By low-temperature spectroscopy, two K-intermediates were found but the L intermediate was not detected. The lack of L indicates extraordinary stability of K at low temperature. ppRM is photoactive similar to M of bR. The ground state ppR contains only all-trans retinal whereas ppRM and ppRO contain 13-cis and all-trans, respectively. ppR has the ability of light-induced proton transport from the inside to the outside. Proton uptake occurs at the formation of ppRO and the release at its decay. ppR associates with its transducer and this complex transmits a signal to the cytoplasm. The proton transport ability is lost when the complex forms, but the proton uptake and release still occur, suggesting that the proton movement is non-electrogenic (release and uptake occur from the same side). The stoichiometry of the complex between ppR and the transducer is 1 : 1. ppR or pR has absorption maximum at approximately 500 nm, which is blue-shifted from those of other archaeal rhodopsins. The molecular mechanism of this color regulation is not yet solved.

Archaeal Proteins↗
PubMed2001

Oncocytic biliary cystadenocarcinoma is a form of intraductal oncocytic papillary neoplasm of the liver.

Biliary cystadenocarcinoma with oncocytic differentiation was first reported in 1992. This is a report of a second case. The patient (a 71-year-old man) was admitted to our hospital complaining of abdominal fullness. Multicystic lesions were identified in the left hepatic lobe radiologically. The patient died of peritoneal dissemination of carcinoma 20 months later. At autopsy, the tumor of the left hepatic lobe was found to be composed of adjoining multiple cystic lesions and a solid lesion with infiltration of the hepatic hilus and peritoneal dissemination. Histologically, the multicystic lesions were covered by papillary neoplastic epithelial cells with an eosinophilic granular cytoplasm resembling that of oncocytes and a fine fibrovascular core. The cyst wall was fibrous, but there was no mesenchymal stroma. In the solid lesion and infiltrated areas, acidophilic and granular carcinoma cells formed small glandular or solid cord patterns with much mucin secretion (mucinous carcinoma). Immunohistochemically, carcinoma cells of both components were found to contain many mitochondria and showed the phenotypes of hepatocytes and cholangiocytes. Interestingly, the intrahepatic biliary tree also was invaded by carcinoma cells. This may be a case of intraductal oncocytic papillary neoplasm of the left hepatic lobe followed by secondary cystic dilatation of the affected bile duct.

Adenoma, Oxyphilic↗
PubMed2001

Ten year progressive ventricular enlargement in schizophrenia: an MRI morphometrical study.

Recent studies of the brain using magnetic resonance imaging (MRI) have suggested progressive structural changes in schizophrenics. However, those studies were conducted over periods of less than 5 years and thus lacked sufficient capacity to determine the course and nature of this process. In this study, MRI scans were obtained in 15 schizophrenics and 12 controls at baseline and after 4- and 10-year follow ups. Volumes of the lateral ventricles were measured. Patients were assessed by the Brief Psychiatric Rating Scale (BPRS) at the same two time points: at baseline and at 10-year follow up. After 10 years, a significant lateral ventricular enlargement was found in patients (mean percentage change: +22.9%) but not in controls (5.1%). Although our results are not in disagreement with the neurodevelopmental hypothesis, they do provide strong evidence that in schizophrenia progressive brain reduction occurs even in its chronic stage.

Adult↗
PubMed2001

Molecular identification of bacterial 16S ribosomal RNA gene in liver tissue of primary biliary cirrhosis: is Propionibacterium acnes involved in granuloma formation?

The etiopathogenesis of primary biliary cirrhosis (PBC) remains speculative. Epithelioid granulomas are often found in the vicinity of damaged interlobular bile ducts in PBC, raising the possibility of a reaction to microbial materials. In this study, we tried to detect and identify bacterial DNA within granulomatous lesions in PBC. Using liver sections from 9 patients with PBC and 13 control livers, granuloma in portal tracts, portal tracts without granuloma, and adjacent hepatic parenchyma were selectively microdissected from sections, and then DNA was extracted from them. First, part of the bacterial 16S ribosomal RNA (rRNA) gene was amplified from DNA samples extracted from 5 PBC and 6 control livers, and their amplicons were sequenced for the identification of bacterial species. Several indigenous bacteria were identified. Among them, Propionibacterium acnes (P. acnes) was detected as a major clone in 20% to 50% of sequenced clones from granuloma of PBC, but the detection rate of P. acnes was 0% to 20% in those cloned from adjacent hepatic parenchyma of PBC. Then, a P. acnes-specific PCR was performed using all microdissected samples. Distinct PCR products were identified in epithelioid granuloma in all 9 PBC cases. The result that P. acnes DNA is present as a major clone in granulomas of PBC, suggest that P. acnes is involved in the pathogenesis of granuloma in PBC.

DNA, Bacterial↗
PubMed2001

Reproducibility of [11 C]FLB 457 binding in extrastriatal regions.

Extrastriatal D2 dopamine receptors represent an important target of research into the pathophysiology and pharmacotherapy of psychiatric disorders. The high affinity radioligand [11C]FLB 457 makes possible the measurement of low concentrations of D2 receptors in extrastriatal regions using positron emission tomography (PET). The aim of this study was to assess the test/retest variability and reliability of [11C]FLB 457 binding using a reference tissue model. Eight healthy male subjects (aged 20-33 years) underwent two [11C]FLB 457 PET examinations. Radioactivity in the cerebellum was used as the reference. The binding potentials (BPs) for five cortical regions of interest (ROIs) were calculated using the reference tissue model. The BP was also calculated for each pixel in the form of parametric images. Reproducibility was assessed both for the ROI method and for the parametric images. The test/retest reproducibility for [11C]FLB 457 binding was good, with a mean variability ranging from 4.5% for the thalamus to 15.5% for the hippocampus. The parametric images also demonstrated good reproducibility. These results support the suitability of using [11C]FLB 457 for the quantitative evaluation of extrastriatal D2 receptors and for protocols requiring repeated measurements in the same individual.

Adult↗
PubMed2001

Pretreatment with FK506 improves survival rate and gas exchange in canine model of acute lung injury.

The novel effects of FK506 on shock induced by lipopolysaccharide and phorbol myristate acetate (LPS/PMA) were studied using beagles. Five groups were studied: endotoxin shock control group (both 0.5 mg/kg of LPS and 30 microg/kg of PMA, n = 6); methylprednisolone-treated endotoxin shock group (n = 5); FK506-treated endotoxin shock groups in which intravenous infusions of FK506 at 2.5 microg/kg/h (low dose, n = 5), 8 microg/kg/h (medium dose, n = 5), and 25 microg/kg/h (high dose, n = 5) were administered. In the control group, the survival rate was 33%. Also, arterial hypoxemia, systemic hypotension, and marked increases in pulmonary vascular resistance (PVR) and wet-to-dry weight ratio (W/D) were observed. FK506 treatment at both medium and high doses significantly attenuated these LPS/PMA-induced physiological changes, and the survival rates were 80 and 100%, respectively. On the other hand, in the methylprednisolone group, no obvious effects were observed. The present study suggests that FK506 could have prophylactic potential against acute lung injury in endotoxin shock.

Animals↗
PubMed2001

Pharaonis phoborhodopsin binds to its cognate truncated transducer even in the presence of a detergent with a 1:1 stoichiometry.

Pharaonis phoborhodopsin (ppR) (also pharaonis sensory rhodopsin II) is a receptor of the negative phototaxis of Natronobacterium pharaonis. ppR forms a complex with its pharaonis halobacterial transducer (pHtrII), and this complex transmits the light signal to the sensory system in the cytoplasm. The expressed C-terminal-His tagged ppR and C-terminal-His tagged truncated pHtrII (t-Htr) in Escherichia coli (His means the 6x histidine tag) form a complex even in the presence of 0.1% of n-dodecyl-beta-D-maltoside, and the M-decay of the complex became about twice slower than that of ppR alone. The photocycling rates under varying concentration ratios of ppR to t-Htr in the presence of detergent were measured. The data were analyzed on the following assumptions: (1) the M-decay of both ppR alone and the complex followed a single exponential decay with different time constants; and (2) the M-decay under varying concentration ratios of ppR to t-Htr, therefore, followed a biexponential decay function which combined the decay of the free ppR and that of the complex as photoreactive species. From these analyses we estimated the dissociation constant (15.2 +/- 1.8 microM) and the number of binding sites (1.2 +/- 0.08).

Archaeal Proteins↗
PubMed2001

Clinical characteristics of B-cell lymphoma-associated hemophagocytic syndrome (B-LAHS): comparison of CD5+ with CD5- B-LAHS.

OBJECTIVE: B-cell lymphoma-associated hemophagocytic syndrome (B-LAHS) has been increasingly reported in Asia and is regarded as a variant of intravascular lymphomatosis (IVL). Recently CD5 was reported to be expressed in some cases of diffuse large cell lymphoma and IVL. We therefore examined the expression of CD5 on lymphoma cells in B-LAHS and compared the clinical and laboratory data between CD5+ and CD5- B-LAHS. METHODS: The expression of CD5 on lymphoma cells was examined using flow cytometry and immunohistochemical analysis of paraffin sections. The clinical records were reviewed to characterize clinical features. PATIENTS: Twelve patients with B-LAHS; ten men and two women, age ranging from 41 to 82 years (median, 63.5 years) were included in this study. RESULTS: B-LAHS is characterized by fever and hepatosplenomegaly without lymphadenopathy at the initial presentation. Histological examination showed hemophagocytosis and infiltration of lymphoma cells in the bone marrow, and in some cases intravascular proliferation of lymphoid cells characteristic of IVL. All patients showed increased levels of lactate dehydrogenase, C-reactive protein, ferritin and soluble interleukin-2 receptor. In eight of the twelve patients, lymphoma cells were positive for CD5. But no differences were observed in the clinical or laboratory findings between CD5+ B-LAHS and CD5- B-LAHS. CONCLUSION: No clinical differences were observed between CD5+ B-LAHS and CD5- B-LAHS. Further studies are required to elucidate the differences in pathogenesis between these two subgroups of B-LAHS.

Adult↗
PubMed2001

Pulsatile cardiopulmonary bypass failed to prevent neuropsychological dysfunction.

To prevent neurological complications during cardiopulmonary bypass, cerebrovascular screenings by magnetic resonance angiography and computed tomographic scan of the brain were performed preoperatively in patients who had ischemic heart disease and all patients aged 60 years or older. From 1996 to 1999, 173 adult patients (mean age 65.1+/-7.7 y) were evaluated. Forty-one patients were considered to be at high risk from the screening tests and pulsatile cardiopulmonary bypass was applied. The remaining 132 patients were placed in the control group. Postoperative cerebral infarction caused by embolism was encountered in three patients (3/173, 1.7%), two in the high-risk group (2/41, 4.8%) and one in the control group (1/132, 0.8%), but the difference between these incidences was not statistically significant. Cerebral infarctions caused by brain hypoperfusion did not occur in this series. A neuropsychological test (Hasegawa's dementia scale, HDS) was done pre- and postoperatively. No one was diagnosed with dementia preoperatively, whereas 7 patients were diagnosed with dementia postoperatively. Among these 7 patients, 6 patients were in the high-risk group (17.1%, 6/35) and one patient was in the control group (0.9%, 1/113). Under these circumstances, using cerebrovascular screening and pulsatile cardiopulmonary bypass, cerebral infarction due to hypoperfusion did not occur, but cerebral infarction due to embolism was encountered, and neuropsychological dysfunction was not prevented.

Aged↗
PubMed2001

Extended aortic grafting for acute ascending dissection after type B dissection.

A 31-year-old man was diagnosed with acute ascending aortic dissection and massive aortic regurgitation following acute type B dissection during drug treatment. Although the aortic arch was not dissected, we performed aortic replacement from the aortic root to the proximal portion of the descending aorta. The aim of the operation was the prevention of aortic arch dissection, and closure of initial entry of type B dissection.

Adult↗
PubMed2000

Strategy for reduction of stroke incidence in coronary bypass patients with cerebral lesions. Early results and mid-term morbidity using pulsatile perfusion.

OBJECTIVES: Cerebral complication is an important factor affecting the outcome after coronary artery bypass surgery under cardiopulmonary bypass. One of the causes for cerebral complication is preoperative cerebrovascular stenotic lesion. Here, we have studied the effect of pulsatile perfusion on the rate of cerebral complication due to a cerebrovascular lesion in patients undergoing coronary arterial bypass graft under cardiopulmonary bypass. METHODS: 261 consecutive elective patients underwent operation using cardiopulmonary bypass for management of the atherosclerotic ascending aorta. Group 1 consisted of 62 patients with a cerebrovascular stenotic lesion (> or = 75%) identified on a magnetic resonance angiogram or multiple cerebral infarction diagnosed using a computer tomogram. Group 2 consisted of 199 patients diagnosed with no significant cerebral lesion. In Group 1, the systolic blood pressure during cardiopulmonary bypass was maintained at a level of 80 mmHg by means of pulsatile flow. In Group 2, non-pulsatile perfusion was used as usual. RESULTS: The overall hospital mortality was 1.5%, and no mortality was caused by a cerebral event. Only one patient in Group 1 suffered from temporary hemiparalysis. A cerebral complication occurred in only 1.6% in Group 1, and 0.4% overall. The actuarial freedom from cerebrovascular accident after 54 months was 84.4% in Group 1, and 96.2% in Group 2 (p = 0.0011). CONCLUSIONS: Management of the atherosclerotic ascending aorta and the use of pulsatile perfusion were helpful in preventing cerebral injury during CABG.

Aged↗
PubMed2000

Serotonin 5-HT2 receptors in schizophrenic patients studied by positron emission tomography.

Using positron emission tomography (PET) and [11C]N-methylspiperone (NMSP), we examined 5-HT2 receptors in the cortex of schizophrenic patients in whom we previously observed decreased prefrontal D1 receptor binding. The subjects were 10 neuroleptic-naive schizophrenic patients, 7 schizophrenic patients who were drug-free but had previously been treated with neuroleptics, and 12 normal controls. A non-significant trend towards decreased prefrontal [11C]NMSP binding was observed in the neuroleptic-treated patients, suggesting a possible effect of previous neuroleptic treatment on the alteration in cortical 5-HT2 function. However, the neuroleptic-naive patients showed no noticeable difference in cortical [11C]NMSP binding compared to controls. Our results do not rule out the role of 5-HT2 function as a crucial site of therapeutic activity of schizophrenia, but they do suggest that cortical 5-HT2 receptors might not be primarily involved in the pathophysiology of schizophrenia.

Adult↗